Treatment of hospital acquired urinary tract infections (UTIs) caused by extended-spectrum beta-Lactamases producing Klebsiella pneumonae is a major problem. This organism expresses a high level of resistance to many ...Treatment of hospital acquired urinary tract infections (UTIs) caused by extended-spectrum beta-Lactamases producing Klebsiella pneumonae is a major problem. This organism expresses a high level of resistance to many groups of antibiotics. Fosfomycin is an agent which is recommended for treatment of UTIs caused by ESBLs producers. The aim of this study is to determine the sensitivity pattern of ESBLs producing urinary K. pneumonae to antimicrobial agents including fosfomycin in patients of MUHs and determine the prevalence of fosfomycin resistance mediated by plasmid mediated fosfomycin modifying enzymes fosA, fosB and fosA3. Methods: Klebsiella pneumonae urinary isolates were collected from patients with hospital acquired UTIs in Mansoura University Hospitals (MUHs). The susceptibility pattern was determined by Kirby Baur method. Isolates resistant to extended spectrum cephalosporins were tested for ESBLs production by double disc diffusion method. Fosfomycin resistance was determined by broth dilution method. Isolates resistant to fosfomycin were tested for fosA, fosB and fosA3 by PCR. Results: A total of 128 ESBLs producing K. pneumonae isolates were collected. The highest sensitivity was to imipenem (94.5%). The lowest was to trimethoprime-sulphamethoxazole (21.8%). Co-resistance of ESBLs isolates with fosfomycin was 23.2%. Eighteen fosfomycin resistant isolates (18/30) were positive to fosA. Conclusion: ESBLs producing urinary Klebsiella pneumonae express moderate sensitivity to fosfomycin. Resistance is mainly mediated by plasmid mediated fosfomycin modifying enzymes fosA.展开更多
The improper use of antimicrobials against infectious diseases has allowed microorganisms to develop defense mechanisms that give them insensitivity to these agents. All bacteria are concerned by this phenomenon. This...The improper use of antimicrobials against infectious diseases has allowed microorganisms to develop defense mechanisms that give them insensitivity to these agents. All bacteria are concerned by this phenomenon. This work aimed to assess prevalence of beta-lactamase produced by enterobacterial isolates. Then, disc diffusion, double disc synergy test (DDST) and combined disc test (CDT) were respectively used for antimicrobial resistance, detection of Extended-Spectrum Beta-Lactamases (ESBL) and Metallo-Beta-Lactamases (MBL). bla genes were detected by PCR. A total of 132 enterobacterial strains were studied. Resistance to antibiotic families was observed with a greater frequency than 50%. Gentamicin was the least active beta-lactam antibiotic, with a resistance rate of 88%. 40.9% of strains show an ESBL phenotype and 16.6% were MBL. An overall prevalence of 74% (40/54) and respectively rates of 29.6%, 27.7% and 16.7% for blaSHV, blaCTX and blaTEM genes were observed. SHV, CTX, CTX/SHV/TEM, CTX/TEM, SHV/TEM and CTX/SHV were different ESBL genotypes observed. ESBL-producing enterobacteria isolation worried about the future of antimicrobial therapy in the Republic of Congo. This is a public health problem that requires careful monitoring and implementation of a policy of rational antibiotics use.展开更多
The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase- producing strains, lactamase-producing and ESBLs-producing isolates was evaluated with twofol...The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase- producing strains, lactamase-producing and ESBLs-producing isolates was evaluated with twofold dilution method after pathogens isolated from pigs and chickens were detected, respectively, for beta-lactamase and extended-spectrum beta- lactamases (ESBLs), The results revealed that most of 43 clinically isolated strains could produce beta-lactamase and 3 strains of shigella isolated from chicken samples produced ESBLs. All of 30 lactamase-producing strains isolated and only one of 16 non-lactamase-producing strains were resistant to amoxicillin and ampicillin. MICs of ampicillin against lactamaseproducing isolates decreased 10-40 and 10-20 times respectively, when it was conbined with sulbactam at ration of 1:2 and 1:4. All clinical isolates were susceptible to third-generation cephalosporins. The MICs of third-generation cephalosporins against lactamase-producing isolates did not change when they were conbined with sulbactam. MICs of ceftiofur and ceftriaxone against ESBLs-producing isolates decreased 2-4 times when they were conbined with sulbactam.展开更多
BACKGROUND Appendicitis, the inflammation of the appendix, is the most common abdominal surgical emergency requiring expedient surgical intervention. Extendedspectrum beta-lactamases(ESBLs) are bacterial enzymes that ...BACKGROUND Appendicitis, the inflammation of the appendix, is the most common abdominal surgical emergency requiring expedient surgical intervention. Extendedspectrum beta-lactamases(ESBLs) are bacterial enzymes that catalyse the degradation of the betalactam ring of penicillins and cephalosporins(but without carbapenemase activity), leading to resistance of these bacteria to beta-lactam antibiotics. Recent increases in incidence of ESBL-producing bacteria have caused alarm worldwide. Proportion estimates of ESBLEnterobacteriaceae hover around 46% in China, 42% in East Africa, 12% in Germany, and 8% in the United States.CASE SUMMARY The impact of ESBL-producing bacteria on appendiceal abscesses and consequent pelvic abscesses are yet to be examined in depth. A literature review using the search words "appendiceal abscesses" and "ESBL Escherichia coli(E. coli)" revealed very few cases involving ESBL E. coli in any capacity in the context of appendiceal abscesses. This report describes the clinical aspects of a patient with appendicitis whodeveloped a postoperative pelvic abscess infected with ESBL-producing E. coli. In this report, we discuss the risk factors for contracting ESBL E. coli infection in appendicitis and post-appendectomy pelvis abscesses. We also discuss our management approach for postappendectomy ESBL E. coli pelvic abscesses, including drainage, pathogen identification, and pathogen characterisation. When ESBL E. coli is confirmed, carbapenem antibiotics should be promptly administered, as was done efficaciously with this patient. Our report is the first one in a developed country involving ESBL E. coli related surgical complications in association with a routine laparoscopic appendectomy.CONCLUSION Our report is the first involving ESBL E. coli and appendiceal abscesses, and that too consequent to laparoscopic appendectomy.展开更多
We report the very rare case of a huge appendical abscess with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) as the pathogen. There have been several reports of appendical infections suc...We report the very rare case of a huge appendical abscess with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) as the pathogen. There have been several reports of appendical infections such as appendicitis and appendical abscess caused by ESBL-producing bacteria in adults. The treatment of ESBL-producing E. coli infection is specific, and ESBL-producing bacteria have recently been reported as pathogens associated appendicitis in children. To the best of our knowledge, this is the second report of perforated appendicitis with abscess due to ESBL-producing E. coli. We discuss the diagnostic modalities and treatments for appendical abscess with ESBL-producing E. coli. and propose that the patients with perforated appendicitis and abscess formation due to ESBL-producing E. coli should be administered the antibiotic MEPM within 2 weeks to treat the abscess more effec-tively without producing other multidrug-resistant bacteria.展开更多
Strains of the Enterobacteriaceae family producing ESBL and AmpC broad-spectrum beta-lactamases that may survive in the hospital setting potentially cause infection in hospitalized patients due to contaminated objects...Strains of the Enterobacteriaceae family producing ESBL and AmpC broad-spectrum beta-lactamases that may survive in the hospital setting potentially cause infection in hospitalized patients due to contaminated objects or health care workers’ hands. Over a period of two months (November-December 2010), a single epidemiological study of microbial contamination of air, surfaces and health care workers (swabs from both nostrils and the right hand without a glove) was carried out at two intensive care units of the University Hospital Olomouc, Czech Republic. The bacteria were identified using standard microbiological methods. Phenotypic detection of ESBL and AmpC enzymes and basic genetic analysis of ESBL- and AmpC-positive isolates was performed. The same approach was used to identify and analyze bacteria isolated from clinical samples of patients hospitalized at the above departments over the study period. From a total of 140 environmental samples collected over the study period, 21 isolates of the Enterobacteriaceae family were identified, with ESBL and AmpC production being detected in 4 and 7 isolates, respectively. Among patients’ clinical samples, 10 ESBL- and 6 AmpC-positive isolates were detected. No similarity was found between environmental isolates and strains isolated from patients.展开更多
Objective: To evaluate the drug susceptibility profiles and the frequency of beta-lactamase encoding genes in Pseudomonas aeruginosa (P. aeruginosa) obtained from burn patients. Methods: Totally 93 non-duplicate clini...Objective: To evaluate the drug susceptibility profiles and the frequency of beta-lactamase encoding genes in Pseudomonas aeruginosa (P. aeruginosa) obtained from burn patients. Methods: Totally 93 non-duplicate clinical isolates of P. aeruginosa were recovered from burn patients of Taleghani Burn Hospital of Ahvaz. Antibiotic susceptibility testing was conducted by disk diffusion method according to the CLSI 2017 recommendations. PCR assay was performed by to find beta-lactamase encoding genes. Results: In this study, most clinical specimen was obtained via wound swabs [65 (69.9%)], followed by blood [14 (15.1%)] and biopsy (7 (7.5%))Forty-two (45.16%) patients were male and 51(54.84%) were female. High resistance was observed for most of antibiotics especially for gentamicin and ciprofloxacin (Up to 85%), whereas the highest susceptibility was reported for colistin (100.0%), followed by ceftazidime (66.7%). According to PCR results, 16.1% (15), 9.7% (9) and 14.0% (13) of isolates carried blaDHA, blaVEB and blaGES genes, respectively. It also revealed that the blaVEB gene was found to coexist within 2 isolates (2.2%). Conclusions: Antibacterial resistance is high among P. aeruginosa isolates. Colistin is highly active against multi-drug resistant P. aeruginosa isolates. Antimicrobial susceptibility testing can confine indiscriminate uses of antibiotics and resistance increase, and can improve management of treatment.展开更多
The aim of this study was to determine the relationship between phenotypic antimicrobial susceptibility patterns and extended-spectrum,carbapenem-resistance genes.A total of 109 clinical Staphilococcus aureus strains ...The aim of this study was to determine the relationship between phenotypic antimicrobial susceptibility patterns and extended-spectrum,carbapenem-resistance genes.A total of 109 clinical Staphilococcus aureus strains were subjected to 19 antimicrobial susceptibility tests.Resistance to methicillin(mecA),penicillin(blaTEM),and tetracycline(tetM)was detected.We compared the presence of the blaTEM genes with extended-spectrum,carbapenem-related genes and identified the types of SCCmec genes.Of 109 clinical S.aureus strains,62(56.88%)had methicillin resistance and 60 strains carried mecA.The prevalence of blaTEM and tetM genes was 81.65%and 37.61%,respectively.The most predominant SCCmec type was SCCmec type Ⅱ 28/60(46.67%),in 60 mecA-positive methicillin-resistant S.aureus(MRSA)isolates.The SCCmec prevalence rates were type ⅣA 30.00%(18/60),type Ⅳb 8.33%(5/60),type Ⅳd 6.67%(4/60),and non-typable 8.33%(5/60).Sixty of the 109(55.05%)MRSA isolates were positive for extended-spectrum carbapenems(31/60)(51.67%),cephalosporins 40/60(66.67%)and carbapenems 31/60(51.67%).The predominant SCCmec type II demonstrated more carbapenem-resistance than the ⅣA,Ⅳb and Ⅳd types.展开更多
The clinical and microbiologic characteristics of 34 patients with extended-spectrum β-lactamase (ESBL) positive E. coli isolated from blood were compared to 66 bacteremic patients with ESBL negative E. coli, from Ja...The clinical and microbiologic characteristics of 34 patients with extended-spectrum β-lactamase (ESBL) positive E. coli isolated from blood were compared to 66 bacteremic patients with ESBL negative E. coli, from January 2007 through December 2009. Of the 21 ESBL positive isolates available for PCR analysis, 13 were positive for CTX-M, 8 for TEM, 4 for SHV β-lactamases, with 6 possessing multiple enzymes. Twenty of 34 (59%) ESBL-positive and 41 of 66 (62%) ESBL-negative blood isolates were considered community-associated. All but one isolate in both groups had MICs of ≤1.0 μg/ml to meropenem. However, when compared to ESBL-negative isolates, ESBL-positive isolates were more frequently resistant to levofloxacin, trimethoprim/sulfamethoxazole and had higher MICs to gentamicin, tobramycin and piperacillin/tazobactam. The use of intravenous and urinary catheters was strongly associated with the isolation of E. coli bloodstream isolates in both groups of patients. Although hospital stay was similar in both groups, appropriate therapy was given in 87% of patients with ESBL positive vs. 98% of patients with ESBL negative isolates and mortality was greater for patients with ESBL positive isolates (26% vs. 17%). Since a large proportion of E. coli blood isolates were ESBL-positive and community-associated, carbapenems should be considered as initial empiric therapy for such infections in our locale.展开更多
Background: Escherichia coli are ubiquitous bacteria colonising both humans and animals. Extended spectrum β-lactamase-producing E. coli has been selected as a suitable indicator for the monitoring and surveillance o...Background: Escherichia coli are ubiquitous bacteria colonising both humans and animals. Extended spectrum β-lactamase-producing E. coli has been selected as a suitable indicator for the monitoring and surveillance of antimicrobial resistance. Death due to resistant bacteria is continuously rising in Cameroon, but the contribution of the aviary sector is not well studied. Therefore, this study aimed to investigate the resistance profile of extended spectrum beta-lactamases-producing Escherichia coli strains, isolated from faeces of broiler chickens in Yaoundé, capital city of Cameroon. Methods: A cross-sectional descriptive study was carried out from February to June 2020. Escherichia coli were isolated from samples of broilers in poultry farms in Yaoundé and submitted to the extended spectrum β-lactamase screening. The logistic regression was used to assess the statistical association of a significance threshold p-value of 0.05. Results: Out of 385 faecal samples collected in broiler farms, 114 Escherichia coli isolates were obtained out of which 30 (26.32%) were Extended Spectrum Beta-Lactamases-producing Escherichia coli. These isolates revealed high resistance to all antibiotic families. Poor storage conditions for feeds and the proximity to latrines, the troughs on the ground, the lack of foot bath and uniforms, the inadequate treatment of faeces, the poor usage of preventive antibiotics and the lack of water treatment have been identified as risk factors to faecal carriage of ESBL-producing Escherichia coli. Conclusion: This work reveals the emergence of Extended Spectrum Beta-Lactamases-producing Escherichia coli in poultry farms in Yaoundé and the failure in the biosecurity system. As such, the awareness of poultry breeders on the respect of biosecurity measures may be an effective tool to tackle antimicrobial resistance, specifically in livestock industries using a One Health approach.展开更多
Background: Extended-spectrum β-lactamases (ESBLs) are enzymes capable of hydrolyzing extended-spectrum cephalosporins, penicillins and monobactams but inactive against cephamycins and carbapenems. The ESBL-producing...Background: Extended-spectrum β-lactamases (ESBLs) are enzymes capable of hydrolyzing extended-spectrum cephalosporins, penicillins and monobactams but inactive against cephamycins and carbapenems. The ESBL-producing organisms are a breed of multidrug-resistant pathogens. Objectives: This study was aimed to determine the susceptibility pattern of ESBL-producing Escherichia coli to ciprofloxacin, amikacin and imipenem. Methods: A total of 75 ESBL-producing E. coli, were obtained from the tertiary care hospitals of Bangladesh and were studied for susceptibility pattern from October, 2010 to December, 2011. These isolates were identified by double disc synergy test (DDST) and were confirmed phenotypically as ESBL-producer by phenotypic confirmatory disc diffusion test (PCDDT). Minimum inhibitory concentrations (MICs) of ciprofloxacin, amikacin and imipenem among ESBL-producing E. coli were determined using agar dilution method. Results: Out of 75 DDST positive ESBL-producing E. coli, 71 (94.67%) were also positive by PCDDT. All ESBL-producing E. coli, were susceptible to imipenem. About 92.95% ESBL-producing E. coli were susceptible to amikacin but only 14.08% were susceptible to ciprofloxacin. Conclusion: In this study, ESBL-producing E. coli, showed high resistance to ciprofloxacin. Imipenem and amikacin were most effective against ESBL positive strains.展开更多
Background: Detection of extended spectrum beta lactamase producing bacteria is an important issue in the clinical settings. Objective: The purpose of the present study was to validate the Cica Beta Test 1 for detecti...Background: Detection of extended spectrum beta lactamase producing bacteria is an important issue in the clinical settings. Objective: The purpose of the present study was to validate the Cica Beta Test 1 for detection of extended spectrum beta-lactamase (ESBL) producing bacteria. Method: This analytical type of cross-sectional study was carried out in the Department of Microbiology and Immunology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from January 2006 to December 2006 for a period of one (01) year. All the patients presented with the clinical features of urinary tract infection and surgical as well as burn wound infection at any age with both sexes were selected as study population. All bacteria were isolated and identified by their colony morphology, staining characters, pigment production, motility and other relevant biochemical tests. Phenotypic confirmation of ESBLs producing isolates were done by inhibitor potentiated disc diffusion test according to CLSI recommendation. The Cica Beta Test 1 was performed according to the manufacturer’s instructions. Result: A total number of 288 Gram negative bacteria were isolated. Among these isolates Cica Beta test 1 was positive in 97 strains and phenotypic confirmatory test was positive in 89 strains. The test sensitivity of Cica Beta Test 1 was 100% (95% CI 95.9% to 100.0%). Specificity of the test was 96.0% (95% CI 92.2% to 98.2%). The positive predictive value (PPV) and negative predictive value (NPV) were 92.7% (95% CI 84.5% to 95.7%) and 100.0% (95% CI 98.0% to 100.0%) respectively. The accuracy of the test was 97.2% (95% CI 95.1% to 99.1%). Area under ROC curve = 0.980 (95% CI 0.964 to 0.996);p value 0.0001. Conclusion: In conclusion, Cica Beta Test 1 is very high sensitivity and specificity for the detection of ESBL from Gram negative bacteria.展开更多
The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only ...The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to establish the carriage of multi-drug resistance and extended-spectrum beta-lactamase genes in Escherichia coli from farmers, their cattle, and cattle slurry within Kiambu County. A total of 286 (81%) E. coli isolates were recovered from 352 samples analysed. Antibiotic resistance profiles showed 114 (40%) isolates were resistant to ≥3 antimicrobial classes and were considered multidrug-resistant. Among multidrug-resistant (MDR) E. coli strains, 40 (14%) were resistant to 3 different antimicrobial classes, while 71 (25%) were resistant to between 4 and 7 antibiotic classes. Extended-spectrum β-lactamase resistance was found in 18 isolates: human (n = 14), cattle (n = 2), and environmental (n = 2). Both the bla<sub>CTX-M</sub> and bla<sub>TEM</sub> genes were detected in 10 and 15 strains, respectively. Sequence analysis showed that the isolates carried the bla<sub>TEM-116</sub> (n = 7), bla<sub>TEM-1</sub> (n = 5), and bla<sub>CTX-M-15</sub> (n = 8) genes. Genotyping MDR isolates using (GTG) <sub>5</sub> PCR demonstrated that the isolates were not clonal. This data shows antimicrobial resistance profiles and different types of resistance genes in the E. coli population on dairy farms. As a result, more effective, targeted public health policies and measures need to be put in place to control and prevent the emergence and spread of resistant bacteria.展开更多
BACKGROUND The survival of microorganisms on textiles and specifically on healthcare profes-sionals’(HCP)attire has been demonstrated in several studies.The ability of microorganisms to adhere and remain on textiles ...BACKGROUND The survival of microorganisms on textiles and specifically on healthcare profes-sionals’(HCP)attire has been demonstrated in several studies.The ability of microorganisms to adhere and remain on textiles for up to hours or days raises questions as to their possible role in transmission from textile to skin via HCP to patients.AIM To evaluate the presence,survival and transmission of different multidrug-resistant bacteria(MDRB)from HCP attire onto skin.METHODS Three MDRB[methicillin-resistant Staphylococcus aureus(MRSA);vancomycin-resistant Enterococcus faecium(VRE);carbapenem-resistant Klebsiella pneumoniae,(CRKP)]were inoculated on textiles from scrubs(60%cotton-40%polyester)and white coat(100%cotton)at concentrations of 108 colony-forming units(CFU),105 CFU,and 103 CFU per mL.The inoculation of swatches was divided in time intervals of 1 min,5 min,15 min,30 min,1 h,2 h,3 h,4 h,5 h,and 6 h.At the end of each period,textiles were imprinted onto pig skins and each skin square was inverted onto three different selective chromogenic media.Growth from the pig skin squares was recorded for the 3 MDRB at the three above concentrations,for the whole length of the 6-h experiment.RESULTS MRSA was recovered from pig skins at all concentrations for the whole duration of the 6-h study.VRE was recovered from the concentration of 108 CFU/mL for 6 h and from 105 CFU/mL for up to 3 h,while showing no growth at 103 CFU/mL.CRKP was recovered from 108 CFU/mL for 6 h,up to 30 min from 105 CFU/mL and for 1 min from the concentration of 103 CFU/mL.CONCLUSION Evidence from the current study shows that MRSA can persist on textiles and transmit to skin for 6 h even at low concentrations.The fact that all MDRB can be sustained and transferred to skin even at lower concentrations,supports that textiles are implicated as vectors of bacterial spread.展开更多
Objective:To analyze the clinical distribution and drug resistance of Klebsiella pneumoniae isolated from patients in a certain hospital and provide a basis for the rational use of antibiotics in the clinical treatmen...Objective:To analyze the clinical distribution and drug resistance of Klebsiella pneumoniae isolated from patients in a certain hospital and provide a basis for the rational use of antibiotics in the clinical treatment for the infection of Klebsiella pneumoniae.Methods:1,192 strains of Klebsiella pneumoniae isolated from clinical specimens from 2012 to 2016 were collected.The strains were identified by VITEK-2 Compact Microbiological Identification System,and the corresponding results of the antimicrobial susceptibility test were interpreted in accordance with the standards recommended by Clinical and Laboratory Standards Institute(CLSI).Results:1,192 strains of Klebsiella pneumoniae were mainly isolated from sputum(65.6%),and most of them were from Respiratory Medicine Department and Medical Intensive Care Unit of Respiratory Medicine Department(MICU),accounting for 41.4%.Out of 1,192 strains,448 strains were detected to produce extended-spectrum beta-lactamases(ESBLs),accounting for 37.6%.In addition,the detection rates of ESBL-producing Klebsiella pneumoniae for 5 consecutive years showed an increasing trend year by year,and they were higher than the national average values published by China Antimicrobial Resistance Surveillance System(CARSS)in the corresponding period.The drug resistance rate of ESBL-producing Klebsiella pneumoniae was significantly higher than that of non ESBL-producing strains.Conclusions:The infection caused by Klebsiella pneumoniae mainly occurs in the lower respiratory tract,and the drug resistance rates of Klebsiella pneumoniae to antibiotics in the drug susceptibility spectrum are maintained at a high level.Therefore,the rational selection of antibiotics for the clinical treatment of lower respiratory tract infection caused by Klebsiella pneumoniae must be based on the production of ESBLs and the results of antimicrobial susceptibility test.展开更多
Background The extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance.Previous stu...Background The extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance.Previous studies have focused on the resistance genes in ESBL-producing strains,and the resistance-associated genetic environment of non-ESBL-producing strains has been ignored until now.Here,we investigated the occurrence and characteristics of non-ESBL-producing K.pneumoniae,which potentially carries unexpressed resistance genes.Methods K.pneumoniae strains were collected from five medical institutions in China from February 2010 to August 2013.The VITEK-2 ESBL detection system was used as a primary screen to identify the ESBL-producing phenotype,and the three primary types of ESBL-associated genes (CTX,SHV,and TEM) were detected by polymerase chain reaction (PCR) to confirm the strains presenting with a non-ESBL-producing phenotype.mRNA expression in the non-ESBL-producing strains was further screened by reverse-transcription PCR (RT-PCR) to validate their transcriptional efficiency.Results Out of 224 clinically isolated antibiotic-sensitive K.pneumoniae strains with a non-ESBL-producing phenotype,5 (2.2%) were identified to carry inactivated ESBL blaSHV genes with intact upstream promoter regions and resistance gene sequences.Interestingly,three of the five antibiotic-sensitive K.pneumoniae strains containing ESBL blaSHV genes still exhibited mRNA transcription of blasHv,while the other two exhibited no mRNA transcription.Conclusion These findings suggest that inactivated ESBL genes exist in non-ESBL-producing antibiotic-sensitive K.pneumoniae strains,which have the potential to transform the strain into an ESBL phenotype if an inappropriate application or overdose of antibiotics is implemented during clinical management.展开更多
AIM: To study the antibiotic susceptibility patterns of gram-negative healthcare associated bacterial infections at two tertiary hospitals in the Sanandaj city, Kurdistan Province, Iran.METHODS: From January 2012 to D...AIM: To study the antibiotic susceptibility patterns of gram-negative healthcare associated bacterial infections at two tertiary hospitals in the Sanandaj city, Kurdistan Province, Iran.METHODS: From January 2012 to December 2012, all positive cultures from potentially sterile body fluids were gathered. They sent to professor Alborzi clinical microbiology center in Shiraz for further analysis and susceptibility testing. The antibiotic susceptibility was determined using the Kirby-Bauer method(disk diffusiontechnique). The Results were interpreted according to Clinical and Laboratory Standards Institute guidelines against a series of antimicrobials. World Health Organization definitions for Healthcare associated infections were followed.RESULTS: Seven hundred and thirty-two positive cultures were reported from both hospitals. Seventynine isolates/patients fulfilled the study criteria for healthcare associated gram-negative infections. The most frequent bacterial cultures were from the pediatric wards(52%). Serratia marcescens(S. marcescens)(38%) Escherichia coli(E. coli)(19%), Klebsiella pneumoniae(K. pneumoniae)(19%), Acinetobacter baumannii(6%), Enterobacter species(6%), Serratia odorifera(4%) and Pseudomonas species(5%) were the most frequently isolated organisms. The susceptibility pattern of common isolates i.e., S. marcescens, E. coli and K. pneumoniae for commonly used antibiotics were as follows: Ampicillin 3.3%, 6.7%, 20%; gentamicin 73.3%, 73.3%, 46.7%; ceftazidim 80%, 73.3%, 33.3%; cefepim 80%, 86.7%, 46.7%; piperacillin/tazobactam 90%, 66.7%, 86.7%; ciprofloxacin 100%, 73.3%, 86.7%; imipenem 100%, 100%, 100%, respectively. CONCLUSION: The most effective antibiotics against gram-negative healthcare associated infections are imipenem followed by ciprofloxacin. The resistance rate is high against ampicillin and cephalothin. The high mortality rate(46.1%) associated with S. marcescens is alarming.展开更多
Carbapenemase-producing Enterobacteriaceae(CPE) isolates are recognized as one of the most severe threats to public health. However, the population structure and genetic characteristics of CPE isolates among bloodstre...Carbapenemase-producing Enterobacteriaceae(CPE) isolates are recognized as one of the most severe threats to public health. However, the population structure and genetic characteristics of CPE isolates among bloodstream infections(BSIs) are largely unknown. To address this knowledge gap, in this study,we included patients with clinically significant BSIs due to Enterobacterales isolates, recruited from 26 sentinel hospitals in China(2014–2015). CPE isolates were microbiologically and genomically characterized,including their susceptibility profiles, molecular typing, phylogenetic features, and genetic context analysis of carbapenemase-encoding genes. Of the 2569 BSI Enterobacterales isolates enrolled, 42(1.6%) were carbapenemase-positive. Moreover, among the 2242 investigated isolates, 1111(49.6%) extendedspectrum β-lactamase(ESBL)-producing isolates were identified in Escherichia coli(E. coli), Klebsiella pneumoniae(K. pneumoniae), Proteus mirabilis(P. mirabilis), and Klebsiella oxytoca. Whole genome sequencing analysis showed the clonal spread of K. pneumoniae carbapenemase(KPC)-2-producing K. pneumoniae sequence type(ST) 11 and New Delhi metallo-β-lactamase(NDM)-5-producing E. coli ST167 in our collection. Plasmid analysis revealed that carbapenemase-encoding genes were located on multiple plasmids. A high prevalence of biofilm-encoding type 3 fimbriae clusters and yesiniabactin-associated genes was observed in K. pneumoniae isolates. This work demonstrates the high prevalence of ESBLs and the wide dissemination of CPE among BSI isolates in China, which represent real clinical threats. Moreover, our findings first illustrate a more comprehensive genome scenario of CPE isolates among BSIs. The clonal spread of KPC-2-producing K. pneumoniae ST11 and NDM-5-producing E. coli ST167 needs to be closely monitored.展开更多
文摘Treatment of hospital acquired urinary tract infections (UTIs) caused by extended-spectrum beta-Lactamases producing Klebsiella pneumonae is a major problem. This organism expresses a high level of resistance to many groups of antibiotics. Fosfomycin is an agent which is recommended for treatment of UTIs caused by ESBLs producers. The aim of this study is to determine the sensitivity pattern of ESBLs producing urinary K. pneumonae to antimicrobial agents including fosfomycin in patients of MUHs and determine the prevalence of fosfomycin resistance mediated by plasmid mediated fosfomycin modifying enzymes fosA, fosB and fosA3. Methods: Klebsiella pneumonae urinary isolates were collected from patients with hospital acquired UTIs in Mansoura University Hospitals (MUHs). The susceptibility pattern was determined by Kirby Baur method. Isolates resistant to extended spectrum cephalosporins were tested for ESBLs production by double disc diffusion method. Fosfomycin resistance was determined by broth dilution method. Isolates resistant to fosfomycin were tested for fosA, fosB and fosA3 by PCR. Results: A total of 128 ESBLs producing K. pneumonae isolates were collected. The highest sensitivity was to imipenem (94.5%). The lowest was to trimethoprime-sulphamethoxazole (21.8%). Co-resistance of ESBLs isolates with fosfomycin was 23.2%. Eighteen fosfomycin resistant isolates (18/30) were positive to fosA. Conclusion: ESBLs producing urinary Klebsiella pneumonae express moderate sensitivity to fosfomycin. Resistance is mainly mediated by plasmid mediated fosfomycin modifying enzymes fosA.
文摘The improper use of antimicrobials against infectious diseases has allowed microorganisms to develop defense mechanisms that give them insensitivity to these agents. All bacteria are concerned by this phenomenon. This work aimed to assess prevalence of beta-lactamase produced by enterobacterial isolates. Then, disc diffusion, double disc synergy test (DDST) and combined disc test (CDT) were respectively used for antimicrobial resistance, detection of Extended-Spectrum Beta-Lactamases (ESBL) and Metallo-Beta-Lactamases (MBL). bla genes were detected by PCR. A total of 132 enterobacterial strains were studied. Resistance to antibiotic families was observed with a greater frequency than 50%. Gentamicin was the least active beta-lactam antibiotic, with a resistance rate of 88%. 40.9% of strains show an ESBL phenotype and 16.6% were MBL. An overall prevalence of 74% (40/54) and respectively rates of 29.6%, 27.7% and 16.7% for blaSHV, blaCTX and blaTEM genes were observed. SHV, CTX, CTX/SHV/TEM, CTX/TEM, SHV/TEM and CTX/SHV were different ESBL genotypes observed. ESBL-producing enterobacteria isolation worried about the future of antimicrobial therapy in the Republic of Congo. This is a public health problem that requires careful monitoring and implementation of a policy of rational antibiotics use.
基金This study was supported by the National Natural Science Foundation of China(30471307).
文摘The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase- producing strains, lactamase-producing and ESBLs-producing isolates was evaluated with twofold dilution method after pathogens isolated from pigs and chickens were detected, respectively, for beta-lactamase and extended-spectrum beta- lactamases (ESBLs), The results revealed that most of 43 clinically isolated strains could produce beta-lactamase and 3 strains of shigella isolated from chicken samples produced ESBLs. All of 30 lactamase-producing strains isolated and only one of 16 non-lactamase-producing strains were resistant to amoxicillin and ampicillin. MICs of ampicillin against lactamaseproducing isolates decreased 10-40 and 10-20 times respectively, when it was conbined with sulbactam at ration of 1:2 and 1:4. All clinical isolates were susceptible to third-generation cephalosporins. The MICs of third-generation cephalosporins against lactamase-producing isolates did not change when they were conbined with sulbactam. MICs of ceftiofur and ceftriaxone against ESBLs-producing isolates decreased 2-4 times when they were conbined with sulbactam.
文摘BACKGROUND Appendicitis, the inflammation of the appendix, is the most common abdominal surgical emergency requiring expedient surgical intervention. Extendedspectrum beta-lactamases(ESBLs) are bacterial enzymes that catalyse the degradation of the betalactam ring of penicillins and cephalosporins(but without carbapenemase activity), leading to resistance of these bacteria to beta-lactam antibiotics. Recent increases in incidence of ESBL-producing bacteria have caused alarm worldwide. Proportion estimates of ESBLEnterobacteriaceae hover around 46% in China, 42% in East Africa, 12% in Germany, and 8% in the United States.CASE SUMMARY The impact of ESBL-producing bacteria on appendiceal abscesses and consequent pelvic abscesses are yet to be examined in depth. A literature review using the search words "appendiceal abscesses" and "ESBL Escherichia coli(E. coli)" revealed very few cases involving ESBL E. coli in any capacity in the context of appendiceal abscesses. This report describes the clinical aspects of a patient with appendicitis whodeveloped a postoperative pelvic abscess infected with ESBL-producing E. coli. In this report, we discuss the risk factors for contracting ESBL E. coli infection in appendicitis and post-appendectomy pelvis abscesses. We also discuss our management approach for postappendectomy ESBL E. coli pelvic abscesses, including drainage, pathogen identification, and pathogen characterisation. When ESBL E. coli is confirmed, carbapenem antibiotics should be promptly administered, as was done efficaciously with this patient. Our report is the first one in a developed country involving ESBL E. coli related surgical complications in association with a routine laparoscopic appendectomy.CONCLUSION Our report is the first involving ESBL E. coli and appendiceal abscesses, and that too consequent to laparoscopic appendectomy.
文摘We report the very rare case of a huge appendical abscess with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) as the pathogen. There have been several reports of appendical infections such as appendicitis and appendical abscess caused by ESBL-producing bacteria in adults. The treatment of ESBL-producing E. coli infection is specific, and ESBL-producing bacteria have recently been reported as pathogens associated appendicitis in children. To the best of our knowledge, this is the second report of perforated appendicitis with abscess due to ESBL-producing E. coli. We discuss the diagnostic modalities and treatments for appendical abscess with ESBL-producing E. coli. and propose that the patients with perforated appendicitis and abscess formation due to ESBL-producing E. coli should be administered the antibiotic MEPM within 2 weeks to treat the abscess more effec-tively without producing other multidrug-resistant bacteria.
基金Supported by the following grant projects:LF_2012_006 and MSM6198959223.
文摘Strains of the Enterobacteriaceae family producing ESBL and AmpC broad-spectrum beta-lactamases that may survive in the hospital setting potentially cause infection in hospitalized patients due to contaminated objects or health care workers’ hands. Over a period of two months (November-December 2010), a single epidemiological study of microbial contamination of air, surfaces and health care workers (swabs from both nostrils and the right hand without a glove) was carried out at two intensive care units of the University Hospital Olomouc, Czech Republic. The bacteria were identified using standard microbiological methods. Phenotypic detection of ESBL and AmpC enzymes and basic genetic analysis of ESBL- and AmpC-positive isolates was performed. The same approach was used to identify and analyze bacteria isolated from clinical samples of patients hospitalized at the above departments over the study period. From a total of 140 environmental samples collected over the study period, 21 isolates of the Enterobacteriaceae family were identified, with ESBL and AmpC production being detected in 4 and 7 isolates, respectively. Among patients’ clinical samples, 10 ESBL- and 6 AmpC-positive isolates were detected. No similarity was found between environmental isolates and strains isolated from patients.
文摘Objective: To evaluate the drug susceptibility profiles and the frequency of beta-lactamase encoding genes in Pseudomonas aeruginosa (P. aeruginosa) obtained from burn patients. Methods: Totally 93 non-duplicate clinical isolates of P. aeruginosa were recovered from burn patients of Taleghani Burn Hospital of Ahvaz. Antibiotic susceptibility testing was conducted by disk diffusion method according to the CLSI 2017 recommendations. PCR assay was performed by to find beta-lactamase encoding genes. Results: In this study, most clinical specimen was obtained via wound swabs [65 (69.9%)], followed by blood [14 (15.1%)] and biopsy (7 (7.5%))Forty-two (45.16%) patients were male and 51(54.84%) were female. High resistance was observed for most of antibiotics especially for gentamicin and ciprofloxacin (Up to 85%), whereas the highest susceptibility was reported for colistin (100.0%), followed by ceftazidime (66.7%). According to PCR results, 16.1% (15), 9.7% (9) and 14.0% (13) of isolates carried blaDHA, blaVEB and blaGES genes, respectively. It also revealed that the blaVEB gene was found to coexist within 2 isolates (2.2%). Conclusions: Antibacterial resistance is high among P. aeruginosa isolates. Colistin is highly active against multi-drug resistant P. aeruginosa isolates. Antimicrobial susceptibility testing can confine indiscriminate uses of antibiotics and resistance increase, and can improve management of treatment.
基金supported by a human resources exchange program in scientific technology through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(No.NRF-2018H1D2A2076169)the Technology Development Program of MSS(S2660881)funded by the Ministry of SMEs and Startups(MSS,Korea).
文摘The aim of this study was to determine the relationship between phenotypic antimicrobial susceptibility patterns and extended-spectrum,carbapenem-resistance genes.A total of 109 clinical Staphilococcus aureus strains were subjected to 19 antimicrobial susceptibility tests.Resistance to methicillin(mecA),penicillin(blaTEM),and tetracycline(tetM)was detected.We compared the presence of the blaTEM genes with extended-spectrum,carbapenem-related genes and identified the types of SCCmec genes.Of 109 clinical S.aureus strains,62(56.88%)had methicillin resistance and 60 strains carried mecA.The prevalence of blaTEM and tetM genes was 81.65%and 37.61%,respectively.The most predominant SCCmec type was SCCmec type Ⅱ 28/60(46.67%),in 60 mecA-positive methicillin-resistant S.aureus(MRSA)isolates.The SCCmec prevalence rates were type ⅣA 30.00%(18/60),type Ⅳb 8.33%(5/60),type Ⅳd 6.67%(4/60),and non-typable 8.33%(5/60).Sixty of the 109(55.05%)MRSA isolates were positive for extended-spectrum carbapenems(31/60)(51.67%),cephalosporins 40/60(66.67%)and carbapenems 31/60(51.67%).The predominant SCCmec type II demonstrated more carbapenem-resistance than the ⅣA,Ⅳb and Ⅳd types.
文摘The clinical and microbiologic characteristics of 34 patients with extended-spectrum β-lactamase (ESBL) positive E. coli isolated from blood were compared to 66 bacteremic patients with ESBL negative E. coli, from January 2007 through December 2009. Of the 21 ESBL positive isolates available for PCR analysis, 13 were positive for CTX-M, 8 for TEM, 4 for SHV β-lactamases, with 6 possessing multiple enzymes. Twenty of 34 (59%) ESBL-positive and 41 of 66 (62%) ESBL-negative blood isolates were considered community-associated. All but one isolate in both groups had MICs of ≤1.0 μg/ml to meropenem. However, when compared to ESBL-negative isolates, ESBL-positive isolates were more frequently resistant to levofloxacin, trimethoprim/sulfamethoxazole and had higher MICs to gentamicin, tobramycin and piperacillin/tazobactam. The use of intravenous and urinary catheters was strongly associated with the isolation of E. coli bloodstream isolates in both groups of patients. Although hospital stay was similar in both groups, appropriate therapy was given in 87% of patients with ESBL positive vs. 98% of patients with ESBL negative isolates and mortality was greater for patients with ESBL positive isolates (26% vs. 17%). Since a large proportion of E. coli blood isolates were ESBL-positive and community-associated, carbapenems should be considered as initial empiric therapy for such infections in our locale.
文摘Background: Escherichia coli are ubiquitous bacteria colonising both humans and animals. Extended spectrum β-lactamase-producing E. coli has been selected as a suitable indicator for the monitoring and surveillance of antimicrobial resistance. Death due to resistant bacteria is continuously rising in Cameroon, but the contribution of the aviary sector is not well studied. Therefore, this study aimed to investigate the resistance profile of extended spectrum beta-lactamases-producing Escherichia coli strains, isolated from faeces of broiler chickens in Yaoundé, capital city of Cameroon. Methods: A cross-sectional descriptive study was carried out from February to June 2020. Escherichia coli were isolated from samples of broilers in poultry farms in Yaoundé and submitted to the extended spectrum β-lactamase screening. The logistic regression was used to assess the statistical association of a significance threshold p-value of 0.05. Results: Out of 385 faecal samples collected in broiler farms, 114 Escherichia coli isolates were obtained out of which 30 (26.32%) were Extended Spectrum Beta-Lactamases-producing Escherichia coli. These isolates revealed high resistance to all antibiotic families. Poor storage conditions for feeds and the proximity to latrines, the troughs on the ground, the lack of foot bath and uniforms, the inadequate treatment of faeces, the poor usage of preventive antibiotics and the lack of water treatment have been identified as risk factors to faecal carriage of ESBL-producing Escherichia coli. Conclusion: This work reveals the emergence of Extended Spectrum Beta-Lactamases-producing Escherichia coli in poultry farms in Yaoundé and the failure in the biosecurity system. As such, the awareness of poultry breeders on the respect of biosecurity measures may be an effective tool to tackle antimicrobial resistance, specifically in livestock industries using a One Health approach.
文摘Background: Extended-spectrum β-lactamases (ESBLs) are enzymes capable of hydrolyzing extended-spectrum cephalosporins, penicillins and monobactams but inactive against cephamycins and carbapenems. The ESBL-producing organisms are a breed of multidrug-resistant pathogens. Objectives: This study was aimed to determine the susceptibility pattern of ESBL-producing Escherichia coli to ciprofloxacin, amikacin and imipenem. Methods: A total of 75 ESBL-producing E. coli, were obtained from the tertiary care hospitals of Bangladesh and were studied for susceptibility pattern from October, 2010 to December, 2011. These isolates were identified by double disc synergy test (DDST) and were confirmed phenotypically as ESBL-producer by phenotypic confirmatory disc diffusion test (PCDDT). Minimum inhibitory concentrations (MICs) of ciprofloxacin, amikacin and imipenem among ESBL-producing E. coli were determined using agar dilution method. Results: Out of 75 DDST positive ESBL-producing E. coli, 71 (94.67%) were also positive by PCDDT. All ESBL-producing E. coli, were susceptible to imipenem. About 92.95% ESBL-producing E. coli were susceptible to amikacin but only 14.08% were susceptible to ciprofloxacin. Conclusion: In this study, ESBL-producing E. coli, showed high resistance to ciprofloxacin. Imipenem and amikacin were most effective against ESBL positive strains.
文摘Background: Detection of extended spectrum beta lactamase producing bacteria is an important issue in the clinical settings. Objective: The purpose of the present study was to validate the Cica Beta Test 1 for detection of extended spectrum beta-lactamase (ESBL) producing bacteria. Method: This analytical type of cross-sectional study was carried out in the Department of Microbiology and Immunology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from January 2006 to December 2006 for a period of one (01) year. All the patients presented with the clinical features of urinary tract infection and surgical as well as burn wound infection at any age with both sexes were selected as study population. All bacteria were isolated and identified by their colony morphology, staining characters, pigment production, motility and other relevant biochemical tests. Phenotypic confirmation of ESBLs producing isolates were done by inhibitor potentiated disc diffusion test according to CLSI recommendation. The Cica Beta Test 1 was performed according to the manufacturer’s instructions. Result: A total number of 288 Gram negative bacteria were isolated. Among these isolates Cica Beta test 1 was positive in 97 strains and phenotypic confirmatory test was positive in 89 strains. The test sensitivity of Cica Beta Test 1 was 100% (95% CI 95.9% to 100.0%). Specificity of the test was 96.0% (95% CI 92.2% to 98.2%). The positive predictive value (PPV) and negative predictive value (NPV) were 92.7% (95% CI 84.5% to 95.7%) and 100.0% (95% CI 98.0% to 100.0%) respectively. The accuracy of the test was 97.2% (95% CI 95.1% to 99.1%). Area under ROC curve = 0.980 (95% CI 0.964 to 0.996);p value 0.0001. Conclusion: In conclusion, Cica Beta Test 1 is very high sensitivity and specificity for the detection of ESBL from Gram negative bacteria.
文摘The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to establish the carriage of multi-drug resistance and extended-spectrum beta-lactamase genes in Escherichia coli from farmers, their cattle, and cattle slurry within Kiambu County. A total of 286 (81%) E. coli isolates were recovered from 352 samples analysed. Antibiotic resistance profiles showed 114 (40%) isolates were resistant to ≥3 antimicrobial classes and were considered multidrug-resistant. Among multidrug-resistant (MDR) E. coli strains, 40 (14%) were resistant to 3 different antimicrobial classes, while 71 (25%) were resistant to between 4 and 7 antibiotic classes. Extended-spectrum β-lactamase resistance was found in 18 isolates: human (n = 14), cattle (n = 2), and environmental (n = 2). Both the bla<sub>CTX-M</sub> and bla<sub>TEM</sub> genes were detected in 10 and 15 strains, respectively. Sequence analysis showed that the isolates carried the bla<sub>TEM-116</sub> (n = 7), bla<sub>TEM-1</sub> (n = 5), and bla<sub>CTX-M-15</sub> (n = 8) genes. Genotyping MDR isolates using (GTG) <sub>5</sub> PCR demonstrated that the isolates were not clonal. This data shows antimicrobial resistance profiles and different types of resistance genes in the E. coli population on dairy farms. As a result, more effective, targeted public health policies and measures need to be put in place to control and prevent the emergence and spread of resistant bacteria.
文摘BACKGROUND The survival of microorganisms on textiles and specifically on healthcare profes-sionals’(HCP)attire has been demonstrated in several studies.The ability of microorganisms to adhere and remain on textiles for up to hours or days raises questions as to their possible role in transmission from textile to skin via HCP to patients.AIM To evaluate the presence,survival and transmission of different multidrug-resistant bacteria(MDRB)from HCP attire onto skin.METHODS Three MDRB[methicillin-resistant Staphylococcus aureus(MRSA);vancomycin-resistant Enterococcus faecium(VRE);carbapenem-resistant Klebsiella pneumoniae,(CRKP)]were inoculated on textiles from scrubs(60%cotton-40%polyester)and white coat(100%cotton)at concentrations of 108 colony-forming units(CFU),105 CFU,and 103 CFU per mL.The inoculation of swatches was divided in time intervals of 1 min,5 min,15 min,30 min,1 h,2 h,3 h,4 h,5 h,and 6 h.At the end of each period,textiles were imprinted onto pig skins and each skin square was inverted onto three different selective chromogenic media.Growth from the pig skin squares was recorded for the 3 MDRB at the three above concentrations,for the whole length of the 6-h experiment.RESULTS MRSA was recovered from pig skins at all concentrations for the whole duration of the 6-h study.VRE was recovered from the concentration of 108 CFU/mL for 6 h and from 105 CFU/mL for up to 3 h,while showing no growth at 103 CFU/mL.CRKP was recovered from 108 CFU/mL for 6 h,up to 30 min from 105 CFU/mL and for 1 min from the concentration of 103 CFU/mL.CONCLUSION Evidence from the current study shows that MRSA can persist on textiles and transmit to skin for 6 h even at low concentrations.The fact that all MDRB can be sustained and transferred to skin even at lower concentrations,supports that textiles are implicated as vectors of bacterial spread.
文摘Objective:To analyze the clinical distribution and drug resistance of Klebsiella pneumoniae isolated from patients in a certain hospital and provide a basis for the rational use of antibiotics in the clinical treatment for the infection of Klebsiella pneumoniae.Methods:1,192 strains of Klebsiella pneumoniae isolated from clinical specimens from 2012 to 2016 were collected.The strains were identified by VITEK-2 Compact Microbiological Identification System,and the corresponding results of the antimicrobial susceptibility test were interpreted in accordance with the standards recommended by Clinical and Laboratory Standards Institute(CLSI).Results:1,192 strains of Klebsiella pneumoniae were mainly isolated from sputum(65.6%),and most of them were from Respiratory Medicine Department and Medical Intensive Care Unit of Respiratory Medicine Department(MICU),accounting for 41.4%.Out of 1,192 strains,448 strains were detected to produce extended-spectrum beta-lactamases(ESBLs),accounting for 37.6%.In addition,the detection rates of ESBL-producing Klebsiella pneumoniae for 5 consecutive years showed an increasing trend year by year,and they were higher than the national average values published by China Antimicrobial Resistance Surveillance System(CARSS)in the corresponding period.The drug resistance rate of ESBL-producing Klebsiella pneumoniae was significantly higher than that of non ESBL-producing strains.Conclusions:The infection caused by Klebsiella pneumoniae mainly occurs in the lower respiratory tract,and the drug resistance rates of Klebsiella pneumoniae to antibiotics in the drug susceptibility spectrum are maintained at a high level.Therefore,the rational selection of antibiotics for the clinical treatment of lower respiratory tract infection caused by Klebsiella pneumoniae must be based on the production of ESBLs and the results of antimicrobial susceptibility test.
文摘Background The extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance.Previous studies have focused on the resistance genes in ESBL-producing strains,and the resistance-associated genetic environment of non-ESBL-producing strains has been ignored until now.Here,we investigated the occurrence and characteristics of non-ESBL-producing K.pneumoniae,which potentially carries unexpressed resistance genes.Methods K.pneumoniae strains were collected from five medical institutions in China from February 2010 to August 2013.The VITEK-2 ESBL detection system was used as a primary screen to identify the ESBL-producing phenotype,and the three primary types of ESBL-associated genes (CTX,SHV,and TEM) were detected by polymerase chain reaction (PCR) to confirm the strains presenting with a non-ESBL-producing phenotype.mRNA expression in the non-ESBL-producing strains was further screened by reverse-transcription PCR (RT-PCR) to validate their transcriptional efficiency.Results Out of 224 clinically isolated antibiotic-sensitive K.pneumoniae strains with a non-ESBL-producing phenotype,5 (2.2%) were identified to carry inactivated ESBL blaSHV genes with intact upstream promoter regions and resistance gene sequences.Interestingly,three of the five antibiotic-sensitive K.pneumoniae strains containing ESBL blaSHV genes still exhibited mRNA transcription of blasHv,while the other two exhibited no mRNA transcription.Conclusion These findings suggest that inactivated ESBL genes exist in non-ESBL-producing antibiotic-sensitive K.pneumoniae strains,which have the potential to transform the strain into an ESBL phenotype if an inappropriate application or overdose of antibiotics is implemented during clinical management.
基金Supported by Kurdistan University of Medical Sciences and Professor Alborzi Clinical Microbiology Research Center affiliated to Shiraz University of Medical Sciences supported the whole study
文摘AIM: To study the antibiotic susceptibility patterns of gram-negative healthcare associated bacterial infections at two tertiary hospitals in the Sanandaj city, Kurdistan Province, Iran.METHODS: From January 2012 to December 2012, all positive cultures from potentially sterile body fluids were gathered. They sent to professor Alborzi clinical microbiology center in Shiraz for further analysis and susceptibility testing. The antibiotic susceptibility was determined using the Kirby-Bauer method(disk diffusiontechnique). The Results were interpreted according to Clinical and Laboratory Standards Institute guidelines against a series of antimicrobials. World Health Organization definitions for Healthcare associated infections were followed.RESULTS: Seven hundred and thirty-two positive cultures were reported from both hospitals. Seventynine isolates/patients fulfilled the study criteria for healthcare associated gram-negative infections. The most frequent bacterial cultures were from the pediatric wards(52%). Serratia marcescens(S. marcescens)(38%) Escherichia coli(E. coli)(19%), Klebsiella pneumoniae(K. pneumoniae)(19%), Acinetobacter baumannii(6%), Enterobacter species(6%), Serratia odorifera(4%) and Pseudomonas species(5%) were the most frequently isolated organisms. The susceptibility pattern of common isolates i.e., S. marcescens, E. coli and K. pneumoniae for commonly used antibiotics were as follows: Ampicillin 3.3%, 6.7%, 20%; gentamicin 73.3%, 73.3%, 46.7%; ceftazidim 80%, 73.3%, 33.3%; cefepim 80%, 86.7%, 46.7%; piperacillin/tazobactam 90%, 66.7%, 86.7%; ciprofloxacin 100%, 73.3%, 86.7%; imipenem 100%, 100%, 100%, respectively. CONCLUSION: The most effective antibiotics against gram-negative healthcare associated infections are imipenem followed by ciprofloxacin. The resistance rate is high against ampicillin and cephalothin. The high mortality rate(46.1%) associated with S. marcescens is alarming.
基金the financial support of the National Key Research and Development Program of China (2017YFC1200203 and 2016YFD0501105)the Mega-projects of Science Research of China (2018ZX10733402-004 and 2018ZX10712001-005)+2 种基金the National Natural Science Foundation of China (81741098 and 81711530049)the Zhejiang Provincial Key Research and Development Program (2015C03032)the Zhejiang Provincial Natural Science Foundation of China (LY17H190003)
文摘Carbapenemase-producing Enterobacteriaceae(CPE) isolates are recognized as one of the most severe threats to public health. However, the population structure and genetic characteristics of CPE isolates among bloodstream infections(BSIs) are largely unknown. To address this knowledge gap, in this study,we included patients with clinically significant BSIs due to Enterobacterales isolates, recruited from 26 sentinel hospitals in China(2014–2015). CPE isolates were microbiologically and genomically characterized,including their susceptibility profiles, molecular typing, phylogenetic features, and genetic context analysis of carbapenemase-encoding genes. Of the 2569 BSI Enterobacterales isolates enrolled, 42(1.6%) were carbapenemase-positive. Moreover, among the 2242 investigated isolates, 1111(49.6%) extendedspectrum β-lactamase(ESBL)-producing isolates were identified in Escherichia coli(E. coli), Klebsiella pneumoniae(K. pneumoniae), Proteus mirabilis(P. mirabilis), and Klebsiella oxytoca. Whole genome sequencing analysis showed the clonal spread of K. pneumoniae carbapenemase(KPC)-2-producing K. pneumoniae sequence type(ST) 11 and New Delhi metallo-β-lactamase(NDM)-5-producing E. coli ST167 in our collection. Plasmid analysis revealed that carbapenemase-encoding genes were located on multiple plasmids. A high prevalence of biofilm-encoding type 3 fimbriae clusters and yesiniabactin-associated genes was observed in K. pneumoniae isolates. This work demonstrates the high prevalence of ESBLs and the wide dissemination of CPE among BSI isolates in China, which represent real clinical threats. Moreover, our findings first illustrate a more comprehensive genome scenario of CPE isolates among BSIs. The clonal spread of KPC-2-producing K. pneumoniae ST11 and NDM-5-producing E. coli ST167 needs to be closely monitored.