Appendical Perforation by Infection with Extended-Spectrum Beta-Lactamase (ESBL)-Producing <i>Escherichia coli</i>: Case Report

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.

Prevalence of Extended Spectrum Beta-Lactamase-Producing Escherichia coli in Broiler Chickens in YaoundéCapital City of Cameroon

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.

Detection of Beta-Lactamase and Extended-Spectrum Beta-Lactamase of Pathogens Isolated from Pig and Chicken and Their Antibiotic Susceptibility Test

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.

Post-appendectomy pelvic abscess with extended-spectrum beta-lactamase producing Escherichia coli : A case report and review of literature

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.

Diagnostic Validity of Cica Beta Test 1 for the Detection of Extended Spectrum Beta-Lactamase (ESBL) Producing Gram Negative Bacteria by Comparing with Phenotypic Method

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.

Phenotypic and Genotypic Characterization of Metallo-Beta-Lactamase and Extended-Spectrum Beta-Lactamase among Enterobacteria Isolated at National Public Health Laboratory of Brazzaville

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.

Activity of Fosfomycin in Extended-Spectrum Beta-Lactamases Producing Klebsiella pneumonae from Hospital Acquired Urinary Tract Infections

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.

Study on the Genotype of Extended-spectrum Beta-lactamases Mediated by Plasmid in Southern China

To investigate the prevalence and genotype of extended spectrum beta-lactamases (ESBLs) mediated by plasmid in Gram-negative bacteria found in southern China, a total of 1184 clinical isolates of non-repetitive strains of Gram-negative bacteria were collected in 2001 from 5 different cities in southern China. The ESBLs-producing isolates were distinguished by means of the phenotype confirmatory test based on the NCCLS criteria and were subjected to plasmid conjugation and electroporation experiments. Those clinical isolates succeeded in plasmid transfers had undergone plasmid conjugation and electro-transformation, plasmid DNA extraction and PstⅠ digest finger-printing analysis, as well as the universal primer PCR amplification of the TEM, SHV, CTX-M, VEB, PER and SFO genes and the DNA sequencing in order to determine the genotypes of ESBLs and their plasmid locations. It was found that the incidence of the ESBLs-producing strains of Gram-negative bacteria was 14.6% (173/1184) with 67 strains of transconjugants and 11 strains of electro-transformants, in which CTX-M-14 type was 33.3% (26/78); CTX-M-3 type was 23.1% (18/78); CTX-M-9 type was 14.1% (11/78); CTX-M-5 type was 6.4% ( 5/78); CTX-M-13 type was 2.6% (2/78); SHV-5 type was 7.7% (6/78); SHV-12 type was 5.1% (4/78), SHV-2a type was 2.6% (2/78) and unidentified type was 5.1% (4/78). 29.5% of the wild strains also carried broad-spectrum beta-lactamases TEM-1 and SHV-1 types. The above mentioned ESBLs genes were located on transferable plasmids with variable sizes (from 35 to 190?kb). The CTX-M type ESBLs was characterized by high-level of resistance to cefotaxime. It concluded that the CTX-M-type was the most prevalent genotype in clinical isolates of Gram-negative bacteria in southern China, and the SHV-type ranks in the second place. TEM-, VEB-, Toho- and PER-types were not found in these isolates.

Analysis of Enterobacteriaceae Producing Broad-Spectrum Beta-Lactamases in the Intensive Care Unit Setting

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.

Oxidative stress-initiated one-carbon metabolism drives the generation of interleukin-10-producing B cells to resolve pneumonia

The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown.Using a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL-10+B cells)play a key role in spontaneously resolving infection-mediated inflammation.Accumulated cytosolic reactive oxygen species(ROS)during inflammation were shown to drive IL-10+B-cell generation by remodeling one-carbon metabolism.Depletion of the enzyme serine hydroxymethyltransferase 1(Shmt1)led to inadequate one-carbon metabolism and decreased IL-10+B-cell production.Furthermore,increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine(SAM),altering histone H3 lysine 4 methylation(H3K4me)at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells.Therefore,the one-carbon metabolism-associated compound ethacrynic acid(EA)was screened and found to potentially treat infectious pneumonia by boosting IL-10+B-cell generation.Overall,these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.

Characterisation of IL-21 and IL-21Rαin grass carp:IL-21-producing cells are upregulated during Flavobacterium columnare infection

Interleukin-21(IL-21)is produced mainly by activated CD4^(+)T cells and promotes the proliferation,survival and differentiation of immune cells.This study characterised a high affinity binding receptor of IL-21(IL-21 Rα)from grass carp(Ctenopharyngodon idella,Ci)and analyzed the expression of CiIL-21 and CiIL-21 Rα.It has been shown that they were modulated by PAMPs and during infection with bacterial and viral pathogens.Recombinant CiIL-21 protein produced in bacteria was active in inducing the expression of genes involved in Th responses.A monoclonal CiIL-21 antibody was generated against the rCiIL-21 and showed good reactive specificity with the rCiIL-21 proteins expressed in E.coli cells,and HEK293 T cells and the native protein from PHA-stimulated kidney leukocytes.In addition,the IL-21-producing cells detected by the CiIL-21 monoclonal antibody were found to be increased to in the kidney,spleen and hindgut after infection with Flavobacterium columnare.Our data indicate that IL-21 is involved in the regulation of immune response to bacterial and viral infection.

碳青霉烯类非敏感肠杆菌科细菌的β-内酰胺酶检测及耐药性分析

目的：探讨碳青霉烯类非敏感肠杆菌科细菌产碳青霉烯酶、超广谱β-内酰胺酶（ESBLs）及对16种抗菌药物的耐药情况，为临床合理用药提供依据。方法收集2010年1月至2013年12月临床分离的对碳青霉烯类非敏感的肺炎克雷伯菌214株、大肠埃希菌111株，采用改良Hodge试验对碳青霉烯酶进行检测，表型确证试验检测ESBLs，K-B纸片扩散法检测药敏试验。结果214株肺炎克雷伯菌单产碳青霉烯酶的阳性率为57.9%，单产ESBLs为12.6%，同时产ESBLs和碳青霉烯酶为20.6%；111株大肠埃希菌单产碳青霉烯酶的阳性率为54.1%，单产ESBLs为5.4%，同时产ESBLs和碳青霉烯酶为23.4%。试验菌株对临床常用的抗菌药物耐药性严重，耐药率在13.5%-98.1%之间，对米诺环素和替加环素耐药率低。结论对碳青霉烯类非敏感的肺炎克雷伯菌和大肠埃希菌产碳青霉烯酶率高，治疗该类细菌引起的感染可根据病原菌药敏试验结果和患者病情合理选用替加环素或米诺环素，以达到有效控制感染目的。

Identification of Klebsiella pneumoniae strains harboring inactive extended-spectrum beta-lactamase antibiotic-resistance genes

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.

Role of Th17 cells in the pathogenesis of rheumatoid arthritis

Since early description of CD4/CD8 T cell duality, continuous discovery of functional T lymphocyte subsets and their related cytokines constitutes major progress in our understanding of the immune response. T-lymphocyte derived lymphokines and environmental cytokines are essential for both innate and antigen-specific immune responses to a wide variety of agents. Following immune battle and aggression overcome, cytokines may return against neighbored cells/organs, causing pathogenic hypersensitivity reactions, including autoimmune diseases. Due to their cytokine production, CD4+ T helper lymphocyte subsets may be considered as one the major players of the immune response. Among CD4+ T cell subsets, the identification of interleukin-17-producing cells(Th17) led to better understanding of coordinated cytokine involvement during inflammatory reactions together with the subsequent clarification of complex interactions between these mediators. In this review, we discuss Th17 cell differentiation, functions, and the role of this cell subset during rheumatoid arthritis pathogenesis together with therapeutic strategies to control these cells.

Clinical and Microbiological Characteristics of Patients with Complicated Intra-abdominal Infections in Intensive Care Unit

In order to investigate the clinical and microbiological characteristics of patients with complicated intra-abdominal infections(cIAIs)in intensive care unit(ICU),the clinical data of 612 cIAIs patients from January 2016 to December 2018 were retrospectively collected.Clinical characteristics,distribution of pathogens and drug resistance were statistically analyzed.It was found that patients with community-acquired intra-abdominal infections(CA-IAIs)made up a majority of cIAIs patients.The positive rate of abdominal drainage fluid culture was 55.56%.Gramnegative bacteria accounted for the majority,the most commonly isolated bacteria of which were Escherichia coli(20.96%),Klebsiella pneumoniae(10.20%)and Pseudomonas aeruginosa(5.57%).The most commonly isolated gram-positive bacteria were Enterococcus(16.88%)and Methicillinresistant staphylococcus aureus(MRSA,3.90%).Enterobacter isolates showed high resistance rate to most cephalosporins and low resistance rate to piperacillin/tazobactam and carbapenems.Extended spectrum beta-lactamase(ESBL)screen positive isolates from CA-IAIs patients showed an increasing trend in past three years.Enterococcus and MRSA showed high resistance rate to clindamycin,quinolone,erythromycin and tetracycline,while they showed high sensitivity rate to linezolid,tegacycline,teicoplanin and vancomycin.Our results indicate that isolated bacteria from abdominal drainage fluid show high resistance rates to commonly used antibiotics in ICU patients with cIAIs.The curative effects on diseases should be monitored continuously when antibiotics are used.Meanwhile,we should always keep eyes on drug-resistant bacteria,especially when the treatment efficacy is not good.

Influence of a probiotic mixture on antibiotic induced microbiota disturbances

AIM: To study the effect of probiotic consumption on the faecal microbiota during and after antibiotic exposure.

Health care associated infections, antibiotic resistance and clinical outcome: A surveillance study from Sanandaj, Iran

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.

Prevalence and Resistance Pattern of <i>Pseudomonas aeruginosa</i>Isolated from Surface Water

Pseudomonas aeruginosa is one of the most common pathogenic bacteria, frequently found in different environmental samples. The prevalence of multidrug resistant isolates has become an alarming concern for both patients and their surroundings. The present study was carried out to record prevalence of P. aeruginosa in surface water of Dhaka city and to screen their antibiotic resistance pattern. The study was also extended to typing of resistant isolates according to extended spectrum beta lactamase production. Hereby, Kirby-Bauer method was applied to test antibiotic sensitivity according to Clinical and Laboratory Standards Institute. Then, the Ampicillin resistant isolates were screened for ESBL production by Double Disk Synergy Test (DDST). In these prospects, 52 water samples were tested, of which 32 were found positive for P. aeruginosa isolates. Hundred percent of the positive isolates were found to Ampicillin (AMP) resistant followed by 93.7% to both Tetracycline and Gentamycin and 71.8% to Co-triimoxazole. P. aeruginosa is completely susceptible to third generation antibiotics ciprofloxacin, Imipenem and Aztreonam followed by moderately susceptible to Polymyxin-B (78.2%) and Colistin (87.5%). According to DDST, all of the susceptible isolates were found positive for AMC type beta-lactamase production. It is evident from this study that the surface water is contaminated with antibiotic resistant P. aeruginosa and that through the water systems antibiotic resistance can be transferred to humans and animals. So, appropriate and rationale use of antibiotic should be applied to minimize the emergence of multidrug isolates to environment.

Detection of presumed genes encoding beta-lactamases by sequence based screening of metagenomes derived from Antarctic microbial mats

Analysis of environmental samples for bacterial antibiotic resistance genes may have different objectives and analysis strategies. In some cases, the purpose was to study diversity and evolution of genes that could be grouped within a mechanism of antibiotic resistance. Different protocols have been designed for detection and confirmation that a functional gene was found. In this study, we present a sequence-based screening of candidate genes encoding beta-lactamases in 14 metagenomes of Antarctic microbial mats. The samples were obtained from different sites, representing diverse biogeographic regions of maritime and continental Antarctica. A protocol was designed based on generation of Hidden Markov Models from the four beta-lactamase classes by Ambler classification, using sequences from the Comprehensive Antibiotic Resistance Database (CARD). The models were used as queries for metagenome analysis and recovered contigs were subsequently annotated using RAST. According to our analysis, 14 metagenomes analyzed contain A, B and C beta-lactamase genes. Class D genes, however, were identified in 11 metagenomes. The most abundant was class C (46.8%), followed by classes B (35.5%), A (14.2%) and D (3.5%). A considerable number of sequences formed clusters which included, in some cases, contigs from different metagenomes. These assemblies are clearly separated from reference clusters, previously identified using CARD beta-lactamase sequences. While bacterial antibiotic resistance is a major challenge of public health worldwide, our results suggest that environmental diversity of beta-lactamase genes is higher than that currently reported, although this should be complemented with gene function analysis.

Prevalence of multi-drug resistant uropathogenic Escherichia coli in Potohar region of Pakistan

Objective:To scrutinize patterns of multi-drug-resistant uropathogenic Escherichia coli(UPEC) strains and particularly of fluoroquinolone-resistance this is an alternative choice for the treatment of urinary tract infections.Methods:Bacterial samples(n = 250) were collected from out-patients from August 2012 to August 2014 Islamabad.Antibiotic susceptibility profiling and determination of minimum inhibitory concentrations(MICs) and minimum bactericidal concentrations were performed according to the guidelines of Clinical and Laboratory Standards Institute(CLSI,2012).Genes,qnrA,qnrB and qnrS were identified by DNA amplification and sequencing.Results:The highest percentage of UPEC isolates were resistant to co-trimoxazole(82%) followed by cephalothin(80%),2nd Gen,3rd Gen and 4th Gen cephalosporins,respectively.Resistance against gentamicin,amikacin remained 29% and 4%.For other drugs including nitrofurantoin,tetracycline,carbapenem and beta-lactam inhibitors remained below 10%.Altogether,59% of the isolates were resistant to at least three antibiotics including one fluoroquinolone.Overall,MICs for ciprofloxacin remained(MIC≥256 μg/mL) and for levofloxacin(MIC≥16 μg/mL and 32 μg/mL).No significant differences were observed regarding MIC values of extended spectrumβ-lactamase(ESBL) and non-ESBL producers.For qnrS and qnrB positive isolates MICs remained above 32 μg/mL.Prevalence of UPEC was significantly higher among females and 40% of the isolates were ESBL producers.Conclusions:Higher percentages of ESBL producing UPEC were associated with urinary tract infections.Moreover,the majority of these isolates were multi-drug resistant and fluoroquinolone-resistant.