Multi Drug Resistance Bacterial Isolates of Surgical Site Infection

Multi drug resistance microorganism is considered to be one of the major health problems. The aim of this study was to determine antibiotic susceptibility pattern of bacterial pathogens of surgical site infection. A total 250 samples were included, out of which 62.4% showed significant bacterial growth. Gram negative bacteria were 85.25% and gram positive bacteria were 14.75%;among them 65.38% of the total isolates were multi drug resistance (MDR). The age group between 31 - 40 found the highest number of isolates 22.4%. Among gram negative bacilli, the highest production of MDR was found in Acinetobacter spp. followed by Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. In gram positive cocci, the highest production of MDR was found in Staphylococcus aureus. Acinetobacter spp. was found highly susceptible to amikacin and gentamycin 20.1% followed by ofloxacin and ciprofloxacin 18.6% and 16.2% respectively. Staphylococcus aureus showed 100% sensitive to clindamycin whereas penicillin showed 100% resistance followed by amoxycillin (93.75%). Amikacine and clindamycin were drugs of choice for gram negative and gram positive bacteria respectively. This study showed that alarming increase of infections was caused by multi drug resistance bacterial organisms. It increases length of stay and may produce lasting sequelae and requires extra resources for investigations, management and nursing care. Surveillance of surgical site infection is a useful tool to demonstrate the magnitude of the problem and find out appropriate preventive methods.

Current concepts and future strategies in the antimicrobial therapy of emerging Gram-positive spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis(SBP) is the most common infection in end-stage liver disease patients.SBP is defined as an ascitic fluid infection with a polymorphonuclear leucocyte count ≥ 250/mm^3 without an evident intra-abdominal surgically treatable source.Several mechanisms contribute to SBP occurrence,including translocation of gut bacteria and their products,reduced intestinal motility provoking bacterial overgrowth,alteration of the gut's barrier function and local immune responses.Historically,Gram-negative enteric bacteria have been the main causative agents of SBP,thereby guiding the empirical therapeutic choice.However,over the last decade,a worryingly increasing prevalence of Gram-positive and multi-drug resistant(MDR) SBP has been seen.Recently,the microbiological spectrum of SBP seems to have changed in Europe due to a high prevalence of Gram-positive bacteria(48%-62%).The overall proportion of MDR bacteria is up to 22%-73% of cases.Consequently,empirical therapy based on thirdgeneration cephalosporins or amoxicillin/clavulanic acid,can no longer be considered the standard of care,as these drugs are associated with poor outcomes.Theaim of this review is to describe,with an epidemiological focus,the evidence behind this rise in Gram-positive and MDR SBP from 2000 to present,and illustrate potential targeted therapeutic strategies.An appropriate treatment protocol should include daptomycin plus ceftaroline and meropenem,with prompt stepdown to a narrower spectrum when cultures and sensitivity data are available in order to reduce both cost and potential antibiotic resistance development.

Six-year analysis of key monitoring for bacterial strain distribution and antibiotic sensitivity in a hospital

BACKGROUND With the widespread use of antimicrobial drugs,bacterial resistance has become a significant problem,posing a serious threat to public health.The prevalence of clinical infection strains in hospitals and their drug sensitivities are key to the appropriate use of antibiotics in clinical practice.AIM To identify prevalent bacteria and their antibiotic resistance profiles in a hospital setting,thereby guiding effective antibiotic usage by clinicians.METHODS Specimens from across the institution were collected by the microbiology laboratory.The VITEK 2 compact fully automatic analyzer was used for bacterial identification and antibiotic sensitivity testing,and the WHONET5.6 software was utilized for statistical analysis.RESULTS A total of 12062 bacterial strains of key monitoring significance were detected.Staphylococcus aureus demonstrated widespread resistance to penicillin,but none of the strains were resistant to vancomycin or linezolid.Moreover,219 strains of methicillin-resistant coagulase-negative staphylococci and 110 strains of methicillin-resistant Staphylococcus aureus were detected.Enterococcus faecalis showed moderate resistance to the third-generation quinolones ciprofloxacin and levofloxacin,but its resistance to nitrofurantoin and tetracycline was low.Enterococcus faecium displayed significantly lower resistance to third-and fourthgeneration quinolones than Enterococcus faecalis.The resistance of two key monitoring strains,Escherichia coli and Klebsiella pneumoniae,to piperacillin/tazobactam was 5%-8%.However,none of the Escherichia coli and Klebsiella pneumoniae strains were resistant to meropenem.The resistance of Acinetobacter baumannii to piperacillin/sulbactam was nearly 90%.Nonetheless,the resistance to tigecycline was low,and Pseudomonas aeruginosa demonstrated minimal resistance in the antibiotic sensitivity test,maintaining a resistance of<10%to the cephalosporin antibiotics cefotetan and cefoperazone over the last 6 years.The resistance to amikacin remained at 0.2%over the past 3 years.CONCLUSION Our hospital’s overall antibiotic resistance rate was relatively stable from 2017 to 2022.The detection rates of key monitoring strains are reported quarterly and their resistance dynamics are monitored and communicated to the entire hospital,which can guide clinical antibiotic selection.

New determinants of prognosis in bacterial infections in cirrhosis

Despite major advances in the knowledge and management of liver diseases achieved in recent decades,decompensation of cirrhosis still carries a high burden of morbidity and mortality.Bacterial infections are one of the main causes of decompensation.It is very important for clinical management to be aware of the population with the highest risk of poor outcome.This review deals with the new determinants of prognosis in patients with cirrhosis and bacterial infections reported recently.Emergence of multiresistant bacteria has led to an increasing failure rate of the standard empirical antibiotic therapy recommended by international guidelines.Moreover,it has been recently reported that endothelial dysfunction is associated with the degree of liver dysfunction and,in infected patients,with the degree of sepsis.It has also been reported that relative adrenal insufficiency is frequent in the non-critically ill cirrhotic population and it is associated with a higher risk of developing infection,severe sepsis,hepatorenal syndrome and death.We advise a change in the standard empirical antibiotic therapy in patients with high risk for multiresistant infections and also to take into account endothelial and adrenal dysfunction in prognostic models in hospitalized patients with decompensated cirrhosis.

Antibiotic sensitivity pattern of common bacterial pathogens in NICU and neonatal ward in Hamedan province of Iran

Bacterial pathogens and drug resistance are different in hospitals of each country. In this study we determined bacterial path- ogens and drug sensitivity in the neonatal ward and neonatal intensive care unit (NICU) in Ekbatan hospital in Hamedan. This cross-sectional descriptive study was done on 1150 hospitalized neonates in neonatal and NICU wards of Ekbatan hospital of the Hamadan university of medical sciences from September 2004 to September 2006. Blood, cerebrospinal fluid (CSF), urine, stool, eye excretion, synovial fluid, umbilical secretion and ascitic fluid were evaluated. Positive cultures were evaluated for antibiotic resistance with disk diffusion test methed. All of the data in questionnaires was analyzed with SPSS 13. Cultures including blood, urine, CSF , stool, eye excretion, synovial fluid, umbilical secretion and ascitic fluid was done in 417 neonates (833 cultures). These cultures were including: urine, 323 cases (38.8%) blood 293 cases (35.2%), CSF 180 cases (21.6%) , stool 17 cases (2%), eye secretion 16 cases (1.9%) and other secretions (synovial, umbilical, etc) 4 cases (0.5%). The cultures were positive in 105 cases (25.2%). 60 male neonates (57.1%) and 45 female neonates (42.9%) were culture positive. The most common microorganisms were E coli 66.7% (70 cases), Klebsiella 10.5% (11 cases). Drug resistance was high in these microorganisms. The most common microorganisms were Ecoli and klebsiella. Drug resistance was high in the isolated microorganisms.

Unresolved issues in the prophylaxis of bacterial infections in patients with cirrhosis

Bacterial infections are highly prevalent and a frequent cause of hospitalization and short-term mortality in patients with cirrhosis. Due to their negative impact on survival, antibiotic prophylaxis for bacterial infections in high-risk subgroups of patients with cirrhosis has been the standard of care for decades. Patients with prophylaxis indications include those at risk for a first episode of spontaneous bacterial peritonitis(SBP) due to a low ascitic fluid protein count and impaired liver and kidney function, patients with a prior episode of SBP and those with an episode of gastrointestinal bleeding. Only prophylaxis due to gastrointestinal bleeding has a known and short-time duration. All other indications imply longlasting exposure to antibiotics-once the threshold requirement for initiating prophylaxis is met-without standardized criteria for re-assessing antibiotic interruption. Despite the fact that the benefit of antibiotic prophylaxis in reducing bacterial infections episodes and mortality has been thoroughly reported, the extended use of antibiotics in patients with cirrhosis has also had negative consequences, including the emergence of multi-drug resistant bacteria.Currently, it is not clear whether restricting the use of broad and fixed antibiotic regimens, tailoring the choice of antibiotics to local bacterial epidemiology or selecting non-antibiotic strategies will be the preferred antibiotic prophylaxis strategy for patients with cirrhosis in the future.

Distribution and drug resistance of pathogens in burn patients in China from 2006 to 2019

BACKGROUND In this study,recent trends in the distribution and drug resistance of pathogenic bacteria isolated from patients treated at a burn ward between 2006 and 2019 were investigated.AIM To develop more effective clinical strategies and techniques for the prevention and treatment of bacterial infections in burn patients.METHODS Clinical samples with positive bacteria were collected from patients at the burn ward in Beijing Jishuitan Hospital in China between January 2006 and December 2019.The samples were retrospectively analyzed,the distribution of pathogenic bacteria was determined,and the trends and changes in bacterial drug resistance during different period were assessed.Drug resistance in several main pathogenic bacteria from 2006 to 2011 and from 2012 to 2019 was comparatively summarized and analyzed.RESULTS Samples from 17119 patients were collected and analyzed from 2006 to 2019.Surprisingly,a total of 7960 strains of different pathogenic bacteria were isolated at this hospital.Among these bacteria,87.98%(7003/7960)of the strains were isolated from burn wounds,and only 1.34%(107/7960)were isolated from the blood of patients.In addition,49.70%(3956/7960)were identified as Grampositive bacteria,48.13%(3831/7960)were Gram-negative bacteria,and the remaining 2.17%(173/7960)were classified as fungi or other pathogens.Importantly,Staphylococcus aureus(21.68%),Pseudomonas aeruginosa(14.23%),and Staphylococcus epidermidis (9.61%) were the top three pathogens most frequentlyisolated from patients.CONCLUSION In patients treated at the burn ward in this hospital from 2006 to 2019,Staphylococcus aureus and Pseudomonas aeruginosa were the predominant clinicalpathogens responsible for bacterial infections. The circumstantial detection anddetailed monitoring of the intensity and growth of different pathogenic bacteria inclinical patients as well as tests of drug sensitivity during burn recovery areparticularly important to provide guidelines for the application of antibiotics andother related drugs. Careful collection and correct, standard culture of bacterialspecimens are also crucial to improve the efficiency of bacterial infectiondetection. Effective monitoring and timely clinical treatment in patients may helpreduce the possibility and rate of infection as well as alleviate the effects of drugresistance among patients in burn centers.

Microbial spectrum and drug resistance of pathogens cultured from gallbladder bile specimens of patients with cholelithiasis:A singlecenter retrospective study

BACKGROUND Bacterial infection is an important cause of cholelithiasis or gallstones and interferes with its treatment.There is no consensus on bile microbial culture profiles in previous studies,and identified microbial spectrum and drug resistance is helpful for targeted preventive and therapeutic drugs in the perioperative period.AIM To analyze the bile microbial spectrum of patients with cholelithiasis and the drug susceptibility patterns in order to establish an empirical antibiotic treatment for cholelithiasis-associated infection.METHODS A retrospective single-center study was conducted on patients diagnosed with cholelithiasis between May 2013 and December 2018.RESULTS This study included 185 patients,of whom 163(88.1%)were diagnosed with gallstones and 22(11.9%)were diagnosed with gallstones and common bile duct stones(CBDSs).Bile culture in 38 cases(20.5%)was positive.The presence of CBDSs(OR=5.4,95%CI:1.3-21.9,P=0.03)and longer operation time(>80 min)(OR=4.3,95%CI:1.4-13.1,P=0.01)were identified as independent risk factors for positive bile culture.Gram-negative bacteria were detected in 28 positive bile specimens,and Escherichia coli(E.coli)(19/28)and Klebsiella pneumoniae(5/28)were the most frequently identified species.Gram-positive bacteria were present in 10 specimens.The resistance rate to cephalosporin in E.coli was above 42%and varied across generations.All the isolated E.coli strains were sensitive to carbapenems,with the exception of one imipenem-resistant strain.K.pneumoniae showed a similar resistance spectrum to E.coli.Enterococcus spp.was largely sensitive to glycopeptides and penicillin,except for a few strains of E.faecium.CONCLUSION The presence of common bile duct stones and longer operation time were identified as independent risk factors for positive bile culture in patients with cholelithiasis.The most commonly detected bacterium was E.coli.The combination ofβ-lactam antibiotics andβ-lactamase inhibitors prescribed perioperatively appears to be effective against bile pathogens and is recommended.Additionally,regular monitoring of emerging resistance patterns is required in the future.

Bacterial contamination of orally-consumed crude herbal remedies:A potential source for multi-drug resistant pathogens in man

Objective:The acceptability of herbal remedies for alleviating discomforts and ill-health has become very popular, on the account of the increasing cost of allopathic medicine for personal health maintenance.The observable non-adherence of herbalists to the established World Health Organization(WHO) / National Agency for Food and Drug Administration Control(NAFDAC) regulations for the quality control of herbal medicines is an issue for concern.In view of this,34 popular and widely consumed crude herbal remedies in southwestern,Nigeria were screened for compliance with standard limits for bacterial contamination,bacteria flora and their antibiotic susceptibility pattern.Methods:Isolates recovered from samples were identified using the cultural, morphological and biochemical characteristics.They were also tested for drug sensitivity using standard procedures. Results:A heavy bacteria load ranging from 3.00×10~3-9.58×10~5 CFU/ML and 1.20×10~5- 5.41×10~5 CFU/ML was observed for water and spirit extracted preparations respectively.The bacteria flora cum contaminants were:Staphylococcus aureus,Bacillus cereus,Bacillus subtilis,Pseudomonas aeruginosa, Micrococcus luteus,Lactobacillus plantarum,Klebsiella pneumoniae,Escherichia coli,streptococcus,Shigella, Neisseria,Arthrobacter,Kurthia and Clostridium species.All the isolates were multi-drug resistant(MDR) strains.Conclusion:The crude herbal preparations consumed in Nigeria failed to comply with the internationally recognized standards regarding bacteria load and flora.The presence of MDR pathogens is of greatest concern. It poses a great risk to consumers health and could be a source of introducing MDR organisms into the human population.There is the need for the enforcement of established guidelines to ensure the safety of these preparations.

Helicobacter pylori acquisition of metronidazole resistance by natural transformation in vitro

AIM To study whether Helicobacter pylori is naturally transformable. METHODS Transformation was performed in BHI broth supplemented with horse serum and yeast extract. Genomic DNA extracted from a metronidazole resistant H. pylori strain was added to H. pylori broth culture. The mixture was incubated at microaerophilic atmosphere. The DNA treated cells were plated on blood agar containing 8mg/L metronidazole to select for transformants. Sterile distilled water was used as a negative DNA control. The DNA profiles of transformants were compared with that of their parent strains by randomly amplified polymorphic DNA (RAPD) fingerprinting. RESULTS Transformation of H. pylori with DNA from a metronidazole resistant strain as a marker was demonstrated. Out of the 12 strains of H. pylori tested, 9 (75%) strains were found to be transformable. The transformation frequencies ranged from 3 4×10 -6 to 2 4×10 -4 . By RAPD, DNA fingerprints of the transformants and their parent strains showed no change in DNA profiles though transformants were all resistant to metronidazole as compared with their metronidazole sensitive parent strains. CONCLUSION Helicobacter pylori is naturally transformable which might be one of the ways that H. pylori develops resistance to metronidazole.

2020—2022年自贡市第一人民医院细菌耐药性监测

目的了解自贡市第一人民医院临床分离菌对抗菌药物的耐药性,为临床合理使用抗菌药物提供依据。方法收集我院2020—2022年临床分离菌株,采用VITEK自动化鉴定及药敏系统、纸片扩散法及E-test方法进行细菌鉴定及药物敏感试验,以2022年美国临床和实验室标准化协会(CLSI)折点标准判断结果。结果共分离出临床菌株13324株,其中革兰阴性菌占69.6%,革兰阳性菌占30.4%。前五位分离菌为大肠埃希菌、肺炎克雷伯菌、金黄色葡萄球菌、铜绿假单胞菌和流感嗜血杆菌。耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)的检出率分别为24.1%和73.0%。耐利奈唑胺屎肠球菌和粪肠球菌的检出率分别为2.1%和12.4%,分离出1株耐万古霉素的屎肠球菌。脑脊液中分离的4株肺炎链球菌均为青霉素非敏感菌株,未检出非脑脊液来源耐青霉素肺炎链球菌。耐碳青霉烯类阴沟肠杆菌的检出率为12.3%。而耐碳青霉烯类大肠埃希菌和肺炎克雷伯菌检出率低,分别为1.1%和2.9%。铜绿假单胞菌对哌拉西林/他唑巴坦、头孢吡肟和庆大霉素的耐药率逐年增加;鲍曼不动杆菌对常见抗菌药物耐药率明显高于铜绿假单胞菌,耐碳青霉烯类菌株检出率分别为41.9%和6.9%。未分离出耐头孢噻肟的流感嗜血杆菌和卡他莫拉菌。结论临床分离菌以革兰阴性菌为主,常见分离菌的耐药率呈现平稳或略有降低的特点。然而,耐利奈唑胺粪肠球菌和耐阿莫西林/克拉维酸流感嗜血杆菌检出率明显升高,应加强医院感染防控措施和抗菌药物的合理使用。

一株多重耐药大肠杆菌全基因组测序及其耐药性分析

为了解大肠杆菌携带的粘菌素耐药基因并筛选敏感药物,解决多重耐药和动物临床无药可选的困局,采用16S rRNA菌种全基因组测序,PCR筛查mcr-4、mcr-5、blaTEM和AmpC酶耐药基因,应用BLAST和MEGA软件进行生物信息学和系统进化树分析,并对该菌株进行了78种抗生素抗菌药物敏感性测试及4种天然植物提取物(黄藤素、黄连素、黄芩苷和博落回)的抑菌、杀菌效果试验。结果表明,从2021年(1—12月)和2022年(1—6月)猪临床腹泻病例肠道中分离鉴定的145株大肠埃希菌(Escherichia coli,E.coli)中,鉴定出1株同时携带粘菌素耐药基因(mcr-4,mcr-5)和β内酰胺酶blaTEM、AmpC基因的猪源大肠埃希氏菌临床菌株HN2149。78种抗生素药敏试验结果显示,HN2149菌株对头孢吡肟、头孢地嗪、磷霉素、头孢克肟、头孢唑林、头孢哌酮、美洛培南、头孢西丁、头孢呋辛、头孢曲松、头孢噻肟、头孢他啶、替卡西林/克拉维酸、头孢哌酮/舒巴坦、氨曲南、哌拉西林/他唑巴坦、头孢噻肟/克拉维酸、头孢唑肟、头孢美唑、头孢他啶/克拉维酸和头孢他美敏感,对其余57种抗菌药物表现为耐药。4种植物提取物的药敏结果显示,博落回对菌株HN2149的抑菌、杀菌效果较好,其余3种提取物均对该菌株无抑菌和杀菌效果。以上研究结果为猪大肠杆菌病的防控提供参考。

急性髓系白血病合并血流感染的病原菌分布与耐药性变迁及患者死亡的危险因素分析

目的探讨成人急性髓系白血病(AML)合并血流感染的病原菌分布与耐药性变迁,并分析患者死亡的危险因素。方法比较85例AML合并血流感染确诊时间的前30个月(2017年1月—2019年6月检出的病原菌)和后30个月(2019年7月—2021年12月)的病原菌检出率和主要病原菌耐药率变迁情况。并按患者血流感染后6个月预后分为死亡组33例和生存组52例。采用Logistic回归分析影响AML合并血流感染患者死亡的危险因素。结果85例AML合并血流感染患者共检出98株病原菌,以革兰阴性菌为主(65/98,66.33%),其次为革兰阳性菌(29/98,29.59%)、真菌(4/98,4.08%)。后30个月检出真菌(均为念珠菌)比例较前30个月增多(P<0.05)。后30个月与前30个月检出革兰阴性菌、革兰阳性菌比例及大肠埃希菌、金黄色葡萄球菌耐药率比较差异均无统计学意义(P>0.05)。Logistic回归分析显示,确诊前1个月内抗生素使用史、感染性休克为AML合并血流感染患者死亡的独立危险因素(P<0.05)。结论成人AML合并血流感染的病原菌以革兰阴性菌为主,但近年念珠菌感染率升高,且血流感染前使用抗生素及并发感染性休克者易出现预后不良。

Bacterial infections post-living-donor liver transplantation in Egyptian hepatitis C virus-cirrhotic patients: A singlecenter study

AIM To determine risk factors, causative organisms and antimicrobial resistance of bacterial infections following living-donor liver transplantation(LDLT) in cirrhotic patients.METHODS This prospective study included 45 patients with hepatitis C virus-related end-stage liver disease who underwent LDLT at Ain Shams Center for Organ Transplant, Cairo, Egypt from January 2014 to November 2015. Patients were followed-up for the first 3 mo after LDLT for detection of bacterial infections. All patients were examined for the possible risk factors suggestive of acquiring infection pre-, intra-and post-operatively. Positive cultures based on clinical suspicion and patterns of antimicrobial resistance were identified. RESULTS Thirty-three patients(73.3%) suffered from bacterial infections; 21 of them had a single infection episode, and 12 had repeated infection episodes. Bile was the most common site for both single and repeated episodes of infection(28.6% and 27.8%, respectively). The most common isolated organisms were gramnegative bacteria. Acinetobacter baumannii was the most common organism isolated from both single and repeated infection episodes(19% and 33.3%, respectively), followed by Escherichia coli for repeated infections(11.1%), and Pseudomonas aeruginosa for single infections(19%). Levofloxacin showed high sensitivity against repeated infection episodes(P = 0.03). Klebsiella, Acinetobacter and Pseudomonas were multi-drug resistant(MDR). Pre-transplant hepatocellular carcinoma(HCC) and duration of drain insertion(in days) were independent risk factors for the occurrence of repeated infection episodes(P = 0.024).CONCLUSION MDR gram-negative bacterial infections are common post-LDLT. Pre-transplant HCC and duration of drain insertion were independent risk factors for the occurrence of repeated infection episodes.

Epidemiological Characteristics, Resistance Patterns and Spread of Gram-Negative Bacteria Related to Colonization of Patients in Intensive Care Units

Our aim was to determine the epidemiological characteristics, the resistance patterns and the spread of Gram negative bacteria related to colonization of patients in adult Intensive Care Units. Methods: A prospective cohort of patients colonized and/or infected with Gram negative bacteria was conducted at two adult ICUs from hospitals in Brazil (April 2012 to February 2013). Nasal, groin and perineum swabs were performed. Samples were incubated on MacConkey and cetrimide agar (48 h at 37℃) and identification tests (Vitek-BioMérieux), antibiogram (Bauer-Kirby method), Carba NP test, Polymerase Chain Reaction (PCR) and sequencing were performed. The patterns of resistant microorganisms were compared by rep-PCR (Diversilab). Results: There were 53 cases of colonization. In these cases, we identified imipenem-resistant Acinetobacter baumannii (51%), Pseudomonas aeruginosa (32%), Klebsiella pneumoniae ESBL (38%) or imipenem resistant (5.6%). The use of antimicrobials and medical devices were related to colonization (p The resistance patterns expressed by Klebsiella pneumoniae were ESBL (CTX-M, SHV e TEM) and KPC2. A verified profile of Acinetobacter baumannii was related to OXA-23 and OXA-253 (OXA-143 variant). The profiles ESBL and KPC2 expressed by Klebsiella pneumoniae were distributed between the both ICUs. The distribution of OXA-23 and OXA-253 was verified only in one ICU. The similarity of strains ranged from 80% to 95%, highlighting the horizontal transference of these microorganisms.

Molecular mechanism of the qnrA genemediated quionlone resistance in Gram-negative bacteria

To explore the prevalence of the plasmid-mediated quinolone resistance gene qnrA in Gramnegative bacteria and to investigate its molecular genetic background and resistance profile in isolates harboring this gene, a total of 629 nalidixic acid-resistant isolates of non-repetitive Gram-negative bacteria were collected from clinical specimens between April 2004 and April 2006 and these isolates were screened for qnrA gene by PCR using specific primers combined with DNA sequencing. The extended spectrum β-1actamase （ESBL） or AmpC-producing isolates were distinguished by the phenotypic confirmatory test combined with DNA sequencing, and the antibiotics susceptibility test for qnrA-positive isolates was carried out by Kirby-Bauer and E-test method. To detect the location of the qnrA gene, plasmid conjugation and Southern hybridization were performed and the integron structure containing the qnrA gene was cloned by PCR strategy and sequenced by primer walking. It was demonstrated that the incidence of the qnrA-positive strains in nalidixic acid-resistant bacteria was 1.9% （12/629）, in which the detection rates for Klebiesiella pneumoniae. Enterobacter cloacae, Enterobacter aerogenes, Citrobacterfreundii and Salmonella choeraesuis were 2.2% （3/138）, 17. 1% （6/35）, 9. 1% （1/11）, 12.5% （1/8）, and 14.3% （1/7）, respectively. The qnrA gene was found to be embedded in the complex sull-type integron located on plasmids with varied size （80-180 kb）. Among them, 4 qnrA-positive isolates carried integron In37 and 8 isolates carried a novel integron, temporarily desig- nated as InX. All the qnrA-positive isolates were ESBL-producing and transferable for the multi-drug resistance. It is concluded that the plasmid-mediated drug-resistance mechanism exists in the quinolone resistant strains of isolates from hospitals in Guangdong area, but the incidence was rather low. Nevertheless, it is still possible that the horizontal transfer of the resistant qnrA gene might lead to the spreading of drug-resistance.

某医院近10年大肠埃希菌分离率和耐药率的变迁情况

目的总结近10年中国医科大学附属第一医院大肠埃希菌的分离率和耐药率,为临床抗感染经验治疗提供依据。方法数据来自2013年至2022年间从中国医科大学附属第一医院就诊患者中分离的大肠埃希菌,使用VITEK 2和VITEK MS进行菌种鉴定,使用VITEK2和KB法进行药物敏感性试验,采用WHONET 5.6软件进行分析。结果2013年至2022年共分离6845株菌株,其中80.5%来自住院患者,19.5%来自门诊和急诊患者。常见标本类型为尿液(57.8%)、血液(15.0%)、分泌物(9.2%)、引流液(8.1%)。大肠埃希菌超广谱β-内酰胺酶(ESBL)分离率为57.2%(54.3%~61.5%)。大肠埃希菌对碳青霉烯类抗菌药物的耐药率较低,仅为1.2%(0.2%~2.6%)。结论大肠埃希菌仍是临床感染的重要病原菌,对多种抗菌药物存在不同程度的耐药,且耐药率有上升趋势,临床医师应给予足够的关注。

2015-2021年CHINET尿液分离菌分布和耐药性变迁

目的了解2015-2021年CHINET细菌耐药监测网中尿液分离菌的分布和耐药性。方法收集CHINET细菌耐药监测网51家医疗机构2015-2021年所有尿液标本临床分离菌的耐药监测数据资料,采用WHONET 5.6软件进行统计分析。结果2012-2021年尿液标本共分离细菌261893株,其中革兰阳性菌62219株,占23.8%,革兰阴性菌199674株占76.2%。常见的分离菌依次为大肠埃希菌(46.7%)、屎肠球菌(10.4%)、肺炎克雷伯菌(9.8%)、粪肠球菌(8.7%)、奇异变形杆菌(3.5%)、铜绿假单胞菌(3.4%)、无乳链球菌(2.6%)和阴沟肠杆菌(2.1%)。上述细菌主要分离自住院患者,女性多见于男性,成人多见于儿童。大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌中产超广谱β内酰胺酶(ESBL)菌株分别占53.2%、52.8%和37.0%。耐碳青霉烯类的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌中检出率分别为1.7%、18.5%、16.4%和40.3%。粪肠球菌对氨苄西林、呋喃妥因、利奈唑胺、万古霉素、替考拉宁和磷霉素的耐药率<10%,屎肠球菌对氨苄西林、左氧氟沙星、红霉素的耐药率>90%,对万古霉素、利奈唑胺和替考拉宁的耐药率<2%。ICU住院患者分离的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌和鲍曼不动杆菌对大部分抗菌药物的耐药率明显高于门诊患者和非ICU住院患者。结论尿液标本临床分离菌主要以大肠埃希菌、肠球菌和肺炎克雷伯菌为主,不同人群尿液标本中分离的细菌种类和耐药性不尽相同,应重视细菌耐药监测,减少抗菌药物的不合理使用。

2020—2022年某医院主要细菌耐药情况分析

目的通过分析福建中医药大学附属第二人民医院2020年1月—2022年12月常见细菌的耐药性,了解医院的细菌耐药情况,为临床提供合理使用抗菌药物的参考依据。方法通过回顾性分析方法对2020年1月—2022年12月福建中医药大学附属第二人民医院患者标本分离的病原菌株进行统计,从病原菌标本分布、病原菌种类及耐药等方面进行分析。结果2020—2022年分离的菌株共计12009株,呼吸道标本(包括痰、肺泡灌洗液)最多。前5位为大肠埃希菌2139株(17.81%)、肺炎克雷伯菌1342株(11.17%)、铜绿假单胞菌1094株(9.11%)、金黄色葡萄球菌为主793株(6.60%)、鲍曼不动杆菌541株(4.50%)。耐碳青霉烯类肺炎克雷伯菌(Carbapenemresistant K.pneumoniae,CR-KP)和耐碳青霉烯类铜绿假单胞菌(Carbapenemresistant Pseudomonas aeruginosa,CR-PA)2022年比2020年明显升高,差异有统计学意义(P<0.01)。其余3种耐甲氧西林金黄色葡萄球菌(Methicillin-resistant S.aureus,MRSA)、耐碳青霉烯类大肠埃希菌(Carbapenemresistant Escherichia coli,CR-EC)、耐碳青霉烯类鲍曼不动杆菌(Carbapenemresistant Acinetobacter baumannii,CRAB)3年间检出率差异无统计学意义(P>0.05)。鲍曼不动杆菌对大多数常用抗菌药物耐药率>50%。结论福建中医药大学附属第二人民医院主要以革兰阴性杆菌为主,鲍曼不动杆菌对大多数常用抗菌药物耐药率>50%,CR-KP(耐碳青霉烯类肺炎克雷伯菌)和CR-PA(耐碳青霉烯类铜绿假单胞菌)的耐药率呈增高趋势,建议临床密切关注病原菌耐药情况的变化,减少多重耐药菌的产生。

PCR荧光探针技术对结核分枝杆菌复合群及利福平耐药性检测性能的评价

目的:评价PCR荧光探针技术检测痰液样本中结核分枝杆菌复合群(Mycobacterium tuberculosis complex,MTBC)和利福平耐药性效果,为进一步开展“结核分枝杆菌复合群及利福平耐药核酸检测试剂盒”多中心临床试验提供可行性研究数据。方法:采用前瞻性研究方法,参照入组标准收集2021年12月至2022年8月上海市3家结核病定点医院肺科门诊就诊的205例初诊疑似肺结核患者的3份痰液样本(即时痰、夜间痰、晨痰),分别进行痰涂片、BACTEC MGIT 960(MGIT 960)、GeneXpert MTB/RIF(Xpert)和PCR荧光探针法检测,评价PCR荧光探针法对痰液样本中MTBC及利福平耐药性的检测效能。另对随机选取同期上海市疾病预防控制中心结核病实验室菌株库中保存的96株MTBC临床菌株(包括利福平表型耐药菌株47株和利福平表型敏感菌株49株)分别进行PCR荧光探针法和Xpert检测利福平耐药性,分析两种检测方法对利福平耐药相关基因突变的检出情况。结果:205例疑似肺结核患者中,PCR荧光探针法对MTBC的检出率为22.44%(46/205),与MGIT 960[21.95%(45/205)]、Xpert[20.98%(43/205)]和痰涂片[16.10%(33/205)]的差异均无统计学意义(χ^(2)=0.014,P=0.904;χ^(2)=0.129,P=0.719;χ^(2)=2.650,P=0.104)。以临床诊断为参照标准,PCR荧光探针法、Xpert、MGIT 960和痰涂片检测MTBC的敏感度(95%CI)分别为48.10%(36.93%~59.56%)、48.10%(36.93%~59.56%)、50.63%(39.23%~61.97%)和40.51%(29.79%~52.15%),特异度(95%CI)分别为93.65%(87.47%~97.12%)、96.03%(90.52%~98.53%)、96.03%(90.52%~98.53%)和99.21%(95.01%~99.96%),一致率分别为76.10%(156/205)、77.56%(159/205)、78.54%(161/205)和76.59%(157/205),Kappa值分别为0.453、0.482、0.507和0.446。PCR荧光探针法检测痰液样本中MTBC的涂阴和极低级别阳性样本的检出率[10.73%(19/177)]与Xpert检测结果[8.47%(15/177)]的差异无统计学意义(χ^(2)=0.793,P=0.373)。PCR荧光探针法在检出MTBC的46份样本中同时检出6份样本发生利福平耐药基因突变,突变率为13.04%(6/46);而Xpert在检出MTBC的43份样本中仅同时检出1份样本发生利福平耐药基因突变,突变率为2.33%(1/43)。在96株临床菌株中,两种分子检测方法均检测到56株菌株发生利福平耐药基因突变,除2株探针突变类型不一致外,其他探针突变类型均一致,且多发生在probe E(529~533)和FAM通道(531/533突变)。结论:以临床诊断为参照标准,PCR荧光探针法检测MTBC的效能与MGIT 960、Xpert和痰涂片基本相当,且与Xpert检测MTBC临床菌株的利福平耐药性效果一致,认为PCR荧光探针法不仅是一种等同于Xpert检测功能的新技术,还具有操作简单、价格低于Xpert、真正实现一体化和全封闭等优势。建议在临床推广过程中进一步优化PCR荧光探针法以提高MTBC检出率,并开展多中心临床试验验证研究。