Drug resistance characteristics and epidemic trend of Escherichia coli in Anning, Yunnan / 公共卫生与预防医学

Objective To investigate the drug resistance characteristics and epidemic trend of Escherichia coli in Anning, Yunnan, and to provide a reference for clinical rational use of antibiotics. Methods A total of 376 strains of Escherichia coli were isolated from June 2018 to June 2019 from Kungang Hospital of Yunnan Province. The ESBLs producing strains were screened by double disk method and the sensitivity of ESBLs to antibiotics was detected by K-B method. The genotyping of ESBLs strains and the class I, II and III integrase genes in integron 3' and 5' conservative regions was conducted using polymerase chain reaction (PCR). Results The detection rate of ESBLs producing Escherichia coli was 53.19% (200/376). ESBLs-producing Escherichia coli had a low resistance rate to carbapenem antibacterial drugs with a relatively high sensitivity. The resistance rates to amikacin and piperacillin were 7.50% and 12.50% respectively, which had good antibacterial activity. The resistance rate to other antibiotics was high. There were 74.00% (148/ 200) of ESBLs-producing Escherichia coli carrying CTX-M gene, 34.50% (69/200) carrying TEM genes, and 1.00% (2/200) of strains carrying SHV genes. In addition, there were 9.00% (18/200) of strains carrying both CTX-M and TEM genes, and 0.50% (1/200) of strains carrying both CTX-M and SHV genes. The detection rate of integrons accounted for 37.00% (74/200), all of which were class I integrons. Conclusion The prevalence of ESBLs-producing Escherichia coli was relatively high in Anning, Yunnan. ESBLs-producing Escherichia coli showed a trend of multi-drug resistance. The genotype was mainly CTX-M, and the integron was classified as class I.

Detection of Extended-Spectrum Beta Lactamases and AmpC Beta Lactamases Producing Uropathogenic Escherichia coli in a Tertiary Care Hospital

Background: The multidrug resistant among uropathogenic E. coli has become a potential threat to global health. The aim of the current study to evaluate the antimicrobial activities of nitrofurantoin and fosfomycin along with other antimicrobials against Extended Spectrum β-Lactamases (ESBL) and AmpC producer isolates from the most common organism E. coli. Methods: A total of 6046 clean catch midstream urine samples were collected and processed in Microbiology department of tertiary care hospital. The antimicrobial susceptibility of E. coli isolates was initially screened by Kirby-Bauer disk diffusion method. The resistant isolates were confirmed to be ESBL and AmpC producers by their respective phenotypic confirmatory tests of combined disc method. Results: Out of 6046 patients there were 1855 E. coli positive patients. Maximum patients in the age group of 21-30 years were 51.5% followed by 31-40 years where patients were 26%. 64.4% E. coli were isolated from female patients and 35.6% from male patients. E. coli showed higher sensitivity towards, fosfomycin (100%), imipenem (100%), nitrofurantoin (84.1%), piperacillin and tazobactam (77.3%), amikacin (76.1%) and while they showed high degree resistance pattern against Penicillin, cotrimoxazole, ciprofloxacin, norfloxacin and 2nd and 3rd generation cephalosporin. Out of 1855 E. coli, multi drug resistance was seen in 520 E. coli isolates. ESBL production was observed among 50% of E. coli isolates by combined disk method. Out of 520 isolates, 150 isolates showed resistance to one or more extended-spectrum cephalosporins and cefoxitin by Kirby-Bauer disk diffusion method. These were selected and screened for ESBL and AmpC production. Among 150 cefoxitin-resistant isolates, AmpC phenotype was detected in 100 isolates (66.6%) by AmpC disc method. The overall occurrence of AmpC in the study was found to be 19.2%. Susceptibility of ESBL and AmpC producers to fosfomycin, imipenem, nitrofurantoin and amikacin were found to be 100%, 98.5%, 89% and 75% respectively. Conclusions: There is increased prevalence of ESBL and AmpC producing E. coli. Thus, early detection of ESBL and AmpC producer E. coli by simple phenotypic methods is necessary to avoid treatment failure, where molecular techniques are not available.

Differences in Antimicrobial Resistance Phenotypes by the Group of CTX-M Extended-Spectrum β-Lactamase / 대한임상미생물학회지

BACKGROUND: Escherichia coli and Klebsiella pneumoniae clinical isolates producing CTX-M extendedspectrum β-lactamases (ESBLs) were assessed for antimicrobial resistance phenotypes varied by group of enzymes. METHODS: A total of 1,338 blood isolates, including 959 E. coli and 379 K. pneumoniae, were studied. All the strains were collected between January and July 2017 from eight general hospitals in South Korea. The species were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Antimicrobial susceptibilities were determined by disk diffusion methods and ESBL phenotypes by double-disk synergy tests using disks containing cefotaxime, ceftazidime, cefepime, aztreonam, and clavulanic acid (CA). The genes for β-lactamases were identified by PCR and sequencing. RESULTS: Of total microbes, 31.6% (303/959) E. coli and 24.0% (91/379) K. pneumoniae were resistant to cefotaxime and 28.1% (269/959) E. coli and 20.1% (76/379) K. pneumoniae were CTX-M-type ESBL producers. Among the detected CTX-M ESBLs, 58.0% (156/269) in E. coli and 86.8% (66/76) in K. pneumoniae belonged to group 1, 46.8% (126/269) in E. coli and 14.5% (11/76) in K. pneumoniae were group 9. Ten E. coli and one K. pneumoniae isolates co-produced both groups of CTX-M ESBL. The group 1 CTX-M producers had a higher level of resistance to cefotaxime, ceftazidime, cefepime, and aztreonam and exhibited stronger synergistic activities when combined with CA compared to group 9. CONCLUSION: ESBL phenotypes differ by CTX-M ESBL group and phenotype testing with drugs including 4th generation cephalosporins and monobactams is critical for screening CTX-M-producers with better sensitivity.

Drug resistance genes and homology of Klebsiella pneumoniae in the pediatric intensive care unit of Guiyang area / 中华实用儿科临床杂志

Objective To investigate the genetic characteristics of drug resistance and homology of extended-spectrum β-lactamase (ESBLs)-producing Klebsiella pneumoniae (Kpn) in hospitalized children in the pediatric intensive care unit (PICU) in Guiyang area.Methods The Kpn strains were collected from hospitalized children at 3 PICU from the Affiliated Hospital of Guizhou Medical University,Guizhou Provincial People's Hospital and Guiyang Children's Hospital from September 2014 to December 2016.Automatic bacteria identification instrument and Kirby-Bauer method were used to identify Kpn strains and confirm ESBLs phenotype respectively.The drug resistance genes were detected by using polymerase chain reaction (PCR),and their homology was analyzed by means of pulsed field gel electrophoresis (PFGE) and cluster analysis.Results (1) A total of 207 non-repetitive Kpn strains were isolated,of which 128 strains produced ESBLs (61.8％).There was no significant difference in the ESBLs detection rates among the different hospitals,years and types of samples (x2 =0.40,5.19,4.68,all P ＞ 0.05).(2) Among those 128 ESBLs-producing Kpn strains,123 strains (96.1％) were found to have drug-resistant genes,of which the detection rate of SHV type was the highest,accounting for 87.5％.These 3 drug resistance genotypes were distributed in 7 modes,of which 85.2％ were carrying more than 2 genotypes.(3) PFGE genotypic assay showed that there were 109 genotypes and 5 dominant clones.The PICU at 3 hospitals were all prevalent with type A strain,accounting for 14.8％.In 2015,there was a short-term outbreak of type A strain in Guiyang Children's Hospital.While,the resistance phenotypes of Kpn and the genotype of PFGE could both be consistent or different.Conclusions The ESBLs-producing Kpn at PICU in Guiyang area has the characteristics of multi-drug resistance,its drug-resistant genotypes have diversified,and there is a small-scale short-term outbreak epidemic,which poses a serious threat to clinical anti-infection treatment.It is necessary to strengthen clinical drug resistance monitoring and adopt effective infection control measures to prevent and control the spread of nosocomial infections.

Drug resistance genes and homology of Klebsiella pneumoniae in the pediatric intensive care unit of Guiyang area / 中华实用儿科临床杂志

Objective@#To investigate the genetic characteristics of drug resistance and homology of extended-spectrum β-lactamase (ESBLs)-producing Klebsiella pneumoniae (Kpn) in hospitalized children in the pediatric intensive care unit (PICU) in Guiyang area.@*Methods@#The Kpn strains were collected from hospitalized children at 3 PICU from the Affiliated Hospital of Guizhou Medical University, Guizhou Provincial People′s Hospital and Guiyang Children′s Hospital from September 2014 to December 2016.Automatic bacteria identification instrument and Kirby-Bauer method were used to identify Kpn strains and confirm ESBLs phenotype respectively.The drug resistance genes were detected by using polymerase chain reaction (PCR), and their homology was analyzed by means of pulsed field gel electrophoresis (PFGE) and cluster analysis.@*Results@#(1) A total of 207 non-repetitive Kpn strains were isolated, of which 128 strains produced ESBLs (61.8%). There was no significant difference in the ESBLs detection rates among the different hospitals, years and types of samples(χ2=0.40, 5.19, 4.68, all P>0.05). (2) Among those 128 ESBLs-producing Kpn strains, 123 strains (96.1%) were found to have drug-resistant genes, of which the detection rate of SHV type was the highest, accounting for 87.5%.These 3 drug resistance genotypes were distributed in 7 modes, of which 85.2% were carrying more than 2 genotypes.(3) PFGE genotypic assay showed that there were 109 genotypes and 5 dominant clones.The PICU at 3 hospitals were all prevalent with type A strain, accounting for 14.8%.In 2015, there was a short-term outbreak of type A strain in Guiyang Children′s Hospital.While, the resistance phenotypes of Kpn and the genotype of PFGE could both be consistent or different.@*Conclusions@#The ESBLs-producing Kpn at PICU in Guiyang area has the characteristics of multi-drug resistance, its drug-resistant genotypes have diversified, and there is a small-scale short-term outbreak epidemic, which poses a serious threat to clinical anti-infection treatment.It is necessary to strengthen clinical drug resistance monitoring and adopt effective infection control measures to prevent and control the spread of nosocomial infections.

Empirical antibiotics for recurrent urinary tract infections in children / 고신대학교의과대학학술지

OBJECTIVES: The purpose of this study was to compare antibiotic resistance patterns between first urinary tract infection (UTI) and recurrent UTI groups and to obtain information regarding empirical antibiotic selection for treating recurrent UTI. METHODS: We retrospectively reviewed 148 children treated for UTIs from January 2009 to June 2016. The patients were divided into two groups: first UTI (N = 148) and recurrent UTI (17 patients and 20 episodes). RESULTS: In both groups, Escherichia coli was the most frequent causative organism, accounting for 89.9% and 75.0% in the first and recurrent UTI groups, respectively. When E. coli or Klebsiella pneumoniae was the causative organism, extended-spectrum β-lactamase (ESBL)-producing organisms were more frequent in the recurrent UTI group (17.6%) than in the first UTI group (14.0%); however, this difference was not statistically significant (P = 0.684). Cefotaxime was the most frequently used first-line empirical antibiotic in both groups. In the first UTI and recurrent UTI groups, 7.4% and 15.0% of patients were treated with intravenous antibiotics as definitive therapy, respectively (P = 0.250). Fifteen out of 17 patients having a second UTI had different causative organisms or antibiotic susceptibility patterns compared to their previous episode. CONCLUSIONS: Escherichia coli was the most frequent causative organism in the recurrent UTI group. There were no differences in the proportion of ESBL-producing organisms between the first UTI and recurrent UTI groups. Therefore, when a UTI recurs in children, the antibiotics effective on the most common causative organism might be administered as empirical antibiotics.

The Usefulness of Active Surveillance Culture of Extended-Spectrum β-Lactamase-Producing Escherichia coli in ICU Settings without Outbreak in the Situation of Wide Spread of Sequence Type 131 ESBL-Producing E. coli in Community / 대한임상미생물학회지

BACKGROUND: In the present study, the prevalence and risk factors for acquisition of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in intensive care unit (ICU) settings without outbreak in the situation of widespread sequence type (ST) 131 ESBL-producing E. coli in a Korean community was investigated. METHODS: Consecutive and prospective screening of ESBL-producing E. coli colonization was performed in all patients admitted to surgical or medical ICUs within 48 hours for two months. ESBL genotype was determined based on PCR and sequencing. PCR for O16-ST131/O25-ST131 was performed for all ESBL producers. Clinical information was obtained from a review of electronic medical record to determine the risk factors for ESBL-producing E. coli colonization. RESULTS: The colonization rate of ESBL-producing E. coli at ICU admission was 14.9% (42/281). CTX-M-15 (N=15), CTX-M-14 (N=12), and CTX-M-27 (N=10) were commonly detected using PCR of ESBL genes. Approximately half (45.2%, 19/42) of ESBL producers were ST131 clone with 14 ST131-O25 and 5 ST131-O16. In univariate analysis, independent risk factor for acquisition of ESBL-producing E. coli compared with controls was ICU type (odds ratio, 2.05; P < 0.032); however, site of acquisition, previous antibiotic use, and hospital stay were not significant risk factors. CONCLUSION: In this study, the colonization of ESBL-producing E. coli at ICU admission without outbreak was frequent and it could be an infection source, regardless of acquisition site. We recommend routine use of ASC to control endemic ESBL-producing E. coli considering the wide distribution of ST131-ESBL-producing E. coli in the Korean community.

Biological and Genetic Characteristics of Clinically Isolated Enterobacter cloacae with Multidrug Resistance

BACKGROUND: From January 2014 to December 2015, 69 clones of Enterobacter cloacae showing multidrug resistance to six classes of antimicrobial agents were collected from two medical centers in Korea. METHODS: Minimum inhibitory concentrations were determined using the E-test method, and 17 genes were detected using polymerase chain reaction (PCR). The epidemiological relatedness of the strains was identified using repetitive element sequence-based PCR and multilocus sequence typing. RESULTS: The 69 E. cloacae clones produced extended spectrum β lactamase (ESBL) and AmpC and showed multidrug resistance to cefotaxime, ceftazidime, and aztreonam. We identified the following sequence types: ST56 of type VI for ESBL SHV (N=12, 17.4%); ST53, ST114, ST113, and ST550 of types I, IV, VI, and VII, respectively, for CTX-M (N=11, 15.9%); and ST668 of type III for the carbapenemase NDM gene (N=1, 1.5%). The AmpC DHA gene (N=2, 2.89%) was confirmed as ST134, although its type was not identified, whereas EBC (MIR/ACT; N=18, 26.1%) was identified as ST53, ST24, ST41, ST114, ST442, ST446, ST484, and ST550 of types V, I, III, IV, VII, and VI, respectively. The formed subclasses were bla CTX-M-3 and bla CTX-M-22 by CTX-M-1, bla CTX-M-9 and bla CTX-M-125 by CTX-M-9, bla DHA-1 by DHA, and bla MIR-7 and bla ACT-15,17,18,25,27,28 by EBC (MIR/ACT). CONCLUSIONS: There were no epidemiological relationships between the gene products and the occurrence of resistance among the strains.

Clinical Significance of Extended-spectrum β-lactamase-producing Bacteria in First Pediatric Febrile Urinary Tract Infections and Differences between Age Groups

PURPOSE: Extended-spectrum β-lactamase-producing bacteria-induced urinary tract infections are increasing and require more potent antibiotics such as carbapenems. We evaluated the clinical significance of extended-spectrum β-lactamase urinary tract infection in children younger than 5 years to select proper antibiotics and determine prognostic factors. Differences were compared between age groups. METHODS: We retrospectively studied 288 patients with their first febrile urinary tract infection when they were younger than 5 years. Patients were divided into extended-spectrum β-lactamase-positive and extended-spectrum β-lactamase-negative urinary tract infection groups. Clinical characteristics and outcomes were compared between the groups; an infant group was separately analyzed (onset age younger than 3 months). RESULTS: Extended-spectrum β-lactamase urinary tract infection occurred in 11% patients who had more frequent previous hospitalization (P=0.02) and higher recurrence rate (P=0.045). During the antimicrobial susceptibility test, the extendedspectrum β-lactamase-positive urinary tract infection group showed resistance to third-generation cephalosporins; however, 98% patients responded clinically. In the infant group, extended-spectrum β-lactamase-positive urinary tract infection occurred in 13% patients and was associated with a longer pre-onset hospitalization history (P=0.002), higher C-reactive protein level (P=0.04), and higher recurrence rate (P=0.02) than that in the older group. CONCLUSION: Extended-spectrum β-lactamase urinary tract infection requires more attention because of its higher recurrence rate. The antimicrobial susceptibility test demonstrated resistance to third-generation cephalosporins, but they can be used as first-line empirical antibiotics because of their high clinical response rate. Aminoglycosides can be second-line antibiotics before starting carbapenems when third-generation cephalosporins do not show bactericidal effects for extended-spectrum β-lactamase urinary tract infection.

Clinical Significance of Extended-spectrum β-lactamase-producing Bacteria in First Pediatric Febrile Urinary Tract Infections and Differences between Age Groups

PURPOSE: Extended-spectrum β-lactamase-producing bacteria-induced urinary tract infections are increasing and require more potent antibiotics such as carbapenems. We evaluated the clinical significance of extended-spectrum β-lactamase urinary tract infection in children younger than 5 years to select proper antibiotics and determine prognostic factors. Differences were compared between age groups. METHODS: We retrospectively studied 288 patients with their first febrile urinary tract infection when they were younger than 5 years. Patients were divided into extended-spectrum β-lactamase-positive and extended-spectrum β-lactamase-negative urinary tract infection groups. Clinical characteristics and outcomes were compared between the groups; an infant group was separately analyzed (onset age younger than 3 months). RESULTS: Extended-spectrum β-lactamase urinary tract infection occurred in 11% patients who had more frequent previous hospitalization (P=0.02) and higher recurrence rate (P=0.045). During the antimicrobial susceptibility test, the extendedspectrum β-lactamase-positive urinary tract infection group showed resistance to third-generation cephalosporins; however, 98% patients responded clinically. In the infant group, extended-spectrum β-lactamase-positive urinary tract infection occurred in 13% patients and was associated with a longer pre-onset hospitalization history (P=0.002), higher C-reactive protein level (P=0.04), and higher recurrence rate (P=0.02) than that in the older group. CONCLUSION: Extended-spectrum β-lactamase urinary tract infection requires more attention because of its higher recurrence rate. The antimicrobial susceptibility test demonstrated resistance to third-generation cephalosporins, but they can be used as first-line empirical antibiotics because of their high clinical response rate. Aminoglycosides can be second-line antibiotics before starting carbapenems when third-generation cephalosporins do not show bactericidal effects for extended-spectrum β-lactamase urinary tract infection.

Multidrug resistance extended spectrum β-lactamase and AmpC producing Escherichia coli isolated from the environment of Bogor Slaughterhouse, Indonesia

Objective To determine the multidrug resistance extended spectrum β-lactamase and AmpC (ESBL/AmpC producing) Escherichia coli (E. coli) isolated from the environment of Bogor slaughterhouse, Indonesia. Methods A total of 35 samples from 7 locations in slaughterhouse i.e., source of water, slaughtering floor, swab of carcass area floor, swab of evisceration area floor, untreated waste water, treated waste water, drinking water for cattle were collected from March to April 2016. Presence of ESBL/AmpC producing E. coli and susceptibility testing against 8 antimicrobial agents (penicillin G, streptomycin, gentamycin, ciprofloxacin, enrofloxacin, tetracycline, trimethoprim-sulfamethoxazole, and polymyxin B) were detected by disk diffusion test according to Clinical and Laboratory Standards Institute. Results ESBL/AmpC producing E. coli were identified in 14.3% (5/35) of the collected samples from the environment of Bogor slaughterhouse. ESBL/AmpC-producing E. coli isolates were detected in untreated waste water (n = 3), slaughtering floor (n = 1), and carcass area floor (n = 1). Most of ESBL/AmpC-producing E. coli isolates (80%) showed multidrug resistance phenotypes against at least three classes of antibiotics. The highest incidence of antibiotics resistance was against penicillin G (100.0%) and streptomycin (100.0%), followed by gentamicin (60.0%), trimethoprim-sulfamethoxazole (60.0%), tetracycline (40.0%), ciprofloxacin (40.0%), enrofloxacin (20.0%), and polymyxin B (0.0%). Conclusions The transmission of antimicrobial resistant bacteria into the environment may be a potential risk for human health.

Antimicrobial Susceptibilities of Enterobacteriaceae in Community-Acquired Urinary Tract Infections during a 5-year Period: A Single Hospital Study in Korea / 감염과화학요법

BACKGROUND: Through investigating antimicrobial susceptibility patterns of Enterobacteriaceae in community-acquired urinary tract infection (CA-UTI), we provide basic evidence for the use of empirical antibiotics in CA-UTI. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients over the age of 19 years who visited a hospital in Seoul between January 2012 and December 2016 for a CA-UTI. Urine cultures were used to identify causative organisms. We investigated extended-spectrum β-lactamase (ESBL) production and the antimicrobial susceptibility of Enterobactereiaceae. We evaluated recommended empirical antibiotics numerically by calculating the syndrome-specific likelihood of inadequate therapy (LIT) for the last 2 years (interpretation of the LIT A value: 1 out of A people is likely to receive inadequate empirical antibiotics). RESULTS: Urine cultures were performed in 1,605 out of 2,208 patients who were diagnosed with CA-UTI, and causative pathogens were identified in 1,134 (70.7%) cases. There were 998 (88.0%) cases of Enterobacteriaceae and Escherichia coli was the most common pathogen, accounting for 80.3% of cases (911 cases). The overall resistance rates to trimethoprim-sulfamethoxazole, fluoroquinolones, and cefotaxime were 31.7%, 23.2%, and 13.5%, respectively. There were 128 (10.8%) cases of ESBL-producing Entererobacteriaceae with an increasing but non-significant trend (P = 0.255). The LIT for CA-UTI in the past two years was highest for ertapenem and imipenem. Fluoroquinolones ranked 11th, with a LIT of 8.2, and cefotaxime ranked higher, at 10.5. In ESBL-producing Enterobacteriaceae, except for carbapenems, amikacin and piperacillin-tazobactam showed the highest susceptibility rates at 99.2% and 94.3%, respectively. CONCLUSION: Empiric treatment with fluoroquinolones in CA-UTI should be carefully considered, given the high resistance rate. The proportion of ESBL-producing Entererobacteriaceae in CA-UTI has increased to a high level in Korea. Amikacin and piperacillin-tazobactam could be considered for empiric treatment in patients at risk for ESBL-producing Entererobacteriaceae when considering alternatives to carbapenems.

Clinical distribution and drug resistance of ESBLs-producing and non ESBLs-producing Escherichia coli isolated from 2014 to 2015 / 国际检验医学杂志

Objective To analyze clinical distribution and drug resistance of extended-spectrum β-lactamase(ESBLs)-producing and non ESBLs-producing Escherichia coli(E.coli) isolated from 2014 to 2015.Methods Collected 4 721 clinical specimens from January 2014 to December 2015,separated and identified by using VITEK 2-Compact automatic microorganism identification and sensitivity analysis system of Biomerieux,France.Results A total of 1 181 E.coli were isolated from 4 721 clinical specimens,the isolation rate was 25.02%,and the isolation rates of 2014 and 2015 were 17.38% and 19.24% respectively.Meanwhile,the isolation rates of ESBLs-producing E.coli from 2014 and 2015 were 44.46% and 51.71%,increased 7.25%.For the ESBLs-producing E.coli,the main specimens from urine,sputum,blood,appendix content,pus and secreta,and general surgery department,pneumology department,urology,Neurosurgery departments were the main infection departments.For the non ESBLs-producing E.coli,the main specimens from urine,blood,sputum,appendix content,pus and secreta.The drug resistance of E.coli to antibiotics showed increasingly upward trend from 2014 to 2015.However,it showed high sensitive to amikacin,imipenem and meropenem.Conclusion As the isolation rate of E.coli increased in 2015,so does the drug resistance,and it is need combine with the actual situation of medication to regulate the usage of antibiotics.

Distrbution and risk factors analysis of infections caused by extended-spectrum β-lactamase-producing Escherichia coli / 国际检验医学杂志

Objective To analyze the specimen types,ward distribution and risk factors for infections caused by extended-spectrum β-lactamase(ESBLs)-producing-Escherichia coli(ECO) in recent two years,so as to provide bacteriological basis for both hospital infection control and clinical anti-infection treatment.Methods Non-repetitive 443 ECO strains isolated from the hospitalized patients in the Third People′s Hospital of Shenzhen were collcted,and the phoenix100 system was employed for bacterial identification and antimicrobial susceptibility tests.ESBLs-ECO was further confirmed by the double-disk synergy test,and the risk factors caused ESBLs-ECO were statistically analyzed.Results A total of 115 strains of ESBLs-ECO were identified among the 443 strains of ECO,which accounted for 26.0%.The ESBLs-ECO strains were mainly isolated from the sputum,urine,and blood specimens.Among the isolated ESBLs-ECO strains,20.9% were isolated from the department of Tuberculosis,13.9% from the department of pediatric,12.2% from the department of live disease,and 8.7% from the department of infection.The male sex,surgery and use of the third generation cephalosporins were independent risk factors of ESBLs-ECO infection.Conclusion The isolation rate of ESBLs-ECO in this hospital is high.It is necessary for the hospital to strengthen the control of nosocomial infections according to the risk factors.More attention should be payed on male patients,the standardization of surgical operation and disinfection,and the restriction of using the third generation cephalosporins,so as to reduce the incidene of ESBLs-ECO infections.

Isolation and characterization of bacteriophage against extended-spectrumβ-lactamase-producing Escherichia coli strains / 上海交通大学学报（医学版）

Objective · To isolate phages which can fight against extended-spectrum β-lactamase (ESBLs)-producing Escherichia coli (E. coli), and provide basic research for establishment of E. coli phage library and treatment of bacterial infection. Methods · Samples collected from sewage were co-cultured with 93 ESBLs-producing E. coli strains. A phage named JDEC001 was isolated by double agar overlay plaque assay. The biological characteristics, complete genome sequence and comparative genome analyses of JDEC001 were studied respectively. Results · JDEC001 belongs to the lytic phage as a member of the Caudovirales order, Podoviridae family. It has high activity at pH from 5 to 11 and with temperature from 0 to 39 ℃ .Whole-genome sequencing of JDEC001 demonstrated double-stranded DNA genome of 38745 bp with GC content of 49.93%, which encoded 46 open reading frames. The comparative genomics also showed that there was no virulent genes or antibiotic resistant genes in its genome. Conclusion · The phage JDEC001 against ESBLs-producing E. coli was isolated and purified, with good stability in a broad range of pH and temperature.

Risk factors and molecular epidemiology of community-onset, multidrug resistance extended-spectrum β-lactamase-producing Escherichia coli infections

BACKGROUND/AIMS: Although multidrug resistance (MDR) among extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) poses significant therapeutic challenges, little is known regarding the risk factors and epidemiology of community-onset MDR-ESBL-EC infections. We performed this study to investigate risk factors and the molecular epidemiology of community-onset MDR-ESBL-EC infections. METHODS: We conducted a case-control-control study of community-onset infections. MDR-ESBL-EC was defined as ESBL-EC that demonstrated in vitro resistance to trimethoprim-sulfamethoxazole, fluoroquinolones (FQs), and gentamicin. Patients with MDR-ESBL-EC infections were designated as case patients. A control group I (CG I) patient was defined as a person whose clinical sample yielded ESBL-EC that did not meet the criteria for MDR. A control group II (CG II) patient was defined as a patient with a non-ESBL-EC infection. RESULTS: Of 108 patients with ESBL-EC infections, 30 cases (27.8%) were due to MDR-ESBL-EC. Compared with CG I, prior use of FQs (odds ratio [OR], 3.16; 95% confidence interval [CI], 1.11 to 8.98) and immunosuppressant use (OR, 10.47; 95% CI, 1.07 to 102.57) were significantly associated with MDR-ESBL-EC. Compared with CG II, prior use of FQs (OR, 15.53; 95% CI, 2.86 to 84.27) and healthcare-associated infection (OR, 5.98; 95% CI, 2.26 to 15.86) were significantly associated with MDR-ESBL-EC. CTX-M-15 was the most common in MDR-ESBL-EC infections (59.1% [13/22]), while CTX-M-14 was the most common in non-MDR-ESBL-EC infections (41.6% [32/77]). CTX-M-15 was significantly associated with MDR-ESBL-EC (59.1% vs. 32.5%, p = 0.028). Pulsed-field gel electrophoresis showed clonal diversity of MDR-ESBL-EC isolates. CONCLUSIONS: The emergence of strains of MDR-ESBL-EC in the community poses an important new public health threat. More information on the emergence and transmission of these strains will be necessary in order to prevent their spread.

Multidrug resistance extended spectrum β-lactamase and AmpC producing Escherichia coli isolated from the environment of Bogor Slaughterhouse, Indonesia

Objective: To determine the multidrug resistance extended spectrum β-lactamase and AmpC (ESBL/AmpC producing) Escherichia coli (E. coli) isolated from the environment of Bogor slaughterhouse, Indonesia. Methods: A total of 35 samples from 7 locations in slaughterhouse i.e., source of water, slaughtering floor, swab of carcass area floor, swab of evisceration area floor, untreated waste water, treated waste water, drinking water for cattle were collected from March to April 2016. Presence of ESBL/AmpC producing E. coli and susceptibility testing against 8 antimicrobial agents (penicillin G, streptomycin, gentamycin, ciprofloxacin, enro-floxacin, tetracycline, trimethoprim-sulfamethoxazole, and polymyxin B) were detected by disk diffusion test according to Clinical and Laboratory Standards Institute. Results: ESBL/AmpC producing E. coli were identified in 14.3％(5/35) of the collected samples from the environment of Bogor slaughterhouse. ESBL/AmpC-producing E. coli isolates were detected in untreated waste water (n =3), slaughtering floor (n =1), and carcass area floor (n=1). Most of ESBL/AmpC-producing E. coli isolates (80％) showed multidrug resistance phenotypes against at least three classes of antibiotics. The highest incidence of antibiotics resistance was against penicillin G (100.0％) and streptomycin (100.0％), followed by gentamicin (60.0％), trimethoprim-sulfamethoxazole (60.0％), tetracycline (40.0％), ciprofloxacin (40.0％), enrofloxacin (20.0％), and polymyxin B (0.0％). Conclusions: The transmission of antimicrobial resistant bacteria into the environment may be a potential risk for human health.

Prevalence and molecular epidemiology of extended spectrum β-lactamase producing Escherichia coli from hospital and community settings in Egypt.

The prevalence and molecular epidemiology of Escherichia coli that produce extended spectrum β-lactamase (ESBL) in Cairo, Egypt was investigated. Ninety E. coli isolates were collected along the period of September to November 2012 from hospital and community settings. Antibiotic susceptibility of the E. coli isolates was determined by disk diffusion method. All isolates were screened phenotypically for ESBL production by combination disk method. The presence of blaCTX-M-I, blaCTX-M-IV, blaTEM and blaSHV genes in ESBL-producing E. coli was examined by PCR and sequencing experiments. The results showed high prevalence of ESBL-producing E. coli, 52% of the collected isolates were ESBL producers. The ESBL-producing isolates significantly (P < 0.05) had increased resistance compared with non–ESBL producers to cefuroxime, cefotaxime, ceftazidime, cefepime, ciprofloxacin, and co-trimoxazole. Imipenem was the most effective drug against ESBL producing isolates. All ESBL producing E. coli isolates were multi drug resistant (MDR) to eight antibiotics or more. Detection of ESBL genes in selected MDR-ESBL producing E. coli revealed that blaCTX-M-I was the most prevalent ESBL type. It is clear that the prevalence of ESBL producing E. coli in Cairo, Egypt is alarming high. This study is useful for clinician in order to improve the empiric treatment.

Application of Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry to Screen the Extended-Spectrum β-Lactamase-Producing ST131 Escherichia coli Strains / 대한임상미생물학회지

BACKGROUND: Sequence type 131 (ST131) O25b serogroup Escherichia coli, producing CTX-M type extended-spectrum β-lactamase (ESBL), is a major clone involved in worldwide pandemic spread in both community- and healthcare-associated infections. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become a routine tool for the identification of bacteria in many laboratories. This study aimed to assess the performance of MALDI-TOF MS for the screening of ESBL-producing E. coli ST131 in a rapid, inexpensive, and simple way. METHODS: A total 26 clinical E. coli, isolated from blood between 2013 and 2014, were used. The characteristics are ST131-O25b ESBL producers (n=6), ST131-O16 ESBL producers (n=4), non-ST131 ESBL producers (n=11), and non-ST131 non-ESBL producers (n=5). Specific biomarker peaks to distinguish the ST131 clonal group from others were investigated by MicroIDSys (ASTA, South Korea) and ASTA Tinkerbell 2.0 software. RESULTS: A peak at 9,713 m/z peak is useful to screen for ST131 E. coli, regardless of serogroup O25 or O16, showing a sensitivity of 100%, specificity of 56.2%, positive predictive value of 58.8%, and negative predictive value of 100% when using a relative intensity cutoff of 15%. CONCLUSION: We can screen for ST131 E. coli using MicroIDSys (ASTA), MALDI-TOF MS in a rapid, inexpensive, and simple way. However, other confirmatory tests are needed to confirm ST131 E. coli due to the low specificity of this method.

Difference in antimicrobial susceptibility of common clinical pathogens to different ratios of cefoperazone/sulbactam antimicrobial disks / 中国感染控制杂志

Objective To understand the antimicrobial resistance of common clinical pathogens to antimicrobial disks containing different ratios of cefoperazone/sulbactam,so as to provide basis for rational application of cefoper-azone/sulbactam in clinic.Methods 1 141 pathogens isolated from clinical specimens in a hospital in the first half year of 2014 were collected,disk diffusion method was adopted to detect antimicrobial activity of two kinds of cef-operazone/sulbactam disks (70/35 μg and 75/75 μg).Results Of 1 141 pathogenic strains,675 (59.16%)were En-terobacteriaceae,447 (39.18%)were non-fermentative bacteria,and 19 (1 .66%)were other gram-negative bacilli. Resistance rates of pathogens to 70/35μg and 75/75 μg cefoperazone/sulbactam antimicrobial disks were as follows:extended-spectrumβ-lactamases(ESBLs)-producing Escherichia coli (n=221)were 7.69% and 2.26% respective-ly,ESBLs-producing Klebsiella pneumoniae (n=92)10.87% and 3.26% respectively,imipenem-resistant Acineto-bacter baumannii (IRAB,n=295)54.92% and 11 .19%respectively;there were significant differences in antimicrobial activity between two ratios of antimicrobial disks(P 0.05).Conclusion Antimicrobial activity of two different ratios of cefoperazone/sulbactam antimicrobial disks to ESBLs-producing Enterobacteriaceae and IRAB is different,attention should be paid to ratios of cefoperazone/sulbactam during the treatment ,so as to achieve the desired therapeutic effect.