Predicting Phenotypic Antimicrobial Resistance in Escherichia coli Isolates, Using Whole Genome Sequencing Data / 대한임상미생물학회지

Background@#The application of genotypic antimicrobial sensitivity tests (ASTs) is dependent on the reliability of the predictions of phenotypic resistance. In this study, routine AST results and the presence of corresponding antimicrobial resistance genes were compared. @*Methods@#Eighty-four extended-spectrum-β-lactamase-producing Escherichia coli isolates from poultry-related samples were included in the study. The disk diffusion method was used to test for susceptibility to antimicrobial compounds, except colistin susceptibility, which was tested using the agar dilution method. Whole-genome sequencing (WGS) was performed using a NextSeq 550 instrument (Illumina, USA). Antimicrobial resistance genes were detected using ResFinder 4.1. @*Results@#Concordance rates between the genotype and phenotype ranged from 35.7% (ciprofloxacin) to 96.4% (tetracycline). The presence of tet was a good predictor of phenotypic resistance. @*Conclusion@#The genotype was a good predictor of tetracycline phenotypic resistance, but there was a gap in the prediction of phenotypic ASTs for trimethoprim-sulfamethoxazole, chloramphenicol, gentamicin, and ciprofloxacin. We concluded that WGS-based genotypic ASTs are inadequate to replace routine phenotypic ASTs.

Relationship between Nurses' Positive Psychological Capital and Adaptation of Job Rotation / 임상간호연구

Purpose@#This study was conducted to identify the nurses’ positive psychological capital and adaptation of job rotation and to examine their relationship. @*Methods@#This cross-sectional study was conducted from March 23, 2021 to March 31, 2021, the study participants were 160 nurses who worked at a general hospital in Seoul.The collected data were analyzed using the IBM SPSS/WIN 24.0 program with descriptive statistics, t-test, ANOVA, and Pearson's correlation coefficient. @*Results@#The positive psychological capital of nurses scored an average of 3.30±0.43 out of 5. Nurses’ adaptation of job rotation scored an average of 3.00±0.35 out of 5. Positive psychological capital and adaptation of job rotation showed a significant positive correlation (r=.70, p<.001). @*Conclusion@#This study shows that the greater level of positive psychological capital was associated with the increased adaptation of job rotation among nurses. It is necessary to develop an practical program to help nurses, who have recently experienced job rotation, adapt to the changed job by improving the positive psychological capital.

Prevalence and Molecular Epidemiology of ExtendedSpectrum-β-Lactamase (ESBL)-Producing Escherichia coli From Multiple Sectors of the Swine Industry in Korea: A Korean Nationwide Monitoring Program for a One Health Approach to Combat Antimicrobial Resistance

Background@#One health is a flexible concept with many facets, including the environment, community, and the nosocomial super-bacteria resistance network. We investigated the molecular prevalence of extended-spectrum-β-lactamase-producing Escherichia coli (ESBL-EC) in workers, livestock, and the farm environment in Korea. @*Methods@#ESBL-EC isolates were obtained from samples from 19 swine farms, 35 retail stores, seven slaughterhouses, and 45 related workers throughout Korea from August 2017 to July 2018, using ChromID ESBL (BioMérieux, Marcy l’Etoile, France) agar and enrichment broth. The presence of ESBL and mobilized colistin resistance (mcr) genes and antimicrobial resistance were determined. Clonality was evaluated with pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). @*Results@#In total, 232 ESBL-EC isolates were obtained from 1,614 non-duplicated samples (14.4% positive rate). The ESBL-EC isolates showed regional and source-related differences. blaCTX-M-55 (N = 100), blaCTX-M-14 (N = 65), blaCTX-M-15 (N = 33), and blaCTX-M-65 (N = 23) were common ESBL types. The ESBL-EC isolates showed high resistance rates for various antimicrobial classes; however, all isolates were susceptible to carbapenem. One swine-originating colistin-resistant isolate did not carry any known mcr gene. PFGE was successful for 197 of the 232 isolates, and most PFGE types were heterogeneous, except for some dominant PFGE types (O, R, T, U, and V). MLST of 88 isolates was performed for representative PFGE types; however, no dominant sequence type was observed. @*Conclusions@#The proportion of ESBL-EC in swine industry-related samples was significant, and the isolates harbored common clinical ESBL gene types. These molecular epidemiologic data could provide important evidence for antimicrobial-resistance control through a one health approach.

Risk Factors Associated with Recurrent Urinary Tract Infection Caused by Escherichia coli / 대한임상미생물학회지

Background@#The purpose of this study was to analyze the clinical and microbiological characteristics of recurrent urinary tract infection (UTI) caused by Escherichia coli— the most common etiological agent. @*Methods@#Cases of recurrent and single episodes of UTI caused by E. coli were evaluated retrospectively for a period of 6 months (January-June 2019) to analyze the clinical and molecular characteristics of this disease. @*Results@#Healthcare-associated UTI, E. coli bacteremia, and poor microbial clearance 7 days post infection were associated more with the recurrent episodes of infection. E. coli isolates from subjects with recurrent UTIs showed higher rates of antimicrobial resistance and extended-spectrum β-lactamase (ESBL) production. The E. coli clone— sequence type 131 was detected in similar proportions in isolates, recovered from subjects in both groups— recurrent episodes and single episode of UTI. @*Conclusion@#The control of antimicrobial-resistant ESBL-producing E. coli strains may be difficult using antimicrobial therapy and subsequently delay the clearance of the etiologic agent. This could play a major role in the development of recurrent UTIs.

Prevalence and Risk Factors for Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Colonization in Intensive Care Units

Active surveillance culture (ASC) can help detect hidden reservoirs, but the routine use of ASC for extended spectrum β-lactamase-producing Enterobacteriaceae is controversial in an endemic situation. We aimed to determine the prevalence and risk factors of extended spectrum β-lactamase-producing Klebsiella pneumoniae (EBSL-Kpn) colonization among intensive care unit (ICU)-admitted patients. Prospective screening of ESBL-Kpn colonization was performed for ICU-admitted patients within 48 hours for two months. A perirectal swab sample was inoculated on MacConkey agar supplemented with 2 µg/mL ceftazidime. ESBL genotype was determined by PCR-sequencing, and clonal relatedness was evaluated by pulsed-field gel electrophoresis (PFGE). The risk factors of ESBL-Kpn colonization were evaluated. The ESBL-Kpn colonization rate among the 281 patients at ICU admission was 6.4% (18/281), and bla(CTX-M-15) was detected in all isolates. ESBL producers also showed resistance to fluoroquinolone (38.9%, 7/18). All isolates had the same ESBL genotype (bla(CTX-M-15)) and a highly clustered PFGE pattern, suggesting cross-transmission without a documented outbreak. In univariate analysis, the risk factor for ESBL-Kpn colonization over the control was the length of hospital stay (odds ratio=1.062; P=0.019). Routine use of ASC could help control endemic ESBL–Kpn for ICU patients.

Whole-Genome Analysis of bla(CTX-M-55)-Carrying Escherichia coli Among Pigs, Farm Environment, and Farm Workers

No abstract available.

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.

Increasing Incidence of Listeriosis and Infection-associated Clinical Outcomes

BACKGROUND: Listeriosis caused by Listeria monocytogenes has a high case-fatality rate (CFR) of approximately 20% to 30%. An increasing incidence of listeriosis has been reported in many countries recently. We investigated the annual incidence, clinical characteristics, and outcomes of listeriosis at three different hospitals in Korea and evaluated the effects of appropriate empiric antimicrobial treatments on patient outcomes. METHODS: We retrospectively collected the data of all culture-positive cases of human listeriosis from three hospitals of different sizes in Korea during 2006–2016 and calculated the annual number of cases and incidence per 100,000 admissions. RESULTS: A total of 58 patients with L. monocytogenes were included in this study. The incidence of listeriosis was significantly higher in 2013–2016 than in 2006–2012 (RR 3.1; 95% CI 1.79–5.36; P < 0.001), mainly because of an increase in patients over 60 years of age (RR 3.69; 95% CI 1.70–8.02; P < 0.001). Multivariate analysis showed that healthcare-associated infection (adjusted OR, 12.15; 95% CI, 2.56–86.01; P=0.004) and empirical treatment with first-line antimicrobial agents (adjusted OR, 0.08; 95% CI, 0.00–0.63; P=0.044) were associated with CFR. CONCLUSIONS: Healthcare-associated infections caused by L. monocytogenes are associated with high CFR. Adequate initial empirical treatments could reduce CFR, suggesting that careful consideration of an empirical antimicrobial regimen is warranted for elderly or immunocompromised patients admitted to the hospital.

The Effects of an Intensive Education Program on Hospital Infection Control on Nursing Students' Knowledge, Attitude, and Confidence in Infection Control

PURPOSE: The purpose of this study was to develop and conduct an intensive education program on infection control and investigated how the program influenced nursing students' knowledge, attitude, and confidence in the infection control. METHODS: The program was conducted for four days between January 5 and 8, 2016, for seven hours per day. The program was conducted by the specialists in infectious diseases and the nurses specializing in infection, and the third year students enrolled in E University participated in the program. Knowledge, attitude, and confidence in infection control were measured before and after the program in the students that participated in the program and those who did not. The experimental group consisted of 33 students while the control group comprised 28 students. RESULTS: The two groups were found to be homogeneous before the education program. After four days of intensive education program, the experimental group showed statistically significant improvements in knowledge (t=2.02, p=.048), attitude (t=2.04, p=.045), and performance confidence (t=2.75, p=.008) in infection control when compared to the control group. CONCLUSION: The present study showed that our intensive education program on hospital infection control was effective for the nursing students who will be professional nurses who will carry out autonomous roles in infection control in a near future.

Antimicrobial Susceptibility of Clinical Isolates of Bacteroides fragilis Group Organisms Recovered from 2009 to 2012 in a Korean Hospital

BACKGROUND: Periodic monitoring of antimicrobial resistance trends of clinically important anaerobic bacteria such as Bacteroides fragilis group organisms is required. We determined the antimicrobial susceptibilities of clinical isolates of B. fragilis group organisms recovered from 2009 to 2012 in a tertiary-care hospital in Korea. METHODS: A total of 180 nonduplicate clinical isolates of B. fragilis group organisms were collected in a tertiary care hospital. The species were identified by conventional methods: the ATB 32A rapid identification system (bioMerieux, France) and the Vitek MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (bioMerieux). Antimicrobial susceptibility was determined by the CLSI agar dilution method. RESULTS: Imipenem and meropenem resistance rates were 0-6% for B. fragilis group isolates. The rate of resistance to piperacillin-tazobactam was 2% for B. fragilis and 0% for other Bacteroides species, but 17% for B. thetaiotaomicron isolates. High resistance rates to piperacillin (72% and 69%), cefotetan (89% and 58%), and clindamycin (83% and 69%) were observed for B. thetaiotaomicron and other Bacteroides spp. The moxifloxacin resistance rate was 27% for other Bacteroides spp. The MIC50 and MIC90 of tigecycline were 2-4 microg/mL and 8-16 microg/mL, respectively. No isolates were resistant to chloramphenicol or metronidazole. CONCLUSIONS: Imipenem, meropenem, chloramphenicol, and metronidazole remain active against B. fragilis group isolates. Moxifloxacin and tigecycline resistance rates are 2-27% and 8-15% for B. fragilis group isolates, respectively.

Erratum

This erratum is being published to correct the printing error on page 96.