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Background Extended-spectrum β-lactamase (ESBL)–producing Enterobacterales have become a global concern owing to increased infections, high mortality, and limited antibiotic treatment options. Carbapenems (CPMs) are effective against ESBL-producing Enterobacterales, but their overuse leads to the emergence of multidrug-resistant bacteria. Cefmetazole (CMZ) is effective in vitro; however, its clinical efficacy remains unclear. Methods We retrospectively reviewed patients who were treated with CMZ or CPMs for bacteremia caused by ESBL-producing Enterobacterales between 1 April 2014 and 31 September 2022 at Tenri Hospital. The primary outcome measure was 90-day mortality. We also evaluated resistance genes and sequence types of ESBL-producing Enterobacterales. Results In total, 156 patients were enrolled in this study. Ninety patients (58%) received CMZ therapy. Patients in the CMZ group were significantly older than those in the CPM group (median [IQR], 79 years [71–86] vs 74 years [64–83]; P =.001). The severity of the Pitt bacteremia score of the CMZ group was lower than that in the CPM group (0 [0–2] vs 2 [0–2], P =.042). Six patients (7%) in the CMZ group and 10 (15%) in the CPM group died by day 90 (P =.110). Charlson Comorbidity Index and prevalence of sequence 131 between the groups were statistically insignificant. Conclusions Our findings suggest that CMZ is a well-tolerated alternative to CPM for treating bacteremia caused by ESBL-producing Enterobacterales. [ABSTRACT FROM AUTHOR]

Fluoroquinolone (FQ) resistant gram-negative pathogens have emerged worldwide, and the recent increase in FQ resistant Escherichia coli is of great concern in Korea. This study investigated FQ resistance determinants and the epidemiological relationship of 56 ciprofloxacin-resistant E. coli isolated from a tertiary hospital in Daejeon, South Korea from June to December 2018. Molecular epidemiology was investigated by multilocus sequence typing (MLST). Polymerase chain reaction (PCR) and sequence analysis were performed to identify chromosomal mutations in the quinolone resistance determining regions (QRDR) of gyrA, gyrB, parC, and parE and to describe the occurrence of the following plasmid-mediated quinolone resistance (PMQR) genes: aac(6)-Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, and qnrS. MLST analysis showed 12 sequence types (STs) and the most prevalent ST was ST131 (31/56, 55.4%), followed by ST1193 (13/56, 23.2%), and ST405 (3/56, 5.4%). In 56 ciprofloxacin-resistant E. coli isolates, Ser83→Leu and Asp87→Asn in gyrA and Ser80→Ile and Glu84 →Val in parC (51.8%, 29/56) were the most frequent amino acid substitutions and aac(6)-Ib-cr (33.9%, 19/56) was the most common PMQR gene. These results of FQ resistance determinants were more frequently observed in ST131 compared with other clones. Continuous monitoring of the epidemiological characteristics of ciprofloxacin-resistant E. coli isolates and further investigation of FQ resistance determinants are necessary.

The threat of antibiotic-resistant bacteria to public health may originate from public restrooms. To better understand the community burden of antimicrobial-resistant Escherichia coli and sequence type complex 131 E. coli (STc131) in the public restroom, we performed a surveillance in public restrooms in southern Taiwan. Swabs were sampled from randomly selected public restrooms in Tainan, Taiwan in 2019. Antimicrobial susceptibility, phylogenetic grouping, and multiplex PCR were performed for the major ST complex in the B2 phylogenetic group. If STc131 isolates were identified, the whole-genome sequencing was performed. A total of 613 collection sites found 132 sites (21.5%) positive for E. coli. The most common phylogenetic group was A (30.9%) followed by B2 (30.3%). Ceftriaxone-resistant E. coli and extended-spectrum β-lactamases–producing E. coli were found in 2.4 and 1.0% of total public restrooms, respectively. The isolates in rural areas had higher ceftriaxone non-susceptibility than those in the city centers (3.9 vs. 1.2%, P = 0.038). Nine STc131 isolates were found in public restrooms, and most (77.8%) belonged to the subtype fimH41, whereas 22.2% belonged to fimH30. With the inclusion of STc131 isolates from human and dog fecal colonization in Taiwan, whole-genome sequencing was performed in 35 isolates. A large cluster of fimH41 in SNP-tree and GrapeTree was found from different sources (human, dog, and environment) and geographical areas. In conclusion, our surveillance of antimicrobial-resistant E. coli showed a higher prevalence of E. coli detected in public restrooms in the rural areas compared to those in city centers. The whole-genome sequence implies that fimH41 STc131 strains are successfully circulated in the community in Taiwan. [ABSTRACT FROM AUTHOR]

배경: 본 연구의 목적은 요로감염의 가장 흔한 원인균인 Escherichia coli에 의한 반복적 요로감염의 임상 및 미생물학적 특성을 분석하여 위험인자를 파악하는 것이다.방법: 2019년 1월부터 6개월동안 E. coli에 의한 반복적 요로감염 환자와 단일 에피소드를 후향적으로 비교하였다.결과: 반복적 요로감염 환자에서 의료기관 관련 요로감염, 대장균 균혈증 동반, 소변 추적배양에서 음전되지 않은 경우가 많았다. 반복적 요로감염 환자에서 분리된 E. coli는 extended-spectrum β-lactamase (ESBL) 생성이 빈번하고 항균제 내성률이 높았다. 자주 검출되는 ST131 E. coli의 비율은 두 군이 유사하였다.결론: ESBL을 생성하는 E. coli는 흔히 다제내성을 보이므로 적절한 항균제 치료의 가능성을 낮추어 요로 내 E. coli의 제거를 지연시켜 반복적인 요로감염과 관련성이 큰 것으로 생각된다.

The threat of antibiotic-resistant bacteria to public health may originate from public restrooms. To better understand the community burden of antimicrobial-resistant Escherichia coli and sequence type complex 131 E. coli (STc131) in the public restroom, we performed a surveillance in public restrooms in southern Taiwan. Swabs were sampled from randomly selected public restrooms in Tainan, Taiwan in 2019. Antimicrobial susceptibility, phylogenetic grouping, and multiplex PCR were performed for the major ST complex in the B2 phylogenetic group. If STc131 isolates were identified, the whole-genome sequencing was performed. A total of 613 collection sites found 132 sites (21.5%) positive for E. coli. The most common phylogenetic group was A (30.9%) followed by B2 (30.3%). Ceftriaxone-resistant E. coli and extended-spectrum β-lactamases–producing E. coli were found in 2.4 and 1.0% of total public restrooms, respectively. The isolates in rural areas had higher ceftriaxone non-susceptibility than those in the city centers (3.9 vs. 1.2%, P = 0.038). Nine STc131 isolates were found in public restrooms, and most (77.8%) belonged to the subtype fimH41, whereas 22.2% belonged to fimH30. With the inclusion of STc131 isolates from human and dog fecal colonization in Taiwan, whole-genome sequencing was performed in 35 isolates. A large cluster of fimH41 in SNP-tree and GrapeTree was found from different sources (human, dog, and environment) and geographical areas. In conclusion, our surveillance of antimicrobial-resistant E. coli showed a higher prevalence of E. coli detected in public restrooms in the rural areas compared to those in city centers. The whole-genome sequence implies that fimH41 STc131 strains are successfully circulated in the community in Taiwan.

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

Abstract Background Escherichia coli (E. coli) is known to cause urinary tract infection (UTI) and meningitis in neonates, as well as existing as a commensal flora of the human gut. Extended-spectrum β-lactamase (ESBL)-producing E. coli has increased in the community with the spread of CTX-M type ESBL-producing sequence type 131 (ST131)-O25-H30Rx E. coli clone. The role of ESBL-producing E. coli in female genital tract infection has not been elucidated. The clinical and molecular features of E. coli isolated from community-onset female genital tract infections were evaluated to elucidate the current burden in the community, focusing on the highly virulent and multidrug-resistant ST131 clone. Methods We collected and sequenced 91 non-duplicated E. coli isolates from the female genital tract of 514 patients with community-onset vaginitis. ESBL genotypes were identified by PCR and confirmed to be ESBL-producers by sequencing methods. ST131 clones were screened by PCR for O16-ST131 and O25b-ST131. Pulsed-field gel electrophoresis (PFGE) and PCR-based replicon typing (PBRT) were conducted in ESBL producers. Independent clinical risk factors associated with acquiring ESBL-producing E. coli and ST131 clone were analyzed using multivariate logistic regression analysis. Results Of the 514 consecutive specimens obtained from the infected female genital tract, 17.7% (91/514) had E. coli infection, of which 19.8% (18/91) were ESBL producers. CTX-M-15 was the most common type (n = 15). O25b-ST131 and O16-ST131 clones accounted for 15.4% (14/91) and 6.6% (6/91), respectively. In plasmid analysis, ten isolates succeeded in conjugation and plasmid types were IncFII (n = 4), IncFI (n = 3), IncI1-Iγ (n = 3) with one non-typable case. Compared to ESBL-nonproducing E. coli, ESBL-producing E. coli acquisition was strongly associated with recurrent vaginitis (OR 40.130; 95% CI 9.980–161.366), UTI (OR 18.915; 95% CI 5.469–65.411), and antibiotics treatment (OR 68.390; 95% CI 14.870–314.531). Conclusion A dominant clone of CTX-M type ESBL-producing E. coli in conjugative plasmids seems to be circulating in the community and considerable number of ST131 E. coli in the genital tract of Korean women was noted. Sustained monitoring of molecular epidemiology and control of the high-risk group is needed to prevent ESBL-producing E. coli from spreading throughout the community.

Hospital-acquired infections caused by extended-spectrum β-lactamase (ESBL)–producing Escherichia coli are a global problem. Healthy people can carry ESBL-producing E. coli in the intestines; thus, E. coli from healthy people can potentially cause hospital-acquired infections. Therefore, the transmission routes of ESBL-producing E. coli from healthy persons should be determined. A foodborne outbreak of human norovirus (HuNoV) GII occurred at a restaurant in Shizuoka, Japan, in 2018. E. coli O25:H4 was isolated from some of the HuNoV-infected customers. Pulsed-field gel electrophoresis showed that these E. coli O25:H4 strains originated from one clone. Because the only epidemiological link among the customers was eating food from this restaurant, the customers were concurrently infected with E. coli O25:H4 and HuNoV GII via the restaurant food. Whole genome analysis revealed that the E. coli O25:H4 strains possessed genes for regulating intracellular iron and expressing the flagellum and flagella. Extraintestinal pathogenic E. coli often express these genes on the chromosome. Additionally, the E. coli O25:H4 strains had plasmids harboring nine antimicrobial resistance genes. These strains harbored ESBL-encoding blaCTX-M-14 genes on two loci of the chromosome and had higher ESBL activity. Multilocus sequence typing and fimH subtyping revealed that the E. coli O25:H4 strains from the outbreak belonged to the subclonal group, ST131-fimH30R, which has been driving ESBL epidemics in Japan. Because the E. coli O25:H4 strains isolated in the outbreak belonged to a subclonal group spreading in Japan, foods contaminated with ESBL-producing E. coli might contribute to spreading these strains among healthy persons. The isolated E. coli O25:H4 strains produced ESBL and contained plasmids with multiple antimicrobial resistance genes, which may make it difficult to select antimicrobials for treating extraintestinal infections caused by these strains. [ABSTRACT FROM AUTHOR]

Escherichia coli (E. coli) causes urinary tract infections, pneumonia, surgical site infections, and bloodstream infections and is the important pathogen for both community-acquired and healthcare-associated infections. To investigate the clonality of E. coli is important for infection control and prevention. We aimed to investigate the clonality of clinical E. coli isolates using Cica Geneus E. coli polymerase chain reaction (PCR)-based open-reading frame typing (POT) KIT and clarify the clinical usefulness of this kit. About 124 E. coli isolates obtained from inpatients at Sapporo Medical University Hospital were used. The POT method was used to classify 124 clinical isolates into 87 POT numbers. In addition to the clonality, it was possible to obtain additional information that 20 of the 124 isolates were extended-spectrum β-lactamase (ESBL) producing E. coli (5 isolates of CTX-M-1 group and 15 isolates of CTX-M-9 group) and 13 were sequence type (ST) 131 clone. Furthermore, when these ESBL-producing 20 isolates were compared with pulsed-field gel electrophoresis (PFGE) or multilocus sequence typing (MLST), Simpson's index of diversity was 0.968 in POT method, 0.979 in PFGE, and 0.584 in MLST. POT method had an analytical power similar to that of PFGE. In conclusion, attention should be paid to the difference in the interpretation of the results between the POT method and the PFGE, but POT method may be useful to timely monitor the spread of E. coli in medical facilities. [ABSTRACT FROM AUTHOR]

Background: The recent molecular epidemiology of ESBL-producing Escherichia coli infection in two Korean community hospitals was evaluated in this prospective observational study. Methods: We collected non-duplicated E. coli isolates from consecutive, sequentially encountered patients with community-onset episodes between March and April 2016 in two community hospitals in Gyeonggi-do province, Korea. We studied the prevalence, clinical characteristics and molecular epidemiology of E. coli sequence type 131 (ST131) isolated from the community. Results: From a total of 213 E. coli isolates collected from the community, 94 (44.1%) were community-onset healthcare-associated isolates and 119 (55.9%) were community-associated isolates, of which urinary tract infection was the majority. A total of 55 (25.8%) of the 213 E. coli isolates were confirmed to have ESBL genes, which were mainly CTX-M types such as CTX-M-14 and CTX-M-15. There was no difference in the proportion of globally epidemic ST131 clones or that of O25, O16, H30, or H30Rx subclones between community-associated and community-onset healthcare-associated isolates. Conclusions: In this study, considerable ST131 E. coli isolations in the community were observed and about half of them were related to the history of a visit to the healthcare facilities, indicating the spread of multidrug-resistant E. coli to the community via healthcare facilities.

Background: This study aimed to investigate the frequency of sequence type (ST) 131 strains and outcome of cirrhotic patients with bloodstream infections (BSIs) caused by extended-spectrum beta-lactamase-producing Escherichiacoli (ESBLEC) and non-extended-spectrum beta-lactamase-producing Escherichiacoli (NESBLEC). Methods: The incidence of ST 131 strains, hospital stay, and 30-day re-admission/mortality were compared between 51 ESBLEC and 51 NESBLEC bacteremic patients with cirrhosis. Results: ST 131 strains were found in 35.3% of the ESBLEC group and 0% of the NESBLEC group (p < 0.001). Mean hospital stay was 26.5 days in the ESBLEC group and 17.1 days in the NESBLEC group (p = 0.006). Thirty-day re-admission rates were 11.8% in the ESBLEC group and 5.9% in the NESBLEC group (p = 0.5). ST 131 strains were associated with 30-day re-admission (odds ratio: 4.5, 95% confidence interval: 1.1–18.9). Thirty-day mortality rate was 31.4% in the ESBLEC group and 23.5% in the NESBLEC group (p = 0.4). Conclusion: In patients with cirrhosis, the ESBLEC BSIs group had a higher frequency of ST 131 strains and longer hospital stay than the NESBLEC BSIs group with similar 30-day re-admission/mortality. ST 131 strains were associated with 30-day re-admission.

Background The recent molecular epidemiology of ESBL-producing Escherichia coli infection in two Korean community hospitals was evaluated in this prospective observational study. Methods We collected non-duplicated E. coli isolates from consecutive, sequentially encountered patients with community-onset episodes between March and April 2016 in two community hospitals in Gyeonggi-do province, Korea. We studied the prevalence, clinical characteristics and molecular epidemiology of E. coli sequence type 131 (ST131) isolated from the community. Results From a total of 213 E. coli isolates collected from the community, 94 (44.1%) were community-onset healthcare-associated isolates and 119 (55.9%) were community-associated isolates, of which urinary tract infection was the majority. A total of 55 (25.8%) of the 213 E. coli isolates were confirmed to have ESBL genes, which were mainly CTX-M types such as CTX-M-14 and CTX-M-15. There was no difference in the proportion of globally epidemic ST131 clones or that of O25, O16, H30 , or H30Rx subclones between community-associated and community-onset healthcare-associated isolates. Conclusions In this study, considerable ST131 E. coli isolations in the community were observed and about half of them were related to the history of a visit to the healthcare facilities, indicating the spread of multidrug-resistant E. coli to the community via healthcare facilities. [ABSTRACT FROM AUTHOR]

The effect of plasmids harbouring bla CTX-M on the virulence and fitness on Escherichia coli sequence type 131 (ST131) isolates was investigated. Plasmids harbouring bla CTX-M-14 or bla CTX-M-15 were transferred by transconjugation into five non-extended-spectrum β-lactamase (ESBL)-producing ST131 isolates. Clinical non-ESBL-producing ST131 isolates demonstrated a higher degree of biofilm formation and serum resistance compared with CTX-M-producing ST131 isolates. In addition, non-ESBL-producing isolates were more competitive than CTX-M-producing isolates. Transconjugants showed no significant defect in growth rate and competitiveness compared with their hosts. However, serum resistance and biofilm formation were diminished in the transconjugants. In conclusion, non-ESBL-producing E. coli ST131 isolates were more competitive and virulent than CTX-M-producing E. coli ST131 isolates. However, transconjugants harbouring bla CTX-M were no less competitive than their susceptible hosts, which may partially explain the global dissemination of CTX-M-14- and CTX-M-15-producing E. coli ST131 isolates, in addition to their increased antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Escherichia coli ST131emerged during the early to mid-2000s is an important human pathogen, has spread extensively throughout the world, and is responsible for the rapid increase in antimicrobial resistance among E. coli. ST131 is known to cause extraintestinal infections, being fluoroquinolone resistant, and is associated with ESBL production most often due to CTX-M-15. Recent molecular epidemiologic studies using whole-genome sequencing and phylogenetic analysis have demonstrated that the H30 ST131 lineage emerged in early 2000s that was followed by the rapid expansion of its sublineages H30-R and H30-Rx. Escherichia coli ST131 clearly has all of the essential characteristics that define a high-risk clone and might be the quintessential example of an international multiresistant high-risk clone. We urgently need rapid cost-effective detection methods for E. coli ST131, as well as well-designed epidemiological and molecular studies to understand the dynamics of transmission, risk factors, and reservoirs for ST131. This will provide insight into the emergence and spread of this multiresistant sequence type that will hopefully lead to information essential for preventing the spread of ST131. [ABSTRACT FROM AUTHOR]

Escherichia coli sequence type 131 is increasingly described in severe hospital infections. We developed a rapid real-time allelic discrimination assay for the rapid identification of E . coli ST131 isolates. This rapid assay represents an affordable alternative to sequence-based strategies before completing characterization of potentially highly virulent isolates of E . coli . [ABSTRACT FROM AUTHOR]

Objectives Prevention and management of Escherichia coli bacteraemia following transrectal ultrasound-guided (TRUS) prostate biopsy has become increasingly complicated by antimicrobial resistance, particularly to fluoroquinolones. Moreover, the globally disseminated, multiresistant sequence type 131 (ST131) E. coli clonal group has recently been described as a major pathogen in the setting of post-biopsy sepsis. Accordingly, we sought to further explore the clinical and molecular epidemiology of post-TRUS biopsy E. coli bacteraemia by comparing the phylogenetic, resistance and virulence characteristics of post-TRUS biopsy E. coli bloodstream isolates with E. coli bloodstream isolates from male patients with spontaneous urosepsis. Methods Multiplex PCR was used to compare the phylogenetic group and virulence-associated genes between post-biopsy E. coli isolates and E. coli bloodstream isolates from males with spontaneous urosepsis. Antimicrobial resistance profiles were also compared between the two groups. In addition, we compared the clinical characteristics and outcomes of post-TRUS biopsy patients with E. coli ST131 versus non-ST131 bacteraemia. Results Although post-TRUS biopsy E. coli isolates were more extensively antimicrobial resistant than isolates from males with spontaneous urosepsis, they harboured significantly fewer virulence-associated genes. In addition, ST131 isolates were significantly less virulent in nature than other isolates from phylogenetic group B2. Clinical outcomes did not differ between patients with post-biopsy ST131 versus non-ST131 bacteraemia. Conclusions Our data provide new insights into the molecular pathogenesis of post-TRUS biopsy E. coli bacteraemia, and suggest that antimicrobial resistance, rather than virulence genotype, is the most important bacterial trait associated with an increased risk of infection following TRUS biopsy. [ABSTRACT FROM PUBLISHER]

Objectives The purpose of this study was to investigate the molecular epidemiology of CTX-M-14-producing Escherichia coli clinical isolates from Korea. Methods A total of 138 non-duplicate E. coli clinical isolates showing reduced susceptibility or resistance to ceftazidime and/or cefotaxime were included in the study. Resistance genes, genetic environment, R plasmid size and replicon type, sequence type (ST) and XbaI-macrorestriction patterns were determined. Results Among 138 isolates, 35 were found to carry the blaCTX-M-14 gene. The ISEcp1 element was identified in the upstream region of the blaCTX-M-14 gene in 32 isolates. The blaCTX-M-14 gene was located on an IncF plasmid in 21 isolates, on an IncA/C plasmid in 1 isolate, on the chromosome in 8 isolates and on both the chromosome and an IncF plasmid in 5 isolates. The most prevalent ST was ST405 (n = 8), followed by ST354 (n = 4), ST38 (n = 3), ST69 (n = 3) and the intercontinental ST, ST131 (n = 3). PFGE and multilocus sequence typing experiments demonstrated no major clonal relationship among the CTX-M-14-producing isolates. Conclusions The blaCTX-M-14 gene was probably mobilized by IncF plasmids, which can readily spread in E. coli, causing horizontal dissemination of the resistance gene in Korea. [ABSTRACT FROM PUBLISHER]

We evaluated the molecular epidemiology and microbiological characteristics of extended-spectrum β-lactamase–producing Escherichia coli (ESBL-EC) isolates that cause bacteremia in Korean hospitals, focusing especially on ST131. Our data suggest that ST131 isolates possessed more virulence traits and showed more multidrug resistance patterns than non-ST131 isolates. Among CTX-M-15 producers, the frequency of serum resistance was significantly higher in ST131 than in non-ST131. As in other parts of the world, the ESBL-EC ST131 clone has emerged and disseminated in both community and hospital settings in Korea, including in blood isolates in patients with bacteremia. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the frequency of sequence type (ST) 131 strains and outcome of cirrhotic patients with bloodstream infections (BSIs) caused by extended-spectrum beta-lactamase-producing Escherichiacoli (ESBLEC) and non-extended-spectrum beta-lactamase-producing Escherichiacoli (NESBLEC). Methods: The incidence of ST 131 strains, hospital stay, and 30-day re-admission/mortality were compared between 51 ESBLEC and 51 NESBLEC bacteremic patients with cirrhosis. Results: ST 131 strains were found in 35.3% of the ESBLEC group and 0% of the NESBLEC group (p < 0.001). Mean hospital stay was 26.5 days in the ESBLEC group and 17.1 days in the NESBLEC group (p = 0.006). Thirty-day re-admission rates were 11.8% in the ESBLEC group and 5.9% in the NESBLEC group (p = 0.5). ST 131 strains were associated with 30-day re-admission (odds ratio: 4.5, 95% confidence interval: 1.1–18.9). Thirty-day mortality rate was 31.4% in the ESBLEC group and 23.5% in the NESBLEC group (p = 0.4). Conclusion: In patients with cirrhosis, the ESBLEC BSIs group had a higher frequency of ST 131 strains and longer hospital stay than the NESBLEC BSIs group with similar 30-day re-admission/mortality. ST 131 strains were associated with 30-day re-admission. [ABSTRACT FROM AUTHOR]

Abstract: Hospital-acquired infections caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are a global problem. Healthy people can carry ESBL-producing E. coli in the intestines; thus, E. coli from healthy people can potentially cause hospital-acquired infections. Therefore, the transmission routes of ESBL-producing E. coli from healthy persons should be determined. A foodborne outbreak of human norovirus (HuNoV) GII occurred at a restaurant in Shizuoka, Japan, in 2018. E. coli O25:H4 was isolated from some of the HuNoV-infected customers. Pulsed-field gel electrophoresis showed that these E. coli O25:H4 strains originated from one clone. Because the only epidemiological link among the customers was eating food from this restaurant, the customers were concurrently infected with E. coli O25:H4 and HuNoV GII via the restaurant food. Whole genome analysis revealed that the E. coli O25:H4 strains possessed genes for regulating intracellular iron and expressing the flagellum and flagella. Extraintestinal pathogenic E. coli often express these genes on the chromosome. Additionally, the E. coli O25:H4 strains had plasmids harboring nine antimicrobial resistance genes. These strains harbored ESBL-encoding blaCTX-M-14 genes on two loci of the chromosome and had higher ESBL activity. Multilocus sequence typing and fimH subtyping revealed that the E. coli O25:H4 strains from the outbreak belonged to the subclonal group, ST131-fimH30R, which has been driving ESBL epidemics in Japan. Because the E. coli O25:H4 strains isolated in the outbreak belonged to a subclonal group spreading in Japan, foods contaminated with ESBL-producing E. coli might contribute to spreading these strains among healthy persons. The isolated E. coli O25:H4 strains produced ESBL and contained plasmids with multiple antimicrobial resistance genes, which may make it difficult to select antimicrobials for treating extraintestinal infections caused by these strains., (Copyright ©, International Association for Food Protection.)

Objectives: The recent expansion of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is a worldwide problem. The purpose of this study was to investigate the molecular characteristics of ESBL-producing E. coli strains in Mashhad, located in the northeast of Iran., Methods: A total of 455 clinical E. coli isolates were collected at three hospitals in Mashhad between April-September 2015. Antimicrobial susceptibility was determined by the Kirby-Bauer disk diffusion test. The combination disk test was performed for phenotypic detection of ESBLs. PCR was used to screen isolates for ESBL typing. Phylogenetic groups and sequence type 131 (ST131) were determined by multiplex PCR., Results: The prevalence of ESBL-producing E. coli among the collected strains was 51.6% (235/455). Among the 235 ESBL-producing strains, 222 (94.5%) tested positive for CTX-M type, whilst 115 (48.9%), 92 (39.1%) and 21 (8.9%) were positive for TEM, OXA and SHV, respectively. Moreover, CTX-M-15 (94.1%; 209/222) was the most common ESBL among E. coli. Based on multiplex PCR, phylogenetic group B2 was predominant (169/235; 71.9%), followed by D (32/235; 13.6%), A (21/235; 8.9%) and B1 (13/235; 5.5%). ST131 was the predominant clonal group among the phylogenetic group B2 isolates (151/169; 89.3%)., Conclusion: The results revealed that an urgent investigation of the source and transmission pathways of the CTX-M-15-B2-ST131 E. coli clone is needed to mitigate this emergent public-health problem., (Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.)

Escherichia coli ST131 emerged during the early to mid-2000s is an important human pathogen, has spread extensively throughout the world, and is responsible for the rapid increase in antimicrobial resistance among E. coli. ST131 is known to cause extraintestinal infections, being fluoroquinolone resistant, and is associated with ESBL production most often due to CTX-M-15. Recent molecular epidemiologic studies using whole-genome sequencing and phylogenetic analysis have demonstrated that the H30 ST131 lineage emerged in early 2000s that was followed by the rapid expansion of its sublineages H30-R and H30-Rx. Escherichia coli ST131 clearly has all of the essential characteristics that define a high-risk clone and might be the quintessential example of an international multiresistant high-risk clone. We urgently need rapid cost-effective detection methods for E. coli ST131, as well as well-designed epidemiological and molecular studies to understand the dynamics of transmission, risk factors, and reservoirs for ST131. This will provide insight into the emergence and spread of this multiresistant sequence type that will hopefully lead to information essential for preventing the spread of ST131., (Copyright © 2015 Elsevier Inc. All rights reserved.)