Surveillance and Resistance of Community-Onset Extended-Spectrum ß-Lactamase-Producing Escherichia coli and Klebsiella pneumonia in Oral and Maxillofacial Surgery Site Infections.

Background: The prevalence of community-onset infections of extended spectrum ß-lactamase (ESBL)-producing strains has increased globally, yet surveillance and resistance in patients with oral and maxillofacial surgery site infections is less investigated. Patients and Methods: A retrospective cohort study was performed to investigate risk factors and resistance of ESBL-producing Escherichia coli (ESBL-EC) and ESBL-producing Klebsiella pneumonia (ESBL-KP) among community-onset patients with oral and maxillofacial surgery during January 2010 to December 2016. Demographic features, predisposing factors, clinical outcomes, and antibiotic agent costs were analyzed. Antimicrobial susceptibility testing of nine antimicrobial agents against ESBL-KP and ESBL-EC were measured. Results: Among 2,183 cultures from infection sites in patients with oral and maxillofacial surgery site (45 cases [2.06%]) were confirmed with community-onset ESBL-KP (24; 1.10%) or ESBL-EC (21; 0.96%) infection. Multivariable analysis showed the independent risk factors for ESBL-producing bacterial infection were prior history of hospitalization (adjusted odds ratio [aOR], 10.984; 95% confidence interval [CI], 5.965-59.879; p = 0.025) and malignant condition (aOR, 3.373; 95% CI 2.947-7.634; p = 0.024). Based on antimicrobial susceptibility testing, 57.8% ESBL-KP and ESBL-EC were found receiving inappropriate antimicrobial therapy, and antibiotic agent costs were higher than non-ESBL-producing bacterial infections ($493.8 ± $367.3 vs. $304.1 ± $334.7; p = 0.031). Conclusions: Infections caused by ESBL-KP and ESBL-EC among patients in sites with oral and maxillofacial surgery are associated with prior history of hospitalization and malignant conditions. Prompt detection and appropriate antibiotic administration for community-onset infections of ESBLs are necessary for such populations.

Multi-drug-resistant Escherichia coli in adult male patients with enlarged prostate attending general hospitals in Benue state.

The aim of this study was to investigate multi-drug-resistant (MDR) Escherichia coli in urine of adult male patients with enlarged prostate. Three hundred and sixty-eight samples of urine and blood were collected. Escherichia coli was isolated, purified, and identified and prostate-specific antigen (PSA) was determined. Multi-drug resistance test and specific drug resistance genes were assessed. Prevalence of Escherichia coli was high (38.5%) in patients with PSA of 60-79 ng ml-1 and 60% were MDR. The isolates showed highest resistance to tetracycline (53.3.0%) and least to cephalosporins (5%). They had intL and gyrA genes, which are integron, and quinolone resistance genes and sul1 and sul2 which are sulphonamide resistance-associated genes. Levofloxacin, ertapenem, and Augmentin (100% susceptibilities) were considered choice drugs for treatment of Escherichia coli infection in patients with elevated PSA.

Pathogens in Crohn's Disease: The Role of Adherent Invasive Escherichia coli.

In Crohn's disease (CD), gut dysbiosis is marked by the prevalence of pathogenic bacterial species. Although several microbes have been reported as risk factors or causative agents of CD, it is not yet clear which is the real trigger of the disease. Thirty years ago, a new pathovar of Escherichia coli strain was isolated in the ileal mucosa of CD patients. This strain, called adherent invasive E. coli (AIEC), for its ability to invade the intestinal mucosa, could represent the causative agent of the disease. Several authors studied the mechanisms by which the AIEC penetrate and replicate within macrophages, and release inflammatory cytokines sustaining inflammation. In this review we will discuss about the role of AIEC in the pathogenesis of CD, the virulence factors mediating adhesion and invasion of AIEC in mucosal tissue, the environmental conditions improving AIEC survival and replication within macrophages. Finally, we will also give an overview of the new strategies developed to limit AIEC overgrowth.

Are enterococcal bloodstream infections an independent risk factor for a poorer 5-year survival or just a marker for severity of illness?-The Munich multicentric enterococci cohort.

IMPORTANCE: The present study provides a substantial contribution to literature, showing that patients with enterococcal bloodstream infections (BSI) have a lower survival rate than those with Escherichia coli (E. coli) bloodstream infections after adjusting for 17 limiting prognostic factors and excluding patients with a limited life expectancy [metastatic tumor disease, Charlson Comorbidity Index (CCI) (greater than or equal to) 5]. This difference in the 5-year long-term survival was mainly driven by Enterococcus faecium (ECFM) bloodstream infections, with vancomycin resistance not being a significant contributing factor. Our findings imply that E. faecium bloodstream infections seem to be an independent risk factor for poor long-term outcomes. As such, future research should confirm this relationship and prioritize investigating its causality through prospective studies.

Atypical diarrhoeagenic Escherichia coli in milk related to a large foodborne outbreak.

A foodborne outbreak related to milk cartons served in school lunches occurred in June 2021, which involved more than 1,800 cases from 25 schools. The major symptoms were abdominal pain, diarrhoea, vomiting, and fever. Although major foodborne toxins and pathogens were not detected, a specific Escherichia coli strain, serotype OUT (OgGp9):H18, was predominantly isolated from milk samples related to the outbreak and most patients tested. The strains from milk and patient stool samples were identified as the same clone by core genome multilocus sequence typing and single-nucleotide polymorphism analysis. The strain was detected in milk samples served for two days related to the foodborne outbreak at a rate of 69.6% and levels of less than ten most probable number/100 mL but not on days unrelated to the outbreak. The acid tolerance of the strain for survival in the stomach was similar to that of enterohaemorrhagic E. coli O157:H7, and the same inserts in the chu gene cluster in the acid fitness island were genetically revealed. The pathogenicity of the strain was not clear; however, it was indicated that the causative pathogen was atypical diarrhoeagenic E. coli OUT (OgGp9):H18.

Fluoroquinolone-resistant Escherichia coli among the rectal flora is the predominant risk factor for severe infection after transrectal ultrasound-guided prostate biopsy: a prospective observational study.

BACKGROUND: Infection of the prostate gland following biopsy, usually with Escherichia coli, is a common complication, despite the use of antimicrobial prophylaxis. A fluoroquinolone (FQ) is commonly prescribed as prophylaxis. Worryingly, the rate of fluoroquinolone-resistant (FQ-R) E. coli species has been shown to be increasing. OBJECTIVE: This study aimed to identify risk factors associated with infection after transrectal ultrasound-guided prostate biopsy (TRUS-Bx). METHODS: This was a prospective study on patients undergoing TRUS-Bx in southeast Sweden. Prebiopsy rectal and urine cultures were obtained, and antimicrobial susceptibility and risk-group stratification were determined. Multivariate analyses were performed to identify independent risk factors for post-biopsy urinary tract infection (UTI) and FQ-R E. coli in the rectal flora. RESULTS: In all, 283 patients were included, of whom 18 (6.4%) developed post-TRUS-Bx UTIs. Of these, 10 (3.5%) had an UTI without systemic inflammatory response syndrome (SIRS) and 8 (2.8%) had a UTI with SIRS. Being in the medium- or high-risk groups of infectious complications was not an independent risk factor for UTI with SIRS after TRUS-Bx, but low-level FQ-resistance (minimum inhibitory concentration (MIC): 0.125-0.25 mg/L) or FQ-resistance (MIC > 0.5 mg/L) among E. coli in the faecal flora was. Risk for SIRS increased in parallel with increasing degrees of FQ-resistance. Significant risk factor for harbouring FQ-R E.coli was travelling outside Europe within the previous 12 months. CONCLUSION: The predominant risk factor for UTI with SIRS after TRUS-Bx was FQ-R E. coli among the faecal flora. The difficulty in identifying this type of risk factor demonstrates a need for studies on the development of a general approach either with rectal swab culture for targeted prophylaxis, or prior rectal preparation with a bactericidal agent such as povidone-iodine before TRUS-Bx to reduce the risk of FQ-R E. coli-related infection.

Occurrence of plasmid-mediated fosfomycin resistance (fos genes) among Escherichia coli isolates, Portugal.

OBJECTIVES: To evaluate the occurrence of plasmid-mediated fos genes among fosfomycin-resistant Escherichia coli isolates collected from patients in Lisbon, Portugal, and characterize the fos-positive strains. METHODS: A total of 19 186 E. coli isolates were prospectively collected between April 2022 and January 2023 from inpatients and outpatients at a private laboratory in Lisbon. Fosfomycin resistance was initially assessed by semi-automated systems and further confirmed by the disc diffusion method. Resistant isolates were investigated for plasmid-mediated fos genes (fosA1-fosA10, fosC and fosL1-fosL2) and extended-spectrum beta-lactamases (ESBLs) by PCR and sequencing. Multilocus sequence typing was performed to evaluate the clonal relationship among fos-carrying isolates. RESULTS: Out of the 19 186 E. coli isolates, 100 were fosfomycin-resistant (0.5%), out of which 15 carried a fosA-like gene (15%). The most prevalent fosfomycin-resistant determinant was fosA3 (n = 11), followed by fosA4 (n = 4). Among the 15 FosA-producing isolates, 10 co-produced an ESBL (67%), being either of CTX-M-15 (n = 8) or CTX-M-14 (n = 2) types. The fosA3 gene was carried on IncFIIA-, IncFIB-, and IncY-type plasmids, whereas fosA4 was always located on IncFIB-type plasmids. Most FosA4-producing isolates belonged to a single sequence type ST2161, whereas isolates carrying the fosA3 gene were distributed into nine distinct genetic backgrounds. CONCLUSION: The prevalence of fosfomycin-resistant E. coli isolates is still low in Portugal. Notably, 15% of fosfomycin-resistant isolates harbour a transferable fosA gene, among which there is a high rate of ESBL producers, turning traditional empirical therapeutical options used in Portugal (fosfomycin and amoxicillin-clavulanic acid) ineffective.

Screening for extended-spectrum beta-lactamase Escherichia coli in recreational beach waters in Singapore.

Aims: As part of Singapore's One Health antimicrobial resistance (AMR) management, this work was designed to understand the AMR burden in recreational beach waters using extended-spectrum beta-lactamase Escherichia coli (ESBL-EC) as an indicator. Materials & methods: A total of 90 water samples were collected from six different recreational beaches over three different time periods. Only 28/90 (31.3%) water samples yielded E. coli colonies ranging from 1 to 80 colony-forming units/100 ml. Results & conclusion: Screening of all colonies using CHROMID® ESBL agar and Luria-Bertani broth supplemented with ceftriaxone showed that none was ESBL-EC. Further monitoring is required to understand the prevalence of ESBL-EC spatiotemporally, contributing to the national AMR surveillance program and providing timely risk assessment for exposure to ESBL-EC.

Detection of Extended-spectrum ß-lactamase-producing Escherichia coli isolates by isothermal amplification and association of their virulence genes and phylogroups with extraintestinal infection.

Extraintestinal pathogenic Escherichia coli (ExPEC) producing extended-spectrum ß-lactamases (ESBL) cause serious human infections due to their virulence and multidrug resistance (MDR) profiles. We characterized 144 ExPEC strains (collected from a tertiary cancer institute) in terms of antimicrobial susceptibility spectrum, ESBL variants, virulence factors (VF) patterns, and Clermont's phylogroup classification. The developed multiplex recombinase polymerase amplification and thermophilic helicase-dependent amplification (tHDA) assays for blaCTX-M, blaOXA, blaSHV, and blaTEM detection, respectively, were validated using PCR-sequencing results. All ESBL-ExPEC isolates carried blaCTX-M genes with following prevalence frequency of variants: blaCTX-M-15 (50.5%) > blaCTX-M-55 (17.9%) > blaCTX-M-27 (16.8%) > blaCTX-M-14 (14.7%). The multiplex recombinase polymerase amplification assay had 100% sensitivity, and specificity for blaCTX-M, blaOXA, blaSHV, while tHDA had 86.89% sensitivity, and 100% specificity for blaTEM. The VF genes showed the following prevalence frequency: traT (67.4%) > ompT (52.6%) > iutA (50.5%) > fimH (47.4%) > iha (33.7%) > hlyA (26.3%) > papC (12.6%) > cvaC (3.2%), in ESBL-ExPEC isolates which belonged to phylogroups A (28.4%), B2 (28.4%), and F (22.1%). The distribution of traT, ompT, and hlyA and phylogroup B2 were significantly different (P < 0.05) between ESBL-ExPEC and non-ESBL-ExPEC isolates. Thus, these equipment-free isothermal resistance gene amplification assays contribute to effective treatment and control of virulent ExPEC, especially antimicrobial resistance strains.

Temporal dynamics of genetically heterogeneous extended-spectrum cephalosporin-resistant Escherichia coli bloodstream infections.

Extended-spectrum cephalosporin-resistant Escherichia coli (ESC-R-Ec) is an urgent public health threat with sequence type clonal complex 131 (STc131), phylogroup B2 strains being particularly concerning as the dominant cause of ESC-R-Ec infections. To address the paucity of recent ESC-R-Ec molecular epidemiology data in the United States, we used whole-genome sequencing (WGS) to fully characterize a large cohort of invasive ESC-R-Ec at a tertiary care cancer center in Houston, Texas, collected from 2016 to 2020. During the study time frame, there were 1,154 index E. coli bloodstream infections (BSIs) of which 389 (33.7%) were ESC-R-Ec. Using time series analyses, we identified a temporal dynamic of ESC-R-Ec distinct from ESC-susceptible E. coli (ESC-S-Ec), with cases peaking in the last 6 months of the calendar year. WGS of 297 ESC-R-Ec strains revealed that while STc131 strains accounted for ~45% of total BSIs, the proportion of STc131 strains remained stable across the study time frame with infection peaks driven by genetically heterogeneous ESC-R-Ec clonal complexes. bla CTX-M variants accounted for most ß-lactamases conferring the ESC-R phenotype (89%; 220/248 index ESC-R-Ec), and amplification of bla CTX-M genes was widely detected in ESC-R-Ec strains, particularly in carbapenem non-susceptible, recurrent BSI strains. Bla CTX-M-55 was significantly enriched within phylogroup A strains, and we identified bla CTX-M-55 plasmid-to-chromosome transmission occurring across non-B2 strains. Our data provide important information regarding the current molecular epidemiology of invasive ESC-R-Ec infections at a large tertiary care cancer center and provide novel insights into the genetic basis of observed temporal variability for these clinically important pathogens. IMPORTANCE Given that E. coli is the leading cause of worldwide ESC-R Enterobacterales infections, we sought to assess the current molecular epidemiology of ESC-R-Ec using a WGS analysis of many BSIs over a 5-year period. We identified fluctuating temporal dynamics of ESC-R-Ec infections, which have also recently been identified in other geographical regions such as Israel. Our WGS data allowed us to visualize the stable nature of STc131 over the study period and demonstrate a limited but genetically diverse group of ESC-R-Ec clonal complexes are detected during infection peaks. Additionally, we provide a widespread assessment of ß-lactamase gene copy number in ESC-R-Ec infections and delineate mechanisms by which such amplifications are achieved in a diverse array of ESC-R-Ec strains. These data suggest that serious ESC-R-Ec infections are driven by a diverse array of strains in our cohort and impacted by environmental factors suggesting that community-based monitoring could inform novel preventative measures.

Detection of Antibiotic Resistance in Feline-Origin ESBL Escherichia coli from Different Areas of China and the Resistance Elimination of Garlic Oil to Cefquinome on ESBL E. coli.

The development of drug-resistance in the opportunistic pathogen Escherichia coli has become a global public health concern. Due to the share of similar flora between pets and their owners, the detection of pet-origin antibiotic-resistant E. coli is necessary. This study aimed to detect the prevalence of feline-origin ESBL E. coli in China and to explore the resistance elimination effect of garlic oil to cefquinome on ESBL E. coli. Cat fecal samples were collected from animal hospitals. The E. coli isolates were separated and purified by indicator media and polymerase chain reaction (PCR). ESBL genes were detected by PCR and Sanger sequencing. The MICs were determined. The synergistic effect of garlic oil and cefquinome against ESBL E. coli was investigated by checkerboard assays, time-kill and growth curves, drug-resistance curves, PI and NPN staining, and a scanning electronic microscope. A total of 80 E. coli strains were isolated from 101 fecal samples. The rate of ESBL E. coli was 52.5% (42/80). The prevailing ESBL genotypes in China were CTX-M-1, CTX-M-14, and TEM-116. In ESBL E. coli, garlic oil increased the susceptibility to cefquinome with FICIs from 0.2 to 0.7 and enhanced the killing effect of cefquinome with membrane destruction. Resistance to cefquinome decreased with treatment of garlic oil after 15 generations. Our study indicates that ESBL E. coli has been detected in cats kept as pets. The sensitivity of ESBL E. coli to cefquinome was enhanced by garlic oil, indicating that garlic oil may be a potential antibiotic enhancer.

Study of antibiotic resistance and virulence genes in Escherichia coli isolated from urinary tract infection patients in Tanta University Hospitals.

This study aimed to investigate the prevalence of antibiotic resistance genes CTX-M and Qnr, as well as the virulence genes HlyA, Pap, CNF1, and Afa, in uropathogenic Escherichia coli (UPEC) isolates from the Egyptian population. In this cross-sectional study, a total of 50 E. coli isolates were collected from urine samples from patients with urinary tract infections (UTIs) admitted to Tanta University Hospital from December 2020 to November 2021. The isolates were cultured, identified, and tested for antibiotic susceptibility by the disc diffusion method. The CTX-M, Qnr (QnrA, B, and S), Pap, CNF1, HlyA, and Afa genes were detected by polymerase chain reaction in UPEC isolates. The Pap, CNF1, HlyA, and Afa genes were found to be positive in 18%, 12%, 10%, and 2% of the isolates, respectively. In addition, CTX-M and QnrS were found to be positive in 44% and 8% of the isolates, while QnrA and B were not detected. Furthermore, positive Pap, CNF1, and HlyA genes were significantly associated with both upper and lower UTIs, increased frequency, urgency, and dysuria, and complicated UTIs, as well as pyuria over 100 white blood cells per high-power field. In conclusion, the prevalence of virulence and antibiotic resistance genes varies by population. At our hospital, the Pap gene is the most prevalent virulence gene and was strongly associated with complicated UTIs, while the CTX-M and QnrS genes were the most prevalent and related to antibiotic resistance. Our findings, however, should be interpreted with caution due to the small sample size.

Prevalence and Genomic Characteristics of mcr-Positive Escherichia coli Strains Isolated from Humans, Pigs, and Foods in China.

Colistin is one of the last-resort antibiotics for treating infections caused by multidrug-resistant (MDR) Gram-negative bacteria. However, mcr genes conferring resistance to colistin have been widely identified, which is considered a global threat to public health. Here, we investigated the prevalence and characteristics of mcr-harboring Escherichia coli strains isolated from humans, animals, and foods in China by PCR, antimicrobial susceptibility testing, conjugation experiments, molecular typing, genome sequencing, and bioinformatics analysis. In total, 135 mcr-1-harboring E. coli isolates were acquired from 847 samples, and 6 isolates carried mcr-3. Among them, 131 isolates were MDR bacteria. Sixty-five resistance genes conferring resistance to multiple antimicrobials were identified in 135 isolates. The diverse pulsed-field gel electrophoresis (PFGE) patterns and sequence types (STs) of mcr-1-carrying isolates demonstrated that clonal dissemination was not the dominant mode of mcr-1 transmission. Seven types of plasmids were able to carry mcr-1 in this study, including IncI2, IncX4, IncHI2, p0111, IncY, and two hybrid plasmids. The genetic structures carrying mcr-1 of 60 isolates were successfully transferred into the recipient, including 25 IncI2 plasmids, 23 IncX4 plasmids, and an IncHI2 plasmid. mcr-1-pap2 was the dominant mcr-1-bearing structure, followed by ISApl1-mcr-1-pap2-ISApl1 (Tn6330) and ISApl1-mcr-1-pap2, among 7 mcr-1-bearing structures of 135 isolates. In conclusion, IncI2, IncX4, and IncHI2 plasmids were the major vectors spreading mcr-1 from different geographical locations and sources. The prevalence of Tn6330 may accelerate the transmission of mcr-1. Continuous surveillance of mcr-1 and variants in bacteria is vital for evaluating the public health risk posed by mcr genes. IMPORTANCE The spread of polymyxin-resistant Enterobacteriaceae poses a significant threat to public health and challenges the therapeutic options for treating infections on a global level. In this study, mcr-1-bearing ST10 E. coli was isolated from pigs, pork, and humans simultaneously, which demonstrated that ST10 E. coli was an important vehicle for the spread of mcr-1 among animals, foods, and humans. The high prevalence of mcr-1-positive E. coli strains in pigs and pork and the horizontal transmission of mcr-1-bearing plasmids in diverse E. coli strains suggest that pigs and pork are important sources of mcr-1-positive strains in humans and pose a potential threat to public health. Additional research on the prevalence and characteristics of mcr-1-positive E. coli is still required to facilitate early warning to improve polymyxin management in hospitals.

Targeted literature review of the burden of extraintestinal pathogenic Escherichia Coli among elderly patients in Asia Pacific regions.

BACKGROUND: Extraintestinal Pathogenic Escherichia coli (ExPEC) is a leading cause of invasive disease, including bacteremia and sepsis. Invasive ExPEC disease (IED) has the potential to complicate the clinical treatment of other conditions and is associated with an increased mortality, hospitalization, and worse outcomes. Older adults and individuals with comorbid conditions are at higher risk of IED. ExPEC is of particular concern in the Asia Pacific region due to aging populations and rising antimicrobial resistance. OBJECTIVES: This study aimed to synthesize most recent data on the epidemiology, clinical and economic burden of IED in the elderly/high risk populations in China, Japan, South Korea, Taiwan, and Australia. METHODS: A targeted literature review was conducted using Embase, Medline, as well as local scientific databases. We included studies published in English and local languages published from January 1, 2010 to October 7, 2020 that were relevant to the research objectives. Studies were narratively synthesized. RESULTS: A total of 1,047 studies were identified and 34 of them were included in this review. ExPEC accounted for 46.0% (1,238/2,692) of bacteria-related invasive diseases in patients aged above 60 years in South Korea, followed by China (44.4% (284/640)), Taiwan (39.0% (1,244/3,194)), and Japan (18.1% (581/3,206)), while Australia reported ExPEC out of all pathogens (54.7% (4,006/7,330)) in general adults. Comorbidities such as diabetes or cancer were common in these patients. Studies reported increases in length-of-stay, and in-hospital 30-day all-cause mortality related to ExPEC associated bacteremia was between 9% to 12%. From a cost perspective, a 3-fold increase in sepsis-associated cost was reported in South Korea between 2005 and 2012. In Australia, antimicrobial resistance contributed to an additional cost of AUD $5.8 million per year (95% uncertainty interval [UI], $2.2-$11.2 million) in the treatment of bloodstream infections (BSIs). CONCLUSION: ExPEC was a major cause of blood stream infection across China, Japan, South Korea, Taiwan, and Australia. Both the clinical and economic burden associated to ExPEC infections as well as the antimicrobial resistance observed in the elderly call for preventive and curative actions in these regions.

Extraintestinal Pathogenic Escherichia coli (ExPEC) is a leading cause of invasive disease, including bacteremia and sepsis.A targeted literature review included the most recent data from 34 published studies on the epidemiology and clinical and economic burden of IED in the elderly/high risk populations in China, Japan, South Korea, Taiwan, and Australia.ExPEC accounted for 46.0% (1,238/2,692) of bacteria-related invasive diseases in patients aged above 60 years in South Korea, followed by China (44.4% (284/640)), Taiwan (39.0% (1,244/3,194)), and Japan (18.1% (581/3,206)), while Australia reported ExPEC out of all pathogens (54.7% (4,006/7,330)) in general adults. Studies reported increases in length-of-stay and in-hospital 30-day all-cause between 9% to 12%. These factors, along with antimicrobial resistance observed in the elderly, call for preventive and curative actions in these regions.Data for costs associated with ExPEC induced BSI or sepsis in this region are limited, but evidence shows increasing expenditures.

Role of adherent and invasive Escherichia coli in Crohn's disease: lessons from the postoperative recurrence model.

OBJECTIVE: We used the postoperative recurrence model to better understand the role of adherent and invasive Escherichia coli (AIEC) bacteria in Crohn's disease (CD), taking advantage of a well-characterised postoperative cohort. DESIGN: From a prospective, multicentre cohort of operated patients with CD, AIEC identification was performed within the surgical specimen (M0) (N=181 patients) and the neoterminal ileum (n=119 patients/181) during colonoscopy performed 6 months after surgery (M6). Endoscopic postoperative recurrence was graded using Rutgeerts' index. The mucosa-associated microbiota was analysed by 16S sequencing at M0 and M6. Relative risks or ORs were adjusted on potential confounders. RESULTS: AIEC prevalence was twofold higher within the neoterminal ileum at M6 (30.3%) than within the surgical specimen (14.9%) (p<0.001). AIEC within the neoterminal ileum at M6 was associated with higher rate of early ileal lesions (i1) (41.6% vs 17.1%; aRR 3.49 (95% CI 1.01 to 12.04), p=0.048) or ileal lesions (i2b+i3) (38.2% vs 17.1%; aRR 3.45 (95% CI 1.06 to 11.30), p=0.040) compared with no lesion (i0). AIEC within the surgical specimen was predictive of higher risk of i2b-endoscopic postoperative recurrence (POR) (aOR 2.54 (95% CI 1.01 to 6.44), p=0.049) and severe endoscopic POR (aOR 3.36 (95% CI 1.25 to 9.06), p=0.017). While only 5.0% (6/119) of the patients were AIEC-positive at both M0 and M6, 43.7% (52/119), patients with history of positive test for AIEC (M0 or M6) had higher risk of ileal endoscopic POR (aOR 2.32 (95% CI 1.01 to 5.39), p=0.048)), i2b-endoscopic postoperative recurrence (aOR 2.41 (95% CI 1.01 to 5.74); p=0.048) and severe endoscopic postoperative (aOR=3.84 (95% CI 1.32 to 11.18), p=0.013). AIEC colonisation was associated with a specific microbiota signature including increased abundance of Ruminococcus gnavus. CONCLUSION: Based on the postoperative recurrence model, our data support the idea that AIEC are involved in the early steps of ileal CD. TRIAL REGISTRATION NUMBER: NCT03458195.

Caracterização fenotípica e molecular de isolados de Salmonella spp. e Escherichia coli Patogênica Extraintestinal resistentes às polimixinas / Phenotypic and molecular characterization of Salmonella spp. and extraintestinal pathogenic Escherichia coli resistant to polymyxins

A resistência antimicrobiana está se tornando um grande desafio para saúde pública devido ao aumento da resistência aos beta-lactâmicos em geral. Os isolados de Salmonella spp. e Escherichia coli são os mais frequentes agentes causadores de doenças de transmissão hídrica e alimentar, mas também podem causar doenças invasivas graves, principalmente em imunodeprimidos, idosos e crianças. Ambos os patógenos vêm apresentando perfis de resistência as principais classes de antibióticos, nestes casos é necessária a busca de uma nova opção terapêutica, como por exemplo, as polimixinas. Em 2015, surgiu o primeiro relato da resistência às polimixinas mediado pelo gene mcr (mobile colistin resistance), que se disseminou por diversos continentes e ocasionou uma grande preocupação global em saúde pública. O objetivo deste trabalho foi identificar e caracterizar os mecanismos que medeiam à resistência à polimixinas em cepas de Salmonella spp. e E. coli Patogênica extraintestinal (ExPEC). Foi realizado a triagem pelo teste da gota e teste da CIM frente a colistina e polimixina B no total de 1026 isolados de Salmonella enterica e 159 isolados de ExPEC. Nos isolados resistentes foi verificado a presença de mutações nos genes (pmrA/B, phoP/Q) associados à resistência às polimixinas, e através da PCR foi feita a identificação dos genes de resistência plasmidial (mcr). Das 124 cepas de Salmonella resistentes a colistina e polimixina B, apenas um isolado foi positivo para o gene mcr-1, e este gene foi detectado em um plasmídeo do grupo IncX4. A cepa 2018.466 foi caracterizada como S. Choleraesuis proveniente de sangue de origem humana. Foram identificados 44 isolados de Salmonella spp. apresentando mutações em pmrA e pmrB. Dos 56 isolados de ExPEC resistentes a colistina, 21 isolados apresentaram o gene mcr-1. Este gene foi detectado em plasmídeos do grupo IncX4 (n=17) e em plasmídeos do grupo IncF (n=4). Cinco isolados de E.coli não apresentaram mutações nos genes estudados,sendo que três eram positivos para o gene mcr-1, enquanto as demais cepas apresentaram mutações em pmrA/B e phoP/Q. A tipagem pela PFGE foi realizada nos isolados de E.coli positivos para o gene mcr-1, com o objetivo de verificar a diversidade genética encontrada entre elas. Foram identificados 18 perfis genéticos, sem um clone principal...(AU)

Antimicrobial resistance is becoming a major public health challenge due to increasing resistance to beta-lactams in general. Salmonella spp. and Escherichia coli are the most frequent causative agents of diseases transmitted by water and food, but they can also cause serious invasive diseases, especially in immunosuppressed individuals, the elderly and children. Both pathogens have shown resistance profiles to the main classes of antibiotics, in these cases it is necessary to search for a new therapeutic option, such as polymyxins. In 2015, the first report of resistance to polymyxins mediated by the mcr gene (mobile colistin resistance) appeared, which spread across several continents and caused a major global concern in public health. The objective of this work was to identify and characterize the mechanisms that mediate resistance to polymyxins in strains of Salmonella spp. and extraintestinal pathogenic E. coli (ExPEC). Screening by drop test and MIC test against colistin and polymyxin B was performed on a total of 1026 Salmonella enterica isolates and 159 ExPEC isolates. In the resistant isolates, the presence of mutations in the genes (pmrA/B, phoP/Q) associated with resistance to polymyxins was verified, and through PCR the plasmid resistance genes (mcr) were identified. Of the 124 Salmonella strains resistant to colistin and polymyxin B, only one isolate was positive for the mcr-1 gene, and this gene was detected in a plasmid from the IncX4 group. Strain 2018.466 was characterized as S. Choleraesuis from blood of human origin. Forty-four Salmonella spp. showing mutations in pmrA and pmrB. Of the 56 colistin-resistant ExPEC isolates, 21 isolates harbored the mcr-1 gene. This gene was detected in plasmids from the IncX4 group (n=17) and in plasmids from the IncF group (n=4). Five E.coli isolates did not show mutations in the genes studied, three of which were positive for the mcr-1 gene, while the other strains showed mutations in pmrA/B and phoP/Q. Typing by PFGE was performed on E.coli isolates positive for the mcr-1 gene, with the objective of verifying the genetic diversity found among them. Eighteen genetic profiles were identified, without a main clone...(AU)

Detection and genetic analysis of Escherichia coli from Tonle Sap Lake and its tributaries in Cambodia: Spatial distribution, seasonal variation, pathogenicity, and antimicrobial resistance.

As an indicator of fecal contamination, Escherichia coli was monitored in Tonle Sap Lake, Cambodia, and its tributaries during low- and high-water seasons, focusing on the impacts on floating villagers inhabiting boathouses. E. coli concentrations in the floating villages (3.6 × 103 and 5.7 × 103 CFU/100 mL during the low- and high-water seasons, respectively) were significantly higher than those in other lake sites (4.0 × 101 and 7.0 × 100 CFU/100 mL during the low- and high-water seasons, respectively) and rivers (3.3 × 102 and 8.9 × 102 CFU/100 mL during the low- and high-water seasons, respectively), most likely because fecal materials from the boathouses were discharged without treatment. At most of the lake sampling sites remote from the boathouses, the E. coli concentration was lower during the high-water season than that during the low-water season, due to dilution by lake water. E. coli colonies detected during monitoring were isolated for pathotyping, antimicrobial susceptibility testing, beta-lactamase gene detection, and multilocus sequencing typing (MLST). Of the 659 E. coli isolates, 101 (15.3%) were diarrheagenic E. coli (DEC). The prevalence of DEC (52.2%) in the floating villages during the low-water season was higher than that during the high-water season (4.2%) and that in other sites during both seasons (10.6-21.3%). The DEC isolates from the floating villages during the low-water season showed high antimicrobial resistance, including ampicillin (83.4%) and ciprofloxacin (83.4%), and frequently possessed a beta-lactamase gene (blaTEM) (83.4%). MLST analysis indicated that the predominant sequence type (ST) of DEC isolates from the floating villages possibly originated from humans, whereas more diverse STs were detected in isolates from other sites. We revealed the wide presence of diarrheagenic and antimicrobial-resistant E. coli in Tonle Sap Lake and identified a considerable infection risk in floating villages, especially during the low-water season.

Distribution of papG alleles among uropathogenic Escherichia coli from reproductive age women.

BACKGROUND: Extraintestinal Escherichia coli (E. coli) causing urinary tract infections (UTIs), and often referred to as uropathogenic E. coli (UPEC), are a major contributor to the morbidity of UTIs and associated healthcare costs. UPEC possess several virulence factors (VFs) for infecting and injuring the host. We studied the papG allele distribution, and its association with other VF genes and phylogenetic groups, amongst 836 UPEC and fecal isolates from reproductive age women. RESULTS: The papGII gene was highly prevalent amongst pyelonephritis isolates (68%), whilst the majority, albeit smaller proportion, of cystitis isolates (31%) harboured the papGIII gene. Among the pyelonephritis and cystitis isolates, papG positive isolates on average had higher VF gene scores, and were more likely to belong to phylogenetic group B2, than their negative counterparts. This was mostly due to the contribution of papGII isolates, which on average contained more VF genes than their papGIII counterparts, irrespective of the uro-clinical syndrome. However, the papGII isolates from the pyelonephritis cohort had higher VF gene scores than the cystitis ones, suggesting presence of possible papGII clones with differing inferred virulence potential. Furthermore, papGII isolates were more likely to possess an intact pap gene operon than their papGIII counterparts. Also of note was the high proportion of isolates with the papGI allele which was not associated with other pap operon genes; and this finding has not been described before. CONCLUSIONS: The association of the papGII gene with several VF genes compared to the papGIII gene, appears to explain the abundance of these genes in pyelonephritis and cystitis isolates, respectively.

Phylogeny and antimicrobial resistance of extended-spectrum beta-lactamaseproducing Escherichia coli from hospitalized oncology patients in Perú / Filogenia y resistencia de cepas de Escherichia coli productoras de betalactamasas de espectro extendido a los antibióticos en pacientes con cáncer hospitalizados en Perú.

Introduction: Healthcare-associated infections are a public health problem due to the increased morbimortality of patients, especially those with risk factors such as immunosuppression due to oncological diseases. It is essential to determine the genetic diversity of the main microorganisms causing healthcare infections by combining traditional epidemiological surveillance and molecular epidemiology for better outbreak follow-up and early detection. Objective: To determine the phylogenetic group and antibiotic resistance of Escherichia coli isolated from hospitalized oncologic patients. Materials and methods: We conducted a cross-sectional study of 67 strains of ESBL-producing Escherichia coli to determine their phylogenetic group and described their antibiotic resistance profile, beta-lactam resistance genes, as well as the type of sample and the hospitalization areas from which they were recovered. Results: The most frequent phylogenetic group was B2 (36%); 57% of B2 strains were isolated from urine and 33% came from the urology department. Resistance to ciprofloxacin and gentamicin was 92% and 53%, respectively, and 79% of the strains had the blaCTX-M gene. A significant association (p<0.05) was found between the phylogenetic groups, ciprofloxacin resistance, and the age of the patients. Conclusion: The predominant E. coli phylogroup was B2. We evidenced high resistance to ciprofloxacin and gentamicin, a high proportion of ESBL strains with the blaCTX-M gene, and a significant association between the phylogenetic group and the resistance to ciprofloxacin.

Introducción. Las infecciones asociadas con la atención en salud constituyen un problema de salud pública porque aumentan la morbimortalidad de los pacientes, sobre todo de aquellos con factores de riesgo, como la inmunosupresión debida a enfermedades oncológicas. Es importante conocer la diversidad genética de los principales microorganimos causantes de infecciones hospitalarias mediante la vigilancia epidemiológica tradicional y la epidemiología molecular, para hacer un mejor seguimiento y detectar brotes tempranamente. Objetivo. Determinar el grupo filogenético y la resistencia a antibióticos de las cepas de Escherichia coli aisladas de pacientes con cáncer hospitalizados. Materiales y métodos. Se hizo un estudio de tipo transversal que incluyó 67 cepas de Escherichia coli productoras de betalactamasas de espectro extendido (BLEE). Se determinó el grupo filogenético, el perfil de resistencia a los antibióticos, los genes de resistencia a betalactámicos, el tipo de las muestras y los servicios de hospitalización de donde fueron recuperadas. Resultados. El grupo filogenético más frecuente fue el B2 (36 %). El 57 % de las cepas B2 fueron aisladas de muestras de orina y el 33 % provenía del servicio de urología. La resistencia a ciprofloxacino y gentamicina fue de 91 y 53 %, respectivamente, y el 79 % de las cepas tenía el gen blaCTX-M. Se encontró una relación significativa (p<0,05) entre los grupos filogenéticos y la resistencia a ciprofloxacina, así como a la edad del paciente. Conclusión. El filogrupo de E. coli predominante fue el B2. Se evidenció una gran resistencia a ciprofloxacina y gentamicina, una proporción elevada de cepas BLEE con el blaCTX-M, y una relación entre el grupo filogenético y la resistencia a ciprofloxacino.

Fecal Carriage of Extended-Spectrum beta-Lactamase Producing Escherichia coli among Health Science Students.

BACKGROUND: The incidence of antibiotic resistance in commensal bacteria is increasing with the production of extended-spectrum beta-lactamase. Therefore, this study was conducted to understand the status of fecal carriage of such enzyme producing Escherichia coli among health science students of seven different faculties of Institute of Medicine, Tribhuvan University. METHODS: This was a cross-sectional study conducted over six months among the health science students. One stool sample collected from each student was cultured and Escherichia coli isolates were identified, antibiotic sensitivity profile was produced, and extended-spectrum beta-lactamase production was detected following Clinical and Laboratory Standards Institute guidelines. RESULTS: A total of 156 students participated in the study, and Escherichia coli was isolated from all. Out of the total 156 Escherichia coli isolates, 11.5% were extended-spectrum beta-lactamase-producers and 14.7% were multidrug-resistant. The highest rate of fecal carriage of extended-spectrum beta-lactamase-producing Escherichia coli was found among Bachelor of Medicine and Bachelor of Surgery students (17.5%) and Bachelor of Science in Medical Imaging Technology (16.7%) students. Such enzyme producing Escherichia coli was found in the range of 6.9% to 25.0% among second- to fifth-year students. A significant number of extended-spectrum beta-lactamase-producing isolates were resistant to ciprofloxacin and gentamicin, apart from other extended-spectrum beta-lactamase substrate antibiotics, when compared with non-producers. CONCLUSIONS: A high rate of extended-spectrum beta-lactamase-producing Escherichia coli was detected from the gut of healthy health science students which indicates their possible dissemination throughout the wider community resulting in potential outbreak of infections caused by such organisms.