Prevalence of specific serogroups, antibiotic resistance and virulence factors of avian pathogenic Escherichia coli (APEC) isolated from clinical cases: A systematic review and meta-analysis.

Pathogenic strains of Escherichia coli infecting poultry, commonly called avian pathogenic E. coli (APEC) present significant risks, to the health of both poultry and the general public. This systematic review aimed to examine the prevalence of APEC serotypes, sequence types (ST), phylogenetic groups, virulence factors and antibiotic resistance patterns based on 189 research papers sourced from PubMed, Web of Science, and ProQuest. Then, data were extracted from the selected studies and analyzed to assess the global distribution and characteristics of APEC strains. The metaprop codes in the Meta and Metafor packages of R as implemented in RStudio were then used to conduct meta-analysis. Among APEC strains identified from these different research reports serogroup O78 had the highest overall prevalence (16 %), followed by serogroups O2 (10 %), and O117 (8 %). The most common ST profiles were ST117 (20 %), ST140 (15 %), ST95 (12 %), and ST131 (9 %). ST117 and ST140 are known reservoirs for pathogenic E. coli in humans. Moreover, phylogenetic assessment highlighted the prevalence of phylogroups A, A1, F, D, and B2 among APEC strains indicating diversity in phylogenetic origin within poultry populations. The presence of antimicrobial resistance was notable among APEC strains against antibiotics such as tetracyclines, penicillins, and cephalosporins. This resistance may be linked to use of antimicrobials in poultry production in certain regions presenting challenges for both animal health management and human infection control. Analysis of sequences linked to adherence or virulence indicated that genes encoding adhesins (csg, fimC), iron/metal uptake (sitB, sitC, iroD) and cytotoxicity (estB, hlyF), and serum resistance (traT, iss) were highly prevalent. These factors have been reported to contribute to APEC host colonization and virulence in poultry. In summary, this overview of the characteristics of APEC highlights the pressing importance of monitoring and implementing management approaches to reduce antimicrobial resistance considering that a phylogenetic diversity of E. coli strains causes infections in both poultry and humans and represents a risk to both animal and public health. Further, determining the major conserved aspects and predominant mechanisms of virulence of APEC is critical for improving diagnostics and developing preventative measures to reduce the burden of infection caused by pathogenic E. coli in poultry and lower risks associated with foodborne transmission of E. coli to humans through poultry and poultry products.

Occurrence, antibiotic resistance and molecular characterisation of Shiga toxin-producing Escherichia coli isolated from broiler chickens in Tunisia.

1. Shiga toxin-producing Escherichia coli (STEC) strains are associated with disease outbreaks which cause a public health problem. The aim of this study was to determine the frequency of STEC strains, their virulence factors, phylogenetic groups and antimicrobial resistance profiles in broiler chickens.2. A total of 222 E.coli isolates were collected from the caecum of chickens intended to be slaughtered. Antibiotic susceptibility was tested against 21 antimicrobial agents and ESBL phenotype was assessed by double-disk synergy test. The presence of STEC virulence genes stx1, stx2,eaeA and ehxA was detected by PCR. The identification of STEC serogroups was realised by PCR amplification. Additive virulence genes, phylogenetic groups and integrons were examined among the STEC isolates.3. Out of 222 E.coli isolates, 72 (32%) were identified as STEC strains and the most predominant serogroups were O103, O145 and O157. Shiga toxin gene 1 (stx1) was found in 84.7% (61/72) of the STEC strains, and eae and stx2 were detected in 38.8% and 13.8%, respectively. The ESBL phenotype was documented in 48.6% (35/72) of isolates. Most of the isolates (90.3%) carried class 1 integron with the gene cassette encoding resistance to trimethoprim (dfrA) and streptomycin (aadA) in 31.9% of the isolates. Class 2 integron was identified in 36.1% of isolates.4. Broilers can be considered as a reservoir of STEC strains which have high virulence factors and integrons that might be transmitted to other chickens, environments and humans. It is important to undertake surveillance and efficient control measures in slaughterhouses and farms to control measures of STEC bacteria.

Correlation of biofilm formation, virulence factors, and phylogenetic groups among Escherichia coli strains causing urinary tract infection: A global systematic review and meta-analysis.

Background: Different virulence factors are involved in the pathogenesis of urinary tract infection (UTI) caused by Uropathogenic Escherichia coli (UPEC); hence, this study aimed to study the prevalence of biofilm formation, virulence factors, and phylogenetic groups and their correlation with biofilm formation among UPEC isolates through a systematic review and meta-analysis. Materials and Methods: A literature search was conducted from 1, 2000, to the end of 2021 in different databases for studies that reported biofilm together with virulence genes or phylogenetic groups in UPEC isolates from patients with UTI according to PRISMA protocol. Data were analyzed by Comprehensive meta-analysis software. Results: The pooled prevalence of biofilm formers was 74.7%. The combined prevalence of phylogenetic Groups A, B1, B2, and D (s) were reported at 19.6%, 11%, 50.7%, and 20.5%, respectively. The most common virulence genes reported worldwide were fimA, ecpA, and fimH, with a combined prevalence of 90.3%, 86.6%, and 64.9%, respectively. The pooled prevalence of biofilm formation in UPEC isolates with phylogenetic Groups A, B1, B2, D, C, and F were 12.4%, 8.7%, 33.7%, 12.4%, 2.6%, and 2.65%, respectively. Several studies showed a correlation between biofilm production and virulence genes, or phylogenetic groups. Conclusion: Regarding data obtained, the high level of combined biofilm formation (74.7%) and the presence of a positive correlation between biofilm production and virulence genes, or phylogenetic groups as reported by the most studies included in the present review, indicates an important role of biofilm in the persistence of UPEC in the UTI.

Prevalence of Extended-Spectrum Beta-Lactamase Resistance and CTX-M-Group 1 Gene in Escherichia coli from the Water and Sediment of Urbanized Mangrove Ecosystems of Kerala.

The study aimed to determine the prevalence of extended-spectrum ß-lactamase resistance and CTX-M-group 1 gene in Escherichia coli from the water and sediment of three urbanized mangrove ecosystems of Kerala. A total of 119 E. coli isolates were screened for antibiotic susceptibility to 16 antibiotics. According to the phylogenetic analysis of E. coli isolates, nonpathogenic group A and pathogenic group D (29.4% and 23.5%) were the predominant phylotypes found in water samples. The most frequent phylotypes found in sediment samples were nonpathogenic groups A and B1 (27.9% and 26.4%). The highest incidence of antibiotic resistance in E. coli was against cefotaxime and colistin (100%). A significant difference in the prevalence of CTX-M-group 1 gene was observed among E. coli isolates in water samples (p < 0.05). The results indicate a high prevalence of ß-lactamase harboring E. coli in the mangrove ecosystems that can hamper mangrove-dependent aquaculture practices and human health.

Characterization of uropathogenic Escherichia coli phylogroups associated with antimicrobial resistance, virulence factor distribution, and virulence-related phenotypes.

In this study, we compared the characteristics of different uropathogenic Escherichia coli phylogroups. A total of 844 E. coli isolated from urine were enrolled and the antimicrobial susceptibility of E. coli to 22 antibiotics was determined by disk diffusion test. The distribution of phylogroups and 20 virulence factor genes was determined by PCR. Phenotypes associated with bacterial virulence, including motility, biofilm formation, and the production of curli and siderophore, were examined. Phylogroup B2 was dominant in our isolates (64.8%), followed by phylogroups D (8.6%), B1 (7.8%), F (6.0%), C (4.5%), A (3.1%), untypable (2.8%), E (1.8%), and clade I (0.5%). The prevalence of multidrug-resistant strains was highest in phylogroup C (86.8%), followed by E (80.0%), F (75.0%), and D (71.2%). Moreover, 23.5% of the phylogroup F E. coli were extensively drug-resistant. Phylogroup B2 E. coli had an average of the highest virulence factor genes (10.1 genes/isolate). Compared to phylogroup B2 E. coli, phylogroups F and clade I E. coli had higher motility while phylogroup C E. coli had lower motility. >60% of phylogroups A and C E. coli showed very low curli production. In contrast, 14%, 10%, and 7%, of E. coli in phylogroups F, B2, and E, produced a very high amount of curli, respectively. Surprisingly, phylogroup A E. coli showed the highest virulence to larvae, followed by phylogroups B2 and C. In summary, we first characterized and revealed that the antimicrobial resistance, virulence gene distribution, motility, and curli production, were associated with in E. coli phylogroups.

Predominance of Multidrug Resistant Escherichia coli of Environmental Phylotype in Different Environments of Dhaka, Bangladesh.

Considering the ecological diversity of E. coli, the main aim of this study was to determine the prevalence, phylogroup diversity, and antimicrobial susceptibility of E. coli isolated from 383 different clinical and environmental sources. In total, varied prevalence was observed of the 197 confirmed E. coli that were isolated (human-100%, animal-67.5%, prawn-49.23%, soil-30.58%, and water-27.88%). Of these isolates, 70 (36%) were multidrug-resistant (MDR). MDR E. coli was significantly associated with their sources (χ2 = 29.853, p = 0.001). Humans (51.67%) and animals (51.85%) carried more MDR E. coli than other environments. The eae gene indicative of recent fecal contamination was not detected in any isolate, indicating that these E. coli isolates could be present in these environments for a long time and became naturalized. Phylogroup B1 (48.22%) was the predominant group, being present in all hosts analyzed and with the commensal E. coli group A (26.9%) representing the second predominant group. According to chi-square analysis, phylogroup B1 was significantly associated with E. coli from humans (p = 0.024), soil (p < 0.001) and prawn samples (p < 0.001). Human samples were significantly associated with phylogroup B1 (p = 0.024), D (p < 0.001), and F (p = 0.016) of E. coli strains, whereas phylogroup A (p < 0.001), C (p < 0.001), and E (p = 0.015) were associated with animal samples. Correspondence analysis results also indicated the association of these phylogroups with their hosts/sources. The findings of this study exhibited a non-random distribution of phylogenetic groups, though the diversity index was highest for human E. coli phylogroups.

A Metagenomic Investigation of the Viruses Associated with Shiraz Disease in Australia.

Shiraz disease (SD) is an economically important virus-associated disease that can significantly reduce yield in sensitive grapevine varieties and has so far only been reported in South Africa and Australia. In this study, RT-PCR and metagenomic high-throughput sequencing was used to study the virome of symptomatic and asymptomatic grapevines within vineyards affected by SD and located in South Australia. Results showed that grapevine virus A (GVA) phylogroup II variants were strongly associated with SD symptoms in Shiraz grapevines that also had mixed infections of viruses including combinations of grapevine leafroll-associated virus 3 (GLRaV-3) and grapevine leafroll-associated virus 4 strains 5, 6 and 9 (GLRaV-4/5, GLRaV-4/6, GLRaV-4/9). GVA phylogroup III variants, on the other hand, were present in both symptomatic and asymptomatic grapevines, suggesting no or decreased virulence of these strains. Similarly, only GVA phylogroup I variants were found in heritage Shiraz grapevines affected by mild leafroll disease, along with GLRaV-1, suggesting this phylogroup may not be associated with SD.

Uropathogenic Escherichia coli in Mexico, an Overview of Virulence and Resistance Determinants: Systematic Review and Meta-analysis.

BACKGROUND: Urinary tract infections (UTI) are one of the most common pathologies in Mexico and the majority are caused by uropathogenic Escherichia coli (UPEC). UPEC possesses virulence and resistance determinants that promote UTI development and affect diagnosis and treatment. This study aims to systematically review published reports of virulence genes, antibiotic resistance, and phylogenetic groups prevalent in clinical isolates of UPEC in the Mexican population. METHODS: Systematic review with meta-analysis was performed following PRISMA guidelines. Articles in both English and Spanish were included. Total prevalence with a 95% confidence interval of each characteristic was calculated. Heterogeneity between studies and geographical areas was assessed by the Cochran Q test (Q), I-square (I2), and H-square (H2). Egger's test was used for risk of bias in publications and asymmetry evaluations. RESULTS: Forty-two articles were analyzed. The most prevalent virulence genes were ecp (97.25%; n = 364) and fimH (82.34%; n = 1,422), which are associated with lower UTI, followed by papGII (40.98%; n = 810), fliC (38.87%; n = 319), hlyA (23.55%; n = 1,521), responsible for with upper UTI. More than 78.13% (n = 1,893) of the isolates were classified as multidrug-resistant, with a higher prevalence of resistance to those antibiotics that are implemented in the basic regimen in Mexico. The most frequently reported Extended Spectrum ß-Lactamase (ESBL) was CTX-M-1 (55.61%; n = 392), and the predominant phylogroup was B2 (35.94%; n = 1,725). CONCLUSION: UPEC strains are responsible for a large portion of both lower and upper UTI in Mexico, and their multi-drug resistance drastically reduces the number of therapeutic options available.

Identification of Virulence Markers and Phylogenetic Groups' Association, and Antimicrobial Susceptibility of Uropathogenic Escherichia coli Isolates.

BACKGROUND: Urinary tract infections represent a world public health problem, which is caused mainly by Uropathogenic Escherichia coli. Although they are originally found in the intestinal microbiota in the majority of the cases, urinary tract infections can also be caused by intra-intestinal pathogenic E. coli. OBJECTIVE: The main objective of our research is to identify the virulence factors generally associated with different pathotypes across phylogenetic groups. METHODS: E. coli were isolated from patients with urinary tract infections. Antimicrobial susceptibility tests, virulence genes and phylogroups were prospected. The data analysis were performed using the chi-square and Fisher exact test. RESULTS: In total, 72.2% of isolates showed multidrug resistant. We have also depicted an important association between E. coli from inpatients with UTIs and pap and hlyA genes (p-0.041 and p-0.019 respectively). The predominant phylogenetic group in our isolates is B2 (45.4%) followed by D (12.4%). Our results showed that 9.3% of isolates have an unknown phylogroup which shows a significant association with astA gene (p-0.008). We have as well found a significant association between B2 and three virulence genes namely pap, hlyA and invE (p-0.002, p-0.001, p-0.025 respectively); B1 and pap, hlyA genes (p-0.049 and p-0.021 respectively); E and afa gene (p-0.024). CONCLUSION: Certain virulence factors have been shown to be potential targets for drug design and therapeutic pathways in order to deal with the antimicrobial resistance problem enhanced by antibiotic therapy.

Antimicrobial Resistance and Prevalence of Extended Spectrum ß-Lactamase-Producing Escherichia coli from Dogs and Cats in Northeastern China from 2012 to 2021.

(1) Background: there has been a growing concern about pet-spread bacterial zoonosis in recent years. This study aimed to investigate the trend in drug-resistance of canine Escherichia coli isolates in northeast China between 2012-2021 and the differences in drug-resistance of E. coli of different origins in 2021. (2) Methods: E. coli were isolated from feces or anal swab samples from dogs and cats, and their antibiotic susceptibility profiles and phylogenetic grouping were identified. PCR was applied on the extended spectrum ß-lactamase (ESBL) E. coli for antibiotic resistance genes. (3) Results: five hundred and fifty-four E. coli isolates were detected in 869 samples (63.75%). The multidrug resistance (MDR) rates of E. coli in pet dogs showed a decreasing trend, but working dogs showed the opposite trend. Resistance genes blaCTX-M and blaCTX-M+TEM were dominant among the ESBL producers (n = 219). The consistency between the resistance phenotypes and genes was high except for fluoroquinolone-resistant ESBL E. coli. All ESBL E. coli-carrying blaNDM were isolated from working dogs, and one of the strains carried mcr-1 and blaNDM-4. Phylogroup B2 was the dominant group in pet cats, and more than half of the isolates from companion cats were ESBL E. coli. (4) Conclusions: the measures taken to reduce resistance in China were beginning to bear fruit. Companion cats may be more susceptible to colonization by ESBL E. coli. The problem of resistant bacteria in working dogs and pet cats warrants concern.

Sequence-based genotyping of extra-intestinal pathogenic Escherichia coli isolates from patients with suspected community-onset sepsis, Sweden.

Extra-intestinal pathogenic Escherichia coli (ExPEC) strains are responsible for a large number of human infections globally. The management of infections caused by ExPEC has been complicated by the emergence of antimicrobial resistance, most importantly the increasing recognition of isolates producing extended-spectrum ß-lactamases (ESBL). Herein, we used whole-genome sequencing (WGS) on ExPEC isolates for a comprehensive genotypic characterization. Twenty-one ExPEC isolates, nine with and 12 without ESBL-production, from 16 patients with suspected sepsis were sequenced on an Illumina MiSeq platform. Analysis of WGS data was performed with widely used bioinformatics software and tools for genotypic characterization of the isolates. A higher number of plasmids, virulence and resistance genes were observed in the ESBL-producing isolates than the non-ESBL-producing, although not statistically significant due to the low sample size. All nine ESBL-producing ExPEC isolates presented with at least one bla gene, as did three of the 12 without ESBL-production. Multi-locus sequence typing analysis revealed a diversity of sequence types whereas phylogroup A prevailed among isolates both with and without ESBL-production. In conclusion, this limited study shows that analysis of WGS data can be used for genotypic characterization of ExPEC isolates to obtain in-depth information of clinical relevance.

Phylogenetic groups and antimicrobial resistance characteristics of Escherichia coli strains isolated from clinical samples in North Iran.

BACKGROUND AND STUDY AIM: Extraintestinal pathogenic Escherichia coli (ExPEC) is one of the most common bacterial pathogens, which causes a remarkable amount of morbidity and mortality. This study was designed to determine the antibiotic resistance profiles, phylogenetic groups, and subgroup analyses among the ExPEC strains isolated from hospitalized patients in north Iran. PATIENTS AND METHODS: This cross-sectional investigation was conducted at five educational hospitals in Rasht in north Iran. Using standard microbiological tests, 150 E. coli isolates were identified. The antibiotic susceptibility pattern of all isolates was determined using the disk diffusion method. The double disk phenotypic confirmatory test was performed to detect extended-spectrum ß-lactamase (ESBL)-producing isolates. A triplex polymerase chain reaction (PCR) was performed to determine the phylogenetic group of each strain. RESULTS: The results of antibiogram pattern showed that E. coli isolates were mostly non-susceptible to ampicillin (79.3%), followed by nalidixic acid (75.3%) and cephalothin (70%), whereas nitrofurantoin (94.7%) was the most effective agent, followed by imipenem (92.7%). The rate of ESBL-producing isolates was 53.3% (80/150). Multiplex PCR screening revealed that the most common phylogroup was the B2 group (97 isolates; 64.6%), followed by the D group (34, 22.7%). In contrast, phylogroup analyses showed that B23 (50.7%) and D2 (16.4%) were the most common subgroups. CONCLUSIONS: Our findings indicated a considerable rate of antibiotic resistance and ESBL-producing isolates among E. coli strains isolated from clinical samples. Moreover, we reported a tendency that most isolates belonged to the B2 and D phylogroups. As a result, the detection of genotypic identical or similar isolates indicated that these isolates have an endurance capability in the hospital environment and could be transmitted among patients.

Antimicrobial susceptibility, plasmid replicon typing, phylogenetic grouping, and virulence potential of avian pathogenic and faecal Escherichia coli isolated from meat chickens in Australia.

Globally, avian colibacillosis is a leading cause of morbidity and mortality in poultry, associated with economic losses and welfare problems. Here, clinical avian pathogenic E. coli isolates (CEC; n = 50) and faecal E. coli isolates from healthy (FEC; n = 187) Australian meat chickens collected between 2006 and 2014 were subjected to antimicrobial susceptibility testing, phylogenetic grouping, plasmid replicon (PR) typing, multilocus sequence typing, and virulence gene (VG) profiling. Extended-spectrum cephalosporin (ESC)- and fluoroquinolone (FQ)-resistant E. coli isolates underwent further genetic characterization. Significant proportions of CEC and FEC were, respectively, susceptible (13/50; 48/187) or MDR (9/50; 26/187) to 20 tested antimicrobials. Phylogenetic groups A and C, and PR types IncFIB and IncFrep were most represented. Five tested CEC-associated VGs were more prevalent in CEC (≥ 90%) than FEC (≤ 58%). Some isolates (CEC n = 3; FEC n = 7) were resistant to ESCs and/or FQs and possessed signature mutations in chromosomal FQ target genes and plasmid-mediated qnrS, blaCMY-2, and blaDHA-1 genes. Sequence type 354 (n = 4), associated with extraintestinal infections in a broad range of hosts, was prevalent among ESC- and/or FQ-resistant FEC. This study confirmed existence of a small reservoir of ESC- and FQ-resistant E. coli in Australian commercial meat chickens despite absence of use in the industry of these drugs. Otherwise, diversity of VGs and PR types in both FEC and CEC populations was identified. We hypothesize that the source of ESC- and FQ-resistant E. coli is external to poultry production facilities.RESEARCH HIGHLIGHTSLow-level resistance to older and newer generation antimicrobial drugs detected.The most common sequence type (ST) associated with FQ resistance was ST354 (4/10).A small proportion of CEC (n = 3) and FEC (n = 7) were resistant to ESCs and/or FQs.

Antibiotic resistance, phylogenetic typing, and virulence genes profile analysis of uropathogenic Escherichia coli isolated from patients in southern Iraq.

Of the most common infectious diseases that occur mainly by uropathogenic Escherichia coli (UPEC) is urinary tract infections (UTIs). The purpose of this study was to investigate virulence factors, antibiotic resistance, and phylogenetic groups among UPEC strains isolated from patients with UTI in southern Iraq. A total of 100 UPEC isolates were collected from urine samples of UTI patients from various hospitals in southern Iraq, and confirmed by morphological and biochemical tests. Antimicrobial susceptibility testing on isolates was performed by disk diffusion method. Multiplex PCR techniques were used to evaluate the phylogenetic groups based on Clermont method and to detect the presence of six virulence factor genes. The majority of isolates belonged to the phylogenetic groups B2 (46%) and C (13%). The most prevalent virulence factors were fimH (96%), followed by aer (47%), papC (36%), cnf1 (17%), hly (15%), and afa (8%). Phenotypic testing showed that the isolates were most resistant to piperacillin, ticarcillin, amoxicillin/clavulanic acid (92%, 91%, and 88%, respectively) and most sensitive to amikacin and imipenem, respectively. The maximum antibiotic resistance and virulence factors were observed in the phylogenetic group B2. The results showed that the UPEC isolates had all six virulence factors with high frequency and the highest drug resistance. Besides, the results showed a direct relationship between virulence factors, gene diversity, phylogenetic background, and antimicrobial resistance in the UPEC isolates.

Escherichia coli urinary tract infections: Host age-related differences in bacterial virulence factors and antimicrobial susceptibility.

BACKGROUND: Urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) are one of the most common outpatient bacterial infections. Although bacterial and host factors are reported to be associated with UTI pathogenesis, little is known about the host age-related differences in bacterial virulence factors and antimicrobial susceptibility. METHODS: PCRs were carried out to detect K1 capsule antigen, 15 virulence factors, and phylogenetic groups in E. coli isolates. Antimicrobial susceptibility of selected agents was determined by the disk diffusion method. Isolates were divided into 6 groups based on their host age. RESULTS: The results showed that virulence factors PapGII, PapGIII, Cnf1, Aer, Usp, Iha, OmpT, HlyA, and Sat, had highest frequencies in the host age group 0-3. Phylogenetic group B2 dominated in our isolates (59.6%) followed by group D (20.7%). In addition, 77.4% of strains isolated from 0 to 3 age group belonged to phylogenetic group B2. Antimicrobial susceptibility tests showed that E. coli strains isolated were significantly more resistant to antimicrobial agents as host age increased. Phylogenetic group B2 isolates were more susceptible to antimicrobial agents, compared to A, B1, and D isolates. CONCLUSION: We found E. coli isolated from elders were more resistant to antimicrobial agents and had less virulence factors.

Phylogenetic groups, serogroups and virulence factors of uropathogenic Escherichia coli isolated from patients with urinary tract infection in Baghdad, Iraq.

Background and Objectives: Uropathogenic Escherichia coli (UPEC) is divided into different phylogenetic groups that differ in their antibiotic resistance patterns, serogroups and pathogenicity. This study aimed to investigate the prevalence of phylogenetic groups of UPEC isolates and their relationship with serogroups and virulence factors in patients with UTIs. Materials and Methods: Of the 412 urine samples tested a total of 150 UPEC were isolated and confirmed with PCR using 16S rRNA gene. Antibiotic resistance of the isolates was tested using disk diffusion method and the isolates were divided into phylogenetic groups by the quadruplex PCR method. The prevalence of serogroups and virulence genes were investigated using multiplex PCR. Results: 87 (58%) of the isolates belonged to phylogroup B2. Virulence genes fimH (95.3%), aer (49.3%) and serogroups O8 (22.3%), O25 (21.5%) showed the highest prevalence. The lowest drug resistance was observed against imipenem (4.6%) and meropenem (3.3%). The prevalence of multidrug-resistant and extended-spectrum beta-lactamases isolates were 60% and 61.3%, respectively. We also found a significant relationship between phylogenetic groups, serogroups and virulence factors among our isolates. Conclusion: The high abundance of phylogenetic group B2, serogroups O8 and O25, and virulence genes fimH and aer indicate their importance in the pathogenesis of UPEC in this country.

Genetic diversity and virulence characteristics of biofilm-producing uropathogenic Escherichia coli.

Uropathogenic E. coli (UPEC) strains exhibit different levels of biofilm formation that help adhesion of the bacteria to uroepithelial cells. We investigated the genetic diversity and virulence-associated genes (VAGs) of biofilm-producing UPEC. A collection of 107 biofilm-producing (BFP) UPEC strains isolated from patients with UTI in Iran were divided into three groups of strong, moderate, and weak BFPs after a quantitative microtiter plate assay, and the involvement of curli and cellulose in adhesion of the strains to T24 cell line was confirmed by the construction of csgD and yedQ mutants of two representative UPEC strains. BFP strains were tested for their genetic diversity, phylogenetic groups, and the presence of 15 VAGs. A significant decrease in adhesion of csgD and yedQ mutant strains confirmed the role of biofilm production in adhesion to uroepithelial cells. A high diversity was found among all three groups of strong (Di = 0.998), moderate (Di = 0.998), and weak (Di = 0.988) BFPs with majority of the strains belonging to phylogroups B2 (44.9%) and A (24.3%). Strong BFP strains carried significantly higher level papEF, hlyA, and iutA than other BFP groups. In contrast, the presence of fimH, focG, sfaS, set-1, and cvaC was more pronounced among weak BFP strains. There exists a high genetic diversity among the BFP strains with different VGA profiles. However, the high prevalence of phylogroup A among BFP strains suggests the fitness of commensal E. coli strains to cause UTI in this country.

Antimicrobial Susceptibility and Detection of Virulence-Associated Genes in Escherichia coli Strains Isolated from Commercial Broilers.

The aim of this study was to investigate the presence of iron-uptake and virulence genes, antibiotic resistance profiles, and phylogenetic relatedness in 115 Escherichia coli (E. coli) strains isolated from broilers in Slovakia and to determine their potential threat to human health. The most frequent phylogroups were B1 (37%) and A (21%), and 33.9% strains were included in pathogenic groups. The commonly observed iron-uptake genes were feoB (94%), sitA (83%), and iutA (58%). Protectins (iss, kpsMTII) were identified in 30% of samples. Four percent of B2-associated broilers carried the papC (P fimbria) gene connected with upper urinary tract infection. The dominant resistance was to tetracycline (49%), ampicillin (66%), ampicillin + sulbactam (27%), ciprofloxacin (61%), and trimethoprim + sulfonamide (34%); moreover, sporadically occurring resistance to cephalosporins, aminoglycosides, fluoroquinolones, and polypeptide colistin was observed. Genotypic analysis of resistance revealed the presence of blaCTX-M-1 and blaCTX-M-2 in two isolates from broilers. Commercial broilers can be reservoirs of virulent and resistant genes as well as E. coli causing (extra-)intestinal infections, which can be a potential threat to humans via direct contact and food.

Enteroaggregative Escherichia coli is associated with antibiotic resistance and urinary tract infection symptomatology.

BACKGROUND: Uropathogenic Escherichia coli (UPEC) is the causative agent of uncomplicated urinary tract infections (UTIs) in ambulatory patients. However, enteroaggregative E. coli (EAEC), an emergent bacterial pathogen that causes persistent diarrhoea, has recently been associated with UTIs. The aim of this study was to determine the frequency of EAEC virulence genes, antibiotic resistance, as well as biofilm production of UPEC isolates obtained from ambulatory patients with non-complicated UTIs that attended to the ISSSTE clinic in Chilpancingo, Guerrero, Mexico, and correlate these with the patients' urinary tract infection symptomatology. METHODS: One hundred clinical isolates were obtained. The identification of clinical isolates, antimicrobial susceptibility testing, and extended spectrum beta-lactamases (ESBLs) production were performed using the Vitek automated system. Assignment of E. coli phylogenetic groups was performed using the quadruplex phylo-group assignment PCR assay. UPEC virulence genes (hlyA, fimH, papC, iutA, and cnf1) and EAEC virulence genes (aap, aggR, and aatA) were detected by multiple PCR. RESULTS: We found that 22% of the isolates carried the aggR gene and were classified as UPEC/EAEC. The main phylogenetic group was B2 (44.1% were UPEC and 77.27% UPEC/EAEC isolates, respectively). Over half of the UPEC/EAEC isolates (63.64%) were obtained from symptomatic patients, however the aatA gene was the only one found to be associated with the risk of developing pyelonephritis (OR = 5.15, p = 0.038). A total of 77.71% of the UPEC/EAEC isolates were ESBL producers and 90.91% multidrug-resistant (MDR). In conclusion, UPEC/EAEC isolates are more frequent in symptomatic patients and the aatA gene was associated with a higher risk of developing pyelonephritis, along with UPEC genes hlyA and cfn1. UPEC/EAEC isolates obtained from UTI showed ESBL production and MDR.

Distinct Characteristics of Escherichia coli Isolated from Patients with Urinary Tract Infections in a Medical Center at a Ten-Year Interval.

Escherichia coli causing urinary tract infections (UTIs) are one of the most common outpatient bacterial infections. This study aimed to compare the characteristics of E. coli isolated from UTI patients in a single medical center in 2009-2010 (n = 504) and 2020 (n = 340). The antimicrobial susceptibility of E. coli was determined by the disk diffusion method. PCRs were conducted to detect phylogenetic groups, ST131, K1 capsule antigen, and 15 virulence factors. Phylogenetic group B2 dominated in our 2009-2010 and 2020 isolates. Moreover, no phylogenetic group E strains were isolated in 2020. E. coli isolates in 2020 were more susceptible to amoxicillin, ampicillin/sulbactam, cefuroxime, cefmetazole, ceftazidime, cefoxitin, tetracycline, and sulfamethoxazole/trimethoprim, compared to the isolates in 2009-2010. Extensively drug-resistant (XDR)-E. coli in 2009-2010 were detected in groups B1 (5 isolates), B2 (12 isolates), F (8 isolates), and unknown (1 isolate). In 2020, XDR-E. coli were only detected in groups A (2 isolates), B2 (5 isolates), D (1 isolate), and F (4 isolates). The prevalence of virulence factor genes aer and fimH were higher in E. coli in 2009-2010 compared to those in 2020. In contrast, afa and sat showed higher frequencies in E. coli isolates in 2020 compared to E. coli in 2009-2010.