Molecular Characterization of Uropathogenic Escherichia coli: Nalidixic Acid and Ciprofloxacin Resistance, Virulent Factors and Phylogenetic Background

vB_EcoM-P896 coliphage isolated from duck sewage can lyse both intestinal pathogenic Escherichia coli and extraintestinal pathogenic E. coli

Pathogenic Escherichia coli strains cause diseases in both humans and animals. The limiting factors to prevent as well as control infections from pathogenic E. coli strains are their pathotypes, serotypes, and drug resistance. Herein, a bacteriophage (vB_EcoM-P896) has been isolated from duck sewage. Furthermore, aside from targeting intestinal pathogenic E. coli strains like enteropathogenic E. coli, Shiga toxin-producing E. coli, entero-invasive E. coli, and enteroaggregative E. coli, vB_EcoM-P896 can cause lysis in extraintestinal pathogenic E. coli strains such as avian pathogenic E. coli. Stability analysis revealed that vB_EcoM-P896 was stable under the following conditions: temperature, 4℃-50℃; pH, 3-11. The sequencing of the vB_EcoM-P896 genome was conducted utilizing an HiSeq system (Illumina, San Diego, CA) and subjected to de novo assembling with the aid of Spades 3.11.1. The characteristics of the DNA genome were as follows: size, 170,656 bp; GC content, 40.4%; the number of putative coding regions, 294. Transmission electron microscopy analysis of morphology and genome analysis revealed that the phage vB_EcoM-P896 belonged to the order Caudovirales and the family Myoviridae. The pan-genome analysis of vB_EcoM-P896 was divided into two levels. The first level involved the analysis of 91 strains of muscle tail phages, which were mainly divided into 5 groups. The second level involved the analysis of 24 strains of myophage with high homology. Of the 1480 gene clusters, 23 were shared core genes. Neighbor-joining phylogenetic trees were constructed using the Poisson model with MEGA6.0 based on the conserved sequences of phage proteins, the amino acid sequence of the terminase large subunit, and tail fibrin. Further analysis revealed that vB_EcoM-P896 was a typical T4-like potent phage with potential clinical applications.

Phylogenetic analysis, biofilm formation, antimicrobial resistance and relationship between these characteristics in Uropathogenic Escherichia coli

BACKGROUND

In the present study, we examine the prevalence of phylogenetic groups, O-serogroups, adhesin genes, antimicrobial resistance, the level of gene expression associated with biofilm formation, and the presence of extended-spectrum beta-lactamase (ESBL) in UPEC strains isolated from both pediatric and adult patients.

METHODS

In this cross-sectional study, 156 UPEC isolates were collected from UTI patients. ESBL-producing isolates were detected using the double-disc synergy (DDS) method, and biofilm formation was assessed through a microplate assay. The presence of O-serogroups, adhesion factors and resistance genes, including ESBLs and PMQR genes, was detected by PCR, and isolates were categorized into phylogenetic groups using multiplex PCR. Additionally, the quantitative real-time PCR method was also used to determine the expression level of genes related to biofilm.

RESULTS

During the study period, 50.6% (79/156) of the samples were obtained from children, and 49.4% (77/156) were from adults. The highest rate of resistance was to NA (91.7%), while FM (10.9%) had the lowest rate of antibiotic resistance. In addition, 67.9% (106/156) of UPEC isolates were ESBL producers. Most of UPEC isolates belonged to phylogenetic group B2 (37.1%). This study revealed that blaCTX-M and qnrS are widely distributed among UPEC isolates. The mean expression levels of fimA genes were significantly higher in non-biofilm producers than in biofilm producers (p < 0.01).

CONCLUSIONS

The high antibiotic resistance rates in this study highlight the significance of local resistance monitoring and investigating underlying mechanisms. Our findings indicate the dominance of phylogroup B2 and group D as the prevailing phylogenetic groups. Consequently, it is imperative to investigate the epidemiological aspects and characterize UPEC isolates across diverse regions and time frames.

Occurrence of Imipenem-Resistant Uropathogenic Escherichia coli in Pregnant Women: An Insight into Their Virulence Profile and Clonal Structure

Uropathogenic Escherichia coli (UPEC) is the predominant pathogen in Urinary Tract Infection (UTI) in pregnant and non-pregnant women. Limited studies were initiated to explore UPEC from pregnant women with respect to imipenem resistance, pathogenicity, and their clonal lineage. In this study, imipenem resistance, phylogenetic background, virulence-associated genes, and clonal characteristics in UPECs isolated from pregnant and non-pregnant cohorts were investigated. E. coli was identified biochemically from urine culture-positive samples from pregnant and non-pregnant women. Carbapenem (meropenem, ertapenem, imipenem) susceptibility was determined by Kirby-Bauer disk diffusion test. The pathogenic determinants were identified by PCR. MEGA 11 was used to interpret clonal lineages from MLST. GraphPad Prism 8.0 and SPSS 26.0 were used for statistical interpretation. Results indicated highest resistance against imipenem compared to meropenem and ertapenem in UPECs isolated from pregnant (UPECp; 63.89%) and non-pregnant (UPECnp; 87.88%) women. Although phylogroup E was predominant in both imipenem-resistant isolates, acquisition of virulence factors was higher among UPECnp than UPECp. Akin to this observation, the presence of PAI III536 and PAI IV536 was statistically significant (p < 0.05) in the former. MLST analysis revealed similar clonal lineages between UPECnp and UPECp, which showed an overall occurrence of ST405 followed by ST101, ST410, ST131, and ST1195 in UPECnp and ST167 in UPECp, respectively, with frequent occurrence of CC131, CC405. Therefore, imipenem-resistant UPECp although discrete with respect to their virulence determinants when compared to UPECnp shared similar STs and CCs, which implied common evolutionary history. Thus, empiric treatment must be restricted in UTIs to especially protect maternal and fetal health.

Occurrence of Major Human Extraintestinal Pathogenic Escherichia coli Sequence Types Among Diarrheic Pet Animals: A Potential Public Health Threat

Background: Extraintestinal pathogenic Escherichia coli (ExPEC) has become a mounting public health concern. The present study was conducted to address the role of diarrheic pet animals as potential reservoirs for major human ExPEC sequence types (STs). Materials and Methods: Rectal swabs were collected from 145 diarrheic pet animals (75 dogs and 70 cats). Samples were processed for isolation and identification of E. coli by culture methods. Afterward, ExPEC isolates were identified on a molecular basis through detection of ExPEC phylogroups (B2 and D) coupled with carriage of two or more of the virulence genes associated with ExPEC (papAH, papC, sfa/focDE, afa/draBC, iutA, and kpsMT II). ExPEC STs 131, 73, 69, and 95 were identified among ExPEC isolates by quadruplex PCR and tested for their antimicrobial susceptibility. Eventually, two isolates underwent gene sequencing for the phylogenetic analysis. Results: Of 145 pet animals, 16 (11%) E. coli strains were identified as ExPEC, in which 15 (10.3%) isolates belonged to phylogroup B2 and 1 (0.69%) strain belonged to phylogroup D. The major human ExPEC STs were detected in 13 (9%) isolates, whereas the prevalence rates were 5.3% and 12.9% for dogs and cats, respectively. The isolation rates of ExPEC STs were 4.8%, 2.8%, 0.69%, and 0.69% for ST73, ST131, ST95, and ST69, respectively. Regarding the prevalence of virulence genes among ExPEC STs, the most prevalent ones were papC and sfa/focDE (92.3%), followed by papAH (76.9%), iutA (53.8%), afa/draBC (30.8%), and kpsMT II (30.8%). Moreover, 38.5% of the obtained human ExPEC STs were multidrug resistant. The phylogenetic analysis of two ExPEC ST73 gene sequences showed high genetic relatedness to those isolated from humans in different countries. Conclusions: The fecal carriage of major human ExPEC STs among diarrheic dogs and cats poses a potential zoonotic hazard with serious public health implications.

Genotypic characteristics of Uropathogenic Escherichia coli isolated from complicated urinary tract infection (cUTI) and asymptomatic bacteriuria-a relational analysis

Background

Uropathogenic Escherichia coli (UPEC) is the predominant agent causing various categories of complicated urinary tract infections (cUTI). Although existing data reveals that UPEC harboured numerous virulence determinants to aid its survival in the urinary tract, the reason behind the occurrence of differences in the clinical severity of uninary tract infections (UTI) demonstrated by the UPEC infection is poorly understood. Therefore, the present study aims to determine the distribution of virulence determinants and antimicrobial resistance among different phylogroups of UPEC isolated from various clinical categories of cUTI and asymptomatic bacteriuria (ASB) E. coli isolates. The study will also attempt a relational analysis of the genotypic characteristics of cUTI UPEC and ASB E. coli isolates.

Methods

A total of 141 UPEC isolates from cUTI and 160 ASB E. coli isolates were obtained from Universiti Malaya Medical Centre (UMMC). Phylogrouping and the occurrence of virulence genes were investigated using polymerase chain reaction (PCR). Antimicrobial susceptibility of the isolates to different classes of antibiotics was determined using the Kirby Bauer Disc Diffusion method.

Results

The cUTI isolates were distributed differentially among both Extraintestinal Pathogenic E. coli (ExPEC) and non-ExPEC phylogroups. Phylogroup B2 isolates were observed to possess the highest average aggregative virulence score (7.17), a probable representation of the capability to cause severe disease. Approximately 50% of the cUTI isolates tested in this study were multidrug resistant against common antibiotics used to treat UTI. Analysis of the occurrence of virulence genes among different cUTI categories demonstrated that UPEC isolates of pyelonephritis and urosepsis were highly virulent and had the highest average aggregative virulence scores of 7.80 and 6.89 respectively, compared to other clinical categories. Relational analysis of the occurrence of phylogroups and virulence determinants of UPEC and ASB E. coli isolates showed that 46.1% of UPEC and 34.3% of ASB E. coli from both categories were distributed in phylogroup B2 and had the highest average aggregative virulence score of 7.17 and 5.37, respectively. The data suggest that UPEC isolates which carry virulence genes from all four virulence genes groups studied (adhesions, iron uptake systems, toxins and capsule synthesis) and isolates from phylogroup B2 specifically could predispose to severe UTI involving the upper urinary tract. Therefore, specific analysis of the genotypic characteristics of UPEC could be further explored by incorporating the combination of virulence genes as a prognostic marker for predicting disease severity, in an attempt to propose a more evidence driven treatment decision-making for all UTI patients. This will go a long way in enhancing favourable therapeutic outcomes and reducing the antimicrobial resistance burden among UTI patients.

Phylogenetic Analysis and Antimicrobial Resistance Profiles of Escherichia coli Strains Isolated from UTI-Suspected Patients

Background:

Escherichia coli as one of the most predominant pathogens is the major cause of urinary tract infections (UTI) worldwide. E. coli strains could be classified into distinct phylo-groups based on PCR method. Additionally, studying the antimicrobial resistance profiles of these strains is essential for finding the effective selection of treatment and evaluating the differences among resistance patterns of particular phylogenetic groups. This study aimed to determine the phylogroups of E. coli isolated from patients with UTI in Tehran, Iran.

Methods:

The urine samples were collected from patients suspected to UTI from four hospitals in Tehran, Iran; Mofid, Vali-Asr, Bu-Ali and Tehran Heart Center (THC) Hospitals during 2014–2016. Assessing the antimicrobial resistance profile of the identified strains was accomplished using ampicillin, ceftriaxone, cefotaxime, and ceftazidime among β-lactam group; gentamicin, and streptomycin among aminoglycosides; nalidixic acid and norfloxacin from quinolones; and chloramphenicol disks. The phylogenetic characterization of 60 E. coli isolates obtained from patients with UTI was done by triplex PCR method.

Results:

E. coli strains showed high resistance toward streptomycin (93.33%), ampicillin (86.6%) and nalidixic acid (73.33%) while resistance against chloramphenicol showed the lowest (10%). The prevalent groups were B2 (n=50/60, 83%), followed by D (n=6/60, 10%), B1 (n=3/60, 5%), and A (n=1, 1.6%).

Conclusion:

The most predominant phylogenetic group was B2 with the major frequent detected with the major drug resistant (48%) compared to other Phylogenetic groups.

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae in hospital and community settings in Chad

Background

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) remains poorly documented in Africa. The objective of this study was to determine the prevalence of ESBL-PE fecal carriage in Chad.

Methods

In total, 200 fresh stool samples were collected from 100 healthy community volunteers and 100 hospitalized patients from January to March 2017. After screening using ESBL-selective agar plates and species identification by MALDI-TOF mass spectrometry, antibiotic susceptibility was tested using the disk diffusion method, and ESBL production confirmed with the double-disc synergy test. The different ESBL genes in potential ESBL-producing isolates were detected by PCR and double stranded DNA sequencing. Escherichia coli phylogenetic groups were determined using a PCR-based method.

Results

ESBL-PE fecal carriage prevalence was 44.5% (51% among hospitalized patients vs 38% among healthy volunteers; p < 0.05). ESBL-producing isolates were mostly Escherichia coli (64/89) and Klebsiella pneumoniae (16/89). PCR and sequencing showed that 98.8% (87/89) of ESBL-PE harbored bla_CTX-M genes: bla_CTX-M-15 in 94.25% (82/87) and bla_CTX-M-₁₄ in 5.75% (5/87). Phylogroup determination by quadruplex PCR indicated that ESBL-producing E. coli isolates belonged to group A (n = 17; 27%), C (n = 17; 27%), B2 (n = 9; 14%), B1 (n = 8; 13%), D (n = 8; 13%), E (n = 1; 1.6%), and F (n = 1; 1.6%). The ST131 clone was identified in 100% (9/9) of E. coli B2 strains.

Conclusions

The high fecal carriage rate of ESBL-PE associated with CTX-M-15 in hospital and community settings of Chad highlights the risk for resistance transmission between non-pathogenic and pathogenic bacteria.

Phylogenetic groups and antimicrobial susceptibility patterns of uropathogenic Escherichia coli clinical isolates from patients at Mulago National Referral Hospital, Kampala, Uganda

Introduction: Uropathogenic Escherichia coli (UPEC) remains the most common cause of urinary tract infections (UTIs). They account for over 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. E. coli strains have been found to belong to evolutionary origins known as phylogenetic groups. In 2013, Clermont classified E. coli strains into eight phylogenetic groups using the quadruplex PCR method. The aim of this study was to identify the phylogenetic groups of UPEC strains in Uganda using Clermont’s quadruplex PCR method and to assess their antibiotic susceptibility patterns in Uganda. Methods: In this cross-sectional study, 140 stored uropathogenic E. coli isolates from the Clinical Microbiology Laboratory, Department of Medical Microbiology, College of Health Sciences Makerere University were subjected to phylogenetic typing by a quadruplex PCR method. Antimicrobial susceptibility testing was performed by disk diffusion method according to Clinical & Laboratory Standards Institute (CLSI) guidelines. Phenotypic detection of extended-spectrum beta-lactamase, AmpC and carbapenemases was done according to CLSI guidelines and Laboratory SOPs. Results: Phylogenetic group B2 (40%) was the most predominant, followed by A (6.23%), clade I and II (5%), D and E (each 2.14%), B1 (1.43%) and F and C (each 0.71%). The most common resistant antibiotic was trimethoprim-sulphamethoxazole (90.71%) and the least was imipenem (1.43%). In total, 73.57% of isolates were multi-drug resistant (MDR). Antibiotic resistance was mainly detected in phylogenetic group B2 (54%). Conclusions: Our findings showed the high prevalence of MDR E. coli isolates, with the dominance of phylogenetic group B2. About 9% of E. coli isolates belonged to the newly described phylogroups C, E, F, and clade I and II.

Multiple antibiotic resistances and virulence markers of uropathogenic Escherichia coli from Mexico

Virulence and antibiotic resistance properties related to different Escherichia coli phylogenetic groups have not been studied in detail in Mexico. We aimed to identify patterns of virulence genes and multidrug resistance in phylogenetic groups of uropathogenic strains (UPEC). Strains of E. coli were isolated from outpatients with urinary tract infections (UTIs), who went to unit of the public health sector in the State of Mexico. E. coli virulence markers and phylogenetic groups were identified by PCR. Susceptibility to 12 antimicrobials was determined by Kirby-Bauer. E. coli was identified in 60.4% (n = 194) of the patients with UTIs. Phylogroups B2 51% (n = 99), A 13.4% (n = 26) and B1 10.3% (n = 20) were the most frequent. Resistance to three or up to eleven antibiotics was detected in most phylogroups (n = 188). The genes fimH (n = 146), feoB (n = 179), iutA (n = 178), sitA (n = 121), fyuA (n = 99), and traT (n = 142) were mainly detected in strains of phylogroups B2, A, B1, C, and D. Seventy-two patterns of virulence markers were distributed across eight E. coli phylogenetic groups. A high frequency of virulence markers and the multiple antibiotic resistance phenotypes was observed in the phylogroups. The genes of extended-spectrum β-lactamases (ESBLs) found with higher frequency among UPEC strains were bla_TEM, bla_SHV y bla_CTX-M group 1, CIT (plasmid-mediated AmpC β-lactamase), and bla_OXA-like. In conclusion, our findings show the importance of surveillance, permanent monitoring, and particularly controlled prescription of antibiotics by physicians in the social security health system to reduce the spread of highly virulent UPEC strains that are resistant to multiple antimicrobial agents.

Distribution of pathogenicity island markers and virulence factors in new phylogenetic groups of uropathogenic Escherichia coli isolates

The present study was aimed at investigating the relationship between the new Clermont's phylogenetic groups, virulence factors, and pathogenicity island markers (PAIs) among uropathogenic Escherichia coli (UPEC) in Iran. This cross-sectional study was carried out on 140 UPEC isolates collected from patients with urinary tract infections in Bushehr, Iran. All isolates were subjected to phylogenetic typing using a new quadruplex-PCR method. The presence of PAI markers and virulence factors in UPEC strains was evaluated by multiplex PCR. The most predominant virulence gene was fimH (85%), followed by iucC (61.4%), papC (38.6%), hlyA (22.1%), cnf-1 (18.6%), afa (10.7%), papG and neuC (each 9.3%), ibeA (3.6%), and sfa/foc (0.7%). The most common phylogenetic group was related to B2 (39.3%), and the least common to A (0.7%). The most prevalent PAI marker was PAI IV536 (77.14%), while markers for PAI III536 (13.57%), PAI IIJ96 (12.86%), and PAI II536 (12.14%) were the least frequent among the UPEC strains. Meanwhile, the PAI IJ96 marker was not detected. There was a significant association between the phylogenetic group B2 and all the studied virulence genes and PAI markers. To our knowledge, this is the first study to compare the relationship between new phylogenetic groups, virulence genes and PAI markers in UPEC strains in Iran. The phylogenetic group B2 was predominantly represented among the studied virulence genes and PAI markers, indicating the preference of particular strains to carry virulence genes.

Network Analysis Reveals Sex- and Antibiotic Resistance-Associated Antivirulence Targets in Clinical Uropathogens

Increasing antibiotic resistance among uropathogenic Escherichia coli (UPEC) is driving interest in therapeutic targeting of nonconserved virulence factor (VF) genes. The ability to formulate efficacious combinations of antivirulence agents requires an improved understanding of how UPEC deploy these genes. To identify clinically relevant VF combinations, we applied contemporary network analysis and biclustering algorithms to VF profiles from a large, previously characterized inpatient clinical cohort. These mathematical approaches identified four stereotypical VF combinations with distinctive relationships to antibiotic resistance and patient sex that are independent of traditional phylogenetic grouping. Targeting resistance- or sex-associated VFs based upon these contemporary mathematical approaches may facilitate individualized anti-infective therapies and identify synergistic VF combinations in bacterial pathogens.

Phylogenetic groups of Escherichia coli strains from patients with urinary tract infection in Iran based on the new Clermont phylotyping method

OBJECTIVES

In 2013, Clermont classified E. coli strains into eight phylogenetic groups using a new quadruplex PCR method. The aims of this study were to identify the phylogenetic groups of E. coli based on this method and to assess their antibiotic resistance patterns in Bushehr, Iran.

METHODS

In this cross-sectional study, 140 E. coli isolates were subjected to phylogenetic typing by a quadruplex PCR method. Antimicrobial susceptibility testing was performed by disk diffusion method.

RESULTS

Phylogenetic group B2 was most predominant (39.3%), followed by unknown (27.1%), E (9.3%), C and clade I (each 6.4%), B1 (5%), F and D (each 2.9%), and A (0.7%). The most common antibiotic resistance was related to amoxicillin (82.1%) and the least to meropenem (0.7%). 82.14% of isolates were multiple drug resistant (MDR). Antibiotic resistance was mainly detected in group B2 (50%).

CONCLUSIONS

Our findings showed the high prevalence of MDR E. coli isolates with dominance of group B2. About 25% of E. coli isolates belong to the newly described phylogroups C, E, F, and clade I. Such studies need to be done also in other regions to provide greater understanding of the antibiotic resistance pattern and the prevalences of different phylogenetic groups.