Characterization of Escherichia coli isolates from hospital inpatients or outpatients with urinary tract infection

Emergence of Carbapenem-Resistant Uropathogenic Escherichia coli (ST405 and ST167) Strains Carrying blaCTX-M-15, blaNDM-5 and Diverse Virulence Factors in Hospitalized Patients

BACKGROUND

Urinary tract infections (UTIs) are common infectious diseases in hospital settings, and they are frequently caused by uropathogenic Escherichia coli (UPEC). The emergence of carbapenem-resistant (Carb-R) E. coli strains poses a significant threat due to their multidrug resistance and virulence. This study aims to characterize the antimicrobial resistance and virulence profiles of Carb-R UPEC strains isolated from hospitalized patients.

METHODS

A total of 1100 urine samples were collected from patients in Lahore and Faisalabad, Pakistan, between May 2023 and April 2024. The samples were processed to isolate and identify E. coli using standard microbiological techniques and VITEK®2, followed by amplification of the uidA gene. Antimicrobial susceptibility was evaluated using the Kirby-Bauer disc diffusion method and broth microdilution. Resistance and virulence genes were detected through PCR and DNA sequencing, and sequence typing was performed using MLST.

RESULTS

Among the 118 Carb-R UPEC isolates, resistance was most frequently observed against sulfamethoxazole-trimethoprim (96.6%) and doxycycline (96.6%). All of the isolates remained sensitive to colistin and tigecycline. Sequence types ST405 (35.6%) and ST167 (21.2%) were predominant and carried the blaCTX-M-15 and blaNDM-5 genes. The distribution of virulence genes and a variety of antimicrobial resistance genes (ARGs), conferring resistance to aminoglycosides, fluoroquinolones, tetracyclines, and sulfonamides, were observed as specifically linked to certain sequence types.

CONCLUSIONS

This study provides insights into the molecular epidemiology of carbapenem-resistant Uropathogenic E. coli (Carb-R UPEC) strains and highlights the presence of globally high-risk E. coli clones exhibiting extensive drug resistance phenotypes in Pakistani hospitals. The findings underscore the urgent need for enhanced surveillance and stringent antibiotic stewardship to manage the spread of these highly resistant and virulent strains within hospital settings.

Virulence genes and antibiotic susceptibility patterns of Escherichia coli isolated from nosocomial urinary tract infections in the northwest of Iran during 2022-2023: A cross-sectional study

Background and Aims

Urinary tract infections (UTIs) are prevalent among hospitalized patients, constituting the most frequent health-care infections. Uropathogenic Escherichia coli (UPEC) is leading causative agent of UTIs. The present study was aimed to examine the susceptibility of UPEC isolates obtained from nosocomial cases to antibiotics, as well as their biofilm formation capability and frequency of virulence genes.

Methods

A total of 100 UPEC isolates were collected from nosocomial UTIs at Imam Reza Hospitals in Tabriz, Iran, spanning from April 2022 to January 2023. The antimicrobial susceptibility patterns were evaluated using the disk diffusion method, along with the detection of broad-spectrum β-lactam enzymes (ESBLs) and carbapenemases. The ability of isolates to form biofilms was assessed using the microtiter-plate method, while the PCR method was employed to identify the presence of virulence genes.

Results

The highest resistance was observed toward piperacillin (82%), followed by aztreonam and ciprofloxacin (81%), while the lowest resistance was found against piperacillin/tazobactam (12%) and meropenem (9%). ESBLs were detected in 62% of the isolates. The microtiter-plate results revealed strong, moderate, and weak biofilm formation abilities in 32%, 33%, and 24% of the isolates, respectively. The most prevalent virulence gene was fimA (74%) followed by hlyF (68%), papA (44%), papC (32%), iroN (26%), and cnf (20%).

Conclusion

The elevated levels of resistance to multiple antimicrobial agents, coupled with the co-presence of virulence genes and biofilm formation abilities, contribute to the persistence of UPEC-related infections, particularly in hospitalized patients. These findings underscore the necessity of implementing an effective program to control nosocomial UTIs caused by UPEC in the healthcare centers.

Investigating trends in antibiotic resistance of Escherichia coli isolated from clinical urine specimens in the Orkney Islands

Urinary tract infections (UTIs) are extremely common, affecting people of all ages and health statuses. Although UTIs do not usually cause severe illness, in some cases they can lead to more serious complications, especially if their initial treatment is ineffective due to antimicrobial resistance (AMR). AMR is an increasing issue, exacerbated by misdiagnosis and inappropriate prescribing of antibiotics, thus facilitating further resistance. The aim of this study was to investigate the rates of AMR in Escherichia coli isolated from clinical urine specimens tested at the Balfour Hospital, Orkney, and determine trends related to patient risk factors. Antibiotic susceptibilities were tested for 100 isolates of uropathogenic E. coli using the VITEK 2 Compact (bioMérieux), and data were analysed using percentage resistance rates. Resistance rates were compared by patient sex, age and source (hospital versus community). The findings showed higher AMR in males compared with females, particularly for trimethoprim (TMP), with 52% in males and only 12% in females. AMR tended to be higher in E. coli isolated from hospital inpatients than from community specimens, except for amoxicillin (AMX) and co-amoxiclav. Finally, the study found that AMR of E. coli isolates was greater in patients aged over 50 than 18-50 years old, particularly for AMX and TMP. The highest resistance rates across all patient demographics were for AMX, implying that the use of this antibiotic for the treatment of E. coli UTIs is not appropriate.

Detection of pathogenic, heteropathogenic and hybrid Escherichia coli strains in psittacines from zoos and breeders in the state of Ceará, Brazil

The current study aimed to detect virulence, hetero-pathogenicity, and hybridization genes in Escherichia coli strains, previously isolated from cloacal swabs in commercial breeding psittacines and zoological collections, via multiplex PCR. A total of 68 strains of E. coli, previously isolated from psittacines in zoos and commercial breeding facilities in Ceará, Brazil, were assessed for the presence of the following genes and/or probes: eae, bfpA (EPEC - Enteropathogenic E. coli), CVD432 (EAEC - Enteroaggregative E. coli); LT gene and ST gene (ETEC - Enterotoxigenic E. coli); ipaH (EIEC - Enteroinvasive E. coli); stx1 and stx2 (STEC - Shiga toxin-producing E. coli); iroN, ompT, hlyF, iss, and iutA (APEC - Avian pathogenic E. coli). Of the 68 E. coli strains analyzed, 61 (98.7 %) were positive for the following genes and/or probes: Stx1 (61/98.7 %), ST gene (54/79.4 %), CVD432 (49/72 %), bfpA (44/64.7 %), eae (42/61.8 %), Stx2 (41/60.3 %), ipaH (34/50 %), LT gene (33/48.5 %), iroN (21/30.9 %), hlyF (11/6.2 %), iss (06/8.8 %) and iutA (06/8.8 %). The following diarrheagenic pathotypes were identified: 66 (97 %) from STEC, 49 (72 %) from EAEC, 35 (52 %) from EIEC, 25 (37 %) from ETEC, and one (1.5 %) from EPEC. Regarding hetero-pathogenicity, 50 (74 %) heterogeneous strains were identified. Positivity for APEC was seen in four (6 %) strains, all characterized as pathogenic hybrids. This study describes significant associations of virulence factors in E. coli strains DEC/DEC and DEC/APEC, which were isolated from psittacines and may be potentially harmful to One Health.

Genomic Dissection of an Enteroaggregative Escherichia coli Strain Isolated from Bacteremia Reveals Insights into Its Hybrid Pathogenic Potential

Escherichia coli is a frequent pathogen isolated from bloodstream infections. This study aimed to characterize the genetic features of EC092, an E. coli strain isolated from bacteremia that harbors enteroaggregative E. coli (EAEC) genetic markers, indicating its hybrid pathogenic potential. Whole-genome sequencing showed that EC092 belongs to phylogroup B1, ST278, and serotype O165:H4. Genes encoding virulence factors such as fimbriae, toxins, iron-uptake systems, autotransporter proteins (Pet, Pic, Sat, and SepA), and secretion systems were detected, as well as EAEC virulence genes (aggR, aatA, aaiC, and aap). EC092 was found to be closely related to the other EAEC prototype strains and highly similar in terms of virulence to three EAEC strains isolated from diarrhea. The genomic neighborhood of pet, pic, sat, sepA, and the EAEC virulence genes of EC092 and its three genetically related fecal EAEC strains showed an identical genomic organization and nucleotide sequences. Also, EC092 produced and secreted Pet, Pic, Sat, and SepA in the culture supernatant and resisted the bactericidal activity of normal human serum. Our results demonstrate that the strain EC092, isolated from bacteremia, is a hybrid pathogenic extraintestinal E. coli (ExPEC)/EAEC with virulence features that could mediate both extraintestinal and intestinal infections.

Molecular typing and virulence characteristics of Escherichia coli strains isolated from hospital and community acquired urinary tract infections

BACKGROUND

The main causes of hospital- and community-acquired urinary tract infections (UTIs) are a group of Escherichia coli (E. coli) strains with multiple virulence factors known as uropathogenic E. coli.

METHODS AND RESULTS

One hundred E. coli isolates from the urine specimens of hospital- and community-acquired UTI patients were characterized based on their virulence factors and genetic relatedness using PCR and RAPD‒PCR, respectively. Among all, the traT (71%), sitA (64%), ompT (54%), malX (49%), ibeA (44%), tsh (39%), hlyD (18%) and cnf1 (12%) genes had the highest to lowest frequencies, respectively. There was no significant difference between the frequency of tested virulence genes in E. coli isolates from inpatients and outpatients. The frequency of the hlyD gene was significantly greater in E. coli isolates from patients hospitalized in gynecology, dermatology and intensive care unit (ICU) wards than in those from other wards. Eight virulence gene patterns were common among the isolates of inpatients in different wards of the same hospital, of which five patterns belonged to the isolates of inpatients in the same ward. More E. coli isolates with similar virulence gene patterns and greater genetic similarity were found in female patients than in male patients. The analysis of the RAPD‒PCR dendrograms revealed more genetic similarities among the E. coli isolates from inpatients than among those from outpatients.

CONCLUSION

Our findings indicate the presence of a wide variety of virulence factors in E. coli isolates and the possibility of spreading the same clones in different wards of the hospital.

Detection and characterization of potentially hybrid enteroaggregative Escherichia coli (EAEC) strains isolated from urinary tract infection

Uropathogenic Escherichia coli (UPEC) have the potential to receive the virulence markers of intestinal pathotypes and transform into various important hybrid pathotypes. This study aimed to investigate the frequency and characteristics of hybrid enteroaggregative E. coli (EAEC)/UPEC strains. Out of 202 UPEC strains, nine (4.5%) were detected as hybrid EAEC/UPEC. These strains carried one to four iron uptake systems. Among nine investigated pathogenicity islands (PAIs), PAI IV536, PAI II536, and PAI ICFT073 were found in 9 (100%), 3 (33.3%), and 1 (11.1%) strains, respectively. The chuA and sitA genes were detected in 5 (55.5%) and 3 (33.3%) hybrid strains, respectively. Six hybrid strains were found to be typical extraintestinal pathogenic E. coli (ExPEC) according to their virulence traits. Most of the hybrid strains belonged to the phylogenetic group E (6/9). Among the hybrid strains, seven (7/9) were able to form biofilm and adhere to cells; however, only two strains penetrated into the HeLa cells. Our findings reveal some of the virulence characteristics of hybrid strains that lead to fitness and infection in the urinary tract. These strains, with virulence factors of intestinal and non-intestinal pathotypes, may become emerging pathogens in clinical settings; therefore, further studies are needed to reveal their pathogenicity mechanisms and so that preventive measures can be taken.

Multidrug resistance in pathogenic Escherichia coli isolates from urinary tract infections in dogs, Spain

Escherichia coli (E. coli) is a pathogen frequently isolated in cases of urinary tract infections (UTIs) in both humans and dogs and evidence exists that dogs are reservoirs for human infections. In addition, E. coli is associated to increasing antimicrobial resistance rates. This study focuses on the analysis of antimicrobial resistance and the presence of selected virulence genes in E. coli isolates from a Spanish dog population suffering from UTI. This collection of isolates showed an extremely high level of phenotypic resistance to 1st-3rd generation cephalosporins, followed by penicillins, fluoroquinolones and amphenicols. Apart from that, 13.46% of them were considered extended-spectrum beta-lactamase producers. An alarmingly high percentage (71.15%) of multidrug resistant isolates were also detected. There was a good correlation between the antimicrobial resistance genes found and the phenotypic resistance expressed. Most of the isolates were classified as extraintestinal pathogenic E. coli, and two others harbored virulence factors related to diarrheagenic pathotypes. A significant relationship between low antibiotic resistance and high virulence factor carriage was found, but the mechanisms behind it are still poorly understood. The detection of high antimicrobial resistance rates to first-choice treatments highlights the need of constant antimicrobial resistance surveillance, as well as continuous revision of therapeutic guidelines for canine UTI to adapt them to changes in antimicrobial resistance patterns.

Detection of phylogrouping, adhesin, and extended spectrum β-lactamases genes in hospital acquired uropathogenic Escherichia coli isolates

BACKGROUND

It has been interesting to compare the levels of antimicrobial resistance and the virulence characteristics of uropathogenic Escherichia coli (UPEC) strains of certain phylogenetic groups. The purpose of this study was to identify the frequency of phylogenetic groups, adhesin genes, antibiotic sensitivity patterns, and extended spectrum-lactamases (ESBLs) genes in hospital-acquired UPEC.

METHODS

After UPEC isolation, the disc diffusion method was used to assess its susceptibility to antibiotics. Combination disc testing confirmed the existence of ESBL producers. Polymerase chain reaction (PCR) was used to detect genes for adhesin and ESBLs.

RESULTS

One hundred and twenty-eight E. coli were isolated which had the highest resistance to tetracycline (96%) followed by cefoxitin (93%), cefepime (92%), ceftazidime (79%), aztreonam (77%) and sulfamethoxazole -trimethoprim (75%). About 57% of isolates were phenotypically ESBLs positive and they were confirmed by PCR. B2 phylogroup (41%) was the most frequent in E. coli isolates then group D (30%), group A (18%), and lastly group B1 (11%). ESBLs genes were more significantly prevalent in phylogroups B2 and D than other phylogroups (P < 0.001). Regarding adhesin genes, both fim H and afa were more significantly associated with group B2 than other groups (P < 0.009, < 0.032), respectively. In ESBL-positive isolates, both genes were more significantly detected compared to negative ones (P < 0.001).

CONCLUSION

Phylogroups B2 and D of UPEC are important reservoirs of antimicrobial resistance and adhesion genes. Detection of ESBL-producing E. coli is important for appropriate treatment as well as for effective infection control in hospitals.

Genotypic Characterization of Uropathogenic Escherichia coli from Companion Animals: Predominance of ST372 in Dogs and Human-Related ST73 in Cats

Extraintestinal pathogenic Escherichia coli (ExPEC) account for over 80% and 60% of bacterial urinary tract infections (UTIs) in humans and animals, respectively. As shared uropathogenic E. coli (UPEC) strains have been previously reported among humans and pets, our study aimed to characterize E. coli lineages among UTI isolates from dogs and cats and to assess their overlaps with human UPEC lineages. We analysed 315 non-duplicate E. coli isolates from the UT of dogs (198) and cats (117) collected in central Germany in 2019 and 2020 utilizing whole genome sequencing and in silico methods. Phylogroup B2 (77.8%), dog-associated sequence type (ST) 372 (18.1%), and human-associated ST73 (16.6%), were predominant. Other STs included ST12 (8.6%), ST141 (5.1%), ST127 (4.8%), and ST131 (3.5%). Among these, 58.4% were assigned to the ExPEC group and 51.1% to the UPEC group based on their virulence associated gene (VAG) profile (ExPEC, presence of ≥VAGs: papAH and/or papC, sfa/focG, afaD/draBC, kpsMTII, and iutA; UPEC, additionally cnf1 or hlyD). Extended-spectrum cephalosporin (ESC) resistance mediated by extended-spectrum β-lactamases (ESBL) and AmpC-β-lactamase was identified in 1.9% of the isolates, along with one carbapenemase-producing isolate and one isolate carrying a mcr gene. Low occurrence of ESC-resistant or multidrug-resistant (MDR) isolates (2.9%) in the two most frequently detected STs implies that E. coli isolated from UTIs of companion animals are to a lesser extent associated with resistance, but possess virulence-associated genes enabling efficient UT colonization and carriage. Detection of human-related pandemic lineages suggests interspecies transmission and underscores the importance of monitoring companion animals.

Biofilm Formation by Escherichia coli Isolated from Urinary Tract Infections from Aguascalientes, Mexico

Uropathogenic Escherichia coli (UPEC) strains are among the leading causes of urinary tract infections (UTIs) worldwide. They can colonize the urinary tract and form biofilms that allow bacteria to survive and persist, causing relapses of infections and life-threatening sequelae. Here, we analyzed biofilm production, antimicrobial susceptibility, virulence factors, and phylogenetic groups in 74 E. coli isolated from diagnosed patients with UTIs to describe their microbiological features and ascertain their relationship with biofilm capabilities. High levels of ceftazidime resistance are present in hospital-acquired UTIs. Isolates of multidrug resistance strains (p = 0.0017) and the yfcV gene (p = 0.0193) were higher in male patients. All the strains tested were able to form biofilms. Significant differences were found among higher optical densities (ODs) and antibiotic resistance to cefazolin (p = 0.0395), ceftazidime (p = 0.0302), and cefepime (p = 0.0420). Overall, the presence of fimH and papC coincided with strong biofilm formation by UPEC. Type 1 fimbriae (p = 0.0349), curli (p = 0.0477), and cellulose (p = 0.0253) production was significantly higher among strong biofilm formation. Our results indicated that high antibiotic resistance may be related to male infections as well as strong and moderate biofilm production. The ability of E. coli strains to produce biofilm is important for controlling urinary tract infections.

Phylogenomic analysis of a global collection of Escherichia coli ST38: evidence of interspecies and environmental transmission?

IMPORTANCE

Extraintestinal pathogenic Escherichia coli (ExPEC) sequence type (ST) 38 is one of the top 10 human pandemic lineages. Although a major cause of urinary tract and blood stream infections, ST38 has been poorly characterized from a global phylogenomic perspective. A comprehensive genome-scale analysis of 925 ST38 isolate genomes identified two broad ancestral clades and linkage of discrete ST38 clusters with specific bla CTX-M variants. In addition, the clades and clusters carry important virulence genes, with diverse but poorly characterized plasmids. Numerous putative interhost and environment transmission events were identified here by the presence of ST38 clones (defined as isolates with ≤35 SNPs) within humans, companion animals, food sources, urban birds, wildlife, and the environment. A small cluster of international ST38 clones from diverse sources, likely representing progenitors of a hospital outbreak that occurred in Brisbane, Australia, in 2017, was also identified. Our study emphasizes the importance of characterizing isolate genomes derived from nonhuman sources and geographical locations, without any selection bias.

Genetic characterization of ESBL-producing and ciprofloxacin-resistant Escherichia coli from Belgian broilers and pigs

Background

The increasing number of infections caused by Escherichia coli resistant to clinically important antibiotics is a global concern for human and animal health. High overall levels of extended-spectrum beta-lactamase (ESBL)-producing and ciprofloxacin-resistant (ciproR) Escherichia coli in livestock are reported in Belgium. This cross-sectional study aimed to genotypically characterize and trace ESBL-and ciproR-E. coli of Belgian food-producing animals.

Methods

A total of 798 fecal samples were collected in a stratified-random sampling design from Belgian broilers and sows. Consequently, 77 ESBL-E. coli and 84 ciproR-E. coli were sequenced using Illumina MiSeq. Minimum inhibitory concentration (MIC) for fluoroquinolones and cephalosporins were determined. Molecular in silico typing, resistance and virulence gene determination, and plasmid identification was performed. Scaffolds harboring ESBL or plasmid-mediated quinolone resistance (PMQR) genes were analyzed to detect mobile genetic elements (MGEs) and plasmid origins. Core genome allelic distances were used to determine genetic relationships among isolates.

Results

A variety of E. coli sequence types (ST) (n = 63), resistance genes and virulence profiles was detected. ST10 was the most frequently encountered ST (8.1%, n = 13). The pandemic multidrug-resistant clone ST131 was not detected. Most farms harbored more than one ESBL type, with blaCTX-M-1 (41.6% of ESBL-E. coli) being the most prevalent and blaCTX M-15 (n = 3) being the least prevalent. PMQR genes (15.5%, n = 13) played a limited role in the occurrence of ciproR-E. coli. More importantly, sequential acquisition of mutations in quinolone resistance-determining regions (QRDR) of gyrA and parC led to increasing MICs for fluoroquinolones. GyrA S83L, D87N and ParC S80I mutations were strongly associated with high-level fluoroquinolone resistance. Genetically related isolates identified within the farms or among different farms highlight transmission of resistant E. coli or the presence of a common reservoir. IncI1-I(alpha) replicon type plasmids carried different ESBL genes (blaCTX-M-1, blaCTX-M-32 and blaTEM-52C). In addition, the detection of plasmid replicons with associated insertion sequence (IS) elements and ESBL/PMQR genes in different farms and among several STs (e.g., IncI1-I(alpha)/IncX3) underline that plasmid transmission could be another important contributor to transmission of resistance in these farms.

Conclusion

Our findings reveal a multifaceted narrative of transmission pathways. These findings could be relevant in understanding and battling the problem of antibiotic resistance in farms.

Bioassay-Guided Isolation of Antimicrobial Components and LC/QToF Profile of Plumeria obtusa: Potential for the Treatment of Antimicrobial Resistance

The methanolic fraction (M-F) of the total extract (TE) of Plumeria obtusa L. aerial parts showed promising antibacterial effects against the MDR (multidrug-resistant) gram-negative pathogens Klebsiella pneumoniae and Escherichia coli O157:H7 [Shiga toxin-producing E. coli (STEC)]. In addition, M-F had a synergistic effect (in combination with vancomycin) against the MDR gram-positive strains MRSA (methicillin-resistant Staphylococcus aureus) and Bacillus cereus. After treating the K. pneumoniae- and STEC-infected mice with M-F (25 mg/kg, i.p.), the level of IgM and TNF-α was decreased and the severity of pathological lesions were reduced better than that observed after administration of gentamycin (33 mg/kg, i.p.). Thirty-seven compounds including 10 plumeria-type iridoids and 18 phenolics, 7 quinoline derivatives, 1 amino acid, and 1 fatty acid were identified in TE using LC/ESI-QToF. Furthermore, five compounds; kaempferol 3-O-rutinoside (M1), quercetin 3-O-rutinoside (M2), glochiflavanoside B (M3), plumieride (M4), and 13-O-caffeoylplumieride (M5) were isolated from M-F. M5 was active against K. pneumoniae (MIC of 64 μg/mL) and STEC (MIC of 32 μg/mL). These findings suggested that M-F and M5 are promising antimicrobial natural products for combating MDR K. pneumoniae and STEC nosocomial infections.

Genotypic Characteristics and Antimicrobial Resistance of Escherichia coli ST141 Clonal Group

Escherichia coli ST141 is one of the ExPEC lineages whose incidence is rising in France, even if no epidemic situation involving multidrug resistant isolates has been reported so far. Nonetheless, in a 2015-2017 monocentric study conducted in our French University hospital, ST141 was the most frequent lineage after ST131 in our collection of phylogroup B2 ESBL-producing E. coli. The genomes of 187 isolates representing ST141 group, including 170 genomes from public databases and 17 from our local collection, of which 13 produced ESBL, were analyzed to infer the maximum likelihood phylogeny SNP-based (Single Nucleotide Polymorphism) free-recombinant tree defining the ST141 population structure. Genomes were screened for genes encoding virulence factors (VFs) and antimicrobial resistance (AMR). We also evaluated the distribution of isolates according to their origin (host, disease, country) and the distribution of VFs or AMR genes. Finally, the phylogenic tree revealed that ST141 isolates clustered into two main sublineages, with low genetic diversity. Contrasting with a highly virulent profile, as many isolates accumulated VFs, the prevalence of AMR was limited, with no evidence of multidrug resistant emerging lineage. However, our results suggest that surveillance of this clonal group, which has the potential to spread widely in the community, would be essential.

Detection and characterization of hybrid uropathogenic Escherichia coli strains among E. coli isolates causing community-acquired urinary tract infection

Introduction. The main aetiological agent of urinary tract infection (UTI) is Escherichia coli, categorized as uropathogenic E. coli (UPEC). The genome of UPEC shows a high degree of plasticity, which leads to the emergence of 'intermediary strains' with different traits from the parental pathotypes.Gap Statement/Aim. We aimed to assess the frequency and types of the hybrid UPEC among isolates causing UTI and characterize virulence properties of these hybrid isolates molecularly and phenotypically.Methodology. After detection of intestinal pathogenic E. coli (IPEC) virulence markers among 200 UPEC isolates, they were assessed for the presence of 40 virulence genes (VGs) of extraintestinal, uropathogenic and diarrhoeagenic E. coli, phylogenetic group typing, phenotypic traits including biofilm formation, adherence and invasion to HeLa cells, haemolysis activity and antimicrobial resistance.Results. The analysis showed 21 (10.5 %) UPEC isolates carried enteroaggregative E. coli (EAEC) and enteropathogenic E. coli (EPEC) virulence markers. Twenty isolates carried the aggR (EAEC) and one the eae and escV genes (EPEC), which were classified as hybrid strains. The most commonly identified genes were fimH (71.5 %), fyuA (66.7 %), iutA (62 %), chuA (57.1) and traT (47.6 %). Biofilm production, adhesion and invasion were found among 17 (81), 18 (85.7) and 11 (52.4 %) hybrids, respectively. Investigation of the genetic characteristics, phylogenetic group and virulence profile of the detected hybrids revealed that they have genetic diversity and do not belong to a particular clonal lineage.Conclusion. The present study reveals that some UPEC may carry virulence markers of IPEC pathotypes. EAEC and EPEC seem to have a greater tendency to form hybrids and cause UTI. Further studies are needed to elucidate what factors contributed to survival in the urinary tract system and facilitate infection and whether these combinations lead to an increase in pathogenicity or not.

Conjugative RP4 Plasmid-Mediated Transfer of Antibiotic Resistance Genes to Commensal and Multidrug-Resistant Enteric Bacteria In Vitro

Many antibiotic-resistant bacteria carry resistance genes on conjugative plasmids that are transferable to commensals and pathogens. We determined the ability of multiple enteric bacteria to acquire and retransfer a broad-host-range plasmid RP4. We used human-derived commensal Escherichia coli LM715-1 carrying a chromosomal red fluorescent protein gene and green fluorescent protein (GFP)-labeled broad-host-range RP4 plasmid with ampR, tetR, and kanR in in vitro matings to rifampicin-resistant recipients, including Escherichia coli MG1655, Dec5α, Vibrio cholerae, Pseudomonas putida, Pseudomonas aeruginosa, Klebsiella pneumoniae, Citrobacter rodentium, and Salmonella Typhimurium. Transconjugants were quantified on selective media and confirmed using fluorescence microscopy and PCR for the GFP gene. The plasmid was transferred from E. coli LM715-1 to all tested recipients except P. aeruginosa. Transfer frequencies differed between specific donor-recipient pairings (10^-2 to 10^-8). Secondary retransfer of plasmid from transconjugants to E. coli LM715-1 occurred at frequencies from 10^-2 to 10^-7. A serial passage plasmid persistence assay showed plasmid loss over time in the absence of antibiotics, indicating that the plasmid imposed a fitness cost to its host, although some plasmid-bearing cells persisted for at least ten transfers. Thus, the RP4 plasmid can transfer to multiple clinically relevant bacterial species without antibiotic selection pressure.

Synthesis, Characterization and Antibacterial Activities of Ferrocene Ligands and Their Binuclear Complexes

6-Chloro-2-ferrocenyl-1H-benzimidazole and (E)-((4-chloro-2-hydroxyphenylimino)methyl)ferrocene ligands and their Fe(III), Co(II), Cu(II), Zn(II) and Pd(II) complexes were synthesized. The structure of ligands and metal complexes has been investigated by different methods. In addition, magnetic moment, molar conductivity measurements and antibacterial activity of the ligands and the complexes were investigated.

Clonal groups of extended-spectrum β-lactamase and biofilm producing uropathogenic Escherichia coli in Iran

Pathogenicity of a bacterium is affected by the social characteristics of the population and environmental factors. The ability of biofilm formation among β-lactamase-producing uropathogenic Escherichia coli (UPEC) could facilitate the exchange of antibiotic-resistance genes, which resulted in widespread dissemination of antibacterial drug resistance. We investigated the prevalence of biofilm and β-lactamase producing UPECs among patients with urinary tract infection (UTI) in two cities with different demographics and climates in Iran. A total of 265 E. coli was isolated from patients with UTIs from two referral hospitals (n = 191) and two outpatient clinics (n = 74) in Isfahan and Zahedan, Iran. Production of curli and cellulose, and, biofilm formation was investigated using Congo red agar and microtiter plate methods, respectively. Biofilm producing (BFP) isolates (n = 107) were further characterized using rep-PCR, antimicrobial susceptibility testing and extended-spectrum β-lactamase (ESBL)/AmpC phenotypic production. Isolates were also screened for the presence of carbapenemase, ESBL and AmpC genes using multiplex PCR.   High diversity was found among BFP strains in both cities, with 58% strains producing ESBL and 21% producing AmpC. ESBL (98%), AmpC (50%) and carbapenemase genes (40%) were identified in BFP strains with ESBL-positive phenotype, respectively. The prevalence of BFP strains, antibiotic resistance and β-lactamase genes in Zahedan, a low socioeconomic city with a warm climate, was significantly higher than that of Isfahan. High prevalence of biofilm and β-lactamase producing UPEC strains among strains from Zahedan suggests that socioeconomic status and environmental factors might have a role in pathogenicity of the strains.

Role of aggregate-forming pilus (AFP) in adherence and colonization of both intestinal and urinary tracts

Hybrid-pathogenic Escherichia coli represent an important group of strains associated with intestinal and extraintestinal infections. Recently, we described strain UPEC-46, a uropathogenic/enteroaggregative E. coli (UPEC/EAEC) strain presenting the aggregative adherence (AA) pattern on bladder and colorectal epithelial cells mediated by aggregate-forming pili (AFP). However, the role of AFP and other uninvestigated putative fimbriae operons in UPEC-46 pathogenesis remains unclear. Thus, this study evaluated the involvement of AFP and other adhesins in uropathogenicity and intestinal colonization using different in vitro and in vivo models. The strain UPEC-46 was able to adhere and invade intestinal and urinary cell lines. A library of transposon mutants also identified the involvement of type I fimbriae (TIF) in the adherence to HeLa cells, in addition to colorectal and bladder cell lines. The streptomycin-treated mouse in vivo model also showed an increased number of bacterial counts in the colon in the presence of AFP and TIF. In the mouse model of ascending urinary tract infection (UTI), AFP was more associated with kidney colonization, while TIF appears to mediate bladder colonization. Results observed in in vivo experiments were also confirmed by electron microscopy (EM) analyses. In summary, the in vitro and in vivo analyses show a synergistic role of AFP and TIF in the adherence and colonization of intestinal and urinary epithelia. Therefore, we propose that hybrid E. coli strains carrying AFP and TIF could potentially cause intestinal and urinary tract infections in the same patient.

Probiotics: Lactic Acid Bacteria have Antibacterial Activity and Downregulate Biofilm Genes of Uropathogenic E. coli

Urinary tract infections (UTIs) are regarded as one of the most serious infections worldwide. Uro Pathogenic E. coli (UPEC) accounts for nearly 80% of UTI infections in females. This study investigated the antibacterial and antibiofilm effects of Lactobacillus acidophilus (l. acidophilus) and Lactobacillus plantarum (lb. plantarum) on multidrug-resistant E. coli obtained from urine samples. Complete bacteriological identification was conducted on 45 E. coli isolated from 80 urine samples of females with UTIs. Antibiotic susceptibility test was performed on all isolates by nine antibiotics. Ten out of the 45 isolates exhibited multidrug resistance (MDR). L. acidophilus and Lb. plantarum showed marked inhibition of MDR E. coli isolates on agar by a diffusion method (16 ± 0.04: 23 ± 0.05 mm). Moreover, L. acidophilus and Lb. plantarum strains inhibited the ability of UPEC to form a biofilm by 56.3% and 39.63%, respectively. The expression of biofilm genes of E. coli are as follows: csgA, crl, csgD showed remarkable downregulation after treatment with probiotics suspension: 0.00364: 0.19078 fold, 0.0005: 0.1894 fold, and 0.0490: 0.0883 for L. acidophilus, respectively. On the other hand, downregulation of biofilm gene expression for csgA, crl, csgD after treatment with Lb. plantarum suspension were expressed by fold changes as follows: 0.0769: 0.3535 fold, 0.05440: 0.12940 fold, and 0.06745: 0.4146, respectively. These findings show that L. acidophilus and Lb. plantarum exhibit potent antibacterial and antibiofilm action against MDR UPEC at both genotypic and phenotypic levels, and appear to be a promising solution in therapeutic applications for recurrent and persistent UTIs.

Virulence genes, phylogenetic analysis, and antimicrobial resistance of Escherichia coli isolated from urinary tract infection in hospitalized patients and outpatients

Uropathogenic Escherichia coli (UPEC) strains are the most common cause of urinary tract infection (UTI) in hospitalized and community patients. The aim was to compare the genetic characteristics of E. coli isolated from inpatients (IPs) and outpatients (OPs) with UTI regarding their phylogenies, virulence traits, and resistance trends. In this cross-sectional study, 130 epidemiologically unrelated E. coli isolates were collected from patients with UTI. Extended-spectrum beta-lactamase (ESBL) production was detected by the combination disk method. UPEC and intestinal pathogenic E. coli (IPEC) virulence genes were detected by polymerase chain reaction. The isolates were analyzed for phylogenetic grouping. A P value of < 0.05 was considered significant. Of the 130 isolates, 62.3% were from OPs and 37.7% from IPs. About 35.8% of the OPs and 49% of the IPs were ESBL positive. Moreover, 56.8% of the OPs and 59.2% of the IPs were positive for UPEC virulence genes. Notably, 50% of the isolates from each group exhibited IPEC virulence properties. The predominant phylogroup was B2 (43.2% in the OPs and 40.8% in the IPs). No significant difference was found between the IP and OP isolates (P > 0.05). Our results may indicate that consideration should also be given to hygienic standards in the community. The marked genetic plasticity of E. coli has allowed the emergence of strains showing arrays of genes from different pathotypes. Characterization of E. coli isolates in different areas may guide the selection of effective infection control strategies.

Cervicovaginal microbiota isolated from healthy women exhibit probiotic properties and antimicrobial activity against pathogens isolated from cervical cancer patients

Abnormal cervicovaginal microbiota play an important role in HPV persistence and progression to cervical cancer. The present study aimed at isolating and identifying potential probiotics from vaginal swabs of healthy women and evaluating their activity against vaginal pathogens isolated from cervical cancer patients. Based on probiotic, acid-bile tolerance and antimicrobial properties, 13 lactic acid bacteria (LAB) from the healthy group were identified by MALDI TOF MS (Matrix Assisted Laser Desorption and Ionisation, Time Of Flight Mass Spectrometry). Among these, four strains, Lactobacillus gasseri P36Mops, Limosilactobacillus fermentum P37Mws, Lactobacillus delbrueckii P31Mcs and Enterococcus faecium P26Mcm, exhibited significant antimicrobial activity against 8 vaginal pathogens (Staphylococcus haemolyticus P41Tcs, Escherichia coli P30Tcs, E. coli P79Bcm, Enterococus faecalis P29Mops, E. faecalis P50Tws, E. faecalis P68Tcb, S. haemolyticus P48Bcb and S. haemolyticus P58Bcb) isolated from precancerous and cervical cancer patients. 16S rRNA sequencing of four potential probiotics revealed congruency with the MALDI-TOF MS identification and phylogenetic analysis showed genetic relationship with previously reported LAB strains. The selected LAB showed strain specific hydrophobicity (35.88-56.70%), auto-aggregation (35.26-61.39%) and antibiotic susceptibility. Interestingly, L. gasseri P36Mops was resistant to five standard antibiotics routinely used against urogenital or vaginal infections. LCMS (Liquid Chromatography Mass Spectrometry) analyses of the CFS (cell-free supernatant) of the four potential probiotics revealed the presence of metabolites such as N-(1-deoxy-1-fructosyl)valine, hygroline, acetoxy-2-hydroxy-16-heptadecen-4-one, avocadyne 4-acetate, avocadyne 2-acetate, taraxinic acid glucosyl ester, 6-hydroxypentadecanedioic acid, with reported antimicrobial activity. The overall data suggest the bio-therapeutic potential of the identified vaginal probiotics against cervical cancer-associated pathogens.

Transfer of bacteria between fabric and surrogate skin

BACKGROUND

Contaminated textiles serve as fomites in healthcare settings. The extent of transfer of pathogens from fabrics depends on the surface properties of the 2 contact surfaces.

METHODS

In the current study, the effect of surface energy and surface roughness of fabrics on the transfer of Escherichia coli and Staphylococcus aureus to and from textiles to surrogate skin were determined. Three fabrics (100% cotton, 100% polyester, and 50-50 blend of cotton and polyester) having identical constructional parameters, were characterised on the basis of surface roughness, and energy. Assessment of transfer of bacteria was carried out by bringing the matrix seeded with inoculum in contact with the sterilized matrix for a predetermined period of time, followed by dislodging of cells from the recipient surface by vortexing, and plating.

RESULTS AND DISCUSSION

Results showed that 100% polyester attracted the highest number of bacterial cells compared to the others. It also released the maximum number of bacteria upon coming in contact with surrogate skin. Properties of fabrics like absorbency, surface energy, and surface roughness, simultaneously affected transfer.

CONCLUSIONS

It is advisable to minimize the use of 100% polyester in healthcare settings to curb the transfer load of bacteria from one surface to another.

Comparative Characteristics and Pathogenic Potential of Escherichia coli Isolates Originating from Poultry Farms, Retail Meat, and Human Urinary Tract Infection

The pathogenicity of many bacterial strains is determined by the acquisition of virulence genes and depends on many factors. The aim of this study was to analyse the phylogenetic background, virulence patterns, and drug susceptibility of 132 E. coli isolates tested in the context of the ExPEC (Extraintestinal Pathogenic E. coli) pathotype and the correlation of these features with bacterial isolation source: food (retail meat), poultry farms (AFEC—Avian Faecal E. coli), and patients with UTI (urinary tract infection) symptoms. The drug-susceptibility results of tested E. coli isolates obtained indicate that the resistance profile—ampicillin/tetracycline/trimethoprim+sulfamethoxazole/ciprofloxacin (AMP/TE/SXT/CIP)—was most frequently observed. The multidrug resistance (MDR) phenotype was found in 31.8% of isolates from poultry farms, 36.8% of strains isolated from food, and 20% of clinical samples. The greatest similarity of virulence profiles applied to isolates derived from poultry farms and food. Most of the AFEC from poultry farms and food-derived isolates belonged to commensals from phylogroups A and B1, while among the isolates from patients with UTI symptoms, the most common was the B2 phylogroup. The collective analysis showed similarity of the three studied groups of E. coli isolates in terms of the presented patterns of antimicrobial resistance, while the virulence profiles of the isolates studied showed great diversity. The phylogroup analysis showed no similarity between the poultry/food isolates and the UTI isolates, which had significant pathogenic potential.

Occurrence and Genomic Characterization of Clone ST1193 Clonotype 14-64 in Uncomplicated Urinary Tract Infections Caused by Escherichia coli in Spain

We conducted a prospective, multicenter, specific pilot study on uncomplicated urinary tract infections (uUTI). One-hundred non-duplicated uropathogenic Escherichia coli (UPEC) from uUTI occurred in 2020 in women attending 15 primary care centers of a single health region of northern Spain were characterized using a clonal diagnosis approach. Among the high genetic diversity showed by 59 different phylogroup-clonotype combinations, 11 clones accounted for 46% of the isolates: B2-ST73 (CH24-30); B2-ST73 (CH24-103); B2-ST131 (CH40-30); B2-ST141 (CH52-5); B2-ST372 (CH103-9); B2-ST404 (CH14-27); B2-ST404 (CH14-807); B2-ST1193 (CH14-64); D-ST69 (CH35-27); D-ST349 (CH36-54), and F-ST59 (CH32-41). The screening of the UPEC status found that 69% of isolates carried ≥ 3 of chuA, fyuA, vat, and yfcV genes. Multidrug resistance to at least one antibiotic of ≥ 3 antimicrobial categories were exhibited by 30% of the isolates, with the highest rates of resistance against ampicillin/amoxicillin (48%), trimethoprim (35%), norfloxacin (28%), amoxicillin-clavulanic acid (26%), and trimethoprim-sulfamethoxazole (24%). None extended-spectrum beta-lactamase/carbapenemase producer was recovered. According to our results, fosfomycin and nitrofurantoin should be considered as empirical treatment of choice for uUTI by E. coli (resistance rates 4% and 2%, respectively). We uncover the high prevalence of the pandemic fluoroquinolone-resistant ST1193 clone (6%) in uUTI, which represents the first report in Spain in this pathology. The genomic analysis showed similar key traits than those ST1193 clones disseminated worldwide. Through the SNP comparison based on the core genome, the Spanish ST1193 clustered with isolates retrieved from the Enterobase, showing high genomic similarity than the global ST1193 described in the United States, Canada and Australia.

IMPORTANCE Analyzing the clonal structure and antimicrobial resistance of E. coli isolates implicated in uncomplicated urinary tract infections, one of the most frequent visits managed in primary health care, is of interest for clinicians to detect changes in the dynamics of emerging uropathogenic clones associated with the spread of fluoroquinolone resistance. It can also provide consensus concerning optimal control and antibiotic prescribing.

Characterization of Uropathogenic Escherichia coli Reveals Hybrid Isolates of Uropathogenic and Diarrheagenic (UPEC/DEC) E. coli

(1) Background: Pathogenic Escherichia coli are divided into two groups: diarrheagenic (DEC) and extraintestinal pathogenic (ExPEC) E. coli. ExPEC causing urinary tract infections (UTIs) are termed uropathogenic E. coli (UPEC) and are the most common cause of UTIs worldwide. (2) Methods: Here, we characterized 112 UPEC in terms of phylogroup, serotype, the presence of virulence factor-encoding genes, and antimicrobial resistance. (3) Results: The majority of the isolates were assigned into the phylogroup B2 (41.07%), and the serogroups O6 (12.5%) and O25 (8.9%) were the most frequent. Five hybrid UPEC (4.5%), with markers from two DEC pathotypes, i.e., atypical enteropathogenic (aEPEC) and enteroaggregative (EAEC) E. coli, were identified, and designated UPEC/aEPEC (one isolate) and UPEC/EAEC (four isolates), respectively. Three UPEC/EAEC harbored genes from the pap operon, and the UPEC/aEPEC carried ibeA. The highest resistance rates were observed for ampicillin (46.4%) and trimethoprim/sulfamethoxazole (34.8%), while 99.1% of the isolates were susceptible to nitrofurantoin and/or fosfomycin. Moreover, 9.8% of the isolates were identified as Extended Spectrum β-Lactamase producers, including one hybrid UPEC/EAEC. (4) Conclusion: Our data reinforce that hybrid UPEC/DEC are circulating in the city of Botucatu, Brazil, as uropathogens. However, how and whether these combinations of genes influence their pathogenicity is a question that remains to be elucidated.

Genomic and Phenotypic Characterization of a Colistin-Resistant Escherichia coli Isolate Co-Harboring blaNDM-5, blaOXA-1, and blaCTX-M-55 Isolated from Urine

Background

Materials and Methods

Results

Conclusion

Molecular Epidemiology and Presence of Hybrid Pathogenic Escherichia coli among Isolates from Community-Acquired Urinary Tract Infection

Urinary tract infections (UTI) affect community and healthcare patients worldwide and may have different clinical outcomes. We assessed the phylogenetic origin, the presence of 43 virulence factors (VFs) of diarrheagenic and extraintestinal pathogenic Escherichia coli, and the occurrence of hybrid strains among E. coli isolates from 172 outpatients with different types of UTI. Isolates from phylogroup B2 (46%) prevailed, followed by phylogroups A (15.7%) and B1 (12.2%), with similar phylogenetic distribution in symptomatic and asymptomatic patients. The most frequent VFs according to their functional category were fimA (94.8%), ompA (83.1%), ompT (63.3%), chuA (57.6%), and vat (22%). Using published molecular criteria, 34.3% and 18.0% of the isolates showed intrinsic virulence and uropathogenic potential, respectively. Two strains carried the eae and escV genes and one the aggR gene, which classified them as hybrid strains. These hybrid strains interacted with renal and bladder cells, reinforcing their uropathogenic potential. The frequency of UPEC strains bearing a more pathogenic potential in the outpatients studied was smaller than reported in other regions. Our data contribute to deepening current knowledge about the mechanisms involved in UTI pathogenesis, especially among hybrid UPEC strains, as these could colonize the host’s intestine, leading to intestinal infections followed by UTI.

Description and comparative genomic analysis of a mcr-1-carrying Escherichia coli ST683/CC155 recovered from touristic coastal water in Northeastern Brazil

Polymyxin resistance is an emerging health issue aggravated by mcr dissemination among Enterobacterales recovered from various sources. Commensal Escherichia coli plays a key role in the spread of antimicrobial resistance in community settings and is likely to spread silently. It may transfer resistance genes to pathogenic bacteria in the gastrointestinal tract and the environment, and may cause difficult-to-treat infections, especially in immunocompromised patients. Unraveling actors disseminating resistance to last-resort antimicrobials might support the future development of control measures. Here we report the occurrence of a commensal ST683/CC155 colistin-resistant mcr-1.1-harboring E. coli (JP24) obtained from touristic coastal water. JP24's genome was sequenced and comparatively analyzed with other genomes from ST683/CC155 isolated worldwide and with mcr-carrying isolates recovered from various sources in Brazil. Besides mcr-1, JP24 carried bla_CTX-M-8, tet(A), tet(34), dfrA12, sul2, sul3, aph(3')-Ia, aph(3')-IIa, aadA1, aadA2, cmlA1, Inu(G), mef(B) and mdf(a). mcr-1 and bla_CTX-M-8 were transferable by IncX4 and IncI1/Iγ plasmids, respectively. Tree-based phylogeny of the ST683/CC155 isolates core genome revealed two larger clades. E. coli JP24 was grouped into a subclade together with an isolate from Thailand (ERR4221036), both carrying mcr-1. The core genome-based tree of the isolates carrying mcr-1 from Brazil revealed proximity with E. coli ECEST9 recovered from a mangrove also located in Northeastern Brazil. Accessory genome-based tree clustered most environmental isolates apart from the clinical ones and remained JP24 closer to ECEST9. High sequence conservation was observed between mcr-1-harboring plasmids detected in different species and reservoirs in Brazil and other countries. In addition to recreational coastal waters being potential sources for community exposure to antimicrobial-resistant bacteria, our findings reinforce a more prominent role of horizontal gene transfer, other than clonal expansion, in mcr dissemination in the community.

The aggregate-forming pili (AFP) mediates the aggregative adherence of a hybrid-pathogenic Escherichia coli (UPEC/EAEC) isolated from a urinary tract infection

Enteroaggregative Escherichia coli (EAEC) comprises an important diarrheagenic pathotype, while uropathogenic E. coli (UPEC) is the most important agent of urinary tract infection (UTI). Recently, EAEC virulence factors have been detected in E. coli strains causing UTI, showing the importance of these hybrid-pathogenic strains. Previously, we detected an E. coli strain isolated from UTI (UPEC-46) presenting characteristics of EAEC, e.g., the aggregative adherence (AA) pattern and EAEC-associated genes (aatA, aap, and pet). In this current study, we analyzed the whole genomic sequence of UPEC-46 and characterized some phenotypic traits. The AA phenotype was observed in cell lineages of urinary and intestinal origin. The production of curli, cellulose, bacteriocins, and Pet toxin was detected. Additionally, UPEC-46 was not capable of forming biofilm using different culture media and human urine. The genome sequence analysis showed that this strain belongs to serotype O166:H12, ST10, and phylogroup A, harbors the tet, aadA, and dfrA/sul resistance genes, and is phylogenetically more related to EAEC strains isolated from human feces. UPEC-46 harbors three plasmids. Plasmid p46-1 (~135 kb) carries some EAEC marker genes and those encoding the aggregate-forming pili (AFP) and its regulator (afpR). A mutation in afpA (encoding the AFP major pilin) led to the loss of pilin production and assembly, and notably, a strongly reduced adhesion to epithelial cells. In summary, the genetic background and phenotypic traits analyzed suggest that UPEC-46 is a hybrid strain (UPEC/EAEC) and highlights the importance of AFP adhesin in the adherence to colorectal and bladder cell lines.

Microbiology of Post-Cardiac Surgery Infections in Children with Congenital Heart Diseases, A Single-Center Experience, Mashhad, Iran

Background: Children who have undergone cardiac surgeries due to congenital heart disease are prone to various kinds of infections. Objectives: This study was done to investigate the prevalence of nosocomial infections and microbiology of post-cardiac surgery infections in pediatric patients with congenital heart disease (CHD). Methods: In this cross-sectional study, the epidemiology and microbiology of post-cardiac surgery for pediatric patients with CHD at Imam Reza Hospital of Mashhad University of Medical Sciences between 2014 and 2017 were investigated. Demographic and clinical information was recorded, and the findings were analyzed using SPSS 16. Results: Out of 1128 patients with open heart surgery during the four years of the study, 135 patients, including 80 males (60.1%) and 55 females (39.9%) with a mean age of 8.06 ± 3.86 months, were enrolled in the study. The prevalence of infection was 11.96%. The most common isolated bacteria were Acinetobacter (19/135, 14.1%), Pseudomonas spp. (13/135, 9.6%), and Enterobacter (13/135, 9.6%) as Gram-negative ones and Corynebacterium diphtheria (10/135, 7.4%) and Staphylococcus epidermidis (10/135, 7.4%) as Gram-positive types. Candida albicans (14/135, 10.4%) were also the most frequent fungi. The frequency of infection-causing masses did not differ significantly between different cardiac abnormalities (P = 0.831), sex (P = 0.621), age (P = 0.571), and weight (P = 0.786) groups. Also, the duration of hospitalization, intubation, bypass time, and urinary catheterization in positive culture cases were significantly longer than in negative cases. Conclusions: In our study, the most common infections in children who underwent heart surgery were Acinetobacter, C. albicans, Pseudomonas, and Enterobacter. It is suggested to reduce the hospitalization, intubation, bypass, and urinary catheterization time to reduce nosocomial infections in these patients and decrease treatment costs.

Identification and characterization of class 1 integrons among multidrug-resistant uropathogenic Escherichia coli strains in Mexico

This study aimed to identify and characterize integrons among multidrug-resistant (MDR) uropathogenic Escherichia coli (UPEC) from outpatients in Mexico City, Mexico. PCR assays were used to screen for the presence of class 1, 2 and 3 integrons, whose PCR products were sequenced to identify the inserted gene cassettes within the variable regions. Out of 83 tested strains, 53 (63.9%) were positive for the presence of class 1 integrons, whereas no integrons were detected in the remaining strains, regardless of their classes. Most of the strains carrying the intI1 gene belonged to the extraintestinal B2 (41.5%) and commensal A (32.1%) phylogroups, and to a lesser extent, the extraintestinal D (20.8%) and commensal B1 (5.7%) phylogroups. Moreover, 8 different gene cassette arrangements were detected, with dfrA17 and aadA5 being the most common (32.1% of the class 1 integron-positive strains), which confer resistance to trimethoprim/sulfamethoxazole and aminoglycosides, respectively. Our results suggest that class 1 integrons are widely distributed among MDR-UPEC strains in Mexico, which may directly or indirectly contribute to the selection of MDR strains. These findings are important for a better understanding of the factors and mechanisms that promote multidrug resistance among UPEC strains.

Phylogenetic Group B2 Expressed Significant Biofilm Formation among Drug Resistant Uropathogenic Escherichia coli

Biofilm is an important virulent marker attributed to the development of urinary tract infections (UTIs) by uropathogenic E. coli (UPEC). Drug-resistant and biofilm-producing UPEC are highly problematic causing catheter-associated or recurrent UTIs with significant morbidity and mortality. The aim of the current study was to investigate the prevalence of biofilm formation and phylogenetic groups in drug-resistant UPEC to predict their ability to cause disease. This prospective study was conducted at the Department of Microbiology, University of Karachi from January to June 2019. A total of 50 highly drug-resistant UPEC were selected for this study. UPEC isolates were screened to form biofilm by Congo-red agar (CRA) and microtiter plate (MTP) technique. The representative biofilm-producing isolates were analysed by scanning electron microscopy (SEM) monitoring. Phylogenetic analysis was done by PCR method based on two preserved genes; chuA, yjaA and TspE4-C2 DNA fragment. On CRA 34 (68%) UPEC were slime producers, while on MTP 20 (40%) were strong biofilm producers, 19 (38%) moderate and 11 (22%) were low to negligible biofilm producers. Molecular typing confirmed that phylogenetic group B2 was prevalent in drug resistant UPEC strains. Pathogenic strains belonged to phylogenetic group B2 and D were found to have greater biofilm forming ability as compare to non-pathogenic commensal strains that belonged to phylogenetic group A. Our results indicate that biofilm formation vary in drug resistant UPEC belonged to different phylogenetic groups. This study indicates possible link between in vitro biofilm formation and phylogenetic groups of UPEC, therefore this knowledge might be helpful to predict the pathogenic potential of UPEC and help design strategies for controlling UTIs.

A genomic data resource for predicting antimicrobial resistance from laboratory-derived antimicrobial susceptibility phenotypes

Antimicrobial resistance (AMR) is a major global health threat that affects millions of people each year. Funding agencies worldwide and the global research community have expended considerable capital and effort tracking the evolution and spread of AMR by isolating and sequencing bacterial strains and performing antimicrobial susceptibility testing (AST). For the last several years, we have been capturing these efforts by curating data from the literature and data resources and building a set of assembled bacterial genome sequences that are paired with laboratory-derived AST data. This collection currently contains AST data for over 67 000 genomes encompassing approximately 40 genera and over 100 species. In this paper, we describe the characteristics of this collection, highlighting areas where sampling is comparatively deep or shallow, and showing areas where attention is needed from the research community to improve sampling and tracking efforts. In addition to using the data to track the evolution and spread of AMR, it also serves as a useful starting point for building machine learning models for predicting AMR phenotypes. We demonstrate this by describing two machine learning models that are built from the entire dataset to show where the predictive power is comparatively high or low. This AMR metadata collection is freely available and maintained on the Bacterial and Viral Bioinformatics Center (BV-BRC) FTP site ftp://ftp.bvbrc.org/RELEASE_NOTES/PATRIC_genomes_AMR.txt.

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.

Comparative phenotypic characterization of hybrid Shiga toxin-producing / uropathogenic Escherichia coli, canonical uropathogenic and Shiga toxin-producing Escherichia coli

Hybrid Shiga toxin (Stx)-producing Escherichia coli (STEC) and uropathogenic E. coli (UPEC) strains are phylogenetically positioned between STEC and UPEC and can cause both diarrhea and urinary tract infections (UTIs). However, their virulence properties and adaptation to different host milieu in comparison to canonical UPEC and STEC strains are unknown. We determined phenotypes of the STEC/UPEC hybrid with respect to virulence including acid resistance, motility, biofilm formation, siderophore production, and adherence to human colonic Caco-2 and bladder T24 cells and compared to phenotypes of commensal strain MG1655, UPEC strain 536, and STEC strains B2F1 and Sakai. Moreover, we assessed the adaptation of the hybrid to artificial urine medium (AUM) and simulated colonic environment medium (SCEM). Overall acid resistance at pH 2.5 was high except in strains B2F1 and hybrid 05-00787 which showed reduced and extremely low acid resistance, respectively. Motility was reduced in hybrid 05-00787 and 09-05501 but strong in the remaining hybrids. While some hybrids showed high biofilm formation in LB, overall biofilm formation in SCEM and AUM were low and non-existent, respectively. All strains tested showed siderophore activity at equilibrium. All strains except MG1655 adhered to Caco-2 cells with the hybrid having similar adherence when compared to 536 but exhibited 2 and 3 times lower adherence when compared to B2F1 and Sakai, respectively. All Stx-producing strains adhered stronger to T24 cells than strains 536 and MG1655. Overall growth in LB, SCEM and AUM was consistent within the hybrid strains, except hybrid 05-00787 which showed significantly different growth patterns. Our data suggest that the hybrid is adapted to both, the intestinal and extraintestinal milieu. Expression of phenotypes typical of intestinal and extraintestinal pathogens thereby supports its potential to cause diarrhea and UTI.

Evidence of potentially unrelated AmpC beta-lactamase producing Enterobacteriaceae from cattle, cattle products and hospital environments commonly harboring the blaACC resistance determinant

The occurrence and genetic relatedness of AmpC beta-lactamase producing Enterobacteriaceae isolated from clinical environments, groundwater, beef, human and cattle faeces were investigated. One hundred seventy-seven (177) samples were collected and cultured on MacConkey agar. A total of 203 non-repetitive isolates were characterised using genus/species-specific PCRs and the identified isolates were subjected to antibiotic susceptibility testing. The production of AmpC beta-lactamases was evaluated using cefoxitin disc, confirmed by the D96C detection test and their encoding genes detected by PCR. The D64C extended-spectrum beta-lactamases (ESBL) test was also performed to appraise ESBLs/AmpC co-production. The genetic fingerprints of AmpC beta-lactamase producers were determined by ERIC-PCR. A total of 116 isolates were identified as E. coli (n = 65), Shigella spp. (n = 36) and Klebsiella pneumoniae (n = 15). Ciprofloxacin resistance (44.4-55.4%) was the most frequent and resistance against the Cephem antibiotics ranged from 15-43.1% for E. coli, 25-36.1% for Shigella spp., and 20-40% for K. pneumoniae. On the other hand, these bacteria strains were most sensitive to Amikacin (0%), Meropenem (2.8%) and Piperacillin-Tazobactam (6.7%) respectively. Nineteen (16.4%) isolates comprising 16 E. coli and 3 Shigella spp. were confirmed as AmpC beta-lactamase producers. However, only E. coli isolates possessed the corresponding resistance determinants: blaACC (73.7%, n = 14), blaCIT (26%, n = 5), blaDHA (11%, n = 2) and blaFOX (16%, n = 3). Thirty-four (27.3%) Enterobacteriaceae strains were confirmed as ESBL producers and a large proportion (79.4%, n = 27) harboured the blaTEM gene, however, only two were ESBLs/AmpC co-producers. Genetic fingerprinting of the AmpC beta-lactamase-producing E. coli isolates revealed low similarity between isolates. In conclusion, the findings indicate the presence of AmpC beta-lactamase-producing Enterobacteriaceae from cattle, beef products and hospital environments that commonly harbour the associated resistance determinants especially the blaACC gene, nonetheless, there is limited possible cross-contamination between these environments.

Antimicrobial resistance patterns among different Escherichia coli isolates in the Kingdom of Saudi Arabia

Antimicrobial resistance patterns among different Escherichia coli isolates in the Kingdom of Saudi Arabia. This study aimed to investigate the patterns of antimicrobial resistance in E. coli isolated from different samples, and to identify potential pathogenic isolates in Riyadh, Kingdom of Saudi Arabia (KSA). In total, 51 bacterial isolates were recovered from 113 samples of human urine, food (raw meat, raw chicken, raw egg surface, and fresh vegetables), water, and air. Twenty-four E. coli isolates were tested for susceptibility to 26 antibiotics. The air sample isolates were most resistant to amoxicillin, ampicillin, amoxicillin/clavulanic acid, amoxicillin/sulbactam, piperacillin/tazobactam, cefalotin, cefuroxime, cefoxitin, cefixime, nitrofurantoin, and trimethoprim/sulfamethoxazol. The isolates from vegetable samples were resistant to amoxicillin, ampicillin, amoxicillin/clavulanic acid, amoxicillin/sulbactam, cefalotin, cefuroxime, cefoxitin, and cefixime. By contrast, the isolates from the water samples were resistant only to amoxicillin and ampicillin. The isolates from the human urine samples were most frequently resistant to norfloxacin (80%) followed by amoxicillin and ampicillin (70%), trimethoprim/sulfamethoxazole (55%), ciprofloxacin and ofloxacin (50%), cefalotin (30%), cefuroxime, cefixime and cefotaxime (25%), ceftazidime, ceftriaxone, cefepime and aztreonam (20%), amoxicillin/clavulanic acid, piperacillin/tazobactam and gentamicin (10%), and amoxicillin/sulbactam and cefoxitin (5%). Almost all (23/25, 95.8%) (n = 23) of the isolates were multi-drug resistant (MDR) (i.e., resistant to 3 or more classes of antibiotics), and 16.7% (n = 4) of those were positive for extended spectrum β-lactamase (ESBL). Of the 4 ESBL-producers, 3 were positive for blaCTX-M-15 and blaCTX-M1group, 2 were positive for blaCMY-2, and 1 each was positive for blaCTX-M-2 group, blaSHV, and blaOXA-47. The quinolone resistance gene qnrS was detected in 25% (n = 6) of the E. coli strains isolated from urine (N = 5) and air (N = 1) samples. The considerable number of antimicrobial resistance genes detected among E. coli isolates tested here is alarming and should raise public health concern.

Covalent Immobilization of Organic Photosensitizers on the Glass Surface: Toward the Formation of the Light-Activated Antimicrobial Nanocoating

Two highly efficient commercial organic photosensitizers—azure A (AA) and 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin (APTPP)—were covalently attached to the glass surface to form a photoactive monolayer. The proposed straightforward strategy consists of three steps, i.e., the initial chemical grafting of 3-aminopropyltriethoxysilane (APTES) followed by two chemical postmodification steps. The chemical structure of the resulting mixed monolayer (MIX_TC_APTES@glass) was widely characterized by X-ray photoelectron (XPS) and Raman spectroscopies, while its photoactive properties were investigated in situ by UV–Vis spectroscopy with α-terpinene as a chemical trap. It was shown that both photosensitizers retain their activity toward light-activated generation of reactive oxygen species (ROS) after immobilization on the glassy surface and that the resulting nanolayer shows high stability. Thanks to the complementarity of the spectral properties of AA and APTPP, the effectiveness of the ROS photogeneration under broadband illumination can be optimized. The reported light-activated nanocoating demonstrated promising antimicrobial activity toward Escherichia coli (E. coli), by reducing the number of adhered bacteria compared to the unmodified glass surface.

Hybrid Atypical Enteropathogenic and Extraintestinal Escherichia coli (aEPEC/ExPEC) BA1250 Strain: A Draft Genome

Diarrheagenic Escherichia coli is the major bacterial etiological agent of severe diarrhea and a major concern of public health. These pathogens have acquired genetic characteristics from other pathotypes, leading to unusual and singular genetic combinations, known as hybrid strains and may be more virulent due to a set of virulence factors from more than one pathotype. One of the possible combinations is with extraintestinal E. coli (ExPEC), a leading cause of urinary tract infection, often lethal after entering the bloodstream and atypical enteropathogenic E. coli (aEPEC), responsible for death of thousands of people every year, mainly children under five years old. Here we report the draft genome of a strain originally classified as aEPEC (BA1250) isolated from feces of a child with acute diarrhea. Phylogenetic analysis indicates that BA1250 genome content is genetically closer to E. coli strains that cause extraintestinal infections, other than intestinal infections. A deeper analysis showed that in fact this is a hybrid strain, due to the presence of a set of genes typically characteristic of ExPEC. These genomic findings expand our knowledge about aEPEC heterogeneity allowing further studies concerning E. coli pathogenicity and may be a source for future comparative studies, virulence characteristics, and evolutionary biology.

Santos AC, Cayô R, Gales AC, A. T. Gomes T. Frequency and Diversity of Hybrid Escherichia coli Strains Isolated from Urinary Tract Infections

(1) Background: Hybrid uropathogenic Escherichia coli (UPEC) strains carry virulence markers of the diarrheagenic E. coli (DEC) pathotypes, which may increase their virulence potential. This study analyzed the frequency and virulence potential of hybrid strains among 452 UPEC strains. (2) Methods: Strains were tested for the DEC virulence diagnostic genes’ presence by polymerase chain reaction (PCR). Those carrying at least one gene were classified as hybrid and further tested for 10 UPEC and extraintestinal pathogenic E. coli (ExPEC) virulence genes and phylogenetic classification. Also, their ability to produce hemolysis, adhere to HeLa and renal HEK 293T cells, form a biofilm, and antimicrobial susceptibility were evaluated. (3) Results: Nine (2%) hybrid strains were detected; seven of them carried aggR and two, eae, and were classified as UPEC/EAEC (enteroaggregative E. coli) and UPEC/aEPEC (atypical enteropathogenic E. coli), respectively. They belonged to phylogroups A (five strains), B1 (three), and D (one), and adhered to both cell lineages tested. Only the UPEC/EAEC strains were hemolytic (five strains) and produced biofilm. One UPEC/aEPEC strain was resistant to third-generation cephalosporins and carried bla_CTX-M-15. (4) Conclusions: Our findings contribute to understanding the occurrence and pathogenicity of hybrid UPEC strains, which may cause more severe infections.

Occurrence and Phenotypic Characterization of Multidrug-Resistant Bacterial Pathogens Isolated from Patients in a Public Hospital in Mogadishu, Somalia

Purpose

This study reports a cross-sectional investigation to determine the antimicrobial resistance pattern of the common bacterial contaminants isolated from hospitalized patients in Mogadishu, Somalia.

Materials and Methods

A total of 328 clinical samples comprising urine, blood, vaginal swab, pus aspirates, and stool were collected from a public hospital located in Mogadishu the capital city of Somalia between October 2019 to March 2020. The isolation and biochemical characterization of the bacterial isolates were performed using the conventional culture and biochemical assay tests. Similarly, antimicrobial susceptibility was determined using the Kirby–Bauer disk diffusion.

Results

A total of 275 pathogenic bacteria that include Staphylococcus aureus, Escherichia coli, Pseudomonas aeroginosa, Proteus vulgare, Klebsiella pneumonia, and Salmonella spp. were detected with an overall detection rate of 78.4% (257/328). Among the bacterial pathogens isolated from clinical specimens, 152 (46.3%) were Staphylococcus aureus, 60 (18.3%) were E. coli, 10 (3.1%) Proteus vulgaris, 6 (1.8%) Klebsiella pneumonia, and 1 (0.3%) isolate was found to be Salmonella sp. The antimicrobial susceptibility assay revealed variable resistance pattern with clindamycin (40%), ampicillin (27%), vancomycin (26%), levofloxacin (23%), amoxicillin (20%), ciprofloxacin (18%) and nitrofurantoin (12%) showing the highest rate of resistance. Moreover, evaluation of multidrug resistance showed that Staphylococcus aureus had the highest multidrug resistance rate, with 19 isolates showing resistance to more than two drugs, followed by E. coli with three isolates. In contrast, each of Proteus vulgare, Salmonella sp. and Klebsiella pneumonia had one isolate each that exhibited multidrug resistance characteristics.

Conclusion

The findings of this study showed the occurrence of a number antimicrobial-resistant bacterial pathogens whose prevalence varies with age and sex. Therefore, there is a need for comprehensive antimicrobial profiling of bacterial isolates during the management of patients in the hospital.

The Superior Adherence Phenotype of E. coli O104:H4 is Directly Mediated by the Aggregative Adherence Fimbriae Type I

Whereas the O104:H4 enterohemorrhagic Escherichia coli (EHEC) outbreak strain from 2011 expresses aggregative adherence fimbriae of subtype I (AAF/I), its close relative, the O104:H4 enteroaggregative Escherichia coli (EAEC) strain 55989, encodes AAF of subtype III. Tight adherence mediated by AAF/I in combination with Shiga toxin 2 production has been suggested to result in the outbreak strain’s exceptional pathogenicity. Furthermore, the O104:H4 outbreak strain adheres significantly better to cultured epithelial cells than archetypal EAEC strains expressing different AAF subtypes. To test whether AAF/I expression is associated with the different virulence phenotypes of the outbreak strain, we heterologously expressed AAF subtypes I, III, IV, and V in an AAF-negative EAEC 55989 mutant and compared AAF-mediated phenotypes, incl. autoaggregation, biofilm formation, as well as bacterial adherence to HEp-2 cells. We observed that the expression of all four AAF subtypes promoted bacterial autoaggregation, though with different kinetics. Disturbance of AAF interaction on the bacterial surface via addition of α-AAF antibodies impeded autoaggregation. Biofilm formation was enhanced upon heterologous expression of AAF variants and inversely correlated with the autoaggregation phenotype. Co-cultivation of bacteria expressing different AAF subtypes resulted in mixed bacterial aggregates. Interestingly, bacteria expressing AAF/I formed the largest bacterial clusters on HEp-2 cells, indicating a stronger host cell adherence similar to the EHEC O104:H4 outbreak strain. Our findings show that, compared to the closely related O104:H4 EAEC strain 55989, not only the acquisition of the Shiga toxin phage, but also the acquisition of the AAF/I subtype might have contributed to the increased EHEC O104:H4 pathogenicity.

Bacterial susceptibility patterns to cotrimoxazole in urinary tract infections of outpatients and inpatients in Jakarta, Indonesia

BACKGROUND Cotrimoxazole, which has been one of the drugs of choice for urinary tract infections (UTIs) since 1960, must be evaluated to determine whether it is still a relevant drug for this use. This study aimed to assess the susceptibility patterns to cotrimoxazole of the bacteria that cause UTIs from urine samples of female outpatients (community-acquired [CA]-UTI) and inpatients (hospital-acquired [HA]-UTI) in Jakarta. METHODS This study was conducted from December 2014 to December 2015. Susceptibility testing of bacteria causing UTIs was conducted on 27 of 311 female outpatient urine samples collected from six clinics in Jakarta, and secondary data susceptibility testing was performed on 27 of 107 urine samples of inpatients from hospitals in Jakarta. These samples were examined in the Clinical Microbiology Laboratory, Faculty of Medicine, Universitas Indonesia, Cipto Mangunkusumo Hospital. RESULTS Susceptibility to cotrimoxazole was reported in 83% of the bacteria causing UTIs in CA-UTI and 44% of the bacteria in HA-UTI patients. Klebsiella pneumoniae was the most common cause of CA-UTI, with all isolates susceptible to cotrimoxazole (100%). Conversely, Escherichia coli was the most common cause of HA-UTI but was only susceptible in some isolates (44%). Bacteria from CA-UTI patients were almost twice as susceptible to cotrimoxazole compared with HA-UTI patients (p = 0.003). CONCLUSIONS Based on the susceptibility patterns identified, cotrimoxazole can be used as a treatment for CA-UTI but not for HA-UTI patients in Jakarta, Indonesia.

Genetic and Virulence Characteristics of a Hybrid Atypical Enteropathogenic and Uropathogenic Escherichia coli (aEPEC/UPEC) Strain

Hybrid strains of Escherichia coli combine virulence traits of diarrheagenic (DEC) and extraintestinal pathogenic E. coli (ExPEC), but it is poorly understood whether these combined features improve the virulence potential of such strains. We have previously identified a uropathogenic E. coli (UPEC) strain (UPEC 252) harboring the eae gene that encodes the adhesin intimin and is located in the locus of enterocyte effacement (LEE) pathogenicity island. The LEE-encoded proteins allow enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) to form attaching and effacing (A/E) lesions in enterocytes. We sought to characterize UPEC 252 through whole-genome sequencing and phenotypic virulence assays. Genome analysis unveiled that this strain harbors a complete LEE region, with more than 97% of identity comparing to E2348/69 (EPEC) and O157:H7 Sakai (EHEC) prototype strains, which was functional, since UPEC 252 expressed the LEE-encoded proteins EspB and intimin and induced actin accumulation foci in HeLa cells. Phylogenetic analysis performed comparing 1,000 single-copy shared genes clustered UPEC 252 with atypical EPEC strains that belong to the sequence type 10, phylogroup A. Additionally, UPEC 252 was resistant to the bactericidal power of human serum and colonized cells of the urinary (T24 and HEK293-T) and intestinal (Caco-2 and LS174T) tracts. Our findings suggest that UPEC 252 is an atypical EPEC strain that emerges as a hybrid strain (aEPEC/UPEC), which could colonize new niches and potentially cause intestinal and extraintestinal infections.

Characterization of water treatment-resistant and multidrug-resistant urinary pathogenic Escherichia coli in treated wastewater

A growing body of evidence has demonstrated that extraintestinal pathogenic E. coli (ExPEC), such as the urinary pathogenic E. coli (UPEC), are common constituents of treated wastewater, and therefore represent a potential public health risk. However, no single virulence gene, or set of virulence genes, can be used to conclusively identify this genetically diverse pathotype. As such we sought to identify and characterize the public health relevance of potential UPEC found in treated sewage/wastewater using a comparative genomics approach. Presumptive wastewater UPEC (W-UPEC) were initially identified by virulence gene screening against 5 virulence genes, and for which isolates containing ≥3 virulence genes were whole genome sequenced (n = 24). Single nucleotide polymorphic (SNP) spanning tree analysis demonstrated that many of these wastewater UPEC (WUPEC) were virtually identical at the core genome (0.4 Mbp) when compared to clinical UPEC (C-UPEC) sequences obtained from NCBI, varying by as little as 1 SNP. Remarkably, at the whole genome level, W-UPEC isolates displayed >96% whole genome similarity to C-UPEC counterparts in NCBI, with one strain demonstrating 99.5% genome similarity to a particular C-UPEC strain. The W-UPEC populations were represented by sequence types (ST) known to be clinically important, including ST131, ST95, ST127 and ST640. Many of the W-UPEC carried the exact same complement of virulence genes as their most closely related C-UPEC strains. For example, O25b-ST131 W-UPEC strains possessed the same 80 virulence genes as their most closely related C-UPEC counterparts. Concerningly, W-UPEC strains also carried a plethora of antibiotic resistance genes, and O25b-ST131strains were designated as extended spectrum beta-lactamase (ESBL) producing E. coli by both genome profiling and phenotypic resistance testing. W-UPEC ST131 strains were found in the effluents of a single treatment plant at different times, as well as different wastewater treatment plants, suggesting a differentially ability to survive wastewater treatment. Indeed, in sewage samples treated with chlorine doses sufficient for inducing a ∼99.99% reduction in total E. coli levels, UPEC represented a significant proportion of the chlorine-resistant population. By contrast, no Shiga toxin-producing E. coli were observed in these chlorinated sewage libraries. Our results suggest that clinically-relevant UPEC exist in treated wastewater effluents and that they appear to be specifically adapted to survive wastewater treatment processes.