Uropathogenic Escherichia coli strains harboring tosA gene were associated to high virulence genes and a multidrug-resistant profile

Molecular epidemiology, antibiotic resistance profile and frequency of integron 1 and 2 in adherent-invasive Escherichia coli isolates of colorectal cancer patients

This study explores the prevalence of adherent-invasive Escherichia coli (AIEC) in colorectal cancer (CRC) patients and investigates the potential of effective intracellular antibiotics as a therapeutic strategy for CRC patients with AIEC infections. Considering the pivotal role of integrons in bacterial antibiotic resistance, the frequency of class 1 and 2 integrons in AIEC isolated from CRC patients, in one of the referenced 3 gastroenterology clinics in Isfahan, Iran was examined. AIEC strains were isolated from the colorectal biopsies and their antimicrobial sensitivity was assessed using the disc diffusion method. Polymerase chain reaction (PCR) was employed to detect intl1 and intl2. The multilocus sequence typing (MLST) method was utilized to type 10 selected isolates. Of the 150 samples, 24 were identified as AIEC, with the highest number isolated from CRC2 (33.4%) and CRC1 (29.16%), and the least from the FH group (8.3%) and control group (12.5%). int1 in 79.2% and int2 in 45.8% of AIEC strains were found and 41.6% of strains had both integrons. AIEC isolates with int1 exhibited the highest sensitivity to trimethoprim-sulfamethoxazole (57.9%), while those with int2 showed the highest sensitivity to ciprofloxacin (63.6%). A significant association between resistance to rifampin and integron 2 presence in AIEC isolates was observed. Furthermore, a significant correlation between integron 1 presence, invasion, survival, and replication within macrophages in AIEC strains was identified. MLST analysis revealed ST131 from CC131 with integron 1 as the most common sequence type (ST). The emergence of such strains in CRC populations poses a serious public health threat. The distribution pattern of STs varied among studied groups, with pandemic STs highlighting the importance of examining and treating patients infected with these isolates. Comprehensive prospective clinical investigations are warranted to assess the prognostic value of detecting this pathovar in CRC and to evaluate therapeutic techniques targeting drug-resistant AIECs, such as phage therapy, bacteriocins, and anti-adhesion compounds, for CRC prevention and treatment.

Uropathogenic Escherichia coli endeavors: an insight into the characteristic features, resistance mechanism, and treatment choice

Uropathogenic Escherichia coli (UPEC) are the strains diverted from the intestinal status and account mainly for uropathogenicity. This pathotype has gained specifications in structure and virulence to turn into a competent uropathogenic organism. Biofilm formation and antibiotic resistance play an important role in the organism's persistence in the urinary tract. Increased consumption of carbapenem prescribed for multidrug-resistant (MDR) and Extended-spectrum-beta lactamase (ESBL)-producing UPECs, has added to the expansion of resistance. The World Health Organization (WHO) and Centre for Disease Control (CDC) placed the Carbapenem-resistant Enterobacteriaceae (CRE) on their treatment priority lists. Understanding both patterns of pathogenicity, and multiple drug resistance may provide guidance for the rational use of anti-bacterial agents in the clinic. Developing an effective vaccine, adherence-inhibiting compounds, cranberry juice, and probiotics are non-antibiotical approaches proposed for the treatment of drug-resistant UTIs. We aimed to review the distinguishing characteristics, current therapeutic options and promising non-antibiotical approaches against ESBL-producing and CRE UPECs.

The Role of Outer Membrane Proteins in UPEC Antimicrobial Resistance: A Systematic Review

Uropathogenic Escherichia coli (UPEC) are one of the most common agents of urinary tract infection. In the last decade, several UPEC strains have acquired antibiotic resistance mechanisms and some have become resistant to all classes of antibiotics. UPEC outer membrane proteins (OMPs) seem to have a decisive role not only in the processes of invasion and colonization of the bladder mucosa, but also in mechanisms of drug resistance, by which bacteria avoid killing by antimicrobial molecules. This systematic review was performed according to the PRISMA guidelines, aiming to characterize UPEC OMPs and identify their potential role in antimicrobial resistance. The search was limited to studies in English published during the last decade. Twenty-nine studies were included for revision and, among the 76 proteins identified, seven were associated with antibiotic resistance. Indeed, OmpC was associated with β-lactams resistance and OmpF with β-lactams and fluoroquinolone resistance. In turn, TolC, OmpX, YddB, TosA and murein lipoprotein (Lpp) were associated with fluoroquinolones, enrofloxacin, novobiocin, β-lactams and globomycin resistances, respectively. The clinical implications of UPEC resistance to antimicrobial agents in both veterinary and human medicine must propel the implementation of new strategies of administration of antimicrobial agents, while also promoting the development of improved antimicrobials, protective vaccines and specific inhibitors of virulence and resistance factors.

Molecular Factors and Mechanisms Driving Multidrug Resistance in Uropathogenic Escherichia coli-An Update

The rapid emergence of multidrug-resistant (MDR) bacteria indisputably constitutes a major global health problem. Pathogenic Escherichia coli are listed among the most critical group of bacteria that require fast development of new antibiotics and innovative treatment strategies. Among harmful extraintestinal Enterobacteriaceae strains, uropathogenic E. coli (UPEC) pose a significant health threat. UPEC are considered the major causative factor of urinary tract infection (UTI), the second-most commonly diagnosed infectious disease in humans worldwide. UTI treatment places a substantial financial burden on healthcare systems. Most importantly, the misuse of antibiotics during treatment has caused selection of strains with the ability to acquire MDR via miscellaneous mechanisms resulting in gaining resistance against many commonly prescribed antibiotics like ampicillin, gentamicin, cotrimoxazole and quinolones. Mobile genetic elements (MGEs) such as transposons, integrons and conjugative plasmids are the major drivers in spreading resistance genes in UPEC. The co-occurrence of various bacterial evasion strategies involving MGEs and the SOS stress response system requires further research and can potentially lead to the discovery of new, much-awaited therapeutic targets. Here, we analyzed and summarized recent discoveries regarding the role, mechanisms, and perspectives of MDR in the pathogenicity of UPEC.

The role of uropathogenic Escherichia coli adhesive molecules in inflammatory response- comparative study on immunocompetent hosts and kidney recipients

Background

Urinary tract infections (UTI) represent one of the most common contagious diseases in humans. Uropathogenic Escherichia coli (UPEC) strains are recognized as the most frequent causative agent, and these express a range of virulence factors including the adhesins. Immune response to UPEC under immunosuppression has not been fully understood yet. Interleukin 1β (IL1β), 6 (IL6) and 17 (IL17) represent clinically relevant markers of inflammation.

Aim

The study aimed to investigate the interplay between UPEC genotype and hosts’ immune status in shaping local inflammatory response in the course of an UTI episode. The respective numbers of: 18 kidney recipients with UPEC UTI, 28 immunocompetent hosts with UPEC UTI and 29 healthy controls were involved. Urine IL1β, IL6, and IL17/creatinine ratios in relation to fimH, csgA, papC, tosA, and flu genes presence in UPEC isolated from the urine samples were analyzed. Apart from traditional statistics, also machine learning algorithms were applied.

Results

The urine levels of IL1β and IL 6 were similar in kidney recipients and the immunocompetent hosts. IL1β levels were higher in both kidney recipients and immunocompetent hosts than in controls, while IL6 levels were higher only in immunocompetent hosts than in controls. In the machine learning classification model, high urine IL17 levels were significantly more prevalent in controls, while low IL17 levels in urines infected with Ag43-positive UPEC strains, regardless of the host’s immune status. In the traditional statistical analysis, IL17 levels appeared significantly higher in urine samples from kidney recipients infected with Ag43–negative UPEC strains.

Conclusions

In the UTI- affected patients, the combination of the immune status of an individual and Ag43 status of the UPEC strain determined urine IL17 level in the analyzed group. However, IL17 levels above median were overall more prevalent in controls.

Phylogenetic Groups/B2 Subgroup Distributions, Serogrouping and Identification of Virulence Factors in Extended-Spectrum Cephalosporin-Resistant Escherichia coli Strains Isolated from the Stool of Healthy Children Under 10 Years Old

Background: Segregation of Escherichia coli (E. coli) into the phylogenetic groups was observed in the experiments so that group B2 contained the enteropathogenic E. coli (EPEC) strains and extraintestinal pathogenic E. coli (ExPEC). Objectives: This study aimed to identify B2 phylogenetic groups in the extended-spectrum Cephalosporins resistant E. coli isolated from the stool of healthy children under 10 years old. Methods: One hundred E. coli resistant to broad-spectrum Cephalosporins were collected from the feces of healthy children under 10. Subsequently, we grouped phylogenetic via PCR based on the genes yjaA, chuA, arpA, as well, as TspE4.C2. Then, according to Clermont et al.’s study, we used two individual multiplex PCRs for identifying B2 sub-groups (I-X subgroups). Serogroup typing with the 12 O-antigen was analyzed via PCR, and finally, 10 virulence genes (cnf1, papG, ibeA, malX, usp, cdt, eae, bfp, and afa-Dr) were identified with PCR. Results: The age range of the healthy children was between 1 and 10 years. The B2 and unknown phylogroups were the most common strains in this study. The most common B2 subgroups were I (STc131) (2%), IX (1%), V (8%), IV, V, VII (1%), IX, V (3%), IX, V, III, I (1%), IX, V, III, VII, I (%1), V, I (6%), V, III, I (3%), and V, III, VII (1%), with each subgroup carrying distinctive sets of ExPEC virulence markers. The results also showed that 29% of E. coli in the healthy children had malX and 23% had papGII. It was also found that 32% of the strains isolated from the healthy children had antigens O2 and 36% were unknown. Conclusions: In this study, 27% of the strains belonged to B2 phylogroup and 6% to B1 phylogroup. Moreover, serogroups O2, O16, and O25 were predominant and belonged to B2 phylogroup. Moreover, malX, papGII, usp, papGIII, aggR, and eae virulence genes also had the highest to lowest supply among the tested strains, respectively. Moreover, B2 isolates were shown to have further virulence-related genes in comparison to the non B2 isolates.

Virulence gene mutations as a differentiator of clinical phenotypes: insights from community-acquired uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) remains an important cause of urinary tract infection during pregnancy. Multiple molecular virulence determinants and antibiotic resistant genes facilitate its pathogenesis and virulence phenotype. Hence it is hypothesized that there will be considerable variation in genes among the isolates from symptomatic as well as asymptomatic bacteriuria (ABU) during pregnancy. The aim of this study was to decipher the genetic variation among the two phenotypes. Six different UPEC isolates collected from urine specimens of consecutive pregnant females (five, symptomatic bacteriuria and one, ABU) were tested for their growth kinetics, and biofilm formation. A total of 87 virulence determinants and 56 antibiotic resistance genes were investigated using whole-genome sequencing, to identify putative drives of virulence phenotype. In this analysis, we identified eight different types of fully functional toxin antitoxin (TA) systems [HipAB, YefM-YoeB, YeeU-YeeV (CbtA), YhaV-PrlF, ChpBS, HigAB, YgiUT and HicAB] in the isolates from symptomatic bacteriuria; whereas partially functional TA system with mutations were observed in the asymptomatic one. Isolates of both the groups showed equivalent growth characteristics and biofilm-formation ability. Genes for an iron transport system (Efe UOB system, Fhu system except FhuA) were observed functional among all symptomatic and asymptomatic isolates, however functional mutations were observed in the latter group. Gene YidE was observed predominantly associated with the biofilm formation along with few other genes (BssR, BssS, YjgK, etc.). This study outlines putative critical relevance of specific variations in the genes for the TA system, biofilm formation, cell adhesion and colonization among UPEC isolates from symptomatic and asymptomatic bacteriuria among pregnant women. Further functional genomic study in the same cohort is warranted to establish the pathogenic role of these genes.

Phylogenetic relationship and virulence gene profiles of avian pathogenic and uropathogenic Escherichia coli isolated from avian colibacillosis and human urinary tract infections (UTIs)

Background

There is evidence representing the possible relationship between avian pathogenic Escherichia coli (APEC) and other extraintestinal pathogenic E. coli (ExPEC) strains such as human uropathogenic isolates.

Aims ‏‏

The present study was conducted to evaluate virulence and phylogenetic relationship between a total of 70 APEC and UPEC isolates (35 APEC and 35 UPEC isolates) obtained from the north of Iran which is one of the core areas of the country's poultry industry.

Methods

Polymerase chain reaction (PCR) and random amplified polymorphism DNA (RAPD) analyses were conducted using specific primers, and data was analyzed using BioNumerics and SPSS softwares.

Results

The most prevalent gene was fliC (70.6%) followed by fimH (67.1%), but APEC and UPEC isolates showed inordinate and obvious differences in the presence of some virulence genes such as fliC, hlyD, and sfa1 and predominant phylogenetic groups in DNA fingerprinting methods.

Conclusion

The results showed obvious differences existed between isolates of APEC and UPEC in terms of phylogenetics and pattern of virulence gene; however, despite having virulence genes such as papC, ibeA, and iss, APEC isolates can have a high potential for causing disease in humans and may generate dangerous outbreaks in communities with low levels of hygiene in public and the poultry industry.

Molecular Epidemiology of Multidrug-Resistant Uropathogenic Escherichia coli O25b Strains Associated with Complicated Urinary Tract Infection in Children

Background: Uropathogenic Escherichia coli (UPEC) has increased the incidence of urinary tract infection (UTI). It is the cause of more than 80% of community-acquired cystitis cases and more than 70% of uncomplicated acute pyelonephritis cases. Aim: The present study describes the molecular epidemiology of UPEC O25b clinical strains based on their resistance profiles, virulence genes, and genetic diversity. Methods: Resistance profiles were identified using the Kirby–Bauer method, including the phenotypic production of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs). The UPEC serogroups, phylogenetic groups, virulence genes, and integrons were determined via multiplex PCR. Genetic diversity was established using pulsed-field gel electrophoresis (PFGE), and sequence type (ST) was determined via multilocus sequence typing (MLST). Results: UPEC strains (n = 126) from hospitalized children with complicated UTIs (cUTIs) were identified as O25b, of which 41.27% were multidrug resistant (MDR) and 15.87% were extensively drug resistant (XDR). The O25b strains harbored the fimH (95.23%), csgA (91.26%), papGII (80.95%), chuA (95.23%), iutD (88.09%), satA (84.92%), and intl1 (47.61%) genes. Moreover, 64.28% were producers of ESBLs and had high genetic diversity. ST131 (63.63%) was associated primarily with phylogenetic group B2, and ST69 (100%) was associated primarily with phylogenetic group D. Conclusion: UPEC O25b/ST131 harbors a wide genetic diversity of virulence and resistance genes, which contribute to cUTIs in pediatrics.

Escherichia coli Strains with Virulent Factors Typical for Uropathogens were Isolated from Sinuses from Patients with Chronic Rhinosinusitis-Case Report

Escherichia coli were isolated from three patients with chronic rhinosinusitis (CRS) by intraoperative sinus tissue biopsy. Taking into account the unusual replicative niche and previous treatment failures, it was decided to focus on the virulence and drug resistance of these bacteria. The strains turned out to be multi-sensitive, but the rich virulence factors profile of bacteria typical for phylogenetic group B2 deserved attention. Tests were carried out for the presence of 32 genes using the PCR method. Particularly noteworthy are the toxins Cnf-1, HlyA, Usp-an extensive iron uptake system (enterobactin, salmochelin, yersiniabactin and outer membrane hemin receptor ChuA)-SPATE autotransporters such as vat and pic, Ag43 autoaggregative protein-important for biofilm formation-and TosA/B which enhance the fitness of E.coli. All these virulence factors are identified predominantly in UPEC strains and provide a fitness advantage during colonization of the sinuses. Patients with CRS should be asked for past or present UTI. The specific virulence factors of E. coli that facilitate the colonization of the GI tract and urinary tract may also favor the colonization of a new ecological niche (sinuses) as a result of microbial imbalance or dysbiosis.