Comprehensive analysis of multiple cytokines to stratify uropathogenic Escherichia coli pathogenesis in mouse model of urinary tract infection.

PURPOSE: Urinary tract infection (UTI) is one of the most common human bacterial infections primarily caused by uropathogenic E. coli (UPEC). Empiric treatment in UTI cause emergence of multidrug resistance and limit treatment options. Understanding UTI at the molecular level with respect to the causative pathogen as well as subsequent host response pose an absolute necessity towards appropriate clinical management. This study aimed to investigate host cytokine response in mouse UTI model with respect to bacterial colonization and associated virulence gene expression upon infection. METHOD: Mouse UTI model was established with two clinical UPEC isolates E. coli NP105 and E. coli P025. UPEC colonization in bladder and kidney was evaluated by bacterial culture (CFU/ml). Histopathology of the tissues were examined by hematoxylin and eosin staining. PCR and real time PCR were used to detect the incidence and expression of respective bacterial genes. Cytokine concentrations in tissues and sera were evaluated using ELISA. GraphPad prism version 8.0.2 was used for statistical interpretation. RESULT: Highest bacterial colonization was observed on 7th and 9th day post infection (p.i). in bladder and kidney of mouse infected with E. coli P025 and E. coli NP105 respectively with a distinct difference in relative expression of fimH and papC adhesin genes in vivo. IL-1ß level in tissues and sera of E. coli NP105 and E. coli P025 infected mouse was significantly different but the IL-17A, GCSF, TGF-ß levels were comparable. CONCLUSION: These findings show a role of IL1ß to stratify pathogenicity of UPEC in mouse UTI model.

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

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

Cytokine profile in HTB-4 cells with respect to fimH, papC and hlyA expression in uropathogenic Escherichia coli invasion.

Background: In this study, uropathogenic Escherichia coli (UPEC) from pregnant and nonpregnant patients were characterized with respect to antimicrobial resistance (AMR) and expression of their virulence factors and cytokines elicited upon infection in urothelial (HTB-4) cells in vitro to frame proper therapeutics. Methods: Antibiotic sensitivity and adherence to HTB-4 cells were tested and PCR and real-time PCR were performed. Results: UPEC from nonpregnant patients showed the most resistance with a significant correlation between the expression of hlyA and TGF-ß and papC and GCSF. The expression of fimH and IFN-γ, fimH and IL-1ß, and fimH and IL-17A, respectively, were significantly correlated in UPEC from pregnant patients. Conclusion: Cytokine expression profiles were correlated with the expression of virulence genes in UPEC that was isolated from different populations, and should be accounted for along with AMR analysis.

Uropathogenic Escherichia coli in India-an Overview on Recent Research Advancements and Trends.

Urinary tract infection (UTI), a prevalent disease in India, also ranks among the most common infections in developing countries. The rapid emergence of antibiotic-resistant uropathogenic Escherichia coli (UPECs), the leading etiologic agent of UTI, in the last few years, led to an upsurge in the health care cost. This caused a considerable economic burden, especially in low-middle income country, India. This review aimed to provide an explicit overview of the recent advancements in E. coli-mediated UTI in India by incorporation of valuable information from the works published in PubMed and Google Scholar in the last six years (2015 to August, 2020). The literature survey demonstrated UPECs as the most predominant uropathogen in India, especially among females, causing both asymptomatic bacteriuria (ABU) and symptomatic UTI. An overall increasing national trend in resistance to penicillins, cephalosporins, aminoglycosides, fluoroquinolones, and sulfonamides was perceived irrespective of ABU and symptomatic UPECs during the aforementioned study period. High incidences of multidrug resistance, extended-spectrum ß-lactamases, metallo ß-lactamases, and AmpCs in UPECs were reported. Notable information on the pathogenic profiles, phylogroups, pathogenicity islands, and evidence of pathoadaptive FimH mutations was described. Alternative therapeutics and potential drug targets against UPECs were also reconnoitered. Therefore, the nationwide widespread occurrences of highly virulent MDR UPEC together with the limited availability of therapeutics highlighted the urgent need for promotion and invention of alternative therapeutics, search for which had already been started. Moreover, investigation of several mechanisms of UPEC infection and the search for potential drug targets might help to design newer therapeutics.

Phylogenetic background of E. coli isolated from asymptomatic pregnant women from Kolkata, India.

INTRODUCTION: Asymptomatic bacteriuria (ABU) in pregnancy generates medical complications. E. coli is the common etiologic agent responsible for ABU-associated infections. This study aimed to identify the phylogenetic background and drug resistance in asymptomatic E. coli from a pregnant population. METHODOLOGY: E. coli was confirmed biochemically from culture-positive urine samples collected from asymptomatic pregnant women. Phylogenetic typing was done by polymerase chain reaction (PCR). The isolates were subjected to antibiotic susceptibility testing and extended-spectrum beta-lactamase (ESBL) production. Statistical significance was determined using SPSS 17.0 software. RESULTS: Bacteriuria was observed in 113 (22.6%) of 500 asymptomatic pregnant females. E. coli was reported in 44 (38.9%) of 113 isolates. The mean age-wise distribution was 25.14 ± 4.63. Although pathogenic phylogroup B2 was predominant (54.5%), incidence of non-pathogenic phylogroup B1 (27.3%) was found to be statistically significant (p ≤ 0.001), and B1 and B2 were correlated with respect to total ABU population. Antibiotic sensitivity against ampicillin (34.1%), ceftazidime (50%), cefotaxime (47.7%), ciprofloxacin (47.7%), amikacin (86.4%), nitrofurantion (79.5%), and co-trimoxazole (36.4%) was observed. Multidrug resistance (MDR) and ESBL production was reported in 26 (59.1%) of 44 and 18 (69.2%) of the 26 MDR isolates, respectively. A significant distribution of phylogroup B1 (p = 0.03) with drug resistance was also observed. CONCLUSIONS: This is the first study that reported significant incidence of non-pathogenic phylogroup B1 in asymptomatic E. coli with high incidence of MDR isolated from pregnant women in Kolkata, India.  These varied resistance patterns present major therapeutic and infection control challenges during pregnancy.