Type 1 fimbrial phase variation in multidrug-resistant asymptomatic uropathogenic Escherichia coli clinical isolates upon adherence to HTB-4 cells.

The adherence of bladder uroepithelial cells, subsequent expression, and regulation of type 1 fimbrial genes (key mediator of attachment) in clinical multidrug-resistant uropathogenic Escherichia coli (MDR-UPECs) isolated from individuals with asymptomatic bacteriuria (ABU) remain unexplored till date. Therefore, this study aimed to investigate the underlying molecular mechanisms associated with the adherence of clinical MDR-ABU-UPECs to human a uroepithelial cell line (HTB-4), both in the absence and presence of D-Mannose. These investigations focused on phase variation, expression, and regulation of type 1 fimbriae and were compared to a prototype ABU-strain (E. coli 83972) and symptomatic MDR-UPECs. Discordant to the ABU prototype strain, MDR-ABU-UPECs exhibited remarkable adhesive capacity that was significantly reduced after D-mannose exposure, fairly like the MDR symptomatic UPECs. The type 1 fimbrial phase variation, determined by the fim switch analysis, asserted the statistically significant incidence of "both OFF and ON" orientation among the adherent MDR-ABU-UPECs with a significant reduction in phase-ON colonies post-D-mannose exposure, akin to the symptomatic ones. This was indicative of an operative and alternating type 1 fimbrial phase switch. The q-PCR assay revealed a coordinated action of the regulatory factors; H-NS, IHF, and Lrp on the expression of FimB and FimE recombinases, which further controlled the function of fimH and fimA genes in ABU-UPECs, similar to symptomatic strains. Therefore, this study is the first of its kind to provide an insight into the regulatory crosstalk of different cellular factors guiding the adhesion of ABU-UPECs to the host. Additionally, it also advocated for the need to accurately characterize ABU-UPECs.

Fusobacterium nucleatum: An Overview of Evidence, Demi-Decadal Trends, and Its Role in Adverse Pregnancy Outcomes and Various Gynecological Diseases, including Cancers.

Gynecological and obstetric infectious diseases are crucial to women's health. There is growing evidence that links the presence of Fusobacterium nucleatum (F. nucleatum), an anaerobic oral commensal and potential periodontal pathogen, to the development and progression of various human diseases, including cancers. While the role of this opportunistic oral pathogen has been extensively studied in colorectal cancer in recent years, research on its epidemiological evidence and mechanistic link to gynecological diseases (GDs) is still ongoing. Thus, the present review, which is the first of its kind, aims to undertake a comprehensive and critical reappraisal of F. nucleatum, including the genetics and mechanistic role in promoting adverse pregnancy outcomes (APOs) and various GDs, including cancers. Additionally, this review discusses new conceptual advances that link the immunomodulatory role of F. nucleatum to the development and progression of breast, ovarian, endometrial, and cervical carcinomas through the activation of various direct and indirect signaling pathways. However, further studies are needed to explore and elucidate the highly dynamic process of host-F. nucleatum interactions and discover new pathways, which will pave the way for the development of better preventive and therapeutic strategies against this pathobiont.

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.

Epidemiologic and molecular characterization of Beta-lactamase-producing multidrug-resistant uropathogenic Escherichia coli isolated from asymptomatic hospitalized patients / Caracterización epidemiológica y molecular de Escherichia coli uropatógena multirresistente productora de Beta-lactamasa aislada de pacientes hospitalizados asintomáticos

Uropathogenic Escherichia coli (UPECs) are the predominant cause of asymptomatic bacteriuria (ABU) and symptomatic UTI. In this study, multidrug-resistant (MDR) ABU-UPECs from hospitalized patients of Kolkata, India, were characterized with respect to their ESBL phenotype, acquisition of β-lactamase genes, mobile genetic elements (MGEs), phylotype property, ERIC-PCR profile, sequence types (STs), clonal complexes (CCs) and evolutionary and quantitative relationships and compared to the symptomatic ones to understand their epidemiology and evolutionary origin. Statistically significant incidence of ESBL producers, β-lactamase genes, MGEs and novel phylotype property (NPP) among ABU-UPECs similar to the symptomatic ones indicated the probable incidence of chromosomal plasticity on resistance gene acquisition through MGEs due to indiscriminate drug usage. ERIC-PCR typing and MLST analysis showed clonal heterogeneity and predominance of ST940 (CC448) among asymptomatic isolates akin to symptomatic ones along with the evidence of zoonotic transmissions. Minimum spanning tree analysis showed a close association between ABU-UPEC with known and unidentified STs having NPPs with isolates that belonged to phylogroups clade I, D, and B2. This is the first study that reported the occurrence of MGEs and NPPs among ABU-UPECs with the predominance of ESBL production which displayed the deleterious effect of MDR among this pathogen demanding alternative therapeutic interventions. Moreover, this study for the first time attempted to introduce a new approach to ascertain the phylotype property of unassigned UPECs. Withal, increased recognition, proper understanding and characterization of ABU-UPECs with the implementation of appropriate therapeutic measures against them when necessary are the need of the era which otherwise might lead to serious complications in the vulnerable population.(AU)

Epidemiologic and molecular characterization of ß-lactamase-producing multidrug-resistant uropathogenic Escherichia coli isolated from asymptomatic hospitalized patients.

Uropathogenic Escherichia coli (UPECs) are the predominant cause of asymptomatic bacteriuria (ABU) and symptomatic UTI. In this study, multidrug-resistant (MDR) ABU-UPECs from hospitalized patients of Kolkata, India, were characterized with respect to their ESBL phenotype, acquisition of ß-lactamase genes, mobile genetic elements (MGEs), phylotype property, ERIC-PCR profile, sequence types (STs), clonal complexes (CCs) and evolutionary and quantitative relationships and compared to the symptomatic ones to understand their epidemiology and evolutionary origin. Statistically significant incidence of ESBL producers, ß-lactamase genes, MGEs and novel phylotype property (NPP) among ABU-UPECs similar to the symptomatic ones indicated the probable incidence of chromosomal plasticity on resistance gene acquisition through MGEs due to indiscriminate drug usage. ERIC-PCR typing and MLST analysis showed clonal heterogeneity and predominance of ST940 (CC448) among asymptomatic isolates akin to symptomatic ones along with the evidence of zoonotic transmissions. Minimum spanning tree analysis showed a close association between ABU-UPEC with known and unidentified STs having NPPs with isolates that belonged to phylogroups clade I, D, and B2. This is the first study that reported the occurrence of MGEs and NPPs among ABU-UPECs with the predominance of ESBL production which displayed the deleterious effect of MDR among this pathogen demanding alternative therapeutic interventions. Moreover, this study for the first time attempted to introduce a new approach to ascertain the phylotype property of unassigned UPECs. Withal, increased recognition, proper understanding and characterization of ABU-UPECs with the implementation of appropriate therapeutic measures against them when necessary are the need of the era which otherwise might lead to serious complications in the vulnerable population.

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.

Incidence of multidrug resistance, pathogenicity island markers, and pathoadaptive FimH mutations in uropathogenic Escherichia coli isolated from asymptomatic hospitalized patients.

Asymptomatic uropathogenic Escherichia coli (UPECs) are the leading cause of asymptomatic bacteriuria (ABU) in humans. So this study aimed to identify and characterize ABU UPECs from hospitalized patients of Kolkata, India, with respect to their antibiogram profile, phylogeny, pathogenicity islands, and virulence factor gene acquisition and FimH mutations in comparison to symptomatic UPECs. E. coli was detected biochemically in 44.44% (20/45) and 32.26% (20/62) of urine culture-positive asymptomatic and symptomatic hospitalized individuals respectively. Ninety-five percent of the asymptomatic isolates were multidrug resistant (MDR) compared to the symptomatic isolates (100%). Significant predominance of unknown phylogroup, pathogenicity island markers (PAI IV536, PAI I CFT073), and distribution patterns of different virulence factor genes respectively was evident among both groups. A significant correlation was observed between both groups of isolates with respect to their antibiotic resistances (except imipenem, amikacin, and nitrofurantoin), prevalence of phylogenetic groups and PAIs, and virulence factor gene (fimH, papC, papEF, papGII, iucD, and cnf1) acquisition. Pathoadaptive FimH adhesin mutations, especially hot spot mutation V27A, were detected in 80% asymptomatic isolates mostly reported in symptomatic ones worldwide. Moreover, this is the first study from India that reported incidence of "Unknown" phylogroup, pathogenicity island markers, and potentially pathoadaptive FimH mutations in asymptomatic UPECs isolated from hospitalized patients which further indicated that these ABU E. coli might have originated from their symptomatic counterparts due to unbridled use of unprescribed antibiotics. Therefore, this study demands antibiotic de-escalation along with regular and intricate monitoring at the molecular level for efficient management of ABU that addresses a major public health concern.