Conjugal transfer of PMQR from uropathogenic E.coli under high ciprofloxacin selection pressure generates gyrA mutation

Chlorpromazine inhibits the plasmid-mediated oqxAB multidrug efflux pump in Escherichia coli isolates of Egyptian patients with utis

Over the past ten years, the prevalence of the OqxAB efflux pump, a plasmid-mediated quinolone resistance determinant, has increased among Escherichia coli (E. coli) isolates. The aim of this study was to genotypically and phenotypically investigate quinolone resistance of isolates and transferability of oqxAB genes by conjugation. One hundred E. coli isolates were collected from UTIs samples and identified using biochemical techniques and confirmed by VITEK-2 System. Antibiotic resistance of isolates was determined by disc diffusion method. MIC of levofloxacin was determined using the broth microdilution method. Efflux pump-mediated resistance was assessed using the chlorpromazine-based efflux-pump inhibitor microplate assay. PMQR genes (oqxA, oqxB) were detected by conventional PCR. A conjugation experiment was run to investigate the transferability of the quinolone resistance in having plasmids carrying oqxAB. DNA sequencing was performed for the identification of genes in both donors and tranconjugants. 80% of E. coli isolates were resistant for levofloxacin. Chlorpromazine significantly decreased the levofloxacin MIC values. oqxA and oqxB genes were detected in 44% and 39% of levofloxacin resistant isolates, respectively. The conjugation experiment revealed the transfer of resistance. MICs of levofloxacin in transconjugants carrying oqxAB significantly increased as compared to the parental recipients MICs. In conclusion, plasmid-mediated quinolone resistance linked to oqxAB may be a factor in rapid rise in and spread of bacterial quinolone resistance among Egyptian E. coli isolates. Chlorpromazine could inhibit efflux pump activity leading to decreased quinolones resistance improving their effectiveness in treatment infectious diseases.

Clinically relevant mutations in regulatory regions of metabolic genes facilitate early adaptation to ciprofloxacin in Escherichia coli

The genomic landscape associated with early adaptation to ciprofloxacin is poorly understood. Although the interplay between core metabolism and antimicrobial resistance is being increasingly recognized, mutations in metabolic genes and their biological role remain elusive. Here, we exposed Escherichia coli to increasing gradients of ciprofloxacin with intermittent transfer-bottlenecking and identified mutations in three non-canonical targets linked to metabolism including a deletion (tRNA-ArgΔ414-bp) and point mutations in the regulatory regions of argI (ARG box) and narU. Our findings suggest that these mutations modulate arginine and carbohydrate metabolism, facilitate anaerobiosis and increased ATP production during ciprofloxacin stress. Furthermore, mutations in the regulatory regions of argI and narU were detected in over 70% of sequences from clinical E. coli isolates and were overrepresented among ciprofloxacin-resistant isolates. In sum, we have identified clinically relevant mutations in the regulatory regions of metabolic genes as a central theme that drives physiological changes necessary for adaptation to ciprofloxacin stress.

Antibiotic susceptibility and genomic analysis of ciprofloxacin-resistant and ESBLs-producing Escherichia coli in vegetables and their irrigation water and growing soil

The rise of antibiotic resistance in Escherichia coli has become a major global public health concern. While there is extensive research on antibiotic-resistant E. coli from human and animal sources, studies on vegetables and their environments are limited. This study investigated the prevalence and characteristics of ciprofloxacin-resistant (CIPR) E. coli in 13 types of edible raw vegetables, along with their irrigation water and soil in Shaanxi, China. Of 349 samples collected (157 vegetables, 59 water, and 133 soil), a total of 48 positive samples were detected, with one CIPRE. coli strain isolated from each sample being selected for further analyses. A striking observation was its high prevalence in irrigation water at 44.1 %, markedly exceeding that in vegetables (12.0 %) and soil (4.5 %). The susceptibility of Forty-eight CIPRE. coli isolates was evaluated using the disc diffusion method for 18 different antibiotics, all these isolates were not only resistant to the tested fluoroquinolones antibiotics (levofloxacin, nalidixic acid), but also displayed a multi-drug resistance (MDR) pattern. Twenty-eight (58.3 %) of 48 CIPRE. coli isolates exhibited extended spectrum β-lactamases (ESBLs) (CIPR-ESBLs) producing phenotype. Subsequently, whole-genome sequencing was performed on these 28 isolates. We identified 12 serotypes and STs each, with O101: H9 (35.7 %, 10/28) and ST10 (21.4 %, 6/28) being the most common. Further classification placed these isolates into five phylogenetic groups: A (57.1 %, 16/28), B1 (32.1 %, 9/28), D (3.6 %, 1/28), B2 (3.6 %,1/28), and F (3.6 %,1/28). Notelly, Identical ST types, serotypes and phylogroups were found in certain CIPR-ESBLs-producing E. coli from both vegetables and adjacent irrigation water. Genomic analysis of the 28 CIPR-ESBLs-producing E. coli isolates unveiled 73 resistance genes, associated with 13 amino acid mutations in resistance-determining regions (QRDRs) and resistance to 12 types of antibiotics. Each isolate was confirmed to carry both ESBLs and fluoroquinolone resistance genes, with the Ser83Ala mutation in GyrA (96.4 %, 27/28) being the most prevalent. A detailed analysis of Mobile Genetic Elements (MGEs) revealed that IncFIB and IncFII plasmid subtypes were most prevalent in 60.7 % and 67.9 % of isolates, respectively, with 75 % containing over 10 insertion sequences (IS) each. Furthermore, we observed that certain ESBL and PMQR genes were located on plasmids or in proximity to insertion sequences. In conclusion, our research highlights the widespread presence of CIPRE. coli in irrigation water and thoroughly examines the genetic characteristics of CIPR-ESBLs-producing E. coli strains, underlining the need for ongoing monitoring and management to reduce multidrug-resistant bacteria in vegetables and their environment.

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 β-lactamases, metallo β-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.

Increasing Prevalence of ESBL-Producing Multidrug Resistance Escherichia coli From Diseased Pets in Beijing, China From 2012 to 2017

We investigated antimicrobial resistance trends and characteristics of ESBL-producing Escherichia coli isolates from pets and whether this correlates with antibiotic usage in the clinic. Clinical samples containing E. coli from diseased cats and dogs were screened for antibiotic sensitivity and associated genotypic features. We identified 127 E. coli isolates from 1886 samples from dogs (n = 1565) and cats (n = 321) with the majority from urinary tract infections (n = 108, 85%). High rates of resistance were observed for β-lactams and fluoroquinolones and resistance to > 3 antibiotic classes (MDR) increased from 67% in 2012 to 75% in 2017 (P < 0.0001). This was especially true for strains resistant to 6-9 antibiotics that increased from 26.67 to 60.71%. Increased rates in β-lactam use for clinical treatment accompanied these increasing resistance rates. Accordingly, the most frequently encountered subtypes were bla _CTX-M (n = 44, 34.65%), bla _CTX-M-65 (n = 19) and bla _CTX-M-15 (n = 18) and qnrB (n = 119, 93.70%). The bla _CTX-M-isolates possessed 36 unique pulsed field electrophoretic types (PFGEs) and 28 different sequence types (STs) in ST405 (7, 15.9%), ST131 (3, 6.8%), ST73, ST101, ST372, and ST827 (2, 4.5% each) were the most prevalent. This data demonstrated a high level of diversity for the bla _CTX-M-positive E. coli isolates. Additionally, bla _NDM-5 was detected in three isolates (n = 3, 2.36%), comprised of two ST101 and one ST405 isolates, and mcr-1 was also observed in three colistin-resistant E. coli with three different STs (ST6316, ST405, and ST46). Our study demonstrates an increasing trend in MDR and ESBL-producing E. coli and this correlated with β-lactam antibiotic usage for treatment of these animals. This data indicates that there is significant risk for the spread of resistant bacteria from pets to humans and antibiotic use for pets should be more strictly regulated.