Identification of Virulence Markers and Phylogenetic Groups' Association, and Antimicrobial Susceptibility of Uropathogenic Escherichia coli Isolates.

BACKGROUND: Urinary tract infections represent a world public health problem, which is caused mainly by Uropathogenic Escherichia coli. Although they are originally found in the intestinal microbiota in the majority of the cases, urinary tract infections can also be caused by intra-intestinal pathogenic E. coli. OBJECTIVE: The main objective of our research is to identify the virulence factors generally associated with different pathotypes across phylogenetic groups. METHODS: E. coli were isolated from patients with urinary tract infections. Antimicrobial susceptibility tests, virulence genes and phylogroups were prospected. The data analysis were performed using the chi-square and Fisher exact test. RESULTS: In total, 72.2% of isolates showed multidrug resistant. We have also depicted an important association between E. coli from inpatients with UTIs and pap and hlyA genes (p-0.041 and p-0.019 respectively). The predominant phylogenetic group in our isolates is B2 (45.4%) followed by D (12.4%). Our results showed that 9.3% of isolates have an unknown phylogroup which shows a significant association with astA gene (p-0.008). We have as well found a significant association between B2 and three virulence genes namely pap, hlyA and invE (p-0.002, p-0.001, p-0.025 respectively); B1 and pap, hlyA genes (p-0.049 and p-0.021 respectively); E and afa gene (p-0.024). CONCLUSION: Certain virulence factors have been shown to be potential targets for drug design and therapeutic pathways in order to deal with the antimicrobial resistance problem enhanced by antibiotic therapy.

First report of blaOXA-24 carbapenemase gene, armA methyltransferase and aac(6')-Ib-cr among multidrug-resistant clinical isolates of Proteus mirabilis in Algeria.

OBJECTIVE: Carbapenemase-producing, or carbapenem-resistant, Enterobacteriaceae are an emerging threat to human and animal health because they are resistant to many of the last-line antimicrobials available for treatment of infection. The aim of this study was to analyse the antimicrobial resistance patterns and their encoding genes of Proteus mirabilis isolated in Constantine, Algeria. METHODS: A total of 108 Proteus, Morganella and Providencia (PMP) strains were isolated from a large variety of clinical specimens at University Hospital of Constantine in Algeria. Isolates were identified using the API 20E system and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Diagnostic accuracy was determined by independent comparison of each method to phylogenetic analysis based on 16S rRNA gene sequencing. Antimicrobial susceptibility was determined by the standard disk diffusion and Etest methods. The presence of antimicrobial resistance genes was screened for by PCR amplification and sequencing. RESULTS: A total of 72 PMP strains were multidrug-resistant (MDR). Among them, one P. mirabilis isolate was resistant to imipenem with a minimum inhibitory concentration (MIC) of ≥12µg/mL. PCR and sequencing showed the presence of various antimicrobial resistance genes, including blaCTX-M-15, blaTEM-1, blaTEM-2, blaPER-1, blaSHV-11, aadA1, aadA2, armA, aac(6')-Ib, aac(6')-Ib-cr, aac(3)-Ia and ant(2″)-I, forming different resistance profiles. Moreover, the blaOXA-24 gene was detected in the imipenem-resistant P. mirabilis strain. CONCLUSION: In this study, a MDR P. mirabilis isolate harbouring the blaOXA-24, armA 16S rRNA methylase and aac(6)-Ib-cr genes was found for the first time in Algeria.