Molecular typing and virulence characteristics of Escherichia coli strains isolated from hospital and community acquired urinary tract infections.

BACKGROUND: The main causes of hospital- and community-acquired urinary tract infections (UTIs) are a group of Escherichia coli (E. coli) strains with multiple virulence factors known as uropathogenic E. coli. METHODS AND RESULTS: One hundred E. coli isolates from the urine specimens of hospital- and community-acquired UTI patients were characterized based on their virulence factors and genetic relatedness using PCR and RAPD‒PCR, respectively. Among all, the traT (71%), sitA (64%), ompT (54%), malX (49%), ibeA (44%), tsh (39%), hlyD (18%) and cnf1 (12%) genes had the highest to lowest frequencies, respectively. There was no significant difference between the frequency of tested virulence genes in E. coli isolates from inpatients and outpatients. The frequency of the hlyD gene was significantly greater in E. coli isolates from patients hospitalized in gynecology, dermatology and intensive care unit (ICU) wards than in those from other wards. Eight virulence gene patterns were common among the isolates of inpatients in different wards of the same hospital, of which five patterns belonged to the isolates of inpatients in the same ward. More E. coli isolates with similar virulence gene patterns and greater genetic similarity were found in female patients than in male patients. The analysis of the RAPD‒PCR dendrograms revealed more genetic similarities among the E. coli isolates from inpatients than among those from outpatients. CONCLUSION: Our findings indicate the presence of a wide variety of virulence factors in E. coli isolates and the possibility of spreading the same clones in different wards of the hospital.

Identification of faecal Escherichia coli isolates with similar patterns of virulence and antimicrobial resistance genes in dogs and their owners.

BACKGROUND: The presence of antimicrobial resistance and virulence genes in Escherichia coli allows them to survive and cause infections. The close contact between humans and pets can reinforce the risk of transmitting resistant and virulent bacteria between them. OBJECTIVES: This study aims to compare the patterns of the presence of tetracycline and streptomycin resistance genes, as well as important virulence genes in E. coli isolated from faeces of healthy dogs and their owners. METHODS: Polymerase chain reactions were performed for detection of antimicrobial resistance (tetA, tetB, tetC, tetD, strA and strB) and virulence (fimH, iss, sitA and malX) genes in 144 faecal E. coli isolates from 28 dog-owner pairs and 16 humans who did not keep any pets as controls. RESULTS: Among the investigated antimicrobial resistance and virulence genes, tetA (52.1%) and fimH (86.8%) genes had the highest prevalence. No statistically significant difference was found between the prevalence of antimicrobial resistance and virulence genes in isolates of dogs and their owners. In total, 46.4% of dog-owner pairs had the same patterns of presence or absence of six antimicrobial resistance genes, 50.0% had the same patterns of presence or absence of four virulence genes and 25.0% had the same patterns of presence or absence of all 10 tested genes. CONCLUSION: The presence of antimicrobial-resistant virulent E. coli in humans and pets may predispose them to infections that are hard to cure with conventional antibiotics. Notable frequency of dogs' and their owners' E. coli isolates with similar patterns of antimicrobial resistance and virulence genes may indicate the possibility of sharing virulent antimicrobial resistant E. coli between them.