Virulence factors, antibiotic resistance phenotypes and O-serogroups of Escherichia coli strains isolated from community-acquired urinary tract infection patients in Mexico.
BACKGROUND/PURPOSE
Uropathogenic Escherichia coli (UPEC) strains isolated from patients with community-acquired urinary tract infections (UTIs) were assessed to determine the prevalence of virulence genes, antibiotic resistance, and the O-serogroup of the strains.


METHODS
Consenting patients with community-acquired UTI were enrolled at Unidad Médica Familiar Number 64 (Instituto Mexicano del Seguro Social, Estado de Mexico, Mexico) and 321 urine samples were collected. Polymerase chain reaction (PCR) was used to assess 24 virulence genes and 14 O-serogroups. The Kirby-Bauer method was used to evaluate the antibiotic susceptibility of the isolated strains to 12 commonly used antibiotics.


RESULTS
A total of 194 strains were identified as E. coli using standard biochemical tests, followed by PCR amplification of 16S ribosomal RNA gene. Only 58.2% of the strains belonged to the assessed 14 O-serogroups. The serogroups O25, O15, O8, and O75 were present in 20.6%, 17%, 6.1%, and 4.6% of strains, respectively. The most frequently occurring virulence genes among UPEC strains included kpsMT (92.2% strains), usp (87.1%), irp2 (79.3%), iha (64.9%), fim (61.3%), set (36%), astA (33.5%), pap (24.7%), and papGII (21.1%). In addition, 97% of the strains were multi-drug resistant (coresistance to 3-11 antibiotics).


CONCLUSION
The isolated UPEC strains predominantly belonged to three serogroups (O25, O15, and O8), harboured numerous virulence genes, and are multiresistant to antibiotics. The findings of this study could be used to orient UTI treatment strategies and in epidemiological studies in Mexico.
['Paniagua-Contreras|Gloria Luz|GL|', 'Monroy-Pérez|Eric|E|', 'Rodríguez-Moctezuma|José Raymundo|JR|', 'Domínguez-Trejo|Pablo|P|', 'Vaca-Paniagua|Felipe|F|', 'Vaca|Sergio|S|']
D000328:Adult D000368:Aged D016000:Cluster Analysis D017714:Community-Acquired Infections D004269:DNA, Bacterial D004275:DNA, Ribosomal D052978:Disk Diffusion Antimicrobial Tests D024881:Drug Resistance, Bacterial D004927:Escherichia coli Infections D005260:Female D006801:Humans D008297:Male D008800:Mexico D008875:Middle Aged D019081:O Antigens D010641:Phenotype D010802:Phylogeny D016133:Polymerase Chain Reaction D012336:RNA, Ribosomal, 16S D017422:Sequence Analysis, DNA D065288:Serogroup D014552:Urinary Tract Infections D056689:Uropathogenic Escherichia coli D037521:Virulence Factors D055815:Young Adult
virulence factors O-serogroup UPEC multidrug-resistance