VIRULENCE FACTORS AND ANTIMICROBIAL RESISTANCE OF ESCHERICHIA COLI ST131 IN COMMUNITY-ONSET HEALTHCARE-ASSOCIATED INFECTIONS IN SICILY, ITALY

Abstract

Escherichia coli ST131 is an emerging resistant agent recently called “superbug” in England. This strain is responsible of community-acquired urinary tract infections and nowadays showing increasing resistance to antibiotics like fluoroquinolones and cephalosporins. Survey of virulent bacterial clone is relevant to control its spreading in community. We aim to assess the circulation of resistant clones Escherichia coli ST131 outside of the hospital to prompt control of outbreak in our geographical area. We selected 105 E. coli resistant isolates from community-acquired urinary infections and performed a multiplex PCR to evaluate if they belonged to the ST131 type. We investigated their set of virulence factors; in particular, kpsMII, papA, sfaS, focG, iutA, papC, hlyD and afa genes, and finally, we evaluated beta lactamases genes and quinolone resistance determinants. E. coli ST 131 clone was present in 66.6% of our isolates and showed positivity to a wide range of resistance genes, in particular blaCTX-M-15 among beta lactamases and plasmid-related quinolone resistance genes (qnrA, qnrS and aac (6’)-Ib-cr). Moreover, 81% of the strains showed positivity to at least one of the virulence factor genes. Our results suggested a high presence of E. coli ST131 in community. We suggest antibiotic stewardship for outpatient clinicians and facilities to contain the spread of “superbug” agents.