Research Article
Extra-Intestinal Fluoroquinolone-Resistant Escherichia coli
Strains Isolated from Meat
Giorgia Caruso,
1
Anna Giammanco,
1
Cinzia Cardamone,
2
Giuseppa Oliveri,
2
Chiara Mascarella,
1
Giuseppina Capra,
1
and Teresa Fasciana
1
1
Department of Sciences for Health Promotion and Mother & Child Care, University of Palermo, Italy
2
Institute for Experimental Veterinary Medicine of Sicily, Palermo, Italy
Correspondence should be addressed to Teresa Fasciana; teresa.fasciana@virgilio.it
Received 26 June 2018; Revised 17 September 2018; Accepted 28 October 2018; Published 18 November 2018
Guest Editor: Maria E. Potes
Copyright © 2018 Giorgia Caruso et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Extra-intestinal E. coli are emerging as a global threat due to their difusion as opportunistic pathogens and, above all, to their wide
set of antibiotic resistance determinants. Tere are still many gaps in our knowledge of their origin and spread pathways, although
food animals have been adjudicated vehicles for passing mult-drug resistant bacteria to humans. Tis study analyzed 46 samples
of meat purchased from retail stores in Palermo in order to obtain quinolone-resistant E. coli isolates. Strains were screened for
their phylogenetic groups, ST131-associated single nucleotide polymorphisms (SNPs), and then typed by ERIC-PCR. Teir set of
virulence factors, namely, kpsMII, papA, sfaS, focG, iutA, papC, hlyD, and afa genes, were investigated and their fuoroquinolone-
resistance determinants evaluated. Te data obtained show a dramatically high prevalence of multidrug resistance patterns in the
Palermo area, with 28% of the isolates having virulence factor genes typical of ExPEC strains. No B2 group or ST131 strains were
detected. Moreover, 20% of our isolates showed positivity to all the plasmid-mediated quinolone resistance (PMQR) determinants,
showing a potential to transfer these genes among other bacteria. Terefore, these data underline the possibility that food animals
and, specifcally, poultry in particular may be a signifcant source of resistant bacterial strains, posing a potential zoonotic risk.
1. Introduction
Te outburst of the antibiotic resistance phenomenon at
global level has occurred due to the excessive and inap-
propriate use of antimicrobials in various felds, both in
human medicine and in veterinary and zootechnical settings,
strongly accelerating the development and difusion of resis-
tant strains. For instance, intensive livestock farming prac-
tices that compel farmers to rely more heavily on antibiotics
have determined a dramatic increase in the prevalence of
antibiotic-resistant bacteria in farm animals and food [1, 2].
Quinolones in particular have long been the main
choice of antimicrobial agent for the treatment of various
Gram-negative infections, both in human and in veterinary
medicine, ostensibly increasing the rate of resistant isolates
all over the world [3]. Furthermore, the World Health
Organization (WHO) has signalled quinolones to be critically
important antibiotics, thus recommending a more prudent
use of them [4]. In fact, since the discovery of the frst
plasmid-mediated quinolone resistance (PMQR) gene in 1998
[5], many other resistance mechanisms have been added [6].
Nontarget, commensal enteric bacteria are also exposed
to this wide variety of antimicrobial substances, leading to an
increase in resistance genes and, potentially, their horizontal
transfer. Hence these bacteria may function as a reservoir of
resistance though largely ignored [7].
According to the EFSA and ECDC report [8], E. coli is an
excellent indicator of resistance level among Enterobacteria
in breeding animals, as it is widespread in farm environments.
Furthermore, there is increasing evidence that E. coli
strains may be conveyed through food and, directly or more
likely indirectly, they fnd their way to humans, account-
ing for a subset of resistant Extra-intestinal Pathogenic E.
coli (ExPEC) [9–11]. Indeed, ExPEC increasingly represent
an emerging category of pathogens that cause illness in
immunocompetent subjects both in nosocomial and in com-
munity settings. ExPEC are in fact implicated in a wide range
of host diseases and are associated with the vast majority of
Hindawi
BioMed Research International
Volume 2018, Article ID 8714975, 7 pages
https://doi.org/10.1155/2018/8714975