Diversity of Multi-Drug Resistant Avian Pathogenic Escherichia coli (APEC) Causing Outbreaks of Colibacillosis in Broilers during 2012 in Spain

• Published in: PloS one Vol. 10; no. 11; p. e0143191
• Main Authors: Solà-Ginés, Marc, Cameron-Veas, Karla, Badiola, Ignacio, Dolz, Roser, Majó, Natalia, Dahbi, Ghizlane, Viso, Susana, Mora, Azucena, Blanco, Jorge, Piedra-Carrasco, Nuria, González-López, Juan José, Migura-Garcia, Lourdes
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 23-11-2015; Public Library of Science (PLoS)
• Subjects: Animal diseases; Animals; Biodiversity; Cephalosporins; Chickens - microbiology; Colibacillosis; Disease Outbreaks - statistics & numerical data; Distribution; Drug resistance; Drug Resistance, Multiple, Bacterial - genetics; E coli; Electrophoresis, Gel, Pulsed-Field; Epidemics; Epidemiology; Escherichia coli; Escherichia coli - classification; Escherichia coli - genetics; Escherichia coli - pathogenicity; Escherichia coli infections; Escherichia coli Infections - epidemiology; Escherichia coli Infections - microbiology; Escherichia coli Infections - veterinary; Food chains; Forecasts and trends; Gel electrophoresis; Gene polymorphism; Genes; Genes, Bacterial; Genotype; Health care; Infections; Iron; Microbial Sensitivity Tests; Multidrug resistance; Multilocus Sequence Typing; Outbreaks; Phenotype; Phylogeny; Plasmids; Plasmids - metabolism; Polymorphism; Poultry; Poultry Diseases - epidemiology; Poultry Diseases - microbiology; Poultry industry; Poultry production; Public health; Pulsed-field gel electrophoresis; Serotypes; Serotyping; Spain - epidemiology; Studies; Test procedures; Virulence; Virulence - genetics; Spain
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0143191

Avian pathogenic Escherichia coli (APEC) are the major cause of colibacillosis in poultry production. In this study, a total of 22 E. coli isolated from colibacillosis field cases and 10 avian faecal E. coli (AFEC) were analysed. All strains were characterised phenotypically by susceptibility testing and molecular typing methods such as pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of 29 virulence genes associated to APEC and human extraintestinal pathogenic E. coli (ExPEC) was also evaluated. For cephalosporin resistant isolates, cephalosporin resistance genes, plasmid location and replicon typing was assessed. Avian isolates belonged to 26 O:H serotypes and 24 sequence types. Out of 22 APEC isolates, 91% contained the virulence genes predictors of APEC; iutA, hlyF, iss, iroN and ompT. Of all strains, 34% were considered ExPEC. PFGE analysis demonstrated a high degree of genetic polymorphism. All strains were multi-resistant, including those isolated from healthy animals. Eleven strains were resistant to cephalosporins; six contained blaCTX-M-14, two blaSHV-12, two blaCMY-2 and one blaSHV-2. Two strains harboured qnrA, and two qnrA together with aac(6')-Ib-cr. Additionally, the emergent clone O25b:H4-B2-ST131 was isolated from a healthy animal which harboured blaCMY-2 and qnrS genes. Cephalosporin resistant genes were mainly associated to the presence of IncK replicons. This study demonstrates a very diverse population of multi-drug resistant E. coli containing a high number of virulent genes. The E. coli population among broilers is a reservoir of resistance and virulence-associated genes that could be transmitted into the community through the food chain. More epidemiological studies are necessary to identify clonal groups and resistance mechanisms with potential relevance to public health.