Distribution of Antimicrobial Resistance and Virulence Genes inEnterococcusspp. and Characterization of Isolates from Broiler Chickens

Abstract

Enterococci are now frequent causative agents of nosocomial infections. In this study, we analyzed the frequency and distribution of antibiotic resistance and virulence genotypes of Enterococcus isolates from broiler chickens. Fecal and cecal samples from nine commercial poultry farms were collected to quantify total enterococci. Sixty-nine presumptive enterococci were isolated and identified by API 20 Strep, and their susceptibilities to antibiotics were determined. Genotypes were assessed through the use of a novel DNA microarray carrying 70 taxonomic, 17 virulence, and 174 antibiotic resistance gene probes. Total enterococcal counts were different from farm to farm and between sample sources (P < 0.01). Fifty-one (74%) of the isolates were identified as E. faecium, whereas nine (13%), seven (10%), and two (3%) isolates were identified as E. hirae, E. faecalis, and E. gallinarum, respectively. Multiple-antibiotic resistance was evident in E. faecium and E. faecalis isolates. The most common multiple-antibiotic resistance phenotype was Bac Ery Tyl Lin Str Gen Tet Cip. Genes conferring resistance to aminoglycoside (aac, aacA-aphD, aadB, aphA, sat4), macrolide (ermA, ermB, ermAM, msrC), tetracycline (tetL, tetM, tetO), streptogramin (satG_vatE8), bacitracin (bcrR), and lincosamide (linB) antibiotics were detected in corresponding phenotypes. A range of 9 to 12 different virulence genes was found in E. faecalis, including ace, agg, agrB Efs (agrB gene of E. faecalis), cad1, the cAM373 and cCF10 genes, cob, cpd1, cylAB, efaA Efs , and gelE. All seven E. faecalis isolates were found to carry the gelE gene and to hydrolize gelatin and bile salts. Results from this study showed the presence of enterococci of public and environmental health concerns in broiler chicken farms and demonstrated the utility of a microarray to quickly and reliably analyze resistance and virulence genotypes of Enterococcus spp.Enterococcus spp., particularly E. faecium and E. faecalis, are important in public health; these species are responsible for approximately 12% of all nosocomial infections in the United States (11,22). In humans, enterococci cause urinary tract infections, bacteremia, peritonitis, and endocarditis, with about 90% of all clinical infections being caused by E. faecalis and E. faecium (22). The virulence of enterococci is associated with several genes, including ace (collagen binding cell wall protein), acm (surface-exposed antigen), agg (aggregative pheromone-inducing adherence to extra-matrix protein), agrB Efs (AgrB protein of E. faecalis), esp (enterococcal surface protein), hyl (hyaluronidase), cad1 (pheromone cAD1 precursor lipoprotein), the cAM373 gene (sex pheromone cAM373 precursor), the cCF10 gene (pheromone cCF10 precursor lipoprotein), cob (pheromone cOB1 precursor/lipoprotein, YaeC family), cpd1 (pheromone cPD1 lipoprotein), cylABLM (hemolysin), efaA Efs (endocarditis-specific antigen), sagA (secreted antigen), and gelE (gelatinase) (22,29). These virulence factors have been reported in enterococci isolated f...

Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry

“…Our results are similar to the resistance profiles of lincomycin, tetracycline, penicillin, ciprofloxacin and tylosin in Enterococcus isolates from the environment of broiler and/or layer farms (Ruzauskas et al, 2009;Diarra et al, 2010;Šeputienė et al, 2012;Furtula et al, 2013). Moreover, in Poland, Różańska et al (2015) noted that the highest number of E. faecalis strains isolated from poultry meat were resistant to lincomycin (24 strains; 100%), the second-highest resistance was to tetracycline (21 strains; 87.5%), followed by tylosin (16 strains; 66.7%).…”

“…In contrast to Diarra et al (2010) and Furtula et al (2013), we found a high sensitivity to penicillin antibiotics in 911 of the isolated Enterococcus strains. Moreover, E. faecalis and E. faecium strains isolated from affected broilers, layers and turkeys were susceptible to ampicillin.…”

Detection of a Common and Persistent tet (L)-Carrying Plasmid in Chicken-Waste-Impacted Farm Soil

“…This is because this waste is rich in antibiotic residues (63), antibiotic-resistant bacteria, and antibiotic resistance genes (ARGs) (10,17,23,29), which can enter the environment through disposal practices (14). Growing evidence further shows that animal waste, including poultry litter, contains various mobile genetic elements (MGEs) harboring ARGs (8,10,11,40), which facilitate the spread of ARGs to soil microbial communities when animal waste is applied onto agricultural soils (30).…”

“…Resistance to these antibiotics has frequently been observed in bacterial isolates from poultry litter (10,17,23,29). Furthermore, some MGEs simultaneously carry genes encoding tetracycline resistance (Tc r ; tet) and MLS B resistance (erm) (13,49) and facilitate the dissemination of resistance to these antibiotics among environmental, commensal, and clinical bacteria (48).…”

Virulência e formação de biofilme microbiano por Enterococcus faecalis isolados de swabs cloacais de frangos de corte infectados com Eimeria spp

“…A frequência do gene ace em ambos os grupos está de acordo com outros estudos que avaliaram a presença deste gene em amostras de swabs cloacais de frangos. Diarra et al (2010) detectaram o gene ace em todos os E. faecalis isolados de frangos pesquisados. Olsen et al (2011) pesquisaram o gene ace em isolados clínicos e de frangos e detectaram a presença do gene em todas as amostras pesquisadas.…”