Multidrug-Resistant Enterococci in Animal Meat and Faeces and Co-Transfer of Resistance from an Enterococcus durans to a Human Enterococcus faecium

Abstract

Forty-eight isolates resistant to at least two antibiotics were selected from 53 antibiotic-resistant enterococci from chicken and pig meat and faeces and analysed for specific resistance determinants. Of the 48 multidrug-resistant (MDR) strains, 31 were resistant to two antibiotics (29 to erythromycin and tetracycline, 1 to erythromycin and vancomycin, 1 to vancomycin and tetracycline), 14 to three (erythromycin, tetracycline and vancomycin or ampicillin) and 3 to four (erythromycin, vancomycin, ampicillin and gentamicin). erm(B), tet(M), vanA and aac (6')-Ie aph (2'')-Ia were the antibiotic resistance genes most frequently detected. All 48 MDR enterococci were susceptible to linezolid and daptomycin. Enterococcus faecalis (16), Enterococcus faecium (8), Enterococcus mundtii (2) and Enterococcus gallinarum (1) were identified in meat, and E. faecium (13) and Enterococcus durans (13) in faeces. Clonal spread was not detected, suggesting a large role of gene transfer in the dissemination of antibiotic resistance. Conjugative transfer of resistance genes was more successful when donors were enterococcal strains isolated from faeces; co-transfer of vanA and erm(B) to a human E. faecium occurred from both E. faecium and E. durans pig faecal strains. These data show that multidrug resistance can be found in food and animal species other than E. faecium and E. faecalis, and that these species can efficiently transfer antibiotic resistance to human strains in inter-specific matings. In particular, the occurrence of MDR E. durans in the animal reservoir could have a role in the emergence of human enterococcal infections difficult to eradicate with antibiotics.

Resistance to the tetracyclines and macrolide-lincosamide-streptogramin group of antibiotics and its genetic linkage – a review

“…Vignaroli et al [48] investigated isolates of enterococci co-resistant to tetracycline and erythromycin originating from meat and faeces of chickens and pigs. They found that under in vitro conditions the isolates from faeces more readily transferred the resistance to enterococci of human origin.…”

Antibiotic resistance profile of Enterococcus faecium andEnterococcus faecalis isolated from broiler cloacal samples

“…Enterococcal infections, particularly nosocomial infections, may be life threatening in humans, as antibiotic treatment of these infections is difficult (6). In the veterinary medicine field, antibiotics are commonly used for the control and treatment of diseases, and antibiotic usage results in a selection of resistant enterococci in the intestinal flora of animals.…”

“…In the veterinary medicine field, antibiotics are commonly used for the control and treatment of diseases, and antibiotic usage results in a selection of resistant enterococci in the intestinal flora of animals. Antibiotic resistant isolates can pass to humans either by food products or direct contact, and antibiotic resistance genes on mobile genetic elements may be transferred to human bacteria (6).…”

Resistência antimicrobiana em Enterococcus faecalis e Enterococcus faecium isolados de carcaças de frango

“…são propensos a sofrer seleção a cada administração de antimicrobiano, levando à formação de um reservatório animal de Enterococcus spp. resistentes, que podem infectar os seres humanos tanto por contato direto com animais como através da ingestão de alimentos de origem animal (Kaszanyitzky et al 2007, Oliveira et al 2010, Vignaroli et al 2011. No trato gastrintestinal, os genes de resistência adquiridos podem ser transferidos por elementos móveis de DNA, tanto para outros da espécie como outros agentes zoonóticos, mesmo que em testes de antibiograma os Enterococcus não apresentem resistência (Bogaard et al 2002, Cauwerts et al 2007.…”