Farm animals as a putative reservoir for vancomycin-resistant enterococcal infection in man

Abstract

Using a highly selective enrichment broth, 62 isolates of vancomycin-resistant Enterococcus faecium were obtained from non-human sources; 35 isolates from raw sewage, 22 from farm animals and 5 from uncooked chickens. All strains possessed the Van A gene, conferring high-level resistance to vancomycin (MIC > or = 256 mg/L). Ribotyping of 42 of these isolates resulted in 14 distinguishable patterns. Two ribotyping patterns were found among isolates from animals and sewage and those from clinical sources. A blood and a urine isolate from separate hospital patients and porcine isolates shared the same ribotyping pattern number 6 and a stool isolate from a patient in the community and sewage isolates shared another pattern, number 10. This finding suggests that animals may serve as a reservoir of vancomycin-resistant enterococci (VRE), which may enter the human food chain. The emergence of VRE in hospital patients may reflect selection of these organisms in the hospital environment by antibiotic usage from which nosocomial spread might occur.

Antimicrobial Drug Resistance Pattern of <i>Escherichia coli</i> Isolated from Chickens Farms with Colibacillosis Infection

“…Earlier studies revealed that use of fluoroquinolones in poultry was not appropriate due to the cross-resistance with fluoroquinolones used to treat human enteric infections. High resistance to chlortetracycline and oxytetracycline is of major concern because of the use of the same antibiotics in human medicine and poultry or in other food animals and the emergence of drug-resistant human pathogen [15] [16]. Antibiotic resistance of fecal E. coli was greater in broilers and turkeys that received antibiotics relatively frequently compared to layers, which had little exposure to antibiotics [14].…”

Animal antibiotic use has an early but important impact on the emergence of antibiotic resistance in human commensal bacteria

“…It was reported that as much as 80% of total antibiotic production in the United States is used in agriculture, with a substantial portion of this used for the nontherapeutic purpose of growth promotion (4,5). AR bacteria have been found in farm animals where antibiotics are heavily used (6)(7)(8), in associated food products (9,10), in environments contaminated by animal waste (11,12), and in farm workers (13)(14)(15). Drugs that are used therapeutically in animals also may generate a reservoir of AR bacteria (16,17).…”

The association between the use of antimicrobial growth promoters and development of resistance in pathogenic bacteria towards growth promoting and therapeutic antimicrobials

“…Recent studies from several countries in Europe have shown a strong association between the use of avoparcin as a growth promoter for animals and the occurrence of VRE in animals and food (Bates et al, 1994;Aarestrup, 1995;Klare et al, 1995;Bager et al, 1997). The detection of VRE in livestock and fresh meat suggests that humans are exposed to VRE either by direct contact with animals or from consumption of meat.…”