Methicillin-resistant staphylococcal colonization in clinically normal dogs and horses in the community

Abstract

Aims: To evaluate the prevalence of methicillin‐resistant staphylococcal (MRS) colonization in clinically normal dogs and horses in the community. Methods and Results: Three hundred clinically normal horses and 200 clinically normal dogs were enrolled. One nasal swab was collected from each horse. Two swabs were taken from each dog: (i) from an anterior nare, and (ii) a combination of the perineal area and 0·5 cm into the anus. Enrichment cultures were performed. Methicillin‐resistant Staphylococcus aureus (MRSA) was not identified. Methicillin‐resistant Staphylococcus intermedius (MRSI) was isolated from the nasal swab from three dogs. Methicillin‐resistant coagulase negative staphylococci (MRCoNS) were isolated from 126/300 (42%) horses and 26/200 (13%) dogs. Conclusions: At present MRSI is not considered to be a significant zoonotic concern; however, it may become an important pathogen in dogs. MRCoNS mostly cause disease in compromised human or animal hosts. However, these bacteria can serve as reservoirs of resistance determinants in the community, which could lead to the emergence of novel MRSA strains. Significance and Impact of the Study: This is the first report of the prevalence of MRS colonization in clinically normal dogs in a community setting. Continued surveillance is indicated to determine whether MRSA will emerge in the animal population and become a concern for animal disease and zoonotic infection.

Isolation and Molecular Characterization of Methicillin-Resistant Staphylococci from Horses, Personnel and Environmental Sites at an Equine Hospital in Turkey

“…The rate of nasal MRCNS carriage in horses (47.8%) was higher than those previously reported in the Netherlands (22%) [4], Japan (13 to 29.5%) [38,39], Slovenia (42%) [34] and Italy (35.2%) [9] but lower than those reported in Denmark (50 to 82%) [2,20]. In previous studies, colonization of horses with methicillin-resistant S. lentus and S. sciuri has been reported [2,4,9,20,38,39].…”

“…A high prevalence of methicillin-resistant staphylococci (MRS) colonization has also been reported in healthy horses in Europe [2,4,9,20,34] and Japan [38,39].…”

Antibiotic Resistance in the Environment, with Particular Reference to MRSA

“…Thus horses may act as a reservoir for this strain, perhaps mirroring the putative association of ST398 with pigs. In Slovenia, MRSA was absent from a total of 300 horses sampled with nasal swabs (Vengust et al, 2006); one explanation for this is that MRSA may also colonise the perineum or the throat, and this has been found to be the sole site of infection in some cases (Coello et al, 1994) so it is possible that sub-clinical carriers of MRSA were missed. Indeed, a study on humans in nursing homes indicated that up to 14% of cases are missed by screening the nares alone (Lee et al, 1997).…”

Methicillin-Resistant Staphylococci Isolated from Healthy Horses and Horse Personnel in Italy

“…32,33 Recently, high prevalence of the CoN staphylococci was found in healthy horses in Europe. 4,28,26 However, no MRSA strains have been isolated. No cases of nasal colonization of horses with MRS have been described in Italy.…”