Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Swiss veterinary health care providers: Detection of livestock- and healthcare-associated clones

Abstract

We screened a total of 340 veterinarians (including general practitioners, small animal practitioners, large animal practitioners, veterinarians working in different veterinary services or industry), and 29 veterinary assistants for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) at the 2012 Swiss veterinary annual meeting. MRSA isolates (n = 14) were detected in 3.8 % (95 % CI 2.1 - 6.3 %) of the participants whereas MRSP was not detected. Large animal practitioners were carriers of livestock-associated MRSA (LA-MRSA) ST398-t011-V (n = 2), ST398-t011-IV (n = 4), and ST398-t034-V (n = 1). On the other hand, participants working with small animals harbored human healthcare-associated MRSA (HCA-MRSA) which belonged to epidemic lineages ST225-t003-II (n = 2), ST225-t014-II (n = 1), ST5-t002-II (n = 2), ST5-t283-IV (n = 1), and ST88-t186-IV (n = 1). HCA-MRSA harbored virulence factors such as enterotoxins, β-hemolysin converting phage and leukocidins. None of the MRSA isolates carried Panton-Valentine leukocidin (PVL). In addition to the methicillin resistance gene mecA, LA-MRSA ST398 isolates generally contained additional antibiotic resistance genes conferring resistance to tetracycline [tet(M) and tet(K)], trimethoprim [dfrK, dfrG], and the aminoglycosides gentamicin and kanamycin [aac(6')-Ie - aph(2')-Ia]. On the other hand, HCA-MRSA ST5 and ST225 mainly contained genes conferring resistance to the macrolide, lincosamide and streptogramin B antibiotics [erm(A)], to spectinomycin [ant(9)-Ia], amikacin and tobramycin [ant(4')-Ia], and to fluoroquinolones [amino acid substitutions in GrlA (S84L) and GyrA (S80F and S81P)]. MRSA carriage may represent an occupational risk and veterinarians should be aware of possible MRSA colonization and potential for developing infection or for transmitting these strains. Professional exposure to animals should be reported upon hospitalization and before medical intervention to allow for preventive measures. Infection prevention measures are also indicated in veterinary medicine to avoid MRSA transmission between humans and animals, and to limit the spread of MRSA both in the community, and to animal and human hospitals.

Poor infection prevention and control standards are associated with environmental contamination with carbapenemase-producing Enterobacterales and other multidrug-resistant bacteria in Swiss companion animal clinics

“…Variable MRSA sequence types were detected in the employees, including healthcare-associated (ST225, ST5, ST45, ST7), livestock-associated (ST398) and community-acquired MRSA (ST97). Veterinarians have an occupational risk for acquisition of MRSA [59]. Contact with horses has been reported to be a risk factor for acquiring MRSA ST398 [60] and was also found to be associated with colonization with MR staphylococci in this study.…”

Antibiotic-resistant pathogens in different patient settings and identification of surveillance gaps in Switzerland – a systematic review

“…MRSA prevalence among pig farmers was 6.6% in 2008 [42], 0% in 2009 [43] and 12% in 2015 [41]. No MRSA was detected among slaughterhouse workers (2009), whereas 3% and 4% of screened veterinarians were MRSA-positive (2009 and 2012) [42–44].…”

Occupational swine exposure and Hepatitis E virus, Leptospira, Ascaris suum seropositivity and MRSA colonization in Austrian veterinarians, 2017–2018—A cross‐sectional study

“…The prevalence of nasal MRSA colonization among the participating veterinarians was with 13% high, compared with a nasal MRSA positivity of 3.8% in 340 veterinarians from Switzerland (Wettstein Rosenkranz et al, ) and of 0.2% detected in 3,309 healthy Austrians within a European‐wide cross‐sectional study in 2013 (den Heijer et al, ). We found, relative to the non‐swine veterinarians, the swine veterinarians five times more likely to be MRSA positive.…”