Antimicrobial resistance inStaphylococcus pseudintermediusand the molecular epidemiology of methicillin-resistantS. pseudintermediusin small animals in Finland

Abstract

Objectives: To investigate antimicrobial susceptibility in Staphylococcus pseudintermedius and the occurrence of methicillin-resistant S. pseudintermedius (MRSP), to explore the molecular structure of the MRSP population and to analyse risk factors for MRSP.Methods: Susceptibility data for clinical S. pseudintermedius isolates in 2011–15 were analysed using WHONET. All MRSP isolates in 2010–14 (n = 362) were typed using PFGE. Representative isolates (n = 87) of clusters were analysed using MLST and staphylococcal cassette chromosome mec (SCCmec) typing. Risk factors were analysed using logistic regression.Results: Of the clinical S. pseudintermedius (n = 1958; 98% from dogs), 14% were MRSP. Resistance to other antimicrobials varied between 12% and 39%. No trends were observed over time. Among clinical specimens (from infection sites) and screening specimens (from potential carriers), respectively, 2.5% (267/10 813) and 9% (211/2434) revealed MRSP. MLST revealed 42 different STs, including 19 new ones. Clonal complexes 71, 45 and 258 were the most common, but the MRSP population diversified over the years. A clinical S. pseudintermedius isolate was more likely to be MRSP if the patient was on antimicrobials at the time of sampling or was male. The presence of MRSP in screening specimens was more likely if the patient was on multiple antimicrobials at the time of sampling. Specimens from private clinics (versus the Veterinary Teaching Hospital of the University of Helsinki) had a higher likelihood of MRSP in both analyses.Conclusions: Resistance to antimicrobials among S. pseudintermedius in Finland is high, emphasizing the importance of infection control measures and susceptibility testing prior to therapy. The diverse MRSP population indicates non-clonal spread.

Antimicrobial prophylaxis is considered sufficient to preserve an acceptable surgical site infection rate in clean orthopaedic and neurosurgeries in dogs

“…Previous data show that the MRSP carriage rate is higher (9%) in these patients than in low-risk patients i.e. the general Finnish dog population (3%) [ 37 , 40 , 41 ]. There is no reason to expect that the MRSP carriage rate would be higher in the non-screened patients in our study than in the general population.…”

S. pseudintermedius and S. aureus lineages with transmission ability circulate as causative agents of infections in pets for years

“…MRSP-ST71 is the major clone in Europe [ 2 , 3 ], and there are already few descriptions of this genetic lineage in healthy dogs in Spain [ 18 ]. However, recent studies have reported a downward trend in the prevalence of the MRSP-ST71 lineage among companion animals in northern Europe [ 11 , 19 ] and France [ 3 ]. The MRSP-ST258 lineage, which was detected in this study in 2009, seems to be replacing MRSP-ST71 in these countries [ 11 , 19 ].…”

Combining MALDI-TOF and genomics in the study of methicillin resistant and multidrug resistant Staphylococcus pseudintermedius in New Zealand

“…MRSP is becoming a major pathogen in veterinary hospitals across the world and is difficult to treat as many MRSP isolates are also MDR 61 . Global studies of MRSP carriage in healthy animals report highly varied observations, ranging from approximately 2% to 50% prevalence although surveillance data is limited 62,63 .…”