Karkaba A, Benschop J, Hill K E, Grinberg A
a Institute of Veterinary, Animal and Biomedical Sciences, Infectious Diseases Group , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand.
b Institute of Veterinary, Animal and Biomedical Sciences, mEpiLab , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand.
N Z Vet J. 2017 Mar;65(2):78-83. doi: 10.1080/00480169.2016.1222919. Epub 2016 Sep 7.
To characterise methicillin-resistant Staphylococcus aureus (MRSA) isolates from infection sites in animals in New Zealand and assess the prevalence of subclinical MRSA colonisation in dogs and cats attending veterinary clinics in Auckland.
MRSA isolates from clinical specimens obtained by the main New Zealand veterinary diagnostic laboratories between June 2012 and June 2013, were genotypically characterised by DNA microarray hybridisation analysis and spa typing. In addition, nasal or perineal skin swabs collected from a cross-sectional sample of dogs (n=361) and cats (n=225) attending 29 veterinary clinics in Auckland during the same period were analysed for MRSA by culture.
Eight MRSA clinical isolates were submitted for characterisation by the participating laboratories. The isolates originated from five dogs, including two isolates from the same dog, one foal, and one isolate had no identification of the source. The strain-types identified were AK3 (ST-5 SCCmecIV t045; n=1), USA500 (ST8 SCCmecIV t064; n=1), WSPP (ST30 SCCmecIV t019; n=1), Rhine Hesse (ST5 SCCmecII t002; n=2), and EMRSA-15 (ST22 SCCmecIV t032; n=3). No MRSA were isolated from 586 cultured swabs. Methicillin-susceptible S. aureus were detected in 9/257 (3.5%) swabs and non-aureus staphylococci in 22/257 (8.5%) swabs. The estimated true MRSA subclinical colonisation prevalence was 0%, with an upper 95% CI boundary of 1.9% for cats and 1.4% for dogs.
The modest number of MRSA isolates submitted for this study by the participating laboratories suggests clinical MRSA infection in animals in New Zealand continues to be sporadic. The wide variety of strain-types found mirrored the evolving strain-type diversity observed in humans. We cannot rule out bias due to the non-random sampling of dogs and cats, but the apparent colonisation prevalence of 0% was consistent with the low prevalence of subclinical colonisation in humans in New Zealand. These similarities indicate the epidemiology of animal and human MRSA infections are linked.
In the last decade, the prevalence of human MRSA infections in New Zealand has steadily increased. This is the second published study of MRSA in animals in New Zealand. The results indicate clinical MRSA infection in animals remains sporadic, but the diversification of the strain-types may pose new therapeutic challenges to veterinarians, due to their diverse resistome.
对来自新西兰动物感染部位的耐甲氧西林金黄色葡萄球菌（MRSA）分离株进行特征分析，并评估奥克兰兽医诊所就诊的犬猫亚临床MRSA定植的患病率。
对2012年6月至2013年6月间新西兰主要兽医诊断实验室获得的临床标本中的MRSA分离株，通过DNA微阵列杂交分析和spa分型进行基因特征分析。此外，同期从奥克兰29家兽医诊所就诊的犬（n = 361）和猫（n = 225）的横断面样本中采集鼻拭子或会阴皮肤拭子，通过培养分析MRSA。
参与实验室提交了8株MRSA临床分离株进行特征分析。分离株分别来自5只犬，其中2株来自同一只犬，1匹小马驹，还有1株来源未明确。鉴定出的菌株类型为AK3（ST-5 SCCmecIV t045；n = 1）、USA500（ST8 SCCmecIV t064；n = 1）、WSPP（ST30 SCCmecIV t019；n = 1）、莱茵黑森（ST5 SCCmecII t002；n = 2）和EMRSA-15（ST22 SCCmecIV t032；n = 3）。586份培养拭子中未分离出MRSA。在257份拭子中有9份（3.5%）检测到对甲氧西林敏感的金黄色葡萄球菌，22份（8.5%）检测到非金黄色葡萄球菌。估计真正的MRSA亚临床定植患病率为0%，猫的95%可信区间上限为1.9%，犬为1.4%。
参与实验室为本研究提交的MRSA分离株数量不多，表明新西兰动物临床MRSA感染仍然是散发性的。发现的多种菌株类型反映了在人类中观察到的不断演变的菌株类型多样性。我们不能排除由于犬猫非随机抽样导致的偏差，但明显的定植患病率为0%与新西兰人类亚临床定植的低患病率一致。这些相似性表明动物和人类MRSA感染的流行病学是相关的。
在过去十年中，新西兰人类MRSA感染的患病率稳步上升。这是新西兰第二项关于动物MRSA的已发表研究。结果表明动物临床MRSA感染仍然是散发性的，但由于其多样的耐药组，菌株类型的多样化可能给兽医带来新的治疗挑战。
