Identification and molecular epidemiology of methicillin resistant Staphylococcus pseudintermedius strains isolated from canine clinical samples in Argentina
Identification and molecular epidemiology of methicillin resistant Staphylococcus pseudintermedius strains isolated from canine clinical samples in Argentina
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DOI：
10.1186/s12917-019-1990-x
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发表时间：
2019-07-27
影响因子：
2.6
通讯作者：
Rosato, Adriana E.
中科院分区：
文献类型：
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作者：
Gagetti, Paula;Wattam, Alice R.;Rosato, Adriana E.
背景假中间葡萄球菌是引起犬化脓性链球菌病的主要原因，抗菌治疗的频繁使用与对几乎所有种类抗生素的耐药性的发展有关。尽管S. pseudintermedius意义，我们对β-内酰胺耐药的分子机制及其遗传多样性的理解仍然有限。我们的目标是：i）确定从阿根廷布宜诺斯艾利斯的三家不同兽医医院的感染狗中分离的耐甲氧西林假中间葡萄球菌（MRSP）的表型抗性谱;以及iii）分析分离株之间的克隆关系，并考虑到在世界上发现的优势谱系。MRSP分离株（n=10）显示对5-6个抗生素家族的耐药性，因此被归类为多重耐药。所有分离株均为SCCmec V的变异株。金黄色;另外的SCCmectin分析将5个基因组分类为SCCmecV型（5C 2和5），具有mecA（编码PBP 2a）、mecRI和mecI，并且所有基因与参考SCCmecVS型密切相关。金黄色葡萄球菌TSGH 17菌株。在其余5个菌株中，mecA存在，但与SCCmec V相关的其他基因（包括mecR 1和mecI）缺失。PBP 2a在低水平耐药菌株（MRSP 8151）中是可诱导的，而在MRSP 8150中是组成性表达的，表明不同的mecA调节机制。MRSP分离株表现出显著的遗传多样性：8个PFGE克隆型和6个多位点序列分型（MLST）序列类型（ST）（339，649，919，920，921和922），包括4个新的ST在遗传上不同于ST在其他地理区域报告。MRSP的比较基因组学和系统发育分析表明，遗传含量和表型之间的相关性，并建立了菌株之间的遗传relationship.ConclusionsMRSP可能是一个威胁动物健康，因为它涉及的抗菌素耐药性水平。我们的研究突出了来自阿根廷的多药耐药MRSP菌株的遗传和流行病学方面，显示了耐药基因与分离株表型之间的高度相关性，此外，它们似乎与全球主要报道的ST 68和ST 71进化更接近。
BackgroundStaphylococcus pseudintermedius is the leading cause of pyoderma in dogs and the frequent use of antimicrobial treatment is associated to the development of resistance to nearly all classes of antibiotics. Despite S. pseudintermedius significance, our understanding of the molecular mechanism of beta-lactam resistance and its genetic diversity remains limited. We aimed to: i) determine the phenotypic resistance profile of methicillin resistant Staphylococcus pseudintermedius (MRSP) isolated from infected dogs in three different veterinary hospitals in Buenos Aires, Argentina; ii) identify the SCCmec elements and resistance genes; and iii) analyze the clonal relationship between isolates and in regard of dominant lineages found in the world.ResultsIn addition to the differential levels of beta-lactam resistance, MRSP isolates (n=10) showed resistance to 5-6 families of antibiotics, and were therefore categorized as multidrug-resistant. All the isolates were variant of SCCmec V homologous to S. aureus; additional SCCmecFinder analysis classified five of the genomes as SCCmec type V (5C2&5) with mecA (encodes for PBP2a), mecRI and mecI and all the genes closely related to the reference SCCmec type V S. aureus TSGH17 strain. In the remaining five strains, mecA was present, although other genes associated with SCCmec V including mecR1 and mecI were missing. PBP2a was inducible in low level resistance strains (MRSP 8151), and constitutively expressed in MRSP 8150, suggesting different mecA regulatory mechanisms. MRSP isolates showed significant genetic diversity: eight PFGE clonal types and six multilocus-sequence typing (MLST) sequence types (STs) (339, 649, 919, 920, 921 and 922), including four new STs genetically distinct from STs reported in other geographic areas. Comparative genomics and phylogenetic analyses of the MRSP showed a correlation between the genetic content and the phenotypes, and established the genetic relationship between the isolates.ConclusionsMRSP could be a threat to animal health due to it concerning level of antimicrobial resistance. Our study highlights genetic and epidemiological aspects of multidrug-resistant MRSP strains from Argentina showing high degree of correlation between the resistance genes and the phenotype of the isolates and, furthermore, they appeared evolutionary closer to major worldwide reported ST68 and ST71.