Mycobacterium Reference Laboratory, Victorian Infectious Diseases Reference Laboratory at the Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Melbourne, 3000, Victoria, Australia.
Department of Infectious Diseases, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Melbourne, 3000, Victoria, Australia.
J Med Microbiol. 2022 Aug;71(8). doi: 10.1099/jmm.0.001581.
Nocardia is an opportunistic pathogen that can cause significant morbidity and mortality, particularly in the immunocompromised host. Antimicrobial susceptibility profiles vary across spp. and vary within Australia as well as worldwide. Knowledge of local susceptibility patterns is important in informing appropriate empiric antimicrobial therapy. This is the largest study to date in Australia that correlates antimicrobial susceptibility profiles with molecular identification of species. It is the first study that examines isolates from multiple institutions across the state of Victoria, Australia. To investigate the species distribution and antibiotic susceptibility of spp. isolates referred to the Mycobacterial Reference Laboratory (MRL) in Victoria, Australia from 2009 to 2019. We conducted a retrospective review of spp. isolates which were identified using molecular sequencing. Antimicrobial susceptibility testing was performed using standardized broth microdilution method with Sensititre RAPMYCO1 plates. Species distribution and antibiotic susceptibility profiles were analysed. In total, 414 isolates were identified to 27 species levels, the majority originating from the respiratory tract (=336, 81.2 %). (=147, 35.5 %) was the most frequently isolated, followed by (=75, 18.1 %). Species distribution varied by isolate source, with and found more commonly from sterile sites. Linezolid and amikacin had the highest proportion of susceptible isolates (100 and 99% respectively), while low susceptibility rates were detected for ceftriaxone (59 %) and imipenem (41 %). Susceptibility to trimethoprim sulfamethoxazole varied by species (0-100 %). This is the largest study to date in Australia of species distribution and antimicrobial susceptibility patterns. and were more likely to be isolated from sterile sites, while and were more likely to be isolated from skin and soft tissue. First line therapeutic antimicrobial recommendations by local guidelines were not necessarily reflective of the susceptibility of isolates in this study, with high susceptibility detected for linezolid and amikacin, but poor susceptibility demonstrated for ceftriaxone and imipenem. Profiles for trimethoprim-sulfamethoxazole varied across different species, warranting ongoing susceptibility testing for targeted clinical use.
诺卡氏菌是一种机会性病原体，可导致重大发病率和死亡率，尤其是在免疫功能低下的宿主中。不同种属的抗生素敏感性谱有所不同，在澳大利亚乃至全球范围内也存在差异。了解当地的敏感性模式对于指导经验性抗生素治疗非常重要。这是迄今为止澳大利亚最大的一项研究，将抗生素敏感性谱与种属的分子鉴定相关联。这也是第一项研究，检查了来自澳大利亚维多利亚州多个机构的分离株。本研究旨在调查 2009 年至 2019 年期间澳大利亚维多利亚州分枝杆菌参考实验室（MRL）送检的诺卡氏菌种属分离株的种属分布和抗生素敏感性。我们对采用分子测序鉴定的诺卡氏菌属分离株进行了回顾性研究。采用 Sensititre RAPMYCO1 板标准化肉汤微量稀释法进行抗生素敏感性试验。分析了种属分布和抗生素敏感性谱。共有 414 株分离株鉴定到 27 个种属水平，其中大部分来源于呼吸道（=336，81.2%）。星状诺卡氏菌（=147，35.5%）是最常分离到的种属，其次是脓肿分枝杆菌（=75，18.1%）。分离株来源不同，种属分布也不同，从无菌部位分离到的 更多。利奈唑胺和阿米卡星的敏感分离株比例最高（分别为 100%和 99%），而头孢曲松（59%）和亚胺培南（41%）的敏感性较低。磺胺甲恶唑/甲氧苄啶的敏感性因种属而异（0-100%）。这是迄今为止澳大利亚最大的一项关于诺卡氏菌属种属分布和抗生素敏感性模式的研究。星状诺卡氏菌和脓肿分枝杆菌更可能从无菌部位分离到，而假诺卡氏菌和皮诺卡氏菌则更可能从皮肤和软组织中分离到。当地指南推荐的一线治疗性抗菌药物不一定反映了本研究中诺卡氏菌属分离株的敏感性，利奈唑胺和阿米卡星的敏感性较高，但头孢曲松和亚胺培南的敏感性较差。磺胺甲恶唑/甲氧苄啶的谱因不同的诺卡氏菌种属而异，需要进行持续的药敏试验，以指导临床应用。
