Rahdar Hossein Ali, Azadi Davood, Shojaei Hasan, Daei-Naser Abbass
Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
J Med Microbiol. 2017 Mar;66(3):334-341. doi: 10.1099/jmm.0.000436. Epub 2017 Mar 23.
Despite hundreds of reports on the isolation of Nocardia from clinical samples, the presence and diversity of Nocardia species that are capable of survival in a harsh and adverse condition, such as a hospital environment, have not been comprehensively studied. The aim of this study was to assess Nocardia species diversity in a hospital environment to provide a better insight into their potential threat as a reservoir for the development of nosocomial infections.
A total of 90 samples of hospital water, dust and soil, collected from 30 hospitals, were analysed for the presence of Nocardia using standard protocols for isolation and characterization of the isolates. Conventional tests were used for preliminary identification, and PCR amplification of the 596 bp amplicon of the 16S rRNA and sequence analysis of 16S rRNA were performed for genus and species identification.
A total of 25 Nocardia isolates (27.7 %) from 10 species were recovered from 90 samples. The three most prevalent species were N. cyriacigeorgica, 24 %, N. asteroides, 16 % and N. kroppenstedtii, 12 %, followed by N. salmonicida-like, 8 % and single isolates of N.otitidiscaviarum, N. flavorozea-like, N. neocaledoniensis-like and N. sungurluensis-like. Thirteen out of twenty five isolates showed characteristics of six novel species.
Our study showed that the hospital environment is a potential reservoir of a diverse range of Nocardia species, due to the remarkable survival capability of these bacteria in an adverse hospital environment, which carries a threat to the health of patients.
尽管有数百篇关于从临床样本中分离出诺卡氏菌的报道，但对于能够在医院环境等恶劣和不利条件下生存的诺卡氏菌种类的存在情况及多样性尚未进行全面研究。本研究的目的是评估医院环境中诺卡氏菌的种类多样性，以便更好地了解它们作为医院感染病原体来源的潜在威胁。
从30家医院收集了总共90份医院用水、灰尘和土壤样本，使用分离和鉴定菌株的标准方案分析其中诺卡氏菌的存在情况。采用常规试验进行初步鉴定，并对16S rRNA的596 bp扩增子进行PCR扩增以及对16S rRNA进行序列分析以进行属和种的鉴定。
从90份样本中总共分离出25株诺卡氏菌（27.7%），分属于10个种。最常见的三个种是乔治亚州诺卡氏菌（24%）、星状诺卡氏菌（16%）和克氏诺卡氏菌（12%），其次是鲑鱼诺卡氏菌样（8%）以及耳炎诺卡氏菌、类弗洛沃泽亚诺卡氏菌、类新喀里多尼亚诺卡氏菌和类松古鲁诺卡氏菌的单株分离菌。25株分离菌中有13株表现出6个新种的特征。
我们的研究表明，由于这些细菌在不利的医院环境中具有显著的生存能力，医院环境是多种诺卡氏菌的潜在储存库，对患者健康构成威胁。
