Molecular analysis and species diversity of Nocardia in hospital environment of a developing country, a potential health hazard

Background: Despite hundreds of reports on the isolation of Nocardia from clinical samples, the presence and diversity of Nocardia species capable of survival in a harsh and adverse condition such as hospital environment have not been comprehensively studied. The aim of this study was to assess the Nocardia species diversity in the hospital environment to provide a better insight on their potential threat as a reservoir for the development of nosocomial infections. Methods: A total of 90 hospital water, dust and soil samples collected from 30 hospitals were analyzed for the presence of Nocardia using standard protocols for isolation and characterization of the isolates. The conventional tests were used for preliminary identification and the PCR amplification of 596-bp amplicon of the 16SrRNAandthe sequence analysis of 16SrRNA was applied for the genus and species identification. Results: A total of 25 Nocardia isolates (27.7%) were recovered from 90 samples that belonged to 10 various species. The three most prevalent species were N.cyriacigeorgica, 24%, N.asteroides, 16%, and N. kroppenstedtii 12%, followed by N.salmonicidalike, 8%, and the single isolates of N. otitidiscavarum, N flavorozealike, and N. neocaledoniensis like and N. Sungurluensis like. Thirteen out of 25 isolates showed characteristics of six novel species. Conclusion: Our study showed that hospital environment can be the reservoir of a diverse range of Nocardia due to remarkable survival capability of these bacteria in adverse environment of hospitals. This in turn, might create a threat to the health of patients.

کلیدواژه ها:

Nocardia ، hospital infection ، 16S rRNA sequencing ، phylogeny