title: Molecular analysis and species diversity of Nocardia in the hospital environment in a developing country, a potential health hazard.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hossein Ali
authors.initials: HA
authors.lastname: Rahdar
authors.affiliation: Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Davood
authors.initials: D
authors.lastname: Azadi
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hasan
authors.initials: H
authors.lastname: Shojaei
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Abbass
authors.initials: A
authors.lastname: Daei-Naser
mesh_terms: D003428:Cross Infection / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D003906:Developing Countries; D004197:Disease Reservoirs; D014644:Genetic Variation; D006761:Hospitals; D006801:Humans; D007492:Iran / Q000453:epidemiology; D009615:Nocardia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D009617:Nocardia Infections / Q000453:epidemiology / Q000382:microbiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S