Species diversity, molecular characterization and antimicrobial susceptibility of opportunistic actinomycetes isolated from immunocompromised and healthy patient of Markazi province of Iran

Background and Aim : Abstract Introduction Actinomycetes are widely exist in nature and these species caused infections in immunocompromised and healthy patients although frequently found as members of the normal microbiota of human and animal. These subsequent infections are often misdiagnosed with malignancy and tuberculosis. Due to this issue in the present study, we aimed to determine the presence and diversity of actinomycetes species causing infections in Iranian patients.Methods : Materials and methods A total of ۷۹ clinical samples collected from ۵ hospitals in Markazi province were analyzed for the existence of actinomycetes using standard protocols for isolation and characterization of the isolates. The conventional tests were used for preliminary identification, the PCR amplification of hsp۶۵ gene, the specific region of the ۱۶S rRNA and sequence analyses of ۱۶S rRNA were applied for the genus and species identification. MICs of the antimicrobial agent were determined by the broth microdilution method and interpreted according to the NCCLS guidelines.Results : Result A total of ۱۷ (۲۱.۵۱ %) actinomycetes isolates were recovered from clinical samples. In other analyzed samples ۸ (۱۰.۱۲%) gram-positive, ۱۲ (۱۵.۱۸) gram-negative bacteria and ۶ (۷.۶) fungi isolates were recovered. The most prevalent actinomycetes species were M. fortuitum ۱۷.۶۴%, N. Mexicana and S.heliomycini ۱۱.۷۶% each and ۱۰ species, i.e., N. farcinica, M. lehmanii, M. flavescens, Arthrobacter crystalopoetis, N. neocaledoniensis, M. phocaicum, M. abscessus, M. arupense M. setense and N.cyriacigeorgica consisted the single isolates. Results of DST illustrated that all of the isolates were susceptible to Amikacin, Levofloxacin, Ofloxacin and Ciprofloxacin, whereas all of them were resistant to Rifampicin and Doxycycline.Conclusion : In conclusion, increasing isolation of actinomycetes found in various clinical case merits special attention by health authorities in developing countries. In health centers, action should be taken to increase awareness of appropriate diagnostic criteria and management guidelines for actinomycetes diseases. Furthermore, an increase in the number as well as the quality of national and regional reference laboratories may facilitate more accurate diagnosis of actinomycetes diseases.

کلیدواژه ها:

actinomycetes ، ۱۶SrRNA ، Drug susceptibility pattern ، immunocompromized