Contaminating microflora at a tuberculosis test: saprophytes or potential pathogens?

Lyamin A.V., Ismatullin D.D., Zhestkov A.V., Kovalev A.V., Persiyantseva T.P., Davydova D.T., Manasyan V.A.

Samara State Medical University, Samara, Russian Federation
Samara Regional Clinical Tuberculosis Dispensary named N.V. Postnikov, Samara, Russian Federation

The article presents data on the prevalence of acid-resistant actinomycetes in the composition of contaminating microflora isolated from clinical material during examination for tuberculosis. The study included inoculation of clinical material in which signs of contamination were detected in the absence of representatives of the Mycobacterium tuberculosis complex. The material was presented by 865 samples collected from January 2016 to January 2019. The third-largest group of microorganisms was acid-resistant representatives of the Actinomycetales order. It was most widely represented in the contaminating microflora isolated from sputum. Moreover, if we calculate the proportion of acid-resistant representatives of the order of Actinomycetales of clinical importance, then it will be 4.6% (50 strains) of all microorganisms identified in the study, and for all acid-resistant actinomycetes, regardless of their potential clinical value, 9.3% (102 strains).