Choice of sanitary-indicative microorganisms for the assessment of the safety of split-systems

Abstract

Purpose of work is a compilation of data about the microflora which colonizes a split-system, with the aim of selection of sanitary-indicative microorganisms, whose presence in the sample would indicate to the need for cleaning and disinfection of split-systems. In the article there were used data of five years author's scientific inquiry, related to the prevention of respiratory diseases, associated with the usage of a local air conditioning systems. We also use the data from the literature. For selection of "indicative" microorganisms, we proposed the usage of nine criteria, each of them have numeric value from 0 to 3 points (risk for health, prevalence rate of the disease, epidemiological link, speed of split system's colonization, difficulty of cultivation, resistance in the environment, resistance to disinfectants, frequency of detection in home air conditioning systems, frequency of detection in air conditioning systems of public buildings). After the calculation Pseudomonas aeruginosa and Staphylococcus aureus received maximal score (20 points). Therefore, these two types of bacteria are indicative microorganisms. The detection of these microorganisms in split systems will indicate to the contamination of air-conditioning system. This microflora also is a criterion of cleaning and disinfection quality--presence of these microorganisms in the samples after this process will mean that the processing of air conditioning systems was performed poorly. Split systems are very faster colonized by conditionally pathogenic and pathogenic microflora. To prevent the possible hazard for population's health it is necessary to develop the normative base, according to which sanitary-and-hygienic control over the split-systems working must be carried out. Proposed criteria suggest that Pseudomonas aeruginosa and Staphylococcus aureus are indicative microorganisms, and it's identification in the air-conditioning system would mean risk for health and necessity for cleaning and disinfection.