Bacterial profiles and phenotypic biomarkers of microbiota isolates in habitat: hazard identification factors

Abstract

The present work focuses on assessing bacterial profiles of microbiota existing on technological equipment applied in food products manufacturing, objects located inside medical and preventive facilities, and water objects in recreation zones; another goal was to examine phenotypic properties of opportunistic pathogenic bacteria isolates as hazard identification factors within the framework of risk assessment concept. Our research objects were strains of Escherichia, Klebsiella, Enterobacter, Staphylococcus, Pseudomonas, Citrobacter and Serratia families that were detected and extracted due to hygienic monitoring activities performed in 2013–2017. Samples were taken via washing, direct inoculation, membrane filtration, and instrumental aspiration technique. Microbial status was analyzed with cultural and biochemical techniques on nutrient and differential-diagnostic media with subsequent confirmation with polymerase chain reaction (PCR). Phenotypic peculiarities were examined in vitro with conventional biochemical and microbiological techniques in conformity with the requirement fixed in Good Laboratory Practice. We revealed peculiarities of microbial profiles belonging to opportunistic pathogenic microbiota on different objects in habitats. The greatest groups included staphylococci detected in the air inside medical organizations with 1–4 cleanness degree (44%); Enterobacteriaceae family bacteria, in washes off objects located in manufacturing and medical and prevention facilities (64% and 69% accordingly); Pseudomonas family bacteria, in water objects (46%). 60 (36%) isolates out of 167 examined ones had modified morphological and tinctorial signs regarding those typical for a family. Most isolates had a set of modified or atypical metabolomic signs such as hemolytic and lecithinase activities, apparent persistent factors, and ability to create biofilms. Opportunistic pathogenic bacteria strains extracted from washes off objects located inside food products manufacturing and medical and preventive facilities were the most potentially aggressive. Isolates from the same families extracted from water objects in recreation zones and air inside medical and preventive facilities had less apparent phenotypic properties that characterized their pathogenic potential. Our experimental data provide useful materials for examining a phenomenon related to changes in phenotypic properties; they can be applied during revealing and drawing up a hazard profile and for minimizing uncertainty within the concept of microbiological risk analysis.

Keywords

• microorganisms
• microbiota
• microbial status
• contamination
• biomarkers
• biofilms creation
• recovery techniques