MICROBIOMES STUDY IN MEDICAL-ASSISTENTIAL ENVIRONMENTS BY ELECTRON MICROSCOPY SWEPT TECHNIQUES

D'ARPINO MARIA CECILIA; FÁTIMA SILVINA GALVÁN; NATALIA NOELIA ALVARADO; GABRIELA MARRANZINO; MARTINEZ, LUCIANO JOSÉ

Tucumán

Congreso; IV Reunión Conjunta de Sociedades de Biología - 2020; 2021

Sociedad de Biología de Tucumán

The identification of microbiomes present in the health field is extremely important given the close relationship with human diseases. The aim of thisstudy was to investigate the composition of microorganisms on the laboratory surfaces of the Central Blood Bank “Dr. César Guerra”, (PRISSI.PRO.SA). Duplicate samples from the countertops, air conditioners and the equipment on the Production, Distribution and Molecular Biologyservices were taken using paper tape and swabs. Plating was carried out in LB pH7 culture medium containing Cycloheximide (CH) andCyclohehimide/Nalidixic Acid (CH/NA) antibiotics. Both the paper tape and the colonies obtained from the cultures were subjected to ScanningElectron Microscopy (SEM). Sampling using paper tape allowed the presence of microbial biofilms to be detected in the internal part of theProduction service centrifuge, in the Distribution service platelet shaker and in the Molecular Biology service countertops. They presented a complexthree-dimensional organization characterized by microorganisms of different morphology arranged in layers immersed in abundant extracellularmaterial. The tape analysis also revealed the presence of isolated bacteria (cocci and bacilli) or the formation of small groups of them at the differentsampling sites. The cultures allowed the isolation of predominant microorganisms from countertops, air conditioners and equipment. A total of 45colonies (Gram+ and Gram−) that exhibited various morphotypes (cocci, bacilli, and coccobacilli) were isolated. Using SEM, it was possible toanalyze in detail the structure, organization, and morphology of the bacteria in culture. Furthermore, it was observed that many colonies establishedclose contacts. The SEM study revealed a wide spectrum of associations among them. It was possible to analyze the contact points among interactingcolonies, revealing morphological changes in the bacteria as well as a large amount of extracellular material at the interaction sites. In addition, thetopographic analysis of the colonies showed differences in the conformation of the different sectors in some of them. This work, aimed at analyzingthe microbiological communities developed in situ in healthcare settings, proposes high-resolution microscopy techniques as key tools for the studyin situ of biofilms on a surface, which study is lacking in our country.