Microbioma urbano: microrganismos aerolizados em terminais de integração de ônibus da cidade de Fortaleza-CE.

Abstract

Microorganisms are abundant in the atmosphere in the form of organic aerosols. The crowding and heavy traffic of people in urban areas can be an aggravating factor in the dispersion of potential pathogens that in contact with sensitive individuals can trigger a series of allergic reactions and other respiratory problems. The goal of this research was to analyze the diversity of the aeromicrobiota in the bus terminals in the city of Fortaleza. For this, four collections were carried out from February to May 2019 in the morning. The collection was made by the spontaneous sedimentation technique on selective culture media for bacterial growth (plate count agar+ fungicide) and fungal growth (potato dextrose agar+ antibiotic). Petri dishes, in triplicate, were opened and exposed to the environment for twenty minutes and then the material was packed in an isothermal box and transported to the Laboratory of Microbiology Environmental Microbiology and Fish, located at the Institute of Marine Sciences of the Federal University of Ceará. The samples were incubated at 35ºC for 48h and 28ºC for 7 days for the growth of bacteria and fungi, respectively. Colony forming units were counted per cubic meter of air and ten bacterial strains were isolated per collection site and according to their morphology. The isolates were purified and characterized using the Gram stain technique. Among the analyzed terminals, the mean values of bacteria varied between 147.94 and 1000.15 CFU/m³ while the fungi between 75.5 and 290.61 CFU / m³. The highest microbiological counts were recorded at the Antônio Bezerra terminal, except for collection three, with higher numbers of bacteria recorded at the Papicu terminal. Regarding the morphotintorial characteristics, in the three terminals there was a predominance of Grampositive cocci (45.2%), followed by Gram positive rods (42.1%) and less frequently Gramnegative rods (12.6%). Fungi were identified by Petri dishes, according to their macroscopic characteristics and the main genera found were: Aspergillus (22.5%), Lichtheimia (18.3%), Trichoderma and Fusarium (14.2%). Due to the lack of Brazilian legislative parameters on aeromicrobiota in external environments, it is difficult to determine the monitoring of air quality in these places and the damage to people's health and well-being. Thus, it is important to produce indices that establish exposure limits for these microorganisms.