AVALIAÇÃO DA VIABILIDADE DE AMOSTRAS BACTERIANAS EM SUPERFÍCIES ABIÓTICAS COM A INFLUÊNCIA DE FLUÍDOS BIOLÓGICOS

Abstract

The environmental and hospital infections, caused by bacteria which are resistant to a wide variety of antibiotics, have shown increasing records in the last years, manifesting themselves in high mortality and lethality. Recent researches report that the bacteria presents a survival profile on dry surfaces in order to maintain their virulence when exposed to biological fluids such as urine, saliva and blood. The objective of this study was to document - through laboratorial analysis the survival capacity of the main bacteria of medical interest on abiotic surfaces. The adopted procedures were completely conducted in the microbiology laboratory at Unoeste, in Presidente Prudente SP. Standard ATCC strains of Staphylococcus aureus (ATCC25923), Enterococcus faecalis (ATCC29212), Escherichia coli (ATCC35218), Klebsiella pneumoniae (ATCC700603) and Pseudomonas aeruginosa (ATCC27583) were used, to which biological fluids and water were added. The surfaces were tile, synthetic fabric, mattress and cotton fabric. The surfaces were contaminated with suspension composed by the ATCC strains, biological fluids and water in addition to the control containing only the ATCC strains, which were stored in petri dishes, kept in room temperature. Every seven days the surfaces were dipped in trypticase soy broth and kept in the oven for 24h at 37ºC. They were spread from the contaminated brothin Mueller Hinton agar and kept for 24h in the oven at 37ºC. The viability analysis was done through the colony-forming unity (CFU) counting. For the statistical analysis, the Software R was used, through the Friedman and Kruskal Wallis tests for multiple comparisons, analyzing within each factor (solution or surface) which differ between one another (Friedman s test) and also which treatments interactions are different (Kruskal-Wallis). Through this analysis it was possible to observe that in the current work that Staphylococcus aureus kept its viability for a longer period than other microorganisms under all the tested conditions, presenting significant differences between the fluids and surfaces, with a particular colony growth in blood and cotton. The Klebsiella pneumoniae showed differences between fluids, with saliva containing the highest colony number. With regards to the other tested bacteria, there was no isolated significance. For the multiple comparisons analysis, only the Pseudomonas aeruginosa presented no significant difference between any pair of treatments, whereas the other bacteria presented significant differences between the correlations. The need to analyze the environmental impact of these microorganisms persistence in environments, which are vulnerable to human beings, guides the creation of measures in order to control the spread of pathogenic microorganisms.