Microbiota associated with tramp ants in a Brazilian University Hospital

Abstract

Our aim was to study the fauna of ants in the Hospital Universitário of the Universidade Federal do Triângulo Mineiro, municipality of Uberaba, Minas Gerais State, Brazil, as well as to identify the microorganisms the ants carry and their patterns of resistance to antibiotics. Sterile tubes (traps) containing honey were used to attract the ants. Traps were exposed for 3h, and those which attracted ants were considered the test group, while the ones that did not attract the insects constituted the control group. Only the ant species Tapinoma melanocephalum (Fabricius) was sampled. Sixty microorganisms were isolated from the sampled ants, including seven Gram-positive bacilli, 14 Gram-negative bacilli, 22 Gram-positive cocci and 17 filamentous fungi. Pseudomonas, Staphylococcus and Group D Streptococcus were the microorganisms with the highest resistance to the tested antibiotics. The ants should be considered an important vector of infections as they carry several pathogenic microorganisms, spreading them on the surface of sterile materials, equipment and uncontaminated food. It is impossible to define the exact role of ants in nosocomial infections at this moment; however, this issue must be better studied and special attention must be given by the commissions of Nosocomial Infection Control.