Ants as Vectors of Bacteria in Hospital Environments

Abstract

Ants in hospital environments may carry pathogenic microorganisms that cause hospital-acquired infections (HAIs), developing resistance to antimicrobials and therefore representing a public health hazard. HAIs increase mortality rates, as a constant threat in the spread of multi-resistant bacteria. This study isolated and identified pathogenic bacteria in ants captured in a hospital in Brazil. We also identified the main genera of ants in these environments. Ants were attracted using protein and carbohydrate traps. A group of five ants was considered a sample. Microbiological analysis included the isolation of <i>Escherichia coli</i> and other enterobacteria and staphylococci. Susceptibility was tested against vancomycin, cefoxitin, oxacillin, and chloramphenicol. The results of resistance to chloramphenicol assays revealed the presence of resistant <i>Enterobacteriaceae</i> (<i>E. coli</i>), resistant isolates of <i>Citrobacter feundii</i>, <i>Enterobacter</i> spp., <i>Klebsiella</i> spp., and <i>Klebsiella oxytoca</i>, and susceptible <i>Hafnia</i> spp., and <i>Yersinia enterocolitica </i>isolates. For vancomycin, oxacillin, and cefoxitin, the bacteria included resistant and sensitive coagulase-negative <i>Staphylococcus </i>spp. and coagulase-positive <i>S. aureus </i>CP<i>.</i> The ant genera identified were <i>Pheidole</i>, <i>Crematogaster</i>, <i>Linepithema</i>, and the species <i>Tapinoma</i> <i>melanocephalum</i>. Ants in hospital environments may carry significant numbers of bacteria resistant to the antimicrobials used. This highlights the risk these bacteria pose in such settings, especially to intensive care patients, who usually are immunodepleted.