Antimicrobial susceptibility of Staphylococcus sp. and Escherichia coli isolated from captive Amazonian manatee (Trichechus inunguis)

Abstract

The Amazonian manatee (Trichechus inunguis) is an aquatic mammal threatened with extinction. However, few studies have investigated the pathogens in this species, which may affect both animal and human health. This study aimed to evaluate the frequency, distribution, and patterns of antimicrobial susceptibility of Staphylococcus spp. and Escherichia coli colonizing the nasal and rectal cavities of Amazonian manatees kept in captivity at the National Institute for Amazonian Research (INPA) in the state of Amazonas, Brazil. Rectal and nasal swabs from44 manatees of different ages were used in this study. The genus Staphylococcus was isolated from the nasal swabs of 32 (72.7%) animals, with two individuals harboring more than one species of Staphylococcus. S. sciuri was the most commonly isolated species. Resistance to penicillin was observed in 13 (40.6%) isolates, more frequent than the other antimicrobials tested (P = 0.01). E. coli was isolated from the rectal swabs ofall animals, with phylogroup B1 being the most frequent among the strains obtained (P = 0.0008). Four isolates (6.8%) were positive for virulence factors, three of which were classified as enterotoxigenic E. coli (ETEC) and one as enteropathogenic E. coli (EPEC). To our knowledge, this is thefirst study to evaluate Staphylococcus spp. and E. coli in Amazonian manatee samples. This study revealed nasal colonization by Staphylococcuss pp., mainly S. sciuri, and diarrheagenic E. coli isolates, including antimicrobial-resistant strains.