The Distribution and Resistance to Antibiotics of Staphylococcus Organisms Among the Equine Population of Central Texas
Staphylococcus species are common microbes capable of causing infection in human and nonhuman populations. Microbial resistance to antibiotics has become a threat to antisepsis and public health. There is limited knowledge of Staphylococcus organisms specific to equine populations and less of their resistance to antibiotics within these populations. To survey the Staphylococcus species in the equine population of the Central Texas region, a total of 65 horses from three farms were swabbed within the nasal cavity, behind the ear, and at the left girth. Swab sites were chosen for accessibility and high moisture levels that could support bacterial growth. The farms varied in level of human contact. Interactions between species may increase the diversity of microbes shared. Biochemical tests were used to characterize strains, which were then identified using the Advanced Bacterial Identification Software (ABIS) and the Siemens Microscan Autoscan System. 25 Staphylococcus species were isolated between the three farms. The most common isolates were Staphylococcus cohnii cohnii, Staphylococcus xylosus, and Staphylococcus haemolyticus. An increase in level of human contact and potential for treatment between Farms One and Three correlated with an increase in microbial resistance to antibiotics, specifically penicillin, oxacillin, trimethoprim-sulfmethoxazole, and ciprofloxacin.