Isolation and identification of emergent multidrug-resistant Stenotrophomonas maltophilia from skin ulcers of Sarcoptes-infested pigs

Stenotrophomonas maltophilia is an emergent multidrug-resistant bacterium. Clinical conditions caused by this bacterium range from skin and soft tissue infection to graver septicaemia and cardiac involvement in immunocompromised humans. A recent whole-genome analysis corroborates the hypothesis of the potential contribution of animals as reservoirs for human infections, strengthening the possibility of zoonoses. This paper reports the isolation of Stenotrophomonas maltophilia from skin ulcers of pigs, associated with sarcoptic mange. Swabs from five pigs with skin ulcers were collected and processed. The cultural, biochemical characterisation and antibiotic susceptibility testing of the isolates were performed. The isolated organisms were found to be of similar cultural morphology and biochemical characteristics. Two representative isolates were subjected to molecular characterisation targeting 16s ribosomal RNA (rRNA). The polymerase chain reaction product was subjected to sequencing followed by basic local alignment search tool analysis, confirming the organism as Stenotrophomonas maltophilia. Antibiotic susceptibility testing using 11 different antibiotics revealed that the organism is multidrug resistant with susceptibility towards oxytetracycline and cotrimoxazole.