Staphylococcus p seudintermedius Isolated from Two Dog Cases with Ophthalmic Lesions

Abstract

Two dog cases with history of recurrent bacterial conjunctivitis were submitted to Purdue University for bacterial culture and sensitivity testing. The bacterial cultures were also tested for their ability to form a biofilm. Biofilm forming Staphylococcus pseudintermedius was isolated from the two cases and identified by Vitek2 and PCR analysis. The bacterial antibiotic sensitivity testing revealed that Isolate one was susceptible to ticarcillin, ceftiofur, cefazolin, moxifloxacin, amikacin and rifampicin with MICs ranging 0.03125-4 μg/ml. Isolate two was susceptible to ceftiofur, gatifloxacin, cefazolin, moxifloxacin, tetracycline, doxycycline and rifampicin with MICs ranging <0.0625–4 μg/ml. Meanwhile, the biofilm antibiotic sensitivity testing revealed that Isolate one biofilm was resistant to all antibiotics except for ceftiofur and moxifloxacin with MICs <0.25 and 8 μg/ml respectively. Isolate two biofilm was resistant to all antibiotics except for tetracycline, amikacin, doxycycline, chloramphenicol and rifampicin with MICs ranged from <0.125 to 8 μg/ml. Case one was resolved with topical cefazolin therapy. Meanwhile case two showed complete recovery after treated with topical levofloxacin plus oral doxycycline.