Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Dogs with Recurrent Pyoderma

Abstract

Methicillin Resistant Staphylococcus aureus (MRSA) has been recently growing problem in small animal clinical practice due to increasing resistance to multiple number of antimicrobials. Present study reports about the antimicrobial susceptibility pattern of MRSA isolated from the dogs with recurrent pyoderma. Based on the cultural and biochemical studies 12 isolates were identified as Staphylococcus aureus. Methicillin resistant Staphylococcus aureus was identified based on the disc diffusion method. Fifty percent of the dogs showed the methicillin resistant Staphylococcus aureus isolates which were resistant to almost all the antimicrobials used in the present study. Other fifty percent dogs had methicillin susceptible Staphylococcus aureus which were susceptible to amoxicillin with sulbactum, cefpodoxime with clavulanic acid, enrofloxacin, cephalexin, ciprofloxacin, chloramphenicol, amoxicillin and clavulanic acid, cephadroxil and cefpodoxime. Most of the cultures were resistant to tylosin, lincomycin, erythromycin, azithromycin, gentamicin, amikacin. IntroductionStaphylococcus species are the normal skin microflora of different animals and these organisms are responsible for skin infections in the majority of domestic animals [1]. Staphylococcus aureus infection causes mild skin infection to life threatening invasive infections and had the ability to rapidly develop resistance to different antibiotics which are in clinical use [2]. Staphylococcus that are resistant to semi-synthetic penicillins such as methicillin and oxacillin are considered to have methicillin resistance. Methicillin resistance is an alarming condition for treatment because it implies resistance not only to beta-lactam antibiotics including cephalosporins, but also to a wide range of antibiotics [3]. MRSA isolates, have been generally isolated from human beings, but increasing number of reports have documented the occurrence of MRSA in various animal species [4]. Previous studies suggested that MRSA can cause infections in dogs and dogs can also act as reservoirs of MRSA [5]. Recurrent pyoderma is an important clinical skin problem in dogs and frequently occurs as a result of uncorrected under lying cause(s) or use of inappropriate antibiotics or improper duration of antibiotic therapy [6]. In recent years, due to increase the number of MRSA has become a therapeutic challenge in veterinary dermatology [7]. Hence, present study was undertaken to ascertain the occurrence of methicillin resistant Staphylococcus aureus in dogs with recurrent pyoderma and their susceptibility to various antimicrobials. Materials and MethodsPresent study was conducted at College Hospital of College of Veterinary Science, Tirupati from 2009 to 2011. A total of 50 dogs belong to the different breeds with a history of recurrent skin problems were included in the study (Figure 1). Dogs were examined clinically and diagnosis of recurrent pyoderma was confirmed by cytological examination of the smears made from the skin lesions [8,9]. After confirmation of rec...