Review on Methicillin-resistant Staphylococcus aureus (MRSA) in Dogs and Cats

Staphylococcal infection is of major importance in both Human and Animals. Some staphylococcal bacteria are Methicillin-resistant. This paper reviews the current information on Methicillin-Resistant Staphylococcus aureus (MRSA) in dogs and cats. Staphylococcus aureus is a Gram positive, non-spore forming coccus. It may be found singly, in pairs, in short chains, or in irregular clusters. The colonies are circular, smooth and glistening. Staphylococcus aureus is a major resident or transient colonizer of the skin and the mucosa of human and primates. These organisms occasionally live on domestic animals, although domestic animals are usually colonized by other species of Staphylococci. When Staphylococcus aureus gains entry into the host, it causes variety of infection, from mild skin infection to life threatening invasive infections. Methicillin resistance exhibited by these organisms is due to the acquisition of mecA gene, that encodes new protein designated PBP2a, belonging to the family of enzymes necessary in building the bacterial cell wall. The protein (PBP2a) has a very low affinity for βlactams antibiotics and confers resistance to Methicillin and the other beta-lactams. In developed countries, companion animals have become an integral part of the household. More than 50% of households in the developed and developing countries have pets hence makes Staphylococcus aureus infection an important zoonotic disease. Methicillin resistance has been reported in Staphylococcal species such as Staphylococcus aureus, Staphylococcus intermedius, Staphylococcus schleiferi and Staphylococcus sciuri. Colonization and infection in-patients remain the major reservoir of MRSA in hospitals, while aerosols, inanimate objects, domestic animals and pets could act as reservoirs and transmit MRSA to humans. Conclusively, Methicillin resistant Staphylococcus aureus is a condition that needs to be given close surveillance due to the zoonotic importance of these bacterial organisms.