ISOLATION AND IDENTIFICATION OF Staphylococus aureus AND METHICILLIN RESISTANT Staphylococcus aureus (MRSA)

ABSTRACT

Dambu nama is a delicatessen made from shredded dried meat, mixed with spices. This study was done to isolate the Staphylococcus aureus and methicillin resistant Staphylococcus aureus from dambu nama and to determine to determine its susceptibility to chitosan. Four (4) samples were purchased from different supermarkets in various locations in Abuja. Standard pour plate technique was used to culture and isolate bacteria present in dambu nama using nutrient agar and mannitol salt agar respectively. Bacteriological analysis was carried out on the samples for enumeration and identification. The methicillin resistant Staphylococcus aureus present were identified based on the cultural and morphological characteristics as well as biochemical test. The susceptibility of the isolate to chitosan was done through agar well diffusion method. The bacteria count ranged from 1.24 x 104 cfu/g to 3.5x104 cfu/g on nutrient agar while Staphylococcus aureus ranged from 1.1x104 cfu/g to 4.6x104 cfu/g on mannitol salt agar. The highest colony count (5.0 x 107 cfu/g) was in the chicken sample while the least colony count (2.1 x 107 cfu/g) was obtained from the beef sample. Of the four samples of Staphylococcus aureus isolates, all were methicillin resistant as confirmed by its resistance to Zinacef, oxacillin and ampliclox. The methicillin resistant Staphylococcus aureus (MRSA) showed various levels of susceptibility to antimicrobial agent chitosan. The susceptibility of MRSA reduced as concentration of chitosan decreased. The result of this study revealed that chitosan is a good antimicrobial agent which can inhibit the growth of some food borne pathogens.