Phenotypic Characters of Staphylococcus Aureus Isolates from Clinical Samples in Aminu Kano Teaching Hospital, Kano, Nigeria

Bacterial colonies can differ greatly in their morphologies. These differences can help us in identifying different species of bacteria. The clinical isolates of Staphylococcus Aureus are subjected to standard biochemical tests, to observe the biochemical characteristics. One hundred and ten (110) pathogenic Staphylococcus Aureus strains were used in this study. Characteristics of these strains were determined by biochemical tests such as catalase, coagulase, DNase test, test for beta haemolysin, fermentation of mannitol and lactose. Staphylococcus Aureus [American Type Culture Collection (ATCC) 25923] was used as a reference control organism. From this study, males were more infected than females, having 60 (61.8%) and 42 (38.2%) respectively. The age group with the highest number of isolates was (0-10) years while blood culture had the highest frequency of Staphylococcus Aureus isolates with a frequency of 42 (38.1%). It was also observed that 100% of Staphylococcus Aureus showed positive results in catalase and tube coagulase, about 101 (91.8%) were positive for slide coagulase production test, 102 (92.7%) strains were positive to DNase test, 63 (57.3%) were positive to beta haemolysin while 79 (71.8%) and 106 (96.4%) strains fermented Mannitol and lactose respectively. This study reveals that no single test that can be used for the identification of Staphylococcus Aureus, hence the need for sequel testing using proper biochemical tests should be used for the identification of Staphylococcus Aureus isolates.