Species distribution of clinical isolates of Staphylococci

Species identification of 103 strains of staphylococci isolated from various clinical specimens revealed as many as eight species. S. aureus was the commonest isolate (57.28%) followed by S. epidermidis (17.47%). S. hominis (8.73%), S. saprophyticus (6.79%), S. intermedius, S. capitis and S. cohni (1.94% each) in decreasing order. They were mostly isolated from pus (41.74%) followed by urine (22.33%) and blood (18.44%) accordingly. Of the total isolates, 65 were coagulase positive while 38 isolates were coagulase negative. Phase typing of S. aureus strains revealed that 49 isolates were typable of which 17 isolates belonged to phase group III, 16 to phase group 1, 4 to group II and 3 belonged to group V while 9 strains could not be grouped. The antibiotic resistance pattern showed maximum resistance to penicillin (63.10%) while resistance was minimum with gentamycin (8.73%). Resistance to ampicillin (51.45%), cephazoline (51.45%), erythromycin (31.06+) and cloxacillin (18.44%) was low to moderate. The increasing recognition of pathogenic potential of various species of staphylococci and emergence of drug resistance amongst them denotes the need to adopt better laboratory procedures to identify and understand the diversity of staphylococci isolated from clinical material.