Antibiograms of Staphylococcus aureus and Pseudomonas aeruginosa which Colonize the Conjunctiva of HIV/AIDS Patients in Relation to their CD4 Counts

Abstract

One hundred (100) conjunctival swabs were collected from Enzyme-linked Immunosorbent Assay (ELISA)-confirmed HIV/AIDS seropositive patients who were referred to the HIV/AIDS laboratory of the University of Benin Teaching Hospital, Nigeria for routine CD4 count check. Swabs were bacteriologically processed and bacterial strains obtained from CD4 count groups were subjected to invitro antibiotic testing by disc diffusion technique in relation to their CD4 groups. Thirty four (34.0%) patients had CD4 counts within group 1 (<500 cells/µl), 36(36.0%) in group 2 (200 cells/ µl) and 30(30.0%) in group 3 (>200 cell/µl). While there was no bacterial growth after 48hrs incubation recorded for group 1, only 5(13.9%) samples yielded growth of Staphylococcus aureus for group 2 with 31(86.1%) yielding no bacterial growth. All group 3 samples yielded profuse growth of which 11(36.7%) yielded Pseudomonas aeruginosa and 19(63.3%) yielded Staph aureus. Staphylococcus. aureus strains isolated from the 19(63.3%) group 3 samples showed invitro sensitivity reactions to ten antibiotics as follows: zinnat (57.9%) pefloxacine (55.3%), rocephine (51.3%) and gentamycin (50.0%). The others recorded less than 50% sensitivity. Multiple resistance to 6(60%) of antibiotics used was shown by 6(31.6%) out of the 19 strains. The antibiogram of the 11(36.7%) Pseudomonas aeruginosa strains showed ciprofloxacin (52.3%) and gentamycin (50.0%) reaction. The remaining eight recorded less than 50% sensitivity of which, 4(36.4%) P. aeruginosa strains showed multiple resistance to 50% of antibiotics used. The 5(13.9%) group 2 Staph. aureus strains showed invitro antibiotic susceptibility reactions as follows: pefloxacine (65.0%), gentamycin (60.0%), rocephine (55.0%), ciprofloxacin (55.0%) and streptomycin (50.0%). Others recorded less than 50% reaction and none of the strains in this group recorded multiple resistances. Unpaired t-test analysis showed that whereas the differences in susceptibilities of both organisms to ofloxacine, pefloxacine, gentamycin, ampicillin, zinnat, rocephine, ciprofloxacin and sperfloxacin were insignificant (P>0.05), differences in susceptibilities to streptomycin was highly significant (P<0.01) and significant to augmentin (P<0.05).