Antibiograms of Staphylococcus Aureus and Pseudomonas Aeruginosa which Colonise the Conjunctiva of HIV/AIDS Patients in Relation to their CD4 Counts

Abstract

One hundred (100) conjunctival swabs were collected from 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 one, only 5(13.9%) samples yielded growth of Staphylococcus aureus for group two with 31(86.1%) yielding no bacterial growth. All group three 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%) samples showed invitro sensitivity reactions to ten antibiotics as follows: zinnat (57.0%) pefloxacine (51.3%), rocephine (51.3%) and genttamycin (50.0%). The others recorded less than 50% sensitivity. Multiple resistance to 50% of antibiotics used was shown by 5(26.3%) out of the 19 strains. The antibiogram of the 11(36.7%) Pseudomonas aeruginosa strains showed ciprofloxacin (52.3%), pefloxacine (50.0%) and gentamycin (50.0%). The remaining seven recorded less than 50% sensitivity. Of the 11(36.7%) strains, 4(36.4%) showed multiple resistance to 50% of antibiotics used. The 5(13.9%) Staph. aureus strains showed invitro antibiotics sensitivity 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 recorded multiple resistance. 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>5.0), differences in susceptibilities to streptomycin was highly significant (P<0.001) and significant to augmentin (P<0.05). The implications/significance of these findings are discussed.