Fifty conjunctival swab samples collected from ELISA confirmed HIV/AIDS seropositive patients who were referred to the HIV/AIDS laboratories of the University of Benin Teaching Hospital and Central Hospital both based in Benin City, Nigeria were aseptically cultured on appropriate media by standard methods. The resulting isolates/strains, after identification by standard methods, were tested for their ability to adhere to two hydrophobic non-ionic daily wear silicone hydrogel soft contact lenses (i.e. lotrafilcon B, WC 33% and polymacon, WC 38%) as well as to two hydrophilic ionic conventional extended wear silicone hydrogel soft contact lenses (i.e. methafilcon A, WC 55% and omafilcon A, WC 60%) by the adhesiveness/slime production modified vortex/Robin device method. Evidence of adhesiveness/slime production was indicated by presence of a visible stained film lining the surface of the contact lens which was measured and recorded as strong or weak according to the density of the adhered bacterial film. Fourteen (28.0%) Staphylococcus aureus strains and 10 (20.0%) Pseudomonas aeruginosa strains were obtained among other organisms. Staphylococcus aureus strains adhered in decreasing order to lotrafilcon B (55.4 ± 4.7), polymacon (46.4 ± 8.4), methfilcon A (46.4 ± 8.4) and omafilcon A (25.0 ± 6.4) with no significant difference in adhesive strengths of individual strains (P > 0.05). Pseudomonas aeruginosa strains also recorded decreasing adhesive strengths to lotrafilcon B (37.5 ± 8.2), polymacon (28.6 ± 6.3), methafilcon A (26.8 ± 5.5) and omafilcon A (23.2 ± 5.5) also with no significant difference in adhesive strengths of individual strains (P > 0.05). Attachment strengths of Staph. aureus strains to all four contact lenses were higher than those of Pseudomonas aeruginosa strains. Both organisms adhered most to hydrophobic lotrafilcon B and least to hydrophilic omafilcon A. This invitro adhesion studies revealed that daily wear silicone hydrogel low water content, non-ionic contact lenses are more prone to bacterial adhesion than the conventional extended wear hydrogel high water content, ionic contact lenses and hence, there is more risk of microbial adhesion to the former compared to the latter. Other implications are highlighted.

Staphylococcus aureus and Pseudomonas aeruginosa strains were isolated from eye swab samples randomly obtained from 100 seropositive HIV/AIDS patients who reported to various anti-retroviral treatment clinics at the University of Benin Teaching Hospital and Central Hospital both based in Benin City, Nigeria. Invitro antibiotic sensitivity patterns of strains before curing were determined by the Kirby-Bauer disc diffusion technique. Resistance plasmid DNA of multidrug resistant strains was cured with 0.1% sodium dodecyl sulphate and cured strains were again subjected to invitro antibiotic sensitivity testing. EcoRI and Hind III restriction endonuclease enzymes were used to make cuts on extracted plasmid DNA whose length sizes were then determined. A total of 36 (36.0%) strains made up of 27 (75.0%) Staphylococcus. aureus and 9 (25.0%) Pseudomonas aeruginosa were isolated of which 7 (19.4%) strains showed multidrug resistance to ciprofloxacin, pefloxacin, ofloxacine, gentamycin, tetracycline, ampicillin, chloramphenicol, nitrofurantoin and erythromycin. All seven multidrug resistant strains before curing, recorded 85.7%, 42.9%, 14.3% and 14.3% sensitivity in that decreasing order to ciprofloxacin, pefloxacin, ofloxacin and gentamycin respectively. There was 0.0% sensitivity each to tetracycline and ampicillin. After curing, there was enhanced sensitivity of 100.0%, 85.7%, 28.6% and 71.4% respectively. There was also 28.6% and 57.1% improved sensitivity to tetracycline and ampicillin after curing. Before curing, there was 76.2% average resistance to all used antibiotics and this reduced to 47.6% after curing Staph. aureus plasmid DNA. In the case of Pseudomonas aeruginosa, there was an average resistance of 76.3% before curing which fell to 42.5% after curing. EcoRI restriction enzyme gave the plasmid DNA length of Staphylococcus aureus strain 04 as 4.0Kb and this size depended upon the distance between recognition sites. Isolation of 36 (36.0%) strains of both isolates from 100 eye swabs shows the danger these organisms portend to all categories of opticians. The cheapness and high sensitivity of gentamycin justifies its use as eye drops for treatment of some eye infections. Curing of plasmid DNA is an indication that if SDS is administered to the organisms in sublethal doses, it can lead to the elimination of plasmid DNA without adverse effect on the genomic DNA of the bacterial strains.

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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).