Frequency of occurence and antimicrobial resistance in isolates of bacterial conjunctivitis in patients at the University Hospital of the West Indies [abstract]

OBJECTIVE: There is paucity of published data on bacterial conjunctivitis in patients at the University Hospital of the West Indies and the wider community in Jamaica. This report analyses 208 bacterial isolates from 198 eye swab cultures of patients with clinical diagnosis of conjunctivitis in this hospital. METHODS: Culture of eye swabs was done by routine methodology, and anti-microbial susceptibility tests were performed by the standard disc-diffusion technique. RESULTS: Two hundred and eight bacterial isolates were encountered in the 198 ocular cultures. Eighty of these (32.9 percent) were likely contaminants (normal commensal from skin of the eyelid). The common isolates in order of frequency in the remaining 128 were: Haemophilus influenzae pneumoniae 12 (9.4 percent) and Pseudomonas aeruginosa 5 (3.9 percent). These four organisms together accounted for over two-thirds (69.5 percent) of the 128 isolates. More than 90 percent of these strains were susceptible to chloraphenicol and gentamicin. CONCLUSIONS: The contamination rate in eye swab cultures is very high and there is need for improvement of the collection procedures. Haemophilus influenzae remains the most common pathogen of bacterial conjunctivitis as in many other parts of the world. The common eye preparations such as chloramphenicol and gentamicin (alternatively, tobramycin) continue to be highly effective against pathogens from conjunctivitis at the University Hospital of the West Indies. (AU)

In vitro activity of ceftazidime and other antipseudomonal antibiotics against mucoid strains of pseudomonas aeruginosa

The minimum inhibitory concentration of ceftazidime, was determined for 132 mucoid strains of pseudomonas aeruginosa (MPA) isolated from patients with cystic fibrosis (CF), using an agar tube dilution method. Using strains collected over a ten-year period, we found that 98 percent were susceptible to achievable serum concentrations with MIC50 and MIC90 of 1.2 and 3.1 ug/ml, respectively. Susceptibility of 60 of these strains was also determined for cefoperazone (100 percent susceptible), tobramycin (97 percent), and carbenicillin (83 percent). Susceptibility of stored strains was similar to that of fresh isolates. We have shown that strains of MPA in a U.S. population were more susceptible to ceftazidime than those currently reported from Europe where this antibiotic was introduced earlier. Cefoperazone, another third generation cephalosporin which has received less attention in the treatment of patients with CF, is as active as ceftazidime in vitro. These data provide a basis for determining the future impact of these agents on pseudomonas susceptibility (AU)