Abstract
Abstract: :
Purpose:Haemophilus influenzae is an important human bacterial pathogen and member of the commensal flora, but little is known about the characteristics of strains causing eye infections. The objectives are to biotype and determine the incidence of antibiotic resistance amongst H. influenzae from infected and healthy eyes, in Saudi Arabia. Methods:During a 7mth period (Nov 1999 – Jun 2000), 100 unique isolates of H. influenzae were collected from 85 outpatients with eye infections attending the King Khaled Specialist Eye Hospital, Riyadh. Mean patient age was 26yrs (range 6mths – 89yrs). Ocular and nasal swabs from 80 healthy hospital workers yielded 18 isolates. Minimum inhibitory concentrations (MICs) of 10 antibiotics were determined by E-test strips (AB Biodisk). NCCLS break points for susceptibility were used. Beta-lactamase was detected by nitrocefin sticks (Oxoid). Biotyping was via API NH strips (BioMerieux). Serotyping and Beta-lactamase typing was by PCR. Results: 15 (18%) of the patient group had bilateral eye infection while 70 (82%) had unilateral. 73 (86%) patients had had no ocular surgery. All isolates were sensitive to ciprofloxacin, ceftazidime, cefuroxime, amoxicillin/clavulanic acid, and ofloxacin. Resistance (% all strains) was detected to the other six antibiotics: ampicillin (27%); tetracycline (17.8%), chloramphenicol (14.4%), clarithromycin (1.6%); and erythromycin (0.8%). 28 (28%) patient isolates produced TEM1-type beta-lactamase compared to just 3 (12%) of the commensal isolates. Biotypes II and IV predominated and all isolates were noncapsulated. Conclusion:This is the first report concerning H. influenzae ocular isolates in Saudi Arabia. The relatively high prevalence of antibiotic resistance, especially to beta-lactams, tetracycline and chloramphenicol, is a cause for concern and further surveillance is warranted. In contrast to H. influenzae respiratory disease, all the eye infections were caused by noncapsulated strains.
Keywords: 319 antibiotics/antifungals/antiparasitics • 328 bacterial disease