Prevalence of Etiologic Bacteria and β-lactamase- Producing Bacteria in Acute and Chronic Maxillary Sinusitis at Phramongkutklao Hospital

Background: To date, there is an increasing trend of prescribing antibiotics that cover -lactamase- producing bacteria as the first line drug for sinusitis patients in Thailand. This practice dose not only increases the treatment cost but might also induce resistance to antimicrobial agents. Objective: To determine the prevalence of the pathogenic bacteria in acute and chronic maxillary sinusitis as well as the prevalence of -lactamase- producing bacteria. Material and Method: The maxillary aspiration fluid specimens of 52 acute and chronic sinusitis patients at Phramongkutklao Hospital, Bangkok, Thailand during May 2002-May 2003, were collected. Aerobic and anaerobic cultures were performed and the -lactamase activities of isolated bacteria were determined. Results: Of 58 specimens, 44 (75.9%) and 14 (24.1%) specimens were collected from acute and chronic maxillary sinusitis patients, respectively. Of 44 specimens of acute maxillary sinusitis, the predominant isolates were Haemophilus influenzae (13, 29.5%), Streptococcus pneumoniae (4, 9%), Streptococcus viridan (4, 9%), and Klebsiella pneumoniae (4, 9%). 6 (13.6%) of them were β-lactamase- producing bacteria. Of 14 specimens of chronic maxillary sinusitis, the predominant isolates were Pseudomonas aeruginosa (3, 16.6%), Staphylococcus spp (3, 17.5%) and Streptococcus spp. (2, 11.6%). 1 (7.1%) Haemophilus influenza isolate from this group was β-lactamase- producing bacteria. The percentage of anaerobe was 8.9%, 23.3 % fo