Frequency of Bacterial Agents Isolated From Patients With Chronic Sinusitis in Northern Iran

BACKGROUND: Sinusitis is a disease with significant health problems. Diagnosis of sinusitis is clinical. The golden standard for detection of microorganisms that cause sinusitis is the culture of sinus drainage discharge.

Objectives: Due to the high prevalence of sinusitis in Iran, especially in Mazandaran province, in this study, bacteriological survey of patients with chronic sinusitis were done in order to help physicians in choosing better antibiotics for the empiric therapy of sinusitis.

METHODS: This was a descriptive study. The population of the study consisted of 100 patients with chronic sinusitis caused by bacteria admitted to the Avicenna teaching hospital. Sampling for bacterial culture was performed by the endoscopy method from middle meatus (a curved anteroposterior passage in each nasal cavity that is situated below the middle nasal concha and extends along the entire superior border of the inferior nasal concha) and the opening of the maxillary sinus. Also sampling of nasal cavity was performed to determine the microbial flora. Identification of the bacteria causing chronic sinusitis was performed according to the standard microbiological procedures. Antimicrobial susceptibility testing method, the disk diffusion (Kirby-Bauer) was performed according to the CLSI (Clinical and Laboratory Standards Institute) standards. Data were analyzed using SPSS17 software. Also Fisher exact test and descriptive statistics were used to analyze the data.

RESULTS: Among the 100 evaluated patients, 58% were male. The average age was 34.2±1.1. The most common complaint of patients were nasal congestion and post-nasal drip. The most common bacteria found in the nasopharynx were Gram-positive bacillus, coagulase negative Staphylococcus and Staphylococcus aureus with rates of 20%, 16% and 15% respectively. Bacteria isolated from opening sinus were Gram-positive bacillus 24%, Enterobacter aerogenes 10%, coagulase negative Staphylococcus 18% and Staphylococcus aureus 19%.

CONCLUSIONS: Antibiotic prescription is often empiric in treatment of sinusitis. In our study resistance to some antibiotics such as penicillin subgroups that are used in treatment of chronic sinusitis was high. Due to the fact that the etiology of chronic sinusitis is not clearly understood, the frequency of all the common causative agents of this disease must be determined.