Airborne bacteria in the atmosphere of El-Taif region, Saudi Arabia

Abstract

Ten districts in El-Taif region, Saudi Arabia, were investigated along 12 months, from October 92 to September 1993 seasonally. Total counts of viable bacteria were much higher during the summer period than in other seasons. Penctinase and gelatinase were the most frequently produced enzymes than other exoenzymes. Seasonal variation in the concentration and distribution of airborne bacteria was reported. Maximum counts of total viable bacteria were obtained in the atmosphere of El-Faisalyia and El-Shuhda during optimum environmental temperature, while lower counts were obtained during early spring. Bacilli and Acinetobacteria were found to be the main components of the airborne bacteria in the atmosphere of El-Faif. They had a higher relative frequency 47.62–14.28% of the samples comprising 18.94–5.68% of total bacteria. Gram positive bacteria were predominant in production of exoenzymes (pectinase and gelatinase) and all bacterial isolates were negative to produce cholesterol oxidase. The antibiotic tetracycline group were found the most effective antibiotic against Gram-negative, Gram-positive as well as to rod-shaped and cocci-forms of bacteria.