Isolation and Identification of Airborne Bacteria Inside Swiftlet Houses in Sarawak, Malaysia

Abstract

Air consists of such microorganisms as bacteria, fu ngi, and viruses. Exposure to these airborne bacter ia indoors may cause infectious and noninfectious adverse health e ffects. However, the sources and origins of bacteri a are not fully understood. The aim of this study was to isolate an d identify the bacteria present in the air inside s wiftlet houses located in Kota Samarahan, Saratok, Betong, Maludam, Miri, Kuching, Semarang, Sepinang, Sarikei, and Sibu in Sarawak, Malaysia. A total of 100 bacterial isolates from 20 samples were collected from swiftlet houses. The b acteria present in the air were collected using Plate Count Agar. Two plates were exposed at the front and back inside sw iftlet houses for 15 sec and then incubated at 37 ± 1 o C for 24 h. The 16S rRNA analysis method was used to identify the isolates from the samples. The air inside the swiftlet houses had a total mean airborne bacteria colony count of 2.0 2 ± 0.72 log 10 cfu/m 2 /sec; the highest was in Miri (3.08 ± 0.29 log 10 cfu/m 2 /sec), and the lowest was in Sibu (1.05 ± 0.85 log 10 cfu/m 2 /sec). Twenty-seven bacteria species were identifie d, and Lysinibacillus sp. B4 (16%) was most frequently isolated.