Indoor and outdoor airborne bacteria in child day-care centers in Edirne City (Turkey), seasonal distribution and influence of meteorological factors

Abstract

This paper presents information about airborne mesophilic bacteria in the indoor and outdoor air of child day-care centers (CDCCs) in the city of Edirne, Turkey. Air samples were collected using the Petri plate gravitational settling method from the indoor and outdoor air of CDCCs. Counts of airborne bacteria were measured as colony forming units (CFU) collected by gravity onto Brain Heart Infusion Agar plates (with 5% sheep blood). Samples were taken monthly over a period of 12 months between January and December 2004. A total of 3,120 bacteria colonies were counted on 192 Petri plates. Four groups of culturable bacteria were identified: gram-positive cocci, gram-positive bacilli, endospore-forming gram-positive bacilli, and gram-negative bacteria. Airborne gram-positive bacteria were the most abundant at more than 95% of the measured population. While gram-positive cocci were more common in indoor environments, gram-positive bacilli were more dominant in outdoor air. Bacteria commonly isolated from CDCCs were identified at a genus level. Staphylococcus (39.16%), Bacillus (18.46%), Corynebacterium (16.25%), and Micrococcus (7.21%) were dominant among the genera identified in the present study. The dominant genera identified in the day-care centers were Staphylococcus, Micrococcus, and Corynebacterium for indoor air and Bacillus, Corynebacterium, and Staphylococcus for outdoor air. Staphylococcus, Streptococcus, Bacillus, and Corynebacterium genera were found in samples from every month. Bacterial colony counts were compared by sampling location (indoors and outdoors), seasons, and meteorological factors. We found negative correlations between the monthly total outdoor bacterial counts and the sampling day's average relative humidity and average rainfall, and the monthly average rainfall. Fluctuations in bacterial counts in different seasons were observed.

Characteristic and Concentration Distribution of Culturable Airborne Bacteria in Residential Environments in Beijing, China

“…Recently, many studies about bacterial investigation in the air have been carried out in such indoor environments as crowded and underground public concourse in Tokyo (Seino et al, 2005), public buildings of Korea (Kim and Kim, 2007), feedstuff-manufacturing factories (Kim et al, 2009), child day-care centers in Edirne city (Aydogdu et al, 2010), Mogao Grottoes (Wang et al, 2010), Polish libraries and archives (Karbowska-Berent et al, 2011), and occupied classroom (Qian et al, 2012). Our study indicated that airborne gram positive bacteria, accounting for about 94.6%, were dominated in residential homes, which was in agreement with other reports (Zhu et al, 2003;Awad, 2007;Aydogdu et al, 2010). However, great difference in the percentage of gram positive bacteria in the air between our result and previous study was observed.…”

“…However, great difference in the percentage of gram positive bacteria in the air between our result and previous study was observed. Aydogdu et al (2010) reported that gram positive bacteria contributed to 97.16% and 95.04% indoors and outdoors in child day-care centers in Edirne City (Aydogdu et al, 2010). Shaffer and Lighthart (1997) found that the percentage of gram positive bacteria ranged from 70.0% to 85.0% at four diverse locations of urban, rural, forest, and coastal.…”

“…The same prevailing airborne bacteria indoors were also found in other studies, while the percentage of dominant bacteria was of great difference in different indoor environments. Aydogdu et al (2010) reported that the dominant indoor bacteria in the air were Staphylococcus (58.67%), Micrococcus (10.88%), Corynebacterium (6.90%), and Bacillus (6.61%) in child day-care centers in Edirne City (Turkey), and the dominant outdoor bacteria were Bacillus (28.18%), Corynebacterium (23.92%), Staphylococcus (17.74%), Micrococcus (4.2%), correspondingly. The predominant bacteria in the crowded, underground public concourse in Tokyo were Staphylococcus and Micrococcus among the 11 genera of airborne bacteria (Seino et al, 2005).…”

“…During recent decades, many studies have been conducted to investigate the level of airborne bacteria in residential settings that were closely related to human health (Pastuszka et al, 2000;Moschandreas et al, 2003;Aydogdu et al, 2005;Mentese et al, 2009;Nasir and Colbeck, 2010;Aydogdu et al, 2010). However, such studies face significant challenges, since there are too many tremendous influence factors such as seasonal effects, local climate, weather patterns, human activities etc.…”

Indoor Fungal Populations Inhabiting Cement Structures - Remedial Measures

“…a. Adhesive tape sampling: transparent cellophane tape was struck on the walls with intact fungal blisters. The cellophane tape was collected in sterile bottles once the blisters break [13,14] b. Scrapings of contaminated materials (Environmental Health Directorate, Canada, 1995). Contaminated structures were scraped with sterilized scalpel and collected into sterile plastic bottles [7].…”