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

Mahdy, H. M.; El-Sehrawi, M H

doi:10.1007/bf02047041

Cited by 15 publications

(11 citation statements)

References 13 publications

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“…Some genera of Gram-positive bacilli can survive for a long time via endospore-formation when conditions are not favorable. Mahdy and El-Sehrawi (1997) investigated airborne bacteria in the atmosphere of Saudi Arabia and found that Gram-positive bacteria, especially rod-shaped, were predominantly most abundant in the Saudi Arabian atmosphere. Fang et al (2007) showed that the percentage of Gram-positive bacteria was significantly higher than that of Gram-negative bacteria in the Beijing atmosphere and the percentage of cocci was significantly higher than that of rods.…”

Section: Discussionmentioning

confidence: 99%

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

Aydoğdu

Asan

Otkun

2009

Environ Monit Assess

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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.

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Section: Discussionmentioning

confidence: 99%

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

Aydoğdu

Asan

Otkun

2009

Environ Monit Assess

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“…The low frequent detection of Gram negative bacteriais attributed to their sensitivity to the air environment 41 , and the initial shock due to desiccation after aerosolization 42 .Firmicutes, Proteobacteria and Actinobacteria are common bacterial types in the urban environment, where Gammaproteobacteria and Betaproteobacteria have been regularly identified 1 . Mouli et al 43 found airborne Gram positive bacteria in the range of 60% -90% of the total bacterial population, in Tirupati, India; however Bacillus constituted 47.62% and Acinetobacteria 14.27% in the atmosphere of El Taief, Saudi Arabia 44 . Bacillus, Micrococcus and Staphylococci differed from place to place depending on the micro-environment 45 .…”

Section: Discussionmentioning

confidence: 99%

Air Microbial Contamination at the Holy Mosque, Makkah, Saudi Arabia

Hameed¹,

Habeeballah²

2013

Curr World Environ

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Airborne microbial contamination was collected from the main directions of the holy mosque (Al-Haram mosque), Makkah city, by using the gravitational method.Bacteria, fungi and actinomycete concentrations ranged between 1470 -21800 CFU/m 3 ; 44 -572 CFU/m 3 , and 0.0 -264 CFU/m 3 , respectively at all directions. Bacterial concentrations significantly differed between directions, and Gram positive bacteria constituted ~ 90-100% of the total bacterial isolates. Gammaproteo bacteria were the common Gram negative bacteria, and Aspergillus was the predominant fungal genera. Mesophilic bacteria negatively related (P< 0.05) with relative humidity. Human activities had more effective influence on the microbial concentrations than the meteorological factors.

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“…Previously-reported seasonal patterns of concentrations of airborne microbes match the patterns we found for fungi (Abdel-Hafez 1984, AlSuwaine et al 1999a, Al-Suwaine et al 1999b), but not for bacteria (Burrows et al 2009). However, only a single study reports seasonal patterns of bacterial concentrations in a desert environment, with inconsistent patterns: bacterial concentrations are higher in spring at half of the sampling sites, but higher in winter or not seasonally variable at the remainder (Mahdy and El-Sehrawi 1997). Perhaps counter to other nondesert locations, conditions for microbial growth at Mahazat might actually be more favorable in winter than spring, due to reductions in temperature and solar radiation, and increases in rainfall v www.esajournals.org and relative humidity (Tong and Lighthart 1997, Talley et al 2002, Burrows et al 2009, Tang 2009).…”

Section: Discussionmentioning

confidence: 99%

Seasonal patterns in immune indices reflect microbial loads on birds but not microbes in the wider environment

et al. 2012

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Abstract. Documenting patterns in immune function is a first step to understanding immune variation, but to comprehend causes and consequences, antigen and parasite exposure that may drive such variation must be determined. We measured host-independent microbial exposure in five species of larks (Alaudidae) in the Arabian Desert by sampling ambient air for culturable microbes during late spring and winter, two periods with contrasting environmental conditions. We developed a novel technique to assay densities of microbes shed from birds, and we quantified four indices of constitutive innate immunity. Birds shed significantly more microbes during spring than winter, and all immune indices except one were also significantly higher during spring. In contrast, concentrations of airborne environmental microbes were higher in winter. Among all birds in both seasons, lysis titers were positively correlated with total densities of microbes shed from birds, suggesting that immune defenses are directed towards the microbes that birds carry, rather than microbes in the wider environment. Our findings highlight the relevance of quantifying non-specific immune challenges in ecological immunology studies, and reinforce the importance of both host-dependent and host-independent measures of antigenic pressure for understanding immune variation.

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

Cited by 15 publications

References 13 publications

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

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

Air Microbial Contamination at the Holy Mosque, Makkah, Saudi Arabia

Seasonal patterns in immune indices reflect microbial loads on birds but not microbes in the wider environment

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