engleski

The assessment of gram-negative bacteria in the air of two swine nursery buildings

Farm environments represent the source of gram-negative bacteria and endotoxin that generate a significant health risk for developing respiratory diseases in farm workers and animals. The aim of this study was to conduct a quantitative analysis of gram-negative airborne bacteria and their correlation with total number of mesophilic bacteria and environmental parameters (temperature, humidity, air velocity, ammonia and carbon dioxide). Air sampling was conducted in two swine nursery buildings. The average values of total number of mesophilic bacteria were 76 x 103 and 99 x 103 CFU/m3, while the ranges of gram-negative bacteria were 14 x 103 and 22 x 103 CFU/m3 in both pig houses. The average concentration of gram- negative bacteria was approximately 18-22% in comparison with total number of mesophilic bacteria. The number of total mesophilic and gram-negative bacteria was significantly lower in the House 1 than in the House 2 (P=0.05). In both houses there was no significant correlation between bacteria count and environmental parameters (P>0.05), except a small negative correlation between gram-negative bacteria count and air velocity (r=-0.48, P=0.05). The most prevalent species in both pig houses was Escherichia coli. The number of gram-negative bacteria in both swine houses exceeded suggested threshold limit values.

mesophilic bacteria ; gram-negative bacteria ; air ; swine nursery building

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