Measurement of culturable airborne staphylococci downwind from a naturally ventilated broiler house

Abstract

The objective of this study was to estimate the possible travel distance of airborne bacteria emitted from a naturally ventilated broiler house by using staphylococci as indicator organisms. Air samples were taken during the second half of three fattening periods with Impinger (AGI-30) in the barn and simultaneously upwind and downwind from the building. Staphylococci concentrations varied between 1 9 10 6 and 1 9 10 7 cfu m -3 in the barn. No Staphylococci were detected in air samples at the upwind side. A strong exponential decrease of these bacteria was observed at three sampling heights (1.5, 4.0 and 9.5 m) in the main wind direction downwind of the barn. Staphylococci concentrations up to 5.9 9 10 3 cfu m -3 were detected at the farthest sampling point (333 m) downwind. Identification to the species level by means of a 16S-23S ITS PCR confirmed that Staphylococcus spp. from downwind samples originated from the barn. Staphylococci served as an useful indicator to demonstrate the travel distance of bacterial emissions originating from a naturally ventilated broiler house. These findings indicate that airborne transmission of viable bacteria from this type of housing system to adjacent residential dwellings or animal houses several hundred metres away is possible.

Longitudinal Study of the Contamination of Air and of Soil Surfaces in the Vicinity of Pig Barns by Livestock-Associated Methicillin-Resistant Staphylococcus aureus

“…and the number and sizes of MRSA particles can also play a role in accumulation during the samplings. A higher number of deposited MRSA can usually be expected on surfaces near the barn, because larger dust particles carry more bacteria and deposit much faster (24). This was not shown by the detection rates at different distances from the barns.…”

“…The relatively low detection rates outside were most likely caused by dilution in the ambient air. Other factors that have been known to influence the tenacity of airborne bacteria (15) likely did not play a major role, because the travel times of staphylococci for a distance of up to 150 meters are too short to suffer a significant decay in viability (19,24).…”

“…Samplings outside were conducted in 30 ml 1:1 glycerolphosphate-buffer solutions to extend the sampling time without seriously influencing the culturability of Staphylococcus spp. (24,26). Air samples were taken only on rainless days and at temperatures above 5°C to avoid formation of ice in the sampling buffer.…”

Occurrence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Turkey and Broiler Barns and Contamination of Air and Soil Surfaces in Their Vicinity

“…Factors like sedimentation of larger particles, temperature, humidity, or solar radiation will probably also have influenced the concentration of culturable MRSA in the ambient air (17).…”

“…Staphylococcus spp. organisms were previously found in air samples from inside a naturally ventilated broiler barn and ambient air samples from upwind and downwind of this barn (17). However, the detection of MRSA was not included in the study.…”