Comparison of methods for processing litter and AIR filter matrices from poultry houses to optimize polymerase chain reaction detection of Salmonella typhimurium

摘要

An integrated effort to reduce the occurrence of Salmonella in pouttry products should include the control of Salmonella in poultry production in early stages, which requires an efficient monitoring of Salmonella spp. in poultry houses. Studies were conducted to evaluate the potential advantages of using air samples as an alternative to litter samples for PCR detection of Salmonella spp. from poultry houses. The air filter and litter samples from a poultry house were spiked with a culture of Salmonella typhimurium. The intact samples and the DNA extracted from the samples were used for amplification of Salmonellaspecific DNA using his gene specific primers. The has gene was more effectively amplified with filter samples than litter samples when the intact sample was used as template. When extracted DNA was used, however, there was no difference between the two samples in their intensities of PCR products as visualized on an agarose gel. The dilution of the matrices from both sampling methods greatly increased the amplification efficiency, indicating that it was the background matrices that hindered the PCR amplification. The results in this study suggest that air filter sampling may be a labor-saving alternative to litter sampling, which can be use dot increase the sensitivity of PCR detection of Salmonella spp. without prior sample processing.