Comparative Analysis of Culture-Based and Real-Time PCR Methods for the Detection of Salmonella spp. in Retail Chicken in Tehran, Iran

Salmonella is a leading cause of foodborne illness worldwide, with poultry products being a primary route of transmission. Rapid and accurate detection methods are crucial for public health and food safety management. This study aimed to determine and compare the prevalence of Salmonella spp. in fresh retail chicken in Tehran, Iran, using the conventional culture method and a probe-based Real-Time Polymerase Chain Reaction (Real-Time PCR) assay. A total of 100 fresh chicken samples were randomly collected from retail outlets across Tehran over a three-month period. Each sample was analyzed in parallel by the ISO 6579 standard culture method and a Real-Time PCR assay targeting the invA gene. The culture method identified Salmonella in 21 out of 100 samples, indicating a prevalence of 21%. In contrast, the Real-Time PCR assay detected Salmonella DNA in 29 samples, yielding a higher prevalence of 29%. All 21 culture-positive samples were also positive by Real-Time PCR. However, 8 samples were found to be positive by Real-Time PCR but negative by the culture method. Based on these findings, the Real-Time PCR method demonstrated a significantly higher detection rate. The results suggest that while the culture method remains the gold standard for isolating viable organisms, Real-Time PCR offers a more sensitive and rapid tool for screening poultry products, potentially identifying low levels of contamination or the presence of non-viable bacteria. This study highlights a notable prevalence of Salmonella in retail chicken in Tehran and underscores the value of incorporating molecular techniques for enhanced food safety surveillance.