Rapid quantitative detection of Salmonella enterica using fluorescence in situ hybridization with filter-cultivation (FISHFC) method

Salmonella enterica

Specific detection and enumeration of Salmonella enterica in food using conventional culture based methods (CCBM) are time-consuming and labor-intensive. This study was done to develop a rapid S. enterica detection and enumeration method that combined fluorescence in situ hybridization (FISH) with micro-colony formation culture, called as FISHFC. The specificity tests of SAL343 probe for S. enterica detection revealed the SAL343-associated fluorescent micro-colonies were observed specifically for S. enterica but not for any other organisms. This finding suggested SAL343 probe is highly specific for detecting S. enterica with FISHFC. For validation, the FISHFC with SAL343-probe were compared with CCBM with multiple selective agar in spiked food samples and there was no significant differences in enumeration was found between FISHFC and CCBMs (p>0.05). The FISHFC methods was able to enumerate S. enterica counts within 10 h and CCBMs takes 5 days to enumerate S. enterica. Therefore, FISHFC methods could be useful in rapid, specific and enumerating S. enterica in food samples compared to other available methods.