Evaluation of the Performance of Two Selective Enrichment Media and Two Selective Plating Media for the Detection of <i>Salmonella</i> from Primary Poultry Production, According to ISO 6579:2002

Abstract

Salmonellosis remains a major problematic food born zoonosis worldwide. Poultry and poultry products have been frequently incriminated as the major sources for the aetiological agent, Salmonella species. The implementation of appropriate surveillance and monitoring programme for food safety ultimately requires the examination of food for the presence of food borne pathogens. This study was aimed at evaluating the effectiveness of Modified Semisolid Rappaport-Vassiliadis (MSRV) and Muller-Kauffmann tetrathionate-novobiocin (MKTTn) selective enrichment media for the isolation of Salmonella, as well as assessment of the performance of xylose-lysine-deoxycholate (XLD) agar as the classical and preferential selective plating medium by comparing it with Brilliant Green (BG) agar for the detection of Salmonella in the primary production of poultry based on the ISO 6579:2002. Three hundred and seventy-four (374) samples from the primary poultry production system underwent the traditional culture method for the detection of Salmonella involving pre-enrichment, selective enrichment, selective plating and confirmation. The rate of recovery of Salmonella from the entire samples was 59.1%. The rate of recovery of Salmonella from XLD and BG selective plating media when MSRV selective enrichment media was used was 98.2% and 95.5% respectively whereas 90.0% and 64.3% respectively when MKTTn selective enrichment media was used. The highest sensitivity was observed in the combination of MSRV/XLD (0.98), followed by MSRV/BG (0.95). The combination of MSRV/BG had the highest specificity (0.88) followed by MKTTn/BG (0.65). Based on the results of this study, selective enrichment media play a substantial role on the sensitivity and specificity of the selective plating media. MSRV * Corresponding author. N. Y. Yhiler et al. 129 was revealed as the most important selective enrichment medium, necessary for the investigation of Salmonella and that its combination with BG selective plating media yielded the best result for the selective isolation of Salmonella in the primary production of poultry.

Occurrence and antibiotic resistance of Salmonella spp. in raw beef from wet market and hypermarket in Malaysia

“…Several studies have also found out that the low specificity of XLD medium created a high number of false positive identification of Salmonella species (Rall et al, 2005;Hyeon et al, 2012;Yhiler et al, 2015). Rall et al (2005) stated that XLD allows the growth of selective bacteria with Salmonella, Proteus, and Citrobacter that displayed similar characteristics as negative lactose fermentation and negative hydrogen sulfide (H 2 S) production on this classical medium.…”

“…Thus, the colonies of Proteus and Citrobacter probably appear and identified as presumptive Salmonella colony on XLD medium. In addition, Hyeon et al (2012) and Yhiler et al (2015) concluded that XLD medium had high sensitivity but with low specificity for the detection of Salmonella.…”

Isolation, Identification, and Genetic Characterization of Antibiotic Resistance of Salmonella Species Isolated from Chicken Farms

“…One colony from each plate that appeared to be Salmonella spp. was chosen for additional examinations based on appearance [ 29 ].…”

Genomic diversity and epidemiological significance of non-typhoidal Salmonella found in retail food collected in Norfolk, UK

“…However, there may have been Salmonella isolates present in the food samples in this study that were missed by all methods. Yangkam Yhiler et al [48] evaluated culturing methods for detecting NTS from chicken, and also found they detected more NTS from chicken by using both MSRV and MKTTn enrichment, but that MSRV was more sensitive. They used XLD and Brilliance Green (BG) for culturing and confirmed NTS using biochemical testing and polyvalent antisera, whilst in this study we used the higher resolution WGS to identify and characterise serovars.…”