Development of Rapid Detection and Genetic Characterization of Salmonella in Poultry Breeder Feeds

Salmonella is a leading cause of foodborne illness in the United States, with poultry and poultry products being a primary source of infection to humans. Poultry may carry some Salmonella serovars without any signs or symptoms of disease and without causing any adverse effects to the health of the bird. Salmonella may be introduced to a flock by multiple environmental sources, but poultry feed is suspected to be a leading source. Detecting Salmonella in feed can be challenging because low levels of the bacteria may not be recovered using traditional culturing techniques. Numerous detection methodologies have been examined over the years for quantifying Salmonella in feeds and many have proven to be effective for Salmonella isolation and detection in a variety of feeds. However, given the potential need for increased detection sensitivity, molecular detection technologies may the best candidate for developing rapid sensitive methods for identifying small numbers of Salmonella in the background of large volumes of feed. Several studies have been done using polymerase chain reaction (PCR) assays and commercial kits to detect Salmonella spp. in a wide variety of feed sources. In addition, DNA array technology has recently been utilized to track the dissemination of a specific Salmonella serotype in feed mills. This review will discuss the processing of feeds and potential points in the process that may introduce Salmonella contamination to the feed. Detection methods currently used and the need for advances in these methods also will be discussed. Finally, implementation of rapid detection for optimizing control methods to prevent and remove any Salmonella contamination of feeds will be considered

Assessment of microbial diversity of the dominant microbiota in fresh and mature PDO Feta cheese made at three mountainous areas of Greece

The aim of the present study was to assess the dynamics and the diversity of dominant microbiota in fresh and mature traditional Feta cheese produced in three mountainous areas and for that purpose a combined approach of culture-independent examination with conventional genotypic typing of the predominant NSLAB microbiota were applied. The microbial communities were monitored by PCR-DGGE on seven fresh and nine mature Feta cheese samples made by three artisanal producers. DGGE profiles suggested variability in the microbial composition of cheeses within the production area and distinctive differences in band profile of NSLAB in cheeses between the areas. PCR-DGGE analysis showed that Lactococcus spp. were the most widespread bacteria, Streptococcus macedonicus was detected often and, among lactobacilli, Lactobacillus plantarum prevailed. The diversity of NSLAB isolates from fresh and mature cheeses was assessed by RAPD-PCR and PFGE. Typing data indicated intraspecies genetic heterogeneity and specificity to the production area. Our results point to the conclusion that the manufacturing environment influence the dynamic and the diversity of microbial groups developed in the cheese and possibly the cheese flavour. In addition, the traditional Feta cheese may be a source of different NSLAB genotypes to make cheese with sensorial peculiarities appropriate for each area