APPLICABILITY OF RAPID METHODS FOR DETECTION OF SALMONELLA SPP. IN POULTRY FEEDS: A REVIEW

Abstract

The rapid detection of pathogenic microbial species in feed is of paramount importance considering its implications for animal production and food safety. More sensitive and rapid detection of contaminated feedstuffs may lead to more selective and therefore less expensive treatment of feeds, reduced rates of transmission to a poultry host and reduced carcass contamination. In order to interrupt the cycle of Salmonella spp. transmission from feed to poultry to the consumer, more rapid detection methods to monitor these sources are needed that provide conclusive results within the time frame of feed mixing or broiler processing. Within the last decade, new variations of selective media have been investigated to increase selectivity without reducing Salmonella spp. recovery. Immunological assay methods may also decrease assay time from 96 h to within 24–30 h. But all commercially available methods still require 16 to 57 h for preenrichment, enrichment, and in some cases, postenrichment to recover sublethally injured cells before the assay can be performed. Among the molecular methods that are currently available, the polymerase chain reaction (PCR) represents a tremendous potential for the detection of low levels of pathogenic bacteria. Once optimized, rapid methods may be used to quickly, reliably and inexpensively screen a variety of feedstuffs and feed components for the presence of Salmonella spp., with the goal of minimizing both the cost of feed treatment and the horizontal transmission of Salmonella spp. from feed to poultry.

Optimization of a rapid and sensitive identification system for Salmonella enteritidis by capillary electrophoresis with laser-induced fluorescence

“…Standard Salmonella identi¢cation methods such as cultural methods coupled with biochemical tests requires more than a few days to con¢rm the results and there may be di⁄culty in rapidly and accurately identifying serovars [4,7]. As more rapid and sensitive techniques, the use of polymerase chain reaction using Salmonella-speci¢c primers for the identi¢cation of Salmonella has been developed [7^10].…”

Animal Feed Production and Contamination by Foodborne Salmonella

“…However, assessing high risk sites will require sampling approaches that are appropriate and detection methodologies that are accurate (Maciorowski et al, 2004). A variety of Salmonella detection methods that have been applied to feeds have been extensively reviewed (Williams, 1981b;Ricke et al, 1998;Maciorowski et al, 2006). Cultural growth-based methods combined with selective media are the traditional approach for the isolation and enumeration of Salmonella in feeds (Williams, 1981b;Ricke et al, 1998;Maciorowski et al, 2006).…”

“…A variety of Salmonella detection methods that have been applied to feeds have been extensively reviewed (Williams, 1981b;Ricke et al, 1998;Maciorowski et al, 2006). Cultural growth-based methods combined with selective media are the traditional approach for the isolation and enumeration of Salmonella in feeds (Williams, 1981b;Ricke et al, 1998;Maciorowski et al, 2006). Several attempts have been made to improve the effi ciency of cultural approaches for assessing bacterial contamination of feeds including development of selective media to eliminate fungal overgrowth on plates (Ha et al, 1995a and b), application of minimal media for more representative bacterial enumeration (Maciorowski et al, 2002a), and extraction procedures to improve recovery of bacterial populations attached to feeds (Maciorowski et al, 2002b).…”

Cultural and Immunological Detection Methods for Salmonella spp. in Animal Feeds – A Review

“…centre around increasing the ease, speci¢city and reliability of detection, and reducing cost and labour (Weenk, 1992). For example, individual biochemical tests have been replaced by standard kits such as the API 20E (BioMe¨rieux, Hazelwood, MO, USA) and the Crystal Enteric/ Nonfermenter (E/NF: Becton Dickinson, Franklin Lakes, NJ, USA), which run numerous tests simultaneously (Micklewright and Sartory, 1995;Ricke et al, 1998). Recovery of injured microorganisms, especially those that may still be infectious, is of particular interest, as injured pathogens may not be detectable but may still recover and multiply in the gastrointestinal tracts of animals.…”

“…A number of methods have been used for and/or have potential for detection of Salmonella spp. in feeds and these include growth culture/selective media and immunological and molecular approaches (Williams, 1981b;Ricke et al, 1998). Although molecular methods have potential, there remain issues regarding speci¢city and reliability before they can be incorporated into routine analysis (Ricke et al, 1998).…”