A comparative evaluation of the sensitivity of Salmonella detection on processed chicken carcasses using Australian and US methodologies (original) (raw)

Comparison of two commercially available rapid detection methods and a conventional culture method to detect naturally occurring salmonellae on broiler carcasses

Journal of Food Safety, 2019

Detection of Salmonella on commercially processed broiler carcasses is essential to reduce the incidences of human salmonellosis. This study was designed to compare the standard procedure for Salmonella detection with two commercial screening methods. During seven separate visits to two processing plants, eight carcasses were obtained (n = 112). Each carcass was rinsed and the rinsate processed according to the U.S. Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS) protocol. Predetermined aliquots of rinsates were screened on the BAX ® and Roka ® instruments according to manufacturer's protocol and analyzed using the USDA, FSIS cultural method. Four Salmonella-like colonies from presumptive positive rinsates were selected, screened biochemically, and serologically confirmed as Salmonella. Results indicated Salmonella was recovered from 15.2% (17/112), 14.3% (16/112), and 12.5% (14/112) of carcasses by cultural methods, BAX, and Roka analysis, respectively. These findings indicate that both rapid, molecular methods tested were as effective as the conventional cultural procedure in detecting Salmonella from broiler carcass rinsates. Practical Applications According to the results of this study, there was no statistical difference in the number of carcass rinsates in which Salmonella was detected by the three methods. The ability of all three methods to detect naturally occurring Salmonella provides the poultry industry and regulatory agencies more tools to increase the safety of poultry products available to the consumer.

Agreement of 3 carcass rinse sampling methods (split carcass, repeat rinse, and adjacent pair) on the detection of Salmonella contamination in broiler carcasses

Whole carcass rinse is the most common method used to determine Salmonella prevalence in broiler carcasses. However, there is a need to determine the carcass rinse sampling method that best measures the Salmonella status of a broiler carcass as it proceeds through processing, thus allowing the assessment of efficacy of interventions to meet Food Safety Inspection Services (FSIS) performance standards. In this study, 3 paired carcass rinse sampling methods , namely split-carcass method (rinses of 2 halves of one carcass), repeat rinse method (rinse and rerinse of same carcass), and adjacent pair method (rinses of 2 adjacent carcasses), were evaluated during actual operations in commercial poultry processing plants in the southeastern United States. The purpose of the work was to determine which method resulted in greatest agreement of Salmonella status on paired broiler carcass rinses. The adjacent pair method showed moderate agreement consistently in 3 trials of 150 pairs per trial with kappa values of 0.46, 0.55, and 0.46. The repeat rinse method showed substantial kappa agreement (0.64) in one trial and moderate kappa agreement (0.47, 0.41) in 2 other trials. In one trial, the repeat rinse method showed a significant difference in prevalence rates between repeated rinses. Even though the split carcass method showed moderate kappa agreement (0.58, 0.45) in 150 carcasses in each of 2 trials, the disadvantages of the split carcass method were that it was more labor and time intensive and the product was damaged, when compared to the other 2 methods. Overall, although prevalence estimates were fairly consistent between pairs by each method, agreement between Salmonella status of the paired samples was less than desired, mostly moderate. This lack of agreement should be considered in the design of studies assessing the efficacy of interventions for the control of Salmonella in broilers to meet FSIS performance standards.

A comparison between broiler chicken carcasses with and without visible faecal contamination during the slaughtering process on hazard identification of Salmonella spp

Journal of Applied Microbiology, 2002

A comparison of the prevalence of Salmonella in chicken carcasses with and without visible faecal contamination during commercial slaughter practice was made. The relationship between Enterobacteriaceae, coliform and Escherichia coli counts and Salmonella status was also evaluated to establish the likelihood of using these groups as 'index' organisms to predict the presence of pathogen. Methods and Results: Samples were removed immediately after evisceration, after the inside-outside shower and after chilling from the processing line for microbiological analysis. Of the carcasses visibly uncontaminated with faeces after the evisceration step 20% harboured salmonellas and 20AE8% of the visibly contaminated carcasses were positive for the pathogen. When E. coli, coliforms and Enterobacteriaceae were used as predictor variables the error rates ranged from 33AE3 to 60% for both sample types. Conclusions: There was no indication that any of the groups of organisms analysed could predict the incidence of salmonellas on the samples studied. Positive results for the pathogen were obtained at every tested step of the slaughtering process regardless of whether or not faecal contamination was present. Significance and Impact of the Study: The present study demonstrated that carcasses not visibly contaminated with faeces carried Salmonella as well as the visibly contaminated carcasses.

The prevalence and PCR detection of Salmonella contamination in raw poultry

Veterinary Microbiology, 2002

Contaminated poultry meat has been identified as one of the principal foodborne sources of Salmonella. The development of rapid detection assays for Salmonella would enable official agencies and food industries to identify contaminated foodstuffs in a more timely manner. In addition, these diagnostic tools could allow more 'real time' decisions to be made regarding end product acceptability. In this study, a survey was carried out to determine the prevalence of Salmonella in raw broiler carcasses. A total of 198 neck skin samples were obtained from within 40 flocks at a commercial broiler slaughtering facility. The presence of Salmonella was assessed by traditional culture methods and by a Salmonella-specific polymerase chain reaction (PCR) test. Salmonella was recovered from 32 (16%) of all samples using traditional culture methods. In contrast, the PCR assay proved to be more sensitive and detected Salmonella DNA in 38 (19%) of the samples tested. The pathogen was detected in 45 (23%) of the 198 samples when culture and PCR results were combined. The sensitivity of the PCR test was also greater than culture when detecting Salmonella from within flocks (53% of flocks by PCR, 30% of flocks by culture). The combination of both tests revealed that 55% of the flocks were contaminated with Salmonella. The PCR assay proved to be a highly specific and sensitive method for detecting Salmonella and the incorporation of a routine PCR test in conjunction with standard culture could be effective in providing a more accurate profile of the prevalence of this pathogen in broiler carcasses. #

Salmonella detection in poultry meat and meat products by the Vitek immunodiagnostic assay system easy Salmonella method, a LightCycler polymerase chain reaction system, and the International Organization for Standardization method 6579

Poultry Science, 2012

This study was conducted to evaluate the capability of the Vitek immunodiagnostic assay system easy Salmonella (VIDAS ESLM) method and a specific real-time PCR system (LightCycler, LCPCR) to complement the International Organization for Standardization Method 6579 (ISO) in detecting Salmonella from a total of 105 naturally contaminated samples comprised of poultry meat and poultry meat products. The detection limit of ISO and LCPCR was 9 cfu/ mL for both poultry meat and poultry meat products, whereas that of VIDAS ESLM with both sample types was determined to be 90 cfu/mL. Twelve (33.33%), 11 (30.55%), and 18 (50.00%) out of 36 poultry meat samples were positive for Salmonella by ISO, VIDAS ESLM, and LCPCR, respectively. Salmonella detection rates from poultry meat products were 5.80% for ISO and 8.69% for LCPCR, whereas none of these products tested positive by VIDAS ESLM. In poultry meat samples, VIDAS ESLM and LCPCR detection results were in substantial agreement with ISO, with the relative accuracy, sensitivity, and specificity rates of 97.2, 91.7, and 100%, respectively, for VIDAS ESLM and 83.3, 100, and 75%, respectively, for LCPCR. This is the first report on the evaluation of both VIDAS ESLM and LCPCR to complement ISO for the rapid detection of Salmonella in poultry meat and meat products. We determined that both VIDAS ESLM and LCPCR have the potential to complement the ISO standard culture method in the rapid screening of Salmonella from naturally contaminated poultry meats. For the poultry meat products, VIDAS ESLM and LCPCR can be used for rapid primary screening, and they should be complemented absolutely by ISO. Although LCPCR can preferentially be used for initial screening poultry meat products, the results should definitely be confirmed by ISO. Also, the VIDAS ESLM did not seem to be a suitable method for detecting Salmonella in poultry meat products.

Use of Three Rapid Detection Systems to Evaluate the Prevalence and Dissemination of Salmonella in a Brazilian Poultry Slaughterhouse

Journal of Rapid Methods and Automation in Microbiology, 2003

Prevalence and dissemination of Salmonella in a Brazilian poultry slaughterhouse were evaluated by three rapid detection systems (SS/SVrM, WCM, OSRTm, Unipath/Oxoid, andREVEAL.m, Neogen), plus the conventional procedure. The carcasses were sampled afler bleeding (PI). de$eathering (P2), evisceration (P3), washing (F4}, chilling {F5} and the packaged end-product (P6). In the first set of carcasses, the Salmonella incidence determined by the conventional method was 38.3% and 22.5% by SS/Svu. In the set for evaluation of OSRTm, the number of positive samples was the same detected by the cultural procedure (49.0%). In the third set, the positivity by the conventional procedure was 33.3%, and 5.0% by REVEALTM. The comparisons ofpositives in the first and third sets of carcasses were significantly different (P < 0.05). The positivity for Salmonella, in carcasses at PI to P6, as determined ' Corresponding author. Address: Caixa Postal 572, Dismto de RubiBo Jdnior, 245 246 J.P.A.N. PINTO ETAL. by at least one of the methods, was 47.5%, 47.5%, 32.5% 30.0%, 30.0% and 37.7%, respectively.

Routes for salmonella contamination of poultry meat: epidemiological study from hatchery to slaughterhouse

Epidemiology and Infection, 2002

Data were collected on the prevalence of salmonella at different stages during the life cycle of 18 broiler flocks on different farms as well as during slaughter in different poultry slaughterhouses. For the isolation of salmonella, the highest sensitivity (93.9%) was obtained by enrichment in the semi-solid agar Diasalm. The ‘overshoe method’ utilizing several pairs of overshoes provided the highest sensitivity for determining the salmonella status of the broilers during rearing. A clear decrease of the relative importance of the first production stages was demonstrated for the salmonella contamination of the end product, whereas horizontal transmission of salmonella to broilers during rearing and to broiler carcasses in the slaughterhouse was shown to be the main determinative factor. Ten of the 18 flocks received a salmonella positive status with the highest shedding occurring during the first 2 weeks of rearing. The shedding of the animals was significantly negatively influenced...

Qualitative Map of Salmonella Contamination on Young Chicken Carcasses

Journal of Food Protection, 2010

Salmonella contamination of poultry is a global public health problem. The objective of this study was to map the distribution of Salmonella on the young chicken carcass, to improve poultry inspection and food safety. Young chickens (n = 70) in the Cornish game hen class were obtained at retail over a 3-year period. Carcasses were aseptically sectioned into 12 parts, and then Salmonella was isolated from whole-part incubations by conventional culture methods. Isolates were characterized for serotype and antibiotic resistance, and by pulsed-field gel electrophoresis (PFGE). Salmonella incidence was 21.5% (181 of 840) for parts and 57.1% (40 of 70) for carcasses. The number of contaminated parts per carcass ranged from 0 to 12, with a mean of 4.5 among contaminated carcasses. Chi-square analysis indicated that Salmonella incidence differed (P < 0.05) among parts, with rib back (38.6%) and sacral back (34.3%) being the most contaminated. Among the 40 contaminated carcasses, there we...

Salmonella spp. Isolated by Miniaturized Most Probable Number and Conventional Microbiology in Poultry Slaughterhouses

Acta Scientiae Veterinariae

Background: Salmonella spp. are frequently isolated from fowls, and their detection in poultry products varies according to the breeding system and the slaughtering process, bringing risks to the consumer and compromising the marketability. The control of Salmonella in poultry slaughterhouses is based on the detection of bacteria, but the quantification of the agent would be important in assessing risk, as well as in obtaining data to determine the capacity of each step of the process to decrease or increase bacterial contamination. The aims of this study were to propose a method for the quantification of Salmonella in poultry slaughterhouses, frequency of isolation and serovars identified.Materials, Methods & Results: Twenty-one broiler flocks from seven federally inspected slaughterhouses in southern Brazil, totaling 1,071 samples, were assessed by miniaturized most probable number (mMPN) and conventional microbiology. The samples were collected in triplicate at 17 points, which i...