Chicken Carcass Rinse Research Articles

Validation of the Neogen® Molecular Detection Assay 2 - Salmonella Enteritidis/Salmonella Typhimurium Method for Specific Detection of Salmonella enterica Ser. Enteritidis and Salmonella enterica Ser. Typhimurium in Chicken Carcass Rinse and Raw Ground Chicken AOAC Performance Tested MethodSM 122302.

The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a rapid, nucleic acid amplification-based test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica 1,4 , [5] , 12: i:-, in select poultry samples. Results for SE and ST are generated separately. The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in chicken carcass rinse and raw ground chicken (325 g) for Performance Tested Methods SM (PTM) certification. The study consisted of inclusivity/exclusivity testing and independent laboratory testing of chicken carcass rinse and raw ground chicken using inoculated matrixes. Data were analyzed using a paired probability of detection model to determine if differences in the number of positive results obtained with the MDA2-SE/ST and reference methods were significant. In inclusivity testing, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1 Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, results for the MDA2-SE/ST and reference methods were in complete agreement for both matrixes. Results of the validation study showed that the MDA2-SE/ST method is an accurate, specific method for detection of SE and ST in select poultry matrixes. The data were reviewed by the AOAC PTM Program and approval was granted for certification of the Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium method as PTM 122302.

Level 2 Modification (Matrix Extension) Study of the Neogen® Molecular Detection Assay 2 - Salmonella Enteritidis/Salmonella Typhimurium Method: Detection of Salmonella enterica ser. Enteritidis and Salmonella enterica ser. Typhimurium in Cooked Breaded Chicken and Raw Ground Chicken (25 g).

The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a nucleic acid amplification test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica 1,4,[5],12:i:-, in select poultry samples. Results for SE and ST are generated separately. The method was previously validated for testing of chicken carcass rinse and raw ground chicken (325 g). The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in cooked breaded chicken and raw ground chicken (25 g) as a Level 2 modification for Performance Tested Methods SM certification. Inclusivity/exclusivity testing and independent laboratory testing of cooked breaded chicken and raw ground chicken (25 g) were conducted. In inclusivity testing with BPW-ISO broth at 41.5 °C, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1 Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, there were no significant differences in the number of positive results obtained with the MDA2-SE/ST and reference methods by probability of detection analysis at the 95% confidence level. Results of the matrix extension study showed that the MDA2-SE/ST method is an accurate method for detection of SE and ST in cooked breaded chicken and raw ground chicken (25 g). Validation of the MDA2-SE/ST method for two additional matrixes provides users with additional capability for specific detection of SE and ST in poultry products.

Bio-Mapping of Microbial Indicators and Pathogen Quantitative Loads in Commercial Broiler Processing Facilities in South America.

A bio-mapping study was conducted with the aim of creating a microbiological baseline on indicator organisms and pathogens in commercial broiler processing facilities located in a country in South America. Whole chicken carcass and wing rinses were collected from five stages of the poultry processing line: live receiving (LR), rehanger (R), post-evisceration (PE), post-chilling (PC), and wings (W). Rinses (n = 150) were enumerated using the MicroSnap™ system for total viable counts (TVC) and Enterobacteriaceae (EB), while the BAX®-System-SalQuant® and BAX®-System-CampyQuant™ were used for Salmonella and Campylobacter, respectively. TVC and EB were significantly different between stages at the processing line (p < 0.01). There was a significant reduction from LR to PC for both microbial indicators. TVC and EB counts increased significantly from PC to W. Salmonella counts at PC were significantly different from the other stages at the processing line (p = 0.03). Campylobacter counts were significantly higher than the other stages at PC (p < 0.01). The development of bio-mapping baselines with microbial indicators showed consistent reduction up to the post-chilling stage, followed by an increase at the wings sampling location. The quantification of pathogens demonstrates that prevalence analysis as a sole measurement of food safety is not sufficient to evaluate the performance of processing operations and sanitary dressing procedures in commercial processing facilities.

Complete Genome Sequences of Two Salmonella enterica Strains Isolated from Chicken Carcass Rinse Water in Thailand.

We report the circularized complete genome sequences, containing a circular chromosome and two circular plasmids, of strains SalSpp05 (4.9 Mbp) and SalSpp10 (4.8 Mbp), which were isolated from chicken carcass rinse water samples; the sequences were obtained by combining Oxford Nanopore Technologies long-read data and Illumina short-read data. Whole-genome alignments indicated that both strains belong to Salmonella enterica.

Validation of RapidChek®Campylobacter Test System for the Detection of C. jejuni, C. coli, and C. lari in Poultry Samples: AOAC Performance Tested MethodSM 052201.

Campylobacter is one of the leading causes of human bacterial gastroenteritis worldwide. Campylobacter infections are most often associated with the consumption of raw milk, undercooked poultry, and contaminated water. The RapidChek®Campylobacter test system (PTM number 052201) was validated for the detection of Campylobacter jejuni, C. coli, and C. lari in raw ground chicken, chicken carcass rinse, and turkey carcass sponges. The method uses a proprietary enrichment medium. Following aerobic enrichment, an immunochromatographic test strip is inserted into the tube containing the enrichment, developed for 20 min, and interpreted. Campylobacter-inoculated food samples were tested by the method, as well as the USDA/FSIS cultural reference method; Isolation and Identification of Campylobacter jejuni/coli/lari from Poultry Rinse, Sponge and Raw Product Samples MLG 41.04. The candidate method was also confirmed by an alternative cultural method. The RapidChek method was tested with 50 Campylobacter strains comprised of C. jejuni, C. coli, and C. lari, and 30 non-target strains. A total of 80 low-level spiked samples were tested by both methods in the study. The candidate method yielded 49 presumptive positives: all presumptive results were confirmed culturally. The reference method produced a total of 41 confirmed positive results. No difference between the alternate confirmation method and reference confirmation method was observed. Probability of detection analysis demonstrated no significant differences in the number of positive samples detected by the candidate method and cultural reference method. The RapidChek method detected all 50 Campylobacter strains and none of the 30 non-target strains, including Campylobacter spp. other than C. jejuni, C. coli, and C. lari. The candidate method performed as well as the reference method in the detection of C. jejuni, C. coli, and C. lari in raw ground chicken, chicken carcass rinse, and turkey carcass sponges. Aerobic enrichment of selected matrixes for 48 h yielded reliable presumptive results for Campylobacter.

Validation of the Modified Clear Safety Salmonella for Detection of Salmonella enterica in Selected Poultry and Pet Food Matrixes and on Stainless Steel: AOAC Performance Tested MethodSM 111802.

The Clear Safety Salmonella method was modified to improve sample preparation, PCR reagents, library preparation, flow cell quality control, library loading mix, priming mix, and sequencing kit reagents and steps. To evaluate the modified Clear Safety Salmonella method (manual and automated) via independent and method developer validation studies according to current AOAC INTERNATIONAL Validation Guidelines. Performance of the modified Clear Safety Salmonella method (manual and automated) was assessed for selectivity (using 105 inclusive and 30 exclusive strains), probability of detection in matrixes, product consistency, stability, and robustness. The modified Clear Safety Salmonella method was compared with the appropriate reference method for Salmonella detection on 4 inch × 4 inch stainless steel environmental surfaces, and in chicken carcass rinse (30 mL), raw ground chicken (375 g), dry pet food (375 g), and ready-to-eat deli turkey breast (375 g). The modified Clear Safety Salmonella method (manual and automated) demonstrated no statistically significant differences between the candidate and reference method probability of detection or between the presumptive and confirmed results for all target food matrixes and the stainless steel surface. Additionally, the modified method (manual and automated) detected all 105 inclusivity organisms and excluded all 30 exclusivity organisms. The product consistency and kit stability studies showed no statistical differences between lots or over the term of the kit's shelf life. In robustness studies, changes in enrichment time, diluted sample volume, and sample volume for PCR did not show any statistical difference in terms of assay performance. The modified Clear Safety Salmonella method (both manual and automated) is statistically equivalent to or better than the reference methods. The Clear Safety Salmonella method utilizes PCR amplification and targeted next-generation sequencing technology to selectively detect Salmonella enterica.

Validation of the AtlasTMCampylobacter Detection Assay: AOAC Performance Tested MethodSM 032101.

Campylobacter spp. are a major causal agent for diarrheal illness in humans. Detection of Campylobacter spp. in food is critical to reduce foodborne illness, and to provide safe foods. The aim was to evaluate the Atlas Campylobacter Detection Assay for AOAC Performance Tested MethodsSM certification for detecting C. jejuni, C. coli, and C. lari in foods after 12 h enrichment. The Atlas Campylobacter Detection Assay was compared to the ISO 10272-1:2017 reference culture method for chicken carcass rinse, turkey carcass sponge, raw ground poultry, raw ground pork, and ready-to-eat (RTE) meats. Inclusivity, exclusivity, product consistency, product stability, and robustness studies were also performed. An independent laboratory evaluated the performance of the Atlas Campylobacter Detection Assay method on chicken carcass rinse. No significant differences were observed between the Atlas Campylobacter Detection Assay and the reference ISO method in spiked food matrixes. The Atlas Campylobacter Detection Assay detected all 50 inclusive organisms and none of the 30 exclusive organisms. Product consistency and stability studies showed no statistical differences between lots or over the term of the shelf-life using accelerated method study. Finally, the robustness study showed no statistical difference between different sample volumes, enrichment times, and storage time after sample transfer. The results of this study indicate that the Atlas Campylobacter Detection Assay is comparable to ISO 10272-1:2017 for detecting Campylobacter in chicken carcass rinse, turkey carcass sponge, raw ground poultry, raw ground pork, and RTE meats. The Atlas Campylobacter Detection Assay is a rapid, accurate molecular method able to detect C. jejuni, C. coli, and C. lari in in chicken carcass rinse, turkey carcass sponge, raw ground poultry, raw ground pork, and RTE meats within 12-18 h.

Validation of the One Broth One Plate for Salmonella Method for Detection of Salmonella Spp. in Select Food and Environmental Samples: AOAC Performance Tested MethodSM 102002.

BackgroundOne Broth One Plate for Salmonella (OBOP Salmonella) is a rapid and simple method for detection of Salmonella spp. in food and environmental samples using traditional culture methodology. The method utilizes single-step enrichment followed by plating to a selective/differential, chromogenic agar.ObjectiveThe purpose of the validation study was to measure the effectiveness of the OBOP Salmonella method in comparison to reference culture procedures.MethodPerformance of the OBOP Salmonella method was compared to that of the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 5 reference method for queso fresco, smoked salmon, cantaloupe, chocolate, black pepper, chili powder, dry pet food, and sponge samples from a stainless steel surface, or to that of the U.S. Department of Agriculture Microbiology Laboratory Guidebook Chapter 4.10 method for raw ground turkey, chicken carcass rinse, and pasteurized liquid egg. Inclusivity/exclusivity, robustness, and stability/lot-to-lot consistency testing was also performed.ResultsIn the matrix study, there were no statistically significant differences in performance between the OBOP Salmonella and reference methods, as determined by probability of detection analysis (P < 0.05), for any of the matrixes examined. All 104 Salmonella spp. strains produced positive results in inclusivity testing, and all 33 non-salmonellae exclusivity strains tested negative with the OBOP Salmonella method.ConclusionsResults of the validation study show that the OBOP Salmonella method is a reliable procedure for detection of Salmonella spp. in select matrixes. The method is simple to perform, requires no specialized equipment, and produces results in as little as 37 h.HighlightsThe OBOP Salmonella method was awarded AOAC PTMSM (#102002) for detection of Salmonella in queso fresco, smoked salmon, cantaloupe, chocolate, black pepper, chili powder, dry pet food, sponge samples on a stainless steel surface, raw ground turkey, chicken carcass rinse, and pasteurized liquid egg. The method is also approved by MicroVal® for a broad range of foods under certification number 2019LR88.

Label-Free Immunoassay for Multiplex Detections of Foodborne Bacteria in Chicken Carcass Rinse with Surface Plasmon Resonance Imaging.

The frequent outbreaks of foodborne pathogens have stimulated the demand of biosensors capable of rapid and multiplex detection of contaminated food. In this study, surface plasmon resonance imaging (SPRi) was used in simultaneous label-free detection of multiple foodborne pathogens, mainly Salmonella spp. and Shiga-toxin producing Escherichia coli (STEC), in commercial chicken carcass rinse. The antibodies were immobilized on the same SPRi sensor chip as a label-free immunoassay. Their immobilization concentrations were optimized to be ranging from 0.25 to 1.0 mg/mL, and independent of pH values. This label-free immunoassay achieved 106 colony-forming unit (CFU)/mL limit of detection for Salmonella, which was further improved to 1.0 CFU/mL with overnight bacteria enrichment. The injected samples with different bacteria, Salmonella Enteritidis, STEC, and Listeria monocytogenes, have been identified by the same biochip. Moreover, the SPRi signals revealed complex interference effects among coexisting bacteria species in heterogeneous bacteria solutions. This SPRi-based immunoassay demonstrates the great potential in high-throughput screening of multiple pathogenic bacteria coexisting in chicken carcass rinse. The reliability of antibody immobilization and cross-reactions of different antibodies on the same biochip are the major challenges of practical application of SPRi.

Prevalence and Antibiogram Assessment of Staphylococcus aureus in Chicken Carcass Rinse Water at Artisanal Slaughterhouses in Abidjan District, Côte d’Ivoire

Aims: The aim of the current study was to determine the antibiotic resistance profile of Staphylococcus aureus strains isolated from rinse water of chicken carcass in artisanal slaughterhouses in Abidjan.&#x0D; Place and Duration of Study: Chicken’s rinse water samples were collected between January and March 2020 in three areas of Abidjan district.&#x0D; Methodology: A total of 75 rinse water samples were collected from three markets of Abidjan district. Enumeration and isolation of S. aureus were carried out on Baird Parker agar supplemented with egg yolk tellurite emulsion followed by morphological and biochemical identification. Antibiotics resistance profiles were performed by using disks diffusion methods.&#x0D; Results: Out of 75 samples, 21 (28%) were contaminated with S. aureus. Among the isolates, 21 (one by positive sample) were tested for antimicrobial resistance against 14 most commonly used antibiotics. All strains were resistant to two antibiotics (minocyclin and fusidic acid). However, some drugs such as gentamiycin, norfloxacin, and Tigecyclin showed great activity on tested isolates.&#x0D; Conclusion: Results of this study suggest that rinse water could consist of a major critical point of chicken carcass contamination by S. aureus with high drugs resistance capacity. Therefore periodic control is need to good hygiene practice and improving the poultry meat sanitary quality produce from these slaughterhouses.

Validation of a Modified Version of Actero™ Salmonella Enrichment Media for Rapid Detection of Salmonella spp. in Environmental and Food Samples.

Actero™ Salmonella Enrichment Media1 (Actero™ Salmonella) is a culture broth developed to recover Salmonella spp. from foods and environmental surfaces. Performance of Actero™ Salmonella broth has already been assessed and validated (AOAC Performance Tested MethodSM 041403) for the detection of Salmonella spp. in various foods, feeds and environmental samples. This study aimed to validate the performance of a modified version of Actero™ Salmonella broth by incorporating one of the two liquid supplements into the powdered formula. Inclusivity, exclusivity, stability, and lot-to-lot studies were carried out. Raw ground beef, chicken carcass rinse, dry pet food and stainless steel samples were enriched for 14-20 h at 35-39°C and analyzed using real-time PCR assay as well as by direct plating. The Probability of Detection assay confirmed the equivalent performance of the alternative methods as compared to the reference methods. All Salmonella strains, except Salmonella II : 57: z29:-, were able to grow in Actero™ Salmonella broth. One-half of the non-target strains did not grow in Actero™ Salmonella broth, whereas the atypical for Salmonella growth was observed for other non-target microorganisms subsequently plated onto selective and differential agars. Lot-to-lot consistency was demonstrated for three consecutively manufactured lots of the broth. The liquid broth was proven to be stable at 4°C for up to 9 weeks of storage. The incorporation of one of the two specific supplements into a powdered formula of Actero™ Salmonella broth made it more convenient to use without compromising the performance and accuracy.

Method Modification to Extend the Matrix Claim of the Thermo Scientific RapidFinder Salmonella species, Typhimurium, and Enteritidis Multiplex PCR Kit.

Background: The Thermo Scientific RapidFinder™ Salmonella species, Typhimurium and Enteritidis Multiplex PCR Kit is a real-time multiplex PCR assay for the detection and differentiation of Salmonella species, Salmonella Typhimurium, and S. Enteritidis from poultry, pork, and environmental samples. The method has previously been granted certification as Performance Tested Method SM (PTM) 081701, validated according to the AOAC Research Institute (RI) PTM program for poultry (chicken thighs with skin, chicken wings with skin, and chicken nuggets), raw pork sausage matrixes, and stainless steel environmental surface sponges. Objective: This report details the method modification study to validate ground turkey (375 g sample size), chicken carcass rinse, and shell egg matrixes. Methods: The candidate method was compared with the U.S. Food and Drug Administration's Bacteriological Analytical Manual Chapter 5 for shell eggs and the U.S. Department of Agriculture Food Safety and Inspection Service's Microbiology Laboratory Guidebook 4.09 for ground turkey (375 g) and chicken carcass rinse matrixes. Results: The statistically significant differences found between the candidate and reference methods upon analysis by probability of detection were in favor of the candidate method. Inclusivity and exclusivity testing demonstrated that the RapidFinder Salmonella species, Typhimurium and Enteritidis Multiplex PCR Kit was able to detect all the major groups of Salmonella. All exclusivity isolates were correctly excluded. Conclusions: The data presented in this report show that the candidate is suitable for the detection and differentiation of Salmonellae from shell egg, chicken carcass rinse, and ground turkey (375 g) matrixes. Highlights: Thermo Scientific RapidFinder Salmonella species, Typhimurium and Enteritidis Multiplex PCR Kit (candidate method) matrix claims extended to include ground turkey (375 g), chicken carcass rinse and shell egg samples.

Microbiological Profile of Three Commercial Poultry Processing Plants in Colombia

Poultry meat production in Colombia has significant growth potential to fulfill national demands and to become an important global exporter. Entering export markets requires compliance with international food safety standards and the support of a rigorous national inspection system. To support the development of national standards, information about the microbiological profiles of poultry operations is needed, and no official microbiological baseline is currently available. A total of 480 chicken carcass rinses and 64 fecal samples were collected at different process sites from three commercial poultry processing establishments located in different regions of Colombia. Samples were analyzed to determine the prevalence of Salmonella and the levels of Escherichia coli in chicken rinse. Six steps were selected for sampling in the slaughter, evisceration, and chilling processes. The overall Salmonella prevalence after water immersion chilling at the three establishments was 12.5% (73 of 584 samples). E. coli levels were 1.2 to 2.2 log CFU/mL (mean, 1.65 log CFU/mL) after the chilling process. Significant differences (P < 0.05) were found for E. coli levels among the processing sites at the three establishments; however, there were no significant differences in the distribution of Salmonella-positive samples through the sites at each plant. These results can be used as reference data for microorganisms in chicken meat facilities in Colombia and will help the poultry industry and regulators in the design of new prevention programs and food safety management systems.

Effect of immunomagnetic bead size on recovery of foodborne pathogenic bacteria

Immunomagnetic separation (IMS) as a culture-free enrichment sample preparation technique has gained increasing popularity in the development of rapid detection methods for foodborne pathogens. While the use of magnetic nanoparticles in IMS is on the rise due to substantially larger surface area compared to conventional magnetic microparticles, the effects of immunomagnetic bead (IMB) size on pathogen cell recovery are not fully understood. In this study we used IMBs of different sizes (100, 500, and 1000nm diameters) to capture Salmonella Enteritidis, a common foodborne pathogen, from buffer solutions as well as food matrices (chicken carcass rinse and liquid egg white). The IMS recovery and non-specific binding rate were compared. The recoveries of Salmonella cells in buffers was highest using the 100nm IMBs (88–96%), followed by the 500nm (31–89%) and 1000nm (4.1–61%) IMBs, demonstrating a significant size effect. The non-specific binding rates of E. coli also increased as IMB size decreased. A 2–72% reduction in Salmonella recovery was observed in chicken carcass rinse and liquid egg white samples compared to in buffers, and this reduction was more significant using 500 and 1000nm IMBs. However, lower IMS recoveries (10–56%) was found in 100nm IMBs two months after preparation. Overall, magnetic nanoparticles yielded superior IMS efficiency to micrometer size IMBs and were less subjective to interference from food matrices. Nevertheless, their long term stability remains an obstacle towards successful use in IMS.

Improvement of Bolton broth by supplementation with tazobactam for the isolation of Campylobacter from chicken rinses.

Overgrowth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) on Campylobacter media prevents the latter's selective isolation, thereby making the improvement of Campylobacter-selective media necessary. We evaluated tazobactam (an ESBL inhibitor) to supplement Bolton enrichment broth (Tz-Bolton broth) for the selective isolation of Campylobacter in chicken carcass rinses. First, using 20 strains of ESBL-producing E. coli and 13 Campylobacter strains, we found 4μg/mL of tazobactam to be optimal for inhibiting the ESBL-producing E. coli while allowing the growth of all tested Campylobacter strains. Next, 80 whole chicken carcasses were rinsed with buffered peptone water (BPW), and 25mL of BPW rinse was mixed with 2 × blood-free Bolton broth (25mL) with or without tazobactam followed by incubation at 42°C for 48h under microaerobic conditions. A loopful of the incubated broth was inoculated on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) and microaerobically incubated at 42°C for 48h. The tazobactam supplemented Bolton broth showed a higher Campylobacter isolation rate (38.8%, p < 0.05) than normal Bolton broth (15%). Moreover, the number of mCCDA plates with non-Campylobacter was much lower (p < 0.05) after enrichment in Tz-Bolton broth (0%) than in the normal Bolton broth (80%), suggesting that selectivity of the modified broth was superior to normal Bolton broth.

Addition of Rifampicin to Bolton Broth to Inhibit Extended-Spectrum β-Lactamase-Producing Escherichia coli for the Detection of Campylobacter.

Exponential growth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Campylobacter media has become a common problem for the detection of Campylobacter in chicken meats. We investigated the minimum inhibitory concentration of 40 ESBL-producing E. coli isolates from meats obtained from various countries against antibacterial agents in Bolton broth (cefoperazone, vancomycin, and trimethoprim). All ESBL-producing E. coli strains were resistant to cefoperazone and vancomycin, whereas 50% of them were resistant to trimethoprim and grew in Bolton broth. We found that 20 μg/mL of rifampicin inhibited the growth of trimethoprim-resistant E. coli strains. Hence, we added 20 μg/mL of rifampicin to Bolton broth to improve the isolation of Campylobacter from chicken carcass rinses. The isolation rate of Campylobacter was significantly higher in the modified broth (44 out of 58, 75.9%, P < 0.05) than in the normal broth (0 out of 58, 0%). Furthermore, the number of agar plates with non-Campylobacter spp. was much lower after enrichment in the modified broth (4 out of 58, 6.9%, P < 0.05) than in the normal broth (58 out of 58, 100%).

Efficacy of Syringe Filtration for the Selective Isolation of Campylobacter from Chicken Carcass Rinse

We investigated the efficacy of syringe filtration for selective isolation of Campylobacter from chicken carcass rinse by combining syringe filtration with the conventional culture method. Whole chicken carcass rinses were incubated in Bolton enrichment broth, set aside or subjected to syringe filtration, and streaked on Campy-Cefex agar with or without cefoperazone antibiotic supplement. Compared with the conventional method without filtration, 0.65-μm-pore-size syringe filtration resulted in a significantly higher number of Campylobacter-positive samples (23.8 to 37.5% versus 70.0 to 72.5%; P < 0.05), a lower number of plates contaminated with non-Campylobacter (93.8% versus 6.3 to 26.3%), and a lower growth index (1 = growth of a few colonies; 2 = growth of colonies on about half of the plate; and 3 = growth on most of the plate) for competing microbiota (2.9 to 3.0 versus 1.2 to 1.4). When syringe filtration was applied, agar plates containing the antibiotic had significantly less contamination (6.3% versus 26.3%; P < 0.05) and a lower growth index (1.2 versus 1.4) compared with plates without the antibiotic, although the Campylobacter isolation rate was similar (P > 0.05). Syringe filtration combined with conventional enrichment improved the rate and selectivity of Campylobacter isolation from chicken carcasses.

Validation of the ANSR® for Campylobacter Method for Detection of Thermophilic Campylobacter spp. in Chicken Carcass Rinse and Turkey Sponge Samples.

A performance validation of the ANSR® for Campylobacter method was conducted in selected matrixes. This assay used selective nicking enzyme amplification technology to amplify target genes. Samples were enriched for 20 to 24 h and then lysed. The assay was completed within 50 min using real-time detection in a combination incubator/fluorescence detector and software. When 50 distinct strains of Campylobacter jejuni, C. lari, or C. coli were tested for inclusivity, all 50 strains produced positive results. In exclusivity testing, 31 strains of related organisms, including seven nontarget Campylobacter strains and other common species, were evaluated. All 31 species generated negative ANSR assay results, including the nontarget Campylobacter strains. The ANSR for Campylobacter method was compared to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference method using naturally contaminated chicken carcass rinse or turkey carcass sponge samples. ANSR method performance was not statistically different from the reference method using two different enrichment options. Equivalent results were observed at both time points (20 and 24 h) and in both atmospheres (microaerobic and aerobic) to reference methods. Method performance with chicken carcass rinse was confirmed in an independent laboratory study. Additionally, in robustness testing, small, deliberate changes to the assay parameters minimally affected ANSR method performance. Finally, accelerated stability results from three independently manufactured lots supported a shelf life of 6 months when stored at 4°C. The ANSR assay offered greater efficiency and flexibility when compared to the reference method with a 20-24 h single-step enrichment in a microaerobic or an aerobic atmosphere.

Validation of the Reveal(®) 2.0 Group D1 Salmonella Test for Detection of Salmonella Enteritidis in Raw Shell Eggs and Poultry-Associated Matrixes.

A study was conducted to assess the performance of the Reveal(®) 2.0 Group D1 Salmonella lateral flow immunoassay for use in detection of Salmonella Enteritidis (SE) in raw shell eggs and poultry-associated matrixes, including chicken carcass rinse and poultry feed. In inclusivity testing, the Reveal 2.0 test detected all 37 strains of SE tested. The test also detected all but one of 18 non-Enteritidis somatic group D1 Salmonella serovars examined. In exclusivity testing, none of 42 strains tested was detected. The exclusivity panel included Salmonella strains of somatic groups other than D1, as well as strains of other genera of Gram-negative bacteria. In matrix testing, performance of the Reveal 2.0 test was compared to that of the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure for chicken carcass rinse and to that of the U.S. Food and Drug Administration Bacteriological Analytical Manual for raw shell eggs and poultry feed. For all matrixes evaluated, there were no significant differences in the ability to detect SE when comparing the Reveal 2.0 method and the appropriate reference culture procedure as determined by probability of detection statistical analysis. The ability of the Reveal 2.0 test to withstand modest perturbations to normal operating parameters was examined in robustness experiments. Results showed that the test can withstand deviations in up to three operating parameters simultaneously without significantly affecting performance. Real-time stability testing of multiple lots of Reveal 2.0 devices established the shelf life of the test device at 16 months postmanufacture.

Isolation Method (Direct Plating or Enrichment) does Not Affect Antimicrobial Susceptibility of Campylobacter from Chicken Carcasses

AbstractTo determine if Campylobacter isolation method influenced antimicrobial susceptibility results, the minimum inhibitory concentrations (MIC) of nine antimicrobials were compared for 291 pairs of Campylobacter isolates recovered from chicken carcass rinse samples using direct plating and an enrichment method. Among the isolates 64.1% were C. jejuni, 35.7% were C. coli, and 0.2% were C. lari. Direct plating yielded significantly less (P &lt; 0.05) C. coli (21.3%) compared to sample enrichment (50.2%). Antimicrobial resistance was most common for tetracycline (41.4%), nalidixic acid (26.3%), and ciprofloxacin (25.9%). Significantly more (P &lt; 0.05) C. coli were resistant to nalidixic acid, ciprofloxacin, gentamicin, azithromycin, and erythromycin as compared to C. jejuni isolates. Nonparametric bootstrap analysis of antimicrobial MICs showed no significant differences between direct plating and the enrichment method for any of the antimicrobials tested. These data indicate that bacterial isolation method can bias Campylobacter species recovery. However, isolation method did not significantly affect antimicrobial susceptibility results of C. jejuni or C. coli recovered from broiler carcasses.Practical ApplicationsTo monitor trends in food safety and public health, antimicrobial susceptibility testing of Campylobacter derived from poultry products and infected patients has become common practice in both regulatory food safety and public health programs. Various methods have been employed for Campylobacter recovery including direct plating for enumeration of contamination levels and enrichment protocols for detection of low numbers or injured cells. This study was conducted to determine if the method of Campylobacter isolation from chicken carcass rinsate, direct plating or enrichment, influences antimicrobial susceptibility testing results.