Chantal W Nde

North Dakota State University, Fargo, ND, United States

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Publications (6)11.49 Total impact

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    ABSTRACT: This study was aimed at comparing the ability of conventional culture, the iQ-Check real-time PCR kit, and invA PCR to detect Salmonella in naturally contaminated premarket and retail turkey parts. Premarket (n = 120) turkey parts collected from a commercial turkey processing plant, and retail turkey parts (n = 138) were examined. Both PCR methods detected a significantly greater (P < 0.05) number of positive samples when compared with the conventional culture method for the premarket turkey parts. The indices of total agreement between the conventional culture method and the iQ-Check kit for the premarket and retail parts were 79.2% (95% CI: 70.8, 86) and 90.6% (95% CI: 84.4, 94.9), respectively. When the conventional culture method was compared with invA PCR for Salmonella detection in the premarket and retail parts, the indices of total agreement were 75.8% (95% CI: 67.2, 83.2) and 84.1% (95% CI: 76.9, 89.7), respectively. The rates of false positives (premarket: 31.9%, retail: 9.7%) and false negatives (premarket: 5.9%, retail: 9.7%) were determined between the culture method and the iQ-Check kit. When invA PCR was compared with the culture method, the rates of false positives (premarket: 37.7%, retail: 11.1%) and false negatives (premarket: 5.9%, retail: 18.3%) were obtained. The higher total agreement and the lower rates of both false positives and false negatives for the iQ-Check kit compared with invA PCR for both premarket and retail turkey parts corroborates the use of the iQ-Check kit as a screening tool for Salmonella in poultry meat.
    Journal of food protection 03/2008; 71(2):386-91. · 1.83 Impact Factor
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    C W Nde, C M Logue
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    ABSTRACT: To determine the antimicrobial susceptibility profiles, distribution of class 1 integrons, virulence genes and genes encoding resistance to tetracycline (tetA, tetC, tetD and tetE) and streptomycin (strA, strB and aadA1) in Salmonella recovered from turkeys. The antimicrobial susceptibility of 80 isolates was determined using National Antimicrobial Resistance Monitoring System. The distribution of resistance genes, class 1 integrons and virulence genes was determined using PCR. Resistances to tetracycline (76 x 3%) and streptomycin (40%) were common. Sixty-two (77 x 5%) isolates displayed resistance against one or more antimicrobials and 33 were multi-drug resistant. tetA was detected in 72 x 5% of the isolates, while tetC, tetD and tetE were not detected. The strA and strB genes were detected in 73 x 8% of the isolates. Two isolates possessed class 1 integrons of 1 kb in size, containing the aadA1 gene conferring resistance to streptomycin and spectinomycin. Fourteen of the virulence genes were detected in over 80% of the isolates. This study shows that continuous use of tetracycline and streptomycin in poultry production selects for resistant strains. The Salmonella isolates recovered possess significant ability to cause human illness. Information from this study can be employed in guiding future strategies for the use of antimicrobials in poultry production.
    Journal of Applied Microbiology 02/2008; 104(1):215-23. · 2.20 Impact Factor
  • Catherine M Logue, Chantal W Nde
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    ABSTRACT: Food safety and the development of an understanding of issues surrounding pathogens associated with food is of considerable importance in modern-day food production. The design and use of risk models to estimate the likelihood of human illness has become an important part of our understanding of food safety issues. In order to quantify food safety risks, the first requirement is to estimate the occurrence of the pathogen associated with a particular production system. As such, an assessment of whether interventions significantly reduce these risks can be made. In light of recent events in food production including pathogens in ready to eat foods and outbreaks of Escherichia coli O157:H7 associated with produce, the development and implementation of risk models will continue to gain importance in the coming years. This paper focuses on some of the current research ongoing at North Dakota State University to develop a greater understanding of Salmonella as it pertains to turkey production and processing in the Midwest. This overview of studies of Salmonella in turkey production stems from a presentation of research made at the Integrated Risk Studies: Gate to Plate-Current Issues and Future Strategies Conference held in Fargo, ND, May 4-5, 2006.
    Foodborne Pathogens and Disease 02/2007; 4(4):491-504. · 2.28 Impact Factor
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    ABSTRACT: Salmonella present on the feathers of live birds could be a source of contamination to carcass skin during defeathering. In this study, the possibility of transfer of Salmonella from the feathers of live turkeys to carcass tissue during the defeathering process at a commercial turkey processing plant was investigated. The contribution of scald water and the fingers of the picker machines to cross contamination were also examined. Over 4 visits, swab samples were collected from 174 randomly selected tagged birds before and after defeathering. Two swab samples from the fingers of the picker machines and a sample of scald water were also collected during each visit. Detection of Salmonella was carried out following standard cultural and identification methods. The DNA fingerprints obtained from pulsed field gel electrophoresis of Salmonella serotypes isolated before and after defeathering, from scald water, and from the fingers of the picker machines were compared to trace cross contamination routes. Salmonella prevalence was similar before and after defeathering during visits 2 and 3 and significantly increased after defeathering during visits 1 and 4. Over the 4 visits, all Salmonella subtypes obtained after defeathering were also isolated before defeathering. The results of this study suggest that Salmonella was transferred from the feathers to carcass skin during each visit. On each visit, the Salmonella subtypes isolated from the fingers of the picker machines were similar to subtypes isolated before and after defeathering, indicating that the fingers facilitate carcass cross contamination during defeathering. Salmonella isolated from scald water during visit 4 was related to isolates obtained before and after defeathering, suggesting that scald water is also a vehicle for cross contamination during defeathering. By using molecular subtyping, this study demonstrated the relationship between Salmonella present on the feathers of live turkeys and carcass skin after defeathering, suggesting that decontamination procedures applied to the external surfaces of live turkeys could reduce Salmonella cross contamination during defeathering.
    Poultry Science 02/2007; 86(1):162-7. · 1.52 Impact Factor
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    ABSTRACT: In this study, whole carcasses were sampled at eight stages on a turkey-processing line and Salmonella prevalence was determined using enrichment techniques. Recovered Salmonella was further characterized using serotyping and the molecular profiles were determined using pulsed-field gel electrophoresis (PFGE). Prevalence data showed that contamination rates varied along the line and were greatest after defeathering and after chilling. Analysis of contamination in relation to serotypes and PFGE profiles found that on some visits the same serotype was present all along the processing line while on other days, additional serotypes were recovered that were not detected earlier on the line, suggesting that the birds harbored more than one serotype of Salmonella or there was cross-contamination occurring during processing. Overall, this study found fluctuations in Salmonella prevalence along a turkey-processing line. Following washing, Salmonella prevalence was significantly reduced, suggesting that washing is critical for Salmonella control in turkey processing and has significant application for controlling Salmonella at the postdefeathering and prechill stages where prevalence increased.
    Journal of food protection 09/2006; 69(8):1794-801. · 1.83 Impact Factor
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    ABSTRACT: The efficacy of rinse, excision, and swab methods for the microbiological analysis of prechill turkey carcasses was investigated. Aerobic plate counts from a 50-cm2 area of the breast sampled by excision and by swabbing were compared. Escherichia coli and Salmonella recoveries were determined from turkeys sampled by a carcass rinse (CR), a modified rinse with the carcass supported in a swing (MCR), a two-site swab of 50 cm2 at the back and thigh (2S), a one-site swab of 50 cm2 beneath the wing (1S), a whole-carcass swab of the inner and outer carcass surface (WS), and excision of 25 g of neck skin tissue (NE). The effect of diluent volume (25, 50, and 100 ml) on E. coli counts from swab samples was also assessed. The aerobic plate count from breast tissue sampled by excision was greater than that by swabbing (P < 0.05). E. coli recoveries by the MCR method were similar to those by CR. E. coli counts from IS and WS samples were higher when swabs were stomached in 50 rather than 25 ml of diluent (P < 0.05). For swabs stomached in 50 ml of diluent, E. coli recoveries by the MCR, 2S, 1S, and WS methods were similar. For swabs stomached in 50 ml of diluent, Salmonella recoveries by the WS and MCR methods were higher than those by the 2S and 1S methods. Excision was more effective than swabbing for obtaining total bacterial counts from reduced turkey carcass areas. Whole-carcass sampling by rinsing or swabbing is necessary for optimum Salmonella recovery. Sampling a reduced area of the carcass is sufficient for E. coli analysis.
    Journal of food protection 02/2005; 68(1):34-9. · 1.83 Impact Factor