Category Archives: Microbiology

Journal of Food Protection

Beef and veal products have been vehicles implicated in the transmission of Salmonella enterica, a gastroenteritis-causing bacteria. Recent regulatory samples collected from veal have indicated bob veal, or calves harvested within days of birth, have higher rates of Salmonella than samples collected from formula-fed veal, or calves raised 20 weeks on milk replacer formula before harvest. To investigate this problem, we collected samples from veal calf hides, preevisceration carcasses, and final carcasses at five veal processors that harvested bob or formula-fed veal or both. Prevalence and concentrations of Salmonellawere determined, and then the isolates were characterized for serovar and antibiotic susceptibility. Salmonella was more prevalent (P < 0.05) among bob veal than formula-fed veal hides, preevisceration carcasses, and final carcass (84.2 versus 15.6%, 62.8 versus 10.1%, and 12.0 versus 0.4%, respectively). Concentrations of Salmonella could be estimated by using regression order statistics on hides and preevisceration carcasses at two veal plants, with one harvesting bob veal and the other bob and formula-fed veal. The concentration of Salmonella on bob veal hides at the plants was 1.45 ± 0.70 and 2.04 ± 1.00 log CFU/100 cm², greater (P < 0.05) than on formula-fed veal hides, which was 1.10 ± 1.51 log CFU/100 cm². Concentrations on carcasses, however, were very low. Seventeen Salmonella serovars were identified among 710 isolates. Salmonella serovars London, Cerro, and Muenster were most common to bob veal and made up 50.7, 18.7, and 6.3% of the isolates, respectively, while serovar Montevideo (6.8% of isolates) was most common to formula-fed veal. Although bob veal had increased prevalence and concentrations of Salmonella, one group of formula-fed veal was found to harbor human disease–related antibiotic-resistant Salmonella serovars Heidelberg and the monophasic variant of Typhimurium (1,4,[5],12:i:−). Veal processors have made changes to improve the safety of veal, but further efforts are necessary from both bob and formula-fed veal to address Salmonella.

The Poultry Site

Dirty chick boxes at hatcheries can be a source of Salmonella, but the risk was still lower than expected in a study conducted at one US hatchery, according to Kathryn McCullough, a DVM candidate at North Carolina State University.

McCullough’s study was aimed at pinpointing where hatcheries need to focus their Salmonella-control efforts to prevent contamination of chicks with the pathogen.

“All of your breeder flocks are sending their eggs to the hatchery, and then those chicks hatching out are being disseminated… through the entire complex for that area. So, any disease measures that you can get under control at the hatchery are really going to have the biggest impact for that complex,” she told Poultry Health Today.

For the study, McCullough used boot swabs to sample chick boxes at a hatchery. Chicks were placed in clean boxes – boxes that were washed and dried – 2 days a week. Due to the hatchery’s schedule, however, dirty but dry boxes were used 2 other days because there wasn’t time to thoroughly wash and dry them.