The influence of fructooligosaccharide (FOS) on the ability of Salmonella typhimurium to grow and colonize the gut of chickens was investigated. In vitro studies showed that Salmonella did not grow when FOS was the sole carbon source. When FOS was fed to chicks at the .375% level, little influence on Salmonella colonization was observed. At the .75% level, 12% fewer FOS-fed birds were colonized with Salmonella compared with control birds. When chicks given a partially protective competitive exclusion (CE) culture were fed diets supplemented with .75% FOS, only 4 of 21 (19%) chickens challenged with 10(9) Salmonella cells on Day 7 became colonized as compared with 14 of 23 (61%) chickens given CE alone. When chickens were stressed by feed and water deprivation on Day 13 and challenged with 10(9) Salmonella on Day 14, 33 of 36 (92%) chickens fed a control diet were colonized compared with only 9 of 36 (25%) chickens fed a .75% FOS diet. Chickens treated with FOS had a fourfold reduction in the level of Salmonella present in the ceca. Feeding FOS in the diet of chickens may lead to a shift in the intestinal gut microflora, and under some circumstances may result in reduced susceptibility to Salmonella colonization.

Recognition of Campylobacter fetus subsp. jejuni (referred to hereafter as C. jejuni) as an important human pathogen and its isolation from meat products indicate the need for knowledge of its survival characteristics in meats. Thermal death times (D-values) for a single strain and a five-strain composite were determined in 1% peptone and autoclaved ground chicken meat at temperatures ranging from 49 to 57°C. Survival was determined for three strains in chicken meat at 4, 23, 37, and 43°C. Survival was also determined on raw chicken drumsticks stored at 4°C in either an ambient or a CO2 atmosphere. D-values were greater in chicken meat than in peptone in all cases. D-values in peptone for strain H-840 at 49, 51, 53, 55, and 57°C were 15.2, 4.90, 1.71, 0.64, and 0.25 min, respectively. The corresponding D-values in ground chicken meat were 20.5, 8.77, 4.85, 2.12, and 0.79 min, respectively. Similar results were obtained with a composite of five strains. When sterile ground chicken meat was inoculated with approximately 106 to 107 C. jejuni cells per g and stored at 37°C in an ambient atmosphere, a 1to 2log count increase occurred during the first 4 days, followed by a gradual decline of about 1 log during the remainder of the 17-day storage period. No growth was observed among similarly inoculated samples that were stored at 4, 23, and 43°C, but counts declined by about 1 to 2 logs at 4°C (17 days), by 2.5 to 5 logs at 23°C (17 days), and to undetectable levels at 43°C (between 10 and 16 days). Survival on raw chicken drumsticks stored at 4°C in CO2 and in an ambient atmosphere declined by about 1.5 and 2.0 logs, respectively, during 21 days of storage. The effect of temperature on the survival of C. jejuni in chicken meat was similar to that reported in other natural and laboratory milieus. Ordinary cooking procedures that destroy salmonellae would be expected to destroy C. jejuni.

The resistance to cecal colonization by Campylobacter jejuni was assessed by challenging three crossbred stocks of commercially available broiler chickens. These three stocks, designated A, B, and C, were related as follows: Offspring from four pedigreed grandparent flocks were used as progenitors. Stock B was derived by cross-breeding grandparent 1 with grandparent 3. Stocks A and C were crossbreeds from grandparents 1 and 2 and grandparents 3 and 4, respectively. Campylobacter jejuni were gavaged into 48-hour-old chicks, using the same levels of challenge dose for each of the different chicken stocks. Six days post-challenge, the birds were sacrificed, and cecal contents were plated onto Campylobacter-selective media. Results from two replicate trials with three isolates of C. jejuni indicated that chicken stock A was colonized in only two of 60 ceca, stock B in six of 60, and stock C in 19 of 60 chicken ceca. Statistical analysis of these data indicate that resistance to cecal colonization by C. jejuni was significantly (P less than 0.05) influenced through chicken host lineage.

Egg fragments from hatching trays, swabs of belting material, and paper pads from three broiler hatcheries were sampled for the presence and level of salmonellae. Salmonella serotypes were recovered from 71, 80, and 74% of the egg fragments, belting material, and paper pads, respectively. Overall, salmonellae were found in 75, 91, and 67% of the samples taken at Hatchery 1,2, and 3, respectively. Thirty-eight of 40 randomly selected samples contained greater than 10(3) salmonellae cells per sample. All of the Salmonella serotypes encountered in the present study had previously been isolated from poultry. The presence and persistence of salmonellae contamination in the hatchery suggests that the vulnerable day-of-hatch chick may be at a greater colonization risk in the hatchery than during grow-out. Contamination and penetration of the shell of hatching eggs may constitute the most important link (or critical control point) in the transmission of salmonellae to young birds and eventually the consumer. An effective intervention method may have to be employed at this point to break the transmission link and significantly impact the overall problem of Salmonella colonization in poultry.

Two hundred and twenty-five pork carcasses were sampled immediately after slaughter and 24 h postmortem for the presence of Campylobacter spp. and Salmonella spp, Campylobacter spp. were present on 23 carcasses with 9 isolates from the shoulder area and 14 isolates from the ham. Salmonella spp. were isolated from 63 carcasses with 29 isolates from the shoulder and 34 isolates from the ham area. Spraying with a 2% solution of lactic acid reduced the numbers of both organisms that could be isolated immediately and 24 h after slaughter from the 75 carcasses sprayed. All of the Campylobacter spp. isolated in this study were confirmed to be Campylobacter coli.

Egg fragments, paper pads from chick boxes, and fluff samples were obtained from six commercial broiler breeder hatcheries and analyzed for the presence and level of salmonellae. Overall, 42 of 380 samples (11.1%) from those hatcheries were contaminated with salmonellae. Salmonellae organisms were detected in 22 of 145 (15.2%), 5 of 100 (4.6%), and 15 of 125 (12%) samples of egg fragments, fluff, and paper pads, respectively. The percentage salmonellae-positive samples from each of the six hatcheries were 1.3, 5.0, 22.5, 11.4, 36.0, and 4.3% respectively. Of the 140 samples randomly selected for enumeration, salmonellae were found in 11 samples. Four of these 11 samples had greater than 10(3) salmonellae per sample, 3 others had greater than 10(2) but less than 10(3), and the remaining 4 had less than 10(2). Salmonella serotypes isolated were S. berta, S. california, S. give, S. hadar, S. mbandaka, S. senftenberg, and S. typhimurium, all of which have previously been isolated from poultry. The incidence and extent of salmonellae-positive samples found in the breeder hatcheries were much less than that previously found in broiler hatcheries. Many factors contribute to the lower incidence and level of salmonellae found in the breeder hatcheries; however both the breeder and broiler hatcheries present critical control points in the prevention of salmonellae contamination during commercial poultry production. The cycle of salmonellae contamination will not likely be broken until contamination at these critical points is eliminated.

No abstract

Title 9 of the Code of Federal Regulations establishes prescribed thermal treatment for a variety of meat and poultry products. These requirements are to ensure the destruction of harmful microorganisms and viruses that cause diseases in humans and livestock. The information presented in this review provides information relative to the current procedures used by the Food Safety and Inspection Service (FSIS) for monitoring the adequacy of heat treatment of meat and poultry products; and the research activities that have been and are currently being conducted to develop new and/or improved methods for determining the maximum internal temperature of meat and poultry products. Currently, FSIS is using a protein “Coagulation Test” for monitoring the maximum internal temperature (MIT) of both beef and pork products heat processed to temperatures lower than 65°C; a residual “Acid Phosphatase Activity Method” for determining the MIT of canned hams, canned picnics and canned luncheon meat, and a third method, known as the “Bovine Catalase Test”, for the determination of catalase which gives a pass/fail indication at a cooking temperature of 62.8°C for rare roast beef and cooked beef. Since 1957, several attempts have been made to develop new and/or improved methods. These include an evaluation of the enzyme systems and various physical techniques. The lack of new and/or improved methods is not due to the lack of research efforts in this area, as evidenced by this review. The challenge is the development of a method which can accurately determine within ± 1.0°C the endpoint temperature in the temperature range (67.8 – 70.0°C) that is of most interest to FSIS.