Biomedical subjects

K S Macklin

Publications and source records attributed to K S Macklin.

6 recordsLinked to original sources

PubMed2006

Effect of different cleaning regimens on recovery of Clostridium perfringens on poultry live haul containers.

Clostridium perfringens is important to both poultry producers and humans. The excretion rate of pathogenic foodborne bacteria increases after live haul; however, the majority of research into flock cross-contamination has been performed on Salmonella and Campylobacter. Research into the sources of C. perfringens in poultry operations have implied that dirty transport containers do harbor this organism and, therefore, can potentially contaminate subsequent flocks. The objectives of this study were to examine both small plastic crates and large dump coops to determine which cleaning regimens were most effective in reducing C. perfringens contamination. Additionally, 2 different holding periods for small crates were compared to determine whether holding time influences C. perfringens recovery before and after cleaning. Two experiments were performed. One involved small plastic crates; the other involved large dump coops. Four small crate cleaning and disinfection treatments consisted of pressure washing, pressure washing and sun-drying, pressure washing with a (5%, vol/vol) sodium hypochlorite dip, and pressure washing with a quaternary ammonium dip. The second experiment involved dump coops. The 5 dump coop cleaning and disinfection treatments consisted of pressure washing, pressure washing with a (5%, vol/vol) sodium hypochlorite spray, pressure washing with a quaternary ammonium spray, 48-h drying after the sodium hypochlorite spray, and 48-h drying after the quaternary ammonium spray. The recovery of C. perfringens from small and large dirty transport containers averaged 1.94 and 4.43 log10 cfu/mL, respectively. There was no significant difference in C. perfringens recovery based on holding time for small crates. With small crates, pressure washing provided a significant decrease in the amount of C. perfringens recovered. The greatest bacterial reduction in dump coops, 2 to 3 log10 cfu/mL, was observed after 48 h of drying. This information provides solutions to poultry operations to reduce the cross-contamination of this food safety pathogen via transport containers.

Animals↗

PubMed2006

A longitudinal study of Salmonella and Campylobacter jejuni isolates from day of hatch through processing by automated ribotyping.

Comparisons of bacterial populations over long periods of time allow researchers to identify clonal populations, perhaps those responsible for contamination of farms or humans. Salmonella and Campylobacter can cause human illness, and our objective was to use a library typing system to track strains that persist in the poultry house and through the processing plant. Two farms, over four consecutive flocks, were studied. Multiple samples were taken of the poultry house environment, feed mill, transport crates, and carcasses in the processing plant. Sample collection on the farm took place on chick placement day, midgrowout, and the day of harvest. This study found that 80.3% of isolates belonged to a single strain of Salmonella Kentucky that persisted in several environmental samples for all flocks at both farms, from chick placement day to the final product at the plant. Surgical shoe covers produced most isolates (n = 26), and processing day yielded the highest recovery (n = 68). Additional serotypes were recovered, but the Salmonella Kentucky-positive eggshells and chick mortality appeared to be the source of the organism for both farms. All Campylobacter isolates recovered were identified as C. jejuni. Most Campylobacter isolates (90.1%) belonged to one of three core strains. C. jejuni was not recovered on chick placement day. Cecal droppings yielded all nine strains. Most isolates (98.2%) were from one farm. Cluster analysis grouped C. jejuni and Salmonella isolates into four and six distinct clusters, respectively, on the basis of a similarity level of 80%.

Animal Husbandry↗

PubMed2002

Major histocompatibility complex effect on cellulitis among different chicken lines.

The chicken major histocompatibility complex (MHC) has been implicated in conferring resistance/susceptibility to several bacterial, parasitic, and viral diseases. Investigators have shown that the chicken MHC plays a major role in determining the outcome of a Marek's disease infection, in that standard B(13) is susceptible to the virus while B(21) confers resistance to the virus. Previous work with a broiler line has shown that B(21) is susceptible to an Escherichia coli-induced cellulitis infection and that B(13) conferred resistance to the infection. For this experiment, a broiler and a Leghorn chicken line shown to contain standard B(13) and B(21) were examined in a challenge model for cellulitis. The birds were challenged with a cellulitis-causing E. coli isolate. Homozygous B(21) had the highest incidence of cellulitis development compared with either homozygous B(13) or the heterozygous B(13)/B(21) for both the broiler and Leghorn lines. Additionally, cellulitis lesion severity was measured in both lines and shown to be independent of MHC type.

Animals↗

PubMedDate not supplied

Evaluation of scratches as an essential element in the development of avian cellulitis in broiler chickens.

Currently, the published cellulitis models do not adequately address the actual pathogenesis as seen in the commercial broiler industry. In this model, small dermal scratches were made on the skin of broiler chickens, which were then placed on litter seeded with avian cellulitis-associated Escherichia coli. The research confirms scratches are required for the induction of avian cellulitis. The research also confirms that "type I" cellulitis lesions or those previously thought to be due to hatchery-borne infections can be induced with scratches. The described methods provide a realistic model for cellulitis development that will improve the reliability of prophylactic and therapeutic-regimen efficacy testing data, thereby providing information more directly useful to the commercial broiler industry.

Animal Husbandry↗

PubMedDate not supplied

The effect of vitamin E on cellulitis in broiler chickens experiencing scratches in a challenge model.

Two experiments are described; each experiment contained five treatments with each treatment consisting of a specific diet and vitamin E at 8.82 mg, 41.89 mg, 74.96 mg, 108.03 mg, or 141.10 mg vitamin E per kilogram of feed. Birds were raised with continuous feed containing the various levels of vitamin E available throughout the experiment. At 4 wk of age, the birds were scratched on the breast and placed onto avian cellulitis Escherichia coli-seeded litter. One week later, the birds were euthanatized and lesion presence was noted. There appeared to be a positive correlation between vitamin E and the inhibition of cellulitis formation when the birds were fed a diet containing 74.96 mg vitamin E/kg feed. Conflicting results were seen in the two experiments when the birds were fed 41.89 and 108.03 mg vitamin E/kg feed. Both experiments had a high incidence of cellulitis in birds whose diets consisted of 141.10 mg vitamin E/kg feed.

Animals↗

PubMedDate not supplied

Differences in the pathogenicity of various bacterial isolates used in an induction model for gangrenous dermatitis in broiler chickens.

A gangrenous dermatitis model was developed in broiler chickens, in which birds previously vaccinated at 14 days of age with a bursal disease virus vaccine were challenged at 4 wk of age with various bacterial combinations with the combination of subcutaneous and intramuscular injection. Gangrenous dermatitis lesions were not produced in birds injected with one of the Staphylococcus aureus isolates, either alone or in combination with various Clostridium septicum isolates. Other S. aureus isolates produced significant levels of gangrenous dermatitis either alone or in combination with the same C. septicum isolates. These same C. septicum isolates when given alone did not produce gangrenous lesions. Data from this experiment show the highest level of mortality occurred in birds challenged with a mixture of C. septicum and S. aureus isolates, whereas lower or no mortality was associated with the same isolates given separately. The data clearly demonstrate that the pathogenicity of isolates responsible for gangrenous dermatitis varies widely, indicating that the frequency and severity of lesion production, as well as the occurrence of mortality, are largely dependent upon the specific isolate or isolates with which the birds are challenged.

Administration, Cutaneous↗