Spectinomycin Sulfate Tetrahydrate

The efficacy of the turkey herpesvirus (HVT) vaccine in protecting chickens challenged with virulent Marek's disease (MD) virus was unaffected by the presence of either the chick embryo fowl pox vaccine or fowl pox vaccine derived from cell culture. Conversely the HVT vaccine did not affect the efficacy of the fowl pox vaccine in chickens challenged with pathogenic fowl pox virus. A combination of spectinomycin dihydrochloride pentahydrate and lincomycin hydrochloride monohydrate as well as spectinomycin sulfate tetrahydrate were found to be compatible with the HVT and fowl pox vaccines as demonstrated by resistance after challenge with virulent MD virus or fowl pox virus.

A pneumatic vaccinator has been successfully used to administer cell-associated turkey herpesvirus (HVT) vaccine without a loss in titer due to the pressure required to administer the vaccine. Laboratory studies have also shown that chickens vaccinated with graded doses of the HVT vaccine using doses as low as 41 PFU offered protection against Marek's disease (MD) when compared to the unvaccinated controls. The pneumatic vaccinator has also been successful in administering a combination of HVT vaccine and tissue culture fowl pox vaccine. Vaccinated birds were protected against challenge with virulent MD virus as well as fowl pox virus. Antibiotics such as spectinomycin pentahydrate or lincomycin hydrochloride monohydrate and spectinomycin sulfate tetrahydrate were used in combination with the HVT and fowl pox vaccine and none of the antibiotics appear to have an adverse effect on the efficacy of either vaccine.

Salmonella represents a major challenge to the pig industry, as pork presents a risk for human salmonellosis. In this study, we have examined the effect of farm type on the prevalence of fattening pigs shedding Salmonella on 12 farms at risk for harboring Salmonella. On six open (grow-to-finish) and six closed (farrow-to-finish) farms, the prevalence of pigs shedding Salmonella was determined on two occasions approximately 2 months apart. The serovar, phage type, and antimicrobial resistance of the obtained Salmonella isolates were determined. On all farms, pigs shedding Salmonella were detected on at least one of the two sampling days. The mean within-herd prevalence was 7.8%. Closed farms were two times less likely to have pigs shedding Salmonella than open farms. On open farms, the odds of finding Salmonella shedding in pigs were 1.9 times higher when sampling was performed at slaughter age than when samples were taken halfway through the fattening period. Salmonella enterica serovar Typhimurium was the most predominant serotype, with a prevalence of 62 to 63% on both farm types. Of all the Salmonella Typhimurium isolates, 65% had the tetraresistant profile ASSuT (ampicillin, streptomycin, sulfonamide, and tetracycline) with or without additional resistance to trimethoprim-sulfonamide. Phage type DT120 seemed to be especially associated with this antimicrobial-resistant profile. The prevalence of Salmonella Typhimurium isolates showing resistance to ampicillin, streptomycin, tetracycline, sulfonamide, trimethoprim-sulfonamide, and lincomycin hydrochloride and spectinomycin sulfate tetrahydrate was significantly higher on open farms than on closed farms.