Design and Validation of RT-PCR Assays to Differentiate Vaccine Strains from Wild-Type Field Isolates.

The timely differentiation of the AviPro Salmonella VAC T and VAC E strains from the wild-type ser. Typhimurium and ser. Enteritidis isolates is crucial for effectively monitoring veterinary isolates.

Early vaccination of laying hens with the live bivalent vaccine AviPro™ Salmonella DUO results in successful vaccine uptake and increased gut colonization.

Introduction: Enteritidis and Typhimurium are the two most clinically important zoonotic serovars and vaccination of breeding and laying hens affords effective control. The use of live vaccines has proven beneficial for a number of reasons, including ease of application, protection from the first day of life onwards and initiation of a strong local immune response. Live vaccines can be applied in the drinking water from the first day of life onwards, but some rearers choose to wait until the end of the first week to ensure sufficient water consumption.

Outbreak of Shiga toxin-producing O157:H7 linked to raw drinking milk resolved by rapid application of advanced pathogen characterisation methods, England, August to October 2017.

An outbreak of Shiga toxin-producing (STEC) O157:H7 occurred on the Isle of Wight between August and October 2017. Of the seven cases linked to the outbreak, five were identified through the statutory notification process and two were identified through national surveillance of whole genome sequencing data. Enhanced surveillance questionnaires established a common link to a farm, and link to the likely food vehicle, raw drinking milk (RDM).

Observations on the distribution and persistence of monophasic Salmonella Typhimurium on infected pig and cattle farms.

Following a rapid rise in cases of monophasic Salmonella Typhimurium DT193 (mST) in humans and pigs since 2007 a detailed study of the prevalence and persistence of mST on pig and cattle farms in Great Britain (GB) was undertaken. Thirteen commercial pig farms and twelve cattle farms, identified as mST-positive from surveillance data, were intensively sampled over a three year period. Five indoor and eight outdoor pig farms and four beef and eight dairy farms were included.

Estimation of the sensitivity of various environmental sampling methods for detection of Salmonella in duck flocks.

Reports of Salmonella in ducks in the UK currently rely upon voluntary submissions from the industry, and as there is no harmonized statutory monitoring and control programme, it is difficult to compare data from different years in order to evaluate any trends in Salmonella prevalence in relation to sampling methodology. Therefore, the aim of this project was to assess the sensitivity of a selection of environmental sampling methods, including the sampling of faeces, dust and water troughs or bowls for the detection of Salmonella in duck flocks, and a range of sampling methods were applied to 67 duck flocks. Bayesian methods in the absence of a gold standard were used to provide estimates of the sensitivity of each of the sampling methods relative to the within-flock prevalence.

A study of the dynamics of Salmonella infection in turkey breeding, rearing and finishing houses with special reference to elimination, persistence and introduction of Salmonella.

In this descriptive study, the dynamics of Salmonella infection of turkey flocks were investigated by repeated sampling of houses where Salmonella had been identified. The aim of the study was to identify the most common scenarios involved in elimination, persistence and introduction of Salmonella in the different branches of the turkey industry. Sixty-two houses on 34 turkey farms (comprising breeding, rearing and finishing farms) were sampled longitudinally, starting with the identification of a positive flock.

Distribution of Cryptosporidium species in sheep in the UK.

There have been few studies of the distribution of Cryptosporidium species and genotypes in sheep, and the anthropozoonotic potential has been questioned since one of the major human pathogens, Cryptosporidium parvum, is not always found. To investigate the situation in the UK we undertook three studies: a reactive sampling programme of flocks identified as exposures for human cases of cryptosporidiosis; investigation of neonatal cryptosporidiosis in lambs; and a screening programme of lambs at an open farm. C.