. The molecular divergence and geographically unique origin lead us to believe that this organism should be considered a novel species. Therefore, we have proposed the name "Orientia chuto," and the prototype strain of this species is strain Dubai, named after the location in which the patient was infected.

c Recent reports in North America and Europe of Clostridium difficile being isolated from livestock and retail meats of bovine origin have raised concerns about the risk to public health. To assess the situation in Australia, we investigated the prevalence and genetic diversity of C. difficile in adult cattle and calves at slaughter. Carcass washings, gastrointestinal contents, and feces were collected from abattoirs across five Australian states. Selective culture, toxin profiling, and PCR ribotyping were performed. The prevalence of C. difficile was 56% (203/360 samples) in feces from <7-day-old calves, 3.8% (1/26) in 2-to 6-month-old calves, and 1.8% (5/280) in adult cattle. Three PCR ribotypes (RTs), RT127, RT033, and RT126, predominated in <7-day-old calves and comprised 77.8% (158/203 samples) of isolates. RT056, which has not been reported in cattle before, was found in 16 <7-day-old calves (7.7%). Surprisingly, RT078 strains, which dominate production animal carriage studies in the Northern Hemisphere, were not isolated.

The ability of a newly identified probiotic lactic acid bacterial strain, Bifidobacterium lactis (HN019), to confer protection against Salmonella typhimurium was investigated in BALB/c mice. Feeding mice with B. lactis conferred a significant degree of protection against single or multiple oral challenge with virulent S. typhimurium, in comparison to control mice that did not receive B. lactis. Protection included a ten-fold increase in survival rate, significantly higher post-challenge food intake and weight gain, and reduced pathogen translocation to visceral tissues (spleen and liver). Furthermore, the degree of pathogen translocation showed a significant inverse correlation with splenic lymphocyte proliferative responses to mitogens, blood and peritoneal cell phagocytic activity and intestinal mucosal anti-S. typhimurium antibody titers in infected mice; all of these immune parameters were enhanced in mice fed B. lactis. Together, these results suggest that dietary B. lactis can provide a significant degree of protection against Salmonella infection by enhancing various parameters of immune function that are relevant to the immunological control of salmonellosis. Thus dietary supplementation with B. lactis provides a unique opportunity for developing immune-enhancing probiotic dairy food products with proven health benefits.

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of poultry movements and trading activities. In particular, our models found that higher number of 36 broiler flocks in the village increased the risk (OR = 1.49, 95% CI: 1.12-1.96), as well as the village 37 having at least one poultry trader (OR =11.53, 95% CI: 1.34-98.86). To a lesser extent, in one of our 2 38 models, we also identified that increased density of ponds and streams, commonly used for waterfowl 39 production, and greater number of duck flocks in the village also increased the risk. The higher 40 percentage of households keeping poultry, as an indicator of households keeping backyard poultry in 41 our study population, was a protective factor (OR= 0.95,. At the farm level, 3 risk 42 factors at the 5% level of type I error were identified by univariate analysis: a greater total number of 43 birds (P=0.006), and increase in the number of flocks having access to water (p=0.027, and a greater 44 number of broiler flocks in the farm (P=0.049). Effect of vaccination implementation (date and doses) 45 was difficult to investigate due to a poor recording system. Some protective or risk factors with limited 46 effect may not have been identified due to our limited sample size. Nevertheless, our results provide a 47 better understanding of local transmission mechanisms of HPAI H5N1 in one province of the Red 48 River Delta region in Vietnam and highlight the need to reduce at-risk trading and production 49 practices. 50

The duration of infection and pulsed-field gel electrophoresis (PFGE) types of bovine intramammary Streptococcus uberis isolates were examined. Milk samples were collected in duplicate from all 4 glands of 503 cows from 5 herds within 1 to 3 d of parturition and from 113 cows with clinical mastitis in the same herds throughout lactation. Glands from which S. uberis was isolated were resampled at 28-d intervals.The prevalence of S. uberis was 12% for cows around parturition, and the median duration of infection was 16 d. Cows >2 yr old had a longer duration of infection than 2 yr old cows, and duration varied among herds. A total of 173 different PFGE types were identified from a total of 234 S. uberis isolates. Each farm had a unique set of PFGE types. Only 3 PFGE types were common to each of 3 pairs of cows, and these occurred on the same farm. Where S. uberis was isolated on more than one occasion from a gland, only 55% of the PFGE types were the same across time. For cows with multiple glands infected, only one-half (9 of 18) had the same PFGE type in more than one gland. No predominant PFGE type was identified in any herd. It is concluded that there was wide heterogeneity of PFGE types, that the environment rather than other cows was the likely source of S. uberis infections, and that glands may be infected with multiple S. uberis PFGE types over a lactation.

Important features of this disease are its high morbidity and mortality within a flock or herd, rapid local spread and its role as an occupational, health and safety risk to farm workers and their families.