Dogs and Cats: Reservoirs for Highly Diverse Campylobacter jejuni and a Potential Source of Human Exposure.

Assessing the carriage of Campylobacter in animal reservoirs is essential to better understand Campylobacter epidemiology. Here, we evaluated the prevalence of thermophilic Campylobacter spp. in dogs and cats, hereafter defined as pets, and characterized Campylobacter jejuni (C. jejuni) isolates to assess their genetic diversity and their potential link with isolates from other animals or human cases. During a 6-month period, 304 feces samples were collected from pets. A significantly higher prevalence of thermophilic Campylobacter spp. was found in dogs compared with cats, as well as in dogs ≤ 1-year-old compared with older dogs. C. jejuni was the predominant species found in pets, and its genomic characterization revealed a high genetic diversity. Genotypes comparison with previously characterized isolates revealed a partial overlap between C. jejuni isolates from pets, chicken, cattle, and clinical cases. This overlap suggests the potential role of livestock and humans in pets' exposure to Campylobacter, or vice versa. The isolation of pets' specific profiles may suggest the existence of other sources of pet contamination or imply that pets may constitute a reservoir for Campylobacter. Because of the proximity between humans and pets, along with their frequent carriage of C. jejuni, human exposure to Campylobacter from pets can be more important than previously thought.

A representative overview of the genetic diversity and lipooligosaccharide sialylation in Campylobacter jejuni along the broiler production chain in France and its comparison with human isolates.

Campylobacter jejuni is the most common cause of bacterial gastroenteritis worldwide and is associated with post-infectious neuropathies. Moreover, the chicken reservoir is described as the main source of human infection and C. jejuni sialylated lipooligosaccharides seem to play an important role in the pathogenesis of neuropathies. In this study, MultiLocus Sequence Typing (MLST) and Comparative Genomic Fingerprinting using 40 assay genes (CGF40) were used to describe C. jejuni populations within clinical isolates and a representative collection of isolates from French poultry production. In addition, the sialylation of C. jejuni LOS was assessed. Here, we report high levels of genetic diversity among both chicken and human disease C. jejuni populations. The predominance of the ST-21, ST-45, and ST-464 complexes in chicken isolates and of the ST-21, ST-206, and ST-48 complexes in the clinical isolates was observed as were correlations between some MLST and CGF40 genotypes. Furthermore, some C. jejuni genotypes were frequently isolated among clinical cases as well as all along the broiler production chain, suggesting a potentially high implication of chicken in human campylobacteriosis in France. Finally, the LOS classes A, B and C were predominant within clinical C. jejuni isolates supporting the hypothesis of a benefit in infectivity for C. jejuni isolates showing sialylated LOS.

Effect of low dose of fumonisins on pig health: immune status, intestinal microbiota and sensitivity to Salmonella.

The objective of this study was to measure the effects of chronic exposure to fumonisins via the ingestion of feed containing naturally contaminated corn in growing pigs infected or not with Salmonella spp. This exposure to a moderate dietary concentration of fumonisins (11.8 ppm) was sufficient to induce a biological effect in pigs (Sa/So ratio), but no mortality or pathology was observed over 63 days of exposure. No mortality or related clinical signs, even in cases of inoculation with Salmonella (5 × 104 CFU), were observed either. Fumonisins, at these concentrations, did not affect the ability of lymphocytes to proliferate in the presence of mitogens, but after seven days post-inoculation they led to inhibition of the ability of specific Salmonella lymphocytes to proliferate following exposure to a specific Salmonella antigen. However, the ingestion of fumonisins had no impact on Salmonella translocation or seroconversion in inoculated pigs. The inoculation of Salmonella did not affect faecal microbiota profiles, but exposure to moderate concentrations of fumonisins transiently affected the digestive microbiota balance. In cases of co-infection with fumonisins and Salmonella, the microbiota profiles were rapidly and clearly modified as early as 48 h post-Salmonella inoculation. Therefore under these experimental conditions, exposure to an average concentration of fumonisins in naturally contaminated feed had no effect on pig health but did affect the digestive microbiota balance, with Salmonella exposure amplifying this phenomenon.

An experimental study of the survival of turkey coronavirus at room temperature and +4°C.

Turkey coronavirus (TCoV) is a gammacoronavirus (Coronaviridae, Nidovirales) responsible for digestive disorders in young turkeys. TCoV has been associated with poult enteritis complex, a syndrome that severely affects turkey production. No medical prophylaxis exists to control TCoV, therefore sanitary measures such as cleaning and disinfection are essential. It is thus important to evaluate temperatures that allow persistence of TCoV in the environment. Two series of aliquots of a suspension of a French isolate of TCoV (Fr TCoV) were stored at room temperature or +4°C for 0 to 40 days. As TCoV does not grow in cell culture, the presence of residual infectious TCoV in the stored samples was tested by inoculating embryonated specific pathogen free turkey eggs. As TCoV does not induce lesions in the embryo, virus replication in the jejunum and ileum of the embryos was detected 4 days post inoculation, using RNA extraction and a real-time reverse transcriptase-polymerase chain reaction based on the nucleocapsid gene. No surviving virus was detected after 10 days storage at +21.6±1.4°C or after 40 days storage at +4.1±1.6°C, these temperatures being representative of the mean summer and winter temperatures, respectively, in the major French poultry-producing region. The relatively short survival of the virus at room temperature should contribute to limited virus survival during summer months. However, infectious virus was still detected after 20 days storage at the cooler temperatures, a finding that suggests prolonged survival of Fr TCoV and easier transmission between poultry farms in a cool environment are possible.