Listeria monocytogenes contamination of finishing pigs: an exploratory epidemiological survey in France

Listeria monocytogenes is a foodborne pathogen of major concern for public health in industrialised countries. Since L. monocytogenes carriage by pigs at the herd level could be a primary source for carcass contamination, control measures should be designed to reduce the L. monocytogenes load at the pre-harvest stage. For this purpose, an exploratory analytical survey was carried out in 2000-2001 in 93 French farrow-to-finish pig farms concerning L. monocytogenes contamination in pigs before they left for the slaughterhouse. On each farm, the L. monocytogenes status of a batch of contemporary fattening pigs housed in the same room was assessed on faecal material samples taken by means of gauze swabs wiped on the perianal region of the pigs. Fourteen percent of the batches studied had at least one contaminated sample and were therefore classified as L. monocytogenes contaminated batches. Two logistic regression models were used to assess the association between managerial and hygiene practices and the risk of L. monocytogenes contamination of the batch at the end of the finishing period on the whole data set (n = 93) and in the wet feeding farms only (n = 57). Wet feeding during the fattening period was identified as a risk factor for L. monocytogenes contamination. Risk factors related to the introduction of L. monocytogenes in pig facilities were identified for both the general and wet feeding farm data sets. Poor care paid to hygiene on the farms was found to increase the risk of being infected (boots cleaning, change room presence). When the duration of the empty period prior to the introduction of growing pigs was less than one day in the fattening section, the risk of L. monocytogenes contamination was significantly increased. For wet feeding farms, a distribution pipeline cleaning procedure including disinfection was found to be associated with a higher risk of contamination than no cleaning or a procedure consisting of rinsing with water only.     

Keratinizing ameloblastoma in a 9-month-old llama (Lama glama).

A 9-month-old male llama (Lama glama) was presented because of a rapidly growing mass on the right side of the face. Radiographs revealed a marked expansion of the right caudal face region with bone lysis involving the maxilla and the nasal, lacrimal, zygomatic, and palatine bones. Cytologically, the mass consisted of atypical round to polygonal cells with round nuclei and basophilic cytoplasms that formed acini and rows. Histologically, the mass consisted of anastomosing cords and sheets of neoplastic odontogenic epithelial cells embedded in a loose fibrovascular connective tissue. Single layers of peripheral, polarized, palisading, columnar epithelial cells were seen at the edges of some cords. Within the centers of the cords, epithelial cells showed rapid progression to keratin production. The histologic diagnosis was keratinizing ameloblastoma. Ameloblastomas are neoplasms of odontogenic epithelium that tend to be locally aggressive and can cause substantial destruction of bony structures. Because ameloblastomas do not tend to metastasize, they can be successfully treated by complete surgical excision, performed before extensive bony destruction occurs. Ameloblastoma, although expected to be rare, should be onthe list of differential diagnoses for facial swelling in llamas.     

Aggressiveness and production of cell-wall degrading enzymes by Pythium violae, Pythium sulcatum and Pythium ultimum, responsible for cavity spot on carrots

This study investigated the relationships between pathogenesis, types of symptoms and in vitro production of cell-wall degrading enzymes by P. violae, P. sulcatum and P. ultimum. The three pathogens, considered as the three Pythium species principally responsible for cavity spot on carrot roots, secreted only low levels of fatty acid esterases activity, suggesting they have limited ability to degrade suberin in the walls of the outer cell layers of carrot tissues. Among the enzymes that degrade cell-wall polysaccharides, only pectate lyases and cellulases were produced by P. violae, and these were produced late and in small amounts: the symptoms caused by P. violae were limited and typical of cavity spot. Conversely, P. ultimum caused maceration of tissues, and secreted polygalacturonases and -1,4-glucanases earlier and in larger amounts than P. violae. P. ultimum also produced a large diversity of proteins and cellulase isoenzymes. Although secreting all the monitored enzymes in higher quantity than the two previous species, P. sulcatum was responsible for only typical limited symptoms of cavity spot, with a brown colouring. The role of plant reactions induced in response to early pectinolytic enzyme production by P. sulcatum may account for this apparent inconsistency.Died on April 11, 1997     

Mediastinal Schwannoma in a horse-cytologic,histologic, and immunochemical evaluation

A 31-kg mediastinal mass from a 24-year-old horse is described. Cytologic imprints contained numerous spindle cells with indistinct cytoplasm and multiple foci of palisading nuclei. Histologic sections had these same characteristics and areas of central fibrillar material between palisading nuclei (Verocay bodies). Within histologic sections, spindle cell cytoplasm had positive immunoreactivity for vimentin and S-100, whereas immunoreactivity was not detected for desmin and cytokeratin. Cytologic, histologic, and immunochemical evaluation confirmed a diagnosis of solitary schwannoma.     

An exploration of the drivers to bio-security collective action among a sample of UK cattle and sheep farmers

At present, collective action regarding bio-security among UK cattle and sheep farmers is rare. Despite the occurrence of catastrophic livestock diseases such as bovine spongiform encephalopathy (BSE) and foot and mouth disease (FMD), within recent decades, there are few national or local farmer-led animal health schemes. To explore the reasons for this apparent lack of interest, we utilised a socio-psychological approach to disaggregate the cognitive, emotive and contextual factors driving bio-security behaviour among cattle and sheep farmers in the United Kingdom (UK). In total, we interviewed 121 farmers in South-West England and Wales. The main analytical tools included a content, cluster and logistic regression analysis.The results of the content analysis illustrated apparent ‘dissonance’ between bio-security attitudes and behaviour.¹ Despite the heavy toll animal disease has taken on the agricultural economy, most study participants were dismissive of the many measures associated with bio-security. Justification for this lack of interest was largely framed in relation to the collective attribution or blame for the disease threats themselves. Indeed, epidemic diseases were largely related to external actors and agents. Reasons for outbreaks included inadequate border control, in tandem with ineffective policies and regulations. Conversely, endemic livestock disease was viewed as a problem for ‘bad’ farmers and not an issue for those individuals who managed their stock well. As such, there was little utility in forming groups to address what was largely perceived as an individual problem.Further, we found that attitudes toward bio-security did not appear to be influenced by any particular source of information per se. While strong negative attitudes were found toward specific sources of bio-security information, e.g. government leaflets, these appear to simply reflect widely held beliefs. In relation to actual bio-security behaviours, the logistic regression analysis revealed no significant difference between in-scheme and out of scheme farmers.We concluded that in order to support collective action with regard to bio-security, messages need to be reframed and delivered from a neutral source. Efforts to support group formation must also recognise and address the issues relating to perceptions of social connectedness among the communities involved.     

A molecular test to identify resistance alleles at the amplified esterase locus in the mosquito Culex pipiens

A new PCR/RFLP method is presented to identify all described alleles involved in resistance at the Ester locus in the mosquito Culex pipiens. The efficiency of this method as well as its advantages compared with the traditional identification technique (starch gel electrophoresis) have been tested in four natural samples from France, Tunisia and California. This simple and fast molecular test is a very convenient tool for studies in field populations and laboratory strains. © 2000 Society of Chemical Industry     

Evaluation of the Antibacterial and Prebiotic Potential of Ascophyllum nodosum and Its Extracts Using Selected Bacterial Members of the Pig Gastrointestinal Microbiota

Ascophyllum nodosum and its extracts are promising antibacterial and prebiotic dietary supplements for pigs. The objectives of this study were to evaluate the effects of the increasing concentrations of: (1) two whole biomass samples of A. nodosum with different harvest seasons, February (ANWB-F) and November (ANWB-N), in a weaned pig faecal batch fermentation assay, and (2) A. nodosum extracts produced using four different extraction conditions of a hydrothermal-assisted extraction methodology (ANE1–4) and conventional extraction methods with water (ANWE) and ethanol (ANEE) as solvent in individual pure culture growth assays using a panel of beneficial and pathogenic bacterial strains. In the batch fermentation assay, ANWB-F reduced Bifidobacterium spp. counts (p < 0.05) while ANWB-N increased total bacterial counts and reduced Bifidobacterium spp. and Enterobacteriaceae counts (p < 0.05). Of the ANE1–4, produced from ANWB-F, ANWE and ANEE that were evaluated in the pure culture growth assays, the most interesting extracts were the ANE1 that reduced Salmonella Typhimurium, enterotoxigenic Escherichia coli and B. thermophilum counts and the ANE4 that stimulated B. thermophilum growth (p < 0.05). In conclusion, the extraction method and conditions influenced the bioactivities of the A. nodosum extracts with ANE1 and ANE4 exhibiting distinct antibacterial and prebiotic properties in vitro, respectively, that merit further exploration.     

Samoan children's sense of place: Experiential landscapes in an urban village

Pacific Island communities are experiencing significant societal changes as a result of rural urban, inter‐island migration and migration to New Zealand. These relocations have significant implications for children's relationship to place. However, virtually nothing is known about children's sense of place in Samoa or places and activities that are important to them. This exploratory study worked with eight children aged 5–12 years growing up in an urban village in Samoa drawing on ‘Talanoa’ as research methodology and method by employing photo‐elicitation. The study provides a first snapshot of Samoan children's sense of place growing up in an urban village.