Survey of Infectious Etiologies of Bovine Abortion during Mid- to Late Gestation in Dairy Herds.

Bovine abortion of unknown infectious etiology still remains a major economic problem. Thus, we investigated whether Brucella spp., Listeria monocytogenes, Salmonella spp., Campylobacter spp. and Coxiella burnetii are associated with abortion and/or stillbirth in Tunisian dairy cattle. Using a pan-Chlamydiales PCR, we also investigated the role of Chlamydiaceae, Waddlia chondrophila, Parachlamydia acanthamoebae and other members of the Chlamydiales order in this setting. Veterinary samples taken from mid to late-term abortions from twenty dairy herds were tested. From a total of 150 abortion cases collected, infectious agents were detected by PCR in 73 (48.66%) cases, 13 (8.66%) of which represented co-infections with two infectious agents. Detected pathogens include Brucella spp (31.3%), Chlamydiaceae (4.66%), Waddlia chondrophila (8%), Parachlamydia acanthamoebae (5.33%), Listeria monocytogenes (4.66%) and Salmonella spp. (3.33%). In contrast, Campylobacter spp. and Coxiella burnetii DNA were not detected among the investigated veterinary samples. This demonstrates that different bacterial agents may cause bovine abortion in Tunisia. This is the first report suggesting the role of Parachlamydia acanthamoebae in bovine abortion in Africa. Further studies with a larger number of samples are necessary to confirm whether this emerging pathogen is directly linked to abortion in cattle.

Infectious Intestinal Diseases on the Island of Ireland

It is increasingly recognised that the burden of infectious intestinal diseases (IID) in a population is an important indicator of food safety. This report has examined four bacterial infections that frequently cause IID on the island of Ireland (IOI). Over the decade covered by this report, levels of Salmonella have declined substantially while levels of Campylobacter remain a real problem for Food Safety professionals on the IOI. Although much less common, the verocytotoxigenic Escherichia coli O157 (VTEC O157) and Listeria infections present an on-going challenge because of their severity and associated long-term sequelae. Northern Ireland (NI) has a higher reported crude incidence rate of three of the included pathogens (Salmonella, Campylobacter and Listeria) than the Republic of Ireland (ROI), while VTEC 0157 was the exception. This may reflect differences in health seeking behaviour and reporting between the two jurisdictions and/or actual differences in incidence rates.

An Assessment of the Microbiology of Hand Contact Surfaces in the Retail Environment

This study aimed to assess the microbiology of food and hand contact surfaces in the retail environment and the potential for these surfaces to act as vehicles for the spread of foodborne pathogens. During the survey, 10 stores in the Republic of Ireland (ROI) were visited by student Environmental Health Officers (EHOs) who took swab samples from four surfaces: conveyor belts, long-life shopping bags, shopping trolley handles and keypads on card payment units. The swab samples were examined for the presence of the pathogens Salmonella, Campylobacter and Listeria. The Aerobic Colony Counts, as well as the levels of E. coli and Enterobacteriaceae, were also determined. In addition, structured questionnaires were used with retailers to establish the stores’ regimes for the cleaning of conveyor belts. Similarly, shoppers donating their long-life shopping bags for sampling were questioned about how they normally use these bags, and the results were compared with those from the microbiological survey. The results indicated that the hygiene of the surfaces sampled was good, with Salmonella, Campylobacter and Listeria not detected in any of the samples, and levels of both Enterobacteriaceae and E. coli were below the limits of detection in all but one sample. Aerobic Colony Counts varied but none of the results obtained would be deemed ‘unacceptable’ or ‘unsatisfactory’ under guidelines for ready-to-eat foods

Engineering, conjugation, and immunogenicity assessment of Escherichia coli O121 O antigen for its potential use as a typhoid vaccine component.

State-of-the-art production technologies for conjugate vaccines are complex, multi-step processes. An alternative approach to produce glycoconjugates is based on the bacterial N-linked protein glycosylation system first described in Campylobacter jejuni. The C. jejuni N-glycosylation system has been successfully transferred into Escherichia coli, enabling in vivo production of customized recombinant glycoproteins. However, some antigenic bacterial cell surface polysaccharides, like the Vi antigen of Salmonella enterica serovar Typhi, have not been reported to be accessible to the bacterial oligosaccharyltransferase PglB, hence hamper development of novel conjugate vaccines against typhoid fever. In this report, Vi-like polysaccharide structures that can be transferred by PglB were evaluated as typhoid vaccine components. A polysaccharide fulfilling these requirements was found in Escherichia coli serovar O121. Inactivation of the E. coli O121 O antigen cluster encoded gene wbqG resulted in expression of O polysaccharides reactive with antibodies raised against the Vi antigen. The structure of the recombinantly expressed mutant O polysaccharide was elucidated using a novel HPLC and mass spectrometry based method for purified undecaprenyl pyrophosphate (Und-PP) linked glycans, and the presence of epitopes also found in the Vi antigen was confirmed. The mutant O antigen structure was transferred to acceptor proteins using the bacterial N-glycosylation system, and immunogenicity of the resulting conjugates was evaluated in mice. The conjugate-induced antibodies reacted in an enzyme-linked immunosorbent assay with E. coli O121 LPS. One animal developed a significant rise in serum immunoglobulin anti-Vi titer upon immunization.

Immunopathology of giardiasis: the role of lymphocytes in intestinal epithelial injury and malfunction

T lymphocyte-mediated pathogenesis is common to a variety of enteropathies, including giardiasis, cryptosporidiosis, bacterial enteritis, celiac's disease, food anaphylaxis, and Crohn's disease. In giardiasis as well as in these other disorders, a diffuse loss of microvillous brush border, combined or not with villus atrophy, is responsible for disaccharidase insufficiencies and malabsorption of electrolytes, nutrients, and water, which ultimately cause diarrheal symptoms. Other mucosal changes may include crypt hyperplasia and increased infiltration of intra-epithelial lymphocytes. Recent studies using models of giardiasis have shed new light on the immune regulation of these abnormalities. Indeed, experiments using an athymic mouse model of infection have found that these epithelial injuries were T cell-dependent. Findings from further research indicate that that the loss of brush border surface area, reduced disaccharidase activities, and increase crypt-villus ratios are mediated by CD8+ T cells, whereas both CD8+ and CD4+ small mesenteric lymph node T cells regulate the influx of intra-epithelial lymphocytes. Future investigations need to characterize the CD8+ T cell signaling cascades that ultimately lead to epithelial injury and malfunction in giardiasis and other malabsorptive disorders of the intestine.

Production, characterization, and application of antibodies against heat-labile type-I toxin for detection of enterotoxigenic Escherichia coli

Strains of enterotoxigenic Escherichia coli (ETEC) are responsible for significant rates of morbidity and mortality among children, particularly in developing countries. The majority of clinical and public health laboratories are capable of isolating and identifying Salmonella, Shigella, Campylobacter, and Escherichia coli O157:H7 from stool samples, but ETEC cannot be identified by routine methods. The method most often used to identify ETEC is polymerase chain reaction for heat-stable and heat-labile enterotoxin genes, and subsequent serotyping, but most clinical and public health laboratories do not have the capacity or resources to perform these tests. In this study, polyclonal rabbit and monoclonal mouse IgG2b antibodies against ETEC heat-labile toxin-I (LT) were characterized and the potential applicability of a capture assay was analyzed. IgG-enriched fractions from rabbit polyclonal and the IgG2b monoclonal antibodies recognized LT in a conformational shape and they were excellent tools for detection of LT-producing strains. These findings indicate that the capture immunoassay could be used as a diagnostic assay of ETEC LT-producing strains in routine diagnosis and in epidemiological studies of diarrhea in developing countries as enzyme linked immunosorbent assay techniques remain as effective and economical choice for the detection of specific pathogen antigens in cultures.

Helicobacter pylori transiently in the mouth may participate in the transmission of infection

Helicobacter pylori infection is associated with peptic ulcer and gastric carcinoma. The oral cavity may be a reservoir for H. pylori; however, the results of studies on this subject are controversial. We employed single-step and nested polymerase chain reactions (PCR) to detect the presence of the vacA, ureA and 16S rDNA genes of H. pylori in the stomach, saliva and dental plaque of 30 subjects. The results were confirmed by sequencing. Nested 16S rDNA and ureA amplification was achieved in 80% of gastric, 30% of saliva and 20% of dental plaque specimens. Sequencing of 10, seven and four 16S rDNA products from stomach, saliva and dental plaque, respectively, showed > 99% identity with H. pylori. Sequencing of the other four oral cavity PCR products showed similarity with Campylobacter and Wolinella species. Additionally, the vacA genotype identified in the samples of different sites was the same within a given subject.H. pylori may be found in the oral cavity of patients with gastric infection, thus it could be a source of transmission. However, results obtained with detection methods based only on PCR should be interpreted with caution because other microorganisms that are phylogenetically very close to H. pylori are also present in the mouth.

Maladies infectieuses en pratique ambulatoire (sauf sida) [Infectious diseases (beside AIDS)]

A simplified version of the US guidelines for prophylaxis of infectious endocarditis was published in 2007. Changes are expected in Switzerland as well. Posaconsole is a new antifungal agent available mostly for prophylaxis in immunocompromised patients. Epidemiology of sexually transmitted infections warrants screening in young adults and after one episode. A meta-analysis clarified the impact of antibiotic therapy in patients with Campylobacter spp. infection. In the field of emerging diseases, we discuss Norovirus epidemics, community-acquired bacteria producing extended-spectrum betalactamases, extensively resistant tuberculosis, and new respiratory viruses. Finally, we address a basic research topic that may change practice in the future: the relationship between individual susceptibility to infection and innate immunity.

Cloning and characterization of Helicobacter pylori succinyl CoA:acetoacetate CoA-transferase, a novel prokaryotic member of the CoA-transferase family.

Sequencing of a fragment of Helicobacter pylori genome led to the identification of two open reading frames showing striking homology with Coenzyme A (CoA) transferases, enzymes catalyzing the reversible transfer of CoA from one carboxylic acid to another. The genes were present in all H. pylori strains tested by polymerase chain reaction or slot blotting but not in Campylobacter jejuni. Genes for the putative A and B subunits of H. pylori CoA-transferase were introduced into the bacterial expression vector pKK223-3 and expressed in Escherichia coli JM105 cells. Amino acid sequence comparisons, combined with measurements of enzyme activities using different CoA donors and acceptors, identified the H. pylori CoA-transferase as a succinyl CoA:acetoacetate CoA-transferase. This activity was consistently observed in different H. pylori strains. Antibodies raised against either recombinant A or B subunits recognized two distinct subunits of Mr approximately 26,000 and 24, 000 that are both necessary for H. pylori CoA-transferase function. The lack of alpha-ketoglutarate dehydrogenase and of succinyl CoA synthetase activities indicates that the generation of succinyl CoA is not mediated by the tricarboxylic acid cycle in H. pylori. We postulate the existence of an alternative pathway where the CoA-transferase is essential for energy metabolism.

Prevalence of Inflammatory Bowel Disease in the Canton of Vaud (Switzerland): A population-based cohort study

Background and aims: Because of the changing epidemiology of Inflammatory Bowel Diseases 0131)), we set out to characterize the population-based prevalence of Crohn's Disease (CD) and Ulcerative Colitis (UC) in a defined population of Switzerland. Methods: Adult IBD patients were identified by a cross-matched review of histological, hospital and gastroenterologist files throughout a geographical defined population (Canton of Vaud). Demographic factors statistically significantly associated with prevalence were evaluated using a stepwise Poisson regression analysis. Results were compared to IBD prevalence rates in other population-based studies and time trends were performed, based on a systematic literature review. Results: Age and sex-adjusted prevalence rates were 205.7 IBD (100.7 CD and 105.0 UC) cases per 105 inhabitants. Among 1016 IBD patients (519 CD and 497 UC), females outnumbered mates in CD (p < 0.001), but mates were more represented in elderly UC patients (p = 0.008). Thus, being a mate was statistically associated with UC (Relative Risk (RR) 1.25; p = 0.013), whereas being a female was associated with CD (RR 1.27; p = 0.007). Living in an urban zone was associated with both CD and UC (RR 1.49; p < 0.001, 1.63; p < 0.001, respectively). From 1960 to 2005, increases in UC and CD prevalences of 2.4% (95%CI, 2.1%-2.8%; p < 0.001) and 3.6% (95%CI, 3.1%-4.1%; p < 0.001) per annum were found in industrialised countries.

Madot tappoivat suden Hämeessä : kuolemaan johtanut Alaria sp. -imumatoinfektio sudella

Summary: Alaria sp. causing fatal enteritis in a wolf

Les infections endo-artérielles, complications redoutables des infections à salmonelles non typhi [Endarterial infections, redoubtable complications of non-typhi salmonella infections].

Three cases are reported of salmonella aortitis observed in three men aged 55, 60 and 48 years, the last of whom had a prosthetic aortic valve and ascending aorta. The microorganisms were S. typhi murium, S. paratyphi B, and S. wien. Despite antibiotic treatment two patients died of perforating aortitis. The third patient developed S. wien gastroenteritis a few days after surgical replacement of the aortic valve and the ascending aorta. Five years later he presented with several bacteremic episodes due to S. wien, which recurred despite several courses of cotrimoxazole treatment. He has now been asymptomatic for over one year under prolonged cotrimoxazole treatment. Since vascular infection may occur following non typhi salmonellosis in 5% of patients over 50, or who have underlying endothelial lesions, the question arises as to whether non typhi S. gastroenteritis should be treated with antibiotics in these high risk patients, in contrast to present recommendations.

Chlamydiaceae and Chlamydia-like organisms in the koala (Phascolarctos cinereus)--organ distribution and histopathological findings.

Chlamydial infections in koalas can cause life-threatening diseases leading to blindness and sterility. However, little is known about the systemic spread of chlamydiae in the inner organs of the koala, and data concerning related pathological organ lesions are limited. The aim of this study was to perform a thorough investigation of organs from 23 koalas and to correlate their histopathological lesions to molecular chlamydial detection. To reach this goal, 246 formalin-fixed and paraffin embedded organ samples from 23 koalas were investigated by histopathology, Chlamydiaceae real-time PCR and immunohistochemistry, ArrayTube Microarray for Chlamydiaceae species identification as well as Chlamydiales real-time PCR and sequencing. By PCR, two koalas were positive for Chlamydia pecorum whereas immunohistochemical labelling for Chlamydiaceae was detected in 10 tissues out of nine koalas. The majority of these (n=6) had positive labelling in the urogenital tract related to histopathological lesions such as cystitis, endometritis, pyelonephritis and prostatitis. Somehow unexpected was the positive labelling in the gastrointestinal tract including the cloaca as well as in lung and spleen indicating systemic spread of infection. Uncultured Chlamydiales were detected in several organs of seven koalas by PCR, and four of these suffered from plasmacytic enteritis of unknown aetiology. Whether the finding of Chlamydia-like organisms in the gastrointestinal tract is linked to plasmacytic enteritis is unclear and remains speculative. However, as recently shown in a mouse model, the gastrointestinal tract might play a role being the site for persistent chlamydial infections and being a source for reinfection of the genital tract.

Loss of intestinal epithelial barrier function in Salmonella Enteritidis infection

Intestinal infection with Salmonella enterica serotype Enteritidis, a food-borne infection spread to humans especially through contaminated eggs and egg-products as well as undercooked contaminated fresh meat, is the most common cause of intestinal inflammation in the European Union. Enteritis caused by Salmonella Enteritidis is characterized by fever, diarrhoea and abdominal pain. The disruption of the intestinal epithelial barrier function contributes to diarrhoea and is responsible for the perpetuation of the inflammatory process. In this sense, oxidative stress and the proinflammatory cytokines TNF-α, IFN-γ and IL-1β are described to induce the disorganization of the tight junctions (TJ), the most apical epithelial intercellular junctions and responsible for the paracellular permeability. The interest of this chapter relies not only in the investigation dealing with the mechanisms of TJ regulation but also in the contribution to the development of new tools for the prevention of epithelial barrier disruption in enteritis caused by Salmonella Enteritidis.

Histological changes caused by experimental Riedeliella graciliflora (Leg. Papilionoideae) poisoning in cattle and laboratory animals

Tissues from cattle, mice, rats and guinea pigs experimentally intoxicated by Riedeliella graciliflora were studied histologically. Cattle lymph nodes, spleen, Peyer patches and peribronchial lymphoid tissues had diffuse necrosis of lymphocytes, mainly in the germinal centers of the follicles. This lesion was less severe in laboratory animals. All species had severe enteritis with infiltration of the lamina propria by mononuclear cells. Some cells in this infiltrate were necrotic. Degeneration and necrosis of the epithelial cells, mainly in the tip of the villi, and detachment of the epithelial lining from the lamina propria were also observed. In the liver the trabecular structure was disrupted and the hepatocytes had some degree of individual necrosis and degeneration. A tubular nephrosis was observed in the kidneys. Liver, lung, kidney, intestine and lymph nodes had different degrees of congestion. Those lesions are similar than those caused by Polygala klotzschii, a plant that contains 5-metoxi-podophyllotoxin.