Influence of cereal non-starch polysaccharides on ileo-caecal and rectal microbial populations in growing pigs

The effect of cereal non-starch polysaccharides (NSP) on the gut microbial populations was studied in 5 growing pigs between 39-116 kg body weight according to a Latin square design. The diets were composed to contain different NSP levels. The control diet had a normal NSP content (139 g/kg dry matter (DM)), 2 diets had a low total amount of NSP (95 and 107 g/kg DM) and 2 diets had a high amount of total NSP (191 and 199 g/kg DM). Furthermore, one of the diets within each category had a content of insoluble NSP similar to the control diet and one had a high content of insoluble NSP. Samples were collected from the ileum, via intestinal post valve T-caecum (PVTC) cannulas surgically inserted at the ileo-caecal ostium, and from the rectum. The total microbial flora of the ileal samples were analysed for by defining base pair length with terminal restriction fraction length polymorphism (T-RFLP). The microbial diversity of the coliform flora of the ileal and rectal samples were defined by biochemical fingerprinting. It was observed that many terminal restriction fragments (TRFs) disappeared when new diets were introduced and that some characteristic TRFs were found in the high and low NSP diets, respectively. Both the total gut microflora and the coliform flora were influenced by the dietary NSP content.     

Interferon-gamma response of PBMC indicates productive pseudorabies virus (PRV) infection in swine

In Chinese Meishan/German Landrace cross-bred swine F2 generation interferon gamma (IFN-gamma) production by peripheral blood mononuclear cells (PBMC) was determined directly ex vivo at different time points after survival of a virulent pseudorabies virus (PRV) infection. This reactivity was compared with the reactivity of na?ve PBMC. Significant IFN-gamma production was determined in ELISA and ELISPOT only after in vitro PBMC re-stimulation with PRV and not with the closely related bovine herpesvirus BHV-1. The PRV-specific IFN-gamma secretion from re-stimulated PBMC showed high levels 6 days after infection, before the presence of serum antibodies, and it persisted at a high level over a 3 months period. The response of a group of eight piglets infected intranasally with PRV varied. Only two animals showed the expected typical fever response. PRV specific IFN-gamma production by PBMC clearly indicated that infection had occurred. Early significant IFN-gamma production by primed PBMC turned out to be a reliable and specific ex vivo marker for cellular response against productive PRV infection in swine before antibody formation.     

Rough vaccines in animal brucellosis: structural and genetic basis and present status

Brucellosis control and eradication requires serological tests and vaccines. Effective classical vaccines (S19 in cattle and Rev 1 in small ruminants), however, induce antibodies to the O-polysaccharide of the lipopolysaccharide which may be difficult to distinguish from those resulting from infection and may thus complicate diagnosis. Rough attenuated mutants lack the O-polysaccharide and would solve this problem if eliciting protective immunity; the empirically obtained rough mutants 45/20 and RB51 have been used as vaccines. Strain 45/20 is reportedly unstable and it is not presently used. RB51 is increasingly used instead of S19 in some countries but it is rifampicin resistant and its effectiveness is controversial. Some controlled experiments have found good or absolute protection in adult cattle vaccinated orally (full dose) or subcutaneously (reduced dose) and in one field experiment, RB51 was reported to afford absolute protection to calves and to perform better than S19. Controlled experiments in calves, however, have shown reduced doses of RB51 to be ineffective, full doses only partially effective, and RB51 less effective than S19 against severe challenges. Moreover, other observations suggest that RB51 is ineffective when prevalence is high. RB51 is not useful in sheep and evidence in goats is preliminary and contradictory. Rough mutants obtained by molecular biology methods on the knowledge of the genetics and structure of Brucella lipopolysaccharide may offer alternatives. The B. abortus manBcore (rfbK) mutant seems promising in cattle, and analyses in mice suggest that mutations affecting only the O-polysaccharide result in better vaccines than those affecting both core and O-polysaccharide. Possible uses of rough vaccines also include boosting immunity by revaccination but solid evidence on its effectiveness, safety and practicality is not available.     

Mycobacterium avium ssp. paratuberculosis--combined serological testing and classification of individual animals and herds

Several serological tests for detection of antibodies to Mycobacterium avium ssp. paratuberculosis, which is the causative agent of Johne's disease are validated, some of which are available commercially. These tests differ in sensitivity and specificity. Test results reported to farmers or veterinarians are therefore dependent upon the test in use. In the present study, three commercially available tests are used to test 2748 bovine sera from 119 Bavarian herds serologically. Serological results are compared with individual animals and on herd level. A scheme for serological testing and classification of herds as well as of individual animals based on a combination of serological test results is proposed.     

Haptoglobin and pig-major acute protein are increased in pigs with postweaning multisystemic wasting syndrome (PMWS)

The objective of this study was to determine the serum concentration levels of selected acute phase proteins (APP), haptoglobin (HPT) and pig-major acute phase protein (pig-MAP), in postweaning multisystemic wasting syndrome (PMWS) affected pigs and PCV2-subclinically infected pigs. In a first study, a group of 15 eight-week-old conventional pigs from a PMWS affected farm were bled and a complete necropsy, histopathology and in situ hybridisation to detect PCV2 were performed. Based on the results, pigs were classified as suffering from PMWS (n = 10) or healthy animals (n = 5). In a second study, a group of 45 pigs from another PMWS affected farm were selected and bled at 3, 7, 12 and 28 weeks of age. The assessment of PCV2 infection status in these pigs was retrospectively done by PCV2 PCR in serum samples. Selected APP were measured in the serum of all studied pigs by means of radial immunodiffusion. Mean HPT and pig-MAP levels were significantly increased (p = 0.004 and p = 0.0006 respectively) in PMWS-affected pigs when compared to levels found in healthy pigs (2.52 +/- 0.88 mg/mL vs. 1.06 +/- 0.73 mg/mL for HPT and 3.81 +/- 1.53 mg/mL vs. 0.76 +/- 0.34 mg/mL for pig-MAP). In the second study, no significant difference in mean HPT and pig-MAP values were observed between PCV2 PCR positive and negative pigs of any age. However, both APP increased significantly with age in PCV2 PCR negative pigs. Altogether, the present results suggest that APP levels are significantly increased in pigs that develop PMWS, but not in animals with a PCV2 subclinical infection.     

Detection of Chlamydophila abortus in ovine milk by immunomagnetic separation-polymerase chain reaction

The present study was carried out to investigate the presence of Chlamydophila abortus, the causative agent of ovine enzootic abortion, in milk samples collected from sheep flocks with and without the history of abortion in Eastern Turkey by means of immunomagnetic separation (IMS) in conjunction with the polymerase chain reaction (PCR). A total number of 201 milk samples collected from 10 flocks with abortion and four flocks without abortion were tested. In the analysis of the milk samples by IMS-PCR, correct amplification was obtained with three (1.5%) samples originating from one flock with abortion. In the digestion of PCR positive products by AluI, restriction profiles observed in all three samples were determined to be the same as C. abortus S26/3.