THE PROTECTIVE VALUE OF AN AUTOGENOUS BACTERIN AND TOXOID AGAINST EXPERIMENTAL CORYNEBACTERIUM PYOGENES INFECTION IN MICE

Bacteria and toxin from a borth culture of a porcine strain of Corynebacterium pyogenes were lethal to white Swiss mice within 24th of inoculation. The pyogenic factor was shown to be a component of the bacterial cells and not of the toxin. Mouse protection tests using a formolised bacterin and formolized toxoid conferred protection to experimental challenge. It is suggested that this toxoid may be of value in protecting animals against the natural infection.

The Influence of Supplementation of Feed with Lactobacillus reuteri L2/6 Biocenol on Intestinal Microbiota of Conventional Mice

FISH (fluorescence in situ hybridization) analysis of the intestinal tract of conventional mice, following 14-day supplementation of feed with host non-specific (porcine) strain L. reuteri L2/6, showed in the presence of complex microbiota, a significant increase in the counts of representatives of the genera Lactobacillus and Bifidobacterium, and a significant decrease in the representatives of the genera Clostridium, Bacteroides and Enterobacteriaceae. At the same time, the supplemented strain stimulated the population of caecal lactobacilli of the species L. reuteri. These results demonstrated that the L. reuteri L2/6 colonised the jejunum, ileum and caecum and modulated the investigated intestinal microbiota.

Cystic echinococcosis in humans and animals: Current epidemiological situation in Poland

The purpose of this article was to present current data on cases of cystic echinococcosis in humans and animals in Poland. Cystic echinococcosis, caused by Echinococcus granulosus, is one of the most important parasitic zoonoses occurring globally. In many regions of the world, the disease is an important epidemiological problem. The life cycle of Echinococcus involves hoofed farm animals and dogs. Among its species and genotypes ascertained in the world, two (G1 and G7) have been confirmed in sheep and pigs as intermediate hosts in Poland. Molecular examinations of postoperative parasitic material from patients established that the porcine strain G7 is the cause of human cystic echinococcosis in Poland. Data on post-slaughter examinations of pigs identified as intermediate hosts of E. granu-losus suggest that the number of cases reported in humans (approx. 40 annually) is probably underestimated. In the last two years, the prevalence of hydatid cysts in pigs in Poland has been estimated at 0.3%, with the highest number of infected animals in central Poland (0.4%-1.2%). This indicates the presence of infection in dogs and the risk of echinococcosis for humans.

Draft Genome Sequence of Escherichia coli AI27, a Porcine Isolate Belonging to Phylogenetic Group B1

ABSTRACTEscherichia coliAI27 is a putatively commensal strain isolated from feces of a pig. Here we report the draft genome sequence ofE. coliAI27. This is the first porcine strain in the phylogenetic group B1 whose genome sequence has been determined.

Different Rotavirus Strains Enter MA104 Cells through Different Endocytic Pathways: the Role of Clathrin-Mediated Endocytosis

ABSTRACT Rotaviruses, the single most important agents of acute severe gastroenteritis in children, are nonenveloped viruses formed by a three-layered capsid that encloses a genome formed by 11 segments of double-stranded RNA. The mechanism of entry of these viruses into the host cell is not well understood. The best-studied strain, RRV, which is sensitive to neuraminidase (NA) treatment of the cells, uses integrins α2β1 and αvβ3 and the heat shock protein hsc70 as receptors and enters MA104 cells through a non-clathrin-, non-caveolin-mediated pathway that depends on a functional dynamin and on the presence of cholesterol on the cell surface. In this work, using a combination of pharmacological, biochemical, and genetic approaches, we compared the entry characteristics of four rotavirus strains known to have different receptor requirements. We chose four rotavirus strains that represent all phenotypic combinations of NA resistance or sensitivity and integrin dependence or independence. We found that even though all the strains share their requirements for hsc70, dynamin, and cholesterol, three of them differ from the simian strain RRV in the endocytic pathway used. The human strain Wa, porcine strain TFR-41, and bovine strain UK seem to enter the cell through clathrin-mediated endocytosis, since treatments that inhibit this pathway block their infectivity; consistent with this entry route, these strains were sensitive to changes in the endosomal pH. The inhibition of other endocytic mechanisms, such as macropinocytosis or caveola-mediated uptake, had no effect on the internalization of the rotavirus strains tested here.

High prevalence of amantadine resistance among circulating European porcine influenza A viruses

Genetic analysis of the M2 sequence of European porcine influenza A viruses reveals a high prevalence of amantadine resistance due to the substitution of serine 31 by asparagine in all three circulating subtypes, H1N1, H3N2 and H1N2. The M segment of all resistant strains belongs to a single genetic lineage. Whereas the first amantadine-resistant porcine strain was isolated in 1989, isolation of the last amantadine-susceptible strain dates to 1987, suggesting a displacement of amantadine-susceptible viruses by resistant strains soon after emergence of the mutation. Analysis of natural selection by codon-based tests indicates negative selection of codons 30, 31 and 34 which confer amantadine resistance. The codons 2, 11–28 and 54 of porcine and human strains exhibit differences in the patterns of substitution rates, suggesting different selection modes. Transfer of amantadine resistance by exchange of the M segment and viability of recombinant A/WSN/33 viruses with avian-like M segments raises concerns about the emergence of natural human reassortants.