Introduction: Infectious bursal disease virus (IBDV) is a causative agent of immunosuppressive disorder resulting in significant losses to the world poultry industry. This study describes the molecular characterisation of an atypical IBDV from a field outbreak that occurred in vaccinated chicken flocks in Latvia in 2011.Material and Methods: Ten bursae of Fabricius from each flock were collected for laboratory examination. Virus isolation was performed in embryonated eggs and CEF culture. The RT-PCR aimed at hypervariable domain of VP2 gene combined with sequencing was performed for detection and identification of IBDV.Results: The molecular examinations confirmed the IBDV infection. The analysis of the amino acid sequence revealed that the strain possessed four amino acids at VP2 protein (222A, 256I, 294I, and 299S), indicating a genetic relatedness to a very virulent IBDV. However, some unique or rare amino acid substitutions (219L, 220F, 254D, 279N, and 280T) were also detected.Conclusion: The obtained results demonstrate the occurrence of IBDV with a high mutation rate within the hypervariable domain of VP2 peptide, and highlight the necessity of implementation of IBDV surveillance in Eastern European poultry industry to determine whether this strain is an exception or a new wave of IBDV with new genetic features emerged in the field.

Introduction: Colibacillosis – the most common disease of poultry, is caused mainly by avian pathogenic Escherichia coli (APEC). However, thus far, no pattern to the molecular basis of the pathogenicity of these bacteria has been established beyond dispute. In this study, genomes of APEC were investigated to ascribe importance and explore the distribution of 16 genes recognised as their virulence factors. Material and Methods: A total of 14 pathogenic for poultry E. coli strains were isolated, and their DNA was sequenced, assembled de novo, and annotated. Amino acid sequences from these bacteria and an additional 16 freely available APEC amino acid sequences were analysed with the DIFFIND tool to define their virulence factors. Results: The DIFFIND tool enabled quick, reliable, and convenient assessment of the differences between compared amino acid sequences from bacterial genomes. The presence of 16 protein sequences indicated as pathogenicity factors in poultry resulted in the generation of a heatmap which categorises genomes in terms of the existence and similarity of the analysed protein sequences. Conclusion: The proposed method of detection of virulence factors using the capabilities of the DIFFIND tool may be useful in the analysis of similarities of E. coli and other sequences deriving from bacteria. Phylogenetic analysis resulted in reliable segregation of 30 APEC strains into five main clusters containing various virulence associated genes (VAGs).

Colibacillosis is a disease caused by avian pathogenic E. coli (APEC) and is one of the principle cause of morbidity and mortality in poultry worldwide which is represented by a complex syndrome characterized by multiple organ lesions. This study was carried out to determine phylogenetic grouping and virulenceassociated genes contained by E. coli isolates which is related in causing disease in chicken. E. coli isolates obtained from clinical cases of Veterinary ResearchInstitute were re-identified by conventional methods. Phylogenetic grouping of the isolates was determined by triplex polymerase chain reaction (PCR), and the presence of eight virulence genes were identified by multiplex PCR. A total of 125 E. coli isolates were subjected toanalysis of phylogenetic background and virulence associated genes profiling. Phylogenetic analysis demonstrated that most of the E. coli isolated from chicken in this study belonged to group B1 (36.0%),group D (28.0%), group A (27.2%) and group B2 (8.8%). Multiplex PCR analysis demonstrated that 96 (78.6%) of the E. coli isolates harbored at least one virulencegene, while 29 (23.3%) did not contain any virulence genes tested. The most prevalent virulence genes identified were iss (51.2%), followed by iucD (36.0%),tsh (32.8%), vat (16.0%), astA (13.6%), irp2 (11.2%), papC (9.6%) and the least is cva/cvi gene (0%). None of the isolates harbored more than four virulence genes.Each of phylogenetic groups presented with different combinations of virulence genes, with no specific combinations of virulence genes found to correlate withE. coli phylogroups. None of the E. coli isolates harbored more than four virulence genes, suggesting that E. coli isolates from chicken in this study appear to bederived from commensal strains and may relate to environmental predispose factors especially stress factors in the host to establish infection.

OBJECTIVE To develop a noninvasive biomarker-based detection system specific for Mycobacterium bovis for monitoring infection in wild animals. SAMPLE Serum samples from 8 experimentally infected yearling white-tailed deer (Odocoileus virginianus) and 3 age-matched control deer and from 393 Minnesota Department of Natural Resources hunter-harvested white-tailed deer in northwest Minnesota. PROCEDURES 8 yearling deer were inoculated with 2 × 10(8) CFUs of virulent M bovis strain 1315 (day 0), and sera were obtained on days 0, 19, 48, and 60; sera were obtained from 3 uninoculated control deer on those same days. Sera from these deer and 9 M bovis-positive hunter-harvested deer were tested for 3 Mycobacterium-specific biomarkers (MB1895c, MB2515c, and polyketide synthase 5) by use of an indirect ELISA. That same ELISA was used to test sera obtained from 384 exposed noninfected deer in northwest Minnesota from 2007 through 2010, concurrent with an outbreak of tuberculosis involving cattle and deer in that region. RESULTS ELISA results revealed that tuberculosis infection could be detected as early as 48 days after inoculation in experimentally infected deer. Results for 384 deer sera revealed that prevalence of tuberculosis decreased over the 4-year period. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the prevalence of tuberculosis in Minnesota deer decreased after 2009 but tuberculosis may have persisted (as subclinical disease) at extremely low levels, as indicated by the presence of low concentrations of circulating biomarkers. Biomarker-based diagnostic tests may offer a specific approach for early identification of M bovis infection.

A Salmonella Typhimurium ghost vaccine was constructed with the use of a recombinant fusion protein consisting of lysozyme and porcine myeloid antimicrobial peptide 36 expressed by the Escherichia coli overexpression system. After confirmation of its effectiveness by transmission electron microscopy the vaccine was evaluated in a murine model. Of the 60 BALB/c mice equally divided into 4 groups, group A mice were intramuscularly inoculated with 100 μL of sterile phosphate-buffered saline, and the mice in groups B, C, and D were intramuscularly inoculated with approximately 1.0 × 10(4), 1.0 × 10(5), or 1.0 × 10(6) cells of the S. Typhimurium ghost vaccine, respectively, in 100-μL amounts. The serum I gG titers against S. Typhimurium outer membrane proteins were significantly higher in groups B to D than in group A, as were the concentrations of interleukin-10 and interferon gamma in supernatants of harvested splenocytes. After challenge with wild-type S. Typhimurium, all the vaccinated groups showed significant protection compared with group A, notably perfect protection in groups C and D. Overall, these results show that intramuscular vaccination with 1.0 × 10(5) cells of this ghost vaccine candidate provided efficient protection against systemic infection with virulent S. Typhimurium.

OBJECTIVE To measure immunologic responses of snakes after experimentally induced infection with ferlaviruses. ANIMALS 42 adult corn snakes (Pantherophis guttatus) of both sexes. PROCEDURES Snakes were inoculated intratracheally with genogroup A (n = 12), B (12), or C (12) ferlavirus (infected groups) or cell-culture supernatant (6; control group) on day 0. Three snakes from each infected group were euthanized on days 4, 16, 28, and 49, and 3 snakes from the control group were euthanized on day 49. Blood samples were collected from live snakes on days −6 (baseline), 4, 16, 28, and 49. Hematologic tests were performed and humoral responses assessed via hemagglutination-inhibition assays and ELISAs. Following euthanasia, gross pathological and histologic evaluations and virus detection were performed. RESULTS Severity of clinical signs of and immunologic responses to ferlavirus infection differed among snake groups. Hematologic values, particularly WBC and monocyte counts, increased between days 4 and 16 after infection. A humoral response was identified between days 16 and 28. Serum IgM concentrations increased from baseline earlier than IgY concentrations, but the IgY relative increase was higher at the end of the study. The hemagglutination-inhibition assay revealed that the strongest reactions in all infected groups were against the strain with which they had been infected. Snakes infected with genogroup A ferlavirus had the strongest immune response, whereas those infected with genogroup B had the weakest responses. CONCLUSIONS AND CLINICAL RELEVANCE Results of this experimental study suggested that the ferlavirus strain with the highest virulence induced the weakest immune response in snakes.