Antigenic analysis of monoclonal antibodies against different epitopes of σB protein of avian reovirus.

BACKGROUND: Avian reovirus (ARV) causes arthritis, tenosynovitis, runting-stunting syndrome (RSS), malabsorption syndrome (MAS) and immunosuppression in chickens. σB is one of the major structural proteins of ARV, which is able to induce group-specific antibodies against the virus. METHODS AND RESULTS: The present study described the identification of two linear B-cell epitopes in ARV σB through expressing a set of partially overlapping and consecutive truncated peptides spanning σB screened with two monoclonal antibodies (mAbs) 1F4 and 1H3-1.The data indicated that (21)KTPACW(26) (epitope A) and (32)WDTVTFH(38) (epitope B) were minimal determinants of the linear B cell epitopes. Antibodies present in the serum of ARV-positive chickens recognized the minimal linear epitopes in Western blot analyses. By sequence alignment analysis, we determined that the epitopes A and B were not conserved among ARV, duck reovirus (DRV) and turkey reovirus (TRV) strains. Western blot assays, confirmed that epitopes A and B were ARV-specific epitopes, and they could not react with the corresponding peptides of DRV and TRV. CONCLUSIONS AND SIGNIFICANCE: We identified (21)KTPACW(26) and (32)WDTVTFH(38) as σB -specific epitopes recognized by mAbs 1F4 and 1H3-1, respectively. The results in this study may have potential applications in development of diagnostic techniques and epitope-based marker vaccines against ARV groups.

Identification of a linear B-Cell epitope on avian reovirus protein sigmaC.

SigmaC (σC) protein, which mediates virus attachment to target cells, is the most variable proteins of avian reovirus (ARV). It is responsible for inducing protective antibody immune responses in animals. To understand the antigenic determinants of σC protein, a set of partially overlapping and consecutive peptides spanning σC were expressed and then screened with the monoclonal antibody (mAb) 2B5 directed against σC. The mAb 2B5 recognized peptides with the σC motif (45)ELLHRSISDISTTV(58). Further identification of the displayed B-cell epitope was conducted with a set of truncated peptides expressed as GST fusion proteins. The Western blot and ELISA results indicated that (45)ELLHRSISDI(54) was the minimal determinant of the linear B-cell epitope. Using sequences analysis, we found that this epitope was not a common motif shared among the other members of the ARV and DRV groups. Furthermore, cross reactivity analysis showed that the associated coding motif of other ARV and DRV groups was not recognized by 2B5. These data suggested that (45)ELLHRSISDI(54) was a type-specific linear B-cell epitope of avian reovirus. The results in this study may have potential applications in the development of diagnostic techniques and epitope-based marker vaccines against ARV, which is prevalent in China.

A Disaster Response and Management Competency Mapping of Community Nurses in China.

BACKGROUND: It is widely accepted in many parts of the world thatcommunity nurses are of vital importance in various phases of disaster response and management. In China, however, it is not clear whether the Chinese community nurses are able to assume disaster-related duties due to the lack of a systematic assessment. METHODS: A pre-designed and well-tested questionnaire was employed to evaluate the competency in disaster response and management among 205 valid registered Chinese community nurses between September and October 2009. Statistical analyses were performed with SPSS Version 13.0 using one way ANOVA, Least Significant Difference (LSD) and multiple stepwise regression analysis. RESULTS: This group of Chinese community nurses scored at an intermediate level of competency (a score of 3.68 (SD 0.48) out of a perfect score of 5) in disaster response and management, suggesting that they have the basic ability to participate in disaster-related nursing. Four factors, namely, Experiences in Disaster Relief, Participation in Disaster Training, the Age and Duration in Job, were identified to be the predominant factors contributing significantly to the integrated competency in disaster response and management of an individual. CONCLUSION: Most of the Chinese community nurses have basic qualifications and competencies to undertake the responsibilities of disaster response and management. However, more targeted disaster training including virtual-reality based drills should be provided in order to improve their competency.

[Isolation and analysis of the drug resistance of the flavobacterium and its production of beta-lactamases].

OBJECTIVE: To investigate the drug resistance of flavobacterium and its ability to produce BLA (beta-lactamases) and ESBLs (Extended-spectrum beta-lactamases). METHODS: The production of BLA and ESBLs from 6 clinical isolated flavobacterium strains was determined by nitrocefin disc test and double-disc synergy method, respectively. The antibiotic susceptibilities of the strains were determined by Kirby-Bauer disc diffusion test and the agar dilution method and the MIC was assessed. RESULTS: All the six flavobacteria were BLA-producing strains and more than 80% of them were ESBLs-producing, and they were highly resistant to beta-lactamase antibiotics (MIC 32 - 256 mg/L), but susceptible to fluoroquinolones and cephalosporin with beta-lactamase inhibitors (MIC 0.125 - 8 mg/L). CONCLUSION: Most of the flavobacteria in nosocomial infections were beta-lactamase-producing and were highly resistant to beta-lactamase antibiotics. Fluoroquinolones and beta-lactamase antibiotics with lactamase inhibitors should be the first choice for the management of infection caused by flavobacterium.