Genetic characterization of parvoviruses identified in stray cats in Nigeria.

Parvoviruses are a major cause of haemorrhagic gastroenteritis, leukopenia and high mortality in cats and dogs. In this study, the presence and genetic characteristics of parvoviruses circulating among cats in Nigeria are reported. Faecal samples of stray cats from live animal markets in southwestern (Oyo and Osun States) and north-central (Kwara State) Nigeria were screened for the presence of parvoviral DNA using a qPCR. Positive samples were further characterized using a qPCR based on minor groove binder probes. Overall, 85/102 (83.3 %) stray cats tested positive for feline panleukopenia virus (FPV) DNA and one cat was co-infected with canine parvovirus-2 type a. Sequence analysis of the complete capsid region of 15 Nigerian FPV strains revealed that they were up to 99.9 % similar to the American reference strain FPV-b at the nucleotide level, and three of them presented amino acid mutations in key capsid residues. This is the first report of identification and molecular characterization of FPV strains in cats in Nigeria. The high prevalence of the virus emphasizes the need for constant surveillance of the circulation of parvoviruses in Nigeria and underscores the need to deploy an effective vaccination strategy.

Flow cytometric analysis of equine bronchoalveolar lavage fluid cells in horses with and without severe equine asthma.

Severe equine asthma (SEA) is a common, debilitating lower airway inflammatory disorder of older horses. Alveolar macrophages (AMs) survey inhaled particulates from barn sources causing them to switch from an anti-inflammatory to a proinflammatory phenotype, resulting in neutrophil recruitment to the lung. This proinflammatory switch may contribute to the development and prolongation of SEA. Validated antibodies to identify the cells involved in the pathogenesis of SEA are lacking. In this study, monoclonal antibodies against CD90, CD163, and CD206 were tested for reactivity with equine leukocytes by immunocytochemistry and flow cytometry. A multi-color flow cytometric assay was developed to identify leukocytes in equine bronchoalveolar lavage fluid (BALF). Four control and 4 SEA-susceptible horses had BALF collected before and after a 48-hour moldy hay challenge. Antibodies against CD90 uniquely labeled equine neutrophils, and antibodies against CD163 and CD206 identified equine macrophages. Postchallenge AM surface expression of CD163 increased in both groups of horses, but the increase was statistically significant in only the SEA-susceptible group (P = .02). The surface expression of CD206 on AMs increased significantly in the SEA-susceptible group (P = .03) but was unchanged in the control group (P = .5). Increased expression of CD163 and CD206 during exacerbation of SEA suggested an association between AM phenotype and lung inflammation. However, functions of AMs in the pathogenesis of SEA remain to be elucidated.

The eosinophil as a therapeutic target in asthma: beginning of the end, or end of the beginning?

A major goal in asthma therapy is to reduce or prevent the inflammatory response associated with bronchial hyperresponsiveness, reversible airway obstruction and airway remodelling. However, because of the complex nature of the disease, a single target for such an ideal therapeutic approach remains elusive. To ensure a more rational design of anti-asthma drugs, recent investigations have attempted to elucidate the roles of inflammatory cellular components in asthma. Such studies have shown that eosinophilic infiltration is a prominent feature in the pathophysiology of asthma. Nonetheless, the role of the eosinophil in asthma has been questioned following recent human studies investigating the efficacy of a novel therapeutic strategy targeted at eosinophils.