Nipah virus (NiV; Paramyxoviridae) caused fatal encephalitis in humans during an outbreak in Malaysia in 1998/1999 after transmission from infected pigs. Our previous study demonstrated that the respiratory, lymphatic and central nervous systems are targets for virus replication in experimentally infected pigs. To continue the studies on pathogenesis of NiV in swine, six piglets were inoculated oronasally with 2.5 x 10(5) PFU per animal. Four pigs developed mild clinical signs, one exudative epidermitis, and one neurologic signs due to suppurative meningoencephalitis, and was euthanized at 11 days post-inoculation (dpi). Neutralizing antibodies reached in surviving animals titers around 1280 at 16 dpi. Nasal and oro-pharyngeal shedding of the NiV was detected between 2 and 17 dpi. Virus appeared to be cleared from the tissues of the infected animals by 23 dpi, with low amount of RNA detected in submandibular and bronchial lymph nodes of three pigs, and olfactory bulb of one animal. Despite the presence of neutralizing antibodies, virus was isolated from serum at 24 dpi, and the viral RNA was still detected in serum at 29 dpi. Our results indicate slower clearance of NiV from some of the infected pigs. Bacteria were detected in the cerebrospinal fluid of five NiV inoculated animals, with isolation of Streptococcus suis and Enterococcus faecalis. Staphylococcus hyicus was isolated from the skin lesions of the animal with exudative epidermitis. Along with the observed lymphoid depletion in the lymph nodes of all NiV-infected animals, and the demonstrated ability of NiV to infect porcine peripheral blood mononuclear cells in vitro, this finding warrants further investigation into a possible NiV-induced immunosuppression of the swine host.
Infectious bronchitis virus (IBV) infection is highly infectious respiratory disease in poultry industry with significant economic importance. The prevalence of IBV in quail industry in Malaysia was not well documented; therefore, its actual role in the epidemiology of the disease is relatively unknown. This study was to determine the susceptibility of Japanese quail, as one of the species in commercial poultry industry, toward IBV. In addition, it will also give a potential impact on the overall health management in the quail industry even though it had been established that quail are resistant to diseases affecting poultry. Moreover, to the best of our knowledge, it is the first experimental study on IBV inoculation in quail. In this experimental study, 20 quails were divided into 4 groups (n = 5 for group A, B, and C, n = 5 for control group). The quails in group A, B, and C were infected via intraocular and intranasal routes with 0.2 mL of 10 × 5 EID50 of the virus. Clinical signs, gross lesions, positive detection of virus, and trachea histopathological scoring were used to assess the susceptibility of these Japanese quails. The results have indicated mild ruffled feathers and watery feces in these inoculated birds. Trachea, lung, and kidney were subjected to one-step reverse transcription polymerase chain reaction for virus detection. The virus was found from trachea and lung samples, whereas it was absent from all kidney samples. Only 3 quails were found with gross lesions. There was a significant difference of tracheal lesion by 0.009 ± 0.845 (P < 0.05) within the treatment groups. In summary, Japanese quails might be susceptible to IBV.
Stressors may influence chicken susceptibility to pathogens such as Salmonella enterica. Feed withdrawal stress can cause changes in normal intestinal epithelial structure and may lead to increased attachment and colonization of Salmonella. This study aimed to investigate modulatory effects of epigenetic modification by feed restriction on S. enterica serovar Enteritidis colonization in broiler chickens subjected to feed withdrawal stress. Chicks were divided into four groups: ad libitum feeding; ad libitum feeding with 24-h feed withdrawal on day 42; 60% feed restriction on days 4, 5, and 6; and 60% feed restriction on days 4, 5, and 6 with 24-h feed withdrawal on day 42. Attachment of S. Enteritidis to ileal tissue was determined using an ex vivo ileal loop assay, and heat shock protein 70 (Hsp70) expression was evaluated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting. Feed withdrawal stress increased S. Enteritidis attachment to ileal tissue. However, following feed withdrawal the epigenetically modified chickens had significantly lower attachment of S. Enteritidis than their control counterparts. A similar trend with a very positive correlation was observed for Hsp70 expression. It appears that epigenetic modification can enhance resistance to S. Enteritidis colonization later in life in chickens under stress conditions. The underlying mechanism could be associated with the lower Hsp70 expression in the epigenetically modified chickens.