Record of Tropical Rat Mite, Ornithonyssus bacoti (Acari: Mesostigmata: Macronyssidae) from Domestic and Peridomestic Rodents (Rattus rattus) in Nilgiris, Tamil Nadu, India

Background: Tropical rat mite (Ornithonyssus bacoti) is reported from many parts of the world and is considered important in transmitting rickettsial pathogens. There have been scanty reports on prevalence of this parasite from India. Following a recent report of O. bacoti infestation in a laboratory mice colony from Nilgiris, Tamil Nadu, In­dia, attempts were made to detect the parasite in its natural reservoir, ie the domestic and peridomestic rats (Rattus rattus). Methods: The National Centre for Disease Control, Coonoor is involved in screening plague in domestic and peridomestic rats in Nilgiris and erstwhile plague endemic areas of Southern India. The parasite samples were identi­fied based on the morphological characteristics attributable to O. bacoti and as per description of published literature. Results: Seven mite samples identified as O. bacoti based on morphological characteristics were isolated inci­dentally from domestic and peridomestic rodents in and around the hilly districts of Nilgiris, Southern India, during the routine plague surveillance programme. The identification was based on the morphological characteristics at­tributable to O. bacoti observed under a low power microscope. Conclusion: In India, this is probably the first record of isolation of O. bacoti from domestic and peridomestic ro­dents. Prevalence of such parasite in domestic and peridomestic rats necessitates further investigation on monitoring and surveillance of rickettsial diseases in the locality, as these parasites are considered to be potential vector of transmitting rickettsial pathogen

Bronchoalveolar lavage is an ideal tool in evaluation of local immune response of pigs vaccinated with Pasteurella multocida bacterin vaccine

Aim: The aim was to study the bronchoalveolar lavage (BAL) technique in evaluating the local immune response of pig immunized with Pasteurella multocida bacterin vaccine. Materials and Methods: Weaned piglets were immunized with formalin-inactivated P52 strain of P. multocida bacterin and evaluated for pulmonary immune response in BAL fluid. BAL was performed before vaccination and at different post vaccination days. The BAL fluid was assayed using enzyme-linked immunosorbent assay to study the development of P. multocida specific antibody isotypes and also evaluated for different cell populations using standard protocol. Results: The average recovery percentage of BAL fluid varies from 58.33 to 61.33 in vaccinated and control group of piglets. The BAL fluid of vaccinated pigs showed increase in antibody titer up to 60th days post vaccination (8.98±0.33), IgG being the predominant isotype reached maximum titer of 6.12±0.20 on 45th days post vaccination, followed by IgM and a meager concentration of IgA could be detected. An increased concentration of the lymphocyte population and induction of plasma cells was detected in the BAL fluid of vaccinated pigs. Conclusion: Though intranasal vaccination with P. multocida plain bacterin vaccine could not provoke a strong immune response, but is promising as lymphocyte population was increased and plasma cells were detected. BAL can be performed repeatedly up to 3/4 months of age in pigs to study pulmonary immune response without affecting their health

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Not AvailableSeasonal outbreaks of swine erysipelas have been reported in back yard pig farms in the Phek district of Nagaland, India. The alpha haemolytic isolate of Erysipelothrix rhusiopathiae was recovered on blood agar from the clinical samples. The organisms were confirmed microscopically, biochemical analysis as well as by polymerase chain reaction (PCR) amplification of 16S rRNA gene and sequence analysis. These Nagaland isolates (KT160358, KT160359) were closely related to the type spp. E. rhusiopathiae in phylogenetic analysis and forms the same clad with Chineese isolates of swine and murine origin indicating an epidemiological link. The isolates were found to be most sensitive to oxytetracycline and responded to treatment. Swine erysipelas occurred in Phek district in a season due to sudden change of weather and temperature. Pigs exposed to such predisposing factors probably favoured to propagation of already persisted organisms in pigs. This is the first confirmed case of E. rhusiopathiae infection from the NE states of Nagaland, India.Not Availabl

Listeriosis in a peri-urban area: Cultural and molecular characterization of Listeria monocytogenes isolated from encephalitic goats

Background and Aim: Listeriosis in food animals bears a significant threat to human health. Detailed investigations into the cause facilitate proper management of the disease. This study reports the cultural, pathological, and molecular characterization of Listeria monocytogenes isolated from encephalitic goats from peri-urban Guwahati, Assam. Materials and Methods: Out of nine suspected samples, five positive isolates of L. monocytogenes were subjected to bacteriological, biochemical, and molecular tests. The genus and species-specific L. monocytogenes 16S rRNA and prs genes were amplified by polymerase chain reaction (PCR) to yield 1200 and 370 bp sized products, respectively. The encephalitic form of the disease was characterized by circling movement, high fever, and terminal recumbence. Results: All the five isolates were confirmed to be L. monocytogenes based on PCR amplification of genus and species-specific 16S rRNA and prs gene products. The isolates were sensitive to ciprofloxacin, oxytetracycline (OTC), and norfloxacin, but resistant to doxycycline and erythromycin. A high dose of OTC was used in a goat at the early stage of clinical symptom and the animal recovered clinically. Conclusion: Listeriosis in goats could pose a significant public health threat as the meat (occasionally milk) or meat products from goats are widely consumed by the people of Assam. Understanding the molecular epidemiological aspects of L. monocytogenes infections of food animal species should, therefore, be the priority in this part of the country