Development of recombinant sialidase (NanH) protein-based Indirect-ELISA for epidemiological survey of anti-Pasteurella multocida antibodies in bovines

697-704Haemorrhagic septicaemia (HS) is a highly contagious and fatal disease of cattle and buffaloes and causes major economic losses to farmers. Though indirect hemagglutination (IHA) test has been used to detect a specific antibody against P. multocida, it has low specificity for sero-diagnosis of HS. Therefore, development of a rapid, highly sensitive and specific serological test is a prerequisite for detection of antibodies against HS. In this context, we explored an in-house ELISA method using recombinant antigens for detection of antibodies against P. multocida in bovines. nanH gene from P. multocida B:2 strain P52 was cloned and the recombinant mature protein with a C- and N-terminal truncation was produced as a fusion protein (∼63 kDa) in Escherichia coli. The immunogenic potential of purified rNanH-Tr was assessed by the Western blot method using specific anti-rNanH-Tr antibody responses in sera collected from immunized rabbits. An indirect-ELISA based on rNanH-Tr was developed and optimized. Furthermore, the rNanH-Tr ELISA was applied to screen bovine serum samples (n=250). The receiver operating characteristic curve analysis for the detection of anti P. multocida specific antibodies indicated a diagnostic sensitivity of 86.2 (CI 73.26-96.80%) and specificity of 80.0 (63.06- 91.56%). No cross reactivity was noted with antibodies against other bovine diseases (e.g., foot-and-mouth disease and brucellosis). Screening of random bovine serum samples showed a 22% sero-positivity for anti P. multocida specific antibodies

Isolation and antibiogram of Staphylococcus, Streptococcus and Escherichia coli isolates from clinical and subclinical cases of bovine mastitis

Aim: The present study was aimed to isolate and evaluate the continuous change in the pattern of drug resistance showed by different mastitogenic organisms, isolated from clinical and subclinical cases of mastitis.Materials and Methods: The study was carried out using 150 milk samples received from various clinical and subclinical cases, from which the causative organisms were isolated and subjected to in vitro antibiotic sensitivity test.Results: The bacteriological analysis of the samples indicated the presence of both Gram positive and Gram negative organisms followed by isolation of isolates like Staphylococcus, E. coli, Streptococcus, Bacillus, Corynebacterium, Listeria, Klebsiella. The in vitro sensitivity of Staphylococcus, E. coli and Streptococcus isolates revealed that they were more sensitive towards newer antimicrobials like Levofloxacin and Enrofloxacin.Conclusion: The prevalence of Staphylococcus was found to be maximum followed by Streptococcus and E. coli among the isolated organisms. Levofloxacin and Enrofloxacin were found to be most effective against the targeted isolates

Serosurveillance of foot-and-mouth disease in ruminant population of Coastal Odisha, India

Foot and mouth disease (FMD) is endemic in India and three serotypes viz, O, A, and Asia1 are prevalent in the country. In the current study a total of 551 serum samples were collected randomly from 51 cattle, 127 sheep and 373 goats from areas with or without the history of recent outbreaks in different districts of coastal Odisha, India. The samples were screened for antibodies against non-structural proteins (NSPs) and structural proteins (SP) of FMD virus to gather evidence with respect to the FMD virus circulation. The study revealed a higher level of NSP antibodies in goats (38.33%) and cattle (33.33%), and lower prevalence in sheep (3.93%). In case of SP antibodies, the prevalence was higher in cattle (68.62%) followed by goats (38.87%) and sheep (17.32%). The study reiterates the importance of strengthening of FMD surveillance in small ruminants as they could pose a potential risk of virus transmission to cattle