Surveillance, monitoring and investigation of diseases outbreaks in the region
Brucellosis in livestock:
The Brucella isolates were confirmed by PCR based on gene for 31kDa OMP and the repetitive genetic element IS711. Out of 68 swine serum samples screened for brucellosis, 5 (7.4%) samples were seropositive for brucellosis. Out of 36 goat serum samples, 2 (5.6%) showed positive reaction for antibodies against brucellosis. The findings indicated the presence of this dreaded disease in the region.
Salmonellosis in poultry:
Out of 53 poultry intestinal samples collected during the postmortem of poultry from various poultry farms in Meghalaya and screened for the presence of Salmonella species, 13 (24.53%) were found positive for Salmonella spp. All the isolates were positive for stn and invA genes. S.Enteritidis with 9,12:g,m:- antigenic structure was the widely encountered serotype that was followed by S.Kentucky serotype with 8,20:i:z6 antigenic structure. One isolate was serotyped as S. Typhimurium with 4,12:i:1,2 antigenic structure.Theantibiogram of these isolates showed a variable pattern of antibiotic resistance/ sensitivity; however, all the isolates were sensitive to Ofloxacin.
The cases were investigated for unusual deaths at an organized poultry farm of Meghalaya during the month of September 2007. The postmortem investigation revealed cachectic condition of birds, dark discoloration of liver, presence of tumors in liver and Hydropericardium. The representative feed samples were collected for detection of mycotoxins. Aflatoxin B1 and Citrinin were detected at a concentration of 24 to 36 ppb and 40 to 120 ppb, respectively in different feed samples. The findings cautioned the poultry farmers for proper processing and storage of feed in the region where high humidity prevails for most of the time.
Clostridium perfringens infection in poultry:
Clostridium perfringens was isolated from 14 out of 16 samples collected during the postmortem of the poultry birds and subjected for bacteriological examination. The birds died after showing the symptoms of enteritis. The isolates were confirmed by PCR on the basis of detection of cpa gene. The isolates were found to be comparatively resistant to wide number of antibiotics. Only 8 (57.1%) isolates were sensitive to Metranidazole and 7 (50%) to Sparfloxacin.
Campylobacter has been shown to be almost exclusively transmitted through foods of animals and poultry origin. The food chain gets contaminated from intestinal contents mainly during slaughter or post slaughter processing. The isolates were confirmed by employing PCR protocol based on 16S rRNA gene. Further characterization of the isolates at subspecies level revealed that only 2 C. jejuni hydrolyzed DNA and thus categorized under biotype II, rest were found to belong to biotype I. The PCR based protocol was employed using the published primer sequences of hipO (Hippuricase O) gene which is specific for C.jejuni to differentiate C. jejuni from C. coli. Purification and identification of immunogenic proteins from C. jejuni was completed. Immunogenic proteins could be identified with molecular weight between 50- 75 kDa by western blot.
Pasteurellosis in Pigs:
Mortality of pigs with severe respiratory problem was reported from two organized farms. The clinical samples were subjected for bacteriological examination in the laboratory. The laboratory findings showed the presence of Pasteurellamultocida in lung and bronchial lymph node. The isolates were confirmed based on cultural, morphological, biochemical tests and PCR based detection of P. multocida specific KMT1 gene. The isolates were found to be pathogenic to mice. The organisms were identified as P. multocida type D based on the PCR capsular typing. The disease outbreak could be controlled by using the antibiotics with highest sensitivity.