Veterinary Epidemiology & Preventive Medicine

· Studies on the prevalence and control of porcine ascariasis revealed that pigs reared by tribal population under unorganized farms were highly susceptible to Ascaris suum infection and the infection was consistently present throughout the year. Vaccination of pigs was not properly done or cared for. Regular deworming schedule was advised to realize visible effects in controlling naturally acquired A. suum infection in pigs.

· Studies on the effect of turmeric (Curcuma longa) on induced Aflatoxicosis in domestic ducks (Anas platyrhenchos) revealed that turmeric powder supplementation @1.5% of feed (30mcg/kg BW) corrected the toxic effect of Aflatoxicosis B1 and improved the various growth parameters viz. daily feed intake, weekly body weight gain and FCR by stimulating the liver function. This dose regimen also improved the biochemical parameters viz. total protein, albumin, cholesterol, triglyceride, AST and ALT in Pati ducklings and improved the growth performance optimizing the FCR.

· Epidemiological studies on Theileriosis in goats of Assam showed highest prevalence in Kamrup (R) and lowest in Dhemaji districts. Age wise, highest infection was recorded in 12-24 months and lowest in 6 months. Sex-wise, prevalence was higher in females than in males. Month-wise highest recorded in September and lowest in February. Molecular diagnosis and gene sequence of T. luwensheni and phylogenetic analysis of the isolates showed similarity with the cattle (Tibet) and Sika deer (China).

Buparvaquone and oxytetracycline combination with supportive treatment was more effective therapy.

· A survey on the community awareness on epidemiology of dog-mediated rabies in Greater Guwahati revealed that there was a significant lack of information on rabies and its prevention. Among the professional communities i.e. medical and veterinary, there was a lack of updated knowledge and training of general practitioners. Further, there was no initiative from the government agencies to conduct awareness camps/ programs to make the general community aware on rabies. Increased awareness to reduce dog-mediated rabies in human and animal was highly warranted.

· Evaluation of humoral immune response in Foot and Mouth Disease (FMD) vaccinated pigs showed that primary vaccination with oil adjuvant and trivalent FMD vaccination of piglets at 2 months of age produced protective titre 30 days PPV. Booster dose at 1 month interval produced higher titre for longer duration. Single vaccination maintained the protective titre 90 PPV. Primary vaccination (3ml) at 2 months age, followed by booster at 30 days PPV and subsequent repetition at 6 months interval protected the piglets against FMD.

· Epidemiology and therapeutic management of wound infection in captive and wild Asian elephants (Elephas maximus) showed that captive elephants have higher prevalence of wound infection in comparison to wild elephants. Highest prevalence was recorded in Laokhowa Wildlife Sanctuary and lowest in Kaziranga National Park.

Antibiotics and wound management resulted in faster healing and return to work.

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Prevalence of Newcastle Disease virus in backyard and commercial poultry in Assam showed overall sero-prevalence as 23.89%. The virus was detected in 61.67% tissue samples and 21.15% from cloacal swabs. Risk factors related to the disease based on questionnaire survey was conducted. Sequencing and phylogenetic analysis of circulating NDV belonged to genotype XIII in Class II of APMV-1. Biological and molecular pathotyping revealed that the strains were of Mesogenic nature.

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 A study on the epidemiology and antimicrobial resistance pattern (s) of Streptococcus suis and other Streptococci of porcine origin revealed a total of 8 different Streptococcal species of which S. equi subsp. Zooepidemicus was the predominant isolate. Seven isolates of S. suis were confirmed by PCR which was of significance due to the zoonotic potential of the pathogen. Age wise highest prevalence of S. suis was observed in the age group of 8-24 weeks and other Streptococci in the age group of >24 weeks. Sex-wise prevalence of Streptococcal isolate was higher in females than in male pigs. S. suis was more prevalent in the pig herds managed under organized systems than in unorganized system of management. The antimicrobial sensitivity testing showed that all the isolates were sensitive to Gentamicin whereas Cefalexin was the least effective.A total of 24 antimicrobial resistance patterns were exhibited by the isolates. Isolation of multi-host Streptococcal species in the present study indicated adaptation of the organism in porcine hosts.

· Study on emerging antibiotic resistance in Escherichia coli and Salmonella and antibacterial effects of silver nanoparticles showed that 85.1% of the E. coli isolates tested were multidrug resistant (MDR). Antibiotic resistance genes were detected in both E. coli and Salmonella isolates. Antibiotic resistance genes with putative virulence determining genes were detected in the Salmonella isolates. The resistant traits both in E. coli and Salmonella were transferable from donor to recipient by in vitro assay with variable frequency of transfer. Efflux pump genes in MDR E. coli and Salmonella isolates exhibited over expression of marA gene. A total of 10 plants were selected for silver nanoparticles (SNP) synthesis possessing good antioxidants property. SNPs were rapidly synthesized using silver nitrate and the Methanol extracts of all the plants. The synthesized SNPs were successfully characterized using UV-Vis spectroscopy.Electron microscopic analysis by TEM, and SEM revealed the size of SNPs ranging from 5-50 nm. Antibacterial effects of SNPs against E. coli and Salmonella gave encouraging results and the inhibitory effect was time and dose dependent. The synthesized SNPs were also found to be biocompatible to normal cells (vero cells) and possessed inhibitory effect to cancerous cells.

· Outer membrane vesicle (OMV) of Pasteurella multocida as potential immunogen for pigs was studied which showed that out of 171 field samples tested, 17 (9.94%) were positive bacteriologically for Pasteurella multocida. Out of 17 samples, 14 field isolates were confirmed to be P. multocida based on detection of KMT-1 gene (460 bp) by pm-PCR. Variation among the isolates of P. multocida in terms of their potential pathogenecity to mice was observed. Outer membrane vesicles (OMV) of P. multocida were found superior to bacterin based on post vaccinal antibody titre. In respect of antibody titre, no significant difference could be observed between OMV and bacterin preparations of P. multocida capsular type. However protection conferred by OMV preparation was quicker and found to be superior to conventional bacterin preparation.

· The study on non-cerebral Coenurosis with special reference to epidemiology and molecular characterization of Coenurus gaigeri in goats revealed that the occurrence was 5.4% and 1.33% respectively. Hajo area under undivided Kamrup district of Assam had significantly highest occurrence of non-cerebral coenurosis in goats while cerebral coenurosis was mostly recorded from Khanapara area. Non-cerebral coenurosis was significantly higher in female goats than in males. The thigh and brain were the most common site of predilection of non cerebral and cerebral coenurus cysts, respectively. Average pre-patent period of adult taeniid in dogs derived from non-cerebral and cerebral coenurus cyst were 60.20 days and 56.80 days, respectively. Molecular study targeting amplification of CO1 and NAD1 gene of Taenia multiceps yielded the expected 444 bp and 530 bp products showing the GeneBank database confirmed as Taenia multieps. The phylogenetic analysis of CO1 gene sequences revealed close similarity of both isolates to one of the Taenia multiceps isolates from China forming a single clade and confimed as Taenia multieps. The phylogenetic analysis of NAD1 gene sequences revealed close similarity of a cerebral isolate with one each isolates of Taenia multiceps from Greece and Iran and two from Turkey with which it formed a single clade and confirmed as Taenia multiceps. A non-cerebral isolate in the present study although showed similarity with an isolate from Greece, but it formed a separate clade within the same cluster in the phylogenetic tree. Based on the phylogenetic analysis of CO1 and NAD1 gene sequences, Taenia multiceps was the single valid species and the origin of both non-cerebral (Coenurus gaigeri) and cerebral (Coenurus cerebralis) cysts in goats. The molecular data based on CO1 and NAD1 sequences of both non-cerebral and cerebral coenurus cysts in goats was reported for the first time from Assam, India.