Sukdeb Nandi

Bovine herpes virus infections in cattle.

Abstract Bovine herpes virus 1 (BHV-1) is primarily associated with clinical syndromes such as rhinotracheitis, pustular vulvovaginitis and balanoposthitis, abortion, infertility, conjunctivitis and encephalitis in bovine species. The main sources of infection are the nasal exudates and the respiratory droplets, genital secretions, semen, fetal fluids and tissues. The BHV-1 virus can become latent following a primary infection with a field isolate or vaccination with an attenuated strain. The viral genomic DNA has been demonstrated in the sensory ganglia of the trigeminal nerve in infectious bovine rhinotracheitis (IBR) and in sacral spinal ganglia in pustular vulvovaginitis and balanoposthitis cases. BHV-1 infections can be diagnosed by detection of virus or virus components and antibody by serological tests or by detection of genomic DNA by polymerase chain reaction (PCR), nucleic acid hybridization and sequencing. Inactivated vaccines and modified live virus vaccines are used for prevention of BHV-1 infections in cattle; subunit vaccines and marker vaccines are under investigation.

Occurrence of canine parvovirus type 2c in the dogs with haemorrhagic enteritis in India.

Canine parvovirus 2 (CPV-2) causes a highly contagious and often fatal disease in dogs. Since its sudden emergence in the early 1970s, CPV-2 has been evolving through the generation of novel genetic and antigenic variants (CPV-2a/b/c) that are unevenly distributed throughout the world. In the present study we have examined 36 clinical cases of dogs suspected of CPV collected during year 2006. A fragment of the VP2 gene of the virus was analyzed using polymerase chain reaction (PCR), restriction endonuclease (RE) and DNA sequence analysis. Out of the 36 samples analyzed, 16 were found positive for CPV-2a/2b by conventional PCR. DNA sequencing was done for 6 PCR positive samples, out of which three were characterized as CPV-2c, indicating that this CPV type 2c is currently circulating in India.

Immune responses and protective efficacy of binary ethylenimine (BEI)-inactivated bluetongue virus vaccines in sheep

Abbreviations: Al(OH)3, aluminium hydroxide; BEI, binary ethylenimine; BTV, bluetongue virus; CMI, cellmediated immune response; CPE, cytopathic effect; CRI, clinical reaction index; d.p.i., days post inoculation; DTH, delayed-type hypersensitivity; EHDV, epizootic haemorrhagic disease virus of deer; FIA, Freund’s incomplete adjuvant; PBS, phosphate-buffered saline; pfu, plaque-forming unit; PHA, phytohaemagglutinin; RBC, red blood cell

Oxidative stress indices in gastroenteritis in dogs with canine parvoviral infection

Abstract Gastroenteritis of viral origin has emerged as a major cause of morbidity and mortality in dogs during the last two decades. Amongst the viral etiologies responsible for gastroenteritis in dogs, canine parvovirus (CPV) is considered as the most pathogenic. The disease is characterized by hemorrhagic enteritis, bloody diarrhoea and myocarditis in young pups. The present study was carried out to examine alterations in oxidative stress indices in the erythrocytes from dogs suffering from gastroenteritis with or without canine parvoviral infection as confirmed by CPV-DNA amplification from faeces using specific primers for CPV-2 as well as CPV-2a and CPV-2b variants by polymerase chain reaction (PCR). The present investigation utilized clinical cases of dogs with signs of acute diarrhea (n =56), and 14 more apparently healthy dogs of similar age group. Erythrocytic oxidative stress indices such as lipid peroxides level and antioxidant enzymes like superoxide dismutase and catalase activity, and blood micro-mineral (iron, copper, cobalt and zinc) status were analyzed in each dog (n =70). The acute cases of gastroenteritis in dogs were associated with altered erythrocytic lipid peroxidation as evident by estimation of malonaldehyde (MDA) concentration. The activities of antioxidant enzymes catalase and superoxide dismutase, the first line of antioxidant defense against damaging effects of free radicals, were also altered. The alterations in oxidative stress indices were more pronounced in cases with involvement of canine parvovirus as compared to parvo-negative cases. Our results also revealed decreased blood zinc level in diarrhoea in dogs irrespective of involvement of canine parvovirus.

Determination of anti-inflammatory cytokine in periparturient cows for prediction of postpartum reproductive diseases

Forty-one pregnant cows at 240 days of gestation were selected from the cattle herd at the Indian Veterinary Research Institute, Izatnagar, Bareilly, India. The cows were critically observed daily during the periparturient period until 45 days postpartum. The prepartum sampling day was fixed on the basis of AI date supported by the external signs of the animals approaching parturition. Blood sampling was done for each experimental animal on 15 days prepartum (-15 d), calving day (0 d), 15 days (15 d), and 30 days (30 d) postpartum, and thorough gynecological examinations were performed on 0 d, 15 d, 30 d, and 45 d for diagnosis of postpartum reproductive diseases like retained placenta (ROP), clinical metritis (CM), clinical endometritis, cervicitis, and delayed involution of the uterus. The blood serum was used for estimation of the anti-inflammatory cytokine interleukin 10 (IL-10). Determintaion of IL-10 concentration in serum was done by using a commercially available bovine-specific ELISA kit. The IL-10 concentration (pg/mL) was significantly (P < 0.01) higher for ROP (1956.96 ± 325.30) and CM (2283.01 ± 326.82) than normal cows (827.19 ± 127.11) at 15 days before calving. The values for IL-10 was also significantly (P < 0.05) higher for cows with ROP and CM than for normal cows at 0 d and 15 d postpartum. However, the values for IL-10 were significantly (P < 0.05) higher for cows with clinical endometritis (1847.83 ± 539.38) than for normal cows (770.75 ± 29.22) at 30 d postpartum. The concentration of IL-10 was lower (P > 0.05) in cows with delayed involution of uterus than other groups of cows at all days of the periparturient period. The cytokine level in cows with delayed involution of the uterus was 328.906 ± 107.19, 263.08 ± 84.92, 415.26 ± 102.14, and 386.28 ± 111.11 on -15 d, 0 d, 15 d, and 30 d, respectively. According to the results of this study it can be concluded that increased serum concentration of IL-10 at 15 d prepartum was observed in cows that developed ROP and CM and remained significantly higher until 15 d postpartum. Therefore, this cytokine might be used as a prognostic marker to identify the cows that are going to develop ROP and CM.

Development of a SYBR Green based real-time PCR assay for detection and quantitation of canine parvovirus in faecal samples

Abstract The present study describes the development of SYBR Green based real-time polymerase chain reaction (real-time PCR) for detection and quantitation of canine parvovirus type 2 (CPV 2) in faecal samples of dogs. In this assay, the primers were designed and custom-synthesized based on nucleotide sequence of VP2 gene of CPV 2. A standard curve was plotted using 10-fold serial dilution of standard plasmid DNA and Ct value. The standard curve was found to be linear over a 10−7 dilution. The real-time PCR results were expressed as the number of DNA copies of CPV 2 per mg of faecal samples and showed range of 1.0×103 to 7.0×109 copies of viral DNA per mg of stool samples. The analytical sensitivity of the SYBR Green based real-time PCR was shown to be equivalent to 10 copies. Faecal samples (47) from dogs suspected of CPV 2 infection were analyzed by real-time PCR, haemagglutination (HA) assay and by a conventional PCR and 24, 20 and 22 samples were found positive for CPV 2, respectively. Comparison between the results of three different assays revealed that real-time PCR is more sensitive than HA and conventional PCR and allow the detection of low titers of CPV 2 in infected dogs.

Differential expression of pro-inflammatory cytokines in endometrial tissue of buffaloes with clinical and sub-clinical endometritis

The objective of this study was to investigate the endometrial expression of pro-inflammatory cytokines (IL1β, IL6, IL8 and TNFα) along with TLR4 and CD14 in normal and endometritic buffaloes. The genitalia were collected in the abattoir and divided into three groups as normal (gr. I=12), clinical endometritis (CE, gr. II=12) based on positive color reaction to white side test of uterine discharge and sub-clinical endometritis (SCE, gr. III=12) based on endometrial cytology (presence of ≥5% PMNs) and histopathology. The equal numbers of genitalia were grouped into follicular and luteal stage in each group. Endometrial tissue scrapings were used for total RNA extraction and cDNA was transcribed and amplified by Real time PCR. The results showed several fold higher expression of all cytokine transcripts in CE (gr. II), whereas significant up-regulation of CD14 (1 to 2-fold), IL6 (15 to 36-fold), IL8 (8 to 14-fold) and TNFα (10 to 11-fold) mRNA was observed in SCE. This indicates that the evaluation of expression patterns of certain cytokines gene holds promise to diagnose the severity and degree of uterine inflammation.

Canine Parvovirus: Current Perspective

Canine parvovirus 2 (CPV-2) has been considered to be an important pathogen of domestic and wild canids and has spread worldwide since its emergence in 1978. It has been reported from Asia, Australia, New Zealand, the Americas and Europe. Two distinct parvoviruses are now known to infect dogs—the pathogenic CPV-2 and CPV-1 or the minute virus of canine (MVC). CPV-2, the causative agent of acute hemorrhagic enteritis and myocarditis in dogs, is one of the most important pathogenic viruses with high morbidity (100%) and frequent mortality up to 10% in adult dogs and 91% in pups. The disease condition has been complicated further due to emergence of a number of variants namely CPV-2a, CPV-2b and CPV-2c over the years and involvement of domestic and wild canines. There are a number of different serological and molecular tests available for prompt, specific and accurate diagnosis of the disease. Further, both live attenuated and inactivated vaccines are available to control the disease in animals. Besides, new generation vaccines namely recombinant vaccine, peptide vaccine and DNA vaccine are in different stages of development and offer hope for better management of the disease in canines. However, new generation vaccines have not been issued license to be used in the field condition. Again, the presence of maternal antibodies often interferes with the active immunization with live attenuated vaccine and there always exists a window of susceptibility in spite of following proper immunization regimen. Lastly, judicious use of the vaccines in pet dogs, stray dogs and wild canids keeping in mind the new variants of the CPV-2 along with the proper sanitation and disinfection practices must be implemented for the successful control the disease.

Prevalence of classical swine fever virus in India: a 6-year study (2004-2010).

A study was undertaken regarding the prevalence of classical swine fever virus (CSFV) antibodies and antigens in sera and suspected tissue samples of domestic pigs. The samples were received between January 2004 and September 2010. A total of 594 serum samples from 12 states and 287 tissue samples from 13 states of India were tested using commercial enzyme-linked immunosorbent assay (ELISA) kits. The mean prevalence of CSFV antibodies in suspected sera was 63.3% (376/594), whereas 76.7% (220/287) of the suspected samples were found to contain CSFV antigen. The high prevalence of CSFV antibodies suggests that the disease is endemic in the country. This baseline data will be of use in the formulation of control and eradication programmes.

Classical swine fever in pigs: recent developments and future perspectives

Abstract Classical swine fever (CSF) is one of the most devastating epizootic diseases of pigs, causing high morbidity and mortality worldwide. The diversity of clinical signs and similarity in disease manifestations to other diseases make CSF difficult to diagnose with certainty. The disease is further complicated by the presence of a number of different strains belonging to three phylogenetic groups. Advanced diagnostic techniques allow detection of antigens or antibodies in clinical samples, leading to implementation of proper and effective control programs. Polymerase chain reaction (PCR)-based methods, including portable real-time PCR, provide diagnosis in a few hours with precision and accuracy, even at the point of care. The disease is controlled by following a stamping out policy in countries where vaccination is not practiced, whereas immunization with live attenuated vaccines containing the ‘C’ strain is effectively used to control the disease in endemic countries. To overcome the problem of differentiation of infected from vaccinated animals, different types of marker vaccines, with variable degrees of efficacy, along with companion diagnostic assays have been developed and may be useful in controlling and even eradicating the disease in the foreseeable future. The present review aims to provide an overview and status of CSF as a whole with special reference to swine husbandry in India.