V. Balamurugan

Diagnosis and control of peste des petits ruminants: a comprehensive review

Peste des petits ruminants (PPR) is an acute, highly contagious, world organization for animal health (OIE) notifiable and economically important transboundary viral disease of sheep and goats associated with high morbidity and mortality and caused by PPR virus. PPR is considered as one of the main constraints in augmenting the productivity of small ruminants in developing countries and particularly severely affects poor farmer’s economy. The disease is clinically manifested by pyrexia, oculo-nasal discharges, necrotizing and erosive stomatitis, gastroenteritis, diarrhoea and bronchopneumonia. The disease can be diagnosed from its clinical signs, pathological lesions, and specific detection of virus antigen/antibodies/genome in the clinical samples by various serological tests and molecular assays. PPR is the one of the priority animal diseases whose control is considered important for poverty alleviation in enzootic countries. Availability of effective and safe live attenuated cell culture PPR vaccines and diagnostics have boosted the recently launched centrally sponsored control programme in India and also in other countries. This review article primarily focus on the current scenario of PPR diagnosis and its control programme with advancement of research areas that have taken place in the recent years with future perspectives.

Molecular typing of Brucella species isolates from livestock and human

Although host specificity has been observed in different species of Brucella, crossing the animal host boundary is likely to occur at any time. In this study, Bruce ladder PCR and abortus–melitensis–ovis–suis (AMOS) PCR assays were used to characterize 47 Brucella isolates from Indian origin in order to know exact species for understanding epidemiology of brucellosis. Out of them, 28, 14, and 5 isolates were found to be Brucella abortus, Brucella melitensis, and Brucella suis, respectively. Further analysis by AMOS PCR has identified that all the B. abortus isolates belong to any one of the biovar 1, 2, or 4; of the five B. suis isolates, three belong to biovar 1 and two belong to any one of the biovar 2, 3, 4, or 5. Although this multiplex Bruce ladder PCR is useful in differentiating all Brucella species, elaborate study is required to further characterize the isolates at exact biovar level.

Goat pox virus isolated from an outbreak at Akola, Maharashtra (India) phylogenetically related to Chinese strain.

In this study, we investigated a goat pox outbreak that occurred in an organized goat farm in a village named Yerenda near Akola, Maharashtra, India during 2007–2008. The outbreak involved in 175 goats including kids of local nondescript breeds with a morbidity, mortality, and case fatality rate, respectively, of 20%, 11.4%, and 60%. The goat pox virus (GTPV) antigen/nucleic acid in the clinical samples was detected by CIE and PCRs whereas virus-specific antibody was detected by using SNT and indirect ELISA. From classical clinical signs coupled with epidemiological details and various diagnostic assays, the causative agent of the outbreaks, GTPV was identified, successfully isolated in Vero cells and characterized. Further, sequence analysis of P32 envelope protein gene revealed that this isolate phylogenetically related closely to Chinese strain.

Development of loop-mediated isothermal amplification assay for specific and rapid detection of camelpox virus in clinical samples

In this study, development of loop-mediated isothermal amplification (LAMP) assay based on ankyrin repeat protein gene (C18L) for specific and rapid detection of camelpox virus (CMLV) was carried out. The assay was optimized using viral genomic DNA (gDNA) extracted from density gradient purified CMLV and standard control recombinant DNA plasmid containing the target, which resulted in reliable amplification at 62°C for 60 min. The amplified LAMP product was identified by agarose gel electrophoresis and subsequent direct visualization under UV light or observation by naked-eye for the presence of turbidity and color change following the addition of SYBR Green I dye and hydroxy naphthol blue (HNB). The analytical specificity of LAMP and conventional PCR assays was evaluated using other related poxviruses namely buffalopox, goatpox, sheeppox, and orf viruses, which revealed only a specific amplification of CMLV. The LAMP assay was 10-fold more sensitive than the conventional PCR. Further, the assay was evaluated with DNA extracted from the cell culture isolates of CMLV (n=11) and clinical samples (n=23). These results proved that the developed LAMP is a simple, specific, sensitive, rapid and economical diagnostic tool for detection of CMLV from clinical materials.

Prevalence of Peste-des-petits-ruminant virus antibodies in cattle, buffaloes, sheep and goats in India

The present study describes the prevalence of Peste-des-petits-ruminant virus (PPRV) antibodies in cattle, buffaloes, sheep and goats carried out during the period 2011 using the serum samples randomly collected from different villages of five states of India. A total of 1,498 serum samples [nxa0=xa0605 (cattle); nxa0=xa0432 (buffaloes); nxa0=xa0173 (sheep); nxa0=xa0288 (goats)] were collected from 52 districts in five states (Andhra Pradesh, Gujarat, Jammu and Kashmir, Maharashtra and Rajasthan) of India and were screened for PPRV-specific antibodies by using PPR monoclonal antibody-based competitive ELISA kit. Analysis of 1,498 samples indicates that an overall seroprevalence of 21.83xa0% with 11.07xa0% in cattle, 16.20xa0% in buffaloes, 45.66xa0% in sheep and 38.54xa0% in goats. This report presents the results of PPRV-specific antibodies in situations where the subclinical, inapparent or nonlethal or recovery of infection was suspected in cattle, buffaloes, sheep and goats. The presence of PPRV antibodies demonstrate that bovines are exposed to PPRV infection and it implies the importance of cattle and buffaloes as subclinical hosts for the virus besides widespread presence of the disease in sheep and goats. Further, the study showed that the prevalence of PPRV antibodies in apparently healthy livestock under natural situation, 21.83xa0% of the animals were protected from PPRV re-infection. This inturn help in the implementation of disease control strategies such as vaccination in that particular geographical area.

TaqMan hydrolysis probe based real time PCR for detection and quantitation of camelpox virus in skin scabs

The study describes the development of TaqMan hydrolysis probe based real time PCR (rt-PCR) assay targeting the ankyrin repeat protein (C18L) gene sequences for the detection and quantitation of camelpox virus (CMLV) nucleic acid and its comparison with established conventional and SYBR green rt-PCR assays. The assay was specific with an efficiency of 99.4%. The analytical sensitivity was 4 × 10¹ and 0.35 in terms of copy number and picogram of virus genomic DNA, respectively. The assay was linear with an acceptable intra (0.9-2.83% and 0.9-2.3%) and inter-assay (0.46-2.3% and 0.9-3.3) variations, when standard plasmid DNA and genomic DNA from purified CMLV respectively were tested. The assay was rapid, specific and sensitive as that of SYBR green and 1000 times more sensitive than the conventional PCR. It is suitable for the detection of CMLV nucleic acid directly from clinical samples. Further, the assay was evaluated using cell culture adapted CMLV isolates (n=11) and clinical samples (n=23) from camels and humans suspected of camelpox. This is an improved technique over conventional and SYBR green rt-PCR methods for the detection and quantitation of CMLV from skin scabs.

Loop-mediated isothermal amplification assay for rapid and sensitive detection of sheep pox and goat pox viruses in clinical samples.

A Loop-mediated isothermal amplification (LAMP) assay targeting the highly conserved DNA polymerase gene of capripox virus genome was developed and evaluated for rapid detection of sheep pox and goat pox viruses. The optimized LAMP assay is found specific and sensitive for amplification of target DNA with a diagnostic sensitivity and specificity of 96.6% and 100% respectively compared to quantitative PCR. The detection rate of LAMP, PCR and Q-PCR assays is found to be 81.5%, 67% and 83% respectively. This LAMP assay has the potential for rapid clinical diagnosis and surveillance of sheep pox and goat pox in field diagnostic laboratories.

Development and comparative evaluation of loop mediated isothermal amplification (LAMP) assay for simple visual detection of orf virus in sheep and goats

A loop-mediated isothermal amplification (LAMP) assay targeting DNA Pol gene was optimized and evaluated for the rapid detection of orf virus in clinical samples. The LAMP assay was found to be specific and sensitive. The detection rate of LAMP (89.3%) was better than PCR (67.9%) and comparable to real-time PCR (91.1%) in clinical samples by gel electrophoresis and visual detection methods. This LAMP assay is simple and does not rely upon any special equipment and could be employed in clinical diagnosis and epidemiological survey of orf infection.

Pseudo-peptides as novel antileptospiral agents: Synthesis and spectral characterization

In this paper, we describe the synthesis of novel class of pseudo-peptides derived by coupling an amino acid with a heterocyclic moiety containing free amine group using suitable coupling agents. The synthesized compounds were characterized using spectral ((1)H NMR, (13)C NMR and MS) techniques. Preliminary pharmacological assays for Leptospirosis were studied by test tube dilution (TDT) and micro dilution technique (MDT). In particular, all the analyses led to the conclusion that the synthesized compound inhibiting the Leptospira a causal organism of Leptospirosis.

Farm Community Impacts of Foot-and-Mouth Disease Outbreaks in Cattle and Buffaloes in Karnataka State, India.

This study was conducted to assess the impact of Foot-and-mouth Disease (FMD) outbreak in cattle and buffaloes on farming community in Kolar district, Karnataka state, India. Primary data were collected using pre-tested schedule from 178 sample farms using multistage random cluster sample technique. The results revealed that 78% of surveyed villages were affected with FMD. The FMD incidence risk was high across the herd sizes, whereas the mortality risk was high in small herds. In indigenous cattle, the highest loss due to FMD was distress sale (208 USD) followed by other losses, whereas, in Crossbred cattle, the highest loss was mortality loss (515 USD) followed by distress sale (490 USD), milk yield loss (327 USD), treatment cost (38 USD) and extra labour engagement expenses for nursing of FMD-affected bovines (30 USD). In local and upgraded buffaloes, the mean total loss per affected animal was 440 USD and 513 USD, respectively. A very high variability in the loss per animal was observed across the type of losses in the Crossbred cattle, and it may be due to differences in age of the FMD-infected animal, value of the animal, milking stage, lactation levels, herd sizes and labour engagement levels, etc. In local and upgraded buffaloes, the mean total loss per animal was 639 USD and 1008 USD, respectively. The sensitivity analysis for 5% change in price revealed that the mean total loss per animal was positively correlated with price. Further, the social impact elicitation revealed that majority of the livestock owners perceived FMD had caused permanent asset loss, which in turn increased psychological stress of the family. The estimated losses and social impact due to FMD signify the importance of the intervention to control the disease and thus socio-economic gain to the farmer and society at large.