Comparative efficacy of chemical stabilizers on the thermostabilization of a novel live attenuated buffalopox vaccine.

In the present investigation, the thermostability of a live attenuated buffalopox vaccine prepared with an indigenous baffalopox virus isolate (BPXV Vij/96) and freeze-dried under conventional lyophilizing conditions is described. Three different stabilizer combinations like LS (lactalbumin hydralysate + sucrose), LHT (lactalbumin hydralysate + Trehalose dihydrate) and TAA (Trehalose dihydrate + l- Alanine + l-Histidine) were used to prepare the vaccine. The study indicated that the LS stabilizer was found to be the stabilizer of choice followed by LHT and TAA for buffalopox vaccine at all temperatures studied. The presence of stabilizers has beneficial influence in preserving the keeping quality of the vaccine. Further, among the diluents used to reconstitute the freeze-dried buffalopox vaccine, double distilled water, 0.85% normal saline solution and phosphate buffer saline were the choice of diluents in that order. However, 1M MgSO4 did not perform well at higher temperatures. Investigation suggests for using LS as a stabilizer for freeze-drying and any of the three diluents except 1MgSO4 for reconstitution of buffalopox vaccine.

Influence of crystal structure, ligand environment and morphology on Co L-edge XAS spectral characteristics in cobalt compounds.

The electronic structure of a material plays an important role in its functionality for different applications which can be probed using synchrotron-based spectroscopy techniques. Here, various cobalt-based compounds, differing in crystal structure, ligands surrounding the central metal ion and morphology, have been studied by soft X-ray absorption spectroscopy (XAS) at the Co L-edge in order to measure the effect of these parameters on the electronic structure. A careful qualitative analysis of the spectral branching ratio and relative intensities of the L3 and L2 peaks provide useful insight into the electronic properties of compounds such as CoO/Co(OH)2, CoCl2.6H2O/CoF2.4H2O, CoCl2/CoF2, Co3O4 (bulk/nano/micro). For further detailed analysis of the XAS spectra, quantitative analysis has been performed by fitting the spectral profile with simulated spectra for a number of cobalt compounds using crystal field atomic multiplet calculations.

Eradicating successfully yaws from India: The strategy & global lessons.

Yaws, a non-venereal treponematosis, affecting primarily the tribal populations, has been considered historically as one of the most neglected tropical diseases in the world. In 1996, India piloted an initiative to eradicate yaws based on a strategy consisting of active case finding through house-to-house search and treatment of cases and their contacts with long acting penicillin. Thereafter, the campaign implemented in all 51 endemic districts in 10 states of the country led to the achievement of a yaws-free status in 2004. In the post-elimination phase, surveillance activities accompanied by serological surveys were continued in the erstwhile endemic districts. These surveys carried out among children between the age of 1-5 yr, further confirmed the absence of community transmission in the country. The experience of India demonstrates that yaws can be eradicated in all endemic countries of Africa and Asia, provided that political commitment can be mobilized and community level activities sustained until the goal is achieved.

Evaluation of stability of live attenuated camelpox vaccine stabilized with different stabilizers and reconstituted with various diluents.

In this study, thermostability of a Vero cell attenuated live camelpox vaccine under conventional lyophilization conditions has been evaluated. Three stabilizers were used separately for freeze-drying the vaccine and the stability of the vaccine, both in freeze-dried and reconstituted forms at different temperatures was assessed. The study revealed that the camelpox vaccine lyophilized with TAA stabilizer found superior with a shelf life of 44 months, 227 days, 22 days and 20 days at 4, 25, 37 and 45 °C, respectively followed by LS stabilizer. In terms of half-life, TAA stabilizer proved better followed by LS and BUGS stabilizers at all temperatures except at 25 °C in which LS found relatively superior. Among the four diluents viz. 1x PBS (phosphate buffered saline, pH 7.4), 0.85% NaCl, distilled water and 1 M MgSO4, PBS was a better diluent followed by 0.85% NaCl. Both the diluents maintained the infectivity titer more than the minimum effective dose (3 log10TCID50 with a maximum titre of 6.53 log10TCID50 in both the diluents) for 60 h at 37 and 45 °C. However, 1 M MgSO4 found less suitable for camelpox vaccine dilution. The study indicates that the TAA and 1× PBS are the choice of stabilizer and diluent, respectively for camelpox vaccine.

Host plant selection by larvae of the muga silk moth, Antheraea assamensis, and the role of the antenna and maxillary palp.

The importance of olfactory senses in food preference in fifth instar larvae of Antheraea assamensis Helfer (Lepidoptera: Saturniidae) was examined by subjecting larvae with only antennae or maxillary palpi after microsurgery to food and odor choice tests. Mean percent consumption, total consumption, and choice indices were used as parameters for drawing conclusions. The foods used were two hosts, two non-hosts, and a neutral medium (water). Both antennae and maxillary palpi were fully competent in preference for host plants, Persea bombycina Kostermans (Laurales: Lauraceae) and Litsea polyantha Juss, over the non-hosts, Litsea grandifolia Teschner and Ziziphus jujuba Miller (Rosales: Rhamnaceae). Both were competent in rejecting the non-hosts, L. grandifolia and Z. jujuba. The odor choice test was carried out using a Y-tube olfactometer and showed similar results to the ingestive tests. The results indicate the necessity of functional integration of a combination of olfactory and gustatory sensilla present in different peripheral organs in food acceptance by A. assamensis larvae.

Influence of silylated nano cellulose reinforcement on the mechanical, water resistance, thermal, morphological and antibacterial properties of soy protein isolate (SPI)-based composite films.

The aim of this research work is to improve the mechanical and water-resistance properties of soy protein isolate (SPI) biofilm. In this work, 3-aminopropyltriethoxysilane (APTES) coupling-agent modified nanocellulose was introduced into the SPI matrix in the presence of citric acid cross-linker. The presence of amino groups in APTES facilitated the formation of - cross-linked structures with soy protein. The incorporation of a citric acid cross-linker made the cross-linking process more productive, and the surface smoothness of the film was confirmed by a Scanning Electron Microscope (FE-SEM). From the study of the mechanical and thermal properties and water resistance of the film, it was confirmed that the results were highly satisfactory for the modified nanocellulose-incorporated film compared to the non-modified one. Additionally, coating of citral essential oil onto SPI nanocomposite film displayed antimicrobial properties due to the presence of various phenolic groups in the citral oil. The Tensile Strength and Young's Modulus of silane-modified nanocellulose containing film were enhanced by ∼119 % and âˆ¼ 112 %, respectively on incorporation of 1 % APTES-modified nanocellulose. Consequently, this work is expected to offer an effective way for silylated nano-cellulose reinforcing soy protein isolate (SPI)-based bio nanocomposite films for packaging applications. As an example, we have demonstrated one of the applications as wrapping films for packing black grapes.

Real time PCR: a rapid tool for potency estimation of live attenuated camelpox and buffalopox vaccines.

In the present study, SYBR Green and TaqMan real time PCRs (rt-PCR) based on the C18L gene (encodes ankyrin repeat protein) of camelpox (CMLV) and buffalopox viruses (BPXV) were, respectively employed for potency evaluation of live attenuated camelpox and buffalopox vaccines. Cells infected with the respective vaccine viruses were harvested at critical time points and subjected to respective PCRs. The critical time points of harvests for CMLV and BPXV respectively, were 36 and 30 h post infection and were respectively determined based on maximum slopes of (-3.324) and (-3.321) standard curves. On evaluation of eight batches of camelpox and seven batches of buffalopox vaccines, the results indicated that the titres estimated by respective rt-PCRs were well comparable to the conventional TCID(50) method. The rt-PCR assays were found relatively more sensitive, specific and rapid than end point dilution assay. Thus, they could be used as additional tools for estimation of live CMLV and BPXV particles in camelpox and buffalopox vaccines.

Classical swine fever in the pygmy hog.

The pygmy hog is a rare, small and highly endangered mammal belonging to the Suidae family, and it is presently found only in the Assam state of India. While investigating the cause of death of pygmy hogs housed at a conservation centre for captive breeding and research at Basistha, Assam, it was confirmed that they were susceptible to and died as a result of contracting classical swine fever (CSF), caused by CSF virus (CSFV), which is a highly infectious endemic disease of domestic pigs in India. The post-mortem findings and serum CSFV-specific antibody titres, along with the isolation of CSFV from two pygmy hogs, and further confirmation by CSFV genomic E2 and 5' untranslated region (UTR) gene amplification in PCR (polymerase chain reaction), clearly established the cause of death of the pygmy hogs. Further, on phylogenetic analysis, the pygmy hog CSFV 5' UTR sequences were grouped in the genotype 1.1 cluster of Indian CSFVs, and hence the strains causing infection were closely related to CSFV isolates circulating in domestic pigs. Therefore, the occurrence of CSF in this endangered species may pose a potent threat to their existence unless properly controlled, and thus it needs urgent attention. To the authors' knowledge this is the first report on CSF in pygmy hogs.

An improved visual closed tube Loop mediated isothermal amplification (LAMP) assay for rapid identification of orf virus in sheep and goats.

The orf virus (ORFV) is an epitheliotropic virus causing a highly contagious skin disease mainly in sheep and goats. Several diagnostics including molecular tools like Loop mediated isothermal amplification (LAMP) assay are available to detect ORFV in affected species. However, the carry-over contamination associated with LAMP as open tube format prevents the assay applicability as point of care test in field diagnostic settings. In this study, the B2L gene based LAMP assay was optimized in a closed tube format using hydroxynaphthol blue (HNB) and calcein as pre-addition dyes and it has shown a clear positive and negative signal at 60 °C using 4 and 5 mM concentrations of MgSO4 respectively for these dyes. Optimitimzed assay that could reveal the result within one hour is highly specific and senstive with a limit of detection at 12.5 femtogram of viral genomic DNA or ~85 virus genome equivalent. This improved method prevented the cross-contamination of future LAMP reactions in the laboratory without compromising diagnostic sensitivity (100%) and specificity (100%) when compared to open tube system. This closed tube LAMP method has potential to act as a simple visual detection assay for the rapid and specific diagnosis of ORFV in sheep and goats.

Comparative efficacy of live replicating sheeppox vaccine strains in Ovines.

In the present study, two sheeppox vaccines made from strains [sheeppox virus-Srinagar (SPPV-Srin) and Ranipet (SPPV-R)] indigenous to India and adapted to Vero cells were compared in terms of their safety, potency, efficacy and antigenic value with the commercial in-use Roumanian Fanar (SPPV-RF) vaccine, a foreign strain adapted in primary lamb testes cells. The safety test indicated that the SPPV (Sri and RF) vaccines were safe while SPPV-R was not completely attenuated and caused excessive adverse reactions at the passage level tested. The immunized animals showed DTH reaction and resisted virulent SPPV challenge, while control animals developed disease. Specific virus could be detected in the controls and animals immunized with lower dilutions of vaccines after challenge but not in any of the sheep immunized with 1 and 100 doses of each vaccine. All vaccines were found potent and the PD(50) was highest for SPPV (Srin and R) followed by RF. The immunized animals were seroconverted following vaccination with sustained antibody responses after challenge. In conclusion, indigenous SPPV-Srin vaccine was found to be as efficacious as SPPV-R and SPPV-RF vaccines. Thus, there is potential benefit in replacing the currently used commercial vaccine SPPV-RF with indigenous SPPV-Srin vaccine for use in India.

Lymphatic filariasis in East District, Sikkim.

East district of Sikkim has been considered as non-endemic for lymphatic filariasis (LF). However, a LF survey conducted during 2008 revealed microfilaria rate (mf rate) of 1.2%. The LF survey was carried out in 15 randomly selected villages and urban localities of East Sikkim. Out of 3,428 night blood smears collected and examined, 42 were found positive for Wuchereria bancrofti. Microfilaria (mf) carriers were detected from 5 surveyed villages and 5 urban localities of Singtam and Rangpoo with mf rate ranging from 0.5% to 4.2%. The mean mf density was 5.4 per 20cmm3 blood. All mf carriers were residents of east district, Sikkim except two persons who were from Bihar. The detection of microfilaria in young children who had never moved from the area indicates probable indigenous transmission. Out of 15 surveyed areas LF disease was found in 11 areas with prevalence ranging from 0.4% to 7.0%.(Disease rate was 1.6%) (1.7% for Males & 1.4% for females). One local individual was found with lymphoedema and also mf positive. Vector density ranged from 70 to 435 per ten-man-hours, sufficient for transmission of LF. 712 female Cx. quinquefasciatus were dissected to detect the filarial infection and none was found positive. The present survey findings indicate endemicity of filariasis in East district of Sikkim.

Status of lymphatic filariasis in Lucknow District, Uttar Pradesh.

Lucknow district was endemic for lymphatic filariasis (LF). During March 2008, LF survey was carried out in 14 randomly selected villages (six Primary Health Centres) and 4 Mohallas of Lucknow city. Out of 3,654 night blood smears (NBS) collected and examined, 209 were found positive for Wuchereria bancrofti (micrifilaria rate: 5.7%). Microfilaria (mf) carriers were detected from all surveyed villages and Mohallas. The age of these positive persons ranged from 6-70 years. In all areas, prevalence of microfilaraemia generally increased with age up to 21-30 years. Males (6.7%) were more affected than females (3.9%). All mf carriers were residents of Lucknow district. Overall disease rate was 4.7%. In all, 175 individuals had disease manifestations of LF. Out of 108 males, 81 had hydrocele(75%). Disease rate was similar in males (4.7%) and females (4.8%). The mean mf density was 9.5 per 20 cmm blood, but no significant difference between males (9.4) and females (9.9). Vector density ranged from 150 to 810 per ten-man-hours. Infectivity and infection rates were 0.14%. The present survey indicates that filariasis is one of the major public health problems in surveyed areas.

Study on the eco-epidemiology of Chikungunya in U.T of Lakshadweep.

An unusual increase in the incidence of viral fever was noticed in Androth and Kalpeni Island, U.T of Lakshadweep during November 2006. The Eco-epidemiology of the disease was studied in detail. The study indicated that Aedes albopictus is the predominant species (98.74%) and it exhibited a wide spectrum of breeding preferences with a clear-cut predilection for rat-damaged coconuts (RDCs). All the entomological indices were very high in both the Islands with a marked increase in Kalpeni Island. The clinical presentation of the cases was typical of chikungunya and the laboratory study confirmed this. Based on the investigation, control and preventive measures were planned, advised and implemented. The details regarding the bio-ecology of vectors, clinical presentation, laboratory investigations and effectiveness of control measures are discussed.

A tetrode based fast pulsed microwave source for electron cyclotron resonance breakdown experiments.

To study electron cylotron resonance (ECR) breakdown and afterglow plasma in an experimental linear plasma system, a pulsed microwave source with rapid rise and fall of microwave power is desired. A pulsed microwave source with fast rise and fall capability for ECR breakdown experiments has been designed and tested for performance in the system. A tetrode, controlled by a modulator card, is used as a fast switch to initiate microwave power from a conventional magnetron operating at 2.45 GHz. The typical rise time of microwave power is approximately 3 micros and a fall time of approximately 10 micros. Using this scheme in a realistic pulsed microwave source at 800 W power, ECR breakdown of neutral gas is achieved and the plasma delay and fall time are observed from the plasma density measurements using a Langmuir probe. The design details of the fast rise pulsed microwave source are presented in this article with initial experimental results.

Lymphatic filariasis in rural areas of Patna District, Bihar. A challenge ahead.

Patna district was endemic for lymphatic filariasis (LF). During November 2004, a lymphatic filariasis survey was carried out in seven randomly selected villages from four PHCs of Patna district. Of 1878 night blood smears (NBS) examined, 117 were found positive for W. bancrofti infection (mf rate 6.2%). Microfilaria carriers were detected from all surveyed villages. In all areas prevalence of microfilaria generally increased with age to maximum 15-34 years and then decline within most age-groups. More males (6.4%) were affected than the females (5.8%). All microfilaria (mf) carriers were residents of Patna district. Over all disease rate was 9.1%. Out of 171 diseased individuals, 121 persons were having hydrocele (6.4%). Disease rate was higher in males (12.0%) than females (4.1%). The mean mf density was 11.7. There was no significant difference of mean mf density in males and females. Vector density ranged from 205 to 780 per ten man hours. The survey indicates that the filariasis situation remained unchanged since last fifty years and still is one of the major public health problem in surveyed areas.

Isolation and characterization of Shiga toxigenic Escherichia coli of animal and bird origin by multiplex polymerase chain reaction.

AIM: The purpose of this study was to determine the virulence genes and serotype of Shiga toxin producing Escherichia coli (STEC) strains isolated from animals and birds. MATERIALS AND METHODS: A total of 226 different samples viz., fecal, intestinal content, rectal swab and heart blood were collected from different clinically affected/healthy animals and birds and were streaked on McConkeys' lactose agar and eosin methylene blue agar for isolation of E. coli, confirmed by staining characteristics and biochemical tests. By polymerase chain reaction (PCR) all the E. coli isolates were screened for certain virulence genes, viz., Shiga toxin 1 (stx1), stx2 and eae and enterohemolytic (Ehly) phenotype was observed in washed sheep blood agar plate. All the isolated E. coli strains were forwarded to the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli (Himachal Pradesh) for serotyping. RESULTS: Out of 226 samples 138 yielded E. coli. All the isolates were screened for molecular detection of different virulent genes, viz. stx1, stx2 and eae, based on which 36 (26.08%) were identified as STEC. Among those STEC isolates, 15 (41.67%), 14 (38.89%), 1 (2.78%) exhibited eae, stx2, stx1 alone, respectively, whereas 4 (11.11%) and 2 (5.56%) carried both stx1 and stx2, stx2 and eae, respectively. Among the STEC isolates 22 were belonged to 15 different sero-groups, viz., O2, O20, O22, O25, O43, O60, O69, O90, O91, O95, O106, O118, O130, O162 and O170 and others were untypable. Ehly phenotype was observed in 10 (27.78%) the STEC isolates. CONCLUSION: The present study concluded that STEC could be isolated from both clinically affected as well as healthy animals and birds. Regular monitoring of more samples from animal and bird origin is important to identify natural reservoir of STEC to prevent zoonotic infection.

Seroprevalence of Rotavirus infection in pig population of Arunachal Pradesh.

AIM: This study was conducted to find out the seroprevalence of Rotavirus(RV) infection among the pig population of Arunachal Pradesh. MATERIALS AND METHODS: Serums samples were collected from piglets of age ranging from 1 week to 6 months and the sows associated with the piglets that were reared under organized and unorganized system of management in six different districts of Arunachal Pradesh. The prevalence of RV specific antibodies was detected using a polyclonal antibody-based indirect enzyme-linked immunosorbent assay (i-ELISA). RESULTS: The study revealed that out of 394 serum samples, 255 (64.72%) samples were found to be positive for RV-specific antibody in i-ELISA. Considering the samples from different districts, Papumpare district of Arunachal Pradesh showed highest numbers of seropositive animals (68.75%) followed by upper Subansiri (64.91%) while West Siang district showed lowest positivity rate (61.22%). CONCLUSION: As considerable seropositivity was recorded among pig population of Arunachal Pradesh in this study, there is urgent need to establish high-impact and cost-effective public health intervention tools, key among them being the introduction of strict hygiene practice and RV vaccination program, to greatly reduce the number of deaths due to diarrheal diseases. To the authors' knowledge, this is the first report on the prevalence of RV infection from pigs of Arunachal Pradesh.

Classical Swine Fever in Wild Hog: Report of its Prevalence in Northeast India.

Classical swine fever virus (CSFV) is the causative agent of a highly contagious disease, hog cholera in pigs. The disease is endemic in many parts of the world and vaccination is the only way to protect the animals from CSFV infection. Wild hogs belong to the species Sus Scrofa Cristatus under the family Suidae are quite susceptible to CSFV infection. The epidemiological role concerning classical swine fever (CSF) in India is largely unknown. We report here the three isolated cases of CSF in wild hogs from three National parks, namely Kaziranga National Park, Manas National Park and Jaldapara National Park, from north-east part of India. The post-mortem and histopathological findings were clearly indicative for CSFV infection. The presence of CSFV genome was demonstrated in several organs and tissues collected from hogs died due to viral infection. In addition, CSF-specific antibodies were detected in two wild hogs as well as in eighteen feral pigs from the same locations. The phylogenetic analysis of the partial E2 protein gene and 5' untranslated region of CSFV isolates from the wild hog showed identities with genotype 2.2 of the Indian isolates. Occurrence of CSF in wild hogs may pose a potent threat in the epidemiology of the virus in Northeast part of India. To the best of our knowledge, the report presented in the manuscript is the first comprehensive report on CSF in wild hogs form Northeast India. The findings reported would help us to understand the epidemiology and biology of CSFV in wild animals.

Yaws and its eradication in India--a brief review.

Until 1996-97, when Yaws Eradication Programme (YEP) in India was launched, there were three initiatives to assess/control the yaws disease in the country. YEP was initially started as pilot study in Koraput district, Orissa and later on extended to ten states covering 49 districts. The first goal has been to get the disease eliminated from the country with ultimate goal being its eradication. Strategies for YEP are active case detection and treatment including contacts and targeted IEC. The number of reported cases reduced from 735 in 1997 to "Zero Case" in 2004 from entire country. The recent Third Independent Appraisal of YEP could not confirm any new yaws case. However, before declaring the elimination (meaning no new early infectious case), there is need to make a thorough search in the affected areas. Future activities under the programme includes sero- surveillance among under-five children to demonstrate cessation of yaws transmission.