Emergence of variant avian infectious bronchitis virus in India

BACKGROUND

Infectious bronchitis virus (IBV) is the etiological agent of an acute and highly contagious disease. Infectious bronchitis (IB) affects chicken of all ages and poses major economic loses to the poultry industry worldwide. The continuous evolution of the spike protein (S1) of IBV is responsible for the prevalence of many serotypes/genotypes around the world. Multiple lineages of IBV strains have been detected in chicken flocks in India since 2003.

AIMS

To detect IBV genotypes prevalent in India.

METHODS

Organ samples from 20 IBV-positive flocks with variable clinical signs were used for the amplification of the S1 gene of IBV by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Positive PCR amplicons were sequenced. Sequence analysis showed that 14 field isolates belonged to the GI-1 genetic lineage (Mass 41 serotype), two field isolates belonged to the GI-13 (UK 4/91 variant IBV strain), one field isolate grouped with GIII, GV, and GVI genetic lineage and three belonged to a variant genotype unique to India (GI-24). Phylogenetic analysis also showed a similar type of grouping within the field isolates. Among the fourteen GI-1 isolates, 12 were isolated between 2003 and 2006 and only two were isolated between 2009 and 2011. The two field isolates belonging to GI-13 were isolated in 2007, another one belonging to GIII, GV, and GVI was isolated in 2010 and three field isolates were not close to any reference IBV sequences isolated in 2006 (IND-TN-168-06), 2010 (IND-TN-280-10) and 2011 (IND-TN-290-11).

CONCLUSION

A unique variant of IBV is emerging in India (GI-24). Our findings will have important implications for future vaccine intervention.

Duck plague outbreak in a Chara-Chemballi duck farm

BACKGROUND

Duck rearing is one of the important livelihoods of rural people. Duck plague is one of the diseases causing heavy mortality resulting in economic losses.

CASE DESCRIPTION

An outbreak of duck plague in a farm in Kadavakathi Village near Tenkasi, Tirunelveli Dt., is reported.

FINDINGS/TREATMENT AND OUTCOME

Two thousands out of 4500 Chara-Chemballi breed of ducks which were recently purchased from Chenganacherry in Kerala died, with a mortality rate of 44.4%. Clinical signs of inappetence, partial closure of eyelid, conjunctivitis, corneal opacity, oculo-nasal discharge, soiled vent with green white watery diarrhoea, ataxia, incoordination and sudden death were observed. Necropsy examination revealed diphtheritic membrane in the oesophagus, congestion, petechial haemorrhages and multifocal gray white areas on the surface of the liver, epicardial haemorrhages, congested trachea, lung, kidneys, splenomegaly with mottled appearance and enteritis. Microscopical examination revealed presence of eosinophilic intranuclear and intracytoplasmic inclusions in the epithelial cells of the intestine and hepatocytes, degeneration and necrosis of enterocytes, dilated crypt epithelial cells with presence of eosinophilic intranuclear and intracytoplasmic inclusions, congestion and lymphoid cell depletion in the spleen, vasculitis, congestion, and haemorrhages in the trachea and lungs, proventriculitis, and congested kidneys. Polymerase chain reaction (PCR) also confirmed the duck plague viral infection by the amplification of polymerase gene fragment (446 bp).

CONCLUSION

Based on the above findings, the Chara-Chemballi duck disease outbreak was diagnosed as duck viral enteritis infection.

Avian parvovirus: classification, phylogeny, pathogenesis and diagnosis

Poultry parvoviruses identified during the early 1980s are found worldwide in intestines from young birds with enteric disease syndromes as well as healthy birds. The chicken parvovirus (ChPV) and turkey parvovirus (TuPV) belong to the Aveparvovirus genus within the subfamily Parvovirinae. Poultry parvoviruses are small, non-enveloped, single-stranded DNA viruses consisting of three open reading frames, the first two encoding the non-structural protein (NS) and nuclear phosphoprotein (NP) and the third encoding the viral capsid proteins 1 (VP1 and VP2). In contrast to other parvoviruses, the VP1-unique region does not contain the phospholipase A2 sequence motif. Recent experimental studies suggested the parvoviruses to be the candidate pathogens in cases of enteric disease syndrome. Current diagnostic methods for poultry parvovirus detection include PCR, real-time PCR, enzyme linked immunosorbent assay using recombinant VP2 or VP1 capsid proteins. Moreover, sequence-independent amplification techniques combined with next-generation sequencing platforms have allowed rapid and simultaneous detection of the parvovirus from affected and healthy birds. There is no commercial vaccine; hence, the development of an effective vaccine to control the spread of infection should be of primary importance. This review presents the current knowledge on poultry parvoviruses with emphasis on taxonomy, phylogenetic relationship, genomic analysis, epidemiology, pathogenesis and diagnostic methods.

Sequence analysis of VP2 hypervariable region of the field isolates of infectious bursal disease viruses from southern region of India

Infectious bursal disease virus isolates obtained from southern parts of India were subjected to comparative sequencing and phylogenetic analysis of 743bp hypervariable region of VP2. The sequence analysis showed that among eight isolates, only HY12 showed the characteristic conserved amino acid residues at 256I, 294I, and 299S of vvIBDV. Six isolates BGE14, PY12, NKL14, VCN14, RPM14 and EDE14 had conserved amino acid residues at 256I and 299S, whereas at residue 294, isoleucine was substituted by valine. The remaining isolate MB11 had leucine at residue 294 and asparagine at residue 299 similar to classical strain 52/70. The serine-rich heptapeptide sequence SWSASGS adjacent to the second hydrophilic region was conserved in all seven Indian IBDV isolates except isolate MB11. Conservation of this sequence was earlier reported to be an indication of a virus isolate being pathogenic in nature. The reported heptapeptide sequence of the classical strain is 'SWSARGS'. In the present study, 'SWSARGS' heptapeptide sequence was observed in MB11 isolate. The pathogenicity trials conducted with these isolates further confirmed the genome analysis in classification. This study further reveals that the circulating IBDV strains in India could be diverse in nature.

Equipping providers with principles, knowledge and skills to successfully integrate behaviour change counselling into practice: a primary healthcare framework

OBJECTIVES

There is an urgent need for healthcare providers and healthcare systems to support productive interactions with patients that promote sustained health behaviour change in order to improve patient and population health outcomes. Behaviour change theories and interventions have been developed and evaluated in experimental contexts; however, most healthcare providers have little training, and therefore low confidence in, behaviour change counselling. Particularly important is how to integrate theory and method to support healthcare providers to engage in behaviour change counselling competently. In this article, we describe a general training model developed from theory, evidence, experience and stakeholder engagement. This model will set the stage for future evaluation research on training needed to achieve competency, sustainability of competency, as well as effectiveness/cost-effectiveness of training in supporting behaviour change.

DESIGN AND METHODS

A framework to support competency based training in behaviour change counselling is described in this article. This framework is designed to be integrative, sustainable, scalable and capable of being evaluated in follow-up studies.

RESULTS AND DISCUSSION

Effective training in behaviour change counselling is critical to meet the current and future healthcare needs of patients living with, or at risk of, chronic diseases. Increasing competency in establishing change-based relationships, assessing and promoting readiness to change, implementing behaviour modification and addressing psychosocial issues will be value added to the healthcare system.

Genotypic characterization of Indian isolates of infectious bursal disease virus strains by reverse transcription-polymerase chain reaction combined with restriction fragment length polymorphism analysis

The reverse transcription PCR (RT-PCR) combined with restriction fragment length polymorphism (RFLP) is used for the differentiation of classical virulent (cv), virulent (v) and very virulent (vv) strains of infectious bursal disease virus (IBDV) isolates from chicken bursal tissues in southern states of India. In the present study, six different isolates (MB11, HY12, PY12, BGE14, VCN14 and NKL14) of IBDV strains were subjected for genotyping along with vaccine virus (Georgia, intermediate strain) using RT-PCR for amplification of a 743 bp sequence in the hypervariable region of VP2 gene followed by restriction enzyme digestion with 5 different restriction enzymes (BspMI, SacI, HhaI, StuI and SspI). The RT-PCR products obtained from vvIBDV strains were digested by SspI enzyme except PY12, BGE14 and MB11 isolates. The SacI digested the isolate MB11, PY12 and the vaccine strain, but it did not cleave the very virulent isolates of IBDV. HhaI cleaved all the isolates with different restriction profile patterns. StuI digested all the vvIBDV isolates and BspMI was not able to differentiate field isolates from vaccine strain. Though RT-PCR combined with RFLP is a genotypic method, further confirmation of serotypes to distinguish the vvIBDV from cvIBDV has to be carried out using pathogenicity studies.

Seroepidemiology of infectious bovine rhinotracheitis infection in unvaccinated cattle

AIM

The present study aimed to investigate the seroepidemiology of infectious bovine rhinotracheitis (IBR) infection in the non-vaccinated cattle population in northern part of Tamil Nadu, India.

MATERIALS AND METHODS

A total of 255 sera samples were collected from cattle having the history of respiratory and reproductive disorder from cattle of different age, breeds, and sex. All the sera samples were subjected to indirect ELISA for the diagnosis of IBR antibodies.

RESULTS

Results revealed that the seroprevalence of IBR infection among non-vaccinated cattle population was of 65.88%. No significant difference was noticed in the prevalence of IBR infection between cattle showing respiratory (63.64%) and reproductive form (70.89%) (p≥0.05). A higher prevalence was noticed in animals above 3 years of age (59.60%) and in crossbred animals (71.26%) than young and non-descript animals. This study showed the higher prevalence of IBR infection in female (67.92%) than in male (33.33%).

CONCLUSION

Cattle population in this part can better be protected with vaccination than leaving them unvaccinated and sero-monitoring shall have to be stressed with regular attempts to isolate and characterize the causative agent for IBR.

Comparison of Immunoprotection of Leptospira Recombinant Proteins with conventional vaccine in experimental animals

Leptospirosis is a bacterial disease caused by bacteria of the genus Leptospira affecting humans and animals. Untreated leptospirosis may result in severe kidney damage, meningitis, liver failure, respiratory distress, and even death. Virulent leptospirosis can rapidly enter kidney fibroblasts and induce a programmed cell death. Thus, it is a challenge for immunologists to develop an effective and safe leptospirosis vaccine. Here, we compared the commercial canine leptospira vaccine and recombinant proteins (OmpL1 and LipL41) with and without adjuvant in terms of immune response and challenge studies in hamsters and immune response studies alone in experimental dogs. The outer membrane proteins viz., lipL41 and OmpL1 of leptospira interrogans serovars icterohaemorrhagiae were amplified. The primers were designed in such a way that amplified products of OmpL1 and lipL41 were ligated and cloned simultaneously into a single vector. The cloned products were expressed in E. coli BL21 cells. The immunoprotection studies were conducted for both recombinant proteins and commercial vaccine. The challenge experiment studies revealed that combination of both rLip41 and rOmpL1 and commercial vaccine gave 83% and 87% protection, respectively. Histopathological investigation revealed mild sub lethal changes were noticed in liver and kidney in commercially vaccinated group alone. The immune responses against recombinant leptospiral proteins were also demonstrated in dogs.

Natural influence of season on follicular, luteal, and endocrinological turnover in Indian crossbred cows

The study was aimed at investigating the effect of seasonal changes on follicular and luteal dynamics in vivo in normally cycling crossbred cows during summer and winter months of the year. Six healthy regularly cycling Jersey crossbred nonlactating pluriparous cows were used for the study. Follicular and luteal developmental pattern was studied every other day throughout the estrous cycle by scanning the ovaries during two periods of a year viz., hot season (April to June; n = 16) and cold season (December to February; n = 12). Plasma progesterone (P4) concentrations were measured on Days 0 (estrus), 6, and 12 of the estrous cycle. Among the 12 cycles studied during the cold season, 11 (91.7%) had three waves and one had two waves. Of 16 cycles studied during the hot season, eight (50%) had two waves, four (25%) had three waves, and the remaining four cycles had single (n = 2) and four waves (n = 2). High P4 concentrations during the midcycle would have suppressed the dominant follicle of the second follicular wave and induced the emergence of the third wave during the cold season. The first follicular wave (wave I) of the cycle emerged much earlier (Day 0.5 ± 0.3) during the cold season than that in the hot season (Day 1.7 ± 0.4). The ovulatory wave emerged significantly earlier during the hot season (Day 11.5 ± 1.3) than in the cold season (Day 14.8 ± 0.4), and hence, the growth phase of ovulatory follicle significantly increased during the former season (11.0 ± 1.4 days) than the latter (5.8 ± 0.2 days). The ovulatory follicle attained a significantly larger diameter (12.8 ± 0.8 mm) to express the estrus during the hot season when compared to the cold season (11.3 ± 0.4 mm), which might be indicative of alterations in steroidogenic activity within the follicular microenvironment. During the midphase of the cycle, a period critical for embryonic sustenance, the P4 level was significantly reduced in the hot months indicating suppression of luteal activity during hot period of the year. Thus, it could be concluded that increased incidence of two follicular waves associated with a prolonged growth phase of the ovulatory follicle, and altered luteal endocrine activity during the hot season might be associated with decreased fertility in crossbred cattle.

Next generation sequencing technologies: tool to study avian virus diversity

Increased globalisation, climatic changes and wildlife-livestock interface led to emergence of novel viral pathogens or zoonoses that have become serious concern to avian, animal and human health. High biodiversity and bird migration facilitate spread of the pathogen and provide reservoirs for emerging infectious diseases. Current classical diagnostic methods designed to be virus-specific or aim to be limited to group of viral agents, hinder identifying of novel viruses or viral variants. Recently developed approaches of next-generation sequencing (NGS) provide culture-independent methods that are useful for understanding viral diversity and discovery of novel virus, thereby enabling a better diagnosis and disease control. This review discusses the different possible steps of a NGS study utilizing sequence-independent amplification, high-throughput sequencing and bioinformatics approaches to identify novel avian viruses and their diversity. NGS lead to the identification of a wide range of new viruses such as picobirnavirus, picornavirus, orthoreovirus and avian gamma coronavirus associated with fulminating disease in guinea fowl and is also used in describing viral diversity among avian species. The review also briefly discusses areas of viral-host interaction and disease associated causalities with newly identified avian viruses.

Co-culture: A quick approach for isolation of street rabies virus in murine neuroblastoma cells

BACKGROUND

Laboratory detection of rabies in most cases is based on detection of the antigen by fluorescent antibody test, however, in weak positive cases confirmative laboratory diagnosis depends on widely accepted mouse inoculation test. Cell lines like neuroblastoma have been used to isolate the virus with greater success not only to target for diagnosis, but also for molecular studies that determine the epidemiology of the circulating street rabies strains and in studies that look at the efficiency of the developed monoclonal antibodies to neutralize the different rabies strains. Due to the recent issues in obtaining ethical permission for mouse experimentation, and also the passages required in the cell lines to isolate the virus, we report herewith a co-culture protocol using the murine neuroblastoma (MNA) cells, which enable quicker isolation of street rabies virus with minimum passages.

OBJECTIVE

This study is not to have an alternative diagnostic assay, but an approach to produce sufficient amount of rabies virus in minimum passages by a co-culture approach in MNA cells.

MATERIALS AND METHODS

The MNA cells are co-cultured by topping the normal cells with infected cells every 48 h and the infectivity was followed up by performing direct fluorescent-antibody test.

RESULTS

The co-culture approach results in 100% infectivity and hence the use of live mouse for experimentation could be avoided.

CONCLUSION

Co-culture method provides an alternative for the situations with limited sample volume and for the quicker isolation of virus which warrants the wild type strains without much modification.

Rapid Detection of Avian Infectious Bronchitis Virus by Reverse Transcriptase-Loop Mediated Isothermal Amplification

A reverse-transcription loop mediated isothermal amplification (RT-LAMP) was developed for rapid diagnosis of infectious bronchitis (IB) in poultry by targeting the spike protein 2 gene (S2). RT-LAMP primers were designed for IBV-S2 targets and optimized to run at 60 °C for 45 min. As compared with RT-PCR, RT-LAMP was 100 times more sensitive for IBV-S2 gene. RT-LAMP showed specific amplification with IB viral genome but not with other avian respiratory pathogens due to their mismatching with IBV-S2-RT-LAMP primers. RT-LAMP reaction products were visually detected by the addition of propidium iodide stain. Out of 102 field samples tested for detection of IBV, RT-LAMP detected IBV in 12 samples for S2 gene whereas RT-PCR detected IBV in six samples for S2 gene. The sensitivity of the RT-LAMP was 100 % and the specificity was 94 % for S2 gene. Since the developed RT-LAMP to detect IBV is simple, rapid, sensitive and specific, it can be a useful diagnostic tool for detection of IB in poultry in less equipped laboratories and in field conditions.

A study on Methicillin resistant Staphylococcus aureus mastitis in dairy cows

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. The study was carried out to evaluate the incidence of Methicillin resistant S. aureus from clinical mastitis milk samples and their antibiotic resistance profile and characterised with respect to the molecular features that contributed to the resistance in these pathogens. Isolation and identification of Methicillin resistant S. aureus were performed from acute clinical mastitis samples. The isolates were tested using agar disc diffusion method for their antimicrobial susceptibility and modified resazurin assay micro dilution technique for MIC to 8 different antimicrobial drugs. A total of 235 clinical mastitis milk samples from dairy cows were cultured for incidence of S. aureus. Methicillin resistant S. aureus was isolated from a total of 12 (44.25%) of the 116 S. aureus samples. Based on the antimicrobial sensitivity and MIC results, MRSA isolates were found sensitive to gentamicin, enrofloxcain, amoxicillin+sulbactam, ceftriaxone and resistant to amoxicillin, oxytetracycline, penicillin G and oxacillin. Most of MRSA isolates were found to be multi-drug resistant. MRSA alert kit test and mecA and blaZ target gene PCR were found to be useful in the confirmation of MRSA.

In vitro propagation of chicken anemia virus in chicken peripheral blood mononuclear cells

KEYWORDS

chicken anemia virus; propagation; mononuclear cells; PCR.

Changes in the Cytokine and Toll-Like Receptor Gene Expression Following Infection of Indigenous and Commercial Chickens With Infectious bursal disease virus

A comparative study of cytokine and toll-like receptor (TLR) mRNA expression in 3 weeks old indigenous and commercial chickens infected with a very virulent strain of Infectious bursal disease virus (IBDV) was performed using a custom-made microarray chip. In uninfected indigenous chickens, the basal levels of interleukin (IL) 15 were lower and IL 16 was higher than their commercial counterparts. In the IBDV infected indigenous chickens, only IL16 gene expression was down regulated, while TLR3 expression was up regulated significantly. In the IBDV infected commercial chickens IL15, IL16 and TLR3 were down regulated. But, IL1-β, IL2, IL8, IL12, IL17, interferon (IFN)-α and β were significantly increased compared with the control. In IBDV infected indigenous chickens, IL15, IFN-γ, beta-defensin and TLR3 were up regulated compared to virus-infected commercial chickens. The results suggested that up regulation of TLR3, a ligand for double-stranded (ds) RNA probably could account for the possible clinical resistance in these birds. There was a 5.2 fold difference by quantitative real-time RT-PCR between indigenous and commercial chickens in TLR3 mRNA expression. Therefore, TLR3, a receptor for dsRNA could be a putative molecule that could play a role in differential innate and adaptive immune responses to IBDV in commercial and indigenous chickens.

Analysis of the Fusion Protein Cleavage Site of Newcastle disease virus Isolates from India Reveals Preliminary Evidence for the Existence of II, VI and VII Genotypes

Newcastle disease virus (NDV) has been a threat to poultry industry in most of the developing countries with a wide variety of avian species being susceptible, coupled with the presence of mobile wild bird reservoirs contributing not only to the vast genomic diversity of this virus but also to the diagnostic failures. NDV of multiple genotypes (I-XI) is known to be prevalent and reported worldwide. However, there is a paucity of information on the circulating genotypes of NDV in India. This study utilized the fusion protein cleavage site (FPCS) sequence to determine the different genotypes of NDV circulating in India. Our results indicate that majority of NDV isolates from southern states of India namely, Tamil Nadu, Kerala and Karnataka were found to belong to genotype II. However, some of the strains from Tamil Nadu and most from Uttar Pradesh belong to genotype groups VI and VII. Interestingly, three isolates recovered from Tamil Nadu grouped with genotype IV viruses (namely Herts/33) which had not been hitherto reported to GenBank since 1989. This preliminary information points to the existence of multiple genotypes and also the need for efficacy studies with vaccines incorporating multiple genotypes in controlling virulent NDV (vNDV) outbreaks in India.

Molecular prevalence and preponderance of Eimeria spp. among chickens in Tamil Nadu, India

Coccidosis is one of the most commonly prevalent and economically important parasitic diseases of poultry worldwide. Chicken coccidia are protozoan parasites of the genus Eimeria. This study aimed at analysing the molecular prevalence of seven species of Eimeria infecting chickens in Tamil Nadu, India. Tissue samples (caecum, rectum and upper and mid intestines) collected from chickens exhibiting symptoms of coccidiosis were used for DNA extraction, followed by amplification of the internal transcribed spacer (ITS) region of Eimeria genome with genus-specific primers and speciation in nested polymerase chain reaction (PCR) with species-specific primers. Of 43 tissue samples examined, 25 were positive in ITS PCR and all the seven species could be identified. However, the prevalence of each species varied. In broilers, Eimeria necatrix was present in all infected chickens with Eimeria brunetti, Eimeria tenella, Eimeria maxima and Eimeria acervulina present in more than 50% of infected chickens, while Eimeria praecox and Eimeria mitis were only present in 11% to 16%. Although only 7 samples were positive among layers, the prevalence was largely similar, but with a higher prevalence of E. praecox and E. mitis and a lower prevalence of E. tenella. Multiple infections were most common, with 2-6 Eimeria species infecting the same chickens. In order to estimate the preponderance of each infecting species of Eimeria, a random cloning technique was adopted. The genus-specific ITS PCR product was cloned in a TA vector and ten clones were randomly picked and used as template for amplification of all the seven genera of Eimeria. If the specific species of Eimeria is preponderant, then the frequency of the clones showing that species-specific PCR amplification would be higher. Using this method, the most preponderant species present in the rectum, mid and upper intestines of layers was assessed to be E. acervulina, E. brunetti and E. necatrix. E. acervulina was present in 60-90%, E. necatrix in 10-30% and E. brunetti in 10-20% of the clones screened, indicating that these species could be the most preponderant Eimeria species. Intervention strategies should aim at these species. This new method of estimating preponderance of infecting Eimeria species could be used to assess the relative importance of each species at the farm or region level instead of relying only on prevalence estimates.

Detection of virulent Marek's disease virus in poultry in India

Marek's disease virus (MDV) isolated from poultry flocks in three states of India was monitored for the virus occurrence in the field. The MDV genome was isolated from feather follicles, spleen, and liver of the chicken (173 samples). Twenty two samples were positive for MDV genome in PCR and belonged to the serotype 1. The sequencing of MEQ gene of 11 samples revealed that nucleotide sequences of the isolate Ind-KA-01-06 was similar to the very virulent MDV, strain RB-1B. In situ hybridization studies also confirmed a presence of MDV serotype 1 in the infected liver tissues. Furthermore, the ability of the virus to induce apoptosis detected by flow cytometry showed that the virulent MDV induced apoptosis more efficiently than Turkey herpesvirus (HVT) vaccine virus. The present study showed the presence of virulent/very virulent MDV strains in the Indian poultry flocks.

Differential expression of toll-like receptor mRNA in selected tissues of goat (Capra hircus)

Pattern recognition receptors (PRRs) expressed by various immune cells and tissues have been shown to play a pivotal role in the recognition of pathogens by the host. The present study was carried out to identify toll-like receptors (TLRs) 1-10 mRNA in goat peripheral blood mononuclear cells (PBMCs) and selected tissues including jejunum, lung, lymph node, skin, spleen and uterus using reverse transcriptase polymerase chain reaction (RT-PCR). Our results confirm earlier reports regarding the evolutionarily conserved nature of these receptors as successful amplification of the goat TLR mRNAs could be obtained with bovine TLR mRNA-specific primers. The partial sequences of the purified TLR PCR amplicons had 93.8-99.7% nucleotide identity with sheep TLR cDNA sequences available in the GenBank. Semi-quantification of the expression levels of the TLR mRNAs was done using densitometric analysis of band intensities. All the TLR mRNAs (1-10) were expressed in high amounts in the lymph node while spleen showed lower expression of TLR 6 and 10 mRNAs. PBMC and lung expressed all TLR mRNAs in high amounts except TLR 10 mRNA. In uterus and jejunum, lower expression of TLR 3, 4 and 10 mRNAs was seen. Skin had the lowest repertoire of TLR mRNA expression with lower or no expression of TLR 2, 3, 4, 8, 9 and 10 mRNAs. Another interesting observation was that tissues such as uterus, lung and skin that exhibited lower levels of TLR 2 had higher levels of TLR 6 mRNAs.

Adaptation of a Velogenic Newcastle Disease Virus to Vero Cells: Assessing the Molecular Changes Before and After Adaptation

A velogenic Newcastle disease virus isolate was passaged 50 times in Vero cell culture and the virus was assessed for the molecular changes associated with the passaging. At every 10th passage, the virus was characterized conventionally by mean death time (MDT) analysis, intracerebral pathogenicity index (ICPI) and virus titration. At increasing passage levels, a gradual reduction in the virulence of the virus was observed. Molecular characterization of the virus included cloning and sequencing of a portion of the fusion gene (1349 bp) encompassing the fusion protein cleavage site (FPCS), which was previously amplified by reverse transcription-polymerase chain reaction. Sequence analysis revealed a total of 135 nucleotide substitutions which resulted in the change of 42 amino acids between the velogenic virus and the 50th passage virus. The predicted amino acid motif present at the cleavage site of the virulent virus was (109)SRRRRQRRFVG(119) and the corresponding region of the adapted adapted virus was (109)SGGRRQKRFIG(119). Pathogenicity studies conducted in 20-week-old seronegative birds revealed gross lesions such as petechial haemorrhages in the trachea, proventricular junction and intestines, and histopathological changes such as depletion and necrosis of the lymphocytes in thymus, spleen, bursa and caecal tonsils in the birds injected with the velogenic virus and absence of the lesions in birds injected with the adapted virus. The 50th-passage cell culture virus was back-passaged five times in susceptible chickens and subjected to virulence attribute analysis and sequence analysis of the FPCS region, with minor difference found between them.

Effect of a derivatized tetrapeptide from lactoferrin on nitric oxide mediated matrix metalloproteinase-2 production by synovial fibroblasts in collagen-induced arthritis in rats

Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteolytic enzymes, which degrade several components of extracellular matrix, in arthritic synovial cells. In cultured synovial fibroblasts, both nitric oxide (NO) and reactive oxygen species (ROS) are potent inducers of MMPs production. PEP1261, a tetrapeptide derivative used in this study, corresponds to residues of 39-42 human lactoferrin. The parent protein lactoferrin is able to inhibit the production of free radicals in rheumatoid joints and it regulates many aspects of inflammation. This study is aimed to examine the effects of PEP1261 on MMP-2 production in the presence of nitric oxide donor in cultured synovial fibroblasts from collagen-induced arthritic rats. PEP1261 affects a significant reduction in nitrite levels as well as in MMP-2 production in SNAP stimulated synovial fibroblasts and this is validated by gelatin zymography and immunoblot analysis. Furthermore, RTPCR analysis has demonstrated that PEP1261 inhibits MMP-2 mRNA expression in SNAP treated synovial fibroblasts. The results of this study suggest that PEP1261 possesses antiarthritic activity by inhibiting nitrite levels as well as MMP-2 expression better than control peptides viz., KRDS and RGDS.

Inhibition of nitric oxide and caspase-3 mediated apoptosis by a tetrapeptide derivative (PEP1261) in cultured synovial fibroblasts from collagen-induced arthritis

In this study, the effect of (Boc-Lys (Boc)-Arg-Asp-Ser (tBu)-OtBu), a tetrapeptide derivative (PEP1261) was examined for antiproliferative potency and apoptotic induction. Synovial fibroblasts were isolated from collagen-induced arthritic (CIA) rats and exposed to peptides viz., PEP1261, and parental peptides (KRDS and RGDS). Viability of the cells decreased in the presence of PEP1261 at a lower concentration (0.1 mM) when compared to RGDS and KRDS (1 mM). The treatment of cells with peptides showed induction of apoptosis, resulting in the cleavage of caspase-3 as well as its substrate poly-(ADP-ribose) polymerase (PARP). Pretreatment of cells with caspase-3 inhibitor prevented inhibition of [(3)H] thymidine incorporation, DNA fragmentation, and cleavage of caspase-3 and PARP as confirmed by western blotting as well as annexin-V/PI-staining using flow cytometry. However, caspase-1 and caspase-2 inhibitors did not prevent the peptides from inducing apoptosis indicating that caspase-3 might have a role in the process of apoptosis induced by peptides. Treatment of synovial fibroblasts with nitric oxide donor, S-nitroso-N-acetyl-DL: -penicillamine (SNAP) (500 microM) showed significant elevation of nitric oxide levels and resulted in absence of apoptosis by preventing the inhibition of [(3)H] thymidine incorporation. This was further evidenced by annexin V/propidium iodide (PI) staining and absence of DNA fragmentation, intra cellular caspase-3 activity and PARP cleavage. In contrast, SNAP followed by PEP1261 and parental peptides-induced apoptosis by lowering the levels of nitric oxide. These results suggested that PEP1261 suppressed the proliferation and induced apoptosis in cultured synovial fibroblasts from CIA rats. This study also confirmed that PEP1261 inhibited nitric oxide level in cultured synovial fibroblasts.

Restriction enzyme analysis of tissue culture-adapted velogenic Newcastle disease virus

A velogenic Newcastle disease virus isolate typed to belong to group C1 by monoclonal antibody typing was adapted 50 times in chicken embryo fibroblast cell culture and 60 times in Vero cells. At every 10th passage the virus was characterized on the basis of mean death time, intracerebral pathogenicity indices and viral titration studies. A gradual reduction in the virulence of the virus was noted as the passage number increased. RT-PCR of a 254 bp region of the fusion gene encompassing the fusion protein cleavage site was carried out for the virulent as well as cell culture-adapted viruses at every 10th passage level. The amplicons were subsequently digested with three restriction enzymes, viz. AluI, HaeIII and PstI. It was found out that there was difference in banding patterns between the virulent and adapted viruses, indicating nucleotide substitutions in the virulent virus when it was sequentially passaged onto cell culture systems.

Molecular changes of the fusion protein gene of chicken embryo fibroblast-adapted velogenic Newcastle disease virus: effect on its pathogenicity

Molecular changes of cell culture-adapted Newcastle disease virus (NDV) were studied by adapting a velogenic NDV isolated from commercial layer chicken-to-chicken embryo fibroblast (CEF) cells. The isolate was passaged 50 times in CEF cells. At every 10th passage the virus was characterized conventionally by mean death time analysis, intracerebral pathogenicity index, and virus titration. As the passage level increased, a gradual reduction in the virulence of the virus was observed. Molecular characterization of the virus included cloning and sequencing of a portion of the fusion gene (1349 bp) encompassing the fusion protein cleavage site (FPCS), which was previously amplified by reverse transcription-polymerase chain reaction. Sequence analysis revealed a total of 134 nucleotide substitutions, which resulted in the change of 41 amino acids between the parent and the 50th passage virus. Pathogenicity studies conducted in 20-wk-old seronegative chickens revealed gross and histopathologic changes in the chickens injected with the parent virus and absence of the lesions in chickens injected with the adapted virus. The 50th passage cell culture virus was back-passaged five times in susceptible chickens and was subjected to virulence attribute analysis and sequence analysis of the FPCS region, with minor differences between them.

Pathotyping of Newcastle disease virus isolates from pet birds

Four Newcastle disease virus (NDV) isolates obtained from a pigeon, lory, parrot, and love bird were subjected to biological and molecular characterization. All the isolates were identified as velogenic with intracerebral pathogenicity indices (ICPI) of 1.9-2.0. All the isolates had a 112RRQKRF117 motif in the fusion protein cleavage site (FPCS), typical for pathogenic NDV. Phylogenetic analysis placed the isolates along with a velogenic Indian isolate of Cl group recovered during 1987.

Biological and molecular characterization of Indian isolates of Newcastle disease virus from pigeons

Five Newcastle disease virus (NDV) isolates from pigeons were characterized by biological and molecular methods. Four of the five isolates were found to be velogenic with high intracerebral pathogenicity indices (ICPI). The fusion protein cleavage site (FPCS) sequences of these isolates had multiple basic amino acids RRQKRF at positions 112-116 and a phenyl alanine at position 117 characteristic of velogenic isolates. Three of these velogenic isolates were phylogenetically related to mesogenic vaccine virus strain and the fourth one to a few exotic velogenic isolates. The lentogenic isolate obtained in this study was identical with the LaSota strain.

Characterization of a Newcastle disease virus isolated from apparently normal guinea fowl (Numida melagridis)

This report describes the isolation and molecular characterization of Newcastle disease virus isolated from an apparently normal guinea fowl (Numida melagridis). With a mean death time of 54 h and intracerebral pathogenicity index of 1.80, the isolate has been identified as velogenic by biological methods. Fusion protein cleavage site amino acid sequence analysis of the isolate indicated the presence of two pairs of basic amino acids at the C-terminus of the F2 region and phenylalanine at the N-terminus of the F1 region, confirming the velogenic nature of the isolate. Phylogenetic analysis of the isolate revealed that this isolate is genotypically related to other neurotropic velogenic isolates like Iowa/Salsbury, Texas GB, Kansas/Manhattan and mesogenic Michigan.

Characterization of nucleoprotein gene sequence of an Indian isolate of rabies virus

Rabies occurs in all parts of Indian sub-continent except Andaman and Nicobar and Lakshadweep group of islands. The full-length nucleoprotein (N) gene sequence of a rabies virus isolate from India is reported for the first time and the same has been compared with available N gene sequences from the database. A central domain of 230 amino acids (aa) from aa 141 to aa 370 exhibited more than 95% similarity. There were 8 amino acid positions (aa 29, 32, 38, 84, 119, 379, 438, and 439) at which substitution was unique for Indian isolates but common for laboratory strains. In antigenic epitopes, except for a single amino acid difference at the antigenic site IV, the amino acids were conserved. The Indian isolate also possessed two Bam HI sites (aa 247 and 278), while the other Asian isolates had only one site at aa 278 or were not digested with Bam HI at all. Phylogenetic analysis also demonstrated that the Indian isolate was closely related to the Sri Lankan isolate and grouped in the cluster that comprised of the isolates from other Asian countries namely China and Pakistan.

Interaction between genomes of infectious bronchitis and Newcastle disease viruses studied by reverse transcription-polymerase chain reaction

Reverse transcription-polymerase chain reaction (RT-PCR) with specific primers for the S1 gene of IBV and for the fusion protein cleavage site of NDV was used for detection of Infectious bronchitis virus (IBV, the family Coronaviridae) and Newcastle disease virus (NDV) genomes. The sensitivity of IBV and NDV RT-PCR was 10(3.7) and 10(3.0) EID50, respectively. Although a multiplex RT-PCR could detect and differentiate NDV and IBV genomes present in the same sample, there was a slight inhibition of the IBV PCR if a high amount of NDV genome was present in the sample. To overcome this problem a separate PCR for each virus was used to assess the interaction between vaccine IBV and NDV either inoculated singly or together into chickens. In the group vaccinated with the Newcastle disease (ND) vaccine alone, the viral genome was detected on days 2, 4 and 7 post vaccination (p.v.), while in the chickens given the infectious bronchitis (IB) vaccine alone, the viral genome was detected only on day 4 p.v. In the group inoculated with both vaccine viruses there was a 10(3)-fold reduction in the cDNA dilution factor on day 4 p.v. for both IBV and NDV genomes. This demonstrated clearly that when both these vaccines are administered there is a transient reduction in the replication of both viruses, probably due to their competition for the same target epithelial cells in the respiratory tract.

Comparison of various diagnostic methods in characterizing Newcastle disease virus isolates from Desi chickens

Eleven Newcastle disease viruses (NDV), isolated from apparently healthy and ailing Desi chickens were subjected to both conventional and modern characterization techniques. The virulence and strain differentiating experiments placed 10 isolates in the velogenic group and one in the mesogenic group. In MDBK cells, 9 isolates produced characteristic cytopathogenic effects up to 5 and 2 up to 3 passages. Molecular characterization with a 21-mer oligonucleotide probe placed all the isolates in the velogenic/mesogenic group. The results of this study clearly indicated that the isolates obtained are either velogenic or mesogenic but not lentogenic.

Latex immunoassay for rapid detection of Newcastle disease virus

A rapid test has been developed based on the technique of latex immunoassay for the detection of Newcastle disease virus from suspected tissue suspensions. The latex particles were sensitised with globulins and were used for antigen detection. Of the 258 samples tested, 165 samples were positive by this kit which was compared for its efficacy with the standard OIE approved haemagglutination (HA) and haemagglutination inhibition (HI) tests. No significant difference (P > 0.05) was observed between the tests. The sensitivity and specificity of the developed test was 94.19% and 87.63% respectively.

Serological evidence of bovine herpesviruses 1 and 2 in Asian elephants

Antibodies were detected against bovine herpesviruses 1 (BHV 1) and 2 (BHV 2) in Asian elephants (Elephas maximus) using the passive hemagglutination (PHA) test. The study was conducted during May to December 1994 using sera collected from zoological gardens and national parks in India. Four (4%) of 109 elephant sera had PHA titers ranging from 1:8 to 1:32 against BHV 1. Twenty-five (23%) of the 109 elephant sera had PHA titers ranging from 1:8 to 1:64 against BHV 2. Asian elephants appear to be better reservoirs for herpesviruses which are serologically related to BHV 2.

Differentiation of peste des petits ruminants and rinderpest viruses by neutralisation indices using hyperimmune rinderpest antiserum

Six field isolates believed to be rinderpest viruses and 2 known strains of peste des petits ruminants (PPR) viruses were titrated in the presence of normal rabbit serum and with hyperimmune rinderpest antiserum prepared in rabbits. The known PPR viruses had indices less than 10 whereas 4 of the suspect field isolates had indices greater than a hundred. Two suspect field isolates had indices less than 20; both were collected from small ruminant wild life and are probably PPR viruses.

Agglutination of chicken lymphocytes by infectious bursal disease virus

Four serotype 1 field strains of infectious bursal disease virus (IBDV) and one reference standard serotype 1 strain were tested for their ability to agglutinate peripheral blood lymphocytes of chickens. All the five strains agglutinated chicken lymphocytes. The agglutination was not inhibited by serotype 1 reference anti-IBDV serum. These results suggest the need for detailed analysis of IBDV ligand(s) and cell surface receptor(s) relationships.

Characterisation of Newcastle disease viruses isolated in India

Eleven Newcastle disease virus (NDV) isolates obtained from outbreaks of disease in chickens (9) and Japanese quail (2) in Tamil Nadu, India were characterised in pathogenicity tests, antigenically, using mouse monoclonal antibodies (MAbs), and other established tests devised to distinguish between different strains. All 11 isolates were shown to be highly virulent for chickens. In indirect immunoperoxidase tests used to assess the ability of a panel of 28 MAbs to bind to infected cell cultures, 10 of the isolates showed an identical reaction pattern, the other isolate (No. 4) failed to react with one MAb which bound to cells infected with the other isolates. Isolates 9 was unstable at pH 3 while the other 10 were stable. All other properties were shared by the 11 isolates.