Search

Ducks are the "Trojan Horses" for Asian H5N1 avian influenza viruses (AIV) and attain carrier status without displaying overt infection. These birds help in the spread of the virus among the poultry and human population through direct or indirect contact. Preen oil is the secretion of preen gland of water birds such as ducks. In a process called preening, the water birds spread preen oil across their feather and body. Preen oil has been known to play a significant role in the accumulation of various pathogens including Highly Pathogenic Avian Influenza (HPAI) from water onto feathers. However, the studies are scarce on the role of preen oil in the survivability of HPAIV. We conducted a simulative study to analyse the effect of preen oil on the survivability of the HPAI virus (H5N1) on duck feathers. Duck feather samples along with relevant controls were spiked with the H5N1 virus at two different initial concentrations (104 EID50 and 106 EID50 ), stored at 37°C, 25°C and 10°C temperatures and tested at regular intervals for percent infectivity by egg culture method and qRT-PCR. The infectivity and viral load were significantly higher in naturally preened duck feathers in comparison to the three preen oil deficit controls at both low and high initial concentrations of virus (104 EID50 and 106 EID50 ). Maximum persistence was seen at 10°C in naturally preened duck feathers spiked with 106 EID50 concentration of viruses. It was also seen that depletion of preen oil from duck feathers reduced the persistence of the virus. These results demonstrate that preen oil plays a significant role in survivability and protection of HPAIV on duck feathers. This study herein will present new avenues in understanding one of the epidemiological niches of HPAIV.

Shiga toxin-producing Escherichia coli (STEC), Enteropathogenic E. coli (EPEC), and Enterotoxigenic E. coli (ETEC) make up an important group of pathogens causing major animal and public health concerns worldwide. The aim of this study was to determine the prevalence of different pathotypes of E. coli in captive wildlife. We analyzed 314 fresh fecal samples from captive wildlife, 30 stool swabs from animal caretakers, and 26 feed and water samples collected from various zoological gardens and enclosures in India for the isolation of E. coli, followed by pathotyping by multiplex PCR. The overall occurrence rate of E. coli was 74.05% (274/370). The 274 E. coli isolates were pathotyped by multiplex PCR targeting 6 genes. Of them, 5.83% were pathotyped as EPEC, 4.74% as STEC, and 1.09% as ETEC. The 16S rRNA genes from the selected isolates were amplified, sequenced, and a phylogenetic tree was constructed. The phylogenetic tree exhibited indiscriminate genetic profiling and some isolates from captive wild animals had 100% genetic identity with isolates from caretakers, suggesting that captive wildlife may serve as a reservoir for infection in humans and vice-versa. The present study demonstrates for the first time the prevalence of these E. coli pathotypes in captive wildlife in India. Our study suggests that atypical EPEC strains are more frequent than typical EPEC strains in captive wildlife. Discovering the implications of the prevalence of these pathotypes in wildlife conservation is a challenging topic to be addressed by further investigations.

A non-blinded randomized clinical trial was conducted to assess the immunomodulatory potential of β-glucan (BG) in piglet diarrhoea associated with type A rotavirus infection. A total of 12 rotavirus-infected diarrheic piglets were randomly divided into two groups: wherein six rotavirus-infected piglets were treated with supportive treatment (ST) and other six rotavirus-infected piglets were treated with BG along with ST (ST-BG). Simultaneously, six healthy piglets were also included in the study which served as control. In rotavirus-infected piglets, marked increase of Intestinal Fatty Acid Binding Protein-2 (I-FABP2), nitric oxide (NOx), Interferon-γ (IFN-γ) concentrations and decrease of immunoglobulin G (IgG) were noticed compared to healthy piglets. The faecal consistency and dehydration scores were significantly higher in rotavirus-infected piglets than healthy piglets. The ST-BG treatment progressively reduced the I-FABP2 and increased the IgG concentrations over the time in rotavirus-infected piglets compared to piglets received only ST. A pronounced enhancement of NOx and IFN-γ concentrations was observed initially on day 3 and thereafter the values reduced on day 5 in ST-BG treated piglets in comparison to piglets which received only ST. Additionally, ST-BG treatment significantly reduced faecal consistency and dehydration scores on day 3 compared to ST in rotavirus-infected piglets. These findings point that BG represents a potential additional therapeutic option to improve the health condition and reduce the piglet mortality from rotavirus associated diarrhoea where porcine rotavirus vaccine is not available.

Aim: The present study was aimed at polymerase chain reaction (PCR) amplification and cloning of NAD-dependent betahydroxybutyryl coenzyme A dehydrogenase (BHBD) gene of Clostridium chauvoei. Materials and Methods: C. chauvoei was cultured and confirmed by 16-23S rDNA spacer region primers. The primers for nad-bhbd gene of C. chauvoei were designed to aid in cloning into pRham-N-His SUMO-Kan vector, and nad-bhbd gene was amplified by PCR. The amplified nad-bhbd gene was purified and cloned into pRham-N-His SUMO-Kan expression vector. The recombinant plasmid was transformed into E. cloni 10 G cells and the clone was confirmed by colony PCR using the pRham-SUMO-NAD-For and pRham-SUMO-NAD-Rev primers and also by sequencing. Results: PCR amplification of nad-bhbd gene yielded a product length of 844 base pairs which was cloned into pRham-NHis SUMO-Kan vector followed by transformation into E. cloni 10G chemically competent cells. The recombinant clones were characterized by colony PCR, sequencing, followed by basic local alignment search tool (BLAST) analysis to confirm the insert. Conclusions: Immunogenic protein NAD- dependent BHBD of C. chauvoei was cloned and the recombinant clones were confirmed by colony PCR and sequencing analysis.

A total of 19 Salmonella strains isolated from diverse sources were subjected to DNA fingerprinting by repetitive sequence PCR using ERIC and (GTG)5 primers for the discrimination of Salmonella enterica isolates at the serotype level. Fingerprints were binary scored and dendrogram was constructed for ERIC and (GTG)5 fingerprint bands. ERIC PCR produced unique patterns consisting of 4 to 16 bands ranging between 0.15 kb to 1.5 kb. Two distinct polymorphic bands at 210 bp and 300 bp were found in all the serotypes. (GTG)5 PCR fingerprint consist of 3 to 15 bands ranging from 0.29 kb to 1.25 kb. All the serotypes tested revealed single polymorphic bands at 900 bp. ERIC and (GTG)5 dendrogram presented fingerprint for all the 19 isolates and serotypes were grouped into three major branches A, B and C which was further subdivided into small groups. The results obtained in the present study indicated ERIC-PCR and (GTG)5-PCR fingerprinting were not so efficient in discriminating Salmonella isolates.

Chicken (Gallus gallus), duck (Anas platyrhynchos), turkey (Meleagris gallopavo), guinea fowl (Numida meleagris) and quail (Coturnix japonica) are the common poultry species consumed as meat throughout the world. In this work, a molecular technique has been developed for identification and differentiation of meat originating from these species. This tool helps in detection of misrepresentation of different poultry meats. The technique involves the extraction of DNA from the given sample, polymerase chain reaction (PCR) amplification of mitochondrial 12S rRNA gene using universal primers, restriction analysis with selected restriction enzymes, followed by identification of meat species based on restriction fragment length polymorphism (RFLP) pattern. In this study, we used HinfI, Mph1 103I, MvaI, and Eco47I to identify and differentiate to poultry species referred to above. This species identification technique has also been applied successfully to processed meat products including those cooked at 120 degrees C for 30 min. Simplicity of interpretation of results combined with versatility makes this a convenient and appropriate technique in the hands of meat analysts for identifying poultry meat species.

Aim To evaluate the efficacy of recombinant outer membrane proteinC (rOmpC) based enzyme-linked immunoassay (ELISA) for the diagnosis of salmonellosis in poultry. Materials and methods Three antigens were prepared, and the indirect ELISA was standardized using the antigens and the antiserum raised in chicken against Omp and rOmpC. Sera were collected from a total of 255 apparently healthy field chickens and screened for the presence of Salmonella antibodies by this ELISA. Results The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of Omp revealed major polypeptides at 36, 42 and 52 kDa, and the rOmpC was evident by a single protein band of 43 kDa. The Omp and rOmpC antigen revealed an optimum concentration of 78 and 156 ng, respectively, in the assay, while the whole cell antigen gave an optimum reaction at a concentration of 10(6) organisms/ml. The test was found to be specific as it did not react with any of the antisera of seven other organisms. The developed ELISA detected Salmonella antibodies from 22 (8.62%) samples with rOmpC antigen, while 24 (9.41%) samples gave a positive reaction with both Omp and whole cell antigens. Conclusion We suggest rOmpC based indirect ELISA as a suitable screening tool for serological monitoring of poultry flocks.

Brucella abortus, the major causative agent of abortion in cattle and a zoonotic pathogen, needs to be diagnosed at an early stage. Loop-mediated isothermal amplification (LAMP) test is easy to perform and also promising to be adapted at field level.To develop a LAMP assay for specific and rapid detection of B. abortus from clinical samples of cattle.LAMP primers were designed targeting BruAb2_0168 region using specific software tool and LAMP was optimized. The developed LAMP was tested for its specificity with 3 Brucella spp. and 11 other non-Brucella spp. Sensitivity of the developed LAMP was also carried out with known quantity of DNA. Cattle whole blood samples and aborted fetal stomach contents were collected and used for testing with developed LAMP assay and results were compared with polymerase chain reaction (PCR).The developed LAMP assay works at 61 °C for 60 min and the detection limit was observed to be 100-fold more than the conventional PCR that is commonly used for diagnosis of B. abortus. Clinical sensitivity and specificity of the developed LAMP assay was 100% when compared with Rose Bengal plate test and standard tube agglutination test. SYB® green dye I was used to visualize the result with naked eye.The novelty of the developed LAMP assay for specifically detecting B. abortus infection in cattle along with its inherent rapidness and high sensitivity can be employed for detecting this economically important pathogen of cattle at field level as well be exploited for screening of human infections.

In vitro cytotoxicity is an important virulence property of motile mesophilic Aeromonas species. Cell-free supernatant prepared from 55 Aeromonas isolates including one A. hydrophila type strain (MTCC 646) were examined for their cytotoxic potential on four different cell lines (Vero, BHK-21, MDBK, B 95a). Results of the study revealed cytotoxic potential in 92.72% of the isolates. Analysis of data exposed significant variation among isolates in respect of their cytotoxicity. Vero cells proved to be most sensitive to aeromonal toxins and B 95a cells showed significantly (P

For monitoring the activity of Japanese encephalitis (JE) in pigs, no effective assay is available in Indian context. Being its endemicity in India and role of pigs as amplifiers, there was need to develop rapid and sensitive assay for serosurveillance of JE in pigs. An Indirect ELISA (I-ELISA) was standardized using ultracentrifuge sucrose density gradient purified JE antigen from standard virus strain. Cross reaction studies were done with West Nile antigen and comparative efficacy of I-ELISA assessed with Virus Neutralization Test (VNT). Optimum results recorded for detection of IgG and IgM, respectively, at 50 ng/well antigen and 1:200 and 1:300 serum dilutions. The positive - to - negative ratio of ³2 considered positive for JE antibodies. The overall prevalence of JE in pigs recorded to be 28.89 %. The concordance of the indirect ELISA (IgG) vis-a-vis VNT revealed good agreement (kappa = 0.66) and moderate agreement (kappa = 0.56) of standardized I- ELISA towards detection of IgG and IgM, respectively. The assay standardized in the present study could be useful for JE serosurveillance in pig population from endemic and non endemic areas in India.

Mesophilic aeromonads are being increasingly reported pathogen of humans and lower vertebrates. Water and foods are considered to be the chief source of Aeromonas spp. At present there are several techniques available for the detection of Aeromonas spp. from water and foods. However, there is still need to develop immunodiagnostics for rapid detection of Aeromonas spp. irrespective of their species or serotype. To meet out this requirement present study was undertaken to identify the common protein moiety in their OMPs by SDS-PAGE so, that immunoassays can be developed for efficient and rapid detection of Aeromonas spp. from foods. [Vet. World 2012; 5(3.000): 173-177]