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Biomedical subjects

S K Srivastava

Publications and source records attributed to S K Srivastava.

At least 19 recordsLinked to original sources

Cloning and sequence analysis of the gene encoding LipL32 of Leptospira interrogans serovar Sejroe.

Leptospira, a member of the order Spirochaetales, is the causative agent of leptospirosis, an important zoonosis encountered worldwide. The Leptospira interrogans serovar Sejroe was grown in EMJH medium and its DNA was isolated using standard techniques. The LipL32 gene was amplified using the reported primer of Kirschneri of LipL32. The amplified product was found to comprise 756 base pairs. This amplified gene fragment of LipL32 lipoprotein was cloned in E. coli (DH5 alpha) cells using pDrive plasmid as a vector. The recombinant cells were selected on LB agar medium containing ampicillin, X-gal and isopropyl-beta-D-thiogalactopyranoside. Plasmid was extracted from the recombinant white colonies, and restriction endonuclease (RE) analysis was carried out using PstI and SalI. On partial sequence analysis, the product exhibited 756 base pairs, corresponding to 251 amino acids. The cloned gene could be further used for expression of recombinant protein for serodiagnosis of leptospirosis.

Bacterial Outer Membrane Proteins↗

Evaluation of a recombinant LipL41 antigen of Leptospira interrogans serovar canicola in ELISA for serodiagnosis of bovine leptospirosis.

The efficacy of a recombinant leptospiral lipoprotein LipL41 as an antigen for conducting enzyme-linked immunosorbent assay (ELISA) for diagnosis of bovine leptospirosis was evaluated. Using known positive and known negative cattle sera the recombinant antigen was found to be highly reactive in the concentration of 100 ng/well. Using a total of 321 field cattle sera the sensitivity of ELISA as compared to microscopic agglutination test (MAT) was calculated to be 100% whereas the specificity was 85.3%. The seropositivity of leptospirosis among bovine population was found to be 21.18% having the predominance of serovars Sejroe and Pomona. It was concluded that rLipL41 protein could be a putative diagnostic candidate for serodiagnosis of bovine leptospirosis.

Agglutination Tests↗

Dose dependent effect of GnRH analogue on pregnancy rate of repeat breeder crossbred cows.

The aim of this study was to investigate the effect of treating repeat breeder dairy crossbred cows with different doses of GnRH analogue through i.m. at the time of artificial insemination, on pregnancy rates from their first service after treatment and overall pregnancy rates. One hundred and thirty seven crossbred dairy cows with a history of repeat breeding and eligible after 6-8 infertile services but clinically free of diseases were selected for the study. The animals were randomly divided into three groups. Group 1 (n = 55) cows were treated intramuscularly with each 20 microg Buserelin-acetate (Receptal, Hoechst Roussel Vet GmbH) at the time of artificial insemination. Group 2 (n = 40) cows were treated intramuscularly with each 10 microg Buserelin-acetate at the time of artificial insemination. Group 3 (n = 42) cows were treated intramuscularly with saline as control at the time of artificial insemination. The first service pregnancy rates in Groups 1-3 were 45, 25 and 17%, respectively. Similarly, the overall conception rates in Groups 1-3 were 87, 58 and 48%, respectively. The results indicated that the pregnancy rate in crossbred cows could be improved by the GnRH treatment. The higher dose of GnRH significantly increased (P < 0.05) the first service as well as overall pregnancy rate in a dose dependent manner in repeat breeder crossbred cow bred previously 6-8 times unsuccessfully.

Animals↗

Characterization of avian strains of Pasteurella multocida by restriction endonuclease and amplified fragment length polymorphism.

Avian strains of Pasteurella multocida were typed by employing restriction endonuclease analysis (REA) and single enzyme-amplified fragment length polymorphism (AFLP) to evaluate their applicability for epidemiological studies of fowl cholera outbreaks. A total of 72 strains isolated from different avian species (chicken, duck, turkey, quail and goose) belonging to various geographical regions of India were characterized. REA using two different enzymes HhaI and HpaII produced 9 and 18 clusters respectively, whereas Single enzyme-AFLP recognized 32 patterns out of 72 strains typed. The study indicated that REA using HpaII is a simple and resource efficient method, however, further typing with more stringent and rapid method like Single enzyme-AFLP, could drastically enhance investigation in epidemiological studies of fowl cholera outbreaks.

Animals↗

Effect of a Homeopathic complex on oestrus induction and hormonal profile in anoestrus cows.

This study was undertaken to evaluate the efficacy of a homeopathic complex in the management of true anoestrus in crossbred cows. Six anoestrus cows were treated with a homeopathic complex (Calcarea phosphorica 30c, Aletris farinosa 30c, Pulsatilla 30c, Aurum muriaticum natronatum 30c, Sepia 30c and Phosphorus 30c in equal proportion, 15 pills twice daily orally for 10 days). Six animals acted as control without any treatment. Treatment was 100% effective in inducing oestrus in anoestrus cows with mean interval of 27.5+/-5.3 days. All animals conceived and overall conception rate was 54.5% with 1.83 services per conception. In the homeopathic complex treated group, increased serum oestradiol concentration (20.88+/-5.60 to 27.80+/-7.28 pg/ml) was observed compared to the pretreatment (11.71+/-2.06 pg/ml) and control value (10.43+/-1.77 to 13.94+/-3.14 pg/ml). The homeopathic complex medicine may be effective and economical in the treatment of true anoestrus condition in cows.

Anestrus↗

Detection of Pasteurella multocida in experimentally infected embryonated chicken eggs by PCR assay.

Applicability of polymerase chain reaction (PCR) assay to detect Pasteurella multocida in experimentally infected embryonated chicken egg was assessed in the present study. PCR assay rapidly and specifically detected the genome of P. multocida in amniotic fluid, allantoic fluid and homogenates of infected embryo and its membranes. The sensitivity of detection was as low as 20 bacterial cells/ml of allantoic or amniotic fluids. Detection of P. multocida in dead embryos by PCR was possible up to 6 and 30 days or more following storage of dead embryos at 37 degrees C, and at 4 degrees C as well as at -20 degrees C, respectively. The study revealed that PCR assays could be employed directly for detection and confirmation of P. multocida infection in experimentally infected chicken embryos.

Animals↗

Immunoreactive outer membrane proteins of Leptospira interrogans serovar Canicola strain Hond Utrecht IV.

BACKGROUND & OBJECTIVES: Leptospirosis is a severe and complex zoonotic disease prevalent in many countries including India. Current leptospiral research is focussed on the identification of the outer membrane proteins (OMPs) of the organism that could be used in developing diagnostic assays for leptospirosis. METHODS: The Leptospira interrogans serovar Canicola was grown in EMJH medium and the cells were subjected to sarcosyl detergent treatment. The sarcosyl soluble (SS) and sarcosyl insoluble (SI) fractions were analyzed by SDS-PAGE and immunoblotting to deduce their protein profile and identifying various immunodominant antigens. RESULTS: The protein profile of SS fractions indicated the presence of three major bands of 41, 32 and 25 kDa and minor bands of 85 and 46 kDa. The SI fraction in serovar Canicola revealed the presence of 112, 93, 77, 43, 36, 29 and 22.5 kDa as major bands and minor bands of 102 and 53 kDa. In immunoblotting, the SS proteins of 41, 32 and 25 kDa and SI proteins of 112, 77, 36 and 22.5 kDa were detected to be major immunogenic proteins. INTERPRETATION & CONCLUSION: In our study immunogenic proteins were extracted from SS and SI fractions and OMPs were similar to those reported in other pathogenic Leptospira strains. These OMPs being unique to all the pathogenic leptospires, can be targeted for diagnostic purpose. Further analysis of the cellular location and expression of leptospiral proteins will be useful in the annotation of genomic sequence data and in providing insight into the biology of Leptospira cells.

Animals↗

Identification of avian strains of Pasteurella multocida in India by conventional and PCR assays.

The prevalence of capsular and somatic serotypes were studied among 123 Pasteurella multocida strains isolated from chickens (n=94), ducks (22), quails (4), turkeys (2) and geese (1) from different geographical regions of India. All strains exhibited similar cultural and morphological characteristics. Ninety-two of the isolates belonged to serotype A:1, the most prevalent serotype, with serotypes A:3, A:1,3, D:3 and F:3 having two isolates each. Only one isolate was positive for serotypes A:4 and D:1. Twenty isolates were untyped. A multiplex capsular PCR assay generated amplicons of sizes approximately 460, approximately 1044, approximately 657 and approximately 854 bp in 106 isolates identified as capsular serotype-A, 15 in serotype D and two in serotype F. Capsular types B and E were not detected in any of the avian isolates studied. The present findings suggest that a multiplex capsular PCR assay may be suitable for the rapid initial identification serotypes P. multocida during epidemiological studies of fowl cholera.

Animals↗

Detection of multiple strains of Pasteurella multocida in fowl cholera outbreaks by polymerase chain reaction-based typing.

Applicability of molecular methods for the detection and differentiation of Pasteurella multocida strains involved in two separate fowl cholera outbreaks in a single poultry farm was investigated. A total of 12 and 18 strains of P. multocida obtained from two separate outbreaks were subjected to phenotypic and genotypic characterization. Phenotypically, all strains were similar; however, DNA-based techniques by employing polymerase chain reaction (PCR) assays were found to be highly specific and sensitive for rapid detection and differentiation of strains. All 30 strains gave amplicons of approximately 460 bp and approximately 1,044 bp specific for P. multocida and capsular serogroup A in the Multiplex Capsular PCR typing system. Molecular typing techniques such as repetitive extragenic palindromic PCR, enterobacterial repetitive intergenic consensus PCR and single primer PCR differentiated all 30 strains into different profiles. However, similar patterns of genome fragments were observed among all strains following restriction endonuclease analysis using the enzyme HpaII. The current investigation revealed involvement of the same and multiple strains of P. multocida in two outbreaks. The results also indicated that molecular methods of detection and typing are rapid in comparison with conventional methods for epidemiological investigations of fowl cholera outbreaks.

Animals↗

Dysplasia epiphysealis hemimelica of the talus: two case reports.

Trevor's disease, also known as dysplasia epiphysealis hemimelica, is an uncommon skeletal developmental disorder representing an osteochondroma occurring in one or more epiphyses. We present 2 cases of dysplasia epiphysealis hemimelica in an 8-year-old female and a 12-year-old male who suffered from a hard swelling of the ankle joint. The female patient was treated by surgical excision and the male patient conservatively.

Bone Neoplasms↗

Immunodetection of aldose reductase in normal and diseased human liver.

Aldose reductase is an NADPH-dependent aldo-keto reductase best known as the rate-limiting enzyme of the polyol pathway that is implicated in the complications of diabetes. Aldose reductase appears to be involved in a variety of disease states other than diabetes, presumably due to its ability to catalyze the reduction of a broad spectrum of aldehydes, including some cytotoxic products of lipid peroxidation. Although the data regarding expression of aldose reductase in normal liver are conflicting, prior studies have suggested that the enzyme may be induced in diseased liver. The goal of these studies was to characterize expression of aldose reductase in normal and diseased human liver, using RT-PCR, Western analysis and immunohistochemistry. Aldose reductase transcripts and protein were detected at low levels in control human livers. In contrast, levels of aldose reductase mRNA and protein were increased in chronically diseased human livers. Immunohistochemistry demonstrated localization of aldose reductase in sinusoidal lining cells; dual immunofluorescence confocal microscopy with the macrophage marker, CD68, confirmed that the aldose reductase-positive sinusoidal lining cells were Kupffer cells. Abundant aldose reductase-positive, CD68-positive cells were present in the fibrous septa of cirrhotic livers, accounting for the increase in immunoreactive aldose reductase in diseased livers. Immunostaining of human lung, spleen and lymph node revealed that macrophages in those tissues also express aldose reductase. These data are the first to demonstrate that aldose reductase is expressed by human macrophages in various tissues and suggest that this enzyme may play a role in immune or inflammatory processes.

Aldehyde Reductase↗

Cloning and sequencing of 28 kDa outer membrane protein gene of Brucella melitensis Rev. 1.

Brucella melitensis is an organism of paramount zoonotic importance. The 28 kDa outer membrane protein (OMP) is one of the immunodominant antigens of B. melitensis. The gene encoding 28 kDa OMP (omp28) has been amplified from B. melitensis Rev. 1 strain. A PCR product of 753 bp, encoding complete omp28 gene of B. melitensis, was obtained. The gene was further cloned and sequenced. The nucleotide sequence of B. melitensis Rev. 1 strain showed substitution of 2 nucleotides from that of 16M strain.

Antigens, Bacterial↗