Diastereoselective Hydrogenation of Tetrasubstituted Olefins using a Heterogeneous Pt-Ni Alloy Catalyst.

Stereoselective hydrogenation of tetrasubstituted olefins is an attractive method to access compounds with two contiguous stereocenters. However, homogeneous catalysts for enantio- and diastereoselective hydrogenation exhibit low reactivity toward tetrasubstituted olefins due to steric crowding between the ligand scaffold and the substrate. Monometallic heterogeneous catalysts, on the other hand, provide accessible surface active sites for hindered olefins but exhibit unpredictable and inconsistent stereoinduction. In this work, we develop a Pt-Ni bimetallic alloy catalyst that can diastereoselectively hydrogenate unactivated, sterically-bulky tetrasubstituted olefins, utilizing the more oxophilic Ni atoms to adsorb a hydroxyl directing group and direct facially-selective hydrogen addition to the olefin via the Pt atoms. Structure-activity studies on several Pt-Ni compositions underscore the importance of exposing a uniform PtNi alloy surface to achieve high diastereoselectivity and minimize side reactions. The optimized Pt-Ni/SiO2 catalyst exhibits good functional group tolerance and broad scope for tetrasubstituted olefins in a cyclopentene scaffold, generating cyclopentanol products with three contiguous stereocenters. The synthetic utility of the method is demonstrated in a four-step synthesis of (1R,2S)-(+)-cis-methyldihydrojasmonate with high yield and enantiopurity.

Dot-ELISA based on recombinant Hypodermin C of Przhevalskiana silenus for field diagnosis of goat warble fly infestation.

Goat warble fly infestation (GWFI) is an economically important myiasis caused by larvae of Przhevalskiana silenus (Diptera, Oestridae), prevalent in countries of the Mediterranean Basin and Indian subcontinent. GWFI is characterized by the presence of subcutaneous warbles at the lumbar and sacral region of dorsum in the infested animal. The early larval instars (L1 and L2) remain inaccessible to physical detection due to their small size and subcutaneous presence thus causing hindrance in the diagnosis. The objective of present study was to develop a field applicable early diagnostic intervention for GWFI monitoring and prophylactic management for effective control of the disease. Recombinant Hypodermin C (rHyC) antigen of P. silenus was expressed in Escherichia coli. The purified protein was used for optimizing dot-ELISA in a checkerboard titration using goat warble fly infested serum as known positive. The optimized assay was further tested for lower temperature (18°C) and incubation time (30 min). The optimized assay was assessed for inter-rater reliability and field samples. The optimized conditions require 188 ng of protein/dot, 1:800 dilution of serum sample, 1:4000 dilution of anti-goat IgG conjugate and 5% skim milk powder in phosphate buffer saline as blocking buffer. The assay was found to have a diagnostic sensitivity and specificity of 97.3% and 95.8%, respectively. The inter-rater reliability of dot ELISA with rHyC indirect ELISA was found to be almost perfect with a Cohen's kappa index of 0.973. Further testing at ambient temperature (18°C) and shorter incubation steps (30 min) supported suitability of the assay for field diagnosis of GWFI. The present study provides the first report of a sensitive and specific dot-ELISA for early diagnosis of GWFI which is rapid and cost effective. The test may provide an effective field applicable tool for sustainable control of GWFI.

Prevalence and molecular characterization of Eimeria species affecting backyard poultry of Jammu region, North India.

The present study was conducted from January 2018 to December 2019 to know the prevalence of coccidiosis in backyard poultry in Jammu, Samba, and Udhampur districts of Union Territory of Jammu and Kashmir, North India. A total of 600 pooled fecal samples collected from backyard poultry were examined for presence of Eimeria oocysts. Morphometry and Polymerase Chain Reaction (PCR)-based amplification of ITS-1 gene was carried to characterize the Eimeria species infecting the backyard poultry of the study area. An overall prevalence of 28.5% Eimeria spp. infection among backyard poultry birds was recorded. Among the seasons, highest prevalence was recorded during rainy season (32%) with significantly (p < 0.05) high oocyst excretion (1.77 ± 0.01) and lowest during summer (19.3%) with low oocyst excretion (0.17 ± 0.006). Young birds up to 3 months of age were found to be more susceptible to infection than older birds, with a significantly (p < 0.05) high prevalence percentage of 38.02. Morphometry with COCCIMORPH software revealed presence of Eimeria tenella, Eimeria necatrix, Eimeria acervulina, and Eimeria maxima species with prevalence rates of 27.6%, 21.3%, 16.5%, and 3.6%, respectively. The amplified fragments of ITS-1 gene presented different sizes of Eimeria spp. viz. E. acervulina (321 bp), E. tenella (278 bp), E. maxima (145 bp), and E. necatrix (383 bp). The study concluded that although backyard poultry did not show clinical form of coccidiosis, it may act as source of potential reservoir.

First report of Przhevalskiana silenus derived recombinant hypodermin C based indirect ELISA for serodiagnosis of goat warble fly myiasis.

Goat warble fly infestation (GWFI) is a subcutaneous myiasis caused by larvae of Przhevalskiana silenus, an insect belonging to the order Diptera. The diagnosis of GWFI is challenging in the early larval instars (L1 and L2) as they are occult under the skin and hair coat causing prolonged economic loss in form of meat and hide damage. This necessitates early diagnosis for disease control at herd level and its prophylactic management to prevent economic losses. Hypodermins, a class of serine proteases from Hypoderminae subfamily have been used as serodiagnostic antigens for the past four decades for diagnosis of warble fly myiasis. In this study,the immunodominant antigen Hypodermin C (HyC) from P. silenus has been recombinantly expressed in E. coli and immunogenic characterisation of expressed protein was done. The protein shows hallmark residues in conserved cysteine and catalytic triad typical of serine proteases along with similar profile of immunoreactivity towards Hypoderminae infestation. The present study reports an optimised indirect-ELISA based on recombinant HyC derived from P. silenus for early diagnosis of GWFI. The optimised indirect ELISA provides a sensitive and specific immunodiagnostic for mass surveillance of the GWFI with diagnostic specificity and sensitivity of 96% and 100%, respectively and not showing any cross reactivity against other important parasitic and bacterial diseases of goats. This study presents the first report of indirect ELISA based on recombinant Hypodermin C antigen derived from P. silenus for the serosurveillance of goat warble fly disease.

Status of ivermectin resistance in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) populations from north-western Himalayas, India.

Status of ivermectin resistance was studied in 16 isolates of Rhipicephalus (Boophilus) microplus ticks collected from north-western Himalayan region of India using larval immersion test (LIT). Regression graphs of probit mortality of larval ticks plotted against log values of concentrations of ivermectin were utilized for the determination of slope of mortality, lethal concentrations (LC50 and LC95) and resistance ratios (RRs). Out of 16 isolates examined, 15 were found resistant against ivermectin. Level II resistance was detected in eleven isolates (RR50 ranged from 5.72 to 7.62), whereas four isolates exhibited level I resistance (RR50 ranged from 1.58 to 2.77). Only one isolate was found susceptible (RR50: 1.23). Higher RR values were observed in tick isolates from low altitude areas where intensive animal husbandry activities are practiced as compared to tick isolates of high altitudes accredit the fact that managemental practices, availability of drug and its frequency of application play an important role in development of resistance.

Epidemiology, haematology and molecular characterization of haemoprotozoon and rickettsial organisms causing infections in cattle of Jammu region, North India.

BACKGROUND: The present study was aimed at establishing the prevalence, epidemiology and molecular characterization of major haemoprotozoons (Babesia and Theileria) and rickettsia (Anaplasma) of cattle in Jammu region (North India) using microscopy and Polymerase Chain Reaction (PCR). Hematology, microscopy and PCR based prevalence studies were undertaken with 278 whole blood samples from cattle. Molecular prevalence studies were followed by genetic characterization of the isolates of Babesia, Anaplasma and Theileria spp. based on 18S rRNA, 16S rRNA and Tams1 gene, respectively. The data related to metrology and epidemiological variables like temperature, rainfall, season, age and type of livestock rearing was analyzed and correlated with occurrence of disease by statistical methods. RESULTS: The prevalence based on microscopy was 12.9% (36/278) whereas PCR recorded 30.22% (84/278) animals positive for haemoparasitic infections. All the samples found positive by microscopy were also recorded positive by PCR. Thus the study revealed prevalence of Babesia bigemina, Anaplasma marginale and Theileria annulata to be 9.7, 16.5 and 0.7% respectively. The metrological and epidemiological variables made inroads for the propagation of vector ticks and occurrence of infection. Haematological alterations predominantly related to decrease in haemoglobin, red blood cell count and packed cell volume were evident in diseased animals and collaterally affected the productivity. Further the genetic characterization of Babesia bigemina. (MN566925.1, MN567603, MN566924.1), Anaplasma marginale. (MH733242.1, MN567602.1) and Theileria annulata (MT113479) provided a representative data of the isolates circulating in the region and their proximity with available sequences across the world. CONCLUSIONS: Despite holding much significance to the animal sector, comprehensive disease mapping has yet not been undertaken in several parts of India. The present study provides a blue print of disease mapping, epidemiological correlations and genomic diversity of Babesia bigemina, Anaplasma marginale and Theileria annulata circulating in the region.

Myiasis of domestic and wild ruminants caused by Hypodermatinae in the Mediterranean and Indian subcontinent.

Myiasis caused by Hypodermatinae flies is an economically important disease affecting domesticated and wild ruminants in countries of the Mediterranean and Indian subcontinent. The adult flies have a short life span of 1 week, and they spread disease by laying their eggs on the coat of animals. Hypoderma spp. primarily lay their eggs on cattle, buffalo, roe deer, red deer and reindeer, while Przhevalskiana spp. lay eggs on the coat of goats. The larvae live as tissue parasites, inducing myiasis in the host, and have a major impact on the productivity and welfare of infested animals. Diagnosis of myiasis is mainly based on clinical examination of the animal and immunodiagnosis using serum and milk samples. Chemical control of this pest is considered the best treatment option. Treatment with microdoses of ivermectin (2µg/kg body weight) combined with immunosurveillance strategies has led to the eradication of bovine hypodermosis in a few countries; however, these flies are still prevalent throughout the northern hemisphere. This paper reviews the current status, diagnosis and control measures for Hypodermatinae myiasis of domestic and wild ruminants in the Indian subcontinent and Mediterranean region.

Alterations in oxidative stress parameters and its associated correlation with clinical disease on experimental Cryptosporidium parvum infection in Swiss albino mice.

The present study was conducted to evaluate the changes in oxidative stress parameters on experimental infection with Cryptosporidium parvum in Swiss albino mice. The mice were divided into four groups viz., group I-IV, each group comprising of 15 mice. Group I mice served as healthy control. In Group II mice, C. parvum oocysts @ 104/os were administered, mice of group III were given dexamethasone @ 30 µg/ml in drinking water whereas group IV mice were given dexamethasone @ 30 µg/ml along with C. parvum oocysts @ 104/os. Significant changes were seen in oxidative stress parameters which included significant increase in LPO and decrease in levels of SOD, CAT and GSH in liver and intestine in group IV mice at 10th DPI when compared to others indicating an important role played by free radical induced oxidative stress in the development of C. parvum infection in mice which was clinically characterized by loss of body condition, profuse bloody diarrhoea and peak oocyst shedding intensity occurring at 10th DPI.

Comparative efficacy of pour-on eprinomectin and ivermectin against Sarcoptes scabiei in buffaloes.

The efficacy of eprinomectin and ivermectin pour-on was evaluated against Sarcoptes scabiei in naturally infested buffaloes. Eighteen animals were allocated into three groups (A, B and C) of six animals each. Animals in group A were treated with eprinomectin (pour-on) @ 0.5 mg/kg; group B with ivermectin (pour-on) @ 0.2 mg/kg while group C served as untreated controls. Skin scrapings were examined on days 0, 7, 14, 21, 28 and 42 post-treatment (PT). Skin scrapings were found free for mites on day 21 PT, with marked clinical improvement in the lesions after day 28 of treatment. Untreated control group continued to show severe progressive lesions throughout the study period. No clinical side-effects of the tested drugs were observed after treatment. This preliminary report on the efficacy of eprinomectin (pour-on) against S. scabiei in buffaloes is encouraging and results could be of considerable importance.

Prevalence of ixodid ticks in dairy animals of Jammu region.

To determine the prevalence of ticks, 960 bovines (cattle 480, buffaloes 480) were examined from organised and unorganised dairy units of Jammu district during March 2012 to February 2013. The overall infestation rate was found to be 42.18 %. The infestation rate in cattle was found to be 47.08 % while 37.29 % of examined buffaloes were infested with ixodid ticks. Among the ixodid ticks, only one species i.e. Rhipicephalus (Boophilus) microplus was recorded. A significantly (p < 0.05) higher prevalence was recorded in monsoon season as compared to other seasons. Agewise, the animals aged <6 months showed the highest prevalence and the lowest was found in animals >1 year of age. Sexwise, the males had higher infestation rate than the females.

Prevalence and analysis of associated risk factors for Cryptosporidium infection in lambs in Jammu district.

An epidemiologic study was carried out to investigate the prevalence and analysis of risk of Cryptosporidium infection in lambs in Jammu district. Faecal samples of 120 lambs of different age groups viz., <1 month, 1-3 months and 3-6 months were assessed. Cryptosporidium oocysts were identified by using modified Zeihl Neelsen technique. Statistical analysis showed that infection rates were significantly higher in lambs of <1 month age group (65 %) than other two age groups (p < 0.05). Similarly, cryptosporidial infection rates were significantly higher in diarrhoeic (54.41 %) than in non diarrhoeic lambs (34.61 %). Winter records highest prevalence (73.33 %) which varied significantly. Sex wise higher prevalence was observed in females (51.56 %) as compared to males (39.28 %). The relationship between intensity of infection and various epidemiological factors showed that highest intensity was observed in lambs of 0-1 month age group, having diarrhoea, in winter season.

Incidence of Haemoproteus columbae in pigeons of Jammu district.

Haemoproteus columbae is the major protozoan infection reported in pigeon and appeared in the erythrocyte of the peripheral circulation. Incidence and parasitaemia of H. columbae in pigeon was studied in different localities of Jammu, India for a period from April to September 2010 using thin blood smear examination. Of the 150 pigeons (wild: 70, domestic: 80), 92 (61.33 %) were found to be infected with H. columbae. Domestic pigeon showed higher incidence rate (74.28 %) than the wild (50 %). Mature and immature gametocyte encircled the erythrocyte nucleus to form a halter shaped appearance were characteristic feature of the parasite. Pseudolynchia canariensis, the vector for H. columbae was also recovered from beneath the feathers of pigeons. No other haemoprotozoan parasite was observed in the blood smear of examined pigeon. Counting of infected erythrocyte revealed higher affection of 1-2 erythrocytes indicative of milder infection in the birds. A long term study within bird population is essential in order to disclose seasonal variation in parasite, vector density and age of infection such as nesting area.

Incidence of Buxtonella sulcata in bovines in R.S. Pura, Jammu.

Incidence of Buxtonella sulcata was recorded as 20.9 % in bovines (n = 374) of R.S. Pura, Jammu with cattle showing higher infection rate (23.6 %) than the buffaloes (18.5 %). The infection was significantly (p < 0.0001) higher in young animals (33.1 %) than the adults (13.9 %). Animals with diarrhoeic faeces had a significantly higher (p < 0.0001) infection rate (38.5 %) than the animals with normal faeces (9.9 %), suggesting the influence of protozoan on the incidence of diarrhoeal symptoms in bovines.

In vitro acaricidal activity of Atropa belladonna and its components, scopolamine and atropine, against Rhipicephalus (Boophilus) microplus.

In vitro efficacy of methanolic extract of Atropa belladonna and its components scopolamine and atropine was assessed against Rhipicephalus (Boophilus) microplus. Five concentrations of the extract (1.25%, 2.5%, 5%, 10%, and 20%) were used whereas scopolamine and atropine were each tested at 0.1%. In adult immersion test, the extract was lethal to ticks at 20% concentration. The LC50 and LC95 values were determined as 6.875% and 17.306%, respectively. The extract caused a significant reduction (P < 0.05) in egg mass production at 10% concentration. In larval packet test, the extract was lethal to larvae in the concentrations of 10% and 20% after 24 h, with LC50 and LC95 values of 1.321% and 4.935%, respectively. Scopolamine and atropine showed 93.3% and 60.0% mortality of adult ticks, respectively, but they caused complete (100%) blocking of hatching as well as 100% larval mortality. Scopolamine and atropine were observed to be more potent than the crude extract at an equivalent concentration in both the bioassays.

Occurrence of Chrysomya bezziana in a buffalo in Jammu.

Cutaneous myiasis caused by the Old World screw-worm fly, Chrysomya bezziana, is a commonly occurring infestation of livestock and man in Southeast Asian and African countries. A buffalo, aged five years was presented with traumatic wound in the abnormal growth at the base of tail, housing maggots in it. Based on morphological features, the collected larvae were identified as C. bezziana larvae. The first ever occurrence of C. bezziana in a buffalo from this part of country and its public health significance have been discussed.

Epidemiology of paramphistomosis in sheep and goats in Jammu, India.

Epidemiology of paramphistomosis in sheep and goats was studied using field and abattoir samples at Jammu, India. Abattoir examination revealed that 36.2 % of sheep and 30.9 % of goats were positive for paramphistomosis. The mean worm counts (±SEM) were 23.5 ± 5.7 in sheep and 19.9 ± 3.5 in goats. On coprological examination, 16.3 % of sheep and 13.6 % of goats were found positive for paramphistomosis. The mean egg counts (±SEM) were 4.4 ± 2.6 in sheep and 3.6 ± 2.1 in goats. Season was found to have a significant (p < 0.05) influence on the prevalence of paramphistomosis. A higher percentage of animals were found positive in rainy and post-rainy seasons as compared with summer and winter seasons. The distributions of eggs and adult flukes were significantly (p < 0.01) different among seasons. The prevalences observed according to age and sex of sheep and goats were not significant. The study conclude that the late summer months are major risk period for paramphistomosis in the pasture grazing sheep and goats and the administration of an efficient anthelmintic in May-June and September-October should be strongly recommended to reduce the infection and minimise the perpetuating financial losses to animal owners in the region.

Occurrence and histopathology of Przhevalskiana silenus larvae infestation in sheep of Jammu, India.

Warble fly infestation is primarily a myiasis of cattle and goat. However, a nondescript sheep from an endemic region was observed with nodules under subcutaneous tissue. So, this paper reports infestation of a sheep with Przhevalskiana silenus larvae in Jammu region of North India. The myiasis was confirmed with parasite morphology and specific histopathological changes observed in cutaneous myiasis.

Dicrocoeliosis in goats in Jammu, India.

The prevalence of dicrocoeliosis was estimated by the examination of liver of slaughtered goats (n = 228) brought from two major goat rearing regions (Kandi and R.S. Pura) of Jammu province of India. Dicrocoelium dendriticum was found in 18.9 % of the goats, with mean fluke count (±SEM) of 24.9 ± 4.4 (ranged from 0 to 478). A significant seasonal variation (p < 0.01) was recorded with maximum prevalence in winter (28.9 %), followed by post-rainy (22.2 %) and minimum in rainy season (9.4 %). The highest fluke count was observed in January (47.8 ± 24.6) while none of the examined animals was found positive in May and June. The origin of the goats had a significant association (p < 0.0001) with prevalence rates and the goats from Kandi region (27.3 %) showed higher prevalence rates as compare to R.S. Pura (8.0 %). However, the age and sex had no significant effect on the prevalence of dicrocoeliosis in goats. The histopathological examination of infected livers revealed excessive thickening and proliferation of bile duct glandular epithelium with inflammatory exudates. Also, intense mononuclear cells infiltration with young fibroblasts was observed in the surroundings of bile ducts in portal areas along with atrophy of hepatocytes.

Hydatidosis in goats in Jammu, India.

The prevalence of hydatidosis was carried out in slaughtered goats (n = 177) by liver and lung examination at Jammu. The prevalence rate of hydatidosis was 19.8 %. A total of 14.1 % goats had cysts in both the livers and lungs while 2.3 and 3.4 % goats had cysts in the livers or lungs, respectively. A total of 9.1 % goats had fertile cysts. The adult goats (>4 years) had a significantly higher (p = 0.01) prevalence rate as compared to the young goats (<2 years). Sex had no significant effect on the prevalence of hydatidosis in goats. The histopathological section of the affected lungs revealed a thick coat of granulation tissue causing fibrosis. The cysts caused progressive focal pressure atrophic lesions at the sites of predilection, resulting in atelectasis, desquamation of bronchial epithelium and interalveolar haemorrhages. It may be concluded that the slaughter of food animals at an early age would help to reduce the infection prevalence in dogs and subsequently in the food animals.

Field efficacy of minidosed pour-on ivermectin and eprinomectin against goat warble fly infestation by Przhevalskiana silenus.

The efficacy of minidose of pour-on ivermectin and eprinomectin formulations against first instar larvae of Przhevalskiana silenus was observed in naturally infested goats in the Jammu region, North India. The study was performed in mid August 2011. A total of 280 goats were randomly divided in to 7 groups of 40 each. Goats of the first three groups were treated with pour-on ivermectin at dosage of 2, 5, and 200 µg/kg body weight, respectively, whereas animals of the fourth to sixth groups were treated with pour-on eprinomectin at 25, 50, and 500 µg/kg body weight, respectively. Group VII animals were kept as untreated control. The results indicated that no warbles were recorded between December 2011 and March 2012 on back of animals treated with pour-on preparations of ivermectin at dosage of 5 and 200 µg/kg body weight, respectively, and eprinomectin at dosage of 50 and 500 µg/kg body weight, respectively. Thus, it is concluded that administration of minidose of pour-on ivermectin (5 µg/kg body weight) and eprinomectin (50 µg/kg body weight) is cost effective and so can be used for warble fly control campaign in Jammu region.