Efficacy of herbal extracts and closantel against fenbendazole-resistant Haemonchus contortus.

This study assessed the efficacy of closantel vis-à-vis herbal extracts with known anti-parasitic properties, against fenbendazole-resistant nematodes in goats maintained under a semi-intensive system of management at the University goat farm, Jabalpur. Fifty goats were randomly assigned to five groups, each comprising 10 animals, irrespective of their breed, age and sex. Each animal in Group I, II and III was orally administered with aqueous leaf extracts of neem (Azadirachta indica) at 1 g/kg body weight, sitaphal (Annona squamosa) at 1.5 g/kg body weight and tobacco (Nicotiana tabacum) at 1 g/kg body weight, respectively, whereas Group IV was an untreated control group. Each animal in Group V was orally treated with closantel at 10 mg/kg body weight. During the course of the study, all animals were maintained under an identical semi-intensive system of management. Compared to the untreated control group (Group IV), there was no conspicuous reduction in post-treatment (day 10) faecal egg counts (FEC) in animals administered with the herbal extracts (Groups I, II and III), which is suggestive of poor anti-parasitic activity. However, using the faecal egg count reduction test (FECRT), the overall efficacy of closantel was recorded as 95.64%. This supports the rotational use of closantel as a preferred choice over the benzimidazole group of anthelmintics and/or herbal extracts to meet the acute challenge of in situ development of drug-resistant gastrointestinal nematodes, especially Haemonchus contortus.

An assessment of benzimidazole resistance against caprine nematodes in Central India.

Current status of resistance to benzimidazole (BZ) group of anthelmintic drugs against caprine nematodes in Central India at Amanala goat farm, Jabalpur, Madhya Pradesh (M. P.), was systematically investigated using faecal egg count reduction (FECR) test and egg hatch test (EHT). Besides, allele-specific PCR (AS-PCR) was deployed to ascertain the susceptible genotype (alleles) especially of the Haemonchus contortus. Randomly selected 30 goats, irrespective of age and sex, were divided into three groups of 10 each, to serve as treated and untreated controls. It was ensured that the animals were not administered with an anthelmintic drug for the past 3 months prior to undertaking the study, and faecal egg counts were estimated. FECR test evidenced fenbendazole resistance by partial elimination (24.90%) copro-egg counts in the treated group of animals vis-à-vis controls with a lower confidence interval of -26%. Further, EHT revealed ED-50 value of 0.335 µg of thiabendazole/ml, confirming benzimidazole resistance in the animals of that farm. AS-PCR showed that 62% of H. contortus larvae were homozygous resistant (rr), 24% heterozygous (rS) and 14% homozygous susceptible (SS). The genotypic frequencies of three genotypes (rr, rS and SS) were significantly (P < 0.01) different. The prevalence of benzimidazole resistance allele (r) was also significantly (P < 0.01) higher (74%) as compared to susceptible allele (S) (26%). The resistance to benzimidazole has been discussed while emphasizing improved managemental practices designed to reduce exposure of the goat population to parasites, minimize frequency of anthelmintic use at optimum dose and rotational use of different chemical groups of medicines with different mode of action, so as to overcome and combat the upcoming problem in the field.

Intestinal helminths induce haematological changes in dogs from Jabalpur, India.

The effect of canine intestinal helminths on the haematological profile of 200 dogs, of both sexes and variable age, visiting university veterinary clinics for routine examination was investigated. The dogs were assigned to parasitized (n = 39) and non-parasitized (n = 161) groups of animals. Coprological examination revealed a 19.5% prevalence of different species of the helminths. Of these animals, 10.25% had mixed infections with Ancylostoma caninum, Toxascaris spp. and Dipylidium caninum. The intensity of A. caninum infection was the highest, with mean egg counts of 951.43 (standard error 88.66), followed by Toxascaris 283.33 (standard error 116.81) and D. caninum. The parasitized animals had significantly lower levels of haemoglobin, packed cell volume and total erythrocyte counts than non-parasitized animals (P < 0.01). Values of other parameters, except for lymphocytes and eosinophils, were not different between the two groups. Analyses of the haematological profile revealed normocytic hypochromic anaemia in the parasitized group of animals.

Serum enzyme and hematological profile of Fasciola gigantica immunized and experimentally infected riverine buffaloes.

Sixteen male, yearling Murrah buffaloes were randomly assigned to four groups of four buffaloes each. Each animal in Gr-I and II were immunized, respectively, with 4.8 mg of excretory secretory antigen and 1,300 microg Infection Specific Antigen, in three divided doses. Subsequently, each animal in Gr-I, II, and III was per os infected with 800 viable Fasciola gigantica metacercariae (bubaline origin) on week-6 after the start of the experiment, while animals in Gr-IV served as healthy controls. The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations progressively increased during the prepatency and respectively attained the highest levels during week-6 and 8 post-infection (PI). The alkaline phosphatase (AP) exhibited elevated trends from eighth week PI onward and continued to be higher until the end (p < 0.05-0.01). With the cessation of traumatic activities of the diastomes, the AST and ALT levels declined yet were throughout significantly higher than the healthy controls (p < 0.05-0.01). In the immunized animals (Gr-I and II), the fluctuation patterns were similar but the values were significantly lower than the non-immunized (Gr-III) animals (p < 0.05-0.01). The elevated levels of the enzymes had positive correlation with depressed erythrocytic indices, leucocytosis, eosinophilia, necropsy worm recovery, and hepatic lesion score in the respective groups. The increased concentrations of the enzymes revealed two clearly demarcated stages: (a) remarkably elevated AST (40.8%) and ALT (140.0%) levels during the prepatency, signifying traumatic lesions inflicted by the F. gigantica adolescercariae and (b) the significant increase in AP (107.9%), suggestive of bile duct hyperplasia, cholangitis, periportal fibrosis, and biliary obstruction etc. from sixth week PI onward. None of healthy controls developed clinical signs and had normal hematological and serum enzyme profiles. Diagnostic significance of these marker enzymes in the disease forecasting and in time application of control strategies to combat tropical fasciolosis in buffaloes in the endemic areas has been discussed.

Aberrant infestation of goat mandibles with Oestrus ovis larvae.

Nasal oestrosis is primarily an infestation of sheep. However, a non descript goat, aged three years was presented in lateral recumbency with clinical history of sneezing fits, laboured breathing, eroded mandibular lesions and bilaterally housing nasal bots therein. The first ever occurrence of nasal bots in an aberrant location (mandibles) in a goat, its therapeutic management and public health significance have been documented and discussed.

Immunodiagnostic/protective role of cathepsin L cysteine proteinases secreted by Fasciola species.

Cathepsin L, a major cysteine proteinase secreted by the parasite plays a pivotal role in various aspects of its pathogenecity. The enzyme takes part in nutrient acquisition by catabolizing host proteins to absorbable peptides, facilitates the migration of the parasite through the host intestine and liver by cleaving interstitial matrix proteins such as fibronectin, laminin and native collagen and is implicated in the inactivation of host immune defenses by cleaving immunoglobulins. Recently, Cathepsin L has been shown to suppress Th1 immune response in infected laboratory animals making them susceptible to concurrent bacterial infections. Accordingly, the protease has been recognized as an important target at which parasite intervention strategies should be directed. Fluke Cathepsin L cysteine proteinases are also reported as sensitive and specific markers for the immunodiagnosis of fasciolosis in ruminants. Further, vaccination of laboratory or large animals with these proteases resulted in a significant reduction in fluke burden and/or fecundity.

Effect of Fasciola gigantica infection on adrenal and thyroid glands of riverine buffaloes.

Effect of Fasciola gigantica infection on adrenal and thyroid glands was investigated using eight male, yearling Murrah buffaloes. The animals were randomly assigned to two groups of four buffaloes each (Group-A, infected; Group-B, non-infected control). Animals of Group-A were orally infected with 1000 F. gigantica viable metacercariae, keeping other four animals of Group-B as uninfected control. In the infected buffaloes, the clinical signs began appearing from 7th week postinfection (p.i.) and eggs were detected in the faeces between day 93 and 99 (95.5+/-1.25) postinfection (p.i.). The serum cortisol level, revealed a significant (P<0.05) rise during initial stage of the infection, followed by a continuous fall from 12th week onward. Peak cortisol level on 10th week (13.30+/-2.57ngml(-1)) was associated with eosinophilia (11.0+/-0.95%). However, non-infected controls maintained almost uniform cortisol levels (3.97+/-0.15-5.88+/-0.09ngml(-1)) throughout the period of the study. The pathological changes of adrenal glands were correlated with physiological dysfunction of the glands. The levels of T(3) and T(4) were significantly (P<0.05-0.01) low from 14th week onward and were synchronous with in situ migration, growth and development of F. gigantica. Significant reduction in the thyroid hormones was further supported by histopathological evidence of lymphocytic thyroiditis confirming hypothyroidism. A decrease in Hb, PCV, total erythrocyte counts and appearance of reticulocytes in the blood of the infected buffaloes suggested regenerative anemia, which could partly be due to hypothyroidism.

Effect of Fasciola gigantica excretory secretory antigen on rat hematological indices.

The present study was undertaken to investigate the effect of Fasciola gigantica excretory secretory antigen (Fg-ESA) on rat hematological indices. Fg-ESA was prepared by keeping thoroughly washed 40 F. gigantica flukes in 100 ml phosphate buffer saline (PBS) for 2 h at 37 degrees C, and centrifuging the supernatant at 12,000 g at 4 degrees C for 30 min. The protein content of Fg-ESA was adjusted to 1.8 mg/ml. The rats were randomly divided into two groups of six rats each. Rats in group A received 0.5 ml of Fg-ESA intraperitoneally (i.p.) for 7 days, whereas control rats in group B received 0.5 ml of PBS i.p. for 7 days. Hemograms of both groups were studied initially and on days 0, 2, 4, 14 and 21 after the final injection of Fg-ESA or PBS. Progressive and significant (p < 0.01) declines in the values of hemoglobin, hematocrit, and total erythrocyte count were observed without significant (p > 0.05) changes in the values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, or mean corpuscular volume in group A. Thus, we conclude that Fg-ESA induces normocytic normochromic anemia in rats.

Transcutaneous bilirubinometer in assessment of neonatal jaundice in northern India.

This study was undertaken from April 2002 to March 2003 to find out the correlation of transcutaneous bilirubinometer index with serum bilirubin levels in term, pre-term, small for gestation age babies, with and without phototherapy in neonates with jaundice. Another aim was to evaluate the transcutaneous bilirubinometer as a screening device for neonatal hyperbilirubinemia by finding the action levels for TcBI at forehead and sternum at which sample for serum bilirubin estimation should be taken. A total of 104 neonates were evaluated. Mean (SD) age (hours), birth weight (grams) and gestational age (weeks) were 100.4 (37.90), 2264.9 (634.4) and 36.8 (2.9) respectively. Mean serum bilirubin was 16.6 (6) mg/dL. Overall a correlation coefficient of 0.878 at forehead and 0.859 at sternum was observed. On excluding infants receiving phototherapy coefficients of 0.900 at forehead and 0.908 at sternum were noted. Correlation coefficient over forehead and sternum was found to drop from 0.85 to as low as 0.33 with duration of phototherapy exceeding 48 hrs. Lastly the determined action levels had a sensitivity of 77.8 to 100 % in assessing the need for serum bilirubin estimation in various groups.

Osmotic fragility of sheep erythrocytes and alterations in their membrane constituents in Dictyocaulus filaria infection.

Alterations in the sheep erythrocyte membrane constituents during the course of Dictyocaulus filaria infection were studied in 4-6 month old Nali lambs. During the acute course of infection, plasma cholesterol, membrane cholesterol, cholesterol: phospholipid ratio and acetylcholinesterase activity fell significantly when compared with uninfected controls. The onset of the fall in the values of these parameters was observed 1-2 weeks prior to an increase in the osmotic fragility of erythrocytes. The altered values persistently remained at sub-normal levels during the chronic stage of the infection. However, the membrane proteins and phospholipids of sheep erythrocytes remained unaffected during the entire period of study. The clinico-parasitological picture of the disease, as judged by the clinical course of disease, faecal larval output and necropsy worm recovery, was typical of ovine dictyocauliosis.

Experimental studies on anaemia in sheep infected with Dictyocaulus filaria.

The pathogenesis of Dictyocaulus filaria induced anaemia was experimentally investigated. Nineteen Dorset-Muzaffarnagri male lambs were divided into two groups of 13 and six. The lambs in the former group received a primary infection dose of 2000 D. filaria infective larvae, whereas animals in the latter group were kept as uninfected controls. The haematological alterations and faecal larval output were monitored weekly until day 220 post-infection. The infection caused an increase in erythrocyte sedimentation rate (ESR) and total leukocyte count (TLC). However, a decrease in packed cell volume (PCV), haemoglobin, total erythrocyte count (TEC) and blood pH was observed in acute infection. The shape and size of the erythrocytes, serum bilirubin level, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) remained unaffected In carriers, except for TEC, the values of these parameters returned to near-normal levels. The analysis of the results suggests that the infected animals developed a normocytic normochromic anaemia which persisted during the later stage of infection.

Derivative spectrophotometric determination of mercury(II) with pan in the aqueous phase.

The Hg-PAN complex can be made soluble in water by addition of surfactant, and this can be made the basis of a spectrophotometric determination of Hg at ppm level. The selectivity and sensitivity can be improved by use of derivative spectrometry. The method has been applied to mercury-containing pesticides.

Simultaneous determination of beryllium and aluminium in mixtures using derivative spectrophotometry.

The spectrophotometric determination of beryllium and aluminium with 5,8-dihydroxy-1,4-naphthoquinone in the presence of a non-ionic surfactant is reported. Absorption maxima, molar absorptivity and Sandell's Sensitivity of 1:2 (M:L) beryllium and aluminium complexes are, 585 nm and 598 nm, 1.63 x 10(4) l.mole(-1).cm(-1) and 2.04 x 10(4) l.mole(-1).cm(-1), and 0.55 ng/cm(2) and 1.32 ng/cm(2) respectively. Beer's law is obeyed between 7.20-3.96 x 10(2) ng/ml beryllium and 1.08 x 10(1)-1.08 x 10(3) ng/ml aluminium. A method for simultaneous determination of beryllium and aluminium in their mixture using derivative spectra is described. The range 3.6 x 10(1)-3.6 x 10(2) ng/ml beryllium could be determined in the presence of 1.08 x 10(2)-1.08 x 10(3) ng/ml aluminium, and vice versa.

Parasitic bronchitis in goats and the possible use of Dictyocaulus filaria vaccine for its control.

Parasitic bronchitis is widely prevalent in migratory flocks of small ruminants in the northwest Himalayan regions of India. The prevalence data collected from 5554 goats, maintained in 31 villages in different agroclimatic regions of the Himalayas, showed that the prevalence of the disease in goats varied from 18.7 to 47.6% with an overall prevalence of 21.8%. Interestingly, 27.6% of goats maintained at an altitude of 2700-3900 m above mean sea level in Kargil (Jammu and Kashmir), where the climate is cold and dry for the major part of the year, were positive for the lungworm infections. The common lungworms observed were Dictyocaulus filaria, Protostrongylus rufescens, Varestrongylus pneumonicus and occasionally Muellerius spp. The kids were more susceptible to lungworm infections than adult goats. In experimental studies, it was seen that goats were more susceptible to Dictyocaulus filaria infection than sheep and two vaccine doses comprising 1000 and 2000 gamma-attenuated D. filaria (ovine strain) infective larvae conferred 97% protection in male Beetal kids against a homologous challenge dose of 4200 normal D. filaria larvae. The importance of simultaneous control of the disease in goats and sheep is discussed.

Parasitic infections of Indian yak Bos (poephagus) grunniens--an overview.

For centuries, the yak and its hybrids with domestic cows (dzomo/dzo) have been contributing to the socio-economic status of their owners in desolate regions of the Greater Himalayas. Studies on the prevalence of parasitic diseases in these animals were undertaken in Ladakh (Jammu and Kashmir), Sikkim and villages near the Indo-Nepal border of Uttar Pradesh. Visceral organs of necropsied animals were observed for the presence of adult metazoan parasites, fresh or preserved faecal samples were examined for the eggs of helminth parasites and protozoan cysts, and blood smears were examined for haemo-protozoa and microfilariae. In all, examination of 225 faecal samples, 180 blood smears and the visceral organs of thirteen yaks and dzomo/dzo was undertaken. On necropsy, visceral organs revealed various adult liver and stomach flukes, gastrointestinal nematodes, tapeworms, cysts of Coenurus spp. and hydatid cysts, as well as Setaria cervi worms and large and/or small sized Sarcocystis cysts. On coprological examination, egg prevalences of 10% for Fasciola spp., 6.6% for various amphistomes, 10% for Moniezia spp., 76.4% for Strongylate spp., 24% for Neoascaris spp. and 13.7% for Nematodirus spp. were recorded. Identification of infective larvae from the faecal cultures showed that a majority of eggs (86.3%) in the host faeces were contributed by nematodes belonging to Trichostrongyle spp., Ostertagia spp. and Cooperia spp. This was followed by Chabertia spp. (6.5%). Haemonchus spp., Bunostomum spp. and Nematodirus spp. together contributed only 7.2% of the eggs found. Among protozoan infections, Eimeria brasiliensis and E. zurnii were common. None of the blood smears evidenced any haemoprotozoa or microfilariae. Likewise, none of the animals were positive for Trichuris spp.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunization with irradiated larvae against Dictyocaulus filaria in young lambs.

In the lungworm-endemic areas of Kashmir, 6-10 week old lambs of Karnah and Kashmir Merino breeds were vaccinated with two doses of 50 kR gamma-irradiated larvae of Dictyocaulus filaria, given a month apart. Assessed on the basis of reduced prevalence and significantly lower faecal larval output over an eight-month observation period, vaccinated lambs showed a high degree of resistance to naturally acquired D. filaria infection. The results also show that vaccination against D. filaria provided some degree of protection against infection with other lungworm species.

Anthelmintic activity of ivermectin against experimental Ascaridia galli infection in chickens.

The efficacy of ivermectin against Ascaridia galli infection was evaluated in chickens under controlled laboratory conditions in two separate experiments. In each experiment 22 White Leghorn chicks were randomly assigned to three groups of 10 (infected-treated), 9 (infected-control) and 3 (uninfected-control) birds. Each bird in the former two groups was orally infected with 1,500 embryonated A. galli eggs. The chicks in the treated group were subcutaneously injected with ivermectin at a dose of 0.3 mg kg-1 body weight on Day 10 (Experiment 1) and Day 35 post-infection (Experiment 2) for immature and adult infections, respectively. The treated birds had 0.9% (Experiment 1) and 0.4% (Experiment 2) worm recovery compared with 8.7 and 8% in the infected-untreated controls of the respective experiments. The fall in post-treatment faecal egg counts was 81 and 92% in birds treated on Days 10 and 35, respectively. The drug was found to be 90 and 95% effective against immature and adult worms, respectively. The lower lesion score and post-treatment near-normal haematobiochemical picture in treated birds confirmed these observations. The treated birds also had a better growth rate than the untreated chickens. The mature worms in the intestinal lumen of the host were more sensitive to the treatment than the immature stages of the parasite in the tissue phase.

Effect of bronchodilator and intravascular oxygen releaser on the course of Dictyocaulus filaria infection in lambs.

The effect of a bronchodilator (or ciprenaline sulphate) and intravascular oxygen releaser (sodium dihydrogen orthophosphate) on the host in experimental Dictyocaulus filaria infection was studied. Fifteen male lambs of Dorset-Muzaffarnagri breed, aged 4-6 months, were divided into four groups of four (infected bronchodilator), four (infected i.v. O2 releaser), four (infected untreated controls) and three (uninfected controls). The administration of i.v. O2 releaser helped in increasing the length of useful patency, estimated total larval production and survival rate of D. filaria producer lambs. The administration of I.V. O2 releaser and bronchodilator helped in efficiently restoring the altered values of blood pH, haemoglobin, packed cell volume, erythrocyte sedimentation rate and osmotic fragility of erythrocytes to near normal levels. However, the blood clotting time and level of lactate dehydrogenase activity remained altered and followed a course typical of ovine dictyocauliosis.

Detection of circulating 54 kDa antigen in sera of bovine calves experimentally infected with F. gigantica.

The antibody response and circulating antigen levels in bovine calves, infected experimentally with Fasciola gigantica, were monitored using enzyme-linked immunoelectrotransfer blot (EITB) and sandwich ELISA, respectively. By EITB, the infected calves' sera recognized the polypeptides in the range of 54-58 kDa as early as 2 weeks post-infection. By 12th week post-infection, the lower two polypeptides of 12 and 8 kDa had disappeared. In sandwich ELISA, the circulating 54 kDa and whole worm antigen of F. gigantica were detected in the sera samples of infected calves as early as 2 weeks post-infection and persisted until the end of experiment (26th week PI). The 54 kDa antigen of F. gigantica appears to be specific and possesses promising immunodiagnostic potential for early prepatent diagnosis of bovine fasciolosis.