In vitro acaricidal activity of Piper longum L. against amitraz resistant Rhipicephalus microplus (Acari: Ixodidae)

The cattle tick, Rhipicephalus microplus Canestrini (Acari: Ixodidae) is one of the most important tick species severely affecting health and causes huge losses to dairy industry. Chemical acaricides are mainly applied for tick control but development of resistance, environmental pollution and contamination of milk and meat products with residues has led to exploration alternative eco-friendly tick control strategies. The dried fruits of Piper longum L. (Indian long pepper, Thippali or Pippali) generally used as flavoring agent have also been shown to have insecticidal property. Different concentrations (0.625%-10%) of alcoholic and aqueous extracts of Piper longum L. were prepared and evaluated for acaricidal activity against amitraz resistant R. microplus adult and larval stages. Against larval stages a dose-dependent mortality response was recorded for both extracts and higher acaricidal property was exhibited by the alcoholic extract with LC₅₀ and LC₉₅ (95% CL) values of 0.488% (0.48-0.49) and 1.39% (1.35-1.44), respectively. Similarly, against adult engorged females, ethanolic extract showed higher acaricidal property with LC₅₀ and LC₉₅ (95% CL) values of 4.67% (4.61-4.74) and 12.38% (12.05-12.73), respectively. Significant (p < 0.05) reduction was recorded in reproductive index of ticks treated and but no effect on hatchability of eggs was recorded in treated groups. The present study establishes acaricidal activity of P. longum fruit extracts against both larval and adult stages of amitraz resistant population of cattle tick.

Molecular prevalence of Babesia bigemina in Rhipicephalus microplus ticks infesting cross-bred cattle of Punjab, India

Babesiosis is an economically important tick-borne apicomplexan protozoan disease of cattle in tropical and subtropical regions. In the present study, Rhipicephalus microplus engorged female ticks were collected from 135 apparently healthy cattle from different agro-climatic zones of Punjab, India, to investigate the carrier status of Babesia bigemina infection in vector tick by using microscopy and PCR based assays. PCR when applied on DNA extracted from the egg masses harvested from ticks showed 1.48% (2/135) samples as positive, whereas 4.44% (6/135) samples were positive when product of primary PCR was used as template in nPCR. Further, among the DNA samples isolated from the unfed larval stages that emerged from egg masses laid by ticks, only 1.48% (2/135) samples were detected as positive for B. bigemina in PCR, while 7.41% (10/135) samples were detected positive in nPCR assay. Statistically, non-significant (p > 0.05) difference in prevalence rates was observed across different agro-climatic zones and between different age groups of cattle from which engorged ticks were collected. It can, thus, be concluded that prevalence of B. bigemina in the vector tick, R. microplus in Punjab state of India indicates an endemic status of the organism and a further study is needed for the management and control of the bovine babesiosis.

In vitro assessment of the acaricidal activity of Piper longum, Piper nigrum, and Zingiber officinale extracts against Hyalomma anatolicum ticks

Ticks and tick-borne diseases are a major constraint for the sustainable cattle industry in the tropical and subtropical regions including the Indian subcontinent. The development of resistance to most of the commonly used acaricides leads to an attempt to screen plant extracts and their combinations for their possible acaricidal activity to develop an eco-friendly tick control alternative. An alcoholic and various aqueous extracts of Piper longum, Piper nigrum and Zingiber officinale and their combinations were evaluated for acaricidal activity against the three-host ixodid tick, Hyalomma anatolicum by larval immersion test using 14-21 days old unfed larvae. The efficacy was assessed by measuring larval mortality (%) and the lethal concentrations for 50% (LC50) and 95% (LC95) with their 95% confidence limits (CL) values were estimated by applying regression equation analysis to the probit transformed data of mortality. A concentration-dependent mortality response was recorded in all extracts prepared from seeds of P. longum and P. nigrum and their combinations. The highest acaricidal property was exhibited by the alcoholic extract of P. longum seeds with the minimum LC50 and LC95 (95% CL) values of 0.071% (0.07-0.072) and 0.135% (0.13-0.14), respectively, followed by alcoholic combinations. Interestingly, no acaricidal activity was recorded in extracts prepared from the rhizome of Z. officinale. The results indicated that the ethanolic extracts of P. longum and P. nigrum and their combinations can be used effectively for tick control in an integrated format.

Detection of Malathion Resistance in Hyalomma anatolicum anatolicum from Bathinda District, Punjab

Objective:

The resistance status against malathion in Hyalomma anatolicum anatolicum ticks collected from Bathinda district, Punjab, was evaluated by adult immersion test (AIT).

Materials and Methods:

Technical grade malathion was used for conduction of AIT with 2 min immersion time protocol. The regression graph of probit mortality of ticks was plotted against log values of increasing concentrations of malathion and was utilized for the determination of slope of mortality, LC₅₀, LC_{95 (}95% confidence interval [CI]) and resistance factor (RF). The reproductive parameters of treated ticks viz. egg mass weight, reproductive index (RI), and percentage inhibition of oviposition (% IO) were also studied.

Results:

The increasing concentration of malathion showed an upward trend in per cent tick mortality. The slope of mortality (95% CI) was 2.489 ± 0.719 (2.489 ± 0.719) and value of goodness of fit (R²) was 0.799. The LC_{50 (}95% CI) and LC_{95 (}95% CI) values were recorded as 9099.2 (8378.6–9881.7) and 41,511.3 (35,060.2–49,149.4) ppm, respectively, with RF as 16.60 indicating level II resistance status. A negative dose-dependent slope of egg mass weight (−91.79 ± 25.15 [−171.8 to −11.76]) was recorded as the survived ticks laid significantly (P = 0.0355) fewer eggs. The mean RI of treated ticks decreased with increasing concentrations of drug and the slope (95% CI) was −0.293 ± 0.059 (−0.482 to −0.105). Further, a dose-dependent significant increase (P = 0.0157) in the mean % IO was recorded in treated ticks.

Conclusions:

The results of the current study would be useful in the formulation and implementation of effective tick strategies in the region.

Molecular detection of Babesia bigemina infection in apparently healthy cattle of central plain zone of Punjab

Bovine babesiosis is an important tick-borne disease caused by the parasites belonging to the genus Babesia, distributed worldwide and infecting a wide range of domesticated and wild cattle, occasionally man. The present study was conducted to determine the prevalence of B. bigemina infection in apparently healthy cattle from central plain zone of Punjab, India. Examination of Giemsa-stained peripheral thin blood smears revealed 2.45 % (5/204) animals to be positive for piroplasms of B. bigemina. However, genomic DNA isolated from these blood samples when subjected to primary PCR revealed a positivity of 7.35 % (15/204) as detected by the amplification of a 278-bp product in the agarose gel. PCR products obtained from the primary PCR of B. bigemina, when employed as template in nested PCR produced the amplicons of desired size (170 bp) was detected in 30.39 % (62/204) of the samples. It can thus be concluded that B. bigemina infection is prevalent in apparently healthy cattle population of this region and PCR assays can serve as a valuable tool for epidemiological studies in endemic areas.

Assessment of risk factors associated with prevalence of strongyle infection in equines from Central Plain Zone, Punjab

A total of 311 equine faecal samples (190 horses and 121 mules) collected from six districts of Central Plain Zone, Punjab were examined using standard coprological methods. The results showed an overall prevalence of 27.33 % for strongyles with rare to mild type of infection as evident from egg per gram of faeces. In particular, amongst the examined samples, 17.90 % of horses and 42.14 % of mules were infected and the difference was statistically significant (P < 0.01). Identification of the faecal culture harvested larval stages, showed 56 % and 46 % of horses and mules, respectively, positive for small strongyles (Cyathostomes). Amongst the large strongyles, highest proportion was recorded for Strongylus vulgaris whereas, S. equinus was found in least proportion. Results indicated that the various risk factors viz. area, season, age and sex of the host had no significant effect on prevalence of strongyle infection in equines.

Assessment of risk factors associated with prevalence of coccidiosis in dairy animals of Punjab

A total of 2089 faecal samples (956 buffaloes and 1133 cattle) were collected from 21 districts of five major agro-climatic zones of Punjab during April, 2013-May, 2014. An overall prevalence rate of 32.17 % (672/2089) was recorded for coccidiosis in dairy animals with a significantly higher (P < 0.01) infection rate in buffaloes (35.46 %) in comparison to cattle (29.39 %). Quantitative analysis revealed oocyst per gram of faeces ranging from 200 to 10,000 (1083.72 ± 227.20) and 100 to 2400 (748.72 ± 81.38), in cattle and buffalo populations, respectively. The results of multivariate analysis showed that prevalence of coccidiosis in cattle population was associated with various risk factors viz. districts (P = 0.000; OR 2.749; 95 % CI 1.238-6.107), agro-climatic zones (P = 0.004; OR 2.707; 95 % CI 1.707-4.293) and seasons (P = 0.000; OR 1.106; 95 % CI 0.811-1.509). Similarly, in buffalo population an association with districts (P = 0.000; OR 2.163; 95 % CI 0.702-6.668), agro-climatic zones (P = 0.000; OR 1.237; 95 % CI 0.673-2.277) and seasons (P = 0.100; OR 1.382; 95 % CI 1.003-1.903) was recorded. The findings of the current study would provide a basis for evolving effective control strategy for the management of coccidiosis in dairy animals of the region.

Prevalence of Theileria annulata infection in Hyalomma anatolicum anatolicum collected from crossbred cattle of Ludhiana, Punjab

The prevalence of Theileria infection in tick vector Hyalomma anatolicum anatolicum collected from healthy animals of Ludhiana district, Punjab was recorded to assess the natural infection level of theilerial parasite in the field condition. A total of 60 semi-engorged H. a. anatolicum were collected from cattle and their salivary glands were dissected out. One half of the salivary gland was stained with methyl green pyronin (MGP) and the other half was utilized for DNA isolation for molecular detection of Theileria infection. A PCR and nested PCR assays were standardized for the detection of T. annulata infection in salivary gland of H. a. anatolicum. The prevalence of T. annulata infection was recorded as 8.3, 20.0 and 60.0 % by MGP staining, primary PCR and nested PCR, respectively. Further, the prevalence was higher in female ticks (8.8 %) than male ticks (6.6 %). The results demonstrated that both primary and nested PCR assays are a valuable technique for detection of T. annulata infection in vector tick under field conditions.

Malathion resistance in Rhipicephalus (Boophilus) microplus from Ludhiana district, Punjab

The resistance status of Rhipicephalus (Boophilus) microplus collected from Noorpur Bet village of Ludhiana district, Punjab was evaluated against malathion by Adult Immersion Test. The adult female ticks showed an upward trend in the mortality percentage with increase in drug concentration. The regression graph of probit mortality of ticks plotted against log values of progressively increasing concentrations of malathion was utilized for the determination of slope of mortality (95 % confidence intervals) which was 2.469 ± 0.5744 (0.6413-4.297) whereas, the value of goodness of fit (R(2)) was 0.8603. The LC50 (95 % CI) and LC95 (95 % CI) were recorded as 1875.05 (1725.14-2,038) and 8,654 (7296.8-10263.8) ppm, respectively and the resistance factor was 3.46 (Level I). The slope of egg mass (95 % CI) was -0.1500 ± 0.04071 (-0.2795 to -0.02045) and was negative because with the increasing concentrations of acaricide the ticks died. The reproductive index when plotted against increasing log concentrations of malathion revealed a slope value of -0.414 ± 0.055. Further, a significant variation (p = 0.0049) was recorded in the inhibition of oviposition among the various groups treated with increasing concentrations of malathion.

Detection of amitraz resistance in Rhipicephalus (Boophilus) microplus from North Gujarat, India

Amitraz has become one of the most extensively used chemical acaricide for control of cattle tick due to development of resistance against most of the organophosphates and synthetic pyrethroid acaricides. The resistance status of amitraz was evaluated against Rhipicephalus (Boophilus) microplus collected from Banaskantha district, Gujarat, India by adult immersion test (AIT). The different concentrations of amitraz utilized in the AIT were 125, 250, 500, 750 and 1,000 ppm. The adult female ticks showed an upward trend in the mortality percentage with increase in drug concentration. The regression graph of probit mortality of ticks plotted against log values of progressively increasing concentrations of amitraz was utilized for the determination of slope of mortality which was 1.868 ± 0.2068. The lethal concentration (LC95) was calculated as 3098.2 ppm and the RF was 24.78 which indicated level II resistance status. The dose response curves for egg masses, reproductive index and inhibition of oviposition of R. (B.) microplus were also validated and the slope was -0.5165 ± 0.08287, -0.1328 ± 0.04472 and 24.22 ± 8.160, respectively. The current study appears to be the pioneer report of amitraz resistance in R. (B.) microplus from India and the data generated could be of immense help to develop effective control strategies against ticks.

Prevalence of parasitic infections in cattle of Ludhiana district, Punjab

A total of 862 cattle were sampled for both haematological (703) and coprological (159) investigations at the Large Animal Clinics, GADVASU, Ludhiana, Punjab, India. Examination of Giemsa-stained peripheral blood smears exhibited that 22.9 % (161/703) of cattle were infected with haematozoa comprising Theileria annulata (14.65 %), Trypanosoma evansi (0.28 %), Babesia bigemina (1.56 %) and Anaplasma marginale (8.53 %) while mixed infection appeared in 2.13 % (15/703) animals. The prevalence of total haemoparasites and A. marginale infections were significantly higher (p < 0.01) in younger animals <1 year of age whereas, T. evansi and A. marginale infections were significantly higher (p < 0.05) in males. Coprological examination revealed that the overall prevalence of gastrointestinal (GI) parasitic infection was 16.98 % (27/159). Among the revealed parasites, amphistomes, Fasciola spp., Eimeria spp., Balantidium coli, strongyles and Trichuris spp. were detected from 3.77, 1.88, 3.77, 2.52, 10.69 and 1.26 % of examined animals. Except coccidiosis, there was no significant variation of GI parasitic infections in relation to sex as Eimeria spp. were found higher (p < 0.01) in males. The prevalence of Trichuris spp. was significantly higher (p < 0.05) in younger animals <6 months of age. The present work emphasized that strongyles and T. annulata were the most prevalent GI and haemoparasites, respectively.

First report of Ctenocephalides felis felis infestation of buffalo calves in Punjab, India

Two female buffalo calves of approximately 3 months of age from Hoshiarpur and Gurdaspur districts of Punjab state, India were found to be moderately infested with the cat flea Ctenocephalides felis felis. The calves were apparently healthy with no clinical signs and skin lesions. The calves were also found to be simultaneously infested with ixodid tick (Rhipicephalus (Boophilus) microplus). Infestations of buffalo calves by C. felis felis is reported for the first time.

Prevalence of Theileria annulata infection in Hyalomma anatolicum anatolicum in Punjab state, India

The study was conducted to assess the prevalence of Theileria infection in tick vectors collected from healthy animals to record the natural infection level of theilerial parasite in the field condition. A total of 156 male and 110 semi-engorged female of Hyalomma anatolicum anatolicum were collected from cattle and buffaloes of two different agro climatic zones of Punjab, dissected and their salivary glands were stained with Methyl Green Pyronin (MGP) stain. The prevalence, intensity and abundance of Theileria annulata infection were higher in female ticks (15.45%, 5.08 and 32.88, respectively) than male ticks (8.97%, 1.69 and 18.86, respectively). The ticks collected from cattle had a higher prevalence, abundance and intensity (15.15%, 5.38 and 35.53, respectively) of T. annulata infection than the ticks collected from buffaloes (9.58%, 1.74 and 18.13, respectively). Hot and dry climate favored the development of T. annulata sporozoites in H. a. anatolicum ticks as the prevalence, abundance and intensity of T. annulata infection were higher in ticks collected from Western semi arid zone of Punjab as compared to those collected from the central plain zone with hot and humid climate.

Parasitization of fifth instar tasar silkworm, Antheraea mylitta, by the uzi fly, Blepharipa zebina; a host-parasitoid interaction and its effect on host's nutritional parameters and parasitoid development

The uzi fly, Blepharipa zebina, is a well-known larval endoparasitoid of the tropical tasar silkworm, Antheraea mylitta. The present study dealt with the effect of the number of maggots developing per host on host nutritional parameters, parasitoid development and reproduction. Nutritional indices for ingestion, digestion, approximate digestibility, relative consumption rate, relative growth rate, and gain in body weight declined significantly with the increase in parasitoid burden, but the efficiency of conversion of digested food recorded a significant increase. The efficiency of conversion of ingested food remained little affected. The developmental period was significantly extended in larvae parasitized with 5 and 10 maggots per larva (mpl). Cocoon shell weight decreased by 27-63.5% in parasitized groups (1, 2, and 5 mpl) while larvae parasitized with 10 mpl could not spin cocoons. The maggot development period, recovery percentage, and fecundity of the uzi fly declined significantly with the increase in number of maggots developing per host.

Food utilization efficiency in fifth instar larvae of Antheraea mylitta (Lepidoptera: Saturniidae) infected with Nosema sp. and its effect on reproductive potential and silk production

Antheraea mylitta, a sericigenous insect of economical importance is often infected with an intracellular parasite of the genus Nosema. This pathogen is known to cause fatal pebrine disease and is considered as an important factor that strongly influences the development of the host. Larvae developed from the eggs laid by a female infected with Nosema sp. showed extended development period. The increment in the larval weight declined significantly in infected larvae in comparison to uninfected ones. Food consumption, digestion, relative consumption rate (RCR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and relative growth rate (RGR) values declined significantly, but at the same time a significant increase in approximate digestibility (AD) was also observed. Silk production declined in infected larvae. Silk gland weight and shell weight also significantly declined following infection over uninfected larvae. The reproductive potential in adults declined significantly (P<0.001) with decrease in ovary weight (31.6%), fecundity (54.1%), and fertility (34.9%). Egg chorionation was also affected in adults, which developed from infected larvae. The maternal infection level in one generation (10.4 x 10(6) spores/female) decreased significantly in the next generation (8.0 x 10(6) spores/female).

Effect of short-term starvation stress on the age-related changes in hepatic SDH activity of the indian murrel, Channa punctatus

Judging from correlation analysis it is evident that the fed control male and female murrels of the oldest classes have significantly higher SDH (EC 1.3.99.1) activity than the youngest classes of respective sexes. This is true for starved groups also. Starvation for 3 days led to an increase in hepatic enzyme activity over fed controls in three oldest groups (3+-, 4+- and 5+-yr classes) of female. This trend of raised activity was maintained in the same groups even in 7 days of starvation. On the other hand, in the male fish, 3 days of starvation caused an increase in hepatic enzyme activity over that in fed control fishes of all year classes barring those of 0+-yr class. Seven days of starvation failed to produce a significant change in enzyme activity in almost all age classes except in the 5+-yr class where the activity still remained at a higher level over that of fed controls.