Acaricides resistance in Rhipicephalus microplus and expression profile of ABC-transporter genes in the sampled populations

Currently, livestock owners manage tick infestations using chemicals, but the method is increasingly losing effectiveness as resistant tick populations have established in the field conditions. Thus, to develop effective tick management strategies, monitoring of resistance in most predominant tick species, Rhipicephalus microplus was targeted. The ticks were collected from eleven districts of Madhya Pradesh and one district of Punjab and tested against deltamethrin (DLM), cypermethrin (CYP), coumaphos (CMP), ivermectin (IVM) and fipronil (FIP), through adult immersion and larval packet tests. The field isolates were highly resistant to DLM [Resistance factor (RF) = 3.98-38.84]. Against CYP, resistance was observed in BWN (Barwani; RF = 2.81) and MND (Mandsaur; RF = 3.23) isolates. Surprisingly, most of the isolates were susceptible to CMP (0.34-1.58). Emerging level of resistance against IVM (1.05-4.98) and FIP (0.40-2.18) was also observed in all the isolates. Significantly elevated production of esterases (p < 0.01) was 90% correlated with RF of DLM while no positive correlation between production of monooxygenase and Glutathione S-transferase with RF to DLM was noted. Multiple sequence analysis of S4-5 linker region of the sodium channel gene of all the isolates revealed a point mutation at 190th position (C190A) which is associated with DLM resistance. Treatment of resistant LDH (Ludhiana) isolate with IVM resulted in upregulation of RmABCC2 gene and insignificant upregulation of RmABCC1 and RmABCB10 genes indicating the probability of linking IVM resistance with over-expression of RmABCC2 gene. The possible tick management strategies are discussed.

Bovine cerebral theileriosis: first molecular report in cross bred cattle calf in India

Bovine tropical theileriosis caused by Theileria annulata, is a serious constraint to Indian dairy industry with more fatal infections in exotic cattle and substantial losses to cross-bred and indigenous zebu cattle. The present communication is to place on record the first report of molecular based confirmed case of cerebral theileriosis caused by T. annulata coupled with its morphological detection, clinical manifestations, haematological alterations and therapeutic management in a cross bred cattle calf from India. After preparation of peripheral thin blood smear from cross bred cattle calf at the site of collection and fixation with methanol, blood sample brought to Department of Veterinary Parasitology, College of Veterinary Science and A.H, Jabalpur and stained by standard protocol for Giemsa staining. Genomic DNA was isolated from the collected blood sample using QIAamp® DNA blood mini kit following the manufacturer's recommendations and PCR was performed. The cross bred cow calf revealed high rise in temperature (105.5°F), increased heart rate, labored breathing with seromucous nasal discharge, enlargement of prescapular lymph node and animal exhibited tonic clonic convulsions in response to any sudden noise. Giemsa stained thin blood smear revealed intraerythrocytic piroplasm and Koch'sblue bodies of T. annulata within the cytoplasm of lymphocytes. The species of Theileria was confirmed by molecular amplification of genomic DNA as T. annulata.

Synergistic property of piperonyl butoxide, diethyl maleate, triphenyl phosphate and verapamil hydrochloride with deltamethrin and ivermectin against Rhipicephalus microplus ticks

The present study was taken up to evaluate the synergistic properties of piperonyl butoxide (PBO), diethyl maleate (DEM), triphenyl phosphate (TPP) and verapamil (VER) with deltamethrin (DLM) and ivermectin (IVM) against DLM and IVM resistant tick populations collected from Madhya Pradesh and Punjab states of India. The collected field tick populations were resistant to DLM (Resistance Factor [RF] in the range of 21.71-32.98) and IVM (RF in the range of 1.89-4.98). A strong synergism between DLM and, IVM with PBO and IVM with VER was noticed. The synergistic efficacy of PBO and VER with IVM in reducing the lethal concentration 50 (LC50) value (1.69-5.72 times for PBO and 3.00-10.62 times for VER) of IVM in resistant ticks suggest that a combination of these synergists with IVM can significantly enhance the effectiveness of IVM against IVM-resistant Rhipicephlaus microplus populations gradually establishing in the different parts of the country. The synergistic efficiency of PBO with DLM in reducing the LC50 value was 2.65 and 18.01 times, respectively, against DLM- resistant two R. microplus populations (KTN and LDH). The study revealed the gradual establishment of DLM and IVM resistant populations in the surveyed states suggesting the need to adopt required resistance management strategies. The use of synergists with DLM and IVM has emerged as an effective approach for controlling the acaricide-resistant ticks.

Evaluation of acaricidal resistance status of Rhipicephalus microplus ticks from the hilly state (Uttarakhand) of India and evaluation of efficacy of a natural formulation for the management of resistant ticks

The resistance status against deltamethrin, cypermethrin, coumaphos and ivermectin was assessed of Rhipicephalus microplus from five districts of Uttarakhand, through adult immersion test and larval packet test. The field isolates were highly resistant to deltamethrin (median resistance ratio [RR₅₀] = 9.10-29.13-fold) followed by cypermethrin (2.23-3.55). Surprisingly the isolates were susceptible to coumaphos (0.34-3.17). Emerging resistance against ivermectin (1.55-3.27) was also observed in all the isolates. Elevated levels of esterases (enzyme ratio = 2.93-5.84-fold), glutathione S-transferases (5.10-10.06) and monooxygenases (1.68-4.02) in resistant fields isolates were highly correlated (47.4-86.0%) with the resistant factor (RR₅₀) determined by bioassay. All the isolates except Uttarkashi possess mutation at the 190th position in domain II of the sodium channel gene. As a mitigation strategy an Ageratum conyzoides-based characterized natural formulation was tested against all the isolates and was found effective at the concentration of 10.1-11.5%. The possibility of using the natural formulation for the management of multi-acaricide resistant ticks is discussed.

Characterization of deltamethrin, cypermethrin, coumaphos and ivermectin resistance in populations of Rhipicephalus microplus in India and efficacy of an antitick natural formulation prepared from Ageratum conyzoides

Rhipicephalus microplus is posing a serious threat to productive animal husbandry. Excessive use of synthetic chemicals in tick management has led to the development of resistant tick populations. Characterization of resistance to deltamethrin, cypermethrin, coumaphos and ivermectin in ticks is necessary to develop a suitable and sustainable control strategy. Based on adult immersion test and larval packet test, the resistance ratios (RR₅₀) for adults and larvae of R. microplus populations from two Indian states ranged from 3.8 to 19.4 and 1.35-25.0 against deltamethrin, 0.061-26.3 and 0.22-19.2 against cypermethrin, and 0.2-9.5 and 0.01-3.1 against coumaphos, respectively, were recorded. Moreover, the RR₅₀ for adults ranged from 0.212 to 3.87 against ivermectin. The RR₅₀ for different acaricides was significantly (p<0.01) correlated with esterases, Glutathione S-transferase and monooxygenase activity. A point mutation at the 190th position of the domain II S4-5 linker region of the sodium channel gene in synthetic pyrethroids (SP) resistant populations was also detected. An antitick natural formulation prepared from the plant Azeratum conyzoides and containing two major compounds, Precocene-I (7‑methoxy-2, 2-dimethyl 2H-chromene) and Precocene II (6, 7-dimethoxy-2, 2-dimethyl- 3-chromene), was developed and tested against the resistant ticks. The LC₅₀ values of the natural formulation against the resistant populations were in the range of 4.31-5.33% irrespective of their RR₅₀ values. Multi-acaricide resistant populations of R. microplus are established in India and the A. conyzoides based natural formulation can be used for its management.

Emergence of fipronil resistant Rhipicephalus microplus populations in Indian states

The intensive usage of chemical acaricides for the control of the cattle tick Rhipicephalus microplus has resulted in the development and establishment of multi-acaricide resistant populations. Fipronil, a phenylpyrazole insecticide, is currently marketed in India for the management of this important veterinary tick species. Here, we tested Indian isolates of R. microplus which have developed multi-acaricide resistance, for their susceptibility to fipronil. Twenty-five field isolates from five agro-climatic zones of the country were collected and tested by adult immersion test (AIT) and larval packet test (LPT). Sixteen isolates with resistance factor (RF) in the range of 1.56-10.9 were detected using LPT, whereas only 11 isolates with RF ranging from 1.05 to 4.1 were detected using AIT. A significant variation of RF between both tests was found, which raises doubt about the suitability of larva-based assays in screening of fipronil resistance. The data indicated possible cross-resistance between groups of acaricides in fipronil-resistant tick populations.

Standardization of tick specific biochemical tools for estimation of esterases, monooxygenases and glutathione S-transferase for characterization of acaricide resistance

Protocols to determine metabolic resistance in ticks were mainly derived from reports published using mosquitoes and agriculturally important insects without prior standardization. In the present study, biochemical assays were standardized to quantify acaricide metabolizing enzymes in tick homogenates. Three variables viz., age, number of larvae and reaction time were optimized using reference susceptible IVRI-I and deltamethrin resistant IVRI-IV (Resistance Factor = 194) tick strains. The optimum conditions for estimation of general esterases were 10-15 day old 40 larvae with 15 mins reaction time, 15-20 day old 40 larvae with 20 mins reaction time for Glutathione S- transferase, while 10-15 day old 80 larvae with 5 mins reaction time for monooxygenase. The standardized protocols were further validated in multi acaricide resistant strain (IVRI-V) and in nine field isolates having variable resistant factors to different acaricides. In all the nine heterogeneous field isolates, a significant correlation (p < .05) between resistance to synthetic pyrethroids and over-expression of esterases and monooxygenase was noticed. Similarly, esterases and GST activities were significantly correlated with resistance to organophosphates. The details of the assay protocol are explained for adoption in different laboratories.

Characterization of acaricide resistance in Rhipicephalus microplus populations infesting cattle in northeastern India and assessment of local plant extracts for tick management

In the present study, the tick isolates were collected from Assam state, of northeastern region (NER) and characterized using in vitro bioassay, biochemical and molecular assays. Comparing LC₅₀ value of susceptible IVRI-I and larvae of field isolates, revealed that RF against deltamethrin was highest for Morigaon (MGN = 21.8) and lowest for Sonitpur (SNP = 3.3) isolate. The RF against cypermethrin was highest for Nagaon (NGO = 5.0) and lowest for Barpeta (BPT = 1.2) isolate. Against coumaphos, the highest RF of 4.5 was calculated for BPT (4.5) and lowest for NGO (1.3) isolate. While using adults based assay, highest RF of 24.68 against deltamethrin and lowest RF of 4.96 was determined for MGN and SNP isolate, respectively. In contrast to the results obtained using larvae, against cypermethrin, highest RF was recorded for Kamrup Metropolitan (KMP) while it was NGO isolate using larvae. In case of coumaphos, both larvae and adults of BPT isolate were also highly resistant and lowest RF was detected in SNP (2.30) isolate. All the isolates were susceptible to ivermectin. A significant correlation (p < 0.01) between deltamethrin resistance and higher expression of glutathioneS-transferase was observed while no correlation with esterase and monooxygenase enzymes activity was noted. For the development of possible ecofriendly control measure, different accessions of Argemone mexicana and Datura metel plant species were collected, extracted and screened against adult ticks. Two accessions, NEA-03 and NED-06 collected from Amlighat and Diphu (East Karbi Anglong) were more than 90 % effective. Further dose response study of these accessions determined the LC₅₀ values of 4.86 and 3.96 %, respectively.The resistance status of the collected tick isolates was compared with the data generated from other regions having higher livestock population and possibility of exploitation of identified plant species for the development of natural antitick product is discussed.

Clinical Evaluation of Nd:YAG Laser With and Without Dentin Bonding Agent for the Treatment of Occlusal Hypersensitivity

Purpose:

The aim of the present study was to evaluate and compare both the immediate and delayed desensitizing effects of the Nd:YAG (neodymium-doped:yttrium aluminum garnet; Nd3+:Y3Al5O12) laser with and without dentin bonding agent (DBA) on occlusal dentinal hypersensitivity (DH).

Methods and Materials:

Twenty-one patients with a total of 117 chronic occlusal hypersensitive teeth were selected. Each subject had at least three hypersensitive teeth. These teeth were randomly allocated into three groups: group 1, DBA on the occlusal surface; group 2, Nd:YAG laser (1064-nm wavelength, 30 mJ of energy, 10 pulse/s, 60 seconds, two times); and group 3, Nd:YAG laser (1064-nm wavelength, 30 mJ of energy, 10 pulse/s, 60 seconds, two times) with DBA. Pain was assessed using a visual analog scale after stimulation of the sensitive teeth by using the sharp tip of an explorer and an air blast prior to treatment and immediately, one week, one month, and three months after treatment by one blinded examiner.

Results:

A significant reduction in occlusal DH occurred at all time points in all of the experimental groups. The three groups showed significant improvements in discomfort immediately after treatment and after one week (p&lt;0.001), but the Nd:YAG laser with DBA group had greater efficacy when compared with the other groups. The Nd:YAG laser group and Nd:YAG laser with DBA group had no significant differences at one month and three months after treatment (p&gt;0.05); however, their desensitizing efficacy was superior to the DBA group.

Conclusions:

The Nd:YAG laser with DBA may be most effective in the long-term treatment of occlusal DH, although other measures also reduce DH.

Pubic lice infestation in man from Mhow, Madhya Pradesh

Worldwide, 2-10% of human population is infested with pubic lice which are mostly found in the hair of pubic area, occasionally under the armpits, in the beard or mustache and on the eyebrows and eyelashes. They are usually transmitted through sexual contact or through toilet seats and bedding material. A twenty-year-old boy suffering from severe itching in the genital region during night hours submitted the lice for their identification in Department of Veterinary Parasitology, College of Veterinary Science and Animal Husbandry, Mhow. These lice were identified as Phthirus pubis.

Dynamics of MDR Enterobacter cloacae outbreaks in a neonatal unit in Nepal: insights using wider sampling frames and next-generation sequencing

Objectives

There are limited data on Enterobacter cloacae outbreaks and fewer describing these in association with NDM-1. With whole-genome sequencing, we tested the hypothesis that a cluster of 16 E. cloacae bacteraemia cases in a Nepali neonatal unit represented a single clonal outbreak, using a wider set of epidemiologically unrelated clinical E. cloacae isolates for comparison.

Methods

Forty-three isolates were analysed, including 23 E. cloacae and 3 Citrobacter sp. isolates obtained from blood cultures from 16 neonates over a 3 month period. These were compared with two contemporaneous community-associated drug-resistant isolates from adults, a unit soap dispenser isolate and a set of historical invasive isolates (n = 14) from the same geographical locality.

Results

There were two clear neonatal outbreaks and one isolated case in the unit. One outbreak was associated with an NDM-1 plasmid also identified in a historical community-associated strain. The smaller, second outbreak was likely associated with a contaminated soap dispenser. The two community-acquired adult cases and three sets of historical hospital-associated neonatal isolates represented four additional genetic clusters.

Conclusions

E. cloacae infections in this context represent several different transmission networks, operating at the community/hospital and host strain/plasmid levels. Wide sampling frames and high-resolution typing methods are needed to describe the complex molecular epidemiology of E. cloacae outbreaks, which is not appropriately reflected by routine susceptibility phenotypes. Soap dispensers may represent a reservoir for E. cloacae and bacterial strains and plasmids may persist in hospitals and in the community for long periods, sporadically being involved in outbreaks of disease.

Investigation of the effects of hydrogenotrophic denitrification and anammox on the improvement of the quality of the drinking water supply system

A drinking water supply system operates at Chyasal (in the Kathmandu Valley, Nepal) for purifying the groundwater that has high levels of ammonium nitrogen (NH4-N). However, high NO3-N concentrations were seen in the water after treatment. To further improve the quality of the drinking water, two types of attached growth reactors were developed for the purification system: (i) a hydrogenotrophic denitrification (HD reactor) and (ii) a concurrent reactor with anammox and hydrogenotrophic denitrification (AnHD reactor). For the HD reactor fed by water containing NO3-N, the denitrification efficiency was high (95-98%) for all NO3-N feed rates (20-40 mg/L). The nitrite-nitrogen (NO2-N) and nitrate-nitrogen (NO3-N) concentrations in the effluent were ∼0.5 mg/L. On the other hand, the AnHD reactor fed with water containing NH4-N and NO2-N was operated under varying flow rates of H2(30-70 mL/min) and intermittent supply periods (1-2 h). The efficiency of the anammox process was found to increase with decreasing H2flow rates or with increasing intermittency of the H2supply, while the efficiency of denitrification decreased under these conditions. For the optimal condition of 1.5 h intermittent H2supply, the anammox and denitrification efficiencies of the AnHD reactor reached 80% and 42%, respectively, while the concentrations of both NH4-N and NO2-N in the effluent were <1.0 mg/L, and no NO3-N was detected. From the experimental results, it is clear that both HD and AnHD reactors can function as efficient and critical units of the water purification system.

Inter-field variability in the microbial communities of hydrothermal vent deposits from a back-arc basin

Diverse microbial communities thrive on and in deep-sea hydrothermal vent mineral deposits. However, our understanding of the inter-field variability in these communities is poor, as limited sampling and sequencing efforts have hampered most previous studies. To explore the inter-field variability in these communities, we used barcoded pyrosequencing of the variable region 4 (V4) of the 16S rRNA gene to characterize the archaeal and bacterial communities of over 30 hydrothermal deposit samples from six vent fields located along the Eastern Lau Spreading Center. Overall, the bacterial and archaeal communities of the Eastern Lau Spreading Center are similar to other active vent deposits, with a high diversity of Epsilonproteobacteria and thermophilic Archaea. However, the archaeal and bacterial communities from the southernmost vent field, Mariner, were significantly different from the other vent fields. At Mariner, the epsilonproteobacterial genus Nautilia and the archaeal family Thermococcaceae were prevalent in most samples, while Lebetimonas and Thermofilaceae were more abundant at the other vent fields. These differences appear to be influenced in part by the unique geochemistry of the Mariner fluids resulting from active degassing of a subsurface magma chamber. These results show that microbial communities associated with hydrothermal vent deposits in back-arc basins are taxonomically similar to those from mid-ocean ridge systems, but differences in geologic processes between vent fields in a back-arc basin can influence microbial community structure.

Role of physicochemical properties in the estimation of skin permeability: in vitro data assessment by Partial Least-Squares Regression

Skin provides passage for the delivery of drugs. The in vitro and in vivo testing of chemicals for estimation of dermal absorption is very time consuming, costly and has many ethical difficulties related to human and animal testing. The solution to the problem is Quantitative structure-permeability relationships. This method relates dermal penetration properties of a range of chemical compounds to their physicochemical parameters. In the present study, an effort has been made to develop models for the accurate prediction of skin permeability using a large, diverse dataset through the combination of various regression methods coupled with the Genetic Algorithm (GA)/Interval Partial Least-Squares Algorithm (iPLS). The descriptors were calculated using e-DRAGON and ADME Pharma Algorithms-Abrahams descriptors. The original dataset was divided into a training set and a testing set using the Kennard-Stone Algorithm. The selection of descriptors was made by the GA and iPLS. The model applicability domain was determined. The results showed that a three-parameter model built through Partial Least-squares Regression was most accurate with r(2) of 0.936.