scholarly journals Worm-control practices and prevalence of anthelmintic resistance using in vivo FECRTs on smallholder sheep farms in Lithuania

2016 ◽  
Vol 53 (1) ◽  
pp. 24-30 ◽  
Author(s):  
T. Kupčinskas ◽  
I. Stadalienė ◽  
A. Šalomskas ◽  
P. Trusevičius ◽  
M. Varady ◽  
...  

SummaryThis study determined the prevalence of anthelmintic resistance (AR) in parasitic nematodes on smallholder sheep farms in Lithuania from April to November 2014. Faecal samples were collected from two groups of 10-15 sheep treated with fenbendazole (FBZ) or ivermectin (IVM) on 18 sheep farms. Two samples were collected from each group: on day zero (T1) and 10-14 days after treatment. Faecal egg counts (eggs per gramme, EPG) were determined using a modified McMaster technique. Animals with < 140 EPG on day zero were removed from the analysis. The prevalence of AR was estimated using the in vivo faecal egg count reduction test. AR to FBZ was detected on three of 15 farms where FBZ was used (20 %) and was suspected on one farm (6.7 %). AR to IVM was detected on two of 16 farms where IVM was used (12.5 %). The main species of resistant gastrointestinal nematodes (GINs) identified after treatment were Teladorsagia spp. and Trichostrongylus spp. A questionnaire surveying 71 sheep farmers estimated that 71.8 % of sheep farmers used anthelmintics against GINs. IVM was the most frequently (68.6 %) applied anthelmintic, and 62.7 % of the respondents reported treating their animals twice a year. This study confirmed the presence of AR to GIN infections on sheep farms in Lithuania. Future studies should assess the prevalence of AR to GIN infection using in vitro methods.

2021 ◽  
Vol 8 (11) ◽  
pp. 249
Author(s):  
Michal Babják ◽  
Alžbeta Königová ◽  
Ľudmila Burcáková ◽  
Michaela Komáromyová ◽  
Michaela Urda Dolinská ◽  
...  

This study was performed on a cattle farm with a long-term use of albendazole (ABZ) and a permanent history of fasciolosis for comparing in vivo and in vitro methods for the detection of anthelmintic resistance and drug efficacy. A selected group of 10 Charolais cows was treated in autumn 2020 with ABZ at a dose of 7.5 mg/kg body weight. Another group of 10 cows remained untreated as a control. The faecal egg count reduction test was used to determine in vivo efficacy. The percentage reduction of eggs on day 14 after treatment ranged from 77 to 81.8%, depending on the formula used for calculation. The in vitro egg hatch test (EHT) was used as a second diagnostic method. F. hepatica eggs for the EHT were isolated from faecal samples. The test was performed in two versions differing in the length of incubation with ABZ (12 h and 15 d). The percentage of eggs with inhibited development at a concentration of 0.5 μM in both versions of the EHT agreed with the in vivo results. Ovicidal activity at a concentration of 0.5 μM in the 12-h version suggested a reduced efficacy of ABZ (65.40%). An EHT prepared using pooled faecal samples was a prospective method for the detection of efficacy and ABZ resistance in F. hepatica.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiewa Othman Dyary ◽  
Hamasalih Qadir Banaz

Abstract Introduction The control of gastrointestinal nematodes (GINs) in small ruminants is principally dependent on anthelmintic therapy, which encounters the rising problem of anthelmintic resistance (AR) development. Veterinarians reported anthelmintic failure in several sheep farms in Arbat District, Sulaymaniyah, northern Iraq, which called for a systematic study about the efficacy of three commonly used drugs: albendazole, ivermectin, and levamisole. Material and Methods A faecal egg count reduction test (FECRT) was conducted to elucidate the anthelmintics’ efficacies, with coprocultures to determine the GINs parasitising sheep in the study area. Larval development assays (LDAs) were conducted to determine the drugs’ median inhibitory concentrations (IC50). Results The FECRT revealed that AR was widespread to all three drugs, and ivermectin was the least effective, reducing the faecal egg counts (FECs) by 50.5% to 57.1%. The coprocultures revealed that the GIN genera of sheep in Arbat District were Trichostrongylus, Nematodirus, and Trichuris, and the resistance was mainly due to Trichostrongylus species. The mean IC50 of albendazole, ivermectin, and levamisole were 0.073 ng/mL, 7.97 ng/mL, and 1.43 ng/mL, respectively. Conclusion This study is the first Iraqi report of AR confirmed by both in vivo FECRT and in vitro LDA methods.


2016 ◽  
Vol 53 (2) ◽  
pp. 120-125 ◽  
Author(s):  
M. Urda Dolinská ◽  
A. Königová ◽  
M. Babják ◽  
M. Várady

SummaryGastrointestinal parasitic nematodes in sheep cause severe economic losses. Anthelmintics are the most commonly used drugs for prophylaxis and therapy against parasitic helminths. The problem of drug resistance has developed for all commercially available anthelmintics in several genera and classes of helminths. In vitro and in vivo tests are used to detect anthelmintic resistance. Two in vitro methods (larval migration inhibition test and micromotility test) for the detection of ivermectin (IVM) resistance were compared using IVM-resistant and IVM-susceptible isolates of Haemonchus contortus. The degree of resistance for each test was expressed as a resistance factor (RF). The micromotility test was more sensitive for quantitatively measuring the degree of resistance between susceptible and resistant isolates. The RFs for this test for IVM and eprinomectin ranged from 1.00 to 108.05 and from 3.87 to 32.32, respectively.


Author(s):  
Syed Nadeem Badar ◽  
Zafar Iqbal ◽  
Muhammad Sohail Sajid ◽  
Hafiz Muhammad Rizwan ◽  
Muhammad Shareef ◽  
...  

Abstract In the present study, anthelmintic activities of Arundo (A.) donax L., Areca (Ar.) catechu L., and Ferula (F.) assa-foetida L. were determined. Leaves of A. donax L., latex of F. assa-foetida L. and seeds of Ar. catechu L. in different solvent fractions were subjected to in vitro (egg hatch assay; EHA, and adult motility assay; AMA) and in vivo (faecal egg count reduction test; FECRT) tests of anthelmintic activity using Haemonchus contortus model. In the AMA, crude aqueous methanol extracts (CAME) and ethyl acetate fractions of F. assa-foetida at 10 hr post-treatment showed maximum mortality of H. contortus at 12.5-50 mg mL-1. In the EHA, CAME of F. assa-foetida was identified as a potent ovicide based on its low LC50 (16.9 µg mL-1), followed in order by Ar. catechu and A. donax. Results from the FECRT also showed the extract of F. assa-foetida L. to be more effective than those of Ar. catechu L. and A. donax L., against the gastrointestinal parasitic nematodes. Chloroform and ethyl acetate fractions showed better anthelmintic activities against the adult worms in vitro, while CAME of these plants were better than their crude powders in vivo. It is recommended to document and investigate indigenous knowledge of possible medicinal plants to plan scientific trials that may justify their endorsement.


2021 ◽  
Vol 58 (2) ◽  
pp. 173-178
Author(s):  
M. Babják ◽  
A. Königová ◽  
M. Várady

Summary Cases of parasite resistance to the main classes of anthelmintics are increasingly reported from small ruminants at farms in Europe. We visited a goat farm in Slovakia in November 2019 with suspected parasite problems that reduced productivity and performed an in vivo faecal egg count reduction test (FECRT) and an in vitro larval development test (LDT) for all three main classes of anthelmintics. The lowest efficacy (60 %) detected by FECRT was for ivermectin (IVM). Benzimidazole (BZ) efficacy ranged between 80.3 and 86.5 %, and levamisole (LEV) efficacy was 94 %. The results from the in vivo FECRT test were confirmed by the in vitro LDT. Minimum inhibitory concentration (MIC) 173.6 ng/ml for IVM several times exceeded the recommended threshold of 21.6 ng/ml. Mean LD50 for BZ was equal to the threshold concentration, but the other threshold criteria indicated a low level of resistance in the population. The LDT did not indicate the presence of resistance only for LEV. The MIC 1.0 μg/ml for LEV was evaluated as susceptible with respect to species composition. Teladorsagia was the dominant genus after treatment with BZ, IVM, and LEV. Haemonchus contortus was identifi ed after treatment with BZ and LEV.


Parasitology ◽  
2014 ◽  
Vol 141 (7) ◽  
pp. 948-956 ◽  
Author(s):  
JANINA DEMELER ◽  
GEORG VON SAMSON-HIMMELSTJERNA ◽  
NICHOLAS C. SANGSTER

SUMMARYThe mechanism of anthelmintic resistance against the widely used macrocyclic lactones (MLs) is still not fully understood. Pharyngeal, somatic body muscles and the ovijector have been proposed as putative sites of action as well as resistance. In the present study the effects of three avermectins and three milbemycins on adult parasitic nematodes were evaluated in vitro. The Muscle Transducer system was used to investigate the effects of MLs on muscle contraction in female Haemonchus contortus and effects on motility were measured in Ostertagia (Teladorsagia) circumcincta using the Micromotility Meter. Concentration-response curves for all substances in both systems shifted to the right in the resistant isolates. Resistance was present to ivermectin (IVM) and its components IVM B1a and IVM B1b, suggesting that both components are involved in the mode of action and resistance. No consistent patterns of potency and resistance of the substances were observed except that milbemycins generally showed lower resistance ratios (RRs) than IVM. IVM and IVM B1b were the most potent inhibitors of contraction and motility in both susceptible isolates and also showed the highest RR in both species. Low RRs for milbemycins recorded in vitro for highly resistant isolates in vivo suggest that other factors such as pharmacokinetics influence drug potency in vivo.


2013 ◽  
Vol 89 (1) ◽  
pp. 80-85 ◽  
Author(s):  
E. Liébano-Hernández ◽  
M. González-Olvera ◽  
C. Vázquez-Peláez ◽  
P. Mendoza-de-Gives ◽  
G. Ramírez-Vargas ◽  
...  

AbstractBecause of the natural adaptation of Mexican sheep, the aim of the present study was to identify the presence or absence of gastrointestinal parasitic nematodes (GIN) resistant to benzimidazole (BZ) in both Chiapas and Pelibuey sheep breeds on local farms. Both male and female GIN-infected grazing sheep of the two breeds were selected. Sheep faecal samples were collected to obtain infective larvae (L3). This evolving stage of the parasite was used for taxonomic identification of the genus, based on its morphological characteristics. BZ anthelmintic resistance was evaluated using a nematode–compound in vitro interaction bioassay and the allele-specific polymerase chain reaction technique to detect mutations of residues 198 and 200 on isotype 1 of the β-tubulin gene. Three BZ-based compounds (febendazole (FBZ), tiabendazole (TBZ) and albendazole (ABZ)) at concentrations of 1, 0.5, 0.25, 0.125, 0.062 and 0.03 mg/ml were used to estimate the anthelmintic efficacy and lethal dose (LD50, LD90 and LD99) of the drugs. Two parasitic nematodes, Haemonchus and Teladorsagia, were identified in both isolates. Also, the proportions of anthelmintic resistance identified in GIN of the two sheep breeds were 68% in isolates from the Chiapas breed and 71.8% in the Pelibuey breed. The specific lethal activity obtained with FBZ was higher than 90%. However, TBZ and ABZ showed a lethal activity lower than 50%. High variability in the discriminating dose values was found among the BZ drugs. For example, FBZ LD ranged from 0.01 to 1.20 mg/ml; on the other hand, TBZ and ABZ required a dose ranging from 0.178 to 759 mg/ml. In addition, amino acid changes of Phe (TTC) to Tyr (TAC) at codon 200 of the β-tubulin gene, showing resistance to BZ, and no changes at codon 198 Glu (GAA) to Ala (GCA) were observed for both isolates. These results confirmed the presence of a genetic mutation associated with BZ in both Chiapas and Pelibuey nematode isolates.


Author(s):  
Ambalathaduvar Meenakshisundaram ◽  
Tirunelveli Jayagopal Harikrishnan ◽  
Thavasi Anna

The study was aimed at to investigate the anthelmintic efficacy of aqueous and ethanolic extracts of Cucurbita pepo against gastrointestinal nematodes of sheep by scientifically validated in vitro and in vivo tests. In vitro anthelmintic activity was determined by egg hatch assay, larval migration inhibition assay and larval development assay against eggs and larvae of mixed gastrointestinal nematodes of sheep. The extracts which were found to be effective in in vitro assays were further evaluated by in vivo faecal egg count reduction test against mixed species of sheep gastrointestinal nematodes with 3 different doses (125, 250 and 500 mg kg-1). Haematological and serum parameters were estimated before and after treatment to determine the impact of plant extracts on health of the animal. Aqueous extract of C. pepo demonstrated significant inhibition of egg hatch at 40 and 80 mg/ml. The ED50 value of egg hatch inhibition was 3.51mg/ml. In larval migration inhibition assay, both aqueous and ethanolic extracts of C. pepo demonstrated inhibition of larval migration and the LM50 was 1.75 and 0.32 mg/ml respectively. However, in larval development assay, both aqueous and ethanolic extracts showed only marginal inhibition of larval development at all concentrations tested. In faecal egg count reduction test (FECRT), aqueous extracts of C. pepo at 500 mg/kg caused significant reduction in eggs per gram (96.61 per cent) the reduction being higher than the result obtained with albendazole, the positive control (93.25 per cent). There was a significant difference in EPG reduction between sheep treated with albendazole and C. pepo. Haematological and serum parameters were not affected in both the treated and untreated sheep indicating that the extracts did not cause toxic effects. Based on the results obtained in this study, the aqueous extract of C. pepo possesses anthelmintic activity and could offer an alternative source for the control of gastrointestinal nematodes of sheep.


2007 ◽  
Vol 76 (1) ◽  
pp. 79-85 ◽  
Author(s):  
M. Saeed ◽  
Z. Iqbal ◽  
A. Jabbar

This study was carried out to screen goat farms for anthelmintic resistance (AR) against oxfendazole (OXF) and to determine contributory factors for its development. For this purpose, Beetal goat farms (n = 18) were randomly selected, with natural mixed gastrointestinal nematodosis infection. In vivo (faecal egg count reduction test) and in vitro (egg hatch assay) tests were used to ascertain the presence of AR while a scorecard was used to determine the role of possible contributory factors for oxfendazole resistance. For in vivo test, the experimental animals were divided into two groups of 10 animals each; one group received OXF treatment, while the other served as control. Pre- and post-treatment coproculture was performed to identify the species and genera of nematodes. Egg hatch assay (EHA) was used to confirm the results of FECRT. Fecal egg count reduction test (FECRT) revealed the development of resistance on six farms and post-treatment larval cultures indicated Haemonchus contortus, Trichostrongylus colubriformis, Cooperia curticei, Teladorsagia circumcincta and Oesophagostomum spp. as dominant species with resistance. Furthermore, EHA confirmed the results of FECRT. Among the presumptive factors for AR, the highest composite score was for rotation of anthelmintics followed by treatment frequency, dose rate and nature of medication. The scorecard for the development of AR, used in this study, may be helpful for the assessment of contributory factors of AR.


2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Evelina Dauparaitė ◽  
Tomas Kupčinskas ◽  
Georg von Samson-Himmelstjerna ◽  
Saulius Petkevičius

Abstract Background With intensive use of anthelmintic drugs in recent decades, anthelmintic resistance (AR) in horse nematodes is becoming a growing issue in many countries. However, there is little available information about the parasites, treatment practices or AR in the horse population in Lithuania. The aim of this study was to assess the current situation of AR on horse farms in Lithuania. The study was conducted in 25 stables on horses with a strongyle faecal egg count (FEC) of ≥ 200 eggs per gram. A faecal egg count reduction test (FECRT) was performed on each farm after administration of ivermectin (IVM) or pyrantel (PYR). Results The efficacy of IVM was comparatively high, with 98.8% of 250 horses having a zero egg count 14 days after treatment. Two conditions were used to interpret the FECRT results for PYR: firstly, resistance was determined when FECR was < 90% and the lower 95% confidence interval (LCL) was < 80%, and secondly when in addition the upper confidence level (UCL) was < 95%. Under the first condition, resistance against PYR was found in five stables (25% of all tested herds), while when considering the UCL as well, resistance was only detected in two stables (8%). The FEC showed a significant (P < 0.01) difference between the treatment and control groups. Only cyathostomin larvae were detected in larval cultures derived from strongyle-positive faecal samples collected 14 days after treatment of a test group with PYR. Conclusions This in vivo study showed that PYR resistance is prevalent on horse farms in Lithuania, while the efficacy of IVM still appears to be unaffected. However, further studies of ivermectin resistance are needed. These findings should guide the implementation of more sustainable management of strongyle infections in horses in Lithuania.


Sign in / Sign up

Export Citation Format

Share Document