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Heylen DJA, Labuschagne M, Meiring C, van der Mescht L, Klafke G, Costa Junior LM, Strydom T, Wentzel J, Shacklock C, Halos L, Maree F, Fourie J, Madder M, Evans A. Phenotypic and genotypic characterization of acaricide resistance in Rhipicephalus microplus field isolates from South Africa and Brazil. Int J Parasitol Drugs Drug Resist 2024; 24:100519. [PMID: 38168594 PMCID: PMC10797136 DOI: 10.1016/j.ijpddr.2023.100519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/20/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024]
Abstract
Rhipicephalus (Boophilus) microplus is one of the most successful ticks infesting cattle around the world. This highly-invasive species transmits cattle parasites that cause cattle fever leading to a high socio-economic burden. Tick eradication programs have often failed, due to the development of acaricide resistance. Here we characterize acaricide resistance in a large number of tick isolates from regions in South Africa (KwaZulu Natal, Mpumalanga, Western & Eastern Cape provinces) and two Brazilian regions. By means of Larval Packet Tests (LPT's) acaricide resistance was evaluated against five commonly used acaricides (chlorfenvinphos, fipronil, deltamethrin, amitraz, and ivermectin). Furthermore, the coding region containing the knock down resistance (kdr) mutation, known to result in pyrethroid resistance, was sequenced. Resistance to at least one acaricide class was reported in each of the five regions, and a high proportion of tick isolates exhibited multi-resistance to at least two acaricide classes (range: 22.2-80.0%). Furthermore, resistance ratios (RR) showed high spatial variation (intercontinental, as well as regional) but low regional spatial autocorrelation. Previous and current acaricide use correlated with current RR, and several combinations of acaricide RR were positively correlated. Moreover, fipronil resistance tended to be higher in farms with more intense acaricide use. The kdr-mutations provided the ticks a fitness advantage under the selection pressure of synthetic pyrethroids based on population (kdr-allele frequency) and individual level data (genotypes). The data show the threat of acaricide (multi-)resistance is high in Brazil and South Africa, but acaricide specific levels need to be assessed locally. For this purpose, gathering complementary molecular information on mutations that underlie resistance can reduce costs and expedite necessary actions. In an era of human-caused habitat alterations, implementing molecular data-driven programs becomes essential in overcoming tick-induced socio-economic losses.
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Affiliation(s)
- Dieter J A Heylen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Wilrijk, Belgium; Interuniversity Institute for Biostatistics and statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium.
| | - Michel Labuschagne
- Clinomics, P.O. Box 11186, Universitas, Bloemfontein, 9321, Uitzich Road, Bainsvlei, Bloemfontein, 9338, South Africa; Clinglobal, B03/04, The Tamarin Commercial Hub, Jacaranda Avenue, Tamarin, 90903, Mauritius.
| | - Christina Meiring
- Clinomics, P.O. Box 11186, Universitas, Bloemfontein, 9321, Uitzich Road, Bainsvlei, Bloemfontein, 9338, South Africa; Clinglobal, B03/04, The Tamarin Commercial Hub, Jacaranda Avenue, Tamarin, 90903, Mauritius.
| | - Luther van der Mescht
- Clinvet International Pty (Ltd), Uitzich Road, Bainsvlei, Bloemfontein, 9338, South Africa; Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa.
| | - Guilherme Klafke
- Instituto de Pesquisas Veterinárias Desidério Finamor, Centro de Pesquisa em Saúde Animal, Estrada do Conde 6000, Eldorado do Sul, RS, 92990-000, Brazil.
| | | | - Tom Strydom
- MSD ANIMAL HEALTH, Private Bag X2026, Isando, 1600, South Africa.
| | - Jeanette Wentzel
- Hans Hoheisen Wildlife Research Station, Department of Veterinary Tropical Diseases, University of Pretoria, South Africa.
| | | | - Lénaig Halos
- Bill & Melinda Gates Foundation, Seattle, WA, USA.
| | - Francois Maree
- Clinomics, P.O. Box 11186, Universitas, Bloemfontein, 9321, Uitzich Road, Bainsvlei, Bloemfontein, 9338, South Africa.
| | - Josephus Fourie
- Clinvet International Pty (Ltd), 1479 Talmadge Hill South, Waverly, NY, 14892, USA.
| | - Maxime Madder
- Clinglobal, B03/04, The Tamarin Commercial Hub, Jacaranda Avenue, Tamarin, 90903, Mauritius.
| | - Alec Evans
- Clinglobal, B03/04, The Tamarin Commercial Hub, Jacaranda Avenue, Tamarin, 90903, Mauritius.
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Zapa DMB, de Aquino LM, Couto LFM, Heller LM, de Morais IML, Salvador VF, Leal LLLL, Trindade ASN, de Freitas Paula WV, de Lima NJ, Ferreira LL, de Castro Rodrigues D, Strydom T, Torres S, Soares VE, de Oliveira Monteiro CM, da Silva Krawczak F, Lopes WDZ. Enzootic stability of tick fever in Holstein calves grazing in a tropical region, subjected to strategic cattle tick control with fluralaner. Parasit Vectors 2024; 17:120. [PMID: 38461304 PMCID: PMC10924980 DOI: 10.1186/s13071-024-06212-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 03/11/2024] Open
Abstract
BACKGROUND In 2022, fluralaner was launched on the market for use in the control of the cattle tick Rhipicephalus microplus after showing 100% efficacy in registration trials against the causative agents of cattle tick fever (TFAs). The aim of the present study was to determine whether a strategic control regimen against R. microplus using fluralaner (FLU) in Holstein calves grazing in a tropical region would alter the enzootic stability status of cattle tick fever, triggering outbreaks in these animals up to 22 months age. METHODS In this study, a group of calves treated with FLU was compared with a control group treated with the regimen currently being used on the farm, which consisted of the fipronil + fluazuron formulation (FIFLUA). In the first experiment, the efficacy of the FIFLUA pour-on formulation was evaluated in a field study. In the second experiment, which lasted 550 days, two experimental groups (n = 30/group) of Holstein calves naturally infested with R. microplus were analyzed. Calves aged 4 to 10 months received either a specific treatment regimen with FLU (experimental group) or FIFLUA (control group). During this period, tick counts, animal weight measurement, feces collection (to determine eggs and oocysts per gram of feces), tick fever monitoring, blood smears (to ascertain enzootic stability of the herd), PCR testing for TFAs and serology (indirect enzyme-linked immunosorbent assay [iELISA]) were performed. All calves were evaluated for signs of tick fever between ages 11 and 22 months. RESULTS FIFLUA showed an acaricidal efficacy of > 90% from post-treatment days 14 to 35. Regarding treatments against the TFAs, the average number of treatments was similar between groups, but animals treated with FLU had a smaller reduction in packed cell volume on some of the evaluation dates of the second and third treatment against TFAs. In calves aged 10 months in the FLU group, B. bovis was not detected by PCR (0/15 samples), 40% of the samples had antibody titers and 33% (10/30) of the samples had positive blood smears. Regarding B. bigemina, > 86% of the samples in both groups tested positive for B. bigemina DNA and antibodies; there was no difference in the antibody titers between the groups. There were no clinical cases of cattle tick fever in calves aged 11 to 22 months. CONCLUSIONS In comparison with the control treatment, the strategic control regimen against R. microplus with FLU that was implemented in the present study did not negatively affect the enzootic stability status of A. marginale and B. bigemina in the herd up to 22 months of age. The enzootic stability status of B. bovis was not reached by either group. These results likely represent a characteristic of the local tick population, so further studies should be performed.
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Affiliation(s)
- Dina Maria Beltran Zapa
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Lidia Mendes de Aquino
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Luiz Felipe Monteiro Couto
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Luciana Maffini Heller
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Igor Maciel Lopes de Morais
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Vanessa Ferreira Salvador
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Luccas Lourenzzo Lima Lins Leal
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Artur Siqueira Nunes Trindade
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Warley Vieira de Freitas Paula
- Department of Preventive Veterinary Medicine, School of Veterinary and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Nicolas Jalowitzki de Lima
- Department of Preventive Veterinary Medicine, School of Veterinary and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Lorena Lopes Ferreira
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Daniel de Castro Rodrigues
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
- MSD Animal Health, Franca, São Paulo, Brazil
| | - Tom Strydom
- MSD Animal Health, 20 Spartan Road, Isando, Kempton Park, 1619, South Africa
| | | | | | - Caio Marcio de Oliveira Monteiro
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
- Department of Biosciences and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Felipe da Silva Krawczak
- Department of Preventive Veterinary Medicine, School of Veterinary and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Welber Daniel Zanetti Lopes
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil.
- Department of Biosciences and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil.
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Reckziegel GH, de Freitas MG, Tutija JF, Rodrigues VD, Borges DGL, de Freitas MDB, Gallina T, Lopes WDZ, de Castro Rodrigues D, de Oliveira Arriero Amaral H, Strydom T, Torres S, de Almeida Borges F. Efficiency of fluralaner pour-on in different strategic control protocols against Rhipicephalus microplus on Brangus cattle in a tropical area. Parasit Vectors 2024; 17:110. [PMID: 38449052 PMCID: PMC10916271 DOI: 10.1186/s13071-024-06199-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/15/2024] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND The occurrence of higher winter temperatures in Brazilian areas with tropical and highland climates may result in a fifth peak of tick populations during winter in addition to the four generations previously described. Therefore, a strategic control protocol was developed with treatments in two seasons with the objective of controlling the generations of ticks that occur in spring/summer and those that occur in autumn/winter. METHODS The study was conducted in Mato Grosso do Sul, Brazil, from the beginning of the rainy season, November 2020, to October 2021. In a randomized block design, 36 calves were distributed into three groups: (i) negative control; (ii) traditional strategic control in one season (SC1S), at the beginning of the rainy season; and (iii) strategic control in two seasons (SC2S), at the beginning and end of the rainy season. The SC1S strategic control group was treated on day 0, November 2020, and twice more with intervals of 42 days. The SC2S group received three more treatments beginning on day 182, May 2021, with intervals of 42 days. All treatments consisted of 5% fluralaner (Exzolt® 5%) delivered via a pour-on dose of 1 mL/20 kg body weight. Counts of semi-engorged female ticks were performed on day 3 and every 14 days thereafter, and the animals were weighed at the same time. RESULTS Fluralaner showed a mean efficacy of more than 95% up to day 294. The two treated groups showed a decrease (P < 0.05) in the average number of ticks on day 3. In the SC2S group, the means were close or equal to zero throughout the study, while in the SC1S group, the means did not differ (P > 0.05) from those of the control group from day 231 onward. The final mean weight gain of each group was 76.40 kg, 98.63 kg, and 115.38 kg for the control, SC1S, and SC2S groups, respectively, differing (P < 0.05) from each other. CONCLUSIONS Therefore, three applications of fluralaner, with one application every 42 days from the beginning of the rainy season in the middle spring, resulted in effective tick control for 224 days. When three additional treatments were given in autumn/winter with intervals of 42 days between applications, tick counts were reduced throughout the year. This strategic control approach may be indicated in years with climatic conditions that allow that population peaks are expected to occur in the autumn/winter period.
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Affiliation(s)
- Guilherme Henrique Reckziegel
- Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
- Federal University of Acre, Rio Branco, Acre, Brazil
| | | | | | | | | | | | | | | | | | | | - Tom Strydom
- MSD Animal Health, 20 Spartan Road, Kempton Park, Isando, 1619, South Africa
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Gallina T, Dos Santos Lagranha C, Bilo G, Malavolta C, Ferreira LL, de Almeida Borges F, de Castro Rodrigues D, Strydom T, Torres S, Arnhold E, Lopes WDZ. Control of Rhipicephalus microplus on taurine cattle with fluralaner in a subtropical region. Parasit Vectors 2024; 17:101. [PMID: 38429835 PMCID: PMC10908041 DOI: 10.1186/s13071-024-06200-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 02/15/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND In Rio Grande do Sul, Brazil, a region with a subtropical climate, Rhipicephalus microplus is present in taurine cattle raised for beef and milk. In addition, ticks resistant to multiple acaricides are present in this region. Recently, fluralaner (isoxazoline) was launched on the market. Thus, there is a need to evaluate the effects of fluralaner for the control of R. microplus on taurine cattle. In addition, occurrence of myiasis by Cochliomyia hominivorax larvae after tick parasitism and weight gain of cattle during the experimental period were evaluated. METHODS Thirty naturally infested cattle were divided into two experimental groups: T01, treated with fluralaner (2.5 mg/kg) pour-on; T02, control. T01 received fluralaner on Days 0 (early summer in January), 42 and 84 (early autumn), whereas T02, a control group, received palliative treatment with a spray formulation when the group mean was ≥ 30 ticks. Counts of R. microplus females and calculation of the efficacy of fluralaner were performed on Days 3, 7, 14, 28, 35, 42, 56, 70, 84, 98, 112 and 126. The occurrence of myiasis was assessed throughout the study period. In addition, the weight, weight gain and daily weight gain of the animals were evaluated. RESULTS In the 12 evaluations performed, the parasitic load of T01 was near zero. Fluralaner showed 99.5% efficacy on the 3rd day after the first treatment and 100% efficacy from Day 7 to Day 126. Cochliomyia hominivorax larvae (n = 6; p = 0.0251) were found only in the control group (T02). At the end of the study, the animals subjected to treatments with fluralaner gained 32.8 kg more than the animals in the control group. CONCLUSIONS Application of fluralaner in summer and autumn, with 42-day intervals between treatments, was effective to control R. microplus on taurine cattle, which also gained more weight than control cattle. Additionally, no cases of myasis were documented in animals treated with fluralaner.
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Affiliation(s)
- Tiago Gallina
- Federal University of Pampa, Uruguaiana, Rio Grande Do Sul, Brazil
| | | | - Giancarlo Bilo
- Federal University of Pampa, Uruguaiana, Rio Grande Do Sul, Brazil
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de Aquino LM, Zapa DMB, de Castro Rodrigues D, Strydom T, Torres S, Ferreira LL, Barufi F, de Amaral HOA, de Borges FDA, Gallina T, de Mendonça RP, Soares VE, Monteiro CMO, Lopes WDZ. Two protocols using fluralaner for Rhipicephalus microplus strategic control on taurine cattle in a tropical region. Parasit Vectors 2024; 17:15. [PMID: 38191412 PMCID: PMC10775593 DOI: 10.1186/s13071-023-06107-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/19/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUND The present study aimed to evaluate the effects of different treatment strategies using a new commercial formulation containing pour-on fluralaner on Rhipicephalus microplus infestation in cattle and in pastures in a tropical climate region where up to five generations of this tick species can occur per year. METHODS Forty-five naturally infested cattle were divided into three experimental groups: T01, treated with fluralaner (2.5 mg/kg) pour-on every 42 days; T02, the cattle received the first treatment with fluralaner on Day 0 but the next treatment involved a weekly visual evaluation; T03, control, received palliative treatment with a spray formulation when the group mean was ≥ 30 ticks. Counts of female R. microplus were performed weekly until day 343, and larval counts on pasture were performed on Days 0, 30, and 60 and every 30 days until Day 330. RESULTS Using fluralaner, six applications were performed in Group T01, and four were performed in Group T02. In the control group (T03), it was necessary to perform eight palliative acaricide treatments with the spray formulation. The animals in T01 and T02 showed lower mean tick counts (p ≤ 0.05) than the control group (T03) on 28 and 27 of the 49 evaluated dates, respectively. In the paddock where the animals were kept as controls, the R. microplus larvae counts increased to 1458. In the paddocks where the animals were treated with fluralaner, the number was ≤ 19 per paddock during the study. CONCLUSIONS The different strategic treatment protocols performed with pour-on fluralaner (2.5 mg/kg) over a year in taurine cattle in a tropical region with a history of up to five annual generations of cattle ticks were effective, maintaining levels of R. microplus infestations in animals and in pastures close to zero in most of the study. Depending on the retreatment criterion adopted, the number of applications per year may be lower, resulting in a reduction in the mean cost of acaricide treatment per year and lower exposure of R. microplus populations to the active ingredient, resulting in lower resistance and selection pressure.
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Affiliation(s)
- Lidia Mendes de Aquino
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Dina Maria Beltran Zapa
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Daniel de Castro Rodrigues
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
- MSD Animal Health, São Paulo, Brazil
| | - Tom Strydom
- MSD Animal Health, 20 Spartan Road, Isando, Kempton Park, 1619, South Africa
| | | | - Lorena Lopes Ferreira
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Fernando de Almeida de Borges
- Department of Veterinary Medicine, Federal University of Mato Grosso Do Sul, Campo Grande, Mato Grosso Do Sul, Brazil
| | | | | | - Vando Edésio Soares
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
- University of Brazil, Descalvado, São Paulo, Brazil
| | - Caio Marcio Oliveira Monteiro
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil
- Department of Biosciences and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil
| | - Welber Daniel Zanetti Lopes
- Center of Veterinary Parasitology, School of Veterinary Science and Animal Science, Federal University of Goiás, Goiânia, Goiás, Brazil.
- Department of Biosciences and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil.
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Sánchez-García C, Santín C, Neris J, Sigmund G, Otero XL, Manley J, González-Rodríguez G, Belcher CM, Cerdà A, Marcotte AL, Murphy SF, Rhoades CC, Sheridan G, Strydom T, Robichaud PR, Doerr SH. Chemical characteristics of wildfire ash across the globe and their environmental and socio-economic implications. Environ Int 2023; 178:108065. [PMID: 37562341 DOI: 10.1016/j.envint.2023.108065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/26/2023] [Accepted: 06/24/2023] [Indexed: 08/12/2023]
Abstract
The mobilisation of potentially harmful chemical constituents in wildfire ash can be a major consequence of wildfires, posing widespread societal risks. Knowledge of wildfire ash chemical composition is crucial to anticipate and mitigate these risks. Here we present a comprehensive dataset on the chemical characteristics of a wide range of wildfire ashes (42 types and a total of 148 samples) from wildfires across the globe and examine their potential societal and environmental implications. An extensive review of studies analysing chemical composition in ash was also performed to complement and compare our ash dataset. Most ashes in our dataset had an alkaline reaction (mean pH 8.8, ranging between 6 and 11.2). Important constituents of wildfire ash were organic carbon (mean: 204 g kg-1), calcium, aluminium, and iron (mean: 47.9, 17.9 and 17.1 g kg-1). Mean nitrogen and phosphorus ranged between 1 and 25 g kg-1, and between 0.2 and 9.9 g kg-1, respectively. The largest concentrations of metals of concern for human and ecosystem health were observed for manganese (mean: 1488 mg kg-1; three ecosystems > 1000 mg kg-1), zinc (mean: 181 mg kg-1; two ecosystems > 500 mg kg-1) and lead (mean: 66.9 mg kg-1; two ecosystems > 200 mg kg-1). Burn severity and sampling timing were key factors influencing ash chemical characteristics like pH, carbon and nitrogen concentrations. The highest readily dissolvable fractions (as a % of ash dry weight) in water were observed for sodium (18 %) and magnesium (11.4 %). Although concentrations of elements of concern were very close to, or exceeded international contamination standards in some ashes, the actual effect of ash will depend on factors like ash loads and the dilution into environmental matrices such as water, soil and sediment. Our approach can serve as an initial methodological standardisation of wildfire ash sampling and chemical analysis protocols.
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Affiliation(s)
- C Sánchez-García
- Centre for Wildfire Research, Department of Geography, Swansea University, Swansea, United Kingdom
| | - C Santín
- Centre for Wildfire Research, Department of Geography, Swansea University, Swansea, United Kingdom; Research Institute of Biodiversity (IMIB; CSIC-UniOvi-PA), Mieres, Spain
| | - J Neris
- Centre for Wildfire Research, Department of Geography, Swansea University, Swansea, United Kingdom; Universidad de La Laguna, Tenerife, Spain
| | - G Sigmund
- Environmental Technology, Wageningen University & Research, Wageningen, The Netherlands; Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - X L Otero
- CRETUS, Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, Campus Vida, Santiago de Compostela, Spain
| | - J Manley
- Centre for Wildfire Research, Department of Geography, Swansea University, Swansea, United Kingdom
| | | | - C M Belcher
- University of Exeter, Exeter, United Kingdom
| | - A Cerdà
- Universitat de València, Valencia, Spain
| | - A L Marcotte
- Plant Ecology and Nature Conservation, Wageningen University & Research, Wageningen, The Netherlands
| | - S F Murphy
- U.S. Geological Survey, Boulder, CO, USA
| | - C C Rhoades
- U.S. Department of Agriculture Forest Service, Rocky Mountain Research Station, Fort Collins, CO, USA
| | - G Sheridan
- The University of Melbourne, Parkville, Australia
| | - T Strydom
- South African National Parks, Skukuza, South Africa
| | - P R Robichaud
- U.S. Department of Agriculture Forest Service, Rocky Mountain Research Station, Fort Collins, CO, USA
| | - S H Doerr
- Centre for Wildfire Research, Department of Geography, Swansea University, Swansea, United Kingdom.
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Strydom T, Lavan RP, Torres S, Heaney K. The Economic Impact of Parasitism from Nematodes, Trematodes and Ticks on Beef Cattle Production. Animals (Basel) 2023; 13:1599. [PMID: 37238028 PMCID: PMC10215612 DOI: 10.3390/ani13101599] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Global human population growth requires the consumption of more meat such as beef to meet human needs for protein intake. Cattle parasites are a constant and serious threat to the development of the beef cattle industry. Studies have shown that parasites not only reduce the performance of beef cattle, but also negatively affect the profitability of beef agriculture and have many other impacts, including contributing to the production of greenhouse gases. In addition, some zoonotic parasitic diseases may also threaten human health. Therefore, ongoing cattle parasite research is crucial for continual parasite control and the development of the beef cattle industry. Parasitism challenges profitable beef production by reducing feed efficiency, immune function, reproductive efficiency, liveweight, milk yield, calf yield and carcass weight, and leads to liver condemnations and disease transmission. Globally, beef cattle producers incur billions (US$) in losses due to parasitism annually, with gastrointestinal nematodes (GIN) and cattle ticks causing the greatest economic impact. The enormity of losses justifies parasitic control measures to protect profits and improve animal welfare. Geographical differences in production environment, management practices, climate, cattle age and genotype, parasite epidemiology and susceptibility to chemotherapies necessitate control methods customized for each farm. Appropriate use of anthelmintics, endectocides and acaricides have widely been shown to result in net positive return on investment. Implementing strategic parasite control measures, with thorough knowledge of parasite risk, prevalence, parasiticide resistance profiles and prices can result in positive economic returns for beef cattle farmers in all sectors.
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Affiliation(s)
- Tom Strydom
- MSD Animal Health, 20 Spartan Road, Isando, Kempton Park 1619, South Africa;
| | - Robert P. Lavan
- Merck & Co., Inc., 126 E. Lincoln Avenue, Rahway, NJ 07065, USA
| | - Siddhartha Torres
- Merck Animal Health, 2 Giralda Farms, Madison, NJ 07940, USA; (S.T.); (K.H.)
| | - Kathleen Heaney
- Merck Animal Health, 2 Giralda Farms, Madison, NJ 07940, USA; (S.T.); (K.H.)
- Heaney Veterinary Consulting, 303 Fletcher Lake Avenue, Bradley Beach, NJ 07720, USA
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Van Sittert SJ, Drew TM, Kotze JL, Strydom T, Weyer CT, Guthrie AJ. Occurrence of African horse sickness in a domestic dog without apparent ingestion of horse meat. J S Afr Vet Assoc 2013. [DOI: 10.4102/jsava.v84i1.948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
This is the first case of African horse sickness (AHS) in a dog where there was no apparent ingestion of horse meat. Significantly, the dog was part of a colony that resides in a Good Clinical Practice and Good Laboratory Practice accredited facility where complete history, weather and feeding records are maintained. The dog died after a week-long illness despite therapy. The principal post-mortem findings were severe hydrothorax and pulmonary consolidation (red hepatisation of the lungs). Histopathology revealed severe oedema and congestion of the lungs, hyaline degeneration of the myocardium and congestion of the liver sinusoids. Immunohistochemistry detected AHS-positive staining granules in the myocardium, whilst a real-time reverse transcription quantitative Polymerase chain reaction assay of tissue samples was strongly positive for African horse sickness virus nucleic acid. Other dogs on the property showed a 43%seroconversion rate to AHS.
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Schetters TPM, Strydom T, Crafford D, Kleuskens JAGM, van de Crommert J, Vermeulen AN. Immunity against Babesia rossi infection in dogs vaccinated with antigens from culture supernatants. Vet Parasitol 2006; 144:10-9. [PMID: 17056181 DOI: 10.1016/j.vetpar.2006.09.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 09/06/2006] [Accepted: 09/13/2006] [Indexed: 11/19/2022]
Abstract
Soluble parasite antigens (SPA) from different Babesia species have been shown earlier to induce protective immunity when used as vaccine. However, initial attempts to produce such vaccine against Babesia rossi infection using SPA from B. rossi culture supernatants were not or only partially successful. Here we show that when dogs were vaccinated with a vaccine comprising SPA from B. rossi combined with SPA from Babesia canis protective immunity against experimental challenge infection was induced. Immunity was reflected in reduced clinical signs that resolved spontaneously, and reduction of parasitaemia and SPA in the blood. Not a single infected erythrocyte could be found in blood smears of dogs that had been repeatedly boosted (three vaccinations in total). In contrast, three out of four control dogs required chemotherapeutic treatment to prevent death. The fourth control dog showed a transient parasitaemia that resolved spontaneously. Vaccination did not prevent the development of a transient anaemia. It is concluded that a vaccine containing a mixture of SPA obtained from in vitro culture supernatants of B. rossi and B. canis induces protection in dogs against heterologous challenge infection with B. canis (as shown before) or B. rossi.
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Affiliation(s)
- Th P M Schetters
- Parasitology R&D Department, Intervet International B.V., P.O. Box 31, 5830 AA Boxmeer, The Netherlands.
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Mekonnen S, Bryson NR, Fourie LJ, Peter RJ, Spickett AM, Taylor RJ, Strydom T, Kemp DH, Horak IG. Comparison of 3 tests to detect acaricide resistance in Boophilus decoloratus on dairy farms in the Eastern Cape Province, South Africa. J S Afr Vet Assoc 2003; 74:41-4. [PMID: 12967049 DOI: 10.4102/jsava.v74i2.502] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The susceptibility of the larval offspring of engorged female Boophilus decoloratus, and of the engorged females, collected from cattle on the dairy farms Brycedale, Sunny Grove and Welgevind in the Eastern Cape Province, South Africa, was tested against the acaricides amitraz, chlorfenvinphos and cypermethrin. Resistance was determined by means of the Shaw Larval Immersion Test (SLIT) for larvae and the Reproductive Estimate Test (RET) and Egg Laying Test (ELT) for adults. At Brycedale the tests all indicated resistance to chlorfenvinphos, and RET and ELT indicated resistance to amitraz and emerging resistance to cypermethrin. At Sunny Grove, B. decoloratus was resistant to cypermethrin using SLIT and exhibited emerging resistance to chlorfenvinphos with SLIT and to cypermethrin with both RET and ELT At Welgevind, resistance was recorded against chlorfenvinphos (SLIT) and against cypermethrin (ELT), and emerging resistance against permethrin (RET). The results obtained with RET and ELT were generally comparable, but often differed from those obtained with SLIT. Resistance could be detected within 7 days with ELT compared to 42 days with RET and 60 days with SLIT.
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Affiliation(s)
- S Mekonnen
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
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Mekonnen S, Bryson NR, Fourie LJ, Peter RJ, Spickett AM, Taylor RJ, Strydom T, Horak IG. Acaricide resistance profiles of single- and multi-host ticks from communal and commercial farming areas in the Eastern Cape and North-West Provinces of South Africa. Onderstepoort J Vet Res 2002; 69:99-105. [PMID: 12234005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Abstract
A field study (February 2000 to August 2001) was conducted on communal and commercial farms in the Eastern Cape and North-West Provinces of South Africa to detect the levels of tick resistance to commonly used acaricides. The larvae obtained from engorged females of the one-host tick Boophilus decoloratus, the two-host tick Rhipicepalus evertsi evertsi and the three-host ticks Amblyomma hebraeum and Rhipicephalus appendiculatus were tested against various concentrations of amitraz, chlorfenvinphos and cypermethrin using the Shaw Larval Immersion Test method. Ticks from the communal farms showed higher levels of resistance to cypermethrin and some resistance to chlorfenvinphos whilst no resistance was detected against amitraz. However, ticks from commercial farms were equally resistant to amitraz, chlorfenvinphos and cypermethrin. The B. decoloratus populations tested were considerably more resistant to all the acaricides tested than the R. evertsi evertsi, A. hebraeum and R. appendiculatus populations. This supports the hypothesis that single-host ticks develop resistance faster than multi-host ticks. This trend was recorded on most of the farms where single- and multi-host ticks co-existed. It was concluded that the use of acaricides at high frequencies and high concentrations was one of the main causes of tick resistance in the study areas. Possible factors which caused the resistance problems are discussed and acaricide management strategies recommended.
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Affiliation(s)
- S Mekonnen
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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