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1.
Parasitology ; 149(9): 1229-1248, 2022 08.
Article in English | MEDLINE | ID: mdl-35641880

ABSTRACT

South Africa boasts a rich diversity of small mammals of which several are commensal and harbour parasites of zoonotic importance. However, limited information is available on the parasite diversity and distribution associated with rodents in South Africa. This is particularly relevant for Micaelamys namaquensis (Namaqua rock mouse), a regionally widespread and locally abundant species that is often commensal. To address the paucity of data, the aims of the study were to record the ectoparasite diversity associated with M. namaquensis and develop distribution maps of lice and mites associated with M. namaquensis and other rodents in South Africa. Micaelamys namaquensis individuals (n = 216) were obtained from 12 localities representing multiple biomes during 2017­2018. A total of 5591 ectoparasites representing 5 taxonomic groups ­ fleas, lice, mesostigmatid mites, chiggers and ticks was recorded. These consisted of at least 57 taxa of which ticks were the most speciose (20 taxa). Novel contributions include new host and locality data for several ectoparasite taxa and undescribed chigger species. Known vector species were recorded which included fleas (Ctenocephalides felis, Dinopsyllus ellobius and Xenopsylla brasiliensis) and ticks (Haemaphysalis elliptica, Rhipicephalus appendiculatus and Rhipicephalus simus). Locality records indicate within-taxon geographic differences between the 2 louse species and the 2 most abundant mite species. It is clear that M. namaquensis hosts a rich diversity of ectoparasite taxa and, as such, is an important rodent species to monitor in habitats where it occurs in close proximity to humans and domestic animals.


Subject(s)
Flea Infestations , Murinae , Phthiraptera , Rhipicephalus , Siphonaptera , Trombiculidae , Animals , Murinae/parasitology , South Africa/epidemiology
2.
Exp Oncol ; 44(1): 31-38, 2022 05.
Article in English | MEDLINE | ID: mdl-35548969

ABSTRACT

BACKGROUND: Cell surface plasmin is involved in tumor growth and metastatic dissemination by regulating cancer cells adhesion, migration and invasion. Plasmin-induced cell detachment is accompanied by an increased rate of reactive oxygen species (ROS) generation and cell death. However, cancer cells acquire the ability to develop adaptive mechanisms to resist ROS-mediated apoptosis. AIM: To establish the role of adaptor protein Ruk/CIN85 in the control of viability and redox balance in breast adenocarcinoma cells exposed to plasmin(ogen). MATERIALS AND METHODS: Mouse 4T1 cells with the stable overexpression of adaptor protein Ruk/CIN85 (RukUp subline) and corresponding control (Mock subline) were treated with Glu-plasminogen (1-100 nM). Plasminogen to plasmin conversion was monitored spectrophotometrically by cleavage of the specific chromogenic substrate S2251. Specific uPA inhibitor BC11 was used to verify the uPA-mediated mechanism of plasminogen pericellular activation by 4T1 cells. Cell survival rate was assessed by MTT-test and cell proliferation was estimated by colony formation assay. Enzymatic activities of catalase, glutathione peroxidase, superoxide dismutase, as well as hydrogen peroxide (H2O2) levels were measured by spectrophotomertric and fluorometric assays. The intracellular ROS generation was monitored by flow cytometry using H2DCF-DA fluorescent probe. RESULTS: Plasminogen was shown to be converted into an active proteinase plasmin on the surface of carcinoma cells in uPA-dependent manner. Plasmin(ogen) suppressed proliferation and affected survival of both studied 4T1 sublines. However, RukUp cells displayed higher resistance to plasmin(ogen)-induced cytotoxicity than Mock cells. Plasmin(ogen) promoted significant elevation in ROS generation rate in cells with the basal level of Ruk/CIN85 expression. In contrast, RukUp cells appear to be more effective in counteracting prooxidant changes due to the activation of some enzymes of the glutathione system, in particular glutathione peroxidase, and a concomitant decrease of H2O2 accumulation. CONCLUSION: Adaptor protein Ruk/CIN85 is involved in the regulation of redox homeostasis in cancer cells to maintain levels of ROS, thus promoting redox adaptation in cancer cells exposed to plasmin(ogen). Thus, Ruk/CIN85 may represent one of the relevant targets in order to diminish the resistance of cancer cells to ROS-mediated apoptosis.


Subject(s)
Adaptor Proteins, Signal Transducing , Breast Neoplasms , Fibrinolysin , Adaptor Proteins, Signal Transducing/metabolism , Animals , Estrone/analogs & derivatives , Female , Fibrinolysin/metabolism , Glutathione Peroxidase/metabolism , Hydrogen Peroxide/metabolism , Hydrogen Peroxide/pharmacology , Mice , Oxidation-Reduction , Plasminogen/metabolism , Reactive Oxygen Species/metabolism
3.
J Appl Microbiol ; 127(2): 326-343, 2019 Aug.
Article in English | MEDLINE | ID: mdl-30739384

ABSTRACT

Root-knot nematodes are destructive phytopathogens that damage agricultural crops globally, and there is growing interest in the use of biocontrol based on rhizobacteria such as Bacillus to combat Meloidogyne species. It is hypothesized that nematicidal activity of Bacillus can be attributed to the production of secondary metabolites and hydrolytic enzymes. Yet, few studies have characterized these metabolites and their identities remain unknown. Others are speculative or fail to elaborate on how secondary metabolites were detected or distinguished from primary metabolites. Metabolites can be classified based on their origin as either intracellular or extracellular and based on their function, as either primary or secondary. Although this classification is in general use, the boundaries are not always well defined. An understanding of the secondary metabolite and hydrolytic enzyme classification of Bacillus species will facilitate investigations aimed at bionematicide development. This review summarizes the significance of Bacillus hydrolytic enzymes and secondary metabolites in bionematicide research and provides an overview of known classifications. The importance of appropriate cultivation conditions for optimum metabolite and enzyme production is also discussed. Finally, the use of metabolomics for the detection and identification of nematicidal compounds is considered.


Subject(s)
Bacillus/metabolism , Biological Control Agents , Nematoda , Animals , Antinematodal Agents , Bacillus/enzymology , Bacillus/growth & development , Culture Media , Metabolomics , Secondary Metabolism , Tylenchoidea
4.
Ukr Biochem J ; 88(1): 119-25, 2016.
Article in English | MEDLINE | ID: mdl-29227594

ABSTRACT

NADPH oxidases are key components of redox-dependent signaling networks involved in the control of cancer cell proliferation, survival and invasion. The data have been accumulated that demonstrate specific expression patterns and levels of NADPH oxidase homologues (NOXs) and accessory genes in human cancer cell lines and primary tumors as well as modulation of these parameters by extracellular cues. Our previous studies revealed that ROS production by human colorectal adenocarcinoma HT-29 cells is positively correlated with adaptor protein Ruk/CIN85 expression while increased levels of Ruk/CIN85 in weakly invasive human breast adenocarcinoma MC F-7 cells contribute to their malignant phenotype through the constitutive activation of Src/Akt pathway. In this study, to investigate whether overexpression of Ruk/CIN85 in MC F-7 cells can influence transcriptional regulation of NOXs genes, the subclones of MCF-7 cells with different levels of Ruk/CIN85 were screened for NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1 and DUOX2 as well as for regulatory subunit p22Phox mRNA contents by quantitative RT-PCR (qPCR). Systemic multidirectional changes in mRNA levels for NOX1, NOX2, NOX5, DUOX2 and p22Phox were revealed in Ruk/CIN85 overexpressing cells in comparison to control WT cells. Knocking down of Ruk/CIN85 using technology of RNA-interference resulted in the reversion of these changes. Further studies are necessary to elucidate, by which molecular mechanisms Ruk/CIN85 could affect transcriptional regulation of NOXs genes.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Gene Expression Regulation, Neoplastic , NADPH Oxidase 1/genetics , Reactive Oxygen Species/metabolism , Transcription, Genetic , Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Adaptor Proteins, Signal Transducing/metabolism , Clone Cells , Dual Oxidases/genetics , Dual Oxidases/metabolism , Humans , Isoenzymes/genetics , Isoenzymes/metabolism , MCF-7 Cells , NADPH Oxidase 1/metabolism , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Reverse Transcriptase Polymerase Chain Reaction
5.
Cancer Chemother Pharmacol ; 76(1): 13-20, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25952795

ABSTRACT

PURPOSE: The purpose of the trial was to assess the efficacy and tolerability of Sym004, a novel 1:1 mixture of two chimeric monoclonal antibodies (992 and 1024) targeting non-overlapping epitopes of the anti-epidermal growth factor receptor (EGFR), in patients with squamous cell carcinoma of the head and neck (SCCHN). METHODS: Incurable, recurrent and/or metastatic SCCHN patients with acquired resistance to anti-EGFR monoclonal antibody-containing treatment received weekly infusions of 12 mg/kg Sym004 until disease progression or unacceptable toxicity. RESULTS: Among the 26 patients treated with Sym004, the proportion of patients alive without disease progression at 6 months was 12 % (95 % CI 1-39 %). The median duration of progression-free survival was 82 days (95 % CI 41-140 days). Of 19 patients evaluable for response, eight showed a decrease in the sum of the largest diameter in their target lesions (median 11 %; range 7-27 %). The best overall response was stable disease in 13 patients (50 %). Paired biopsies showed a significant down-regulation of EGFR in both skin and tumors following exposure to Sym004. All patients had EGFR-related adverse events, including grade 3 skin toxicities and grade ≥3 hypomagnesemia reported in 13 (50 %) and 10 (38 %) of 26 patients, respectively. One event fulfilling the protocol-defined criteria for infusion-related reactions (grade 2) was reported. No anti-drug antibodies were detected. CONCLUSIONS: The marked EGFR down-regulation shown in target tissues supports the proposed mechanism of action of Sym004. This trial revealed modest anti-tumor activity of Sym004 in extensively pretreated advanced SCCHN patients.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Carcinoma, Squamous Cell/drug therapy , ErbB Receptors/antagonists & inhibitors , Head and Neck Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/enzymology , Cell Line, Tumor , Disease Progression , Disease-Free Survival , ErbB Receptors/immunology , Female , Head and Neck Neoplasms/enzymology , Humans , Male , Middle Aged , Squamous Cell Carcinoma of Head and Neck
6.
Exp Appl Acarol ; 61(3): 371-82, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23771510

ABSTRACT

The objective of the study was to establish to what extent the native tick species Rhipicephalus decoloratus has been displaced by the invasive introduced tick, Rhipicephalus microplus at two communally grazed areas in the Eastern Cape Province, South Africa. To this end ticks were collected monthly from five cattle over a period of 2 years and from 10 drag-samples of the vegetation over a period of 1 year at each locality. Whereas 10 years previously only R. decoloratus and no R. microplus had been recorded in the vicinity of the two sites, R. microplus now comprised the bulk of collections at both. Furthermore, significantly more R. microplus were collected from cattle at both localities during the 2nd year of the survey than during the 1st. In addition to 83 instances of intraspecific coupling, there were 17 instances of R. microplus males coupled with R. decoloratus females. Collections made from cattle and goats on two farms close to the study sites revealed that R. microplus was present on both host species and that it significantly outnumbered R. decoloratus on one of the farms. Rhipicephalus decoloratus and R. microplus larvae as well as larvae exhibiting characteristics of both species were collected from the vegetation.


Subject(s)
Cattle Diseases/parasitology , Rhipicephalus/physiology , Tick Infestations/veterinary , Animals , Cattle , Cattle Diseases/epidemiology , Female , Male , Rhipicephalus/classification , South Africa/epidemiology , Tick Infestations/epidemiology , Tick Infestations/parasitology , Time Factors
7.
Vet Parasitol ; 188(3-4): 346-54, 2012 Sep 10.
Article in English | MEDLINE | ID: mdl-22521977

ABSTRACT

Rodents are recognised as important hosts of ixodid ticks and as reservoirs of tick-borne pathogens across the world. Sympatric insectivores are usually inconspicuous and often overlooked as hosts of ticks and reservoirs of disease. Elephant shrews or sengis of the order Macroscelidea are small insectivores that often occur in sympatry with rodents in southern Africa. Sengis are invariably parasitised by large numbers of immature ticks while sympatric rodents are infested with very few. The reason for the difference in tick parasitism rates between these hosts is unknown. While a number of mechanisms are possible, we hypothesised that certain tick species exhibit "true host specificity" and as such would only attach and feed successfully on their preferred host or a very closely related host species. To investigate this, we conducted feeding experiments using two economically important tick species, the brown paralysis tick, Rhipicephalus warburtoni and the Karoo paralysis tick, Ixodes rubicundus and two sympatric small mammal species as potential hosts, the eastern rock sengi, Elephantulus myurus and the Namaqua rock mouse, Micaelamys namaquensis. Ticks attached and fed readily on E. myurus, but did not attach or feed successfully on M. namaquensis suggesting that these ticks exhibit true host specificity. We suggest that a kairomonal cue originating from the odour of E. myurus may stimulate the attachment and feeding of these ticks and that they further possess immunosuppressive mechanisms specific to E. myurus, allowing them to feed on this host species but not on M. namaquensis. This study highlights the importance of small mammalian insectivores as potential hosts of ixodid tick species and hence their potential as reservoirs of tick-borne pathogens.


Subject(s)
Ixodes/parasitology , Murinae/parasitology , Rhipicephalus/parasitology , Rodent Diseases/parasitology , Shrews/parasitology , Tick Infestations/veterinary , Africa, Southern , Animals , Female , Genetic Speciation , Host Specificity , Host-Parasite Interactions , Male , Sympatry , Tick Infestations/parasitology , Tick Paralysis/parasitology , Tick Paralysis/veterinary
8.
Leukemia ; 26(2): 271-9, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21844871

ABSTRACT

Although the cure rate of newly diagnosed acute lymphoblastic leukemia (ALL) has improved over the past four decades, the outcome for patients who relapse remains poor. New therapies are needed for these patients. Our previous global gene expression analysis in a series of paired diagnosis-relapse pediatric patient samples revealed that the antiapoptotic gene survivin was consistently upregulated upon disease relapse. In this study, we demonstrate a link between survivin expression and drug resistance and test the efficacy of a novel antisense agent in promoting apoptosis when combined with chemotherapy. Gene-silencing experiments targeting survivin mRNA using either short-hairpin RNA (shRNA) or a locked antisense oligonucleotide (LNA-ON) specifically reduced gene expression and induced apoptosis in leukemia cell lines. When used in combination with chemotherapy, the survivin shRNA and LNA-ON potentiated the chemotherapeutic antileukemia effect. Moreover, in a mouse primary xenograft model of relapse ALL, the survivin LNA-ON decreased survivin expression in a subset of animals, and produced a statistically significant decrease in tumor progression. Taken together, these findings suggest that targeting endogenous levels of survivin mRNA by LNA-ON methods may augment the response to standard chemotherapy by sensitizing otherwise resistant tumor cells to chemotherapy.


Subject(s)
Antineoplastic Agents/therapeutic use , Gene Knockdown Techniques , Inhibitor of Apoptosis Proteins/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Base Sequence , DNA Primers , Humans , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Reverse Transcriptase Polymerase Chain Reaction , Survivin , Treatment Outcome
9.
Med Vet Entomol ; 26(3): 255-62, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22187948

ABSTRACT

Ticks are important vectors of pathogens of medical and veterinary importance worldwide. In spite of their economic importance, our current knowledge about the factors affecting tick prevalence and abundance in tropical and subtropical regions is rather limited. Both abiotic (e.g. temperature) as well as biotic variables (e.g. host sex) have been identified as key determinants of distributions. Eastern rock sengis or elephant shrews (Elephantulus myurus, Macroscelidea: Cacroscelididae, Thomas & Schwann) are widely distributed throughout Africa and can harbour a large number of tick species and substantial tick burdens. In the present study, we evaluated the contribution of climate and host factors on tick burdens of sengis. Throughout the year sengis carried high abundances of immature stages of a single tick species, Rhipicephalus sp. near warburtoni. There was no evidence that host parameters affected tick burdens. However, larval abundance decreased with increasing ambient temperatures and both larvae and nymphs were negatively affected by rainfall 2 months before the sampling month. In addition, nymphal burdens decreased with increasing minimum temperatures. Our results suggest that climate factors are the largest constraint for the immature stages of R. sp. near warburtoni and that eastern rock sengis could play a crucial role in the dynamics of tick-borne diseases as a result of the large tick burdens they can sustain.


Subject(s)
Mammals/physiology , Mammals/parasitology , Rhipicephalus/physiology , Tick Infestations/veterinary , Animals , Body Size , Climate , Female , Larva/physiology , Linear Models , Male , Nymph/physiology , Rain , Seasons , Sex Factors , South Africa , Temperature , Tick Infestations/parasitology
10.
Vet Parasitol ; 177(1-2): 111-8, 2011 Apr 19.
Article in English | MEDLINE | ID: mdl-21168275

ABSTRACT

The aim of this investigation was to determine the efficacy of milbemycin oxime in preventing the oesophageal encapsulation of Spirocerca lupi, following the experimental infection of dogs. Two studies were conducted which involved a total of 21 purpose-bred Beagles. Each dog was infected with approximately 40, third stage infective S. lupi larvae. The larvae were dissected from scarabaeid beetles that had been collected from areas endemic for spirocercosis. In the first study, milbemycin oxime (minimum dose 0.5mg/kg body weight) was administered to seven dogs on day 30 post-infection. Seven other dogs served as untreated controls. In the second study, milbemycin oxime (also at a minimum dose of 0.5mg/kg body weight) was administered to four of seven infected dogs on day 28 post-infection. Treatment was repeated at 14- or 28-day intervals. All of the dogs, from both studies, were euthanized 168 or 169 days after infection. All S. lupi were recovered, and lesions in the thoracic aorta and oesophagus were described and quantified. A single treatment with milbemycin oxime was 79.8% effective in preventing the establishment of S. lupi in the oesophagus. This treatment significantly (p<0.05) reduced both the number of S. lupi within the oesophagus and the size of the oesophageal nodules. The efficacy of anthelmintic treatment was increased to 100% when repeat doses of milbemycin oxime were administered at 14- or 28-day intervals. These repeat treatments completely prevented the establishment of S. lupi within the oesophagus and thereby averted the development of oesophageal nodules. As expected, none of the treatment protocols reduced S. lupi related damage within the aorta because the administration of milbemycin oxime only began after the larvae had completed their first stage of migration.


Subject(s)
Dog Diseases/drug therapy , Macrolides/therapeutic use , Spirurida Infections/veterinary , Thelazioidea/classification , Animals , Dog Diseases/parasitology , Dog Diseases/pathology , Dogs , Drug Combinations , Female , Macrolides/administration & dosage , Male , Praziquantel/administration & dosage , Praziquantel/therapeutic use , Spirurida Infections/drug therapy , Spirurida Infections/parasitology , Spirurida Infections/pathology
11.
Gene Ther ; 18(4): 326-33, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21179173

ABSTRACT

Usually, small interfering RNAs and most antisense molecules need mechanical or chemical delivery methods to down-modulate the targeted mRNA. However, these delivery approaches complicate the interpretations of biological consequences. We show that locked nucleic acid (LNA)-based antisense oligonucleotides (LNA-ONs) readily down-modulate genes of interest in multiple cell lines without any delivery means. The down-modulation of genes was quick, robust, long-lasting and specific followed by potent down-modulation of protein. The efficiency of the effect varied among the 30 tumor cell lines investigated. The most robust effects were found in those cells where nuclear localization of the LNA-ON was clearly observed. Importantly, without using any delivery agent, we demonstrated that HER3 mRNA and protein could be efficiently down-modulated in cells and a tumor xenograft model. These data provide a simple and efficient approach to identify potential drug targets and animal models. Further elucidation of the mechanism of cellular uptake and trafficking of LNA-ONs may enhance not only the therapeutic values of this platform but also antisense molecules in general.


Subject(s)
Gene Expression Regulation , Neoplasms/genetics , Oligonucleotides, Antisense/pharmacology , Animals , Cell Line, Tumor , Gene Silencing , Gene Targeting , Humans , Receptor, ErbB-3/genetics , Transfection
12.
Vet Rec ; 167(12): 442-5, 2010 Sep 18.
Article in English | MEDLINE | ID: mdl-20852247

ABSTRACT

To determine the efficacy of a 12.5 per cent spot-on formulation of pyriprole (Prac-Tic; Novartis Animal Health) and that of a combination of 10 per cent imidacloprid and 2.5 per cent moxidectin (Advocate; Bayer Animal Health) against Sarcoptes scabiei on dogs, 20 naturally infested adult dogs were ranked according to their pretreatment mite counts, allocated to one of two groups and housed individually in pens. Two spot-on treatments with each product, 30 days apart, were administered. Mite counts and clinical assessments were performed on each dog two days before treatment, and 28, 60 and 90 days after treatment. Efficacy was measured on the basis of the presence or absence of live mites. Except for day 60 following treatment, on which a single dog in the group treated with pyriprole was positive, no live mites were found on the treated dogs during the assessments on days 28, 60 and 90. Thus, efficacy measured on the basis of this finding (day 90 assessment) was 100 per cent. On final assessment, all dogs treated with pyriprole had 100 per cent resolution of papules, but crusts resembling healing lesions were still present on two dogs. Those treated with imidacloprid and moxidectin had 100 per cent resolution of papules and crusts. Hair regrowth, to greater than 90 per cent of pretreatment hair cover, was observed on all 20 dogs.


Subject(s)
Dog Diseases/drug therapy , Insecticides/therapeutic use , Pyrazoles/therapeutic use , Pyridines/therapeutic use , Sarcoptes scabiei/drug effects , Scabies/veterinary , Animals , Chemistry, Pharmaceutical , Dogs , Drug Therapy, Combination/veterinary , Female , Imidazoles/therapeutic use , Macrolides/therapeutic use , Male , Neonicotinoids , Nitro Compounds/therapeutic use , Scabies/drug therapy , Treatment Outcome
13.
Vet Parasitol ; 174(3-4): 277-84, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-20869809

ABSTRACT

Spirocerca lupi is primarily a parasite of dogs and other carnivores. Clinical signs of infection are regurgitation, vomiting, weight loss, coughing and dyspnoea. Sudden death can also occur due to a ruptured aortic aneurysm. In this study, the Eastern Cape Province of South Africa was identified as an area with a high prevalence of S. lupi. A subsequent investigation, to evaluate the efficacy of milbemycin oxime as a prophylactic agent for canine spirocercosis, involved 58 puppies that were raised in this area in accordance with local husbandry procedures. Approximately half of the puppies served as untreated controls. Puppies in the treatment group received milbemycin oxime (minimum dose of 0.5mg/kg body weight) when they were between 2 and 6 weeks old. They then received five further treatments at approximately 28-day intervals. The treatment was orally administered in tablet form. After the sixth treatment, puppies from both the treated and control groups were euthanized and post-mortem examinations were performed. Twenty-four out of 27 dogs in the untreated control group had become infected by S. lupi. In comparison, only 19 out of 31 dogs in the treatment group had evidence of spirocercosis as demonstrated by aortic nodules. The prophylactic regimen reduced the severity of aortic lesions and prevented 86.5% of S. lupi from becoming established in the thoracic aorta. It also prevented 89.4% of S. lupi from becoming established in the oesophagus and significantly reduced the number of oesophageal nodules. Milbemycin oxime markedly reduced the level and severity of S. lupi infection in treated puppies raised in an endemic area of South Africa. It deserves further evaluation as a potential prophylactic treatment for spirocercosis.


Subject(s)
Anthelmintics/pharmacology , Dog Diseases/prevention & control , Macrolides/pharmacology , Spirurida Infections/veterinary , Thelazioidea , Animals , Anthelmintics/administration & dosage , Dog Diseases/parasitology , Dogs , Female , Macrolides/administration & dosage , Male , South Africa/epidemiology , Spirurida Infections/epidemiology , Spirurida Infections/parasitology , Spirurida Infections/prevention & control
14.
J S Afr Vet Assoc ; 81(1): 33-6, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20649152

ABSTRACT

The objective of this study was to determine the therapeutic and residual efficacy of a topically applied combination of cyphenothrin (40%) and pyriproxyfen (2%) against the tick Haemaphysalis elliptica and the flea Ctenocephalides felis on dogs. Twelve dogs were infested with 50 ticks 2 days before they were treated and with approximately 100 fleas 6 days before treatment and again 2 days before treatment and with 50 ticks and approximately 100 fleas at weekly intervals thereafter. They were ranked according to their flea counts and sex 5 days before treatment and randomly allocated to an untreated control group of 6 dogs and a treated group of 6 dogs. Ticks and fleas were collected from the dogs 48 h after treatment and 48 h after each infestation and live and dead ticks and live fleas were counted. The counts of ticks and fleas were transformed to geometric means, and efficacy was calculated by comparing these means. The product had a therapeutic efficacy of 83.1% against H. elliptica and 97.5% against C. felis 2 days after treatment. The residual period of protection during which efficacy was > or = 90% was 5 weeks for both H. elliptica and C. felis.


Subject(s)
Dog Diseases/drug therapy , Ectoparasitic Infestations/veterinary , Insecticides/pharmacology , Ixodidae/drug effects , Pyrethrins/pharmacology , Pyridines/pharmacology , Siphonaptera/drug effects , Administration, Topical , Animals , Dog Diseases/parasitology , Dogs , Ectoparasitic Infestations/drug therapy , Female , Insecticides/administration & dosage , Ixodidae/growth & development , Male , Parasite Egg Count/veterinary , Pyrethrins/administration & dosage , Pyridines/administration & dosage , Random Allocation , Siphonaptera/growth & development , Time Factors , Treatment Outcome
15.
J S Afr Vet Assoc ; 81(2): 126-8, 2010 Jun.
Article in English | MEDLINE | ID: mdl-21247023

ABSTRACT

The objective of this study was to determine the species composition of ixodid ticks infesting domestic dogs in the northwestern region of the Northern Cape Province of South Africa and in Namibia. Ticks were collected from February 2008 to January 2009 from dogs presented for a variety of reasons at a veterinary clinic in the Northern Cape Province and at 3 clinics in Namibia. The ticks collected at each place were pooled separately for each month at each locality. Eleven ixodid tick species were collected from dogs in the Northern Cape Province and new locality records for Haemaphysalis colesbergensis and Ixodes rubicundus, new locality and host records for Hyalomma glabrum, and a new host record for Rhipicephalus neumanni are reported. Six tick species were collected from dogs at the 3 clinics in Namibia. The most numerous species on dogs in both countries was R. sanguineus. The present results increase the total number of ixodid tick species collected from dogs in South Africa from 25 to 28.


Subject(s)
Dog Diseases/parasitology , Ixodidae , Tick Infestations/epidemiology , Animals , Dog Diseases/epidemiology , Dogs , Namibia/epidemiology , South Africa/epidemiology
16.
Onderstepoort J Vet Res ; 76(1): 69-74, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19967930

ABSTRACT

Eighty ixodid tick species, 25 argasid tick species and Nuttalliella namaqua occur in South Africa. Twenty-one of the 80 ixodid species and two of the argasid species occur only in this country, while N. namaqua is present only in South Africa and Namibia. Forty-six of the 80 ixodid species and 16 of the 25 argasid species as well as N. namaqua have been described as new species since 1908. People working in South Africa have written or contributed to the descriptions of 24 of these 63 new species, while foreign researchers have described the remainder. New species indigenous to South Africa are still being discovered, while the names of some species, well known because of their veterinary importance, have been altered.


Subject(s)
Phylogeny , Ticks/classification , Animals , South Africa , Species Specificity
17.
Onderstepoort J Vet Res ; 76(3): 263-76, 2009 Sep.
Article in English | MEDLINE | ID: mdl-21105593

ABSTRACT

The species and distribution of ticks infesting cattle, goats and dogs in the eastern region of the Eastern Cape Province, South Africa and Maputo Province, Mozambique were determined from collections made from these animals at 72 localities in the former region and 30 in the latter. Eleven ixodid and one argasid species were recovered in the Eastern Cape Province and 15 ixodid species in Maputo Province. The most common ticks infesting cattle and goats in both provinces were Amblyomma hebraeum, Rhipicephalus (Boophilus) microplus, Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi. The dominant species on dogs were Haemaphysalis elliptica and Rhipicephalus simus. The geographic distributions of the major species and some of the minor species in both regions were plotted. The partial or complete displacement of the indigenous tick Rhipicephalus (Boophilus) decoloratus by the introduced species R. (B.) microplus was a major feature of both surveys.


Subject(s)
Cattle Diseases/epidemiology , Dog Diseases/epidemiology , Goat Diseases/epidemiology , Tick Infestations/veterinary , Ticks/growth & development , Animals , Cattle , Cattle Diseases/parasitology , Dog Diseases/parasitology , Dogs , Female , Goat Diseases/parasitology , Goats , Male , Mozambique/epidemiology , Prevalence , South Africa/epidemiology , Species Specificity , Tick Infestations/epidemiology , Tick Infestations/parasitology , Ticks/classification
18.
Onderstepoort J Vet Res ; 76(2): 167-75, 2009 Jun.
Article in English | MEDLINE | ID: mdl-20698437

ABSTRACT

Approximately 3000 birds, mainly passerines, caught in mist nets in the northern provinces of South Africa, were examined for ticks. A total of 178 ticks, belonging to 14 species, were recovered from 83 birds of 43 different species. Hyalomma rufipes was the most numerous tick, with 26 larvae and 109 nymphs collected, followed by Amblyomma marmoreum, with 13 larvae and two nymphs. Despite the study being conducted within the distribution range of Amblyomma hebraeum, it was not seen on any passerines, whereas three larger species were infested. The potential for small birds to spread ticks with their associated tick-borne pathogens is discussed.


Subject(s)
Bird Diseases/epidemiology , Birds/parasitology , Tick Infestations/veterinary , Ticks/growth & development , Animals , Animals, Wild/parasitology , Bird Diseases/transmission , Birds/classification , Female , Larva , Male , Nymph , Seasons , South Africa/epidemiology , Species Specificity , Tick Infestations/epidemiology , Tick Infestations/transmission , Ticks/classification
19.
Onderstepoort J Vet Res ; 76(2): 201-8, 2009 Jun.
Article in English | MEDLINE | ID: mdl-20698440

ABSTRACT

This study compares the prevalence of ixodid tick species on cattle and goats in Maputo Province. Adult ticks as well as the nymphs of three species, and only the adults of two species were collected from sets of five cattle at 21 localities throughout the province and compared with those collected from similar sets of goats at the same places. Amblyomma hebraeum adults and/or nymphs were present on cattle and on goats at all 21 localities, and 90 cattle and 22 goats were infested with adult ticks. Rhipicephalus (Boophilus) microplus adults and/or nymphs were collected from cattle at 20 and from goats at 15 localities, and 92 cattle and 34 goats were infested [Chi-square test (chi2), P<0.001]. The total length of several maturing female R. (Boophilus) microplus collected from cattle and goats exceeded 5 mm, indicating that they successfully engorge on both host species. Rhipicephalus appendiculatus adults and/or nymphs were present on cattle at 15 and on goats at 13 localities, but 28 cattle and only one goat were infested with adult ticks (chi2, P<0.001). Adult Rhipicephalus evertsi evertsi were recovered from cattle at 20 and from goats at 17 localities, and 74 cattle and 69 goats were infested. Adult Rhipicephalus simus were collected from cattle at 18 and from goats at 11 localities (Fisher's exact test, P=0.04), and 60 cattle and 14 goats were infested (chi2, P<0.001). These findings underscore the advisability of including goats in acaricide application programmes designed for the control of tick-borne diseases in cattle at the same locality.


Subject(s)
Acaricides/pharmacology , Cattle Diseases/epidemiology , Goat Diseases/epidemiology , Ixodidae/growth & development , Tick Infestations/veterinary , Animals , Cattle , Cattle Diseases/parasitology , Cattle Diseases/prevention & control , Female , Goat Diseases/parasitology , Goat Diseases/prevention & control , Goats , Ixodidae/classification , Ixodidae/drug effects , Male , Mozambique/epidemiology , Nymph , Prevalence , Rhipicephalus/classification , Rhipicephalus/drug effects , Rhipicephalus/growth & development , Species Specificity , Tick Infestations/epidemiology , Tick Infestations/parasitology , Tick Infestations/prevention & control
20.
Onderstepoort J Vet Res ; 75(2): 103-8, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18788203

ABSTRACT

The species composition and geographic distribution of ixodid ticks infesting domestic dogs owned by people in rural communities and villages in Maputo Province was established by collecting ticks from dogs at each of 27 localities spread throughout the province. Ticks were collected from a total of 132 dogs, and nine species belonging to four genera were identified. One dog was infested with six species, three with five and 13 with four species. Haemaphysalis elliptica followed by Rhipicephalus simus were present on dogs at most localities, and their geographic distribution in Maputo Province has been mapped for the first time.


Subject(s)
Dog Diseases/epidemiology , Ixodidae/classification , Ixodidae/growth & development , Phylogeny , Tick Infestations/veterinary , Animals , Demography , Dog Diseases/parasitology , Dogs , Female , Humans , Ixodes/classification , Ixodes/growth & development , Male , Mozambique/epidemiology , Population Density , Rural Population , Species Specificity , Tick Infestations/epidemiology
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