Glands Of Ticks Research Articles

«CANDIDATUS MIDICHLORIA MITOCHONDRII»: A NEW MEMBER OF ORDER RICKETTSIALES, ENDOSYMBIONT OF IXODES RICINUS TICK

Candidatus Midichloria mitochondrii is the sheep tick Ixodes ricinus endosymbiont. This unique bacteria can occupy and persist within the mitochondria of animals. I. ricinus is an important vector of human pathogens in natural focal of infections. Candidatus M. mitochondrii found in the intermembrane space of mitochondria and in the cytoplasm of ovarian cells in 100% females of I. ricinus. The bacteria contain flagella in the salivary glands of ticks. Candidatus M. mitochondrii has two groups of unique genes for the members of the order Rickettsiales (cbb3 cytochrome oxidase and flagellin), which allows it to play an important role in embryogenesis of the I. ricinus ticks and cause seroconversion in 58% of patients after ticks bloodsucking. This bacterium formed MALOs group (midichloria and like organisms) with genetically closely related organisms which demonstrated a association with a wide range of host from arthropods to ciliates, amoebae, sponges, fish and various animals and humans. Now there is no data about replication the Candidatus M. mitochondrii in humans and pathogenicity of this microorganism. Although a high percentage of seropositive samples obtained from patients after bloodsucking of I. ricinus in anamnesis, this bacterium cannot yet be regarded as responsible for the pathology as known human pathogenic from order Rickettsi-ales (Rickettsia, Anaplasma and Ehrlichia spp.). Needed to reconsider the attitude to an immune response to the saliva of I. ricinus, taking into account the potential impact of Candidatus M. mitochondrii. It is considered highly possible role of this bacterium in the immune response and immunomodulation in humans with bloodsucking of I. ricinus in anamnesis. DNA of Candidatus M. mitochondrii was the first time detected in I. ricinus ticks from European part of Russia.

Salivary Glands of Female Ticks Rhipicephalus sanguineus Like a Potential Source of Molecules with Inhibitory Action: In vivo study with Walker 256 Tumor Cells

This study evaluated the effects of one or two injection of differents concentrations (0.2 and 0.04μg/μL) of extracts obtained from the salivary glands of female ticks Rhipicephalus sanguineus (Acari: Ixodidae) (Latreille, 1806) also called “brown dog tick” fed for 2 days on the rabbit hosts on the morpho-physiology of the leg musculature of female Wistar rats inoculated with Walker 256 tumor cells. The number of leukocytes and the creatinine levels were quantified for individuals from all groups. The results of both histology and electron microscopy revealed that a single, low-concentration injection of the extract (0.04μg/μL) was more effective in containing tumor invasion and caused less ‘collateral damage’ to the muscle tissue, which was the object of this study. The results also revealed that creatinine levels were higher in rats subjected to both one and two injections of the extract at a concentration of 0.04μg/μL than in those subjected to one and two injections of the extract at the higher concentration (0.2μg/μL), suggesting that in the first group, injection of the extract contributed to maintaining the integrity of the muscle tissue. With regard to the number of leukocytes, the results suggested that in all the inoculated rats (Walker 256 cells), there was a significant increase in the total number of leukocytes. The inoculated rats that received both one and two injections of the extract at a concentration of 0.2μg/μL experienced a significant increase in the number of leukocytes compared with those inoculated but not exposed to the extract; this result can be explained by the fact that beyond the tumor cells, the extract itself acted to boost the defense response at this concentration. However, inoculated rats subjected to injections (one and two) of the extract at a concentration of 0.04μg/μL showed a significant decrease in the total number of leukocytes compared with rats that were only inoculated and those inoculated and injected with the extract at a concentration of 0.2μg/μL. These results reinforced that the extract at the 0.04μg/μL concentration not only acted more effectively to inhibit Walker 256 tumor cells but also did not act as a stressor, because the number of leukocytes was lower. Therefore, the data obtained here indicated that the same molecules or a pool of molecules produced by the salivary glands of ticks belonging to this species have the ability to inhibit tumor growth, while minimizing ‘collateral damage’ to the body.

B36 マダニ唾液腺からのBabesia microtiの検出(一般講演,演題要旨,第58回日本衛生動物学会大会)

B36 マダニ唾液腺からのBabesia microtiの検出(一般講演,演題要旨,第58回日本衛生動物学会大会)

Large dermal gland secretions in ticks (Acari: Ixodidae) provide no water-proofing to the integument

The large dermal glands of ticks release a wax-based fluid that acts in defense (allomone) and prompts ticks to cluster (aggregation-attachment pheromone; clustering ‘alarm’ pheromone). This study investigates whether this secretion protects against dehydration in the lone star tick, Amblyomma americanum. No significant differences were observed in net water loss rates, critical transition temperatures and activation energies for water loss between controls versus ticks that had secreted. Thus, tick secretion is ineffective at retarding water loss through the cuticle and has no apparent role in tick water balance. The role of the large dermal glands appears to be restricted to semiochemical production, implying that these glands are uniquely modified for this function.

Allomonal defence secretions of the American dog tick Dermacentor variabilis (Acari: Ixodidae) promote clustering

The release of the defence secretion from the large wax glands (‘sensilla sagittiformia’) of Dermacentor variabilis ticks modifies the behaviour of other ticks by inducing clustering. A coating of natural tick secretion onto test objects (delipidized ticks, glass beads or filter paper discs) also elicits a clustering response, but a topically applied squalene, its major component, does not have this effect. The clustering response appears to be species specific: D. variabilis cluster on conspecific ticks that secreted but they fail to cluster on Amblyomma americanum or Ixodes scapularis ticks unless coated with secretions from D. variabilis. Volatile components in the defence secretion are involved in recruiting conspecific ticks to those that secreted. When attacked by predatory fire ants, Solenopsis invicta, D. variabilis clustered on individuals that had released the defence secretion. This suggests that the secretion protects ticks from predation by functioning as an alarm pheromone. If confirmed, this is the first report of an alarm pheromone and its glandular source in ticks. The terminology applicable to the integumental glands of ticks is discussed.

Theileria parva carrier state in naturally infected and artificially immunised cattle

Rhipicephalus appendiculatus adult ticks, collected in the field from zebu (Bos indicus) and exotic (Bos tarus) cattle with high antibody titres to Theileria parva schizont antigen, transmitted Theileria parva infection typical of East Coast fever to susceptible cattle. Uninfected R. appendiculatus nymphs applied to naturally recovered zebu and exotic cattle kept under tick-free conditions in the laboratory for 16 and 7 months respectively, transmitted fatal theileriosis to susceptible cattle. Cattle immunised by the infection and treatment method were shown to be carriers of Theileria parva by examination of the salivary glands of ticks applied to them and by tick transmission. Three and 7 months after immunisation, Theileria parva infected lymphocytes were established in vitro from peripheral blood lymphocytes. This was the first demonstration, in vitro, of the existence of schizonts in Theileria parva (East Coast fever) infection carrier status. These studies show that cattle from endemic and epidemic areas of East Coast fever (ECF) become carriers thereby maintaining the T. parva population. The relevance of the findings in this study to the control of ECF by dipping, immunisation and treatment is discussed.

Putative New Expression of Genes in Ixodid Tick Salivary Gland Development during Feeding

Poly(A+) mRNA-enriched fractions from salivary glands of partially fed Amblyomma americanum female ticks were translated in vitro with a rabbit reticulocyte translation system. Translated proteins were labeled with [35S]methionine, separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and identified by autoradiography. Thirty major identifiable polypeptides with molecular weights ranging from 14 to 136 kDa were synthesized from mRNA isolated from salivary glands of ticks weighing less than 100 mg. Polypeptides that comigrated at the same molecular weight were translated by mRNA from ticks at a more advanced stage of feeding (more than 300 mg) as were 8 others with molecular weights of 31, 71, 91, 106, 113, 118, and 128 kDa. Results demonstrated that differential gene expression may be stimulated in the developing salivary glands as the tick feeds.

Correlation between the infection rate of the vector tick, Haemaphysalis longicornis and the parasitaemia of cattle infected with Theileria sergenti.

The infection rate of Theileria sergenti in salivary glands of nymphal Haemaphysalis longicornis which had dropped from cattle showing different piroplasm parasitaemias was examined by the methyl green-pyronin staining method. The results suggested that there was some correlation between parasitaemia and the subsequent infection rate in salivary glands of ticks. It seemed possible that the parasitaemia in cattle, especially the number of parasitized erythrocytes in blood imbibed by ticks, might be an important influence on the number of infected acini of ticks.

Role of Cyclic Nucleotides and Calcium in Controlling Tick Salivary Gland Function

The paired salivary glands of female ixodid ticks are essential organs of osmoregulation. As the female feeds, the rate of salivary fluid secretion increases greatly enabling the tick to concentrate its bloodmeal by returning excess water and ions to the host via the salivary ducts. The glands are controlled by nerves and the neurotransmitter at the neuroeffector junction is dopamine. Cyclic AMP is a “second messenger” of the fluid secretory process. Specific endogenous salivary gland proteins are phosphorylated by cyclic AMP-dependent protein kinases which facilitate in some way the fluid secretory process. Fluid secretory capability and dopamine sensitive adenylate cyclase activity in glands of feeding females are dependent on weight of the feeding tick from which they are obtained. Conversely, cyclic AMP-dependent phosphodiesterase is inversely related to the magnitude of fluid secretory capability of the glands. Deletion of calcium or addition of verapamil to the bathing medium during experiments with isolated glands inhibits dopamine-stimulated fluid secretion. The precise role(s) of calcium in secretion is(are) unknown but it may help regulate cyclic AMP by regulating activator and inhibitor proteins of cyclic AMP phosphodiesterase. The inhibitor modulators are at much higher concentrations in salivary glands of ticks in the rapid phase of feeding.

Identification of Theileria infections in the salivary glands of Hyalomma anatolicum anatoli cum and Rhipicephalus appendiculatus using isoenzyme electrophoresis.

Lysates prepared from the salivary glands of uninfected Hyalomma anatolicum anatolicum and Rhipicephalus appendiculatus and from ticks of these species infected with 2 strains of Theileria annulata and 1 strain of T. parva respectively have been examined for enzyme polymorphism using thin layer starch gel electrophoresis. Representative enzymes from 3 of the major metabolic pathways, the tricarboxylic acid cycle, the glycolytic pathway and the pentose phosphate pathway were investigated. Only 1 enzyme, glucose phosphate isomerase, showed differences between the host cell activity and the parasite activity and also inter- and intraspecific differences between the parasites. This technique represents a useful complement to the present histochemical methods for identification of Theileria infections in the salivary glands of ticks.

Electron microscopic detection of initial and some subsequent developmental stages ofBabesia bigemina in salivary glands of ticks

Electron microscopic detection of initial and some subsequent developmental stages ofBabesia bigemina in salivary glands of ticks

New Cell Types in the Salivary Glands of the Brown Ear Tick, Rhipicephalus appendiculatus Neumann

IN previous literature on the salivary glands of ticks, two types of alveoli have been recognized, namely, the multicellular, granule-secreting and the unicellular, non-granular alveoli. (1, 2, 3) In the multicellular alveoli, two cell types have been distinguished, the ‘Mundungszellen’ with coarse secretory granules and the ‘Funduszellen’ with line secretory granules.(4)