Ozcan Ozkan

Evaluation of scorpion sting incidence in turkey

Scorpion stings are common in Turkey due to its geographical location, climate and socioeconomic structure. Scorpion envenomation cases are a considerable public health problem in all regions of the country. Important health-threatening scorpions in Turkey are Androctonus crassicauda, Leiurus quinquestriatus, Mesobuthus gibbosus and M. eupeus, all of which belong to the Buthidae family. They are described to be potentially dangerous to humans. So far, there is no study about scorpion sting incidence covering all geographical regions of Turkey; therefore, in this study, we analyzed the frequency of scorpion sting cases in the country. A total of 24,261 scorpion sting cases were reported during 2005. Most of which (about 80%) occurred in the Southeastern Anatolia (30.4%), Mediterranean Sea (24.9%) and Aegean regions (23.5%), where medically important scorpion species are found. The sting cases mostly occurred during the summer period. Our results suggest that scorpion stings are an important problem in Turkey. This simple descriptive study will help develop interventions to prevent scorpion stings, which should take local sting cases into consideration.

The neutralizing capacity of Androctonus crassicauda antivenom against Mesobuthus eupeus scorpion venom.

Scorpion envenomations are considerable health problem in tropical and subtropical regions. There are approximately 1,500 species of scorpions worldwide. The number of dangerous species in the Buthidae family is significantly higher than in other families of scorpions. Mesobuthus eupeus is a member of Mesobuthus genus, Buthidae family. In this study, the potency and para-specific activities of Androctonus crassicauda antivenom were investigated against M. eupeus scorpion venom. The median lethal dose of M. eupeus and A. crassicauda scorpion venoms were found to be 0.18 mg/kg, 15.45 microg/kg by i.c.v injection route. The antivenom showed neutralization effect against the venoms of M. eupeus. One milliliter of A. crassicauda antivenom neutralizes 464LD(50) of M. eupeus and 940LD(50)A. crassicauda venom on mice. Western blotting demonstrated immunologic reaction with the venoms. The monovalent antivenom has immunoactivity and neutralizing capacity to the scorpion venoms. This study indicates that the antivenom produced by Refik Saydam Hygiene Center could be used for the treatment of M. eupeus stings in Turkey.

Study of the relationship between Androctonus crassicauda (Oliver, 1807; scorpiones, buthidae) venom toxicity and telson size, weight and storing condition

Scorpions are included in the order Scorpiones; class Arachnida. Lethal scorpions are mostly of the Buthidae family. Among these, species belonging to Androctonus, Leiurus and Mesobuthus genera cause most scorpion envenomations in Turkey. This study was performed aiming the production of antivenom by using Androctonus crassicauda telsons. Venom toxicity is related to telson weight, size, and storing condition (open or closed). Telsons of A. crassicauda were collected in Southeastern Anatolia (especially in Harran town, Sanliurfa), Turkey. They were separated according to weight, size, and storing condition - open (a) and closed (b). Venom solution was prepared by maceration of telsons. Swiss albino mice were used to determine the lethal dose 50% (LD50), which was as follows: Group 1a - 2.31mg; Group 1b - 2.66mg; Group 2a - 2.32mg; Group 2b - 2.66mg; Group 3a - 6.66mg; Group 3b - 6.88mg. Among the groups of telsons, the first and the second groups showed different characteristics. However, there were no differences between their toxicity. In the third group, a fourfold amount of telsons was used for toxicity. In other words, telsons weighting from 19.99 to 20mg (first group) and from 29.99 to 30mg (second group) presented similar LD50 values, and telsons weighting from 10 to 19.99mg (third group) showed a fourfold higher LD50 value. This difference was caused by the maturity of scorpions and venom toxicity was related to their size. The first and second groups were considered to be mature and the third group, not adult. Therefore, we can conclude that obtaining open telsons due to environmental factors was not effective for venom toxicity.

Determination of potency and paraspecific effects of Androctonus crassicauda (Olivier, 1807) antivenom against Mesobuthus gibbosus (Brullé, 1832) venom (Scorpiones: Buthidae)

Scorpion envenomation remains a real health problem in many countries. In scorpionism cases, it is often recommended that patients be treated with species-specific antivenom. Androctonus crassicauda venom has been used as antigen for antivenom production in Turkey, where this antivenom, called Turkish antivenom, has also been effective in the treatment of envenomation caused by species other than A. crassicauda. The present study aimed at determining the paraspecific effects and potency of the Turkish antivenom against Mesobuthus gibbosus (Brulle, 1832) venom. To assess the venom toxicity and the antivenom efficacy, we determined the Minimum Lethal Dose (MLD) and the Minimum Effective Dose (MED) instead of LD50 and ED50, respectively. Androctonus crassicauda antivenom was capable of neutralizing M. gibbosus venom (20 MLD). This was the first study indicating that A. crassicauda antivenom can be used for the treatment of Mesobuthus gibbosus stings, especially in Aegean Region, Turkey.

Evaluation of the neutralizing capacity of Androctonus crassicauda (Olivier, 1807) antivenom against Leiurus quinquestriatus (Ehrenberg, 1928) venom (Scorpiones: Buthidae)

The two most venomous species of the family Buthidae, Leiurus quinquestriatus and Androctonus crassicauda, are found in Africa and in the Middle East. Potency and paraspecific activities of A. crassicauda antivenom (RSHC anti-Ac) were tested against L. quinquestriatus venom. The sera produced by Refik Saydam Hygiene Center (RSHC) showed strong reactivity against the venoms of A. crassicauda and L. quinquestriatus in western blotting and dot-blot analysis. RSHC anti-Ac presents immunoactivity and neutralizing potential against Leiurus quinquestriatus venom. Neutralization capacity of antivenom was found to be 400 µL against 40 minimum lethal doses (MLD) of A. crassicauda scorpion venom and 10 MLD of L. quinquestriatus venom. This study indicates that the RSHC anti-Ac could be used for treating L. quinquestriatus stings.

Parametric values of Androctonus crassicauda (Oliver, 1807) (scorpiones: buthidae) from Turkey

The aim of the present study was to analyze the parametric values of Androctonus crassicauda (Oliver, 1807), the most significant scorpion species in Turkey. For this purpose, 11 male and 11 female A. crassicauda specimens were collected from Sanliurfa region. The body parts most important for species identification were measured by using sensitive calipers. Differences between sexes were statistically significant for pectinal organ length (female: 7.50±1.26mm;male: 8.63±1.05mm; p=0.033), pectinal tooth count (female: 25.36±0.86;male: 33.36±0.80; p=0.000), and carapace width (female: 10.27±1.19mm;male: 9.09±0.73mm; p=0.000). However, body length (female: 90.09±14.74mm;male: 82.95±5.40mm), abdomen width (female: 12.09±1.90mm;male: 11.09±0.88mm), and metasoma length (female: 43.09±3.08mm;male: 44.63±6.50mm) were not significantly different between sexes.

Effects of Androctonus crassicauda (Olivier, 1807) (scorpiones: buthidae) venom on rats: correlation among acetylcholinesterase activities and electrolytes levels

Scorpions can be considered living fossils because they have changed so little during the last 400 million years. They are venomous arthropods of the Arachnida class and regarded as relatives of spiders, ticks and mites. The aim of the present study was to evaluate the toxicity of Androctonus crassicauda (Olivier, 1807) venom and its effects on the acetylcholinesterase (AchE) activity and on electrolytes levels in rats. Animals were divided into seven groups of five rats each. Test groups received 250µg/kg of venom solution while control group was treated with 200µl of physiological saline solution (PSS). Blood samples were collected from the animals on the 1st, 2nd 4th, 8th, 12th, and 24th hours after subcutaneous injection of venom. Animals were monitored for 24 hours. Androctonus crassicauda venom significantly reduced AchE activity on the 12th hour when compared with control group. A statistically negative correlation between Na+ and K+ (p<0.05) and a positive correlation between Na+ and CL- (p<0.001) ions levels were observed after the administration of A. crassiccauda venom to rats. We can conclude that the differences in the electrolytes levels are due to acute renal failure, since elimination of toxin occurs primarily via the kidney.

A study on the genetic diversity of Androctonus crassicauda (Olivier, 1807; Scorpiones: Buthidae) from Turkey

Mitochondrial DNA (mtDNA) has been widely employed in phylogeographic and phylogenetic studies. In the present study, the genetic identification of the scorpion Androctonus crassicauda (Olivier, 1807) was carried out by using the 16S mitochondrial gene, since this scorpion represents the most important species in Turkey regarding scorpionism and antivenom production. Two genetic groups were found according to the sequence analysis results, while five different loci at the nucleotide level presented genetic variation in the 16S region when compared to a known A. crassicauda sequence data (GenBank, AJ277598). Nucleotide variations found in the current work constitute the first descriptive report for A. crassicauda. Moreover, future studies may enlighten the genetic and venom composition variations for this scorpion species.