Nazife Yigit

Scorpions are venomous arthropods in Arachnida classis; they are thought to be related with the spiders, ticks and mites. However, scorpions have sensory organs called sensory comb organ (pectine) and their structure are distinctive other relatives. The objective of the present study, is to characterize the morphological and histological features of pectines (sensory comb) organ of scorpion species Mesobuthus gibbosus (Brullé, 1832) (Scorpionidae: Buthidae) were identified by using light microscope and scanning electron microscope (SEM). The pectines were prepared by following routine electron microscope procedures and routine paraffin methods and the sections were stained by hematoxylin-eosin stain. The pectines of M. gibbosus are paired sensory organs located on the ventrolateral of second segments of mesosoma, the comb like each pectin organ consist of marginal lamella, different number of median lamella and teeth. Pectines have several sensory hairs and peg sensilla of tip of th...

The antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of Ocimum basilicum L. were studied. These extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. The results indicated that the methanol extracts of O. basilucum exhibited the antimicrobial activity against tested microorganisms. While the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strains of Pseudomonas aeruginosa, Shigella sp., Listeria monocytogenes, Staphylococcus aureus and two different strains of Escherichia coli. The cells of microorganisms, which were treated and untreated with plant extracts, were observed by using the scanning electron microscope. It was observed that the treated cells were damaged.

The objective of the present study was to describe functional morphological features of venom apparatus in the tube web spider, Segestria florentina (Rossi, 1790) (Araneae: Segestriidae) by using scanning electron microscope (SEM). The venom apparatus is situated in the anterior part of the prosoma, and is composed of a pair of venom glands and chelicerae. The chelicera of S. florentina has two parts: basal segment and a movable articulated apical segment (fang). The cheliceral fang rests in a groove on the basal segment of chelicerae. A venom hole is located on the subterminal part of each fang. A pair of venom glands is completely separate but similar to each other within the prosoma. Each venom gland is surrounded by striated muscle bundles, such as with the capsules. The venom, produced in the venom glands, is carried by venom ducts passing throughout the chelicerae. Each venom gland has its own venom duct, chelicera and fang. The venom is excreted from the venom pore on the sub...

Up to now an increasing number of antibiotic-resistant bacteria have been reported and thus new natural therapeutic agents are needed in order to eradicate these pathogens. Through the discovery of plants such as Crataegus tanacetifolia (Lam.) Pers that have antimicrobial activity, it will be possible to discover new natural drugs serving as chemotherapeutic agents for the treatment of nosocomial pathogens and take these antibiotic-resistant bacteria under control. The objective of the present study was to determine antimicrobial activity and the activity mechanism of C. tanacetifolia plant extract. The leaves of C. tanacetifolia, which is an endemic plant, were extracted using methanol and tested against 10 bacterial and 4 yeast strains by using a drop method. It was observed that the plant extract had antibacterial effects on Bacillus subtilis, Shigella, Staphylococcus aureus, and Listeria monocytogenes among the microorganisms that were tested. Minimum inhibitory concentration (MIC) results obtained at the end of an incubation of 24 h were found to be > or =6.16 mg ml(-1) for B. subtilis, < 394 mg ml(-1) for Shigella, and > or =3.08 mg ml(-1) for L. monocytogenes and S. aureus and minimum bactericidal concentration (MBC) were found as > or =24.63 mg ml(-1) for B. subtilis, > or =394 mg ml(-1) for Shigella, > or =6.16 mg ml(-1) for L. monocytogenes, and > or =98.5 mg ml(-1) for S. aureus. According to the MBC results, it was found that the plant extract had bactericidal effects and in order to explain the activity mechanism and cell deformation of bacterial strains treated with plant extract, the scanning electron microscopy (SEM) was used. The results of SEM showed that the treated cells appeared shrunken and there was degradation of the cell walls. This study, in which the antibacterial effect of C. tanacetifolia was demonstrated, will be a base for further investigations on advanced purification and effect mechanism of action of its active compounds.

Antimicrobial activity of the methanolic extracts of leaves and flowers of D. lamarckii Ivan, (Scophulariaceae), an endemic plant species of Turkey, was tested on ten bacterial and four yeast strains. Effective antibacterial activity was observed in four bacterial strains. Minimum inhibitory concentration (MIC) was calculated by use of liquid culture tests and in all the four effective bacterial strains, the MIC was found to be > or = 199.5 mg/ml. The minimum bactericidal concentration (MBC) of B. subtilis, S. aureus, and L. monocytogenes was calculated to be > or = 199.5 mg/ml, and MBC value for Shigella was calculated as > or = 399 mg/ml.

... Nazife Yigit2, Abdullah Bayram2, Tarik Danisman2, and Zafer Sancak3. ... In recent years, there has been a noticeable increase in studies on spider venoms (Herzig et al., 2004; Kalapothakis et al., 2003; Rash and Hodgson, 2002; King, 2004). ...

Spider venoms are biologically active substances which affect a variety of vital physiological functions in both insects and mammals. The major constituents of spider venoms are protein, polypeptide and polyamine neurotoxins, enzymes, nucleic acids, free amino acids, monoamines and inorganic salts. The identification of the proteins in spider venoms is an essential step for identification of venom. In this study,

The antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of Artemisia dracunculus L. were studied. These extracts were tested against nine bacteria and four yeasts strains by the disc diffusion method. The results indicated that the ...

... Nazife Yigit2, Abdullah Bayram2, Tarik Danisman2, and Zafer Sancak3. ... In recent years, there has been a noticeable increase in studies on spider venoms (Herzig et al., 2004; Kalapothakis et al., 2003; Rash and Hodgson, 2002; King, 2004). ...

Larinioides ixobolus (Thorell, 873) is widely distributed throughout Middle Europe, Turkey and Middle Asia. The morphology of the venom apparatus of L. ixobolus using adult spiders that were collected from Kirikkale (Turkey) were investigated by scanning electron microscopy. The ...

A 69-year-old woman was awakened with redness and swelling of the left upper eyelid a few days before her presentation. She also noticed a dead spider on her bed. Ophthalmic examination revealed severe left periorbital hyperemia, edema and a wide necrotic area on the upper ...