Browsing by Author "Zeyrek, Fadile Yildiz"

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Determination of Antimony Resistance Mechanism of Leishmania tropica Causing Cutaneous Leishmaniasis in Turkey
(ANKARA MICROBIOLOGY SOC, 2020-01-01) Ozbilgin, Ahmet; Zeyrek, Fadile Yildiz; Guray, Melda Zeynep; Culha, Gulnaz; Akyar, Isin; Harman, Mehmet; Ozbel, Yusuf; Ertabaklar, Hatice; Cavus, Ibrahim; Gunduz, Cumhur
World Health Organization reported that approximately one billion people are at risk in endemic areas, one million cases of cutaneous leishmaniasis (CL) and approximately 300,000 cases of visceral leishmaniasis (VL) were reported per year in the last five years. The number of deaths due to VL is reported to be approximately 20,000 per year. Approximately 2500 cases/year have been reported as CL, caused by Leishmania tropica and Leishmania infantum, in Turkey. The significant increase observed in many cities mainly in the provinces of Mediterranean and Aegean regions in cases and foci in recent years, suggests that there may be an increase in this infections in the following years as well. In Turkey, the causative agent of CL is L.tropica and meglumine antimoniate is used in the treatment of CL. We aimed to determine antimony resistance genes specific for L.tropica by comparing the gene and protein expressions of antimony-resistant and non-resistant L.tropica strains. Ltropica isolates obtained from 3 CL patients without antimonate resistance from Aegean, Mediterranean and Southeastern regions of Turkey were provided to transform into 3 resistant isolates against meglumine antimony in the laboratory conditions. Gene expression alterations by microarray method
Diversity of Leishmania Strains Isolated from Cutaneous Leishmaniasis Patients in Turkey and its Reflection to Clinics in Mice Model
(ANKARA MICROBIOLOGY SOC, 2020-01-01) Ozbilgin, Ahmet; Culha, Gulnaz; Guray, Melda Zeynep; Zeyrek, Fadile Yildiz; Akyar, Isin; Toz, Seray; Ural, Ipek Ostan; Kurt, Ozgur; Kocagoz, Tanil; Cavus, Ibrahim; Gunduz, Cumhur
Although asexual reproduction has been attributed to Leishmania species, genetic exchange has recently been demonstrated, which helped emerging of hybrid isolates. Situated on the crossroads between three continents, Leishmania hybrids may be present in Turkey. In Turkey, visceral leishmaniasis caused by Leishmania infantum is less common, while cutaneous leishmaniasis (CL) caused by Leishmania tropica and L.infantum could reach 2500 reported cases a year. Our aim was to investigate genetic variability of local Leishmania species and presence of hybrid Leishmania strains in Turkey. Twenty CL patients from Sanliurfa and Hatay, where only L.tropica and both L.tropica and L.infantum cause CL, respectively, were registered equally. All isolates were assessed with real-time polymerase chain reaction (Rt-PCR), isoenzyme analysis, gene sequencing, two-dimensional gel electrophoresis (2D-PAGE) and MALDI-TOF/TOF-MS followed by in vivo analyses on mouse model. Identification of differentially expressed proteins was performed. These proteins were confirmed by sequence analysis. All isolates from Sanliurfa were found to be L.tropica which caused cutaneous infection in mice. However, one of 10 isolates from Hatay was found as Leishmania major which caused cutaneous infection. Five isolates were found as L.tropica with Rt-PCR and gene sequencing, one of which had one different protein from the reference L.tropica strain and caused cutaneous infection. Four of the five isolates had five different proteins compared to reference strain and caused both cutaneous and visceral infections. Remaining four isolates showed double melting curves in Rt-PCR, which were concordant with L.tropica and L.infantum. Their sequencing and isoenzyme analyses indicated them as L.infantum. They had six different proteins compared to reference L.infantum strain and caused cutaneous and visceral infections. It is concluded that the isolates with different proteins were hybrid Leishmania species. In the present study, outcomes of the proteomics, genomics, clinical manifestations and tissue tropism on animal models were evaluated together for the first time. In addition to L. tropica and L.infantum, L.major was identified as a causative agent for CL and hybrids of Linfantum/tropica were also shown to be present.
In Vitro Efficacy of the Venome of Black Scorpion (Androctonus crassicauda) on Leishmania tropica Promastigotes
(ANKARA MICROBIOLOGY SOC, 2021-01-01) Zeyrek, Fadile Yildiz; Toprak, Sahin; Okullu, Sinem Oktem; Gurses, Gulcan; Doni, Nebiye Yentur; Kurt, Ozgur
Scorpion venom is a substance that shows strong neurotoxic effects with its complex protein content and thus plays an important role for the scorpion in catching and digesting the hunt. Human body stung by a scorpion can show life-threatening systemic effects in a short time, ranging from erythema, pain, edema and local fever to abdominal pain, nausea and vomiting, diplopia and even coma. Scorpion venome is known to possess antimicrobial activity, and some of its compounds have potent antibacterial and antifungal activities. Leishmaniasis is a common vector-borne parasitic infection caused by Leishmania sp. protozoa and can lead skin, mucosa and fatal internal organs involvement in patients. There is a need for new drugs in the treatment of leishmaniasis, because it has been documented lately that there is a growing resistance against antimonial compounds which have been used in its treatment for decades. Leishmania species are known to be susceptible to antimicrobial peptides that act as ion-channel inhibitors, which are known to be present in scorpion venome. In this study, it was aimed to investigate the anti-leishmanial activity of scorpion venome extract obtained from Androctonus crassicauda species in our country. In this context, Leishmania tropica promastigotes which were thawed from liquid nitrogen in our laboratory and first grown in NNN and then RPMI-1640 media, were exposed to different dilutions of the extract containing A.crassicauda venom and meglumine antimonate used in the standard treatment of leishmaniasis and the efficacies on the promastigotes were compared and measured in vitro. This was followed by XTT cell viability test, which assessed whether anti-leishmanial dose of the extract was lethal for human cells or not. Trials showed that the half maximal inhibitory concentration (IC50) values of the venome extract and meglumine antimoniate were 18.12 mu g/ml (17.33-18.94) and 8.411 mu g/ml (7.922-8.927), respectively. This preliminary study showed that scorpion venome can be lethal on L.tropica promastigotes in vitro, on relatively higher doses compared to meglumine antimonate. Next step will be to determine the anti-leishmanial proteins in the extract and thus to identify new drug candidates with more specific studies.