Ahmet Özbilgin

A comparison of metronidazole and single-dose ornidazole for the treatment of dientamoebiasis

Recent reports of the pathogenic potential of Dientamoeba fragilis have underlined the need for an effective treatment against this colon-dwelling protozoan. Metronidazole is a well-known and commonly used anti-protozoal agent, but another 5-nitroimidazole derivative, ornidazole, may be preferable, where available, because of its longer half-life and fewer side-effects. This study compared the efficacies of metronidazole and ornidazole in a group of 112 patients with dientamoebiasis. Patients were randomised into two treatment groups: group 1 (n = 56) received metronidazole for 5 days, 20 mg/kg/day for children and 1.5 g/day for adults, in three oral doses, while group 2 (n = 56) received a single oral dose of ornidazole, 30 mg/kg for children and 2 g for adults. Stool samples were examined on the seventh and 14th days after treatment, and clinical symptoms were recorded to evaluate the efficacy of treatment. A statistically significant difference was recorded between the efficacies of ornidazole and metronidazole, both parasitologically (92.9% vs. 69.6%, p 0.001) and clinically (96.4% vs. 76.8%, p 0.001). Patients in the metronidazole group reported more side-effects than patients in the ornidazole group, none of whom required termination of treatment. These results suggest that single-dose ornidazole may be an important alternative agent for the treatment of dientamoebiasis.

Efficacy of azithromycin in a murine toxoplasmosis model, employing a Toxoplasma gondii strain from Turkey.

A murine toxoplasmosis model with Balb/C mice was used to investigate the therapeutic and prophylactic efficacy of azithromycin in a native strain of Toxoplasma gondii. Initially, seven groups--four studies and three controls--were established and 10(3) tachyzoites of this native strain of T. gondii were injected intraperitoneally to the mice in groups 1, 2, 3, 4 and 7. Azithromycin was given to groups 1-4 at different times of infection orally between 100 and 300 mg/kg/day for 10 days. Azithromycin was found to be effective at 200 mg/kg/day and above in the prophylaxis, at 250 mg/kg/day and above in the treatment of toxoplasmosis. These results suggest that azithromycin is effective in the prophylaxis and early infection of a highly virulent strain of T. gondii, and it doubled the survival time in the late infection. Azithromycin could be an alternative treatment regimen for human toxoplasmosis, if supported by further clinical investigations.

Giardiasis Treatment in Turkish Children with a Single Dose of Ornidazole

This study was designed to compare the treatment efficacy of single dose of ornidazole with 5 d treatments of ornidazole and metronidazole in children with giardiasis. 175 children, between 2 and 15 y old, whose stool samples were found to be positive for Giardia lamblia cysts and/or trophozoites by either saline-Lugol, formalin-ethyl acetate or trichrome staining, were enrolled in the study. Of these children, 105 were treated with a single dose of ornidazole: 35 with 30 mg/kg, 35 with 25 mg/kg and 35 with 20 mg/kg; 35 were treated with 25 mg/kg per day of ornidazole for 5 d in 2 doses and 35 children were treated with 20 mg/kg per day metronidazole for 7 d in 3 doses. All cases were examined on the 7th, 10th and 14th days after treatment by the same methods; clinical symptoms were also evaluated. Giardia lamblia was eradicated in 34 of 35 (97%), 34 of 35 (97%) and 33 of 35 (94%) patients treated with 30, 25 and 20 mg/kg single doses of ornidazole, respectively. Eradication was achieved in all 35 patients treated with 25 mg/kg per day ornidazole for 5 d and in 31 of 35 (89%) patients treated with metronidazole. There was no statistically significant difference among doses of ornidazole (p > 0.05); however, all ornidazole treatment regimens were significantly more effective than metronidazole treatment (p < 0.05). No important side-effects were detected in any patients and clinical symptoms disappeared in all. Single-dose ornidazole treatment could be considered as a proper and effective alternative method for the treatment of giardiasis in children.

Cutaneous Leishmaniasis Infection in Balb/c Mice Using a Leishmania tropica Strain Isolated From Turkey

Leishmania tropica, which is endemic in Turkey, is the causative agent of cutaneous leishmaniasis. Leishmania tropica promastigotes (2 × 107) isolated from a patient with dermal leishmaniasis and reproduced in NNN medium were inoculated subcutaneously into the footpads of 10 Balb/c mice. Cutaneous leishmaniasis developed on the footpads of 4 mice approximately 45 days later. Leishmania tropica amastigotes were observed in smear slides and then cultivated in NNN medium. Balb/c mice are a suitable laboratory model for this isolate of L. tropica and thus a source of amastigotes for studies on the immunology, chemotherapy, and pathogenicity of cutaneous leishmaniasis.

Leishmaniasis in Turkey: first clinical isolation of Leishmania major from 18 autochthonous cases of cutaneous leishmaniasis in four geographical regions.

To report isolation of Leishmania major strains obtained from 18 Turkish autochthonous cutaneous leishmaniasis (CL) patients infected with L. major between 2011 and 2014.

Incidence of giardiasis among siblings in Turkey

Abstract Background : Giardiasis, a common infection among children, is caused by a flagellated protozoan called Giardia lamblia. It is well known to be contagious in common living places. This is an epidemiologic study investigating the incidence of giardiasis among the siblings of patients with giardiasis living in the same household.

Epidemiological analysis of Leishmania tropica strains and giemsa-stained smears from Syrian and Turkish leishmaniasis patients using multilocus microsatellite typing (MLMT)

Turkey is located in an important geographical location, in terms of the epidemiology of vector-borne diseases, linking Asia and Europe. Cutaneous leishmaniasis (CL) is one of the endemic diseases in a Turkey and according to the Ministry Health of Turkey, 45% of CL patients originate from Şanlıurfa province located in southeastern Turkey. Herein, the epidemiological status of CL, caused by L. tropica, in Turkey was examined using multilocus microsatellite typing (MLMT) of strains obtained from Turkish and Syrian patients. A total of 38 cryopreserved strains and 20 Giemsa-stained smears were included in the present study. MLMT was performed using 12 highly specific microsatellite markers. Delta K (ΔK) calculation and Bayesian statistics were used to determine the population structure. Three main populations (POP A, B and C) were identified and further examination revealed the presence of three subpopulations for POP B and C. Combined analysis was performed using the data of previously typed L. tropica strains and Mediterranean and Şanlıurfa populations were identified. This finding suggests that the epidemiological status of L. tropica is more complicated than expected when compared to previous studies. A new population, comprised of Syrian L. tropica samples, was reported for the first time in Turkey, and the data presented here will provide new epidemiological information for further studies.

[Successful treatment of cutaneous leishmaniasis with amphotericin B; a case of unresponsive to pentavalent antimony therapy].

Cutaneous Leishmaniasis (CL) is a skin infection caused by various species of Leishmania parasites, which is transmitted by infected Phlebotomus sandfly bites. Pentavalent antimonials (meglumine antimoniate and sodium stibogluconate) are used for the treatment of adult CL patients as an effective and safe method. Liposomal amphotericin B is an alternative for the treatment of choice in cutaneous leishmaniasis cases which pentavalan antimony contraindicated or unresponsive to pentavalent antimony therapy. In this study, successful treatment with systemic liposomal amphotericin B of a cutaneous leishmaniasis case developing local side effects related both systemic and intralesional meglumine antimonate treatment was presented.

Leishmaniasis in Turkey: Visceral and cutaneous leishmaniasis caused by Leishmania donovani in Turkey

In Turkey, the main causative agents are Leishmania tropica (L. tropica) and Leishmania infantum (L. infantum) for cutaneous leishmaniasis (CL) and L. infantum for visceral leishmaniasis (VL). In this study, we investigated leishmaniasis cases caused by L. donovani and established animal models for understanding its tropism in in vivo conditions. Clinical samples (lesion aspirations and bone marrow) obtained from CL/VL patients were investigated using parasitological (smear/NNN) and DNA-based techniques. For species identification, a real time ITS1-PCR was performed using isolates and results were confirmed by hsp70 PCR-N/sequencing and cpb gene PCR/sequencing in order to reveal Leishmania donovani and Leishmania infantum discrimination. Clinical materials from CL and VL patients were also inoculated into two experimental groups (Group CL and Group VL) of Balb/C mice intraperitoneally for creating clinical picture of Turkish L. donovani strains. After 45days, the samples from visible sores of the skin were taken, and spleens and livers were removed. Measurements of the internal organs were done and touch preparations were prepared for checking the presence of amastigotes. The strains were isolated from all patients and amastigotes were seen in all smears of the patients, and then isolates were immediately stored in liquid nitrogen. In real time ITS1-PCR, the melting temperatures of all samples were out of range of L. infantum, L. tropica and L. major. Sequencing of hsp70 PCR-N showed that all isolates highly identical to previously submitted L. donovani sequences in GenBank, and cpb gene sequencing showed five isolates had longer cpbF allele, whereas one isolate contained a mixed sequence of both cpbF and cpbE. All mice in both experimental groups became infected. Compared to controls, the length and width of both liver and spleen were significantly elevated (p<0.001) in both groups of mice. However, the weight of the liver increased significantly in all mice whereas the weight of spleen increased only in VL group. Amastigotes were also seen in all touch preparations prepared from skin sores, spleen and liver. L. donovani strain was isolated from autocutaneous a VL patient first time in Turkey. Animal models using clinical samples were successfully established and important clinical differences of the isolated strains were observed.

Evaluation of 131I-Pentamidine for scintigraphy of experimentally Leishmania tropica-infected hamsters

Abstract We aimed to assess the ability of 131I-Pentamidine scintigraphy to detect the lesions of Leishmania tropica infection. An experimental model of cutaneous leishmaniasis was developed. The presence of cutaneous leishmaniasis was confirmed. Pentamidine was radioiodinated with 131I. The radiolabeled pentamidine was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability. 131I-Pentamidine (activity: 18.5 MBq/100 µl) was injected intracardiacally into infected hamsters. Static whole body images of the hamsters were acquired under the gamma camera at 5 and 30 min, 2, 6 and 24 h following the administration. On the scintigrams, anatomically adjusted regions of interest (ROIs) were drawn over the right feet (target) and left feet (not-target) and various organs. Accumulation of 131I-Pentamidine at sites of infection is expressed as the target to non-target (T/NT) ratio. The results T/NT ratio decreased with time. In concluding the 131I-Pentamidine has poor sensitivity in detection of L. tropica infection.