Kemal Altas
Istanbul University
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Featured researches published by Kemal Altas.
Vector-borne and Zoonotic Diseases | 2011
Aysen Gargili; Kenan Midilli; Onder Ergonul; Sevgi Ergin; Hatice Alp; Zati Vatansever; Selma Iyisan; Çiğdem Cerit; Gülden Yilmaz; Kemal Altas; Agustín Estrada-Peña
A survey of ticks from domestic ruminants, together with a serosurvey in humans was conducted in Thrace (northwestern Turkey) to evaluate the prevalence of Crimean-Congo hemorrhagic fever virus (CCHFV) in ticks and humans. More prevalent ticks were Hyalomma marginatum, Hyalomma aegyptium, Rhipicephalus bursa, and Rhipicephalus (Boophilus) annulatus, with low numbers of Dermacentor marginatus, Rhipicephalus sanguineus group, and Ixodes ricinus. No differences in the tick faunal composition were found among surveyed provinces. CCHFV was detected using specific primers for strains belonging to both Europe 1 and Europe 2 clades in a total of 15 pools of ticks collected in nine localities. The maximum likelihood estimate of infection rate was calculated as 0.72/100 ticks (95% CI = 0.42-1.16). Viral RNA was observed only in H. marginatum, R.(B.) annulatus, and R. bursa with overall maximum likelihood estimate infection rates being 0.93 (95% CI = 0.35-2.05), 0.74 (95% CI = 0.24-1.78), and 1.67 (95% CI = 0.69-3.46), respectively. The surveyed region is the only place where both viral strains are circulating together in nature in Turkey. Results from serosurvey on 193 samples from three localities in the region showed that immunoglobulin M and immunoglobulin G rates are compatible with an epidemiological situation in which the virus has been present for a long time and is not the result of a recent invasive event from the main epidemic center in Anatolia (north-central Turkey). Seropositivity rates cannot be compared against the tick faunal composition, because of the homogeneity in the results about tick surveys. The high rate of seropositivity, and the prevalence of CCHFV in both Europe 1 and 2 clades among the ticks, but few clinical cases suggest that the circulation of both viral strains may confer protection against the CCHFV infection.
Chemotherapy | 2007
Fatma Koksal; N. Oguzkurt; Mustafa Samasti; Kemal Altas
The aim of this study was to determine the prevalence and the resistance patterns of Aeromonas spp. in drinking water in Istanbul, Turkey. We investigated a total of 1,680 drinking water samples (840 tap water and 840 domestic water tank samples) for Aeromonas strains between June 2002 and October 2005. A total of 147 Aeromonas strains were isolated from 49 (6%) of 840 tap water samples and from 98 (12%) of 840 domestic water tank samples. Antibiotic susceptibility of Aeromonas strains was determined by the disc diffusion method, according to the CLSI (Clinical Laboratory Standards Institute) recommendation. Among the 147 Aeromonas strains, the prevalence was: A. hydrophila 68 (46%), A. sobria 50 (34%), A. caviae 11 (8%), A. salmonicida 9 (6%), A. veronii 5 (3%) and A. jandaei 4 (3%). Approximately 55% of the strains were resistant to ampicillin, 48% to erythromycin, 41% to amoxicillin-clavulanic acid, 28% to ceftazidime, 27% to cefoxitin, 26% to ceftriaxone and cefotaxime, 22% to piperacillin, 14% to trimethoprim-sulfamethoxazole, 12% to tetracycline, 11% to aztreonam, 8% to meropenem, 6% to imipenem, 2% to nalidixic acid, 1% to ciprofloxacin, tobramycin and gentamicin. None of the strains were resistant to amikacin and netilmicin. In conclusion, Aeromonas spp. isolated from drinking water in Istanbul have a resistance potential and the antibiotic resistance rates of A. hydrophila, A. sobria and A. caviae were usually higher than those of other Aeromonas strains. It should be kept in mind that these microorganisms in drinking water might be a potential risk for public health.
Medical Mycology | 2009
A. Serda Kantarcioglu; Tiraje Celkan; Ayhan Yücel; Yuzuru Mikami; Sebuh Kurugoglu; Hiroki Mitani; Kemal Altas
We report the repeated isolation for Trichoderma.harzianum, a rare opportunistic pathogen from three sets of each of the following clinical samples; blood serum, skin lesions, sputum and throat of a pediatric ALL patient with neutropenia. The definition of invasive fungal infection requires evidence of the presence of fungal elements in tissue samples, in addition to the isolation of suspected etiologic agent in culture. However, invasive procedures are not always applicable due to several factors, as for example in our case, the poor general status of the individual patient or thrombocytopenia. The present paper also emphasizes the problems encountered in obtaining appropriate samples and diagnosing invasive fungal disease in immunocompromised patient populations, including those with hematological malignancy. Three cases involving T. harzianum, including this one, have been described thus far in the literature. All were fatal and the fungus was resistant to antifungal therapy. A critical review of the other two cases of Trichoderma infections in humans is provided.
Auris Nasus Larynx | 2010
Melih Güven Güvenç; Kenan Midilli; Ender Inci; Mert Ahmet Kuskucu; Rauf Tahamiler; Emel Özergil; Sevgi Ergin; Mehmet Ada; Kemal Altas
OBJECTIVE To investigate the presence of Chlamydophila pneumoniae and other bacterial pathogens in middle ear effusion samples obtained from children with otitis media with effusion (OME). MATERIALS AND METHODS Twenty-eight children (mean age 7.03; standard deviation 2.18) with OME unresponsive to medical therapy were included in the study. All of the children underwent ventilation tube insertion under general anesthesia. Eighteen patients were bilaterally affected whereas 10 children had unilateral disease. The middle ear fluids (46 samples in total) were collected during ventilation tube insertion, and were evaluated subsequently for the presence of C. pneumoniae and other bacterial pathogens using polymerase chain reaction (PCR). RESULTS Although all samples were negative for C. pneumoniae, bacterial DNA was detected in 21 of 46 samples. Overall 40% of the patients (4/10) with unilateral involvement, and 61% of the patients (11/18) with bilateral involvement were positive for bacterial DNA. In 6 patients with bilateral OME bilateral samples were positive, whereas 5 patients with bilateral OME showed only unilateral positivity. According to the results of DNA sequencing analysis, all of the positive samples harbored only one bacterial species. In 12 of 46 samples Alloiococcus otitidis DNA (26%), in 7 Haemophilus influenzae DNA (15%), in one Streptococcus pneumoniae DNA (2%) and in one Moraxella catarrhalis DNA (2%) were present. CONCLUSIONS Our findings support that C. pneumoniae does not seem to have a role in OME in children whereas A. otitidis was found to be more frequent than the other common pathogens. Further studies are required to elucidate the exact pathogenetic role of these microorganisms in OME.
Medical Mycology | 2007
A. Serda Kantarcioglu; Teun Boekhout; G. Sybren de Hoog; Bart Theelen; Ayhan Yücel; Tuba R. Ekmekci; Bettina C. Fries; Reiko Ikeda; Adem Koslu; Kemal Altas
Environmental fungi, in particular primary pathogens and Cryptococcus spp. can be responsible for skin lesions mimicking sporotrichosis. In this paper, we report a case of subcutaneous cryptococcosis in an apparently healthy, young male patient due to a non-C. neoformans Cryptococcus species, C. diffluens. The isolate showed in vitro phenotypic switching that may affect virulence and host inflammatory and immune responses, and in vitro resistance to amphotericin B and 5-flucytosin. This species shares several phenotypic traits with C. neoformans, and, therefore, decisive diagnosis should be based on biopsy and culturing results followed by molecular identification.
Medical Mycology | 2006
A. Serda Kantarcioglu; Mustafa Gulenc; Ayhan Yücel; Tugba Taskin; Damlanur Sakiz; Kemal Altas
We describe a cryptococcal infection localized in the parotid gland of an otherwise healthy 72-year-old woman. The patient presented with a painful, approximately 4.5 cm diameter mass in the anterior region of her right ear. Her symptoms were mild and uncharacteristic. The patient had previously fallen on her face in her garden, causing the loss and breakage of her dentures. Since the soil of the garden contained chicken droppings, it is quite likely that the oral prothesis became contaminated on contacting the soil. The fungus probably entered the parotid gland through the traumatization of the posterior lateral wall of her oral cavity by her broken denture. Numerous intra- and extracellular cryptococcal yeast cells were observed in both histopathological and mycological slide preparations. The yeastlike fungus was recovered in cultures inoculated with tissue collected through three biopsies of her parotid region. The isolates were identified as Cryptococcus neoformans by classical mycology methods and found to be susceptible, in vitro, to fluconazole, amphotericin B and flucytosine. Fluconazole treatment (400 mg/d, for 6 months) was started and the patients facial swelling resolved and the pain significantly reduced within 5 weeks of the initiation of treatment. While fungal infection of the parotid gland have been reported, to our knowledge, this is the first description of a non-disseminated primary parotid infection due to C. neoformans.
Chemotherapy | 2003
Hüseyin Çakan; Erdal Polat; Bekir Kocazeybek; Pelin Ocal; Ismail Cepni; Mustafa Aslan; Funda Salihoğlu; Kemal Altas
In this study, a total of 647 vaginal discharge samples were examined. Ureaplasma urealyticum growth was seen in 68 samples (10.5%). The antibiotic sensitivity of 30 types of U.urealyticum was determined with the E-test and agar dilution method. With the agar dilution method, all types were sensitive to ciprofloxacin and ofloxacin (MIC 0.94 µg/ml), tetracycline (MIC 0.125 µg/ml) and doxycycline (MIC 0.125 and 0.190 µg/ml). Furthermore, with the agar dilution method, 18 types (60%) were resistant to roxithromycin and 12 (40%) were sensitive (MIC 12 µg/ml); 3 types (10%) were resistant to erythromycin and 27 (90%) were sensitive (MIC 12 µg/ml); 9 types (30%) were resistant to clarithromycin and 21 (70%) were sensitive (MIC 12 µg/ml), and all types were sensitive to azithromycin (MIC 14 µg/ml).
Medical Mycology | 2009
A. Serda Kantarcioglu; Richard C. Summerbell; Deanna A. Sutton; Ayhan Yücell; Ebru Sarikaya; Gültekin Kaner; Aydin Iscimen; Kemal Altas
Fusarium species are hyaline hyphomycetes widely distributed in nature and documented agents of both superficial and systemic infections in humans. In this paper, we report a darkly-pigmented and initially non-sporulating isolate in the Fusarium solani species complex (FSSC) causing a post-traumatic sporotrichoid infection in an otherwise healthy, male patient. Sequencing of multiple loci showed that the isolate represented an otherwise unknown lineage, possibly corresponding to a separate species, within the multi-species F. solani complex. In prolonged culture, the non-sporulating isolate produced revertant wild-type subcultures with typical Fusarium conidiation. This suggests that the original dense, dark, non-sporulating isolate was a host-adapted form selected in vivo for characters compatible with human pathogenicity. The production of such forms by Fusarium species is increasingly recognized now that sequencing has allowed the identification of highly atypical isolates. In vitro antifungal susceptibility of the isolate was investigated against seven conventional and two newly approved antifungal agents. The isolate showed in vitro resistance to amphotericin B, but appeared susceptible to itraconazole and terbinafine. A cure was ultimately achieved with combined terbinafine/itraconazole therapy with prolonged itraconazole follow-up therapy.
Medical Mycology | 2009
A. Serda Kantarcioglu; Teun Boekhout; Ayhan Yücel; Kemal Altas
Cryptococcus diffluens is a recently re-established species that shares several phenotypic features with Cryptococcus neoformans. We evaluated the application of the Clinical Laboratory Standards Institute (CLSI, formerly NCCLS) macro- and microbroth dilution methods and the E-test agar diffusion method to determine the in vitro susceptibilities of known strains of C. diffluens against amphotericin B (AMB), flucytosine (5-FC), fluconazole (FLC), itraconazole (ITC) and the novel triazoles, voriconazole (VRC) and posaconazole (PSC). Seven strains were found to be resistant in vitro to AMB (MICs >/=2 microg/ml), five were resistant to 5-FC (MICs of >/=32 microg/ml), four were resistant to FLC (MICs of FLC >/=32 microg/ml) and nine were resistant to ITC (MICs of ITC >1 microg/ml). In contrast, VRC and PSC showed good in vitro activity against C.diffluens strains, even those with elevated MICs to amphotericin B and/or established azoles. Most of the isolates were inhibited by 0.5 microg/ml of both VRC and PSC. A clinical isolate showing phenotypic switching exhibited elevated MICs to both agents, i.e., VRC (>16 microg/ml) and PSC (>8 microg/ml).
Medical Mycology | 2006
A. Serda Kantarcioglu; Ayhan Yücel; Keisuke Nagao; Tomotaka Sato; Ender Inci; Sahin Ogreden; Asim Kaytaz; Saadet Alan; Zehra Bozdağ; Naci Edali; Mehmet Sar; Nuray Kepil; Buge Oz; Kemal Altas
We report a histologically and mycologically proven sinonasal mucormycosis case causing palatal necrosis in a nondiabetic patient with renal failure. Mycological examination of Giemsa stained imprinted tissue preparations revealed abundant yeast-like cells besides the typical mucoraceous hyphae. The fungus was isolated from surgical specimens and identified as Rhizopus oryzae by phenotypic and genotypic tests. Laboratory studies were performed to investigate the association of the yeast-like cells observed in tissue specimens and the fungus recovered in culture. In vitro induced yeast-like cell development of the case isolate was found under certain growth conditions and documented by photomicrographs.