Faruk Aydin

Breakthrough Trichosporon asahii Fungemia in Neutropenic Patient with Acute Leukemia while Receiving Caspofungin

A 47-year-old man with newly diagnosed acute myeloblastic leukemia and non-insulin-dependent diabetes mellitus developed Trichosporon asahii fungemia while receiving caspofungin as empirical antifungal therapy. The diagnosis was based on repeated isolation of T. asahii in culture of blood for three times. Despite treatment with amphotericin B and voriconazole, the patient died. The in vitro antifungal susceptibilities of the T. asahii isolates were only available after the patient died. In vitro antifungal susceptibility tests showed high caspofungin and amphotericin B minimal inhibitory concentrations (MICs) value for this Trichosporon strain (MICs, 16 μg/ml, and > 32 μg/ml, respectively). Fluconazole, itraconazole, and voriconazole exhibited low MICs in vitro (MICs, 4 μg/ml, 0.5 μg/ml, and ≤ 0.015 μg/ml, respectively). Our experience strongly suggest that identification and antifungal susceptibility testing for T. asahii in neutropenic patients who may develop signs of infection in the presence of caspofungin as well as broadspectrum antibiotics treatment should not be overlooked.

Geochronology, geochemistry, and petrogenesis of the Maçka subvolcanic intrusions: implications for the Late Cretaceous magmatic and geodynamic evolution of the eastern part of the Sakarya Zone, northeastern Turkey

The Maçka subvolcanic intrusions (MSIs) in the eastern part of the Sakarya zone, northeastern Turkey, play a critical role in understanding the petrogenetic and geodynamic processes that took place during the growth of Late Cretaceous arc crust of this region. U–Pb zircon (79.97 ± 0.97 Ma) and two 40Ar–39Ar amphibole ages (average 81.37 ± 0.5 Ma) indicate that the MSIs were emplaced in Late Cretaceous (Campanian) time into the coeval volcanic rocks. A slightly younger zircon fission track (FT) age (73 ± 9 Ma) points to a rapid exhumation and cooling after crystallization. The intrusions are observed in areas less than 1 km2 in the field and contain abundant mafic microgranular enclaves (MMEs). The host rocks (HRs) are entirely composed of tonalite (SiO2 = 63–65 wt.%, Mg# = 43–52), and the MMEs are gabbro-diorite in composition (SiO2 = 53–57 wt.%, Mg# = 45–48). Both the HRs and the MMEs are I-type, high-K calc-alkaline in composition and display a metaluminous character. They are characterized by geochemical features typical for magmas of subduction-related environments. Chondrite-normalized REE patterns are moderately fractionated [(La/Yb)N = 6–11] and display slightly negative Eu anomalies (Eu/Eu* = 0.7–0.9), with weak concave-upward REE patterns, suggesting that amphibole fractionation played a role during their evolution. The MMEs have slightly different ISr (0.7081–0.7085) and εNd (−5.0 to −5.4) values compared with those of their HRs (ISr = 0.7084–0.7087 and εNd = −5.7 to −6.9), indicating that variable amounts of crustal and mantle components were involved in the generation of parental magma to these rocks. All of these data, combined with those of previous regional studies, suggest that the MSIs are hybrid in origin, produced by the mixing of enriched lithospheric mantle- and lower crust-derived melts in an extensional arc setting that was caused by slab rollback.

Mineralogy and Chemistry of Biotites from Eastern Pontide Granitoid Rocks, NE-Turkey: Some Petrological Implications for Granitoid Magmas

Abstract The Eocene Zigana Granitoid in the northern zone and the Middle-Upper Eocene Dolek and Saricicek Plutons in the southern zone of the Eastern Pontides (NE-Turkey) consist of different rock series ranging in composition from intermediate to felsic compositions containing from X Fe = Fe 2+ /Fe 2+ + Mg) = 0.28 – 0.49) in the southern zone plutons and Mg- to Fe-rich ( X Fe = Fe 2+ /Fe 2+ + Mg) = 0.33 – 0.78) in the northern zone pluton. They coexist with K-feldspar, plagioclase, quartz, amphibole, pyroxene, low titanium magnetite, minor ilmenite ± titanite. Biotites have been buffered by the Ni-NiO. The plutons equilibrated under low oxygen fugacities (Log f O 2 ) ranging from –16.01 to –20.23 bars for Dolek and Saricicek, and –16.70 to –17.90 bars for Zigana. EPMA indicate that the composition of biotite is related to the mineral assemblages of Dolek, Saricicek and Zigana biotites as a consequence of chemistry of the magma and the physical conditions during crystallization. The biotite compositions were used to discriminate the tectonic setting of the plutons. The intrusions appear to be related to calc-alkaline to high-K calc-alkaline orogenic suites. Furthermore, Mg [6] -Fe tot substitution has played a significant role during the crystallization of the biotites.

Distribution, virulence attributes and antifungal susceptibility patterns of Candida parapsilosis complex strains isolated from clinical samples

It was recently proposed that Candida parapsilosis represents a complex composed of three closely related species, i.e., C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis. The aim of this study was to describe the distribution of C. parapsilosis complex isolates among clinical samples. We also evaluated antifungal susceptibility profiles, in vitro presence of lipase and secreted aspartyl proteinase, as well as their ability to grow in total parenteral nutrition (TPN) solution, and biofilm production. A total of 413 non-C. albicans Candida isolates were obtained from various clinical samples between 2010 and 2011 in a Turkish Tertiary Care Hospital. Of them, 42 were identified as members of the C. parapsilosis complex. Among these, 38 (90.5%) were C. parapsilosis sensu stricto, 3 (7.1%) C. metapsilosis, and 1 (2.4%) C. orthopsilosis. All isolates recovered from blood were found to be C. parapsilosis sensu stricto and C. metapsilosis. In phenotypic tests, all 42 isolates grew in TPN solution and, although 26.2% of C. parapsilosis sensu stricto-isolates were capable of forming biofilms in vitro, neither C. orthopsilosis nor C. metapsilosis isolates were able to do so. Acid proteinase activity was detected in 31% of isolates and lipase activity in 33%. All isolates were sensitive to voriconazole, caspofungin, and anidulafungin, with only a single C. parapsilosis sensu stricto isolate showing dose-dependent susceptible to fluconazole. While the number of C. metapsilosis and C. orthopsilosis isolates remained low, there were no significant differences in antifungal MIC as compared to C. parapsilosis sensu stricto.

Bloodstream yeast infections in a university hospital in Northeast Turkey: a 4-year survey

This study presents data on species distribution and antifungal susceptibility profiles of Candida bloodstream isolates obtained from a Turkish Tertiary Care Hospital during a 4-year period. All hospitalized patients who had ≥ 1 blood culture positive for yeast during their hospital stay from January 2005 through 2009 were included in this study. All isolates were identified to species level using CHROMagar and ID 32 C. Fluconazole and voriconazole antifungal susceptibility testing was performed using the disk diffusion method according to CLSI M44-A. In vitro activity of amphotericin B was determined by the Etest. Of all 166 yeast isolates, C. albicans was the dominant species (34.3%), followed by Candida parapsilosis (28.9%) and C. tropicalis (8.4%). All of the 48 C. parapsilosis strains were identified as C. parapsilosis sensu stricto. Resistance to fluconazole was more common among C. krusei isolates. Voriconazole resistance was absent. One C. lusitaniae strain showed a high amphotericin MIC (4 μg/ml). Our survey indicated an increase of some non-C. albicans Candida species in our hospital while antifungal resistance was uncommon.

Induction of secretory aspartyl proteinase of Candida albicans by HIV-1 but not HSV-2 or some other microorganisms associated with vaginal environment

The most common type of candidiasis involves mucosal sites such as the oral cavity, the gastrointestinal tract and the vagina. Among many of virulence factors, the production of secretory aspartyl proteinase (Sap) by Candida albicans (C. albicans) has gained much attention, and factors leading to Sap induction are thus under intense study. The aim of this study was to examine whether some microorganisms such as Lactobacillus, Gardnerella vaginalis (G. vaginalis), human immunodeficiency virus type-1 (HIV-1) and human herpes simplex virus type-2 (HSV-2) had any Sap inducing effect on C. albicans. Here we showed that among the microorganisms tested in vitro only HIV-1 induced Sap production from C. albicans.

Significance of cagA status and vacA subtypes of Helicobacter pylori in determining gastric histopathology: Virulence markers of H. pylori and histopathology

Background:  It has been suggested that Helicobacter pylori strains containing the cytotoxin‐associated gene A (cagA), and s1m1 genotype of vacuolating cytotoxin gene A (vacA) may have been associated with peptic ulcer disease. The aim of the present study was to analyze such an association of cagA presence and vacA subtypes of H. pylori with histopathological findings in patients with gastritis.

Frequency of bacterial vaginosis among women attending for intrauterine device insertion at an inner-city family planning clinic.

The aim of this study was to investigate the rate of bacterial vaginosis in women attending an inner-city family planning clinic for intrauterine device (IUD) insertion. In a population of 86 women, eight (9.3%) and 20 (23.2%) were found to have bacterial vaginosis according to the criteria of Amsel and Nugent, respectively. Sensitivity, specificity, positive and negative predictive values were calculated in relation to bacterial vaginosis for Amsels criteria. The detection of clue cells demonstrated excellent sensitivity (85%). Positive amine test and vaginal discharge demonstrated poor sensitivity (50% and 55%, respectively). Our results suggest that Gram staining of vaginal specimens may be of use to identify the presence of bacterial vaginosis prior to IUD insertion.

Serotype distribution of Streptococcus pneumoniae in children with invasive diseases in Turkey: 2008–2014

Successful vaccination policies for protection from invasive pneumococcal diseases (IPD) dependent on determination of the exact serotype distribution in each country. We aimed to identify serotypes of pneumococcal strains causing IPD in children in Turkey and emphasize the change in the serotypes before and after vaccination with 7-valent pneumococcal conjugate vaccine (PCV-7) was included and PCV-13 was newly changed in Turkish National Immunization Program. Streptococcus pneumoniae strains were isolated at 22 different hospitals of Turkey, which provide healthcare services to approximately 65% of the Turkish population. Of the 335 diagnosed cases with S. pneumoniae over the whole period of 2008–2014, the most common vaccine serotypes were 19F (15.8%), 6B (5.9%), 14 (5.9%), and 3 (5.9%). During the first 5 y of age, which is the target population for vaccination, the potential serotype coverage ranged from 57.5 % to 36.8%, from 65.0% to 44.7%, and from 77.4% to 60.5% for PCV-7, PCV-10, and PCV-13 in 2008–2014, respectively. The ratio of non-vaccine serotypes was 27.2% in 2008–2010 whereas was 37.6% in 2011–2014 (p=0.045). S. penumoniae serotypes was less non-susceptible to penicillin as compared to our previous results (33.7 vs 16.5 %, p=0.001). The reduction of those serotype coverage in years may be attributed to increasing vaccinated children in Turkey and the increasing non-vaccine serotype may be explained by serotype replacement. Our ongoing IPD surveillance is a significant source of information for the decision-making processes on pneumococcal vaccination.

Geochemical modelling of early Eocene adakitic magmatism in the Eastern Pontides, NE Anatolia: continental crust or subducted oceanic slab origin?

Early Eocene adakitic volcanic and granitoid rocks are widespread in the Eastern Pontides of NE Turkey, providing significant constraints for the early Cenozoic tectonomagmatic evolution of the region. These adakitic rock units exhibit relatively high Sr/Y and La/Yb ratios, but low Y and Yb values, similar to modern adakites generated by partial fusion of a subducted oceanic slab. They also have high K2O and low MgO contents, and show moderately enriched ISr and low ϵNd(t) isotopic signatures. Our trace element modelling suggests that these adakitic magmas were generated from partial melting at low pressures of a garnet-bearing amphibolitic source in the continental lower crust. This lower crustal melting resulted from slab break off-induced asthenospheric upwelling and related magmatic underplating beneath the Eastern Pontides. We interpret this melting event and the adakitic magmatic activity as a syn- to post-collisional process involving early Cenozoic collision of the Pontide and Anatolide–Tauride continental blocks. The geochemical and tectonic constraints presented here indicate that early Eocene adakitic magmatism in the Eastern Pontides did not result from partial fusion of a subducted oceanic slab, but instead represent continental-type adakite formation.