Gulsen Hascelik

Carbapenem-resistant Escherichia coli and Klebsiella pneumoniae isolates from Turkey with OXA-48-like carbapenemases and outer membrane protein loss

Treatment options are limited in infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, with carbapenems generally preferred. Disturbingly, however, carbapenem-resistant strains are emerging worldwide. Here we report two clinical isolates, one Escherichia coli and one Klebsiella pneumoniae, each with high-level carbapenem resistance (imipenem minimum inhibitory concentration of 32 microg/mL). They were isolated following imipenem therapy from two hospital patients who had received imipenem therapy in different regions of Turkey. Both isolates produced OXA-48-like carbapenemases, enzymes so far reported only from Turkey. Both isolates also had group 1 CTX-M-type ESBLs and had lost major outer membrane proteins. OXA-48-like carbapenemases appear to be scattered in Turkey and surveillance to determine their prevalence is warranted.

Seroprevalence of Helicobacter pylori infection in an asymptomatic Turkish population

OBJECTIVES Helicobacter pylori infection is recognized as being strongly associated with chronic gastritis, duodenal ulceration and probably gastric carcinoma. Seroepidemiological studies have shown that a large proportion of healthy people have antibodies against H. pylori. A serological study was conducted in an asymptomatic Turkish population to investigate the seropositivity rate of H. pylori and to detect the relationship with age. SUBJECTS AND METHODS A total of 657 serum samples collected from 331 male and 326 female people in different age groups who had no gastrointestinal complaints were studied by a commercial ELISA test for the presence of H. pylori-IgG antibodies. RESULTS Three hundred and forty-eight subjects (53%) were seropositive. The overall seropositivity rates did not differ with sex. Antibody prevalence increased progressively with age. The seropositivity rates were as follows: 17.4% < 1 year old; 15.5% aged 1-4; 30.6% aged 5-9; 47.3% aged 10-14; 58.4% aged 15-19; 62.6% aged 20-29; 67.6% aged 30-39; 81.3% aged 40-49; and 66.3% over 50 years of age. CONCLUSIONS This study indicated that more than 30% of the subjects acquired infection before teenage and that about 70% of adults had antibodies against H. pylori in our population. The high prevalence and early acquisition of H. pylori infection may be related in part to socioeconomic status and traditional living conditions in Turkey.

Screening of tissue transglutaminase antibody in healthy blood donors for celiac disease screening in the Turkish population.

Celiac disease (CD) is a disease having the characteristic pathology of the mucosa of the small intestine. The prevalence of CD in the Turkish population has not been investigated previously. The present study was designed to determine the prevalence of CD in healthy blood donors. Serum samples of 2000 healthy blood donors presenting to Hacettepe University Faculty of Medicine Hospital Blood Bank were tested for tissue transglutaminase (tTG) IgA and IgG antibodies with enzyme-linked immunosorbent assay (ELISA; Euroimmune, Germany). The histopathological findings for the cases with positive serology were evaluated. The distribution of sex was 95.7% male, and 4.3% female. The mean age was 33±9. Among 2000 donors, 23 (1.15%) were positive for tTG IgA antibody and 3 (0.15%) were positive for tTG IgG antibody. None of the samples was positive for both antibodies. Serum total IgA was measured in two cases with only tTG IgG positivity and was found to be low in one case. Twelve subjects positive for tTG agreed to endoscopy and biopsy. Histopathological examination revealed changes classified as Marsh III–II in one, Marsh II in two, Marsh I in seven, and Marsh 0 in two donors. This was the first study conducted to determine the prevalence of tTG positivity in the Turkish population. The tTG antibody positivity prevalence in healthy blood donors was as high as 1.3%. This study shows that the prevalence of CD in the Turkish population is relatively high in comparison to that in the Western world.

The bactericidal activity of tea against Campylobacter jejuni and Campylobacter coli

Extracts of black and green tea inhibited the growth of clinical isolates of Campylobacter jejuni and C. coli. Tea extracts killed C. jejuni and C. coli within 4 h. Heat treatment of extracts did not affect inhibitory or bactericidal activity.

Comparative in vitro activities of posaconazole, voriconazole, itraconazole, and amphotericin B against Aspergillus and Rhizopus, and synergy testing for Rhizopus

We compared the in vitro activities of posaconazole, voriconazole, itraconazole, and amphotericin B against clinical isolates of Aspergillus spp. and Rhizopus spp., and explored the in vitro interaction between posaconazole and amphotericin B against Rhizopus spp. Clinical strains of 82 Aspergillus spp. (43 Aspergillus fumigatus, 29 A. flavus, 7 A. niger, 2 A. terreus, 1 A. nidulans) and 11 Rhizopus oryzae isolates were tested in accordance with CLSI M38-A microdilution guidelines. In vitro activity of posaconazole against Aspergillus spp. was also investigated with the Etest. The combination of posaconazole and amphotericin B against R. oryzae isolates was investigated by the checkerboard methodology. Voriconazole was the most active drug in vitro against Aspergillus spp., followed by posaconazole, itraconazole, and amphotericin B, in order of decreasing activity. In studies with R. oryzae isolates, posaconazole was found to be the most potent drug followed by itraconazole and amphotericin B. Voriconazole had no meaningful activity against Rhizopus. Posaconazole Etest MICs (microg/ml) with Aspergillus spp. were found to be considerably lower than those obtained with the CLSI microdilution method (4-9 and 3-7 two-fold lower than CLSI MICs at 24 and 48 h, respectively). The interaction between posaconazole and amphotericin B was indifferent for all R. oryzae isolates tested; importantly no antagonism was observed.

The bactericidal activity of tea against Helicobacter pylori

Extracts of black and green tea inhibited in‐vitro growth of six clinical isolates of Helicobacter pylori in an agar diffusion assay. Tea extracts killed H. pylori (106 cfu ml‐1) within 5 h. Heat treatment of extracts did not affect the inhibitory or bactericidal activity.

Sandfly fever virus activity in central/northern Anatolia, Turkey: first report of Toscana virus infections.

Sandfly fever viruses (SFVs) cause febrile diseases as well as aseptic meningitis/encephalitis and include serotypes sandfly fever Sicilian virus (SFSV), sandfly fever Naples virus (SFNV) and Toscana virus (TOSV). Infections are endemic in the Mediterranean basin and data on SFV activity in Turkey are limited. In this study, sera from 1533 blood donors from the Ankara, Konya, Eskisehir and Zonguldak provinces of Turkey were evaluated for SFV exposure by indirect immunofluorescence test (IIFT) and confirmed by virus neutralization test (VNT). One hundred and two patients with central nervous system (CNS) infections of unknown aetiology were also tested via IIFT and real-time reverse-transcription PCR for SFV/TOSV. Rate of overall IgG reactivity in IIFT was 32.9% (505/1533) among blood donors. TOSV exposure was confirmed by VNT in all study regions. Exposure to the recently-identified serotype sandfly fever Turkish virus, as evaluated by VNT, was revealed in Konya and Ankara. SFNV exposure was identified in Konya and SFSV was observed to be present in all regions except Zonguldak. TOSV RNA was detected in 15.7% (16/102) and was accompanied by TOSV IgM in 25% (4/16) of the patients. Partial L and S sequences suggested that TOSV circulating in Turkey can be grouped into TOSV genotype A strains. Exposure to TOSV and other SFV serotypes was revealed in blood donors and CNS infections by TOSV were identified for the first time in Turkey. Infections are observed to be endemic in central Anatolia and should be considered as aetiologic agents in cases/outbreaks of fever and meningoencephalitis.

Comparison of two methods and three end points in determination of in vitro activity of micafungin against Aspergillus spp.

ABSTRACT We investigated the in vitro activity of micafungin against clinical Aspergillus isolates (n = 37) (Aspergillusfumigatus [n = 21], Aspergillusflavus [n = 14], and Aspergillus niger [n = 2]) by using NCCLS M38A microdilution and an investigational disk diffusion assay. Microdilution assay results were evaluated by using the end points of a MIC-2 (measured in micrograms per milliliter) and minimum effective concentration (MEC, measured in micrograms per milliliter; the lowest concentration of micafungin that produces short and aberrant hyphal branchings microscopically). Disk diffusion results were interpreted by measuring the zone(s) of inhibition (ZOI, measured in millimeters). Micafungin proved to be similarly active against all Aspergillus species tested. At 24 h, MIC-2s and MECs were identical. At 48 h, however, MIC-2s increased unpredictably, leading to the loss of a consistent correlation between the two end points. MECs and ZOI remained consistent and correlated at both reading times, suggesting their use as relevant end points in susceptibility testing of micafungin against Aspergillus. All Aspergillus isolates yielded intrazonal growth on disk diffusion agar plates. The intrazonal colonies contained short, aberrant hyphal branchings microscopically. The in vivo significance of these findings remains to be further investigated.

Investigation of HSV-1, HSV-2, CMV, HHV-6 and HHV-8 DNA by real-time PCR in surgical resection materials of epilepsy patients with mesial temporal lobe sclerosis

OBJECTIVE The objective of this study is to investigate the presence of viral DNAs of HSV-1, HSV-2, HHV-6, HHV-8, and CMV in hippocampus of the patients with mesial temporal lobe epilepsy (MTLE) syndrome. METHODS Pathological specimens were obtained from 33 patients with MTLE undergone temporal lobectomy with amygdalo-hippocampectomy due to intractable seizures. Autopsy materials from the hippocampus of 7 patients without neurological disease were used as controls. The data was also correlated with the clinical history of patients including febrile convulsions, age, and history of CNS infections. Real-time polymerase chain reaction method was performed for detection of DNAs of these viruses. RESULTS HHV-6, HSV-1 and HHV-8 were detected in the hippocampus of 3, 2 and 1 patients with MTLE respectively. None of the hippocampus of patients with MTLE was positive for DNA of HSV-2 and/or CMV. Three patients with positive HHV-6 DNAs had febrile convulsions and family history for epilepsy. None of our control specimens showed PCR positivity to any of the 5 tested viruses. CONCLUSIONS Our study is the first to report the presence of HHV-8 viral genome in the brain tissue of patient with MTLE. Viral DNAs were detected in a total of 18% of the patients in this study; we can conclude that activity of the latent virus in patients with hippocampal sclerosis should be more extensively studied to establish its role in active infection.

Comparison of NCCLS microdilution method and Etest in antifungal susceptibility testing of clinical Trichosporon asahii isolates

We investigated the in vitro activity of amphotericin B, fluconazole, and itraconazole against clinical Trichosporon asahii isolates (n = 43) by NCCLS M27A reference microdilution method and explored the correlation between Etest and NCCLS reference method. Microdilution MIC ranges following 48 h of incubation were 1-8, 0.25-16, and 0.06-4 microg/ml for amphotericin B, fluconazole, and itraconazole, respectively. The corresponding Etest MIC ranges were determined as 0.125- > 8, 0.25- > 64, and 0.03-8 microg/ml. Of interest, Etest tended to produce lower amphotericin B MICs and widen the MIC range compared to microdilution. The influence of Etest on fluconazole and itraconazole MICs was in contrary with that observed for amphotericin B. Etest MICs of fluconazole and itraconazole tended to be higher than microdilution MICs. The wider range of amphotericin B MICs obtained by using Etest methodology may facilitate discrimination of isolates with reduced susceptibility to amphotericin B. However, clinical significance of these findings remain yet unknown and determination of MIC breakpoint values is required.