Mustafa Özyurt

Molecular epidemiology of Blastocystis infections in Turkey.

Blastocystis is a very common unicellular intestinal parasite of ubiquitous occurrence. In order to describe the molecular epidemiology of Blastocystis infections in Turkey, 87 isolates from 69 symptomatic and 18 asymptomatic individuals were sequenced. Sequence data were phylogenetically analyzed and statistically tested against unmodifiable risk factors such as gender and age. Blastocystis-positive males were complaining mainly of gastroenteritis, whereas dyspepsia was the chief complaint among Blastocystis-positive females. Blastocystis sp. subtypes detected in the study included subtypes 1, 2, 3 and 4, subtype 3 being the most predominant (75.9%). No association was detected between Blastocystis sp. subtype and symptoms (p>0.365), or between infection intensity and symptoms (p>0.441). There was a tendency of subtype 2 isolates being more common among older study individuals, and subtype 2 isolates were significantly associated with higher parasite abundance (p=0.017). Compared to data from similar studies, the distribution of Blastocystis sp. isolates in Turkey was found to more or less reflect the one seen in other countries, and it was deduced that subtype 3 is generally by far the most common subtype infecting humans, followed by subtypes 1, 2 and 4.

Nosocomial infection characteristics in a burn intensive care unit: Analysis of an eleven-year active surveillance

AIMS The objective of this study was to describe nosocomial infection (NI) rates, risk factors, etiologic agents, antibiotic susceptibility, invasive device utilization and invasive device associated infection rates in a burn intensive care unit (ICU) in Turkey. METHODS Prospective surveillance of nosocomial infections was performed according to Centers for Disease Control and Prevention (CDC) and National Healthcare Safety Network (NHSN) criteria between 2001 and 2012. The data was analyzed retrospectively. RESULTS During the study period 658 burn patients were admitted to our burn ICU. 469 cases acquired 602 NI for an overall NI rate of 23.1 per 1000 patient days. 109 of all the cases (16.5%) died. Pseudomonas aeruginosa (241), Acinetobacter baumannii (186) and Staphylococcus aureus (69) were the most common identified bacteria in 547 strains. CONCLUSION Total burn surface area, full thickness burn, older age, presence of inhalation injury were determined to be the significant risk factors for acquisition of NI. Determining the NI profile at a certain burn ICU can lead the medical staff apply the appropriate treatment regimen and limit the drug resistance. Eleven years surveillance report presented here provides a recent data about the risk factors of NI in a Turkish burn ICU.

Real-time PCR detection of Helicobacter pylori and virulence-associated cagA in nasal polyps and laryngeal disorders:

Objective: To identify Helicobacter pylori and major virulance factor, cagA, in patients with laryngeal diseases and nasal polyps. Study Design: Cross-sectional study with planned data collection. Setting: The study was performed on fresh tissue samples from patients with 32 nasal polyps, 29 normal nasal mucosa, and 27 laryngeal diseases presenting to the Otolaryngology–Head and Neck Surgery department of a major military hospital in Istanbul, Turkey. Subjects and Methods: Tissue specimens were evaluated by in-house polymerase chain reaction (PCR) and real-time PCR for bacterial DNA and by real-time PCR for cagA. The impact of commercial and in-house DNA extraction methods was also evaluated. Results: H pylori DNA was detected only by real-time PCR in 59.4 percent of nasal polyps, 70.4 percent of nasal mucosa samples, and 58.6 percent of larynx samples. cagA was identified in 78.9, 89.5, and 82.4 percent of positive polyp, nasal mucosa, and larynx samples, respectively. No statistically significant differences were observed between groups. DNA purification methods were equally effective. Conclusion: H pylori DNA is present in nasal polyp and larynx tissues as well as normal nasal mucosa, as detected by a sensitive real-time PCR assay. cagA-positive strains dominate in all groups.

Comparison of octenidine dihydrochloride (Octenisept®), polihexanide (Prontosan®) and povidon iodine (Betadine®) for topical antibacterial effects in Pseudomonas aeruginosa-contaminated, full-skin thickness burn wounds in rats

Pseudomonas aeruginosa is one of the most frequently isolated organisms from infected burn wounds and a significant cause of nosocomial infection and septic mortality among burn patients. In this animal study, three antiseptic agents which were Octenidine dihydrochloride (Octenisept®, Schülke & Mayr, Norderstedt, Germany), polyhexanide (Prontosan®, B. Braun, Melsungen AG, Germany) and povidon iodine (Betadine, Purdue Pharma L.P, Stamford, USA) were compared to assess the antiseptic effect of their applications on experimental burn wounds in in rats contaiminated with P. aeruginosa. All treatment modalities were effective against P. aeruginosa because there were significant differences between treatment groups and control groups. The mean eschar concentrations were not different between polyhexanide and povidon iodine groups, but there were significant differences between the octenidine dihydrochloride group and the other treatment groups, indicating that the Octenidine dihydrochloride significantly eliminated P. aeruginosa more effectively in the tissues compared to the to other agents. All treatment modalities were sufficient to prevent the P. aeruginosa invasion into the muscle and to cause systemic infection. In conclusion, Octenidine dihydrochloride is the most effective antiseptic agent in the treatment of the P. aeruginosa-contaminated burn wounds; Octenidine dihydrochloride can be considered as a treatment choice because of its peculiar ability of limit the frequency of replacing wound dressings.

The relationship between severity of coronary artery disease and plasma level of vascular endothelial growth factor.

OBJECTIVE It has been known that ischemia or occlusion of coronary arteries in animal models increases the production of vascular endothelial growth factor (VEGF); however, little is known about the relationship between coronary artery disease and VEGF in humans. In this study, our aim was to evaluate the relationships between the degree of coronary occlusion and plasma VEGF level as well as other risk factors, including age, weight, arterial blood pressure, cholesterol, triglyceride, blood glucose, and high-sensitive C-reactive protein (hsCRP) in patients with established coronary artery disease. MATERIALS AND METHODS Our study group consisted of 77 patients. Of these, 38 patients had normal coronary angiography (control group; group C) and 39 had abnormal angiography (17 critical lesion; group CL, 22 noncritical lesion; non-CL group). RESULTS Plasma VEGF level was 116.95+/-30.12 pg/ml in the control group, 212.47+/-75.28 pg/ml in group CL, and 138.89+/-45.18 pg/ml in the non-CL group. Plasma VEGF level of group C was found to be lower than that of group CL (P<.05), but the difference between groups C and non-CL was insignificant (P>.05). However, logistic regression analysis showed that VEGF level of group CL was significantly higher (P<.001). There was a negative correlation between VEGF and haemoglobin (r=-0.58, P<.01), and positive correlation between VEGF and age (r=0.29, P<.04). There was no relationship between plasma VEGF level and other cardiac risk parameters. Group CL had a higher level of total and LDL-cholesterol levels. CONCLUSION Increased plasma VEGF levels in patients with coronary artery disease may point that the coronary lesion is critical, and VEGF increase in patients with established coronary artery disease may be used as an indicator of the need for revascularization.

Antimicrobial susceptibility and resistance mechanisms of methicillin resistant Staphylococcus aureus isolated from 12 Hospitals in Turkey

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) is one of the most important nosocomial pathogens and is also emerging in Turkish hospitals. The aim of this study was to determine the antimicrobial susceptibility profiles of MRSA isolated from Turkish hospitals.Materials and methodsA total of 397 MRSA strains isolated from 12 hospitals in Turkey were included to present study. Antimicrobial susceptibilities were tested using agar dilution method. Presence of ermA, ermB, ermC, msrA, tetM, tetK, linA and aac-aph genes were studied by PCR.ResultsAll strains were susceptible to vancomycin and linezolid. The susceptibility rates for fusidic acid, lincomycin, erythromycin, tetracyclin, gentamycin, kanamycin, and, ciprofloxacin were 91.9%, 41.1%, 27.2%, 11.8%, 8.5%, 8.3% and 6.8%, respectively. Lincomycin inactivation was positive for 3 isolates. Of 225 erythromycin resistant isolates 48 had ermA, 20 had ermC, and 128 had ermA-C. PCR was negative for 15 strains. Of 3 isolates with lincomycin inactivation one had linA and msrA. Of 358 gentamycin resistant isolates 334 had aac-aph and 24 were negatives. Among 350 tetracyclin resistant isolates 314 had tetM. Of 36 tetM negative isolates 10 had tetK.ConclusionMRSA isolates from Turkish hospitals were multiresistant to antimicrobials. Quinolone and gentamycin resistance levels were high and macrolide and lincosamide resistance were relatively low. Susceptibility rates for fusidic asid were high. Linezolide and vancomycin resistance are not emerged. The most common resistance genes were ermA, tetM and aac-aph. Evolution of antimicrobial susceptibilities and resistance genes profiles of MRSA isolates should be surveyed at regional and national level for accurate treatment of patients and to control dissemination of resistance genes.

Determination of antimicrobial susceptibilities of clinically isolated anaerobic bacteria by E-test, ATB-ANA and agar dilution.

A total of 60 anaerobic strains were isolated from 322 clinical specimens. These isolates were tested for susceptibility to seven antibiotics (penicillin G, amoxicillin/clavulanic acid, cefoxitin, imipenem, chloramphenicol, metronidazole, clindamycin) by using ATB-ANA and Epsilometer test (E-test) strips and the results were compared with the gold standard agar dilution method. Imipenem was found as the most effective agent in vitro among the agents tested (100%). Susceptibility to penicillin G, amoxicillin/clavulanic acid, cefoxitin, chloramphenicol, metronidazole and clindamycin are 36.7%, 83.3%, 88.3%, 96.6%, 85% and 90%, respectively. E-test has showed a good correlation (r=0.62, p=0.001) statistically with the results of agar dilution (total agreement for all antibiotics changing between 90.01% and 98.45%) and a moderate correlation (r=0.45, p=0.048) with the results of ATB-ANA method (total agreement for all antibiotics changing between 75.46% and 98.76%). However, the routine use of agar dilution procedure is concluded to be cumbersome, whereas E-test method offers a reliable alternative.

Multicenter evaluation of crystal violet decolorization assay (CVDA) for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis

The aim of this multicenter study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for detection of multidrug resistant tuberculosis (MDR-TB). This study was performed in 11 centers in two phases. A total of 156 isolates were tested for INH and RIF resistance. In the phase I, 106 clinical isolates were tested in the Center 1–7. In the phase 2, 156 clinical isolates were tested in the center 1–6, center 8–11. Eighty six of 156 tested isolates were the same in phase I. Agreements were 96.2–96.8% for INH and 98.1–98.7% for RIF in the phase I-II, respectively. Mean time to obtain the results in the phase I was 14.3 ± 5.4 days. In the phase II, mean time to obtain the results was 11.6 ± 3.5 days. Test results were obtained within 14days for 62.3% (66/106) of isolates in the phase I and 81.4% (127/156) of isolates in the phase II. In conclusion, CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of MDR-TB isolates. In addition, it could be adapted for drug susceptibility testing with all drugs both in developed and developing countries.

The effect of hyperbaric oxygenation on thein vitro growth ofEscherichia coli in environments with and without blood cells

The aim of this study was to investigate whether thein vitro presence of blood cells influences the anti-microbial activity of hyperbaric oxygen (HBO) againstEscherichia coli. FiftyE. coli isolates from clinical samples were used in the study. A small number of colonies belonging to each isolate from the nutrient media were transferred into two K3EDTA tubes (the blood group) and two Mueller-Hinton broth tubes (the broth group). Then, both groups were divided into subgroups according to whether HBO was administered (HBO subgroup) or not (non-HBO subgroup). HBO treatment was applied for one hour at 2.5 absolute atmospheres. The tubes in the non-HBO subgroup were left at room temperature during this period. Subsequently, all the tubes were cultured on Mueller-Hinton and Eosin Methylene Blue agar using the quantitative counting technique. After 18 to 24 h incubation at 37 °C, the colonies formed in the plates were counted. In the blood group, compared with non-HBO subgroup samples, the number of colonies decreased in 56% of samples, increased in 32% of samples and did not change in 12% of samples in the HBO subgroup. Whereas, in the broth group the number of colonies decreased in only 32% of samples increased in 38% of samples and did not change in 30% of samples in the HBO subgroup compared with the non-HBO subgroup. The difference between the blood and the broth groups revealed a statistical significance using Pearson’s Chi-square test (P=0.025). We concluded that the antibacterial effect of HBO onE. coli increases in the cellular environment belonging to the host organism.

Distribution of Parasites Detected in Stool Samples of Patients Admitted to Our Parasitology Laboratory during a Three-Year Period between 2012 and 2014.

OBJECTIVE Parasitic diseases are among the major public health issues worldwide. A number of tests are available for diagnosis, but the sentivity and specifity of these tests are assumed to be insufficient. Nevertheless, the most common diagnostic method is microscopic examination. In this study, we aimed to introduce the distribution of parasites detected in stool samples of patients admitted to our laboratory on the basis of parameters such as, age, and gender during a 3-year period between 2012 and 2014. METHODS In total, 6757 stool samples were included in the study. After macroscopic examination, wet mounts of all samples were examined under a light microscope using ×100 and ×400 magnification lenses. Wet mounts were prepared with physiological saline and Lugols iodine. RESULTS Parasites were detected in 3.7% (252) of the samples, while no parasites were detected in 96.3% (6505) of the samples. The distribution of intestinal parasites was as follows: Blastocystis hominis (63.5%), Giardia intestinalis (26.2%), Taenia sp. (4.8%), Enterobius vermicularis (2.4%), Entamoeba histolytica/dispar (1.6%), and Hymenolepis nana (1.6%). CONCLUSION When the burden of intestinal parasites on public health is considered, they are still a major health issue in Turkey. The frequency of parasitic diseases can be reduced by the education of individuals and implementation of effective diagnostic methods, treatments, and preventive measures.