Burçin Şener

Evaluation of the microbiology of chronic sinusitis.

Chronic sinusitis is one of the most common diseases treated in outpatient centres. In this prospective study, 49 patients with the diagnosis of chronic maxillary sinusitis were evaluated microbiologically by using sinus swab, irrigation fluid and sinus mucosal tissue specimens obtained during endoscopic sinus surgery. There was no bacterial growth in seven cases. In the remaining 42 cases a total of 89 bacteria were isolated, 28 of them being classical pathogens and 61 being non-classical pathogens. Among the classical pathogens Staphylococcus aureus was the most common one. The correlation between the isolates obtained from maxillary sinus and isolates obtained from throat, nose and nasopharynx did not have a predictive value. Since the overall rate of classical pathogen isolation from patients with chronic sinusitis was not significantly high, the possible role of factors other than bacterial growth should be identified in the pathogenesis of chronic sinusitis.

Utility of a commercial quantitative hepatitis C virus core antigen assay in a diagnostic laboratory setting.

In this study, the utility and impact of hepatitis C virus (HCV) core antigen (Cag) detection via a commercial assay have been evaluated in diagnostic laboratory conditions. In a total of 272 samples from 226 individuals, HCV RNA was detected in 81.3% and anti-HCV antibody prevalence was 86.4%. HCV Cag reactivity was identified in 59.9% of the samples and in 75.8% with detectable RNA. The sensitivity and specificity of HCV Cag assay have been calculated as 75.8% and 95.1%, respectively, and agreement between HCV RNA and HCV Cag was moderate (κ = 0.554). HCV Cag and RNA levels were highly correlated (r = 0.915 and 0.937). A viral load threshold of 10(3) IU/mL has been recognized, above which the correlation with RNA became statistically significant and sensitivity increased to 90.9%. Detection and quantification of HCV core antigen have been observed as a strong alternative to nucleic acid testing for HCV monitorization.

Pleural fluid PCR method for detection of Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae in pediatric parapneumonic effusions.

Background: Parapneumonic effusions cause significant morbidity and mortality despite current developments in diagnostic and therapeutic approaches. Causative microorganisms may remain unidentified in a significant number of patients by cultures and Gram smears. Polymerase chain reaction (PCR) is a molecular technique for the detection of causative bacteria; however, its efficiency in pleural fluids is less known. Objectives: The present study was performed to compare the efficiency of PCR in the detection of the three most common organisms (Staphylococcus aureus, Streptococcus pneumoniae and Haemophylus influenzae) with conventional methods. Methods: Twenty-eight consecutive patients with parapneumonic pleural effusions were studied. On admission, pleural fluid samples were obtained for Gram staining, routine culture and PCR analysis for S. aureus, S. pneumoniae and H. influenzae. Results: PCR analysis allowed detection of 11 microorganisms in 10 patients (35.7%), whereas pleural fluid cultures detected the etiological agent in only 2 (7.1%). S. pneumoniae was the most frequent agent. Conclusions: Pleural fluid cultures may have low diagnostic yields, partly due to prior antibiotic use. Pleural fluid PCR analysis may improve the etiologic diagnosis in parapneumonic pleural effusions, with technical advances leading to higher yields than obtained in this study.

Screening for latent tuberculosis infection in psoriasis and psoriatic arthritis patients in a tuberculosis-endemic country: a comparison of the QuantiFERON®-TB Gold In-Tube test and tuberculin skin test.

Since the introduction of biologic therapies for tuberculosis (TB), screening for latent TB infection has increased in importance, especially in countries in which TB is endemic. The aim of this study was to evaluate the effect of psoriasis on tuberculin skin test (TST) results and to compare two TB screening tests, the TST and QuantiFERON®‐TB Gold In‐Tube (QFT–GIT) test, in psoriasis and psoriatic arthritis (PA) patients living in a TB‐endemic country (Turkey). This prospective study included 61 psoriasis and 40 PA patients, and 58 healthy controls. Demographic data, medical history, human immunodeficiency virus (HIV) status, level of education, smoking status, exposure to TB, personal and family histories of TB, and bacillus Calmette–Guérin (BCG) vaccination status were recorded for all participants. The TST and QFT–GIT were performed in all participants. The mean ± standard deviation TST indurations in the patient and control groups were 12.6 ± 6.4 mm and 10.2 ± 6.5 mm, respectively (P = 0.051). The TST positivity rate was higher in patients than in controls (86.1% vs. 37.9%; P < 0.001), whereas QFT–GIT positivity did not differ significantly (patients: 20.8%; controls: 17.2%; P = 0.737). False positive results can lead to unnecessary prophylactic TB treatment; therefore, the cut‐off point for TST positivity in psoriasis and PA patients should be re‐evaluated, or other tests, such as the QFT–GIT, should be used.

Rate of carriage, serotype distribution and penicillin resistance of Streptococcus pneumoniae in healthy children

This study was aimed to define the carriage rates for Streptococcus pneumoniae in a given population in Ankara and also to determine the serotypes and penicillin resistance of these strains. Oropharyngeal swabs were taken from a total of 661 children aged between 0-11 years and living in a province of Ankara between January 1995-January 1997. Serotyping was performed by detection of the Quellung reaction. The isolates were screened for penicillin susceptibility by the agar dilution method according to the guidelines of NCCLS. The total rate of pneumococcal carriage in the study population was 23.90% and the isolation rate was found to be statistically associated with age, being higher in small children. Among the 158 S. pneumoniae isolates, the most prevalent serotypes (in order of frequency) were 6, 19, 9, 23, 3 and 14. Penicillin susceptibility was examined in 120 of the isolates. 55 of them (45.83%) were susceptible, 53 (44.17%) were intermediately and 12 (10.0%) were highly resistant to penicillin. Evaluation of the results showed that serotypes 6, 14 and 23 were those most often associated with penicillin resistance. The significant rate of isolation of penicillin-resistant pneumococci in healthy carriers points to the importance of active immunization in risk groups and also the importance of the rational use of antibiotics to limit the spread of resistant strains.

The effect of tonsillectomy on neutrophil chemotaxis in adults with chronic tonsillitis

Neutrophil random motility and chemotactic responsiveness were determined in 17 healthy adults and 19 adult patients with chronic tonsillitis before and 10 days after tonsillectomy, using a modified Boyden chamber method. The mean chemotactic index values of the healthy controls were significantly higher when compared with the chronic tonsillitis patients before tonsillectomy. The postoperative mean chemotactic values were increased, and there was a statistically significant difference between the mean chemotactic index of neutrophils in preoperative and postoperative patients. The authors conclude that this change in host defense mechanism may be the reason for frequent attacks of acute tonsillitis in these patients.

The effect of trabeculectomy on serum brain-derived neurotrophic factor levels in primary open-angle glaucoma

PurposeWe aimed to investigate the effect of trabeculectomy on serum brain-derived neurotrophic factor (BDNF) levels. Our secondary goal was to compare serum and aqueous humor (AH) BDNF levels in primary open-angle glaucoma (POAG) and control subjects.MethodsThis prospective, cross-sectional study consists of 20 eyes of with advanced-stage POAG who had trabeculectomy and 19 eyes of age- and sex-matched control healthy subjects who had cataract surgery. Serum and AH samples were obtained preoperatively in trabeculectomy group and control subjects. Serum samples were obtained at the third postoperative month in both groups.ResultsThe aqueous humor and serum levels of BDNF at the surgery day were found to be strongly positive correlated (r = 0.868; p < 0.001). Serum and AH BDNF levels of POAG cases were significantly lower than control subjects at the surgery day (respectively p = 0.038, p = 0.011). In POAG cases, serum BDNF levels significantly increased at the third month after trabeculectomy while there was not a significant difference in control subjects with cataract surgery (p < 0.001; p = 0.717 respectively).ConclusionTrabeculectomy was found to have a positive effect on serum BDNF levels in POAG cases.

Staphylococcus aureus küçük koloni varyantı: kolaylıkla atlanan bir tanı

Normal fenotip Staphylococcus aureus izolatlarına göre yavaş üreyen, pigmentsiz, hemoliz yapmayan, çok küçük kolonilerle karakterize S. aureus küçük koloni varyantlarının (KKV), atipik fenotipik ve metabolik özellikleri nedeniyle laboratuvar tanısı güçlükle konabilmektedir1. Klinik mikrobiyoloji laboratuvarlarında doğru tanımlanması gereken bu suşlar, atipik koloni morfolojileri nedeniyle gözden kaçırılabilmekte veya sıklıkla kontaminasyon olarak değerlendirilerek hatalı sonuçlar verilebilmektedir2. Antibiyotik duyarlılıklarının saptanması açısından da farklılık gösteren bu izolatlar Gram boyama sonuçlarının değişkenlik göstermesi nedeniyle de kolay tanımlanamamaktadır. Bu olgu, kistik fibrosizli (KF) bir hastanın balgamından izole edilen bir KKV suşu üzerinden, laboratuvarda saptanması ve tanımlanması sorunlu olan bu mikroorganizmaya dikkat çekilmesi amacıyla sunulmuştur.

Serotype Prediction for Frequently Isolated Serotypes of Streptococcus Pneumoniae by Heteroduplex Analysis and Modification of This Technique to Real-Time Fluorometric Nucleic Acid Detection System

ABS TRACT Ob jec ti ve: Se ve ral mo le cu lar se roty pe pre dic ti on met hods ha ve be en pub lis hed in or der to simp lify the pne u mo coc cal se roty ping. The aim of this study is to de ve lop a mo le cu lar se roty pe pre dic ti on tech ni qu e al ter na ti ve to ot her mo le cu lar ap pro ac hes. Ma te ri al and Met hods: S. pne u mo ni a e se roty pes 1, 3, 5, 6A, 7F, 8, 9V, 11A, 14, 15B, 18C, 19A, 19F and 23B, that are the most fre qu ently iso la ted se roty pes from in fec ti ons in Tur key, we re inc lu ded in the study. S. pne u mo ni a e cpsA and cpsB ge nes that are in vol ved in the pro ces sing, re gu la ti on and ex port of the cap su lar poly sacc ha ri des, we re amp li fi ed by polymerase chain reacsion (PCR). Then, he te ro dup lex analy sis was per for med to the 1.8 kb PCR pro ducts ob ta i ned from all se roty pes with cons tant se roty pe 1. This tech ni qu e was then mo di fi ed to re al-ti me flu o ro met ric nuc le ic acid de tec ti on system. Re sults: The PCR pro ducts ob ta i ned from se roty pes 1, 6A, 14 and 19F sho wed only ho mo dup lex bands whi le tho se from se roty pes 3, 5, 7F, 8, 9V, 11A, 15B and 23B sho wed spe ci fic he te ro dup lex bands. Alt ho ugh se roty pes 18C and 19A sho wed a spe ci fic he te ro dup lex ban ding pat tern, they co uld not be dif fe ren ti a ted from each ot her. When furt her he te ro dup lex analy sis was per for med to se roty pes 1, 6A, 14 and 19F with se roty pe 5 as a cons tant com po nent, se roty pe 1 and 6A co uld be dif fe ren ti a ted from the ot hers. He te ro dup lex and ho mo dup lex DNA strands co uld be dis tin gu is hed by mel ting cur ve analy sis in re al-ti me flu o ro met ric nuc le ic acid de tec ti on system. Conc lu si on: As a ra pid and cost-ef fec ti ve met hod, re al-ti me he te ro dup lex analy sis may be an al ter na ti ve to ot her mo le cu lar met hods for se roty pe pre dic ti on of pne u mo coc ci.

Influence of Campylobacter Jejuni on Human Neutrophil Chemotaxis

C.jejuni has been shown to be a major cause of human gastroenteritis1. The pathogenic mechanisms of C.jejuni diarrhoea are not yet clarified. Invasiveness, enterotoxin production and elaboration of cytotoxin have been suggested as potential pathogenicity factors5.