Tanil Kocagöz

Rapid Detection of Rifampin Resistance in Mycobacterium tuberculosis Isolates by Heteroduplex Analysis and Determination of Rifamycin Cross-Resistance in Rifampin-Resistant Isolates

ABSTRACT Direct heteroduplex analysis and a universal heteroduplex generator assay were performed to detect rifampin resistance rapidly in Turkish Mycobacterium tuberculosis isolates. Cross-resistance to rifapentine, rifabutin, and rifalazil was investigated. A relationship between specific mutations and resistance patterns, which can guide the choice of an appropriate therapeutic regimen for tuberculosis patients, was identified.

Polymerase chain reaction in cutaneous tuberculosis: is it a reliable diagnostic method in paraffin-embedded tissues?

Background Most cutaneous tuberculosis lesions contain few bacilli, so identification of Mycobacterium tuberculosis in conventional laboratory tests is difficult. In vitro amplification of specific DNA sequences using polymerase chain reaction (PCR) has become a valuable tool in the rapid detection of slow‐growing organisms like M. tuberculosis.

Examination of mycosis fungoides for the presence of Epstein–Barr virus and human herpesvirus‐6 by polymerase chain reaction

The aetiology of cutaneous T‐cell lymphoma (CTCL) remains unknown despite numerous investigations. In recent years, retroviruses and human herpesviruses have been implicated to play a causal part in CTCL.

Epidemiology of chronic Pseudomonas aeruginosa infections in cystic fibrosis

Chronic lung infection with Pseudomonas aeruginosa is primarily responsible for pulmonary deterioration of cystic fibrosis patients. The purpose of this study was to type the P. aeruginosa isolates collected sequentially from cystic fibrosis patients, chronically colonized with P. aeruginosa, by random amplified polymorphic DNA fingerprinting-PCR (RAPD-PCR). Sequential P. aeruginosa isolates (n: 130) that had been collected from 20 CF patients over at least 9 years were investigated. The isolates were analyzed by RAPD-PCR using two arbitrary primers. Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. RAPD-PCR typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some CF patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. However, some patients may be colonized with more than one genotype. The results also demonstrated that there might be a risk of cross-colonization between CF patients followed-up at the same center.

Evaluation of 120 Mycobacterial Strains Isolated from Clinical Specimens to the Species Level by Polymerase Chain Reaction-Restriction Enzyme Analysis

In this study, a total of 120 mycobacterial strains isolated from clinical specimens in Hacettepe University Hospital Clinical Pathology Laboratories were evaluated by polymerase chain reaction-restriction enzyme analysis (PRA), which analyses the common mycobacterial heat shock protein gene (hsp65). 95 of 120 strains (79.1%) were identified as Mycobacterium tuberculosis and 25 (20.8%) were identified as non-tuberculous mycobacteria (NTM). M. gordonae I and IV were the most common NTM species (3.3% each) followed by M. chelonae (2.5%). Other NTM species isolated were M. gordonae III, M. avium, M. peregrinum (1.6%), M. fortuitum, M. flavescens, M. malmoense and M. mucogenicum (0.8%). Four isolates had PRA patterns that did not match any patterns previously described. The patients who had NTM had underlying diseases; the most frequent clinical diagnosis among these was chronic obstructive pulmonary disease (COPD) and chronic renal failure. AIDS and pulmonary carcinoma were the other underlying diseases detected.In this study, a total of 120 mycobacterial strains isolated from clinical specimens in Hacettepe University Hospital Clinical Pathology Laboratories were evaluated by polymerase chain reaction-restriction enzyme analysis (PRA), which analyses the common mycobacterial heat shock protein gene (hsp65). 95 of 120 strains (79.1%) were identified as Mycobacterium tuberculosis and 25 (20.8%) were identified as non-tuberculous mycobacteria (NTM). M. gordonae I and IV were the most common NTM species (3.3% each) followed by M. chelonae (2.5%). Other NTM species isolated were M. gordonae III, M. avium, M. peregrinum (1.6%), M. fortuitum, M. flavescens, M. malmoense and M. mucogenicum (0.8%). Four isolates had PRA patterns that did not match any patterns previously described. The patients who had NTM had underlying diseases; the most frequent clinical diagnosis among these was chronic obstructive pulmonary disease (COPD) and chronic renal failure. AIDS and pulmonary carcinoma were the other underlying diseases detected.

INDUCTION OF MYCOBACTEREMIA BY INTRAVESICAL BACILLUS CALMETTE-GUERIN INSTILLATION IN AN EXPERIMENTAL ANIMAL MODEL AND DETECTION WITH POLYMERASE CHAIN REACTION

PURPOSE The aim of this study was to detect mycobacteremia by polymerase chain reaction (PCR), induced by the instillation of bacillus Calmette-Guerin (BCG) to guinea pig bladder. We also investigated the peak time and the effect of the dose of BCG in injured and non-injured bladder. The sensitivities of routine culture and PCR were also compared. MATERIALS AND METHODS Five different doses (0, 0.069, 0.69, 6.9 and 69 mg.) of BCG were instilled into 5 injured and 5 non-injured bladders. Blood samples were collected at 0, 5, 15, 30 and 60 minutes following instillation for routine culture and PCR for each dose. A total of 50 female guinea pigs were used. RESULTS Three of 5 samples (60%) obtained 30 minutes after the instillation of 69 mg. BCG into injured bladders were PCR positive. Furthermore, 4 of 5 samples (80%) were PCR positive when samples were obtained at the 60th minute following instillation. All the other samples were negative for PCR and routine culture. All the routine tuberculosis culture results were negative, including those which were PCR positive. CONCLUSIONS Mycobacteremia was detected only in injured bladders and with high doses of BCG. PCR is a highly sensitive and rapid diagnostic method for detection of mycobacteremia.

Detection of Listeria monocytogenes in Milk by the Polymerase Chain Reaction

A on the polymerase chain reaction (PCR) method based was developed for detection of Listeria monocytogenes in milk samples after enrichment culture. It consists of culturing samples in Listeria enrichment broth, followed by DNA extraction and detection of the organism using PCR. Dilutions of L. monocytogenes in milk were subjected to PCR amplification after enrichment culture. When determining the sensitivity of the method, it was found to be possible to detect 37 CFU (colony forming unit gl/ml) of the bacterium in milk. The method was assessed as a sensitive, specific, times-saving and practical way of detecting L. monocytogenes in milk samples.