[In vitro Activity of Rifabutin and Clofazimine to Macrolide-Resistant Mycobacterium abscessus Complex Clinical Isolates]. / Rifabutin ve Klofaziminin Makrolidlere Dirençli Mycobacterium abscessus Kompleks Klinik Izolatlarina In vitro Etkinligi.

Mycobacterium abscessus complex (MABSC) is one of the most resistant bacteria against antimicrobial agents. The number of agents that can be used by oral route, such as macrolides, is limited in antimicrobial therapy. In recent years, rifabutin and clofazimine have gained importance as they can be administered by oral route and have shown synergistic effects with macrolides and aminoglycosides. The aim of this study was to determine the in vitro activity of rifabutin and clofazimine against clinical isolates of MABSC resistant to macrolides. A total of 48 MABSC isolates obtained from respiratory tract and other clinical samples in the Tuberculosis Laboratories of the Faculty of Medicine of Manisa Celal Bayar and Ege Universities were included in the study. Subspecies differentiation and aminoglycoside and macrolide resistance of the isolates were determined by GenoType NTM-DR test. Rifabutin and clofazimine susceptibilities were determined by standard broth microdilution method. Of the MABSC isolates 42 were identified as M.abscessus subsp. abscessus, three as M.abscessus subsp. bolletii and three as M.abscessus subsp. massiliense. None of the isolates exhibited rrs and rrl mutations indicating acquired macrolide resistance and aminoglycoside resistance. However, the erm(41) T28 genotype which is associated with inducible macrolide resistance was detected in 41 (85%) of the strains. All M.abscessus subsp. massiliense isolates were found to be genotypically susceptible to macrolides. The minimum inhibitory concentration (MIC) range values for rifabutin were 0.0625 to 32 µg/mL, while for clofazimine, the range was 0.0625 to 1 µg/mL. Rifabutin MIC values were significantly higher (mean 5.98 µg/mL vs 0.5 µg/mL, p= 0.026) in the isolates with macrolide resistance. There was no correlation between macrolide resistance and clofazimine MIC values (mean 0.25 µg/mL vs. 0.214 µg/mL, p= 0.758). The MIC50 and MIC90 values for rifabutin were 1 and 8 µg/mL, respectively, while for clofazimine they were 0.25 and 0.5 µg/mL. Macrolide resistance was found to be higher in isolates with rifabutin MIC values above the MIC50 value (p= 0.045). In conclusion, the determination of higher rifabutin MIC values in isolates resistant to macrolides suggested that susceptibility testing should be performed before adding rifabutin to the treatment regimen. The low MIC values of clofazimine in all strains indicated that it may be used as a first choice in the combination therapy. However, further studies using a larger number of clinical isolates and applying genotypic and phenotypic susceptibility tests are needed to determine threshold MIC values to assist clinicians in making treatment decisions.

The reliability of tuberculin skin test in the diagnosis of latent tuberculosis infection in psoriasis patients: A case-control study.

Tuberculin skin test (TST), which is used in the diagnosis of latent tuberculosis infection, may cause Koebner's phenomenon and false-positive results in psoriasis patients. The purpose of this study is to compare TST with QuantiFERON-TB Gold Plus (QFT-plus) test in psoriasis patients and to determine the effects of psoriasis on TST results. Ninety-two psoriasis patients and 30 control subjects were included in the study. QFT-plus test, TST, and prick test to distinguish the increase of induration because of the skin trauma were performed on both groups. The demographics, risk factors for latent tuberculosis infection, BCG vaccination history, Koebner's history, psoriasis severity, and treatment history of the patients were recorded. The effects of these variables on test results were investigated by comparing those with control group. The criteria of National Tuberculosis Diagnosis and Treatment Guidelines were used in the evaluation of test results, and threshold value of positivity for TST was taken as 10 mm in BCG-vaccinated patients who are planned to start biological treatment. Prick test results were negative in the control group. There was no significant relation between the results of prick test and TST induration diameters in the patient group. Although TST positivity was significantly higher in patients (62%) compared with control group (33%), QFT-plus test results were not statistically different between two groups. Agreement between two tests was determined to be low in patient group with 48% (K = 0.1), and it was determined to be moderate with 77% in control group (K = 0.4). QFT-plus test was found to be negative in 46 of 57 TST-positive patients (80.7%) in patient group. It was determined in both groups that vaccination did not have any effect on test results. When threshold value was lowered to 5 mm in patient group without considering BCG reaction, the number of TST-positive patients increased from 57 to 65. Mean TST induration diameter was 10 mm and 14 mm in cases with mild and moderate to severe clinical manifestation, respectively (P = .04). However, no effect of disease period and treatment was determined on both test results. TST positivity was higher in psoriasis patients compared with control group. It was considered due to the increased reaction of the skin to mycobacterial antigens rather than the Koebner's response. Although TST results were not affected by BCG, it was concluded that a 10-mm threshold value of positivity was a suitable approach in order to reduce the number of patients receiving unnecessary preventive treatment in patients who are considered to initiate biologic agents. Furthermore, it was also concluded that QFT-plus test may be preferred in psoriasis patients since it is applied in vitro and its specificity is higher and not affected by disease severity.

A new colorimetric method for rapid detection of ethambutol and streptomycin resistance in Mycobacterium tuberculosis: crystal violet decolorization assay (CVDA).

Streptomycin (STR) and ethambutol (EMB) are important drugs used for the treatment of tuberculosis. There is a need for fast, reliable and inexpensive methods for detecting resistance to these drugs. The aim of this study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for the detection of STR and EMB resistance that is important drugs in tuberculosis treatment. In this study, drug susceptibility testing was performed on 140 Mycobacterium tuberculosis isolates provided from nine centers. Three tubes were used for each isolate. One of the tubes had a concentration of 2 mg/L STR and the other 5 mg/L EMB. The third was drug-free control tube. Sensitivity, specificity, positive predictive value (PPD), negative predictive value (NPD) and agreement for STR were found to be 81.8%, 94.6%, 87.8%, 91.5% and 90.57%, respectively. For EMB, sensitivity, specificity, PPD, NPD, and agreement were found to be 76%, 98.23%, 90.47%, 94.87% and 94.2%, respectively. The results were obtained in 11.3 ± 2.7 days (8-21 days). CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of STR and EMB resistance, and it could be adapted for drug susceptibility testing.

Immune responses elicited by the recombinant Erp, HspR, LppX, MmaA4, and OmpA proteins from Mycobacterium tuberculosis in mice.

Immunogenic potency of the recombinant Erp, HspR, LppX, MmaA4, and OmpA proteins from Mycobacterium tuberculosis (MTB), formulated with Montanide ISA 720 VG adjuvant, was evaluated in BALB/c mice for the first time in this study. The five vaccine formulations, adjuvant, and BCG vaccine were subcutaneously injected into mice, and the sera were collected at days 0, 15, 30, 41, and 66. The humoral and cellular immune responses against vaccine formulations were determined by measuring serum IgG and serum interferon-gamma (IFN-γ) and interleukin-12 (IL-12) levels, respectively. All formulations significantly increased IgG levels post-vaccination. The highest increase in IFN-γ level was provided by MmaA4 formulation. The Erp, HspR, and LppX formulations were as effective as BCG in enhancement of IFN-γ level. The most efficient vaccine boosting the IL-12 level was HspR formulation, especially at day 66. Erp formulation also increased the IL-12 level more than BCG at days 15 and 30. The IL-12 level boosted by MmaA4 formulation was found to be similar to that by BCG. OmpA formulation was inefficient in enhancement of cellular immune responses. This study showed that MmaA4, HspR, and Erp proteins from MTB are successful in eliciting both humoral and cellular immune responses in mice.

[Risk of travel associated tuberculosis]. / Seyahat ile iliskili tüberküloz riski.

Tuberculosis has spread by human movements throughout history. There have been reports indicating tuberculosis transmission on all travel vehicles, including aircrafts, ground vehicles and vessels until today. However, due to the ever increasing of air transportation and air travelling among countries with low and high tuberculosis incidence, transmission risk especially in aircrafts has become an important issue worldwide. But in many of the studies conducted in this regard, transmission of tuberculosis in aircrafts was found very low. The case of active tuberculosis has not yet been reported. This is due to the fact that in modern aircrafts, there are ventilation systems that provide hepa filtered laminar air flow and change the air 15-20 times per hour. The guidelines for the prevention of tuberculosis infection in aircrafts published by the World Health Organization "Tuberculosis and Air Travel, 2008" and European Centre for Disease Prevention and Control "RAGIDA-TB, 2014" confirm each other. According to these guidelines, air travelling of patients with active pulmonary tuberculosis should be prohibited until smears of two consecutive sputum samples become negative for drug susceptible cases, and cultures of two consecutive of sputum samples become negative for multidrug or extensively drug resistant cases. When it is reported that a tuberculosis patient has travelled by the aircraft, it is recommended that the exposed passengers should be investigated for tuberculosis infection if the flight duration equal to or exceeding eight hours including ground delays and the time elapsed between flight and diagnosis of the case is no longer than three months. Contact screening is only recommended for passengers sitting in the same row, two rows ahead and two rows behind the index case. Tuberculin skin test or interferon gamma release assay can be used for investigation. It is very difficult to determine the risk of tuberculosis transmission in ground vehicles like buses, subways and trains. The reason is that it is often not possible to access the information of the passengers travelling in these vehicles. Because the ventilation systems in ground vehicles are not as reliable as in aircrafts and the crowded environment in the ground vehicles, the risk of tuberculosis transmission is theoretically higher. In modelling studies, the transmission risk in the buses was found to be higher than the trains. In the case of regular travelling with an index case such as school bus riders, the risk increases significantly. The increased human population travelling all over the world nowadays has also raised concerns about travel-related tuberculosis risk. However, because of the limited evidence, it may be more efficient to spend time and resources for the other actions in order to prevent tuberculosis. In this review article, the transmission risk of tuberculosis in vehicles has been discussed.

Evaluation of the performance of MALDI-TOF MS and DNA sequence analysis in the identification of mycobacteria species

Background/aim: Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry is an alternative way of identifying mycobacteria via the analysis of biomolecules. It is being increasingly used in routine microbiology practice since it permits early, rapid, and cost-effective identification of pathogens of clinical importance. In this study, we aimed to evaluate the efficacy of phenotypic identification of mycobacteria by the MALDI-TOF MS MBT Mycobacteria Library (ML) 4.0 (Bruker, Daltonics) compared to standard sequence analysis. Materials and methods: A total of 155 Mycobacterium clinical and external quality control isolates, comprising nontuberculous mycobacteria (NTM) (n = 95) and the Mycobacterium tuberculosis complex (MTC) (n = 60), were included in the study. Results: Identification by MBT ML4.0 was correctly performed in 100% of MTC and in 91% of NTM isolates. All of the MTC isolates were correctly differentiated from NTM isolates. Conclusion: Based on our results, MBT ML4.0 may be used reliably to identify both NTM and MTC.

[Multicenter evaluation of the indirect nitrate reductase assay for the rapid detection of multidrug-resistant tuberculosis]. / Çok ilaca dirençli tüberkülozun hizli tespiti için dolayli nitrat redüktaz testinin çok merkezli degerlendirilmesi.

Multidrug-resistant tuberculosis (MDR-TB) is defined as resistance to at least isoniazid (INH) and rifampicin (RIF), and it complicates the implementation of tuberculosis control programmes. The rapid detection of MDR-TB is crucial to reduce the transmission of disease. The nitrate reductase assay (NRA) is one of the colorimetric susceptibility test methods for rapid detection of MDR-TB and based on the ability of reduction of nitrate to nitrite by Mycobacterium tuberculosis. The aim of this study was to evaluate the performance of the NRA for the rapid detection of MDR-TB. A total of 237 M.tuberculosis complex (MTC) isolates that were identified by the same method (BD MGIT(TM) TBc Identification Test, USA) from nine different medical centers in Turkey were included in the study. The susceptibility results of the isolates against INH and RIF obtained by reference test (Bactec MGIT(TM) 960, BD, USA) were then compared with NRA. In order to ensure consistency between centers, Löwenstein-Jensen (LJ) medium with antibiotics and without antibiotics (growth control) and Griess reagent solution were prepared in a single center (Ondokuz Mayis University School of Medicine, Medical Microbiology Department) and sent to all participant centers with the standardized test procedure. After the inoculation of bacteria into the test tubes, the tubes were incubated at 37°C, and after seven days of incubation, 500 µl Griess reagent was added to the LJ medium without antibiotics. If a color change was observed, an equal volume of Griess reagent was added to test LJ media with antibiotics. When a color change was observed in LJ media with antibiotics, it was considered that the isolate was resistant to tested antibiotics. Among 237 MTC isolates, 16 were resistant only to INH and nine were resistant only to RIF; 93 isolates (39.2%) were resistant (MDR) and 119 isolates (50.2%) were susceptible to both of the drugs determined with the reference susceptibility test. In the study, five INH-resistant isolates determined with reference method were found susceptible with NRT and eight INH-susceptible isolates determined with reference method were found resistant with NRT. In contrast, one RIF-resistant isolate determined with reference method was found susceptible with NRT and three RIF-susceptible determined isolates were found resistant with NRT. Accordingly, the concordance rate between the reference method and NRA were estimated as 94.5% for INH and 98.3% for RIF. The sensitivity, specificity, positive and negative predictive values of NRA were detected as 95.4%, 93.7%, 92.8% and 96% for INH, and 99%, 97.8%, 97.1% and 99.2% for RIF, respectively. The results of the 111 isolates were obtained on the seventh day, while the rest of the results were obtained between 10-14 days. In conclusion, the data of this multicenter study showed that NRA is a reliable, relatively inexpensive and practical method to perform for the rapid detection of MDR-TB.

[Distribution of nontuberculous mycobacteria isolated from clinical specimens and identified with DNA sequence analysis]. / Klinik örneklerden soyutlanan ve DNA dizi analizi ile tanimlanan tüberküloz disi mikobakterilerin dagilimi.

The aims of the study were to perform the identification of nontuberculous mycobacteria (NTM) isolated from different clinical specimens in the Mycobacteriology Laboratory of Celal Bayar University, Manisa (located at Aegean region of Turkey), by DNA sequence analysis, and to discuss the epidemiological aspects of the data obtained. Out of 5122 clinical specimens sent to the laboratory with the initial diagnosis of tuberculosis in the period April 2007 to July 2011, M.tuberculosis complex and NTM were identified in 225 (4.39%) and 126 (2.46%) samples, respectively. DNA sequence analysis by targeting hsp65 and 16S rDNA gene regions was performed on 101 of the NTM strains in Mycobacteriology Laboratory of Ege University, Izmir. DNA sequence analysis data was evaluated using RIDOM and GenBLAST data bases. NTM strains were identified as 40 M.porcinum (39.60%), 36 M.lentiflavum (35.65%), six M.abscessus (5.64%), five M.peregrinum (4.95%), four M.gordonae (3.96%), three M.fortuitum (2.97%), two M.chelonae (1.98%), and one for each M.alvei (0.99%), M.scrofulaceum (0.99%), M.kansasii (0.99%) species. Two strains which were both 95-98% compatible with other mycobacteria in the data bases could not be identified with certainty. Seventy-two (94.73%) strains of M.lentiflavum and M.porcinum, which were the most frequent (75.24%) species in the study, were isolated from bronchoalveolar lavage (BAL) specimens. The remaining 99 strains examined could not be proven as the cause of the disease due to absence of patients' clinical data, whereas two M.abscessus strains isolated from the sputum were considered as the cause of the disease according to the ATS/IDSA criteria. The isolation rate of NTM in 2010 was found significantly higher (5.33%) than previous years. Review of the 2010 data showed that all strains of M.porcinum and M.lentiflavum, which were the most frequently identified strains were isolated from BAL specimens. This situation is in line with the start of using of an automatic bronchoscope washing machine in our hospital in the same year. In conclusion, NTM were isolated in 2.46% of the clinical specimens of the patients with the initial diagnosis of tuberculosis and these strains belonged to 10 different NTM species. The two NTM species most frequently isolated in our study were M.lentiflavum and M.porcinum which are known for their potential to cause human infections and antibiotic resistance. As these strains were mostly isolated in BAL specimens, it is concluded that automatic bronchoscope washing machines and water delivery system in the hospitals should be examined in terms of contamination by NTM. The isolated NTM strains could not be distinguished as the cause of the disease or a contaminant, which is the limiting factor in this study. However, knowing that the environmental mycobacteria can cause hospital infections, the data obtained in this study can contribute to epidemiology of NTM infections in Turkey.

[Evaluation of the Xpert MTB/RIF assay for the diagnosis of pulmonary and extrapulmonary tuberculosis in an intermediate-prevalence setting]. / Orta prevalansli bölgede akciger ve akciger disi tüberküloz tanisinda Xpert MTB/RIF testinin degerlendirilmesi.

Early and accurate detection of tuberculosis (TB) is a global priority for TB control. In order to obtain results in a short period of time, nucleic acid amplification tests are increasingly used worldwide for the rapid diagnosis of tuberculosis. The Xpert MTB/RIF® (Cepheid, USA) is a commercially available, real-time PCR-based assay, which can detect both TB and resistance to rifampicin directly in clinical samples. The aim of this study was to evaluate the performance of Xpert MTB/RIF assay for M.tuberculosis detection in pulmonary and extrapulmonary clinical samples in routine laboratory practice in Turkey, an intermediate-prevalence setting. A total of 2639 clinical specimens, 1611 of which were pulmonary and 1028 were extrapulmonary, were included in the study. The results of Xpert MTB/RIF assay were evaluated by comparing the results with those obtained by culture [BACTEC MGIT 960 (Becton Dickinson, USA) and Löwenstein Jensen medium]. Overall sensitivity, specificity, positive and negative predictive values of Xpert MTB/RIF assay were determined as 73.9%, 98.6%, 79.6% and 98.1%, respectively. These values were calculated as 80.8%, 98.8%, 84.9% and 98.4% for pulmonary specimens, and 58.2%, 98.4%, 66.7% and 97.7% for extrapulmonary specimens. The sensitivity and specificity were 100% and 58.1%, respectively, for acid-fast bacilli (AFB) smear-positive specimens, 39.7% and 99.1%, respectively for smear-negative specimens. The sensitivity and specificity were 100% and 76.2% for smear-positive pulmonary specimens; 100% and 20% for smear-positive extrapulmonary specimens; 47.8% and 99.1% for smear-negative pulmonary specimens; and 28.2% and 99.2% for smear-negative extrapulmonary specimens, respectively. The sensitivity and specificity of microscopic examination were found to be 56.7% and 98.7% for all specimens; 63.2% and 98.6% for pulmonary specimens; and 41.8% and 99% for extrapulmonary specimens, respectively. Rifampicin resistance was detected by Xpert MTB/RIF assay in only two specimens, however, rifampicin resistance was failed to be detected by BACTEC MGIT 960 TB method in one of these samples. Xpert MTB/RIF assay appeared to be a reliable method for the diagnosis of TB for AFB smear-positive samples, but less sensitive for smear-negative samples, particularly for extrapulmonary samples which include low numbers of bacilli. However, we concluded that the MTB/RIF is a useful assay for rapid diagnosis of tuberculosis, considering that the results can be given in the same day of sample collection and the assay is superior in sensitivity than microscopic examination.

[Investigation of bacterial etiology with conventional and multiplex PCR methods in adult patients with community-acquired pneumonia]. / Toplum Kökenli Pnömonisi Olan Eriskin Hastalarda Konvansiyonel ve Multipleks PCR Yöntemleriyle Bakteriyel Etiyolojinin Arastirilmasi

Community-acquired pneumonia (CAP) is still a serious life-threatening disease, in which the etiologic agent cannot be identified in more than 50% of patients despite advanced diagnostic methods. The most commonly used methods in the determination of CAP etiology are culture and serological tests. Since early and accurate therapy reduces the mortality in CAP cases, rapid and reliable diagnostic methods are needed. The aim of this study was to determine the bacterial etiology in adult patients with CAP by implementing multiplex polymerase chain reaction/reverse line blot hybridization (M-PCR/RLBH) assay combined with conventional methods. A total of 128 cases (94 were male; age range: 19-81 years, mean age: 58) who were admitted to our hospital and clinically diagnosed as CAP between November 2008 - November 2010, were included in the study. Respiratory samples (sputum and/or bronchoalveolar lavage) obtained from patients were searched by M-PCR/RLBH method (Gen ID®, Autoimmun Diagnostika GmbH, Germany) in terms of the presence of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila nucleic acids. The samples were simultaneously inoculated onto 5% sheep blood agar, chocolate agar, haemophilus isolation agar, buffered charcoal yeast extract-selective agar and EMB agar media for cultivation. Serum samples obtained from the cases were tested for IgM and IgG antibodies against C.pneumoniae by microimmunofluorescence (Focus Diagnostic, USA) and against L.pneumophila and M.pneumoniae by indirect immunofluorescence (Euroimmun, Germany) methods. The bacterial etiology was identified in 59 (46.1%) of 128 patients with CAP and a total of 73 pathogens were detected. The leading organism was S.pneumoniae (n= 32, 25%), followed by H.influenzae and M.pneumoniae (n= 9, 7%), gram-negative bacilli (n= 10, 7.8%), M.catarrhalis (n= 6, 4.7%), C.pneumoniae (n= 4, 3.2%), L.pneumophila (n= 2, 1.6%) and Staphylococcus aureus (n= 1, 1.4%). Infection with atypical pathogens were detected in 15 (11.7%), and mixed infections in 14 (10.9%) patients. The detection rate of microorganisms (S.pneumoniae, H.influenzae, M.catarrhalis, C.pneumoniae, L.pneumophilia, M.pneumoniae) searched by M-PCR/RLBH method was 41.4% (53/128), while those microorganisms were detected in 23.4% (30/128) of the patients by conventional methods, representing a significant difference (p< 0.05). It was concluded that M-PCR/RLBH method supplemented the determination of bacterial etiology in CAP cases by increasing the rate of detection from 23.4% to 41.4%. The results indicated that empirical treatment of CAP should primarily include antibiotics against S.pneumoniae, M.pneumoniae and H.influenzae in our region.

Recent trends in the antibiotic resistance of Helicobacter pylori in patient with dyspepsia.

The aim of this study was to determine the resistance status and to identify the point mutations conferring resistance to clarithromycin and fluoroquinolones among dyspeptic patients in Manisa, Turkey. The study included a sample of 140 patients with an indication for upper gastrointestinal endoscopy randomly selected from 2100 dyspeptic patients attending to the Gastroenterology and Endoscopy Unit at Manisa Celal Bayar University Hafsa Sultan Hospital between April 2016 and May 2018. A commercially available GenoType Helico DR test was used to detect the presence of Helicobacter pylori and mutations associated with resistance to clarithromycin and fluoroquinolones in biopsy specimens. In total, 116 (82.9%) of 140 biopsies obtained from the same number of dyspeptic patients were positive for H pylori and 82 (approximately 71%) of them harbored resistance mutations in 23SrRNA and/or gyrA. Resistance to clarithromycin, levofloxacin, or both were detected in 43.1% (50/116), 27.6% (32/116), and 16/116 (13.8%) of tested biopsies, respectively. The most common mutation conferring resistance to clarithromycin was A2147G (96%, 48/50). Resistance to fluoroquinolones was frequently due to mutation in codon 91 and the most common mutation detected was D91G (34.4%). Heteroresistance patterns were observed in 48.0% (24/50) of clarithromycin-resistant samples and 28.1% (9/32) of levofloxacin-resistant samples. The resistance rates and detected mutations in this study are in line with the country data. However, to achieve better H pylori eradication and to prevent the spread of multidrug-resistant strains in Turkey, the molecular-based susceptibility tests should be considered routinely. Further studies are needed to determine the various mutations among resistant strains.

Multicenter evaluation of AYC.2.2 agar for the isolation of mycobacteria from clinical samples.

PURPOSE: The aim of this multicenter study is to evaluate AYC.2.2 agar for the isolation of mycobacteria from clinical samples. METHODS: Totally 5559 media were tested in 7 centers. AYC.2.2 agar media for the study were prepared by C1 and sent to other centers under appropriate conditions. Other media except AYC.2.2 agar were purchased commercially. The media were subjected to routine laboratory operations in the center where they were sent. After the samples received for routine processing (in all centers, samples were processed with the same method (NALC-NaOH)), they were cultivated on routine media and AYC.2.2 agar afterward. RESULTS: C1: Average growth time was determined as 12.74±3.74 days with MGIT 960 system; 24.42±4.75 days with LJ and 24.37±4.96 days with AYC.2.2 agar. C2: Average growth time was determined as 18.25±9.32 days with TK-Medium, 28.73±7.44 days with LJ, and 31.72±6.35 days with AYC.2.2 agar. C3: Average growth time was determined as 20.48±7.24 days with Ogawa medium, 20.74±7.12 days with LJ, and 20.26±7.43 days with AYC.2.2 agar. C4: Average growth time was determined as 15.27±6.37 days with MGIT 960 system, 22.14±9.1 days with LJ, and 22±8.45 days with AYC.2.2 agar. C5: Average growth time was determined as 13±4.24 days with MGIT 960 system, 32.16±6.23 days with LJ, and 33±5.73 days with AYC.2.2 agar. C6: Average growth time was determined as 9±3.11 days with MGIT 960 system, 18.68±5.32 days with LJ, and 18.34±4.63 days AYC.2.2 agar. C7: Average growth time was determined as 14.74±7.65 with MGIT 960 system, 26.01±8.21 days with LJ, and 26.24±7.88 days with AYC.2.2 agar. CONCLUSIONS: In conclusion, similar results were obtained with LJ and Ogawa media and AYC.2.2 agar. Furthermore, more studies should be conducted for isolation of M. tuberculosis and performing antibiotic susceptibility tests using AYC.2.2 agar before it can be used as a routine media in the laboratories.

Evaluation of real-time PCR method for rapid diagnosis of brucellosis with different clinical manifestations.

In this study, we tested the advantages of TaqMan real time PCR technique and compare it to conventional methods using serum samples from patients with different clinical forms of brucellosis. A total of 50 patients were included in the study. Blood culture using BACTEC 9240 system, Standard Wright's tube agglutination, and real time PCR methods were used. Control blood samples from 30 people with no history of brucellosis or exposure to Brucella spp. were examined too. Serological assay was positive for 49 patients (98%). Forty-four (88%) of the 50 patients had a positive PCR result, whereas Brucella spp were isolated from blood cultures of 18 patients (36%). STA test was all positive for focal brucellosis. Real time PCR test was positive in 9 patients with focal disease (90%), whereas blood culture was positive only in 4 patients (40%). The sensitivity, specificity, positive and negative predictive values of the real time PCR method were calculated as 88%, 100%, 100%, and 83%, respectively. Our results suggest that the high sensitivity and specificity of real time PCR method make it a useful tool for diagnosis of brucellosis with different clinical manifestations.

[Pyrazinamide monoresistant Mycobacterium tuberculosis in Manisa region, Turkey]. / Manisa bölgesinde pirazinamid-monorezistan Mycobacterium tuberculosis.

Pyrazinamide (PZA) is a primary antituberculous drug. BACTEC 460TB is the recommended reference method for the detection of PZA resistance in Mycobacterium tuberculosis. This method is more expensive than the conventional susceptibility methods and therefore, it is recommended that each laboratory should establish their own protocol for the inclusion of PZA in the panel of primary drugs tested. One of the most important factors that help this decision is the prevalence of PZA resistance, particularly PZA monoresistance in the related community. The aim of the present study was to determine the extent of PZA monoresistance in M. tuberculosis complex (MTBC) isolates in our region. In this study, PZA susceptibility testing of 109 MTBC strains (susceptible to isoniazid, rifampicin, ethambutol and streptomycin) isolated from Manisa province in the Aegean region of Turkey was performed by using the BACTEC 460TB radiometric system (Becton Dickinson, MD). Two (1.8%) of the 109 isolates which were susceptible to all primary drugs revealed monoresistance against PZA. One of the PZA-monoresistant isolates has been identified as M. bovis and the other as M. tuberculosis by molecular method (Genotype MTBC, Hain Lifescience, Germany). The results of our study indicated that since the rate of PZA monoresistance was low, susceptibility testing of a panel of primary drugs without PZA may be an economical alternative in our region.

Characterization of rpoB mutations by line probe assay in rifampicin-resistant mycobacterium tuberculosis clinical isolates from the aegean region in Turkey.

The nature and frequency of mutations in the rpoB gene of rifampicin (RIF)-resistant Mycobacterium tuberculosis clinical isolates vary considerably according to the geographical location, and very little information is available regarding specific mutational patterns in our country. The main objective of this study was to determine the frequency of mutations in the hypervariable region of the rpoB gene in RIF-resistant M.tuberculosis isolates recovered from tuberculosis patients in our region by using the INNO-LiPA Rif. TB kit and to evaluate the performance of the kit for the detection of RIF-resistance. Mutations associated with RIF resistance were studied by line probe assay (LiPA) in 65 RIF-resistant and 56 RIF-susceptible M. tuberculosis strains isolated from different patients in the Aegean region of Turkey. The LiPA identified all susceptible strains (100%) as RIF-sensitive and 63 of 65 (96.9%) phenotypically documented RIF-resistant M. tuberculosis isolates as RIF-resistant, with specific detection of mutation in 44 (67.7%) isolates, whilst 2 strains were identified as RIF-susceptible. The R5-pattern (Ser-531-Leu mutation) was the most frequently observed (35 of 65, 53.8%), followed by the deltaS2-pattern (7.7%) and deltaS4-pattern (7.7%).

[Assessment of performance of "amplified Mycobacterium tuberculosis direct test" in pulmonary and extrapulmonary specimens]. / Akciger ve akciger disi orneklerde "amplifiye Mycobacterium tuberculosis direk test" in güvenilirliginin degerlendirilmesi.

Since rapid diagnosis is critical in control of tuberculosis, nucleic acid amplification techniques have been widely used. The purpose of the present study was to assess the performance of Amplified Mycobacterium tuberculosis Direct Test (Amplified MTD Test, Gen-Probe) for the diagnosis of pulmonary and extrapulmonary tuberculosis in our laboratory. A total of 267 specimens (170 pulmonary and 97 extrapulmonary) were tested in the Clinical Mycobacteriology Laboratory of Manisa (a province located in Aegean part of Turkey) University Hospital from September 2001 to March 2005. When Amplified MTD (AMTD) test results were compared to the culture results taken as the gold standard, the sensitivity, specificity, positive and negative predictive values (PPV, NPV) for pulmonary specimens were found to be 84%, 96%, 73%, and 98%, respectively. When AMTD test positive, culture negative discrepant results were evaluated against the clinical history of the patients, these rates were detected as; 88%, 100%, 100%, and 98%, respectively. For 97 extrapulmonary specimens, sensitivity, specificity, PPV and NPV of AMTD test were 60%, 100%, 100%, and 98%, respectively. In conclusion, the results of the AMTD assay were reliable for the rapid diagnosis of pulmonary tuberculosis; if the results were evaluated together with the clinical status of patients, the performance of the test would be increased. However, even though the culture positive extrapulmonary specimens were sparse in our study (5%), the sensitivity of the AMTD test in extrapulmonary specimens was found less than that in pulmonary specimens. Therefore it is thought that AMTD test results should be evaluated carefully for the diagnosis of extrapulmonary tuberculosis.

[Comparison of interferon-gamma whole blood assay with tuberculin skin test for the diagnosis of tuberculosis infection in tuberculosis contacts]. / Temaslilarda tüberküloz enfeksiyonunun tanisi için interferon-gama tam kan testi ile tüberkülin deri testinin karsilastirilmasi.

Tuberculin skin test which is used for the detection of latent tuberculosis (TB), has many disadvantages such as false positivities due to cross reactions between environmental mycobacteria and BCG strain, false negativities due to immunosuppression and malpractice, and also difficulties in application and evaluation. Recently a new diagnostic test which measures the production of interferon (IFN)-gamma in whole blood upon stimulation with specific ESAT-6 and CFP-10 antigens of Mycobacterium tuberculosis has been introduced. Since most of the mycobacteria other than tuberculosis and BCG strain do not contain these antigens, the detection of IFN-gamma levels indicates the specific T-cell response against M. tuberculosis. The aim of the study was to compare the tuberculin skin test and whole blood IFN-gamma assay (QuantiFERON-TB Gold, Cellestis Ltd, Carnegie, Victoria, Australia) for the identification of latent TB infection in the contacts with active TB patients. The tests results were evaluated by using Kappa (K) analysis, and K coefficients of < 0.4, 0.4-0.75 and > 0.75 were accepted as poor, moderate and excellent agreements, respectively. A total of 233 subjects from three risk groups were included to the study. Group 1 included the household members (n = 133) who had contact with smear positive index cases, Group 2 included the subjects from community (n = 46) who had contact with smear positive index cases, and Group 3 included health care workers (n = 74) who had contact with TB patients or their specimens. The positivity rates of tuberculin skin test and IFN-gamma assay in the cases were found as 37% and 42%, respectively. There were no significant differences among the three patient groups with regard to the results of the tuberculin skin test (p > 0.05). However, the positive result of the IFN-gamma assay in Group 1 was found statistically higher than the other groups (51.3%, p = 0.013). A poor agreement between the two tests was detected in the results taken from 233 subjects (65.7%, K = 0.28), while agreement was moderate in unvaccinated group (72.7%, K = 0.44). Evaluation of agreement rates of the tests according to the risk groups yielded 64.6% (K = 0.3) for Group 1, 71.7% (K = 0.32) for Group 2, and 63.5% (K = 0.21) for Group 3, which all coefficients showed poor agreement. Although IFN-gamma blood assay has many advantages such as objective and quantitative results, no interference with vaccination due to the use of specific antigens and being practical, the high cost and the need for well-equipped laboratory are its disadvantages. As a result it was concluded that, IFN-gamma blood assay has limited value for the detection of latent TB infection in our country, since the prevalence of TB infection and BCG vaccination rates are high in Turkey.

Use of DNA hybridization test for diagnosing bacterial vaginosis in women with symptoms suggestive of infection.

The purpose of this study was to evaluate a DNA hybridization test (Affirm VPIII) as an alternative to Gram stain for the rapid diagnosis of bacterial vaginosis in women with clinical signs of vaginal infection. Vaginal specimens were collected from 321 symptomatic women, and analyzed for bacterial vaginosis by both Gram stain using Nugent criteria and DNA hybridization test. Sensitivity, specificity, positive predictive value, and negative predictive value of the DNA hybridization test were determined using the Gram staining as the standard for diagnosis of bacterial vaginosis. Of the 321 patients, 115 (35.8%) were Gram positive for bacterial vaginosis and 126 (39.2%) were negative. 80 patients (25.0%) demonstrated intermediate Gram staining that was also considered negative. The Affirm system detected G. vaginalis in 107 (93.0%) of 115 vaginal specimens positive for bacterial vaginosis diagnosed by Gram stain. Compared to the Gram stain, DNA hybridization test had a sensitivity of 87.7% and a specificity of 96.0%. Positive and negative predictive values of the DNA hybridization test were 93.0% and 92.7%, respectively. In conclusion, Affirm VPIII hybridization test correlated well with Gram stain and may be used as a rapid diagnostic tool to exclude bacterial vaginosis in women with genital complaints.

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.

Increasing antimicrobial resistance in Escherichia coli isolates from community-acquired urinary tract infections during 1998-2003 in Manisa, Turkey.

Urinary tract infections are among the most common infections with an increasing resistance to antimicrobials. The aim of this study was to determine the change in antimicrobial susceptibility of Escherichia coli isolates from patients with community-acquired urinary tract infection (UTI) for the years 1998 through 2003 and to suggest that the current empirical antibiotic therapy used for these patients is inappropriate. During the study period, 7,335 community urine samples of which 1,203 (16.4%) grew bacterial isolates were analyzed. Among the total of 1,203 isolates, 880 (73.2%) were E. coli. The range of resistance of E. coli to ampicillin was 47.8 to 64.6% and that to trimethoprim-sulfamethoxazole was 37.1 to 44.6% during the study period. The susceptibility pattern of E. coli to nitrofurantoin and cefuroxime did not vary significantly over the 6-year period. There was a significant increase in the susceptibility of E. coli to ciprofloxacin (11.3 - 26.7%), amoxicillin-clavulanate (18.4 - 29.2%) and gentamicin (7.0 - 25.6%) (P < 0.05). Empirical initial treatment with ampicillin and trimethoprim-sulfamethoxazole was thus inadequate in approximately half of UTI cases in our region.