Evaluating the effectiveness of anti-tuberculosis treatment by detecting Mycobacterium tuberculosis 85B messenger RNA expression in sputum.

BACKGROUND: The antigen 85 complex (85B) is secreted in large quantities from growing mycobacteria and the presence of bacterial mRNA is an indicator of cell viability. The quantitative detection of 85B mRNA expression levels can be used to assess the success of anti-tuberculosis treatment outcomes to detect viable mycobacteria cells. Therefore, we evaluated the levels of 85B mRNA of Mycobacterium tuberculosis strains in patients with pulmonary tuberculosis. METHODS: Thirty patients with primary tuberculosis were included in this study. The sputum specimens of patients were collected on days 0, 15, and 30 days and were cultured and evaluated by 85B mRNA-based RT-qPCR. RESULTS: Overall, 23 of the studied tuberculosis strains were susceptible to the primary anti-tuberculosis antibiotics used in this study, 7 were resistant. By the 30th day of treatment, 85B mRNA was detected in only one of the susceptible strains, but in all 7 of the resistant strains, though the relative gene expression varied between the strains. This difference between the susceptible and resistant strains at day 30 was statistically significant (p < 0.05). CONCLUSION: 85B mRNA expression levels could be used to follow up on primary tuberculosis cases. 85B mRNA seems to be a good diagnostic marker for monitoring anti-tuberculosis treatment outcomes.

Diagnostic performance of the RT-qPCR method targeting 85B mRNA in the diagnosis of pulmonary Mycobacterium tuberculosis infection.

BACKGROUND: Several nucleic acid amplification techniques (IS6110, 16S rRNA, and 85B mRNA) were developed for the rapid, direct detection of Mycobacterium tuberculosis. We aimed to assess the diagnostic performance of 85B mRNA-based RT-qPCR by comparing with the real-time PCR COBAS TaqMan MTB Kit while using the BACTEC MGIT 960 method as the gold standard. METHODS: 60 patients with confirmed pulmonary TB and 60 individuals without TB were included as the study and control groups, respectively. Sputum specimens were cultured using LJ and BACTEC MGIT 960 systems. Extracted DNA was used for COBAS PCR in a CONAS TaqMan 48 analyzer. 85B mRNA detection was performed by RT-qPCR. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of COBAS TaqMan MTB Test were detected as 93.3%, 83.3%, 84.8%, 92.6%, and 88.3%, respectively. The same diagnostic parameters of RT-qPCR were: 98.3%, 95.0%, 95.2%, 98.3%, and 96.7%, respectively. According to the binary logistic regression analysis, RT-qPCR (OR: 19,924, p<0.001) was identified as the more optimal test. CONCLUSION: RT-qPCR targeting the 85B gene of M. tuberculosis seems to be a more useful and rapid technique than DNA-based methods for detecting live M. tuberculosis bacilli from sputum specimens.

Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results.

BACKGROUND: The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years. OBJECTIVES: Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern. METHODS: The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius™ HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR. RESULTS: LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius™ HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA. CONCLUSION: Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests.

The Prevalence of Cyclospora cayetanensis and Cryptosporidium spp. in Turkish patients infected with HIV-1.

Opportunistic infections such as cryptosporidiosis and cyclosporiasis are commonly encountered in patients with acquired immunodeficiency syndrome (AIDS). We investigated the existence of opportunistic protozoans that significantly affect the quality of life in HIV-1 infected patients using conventional and molecular methods. The study group comprised 115 HIV-1 positive patients. In the identification of Cyclospora cayetanensis and Cryptosporidium, the formol-ether precipitation method was used and smears were evaluated in optical microscope by staining modified Ziehl-Neelsen (ZN). The primers and probes used for PCR were Heat shock protein 70 for C. cayetanensis and the oocysts wall protein for Cryptosporidium spp.. Cyclospora and Cryptosporidium spp. oocysts were detected in one and two patients, respectively, by staining, whereas we detected C. cayetanensis in three patients out of 115 (2.6%) by PCR, and Cryptosporidium spp. in a further three patients (2.6%). C. cayetensis was detected in patients with CD4 counts of 64 cells/µm, 182 cells/µm and 287 cells/µm, respectively. Cryptosporidium spp. was detected in patients with CD4 counts of 176 cells/µm, 241 cells/µm and 669 cells/µm. As conclusion, PCR method is faster and more sensitive than microscopic methods and to screen intestinal pathogens routinely in patients infected with HIV should not be neglected in developing countries like Turkey.

Patterns of EPIYA motifs among cagA-positive Helicobacter pylori strains: a case-control study in a Turkish population with Eurasian geographical features.

Geographical variation in the frequency of various gastroduodenal pathologies was shown to be related to the geographical diversity of H. pylori CagA Glu-Pro-Ile-Tyr-Ala (EPIYA) patterns. We examined the EPIYA patterns of H. pylori and the association of EPIYA patterns with gastric cancer (GC) for the first time, to the best of our knowledge, in Turkey. The patient group (PG) contained 60 patients [38 GC and 22 duodenal ulcer (DU) patients]. The control group (CG) was 110 individuals [94 gastritis patients and 16 persons with a normal gastrointestinal system (NGIS)]. Specific primers were used for the detection of cagA including empty-site-positive and EPIYA-A, -B, -C, -D PCR. Bands of EPIYA-A, -B, -C were confirmed by DNA sequencing. One hundred and forty-two (83.5 %) strains [60 in the PG (38 GC, 22 DU), 82 in the CG (72 gastritis, 10 NGIS)] were positive for the cagA gene. EPIYA-C with multiple repeats was detected in 34 (23.9 %) strains, and 22 (64.7 %) were from GC patients. EPIYA-C with one repeat was detected in 89 (62.7 %) strains, and 54 (60.7 %) were from gastritis patients. EPIYT was detected in 10 strains, and EPIYA-D was not detected. The number of EPIYA-C with multiple repeats was significantly higher for the PG than for the CG (P < 0.0001). In GC patients, the number of EPIYA-C with multiple repeats was significantly higher than one repeat (P < 0.0001). In conclusion, our study showed that multiple EPIYA-C repeats increases the GC risk by 30.6-fold and the DU risk by 8.9-fold versus the CG. This indicates that Western-type H. pylori strains in Turkey have similar EPIYA motifs to those of neighbouring countries and Western populations.

The cytokine response in THP-1 (monocyte) and HL-60 (neutrophil-differentiated) cells infected with different genotypes of Helicobacter pylori strains.

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) is a microaerophilic bacterium related with peptic ulcer and gastric cancer. Its virulence factors include cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene A (VacA) proteins. Cytokine release inducted by H. pylori colonization has an important role in pathogenesis of H. pylori. The severity of gastric pathologies depends on the H. pylori genotypes found in different geographical regions. We aimed to determine the relationship between different H. pylori genotypes and their effects on the cytokine release levels. MATERIALS AND METHODS: ureC, cagA, vacAs1/s2, vacAm1/m2, and blood group antigen-binding adhesion protein A2 (babA2) virulence related genes were investigated in 21 H. pylori strains. Genotyping of 21 strains were made due to the presence of cagA, vacAs1/s2, vacAm1/m2, and babA2 genes. The H. pylori strains were cultured together with THP-1 and neutrophil-differentiated Human promyelocytic leukemia cells (HL-60) cells. The levels of cytokines interleukin (IL)-1ß, IL-6, IL-8, IL-12, tumor necrosis factor-alpha (TNF-α), and IL-10 in these cells were measured after co-culturing with H. pylori strains. RESULTS: The following five different genotypes were detected: Genotype1: cagA and vacAs1m2; Genotype2: cagA and vacAs1m1; Genotype3: cagA, vacAs1m2, and babA2; Genotype4: vacAs2m2; and Genotype5: cagA and vacAs2m2. All these genotypes significantly induced the levels of IL-1ß, IL-6, IL-8, IL 10, and TNF-α in THP-1 cells. Genotype 5 caused higher amounts of IL-1ß, IL-6, TNF-α, and IL-10, whereas genotype 1 induced the highest levels of IL-8. In neutrophil-differentiated HL-60 cells, genotype 4 increased IL-6 levels and genotype 3 and 4 elevated IL-8 levels significantly. CONCLUSION: These results suggested that cytokine response of the host varies depending on the specific immune response of the host against different H. pylori strains.

The role of Porphyromonas gingivalis in the development of atherosclerosis and its relationship with fim A genotype.

BACKGROUND: Porphyromonas gingivalis, a major periodontal pathogen, is gaining increasing attention for its possible association with atherosclerosis. Its fimbriae are classified into six genotypes (Types I-V, Ib) based on the diversity of the fim A genes encoding the fimbrial subunits. In this study, fim A genotype's distribution of P. gingivalis was analyzed in atherosclerotic plaque specimens. METHODS: A total of 50 atherosclerotic plaque specimens and 50 non-atherosclerotic, post stenotic aneurysm specimens were collected from patients undergoing cardiovascular surgery. Bacterial DNA was also extracted from each specimen, as real-time PCR was carried out with P. gingivalis-specific primer sets. The positive specimens of P. gingivalis were further analyzed to discriminate the fim A genotype using real-time and nested PCR methods. RESULTS: P. gingivalis was detected only in one atherosclerotic plaque; however, the genotype was nontypable in this specimen. CONCLUSIONS: We state that it is not easy to show a significant relationship between P. gingivalis, its fim A genotype, and atherosclerosis. We suggest that new extended studies based especially upon the quantitave determination of P. gingivalis and its genotype distribution on atherosclerotic specimens are needed to show an evident relationship between atherosclerosis and P. gingivalis.

The importance of transmission time in HIV infections and an epidemiological prospective follow-up study for 1 year in the Marmara Region of Turkey.

It is important to detect recent and new HIV/1 infections and to take preventative measures in order to prevent rapid disease progression in AIDS and to decrease the incidence of infection. We aimed to detect long standing or recent HIV infections by determining transmission times for the cases in which first-time HIV/1 seropositivity were detected. The serum samples of 323 cases which were found to be seropositive by ELISA and Western-blotting were included in this study. The discrimination between long-term and recent HIV/1 infection was made by determining transmission-time with the Aware BED-EIA, HIV-1 incidence test (IgG capture HIV-EIA) tests. Ninety-six healthy blood donors who did not have a positive anti-HIV test and a chronic infectious disease for at least 1 year were included in this study as a negative healthy control group. In the discrimination of long-term and recent HIV/1 infections, only in vitro ODn values were used. The cases with normalized optical density (OD) (OD(specimen)/OD(calibrator))<0.8 by commercial kit were accepted as recent HIV infection (155 days history or seroconversion less than 6 months). The cases with ODn >1.2 were accepted as long-term HIV/1 infections (more than 155 days history or more than 6 months). The cases with ODn between 0.8 and 1.2 were accepted as "additional tests needed" cases. We detected recent HIV/1 infections (<6 months) in 60 (18.5%) out of 323 cases and long-term HIV/1 infections (>6 months) in 263 (81.5%) out of 323 cases. The most frequently encountered transmission route in long-term and recent HIV/1 infections was heterosexual sexual intercourse as 54 (50%) and 257 (97%), respectively. 63.3% of newly infected patients were married females and 65.3% of recently infected patients were males. In conclusion, the detection of the high ratio of long-term HIV/1 infection cases (81.5%) compared to recent infections (18.5%) suggested to us, that the long standing cases may have some activities related with transmission of HIV/1 in the past. The detection of higher HIV/1-infections in individuals which had heterosexual sex and also in married males suggested that this situation poses a very great threat for the health of society.

New approaches to in vitro diagnosis of hepatitis C infection a reason for post transfusion hepatitis: Diagnostic value of determination of hepatitis C virus core antigen.

In between the dates of February 2008-March 2009, by applying to Istanbul University CTF Microbiology and Clinical Microbiology Basic Sciences Branch and Duzen laboratories, 123 cases, where HCV RNA and anti-HCV positivity are identified with molecular (real-time PCR) and serologic (ELISA) methods as a positive control group, and 48 cases where HCV RNA and anti-HCV negativity are identified as a negative control group are established. The values of sensitivity, specificity, positive and negative approximation of recently developed HCV Core Ag (Abbott Diagnostics, Germany) kit are determined successively as 94.3%, 97.9%, 99.1%, 87%, 95.3% and 88%. Although the new HCV Ag assay is clearly not sensitive enough to replace HCV NAT it may serve as a valuable tool in the HCV diagnostic algorithm as it is able to pick up a great majority of anti-HCV and HCV RNA positive samples, thus allowing a timely and less expensive serological diagnosis of an active HCV infection. This may be an advantage for labs that do not have access to PCR easily.

Aneurysm and Helicobacter pylori relationship: the seropositivity of CagA, VacA and other antigens of Helicobacter pylori in abdominal and ascending aortic aneurysms.

Helicobacter pylori is thought to be related to atherosclerosis and aneurysm development. We aimed to detect virulance factors of H. pylori and examine the potential etiopathogenetic relationship between aortic aneurysm and H. pylori, 58 abdominal aortic aneurysm (AAA) and 38 ascending aortic aneurysm (AsAA) cases and 57 Healty control group (HCG) were included. We investigated H. pylori IgG by ELISA and virulance factors by Western-Blot (WB) method. No difference was found between AAA (67.24%), AsAA (73.68%) and HCG (57.89%) for H. pylori IgG (p > 0.05). A significant difference was found between AsAA (78.95%) and HCG (57.89%) for H.pylori IgG (p < 0.05) by ELISA and a significant difference was found only between AsAA (100%) and HCG (37.5%) for H. pylori IgG in the 45-55 age group by WB. A statistically significant difference was found between AAA and AsAA for VacA and CagA + VacA and CagA + VacA + UreA antigens and also a significant difference was found between AsAA and HCG for CagA + UreA antigens (p < 0.05). Finally, we suggest that H. pylori VacA has a more important role than CagA in the development of two aneurysms especially in ruptured AAA. New extended studies detecting H. pylori DNA are needed to detect the aetiopathogenesis between aneurysm types and H. pylori.