A Diagnostic Algorithm for the Detection of Clostridium difficile-Associated Diarrhea.

BACKGROUND: Clostridium difficile is a common cause of hospital-acquired diarrhea, which is usually associated with previous antibiotic use. The clinical manifestations of C. difficile infection (CDI) may range from mild diarrhea to fulminant colitis. Clostridium difficile should be considered in diarrhea cases with a history of antibiotic use within the last 8 weeks (community-associated CDI) or with a hospital stay of at least 3 days, regardless of the duration of antibiotic use (hospital-acquired CDI). AIMS: This study investigated the frequency of CDI in diarrheic patients and evaluated the efficacy of the triple diagnostic algorithm that is proposed here for C. difficile detection. STUDY DESIGN: Cross-sectional study. METHODS: In this study, we compared three methods currently employed for C. difficile detection using 95 patient stool samples: an enzyme immunoassay (EIA) for toxin A/B (C. diff Toxin A+B; Diagnostic Automation Inc.; Calabasas, CA, USA), an EIA for glutamate dehydrogenase (GDH) (C. DIFF CHEK-60TM, TechLab Inc.; Blacksburg, VA, USA), and a polymerase chain reaction (PCR)-based assay (GeneXpert(®) C. difficile; Cepheid, Sunnyvale, CA, USA) that detects C. difficile toxin genes and conventional methods as well. In this study, 50.5% of the patients were male, 50 patients were outpatients, 32 were from inpatient clinics and 13 patients were from the intensive care unit. RESULTS: Of the 95 stool samples tested for GDH, 28 were positive. Six samples were positive by PCR, while nine samples were positive for toxin A/B. The hypervirulent strain NAP-1 and binary toxin was not detected. The rate of occurrence of toxigenic C. difficile was 5.1% in the samples. Cefaclor, ampicillin-sulbactam, ertapenem, and piperacillin-tazobactam were the most commonly used antibiotics by patients preceding the onset of diarrhea. Among the patients who were hospitalized in an intensive care unit for more than 7 days, 83.3% were positive for CDI by PCR screening. If the PCR test is accepted as the reference: C. difficile Toxin A/B ELISA sensitivity and specificity were 67% and 94%, respectively, and GDH sensitivity and specificity were 100% and 75%, respectively. CONCLUSION: Tests targeting C. difficile toxins are frequently applied for the purpose of diagnosing CDI in a clinical setting. However, changes in the temperature and reductant composition of the feces may affect toxin stability, potentially yielding false-negative test results. Therefore, employment of a GDH EIA, which has high sensitivity, as a screening test for the detection of toxigenic strains, may prevent false-negative results, and its adoption as part of a multistep diagnostic algorithm may increase accuracy in the diagnosis of CDIs.

Association of doripenem resistance with OXA-type carbapenemases in Acinetobacter baumannii isolates.

OBJECTIVES: To evaluate the in vitro activity of doripenem in Acinetobacter baumannii (A. baumannii) clinical isolates that possess different OXA-type carbapenemases, and to evaluate the roles of these enzymes in the development of carbapenem resistance. METHODS: This retrospective study was conducted with 25 A. baumannii isolates at Sakarya University Training and Research Hospital, Sakarya, Turkey from June to October 2014. Antibiotic susceptibility testing was carried out using the Vitek-2 automated system (bioMérieux, Marcy l'Etoile, France). Minimum inhibitory concentrations (MICs) were determined using Etest strips (bioMérieux, Marcy l'Etoile, France). Quantitative polymerase chain reaction was performed in a Fluorion Instrument (Iontek, Istanbul, Turkey).  RESULTS: Isolates were divided into 5 groups based on their susceptibility profiles and OXA-type carbapenemase positivity. Group 2 isolates whose MIC of both meropenem and doripenem are in the range of 4-32 µg/mL were negative for both blaOXA-23 and blaOXA-58. Group 3 isolates whose MIC of meropenem and doripenem is in the range of 4-32 µg/mL, blaOXA-23 is positive, and blaOXA-58 is negative. Group 5 isolates whose MIC of meropenem is more than 32 µg/mL, and that of doripenem is in the range of 16-32 µg/mL were positive for both blaOXA-23 and blaOXA-58.  CONCLUSION: The blaOXA-23 and blaOXA-58 gene combinations may confer resistance with a much greater MIC of both meropenem and doripenem. But the blaOXA-58 presence alone was not correlated with doripenem resistance.

A Rare Cause of Calcified Subdural Empyema and Ventriculitis in a Pediatric Patient: Achromobacter Denitrificans.

Intracranial infections in the pediatric age group are still important causes of morbidity in developing countries. A 2-year-old male patient presented with acute onset of seizures and loss of consciousness to our emergency department with a past history of being followed for hypogammaglobulinemia. Unenhanced computerized tomography scan of the brain revealed a right frontoparietal peripherally calcified extraaxial collection, brain edema and a left sided shift. Contrast enhanced magnetic resonance imaging revealed a subdural empyema associated with the brain parenchyma and the ventricular system. In spite of a decompression procedure and subsequent medical therapy, the patient succumbed on the 9. postoperative day. This is the first case report of a pediatric patient with subdural empyema and ventriculitis due to Achromobacter denitrificans.

Assessment of pulsed electromagnetic field therapy with Serum YKL-40 and ultrasonography in patients with knee osteoarthritis.

AIM: The use of biomarkers of osteoarthritis (OA) have potential for early diagnosis, evaluation of disease severity and monitoring treatment. Serum and synovial fluid YKL-40 levels are increased in severe knee OA. Pulsed electromagnetic field (PEMF) therapy is a novel treatment method for OA. However, studies evaluating the PEMF therapy in treatment of knee OA revealed conflicting results. This study was conducted to objectively assess the effect of PEMF therapy in patients with knee OA, by using ultrasonographic measurements and a novel biomarker, YKL-40. METHODS: Forty patients were randomized into two treatment groups. Both groups received conventional physical therapy, while Group 1 received additional PEMF therapy. The patients were asked to rate their pain on a visual analogue scale (VAS) and complete a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. Serum YKL-40 levels were measured, and knee effusion and cartilage degeneration level were evaluated with ultrasonography before and after treatment. RESULTS: Pre-treatment YKL-40 level was correlated with WOMAC pain subscale (P = 0.032, r = 0.339). VAS and WOMAC scores significantly improved in both treatment groups (P < 0.05). The effusion in the right knee significantly decreased in Group 1. The change in YKL-40 level was not correlated with the change in VAS, WOMAC scores and knee effusion. CONCLUSION: This study revealed that adjuvant PEMF therapy has no additional effect on pain in patients with knee OA. Serum YKL-40 level seems to be unuseful for monitoring the treatment in knee OA.

[Molecular epidemiology of beta-lactamases in ceftazidime-resistant Pseudomonas aeruginosa isolates]. / Seftazidime dirençli Pseudomonas aeruginosa izolatlarinda beta-laktamazlarin moleküler epidemiyolojisi.

Pseudomonas aeruginosa is an important opportunistic pathogen that cause mainly nosocomial infections especially in the immunocompromised patients, the elderly and patients with severe burns. The bacterial feature of developing high degree of resistance against several antibiotics leads to increased morbidity and mortality of P.aeruginosa infections. The aims of this study were to investigate the antibiotic susceptibilities of P.aeruginosa strains isolated from hospitalized patients and to determine the presence of resistance enzymes namely PER, GES, KPC, VIM, IMP and OXA. A total of 195 P.aeruginosa strains isolated from different clinical samples (29 sputum, 67 wound, 53 tracheal aspirate, 23 blood, 18 urine, 3 cerebrospinal fluid, 2 pleural fluid) of inpatients (134 male, 61 female) in Afyon Kocatepe University School of Medicine Hospital between 2010-2012, were included in the study. The isolates were identified by conventional methods and automated systems (VITEK 2, BioMerieux, France), and their antibiotic susceptibilities were detected by disk diffusion and E-test methods. Inducible beta-lactamase (IBL), extended-spectrum beta-lactamase (ESBL) and metallo-beta-lactamase (MBL) productions of the isolates were phenotypically investigated by double disk induction, double disk synergy and E-test methods, respectively. The presence of resistance genes encoding PER, GES, KPC, VIM, IMP and OXA enzymes were determined by real-time polymerase chain reaction, and sequence analysis was applied to positive samples. In our study, the antibiotic resistance rates of 195 P.aeruginosa strains were found as follows: ceftazidime 100%, tazobactam/piperacillin 90.8%, aztreonam 60.5%, cefepime 50.2%, imipenem 48.2%, meropenem 47.2%, ofloxacin 47.2%, piperacillin 44.1%, levofloxacin 31.3%, ciprofloxacin 26.2%, gentamicin 11.8%, amikacin 8.7% and tobramycin 6.2%. With the use of phenotypical methods, IBL, ESBL and MBL production rates in the isolates were detected as 89.2% (174/195), 30.7% (60/195) and 26.7% (52/195), respectively. Molecular studies showed that, five strains harboured OXA-10, four OXA-14, four VIM-2, two IMP-1, 26 GES-1 and 87 ABC transporter permease genes, while PER and KPC genes were not detected in any of the isolates. In conclusion, it was considered that the detection of beta-lactamase genes in bacteria and the identification of beta-lactamase types may provide facilities in selection of antibiotics, monitorization of therapy, prevention of resistance development of infection control programs.

Assessment of the Frequency of Autoantibodies in Chronic Viral Hepatitis.

OBJECTIVE: To examine the occurrence frequency of auto-antibodies and autoimmune diseases in patients with chronic hepatitis B or C. METHODS: A total of 67 patients diagnosed with chronic hepatitis B and 77 patients diagnosed with chronic hepatitis C infection based on HBs Ag, Anti HCV, HBe Ag, Anti HBe Ag, HBV DNA, HCV RNA, liver ultrasound, and liver biopsy results as well as 48 healthy individuals were included in this study. ANA, anti dsDNA, anti LKM, Anti-SMA, AMA, C-ANCA, P-ANCA, anti-SSA, anti-SSB, anti-Scl-70, anti Jo-1, anti-U1snRNP, anti-centromere, anti-Jo-1, anti tpo, and anti tg were studied in all individuals in each study group. RESULTS: ANA positivity was detected in 8 (12%), 15 (19%) and 2 (4%) individuals in HBV, HCV and control groups, respectively. The difference between the groups was significant (P=0.04). Similarly, anti Tg was positive in one subject in HBV group, in 6 subjects (7%) in HCV group, and in one subject among controls, the difference being significant (P=0.04). There were no significant differences between the study groups in the frequency of other auto-antibodies. CONCLUSION: Similar to studies involving patients who received interferon and/or antiviral agents, an increased frequency of auto-antibodies was also detected in our patient group consisting of interferon and anti-viral naive subjects. The increase in the frequency of auto-antibodies reached statistical significance among individuals with HCV infection. Thus, pre-treatment assessment of auto-antibodies in newly diagnosed cases of chronic hepatitis B or hepatitis C infection may provide beneficial information on the future occurrence of auto-immune responses in these patients.

Evaluation of nasal and oropharyngeal flora in patients with acne vulgaris according to treatment options.

The aim of this study was to evaluate changes in nasal and oropharyngeal flora in patients with acne during treatments with tetracycline and isotretinoin. Swab specimens were taken from the right and left nasal cavities and oropharynx of 55 patients with acne and 20 healthy volunteers who were admitted to the dermatology department (Etlik Educational and Research Hospital, Ankara, Turkey) before the administration of treatment and in the third month of treatment. Study participants were divided into four groups as follows: patients with acne on topical treatment only, systemic isotretinoin, and systemic tetracycline, and the control group. Of 55 patients with acne, 18 were male and 37 were female. The mean age of the patients and the control group was 22.21 ± 4.22 and 21.95 ± 7.64, respectively. Staphylococcus aureus was isolated from the nasal flora of five patients, normal flora was suppressed in the oropharyngeal cultures of seven patients, and normal flora grew in the cultures of the other 20 patients who were on tetracycline treatment. On the other hand, normal flora grew in the nasal and oropharyngeal cultures of all the patients who were on isotretinoin treatment. Treatment options and follow-up procedures for acne vulgaris may lead to the development of bacterial resistance and damage to flora. In particular, systemic tetracycline treatment leads to changes in flora of the nose and throat in patients with acne with an increased carriage of S. aureus. Therefore, careful attention should be paid to the duration of tetracycline treatment in order to not increase the risk of disturbance of microbial flora.

Rapid detection of resistance in Staphylococcus aureus by using Quicolor ES.

Traditional microbiological methods are dependent on the growth of microorganisms, and hence require prolonged periods. The methods used to detect resistance in Staphylococcus aureus should have high sensitivity and specificity, yet provide results in a timely manner. The aim of this study was to evaluate the use of Quicolor (QC) ES(®) agar for the rapid detection of resistance in S. aureus. We evaluated 100 clinical S. aureus isolates. Resistance detection was performed using traditional microbiological methods. Methicillin resistance detection was evaluated using traditional and molecular microbiological methods. Traditional antibiotic susceptibility testing methods, such as disc diffusion, were conducted using QC ES and Mueller-Hinton (MH) media. The plates were incubated at 36 °C for 5, 6 and 24 h. Rapid results obtained using QC ES agar after 5 h of incubation were consistent with those using the overnight procedure with MH agar for 83 of the 100 S. aureus (including methicillin-susceptible S. aureus) strains. However, the correlation for oxacillin between MH (24 h) and QC ES (5 h) was not satisfactory (r = 0.770). The total agreement between QC ES and MH agar was 83% after 5 h, 89% after 6 h, and 94% after 24 h. The accurate and rapid detection of resistance in S. aureus is critical due to the associated therapeutic problems and infection control measures. We believe that the use of QC ES for S. aureus will reduce the delay in resistance detection, thus providing physicians and infection control practitioners with early information for better management.

Comparison of FISH, RFLP and agar dilution methods for testing clarithromycin resistance of Helicobacter pylori.

BACKGROUND/AIMS: Clarithromycin resistance is an important factor of Helicobacter pylori (H. pylori) eradication failure in adults and children. There are some tests to determine resistance such as restriction fragment length polimorphism (RFLP), fluorescence in situ hibridisation (FISH), PCR and (culture) agar dilution. Clarithromycin resistance is reported between 16.8%-48.2% in Turkey using PCR, 18% in Japan using RFLP. The aim of the study is to compare the efficacy of FISH, RFLP and culture. MATERIALS AND METHODS: Patients with gastric complaint underwent endoscopic examination. H. pylori status of all patients was tested with urea breath test. Gastric biopsy samples obtained from adult patients and children were studied. Each tissue was analised with FISH, PCR-RFLP anda gar dilution. RESULTS: A total 100 patients were positive by UBT and histology for H. pylori. Tissues from 89 adults and 11 children were evaluated. According to FISH and RFLP clarithromycin resistance was 26% and 16% respectively. Among 100 patients H. pylori was cultured in 52 tissue samples, among these samples 7 were resistant to clarithromycin. There was strong correlation between the results of FISH and RFLP; RFLP and culture; and FISH and culture. CONCLUSION: There is a high ratio of clarithromycin resistance in the studied population. All 3 tests are valuable, but FISH seems to be more sensitive among these tests. We suggest FISH should be used for detecting clarithromycin resistance among H. pylori infected patients before eradication therapy.

Detection of the frequency of PER-1 type extended-spectrum ß-lactamase-producing Acinetobacter baumannii clinical isolates in Turkey: a multicenter study.

BACKGROUND/AIM: ß-Lactamases are an important resistance mechanism in Acinetobacter baumannii. Pseudomonas extended-resistance (PER-1) type ß-lactamase-producing strains have been reported from various geographic locations; however, PER-1 type ß-lactamases from Turkish hospitals have not been investigated extensively. The aim of this study was to determine the prevalence of PER-1 type ß-lactamases in A. baumannii isolates in various regions of Turkey. MATERIALS AND METHODS: A total of 763 clinical A. baumannii isolates were collected from 9 university hospitals and 2 state hospitals between 2008 and 2011. Molecular amplification of the OXA-51 gene from the A. baumannii genome was performed in order to verify identification of the species. Real-time polymerase chain reaction was used to detect blaPER-1 genes. RESULTS: PER-1 was detected in 24.6% of the isolates. The annual frequencies of the PER-1 enzyme were detected as 52.2%, 35.9%, and 8.3% in 2008, 2009, and 2010, respectively. PER-1 prevalence decreased gradually over time. The differences observed in PER-1 prevalence among the regions of Turkey were statistically significant (chi-square test; P < 0.001). CONCLUSION: These data demonstrate that the frequency of detection of PER-1 type ß-lactamases in A. baumannii species has decreased in Turkey. However, the increased carbapenem resistance, together with multidrug resistance, has created a worrisome situation regarding this pathogen.

[Distribution of blaOXA genes in Acinetobacter baumannii strains: a multicenter study]. / Acinetobacter baumannii Izolatlarinda blaOXA Genlerinin Dagilimi: Çok Merkezli Bir Çalisma.

Acinetobacter baumannii is the most important agent of nosocomial infections within the Acinetobacter genus. This gram-negative coccobacillus is intrinsically resistant to many antibiotics used in antimicrobial therapy, and capable of developing resistance including carbapenems. The objective of this study was to develop a multiplex real time polymerase chain reaction (qPCR) kit for OXA subgroups in A.baumannii, and to investigate the distribution of OXA subgroups in A.baumannii strains isolated from geographically different regions of Turkey. A total of 834 A.baumannii clinical isolates collected from different state and university medical centers in 13 provinces (Afyonkarahisar, Ankara, Bolu, Elazig, Erzurum, Isparta, Istanbul, Kahramanmaras, Konya, Sakarya, Van) between 2008-2011, were included in the study. The isolates were identified by conventional methods and automated systems [Vitek2 (bioMerieux, ABD) and Phoenix (BD Diagnostic, MD)]. The susceptibility profiles of the isolates were studied with automated systems and standard disc diffusion method. All samples were subjected to qPCR to detect blaOXA-51-like, blaOXA-23-like and blaOXA-58-like genes. A conventional PCR method was also used to detect blaOXA-24-like gene. The resistance rates observed during the study period were as follows: 96.8% for amoxicillin-clavulanate, 86.8% for ciprofloxacin, 74.7% for gentamicin, 71.7% for amikacin, 73.5% for cefaperozone-sulbactam, 72.1% for imipenem and 73% for meropenem. Six hundred and two (72.2 %) isolates were resistant to both imipenem and meropenem. Colistin was found to be the most effective antibiotic against A.baumannii isolates with 100% susceptibility rate. All isolates were positive for blaOXA-51-like, however blaOXA-24-like gene could not be demonstrated in any isolate. Total positivity rates of blaOXA-23-like and blaOXA-58-like genes were found as 53.7% and 12.5%, respectively, while these rates were 74.4% and 17.3% in carbapenem-resistant isolates, respectively. Twenty-five isolates were positive for both blaOXA-23-like and blaOXA-58-like genes. All of the carbapenem-resistant isolates have OXA type genes with the exception of blaOXA-24-like gene. The positivity rates for blaOXA-23-like and blaOXA-58-like genes varied for each center. In addition, there was a decrease in the frequency of blaOXA-58-like gene, however both blaOXA-23-like gene and carbapenem resistance rates increased during the study period. In conclusion, high rates of resistance to carbapenems were also remarkable but A.baumannii strains keep on sensitivity to colistin. Both blaOXA-23-like and blaOXA-58-like genes were shown to be widespread in carbapenem-resistant A.baumannii clinical isolates. However, blaOXA-23-like gene positive strains were increased throughout the study. Currently, multiplex qPCR is the best way for rapid diagnosis of resistant bacteria for prevention of hospital-acquired infections. The multiplex qPCR kit developed in this study could be useful for rapid diagnosis and identify the frequencies of blaOXA-23-like, blaOXA-51-like and blaOXA-58-like genes in carbapenem-resistant A.baumannii clinical isolates.

[Investigation of plasmid-mediated quinolone resistance in Escherichia coli strains]. / Escherichia coli Suslarinda Plazmide Bagli Kinolon Direncinin Arastirilmasi

Quinolones are widely used antimicrobial agents, particularly for the treatment of infections caused by gram-negative bacilli such as E.coli. As a consequence, quinolone resistance has been increasing among this species in recent years. Bacterial resistance to quinolones usually results from mutations in the chromosomal genes which encode topoisomerases and also the expression of efflux pumps and loss of porines contributed to development of quinolone resistance. However, recent studies have shown that the spread and increase of quinolone resistance may be due to the transfer of plasmid-mediated genes. To date, three groups of plasmid-mediated quinolone resistance genes, namely qnr, aac(6')-Ib-cr, and qepA, have been described. The aim of this study was to investigate the presence of plasmid-mediated quinolone resistance genes in E.coli clinical isolates. A total of 112 quinolone-resistant E.coli strains isolated from different clinical specimens (84 urine, 16 blood, 10 wound, 2 bronchoalveolar lavage) of which 78 (69.6%) were extended-spectrum beta-lactamase (ESBL) positive, in Afyon Kocatepe University Hospital, Microbiology Laboratory were included in the study. In the isolates, qnrA, qnrB, qnrS, qnrC, qepA, and aac(6')-1b-cr plasmid genes were analysed by polymerase chain reaction (PCR). After aac(6')- 1b determinant was amplified by PCR, all aac(6')-1b positive amplicons were analyzed by digestion with BseGI restriction enzyme to identify aac(6')-1b-cr variant. It was found that, none of the strains horboured qnrA, qnrB, qnrS, qnrC and qepA genes, however, plasmid-mediated quinolone resistance gene aac(6')-1b-cr was found positive in 59.8% (67/112) of the strains. It was notable that 86.6% (58/67) of those isolates were ESBL producers. The rates of quinolone resistance among E.coli isolates infections were high in our region and an increasing trend has been observed in recent years. Our data indicated that the presence of plasmid- mediated resistance genes such as aac(6')-1b-cr, might have contributed to the high quinolone resistance rates. In conclusion, not only qnr genes but all other plasmid-mediated quinolone resistance genes, should be tested for the detection of plasmid-mediated quinolone resistance and this fact should be taken into consideration when the reservoirs are being searched for.

[Investigation of Helicobacter pylori iceA1 and iceA2 genes in patients with chronic gastritis and gastric cancer]. / Kronik Gastrit ve Gastrik Kanserli Hastalarda Helicobacter pylori iceA1 ve iceA2 Genlerinin Arastirilmasi

Several virulence factors of Helicobacter pylori play crucial role in the pathogenesis of the infections.H.pylori iceA gene which is induced by the contact with epithelium during the attachment of bacterium to the gastric mucosa, possess two variants (iceA1 and iceA2). Although there are some data indicating the relationship between H.pylori iceA1 and peptic ulcer, this concept is still controversial. The aims of this study were to investigate the presence and prevalence of H.pylori iceA1 and iceA2 gene regions in the tissue samples of patients diagnosed as chronic gastritis and gastric cancer, and to evaluate whether any correlation existed between these genotypes and clinical manifestations. A total of 109 tissue samples obtained from chronic gastritis (n= 55) and gastric cancer (n= 54) patients whose H.pylori infections have been confirmed by histopathologic examination of biopsy samples, were included in the study. The presence of H.pylori in the samples were also confirmed by amplification of the ureA gene region by inhouse polymerase chain reaction (PCR). H.pylori iceA1 and iceA2 genes were directly genotyped with the use of specific primers in the gastric biopsy specimens by PCR. The total positivity rates of iceA1 and ice- A2 genotypes in patients were found as 58% (63/109) and 24% (26/109), respectively. With the special attention to chronic gastritis and gastric cancer patients, the frequencies of iceA1 gene were 51% (28/55) and 65% (35/54), while the frequencies of iceA2 gene were 20% (11/55) and 28% (15/54), respectively. The difference of positivity rates of iceA1 and iceA2 genotypes between the patient groups were not statistically significant (p> 0.05). There was also no statistically significant correlation between the genotypes and clinical manifestation (r> 0.01). As a result, H.pylori iceA1 genotype was predominant (58%) in chronic gastritis and gastric cancer patients in our region, however the prevalence of iceA2 genotype was lower (24%) similar to those data reported in the literature. Our results supported the concept that iceA gene reflects geographical differences rather than determining the clinical picture and virulence. In conclusion, multicenter and large scaled studies are needed for better evaluation of H.pylori iceA gene and disease relationship.

[Current approaches to explain the virulence of Acinetobacter baumannii]. / Acinetobacter baumannii Virülansinin Açiklanmasinda Güncel Yaklasimlar.

Acinetobacter baumannii which is one of the most frequent nosocomial pathogens, has drawn attention in the last years owing to multi-drug resistant strains. A.baumannii may give rise to nosocomial epidemics especially in intensive care units and may lead to treatment failure due to its increasing antimicrobial resistance. These gram-negative non-fermentative coccobacilli may be encountered also in community associated infections. However, they are frequently isolated in pneumonia, urinary tract infection, bacteremia, meningitis and wound infections that develop in patients hospitalized for serious diseases. Although detailed data about the epidemiology and antimicrobial resistance patterns related to this bacteria exist, relatively limited data is present about the virulence factors and environmental physiology of A.baumannii. The role of some bacterial virulence factors in the pathogenesis of Acinetobacter infections have been enlightened by recent investigations. Among these virulence factors, production of extracellular enzymes with lipolytic and cytolytic activities, outer membrane protein (AbOmpA) with apoptotic effects on epithelial cells, adhesion molecules (fimbria and AbOmpA) that function during attachment to epithelial cells, K1 type capsular structure, type-1 pili and AbOmpA induced biofilm formation, siderophore (acinetobactin) or hemin mediated iron acquisition mechanisms, quorum sensing system that functions by the help of N-acyl homoserine lacton signal molecules and cellular components that enable Acinetobacter species to live under inappropriate environmental conditions like dryness, low temperature, restricted nutritional elements, can be counted. New information about the virulence factors will help better understanding of the adaptive response of A.baumannii in the host setting. This review is focused on the current information about the virulence factors of of A.baumannii.

[Evaluation of Xpert MTB/RIF results for the detection of Mycobacterium tuberculosis in clinical samples]. / Klinik Örneklerde Mycobacterium tuberculosis Varliginin Gösterilmesinde Xpert MTB/RIF Sonuçlarinin Degerlendirilmesi.

Tuberculosis is still a major global health problem. Nowadays nucleic acid amplification tests which are recommended by the World Health Organization (WHO) become popular methods for the rapid detection of Mycobacterium tuberculosis complex (MTC). Recently introduced commercial Xpert MTB/RIF (Cepheid, USA) system is also a molecular method based on real-time polymerase chain reaction for simultaneous detection of both MTC and rifampicin resistance in the clinical sample. The sample processing, nucleic acid extraction, amplification and detection of known mutations related to rifampicin resistance are performed in a single cartridge in this integrated system and the results are obtained in two hours. The aim of this study was to evaluate the performance of Xpert MTB/RIF system for the detection of M.tuberculosis in pre-processed clinical samples by comparing the results obtained by Bactec 460TB 12B (BD Diagnostic, USA), Löwenstein-Jensen (LJ) culture and direct microscopy of smears stained with Ziehl- Neelsen (ZN). A total of 85 clinical specimens (50 sputum, 25 bronchoalveolar lavage, five thorasynthesis fluid and five urine samples) obtained from tuberculosis-suspected patients were included to the study. All specimens were decontaminated and this decontaminated suspension was used in the diagnostic methods, except for Xpert MTB/RIF process. Twenty-five (29%) of the samples yielded positive result with Bactec 460TB, 25 (29%) were found positive with Xpert MTB/RIF, 15 (18%) were found positive with LJ and 11 (13%) were found positive with ZN staining method. High consistency was detected between the results of Bactec 460TB and Xpert MTB/RIF when Bactec 460TB was considered as the gold standard method (r= 0.943; p= 0.000). One specimen yielded false positive result with Xpert MTB/RIF when compared to the reference method. The sensitivity, specificity, positive and negative predictive values of Xpert MTB/RIF test were then estimated as 96%, 98%, 96% and 98%, respectively. No resistance were detected for the tested isolates. This study suggested that the sensitivity of Xpert MTB/RIF system in direct detection of M.tuberculosis in smear positive and smear negative samples was consistent with the reference methods. Moreover, the MTB/RIF test provided sensitive detection of tuberculosis in less than two hours.

Prevalence of cagA and vacA genotypes of Helicobacter pylori isolated from Turkish patients with active or non-active chronic gastritis.

Several virulence factors of Helicobacter pylori may contribute to gastric mucosal damage. In this study, the prevalence of cagA and vacA genotypes of H. pylori was examined in different patterns of chronic gastritis. Oesophagogastroendoscopy was performed in 147 dyspeptic patients. Antrum biopsies were obtained for isolation of H. pylori and for histopathological assessment. H. pylori vacAs1 and cagA genes were directly genotyped in the gastric biopsy specimens by polymerase chain reaction (PCR). A total of 102 dyspeptic patients, all H. pylori-positive by PCR, were included in the study. Of these, 59 had active chronic gastritis and 37 had non-active chronic gastritis. The prevalence of cagA and vacAs1 was higher among patients with active chronic gastritis than among those with non-active chronic gastritis (45.8% vs 21.6% (p = 0.02) and 78.0% vs 40.5% (p < 0.001), respectively). In conclusion, both cagA and vacAs1 genotypes are associated with the activity of chronic gastritis.

In vitro anti-Helicobacter pylori activity of usnic acid.

Eradication of Helicobacter pylori is an important objective in overcoming gastric diseases. Many regimens are currently available but none of them could achieve 100% success in eradication. Medicinal lichen is used in the treatment of gastric ulcer in local folk medicine in Anatolia (Turkey). The present study was performed to assess the in vitro effects of usnic acid from Usnea dasypoga against clinical isolates and standard H. pylori strains and their minimum inhibitory concentrations (MICs). A total of 38 strains was assayed for anti-H. pylori activity. The agar dilution method was used for the determination of usnic acid and clarithromycin resistance.Six (16.2%) clinical isolates were resistant to usnic acid and five (13.5%) were resistant to clarithromycin. Dual susceptibility to usnic acid and clarithromycin rate was detected as very high (97.3%). Usnic acid has a strong and dose-dependent activity against H. pylori strains. The synergism between usnic acid and clarithromycin may be effective in the treatment of H. pylori infection.

The effects of caspofungin and voriconazole in an experimental fungal infection of the ear due to Aspergillus.

The purpose of the study was to evaluate the effectiveness of caspofungin and voriconazole in the treatment of experimental Aspergillus otitis media in an experimental rabbit model. A total of 30 New Zealand white rabbits were divided into four treatment groups and one control group. The rabbits were immunosuppressed by cyclophosphamide and triamcinolone acetonide. The right ear of each rabbit was infected by an injection of the inoculum of 0.1 ml (8.6 x 103 CFU/0.1 ml) of Aspergillus fumigatus into the middle ear cavity. At 72 h after the inoculation, amphotericin B 1 mg/kg per day (n = 6), itraconazole 10 mg/kg per day (n = 6), voriconazole 10 mg/kg per day (n = 6) and caspofungin 5 mg/kg per day (n = 6) were injected to each treatment group. No antifungal drug was administered to the control group (n = 6). Clinical and histopathological examination scores and microbiological analysis of middle ear mucosa were compared.There was statistically significant difference in the clinical scores, histopathological scores, and mean CFU/g between the treatment and control groups (P < 0.05). There was no statistically significant difference among the treatment groups in the clinical and histopathological scores, whereas there was statistically significant difference in the mean CFU/g (P < 0.05). The mean CFU/g of amphotericin B and caspofungin groups were similar and both were lower than the itraconazole and voriconazole groups. Also, the mean CFU/g of voriconazole group was lower than the itraconazole group (P < 0.05). Caspofungin and voriconazole were demonstrated at least as effective as amphotericin B and itraconazole. We suggest that caspofungin and voriconazole may be considered for the treatment of fungal infection of the ear.