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Yamur G.,Istanbul Forensic Medicine Institute | Albayrak N.,Public Health Agency of Turkey | Das T.,Istanbul Forensic Medicine Institute | Yildirim M.,Istanbul Forensic Medicine Institute | And 2 more authors.
Mikrobiyoloji Bulteni

Tuberculosis (TB) is one of those infections with high morbidity and mortality in all around the world. Hundreds of people died from this disease without diagnosed or due to resistant strains in Turkey. Therefore, it is important to identify postmortem cases who have died from tuberculosis. Molecular methods have been widely used as well as conventional methods in the diagnosis of tuberculosis. The aim of this study was to compare the two different real-time polymerase chain reaction (Rt-PCR) system in the postmortem diagnosis of Mycobacterium tuberculosis infections in paraffin-embedded tissues. A total of 40 paraffin-embedded tissue samples [lung (n= 35), brain (n= 2), heart (n= 2), lymph node (n= 1)] in which histopathologic findings consistent with TB (necrotizing granulomatous inflammation, gelatinous caseous pneumonia, necrotic fibrous nodul) obtained from 37 autopsy cases (31 male, 6 female; age range: 25-85 yrs) were included in the study. Paraffin-embedded tissues were deparafinized with xylene and ethyl alcohol and then DNA isolation was done with QIAsymphony DSP Virus/Pathogen Midi kit in the QIAsymphony device. DNA amplification process was performed by Rt-PCR using the kit Artus® M. tuberculosis RC-PCR in the Rotor-Gene® Q device (Qiagen, Germany). Likewise, after deparafinization process, samples placed in the cartridge and isolation and Rt-PCR was performed by Xpert® MTB/RIF (Cepheid, USA) system, simultaneosly. Seventeen and 20 out of the 40 paraffin-embedded tissues yielded positive results with Qiagen and Xpert system, respectively. M.tuberculosis DNA was found positive in 13 (32.5%) and negative in 16 (40%) of the samples by both of the systems, exhibiting 72.5% (29/40) of concordance. On the other hand, seven (17.5%) samples that were positive with Xpert system yielded negative result with the Qiagen, while four (10%) samples that were positive with Qiagen yielded negative result with the Xpert system. Of the 20 positive cases detected with Xpert MTB/RIF system, 15 were found rifampicin-susceptible, and three were rifampicin-resistant. In two samples in which M. tuberculosis DNA was low positive, rifampicin resistance could not be detected. The identification of M.tuberculosis infections in postmortem cases will contribute epidemiological data in Turkey. In these cases, effective sampling and diagnosing of M.tuberculosis infections by acid-fast stain and culture methods are crucial. However, in cases without microbiological sampling the detection of M.tuberculosis DNA in paraffin-embedded tissues with PCR, although there are differences between PCR systems has diagnostic value. In conclusion, our data indicated that Xpert MTB/RIF system is more favourable to detect M.tubercuiosis DNA in paraffin-embedded tissues, with the advantages of determination of rifampicin resistance, and detection of more positive results within a shorter time. Source

Kara S.S.,Gazi University | Polat M.,Gazi University | Tapisiz A.,Gazi University | Nar Otgun S.,Public Health Agency of Turkey | Tezer H.,Gazi University
Mikrobiyoloji Bulteni

Pneumococci are one of the most common causes of bacterial meningitis in children. It's also responsible for the other invasive pneumococcal diseases (IPD) including bacteremia and pneumonia worldwide. Unvaccinated children are more prone to IPD. Although IPD tend to have a higher prevalence under 2 years of age and in children with primary/secondary immunodeficiencies, and various predisposing factors, older age groups with no underlying diseases also experience IPD. In this report, a pediatric case diagnosed with meningitis due to Streptococcus pneumoniae serotype 35F with no underlying condition and no history of pneumococcal vaccination was presented. An 11-year-old male patient was admitted to the hospital with the complaints of high (39.4°C) fever, headache, vomiting and sleepiness. On the basis of findings from physical examination and laboratory results, the patient was prediagnosed as bacterial meningitis and empirical ceftriaxone and vancomycin therapy was initiated. The cerebrospinal fluid culture of the patient yielded penicillin-susceptible pneumococci and the isolate was identified as serotype 35F by quellung reaction. Vancomycin treatment discontinued depending on the culture result, and the patient fully recovered with 14-days of ceftriaxone therapy without any complications during his follow-ups. Although effective antibiotics are available for IPD, vaccination is indispensable considering the high mortality rates. Seven serotypes (1, 5, 6A, 6B, 14, 19F, 23F) which are currently included in the vaccine, were the most common serotypes related to IPD globally. After mass infant vaccination has been introduced, invasive pneumococcal diseases due to the vaccine serotypes have tended to decrease in both vaccinated young children and non-vaccinated age groups due to herd immunity. Nevertheless, non-vaccine serotypes (NVTs) have emerged as the agents of IPD as a result of serotype replacement. 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in April, 2011 nationwide in our country. This case report was about a patient who had developed meningitis after the introduction of PCV13. There has been no data evaluating the pneumococcal serotype distribution after PCV13 in our country yet. On February, 2013, the Advisory Committee on Immunization Practices (ACIP) recommended routine use of PCV13 for children aged 6-18 years with underlying disease conditions. However, there is no recommendation for children with no underlying diseases in this age group. Vaccination can be extended for otherwise healthy children older than 6 years of age because of increasing trends in incidence of IPD both with vaccine and NVTs like serotype 35F. Recent studies have indicated the emergence of serotype 35F as a cause of IPD in children over 6 years of age and there have been also reports of IPD cases with 35F after the introduction of PCV13. Although serotype 35F is not yet a well-known serotype causing IPD, it might probably gain importance owing to its increasing frequency and virulence and might attract attention to be considered for inclusion in the future pneumococcal vaccines. Source

Aeromonads infect human through potable water and causes various infections. Their existence in animal are being assessed as potential risk for human health. The aim of this study was to investigate clonal relationship among 52 Aeromonas strains isolated from human with diarrhea (14 strains), healthy food workers (2 strains), animals (24 strains) and drinking water (12 strains) by pulsed-field gel electrophoresis (PFGE). Clonal relation was determined between one diarrheic human isolate and one cattle isolate. No clonal relation was determined between drinking water and human isolates. Two fish isolates, A. caviae and A. sobria, were not distinguished PFGE patterns. Consequently no predominant clone was determined while clonal related strains were determined. Particularly, it is necessary to elicit the epidemiological importance of animals in respect of human Aeromonas infections and extensive studies are required for identification of environmental isolates. Source

Multidrug-resistant (MDR) tuberculosis (TB) constitutes a restricting factor for the effective treatment of TB worldwide. Early diagnosis and appropriate treatment of patients are the most effective strategy in the control of MDR-TB. Therefore, knowledge of drug resistance patterns of the MDR-TB clinical isolates are necessary in planning of an appropriate treatment regimen for the patient. The aims of this study were to detect the susceptibilities of MDR-TB isolates to second-line anti-TB drugs by E-test method, and to compare their results with Löwenstein-Jensen (LJ) proportion method. A total of 122 MDR (resistant to isoniazid and rifampicin) Mycobacterium tuberculosis complex (MTC) strains isolated from samples of patients with pulmonary TB were included in the study. The isolates were identified by conventional methods and first-line anti-TB drug susceptibility testing was performed by the proportion method using LJ medium. The susceptibilities of the isolates to second-line anti-TB drugs [kanamycin (KN), ofloxacin (OFL), ethionamid (ETN), linezolid (LIN)] were tested by proportion method on LJ medium and E-test method on Middlebrook 7H11 medium. For this purpose, E-test strips (bioMerieux, Fransa) of KN (0.016-256 mg/ml), OFL (0.02-32 mg/ml), ETN (0.016-256 mg/ml), and LIN (0.016-256 mg/ml) were used. The susceptibility tests were evaluated in 5., 7., and 10. days after application of the E-test strips, and proportion method on LJ medium was evaluated 28 days later. Second line-anti-TB drug susceptibility results were obtained in 5 to 10 days by E-test. Of the MDR MTC strains 98% (119/122) were susceptible to KN, OFL and LIN, while 2% (3/122) of the strains were resistant to KN and ETN. The correlation between E-test and LJ proportion method was estimated as 96% for KN and ETN, 98% for OFL, and 100% for LIN. When compared with LJ proportion method, the specificity of E-test in the detection of susceptibility to KN, OFL, ETN and LIN were 60%, 38%, 60%, and 100%, respectively, while the sensitivity was 100% for all drugs. Our results indicated that E-test method exhibited high sensitivity and specificity (100%) for LIN, so it may be used alone in susceptibility testing for this drug, however since the specificity is low (38%) for OFL it should be used together with the proportion method. In conclusion, E-test method might contribute for initiation of an early and effective anti-TB drug treatment and control of infection by rapid diagnosis in MDR-TB cases. Source

Cekin Y.,Antalya Training and Research Hospital | Karagoz A.,Public Health Agency of Turkey | Kizilates F.,Antalya Training and Research Hospital | Cekin A.H.,Antalya Training and Research Hospital | And 3 more authors.
Mikrobiyoloji Bulteni

Pseudomonas aeruginosa is an important nosocomial pathogen that causes opportunistic infections and hospital outbreaks. During October 2012, carbapenem-resistant P.aeruginosa strains with similar antibiotic resistance patterns, were isolated from specimens sent from the intensive care and plastic surgery units in our hospital. Thus a hospital outbreak was suspected. The microbiology laboratory database was retrospectively searched and all strains of P.aeruginosa isolated during the four month period, starting with the initial carbapenem-resistant strain in August 2012, was evaluated as a hospital outbreak. The aim of this study was to define the outbreak by investigating the clonal relationship between the strains, to detect the potential environmental sources and to evaluate the period of the outbreak, risk factors and the efficiency of infection control measures. The study was conducted between August-November 2012. Twenty patients with carbapenem-resistant P.aeruginosa (CRPA) positive cultures were included in the study. The control group consisted of 22 patients with carbapenem-susceptible P.aeruginosa (CSPA) positive cultures. The clonal relationship between 26 CRPA strains was studied by pulsed-field gel electrophoresis (PFCE). The PFGE results indicated that CRPA strains in our hospital were not related to a single clone, however, there were four major clones composed of four to eight strains. Logistic regression analysis indicated that the risk increased 15.7 fold (95% CI: 1.19-207.76) by the use of carbape-nem, 76.8 fold (95% CI: 2.03-2901.30) by surgical procedures and 0.787 fold (95% CI: 0.63-0.97) by the duration of hospital stay. Surveillance cultures from health-care personel and the environment performed in course of the outbreak, yielded no growth of a strain with the similar antibiotic resistance pattern. The spread of CRPA has been controlled by the use of effective precautionary measures, regressing the isolate number to 0-1 strain/month. Since CRPA infections have high mortality and lack therapeutic alternatives, they should be regarded among the priorities of the infection control programmes. This study has enabled to test the effectiveness of the infection control program, to make plans for the possible future outbreaks and to train the staff. Source

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