Özlem Aydemir

relationship between the gOlD combined COPD assessment staging system and bacterial isolation

Background Acute exacerbations, which are a significant cause of mortality and morbidity, adversely affect chronic obstructive pulmonary disease (COPD) prognosis by accelerating loss of lung function. It is important to know the microorganisms that commonly cause exacerbations in the patient groups classified according to clinical and functional characteristics for fast and accurate treatment of acute exacerbations. Objectives The last Global Initiative for Chronic Obstructive Lung Disease (GOLD) publication recommended a new staging system containing obstruction degree, frequency of exacerbations, and quality of life questionnaires. This study is designed to analyze the relationship between the bacteria isolated in acute exacerbations and new GOLD stages. Methods Potentially pathogenic bacteria (PPB) isolation with culture and polymerase chain reaction methods were obtained from 114 acute exacerbation COPD patients, classified into A, B, C, and D groups by analyzing the forced expiratory volume in 1 second (FEV1) value, COPD Assessment Test (CAT) score, and exacerbation frequency according to the new GOLD staging system. Results There was a significant correlation between exacerbation frequency and PPB isolation (P=0.002). There was no relationship between GOLD stage, FEV1, and CAT score with PPB isolation. The isolated bacteria diversity and mixed infection frequency were higher in the GOLD stage D group. Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii were isolated only from D group patients. Conclusion Bacterial infection may cause an acute exacerbation equally in each stage for COPD. The difference in bacterial etiology is more related to exacerbation frequency than FEV1 and CAT scores for an acute exacerbation. Determining exacerbation frequency is significant for treatment success in empirical antibiotic selection.

Value of multiplex PCR to determine the bacterial and viral aetiology of pneumonia in school-age children

Background: Conventional methods for the aetiological diagnosis of community-acquired pneumonia (CAP) are often insufficient owing to low sensitivity and the long wait for the results of culture and particularly serology, and it often these methods establish a diagnosis in only half of cases. Aim: To evaluate the most common bacterial and viral agents in CAP using a fast responsive PCR method and investigate the relationship between clinical/laboratory features and aetiology, thereby contributing to empirical antibiotic selection and reduction of treatment failure. Methods: In children aged 4–15 years consecutively admitted with a diagnosis of CAP, the 10 most commonly detected bacterial and 12 most commonly detected viral agents were investigated by induced sputum using bacterial culture and multiplex PCR methods. Clinical and laboratory features were compared between bacterial and viral pneumonia. Results: In 78 patients, at least one virus was detected in 38 (48.7%) and at least one bacterium in 32 (41%). In addition, both bacteria and viruses were detected in 16 (20.5%) patients. Overall, the agent detection rate was 69.2%. The most common viruses were respiratory syncytial virus and influenza and the most frequently detected bacteria were S. pneumoniae and H. influenzae. PCR was superior to culture for bacterial isolation (41% vs 13%, respectively). Fever, wheezing and radiological features were not helpful in differentiating between bacterial and viral CAP. White blood cell count, CRP and ESR values were significantly higher in the bacterial/mixed aetiology group than in the viral aetiology group. Conclusion: In CAP, multiplex PCR is highly reliable, superior in detecting multiple pathogens and rapidly identifies aetiological agents. Clinical features are poor for differentiation between bacterial and viral infections. The use of PCR methods allow physicians to provide more appropriate antimicrobial therapy, resulting in a better response to treatment, and it may be possible for use as a routine service if costs can be reduced.

Comparative evaluation of the Brucella Coombs gel test in laboratory diagnosis of human brucellosis

ABSTRACT Brucellosis is widespread among humans and animals. Diagnosis of brucellosis mostly depends on serological methods. Serological tests are preferred over time-consuming and hazardous bacterial cultures in routine laboratory practice. However, these tests are somehow challenging due to ‘incomplete/blocking antibodies’ that prevent agglutination. Brucella Coombs gel test (BCGT) is newly developed test that contains Coombs antibodies (anti-human IgG) in gel microtubes and depends on gel centrifugation methods for the serological diagnosis of brucellosis. Here, performance of the BCGT is compared with standard serum tube agglutination (STA), standard serum tube agglutination with Coombs (C-STA) and immune capture agglutination (Brucellacapt). In total, 78 positive samples for study group and 16 samples for the control group were enrolled in the study. The samples were tested at dilutions of 1:40–1:5120. Titres at 1:160 and above were considered positive for brucellosis, whereas those lower than 1:160 were considered negative. Excellent agreement levels were determined between BCGT test and C-STA (κ, 0.894; p < 0.001), and BCGT and Brucellacapt (κ, 0.802; p < 0.001), when the diagnostic titre was accepted as 1:160. BCGT is easy to apply and interpret and provides reliable titre results in less than 2 h. It is also advantageous for screening.

Hepatitis C Prevalence in Different Age Groups; People Over 50 Years of Age May Receive One-Time Testing for Anti-HCV

ÖZET