Community-acquired S. aureus infection in childhood: a multi-center study.

BACKGROUND: The prevalence of community-acquired methicillin-resistant S. aureus (CA-MRSA) has been increasing worldwide. We aimed to investigate the prevalence of MRSA in community-acquired S. aureus infections, the risk factors for CA-MRSA infection and the clinical features of CA-MRSA. METHODS: A multi-center study with prospective and retrospective sections was conducted. Patients ≥ 3 months old and ≤18 years of age who were diagnosed with community-acquired S. aureus infections were included in this study and the patients` information were reviewed from the medical and microbiological database of the hospital. A standard question form about living conditions and exposure risk factors was administered to the parents of patients. The CA-MRSA infections were compared with the methicillin-susceptible S. aureus (CAMSSA) infections in terms of the queried risk factors and clinical variables. RESULTS: We identified 334 pediatric patients with S. aureus infection, 58 (17.4%) had an infection with CAMRSA. The refugee rate was higher in the CA-MRSA group. There was no significant difference regarding the exposure risk. The treatment modalities and outcomes were similar. CONCLUSIONS: The study was not able to show reliable clinical variables or epidemiological risk factors except for being a refugee for CA-MRSA infections. Empirical antibiotic treatment should therefore be determined according to the local CA-MRSA prevalence in patients presenting with a possible staphylococcus infection.

[Susceptibilities of Mycobacterium tuberculosis strains collected from regional tuberculosis laboratories to major antituberculous drugs]. / Bölge tüberküloz laboratuvarlarindan gonderilen Mycobacterium tuberculosis suslarinin majör antitüberküloz ilaçlara duyarliliklari.

The aim of this study was to investigate the susceptibility rates of Mycobacterium tuberculosis strains sent to Refik Saydam Hygiene Center, Tuberculosis Reference and Research Laboratory, Ankara, from seven different regional tuberculosis laboratories between the 1999-2002 period against major antituberculous drugs. The sensitivities of a total 505 M. tuberculosis strains to isoniazid (INAH), rifampicin (RIF), streptomycin (SM) and ethambutol (EMB) were determined by using proportion method in Lowenstein-Jensen medium. Of the strains, 385 (76.2%) were found sensitive to all of the tested drugs, while 120 strains were resistant to at least one of the antituberculous drugs. The resistant strains showed 14 different resistance patterns. The resistance rates were detected as 13.3% for INAH and RIF (67 strains of each), 9.1% for SM (46 strains), and 3.4% (17 strains) for EMB. Multidrug resistant (INAH+RIF) M. tuberculosis was 7.9% (40 strains). The highest resistance rate to INAH, RIF and EMB (21.2%, 21.2% and 10.6%, respectively) was detected in the isolates which were sent from Bursa province (located in northwestern Turkey); the highest SM (18.8%) and multidrug resistance (INAH+RIF) rates (18.8% and 10.6%, respectively) were detected in the strains sent from Elazig and Van provinces (both located in eastern Turkey). Since the inappropriate use of the first and second line antituberculous drugs leads to the development and spread of the resistant strains, "Directly Observed Therapy Shortcourse (DOTS)" is a very important practice. Therefore regional tuberculosis laboratories should be worth considering as the chains of a well-organized national laboratory network, in order to detect the antituberculous drug resistance patterns of the M. tuberculosis strains over the country.

[The rates of resistance to second-line drugs in multidrug resistant Mycobacterium tuberculosis strains]. / Cok ilaca dirençli Mycobacterium tuberculosis suslarinin minör antitüberküloz ilaçlara duyarliliginin saptanmasi.

The treatment of multidrug resistant tuberculosis (MDR-TB) requires the use of minor antituberculosis drugs, thus susceptibilities against these minor drugs should be performed. The aim of this study was to establish and standardize the susceptibility testing methods for minor antituberculosis drugs in this laboratory and to obtain data about the resistance rates. Drug susceptibility tests were performed by proportion method in Lowenstein-Jensen media for 50 MDR Mycobacterium tuberculosis isolates that have been collected from different regions of our country. Resistance rates to ethionamide, cycloserin, kanamycin, p-aminosalicylic acid, ofloxacin, thiacetasone, and capreomycin were found as 22%, 8%, 6%, 6%, 2%, 2%, and 0%, respectively. Multidrug resistance was observed in 8% of the isolates. As a result, the resistance rates of multidrug resistant M. tuberculosis strains against the tested minor antituberculosis drugs seem to be low in this study.

[Retrospective evaluation of Cobas Amplicor system in the rapid diagnosis of Mycobacterium tuberculosis complex]. / Mycobacterium tuberculosis kompleksinin hizli tanisinda cobas amplicor sisteminin retrospektif olarak degerlendirilmesi.

The aim of this study was to evaluate the value of Cobas Amplicor Mycobacterium tuberculosis (MTB) polymerase chain reaction (PCR) system in the rapid diagnosis of tuberculosis. During the study period, the results of acid-fast stain (AFS), culture and Cobas Amplicor MTB system obtained from 937 clinical (158 respiratory and 779 non-respiratory) specimens were retrospectively evaluated. When culture results were accepted as the gold standard, the sensitivity, specificity, positive and negative predictive values of Cobas Amplicor MTB PCR system were found as 100% for smear-positive respiratory specimens, 75%, 91.7%, 40% and 98% for smear-negative respiratory specimens, and 89.5%, 91.8%, 65.4% and 98.1% for all of the respiratory specimens, respectively. These rates were found as follows for smear-positive, smear-negative and all of the non-respiratory specimens, respectively; 100%, 66.7%, 83.3% and 100%; 29.2%, 97.3%, 26.9% and 97.6%; and 50%, 97.1%, 44.7% and 97.6%. The overall inhibition rate for Cobas Amplicor MTB was 4.8%. In conclusion, Cobas Amplicor MTB PCR system was considered as a rapid and reliable method for the diagnosis of tuberculosis in smear positive pulmonary samples. However, in smear negative pulmonary samples and non-respiratory samples, test results should be evaluated together with clinical and other laboratory data.

[Isolation frequency of Burkholderia cepacia from cystic fibrosis patients]. / Kistik fibrozisli hastalarda Burkholderia cepacia izolasyon sikligi.

Microorganisms such as Pseudomonas aeruginosa, Staphylococcus aureus and Haemophilus influenzae frequently cause colonization and infection in airways of patients with cystic fibrosis. Burkholderia cepacia has also been isolated in patients with cystic fibrosis since 1980. In this study, we aimed to determine the colonization rate of B. cepacia in 286 sputum samples obtained from 129 cystic fibrosis patients. Selective media for B. cepacia were used besides the routine microbiological media in order to increase the isolation rate. The colonies were identified by biochemical tests and the antibiotic susceptibilities of the strains were determined by disc diffusion method. Pathogenic bacteria (S. aureus, P. aeruginosa, Enterobacteriaceae, Streptococcus pneumoniae, H. influenzae) were isolated in 52 of 129 patients (40%) and 66 of 286 sputum samples (23%). In addition 2 B. cepacia strains were isolated from two different patients (1.55%). B. cepacia is now being considered as a pathogen isolated from sputum samples of patients with cystic fibrosis with an increasing frequency and causing severe clinical features. According to these results it can be concluded that, the use of selective media for B. cepacia isolation, should be taken into consideration especially by the clinical microbiology laboratories collaborating with the cystic fibrosis centers.