Biomedical subjects

Suat Saribas

Publications and source records attributed to Suat Saribas.

3 recordsLinked to original sources

PubMed2004

Vancomycin tolerance in enterococci.

BACKGROUND: Tolerance can be defined as the ability of bacteria to grow in the presence of high concentrations of bactericide antimicrobics, so that the killing action of the drug is avoided but the minimal inhibitory concentration (MIC) remains the same. We investigated vancomycin tolerance in the Enterococcus faecium and Enterococcus faecalis strains isolated from different clinical specimens. METHODS: Vancomycin was obtained from Sigma Chemical Co. We studied 100 enterococci strains. Fifty-six and 44 of Enterococcus strains were idendified as E. feacalis and E. faecium, respectively. To determine MICs and minimal bactericidal concentration (MBC), we inoculated strains from an overnight agar culture to Muller-Hinton broth and incubated them for 4-6 h at 37 degrees C with shaking to obtain a logarithmic phase culture. The inoculum was controlled by performing a colony count for each test. We determined MBC values and MBC/MIC ratios to study tolerance to vancomycin. Vancomycin tolerance was defined as a high MBC value and an MBC/MIC ratio > or =32. RESULTS: Fifty-six and 44 of the Enterococcus strains were identified as E. faecium and E. faecalis, respectively. Thirty-one E. faecium and 48 E. faecalis were found to be susceptible to vancomycin and these susceptible strains were included in this study. The MICs of susceptible strains ranged from < or =1 to 4 mg/l, the MBCs were > or =512 mg/l. Tolerance was detected in all E. faecalis and E. faecium strains. The standard E. faecalis 21913 strain also exhibited tolerance according to the high MBC value and the MBC/MIC ratio. We defined the tolerant strains as having no bactericidal effect and MBC/MIC > or =32. We found that a 100% tolerance was present in susceptible strains. CONCLUSIONS: One of the hypotheses for tolerance is that tolerant cells fail to mobilize or create the autolysins needed for enlargement and division. Our data suggests that tolerance may compromise glycopeptide therapy of serious enterococci infections. To add an aminoglycoside to the glycopeptide therapy unless MBCs are unavailable can be useful in the effective treatment of serious Enterococcus infections.

Agar↗

PubMed2004

Do procalcitonin and C-reactive protein levels have a place in the diagnosis and follow-up of Helicobacter pylori infections?

The aims of this study were to determine the levels of procalcitonin (PCT) and C-reactive protein (CRP) in Helicobacter pylori-positive (HP+) patients diagnosed with duodenal and gastric ulcer and to evaluate the correlation of PCT and CRP levels with other invasive and non-invasive diagnostic methods for determination of H. pylori eradication in post-treatment follow-up. Thirty-five HP+ patients with dyspepsia were included in this study. Serum samples (5 ml) were collected at admission and after 24 h. Antimicrobial therapy (omeprazole, amoxycillin and clarithromycin) was given for 1 week to HP+ patients who were positive only by culture or by urease test plus pathology. After 1 month, serum samples (5 ml) were collected again and culture, urease and pathology investigations were performed on endoscopic samples. PCT and CRP levels were measured in the collected blood samples. Thirty-five H. pylori-negative (HP-) cases with dyspepsia, 38 cases with bacteraemia and 35 healthy blood donors were included in this study as control groups. The mean and minimum-maximum levels of PCT were 1.39 (0.25-6.75), 0.35 (0.12-0.71), 7.45 (0.68-51.5) and 0.40 (0.12-0.71) ng ml(-1) for the groups of HP+, HP- and bacteraemia patients and healthy donors, respectively. Mean CRP levels were 1.00 (<0.5-8.11), 0.62 (<0.5-3.2), 11.5 (3.2-43.5) and 0.63 (<0.5-5.46) mg dl(-1) for the same groups. A statistically significant difference was found between HP+ patients and both HP- cases and healthy blood donors for PCT levels, and higher PCT levels were found on admission in cases of bacteraemia than in the other groups (P < 0.05). PCT levels of HP+ cases decreased significantly (from 1.39 to 0.86) between admission and the post-treatment period (30 days); however, PCT levels remained higher than the cut-off value (0.5 ng ml(-1)). Similar ranges of CRP levels were found over the same time-period. The sensitivity of PCT was found to be higher than that of CRP on admission, but the specificity of PCT was found to be lower than that of CRP on the day of admission (65 and 74%, respectively). The sensitivity of PCT was the same as that of CRP for the post-treatment period, but specificity of PCT was higher than that of CRP for the post-treatment period (83 and 76%, respectively). It was concluded that PCT and CRP are not very effective markers for H. pylori infection in primary diagnosis or in eradication follow-up after therapy when used in parallel with conventional diagnostic methods, even if there is a difference in PCT and CRP levels between HP+ and HP- cases on admission.

Adult↗

PubMed2004

Is there any relationship between Chlamydophila pneumoniae infection and juvenile idiopathic arthritis?

The role of Chlamydophila pneumoniae in the development and exacerbation of juvenile idiopathic arthritis (JIA) was investigated. Blood samples were taken from 60 JIA patients during an active disease period and for 4 weeks after. Synovial fluid samples were obtained from 20 of the 60 patients. In addition, 22 patients with familial Mediterranean fever (FMF) during the active period and 35 healthy children were included in the study as control groups. Synovial fluid samples were also obtained from three children with FMF. IgG, IgM and IgA levels against C. pneumoniae in serum samples were studied by immunofluorescence and IgG antibody and PCR studies were performed for C. pneumoniae DNA in synovial fluid samples. Twenty-nine (48.3 %) patients with JIA, 18 (81.8 %) patients with FMF and 22 (62.8 %) healthy children were found to be pre-infected with C. pneumoniae. Pre-infection with C. pneumoniae among FMF patients was found to be significantly higher than among those with JIA. We did not find a significant difference between JIA patients and healthy children. Chronic C. pneumoniae infection was observed only in six JIA patients, one FMF patient and two healthy children. Synovial fluid antibodies were found at higher than 1/512-fold dilution in one JIA patient and four times higher than normal serum in three JIA patients. C. pneumoniae DNA was not detected in any synovial fluid sample from FMF or JIA patients by PCR. In conclusion, C. pneumoniae infection does not have a triggering or a progressive effect on the clinical situation in JIA aetiopathogenesis, as a result of a multifactorial aetiology. New, extensive and serial studies (especially PCR studies of synovial tissue) are needed in order to confirm the indirect results.

Adolescent↗