Akgün Yaman

Serotype distribution and antibiotic susceptibility of invasive Streptococcus pneumoniae disease isolates from children in Turkey, 2001–2004

Streptococcus pneumoniae is a major cause of childhood invasive infections, including sepsis, pneumonia and meningitis, and of non-invasive disease such as otitis media. Most S. pneumoniae strains from invasive infections capable of creating treatment problems in children because of antibiotic resistance belong to serogroups 14, 6, 9, 19 and 23. Despite progress in antimicrobial therapy, effective treatment is becoming increasingly complicated because of the rising worldwide emergence of pneumococci resistant to penicillin G and other commonly used antimicrobial agents [1, 3, 5].The aim of the present study was to investigate the antibiotic susceptibility pattern and serotype distribution of S. pneumoniae isolates from children younger than 10 years of age hospitalized with invasive pneumococcal disease (IPD) in Turkey during the years 2001–2004. All patients admitted and treated for invasive infections attributable to S. pneumoniae, between November 2001 and April 2004, in the six large university hospitals in Turkey, located in Istanbul, Adana, Ankara and Izmir, were included in this study. The study cohort represents roughly 30% (20 million) of the population of Turkey. Cases were eligible for evaluation if S. pneumonia, isolated from a normally sterile body site, was identified on the basis of typical colony morphology on blood agar as well as Gram strain, optochin sensitivity and bile solubility tests. Isolate identity was confirmed at the central study laboratory (Department of Microbiology and Infection Disease, Istanbul Faculty of Medicine). Susceptibility tests to antimicrobial agents (penicillin G, amoxicillin-clavulanic acid, cefotaxime, erythromycin and trimethoprim-sulfamethoxazole) were performed by standard disc diffusion method on Müller Hinton agar supplemented with 5% sheep blood. The susceptibility for penicillin was detected with a 1-μl oxacillin disc. The minimal inhibitory concentration (MIC) of the antibiotics was determined by the E test. Disc diffusion tests were employed according to the Clinical and Laboratory Standards Institute guidelines (formerly known as the NCCLS guidelines). An inoculum density equivalent to 0.5 MacFarland standard was prepared in Muller Hinton broth. Capsular typing was carried out by the Quellung reaction, using group and factor sera provided by the Statens Serum Institute (Denmark). Vaccine-type strains included serotypes 4, 6B, 9V, 14, 18C, 19F and 23F. We defined vaccine-related strains as pneumococci with serotypes within the same serogroup as the vaccine types (i.e. serotypes 6A, 9A, 9L, 9N, 18A, 18B, 18F, 19A, 19B, 19C, 23A and 23B) [6]. I. Yalçın Department of Paediatrics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey

Risk factors of carbapenem-resistant Klebsiella pneumoniae infection: a serious threat in ICUs.

Background Nosocomial infections caused by Carbapenem-resistant Klebsiella pneumoniae (CRKP) are increasing. Our aim in this study was to investigate the risk factors of CRKP infections. Material/Methods A retrospective cohort study was performed between 1 January and 31 December 2012 in ICU patients. Data was taken from the hospital infection control database for CRKP. The clinical samples collected from the patients were tested by an automatized system and disk diffusion. SPSS software v11.5 was used for statistical analysis. Results Totally, 105 Klebsiella pneumoniae isolates were found in 2012 and the carbapenem resistance rate was 48%. The first episode of infection was taken into risk factor analysis. Of the 98 patients, 61 (62.2%) were male and the mean and median ages were 30.4±29.8 and 25 (0–93). The length of stay was longer in the resistant group (p=0.026). Mortality was 48% in the whole group and similar between groups (p=0.533). There was a relationship between meropenem and third-generation cephalosporin use and resistance (OR 3.244 (1.193–8.819) and OR: 3.590 (1.056–12.209). The other risk factors in univariate analysis were: Immunosuppression OR: 2.186 (1.754–2.724), nasogastric catheter OR: 3.562 (1.317–9.634), peripheral arterial catheter OR: 2.545 (1.027–6.307), and being admitted to the neurosurgical unit OR: 4.324 (1.110–16.842). The multivariate analysis showed use of third-generation cephalosporin OR: 4.699 (1.292–17.089), nasogastric catheter use OR: 3.983 (1.356–11.698), and being admitted to neurosurgical ICU OR: 4.603 (1.084–19.555) as independent risk factors. Conclusions Restriction of third-generation cephalosporin and carbapenem use and invasive procedures, along with infection control precautions and disinfection policies, may be effective in reducing the carbapenem resistance in ICUs.

Reference Ranges of Lymphocyte Subsets of Healthy Adults in Turkey

Abstract: The aim of this study was to determine the reference ranges of lymphocyte subsets in serologically HIV-negative healthy adults in Turkey. Materials and Methods: Blood samples from 220 healthy adults, 105 female and 115 male, collected into tubes containing EDTA were investigated for lymphocyte subsets using flow cytometry. The age range was 18–80 years (44.80 ± 16.69). Results: The mean percentage and absolute values of the lymphocyte subsets were as follows: CD3: 72.70 ± 8.44%, 1,680 ± 528 cells/µl; CD4: 47.37 ± 9.10%, 1,095 ± 391 cells/µl; CD8: 28.99 ± 5.99%, 669 ± 239 cells/µl; CD19: 10.96 ± 4.44%, 254 ± 122 cells/µl and CD56: 7.03 ± 3.26%, 161 ± 92 cells/µl, respectively. The ratio of CD4/CD8 was 1.68 ± 0.43. There was no statistically significant difference in the percentages and absolute values of lymphocyte subsets between the genders (p > 0.05). Conclusion: Immunophenotyping has been used to establish reference values of lymphocyte subsets in normal healthy adults in Turkey.

Serotypes of Streptococcus pneumoniae Isolates from Children with Invasive Pneumococcal Disease in Turkey: Baseline Evaluation of the Introduction of the Pneumococcal Conjugate Vaccine Nationwide

ABSTRACT Before use of the pneumococcal conjugate vaccine PCV7 became widespread in Turkey, 202 invasive pneumococcus isolates were analyzed. The most common serotypes were 19F and 6B. In children ≤2 years of age, the potential coverage rate of PCV7 was 69.5%. The most frequent non-PCV7 serotypes were 19A, 3, 1, 6A, and 8.

Serotypes of Streptococcus pneumoniae Isolates of Children with Invasive Pneumococcal Disease in Turkey: A Baseline Evaluation of the National Introduction of the Pneumococcal Conjugate Vaccine

ABSTRACT Before use of the pneumococcal conjugate vaccine PCV7 became widespread in Turkey, 202 invasive pneumococcus isolates were analyzed. The most common serotypes were 19F and 6B. In children ≤2 years of age, the potential coverage rate of PCV7 was 69.5%. The most frequent non-PCV7 serotypes were 19A, 3, 1, 6A, and 8.

Aetiological agents, interleukin-6, interleukin-8 and CRP concentrations in children with community- and hospital-acquired pneumonia

Abstract Objective: To determine the pathogens causing pneumonia in community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) and to investigate serum levels of interleukin-6 (IL-6), interleukin-8 (IL-8) and CRP in pneumonia caused by different aetiological agents. Study design: Eighty-seven children (mostly < 5 years of age) were recruited in a prospective study, 55 of them with CAP without prior antibiotic treatment and 32 with HAP. Thirty healthy outpatient children served as controls. Results: The causative micro-organisms were determined by serological and microbiological methods in 40 cases with CAP (72.7%) and 30 with HAP (93.7%). In CAP, M. pneumoniae was the most common causative agent (43.6%), followed by S. pneumoniae (20%) and C. pneumoniae (18.1%). Bacteria alone were the sole causative agents in only 21.8% of cases with HAP. Pseudomonas aeruginosa (34.3%) and K. pneumoniae (32.5%) were the most frequently isolated. Although IL-6 and IL-8 levels were raised, there was no statistical difference between the CAP and HAP groups, or between bacterial and mycoplasma infections; neither was there a difference in CRP levels between these two groups. Conclusion: The causes of pneumonia differ between CAP and HAP. Levels of IL-6, IL-8 and CRP are raised in pneumonia but are unhelpful in differentiating the various aetiologies.

Role of KIR genes and genotypes in susceptibility to or protection against hepatitis B virus infection in a Turkish cohort

Background Killer cell immunoglobulin-like receptors (KIRs) are a family of inhibitory and activating receptors expressed by natural killer (NK) cells and regulate NK cell activity in the innate response against viral infections. The aim of this study was to determine the possibility of KIR genes and genotypes as a candidate for susceptibility to or protection against chronic hepatitis B virus (HBV) infection or spontaneous remission of the infection in a Turkish cohort. Material/Methods The present study was carried out on 37 patients with chronic HBV infection, 36 patients in spontaneous remission of HBV infection, and 85 healthy subjects. Sequence-specific oligonucleotide probes analysis was used to investigate 16 KIR genes. All data were statistically analyzed by the Fisher exact test. Results The rate of inhibitory KIR2DL3 (p=0.0) and 3DS1 (p=0.0) were higher in the healthy group than the group composed of chronic HBV patients and patients with spontaneous remission. There were no statistically significant differences between the rate of AA and Bx genotypes of chronic HBV patients and patients with spontaneous remission and the control group (p>0.05). Conclusions Our results suggest that KIR2DL3 and KIR3DS1 genes could be protector genes for HBV infection and they could be important immuno-genetic markers in determining antiviral immunity in the Turkish population.

Serotype distribution of Streptococcus pneumoniae in children with invasive diseases in Turkey: 2008–2014

Successful vaccination policies for protection from invasive pneumococcal diseases (IPD) dependent on determination of the exact serotype distribution in each country. We aimed to identify serotypes of pneumococcal strains causing IPD in children in Turkey and emphasize the change in the serotypes before and after vaccination with 7-valent pneumococcal conjugate vaccine (PCV-7) was included and PCV-13 was newly changed in Turkish National Immunization Program. Streptococcus pneumoniae strains were isolated at 22 different hospitals of Turkey, which provide healthcare services to approximately 65% of the Turkish population. Of the 335 diagnosed cases with S. pneumoniae over the whole period of 2008–2014, the most common vaccine serotypes were 19F (15.8%), 6B (5.9%), 14 (5.9%), and 3 (5.9%). During the first 5 y of age, which is the target population for vaccination, the potential serotype coverage ranged from 57.5 % to 36.8%, from 65.0% to 44.7%, and from 77.4% to 60.5% for PCV-7, PCV-10, and PCV-13 in 2008–2014, respectively. The ratio of non-vaccine serotypes was 27.2% in 2008–2010 whereas was 37.6% in 2011–2014 (p=0.045). S. penumoniae serotypes was less non-susceptible to penicillin as compared to our previous results (33.7 vs 16.5 %, p=0.001). The reduction of those serotype coverage in years may be attributed to increasing vaccinated children in Turkey and the increasing non-vaccine serotype may be explained by serotype replacement. Our ongoing IPD surveillance is a significant source of information for the decision-making processes on pneumococcal vaccination.

Biological Variation and Reference Change Value Data for Serum Neuron-Specific Enolase in a Turkish Population

Neuron‐specific enolase (NSE) is a recognized biomarker for the assessment of cerebral injury in neurological disorders. This study aims to report a definitive assessment of the biological variation (BV) components of this biomarker, including within‐subject BV (CVI), between‐subject BV (CVG), index of individuality (II), and reference change value (RCV), in a cohort of Turkish participants using an experimental protocol.

Biological Variations of Some Analytes in Renal Posttransplant Patients: A Different Way to Assess Routine Parameters

Biological variation (BV) data of analytes have been used to evaluate the significant changes in serial results (reference change value, RCV) of healthy individuals in clinical laboratories. However, BV data of healthy subjects may not be identical to the analytes of patients with ongoing clinical condition. The aim of this study was to calculate intra‐(CVw) (coefficient of variation for intra‐individual BV) and inter‐individual (CVg) BV, index of individuality, and RCV of nine serum analytes of renal posttransplant patients.