Duygu Percin

Molecular characterization of carbapenem-resistant Klebsiella pneumoniae in a tertiary university hospital in Turkey.

The aim of this study was to identify the resistance genes and genetic relationship of carbapenemase-resistant Klebsiella pneumoniae (CRKP) identified in a tertiary university hospital in Turkey. During the study, CRKP was isolated from 137 patients. Resistance genes were studied in 94 isolates. Among these isolates, most of the CRKP produced only oxacillinase (OXA)-48 (91.5%); however, 4.3% of the isolates produced only New Delhi metallo-beta-lactamase 1 (NDM-1), 1% produced both OXA-48 and NDM-1, and 3.2% produced imipenem. This study adds Turkey to the growing list of countries with NDM-1-producing bacteria and shows that NDM-1 may easily spread worldwide.

Locking Tunneled Hemodialysis Catheters with Hypertonic Saline (26% NaCl) and Heparin to Prevent Catheter-Related Bloodstream Infections and Thrombosis: A Randomized, Prospective Trial

Objective: Tunneled cuffed dual-lumen catheters (TCCs) are commonly used for vascular access in hemodialysis (HD) patients. Catheter-related bloodstream infection (CRBSI) is the major problem leading to morbidity and mortality. We investigated whether 26% NaCl solution has any favorable effect on the infections and thrombosis caused by HD catheters. Methods: TCCs were locked with either 26% NaCl and heparin or standard heparin. The primer end point of the study was the CRBSI or thrombosis of the TCC. We compared the antimicrobial activity of the NaCl solutions (6.5%, 13%, 26%) with 0.9% NaCl solution by time–kill kinetic assay. All tests were performed in triplicate by incubation of test fluids with Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. Results: The mean catheter survival was significantly higher in the 26% NaCl and heparin group (129.5 ± 50.1 catheter days to 103.3 ± 59.8, p = 0.008). CRBSI rates (10–15.4%) did not differ significantly between the two groups (p = 0.54). The hypertonic 13% NaCl solution had bactericidal effects on E. coli and P. aeruginosa, but had bacteriostatic effect on S. aureus and S. epidermidis. Conclusion: In this study we demonstrated that the 13% NaCl solution and more hypertonic NaCl solutions revealed potent in vitro antimicrobial properties against all checked Gram-negative microorganisms.

Changing pattern of antibiotic susceptibility in intensive care units: ten years experience of a university hospital.

The study was performed to assess microorganisms and antibiotic susceptibility patterns during ten years in intensive care units of a University Hospital. Infection Control Committee has active, prospective surveillance in ICUs for thirteen years. Ten years data of ICUs was evaluated retrospectively from surveillance forms. Microorganisms and their antibiotic resistance were recorded according to the years. During ten years, gram negative microorganisms were the most frequent isolated microorganisms from clinical specimens. Acinetobacter baumannii (21.8%), Pseudomonas aerigunosa (16%), Escherichia coli (10.4%) and Klebsiella pneumoniae (8%) were the most common gram negative microorganisms. However, Staphylococcus aureus was the most prevalent gram positive microorganism, the incidence decreased from 18.6% to 4.8% during ten years. Also antibiotic susceptibility of microorganisms changed during ten years. Carbapenem resistance increased from 44% to 92% in A. baumannii and ciprofloxacin resistance increased in E. coli from 28% to 60% and in K. pneumoniae from 21% to 55% during ten years. However, methicilin resistance decreased in S. aureus from 96% to 54%. In conclusion, antibiotic resistance is growing problem in ICUs. Rationale antibiotic policies and infection control measures will prevent the development of resistance.

Antimicrobial susceptibility and molecular subtyping of 55 Turkish Bacillus anthracis strains using 25-loci multiple-locus VNTR analysis

Anthrax, which is caused by the bacterium Bacillus anthracis, is one of the oldest documented infectious diseases in both livestock and humans. The differentiation of B. anthracis strains is difficult because of their highly homogeneous genomes. We used multiple-locus variable-number tandem repeat analysis (MLVA) with 25 markers to genotype 55 B. anthracis isolates from 16 distinct regions of Turkey. The antimicrobial susceptibility of the isolates was investigated using the agar dilution method. An eight-loci MLVA assay revealed six unique genotypes (G(K)13, G(K)27, G(K)35, G(K)43, G(K)44, and G(K)61). However, the 25-loci MLVA was more discriminatory, revealing the presence of ten genotypes instead of six. The additional genotypes resulted from the split of four subtypes: G(K)35 (b and c), G(K)43 (a and f), G(K)44 (d and e), and G(K)61 (i and j). All of the Turkish B. anthracis isolates were susceptible to ciprofloxacin, levofloxacin, tigecycline, linezolid, and vancomycin. One isolate was resistant to penicillin and to doxycycline. A total of 34 isolates were susceptible, 20 isolates were partially susceptible, and one isolate was resistant to erythromycin. None of the isolates exhibited susceptibility to cefotaxime. A total of 53 isolates were susceptible to gentamicin, and two were resistant. The genotypes G(K)35 (n=24), G(K)44 (n=13), and G(K)43 (n=10) were the most prevalent in 10, 6, and 5 regions, respectively, of the total 16 provinces. The B. anthracis isolates collected from these regions implied that the movement of B. anthracis is a result of the increased transportation of livestock and the resultant cross contamination.

Relationship between odontogenic bacteremia and orthodontic stripping.

INTRODUCTION The aim of this study was to evaluate the prevalence of bacteremia associated with an orthodontic stripping procedure. METHODS The study included 29 orthodontic patients (mean age, 18.2 ± 3.4 years). We used a standardized stripping procedure: a perforated stripping disk with a contra-angle hand piece was used at a low speed (<15,000 rpm; 10 seconds) on the mandibular anterior teeth. Blood samples were collected by inserting a cannula into the left antecubital fossa. A baseline sample was taken before treatment, and a second sample was taken after the stripping procedure. These samples were inoculated into aerobic and anaerobic blood culture bottles and incubated, and the bacterial cultures were identified; the samples collected before and after the stripping procedure were statistically analyzed. RESULTS Transient bacteremia was not detected in any pretreatment blood sample, but it was found in 1 postoperative blood sample; this sample tested positive for Streptococcussanguis. CONCLUSIONS The bacterial species in the positive postoperative blood sample was S sanguis, which might be associated with infective endocarditis. Clinicians should explain the level of risk to the patient and consult a concerned medical specialist.

In vitro synergism of combinations of colistin with selected antibiotics against colistin-resistant Acinetobacter baumannii

Aim: The in vitro activity of colistin in combination with sulbactam, netilmicin, and vancomycin against colistin-resistant A. baumannii strains was investigated. Furthermore, the clonal relationship of the strains was analyzed. Methods: Clonal relationship was investigated using rep-PCR. To screen for synergysm, the fractional inhibitory concentration index (FICI) was calculated using checkerboard assay. The killing kinetics of the combination of colistin with vancomycin was assessed using time-kill assay. Results: Three different clones were found among 10 clinical isolates of colistin-resistant A. baumannii strains. Thereof, 8 strains were susceptible to netilmicin. Synergistic interaction was detected in 1 strain with the combination of colistin-netilmicin, in 5 strains with colistin-sulbactam, and in 9 strains with colistin-vancomycin. None of combinations had antagonistic activity. Colistin-vancomycin combination resulted in rapid bactericidal activity. Conclusion: These results show a distinct in vitro synergism between colistin and vancomycin, which might be useful to treat infection with multiple-resistant strains, prevent emergence of resistant strains, and to lower doses for both antibiotics to be used.

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.

Is it worth screening for vancomycin-resistant Enterococcus faecium colonization?: Financial burden of screening in a developing country

BACKGROUND The screening of critically ill patients at high risk of vancomycin resistant enterococci (VRE) colonization, to detect and isolate colonized patients, is recommended to prevent and control the transmission of VRE. Screening asymptomatic carriers brings financial burden for institutions. In this study, we performed risk analysis for VRE colonization and determined the financial burden of screening in a middle-income country, Turkey. METHODS We retrospectively analyzed the VRE surveillance data from a pediatric hospital between 2010 and 2014. A case-control study was conducted to identify the risk factors of colonization. Total cost of VRE screening and additional costs for a VRE colonized patient (including active surveillance cultures and contact isolation) were calculated. RESULTS During the 4-year period, 6,372 patients were screened for perirectal VRE colonization. The rate of culture-positive specimens among all patients screened was 239 (3.75%). The rate of VRE infection was 0.04% (n = 3) among all patients screened. Length of hospital stay, malignancy, and being transferred from another institution were independently associated risk factors for colonization. Annual estimated costs for the laboratory were projected as

Risk factors for carbapenem resistant Klebsiella pneumoniae rectal colonization in pediatric units

19,074 (76,295/4) for all patients screened. Cost of contact isolation for each patient colonized in a ward and an intensive care unit was

In vitro antimicrobial efficiency of different root canal sealers against Enterecoccus faecalis

270 and