Ayşegül Çopur Çiçek

Postoperative Chryseobacterium indologenes Bloodstream Infection Caused by Contamination of Distillate Water

Chryseobacterium indologenes was isolated from blood samples from a 5-month-old infant with bloodstream infection. Environmental sampling was performed. Molecular typing with arbitrarily primed polymerase chain reaction demonstrated the cross-contamination of commercial distillate water. The infant was infected by this water as a result of medical assistance received during hospitalization.

Characterization of novel VIM carbapenemase, VIM-38, and first detection of GES-5 carbapenem-hydrolyzing β-lactamases in Pseudomonas aeruginosa in Turkey.

Pseudomonas aeruginosa isolates were collected form a Turkish hospital. Antimicrobial susceptibility was performed using the Vitek 2 Compact system, and 24 isolates were categorized as multidrug resistant (n = 18), extensively-drug resistant (n = 5), or pan-drug resistant (n = 1). PCR and DNA sequence analysis revealed that 1 strain possessed the blaGES-5 and another carried a novel blaVIM variant, named VIM-38. This new gene exhibited 1 amino acid substitution (Ala265Val) in comparison to its closest variant, VIM-5. Both VIM encoding genes were clones and demonstrated similar susceptibility profile when expressed in identical background. The presence of VIM-38 increases the diversity of carbapenemases in Turkey.

Comparison of Verona Integron-Borne Metallo-β-Lactamase (VIM) Variants Reveals Differences in Stability and Inhibition Profiles

ABSTRACT Metallo-β-lactamases (MBLs) are of increasing clinical significance; the development of clinically useful MBL inhibitors is challenged by the rapid evolution of variant MBLs. The Verona integron-borne metallo-β-lactamase (VIM) enzymes are among the most widely distributed MBLs, with >40 VIM variants having been reported. We report on the crystallographic analysis of VIM-5 and comparison of biochemical and biophysical properties of VIM-1, VIM-2, VIM-4, VIM-5, and VIM-38. Recombinant VIM variants were produced and purified, and their secondary structure and thermal stabilities were investigated by circular dichroism analyses. Steady-state kinetic analyses with a representative panel of β-lactam substrates were carried out to compare the catalytic efficiencies of the VIM variants. Furthermore, a set of metalloenzyme inhibitors were screened to compare their effects on the different VIM variants. The results reveal only small variations in the kinetic parameters of the VIM variants but substantial differences in their thermal stabilities and inhibition profiles. Overall, these results support the proposal that protein stability may be a factor in MBL evolution and highlight the importance of screening MBL variants during inhibitor development programs.

Nationwide study of Escherichia coli producing extended-spectrum β-lactamases TEM, SHV and CTX-M in Turkey

Four hundred and forty extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates were collected from 10 different hospitals in Turkey between 2011 and 2012. Clinical specimens consisted of urine (80.45%), blood (6.59%), cerebrospinal fluid (1.13%), pleural fluid (2.95%), wound (4.31%) and sputum (4.54%). ESBL-coding genes (CTX-M1, CTX-M2, TEM, SHV) were detected by PCR. According to the PCR and sequencing results, CTX-M1 was the most prevalent β-lactamase 83.18% (366/440), followed by TEM 44.09% (194/440), CTX-M2 31.81% (140/440) and SHV 1.81% (8/440). Sequencing results showed that TEM and SHV types were TEM-1b and SHV-11, respectively. Rate of the strains harboring only CTX-M1, CTX-M2, TEM-1b and SHV-11 were 30.90%, 3.63%, 2.27% and 0.23%, respectively. Rate of the strains harboring the combinations of CTX-M1-CTX-M2, CTX-M1-CTX-M2-TEM-1b, CTX-M2-TEM-1b, CTX-M1-TEM-1b, CTX-M1-CTX-M2-TEM-1b-SHV-11, CTX-M1-TEM-1b-SHV-11, CTX-M1-SHV-11, CTX-M1-CTX-M2-SHV-11, CTX-M2-SHV-11, CTX-M2-TEM-1b-SHV-11, TEM-1b-SHV-11 were 12.95%, 11.59%, 2.95%, 26.13%, 0.45%, 0.68%, 0.22%, 0.22%, 0%, 0% and 0%, respectively. This is a nationwide study of ESBL-producing E. coli in Turkey. These results shows that CTX-M1 group is the most common type of class A β-lactamases among ESBL-producing E. coli strains in Turkey.

The effects of Gilbert's syndrome on the mean platelet volume and other hematological parameters.

The protective effect of increased levels of indirect bilirubin on atherosclerotic heart disease in patients of Gilberts syndrome is well known. The aim of the study was to investigate the effects of increased levels of bilirubin on the mean platelet volume (MPV) and other hematological parameters. Thirty-two men and 36 women (a total of 68 Gilberts syndrome patients) and a similar age group of 68 healthy individuals (32 men and 36 women) were included in the study. Hematologic tests, C-reactive protein (CRP) and biochemical values of the two groups were checked. MPV level of Gilberts syndrome group was 7.8 ± 1.0 fl and CRP 0.2 ± 0.27 mg/dl. In the control group MPV was 8.6 ± 1.0 fl and CRP 0.3 ± 0.38 mg/dl. MPV of patients group (P < 0.001) and CRP (P = 0.037) were significantly lower than the control group. When dividing Gilberts syndrome and control groups according to sex into subgroups the level of indirect bilirubin in men with Gilberts syndrome (1.8 ± 0.8 mg/dl) was found to be higher than other groups. Healthy men had higher levels of MPV (8.8 ± 0.9 fl) whereas Gilberts syndrome male patients had lower levels (7.7 ± 1.1 fl), (P < 0.001). The elevated levels of bilirubin and decreasing levels of MPV and CRP in Gilberts syndrome patients may have an effect on the slowing down of the atherosclerotic process.

Detection of class 1 integron in Acinetobacter baumannii isolates collected from nine hospitals in Turkey

OBJECTIVE To investigate the antibiotic resistance genes inserted into class 1 and class 2 integrons in Acinetobacter baumannii (A. baumannii) isolates obtained from nine different cities in Turkey. METHODS A collection of 281 A. baumannii clinical isolates were collected from nine diferent state hospitals in Turkey and were confirmed as A. baumannii by conventional biochemical, API testing and bla-OXA-51 specific PCR. The isolates were examined by PCR for existence of class 1 and 2 integron gene cassettes. RESULTS They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin (90.03%), ciprofloxacin (87.54%), cefepime and trimethoprim/sulfamethoxazole (81.13%). The lowest resistance rates was for cefotaxime (3.55%). class I integrons were detected in 6.4% (18/281) of A. baumannii strains and no class 2 integron was detected. The gene cassettes of class 1 integrons AacC1-AAC(3)I-aadA1, AacC1-aadA1, AAC(3)-I, AAC(3)-I -AAC(3)-I -aadA1, TEM-1, AAC(3)-I-aadA1 - AAC(3)-I -AAC(3)-I, AAC(3)-I -AAC(3)-I -AAC(3)-I -aadA1, AAC(3)-I - aadA1, AAC(3)-I-AAC(3)-I, AAC(3)-I-aadA1- AAC(3)-I-aadA1, AAC(3)-I- AAC(3)-I- aadA1-AAC(3)-I-aadA1 were detected in eighteen strains. The aac genes family were most frequently found integrated into the class 1 integrons and it was followed by aadA genes and TEM-1 genes. CONCLUSIONS This is an extensive study on the distribution of class 1 integron among A. baumannii in Turkey. In addition to these, two new alleles were observed. Their percentage rates of similarity to other cassettes are 95% aadA1 ( TKA18) and 89% aadA1 (ANKA3).

Prevalence and genotype distribution of rotaviruses in children with gastroenteritis in Rize province

Determination of the distribution of rotavirus genotypes is essential for understanding the epidemiology of this virus responsible for nearly half a million of deaths in patients with gastroenteritis worldwide. In the present study, we aimed to genotype the rotavirus strains isolated from diarrheal stool samples in children under 5 years old. A total of 1297 fecal samples were collected, and rotavirus antigen was detected in 73 of these samples. Antigen-positive samples were transferred to the Public Health Agency of Turkey, Molecular Microbiology Research Laboratory, and were tested for determination of genotypes G and P using semi-nested multiplex polymerase chain reaction method performed with consensus- and genotype-specific primers. Twelve specimens were found to be negative for rotavirus in genotyping method. All the positive-strains were in G1-4, G8-9, P(4), P(8), and P(9) genotypes. The most frequent GP genotype combinations were found to be G9P(8) in 21 strains (34.4%), G2P(4) in 14 strains (23.0%), and G1P(8) in 12 strains (19.7%). We found 10 distinct genotypes amongst a total of 61 strains. Among the strains isolated and genotyped in our study, 90.2% (55/61) and 67.2% (41/61) have already been included in the two existing commercial vaccines. In conclusion, these findings implicate the necessity of development of region-specific vaccines after evaluation of the local genotype distribution. Further studies on the large number of rotavirus strains would contribute to this process.

Distribution of β-lactamase genes among carbapenem-resistant Klebsiella pneumoniae strains isolated from patients in Turkey.

Background The emergence of carbapenem-resistant Klebsiella pneumoniae poses a serious problem to antibiotic management. We investigated the β-lactamases in a group of carbapenem-resistant K. pneumoniae clinical isolates from Turkey. Methods Thirty-seven strains of K. pneumoniae isolated from various clinical specimens were analyzed by antimicrobial susceptibility testing, PCR for the detection of β-lactamase genes, DNA sequencing, and repetitive extragenic palindronic (REP)-PCR analysis. Results All 37 isolates were resistant to ampicillin, ampicillin/sulbactam, piperacillin, piperacillin/tazobactam, ceftazidime, cefoperazone/sulbactam, cefepime, imipenem, and meropenem. The lowest resistance rates were observed for colistin (2.7%), tigecycline (11%), and amikacin (19%). According to PCR and sequencing results, 98% (36/37) of strains carried at least one carbapenemase gene, with 32 (86%) carrying OXA-48 and 7 (19%) carrying NDM-1. No other carbapenemase genes were identified. All strains carried a CTX-M-2-like β-lactamase, and some carried SHV- (97%), TEM- (9%), and CTX-M-1-like (62%) β-lactamases. Sequence analysis of blaTEM genes identified a blaTEM-166 with an amino acid change at position 53 (Arg53Gly) from blaTEM-1b, the first report of a mutation in this region. REP-PCR analysis revealed that there were seven different clonal groups, and temporo-spatial links were identified within these groups. Conclusions Combinations of β-lactamases were found in all strains, with the most common being OXA-48, SHV, TEM, and CTX-M-type (76% of strains). We have reported, for the first time, a high prevalence of the NDM-1 (19%) carbapenemase in carbapenem-resistant K. pneumoniae from Turkey. These enzymes often co-exist with other β-lactamases, such as TEM, SHV, and CTX-M β-lactamases.

Molecular characterisation and control of Acinetobacter baumannii isolates resistant to multi-drugs emerging in inter-intensive care units

BackgroundA nosocomial outbreak of Acinetobacter baumannii (AB) infections occurred among intensive care units (ICU) (surgery, medical, cardiovascular surgery, coronary unit) of Recep Tayyip Erdogan University Medical School (Rize, Turkey) between January 2011 and May 2012. The identification of isolates and clonal relation among them were investigated by molecular techniques.MethodsA total of 109 AB isolates were obtained from 64 clinical materials from 54 ICU patients and 3 from the hands of healthcare workers (HCWs) of 42 environmental samples. The isolates were identified by 16S rDNA sequencing and OXA- specific PCR. The clonal relation between isolates was investigated by PFGE methods using ApaI restriction enzyme.ResultsAll isolates were determined as AB by 16S rDNA sequencing and OXA-spesific PCR. While the blaOXA-51-like gene was amplified in all isolates, the blaOXA-23-like gene was amplified from 103 isolates. The PFGE pattern generated 9 pulsotypes and showed that the isolates from patients, HCWs, and the environment were genetically related. In 7 of these pulsotypes, there were 107 strains (98%) showing similar PFGE profiles that cannot be distinguished from each other, ranging from 2 to 53. The remaining 2 pulsotypes were comprised of strains closely associated with the main cluster. Two major groups were discovered with similarity coefficient of 85% and above. The first group consisted of 97 strains that are similar to each other at 92.7% rate, and the second group consisted of 12 strains that are 100% identical.ConclusionsThe common utilization of the blood gas device among ICU was the reason for the contamination. AB strains can remain stable for a long period of time, although due to the disinfection procedures applied in hospitals, there is a small chance that the same clone might reappear and cause another epidemic. For that reason, the resistance profiles of the strains must be continuously followed with amplification-based methods, and these methods should be used to support the PFGE method in the short term.

A Multicenter Evaluation of Blood Culture Practices, Contamination Rates, and the Distribution of Causative Bacteria

Background: The prognostic value of blood culture testing in the diagnosis of bacteremia is limited by contamination. Objectives: In this multicenter study, the aim was to evaluate the contamination rates of blood cultures as well as the parameters that affect the culture results. Materials and Methods: Sample collection practices and culture data obtained from 16 university/research hospitals were retrospectively evaluated. A total of 214,340 blood samples from 43,254 patients admitted to the centers in 2013 were included in this study. The blood culture results were evaluated based on the three phases of laboratory testing: the pre-analytic, the analytic, and the post-analytic phase. Results: Blood samples were obtained from the patients through either the peripheral venous route (64%) or an intravascular catheter (36%). Povidone-iodine (60%) or alcohol (40%) was applied to disinfect the skin. Of the 16 centers, 62.5% have no dedicated phlebotomy team, 68.7% employed a blood culture system, 86.7% conducted additional studies with pediatric bottles, and 43.7% with anaerobic bottles. One center maintained a blood culture quality control study. The average growth rate in the bottles of blood cultures during the defined period (1259 - 26,400/year) was 32.3%. Of the growing microorganisms, 67% were causative agents, while 33% were contaminants. The contamination rates of the centers ranged from 1% to 17%. The average growth time for the causative bacteria was 21.4 hours, while it was 36.3 hours for the contaminant bacteria. The most commonly isolated pathogens were Escherichia coli (22.45%) and coagulase-negative staphylococci (CoNS) (20.11%). Further, the most frequently identified contaminant bacteria were CoNS (44.04%). Conclusions: The high contamination rates were remarkable in this study. We suggest that the hospitals’ staff should be better trained in blood sample collection and processing. Sterile glove usage, alcohol usage for disinfection, the presence of a phlebotomy team, and quality control studies may all contribute to decreasing the contamination rates. Health policy makers should therefore provide the necessary financial support to obtain the required materials and equipment.