The potential of therapeutic hyperthermia to eradicate Staphylococcus aureus bacteria; an in vitro study.

Staphylococcus aureus is one of the most common infectious agents, causing morbidity and mortality worldwide. Most pathogenic bacteria are classified in the group of mesophilic bacteria and the optimal growth temperature of these bacteria changes between 33 and 41 °C. Increased temperature can inhibit bacterial growth and mobility, which in turn, can trigger autolysis and cause cell wall damage. Hyperthermia treatment is defined as a heat-mediated treatment method applied using temperatures higher than body temperature. Nowadays, this treatment method is used especially in the treatment of tumours. Hyperthermia treatment is divided into two groups: mild hyperthermia and ablative or high-temperature hyperthermia. Mild hyperthermia is a therapeutic technique in which tumour tissue is heated above body temperature to produce a physiological or biological effect but is often not aimed at directly causing significant cell death. The goal of this method is to achieve temperatures of 40-45 °C in human tissues for up to 2 h. Hyperthermia can be used in the treatment of infections caused by such bacterial pathogens. In addition, using hyperthermia in combination with antimicrobial drugs may result in synergistic effects and reduce resistance issues. In our study, we used two different temperature levels (37 °C and 45 °C). We assessed growth inhibition, some virulence factors, alteration colony morphologies, and antimicrobial susceptibility for several antibiotics with three methods (Kirby-Bauer, E-test and broth microdilution) under hyperthermia. In the study, we observed that hyperthermia affected the urease enzyme, antibiotic sensitivity levels showed synergy with hyperthermia, and changes occurred in colony diameters and affected bacterial growth. We hypothesise that hyperthermia might be a new therapeutic option for infectious diseases as a sole agent or in combination with different antimicrobials.

Effects of deferoxamine on intrinsic colistin resistance of Proteus mirabilis.

Proteus mirabilis is a common pathogen, which is responsible for urinary tract infections. Iron is a critical element necessary for both humans and pathogens to maintain their biological functions, and iron limitation via chelator agents may be useful in the treatment of infections. The present study aimed to investigate the synergistic interactions between the iron chelator agent deferoxamine (DFO) and the antibacterial drug colistin. The minimum inhibitory concentration (MIC) values of DFO and colistin for P. mirabilis isolates were determined by broth microdilution. The checkerboard technique was used to examine the potential synergy between DFO and colistin. Furthermore, time-kill assays were used for the confirmation of synergy detected by the checkerboard assay, as well as for determining bacteriostatic and bactericidal interactions throughout a 24-h period. As expected, all P. mirabilis isolates were resistant to colistin. DFO did not inhibit P. mirabilis growth when used alone, even at very high doses (10 µg ml-1). Notably, when in combination with DFO, the MIC values of colistin were markedly reduced, and the checkerboard assay results showed synergy between colistin and DFO for all isolates. In addition, in time-kill assays, colistin + DFO exhibited synergistic activity against all strains at most time intervals and concentrations tested. Colistin + DFO showed bactericidal activity at colistin concentrations of 1xMIC and 2xMIC, although a degree of re-growth was observed in one of the strains at 12-24 h. These findings indicated that DFO has the potential for use as an adjunct to colistin through iron sequestration, thus providing synergistic activity to an antibiotic that would not normally be considered a treatment option against P. mirabilis. In vivo experiments in the future may provide useful information on the efficacy of DFO/colistin since these models effectively reflect physiological parameters.

In vitro effects of deferoxamine on antibiotic susceptibility in Gram-negative bacteria.

BACKGROUND: Iron is a vital element for the growth of bacteria. Bacteria use several strategies to scavenge iron, such as siderophores, which are thought to be important virulence components. The mammalian host uses various iron-binding substances to make iron unavailable for bacterial uptake. Deferoxamine (DFO) is a semi-synthetic iron chelator that has been licensed for medical use. Iron chelators like DFO may provide an alternative therapeutic technique for treating Gram-negative bacteria infections, which frequently display multidrug resistance. OBJECTIVES: We assumed that iron deprivation or interactions with the cell membrane caused by DFO or increased siderophore synthesis may cause the inhibition or inactivation of proteins and enzymes necessary for critical processes in bacteria. Additionally, we proposed that these bacterial alterations might be the origin of synergistic interactions between DFO and several antibiotics. MATERIAL AND METHODS: To test this hypothesis, we used disc diffusion, broth microdilution and checkerboard synergy testing methods on combinations of DFO with ceftriaxone, cefepime, meropenem, amikacin, levofloxacin, and tigecycline, respectively, in a total of 55 isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Proteus mirabilis strains - 11 isolates for each genus). RESULTS: No synergistic or antagonistic interactions were observed between DFO and the tested antibiotics in the E. coli, K. pneumoniae, P. aeruginosa, and A. baumannii isolates, while the addition of DFO significantly increased the inhibition zone diameters of cefepime, amikacin, meropenem, tigecycline, and levofloxacin in P. mirabilis isolates. According to the checkerboard synergy results, a synergistic interaction was found between DFO and tigecycline, cefepime and amikacin for P. mirabilis isolates. CONCLUSIONS: Among the investigated bacteria, a synergy between antibiotics and DFO was only discovered against P. mirabilis. We do not believe that this entirely disproves our hypothesis, though. The production of siderophores triggered by the increased metabolic activity of actively proliferating bacteria at the infection site may provide better results. Therefore, expanding these investigations and developing infection models through animal testing would be advantageous.

Comparison of a novel antigen detection test with reverse transcription polymerase chain reaction assay for laboratory diagnosis of SARS-CoV-2 infection.

Molecular diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription polymerase chain reaction (RT-PCR) in respiratory specimens is considered the gold standard method. This method is highly sensitive and specific but it has some limitations such as being expensive and requiring special laboratory equipment and skilled personnel. RapidFor™ Antigen Rapid Test Kit is a commercially available Ag-RDT which is produced in Turkey and designed to detect the nucleocapsid antigen of SARS-CoV-2 in nasopharyngeal swab samples. The aim of this study was to evaluate the performance of this novel SARS-CoV-2 antigen detection considering the RT-PCR method as the gold standard. Four hundred forty-four nasopharyngeal swab samples which were collected from the patients who met clinical criteria of COVID-19 from ten centers in Turkey between September 2020 and February 2021 were included in the study. All the nasopharyngeal swab samples were tested for SARS-CoV-2 RNA using commercial RT-PCR kits (Bioeksen and A1 Lifesciences, Istanbul, Turkey) according to the manufacturer's instructions. Viral loads were assessed according to the cycle threshold (Ct) values. RapidFor™ SARS-CoV-2 antigen test (Vitrosens Biotechnology, Istanbul, Turkey) was used to investigate the presence of SARS-CoV-2 antigen in all samples following the manufacturer's instructions. Out of 444 nasopharyngeal swab samples tested, 346 (77.9%) were positive and 98 (22.1%) were negative for SARS-CoV-2 RNA by RTPCR. Overall sensitivity of the RapidFor™. Antigen Rapid Test Kit was 80.3% whereas specificity was found to be 87.8%. Positivity rate of rapid antigen test in samples with Ct values over 25 and below 30 was 82.7%, while it increased to 95.7% in samples 20 ≤ Ct < 25 and reached 100% in samples with Ct values below 20. RapidFor™ SARS-CoV-2 Ag test might be a good choice in the screening of symptomatic and asymptomatic patients and their contacts for taking isolation measures early, with advantages over RT-PCR as being rapid, easy and being applicable in every laboratory and even at point of care.

Serotype distribution of Streptococcus pneumoniae and pneumococcal vaccine coverage in adults in Turkey between 2015 and 2018.

OBJECTIVE: To evaluate the serotype distribution and antibiotic resistance in pneumococcal infections in adults and to provide a perspective regarding serotype coverage of both current and future pneumococcal vaccines. PATIENTS AND METHODS: This passive surveillance study was conducted with the Streptococcus pneumoniae strains isolated from the specimens of patients with pneumonia (materials isolated from bronchoalveolar lavage), bacteraemia, meningitis, pleuritis and peritonitis between 2015 and 2018. Serogrouping and serotyping were performed by latex particle agglutination and by conventional Quellung reaction using commercial type-specific antisera, respectively. The strains were analysed for penicillin, cefotaxime, erythromycin and moxifloxacin susceptibilities by E-test. RESULTS: In the whole study group (410 samples from adults aged ≥18 years), the most frequent serotypes were 3 (14.1%), 19 F (12%) and 1 (9.3%). The vaccine coverage for PCV13, PCV15, PCV20 and PPV23 was 63.9%, 66.6%, 74.1% and 75.9%, respectively, in all isolates. Penicillin non-susceptibility in invasive pneumococcal disease (IPD) was 70.8% and 57.1% in the patients aged <65 and ≥65 years, respectively. About 21.1% and 4.3% of the patients with and without IPD had cefotaxime resistance. Non-susceptibility to erythromycin and moxifloxacin was 38.2% and 1.2%, respectively. CONCLUSIONS: The results revealed that novel PCV vaccines may provide improved coverage as compared with the currently available vaccine, PCV13. The significant antibiotic resistance rates imply the need to extend the serotype coverage of the vaccines. Continuing the surveillance in pneumococcal diseases is critical to explore the serotype distribution and incidence changes of IPD cases in the population and to inform policy makers to make necessary improvements in the national immunization programmes.Key messagesThis multicentre study demonstrated the most recent serotype distribution and antibiotic resistance in adult population in Turkey.Shifting from PCV13 to novel conjugated vaccines will significantly increase the coverage.Continuing the surveillance in pneumococcal diseases is critical to explore the serotype distribution changes and the incidence of cases with invasive pneumococcal disease in the population.

Rhodotorula fungemia in a patient with acute lymphoblastic leukemia / Fungemia de Rhodotorula em paciente com leucemia linfoblástica aguda / Fungemia por Rhodotorula en un paciente con leucemia linfoblástica aguda

Objectives: Rhodotorula is an environmental yeast that belongs to Basidiomycota Phylum. Rhodotorula species are ubiquitous in nature, can be found in soil and freshwater. Immunocompromised patients can develop Rhodotorulosis due to wide-ranging exposure to Rhodotorula in the hospital environment. Case Discussion: The patient was a 3-year-old male with a diagnosis of Pro B-Acute Lymphoblastic Leukemia (ALL). He was admitted to the hospital with complaints of malaise, fatigue, weight loss, and diarrhea between courses of chemotherapy. Rhodotorula was isolated from the patient's blood culture obtained during the elevation of temperature. After 14 days of amphotericin B treatment, clinical situation of the patient was improved and he was discharged. Conclusion: Rhodotorula spp. as a rare yet emerging pathogen, often presents as fever of unknown etiology resistant to antibacterial treatment and can be associated with fungemia and other severe complications.(AU)

Objetivos: Rhodotorula é uma levedura ambiental que pertence ao filo Basidiomycota. As espécies de Rhodotorula são onipresentes na natureza, podem ser encontradas no solo e na água doce. Pacientes imunocomprometidos podem desenvolver rodotorulose devido à ampla exposição a Rhodotorula no ambiente hospitalar. Descrição do caso: O paciente era uma criança de 3 anos de idade com diagnóstico de Leucemia Linfoblástica Aguda Pro B (LLA). O paciente deu entrada no hospital com queixas de mal-estar, cansaço, perda de peso e diarreia entre os ciclos de quimioterapia. A Rhodotorula foi isolada da hemocultura do paciente obtida durante a elevação da temperatura. Após 14 dias de tratamento com anfotericina B, a situação clínica do paciente melhorou e o paciente recebeu alta. Conclusão: Rhodotorula spp. como um patógeno raro, porém emergente, frequentemente se apresenta como febre de etiologia desconhecida resistente ao tratamento antibacteriano e pode estar associada a fungemia e outras complicações graves.(AU)

Objetivos: Rhodotorula es una levadura ambiental que pertenece al filo Basidiomycota. Las especies de Rhodotorula son ubicuas en la naturaleza, se pueden encontrar en el suelo y en agua dulce. Los pacientes inmunodeprimidos pueden desarrollar Rhodotorulosis debido a una amplia exposición a Rhodotorula en el entorno hospitalario. Descripción del caso: El paciente era un niño de 3 años con diagnóstico de leucemia linfoblástica aguda Pro B (LLA). El paciente ingresó en el hospital con quejas de malestar, fatiga, pérdida de peso y diarrea entre ciclos de quimioterapia. Se aisló Rhodotorula del hemocultivo del paciente que se obtuvo durante la elevación de la temperatura. Después de 14 días de tratamiento con anfotericina B, la situación clínica del paciente mejoró y fue dado de alta. Conclusión: Rhodotorula spp. como patógeno poco común pero emergente, a menudo se presenta como fiebre de etiología desconocida resistente al tratamiento antibacteriano y puede asociarse con fungemia y otras complicaciones graves.(AU)

Sphingomonas paucimobilis Outbreak a Pediatric Hematology-Oncology Hospital: Epidemiological Investigation and Literature Review of an Emerging Healthcare-Associated Infection.

Sphingomonas paucimobilis is an aerobic, non-fermentative, opportunistic Gram-negative bacillus found in water systems. This study was conducted to analyze concurrent S. paucimobilis bacteremia cases and treatment outcomes, potential outbreak sources, and antimicrobial resistance profiles. This ambidirectional cohort study was conducted in a 30-bed pediatric hematology-oncology hospital. The patients' ages ranged from 1 to 17 years, with a median age of 5 years. Environmental sampling was applied to investigate the outbreak source. Bacterial identification and antimicrobial susceptibility tests of the isolated bacteria were performed using the disk diffusion method and Vitek®2 automated system. S. paucimobilis was detected in 181 blood culture samples from 51 patients over 2 years and was isolated from hot tap water. Acute lymphoblastic leukemia (ALL) was diagnosed for 66% of patients, and two of our patients with ALL died due to S. paucimobilis sepsis. S. paucimobilis isolates are susceptible to carbapenems and quinolones. Surveillance and epidemic control should be performed for hospital-acquired infectious agents such as S. paucimobilis. In additon, water distribution systems should be checked for colonizing agents at regular intervals.

Antimicrobial effect of natural kinds of toothpaste on oral pathogenic bacteria.

INTRODUCTION: Because of the adverse effects on human health of some antimicrobial ingredients in traditional toothpaste, consumers are increasingly turning to toothpastes with natural ingredients. This study evaluates the antimicrobial effect of toothpastes containing different natural active agents against three oral pathogens: Streptococcus mutans, Streptococcus sanguinis, and Enterococcus faecalis. METHODOLOGY: This study tested one traditional toothpaste and seven different natural toothpastes containing theobromine, aloe vera, miswak, propolis, chitosan, enzymes and probiotics. The agar-well diffusion method was used to test the antimicrobial effect. Inhibition zones formed around toothpastes after 24 hours of incubation were measured and the data collected were statistically analyzed. RESULTS: Toothpastes containing theobromine and chitosan and the traditional toothpaste showed antimicrobial efficacy for all tested bacteria. Toothpastes containing aloe vera, miswak, and propolis were only effective on S. mutans, while toothpastes containing probiotics and enzymes did not show any antimicrobial effect on the bacteria. Among toothpastes with natural ingredients, the theobromine-containing toothpaste showed the highest efficacy on S. mutans, while the aloe vera- and propolis-containing toothpastes had the lowest efficacy (p < 0.05). CONCLUSIONS: Theobromine- and chitosan-containing toothpastes, which showed antimicrobial activity against all bacteria, can be recommended as alternatives to traditional toothpastes.

Inhibition of swarming motility using in vitro hyperthermia.

Hyperthermia is a therapeutic technique in which body tissue is exposed to temperatures in the region of 40-45 °C to induce a physiological or biological effect. Swarming motility is an important virulence factor for Proteus mirabilis and Pseudomonas aeruginosa and swarming phenomenon is a coordinated multicellular movement of differentiated bacterial population over semi-solid surfaces. In this study, we aimed to investigate the inhibitory effect of hyperthermia on bacterial swarming motility using a modified thermobiogram method and show the potential of this thermal method to treat bacterial infections. Ten P. mirabilis and 10 P. aeruginosa clinical isolates were included in the study. Sheep blood agar (SBA) plates were prepared and inoculated with bacterial suspensions of clinical isolates. Inoculated SBA plates were incubated inside 2 different incubators; at 37 °C and 45 °C for 20 h. The diameter of bacterial growing zones (swarming diameters) were measured every 2 h and noted. Finally, Gram stains of the isolates were prepared for microscopic examination. Wilcoxon signed-rank test was used to compare the swarming inhibition rates of the isolates incubated at 37 °C and 45 °C. Regarding P. mirabilis species, a significant difference was found between two different temperatures (P = 0.0078). So, a temperature at the level of hyperthermia significantly inhibited the swarming motility of P. mirabilis isolates. In addition, transformation to coccus form was observed at 45 °C. We speculate that these findings might be useful for employing thermal therapies including hyperthermia method to treat infectious diseases caused by swarming bacterial pathogens in the future.

Investigation of an outbreak of Elizabethkingia meningoseptica on a pediatric intensive care unit.

Objective: This paper reports an Elizabethkingia meningoseptica outbreak on a pediatric intensive care unit with emphasis on investigation of outbreak source, infection control interventions, patient characteristics and comparative antimicrobial susceptibility results. Methods: This was an ambidirectional cohort study conducted in a university hospital 20-bed pediatric intensive care unit. Patient ages ranged from 4 to 11 months, with a median age of 9 months. 83% of the patients had severe underlying conditions. Samples from staff and environmental surfaces were obtained to identify a common source of infection. Antimicrobial susceptibility tests of isolated bacteria were done using the disk diffusion method and the Vitek®2 automated system. Results: Environmental surveillance revealed contamination of the water reservoirs of two different mechanical ventilators. In-vitro antimicrobial susceptibility testing results with two different methods (Vitek®2 and disk diffusion) were coherent for most of the investigated antibiotics, but without coherence for ciprofloxacin and levofloxacin. Resistance was found to the relatively new antibiotics ceftaroline and ceftazidime-avibactam. Conclusions: E. meningoseptica is a significant cause of nosocomial infections, with high mortality especially in children. Investigation of the outbreak source and continuation of intensive infection control precautions are vital to handle E. meningoseptica outbreaks in PICUs. Using quinolones according to testing results of automated AST systems may lead to inadequate treatment and foster the selection of resistant strains.

Investigation of heteroresistant vancomycin intermediate Staphylococcus aureus among MRSA isolates.

INTRODUCTION: Heteroresistant vancomycin intermediate Staphylococcus aureus (hVISA) testing is recommended when therapeutic failure is suspected in the clinics. In our research, we aimed to investigate the prevalence of hVISA among methicilline-resistant S. aureus (MRSA) isolates in our university hospital and compared three methods for detection of hVISA. METHODOLOGY: One hundred MRSA clinical isolates were collected in our medical microbiology laboratory between 01.04.2018 and 01.10.2019. For screening of hVISA, we used two screening agar plates and used one commercial medium; brain heart infusion agar (BHI) plates containing 4 µg/mL vancomycin and 16 g/Lt casein (BHIA-VC; Satola's test), BHI agar plates containing 4 µg/mLvancomycin (BHIAV), and commercially obtained vancomycin resistant Enterococci (VRE) agar for detetection of hVISA. Colonies which could grow on plates were counted manually at 24th and 48th hours. RESULTS: Among 100 MRSA isolates, 43 (43%) were found as hVISA using Satola's test. BHIAV and VRE agar screening test results were found 70% and 4%, respectively. Finally, at the step, MIC values of 20 (47%) hVISA isolates reduced to 2 µg/mL after sub culturing for the gradient test. CONCLUSIONS: We found higher rates of hVISA comparing other studies in Turkey. Both VRE agar and BHIAV screening test failed to detect hVISA properly. Meropenem in combination with vancomycin inhibited the growth of 90% hVISA isolates in our study.

Serotype distribution of Streptococcus pneumonia in children with invasive disease in Turkey: 2015-2018.

Objectives: To determine the serotype distribution of pneumococcus causing invasive pneumococcal disease (meningitidis, bacteremia and empyema) in children in Turkey, and to observe potential changes in this distribution in time to guide effective vaccine strategies. Methods: We surveyed S. pneumoniae with conventional bacteriological techniques and with real-time polymerase chain reaction (RT-PCR) in samples of cerebrospinal fluid (CSF), blood and pleural fluid. S. pneumoniae strains were isolated from 33 different hospitals in Turkey, which are giving health services to approximately 60% of the Turkish population. Results: A total of 167 cases were diagnosed with invasive pneumococcal disease between 2015 and 2018. We diagnosed 52 (31.1%) patients with meningitis, 104 (62.2%) patients with bacteremia, and 11 (6.6%) patients with empyema. Thirty-three percent of them were less than 2 years old and 56% less than 5 years old. Overall PCV13 serotypes accounted for 56.2% (94/167). The most common serotypes were 19 F (11.9%), 1 (10.7%) and 3 (10.1%). Conclusions: Besides the increasing frequency of non-vaccine serotypes, vaccine serotypes continue to be a problem for Turkey despite routine and high-rate vaccination with PCV13 and significant reduction reported for the incidence of IPD in young children. Since new candidate pneumococcal conjugate vaccines with more serotype antigens are being developed, continuing IPD surveillance is a significant source of information for decision-making processes on pneumococcal vaccination.

Colonizations on biofilm layers of D-J catheters under sterile urine conditions. / Colonización de las capas de biofilm de los catéteres doble J en condiciones de orina estéril.

OBJECTIVE: To evaluate colonizations onbiofilm layers of Double J (D-J) catheters implanted forkidney stones or ureteral stones under sterile conditions. METHODS: D-J catheters implanted between January2012 and February 2014 and removed in 0-90 days,were examined in microbiology laboratory prospectively.Fifty two patients divided into three groups regardingthe duration of the D-J catheters as; 0-30 days, 31-60days, 61-90 days. The colonization (≥1.000 colony)was reported after biofilm layer on D-J catheter was holdin culture media. The upper, middle and lower parts ofthe catheters were analyzed seperately. RESULTS: Thirty five patients had symptomatic urinarytract infection or positive urine culture after implantationwere excluded from the study. Colonization on biofilm layer was detected in 11 patients (21.15%) [Coagulase-negative staphylococci (CNS): 3, Escherichia coli (E. coli): 3, Candida species (Candida spp.): 3, Klebsiella species (Klebsiella spp.): 2]. The rates of colonization according to the duration of the catheterization were; 12.5% in 0-30 days, 18.51% in 30-60 days, 29.4% in 60-90 days (Group 1 vs 2; .696 , group 1 vs group 3; .356 , group 2 vs group 3; .401). The rates of colonization according to the location of the catheter were; 100% in upper and lower parts, 54.4% in middle part (Group 1 vs 2; .011, group 1 vs group 3; , group 2 vs group 3; .011). CONCLUSIONS: Colonization on catheters is possibleeven in the sterile urinary conditions according to thepresent findings. The risk of colonization increases 1.5times in 30-60 days and 2.5 times in 60-90 days comparedto the first 30 days. Besides the risk of colonizationincreases about 2 times in the convoluted edges ofthe catheter compared with the middle part. Thus, D-Jcatheter should be removed as soon as possible and therisk of colonization should be minimalized.

OBJETIVO: Evaluar la colonización de las capas de biofilm de los catéteres doble J (DJ) implantados por litiasis renal o ureteral bajo condiciones estériles.MÉTODOS: Los catéteres DJ implantados entre enero 2012 y febrero 2014 y retirados en 0-90 días fueron examinados de forma prospectiva en el laboratorio de microbiología. Cincuenta y dos pacientes fueron divididos en tres grupos conforme al tiempo del DJ: 0-30 días, 31-60 días y 61-90 días. La colonización (>100.000colonias) fue comunicada tras el cultivo de la capa de biofilm del catéter. Se analizaron por separado las zonas superior, media e inferior de los catéteres DJ. RESULTADOS: 35 pacientes que tenían infección urinaria sintomática o cultivo de orina positivo después del implante fueron excluidos del estudio. Se detectó colonización de la capa de biofilm en 11 pacientes (21,5%) [estafilococo coagulasa negativo (SCN): 3, Escherichia coli (E.coli): 3, Cándida especies (Cándida spp: 3, Klebsiela especies (Klebsiela spp.): 2] Las tasas de colonización de acuerdo con el tiempo de catéter fueron 12,5% en 0-30 días, 18,51% en 30-60 días, 29,4% en 60-90 días (Grupo 1 vs 2; ,696 , grupo 1 vs grupo 3; ,356, grupo 2 vs grupo 3; ,401). Las tasas de colonización de acuerdo con la localización del catéter fueron del 100% en las porciones superior e inferior y 54% en la porción media (Grupo 1 vs 2; ,011, grupo 1 vs grupo 3; , grupo 2 vs grupo 3; ,011). CONCLUSIONES: La colonización de los catéteres es posible incluso en condiciones de orina estéril de acuerdo con los hallazgos presentes. El riesgo de colonización aumenta 1,5 veces en 30-60 días y 2,5 veces en 60-90 días comparado con los primeros 30 días. Además, el riesgo de colonización aumenta unas 2 veces en los extremos espirales del catéter en comparación con la porción media. Así, los catéteres DJ deben ser retirados tan pronto como sea posible y el riesgo de colonización debe ser minimizado.

Investigation of bacteremia after debonding procedures.

OBJECTIVE: The purpose of this study is to investigate the effect of debonding procedures after completion of orthodontic treatments on bacteremia. MATERIALS AND METHODS: Twenty-eight patients who were treated with fixed orthodontic treatment at the Faculty of Dentistry's Department of Orthodontics at Gaziantep University and who had an indication of debonding were selected for this study, and blood samples were taken from these patients at different times and examined for bacteremia. Blood culture samples were taken from the antecubital veins of the patients prior to debonding (T0), immediately after removing the bracket (T1), and immediately after cleaning the composite residues and plaque deposits on the enamel surface (T2). The blood samples were then inoculated in blood culture bottles and investigated for bacterial growth. RESULTS: The results showed that there was no bacterial growth in the blood samples taken at T0 and T1, whereas 10 of the blood culture samples taken at T2 showed bacterial growth including the following bacteria; Streptococcus viridans, Streptococcus mitis, Streptococcus parasanguinis, Streptococcus salivarius, Streptococcus oralis, Staphylococcus aureus, Actinomyces oris, Actinomyces naeslundii and Klebsiella pneumoniae. CONCLUSION: It was concluded that patients in the risk group could develop bacteremia during debonding procedures. The presence of these bacteria in sterile blood suggested the possibility of bacterial endocarditis.

[Results of a multicenter study investigating plasmid mediated colistin resistance genes (mcr-1 and mcr-2) in clinical Enterobacteriaceae isolates from Turkey]. / Ülkemizde klinik Enterobacteriaceae izolatlarinda plazmit aracili kolistin direnç genlerini (mcr-1 ve mcr-2) arastiran çok merkezli çalismaya ait sonuçlar.

Colistin is a polymyxin antibiotic which is considered as one of the last line agents against infections due to multidrug resistant or carbapenem resistant gram-negative pathogens. Colistin resistance is associated with chromosomal alterations which can usually cause mutations in genes coding specific two component regulator systems. The first plasmid-mediated colistin resistance gene, mcr-1 was described in Escherichia coli and Klebsiella pneumoniae isolates in December 2015 and followed by another plasmid-mediated colistin resistance gene mcr-2 in 2016. The rapid and interspecies dissemination of plasmid-mediated resistance mechanisms through horizontal gene transfer, have made these genes considerably threatening. After the first reports, although mcr-1/mcr-2 producing Enterobacteriaceae isolates have been reported from many countries, there have been no reports from Turkey. Thus, the aim of this study was to investigate the presence of mcr-1/mcr-2 in clinical Enterobacteriaceae isolates from different parts of our country. A total of 329 Enterobacteriaceae isolates from 22 laboratories were collected which were isolated between March, 2015 and February, 2016. mcr-1/mcr-2 were investigated by polymerase chain reaction during February-March, 2016. Two hundred and seventeen of Klebsiella pneumoniae (66%), 75 of Salmonella spp. (22.8%), 31 of Esherichia coli (9.4%), 3 of Enterobacter cloacae (0.9%), 2 of Klebsiella oxytoca (0.6%) and 1 of Enterobacter aerogenes (0.3%) isolates were included to the study. Agarose gel electrophoresis results of PCR studies have shown expected band sizes for positive control isolates as 309 bp for mcr-1 and 567 bp for mcr-2. However, the presence of mcr-1/mcr-2 genes was not detected among the tested study isolates of Enterobacteriaceae. Although mcr-1/mcr-2 were not detected in our study isolates, it is highly important to understand the mechanism of resistance dissemination and determine the resistant isolates by considering that colistin is a last-line antibiotic against infections of multidrug or carbapenem resistant gram-negative bacteria. Thus, it is suggested that these mechanisms should be followed-up in both clinical and non-clinical (e.g. isolates from food animals, raw meats and environment) isolates of special populations.

Apical extrusion of Enterococcus faecalis in different canal geometries during the use of nickel titanium systems with different motion types.

BACKGROUND/PURPOSE: Extrusion of intracanal bacteria leads to treatment failures. Compare the apical extrusion of intracanal bacteria (Enterococcus faecalis) during canal preparation with three different instrumentation techniques [RECIPROC, One Shape (OS), and Twisted-File Adaptive (TFA)] with different motion types. MATERIALS AND METHODS: Ninety teeth with different canal morphologies were divided into three main groups, each including 30 teeth (10 mandibular incisors, 10 mandibular premolars, and 10 curved roots). Roots were resected until 13-mm working length was obtained and fixed to glass vials filled with brain-heart infusion broth. Each canal was filled with E. faecalis suspension. The three main groups were further grouped into three subgroups. Each group was further subgrouped into three, with each subgroup including 10 roots from each type of teeth (10 incisors/subgroup, 10 premolars/subgroup, and 10 curved canals/subgroup). These subgroups were prepared with one of RECIPROC, OS, or TFA. Bacterial colonies extruded into each vial were incubated in brain-heart infusion agar at 37°C for 5 days and counted using a colony counter as the number of colony-forming units per milliliter. Statistical analyses were performed using one-way analysis of variance, post hoc Tukey honest significant difference, and Kruskal-Wallis tests. RESULTS: Apically extruded bacteria were not statistically different from each other (P > 0.05). The amount of apically extruded bacteria was statistically similar for both different instruments in the same type of tooth (P > 0.05) and same instrument in different types of teeth (P > 0.05). CONCLUSION: Neither the motion type of instrument nor the canal morphology affected the degree of bacterial extrusion.

[Comparison of two different antiseptics on contamination of epidural catheter tip]. / Epidural kateter ucu kontaminasyonunda iki farkli antiseptigin etkinliginin karsilastirilmasi.

OBJECTIVES: The aim of the present study was to compare preventive effects of 10% povidone-iodine, and combination of 2-propanol and benzalkonium chloride skin antiseptics on contamination of epidural catheter tip. METHODS: Included were 160 patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status classifications of I-II. Patients were randomized. Povidone-iodine was administered to group P (n=80) prior to insertion of antibiotic prophylaxis catheter; 2-propanol and benzalkonium chloride was administered to group B. Swabs obtained before and after administration of antiseptics were sent for culture. Antiseptics were applied to skin prior to catheter removal, as well as 48 hours after insertion. In sterile conditions, 2-3 cm pieces of catheter tips were sent to laboratory. Preoperative and postoperative complete blood count, body temperature, and signs of postoperative localized skin infection were recorded. RESULTS: Leukocyte, neutrophil, and lymphocyte counts were all within normal ranges in preoperative and postoperative. Swab cultures obtained following use of antiseptics were positive in 6 group P patients; coagulase-negative Staphylococcus was found in 5 patients, E. coli in 1, and were negative in group B. Difference between groups was statistically significant (p=0.013). Epidural catheter tip cultures were negative. CONCLUSION: Combination of 2-propanol and benzalkonium chloride was determined to be more effective in reducing skin flora around epidural catheter insertion site.

[Investigation of carbapenemases in carbapenem-resistant Escherichia coli and Klebsiella pneumoniae strains isolated in 2014 in Turkey]. / Türkiye'de 2014 yili içinde izole edilen karbapeneme dirençli Escherichia coli ve Klebsiella pneumoniae izolatlarinda karbapenemaz varliginin arastirilmasi.

Carbapenems are the choice of treatment in infections caused by multidrug resistant Enterobacteriaceae. In recent years carbapenem-resistant Enterobacteriaceae isolates due to carbapenemases have been increasingly reported worldwide. Multicenter studies on carbapenemases are scarce in Turkey. The aim of this study was to determine the distribution of carbapenemases from different parts of Turkey as a part of the European Survey of Carbapenemase Producing Enterobacteriaceae (EuSCAPE) project. Beginning in November 2013, carbapenem-resistant isolates resistant to at least one of the agents, namely imipenem, meropenem, and ertapenem were sent to the coordinating center. Minimum inhibitory concentrations for these carbapenems were determined by microdilution tests following EUCAST guidelines. Production of carbapenemase was confirmed by combination disk synergy tests. Types of carbapenemases were investigated using specific primers for VIM, IMP; NDM, KPC and OXA-48 genes by multiplex polymerase chain reaction. In a six month period, 155 suspected carbapenemase-positive isolates were sent to the coordinating center of which 21 (13.5%) were E.coli and 134 (86.5%) were K.pneumoniae. Nineteen (90.5%) strains among E.coli and 124 (92.5%) strains among K.pneumoniae were shown to harbour at least one carbapenemase gene by molecular tests, with a total of 92.3% (143/155). Carbapenemases were determined as a single enzyme in 136 strains (OXA-48: 84.6%; NDM: 6.3%; VIM: 2.8%; IMP: 1.4%) and as a combination in seven isolates (OXA-48 + NDM: 2.1%; OXA-48 + VIM: 2.1%; VIM + NDM: 0.7%). KPC was not detected in any of the isolates. According to the microdilution test results, resistance to imipenem, meropenem and ertapenem in OXA-48 isolates were 59.5%, 52.9% and 100%, respectively. The combination disk synergy test was 100% compatible with the molecular test results. As most of the OXA-48 producing isolates were susceptible to meropenem but all were resistant to ertapenem, ertapenem seems to be the most sensitive agent in screening carbapenemases in areas where OXA-48 is prevalent and phenotypic combination tests can be useful in centers where molecular tests are not available.

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.

Investigation of VIM, IMP, NDM-1, KPC AND OXA-48 enzymes in Enterobacteriaceae strains.

Gram-negative bacteria especially Enterobacteriaceae species have become an increasing etiologic agent of nosocomial infections. The development of resistance to carbapenems have become an increasing problem in the treatment of nosocomial infections. Especially carbapenamases are common for Enterobacteriaceae strains. This study was performed to detect the types of carbapenemases in Enterobacteriaceae strains isolated from various clinical samples. Enterobacteriaceae species were isolated from urine, blood, tracheal aspirates, wound, and other respiratory samples. Susceptibility of isolates to imipenem, meropenem and ertapenem was tested. Carbapenemase genes were studied using HyplexSuperBug ID kit. VIM (1-13), IMP (1-22), NDM-1, KPC(1-10) and OXA-48 genes were investigated. Ninety-five isolates of Enterobacteriaceae spp. were included in the study. Sixty isolates were resistant to imipenem, meropenem and ertapenem and 20 isolates were found resistant to imipenem or ertapenem while 15 were susceptible to all carbapenems. Among the isolates with carbapenem resistance, 57 were positive for one carbapenemase gene and susceptible isolates did not have carbapenemase gene. OXA-48 was found in 49 of the isolates (86%), NDM-1 in 6 (10.5%) isolates, VIM in 2 isolates. IMP and KPC gene loci were not identified. Carbapenemase genes play a crucial role in the development and spread of resistant strains.