Registry-Based Retrospective Cohort Study of Mortality among Adults Admitted to Intensive Care Units in Istanbul with Hospital Acquired Pseudomonas aeruginosa Bloodstream-Infection between 2014-2021.

BACKGROUND: Managing Pseudomonas aeruginosa bloodstream infections (BSIs) is challenging due to increasing antimicrobial resistance, limited therapeutic options, and high mortality rates. In this study, we aimed to identify 30-day mortality risk factors and assess infectious diseases consultants' preferences for combination or monotherapy. METHODS: The study was conducted in four hospitals in Istanbul, Turkey, involving 140 adult ICU beds and 336,780 ICU-bed-days between 1 January 2014, and 31 December 2021. A total of 157 patients were included in the study. Cox proportional hazard regression was performed to assess the factors on 30-day mortality. RESULTS: The 30-day mortality rate was 44.6% (70/157). Higher Charlson Comorbidity Index (CCI) score, severe sepsis, primary bloodstream infection, being in COVID-19 pandemic period, and infection caused by MDR strain were associated with higher hazard of 30-day mortality. Combination therapy was more commonly used in patients with BSIs with MDR or DTR (difficult-to-treat) strains but did not significantly improve the hazard of 30-day mortality. CONCLUSIONS: Targeted interventions and vigilant management strategies are crucial for patients with defined risk factors. While infectious disease consultants tended to favor combination therapy, particularly for drug-resistant strains, our analysis revealed no significant impact on 30-day mortality hazard. The increased incidence of P. aeruginosa BSIs during the pandemic emphasizes the need for infection control measures and appropriate antibiotic prescribing practices.

Bloodstream Infections Caused by Multidrug Resistant Bacteria: Clinical and Microbiological Features and Mortality.

Objectives: Bloodstream infections (BSI) are associated with high morbidity and mortality. The aim of our study is to determine whether there is a relationship between certain risk factors such as the underlying disease, patient's medical history, or interventional procedures and multidrug resistant (MDR) bacterial infection and to determine the risk factors for mortality. Methods: Two hundred and twenty-two outpatients and inpatients who were diagnosed with bacteremia over a 6-month period were included in the study. 232 agents from 222 patients were isolated and tested for antimicrobial susceptibility. The relationship between patients demographic and clinical data and MDR was analyzed. Results: The most common microorganisms were Gram-negative bacteria (59.4%), Gram-positive bacteria (36.9%), Candida species (2.2%), and anaerobic bacteria (1.35%). The most common isolates were Escherichia coli 53 (22.8%), Staphylococcus aureus 35 (%15.1), Klebsiella pneumoniae 26 (11.2%), Pseudomonas spp. (n=17, 7.3%), Acinetobacter spp 17 (7.3%), and Enterococcus spp 14 (6%). Microorganisms with the highest antimicrobial resistance observed were 82.3% in Acinetobacter baumannii, 64.5% in coagulase-negative staphylococci, 60.3% in E. coli, 50% in K. pneumoniae, and 27.2% in Enterobacterales spp. Most patients with BSI caused by MDR bacteria were in the intensive care unit (64%). Sepsis diagnosis, urinary catheter use, history of surgery, and use of broad-spectrum antibiotics as well as risk factors for antibiotic-resistant bacteremia, coronary artery disease, inappropriate empirical therapy, healthcare-associated infections, urinary catheterization, and stay in the ICU were determined as risk factors for mortality. Conclusion: Our study identified the risk factors of BSI caused by MDR bacteria and helped to reveal the relationship between these factors and mortality.

Quality of MALDI-TOF mass spectra in routine diagnostics: results from an international external quality assessment including 36 laboratories from 12 countries using 47 challenging bacterial strains.

OBJECTIVES: Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is a widely used method for bacterial species identification. Incomplete databases and mass spectral quality (MSQ) still represent major challenges. Important proxies for MSQ are the number of detected marker masses, reproducibility, and measurement precision. We aimed to assess MSQs across diagnostic laboratories and the potential of simple workflow adaptations to improve it. METHODS: For baseline MSQ assessment, 47 diverse bacterial strains, which are challenging to identify by MALDI-TOF MS, were routinely measured in 36 laboratories from 12 countries, and well-defined MSQ features were used. After an intervention consisting of detailed reported feedback and instructions on how to acquire MALDI-TOF mass spectra, measurements were repeated and MSQs were compared. RESULTS: At baseline, we observed heterogeneous MSQ between the devices, considering the median number of marker masses detected (range = [2-25]), reproducibility between technical replicates (range = [55%-86%]), and measurement error (range = [147 parts per million (ppm)-588 ppm]). As a general trend, the spectral quality was improved after the intervention for devices, which yielded low MSQs in the baseline assessment as follows: for four out of five devices with a high measurement error, the measurement precision was improved (p-values <0.001, paired Wilcoxon test); for six out of ten devices, which detected a low number of marker masses, the number of detected marker masses increased (p-values <0.001, paired Wilcoxon test). DISCUSSION: We have identified simple workflow adaptations, which, to some extent, improve MSQ of poorly performing devices and should be considered by laboratories yielding a low MSQ. Improving MALDI-TOF MSQ in routine diagnostics is essential for increasing the resolution of bacterial identification by MALDI-TOF MS, which is dependent on the reproducible detection of marker masses. The heterogeneity identified in this external quality assessment (EQA) requires further study.

Pediatric Patients with COVID-19: A Retrospective Single-Center Experience.

Objectives: The pandemic of coronavirus disease 2019 (COVID-19) is still effective all over the world. Compared to adults, data on pediatric patients are limited. In this study, we aimed to retrospectively examine the demographic, clinical, and laboratory characteristics of pediatric patients who were followed up with the diagnosis of COVID-19 in the first 3 months of the pandemic in our hospital. Methods: A total of 190 patients, aged 1 month-18 years, who were followed up with a definite/probable diagnosis of COVID-19, who were treated in the Pediatric Infection Clinic, were included in the study. The demographic features, clinical characteristics, and laboratory findings of the patients were retrospectively analyzed from their electronic medical records. Results: Eighty (42.1%) of the patients were laboratory confirmed (Polymerase chain reaction positive in nasopharyngeal swab). Mean age was 72 (2-216 months) and 102 (53.7%) patients were female. Family contact history was present in 115 (60.5%) patients. The patients were classified as asymptomatic (5.8%), mild (73.2%), moderate (18.4%), and severe/critical (2.6%) according to the severity of the disease. The most common symptoms were cough (71.1%) and fever (51.1%). Hydroxychloroquine alone or in combination was the most commonly used agent. Conclusion: In our study, in which we examined the pediatric COVID-19 patients, most of the patients had a mild clinical course, but there were applications with different clinical pictures such as acute appendicitis. Therefore, COVID-19 infection, which is still very unknown, will continue to surprise us with both changing treatment protocols and clinical presentations such as multisystem inflammatory syndrome in children.

Direct Rapid Identification from Positive Blood Cultures by MALDI-TOF MS: Specific Focus on Turnaround Times.

Early availability of pathogen identification in bloodstream infections has critical importance in patients' management. This study investigated the accuracy and feasibility of the direct rapid identification (RID) method from positive blood cultures (BCs) by MALDI-TOF MS and its impact on the turnaround time (TAT) compared to the short-term incubation routine identification (SIRID) method. Pellets prepared from 328 BCs using a serum separator tube in the RID method and colonies on agar plates in the SIRID method were identified with MALDI Biotyper. BCs on weekdays from 6 a.m. to 4 p.m. were defined as the daytime signal group (DSG); BCs from 4 p.m. to 6 a.m. were defined as the night signal group (NSG). Comparison between the two methods was performed with 310 monomicrobial BCs. Two hundred ninety-five (95.2%) monomicrobial BCs yielded an identification result with the RID method. Of the 295 BCs, 289 (97.9%) were identified correctly at the species level, 4 (1.4%) were at the genus level, and 2 (0.7%) were misidentified. In the RID method, at score cutoff values of 1.2, 1.3, 1.4 and 1.5, the rates of correct identifications at the species level were 97.9%, 98.9%, 99.3%, and 100%, respectively. The mean TAT in the DSG was significantly lower (P < 0.001) in the RID method (mean: 2.86 h; 95% CI: 2.65 to 3.07) compared to the SIRID method (mean: 19.49 h; 95% CI: 18.08 to 20.89). Correct identification rates at the species level were 100% in Gram-negative bacteria, 88.9% in Gram-positive bacteria, and 93.2% of all BCs isolates with the RID method. The TAT was improved remarkably in DSG, which might contribute to empirical antibiotic therapies of patients. IMPORTANCE Using MALDI-TOF MS directly from BCs reduces the time required for pathogen identification, and the TATs for final identification have been compared with overnight incubation from solid media in previous studies. However, identification from a short incubation of agar plates has been increasingly accepted and successfully implemented in routine laboratories, but there is no data comparing direct MALDI-TOF MS with the short-term incubated agar plates. Our study showed that the TAT improved remarkably by applying a RID method by MALDI-TOF MS twice a day periodically when compared to the SIRID method.

Comparison of Risk Factors and Outcomes in Carbapenem-Resistant and Carbapenem-Susceptible Gram-Negative Bacteremia.

BACKGROUND: Carbapenem-resistant Gram-negative bacteremia (CR-GNB) is seen with increasing frequency and result in high mortality. The aim of this study was to compare the risk factors and results of carbapenem-resistant and carbapenem-susceptible Gram-negative bacteremia and to determine the factors related to mortality. METHODS: The study was conducted as a retrospective observational comparative case series between June 2016 and November 2017 in Sisli Hamidiye Etfal Training and Research Hospital. The patients were divided into two groups as carbapenem-susceptible and carbapenem-resistant according to antibiotic susceptibility data of blood cultures. The risk factors for the development of carbapenem resistance, length of hospital stay, mortality rates, and mortality related factors were investigated between these two groups. RESULTS: Two hundred and eleven cases were included in the study. Of these cases, 54 were resistant to carbapenem and 157 were susceptible to carbapenem. Mortality occurred in 60 (28.4%) patients. The 14 and 28 day mortality rates of patients with carbapenem resistance were significantly higher than those without carbapenem resistance. There was no statistically significant difference between two groups in length of stay in the hospital after bacteremia. Pittsburgh bacteremia score, cardiovascular disease, urinary catheterization, and inappropriate empirical antibiotic therapy were the most significant risk factors for mortality. CONCLUSIONS: Carbapenem resistance is associated with increased mortality and inappropriate empirical antibiotic treatment increases mortality. Therefore, patients should be evaluated for risk factors in predicting CR-GNB and treatment for resistant pathogens should be applied in appropriate patients.

Antibiotic Stewardship Program Experience in a Training and Research Hospital.

OBJECTIVES: Antibiotic Stewardship Programs (ASP) have been developed for the spread of rational antibiotic use. Our hospital is one of the first centers where ASP applications were launched in Turkey. In this study, we aimed to share our experience with ASP which has been applied in our hospital since 2013. METHODS: We adapted ASP to our hospital program from Centers for Disease Control and Prevention's ASP checklist. Revisions on surgical prophylaxis guidelines and practices were performed. Surgical prophylaxis was evaluated from hospital infection surveillance and antibiotic usage by point prevalence surveys. Antibiotic consumption indexes (ACI) were calculated from hospital pharmacy records. Rapid antigen detection test (RADT) for Group A beta-hemolytic streptococcus and influenza rapid antigen test were started to be used. Cumulative antibiotic susceptibility results were prepared annually. RESULTS: Surgical prophylaxis was started to be administered in the operating room within 60 min of incision. Third-generation cephalosporin usage for surgical prophylaxis could be restricted in all clinics but the duration could only be shortened in neurosurgery and general surgery. There was no statistically significant change in antibiotic usage rates and appropriateness between 2014 and 2018. ACI for the class J01 in adult wards was 80.5 daily defined doses (DDD) per 100 patient days in 2014 and reduced to 64.8 DDD per 100 patient days in 2018. 22.445 pediatric patients presenting with complaints of the upper respiratory tract were evaluated with RADT and 75.1% were treated without antibiotics. CONCLUSION: In this global antimicrobial resistance era, all hospitals should have motivated antimicrobial stewardship teams. Each hospital should establish its own stewardship program and often revise it. Improvement in rational antibiotic use is hard to achieve without multidisciplinary involvement.

HCV Genotype Distribution of Patients with Chronic Hepatitis C in Istanbul.

OBJECTIVES: Hepatitis C virus (HCV), which has no protective vaccine, is a common cause of chronic hepatitis, which is a severe public health threat. There are differences in nucleotide and amino acid sequences in different regions of the HCV genome. As a result of these differences, HCV has been shown to have at least seven major genotypes and many subtypes. In Turkey, the prevalence of genotype 1 is between 51.7% and 97.1%, the highest rate among all genotypes, while subtype 1b is the genotype with the highest rate. It is important to detect mixed genotype infection reliably as it causes treatment failure. This study aims to reveal the distribution of the HCV genotypes in our hospital in Istanbul over the years and to contribute to the epidemiological data of Turkey. METHODS: For this purpose, 385 patient samples sent to Sisli Hamidiye Etfal Training and Research Hospital, Clinical Microbiology Laboratory for HCV genotype determination between January 2016 and June 2019 were evaluated retrospectively. Anti-HCV was screened by enzyme immunoassay and confirmation was performed by Line immunoassay. HCV genotyping assays targeting highly conserved 5'UTR and most variable region NS5B regions were used. RESULTS: The most common genotype was genotype 1 (81.3%) with 313 cases and subtypes 1a and 1b were detected at the rates of 10.9% and 67.8%, respectively. In addition, genotype 3, 2, 4, 5 were detected at the rates of 8.8%, 3.4%, 2.9%, 0.8%, respectively and mixed genotype was found in 2.9% of cases. Although genotype 5 is seen in South Africa, it is found in the Middle East region, albeit at a low rate. In our study, it was observed that genotype 5 was detected in different years from patients of Syrian origin. CONCLUSION: In this study, genotype 1 was the most common genotype with a rate of 81.3% and subtype 1b was 67.8%, in accordance with the literature. However, genotypes 3, 2, 4 and 5 were also present at low rates. It is important to monitor these rare genotypes since some of them are dominant in surrounding countries. In addition, 2.9% of HCV mixed genotype was detected and this should be considered concerning management of HCV infection.

Comparative evaluation of the Bruker Biotyper and Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems for non-albicans Candida and uncommon yeast isolates.

INTRODUCTION: Rapid and accurate diagnosis is critically important in invasive and disseminated fungal infections for appropriate antifungal treatment. HYPOTHESIS: MALDI-TOF MS systems are effective for fast and accurate identification of Candida species. AIM: We aimed to compare two MALDI-TOF MS systems for the rapid identification of non-albicans Candida and rare clinical yeast species. METHODOLOGY: This study included 157 isolates representing 23 yeast species. All isolates were identified using Bruker MALDI Biotyper and VITEK MS systems. If both MALDI-TOF MS systems yielded the same results for a certain isolate, the identification is regarded as correct. We performed internal transcribed spacer (ITS) DNA sequencing on five fungal isolates with discordant species names or that were unidentified by the two MALDI-TOF MS systems. RESULTS: The yeast identification sensitivity of MALDI Biotyper was 98.7%, whereas that of VITEK MS was 96.8%. Both MALDI-TOF MS systems correctly identified all strains belonging to four prevalent species, namely, Candida parapsilosis, Candida tropicalis, Candida glabrata, and Candida krusei. For the 19 rare clinical yeast species, identification rates were 96.7% for MALDI Biotyper and 91.7% for VITEK MS. The ITS sequence analysis of five isolates yielded two Meyerozyma caribbica, two Cyberlindnera fabianii, and one Candida dubliniensis. CONCLUSIONS: This study showed the high performance of both MALDI-TOF MS systems, identifying over 90% of yeast isolates in a short time. The disadvantages of these systems are that some species are not present in the databases and it cannot distinguish closely related species. The sensitivity of MALDI-TOF MS systems constantly improves with the expansion of databases in parallel with taxonomic developments for the identification of rare clinical yeast species.

Could we predict the prognosis of the COVID-19 disease?

OBJECTIVES: Coronavirus 2019 disease (COVID-19) lead to one of the pandemics of the last century. We aimed to predict poor prognosis among severe patients to lead early intervention. METHODS: The data of 534 hospitalized patients were assessed retrospectively. Risk factors and laboratory tests that might enable the prediction of prognosis defined as being transferred to the intensive care unit and/or exitus have been investigated. RESULTS: At the admission, 398 of 534 patients (74.5%) were mild-moderate ill. It was determined that the male gender, advanced age, and comorbidity were risk factors for severity. To estimate the severity of the disease, receiver operating characteristic analysis revealed that the areas under the curve which were determined based on the optimal cut off values that were calculated for the variables of values of neutrophil to lymphocyte ratio (NLR > 3.69), C-reactive protein (CRP > 46 mg/L), troponin I ( > 5.3 ng/L), lactate dehydrogenase (LDH > 325 U/L), ferritin ( > 303 ug/L), d-dimer ( > 574 µg/L), neutrophil NE ( > 4.99 × 109 /L), lymphocyte (LE < 1.04 × 109 /L), SO2 ( < %92) were 0.762, 0.757,0.742, 0.705, 0.698, 0.694,0.688, 0.678, and 0.66, respectively. To predict mortality, AUC of values for optimal cutoff troponin I ( > 7.4 ng/L), age ( > 62), SO2 ( < %89), urea ( > 40 mg/dL), procalcitonin ( > 0.21 ug/L), CKMB ( > 2.6 ng/L) were 0.715, 0.685, 0.644, 0.632, 0.627, and 0.617, respectively. CONCLUSIONS: The clinical progress could be severe if the baseline values of NLR, CRP, troponin I, LDH, are above, and LE is below the specified cut-off point. We found that the troponin I, elder age, and SO2 values could predict mortality.

Early Detection and Control of Methicillin resistant Staphylococcus aureus Outbreak in an Intensive Care Unit.

BACKGROUND: Although Methicillin resistant Staphylococcus aureus (MRSA) is one of the major pathogens of healthcare associated infections, we had only sporadic cases in our intensive care unit (ICU) for years. AIMS: To investigate the sudden increase in the number of MRSA cases in ICU. STUDY DESIGN: Descriptive study. METHODS: From the 5th December 2016 to 26th January 2017, we detected 11 new MRSA cases in ICU. Screening of 73 ICU healthcare workers (HCWs) and screening of 13 patients was performed for outbreak investigation. Nine clinical isolates available in stocks and eight screening MRSA isolates were included in molecular studies. PFGE, spa-mecA-mecC-PVL in-house multiplex PCR assay and spa typing, SCCmec typing were performed for all isolates. Sequence type of the representative strain was determined by Multi-Locus Sequence typing (MLST). RESULTS: All strains were mecA positive, PVL negative, and have the same antimicrobial susceptibility pattern except for two strains. All clinical, two patient screening and three nasal isolates of HCWs showed the same pulsotype, named clone A. The spa type of outbreak isolates is t030 and the SCCmec type is SCCmecIII; the MLST type of representative strain is ST239 (PFGE pulsotype A, ST239-SCCmecIII-t030). Unrelated three isolates had PFGE pulsotype B-SCCmecI-t030, PFGE pulsotype C-SCCmecIII-t459, PFGE pulsotype D-SCCmecIII. CONCLUSION: Molecular typing techniques are the cornerstones for the investigation of outbreaks. Infection control measures, such as enhancing cleaning procedures, promoting hand hygiene, should be enforced in the ICU unit. All patients, including those who have already been discharged to other departments, must be put on contact isolation. HCWs carrying the MRSA strains could be offered decolonization.

Pesticides and their degradates in groundwater reflect past use and current management strategies, Long Island, New York, USA.

Long Island, New York, has a mix of urban/suburban to agricultural/horticultural land use and nearly 3 million residents that rely on a sole-source aquifer for drinking water. The analysis of shallow groundwater (<40 m below land surface) collected from 54 monitoring wells across Long Island detected 53 pesticides or pesticide degradates. Maximum concentrations for individual pesticides or pesticide degradates ranged from 3 to 368,000 ng/L. The highest concentrations and most frequent pesticide detections occurred in samples collected from the pesticide management (PM) network, set in an agricultural/horticultural area in eastern Long Island with coordinated pesticide management by state and local agencies. The other two networks (Suffolk and Nassau/Queens) were set in suburban and urban areas, respectively, and had less frequent detections and lower pesticide concentrations than the PM network. Pesticide detections and concentration patterns (herbicide, insecticide, or fungicide) differed among the three networks revealing broad differences in land use. The predominance of fungicides metalaxyl, 1H-1,2,4-triazole (propiconazole/myclobutanil degradate), and 4-hydroxychlorothalonil (HCTL, chlorothalonil degradate) in samples from the PM network reflects their intensive use in agricultural settings. Total fungicide concentrations in the PM network ranged from <10 to >300,000 ng/L. The widespread detection of imidacloprid and triazine herbicides, simazine and atrazine, reveal a mixture of current and past use pesticides across the Long Island region. Low concentrations (<200 ng/L) of the triazines in the Suffolk and Nassau/Queens networks may reflect a change in land use and application. Acetanilide herbicides and aldicarb have been discontinued for 20 and 40 years, respectively, yet the concentrations of their degradates were among the highest observed in this study. Acetanilide (total concentrations up to 10,000 ng/L) and aldicarb degradates (up to 270 ng/L) are present in the PM network at much lower concentrations than previous Long Island studies and reflect changes in agricultural practices and pesticide management.

Carbapenemase -producing Pseudomonas aeruginosa isolates from Turkey: first report of P. aeruginosa high-risk clones with VIM-5- and IMP-7-type carbapenemases in a tertiary hospital.

We investigated the presence of carbapenemases in carbapenem-resistant Pseudomonas aeruginosa isolates, which were collected over a 14-month period in a Turkish hospital, with in-depth molecular characterization of carbapenemase-producing isolates. Among 45 study isolates, 2 isolates were identified as carbapenemase producers by both Carba NP and Carbapenem Inactivation Method tests, and only 1 of them gave a positive result in polymerase chain reaction tests for a carbapenemase gene (blaVIM). Whole genome sequencing of the 2 isolates revealed the presence of blaVIM-5 gene in an ST308 isolate, while the other one expressed IMP-7 in an ST357 isolate; both STs are considered high-risk clones. The 2 carbapenemase-producing isolates were multidrug resistant, as they harbored other resistance determinants, including a variant of the recently described plasmid-encoded fluoroquinolone resistance determinant crpP gene, crpP-2. We report for the first time P. aeruginosa high-risk clones carrying VIM-5- and IMP-7-type carbapenemases with multiple resistance determinants in Turkey.

Identification of the Mycobacterial Strains Isolated From Clinical Specimens Using hsp65 PCR-RFLP Method.

OBJECTIVES: It is important to identify mycobacteria at the species level, to distinguish pathogen from non-pathogenic species, to choose the appropriate treatment regimen and to collect epidemiological data. For the identification of mycobacteria, which are time-consuming and laborious with traditional methods, faster, more sensitive and reliable methods are needed. This study aims to investigate the suitability of the hsp65 Polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) method for routine laboratory use. METHODS: In this study, 141 mycobacterial isolates were obtained from 1632 samples, which were sent to the Medical Microbiology Laboratory. RESULTS: In the culture, mycobacteria were identified as 138 M. tuberculosis complex (MTBC) and three non-tuberculosis mycobacteria (NTM) by conventional methods. Using the hsp65 PCR-RFLP method, 137 isolates were identified as MTBC, four isolates as NTM. An isolate that was evaluated as MTBC because it was PNB sensitive by the conventional method was determined as NTM with the hsp65 method. In the identification of non-tuberculosis mycobacteria with the hsp65 PCR-RFLP method, one isolate was identified as M. abcessus and three isolates were identified as M. avium complex. CONCLUSION: In our study, it was concluded that the hsp65 PCR-RFLP method, which allows identification of mycobacteria, including NTMs, is a method that is cheap, easy and suitable for routine use to provide rapid information to the clinic. The scope of the agar and database used in the method is effective in the definition of the correct species.

Evaluation of Teicoplanin Resistance Detected by Automated System in Coagulase Negative Staphylococci: A Comparison with Gradient Test and Broth Microdilution Methods.

Upon the observation of an increase in teicoplanin resistance rates in coagulase negative staphylococci (CoNS) isolates determined by the automated system, we aimed to compare the automated system and gradient test methods with the gold standard broth microdilution method. In addition, the effect of standard antimicrobial susceptibility guidelines on teicoplanin susceptibility test results in CoNS was investigated. A total of 81 CoNS isolates, 52 resistant and 29 susceptible to teicoplanin determined by automated system (Phoenix, Becton Dickinson, USA), were tested. The minimum inhibitory concentration (MIC) values were determined by gradient test (M.I.C. Evaluators, OXOID, UK) and broth microdilution methods. Susceptibility categories were determined according to EUCAST and CLSI criteria and the results were compared. Among 29 isolates found to be susceptible by automated system, one isolate was found resistant by gradient and broth microdilution tests. Of the 52 resistant isolates determined by automated system, 12 (23%) were found to be resistant by gradient test and 22 (42.3%) were resistant by broth microdilution. According to CLSI criteria, no resistant isolates were detected by broth microdilution and six isolates were intermediately susceptible while, two isolates were detected to be resistant and five isolates were found to be intermediately susceptible by the gradient test. In conclusion, compared to microdilution, teicoplanin resistance was detected at a higher rate in CoNS isolates by the automated system used. On the other hand, the gradient test method which is frequently used for confirmation was not reliable in MIC values close to the EUCAST breakpoint values (4 µg/mL). In addition, lower resistance rates were observed when the CLSI breakpoints were used in gradient test and broth microdilution methods.

A highly-sensitive rapid test for the diagnosis of streptococcal pharyngitis: BD veritor ™ system.

INTRODUCTION: The diagnosis of streptococcal pharyngitis is very important to prevent complications such as acute rheumatic fever. Throat culture is the gold standard method for the diagnosis of streptococcal pharyngitis, however, rapid antigen tests (RAT) have been developed for faster diagnosis. The purpose of this study is to evaluate the efficacy of the BD Veritor ™ System (USA) rapid antigen assay in detecting Group A Streptococcus (GAS) in throat swab samples. METHODS AND MATERIALS: A total of 12,391 throat swabs, taken with a double swab, were evaluated. The BD Veritor ™ System was used for the detection of GAS antigen. Simultaneous throat cultures were performed. RESULTS: Throat culture yielded positive for 18.5% (2291) while 19.1% (2369) were positive with RAT. The sensitivity of BD Veritor ™ System was determined as 94.1% and specificity as 97.9%, while positive predictive value, negative predictive value and accuracy were determined as 91.0%, 98.7%, 97%, respectively. When all age groups were included, the rate of GAS positivity was 18.5% and this ratio increased to 27.3% in the five-15 age group. CONCLUSION: Our study, conducted with quite a large number of patients, yielded high sensitivity for the BD Veritor System. When the RAT is negative, the necessity of culture for pediatric patients should not be forgotten.

Evaluation of QuantiFERON tuberculosis Gold In-Tube assay for diagnosis of active tuberculosis in children.

AIM: Tuberculin skin test (TST) is still used in diagnostic algorithms of childhood tuberculosis (TB). QuantiFERON TB Gold In-Tube assay (QFT-GIT) is an alternative test to TST based on the detection of interferon-gamma release upon in vitro induction of peripheral mononuclear cells by TB antigens. In this study, we aimed to determine the diagnostic value and performance of QFT-GIT for active childhood TB. METHODS: This retrospective study was conducted between January 2005 and December 2011 in three referral hospitals in Turkey with 124 children who were diagnosed with definite active TB. Sensitivity values of TST and QFT-GIT were determined by accepting the microbiological confirmation as the gold standard of diagnosis of TB. RESULTS: In our study, sensitivity of QFT-GIT and TST was found to be 65 and 66% respectively. However, combined usage of QFT-GIT and TST was found to be more sensitive (85%) than TST or QFT-GIT alone (P < 0.0001). Although negative results of QFT-GIT or TST did not exclude the diagnosis of active TB in children, their positivity supported the diagnosis. Specificity could not be measured as only microbiologically confirmed cases of Mycobacterium tuberculosis disease were enrolled in the study. CONCLUSION: Although sensitivities of TST and QFT-GIT are too low to exclude active TB, their positivity supports diagnosis of active TB in children concomitant with signs and symptoms. QFT-GIT and TST should be used together to enhance diagnostic sensitivity and could help exclude a diagnosis of TB if the pretest probability is low.

Comparison of Carba NP-Direct, Carbapenem Inactivation Method, and ß-CARBA Tests for Detection of Carbapenemase Production in Enterobacteriaceae.

Rapid and accurate detection of carbapenemase-producing isolates are extremely important for management of antimicrobial therapy and the implementation of infection control measures. We evaluated the performance of Carba NP-direct, carbapenem inactivation method (CIM), and the commercial ß-CARBA tests for detection of carbapenemase production in Enterobacteriaceae. Enterobacteriaceae isolates with previously characterized carbapenemase types (n = 110) and non-carbapenemase-producing Escherichia coli (n = 15) isolates were tested. Sensitivities of Carba NP-direct, CIM, and ß-CARBA tests were 99.0%, 92.7%, and 93.6%, respectively, while specificity was 100% for all three tests. For ß-CARBA test, a 60-min incubation time instead of 30 increased the sensitivity to 98.1%, and lessened false negativity, particularly with OXA-48-like producers. Our results showed that Carba NP-direct, CIM, and ß-CARBA tests are useful tools for the reliable detection of carbapenemase activity in enterobacterial isolates. Carba NP-direct is a simple, rapid, and low-cost test for routine use.

Trend in Antibiotic Resistance of Extended-Spectrum Beta-Lactamase-Producing Escherichia Coli and Klebsiella Pneumoniae Bloodstream Infections.

OBJECTIVES: Extended-spectrum beta-lactamases (ESBLs) have been detected more frequently in members of the Enterobacteriaceae family, particularly Escherichia coli and Klebsiella pneumoniae. Infections caused by ESBL-producing bacteria are often resistant to treatment with various antibiotic classes and accompanied by increased complication risks, mortality, and costs. In this study, blood culture results were analyzed to determine the change in the ESBL production rate and antibiotic susceptibilities in E. coli and K. pneumoniae isolates over a period of 3 years. METHODS: The results of blood cultures sent to our laboratory between February 2014 and August 2016 were examined retrospectively. Repeat isolates from the same patient were not included when antibiotic susceptibility rates and clinical distributions were calculated. BD Bactec FX automated blood culture system (Becton Dickinson, Sparks, MD, USA) was used to examine the blood cultures. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (Bruker Daltonics, Bremen, Germany) was used to identify microorganisms. For antibiotic susceptibility tests (AST) and ESBL detection Kirby Bauer disk diffusion method or Phoenix automated system (Becton Dickinson, Sparks, MA, USA) was used. When the AST results were evaluated, Clinical and Laboratory Standards Institute breakpoints were used for 2014 and 2015, and European Committee on Antimicrobial Susceptibility Testing breakpoints were used for 2016. RESULTS: During the 3-year period, 224 (35%) of 632 E. coli and 137 (31%) of 439 K. pneumoniae isolates were determined to be ES BL-producers. The ESBL-positive isolate percentage for E. coli and K. pneumoniae for 2014, 2015, and 2016 was 23%, 36%, 48% and 23%, 32%, 37%, respectively. The increase in ESBL was statistically significant for both E. coli (p<0.001) and K. pneumoniae (p=0.011). ESBL-positive E. coli and K. pneumoniae strains were most sensitive to carbapenem-class antibiotics, amikacin, and colistin. While there was no meropenem-resistant strain, 5 (3.3%) ertapenem-resistant and 1 (0.7%) imipenem-resistant ESBL E. coli strains were detected. The ESBL K. pneumoniae strain resistance rate to ertapenem, imipenem, and meropenem was 12%, 11.2%, and 11.1%, respectively. The resistance rates of K. pneumonia strains to ertapenem, imipenem, meropenem, and piperacillin-tazobactam increased significantly over the study period (p<0.001). CONCLUSION: Monitoring ESBL rates and the antibiotic susceptibility of E. coli and K. pneumoniae strains of bloodstream infections is of the utmost importance in guiding empiric antibiotic therapies and patient management.

Intraventricular tigecycline for the treatment of shunt infection: a case in pediatrics.

Ventriculoperitoneal (VP) shunt infections are seen in 3%-17% of patients with VP shunts. These infections may cause severe morbidity and mortality. Staphylococci are the most common cause of CSF shunt-associated infections, although gram-negative bacteria (especially multidrug-resistant [MDR] and extensive drug-resistant [XDR] bacteria) also play an important role. Due to increased antibiotic resistance, sometimes off-label usage of antibiotics is considered. Tigecycline is one of these antibiotics. It should not be used unless there are no other antibiotic treatment options available, especially in children. It belongs to the glycylcycline class of antibiotic agents and inhibits protein translation in bacteria by binding to the 30S ribosomal subunit. The authors describe the case of a patient who had an XDR Klebsiella pneumoniae-positive VP shunt infection. After removal of his VP shunt, an external ventricular drain was inserted, and the patient was treated with a combination of intravenous (1.2 mg/kg/day) and intraventricular (4 mg/day) tigecycline in addition to his meropenem (120 mg/kg/day) treatment. On the 7th day of the combined therapy, his CSF culture was sterile. Because tigecycline distribution into the tissues is not sufficient with intravenous administration, combining it with intraventricular infusion can provide new treatment methods. However, further studies are needed for its use as a treatment method in children.