Q-Scoring System for the Evaluation of the Superficial Wound Swab Samples: A Clinical Microbiological Aspect.

Purpose: Wound swab cultures are frequently requested from patients suspected of having a wound infection. The quality of the sample should also be evaluated by performing a Gram-stained microscopic examination. "Q-scoring system" is not widely used and the literature on the subject is limited. Methods: A total of 4648 wound swab samples were evaluated. Samples with a Q-score of "0" were considered as "poor quality samples", and those with a score of " ≥ 1" were classified as "good quality samples". Microorganisms grown in the culture of samples that scored above one were identified by mass spectrometry, and antimicrobial susceptibility testing was performed. Results: Gram stain results were found to be consistent with the culture result in 57.10% (n = 1078) of and inconsistent with the culture result in 42.90% (n = 813) of the samples. The number of samples with Q-scores one, two, and three among the 813 samples was 62, 29, and 722, respectively. The value observed in Q3 was found to be statistically significantly higher than the values observed in Q1 and Q2 (p < 0.05). Samples sent from surgical departments (61.92%) with a Q-score of ≥ 1, were statistically significant compared to internal medicine departments (p < 0.0001). There was no significant difference between samples sent from intensive care units and those sent from other inpatient services. For both groups with Q-scores ≥ 1 and "0" similar microorganisms were identified. Conclusion: As a conclusion, the Q-scoring system will provide a common language between the laboratory and the clinic, especially by standardizing the evaluation of wound swab samples.

Clinical Management of a Pandrug-Resistant OXA-48 Klebsiella pneumoniae Infection in the Pediatric Intensive Care Unit.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is one of the serious forms of health care-associated infection. Pan-drug resistant (PDR) CRKP infections can cause severe infections. Mortality and treatment costs in the pediatric intensive care unit (PICU) are high. This study aims to share our experience regarding the treatment of oxacillinase (OXA)-48-positive PDR-CRKP infection in our 20-bed tertiary PICU with isolated rooms and 1 nurse for every 2-3 patients. Methods: Patient demographic characteristics, underlying diseases, previous infections, source of infection PDR-CRKP, treatment modalities, measures used, and outcomes were recorded. Findings: Eleven patients (eight men and three women) were found to have PDR OXA-48-positive CRKP. Because of the simultaneous detection of PDR-CRKP in three patients and the rapid spread of the disease, it was classified as a clinical outbreak, and strict infection control measures were taken. Combination therapy with double carbapenemase (meropenem and imipenem), amikacin, colistin, and tigecycline was used for treatment. The mean duration of treatment and isolation was 15.7 and 65.4 days, respectively. No treatment-related complication was observed, only one patient died, and the mortality rate was 9%. Conclusions: This severe clinical outbreak can be successfully treated with effective treatment with combined antibiotics and strict adherence to infection control measures. ClinicalTrial.gov ID: 28/01/2022 - 1/5.

Clinical evaluation of DIAGNOVIR SARS-CoV-2 ultra-rapid antigen test performance compared to PCR-based testing.

Coronavirus Disease-19 (COVID-19) is a highly contagious infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The development of rapid antigen tests has contributed to easing the burden on healthcare and lifting restrictions by detecting infected individuals to help prevent further transmission of the virus. We developed a state-of-art rapid antigen testing system, named DIAGNOVIR, based on immune-fluorescence analysis, which can process and give the results in a minute. In our study, we assessed the performance of the DIAGNOVIR and compared the results with those of the qRT-PCR test. Our results demonstrated that the sensitivity and specificity of the DIAGNOVIR were 94% and 99.2%, respectively, with a 100% sensitivity and 96.97% specificity, among asymptomatic patients. In addition, DIAGNOVIR can detect SARS­CoV­2 with 100% sensitivity up to 5 days after symptom onset. We observed that the DIAGNOVIR Rapid Antigen Test's limit of detection (LoD) was not significantly affected by the SARS­CoV­2 variants including Wuhan, alpha (B1.1.7), beta (B.1.351), delta (B.1.617.2) and omicron (B.1.1.529) variants, and LoD was calculated as 8 × 102, 6.81 × 101.5, 3.2 × 101.5, 1 × 103, and 1 × 103.5 TCID50/mL, respectively. Our results indicated that DIAGNOVIR can detect all SARS-CoV-2 variants in just seconds with higher sensitivity and specificity lower testing costs and decreased turnover time.

Investigation of the presence of Capnophilic bacteria in routine urine cultures.

Capnophilic Escherichia coli (CEC) strains are rarely isolated from urinary tract infections (UTIs). The purpose of this research was to look into the incidence and traits of the CEC strains that cause UTIs. Nine (0.11%) epidemiologically unrelated CEC isolates with varying antibiotic susceptibility patterns were identified from patients with various co-morbidities after the evaluation of 8500 urine samples. Three of these strains belonged to the O25b-ST131 clone, and none of them possessed the yadF gene. Due to adverse incubation conditions, CEC isolation is difficult. Although rare, capnophilic incubation of urine cultures may be considered particularly for patients with underlying predisposing conditions.

[Evaluation of the Epidemiological, Clinical and Radiological Features of Pneumonia Cases Caused by Mycoplasma pneumoniae in Childhood]. / Çocukluk Çaginda Mycoplasma pneumoniae'nin Etken Olarak Saptandigi Pnömoni Olgularinin Epidemiyolojik, Klinik ve Radyolojik Özelliklerinin Degerlendirilmesi.

The current study aimed to investigate the clinical, laboratory and radiological findings of the pneumonia cases in children that were confirmed as M.pneumoniae by polymerase chain reaction (PCR) testing and to reveal the factors that can be decisive in the diagnosis. Seventy-seven children were included in this study. The median age of the patients was 31 months (1 month-17 years 4 months). The 63.6% of the patients were younger than five years of age, 53.2% were girls and 46.8% were boys. During the eight-year research period, the frequency of M.pneumoniae in the patients hospitalized with the diagnosis of pneumonia was found to be 3.1%. The rate of M.pneumoniae as the underlying factor of pneumonia was found to be statistically significantly lower in patients aged 0-60 months compared to the patients aged 61-216 months. In patients with M.pneumoniae accompanied by viruses, the age group was more likely to between 0-60 months. The most common symptoms were cough (96.1%) and fever (74%). Physical examinations revealed that 70.1% of the patients had rales, 63.6% had tachypnea, 45.5% had oropharyngeal hyperaemia, 35.1% had subcostal-intercostal retraction, 31.2% had long expiration period, 26% had rhonchus, 24.7% had decrease in breath sounds, 15.6% had cervical lymphadenopathy, 13% had tachycardia, 3.9% had otitis media, 3.9% had tonsil hypertrophy and 2.6% had a maculopapular rash. The rate of hypoxemia was found to be 42.2%. When the physical examination findings of patients with only M.pneumoniae detected in multiplex PCR analysis and those with accompanying viruses in M.pneumoniae were compared, tachypnea, oropharyngeal hyperemia and decreased breath sounds were found to be statistically significantly higher in patients with M.pneumoniae only. Retraction was detected more frequently in patients with accompanying viruses. When the laboratory results of the patients were evaluated according to age, leukocytosis was detected in only 18.2% of the patients, while the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were found to be high in 75% and 85.7% of the patients, respectively. In the multiplex PCR analysis, the CRP values of the patients with only M.pneumoniae were found to be higher than the patients with accompanying viruses. M.pneumoniae was accompanied by viruses at the rate of 40.3%. The most common accompanying viruses were rhinovirus, adenovirus, bocavirus and metapneumovirus. The 55.8% of the patients had lobar-segmental consolidation, 46.8% had parahilar-peribronchial thickening, 18.2% had atelectasis, 11.7% had pleural effusion, 9.1% had increase in reticulonodular density, 6.5% had lymphadenopathy whereas no abnormality was observed in 5.2% of them. No diffuse interstitial involvement was recorded. The CRP value of the patients who had lobar segmental consolidation which was detected through chest X-rays were statistically higher than those without consolidation. In multiplex PCR analysis, the rate of parahilar-peribronchial thickening detected in chest X-ray findings was found to be higher in patients with M.pneumoniae accompanied by viruses compared to those with only M.pneumoniae. The rate of the patients who were given empirical antibiotics against atypical agents was 45.5%. The rate of empirically administered antibiotic treatment for atypical agents after being hospitalization was higher in patients diagnosed with only M.pneumoniae compared to patients with M.pneumoniae and viruses. One patient (1.3%) died. As there are no typical clinical, laboratory or radiological findings specific to M.pneumoniae pneumonia, all of the findings should be assessed as a whole to establish a diagnosis. Besides, for the detection of M.pneumoniae, diagnostic tests which are cost effective, with rapid results and are capable of distinguishing colonisation from active infection should be developed.

Pediatric Invasive Aspergillosis: a Retrospective Review of 59 Cases.

Invasive aspergillosis (IA) is a major cause of morbidity and mortality. This study aimed to present our 10-year IA experience at a single center. Fifty-nine pediatric patients with IA were included in this study. The male-to-female ratio was 42/17. The median age was 8.75 years. Hematologic malignancy was present in the majority of the patients (40/59, 68%). The mean neutropenia duration was 18.5 days. Cytosine arabinoside was the most common immunosuppressive therapy directed at T cells during IA diagnosis. IA cases were categorized as proven (27%), probable (51%), or possible (22%) according to the 2008 European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. The lungs (78%) were the most common site of IA, and nodules were the most frequent radiological findings (75.5%). In 38 patients (64.4%) receiving antifungal prophylaxis, prophylactic agents included fluconazole (30.5%), liposomal amphotericin B (23.7%), posaconazole (8.5%), and voriconazole (1.7%). Initial treatment was most commonly administered as monotherapy (69.5%). The median antifungal treatment duration was 67 days. Eleven deaths (18.6%) were due to aspergillosis. With the increased use of corticosteroids, biological agents, and intensive immunosuppressive chemotherapy, IA will most likely continue to occur frequently in pediatric patients.

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.

[Interferon Gamma Release Assay Request Indications: From Laboratory to Clinical Perspective]. / Interferon Gama Salinim Test Istemi Endikasyonlari: Laboratuvardan Klinige Bakis Açisi.

Tuberculosis is a re-emerging infectious disease that causes high morbidity and mortality worldwide and remains a major health threat in many parts of the world. With the increase in the incidence of HIV-positive/AIDS patients and immunocompromised individuals, accurate and timely diagnosis of latent TB (LTB) and active TB (ATB) has gained great importance. The aim of this study was to investigate the rationale lying behind interferon gamma release assay (IGRA) requests for patients applying to various clinics of a tertiary care hospital. In the study, 2905 IGRA tests requested in two years period were analyzed retrospectively. The IGRA test positivity rates were recorded and analyzed by linking with the requesting departments and indications. IGRA test positivity was determined in 503 cases (17.31%). IGRA test positivity rates were above 20% in samples sent from general surgery, pulmonology, nephrology, and transplantation departments, respectively. At all, 54.17% of the cases from whom IGRA requests were made constituted the first group of "pre-treatment investigation", and the positivity rate in this group was 12.96%. The positivity rate was highest [163 (28.69%)] in the patient group from whom the test was requested with the suspicion of TB. As a conclusion, until today, there is no study in which IGRA test requests are evaluated in terms of clinics. In this respect, this study is thought to be important. It is also desired to highlight that it is important for each country to develop its specific guidelines, country specific indications for IGRA test requests. Multi-centered studies are also essential for a global suggestion.

Medically important Candida spp. identification: an era beyond traditional methods.

BACKGROUND: Candida infections are gaining more attention for the last few decades so diagnostic tools are very important for early diagnosis. Conventional identification of yeasts is time-consuming, molecular methods are more complicated and relatively expensive gold-standard methods. Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) was put into the market due to its speed and high accuracy. The aim of this study was to evaluate the performance of corn meal tween-80 agar (CMTA), CHROMagar Candida medium, and MALDI-TOF MS and to compare the obtained results with DNA sequencing. METHODS: The CHROMagar Candida medium, CMTA, and MALDI-TOF MS Biotyper System were used to test 416 isolates. The isolates with discrepant results by at least one of the three methods were subjected to sequence analysis. RESULTS: The identification results of the 351 (%84.4) were compatible with all three methods. When compared to the sequencing results, the most accurate results were obtained by the MALDI-TOF MS, especially for rare Candida species. DISCUSSION: MALDI-TOF MS is found to be the most accurate identification tool for clinically important Candida strains. CMTA alone should not be used for the final identification of Candida species and the chromogenic medium should always be considered presumptive.

Wohlfahrtiimonas chitiniclastica-related soft-tissue infection and osteomyelitis: A rare case report.

Wohlfahrtiimonas chitiniclastica is a rare pathogen that was first isolated from Wohlfahrtia magnifica, a parasitic fly. It is an uncommon, but an emerging human pathogen reported only in Europe and South America. Until today, it has been reported to be a zoonotic pathogen originating from different geographic locations. The present case, a patient suffering from osteomyelitis in Turkey, represents the first report of this pathogen in this country and so far no reports of related osteomyelitis associated with W. chitiniclastica is available. Clin-ical awareness of these emerging human pathogens is crucial for controlling infectious diseases.

Sensitivity Affected by Disease Severity and Serum Sampling Time: a Performance Evaluation of Six SARS-CoV-2 Antibody Immunoassays.

Comparative validation and clinical performance data are essential for the reliable interpretation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibody test results. This study aimed to assess the performance of six SARS-CoV-2 IgG immunoassays in the context of different disease severities. Four automated chemiluminescence immunoassays (Access [Beckman Coulter], Architect [Abbott], Atellica-IM [Siemens], and Elecsys [Roche]) as well as two ELISA assays (SARS-CoV-2 IgG-S1-based and NCP IgG [Euroimmun]) were evaluated using samples from 143 patients as well as 50 pre-pandemic control serum samples. Accuracy and precision tests were performed for validation purposes. Overall sensitivity ranged between 73.38-88.65% and was higher in spike protein-based assays, while the specificity was ≥98% in all immunoassays. The clinical performance of the immunoassays differed depending on disease severity and target antigen. For instance, the IgG response was lower for samples taken <20 days post-symptom onset (87.30%) compared with those taken ≥20 days post-symptom onset (94.80%). Moreover, moderate disease levels led to the highest levels of IgG. Higher levels of antibodies were detected in the clinically moderate disease group. In asymptomatic and mild groups, more antibody positivity was detected with spike protein-based assays. All the assays tested could be used to detect SARS-CoV-2 IgG. However, spike-based assays revealed relatively higher sensitivity rates than nucleoprotein-based assays, particularly in cases of asymptomatic and mild disease.

The role of galactomannan test results in the diagnosis of pediatric invasive aspergillosis.

BACKGROUND: Invasive aspergillosis (IA) is an important cause of morbidity and mortality in immunosuppressed children. Early detection of the infection can improve prognosis in this patient population. OBJECTIVES: To investigate the utility of Aspergillus galactomannan antigen assay (GM-EIA) as a diagnostic tool for IA in at-risk paediatric patients. PATIENTS/METHODS: For the study, 659 GM-EIA results from 59 patients diagnosed with IA and 3368 GM-EIA results from 351 subjects without evidence for IA (controls) were reviewed retrospectively. Three cut-off values (i.e. ≥0.5, ≥1, ≥1.5) were specified to determine GM-EIA positivity. RESULTS: The median age was 6.3 years for boys and 14.5 years for girls. There was a significant difference between the girls and boys in terms of age (p < 0.01). For proven/probable/possible IA patients, sensitivity of 67.8% and specificity of 59.8% were detected when the ≥0.5 cut-off value was used for GM-EIA-positivity. The specificity increased to 80% at the cut-off of ≥1 and to 88% at the cut-off of ≥1.5. False positivity rates were 9.14, 3, and 1.45% at the ≥0.5, ≥1 and ≥1.5 cut-offs respectively. In the proven/probable IA group, sensitivity and negative predictive values were 86.9 and 97.2% at the ≥0.5 cut-off, 85.7 and 97.9%, at the ≥1 cut-off and 84.2 and 98.1% at ≥1.5 cut-off respectively. The positive likelihood ratio was 7.57 and the odds ratio was 42.67 at ≥1.5 cut-off. CONCLUSION: The GM-EIA may be used for both screening and diagnostic purposes in paediatric patients using a cut-off value of ≥1.5 for GM-EIA positivity.

Antibody response to two doses of inactivated SARS-CoV-2 vaccine (CoronaVac) in kidney transplant recipients.

BACKGROUND: Coronavirus Disease-19 (COVID-19) has high mortality in kidney transplant recipients (KTR), and vaccination against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is vital for this population. Although the humoral response to messenger RNA vaccines was shown to be impaired in KTR, there is a lack of data regarding the antibody response to inactivated vaccines. We investigated the antibody response to two consequent doses of the inactivated SARS-CoV-2 vaccine (CoronaVac; Sinovac Biotech, China). METHODS: A total of 118 patients from two centers were included. The levels of anti-SARS-CoV-2 immunoglobulin-G antibodies against the nucleocapsid and spike antigens were determined with enzyme immunoassay (DIA.PRO; Milano, Italy) before the vaccine and one month after the second dose of the vaccine. Thirty-three patients were excluded due to antibody positivity in the serum samples obtained before vaccination. RESULTS: Eighty-five patients, 47 of whom were female, with a mean age of 46 ± 12, were included in the statistical analysis. The maintenance immunosuppressive therapy comprised tacrolimus (88.2%), mycophenolate (63.6%), and low-dose steroids (95.3%) in the majority of the patients. After a median of 31 days following the second dose of the vaccine, only 16 (18.8%) patients developed an antibody response. The median (IQR) antibody level was 52.5 IU/ml (21.5-96). Age (48 vs. 38, p = .005) and serum creatinine levels (1.14 vs. 0.91, p = .04) were higher in non-responders and were also found to be independently associated with the antibody response (odds ratio (OR): 0.93, p = 0.012 and 0.15, p = 0.045, respectively) in multivariate analysis. CONCLUSION: In this study, we found the antibody response to the inactivated vaccine to be considerably low (18.8%) in KTR. Increased age and impaired renal function were associated with worse antibody response. Based on the knowledge that mRNA vaccines yield better humoral responses, this special population might be considered for additional doses of mRNA vaccination.

High mobility group box-1 levels may be associated with disease activity of Behcet's disease

BACKGROUND: High mobility group box- 1 (HMGB- 1) is a nuclear protein acting as a proinflammatory molecule. The serum HMGB- 1 levels were found elevated in chronic inflammatory diseases. In this cross-sectional study, serum HMGB- 1 levels in Behcet's disease (BD) patients and healthy controls (HC) were studied. Also, its association with disease activity scores and clinical findings were evaluated. METHODS: Ninety BD patients and 50 age-sex matched HC were included in the study. Disease activity scores were assessed by Behcet Disease Current Activity Form (BDCAF) and Behcet Syndrome Activity Score (BSAS). Serum HMGB- 1 levels were measured using a commercial ELISA kit. A p value of < 0.05 was considered to be statistically significant. RESULTS: Serum HMGB- 1 levels were significantly higher in BD than in HC (43.26 pg/mL and 16.73 pg/mL; p < 0.001, respectively). Serum HMGB- 1 levels were statistically significantly associated with presence of erythema nodosum (EN) and genital ulcers in the last one month prior to recruitment (p = 0.041 and p < 0.001, respectively). BDCAF and BSAS scores were positively correlated with serum HMGB- 1 level ( p = 0.03 and p = 0.02, respectively). DISCUSSION: HMGB - 1 may play a role in the development of BD. Also, due to its positive correlation with disease activity indices, it can be used as a novel disease activity parameter in BD.

An unusual course of SARS-CoV-2 infection: Challenging diagnosis of Guillain-Barré Syndrome.

COVID-19, caused by severe acute respiratory syndrome coronavirus-2, typically presents with respiratory symptoms and fever, but still a variety of clinical presentations have been reported. In this study, it was aimed to report a case of COVID-19 with an atypical presentation and an atypical course. As well, the recovery phase was complicated with GBS and consequently cytomegalovirus infection. It should be kept in mind that patients with COVID-19 severe disease need to be followed for neurological and other complications which may arise during the course of critical illness.

The incidence and clinical effects of Bordetella pertussis in children hospitalized with acute bronchiolitis.

BACKGROUND: Pertussis is a disease leading to high morbidity and mortality in neonates and infants. Bronchiolitis is the most common cause of hospitalization especially in children < 2 year-old. Although the clinical findings are different in these two diseases, it is sometimes difficult to make this distinction in partially or fully vaccinated children. This study aimed to identify the incidence, clinical and laboratory effects of B. pertussis as a causative agent in hospitalized children with acute bronchiolitis. METHODS: The study included patients diagnosed with acute bronchiolitis and admitted to the Division of Pediatric Infectious Diseases from January 2012 to December 2015, aged 24 months or younger, evaluated for viruses and bacteria with polymerase chain reaction in respiratory tract secretions. RESULTS: The study included 380 patients hospitalized with acute bronchiolitis. Of these patients, 85.8% were identified to be positive for at least one respiratory pathogen. The most commonly identified pathogens were respiratory syncytial virus (RSV) A/B, rhinovirus, parainfluenza virus, adenovirus, bocavirus and metapneumovirus A/B. B. pertussis was only detected in 5 patients (1.5%). In the patients with B. pertussis identified, coinfection with another virus was observed including rhinovirus (n= 2), influenza A virus (n= 1), coronavirus OC43 (n= 1) and RSV A/B (n= 1). The presence of B. pertussis did not appear to cause any significant clinical or laboratory differences in patients. CONCLUSIONS: B. pertussis is a rare pathogen in patients admitted to hospital for acute bronchiolitis. However, in patients who do not respond to standard bronchiolitis treatment, B. pertussis should be considered as a causative agent. Early identification of this pathogen is important in terms of quarantining the patient, administering appropriate antimicrobial treatment, and prophylactic treatment to household and other close contacts.

[Direct Identification of Microorganisms from Positive Blood Cultures by MALDI-TOF MS Using an in-House Tween® 80 Method: Experimental and Clinical Study]. / "In-House" Tween® 80 Yöntemi ile Pozitif Kan Kültürlerinden Mikroorganizmalarin MALDI-TOF MS Yöntemi ile Dogrudan Tanimlanmasi: Deneysel ve Klinik Çalisma.

It has been reported that direct identification from blood culture bottles with positive signals and reporting the results to the clinics earlier has positive effects on mortality and morbidity. Extraction methods especially using detergents are used for the direct identification from the bottles which give positive signal. For this purpose, in-house methods developed based on the usage of saponin are widely available in the literature. In this study, it was aimed to develop a simple, easy-to-apply and reliable protocol for identifying the agent directly from the blood culture bottle that gives positive signal with the use of detergent Tween® 80, and to study the obtained protocol in clinical samples in a routine microbiology laboratory and to evaluate the results. The study was carried out in two stages, the experimental stage where the method was developed and the clinical stage where the method was applied. In the experimental stage, blood culture bottles were created with standard strains and isolates previously diagnosed with the 16S rRNA method. 10% solution of Tween® 80 was prepared with distilled water. 1 ml sample was transferred from the bottle that gave positive signal to the microcentrifuge tube, 100 µl of 10% solution of Tween® 80 was added, vortexed for 10 seconds and then incubated for 5 minutes at room temperature. The tubes were centrifuged for 5 min at 14.000 rpm, the supernatant was discarded and the pellet was washed with 1 ml of distilled water and centrifuged at 14.000 rpm for 5 minutes in three times. Samples taken from the pellets were rubbed on the slide and dried on air. Firstly, 1 µl of 70% formic acid, then 1 µl, of matrix solution was added and it was used after drying. In the second stage of the study, the method was applied to the 502 vials giving positive signal in the Microbiology Laboratory of Ankara University Faculty of Medicine Ibni Sina Hospital between 17 April 2018-31 August 2018 and the results were compared with the subculture results. The results obtained at the end of extraction in the experimental stage were compared with the subculture results and no statistical difference was found. In 383 (82.9%) bottles among 462 (92.1%) bottles with monomicrobial positive cultures, compatible results with the subculture results were obtained. Of the microorganisms correctly identified, 350 (91.3%) were bacteria and 33 (8.7%) were fungi. On the other hand, 216 (56.4%) of the bacteria were gram positive and 134 (34.9%) of them were gram negative bacteria. At least one microorganism was correctly identified in 19 (47.5%) of 40 (7.9%) bottles with polymicrobial blood cultures. Their distribution was gram negative (n= 10) and gram positive (n= 8) and yeast (n= 1). No microorganisms were identified in six bottles with polymicrobial cultures. According to the results, we believe that this in-house method developed using Tween® 80 will be a routinely applicable method for blood culture bottles that give positive signal in microbiology laboratories and it will contribute to the early diagnosis.