The Effect of Total Laboratory Automation on Urine Culture Result Times in a Consolidated Laboratory.

BACKGROUND: The Provincial Health Directorate of Istanbul province (Turkey) established a consolidated laboratory network consisting of four regional central laboratories to reduce general laboratory costs and increase laboratory efficiency and quality in all affiliated hospitals. As part of the consolidation project, the Total Laboratory Automation (TLA) system was installed in the microbiology department of the ISLAB-2 central laboratory. In this study, the turnaround time (TAT) of urine samples of a satellite laboratory where the system was not installed and the ISLAB-2 central laboratory were compared to evaluate the effect of consolidation and the TLA. METHODS: The TAT values of all urine samples processed between March 2021, when the TLA was installed, and October 2021, were retrospectively examined in the laboratory information system. While the TLA was used for the processing and evaluation of samples in the ISLAB-2 central laboratory, manual methods were employed in the satellite laboratory. Both laboratories used MALDI-TOF MS (bioMérieux, France) for bacterial identification and VITEK 2 Compact (bioMérieux, France) for antibiotic sensitivity testing. Kruskal-Wallis test was used to compare TAT between the two laboratories. p < 0.05 was taken as the level of statistical significance. RESULTS: A total of 78,592 urine cultures (71,906 in the central laboratory and 6,686 in the satellite laboratory) were included in the study. Negative samples were reported in 23.5 hours in the central laboratory and 37.1 hours in the satellite laboratory and positive samples in 55 hours and 61.7 hours in the same laboratories, respectively. The mean TAT of both positive and negative urine cultures were found statistically significantly lower in the central laboratory than in the satellite laboratory (p < 0.0001). While 82% of negative urine cultures were completed within the first 24 hours in the central laboratory, only 17% were processed in the satellite laboratory. While 61% of positive samples were processed within the first 48 hours in the central laboratory, 38% were completed in the satellite laboratory. CONCLUSIONS: We assume that TLA has a positive effect on the diagnosis and treatment of patients, thanks to its contribution to standardization, efficiency, increased quality, and earlier reporting.

Evaluation of Broth Disk Elution Method to Determine Colistin Resistance in Klebsiella pneumoniae and Escherichia coli Strains.

BACKGROUND: The reference broth microdilution (rBMD) method for the determination of colistin resistance is very laborious and time consuming, and many manual errors can occur. There are also limitations in detection of colistin heteroresistance. Therefore, alternative methods with satisfactory performance are required for routine laboratory work. In our study, the colistin broth disk elution (CBDE) method recommended by the Clinical and Laboratory Standards Institute (CLSI) for the detection of colistin resistance in routine applications was compared with rBMD. The compatibility and error rates of the method were evaluated and its usability in routine laboratory studies was examined. METHODS: Eighty-nine multidrug resistant Klebsiella pneumoniae and five Echerichia coli strains isolated from various clinical specimens were included in the study. Identification of strains and antibiotic susceptibility tests were performed with MALDI-TOF MS (bioMerieux, France) and Vitek-2 (bioMerieux) system. Minimum inhibitory concentration (MIC) was studied in 0.125 - 128 mg/L dilution range by using polystyrene microplate and colistin sulfate salt according to ISO-standard (20776-1) recommendations for the reference BMD test. The CBDE method was performed according to the CLSI recommendations. Isolates with MIC ≤ 2 mg/L were considered susceptible, while isolates with MIC > 2 mg/L were considered resistant according to EUCAST recommendations. The performance of the CBDE method was evaluated according to ISO criteria (Categorical agreement > 90%; major error and very major error rates < 3%). RESULTS: Categorical agreement for all 58 and 36 isolates found to be resistant and susceptible, respectively, by rBMD was found to be 100% with CBDE test. Since < 1 and > 4 µg/mL values could not be determined with the CBDE method, essential agreement (EA) could not be calculated. No major or very major errors were detected. CONCLUSIONS: Our results showed that the performance of the CBDE test is good when compared to the rBMD method. According to our data, we believe that the CBDE method can be used in routine laboratories for the detection of colistin resistance.

Comparison of performance of LIAISON SARS-CoV-2 antigen assay with RT-PCR during the Omicron wave.

Due to the newly emerging Omicron variant, there is a need to re-evaluate the performance of automated antigen tests. Our study aim was to evaluate the performance of the automated Liaison SARS-CoV-2 antigen assay against reverse transcriptase polymerase chain reaction (RT-PCR) in samples with Omicron variant.A prospective study was performed on 373 combined oro-nasopharyngeal samples (NPS) randomly collected from symptomatic patients. NPS were tested with Liaison SARS-CoV-2 Ag test (DiaSorin, Italy) and DS Coronex COVID-19 Multiplex RT-PCR Diagnosis Kit (DS BioTechnology, Ankara, Turkey).Of 373 samples, 124 (33.2%) were found to be RT-PCR positive and 249 (66.8%) RT-PCR negative. Taking RT-PCR as a reference, the sensitivity and specificity of the Liaison SARS-CoV-2 Ag assay were found as 84.6% (95%CI 77.3%-90%) and 100% (95%CI 98.5%-100%), respectively. For samples with a cycle threshold (Ct) value <25 (high viral load), the sensitivity increased to 100%. When antigen concentration and Ct values were compared, a strong negative correlation between antigen and Ct values was determined (P < 0.001).The Liaison antigen test met the performance criteria recommended by the WHO for samples with the Omicron variant. In addition, it showed excellent sensitivity and specificity in patients with high viral load. Therefore, Liaison antigen test can be a reliable and useful alternative in the diagnosis of SARS-CoV-2 infection, particularly in resource-constrained laboratories.

Investigation of in vitro efficacy of meropenem/polymyxin B and meropenem/fosfomycin combinations against carbapenem resistant Klebsiella pneumoniae strains.

The incidence of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is increasing worldwide, and very limited number of effective antibiotics are available for therapy. In our study, the in vitro efficacy of meropenem/polymyxin B and meropenem/fosfomycin combinations against CRKP strains was investigated. The efficiency of meropenem/polymyxin B and meropenem/fosfomycin combinations was tested by checkerboard microdilution and checkerboard agar dilution methods, respectively, against 21 CRKP strains containing major carbapenem resistant genes (7 blaKPC, 7 blaOXA-48 gene, and 7 blaOXA-48+ blaNDM), and seven additional CRKP strains without carbapenemase genes.Among the 28 CRKP strains, the meropenem/polymyxin B combination was synergistic in ten (35.7%), partially synergistic in 12 (42.8%), and indifferent in six (21.4%) isolates. The meropenem/fosfomycin combination was found to be synergistic in three isolates (10.7%), partially synergistic in 20 (71.4%), and indifferent in five (17.8%). In 21 strains containing carbapenem resistance genes, meropenem/polymyxin B and meropenem/fosfomycin combinations exhibited synergistic/partial synergistic effects in 15 (71.4%) and 16 (76.2%) strains, respectively, compared to 100% synergistic/partial synergistic efficiency in both combinations in seven strains free of carbapenemase genes. No antagonistic effect was detected in either combination.Regardless of presence or absence of carbapenem resistance genes, meropenem/polymyxin B and meropenem/fosfomycin combinations both demonstrated high synergistic and partial synergistic activity against 78.4% and 82.1% of CRKP strains, respectively. Also, they have no antagonistic effects and can be used successfully to prevent therapeutic failure with monotherapy, according to our in vitro studies.

[A Case of Mycobacterium abscessus Identified by Suspicious Gram Staining in the Blood Culture of a Patient with Chronic Renal Failure]. / Kronik Böbrek Yetmezlikli Hastanin Kan Kültüründe Süpheli Gram Boyamasi ile Tanimlanan Mycobacterium abscessus Olgusu.

Mycobacterium abscessus (M.abscessus), which is from the group of non-tuberculosis mycobacteria and is widely found in the natural environment, has been reported with increasing frequency as the causative agent of various infections; especially in the lower respiratory tract and in immuncompromised people. In this report, a case of M.abscessus, which developed tubular adenoma, pancytopenia and sepsis on the basis of chronic renal failure (CRF) was diagnosed by suspecting the causative agent in the Gram stain examination prepared from blood culture, was presented. A 49-year-old patient with CRF, who had complaints of weight loss, weakness, and loss of appetite for the last six months, admitted to the emergency department with a 7-8-day history of severe diarrhea and fever. Besides other tests, as the white blood cell count was 1.6 x 103/µl, neutrophil count was 80.6%, hemoglobin was 9.3 g/ dl and the platelet value was 36 x 103/µl in the blood samples, the patient was first taken into internal medicine service and then to the intensive care unit with a preliminary diagnosis of hypotension and sepsis. Meropenem and teicoplanin were started with the preliminary diagnosis of peritonitis in the internal medicine service. In addition to other tests, on the fifth day of antibiotic treatment, two consecutive sets of blood cultures were taken and sent to the microbiology laboratory. A positive signal was obtained from two aerobic blood culture samples at 42 and 45 hours of incubation in the BacT/Alert device. No bacteria were observed in the Gram staining of these samples and Erhlich Ziehl Neelsen (EZN) staining was performed because the structures considered as dye residues were noted as a result of the examination. Acid-fast bacteria were observed in the EZN-stained slide examination, and a panic report was given to the clinician. The patient died shortly after the notification was made in the evening hours. On culture plates inoculated after a positive signal, at the end of two days of aerobic incubation at 37 °C, small smooth S colonies grew on chocolate and sheep blood agar. Growing bacteria were detected as positive by EZN staining and identified as M.abscessus with 99.9% confidence by MALDI-TOF MS. After the bacterium was named as M.abscessus, the isolates were sent to the tuberculosis central laboratory of Süreyyapasa Chest Diseases and Thoracic Surgery Hospital for molecular typing. After DNA extraction from the growing colonies and polymerase chain reaction (PCR), they were typed using the GenoType NTM-DR (Hain Lifescience GmbH, Germany) kit and identified as M.abscessus, consistent with the MALDITOF MS result. After the species level identification, the erm, rrl (clarithromycin, azithromycin), and rrs (kanamycin, amikacin, and gentamicin) genes were investigated in the isolate, and it was determined that the bacteria were resistant to macrolides and sensitive to aminoglycosides. In the clinic, it should be noted that, non-tuberculous mycobacteria may play a role as an agent in immunocompromised people. On the other hand, it should be considered that non-tuberculosis bacteria may be the causative agent, with gram-positive bacilli appearing as stain residues or pale staining in Gram stains made from samples of such patients. As in this case, if the agent is seen as dye residue in blood culture Gram staining samples, it may be life-saving to suspect the agent and to report the result to the clinician accurately and quickly after EZN staining.

[Evaluation of In vitro Efficacy of Meropenem/Colistin and Meropenem/Fosfomycin Combinations on Multidrug Resistant Gram-Negative Bacilli]. / Çok Ilaca Dirençli Gram-Negatif Basillerde Meropenem/Kolistin ve Meropenem/Fosfomisin Kombinasyonlarinin In vitro Etkinliginin Degerlendirilmesi.

The rate of extensively drug-resistant and pan-resistant gram-negative rods isolated as infectious agents is increasing around the world and in Türkiye. One of the important options in the treatment of these infections is the combined use of antibiotics. Therefore, the aim of this study was to investigate the in vitro effect of meropenem/colistin and meropenem/fosfomycin combinations on carbapenem-resistant gram-negative bacilli isolated as infectious agents. Escherichia coli (n= 6), Klebsiella pneumoniae (n= 10), Pseudomonas aeruginosa (n= 5), and Acinetobacter baumannii (n= 6) isolates were recovered from blood and tracheal aspirate samples of patients hospitalized in our hospital's intensive care unit were included in the study. In the first stage of the combination study, minimal inhibitory concentrations (MIC) were investigated by broth microdilution for meropenem and colistin, and agar dilution methods for fosfomycin. In the second stage of the study, synergy, partial synergy, indifference, and antagonistic effects were investigated with the checkerboard method for the meropenem/colistin combination and the agar dilution method for the meropenem/fosfomycin combination. The checkerboard results were interpreted as follows: fractional inhibitory concentration index (FICI) values ≤ 0.5 synergy, < 0.5-≤ 1 partial synergy, > 1-≤ 4 indifference and FIC values of > 4 antagonism. MIC values obtained in the study were interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Of the 27 isolates studied with the broth microdilution method, 63% were found to be colistin-resistant and 37% susceptible. The MIC values of fosfomycin against Enterobacterales group bacteria were found to be in the range of 2-2048 mg/L. Two of the six E.coli isolates and nine of the 10 K.pneumoniae isolates were found to be resistant to fosfomycin (IV). The MIC values of ≥ 128 mg/L were found in all 11 non-fermentative gram-negative rods with intrinsic resistance to fosfomycin. In the combination of meropenem/ colistin, synergy and partial synergy were observed in 11 (40.7%) of 27 isolates, an indifference effect was observed in 13 (48.2%), and antagonistic effects were observed in three (11.1%) of the isolates. The synergy and partial synergy effects of this combination were 37.5% for Enterobacterales group bacteria, 50% for E.coli, and 30% for K.pneumoniae. Regarding the 11 non-fermentative gram-negative rods included in the study, 83.3% synergy and partial synergy was found in A.baumannii for the meropenem/colistin combination, while no synergy and partial synergistic effect was found in P.aeruginosa. Meropenem/fosfomycin synergy and partial synergy effects were 83.3% (5/6) for E.coli, 100% (8/8) for K.pneumoniae, 100% (6/6) for A.baumannii, and 25% (1/4) for P.aeruginosa. In all of the isolates studied, meropenem/fosfomycin combination was found to be more effective than the meropenem/colistin combination. It would be meaningful to support these data obtained in vitro with clinical efficacy results to be obtained as a result of the application of antibiotics in vivo, taking into account the pharmacokinetic and pharmacodynamic properties of the antibiotics used in this study.

Microorganisms isolated from the bile of the patients who have undergone cholecystectomy and their antibiotic resistance pattern: multicenter prospective study.

BACKGROUND: Gallbladder and biliary tract infections are diseases with high mortality rates if they are not treated properly. Microbiological evaluation of perioperatively collected samples both ensures proper treatment of patients and guides empirical treatment due to the determination of microorganism susceptibility. AIMS: This study aimed to isolate the microorganisms in bile cultures from patients who underwent cholecystectomy and to determine sensitivity results of these microorganisms. METHODS: This study was a multi-center and prospective design, included 360 patients, and was performed between 2019 and 2020. Culture results of bile taken during cholecystectomy were evaluated. RESULTS: Bacterial growth was found in the bile cultures of 84 out of 360 (23.3%) patients. Patients were divided into two groups according to whether they had risk factors for resistant microorganisms or not. While Escherichia coli (n = 11, 13%), Enterococcus spp. (n = 8, 9.5%), and Enterobacter spp. (n = 4, 4.7%) were detected most frequently in patients without risk. Staphylococcus spp. (n = 17, 20.2%), Enterococcus spp. (n = 16, 19%), and E. coli (n = 8, 9.5%) were the most frequently found microorganism at-risk patients. In multivariate analysis, bile culture positivity was found higher in patients who had history of biliary disease (p = 0.004), operation performed concurrently with a cholecystectomy (p = 0.035), and high rate of polymorphonuclear leukocytes (PNL) in total leukocyte count (p = 0.001). CONCLUSIONS: Our study shows that when starting empirical antibiotic treatment for bile ducts, whether patients are at risk for the development of resistant bacterial infection should be evaluated after which antibiotic selection should be made accordingly.

[One-Year Candida Data of the Central Mycology Laboratory: Which Sample, Which Species, How Resistant?] / Merkez Mikoloji Laboratuvarinin Bir Yillik Candida Verileri: Hangi Örnek, Hangi Tür, Ne Kadar Dirençli?

The incidence of fungal infections particularly Candida species, is increasing gradually as a result of the increased life expectancy associated with the advances in the diagnosis and treatment of diseases, and increased number of patients in the risk group over the years. In addition, the incidence of fungal infection types that are resistant to antifungal drugs has been increasing, and rare fungal species have been reported to be isolated more frequently. For this reason, it is indicated that identification to the species level will contribute to the early initiation of an accurate and effective treatment. In this study, it was aimed to define the Candida species isolated from various clinical specimens and to document the performance of antifungal sensitivity tests. The Candida isolates sent to the central mycology laboratory in 2019 for identification and antifungal susceptibility tests were included in the study. The definition of the fungi to the species level was carried out using matrix-assisted laser desorption ionization-time of fl ight mass spectrometry (MALDI-TOF MS) and conventional methods. In vitro antifungal drug susceptibilities were analyzed using the The Clinical and Laboratory Standarts Institute (CLSI, M27-A3) reference broth microdilution method. The minimum inhibitory concentration (MIC) results were interpreted in accordance with the species-specific clinical breakpoints (CBPs) cited in the CLSI-M60 guidelines, and according to the epidemiological cut-off value (ECV) when no CBP was mentioned. The distribution of the species of the total 813 Candida isolates included in the study were as follows: Candida albicans (n= 312 ), Candida parapsilosis (n= 202), Candida tropicalis (n= 92), Candida glabrata (n= 71), Candida dubliniensis (n=28), Candida lusitaniae (n= 26), Candida kefyr (n= 22), Candida utilis (n= 17), Candida krusei (n= 14), Candida orthopsilosis (n= 7), Candida inconspicua (n= 7), Candida guilliermondii (n= 5), Candida metapsilosis (n= 4), Candida norvegensis (n= 4), Candida lambica (n= 1) and Candida lipolytica (n= 1). The evaluation of the results of the antifungal susceptibility tests according to the CBPs revealed that one C.albicans isolate and 60 C.parapsilosis (29.7%) isolates were resistant, and seven C.parapsilosis (3.5%) isolates were dose-dependent susceptible to fluconazole; 32 C.parapsilosis (15.8%) isolates were intermediately susceptible to voriconazole; one C.parapsilosis (0.5%) was resistant and one C.krusei (7.1%) was intermediately susceptible to anidulafungin; and one C.parapsilosis (0.5%) was resistant and one C.krusei (7.1%) isolate was intermediately susceptible to micafungin. In terms of ECVs, one C.lusitaniae isolate for fluconazole and one of each C.lusitaniae and C.kefyr isolates were evaluated as a non-wild type. In the present study, 61 of 813 isolates were found to be resistant to fluconazole and seven were dose dependently susceptible, 32 were intermediately susceptible to voriconazole, one was resistant to anidulafungin, one was intermediately susceptible, and one was resistant to micafungin and one was intermediately susceptible to micafungin. In conclusion, the increased number of non- albicans Candida species and increased levels of resistance to antifungal drugs further establish the importance of early diagnosis at a species level alongside antifungal susceptibility tests.

Bartonella henselae IgM seropositivity in both adult and pediatric patients with diverse clinical conditions in Turkey.

Bartonella henselae is the causative agent of cat scratch disease (CSD). In this study, we aimed to investigate the clinical data of patients with suspicion of CSD and delineate current epidemiological features.A total of 785 patients with suspected CSD were included in the study. B. henselae IgM antibody was determined by indirect fluorescent antibody (IFA) test using a commercial kit (Euroimmun, Germany). Sex, age, clinical pre-diagnosis and animal contact information of the patients were obtained from hospital electronic database records.Seventy-eight (9.9%) of 785 samples were seropositive. Out of 78 patients, 46 with animal contact data were further analyzed. Of these patients, 56% were male, and 41% were under 18 years of age. Seropositivity was more commonly observed in fall and winter. The most common finding was lymphadenitis (63%). Thirty-five patients (76%) had a previous history of animal contact (cat/dog). Of the 46 seropositive patients, 78.3, 15.2, 4.4, and 2.1% had titers of 1:80, 1:160, 1:320, and 1:640, respectively.Our study confirms that CSD is not rare in Turkey. Thus, it should always be considered in the differential diagnosis of patients presenting with lymphadenopathy in all age groups, particularly children. Questioning of cat exposure should never be neglected, especially in areas with intense population of stray cats, such as Istanbul.

Detection of colistin resistance among multidrug-resistant Klebsiella pneumoniae and Escherichia coli clinical isolates in Turkey.

In this study investigation of plasmid-mediated mcr 1-5 resistance genes was performed among multidrug-resistant (MDR) colistin sensitive and resistant Klebsiella pneumoniae and Escherichia coli strains isolated in our laboratory. We aimed to evaluate automated system (Vitek-2), broth microdilution (BMD) reference method and chromogenic media performance. Totally 94 MDR K. pneumoniae and six E. coli isolates were included in the study. CHROMID® Colistin R agar (COLR) (bioMerieux, France) was used to determine the colistin resistance by chromogenic method. Standard PCR amplification was performed using specific primers to screen the plasmid-mediated mcr 1-5 genes. Sixty-one isolates were resistant to colistin and 39 were susceptible with reference BMD. The essential and categorical agreement of Vitek-2 was determined as 100 and 99%. The sensitivity of COLR medium was 100%, the specificity was 97.5%. In our study mcr-1 was detected in eight isolates, while other mcr genes were not detected. Due to the high sensitivity and specificity of the COLR medium, it can be used in routine diagnostics for the detection of colistin resistance. In our study we detected 8% prevalence of mcr-1 among MDR strains however, two mcr-1 positive isolates were found sensitive to colistin by BMD.

Is the Second Treponemal Test Necessary in the Reverse Algorithm for the Diagnosis of Syphilis?

BACKGROUND: This study was performed to investigate the necessity of the second treponemal test and to evaluate the diagnostic performance of the first treponemal test in the reverse algorithm of syphilis diagnosis. METHODS: Abbott Architect Syphilis TP assay, a chemiluminescence immunoassay (CIA), was used as the first step treponemal test. Treponema pallidum haemagglutination assay (TPHA) test results of reactive samples from the first test were recorded. TPHA test result was considered as confirmatory. TPHA test results were grouped according to their Abbott Architect Syphilis TP assay results and they were compared with Mann-Whitney U test. For Abbott Architect Syphilis TP assay, a cutoff value with 100% specificity was determined via a ROC curve analysis which would render TPHA test unnecessary. RESULTS: Out of 146,800 samples 2,646 were reactive in the first step. Of those, 2,002 had a TPHA test result. Of the 2,002 TPHA tests, 1,706 were positive and 296 were negative. TPHA positive and negative groups have significantly different CIA signal/cutoff values. Using a ROC curve built for evaluation of the first-step test, the maximum Youden's index value was found as 5.26. If this value would be accepted as cutoff, it would have a specificity of 85%. The specificity of 100% can be reached if a new cutoff value is set to 27.83. CONCLUSIONS: Calculated cutoff value with 100% specificity is not practically applicable. It achieves saving of TPHA test in only six percent of reactive samples. Architect Syphilis TP assay is advantageous in large laboratories but is not enough to lead diagnosis without a second treponemal assay. Therefore it was decided to continue the reverse algorithm with dual treponemal assays.

[Evaluation of the Two Commercial Methods Based on Broth Microdilution Against Reference Microdilution Method for Klebsiella pneumoniae Isolates]. / Klebsiella pneumoniae Izolatlarinda Sivi Mikrodilüsyon Temelli Iki Ticari Sistemin Referans Mikrodilüsyon Yöntemine Göre Degerlendirilmesi.

A rapid and reliable method for antimicrobial susceptibility test of colistin is needed because of increasing numbers of multi-resistant gram negative bacterial infections and simultaneus increasing of colistin resistance. Although broth microdilution (BMD) is recommended by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) as a reference method, the use in routine laboratory practice is limited because of the difficulties in application and time-consuming characteristics. Recently, many BMD based commercial products were developed. The study was aimed to compare the results of the two commercial systems available for the detection of colistin sensitivity with the reference method. Totally 38 Klebsiella pneumoniae strains isolated from various clinical specimens between 2017-2018 were included in our study. Identification and antibiotic susceptibility tests were performed with "matrix-assisted laser desorption/ionization timeof-flight, mass spectrometry (MALDI-TOF MS)" and Vitek-2 (bioMérieux, Marcyl'Etoile, France) systems. BMD tests were performed with Sensititre (Sensititre custom plate, Thermo Fisher Scientific, UK) and Micronaut MIC-Strip (Merlin Diagnostika GmbH, Germany) kits. Commercial BMD assays containing dehydrated colistin in the concentration range of 0.0625-128 mg/L were tested with 0.5 McFarland bacterial suspensions prepared according to the manufacturer recommendations. The reference BMD test was performed by following the recommendations of the International Organization for Standardization (ISO-20776-1). ATCC 25922 colistin-susceptible Escherichia coli and NCTC 13846 (mcr-1 positive) colistin-resistant E.coli strains were used as the quality control strains. According to the recommendations of EUCAST version 9.0, strains with minimum inhibitory concentration value of ≤ 2 mg/L were considered susceptible and strains > 2 mg/L as resistant. Thirty-five isolates were resistant to colistin by the reference method and three of them were susceptible. The Sensititre kit detected a very major error (2.8%) in one isolate; no major or very major errors were detected for the Micronaut kit. The essential and categorical agreement of the Sensititre and Micronaut kits with the reference method was defined as 74-76% and 97-100%, respectively. Colistin is the last agent for the treatment of the multi drug resistant severe bacterial infections so major and very major error for colistin should be considered equally serious. Although a very major error was detected by the Sensititre kit in one isolate, the categorical agreement of both commercial kits was greater than 90% when compared with the reference method. It was concluded that, commercially available, BMD based systems that do not require additional equipment and experience can be routinely used.

[Investigation of Anti-HCV S/CO Value in Detecting Viremia in Patients with Hepatitis C Virus Infection]. / Hepatit C Virüsü Enfeksiyonu Olan Hastalarda Viremi Tespitinde Anti-HCV S/CO Degerinin Arastirilmasi.

Anti-HCV and HCV RNA tests are used in laboratory diagnosis of hepatitis C virus (HCV) infections. False positive results are frequently observed in anti-HCV tests used as screening tests in societies with low prevalence of HCV. The HCV RNA test, which is a confirmatory test, is not performed in every laboratory because it is a high-cost and high-tech test, which can lead to delay in the diagnosis and treatment of patients. In this study, it was aimed to obtain an optimal anti-HCV S/CO value in our laboratory for demonstrating true antibody positivity and viremia in patients by analyzing the relationship between anti-HCV, alanine aminotransferase (ALT) and HCV RNA using retrospective data. Between July 2014 and July 2017, 754.190 anti-HCV tests were performed. Patients aged 18 years or older who were reactive with anti-HCV and those with simultaneous HCV RNA and ALT prompts were included in the study. The second generation CMIA (Abbott, USA) method was used for anti-HCV detection. For quantitative HCV RNA analysis, viral nucleic acid extraction was performed with the QIAsymphony SP/AS (Qiagen, Germany) using the QIAsymphony DSP Virus/Pathogen Midi Kit; and PCR was performed by Rotor-Gene Q (Qiagen, Germany) using Artus HCV QS-RGQ kit. ARCHITECT c and AEROSET systems (Abbott, USA) were used for ALT measurement. HCV genotype determination (622 cases) was performed using GenoSen's HCV Genotyping 1/2/3/4 RG qualitative real time PCR kit (Corbett Research, Australia) and GEN-C 2.0 Reverse Hybridization Strip Assay (NLM Diagnostics, Italy) kit at different periods covered by our study. The optimal threshold value for the relationship between anti-HCV, ALT and HCV RNA was selected based on ROC analysis. Statistical significance was accepted as p<0.05. Of the anti-HCV test results, 10.679 were found to be reactive. 1754 data of 1290 cases with anti-HCV reactivity who were simultaneously tested for HCV RNA and ALT in the same serum were evaluated. Of these, 742 (42%) were found to be HCV RNA positive and 1012 (58%) were found to be HCV RNA negative. ALT and anti-HCV levels of those who were positive for HCV RNA were significantly higher than those with negative HCV RNA (p= 0.001). The threshold point for anti-HCV S/CO according to HCV RNA was found to be 7.13 (sensitivity of 97.4%, specificity of 50.3%, positive predictive value 58.9%, negative predictive value 96.4%), and the cut-off point for ALT was found to be 27.5 IU/L (sensitivity of 77.6%, specificity of 80.8%). For HCV RNA positivity, the area under the ROC curve for anti-HCV and ALT was significantly higher than 0.5 (p= 0.001). No statistically significant difference was found between HCV genotypes in terms of ALT and anti-HCV levels. By using our new threshold in the laboratory workflow, the need to verify with HCV RNA can be reduced, especially in some patients who have been screened for antiHCV for screening purposes. Anti-HCV values below 7.13 S/CO, considering the high negative predictive value of this threshold; a false positive result in a patient presenting for screening can be predicted without waiting for the HCV RNA result. In anti-HCV reactivities determined above 7.13, the possibility of absence of viremia should be considered due to the low positive predictive value.

[Distribution of Yeast Species Isolated from Blood Cultures for a Six Year Period in Turkey: a Multicentre Study]. / Türkiye'de Alti Yillik Zaman Dilimi Içerisinde Kan Kültürlerinden Soyutlanan Maya Mantarlarinin Tür Dagilimi: Çok Merkezli Bir Çalisma.

Bloodstream infections due to yeast species especially Candida spp. have been reported to be important healthcare associated infections with high mortality and morbidity rates. Candidemia causes prolonged hospital stays as well as increased cost. In order to prevent or treat these life-threatening bloodstream infections successfully, nationwide epidemiological data should be available about the etiological agents of these infections. Multi-centre national epidemiological data on yeast bloodstream infections in Turkey is lacking. A retrospective study was designed and data from six different centres in Turkey between 2011 and 2016 years were gathered and analysed for the distribution and frequency of yeast species in order to assist clinicians in their choice of early and appropriate antifungal therapy. All laboratories used automated blood culture systems for the isolation of blood strains. All the participating centres performed the identification of their own isolates by conventional methods using germ tube test, morphology on corn meal agar with tween 80 and chromogenic media and the identification was confirmed by API 20C AUX, API ID 32C or matrix-assisted laser desorption/ionization time of flight mass spectrophotometry (MALDI-TOF MS) systems. The analysis of the results was performed on the basis of intensive care units (ICUs), other inpatient clinics (OICs) and totally all clinics (ACs). Totally 2547 yeast isolates were determined from six participating centres during six years. According to the total ACs results, Candida albicans was the most prevalent species (43.1%), followed by Candida parapsilosis complex (29.1%), Candida glabrata (10.1%), Candida tropicalis (7.5%), Candida krusei (2.4%) and Candida kefyr (1.6%) and the remaining (6.2%) of them consisted of other yeast species. The distribution of the Candida species did not show statistically significant difference between the years, however the increase of C.parapsilosis complex in 2016 was statistically significant, (p= 0.02). During the study period, totally 1054 yeast isolates were obtained from the ICUs of the centres. C.albicans predominated with 476 (45.2%) isolates and C.parapsilosis complex (28.7%), C.glabrata (10.7%) and C.tropicalis (7.3%) were the other leading species in ICUs. Among 1493 isolates of the OICs of six centres participated in the study, C.albicans was the most prevalent species with 622 (41.7%) isolates. The other frequent species of OICs were C.parapsilosis complex (29.5%), C.glabrata (9.6%) and C.tropicalis (7.6%) resembling ICU results. It can be concluded that C.albicans is still the leading cause of bloodstream infections in the six different centres located in various geographical areas of Turkey.

Complete blood count parameters and neutrophil-to-lymphocyte ratio values as markers for differentiation between systemic infectious and non-infectious uveitis.

PURPOSE: To compare complete blood count (CBC) parameters and neutrophil/lymphocyte ratio (NLR) between patients with infectious uveitis (IU) and those with non-infectious uveitis (NIU) during the first acute uveitis attack (AUA). METHODS: The records of 119 patients admitted with the first AUA between 2016 and 2019 and whose diagnosis was unknown at the time of admission were retrospectively reviewed. The patients were divided into two groups, IU and NIU according to diagnoses after ocular and systemic workup. The IU group was also divided into subgroups as uveitis associated with local ocular infections and systemic infections. The complete blood count and associated indices of patients calculated from samples taken during the attack were compared between the groups. RESULTS: A total of 60 NIU cases (mean age: 43.5 ± 11.6 years) and 59 IU cases (43.3 ± 14.7 years) were examined. Twenty-six of the NIU cases were female and 34 were male, while 32 of the IU cases were female and 27 were male. The localization of uveitis was similar in the IU and NIU groups (anterior: 11 vs. 18, intermediate: 3 vs. 6, posterior: 28 vs. 14, panuveitis: 17 vs. 22). The NLR values were significantly increased in patients with IU compared to those with NIU (p = 0.047). When the NLR is compared between NIU and subgroups of IU, this value was only found significantly increased in uveitis due to a systemic infection (n = 12) (p < 0.001). The mean white blood cell (WBC) count (p < 0.001) and neutrophil values (p < 0.001) were also observed significantly higher in the uveitis associated with systemic infectious diseases when compared with uveitis associated with local ocular infections and NIU group. CONCLUSION: In the current study, NLR values are compared with autoimmune uveitis and systemic infectious uveitis for the first time in patients with AUA. This ratio has been found significantly higher in uveitis associated with systemic infections. The use of CBC parameters and indices, especially the NLR, may be instrumental in assessing patients presenting with first AUA, particularly when there is no clear explanation or underlying cause.

The Prevalence of Mixed Genotype Infections in Turkish Patients with Hepatitis C: a Multicentered Assessment.

BACKGROUND: HCV virus infections are one of the major health problems in the world that can cause cirrhosis and liver cancer at a higher rate than other hepatitis data. The aim of this study was to determine the prevalence of mixed infections with different HCV genotypes in Turkey and also to evaluate the current HCV genotype and sub-type distributions by a multicentered assessment. METHODS: The HCV genotype data of 17,578 hepatitis C patients collected from 23 centers from different geographic regions covering all Turkey were collected. The data included information about the HCV genotypes in the last 10 years (between 2007 and 2016), demographic properties of the patients and the methods/systems used to determine the genotypes. RESULTS: Two hundred twenty-eight of the patients (1.3%) had mixed genotype. The most common mixed genotype combination was 1b + 4 (0.83%) followed by 1a + 1b (0.26%). Genotype distribution varies according to geographical regions. However, genotype 1 (82.92%) was the most common genotype in all regions and all years. This was followed by genotype 3 (7.07%) and genotype 4 (5.43%). A variety of methods were used by the centers including sequencing, pyrosequencing, real-time PCR, in-house RFLP, reverse hybridization (LIPA), and hybridization. CONCLUSIONS: Infection with mixed HCV genotypes in Turkey is uncommon. Genotype distribution varies according to geographic regions; the most common genotype 1 is encountered all over the country, while genotypes 3 and 4 are only in some of the centers. Since there is limited information about mixed HCV infection, further investigations are needed to determine the clinical importance of mixed HCV infection.

[Surveillance of resistance in the intensive care units using a cumulative antibiogram]. / Yogun bakim ünitelerinde kümülatif antibiyogram ile antibiyotik direncinin izlenmesi.

Empiric treatment with broad-spectrum antibiotics exerts condensed pressure in intensive care units (ICUs) for the selection of multidrug-resistant bacteria. Multidrug-resistant gram-negative bacteria became the focus of interest owing to limited treatment options and negative effects on patient survival. Cumulative antibiograms can guide selection of correct empiric treatment, de-escalation treatment according to antibiogram results and development of policies in fight against antibiotic resistance. In this study, we aimed to determine the antibiotic resistance rates of gram-negative bacilli in the intensive care units of the public hospitals in the region where we are connected by using the cumulative antibiogram result and to show the change of resistance over the years and to determine whether there is any difference between the hospitals. Gram-negative bacilli were isolated from ICUs of state hospitals in the second Istanbul State Hospitals Association area during 2014-2016. Isolates were identified using Vitek MS (bioMérieux, France) system and tested for antibiotic susceptibility with Vitek 2 (bioMérieux, France) system according to the Clinical and Laboratory Standards Institute (CLSI) criteria followed during those years. Cumulative antibiogram reports for these strains were prepared according to the CLSI M39-A4 guide. Gram-negative bacilli were divided into three groups: non-fermentative, urinary enteric, and non-urinary enteric bacilli. Total number of strains isolated during three years from these groups were 2626, 1390 and 2011, respectively. Annual trends of susceptibility during the aforementioned years were evaluated. Hospitals were also classified into five groups and differences were evaluated in the susceptibility profiles of these hospitals. Among the non-fermentative bacilli, Acinetobacter baumannii complex was the most commonly isolated species and the most resistant bacteria against antibiotics. The susceptibility rates of A.baumannii complex against the beta-lactam group of antibiotics were < 10%. Colistin susceptibility rates of A.baumannii complex and Pseudomonas aeruginosa isolates were over 98%. Among the non-urinary enteric bacilli, K.pneumoniae was the most commonly isolated species displaying maximum antibiotic resistance. Susceptibility rates for colistin, which is the last resort for treating resistant gram-negative bacteria, ranged between 73% and 80%. Escherichia coli, which was the second most common isolated species among non-urinary bacilli, had susceptibility rates over 90% to carbapenems along with colistin and tigecycline. Although E.coli was the most commonly isolated species among urinary enteric bacilli, K.pneumoniae and Proteus mirabilis were the most resistant isolates. A statistically significant decrease in susceptibility rates against all antibiotics was observed in P.mirabilis isolates between the years 2015-2016. Carbapenem susceptibility rates decreased below 70%. E.coli, Serratia spp., and Stenotrophomonas maltophilia had similar susceptibility profiles among different hospitals, indicating homogenous distribution, whereas other species had different profiles, indicating a more heterogenic distribution, among hospitals. The reports of this study were generated according to a standard guide and they clearly revealed the seriousness of antibiotic resistance in our region which represents approximately one-fourth area of Istanbul. When all the results were considered, best empiric treatment option for enteric bacilli except K.pneumoniae was carbapenems. For K.pneumoniae infections there is no reliable choice other than colistin but a de-escalation treatment can be planned according to antibiogram results. Similarly colistin is the first choice in empiric treatment of infecitons due to non-enteric bacilli. However, the heterogeneity of the susceptibility profile observed in the hospitals, which are geographically close to each other, indicated the difference in the flora of the intensive care unit of hospitals. It would be appropriate to prepare cumulative antibiogram reports similar to those in the present study, to prevent complications, reduce costs and improve patient prognosis in the intensive care units of hospitals and these reports should become part of the infection control policies applied in hospitals.

[The comparison of antibiotic susceptibilities of uropathogenic Escherichia coli isolates in transition from CLSI to EUCAST]. / CLSI'dan EUCAST'e geçiste üriner sistem enfeksiyonu etkeni Escherichia coli izolatlarinin antibiyotik duyarliliklarinin karsilastirilmasi.

Determination of treatment protocols for infections according to antimicrobial susceptibility test (AST) results is are important for controlling the problem of antibiotic resistance. Two standards are widely used in the world. One of them is Clinical Laboratory Standards Institute (CLSI) standards used in Turkey for many years and the other is the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards which is used in European Union member countries and came into use in 2015 in Turkey. Since the EUCAST standards had higher clinical sensitivity limits particularly for gram-negative bacilli compared to CLSI (2009) standards, there will be some changes in antibiotic resistance profiles of Turkey with the use of EUCAST. CLSI has changed zone diameters after 2009 versions and the differences between the two standards were brought to a minimum level. Knowledge of local epidemiological data is important to determine empirical therapy which will be used in urinary tract infections (UTI). The aim of this study was to determine the differences of antibiotic susceptibility zone diameters based on our local epidemiological data among uropathogenic Escherichia coli isolates according to EUCAST 2014 and CLSI 2014 standards. A total of 298 E.coli strains isolated from urine samples as the cause of uncomplicated acute UTI agents, were included in the study. Isolates were identified by conventional methods and with BBL Crystal E/NF ID System (Becton Dickinson, USA). AST was performed with Kirby Bauer disk diffusion method and results were evaluated and interpreted according to the CLSI 2014 and EUCAST 2014 standards. According to the results, susceptibility rates of isolates against amikacin (100%) and trimethoprim-sulfamethoxazole (63.09%) were identical in both standards. However, statistically significant differences were observed between CLSI and EUCAST standards in terms of susceptibilities against gentamicin (91.95% and 84.56%, respectively; p= 0.004), cefuroxime axetil (20.13% and 77.18%, respectively; p= 0.000) and levofloxacin (73.83% and 67.11%, respectively; p= 0.044). No statistically differences between two standards for ampicillin (32.89% and 36.24%, respectively; p= 0.219), ampicillin-sulbactam (65.77% and 69.13%, respectively; p= 0.216), ciprofloxacin (72.48% and 71.14%, respectively; p= 0.392) and imipenem (94.63% and 95.30%, respectively; p= 0.426) were determined. In this transitional period, continuity of cooperation between the clinician and microbiology laboratory should be kept forefront and the maintenance of local surveillance studies should be provided by taking into account the changes in antibiotic susceptibility results.

External auditory canal microbiology and hearing aid use.

OBJECTIVE: The aim of this study was to determine the presence and nature of bacterial flora on hearing aids and the ears of this population. We wonder if the microbiology of the ears with hearing aid wearing differs from the other ear. SETTING: Tertiary referral center. DESIGN: A prospective, clinical study. SUBJECTS AND METHODS: Three samples were taken, one from the surface of the hearing aid's ear mold; one from the hearing aid-wearing ear canal and the last one from the ear without hearing aid. Samples were cultured to determine qualitatively and quantitatively the pathogenic microorganisms present. RESULTS: A total of 123 samples, obtained from 41 hearing aid users, were analyzed. Methicillin-resistant coagulase-negative staphylococci, methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter species, Staphylococcus auricularis, and Stenotrophomonas maltophilia were identified organisms. CONCLUSIONS: We identified unexpected microorganisms both on hearing aids and hearing aid using ears. This study demonstrates that using hearing aid alters the ear canal flora. To avoid otitis externa, it is important to use an appropriate hygiene routine to clean and disinfect hearing aids and ear molds.

The Prevalence of Positive Donor Corneoscleral Rim Culture and its Association with Ocular Infection After Transplantation.

Objectives: The aim of the study was to determine the prevalence of positive corneoscleral donor rim cultures and to report keratitis and endophthalmitis after keratoplasty. Methods: Eye bank records and medical records of patients who underwent keratoplasty between September 1, 2015, and December 31, 2019, were retrospectively reviewed. Patients who had routine donor-rim culture taken during surgery and followed up for at least 1 year in the post-operative period were included in the study. Results: A total of 826 keratoplasty procedures were performed. A total of 120 (14.5%) cases had a positive donor corneoscleral rim culture. Positive bacterial cultures were obtained from 108 (13.7%) of the donors. Bacterial keratitis was observed in one patient (0.83% of recipients) who had a positive bacterial culture. Positive fungal cultures were obtained from 12 (1.45%) donors, of whom one (8.33% of recipients) developed fungal keratitis. Endophthalmitis was observed in one patient whose culture result was negative. Both bacterial and fungal culture results were similar in penetrating and lamellar surgical procedures. Conclusion: Although the donor corneoscleral rims have a high positive culture result, the rate of bacterial keratitis and endophthalmitis is low, the risk of infection is high in patients with a fungal positive donor rim. Closer follow-up of patients with fungal positive donor corneo-scleral rim result and initiation of aggressive antifungal treatment when infection occurs will be beneficial.