Effect of antinuclear antibody positivity on antineutrophil cytoplasmic antibody results by indirect immunofluorescence assay.

BACKGROUND: The indirect immunofluorescence assay (IIFA) utilizing antineutrophil cytoplasmic antibodies (ANCA) is widely used as a diagnostic test for autoimmune vasculitis. The presence of antinuclear antibodies (ANA) might lead to a misleading interpretation of ANCA. This study aims to explore the impact of the presence of ANA on the interpretation of ANCA. METHODS: This retrospective research examined samples negative for antiMPO and antiPR3 ANCA by IIFA and explored correlations between the ANA-IIFA results and the ANCA interpretation frequencies. Our analysis involved the use of suitable statistical methods, including Chi-square and kappa statistics. RESULTS: Up to 75.2% of the ANCA-IIFA-positive samples exhibited a positive p-ANCA pattern when using the ethanol-fixed substrate, with c-ANCA positivity at 24.8%. In the ANA-IIFA-positive samples, ~77.3% displayed p-ANCA patterns on ethanol-fixed substrates. A comparison between the ANA-IIFA titers and the p-ANCA results revealed that p-ANCA positivity was notably more common in samples with higher titers, and this correlation was found to be statistically significant. CONCLUSION: Positive ANA results by IIFA tests are linked to a higher incidence of p-ANCA interpretation, particularly in cases with higher titer patterns. This insight aids laboratories in establishing effective workflows to investigate potential p-ANCA interference.

Determination of amphotericin B antifungal susceptibility in Candida strains using an inverted microscope.

INTRODUCTION: Invasive Candida infections have recently shown a significant increase in prevalence and are associated with high mortality rates. Initiating early antifungal treatment in patients with candidemia is vital. The aim of our study was to compare the antifungal susceptibility results of a new method called Flat Plate Method modified from reference "Clinical and Laboratory Standards Institute (CLSI) microdilution method by us with Sensitititre Yeast One colorimetric method and the reference CLSI method. METHODOLOGY: We tested 100 Candida isolates from blood cultures. We followed the CLSI M27-A3 (reference method for broth dilution antifungal susceptibility testing of yeasts; third edition) guidelines for testing in vitro susceptibility to amphotericin B. In the Flat Plate method, 96-well plates were used for evaluation with an inverted microscope. Minimum inhibitory concentration (MIC) values in the SYO method were measured following the manufacturer's instructions. The MIC values obtained by all three methods were considered compatible if they were within ± 2 dilution limits. RESULTS: The SYO method detected C. albicans and C. glabrata with 100% essential agreement, whereas there was 96.29% essential agreement in the case of C. parapsilosis. In the Flat Plate method, the essential agreement with amphotericin B was 91.42%, for C. albicans isolates and 89.47%.for C. glabrata strains. CONCLUSIONS: When determining early antifungal susceptibility using the Flat Plate method, the results are obtained quickly, with high accuracy, and without incurring additional costs. However, there is a need for comprehensive studies comparing different antifungals.

16s rRNA-based phylogenetic analyses of Elizabethkingia anophelis: Detection of Elizabethkingia anophelis, a rare infectious agent from blood and determination of antibiotic susceptibility in Turkey.

PURPOSE: Elizabethkingia anophelis was firstly isolated from the midgut of the Anopheles gambiae mosquito in 2011. After this year, it was isolated in some intensive care cases in Africa and Asia. This study, it was aimed to confirm the identification of E. anophelis in the blood of a pediatric patient. METHODS: After the suspicious bacteria were grown on blood agar, MALDI-TOF MS and 16s rRNA gene sequencing methods were used to identify and an antibiotic susceptibility test was carried out by Vitek 2 Compact system according to the EUCAST. Finally, a phylogenetic tree was created based on the 16s rRNA gene region. RESULTS: The isolate was identified as E. anophelis by both methods. It was found to be resistant to all beta-lactam antibiotics and also susceptible to ciprofloxacin and levofloxacin. According to the 16S rRNA-based phylogenetic tree, our isolate clustered within a branch containing other E. anophelis. CONCLUSION: These findings will guide clinicians in choosing which antibiotic to choose if they encounter this agent. Also, the clinicians should be vigilant against this agent, as it is a newly emerging infectious agent in Turkey.