Flow cytometry-based analysis by Sysmex-UF1000i® is an alternative method in the assessment of periodontal inflammation

Detection and consistency of mucosal fluid T lymphocyte phenotypes and their relationship with blood, age and gender

Innate and adaptive immune responses at mucosal surfaces play a role in protection against most infectious diseases. However, the relative importance either of mucosal versus systemic, or of cellular versus humoral immunity in protection against such infections remains unclear. We aimed to determine the relative percentages and reproducibility of detection of five major T lymphocyte phenotypes in stimulated whole mouth fluid (SWMF); to compare matched mucosal and blood phenotypes; to evaluate the consistency of phenotypes in SWMF over time; and to determine any associations with age or gender. Peripheral blood and SWMF samples were collected from 194 participants and sequential concomitant samples were collected from 27 of those and from 12 subjects living with HIV. CD3, CD4, CD8, Th1 and Th2 T lymphocyte phenotypes were determined by FACS. All the five T lymphocyte phenotypes were detected consistently by FACS in PBMC and SWMF with experimental replicates (N = 10; PBMC CV: 3-30%; SWMF CV: 12-36%). In longitudinal samples detection rates were reproducible in both fluids but variations were higher in SWMF (CV: 23-79.6%) than PBMC (CV: 9.7-75%). Statistically significant correlations of the percentages of all the T lymphocyte phenotypes except CD8 was seen between the two fluids. In PBMCs a negative correlation with age was found with CD3, CD4 and CD8 phenotypes, whilst a positive correlation was found in both SWMF and PBMC with the Th2 phenotype. CD3, CD4 and CD8 phenotypes in SWMF and PBMCs from an HIV-positive cohort were not significantly correlated in contrast with the HIV-negative controls. Our study provides a robust FACS protocol for the detection of the five major T lymphocyte phenotypes in SWMF which should prove useful for research with other mucosal fluids.

Evaluation of the Sysmex UF-1000i system as an alternative for the screening of genital tract inflammation in male infertility patients

The number of white blood cell (WBC) in semen is an important indicator of genital tract inflammation in male infertility. The peroxidase assay is the recommended reference method for seminal WBC counting. However, it is time-consuming and may cause relatively heavy workload in daily routine. Meanwhile, the main component in the reagent of peroxidase test is harmful to human and the environment. In this study, we evaluated the analytical performance of the Sysmex UF-1000i that is a urine flow cytometer as a screening tool for genital tract infection in male infertility patients through the counting of seminal WBC. We examined 143 semen samples and compared the results of UF-1000i and manual microscopy. The intra-assay variability, stability and linearity studies were performed. The intravariability (CV %) of seminal WBC count by Sysmex UF-1000i was 2.34%-9.65%. The method of UF-1000i displayed a good agreement with the reference assay of manual microscopy, and the r value for correlation of seminal WBC count between UF-1000i and manual microscopy was over 0.999 (p < 0.001). The Sysmex UF-1000i is capable of producing reliable seminal WBC count consistent with that obtained by manual microscopy. It is a suitable alternative to the manual microscopy, thus reduces the workload.

Validation and Search of the Ideal Cut-Off of the Sysmex UF-1000i® Flow Cytometer for the Diagnosis of Urinary Tract Infection in a Tertiary Hospital in Spain

Urinary tract infections (UTI) are one of the most prevalent infections. A rapid and reliable screening method is useful to screen out negative samples. The objective of this study was to validate the Sysmex flow cytometer UF-1000i by evaluating its accuracy, linearity and carry-over; and define an optimal cut-off value to be used in routine practice in our hospital. For the validation of the UF-1000i cytometer, precision, linearity and carry-over were studied in samples with different counts of bacteria, leukocytes and erythrocytes. Between March and June 2016, urine samples were tested in the Clinical Microbiology Laboratory at University Miguel Servet Hospital, in Spain. Samples were analyzed with the Sysmex UF-1000i cytometer, and cultured. Growth of ≥10⁵ CFUs/mL was considered positive. The validation study reveals that the precision in all the variables is acceptable; that there is a good linearity in the dilutions performed, obtaining values almost identical to those theoretically expected; and for the carry-over has practically null values. A total of 1,220 urine specimens were included, of which 213 (17.4%) were culture positive. The optimal cut-off point of the bacteria–leukocyte combination was 138.8 bacteria or 119.8 leukocytes with an S and E of 95.3 and 70.4%, respectively. The UF-1000i cytometer is a valuable method to screen urine samples to effectively rule out UTI and, may contribute to the reduction of unnecessary urine cultures.

Investigation of bacterial viability from incubated saliva by application of flow cytometry and hyphenated separation techniques

The aim of the study was determination of bacterial viability in saliva samples and finding a correlation between microbiological and volatile profiles of saliva depending on incubation time. Bacteria colonizing healthy oral cavities were also identified. Twelve healthy adults donated unstimulated saliva samples. Flow cytometry, optical density measurements and colony-forming unit (CFU) counting method were employed for analyses of native and inoculated saliva after 0, 1, 2, 24, and 48 h of incubation. Volatile profiles were acquired using headspace-solid phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS). Oral bacteria were the most viable within 2 h after collection of saliva. Extension of incubation time to 48 h caused considerable decrease in live bacteria counts and sharp increase in dead bacteria counts. The most prevalent strain was Sphingomonas paucimobilis (26.67%). The number of volatiles raised from 5 to 27 with incubation time and most of them were putrefaction products, such as methanethiol, indole and pyrrole. HS-SPME-GC/MS method is insufficient for volatile profiling of "fresh" saliva and should be directed rather to investigation of bacterial metabolites.