title: Flow cytometry as an improved method for the titration of Chlamydiaceae and other intracellular bacteria.
abstract: Chlamydiaceae is a family of intracellular bacteria causing a range of diverse pathological outcomes. The most devastating human diseases are ocular infections with C. trachomatis leading to blindness and genital infections causing pelvic inflammatory disease with long-term sequelae including infertility and chronic pelvic pain. In order to enable the comparison of experiments between laboratories investigating host-chlamydia interactions, the infectious titer has to be determined. Titer determination of chlamydia is most commonly performed via microscopy of host cells infected with a serial dilution of chlamydia. However, other methods including fluorescent ELISpot (Fluorospot) and DNA Chip Scanning Technology have also been proposed to enumerate chlamydia-infected cells. For viruses, flow cytometry has been suggested as a superior alternative to standard titration methods. In this study we compared the use of flow cytometry with microscopy and Fluorospot for the titration of C. suis as a representative of other intracellular bacteria. Titer determination via Fluorospot was unreliable, while titration via microscopy led to a linear read-out range of 16 - 64 dilutions and moderate reproducibility with acceptable standard deviations within and between investigators. In contrast, flow cytometry had a vast linear read-out range of 1,024 dilutions and the lowest standard deviations given a basic training in these methods. In addition, flow cytometry was faster and material costs were lower compared to microscopy. Flow cytometry offers a fast, cheap, precise, and reproducible alternative for the titration of intracellular bacteria like C. suis. © 2016 International Society for Advancement of Cytometry.
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: T
authors: T
authors: Käser
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: J A
authors: JA
authors: Pasternak
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: G
authors: G
authors: Hamonic
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: M
authors: M
authors: Rieder
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: K
authors: K
authors: Lai
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: M
authors: M
authors: Delgado-Ortega
authors: Vaccine and Infectious Disease Organization (VIDO), Home of the International Vaccine Centre (InterVac), University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E3, Canada.
authors: V
authors: V
authors: Gerdts
authors: Nantes-Atlantic College of Veterinary Medicine and Food Sciences and Engineering, UMR BioEpAR, LUNAM Université, Oniris, Nantes, F-44307, France.|Epidemiology and Risk Analysis in Animal Health, CS 40706, INRA, UMR1300 Biology, Nantes, F-44307, France.
authors: F
authors: F
authors: Meurens
mesh_terms: D002460:Cell Line; D002693:Chlamydiaceae / Q000302:isolation & purification*; D004847:Epithelial Cells / Q000382:microbiology*; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008853:Microscopy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Chlamydia suis; Chlamydiaceae; FCM; flow cytometry; intracellular bacteria; titration