genitalium strains with
MOI=50 for 2–3 h. Heat killed M. genitalium (HKG37) was used as control. Cytotoxic effect was determined by evaluating the integrity of the infected cells using differential interference contrast  at 488 nm in an inverted laser scanning confocal microscope (Olympus FV1000) with 20X objective. Determination of H2O2 in M. genitalium strains Production of H2O2 by mycoplasma strains was measured by colorimetric ferrous ion oxidation in xylenol orange [FOX] method [58, 59]. Protein samples from strains of M. genitalium were used as the source for H2O2. Protein content of samples was determined using Pierce BCA Protein Assay Kit (Pierce). Equal amount of protein samples (each 25 μl) and cold FOX reagent (250 μl) were mixed and selleck chemical incubated for 30 RXDX-106 in vivo min at room temperature. After incubation, absorbance was measured at 560 nm. The amount of hydrogen peroxide in each sample was determined using a standard curve generated with known amounts of H2O2. The results were expressed as μmoles H2O2/per μg protein. Differentiation of monocytic THP-1 cells by M. genitalium strains THP-1 cells were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) and cells (0.5X105) were plated on 4 chamber 1.5 German cover glass slides (Nunc,
Rochester, NY). The cells were then infected with (MOI 1:5) M. genitalium (G37 those or TIM207 or TIM262 or HKG37) for 1 h. After incubation, the chambers were washed with PBS to remove non-adherent cells. Cells adhering to the cover slips were examined under FV1000 laser scanning inverted confocal microscope (Olympus, Japan) with 20X objective. Images were acquired and labeled cells in each image was counted using the NIH analyze particle plug-in of Image J software. Statistical analysis The data were analyzed by paired t-test using graphpad prism software. Acknowledgements This study was partly supported by NIH grant AI08346. We thank Dr. John Glass, J. Craig Venter Institute, Baltimore, MD,
for the TIM207 and TIM262 strain of M. genitalium. Mass spectrometry analyses were conducted in the UTHSCSA Institutional Mass Spectrometry Laboratory. Confocal microscopic analyses were performed at the Optical Imaging Core Facility at UTHSCSA- Regional Academic Health Center at Edinburg, Texas. We thank Drs. Robert Edwards and Robert Gilkerson, Department of Biology, University of Texas Pan American for kindly reading the manuscript and correcting the language. Electronic supplementary material Additional file 1: Figure 1: Viability of M. genitalium strains based on color change assay. M. genitalium G37, TIM207 and TIM262 were grown and harvested as described in method section. The bacteria were resuspended in appropriate amount of PBS to give an OD600 =1.0.