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  1. May 2019
    1. supplemented with amino acids and appropriate antibiotic and grown at 37ºC to an A600of 0.5-0.6. Around 0.1-0.5 ml of culture was made up to 1 ml with Z-buffer and lysedwith addition of one drop of chloroform and 1-2 drops of 1% SDS solution. 0.2 ml offreshly prepared 4 mg/ml ONPG was added to start the reaction and incubated at roomtemperature till the color of the reaction mixture turned yellow. 0.5 ml of 1 M Na2CO3was added to stop the reaction and the time duration from initial addition of ONPG tothe stopping of reaction was noted.The absorbance of reaction mix was taken at 420nm and 550 nm. The A600of the culture used was also noted. The enzyme specificactivity (in Miller units) was calculated using following equation:β-galactosidase specific activity = [1000 X A420-(1.75 X A550)] / t X v X A600Where t isthe time period in minsand v the volume of culture used in ml.Each value reported is the average of at least three independent experiments, and the standard error was <10% ofthe mean in all cases
    2. β-galactosidase assay was performed according to Miller (1992). An overnight grownculture of the bacterial strain was sub-cultured in glucose Minimal A medium
    3. Thialysine or thiosine (S-Aminoethyl-L-cysteine)is a toxic analog of Lys. Strains were testedfor sensitivity/resistance to thialysine by streaking them on minimal A-glucose platessupplemented without and with100-200 μg/ml thialysine(Steffes et al., 1992)
    1. All experiments in this studywere performed with log-phase cellsunless otherwise mentioned. For obtaining log-phase cells, overnight YNB-or YPD medium-grown yeast cellswerere-inoculated in fresh YNB or YPD medium to an initial OD600of 0.1-0.2.Cells were incubated at 30 ̊C with shaking at 200 rpmtill the OD600reached to 0.4-0.6 OD. After incubation, log-phase cellswere collected bycentrifugation at 4,000 rpm for 3 min,washed once with the same medium and usedforfurtheranalysis
    1. Forinfection of THP-1 cells with single C. glabratastrain, PMA-treatedTHP-1 monocytes were seeded in 24 wellcell culture plate toa seeding density of 1 million cells per well. To prepare C. glabratacells for macrophage infection, single colony of the desiredstrain wasinoculated in YPD medium and allowed to grow for 14-16 hat 30°C. C. glabratacellsfrom 1ml overnight culture were harvested, washed with PBS andcell density was adjustedto 2X107cells/ml.50 μl of thisC. glabratacell suspension wasinfectedto macrophages to a MOIof 10:1. Two hours post infection, infected THP-1 macrophages were washed thrice with PBS to removenon-phagocytosed yeast cells and medium was replacedwith fresh prewarmed medium. Atdifferent time points post infection,infected THP-1 macrophages were washed with PBS three timesandlysed in 1 mlsterilewater. Lysates were collected by scrapping the wells with a micropipette tip, diluted in PBS and appropriatelysatedilutions were platedon YPD agar medium. Plates wereincubated at 30°C and colony forming units (CFU) were counted after 1-2 days. Final CFUs per ml were determined by
    2. multiplying CFUs with dilution factor and fold-replication was determined by dividing the CFUs obtained at 24 h time-point by 2 h CFUs
    1. BCA (Bicinchoninic acid) method was used to determine the proteinconcentrationin various samples. The Cu2+ions from cupric sulphate (present inBCA reagent B) reagent arereduced to Cu+by the protein in an alkaline medium. The cuprous ion (Cu+) then combines with BCA (present in BCA reagent A) to give a purple colour whose intensity is proportional to the amount of protein present in the samples. This intensity is measuredby colorimetry at 562 nm. BCA reagent was prepared by mixing reagent A with reagent B in avolumeratio of 50:1. A standard curve was generated using increasing concentrations of BSA (2-10μg) in a 25μl reaction, in a 96 well plate. Cell lysates were also dilutedto same volume in parallel wells. 200μl of BCA reagent was then added to each well and incubated at 370C for 30 minutes. The absorbance readings were then takenin a spectrophotometer at 562 nm. Total protein was quantified by calculation of the slopes of regression lines ofabsorbanceand BSA standards
    1. Table 8: Lipofectamine plasmid-transfection methodology
    2. For transfection with Lipofectamine, cells were plated in antibiotic-free medium 24 h before transfection and were transfected at a confluency of 70-80% as per the manufacturer’s protocol. The plasmid of interest was incubated in serum free media,and Lipofectaminewas incubated in serum free media forseparately5minutes. The plasmid and the Lipofectamine mixtures(Table 8)were mixedgentlyand incubated at room temperature for 20 min.;thetransfection mixture was added dropwise to the cells. Transfection media was replaced with the fresh complete medium after 6 hrs.of transfection and cell are harvested after 24 hours
    1. E.coliDH5α strain was transformed with plasmids carrying appropriate inserts to generate clones, and Xanthomonas deletion strains. Ultracompetent cells stored at -80°C were thawed on ice for 5-10 min. 5 μl ligated plasmid was added to 100 μl ultracompetent cells and incubated on ice for 30 min. Next, competent cells were subjected to heat shock at 42°C for 90 seconds. Cells were immediately transferred on ice for 2-3 min. Next, 1 ml LB medium was added and cells were allowed to recover for 1 h on a shaker incubator set at 37°C. After the recovery, cells were centrifuged at 3000 g for 3 min. Medium supernatant was discarded and cells were resuspended in 100 μl fresh sterile medium. Cells were plated on LB agar containing appropriate antibiotics. Plates were incubated at 37°C for 12-16 h
    1. PMA-treated THP-1 cells were seeded toa24-well tissue culture plate to a cell density of 1 million cells per well and allowed to grow for 12 h. After12 hincubation,spent medium was replaced with fresh pre-warmed RPMI-1640 medium andcells were allowed to recover for 12 h before use.C. glabratacells were grown in YNB medium for 14-16 h at 30°C and 200 rpm. 1 ml of theseC. glabratacells were harvested in 1.5 ml centrifuge tubes, washed twice with 1X sterile PBS and the cell density was adjusted to 2x107cells/ml. 50 μl of this cell suspension was used for infection to a MOI of 1:1. Two hours post infection, wells were washed thricewith 1X sterile PBS to remove the non-phagocytosed yeast cells and 1 ml of fresh pre-warmed RPMI-1640 medium was added. Plates were incubated under tissue culture conditions at 37°C and 5% CO2for 24 h. Supernatants were collected in 1.5 ml microfuge tubes, centrifuged at 3,000 rpmto remove the particulate matter, if any, and stored at -20°C until use. Estimation of different cytokines were performed using BD OptEIA ELISA kits as per the supplier’s instructions