Transcription profiling by array of Burkholderia cenocepacia J2315 at the beginning of the stationary phase compared to mid-log phase
ABSTRACT: Burkholderia cenocepacia J2315 was grown at 37 degrees centigrade in LB broth to the beginning of stationary phase (18 hours incubation time). The expression profile was compared to cultures harvested in mid-log phase (7 hours incubation time).
Burkholderia cenocepacia is a Gram-negative aerobic bacterium that belongs to a group of opportunistic pathogens displaying diverse environmental and pathogenic lifestyles. B. cenocepacia is known for its ability to cause lung infections in people with cystic fibrosis and it possesses a large 8 Mb multireplicon genome encoding a wide array of pathogenicity and fitness genes. Transcriptomic profiling across nine growth conditions was performed to identify the global gene expression changes made w ...[more]
Project description:The response of antibiotic adapted resistant mutants of B. cenocepacia J2315 to antibiotic stress was investigated using expression profiling of three biological replicates and comparing the profiles to the J2315 parent control grown without antibiotics.<br>A reference design was used with Cy3 labeled genomic DNA of B. cenocepacia J2315 as common reference. Three test conditions with three biological replicates each were compared to three replicates of the control condition.<br>Test conditions: J2315-A grown in the presence of 250 ug per ml amikacin, J2315-M grown in the presence of 8 ug per ml meropenem and J2315-T grown in the presence of 60 ug per ml trimethoprim and 300 ug per ml sulfamethoxazole.<br>Control condition: J2315 parent strain grown without antibiotics.
Project description:B. cenocepacia J2315 was grown on LB medium to mid-stationary phase at OD 0.3 under full aeration and then transferred into a 50 ml centrifuge tube and placed upright into a CampyGen Compact (Oxoid, Basingstoke, UK) plastic pouch containing the gas generating paper sachet. The pouch was sealed immediately and then the cap of the centrifuge tube loosened to allow exchange of atmosphere between centrifuge tube and pouch. <br>The culture was further incubated at 37 degrees centigrade and 150 rpm for 2-3 hours until it reached OD 0.5. The centrifuge tube was sealed before opening the pouch and then snap-cooled before harvest to minimise exposure to atmospheric oxygen and to ensure expression profiles reflect the lower oxygen concentration.<br>The expression profile was compared to cells grown to OD 0.5 at atmospheric oxygen concentrations.<br>
Project description:B. cenocepacia J2315 was grown on LB medium to mid-stationary phase at O.D. 0.5 at 150 rpm in a shaking incubator at two different temperatures: 37 degrees and 20 degrees centigrade.
Project description:B. cenocepacia J2315 was grown to mid-log phase in different media: LB broth, iso-sensitest broth, basal salt medium with glucose<br>at pH 7 and pH 6, basal salt medium at pH 7 with a reduced iron content, and basal salt medium with glycerol
Project description:Global gene expression in three clinical isolates of the ET12 lineage of Burkholderia cenocepacia was compared by microarray analysis: Strain J2315 (isolated 1989), and strains BCC1616 (HI4277) and BCC1617 (HI4283), both isolated in 2008.
Project description:B. cenocepacia J2315 was exposed to heat stress and to stress form reactive oxygen species. <br>To expose the cultures to heat stress, cells were grown at 37ºC to an O.D. of 0.4 to 0.45 and then transferred into a different shaking incubator at 42.5ºC, incubated for 1 hour at 150 rpm and harvested.<br>To expose cultures to oxidative stress by reactive oxygen species, cells were grown at 37ºC to an OD of 0.5. Then t butyl hydroperoxide or hydrogen peroxide solution were added to the culture at 0.001% and 0.15% final concentration. The culture was further incubated for 15 min and then harvested. <br>The expression profiles were compared to cells grown in LB medium without exposure to stress.<br>