Journal: mSystems
Article Title: Valine potentiates cefoperazone-sulbactam to kill methicillin-resistant Staphylococcus aureus
doi: 10.1128/msystems.01244-24
Figure Lengend Snippet: Antibacterial efficacy by SCF in the absence or presence of valine. ( A ) Percent survival of MRSA2 in the presence of the indicated antibiotics with or without 5 mM valine. SCF, cefoperazone sodium and sulbactam sodium; ASPC, amoxicillin sodium clavulanate potassium. Antibiotic doses are as follows: 200 µg/mL for SCF; 300 µg/mL for ceftriaxone, cefradine, ceftazidime, cefazolin; 150 µg/mL for vancomycin; and 400 µg/mL for the others. ( B ) Percent survival of MRSA2 in the absence or presence of the indicated concentrations of SCF plus 5 mM valine. ( C ) Percent survival of MRSA2 in the absence or presence of the indicated concentrations of valine plus 200 µg/mL SCF. ( D ) Percent survival of MRSA2 in the absence or presence of the indicated incubation time with 5 mM valine and 200 µg/mL SCF. ( E ) Percent survival of 18 MRSA isolates (2.5 × 10 7 CFU/mL) in the absence or presence of 5 mM valine, 200 µg/mL SCF, and both. ( F ) Bacterial load of liver, kidney, and spleen of mice infected with MRSA2. Mice were intraperitoneally infected with 2.5 × 10 6 CFU of MRSA2 and divided into four groups, four male Balb/c mice per group. The four groups were separately intravenously injected with saline solution, 200 mg/kg SCF, 200 mg/kg valine, or both in an hour later. Spleen, kidney, and liver of these treated mice were collected at 24 h and homogenized for spot plate counting. ( G ) Percent survival of mice in the absence or presence of the indicated dose of SCF or/and the indicated dose of valine. Mice were intraperitoneally infected with 2.5 × 10 7 CFU of MRSA2 and divided into eight (sub)groups to be treated as the indicated post 1 h of infection, 10 mice per group. Survival of mice was monitored for 7 days. ( H ) Bacterial load of mouse thigh infected with MRSA2. Mice were intramuscularly infected with 2.8 × 10 5 CFU of MRSA2 and divided into four groups. The four groups were separately treated with saline solution, 200 mg/kg SCF, 200 mg/kg valine, or both post 2 h infection. The thigh muscle infected was collected at 26 h and homogenized for spot plate counting. ( I ) Percent survival of MRSA2 in the absence or presence of 5 mM leucine or isoleucine plus 200 µg/mL SCF. Data are mean ± SD from three biological replicates. *, P < 0.05; **, P < 0.01.
Article Snippet: All antibiotics tested, including vancomycin (glycopeptides), cefoperazone sodium and sulbactam sodium (cephalosporins), daptomycin (cyclic lipopeptides), oxacillin (penicillins) were purchased from Sangon Biotech (BBI) Limited (Shanghai, China).
Techniques: Incubation, Infection, Injection, Saline
