One milligram per liter (mg/l) is equal to one part per million (ppm) because one liter of water weighs 1000 grams and one milligram is one one-thousandth of a gram. Therefore, there are 1,000,000 ...

The outer membrane of gram-negative bacteria physically blocks some large, water-hating (hydrophobic) antibiotic molecules, such as vancomycin and rifampicin. Because these treatments are blocked ...