Klebsiella is a type of bacterium that commonly causes pneumonia and other infections in the urinary tract, bloodstream, and lungs. However, there are several synonyms used to refer to Klebsiella, including Friedländer's bacillus, Klebsiella pneumoniae, and Klebsiella granulomatis. Each of these terms refers to different strains of the bacterium, and the symptoms they cause can vary. Despite their differences, all Klebsiella strains are commonly treated with antibiotic drugs, although some strains may be resistant to certain types of antibiotics. As with any bacterial infection, early diagnosis and prompt treatment are essential for effective management of the condition.