Gram-negative Bacteria

Gram-negative bacteria are a group of bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation,[1] making positive identification possible.

Medically relevant gram-negative bacilli include a multitude of species. Some of them cause primarily respiratory problems (Hemophilus influenzae, Klebsiella pneumoniae, Legionella pneumophila, Pseudomonas aeruginosa), primarily urinary problems (Escherichia coli, Proteus mirabilis, Enterobacter cloacae, Serratia marcescens), and primarily gastrointestinal problems (Helicobacter pylori, Salmonella enteritidis, Salmonella typhi). Gram-negative bacteria associated with hospital-acquired infections include Acinetobacter baumannii, which cause bacteremia, secondary meningitis, and ventilator-associated pneumonia in hospital intensive-care units.

Digitally-colorized scanning electron micrograph (SEM) depicts a blue-colored, human white blood cell (WBC) known specifically as a neutrophil, interacting with two pink-colored, rod-shaped, multidrug-resistant (MDR) Klebsiella pneumoniae bacteria
Klebsiella pneumoniae which are known to cause severe hospital-acquired, hospital-associated infections.
Source: David Dorward; Ph.D.; National Institute of Allergy and Infectious Diseases (NIAID)



Home Contact RSS