Microorganisms (bacteria, fungi, virus, protozoa, etc.) that cause disease in animals, plants or people. The microorganism causing the infection. Most likely central line-associated blood stream infection (CLABSI) pathogens are coagulase negative staphylococci, Staphylococcus aureus, enterococci, and Candida spp. Approximately 20% of the pathogens are gram negative bacilli. Antibiotic resistance is a problem, particularly in ICU acquired CLABSI. MRSA is significant, though declining. VRE is present. Resistance is increasing in Klebsiella pneumoniae, E. coli, Pseudomonas aeruginosa and Candida spp.