Increasing threat of Gram-negative bacteria

The widespread use of broad-spectrum antibiotics has led to emergence of an tibiotic-resistant strains of many Gram-negative organisms. This problem is particularly serious in critically ill patients, especially those with ven tilator-associated pneumonia, Extensive antibiotic resistance has developed in Gram-negative bacteria, due both to innate resistance in some species a nd the fact that they are highly adept at acquiring antibiotic-resistant de terminants from each other. Antibiotic resistance develops through the foll owing three basic mechanisms: alteration of the drug target, prevention of drug access to the target (including actively removing the drug from the ba cteria), and drug inactivation. Certain Gram-negative microorganisms are pa rticular problems in the intensive care unit, including Pseudomonas aerugin osa, Acinetobacter spp,, Stenotrophomonas maltophilia, and the Enterobacter iaceae. The combination of an increasing population at risk, and the natura l virulence and adaptability of Gramnegative bacteria guarantees that criti cal care physicians will face a persistent and increasing challenge from th ese pathogens.