The recent emergence of multidrug resistance (MDR) in Acinetobacter baumannii, a bacteria that causes infections primarily among seriously ill patients in the intensive care unit who may have reduced immune systems, has raised concern in health care settings worldwide.
When comparing the genome sequence of three MDR A. baumannii isolates and three drug-susceptible A. baumannii isolates, Case Western Reserve University School of Medicine found that one variation of bacteria would respond to antibiotics while another variation of the same bacteria may not.
A. baumannii is currently recognized by the Infectious Diseases Society of America as one of the most important pathogens threatening our health care delivery system.
Over the last 10-15 years, A. baumannii has become increasingly resistant to antibiotics and now more than one-third of infections are MDR, which means these pathogens are resistant to at least three different classes of antibiotics. This pattern of resistance to many antibiotics limits the ability of physicians to treat serious infections caused by A. baumannii .
The study, led by Mark Adams, Ph.D., Associate Professor in the Department of Genetics at Case Western Reserve University School of Medicine, is titled "Comparative Genome Sequence Analysis of Multidrug-Resistant Acinetobacter baumannii ", and is in the December issue of the Journal of Bacteriology .
Adams first sequenced the genome of an MDR isolate and his collaborator in Buffalo, Steven Gill, Ph.D., Associate Professor of Oral Biology at SUNY Buffalo, sequenced two drug susceptible isolates to learn more about the genes (the genome contains the complete set of genes) that control resistance to antibiotics. Adams then compared the new sequence with genomes of other MDR and drug susceptible isolates, comparing six complete genomes.
What they found is that within a hospital or even a person, there can be a variation within the bacteria which means that it can affect how the infection reacts to antibiotics.