Human serum albumin alters specific genes that can play a role in survival and persistence in Acinetobacter baumannii

RODMAN, N; MARTINEZ, J; CANTERA, V; IRIARTE, A.; QUIIN, B; FERNANDEZ J S; MONTAÑA, S.; BONOMO, RA; JARA, E; TRAGLIA G; PLACE, K.; RAMIREZ MS

Scintific Reports

Scientific reports

Año: 2018

2045-2322

In the past few decades Acinetobacter baumannii has emerged as a notorious nosocomial pathogenbecause of its ability to acquire genetic material and persist in extreme environments. Recently,human serum albumin (HSA) was shown to significantly increase natural transformation frequencyin A. baumannii. This observation led us to perform transcriptomic analysis of strain A118 under HSAinduction to identify genes that are altered by HSA. Our results revealed the statistically significantdifferential expression of 296 protein-coding genes, including those associated with motility, biofilmformation, metabolism, efflux pumps, capsule synthesis, and transcriptional regulation. Phenotypicanalysis of these traits showed an increase in surface-associated motility, a decrease in biofilmformation, reduced activity of a citric acid cycle associated enzyme, and increased survival associatedwith zinc availability. Furthermore, the expression of genes known to play a role in pathogenicity andantibiotic resistance were altered. These genes included those associated with RND-type efflux pumps,the type VI secretion system, iron acquisition/metabolism, and ß-lactam resistance. Together, theseresults illustrate how human products, in particular HSA, may play a significant role in both survival andpersistence of A. baumannii.