Phosphorus stress induces the synthesis of novel glycolipids in Pseudomonas aeruginosa that confer protection against a last-resort antibiotic

Abstract

Pseudomonas aeruginosa is a nosocomial pathogen with a prevalence in immunocompromised individuals and is particularly abundant in the lung microbiome of cystic fibrosis patients. A clinically important adaptation for bacterial pathogens during infection is their ability to survive and proliferate under phosphorus-limited growth conditions. Here, we demonstrate that P. aeruginosa adapts to P-limitation by substituting membrane glycerophospholipids with sugar-containing glycolipids through a lipid renovation pathway involving a phospholipase and two glycosyltransferases. Combining bacterial genetics and multi-omics (proteomics, lipidomics and metatranscriptomic analyses), we show that the surrogate glycolipids monoglucosyldiacylglycerol and glucuronic acid-diacylglycerol are synthesised through the action of a new phospholipase (PA3219) and two glycosyltransferases (PA3218 and PA0842). Comparative genomic analyses revealed that this pathway is strictly conserved in all P. aeruginosa strains isolated from a range of clinical and environmental settings and actively expressed in the metatranscriptome of cystic fibrosis patients. Importantly, this phospholipid-to-glycolipid transition comes with significant ecophysiological consequence in terms of antibiotic sensitivity. Mutants defective in glycolipid synthesis survive poorly when challenged with polymyxin B, a last-resort antibiotic for treating multi-drug resistant P. aeruginosa. Thus, we demonstrate an intriguing link between adaptation to environmental stress (nutrient availability) and antibiotic resistance, mediated through membrane lipid renovation that is an important new facet in our understanding of the ecophysiology of this bacterium in the lung microbiome of cystic fibrosis patients.

The Proteobacterial Methanotroph Methylosinus trichosporium OB3b Remodels Membrane Lipids in Response to Phosphate Limitation

“…These lipids produce a characteristic neutral loss of 179 in the positive fragmentation by MS n ( Fig. 2C ), consistent with the monoglucosyldiacylglycerol (MGDG) lipid which was identified previously in other bacteria (see, for example, references 17 and 18 ). At approximately 9.5 to 10 min, two lipids with m/z values of 814.6 and 786.6 were found, which showed a neutral loss of 193 when fragmented in the positive mode ( Fig.…”

A Systematic Strategy to Find Potential Therapeutic Targets for Pseudomonas aeruginosa Using Integrated Computational Models

“…In bacteria, phosphonates and organophosphates are viable sources of inorganic phosphate upon the enzymatic activity of alkaline phosphatases (AP). The gene phoA encodes a periplasmic AP, and it is highly expressed under phosphate-limiting conditions, e.g., human airway epithelial infections such as cystic fibrosis (Chekabab, Harel, and Dozois 2014;Jones et al, 2021). In addition, AP seems to contribute to the cell division cycle in a low-phosphate environment, possibly a consequence of its role in the inorganic phosphate scavenge (Bhatti, DeVoe, and Ingram 1976).…”

reComBat: batch-effect removal in large-scale multi-source gene-expression data integration

“…By mining the harmonized data-set, we can now perform comparisons that have, to the best of our knowledge, never been directly performed before for the purpose of hypothesis generation. For instance, when we compare growth in LB with growth in media that have fewer nutrients, we find that several nutrient (Bains et al ., 2012; Ball et al ., 2002; Faure et al ., 2014; Jones et al ., 2021; Lewenza et al ., 2011; Quesada et al ., 2016) and metal (Alontaga et al ., 2009; Merriman et al ., 1995) uptake pathways are deferentially regulated. Experimental validation of the proposed findings is key in confirming information on the underlying biological mechanisms.…”

“…For instance, when we compare growth in LB with growth in media that have fewer nutrients than standard LB, we find that several nutrient uptake pathways are of particular importance. In particular, genes involved in phosphorous uptake and stress (PA0676, PA0680, PA0683, PA0686, PA0690-0693, PA0842, PA3372, PA3375-3376, PA3378-3379, PA3381-3384, PA4350) [5,6,13,23,29,37] and metal uptake (PA2399, PA3407) [1,34] are deferentially regulated. As such, we were able to demonstrate that biologically meaningful information was retained in the harmonised data.…”