Pseudomonas aeruginosa Phospholipases and Phospholipids

Vasil, Michael L.

doi:10.1007/0-387-28881-3_3

Cited by 16 publications

(31 citation statements)

References 88 publications

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“…aeruginosa produces a number of well-characterized virulence factors that facilitate the establishment of infections. Hemolytic phospholipase C (PlcH) is a secreted hydrolase that degrades host-associated phosphatidylcholine (PC) and sphingomyelin (4)(5)(6). These choline-containing phospholipids are abundant macromolecules in eukaryotic membranes and host lung surfactant.…”

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Anr and Its Activation by PlcH Activity in Pseudomonas aeruginosa Host Colonization and Virulence

et al. 2013

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bPseudomonas aeruginosa hemolytic phospholipase C (PlcH) degrades phosphatidylcholine (PC), an abundant lipid in cell membranes and lung surfactant. A ⌬plcHR mutant, known to be defective in virulence in animal models, was less able to colonize epithelial cell monolayers and was defective in biofilm formation on plastic when grown in lung surfactant. Microarray analyses found that strains defective in PlcH production had lower levels of Anr-regulated transcripts than the wild type. PC degradation stimulated the Anr regulon in an Anr-dependent manner under conditions where Anr activity was submaximal because of the presence of oxygen. Two PC catabolites, choline and glycine betaine (GB), were sufficient to stimulate Anr activity, and their catabolism was required for Anr activation. The addition of choline or GB to glucose-containing medium did not alter Anr protein levels, growth rates, or respiratory activity, and Anr activation could not be attributed to the osmoprotectant functions of GB. The ⌬anr mutant was defective in virulence in a mouse pneumonia model. Several lines of evidence indicate that Anr is important for the colonization of biotic and abiotic surfaces in both P. aeruginosa PAO1 and PA14 and that increases in Anr activity resulted in enhanced biofilm formation. Our data suggest that PlcH activity promotes Anr activity in oxic environments and that Anr activity contributes to virulence, even in the acute infection phase, where low oxygen tensions are not expected. This finding highlights the relationships among in vivo bacterial metabolism, the activity of the oxygen-sensitive regulator Anr, and virulence.

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Anr and Its Activation by PlcH Activity in Pseudomonas aeruginosa Host Colonization and Virulence

et al. 2013

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“…aeruginosa secretes two PLCs from the acid phosphatase superfamily, PlcN and PlcH/PlcS (Table 5), via the twin-arginine translocation (Tat) and type II Xcp-dependent systems (246). PlcN hydrolyzes PC and PS, but not SM, and is nonhemolytic (247), whereas PlcH hydrolyzes PC, SM, and lyso-PC at equal rates (248) and also acts on cardiolipin, PE, and PG (249). P. aeruginosa PlcH, which is expressed during lung infections in humans (250), is hemolytic to human erythrocytes (26) and selectively cytotoxic to endothelial cells (248).…”

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confidence: 99%

Bacterial Sphingomyelinases and Phospholipases as Virulence Factors

Flores-Dı́az

Monturiol-Gross

Naylor

et al. 2016

Microbiol Mol Biol Rev

173

143

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SUMMARYBacterial sphingomyelinases and phospholipases are a heterogeneous group of esterases which are usually surface associated or secreted by a wide variety of Gram-positive and Gram-negative bacteria. These enzymes hydrolyze sphingomyelin and glycerophospholipids, respectively, generating products identical to the ones produced by eukaryotic enzymes which play crucial roles in distinct physiological processes, including membrane dynamics, cellular signaling, migration, growth, and death. Several bacterial sphingomyelinases and phospholipases are essential for virulence of extracellular, facultative, or obligate intracellular pathogens, as these enzymes contribute to phagosomal escape or phagosomal maturation avoidance, favoring tissue colonization, infection establishment and progression, or immune response evasion. This work presents a classification proposal for bacterial sphingomyelinases and phospholipases that considers not only their enzymatic activities but also their structural aspects. An overview of the main physiopathological activities is provided for each enzyme type, as are examples in which inactivation of a sphingomyelinase- or a phospholipase-encoding gene impairs the virulence of a pathogen. The identification of sphingomyelinases and phospholipases important for bacterial pathogenesis and the development of inhibitors for these enzymes could generate candidate vaccines and therapeutic agents, which will diminish the impacts of the associated human and animal diseases.

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“…Washed bacterial cells alone caused low cell lysis (4.9% for Pseudomonas aeruginosa D183 cells and 16.5% for Bacillus cereus D101 cells); however, when partially purified PLC was added, a concentration-dependent increase in cell lysis (6) reported that it is extremely unlikely that the cytotoxicity of PLC is solely due to its ability to hydrolyze phospholipids. He presented data indicating that not only is the hemolytic PLC (PlcH) of Pseudomonas aeruginosa cytotoxic to live eukaryotic cells, it is selectively toxic (i.e.…”

Section: Effect On Mammalian Cell Lysismentioning

confidence: 99%

Phospholipases C from Pseudomonas aeruginosa and Bacillus cereus isolates, chromosome-mediated enzymes with roles in virulence

Elleboudy¹,

Aboulwafa²,

Hassouna³

2013

Turk J Biol

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Phospholipases C (PLCs) from Pseudomonas aeruginosa D183 and Bacillus cereus D101, 2 clinical isolates from 2 pus specimens, were partially purified by ammonium sulfate precipitation followed by dialysis and used to study the possible role of PLC in the virulence of the isolates. Partially purified PLC from both isolates induced lysis of Vero cells in the presence and absence of the producing bacterial cells. Noncytolytic dilutions of the partially purified PLC from Pseudomonas aeruginosa increased adherence of the producing cells to Vero cells but did not affect internalization. However, Bacillus cereus cells neither adhered to nor were internalized within the Vero cells in the presence or absence of noncytolytic dilutions of partially purified PLC from the isolate. Both PLC preparations were hemolytic to human red blood cells but did not induce human platelet aggregation. Thus, we can conclude that PLCs from Pseudomonas aeruginosa and Bacillus cereus are important virulence factors. PLC production by the 2 isolates was found to be chromosomal-mediated rather than plasmid-mediated.

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Pseudomonas aeruginosa Phospholipases and Phospholipids

Cited by 16 publications

References 88 publications

Anr and Its Activation by PlcH Activity in Pseudomonas aeruginosa Host Colonization and Virulence

Anr and Its Activation by PlcH Activity in Pseudomonas aeruginosa Host Colonization and Virulence

Bacterial Sphingomyelinases and Phospholipases as Virulence Factors

Phospholipases C from Pseudomonas aeruginosa and Bacillus cereus isolates, chromosome-mediated enzymes with roles in virulence

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