Targeted mutagenesis of the phospholipase D gene results in decreased virulence ofCorynebacterium pseudotuberculosis

Abstract

The chromosomal gene encoding the phospholipase D from Corynebacterium pseudotuberculosis (biovar ovis) isolate Whetten 1 was replaced with an allele containing a nonsense mutation. The virulence of the mutant strain (W1.31r1) and the isogenic parental strain were then compared by inoculation of goats. The wild-type strain caused abscessation at the site of infection, which then spread to the regional lymph node, while W1.31r1 had a reduced ability to establish a primary infection and was incapable of dissemination. Our results confirm that phospholipase D is a virulence determinant of C. pseudotuberculosis that increases the persistence and spread of the bacteria within the host.

Spider and Bacterial Sphingomyelinases D Target Cellular Lysophosphatidic Acid Receptors by Hydrolyzing Lysophosphatidylcholine

“…A SMaseD-deficient mutant of C. pseudotuberculosis is unable to disseminate from the site of inoculation (13), and a popular theory is that vascular hyperpermeability caused by SMaseD, shown here to be likely a result of LPA production, aids in the escape of bacteria into the lymphatic system and subsequent spread to regional lymph nodes (44).…”

“…C. pseudotuberculosis causes lymphadenitis in animals but is also pathogenic for humans, while C. ulcerans and A. hemolyticum are pathogens of pharyngitis and other human infections (11); in no case is the molecular basis for virulence known (12). The SMaseD from C. pseudotuberculosis, also named SM-specific phospholipase D (PLD), is an essential virulence determinant that contributes to the persistence and spread of the bacteria within the host (13). The Loxosceles and C. pseudotuberculosis SMases D have the same molecular mass (31-32 kDa) and share about 30% sequence similarity (see "Results").…”

Corynebacterium pseudotuberculosis: microbiology, biochemical properties, pathogenesis and molecular studies of virulence

“…This analog protein, though inactive, still had immunological activity [49]. Hodgson et al [51] and McNamara et al [68] used site-specific mutagenesis to produce pld mutants that had reduced ability to establish infection and were unable to disseminate in sheep and goats.…”

Recent Advances in the Immunopathogenesis of Acinetobacter baumannii Infection

“…A similar mutagenesis study using serum sensitivity as the readout and pneumonia as the validation step identified phospholipase D (PLD) as a bona fide virulence factor (47). Interestingly, PLD www.intechopen.com is also associated with virulence in Neisseria gonorrhoeae (48) and Corynebacterium pseudotuberculosis (49). Hence this enzyme could be used as a drug target for the design of novel antimicrobials.…”