Proteus mirabilis strains of diverse type have IgA protease activity

Senior, B. W.; Albrechtsen, Merete; Kerr, Michael A.

doi:10.1099/00222615-24-2-175

Cited by 51 publications

(41 citation statements)

References 33 publications

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“…Thus far, several virulence determinants including urease (Griffith et al, 1976;Jones et al, 1990;Johnson et al, 1993b), fimbriae (for review see Mobley & Belas, 1995), flagella (Belas & Flaherty, 1994;Allison et al, 1994;Mobley et al, 1996), haemolysin (Swihart & Welch, 1990;Mobley et al, 1991), IgA protease (Senior et al, 1987(Senior et al, ,1991Loomes et al, 1990;Wassif et al, 1995) and amino acid deaminase (Massad et al, 1995) have been described for this species. The genes encoding these proteins have been isolated and sequenced and some of the corresponding proteins have been purified and characterized.…”

Section: Introductionmentioning

confidence: 99%

Identification of protease and rpoN-associated genes of uropathogenic Proteus mirabilis by negative selection in a mouse model of ascending urinary tract infection

Zhao

Johnson

et al. 1999

Microbiology

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Proteus rnirabilis, a motile Gram-negative bacterium, is a principal cause of urinary tract infections in patients with functional or anatomical abnormalities of the urinary tract or those with urinary catheters in place. Thus far, virulence factors including urease, flagella, haemolysin, various fimbriae, IgA protease and a deaminase have been characterized based on the phenotypic traits conferred by these proteins. In this study, an attempt was made to identify new virulence genes of P. rnirabilis that may not have identifiable phenotypes using the recently described technique of signature-tagged mutagenesis. A pool of chromosomal transposon mutants was made through conjugation and kanamycin/tetracycl ine selection; random insertion was confirmed by Southern blotting of chromosomal DNA isolated from 16 mutants using the aphA gene as a probe. From the total pool, 2.3% (9/397) auxotrophic mutants and 3.5% (14/397) swarming mutants were identified by screening on minimal salts agar and Luria agar plates, respectively. T h i r t y per cent of the mutants, found to have either no tag or an unamplifiable tag, were removed from the input pool. Then lo7 c.f.u. from a 96-mutant pool (-lo5 c.f.u. of each mutant) were used as an input pool to transurethrally inoculate seven CBA mice. After 2 d infection, bacteria were recovered from the bladders and kidneys and yielded about l o 5 c.f.u. as an output pool. Dot blot analysis showed that two of the 96 mutants, designated B2 and B5, could not be hybridized by signature tags amplified from the bladder output pool. Interrupted genes from these two mutants were cloned and sequenced. The interrupted gene in B2 predicts a polypeptide of 37-3 kDa that shares amino acid similarity with a putative protease or collagenase precursor. The gene in B5 predicts a polypeptide of 32-6 kDa that is very similar to that encoded by ORF284 of the rpoN operon controlling expression of nitrogen-regulated genes from several bacterial species. The virulence of the two mutants was tested further by co-challenging CBA mice with each mutant and the parental strain. After 1 week of infection, the B2 and B5 mutants were recovered in numbers 100-fold and 1000-fold less than the parental strain, respectively. Using an in vitro assay, it was shown that the B2 mutant had significantly less (P = O*OOOl) extracellular protease activity than the wild-type strain. These findings demonstrate that signaturetagged mutagenesis is a viable approach to identify bacterial genes associated with the ability to infect the urinary tract.

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Section: Introductionmentioning

confidence: 99%

Identification of protease and rpoN-associated genes of uropathogenic Proteus mirabilis by negative selection in a mouse model of ascending urinary tract infection

Zhao

Johnson

et al. 1999

Microbiology

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“…mirabilis has multiple mechanisms to evade host defenses, including the extracellular metalloprotease ZapA (27,28), also referred to as an IgA protease (24,25). ZapA is expressed in many strains of P. mirabilis (24).…”

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confidence: 99%

Proteus mirabilis ZapA Metalloprotease Degrades a Broad Spectrum of Substrates, Including Antimicrobial Peptides

2004

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The 54-kDa extracellular metalloprotease ZapA is an important virulence factor of uropathogenic Proteus mirabilis. While ZapA has the ability to degrade host immunoglobulins (Igs), the dramatic attenuation of virulence in ZapA mutants suggests that this enzyme may have a broader spectrum of activity. This hypothesis was tested by in vitro assays with purified ZapA and an array of purified protein or peptide substrates. The data reveal that many proteins found in the urinary tract are substrates of ZapA proteolysis, including complement (C1q and C3), cell matrix (collagen, fibronectin, and laminin), and cytoskeletal proteins (actin and tubulin). Proteolysis of IgA and IgG was significantly enhanced by conditions that denatured the Igs. It was discovered that the antimicrobial peptides human ␤-defensin 1 (hBD1) and LL-37 are readily cleaved by the enzyme. To the best of our knowledge, this is the first report of a bacterial protease capable of cleaving hBD1, a component of the human renal tubule innate immune response. Proteolysis of hBD1 resulted in ca. six peptides, while proteolysis of LL-37 resulted in at least nine products. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis of the molecular masses of the reaction products indicated that ZapA preferred no distinct peptide bond. The antimicrobial activity of hBD1 and LL-37 was significantly reduced following ZapA treatment, suggesting that proteolysis results in inactivation of these peptides. The data suggest that a function of ZapA during urinary tract infections is the proteolysis of antimicrobial peptides associated with the innate immune response.

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“…ZapA, an IgA metalloprotease, is considered to be a virulence factor of the opportunistic bacterium P. mirabilis (Senior et al 1987;Phan et al 2008). During swarming behavior, expression of zapA is coordinately upregulated though quorum sensing systems, lon protease and pnitrophenylglycerol (PNPG) (Walker et al 1999;Liaw et al 2000;Clemmer and Rather 2008).…”

Section: Introductionmentioning

confidence: 99%

Cloning, characterization and molecular analysis of a metalloprotease from Proteus mirabilis

2011

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Proteus mirabilis is an important pathogen that is usually found in complicated urinary tracts infection. It possesses a metalloprotease, ZapA, that acts as a virulence factor. The gene encoding ZapA was cloned from P. mirabilis Pm7-a strain isolated from marine environments-and conditionally expressed in Escherichia coli. Zn 2+ and Co 2+ exhibited an apparently positive effect on the enzyme activity of the 54-kDa protease. Ag + , Cd 2+ , Cu 2+ , Hg 2+ , Pb 2+ , EDTA and sulfhydryl reagents including β-mercaptoethanol and dithiothreitol exhibited an apparently negative effect on enzyme activity. Enzyme activity analysis revealed that the optimum temperature and pH for purified recombinant ZapA were approximately 40°C and 8.0, respectively. Enzyme activity and western immunoblotting analysis were used for the determination of the extracellular location of ZapA. The simultaneously depressed expression of zapA and swarming motility of Pm7 in the presence of glucose were determined by real-time PCR and swarming motility measurements, respectively. Furthermore, the outer membrane proteins of two bacteria (Enterobacter sp. T41 and Edwardsiella tarda strain TX1-a fish pathogen) were found to be substrates of ZapA proteolysis.

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Proteus mirabilis strains of diverse type have IgA protease activity

Cited by 51 publications

References 33 publications

Identification of protease and rpoN-associated genes of uropathogenic Proteus mirabilis by negative selection in a mouse model of ascending urinary tract infection

Identification of protease and rpoN-associated genes of uropathogenic Proteus mirabilis by negative selection in a mouse model of ascending urinary tract infection

Proteus mirabilis ZapA Metalloprotease Degrades a Broad Spectrum of Substrates, Including Antimicrobial Peptides

Cloning, characterization and molecular analysis of a metalloprotease from Proteus mirabilis

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