In Vivo Action of Penicillin on Cell Walls of Proteus Mirabilis

1969 ◽  
pp. 208-209
Author(s):  
H. H. Martin
Keyword(s):  
Proteus Mirabilis ◽  
Cell Walls

Varying influence of the autolysin, N-acetyl muramidase, and the cell envelope proteinase on the rate of autolysis of six commercial Lactococcus lactis cheese starter bacteria grown in milk

2000 ◽  
Vol 67 (4) ◽  
pp. 585-596 ◽  
Author(s):  
SELVARANI GOVINDASAMY-LUCEY ◽  
PRAMOD K. GOPAL ◽  
PATRICK A. SULLIVAN ◽  
CHRISTOPHER J. PILLIDGE
Keyword(s):  
Lactococcus Lactis ◽  
Cell Walls ◽  
Cell Envelope ◽  
Laboratory Strain ◽  
Proteolytic Cleavage ◽  
Zymogram Analysis ◽  
Sds Page ◽  
Derivatives Of ◽  
Free Strains

The autolysin, N-acetyl muramidase (AcmA), of six commercial Lactococcus lactis subsp. cremoris starter strains and eight Lc. lactis subsp. cremoris derivatives or plasmid-free strains was shown by renaturing SDS-PAGE (zymogram analysis) to be degraded by the cell envelope proteinase (lactocepin; EC 3.4.21.96) after growth of strains in milk at 30 °C for 72 h. Degradation of AcmA was less in starter strains and derivatives producing lactocepin I/III (intermediate specificity) than in strains producing lactocepin I. This supports previous observations on AcmA degradation in derivatives of the laboratory strain Lc. lactis subsp. cremoris MG1363 (Buist et al. Journal of Bacteriology180 5947–5953 1998). In contrast to the MG1363 derivatives, however, the extent of autolysis in milk of the commercial Lc. lactis subsp. cremoris starter strains in this study did not always correlate with lactocepin specificity and AcmA degradation. The distribution of autolysins within the cell envelope of Lc. lactis subsp. cremoris starter strains and derivatives harvested during growth in milk was compared by zymogram analysis. AcmA was found associated with cell membranes as well as cell walls and some cleavage of AcmA occurred independently of lactocepin activity. An AcmA product intermediate in size between precursor (46 kDa) and mature (41 kDa) forms of AcmA was clearly visible on zymograms, even in the absence of lactocepin I activity. These results show that autolysis of commercial Lc. lactis subsp. cremoris starter strains is not primarily determined by AcmA activity in relation to lactocepin specificity and that proteolytic cleavage of AcmA in vivo is not fully defined.

scholarly journals Interaction of Proteus mirabilis Urease Apoenzyme and Accessory Proteins Identified with Yeast Two-Hybrid Technology

2001 ◽  
Vol 183 (4) ◽  
pp. 1423-1433 ◽  
Author(s):  
Susan R. Heimer ◽  
Harry L. T. Mobley
Keyword(s):  
Proteus Mirabilis ◽  
Accessory Proteins ◽  
Structural Protein ◽  
Yeast Two Hybrid ◽  
Nickel Ions ◽  
Catalytically Active ◽  
Tract Infections ◽  
Two Hybrid

ABSTRACT Proteus mirabilis, a gram-negative bacterium associated with complicated urinary tract infections, produces a metalloenzyme urease which hydrolyzes urea to ammonia and carbon dioxide. The apourease is comprised of three structural subunits, UreA, UreB, and UreC, assembled as a homotrimer of individual UreABC heterotrimers (UreABC)3. To become catalytically active, apourease acquires divalent nickel ions through a poorly understood process involving four accessory proteins, UreD, UreE, UreF, and UreG. While homologues of UreD, UreF, and UreG have been copurified with apourease, it remains unclear specifically how these polypeptides associate with the apourease or each other. To identify interactions among P. mirabilis accessory proteins, in vitro immunoprecipitation and in vivo yeast two-hybrid assays were employed. A complex containing accessory protein UreD and structural protein UreC was isolated by immunoprecipitation and characterized with immunoblots. This association occurs independently of coaccessory proteins UreE, UreF, and UreG and structural protein UreA. In a yeast two-hybrid screen, UreD was found to directly interact in vivo with coaccessory protein UreF. Unique homomultimeric interactions of UreD and UreF were also detected in vivo. To substantiate the study of urease proteins with a yeast two-hybrid assay, previously described UreE dimers and homomultimeric UreA interactions among apourease trimers were confirmed in vivo. Similarly, a known structural interaction involving UreA and UreC was also verified. This report suggests that in vivo, P. mirabilis UreD may be important for recruitment of UreF to the apourease and that crucial homomultimeric associations occur among these accessory proteins.

In vivo determination of fibril orientation in plant cell walls with polarization CSLM

1995 ◽  
Vol 177 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J.-P. VERBELEN ◽  
D. STICKENS
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls

scholarly journals Transcriptome of Proteus mirabilis in the Murine Urinary Tract: Virulence and Nitrogen Assimilation Gene Expression

2011 ◽  
Vol 79 (7) ◽  
pp. 2619-2631 ◽  
Author(s):  
Melanie M. Pearson ◽  
Alejandra Yep ◽  
Sara N. Smith ◽  
Harry L. T. Mobley
Keyword(s):  
Gene Expression ◽  
Urinary Tract ◽  
Glutamate Dehydrogenase ◽  
Proteus Mirabilis ◽  
Transcriptional Analysis ◽  
Broth Culture ◽  
Pathogenic Potential ◽  
Content Type ◽  
Tract Infections

ABSTRACTThe enteric bacteriumProteus mirabilisis a common cause of complicated urinary tract infections. In this study, microarrays were used to analyzeP. mirabilisgene expressionin vivofrom experimentally infected mice. Urine was collected at 1, 3, and 7 days postinfection, and RNA was isolated from bacteria in the urine for transcriptional analysis. Across nine microarrays, 471 genes were upregulated and 82 were downregulatedin vivocompared toin vitrobroth culture. Genes upregulatedin vivoencoded mannose-resistantProteus-like (MR/P) fimbriae, urease, iron uptake systems, amino acid and peptide transporters, pyruvate metabolism enzymes, and a portion of the tricarboxylic acid (TCA) cycle enzymes. Flagella were downregulated. Ammonia assimilation geneglnA(glutamine synthetase) was repressedin vivo, whilegdhA(glutamate dehydrogenase) was upregulatedin vivo. Contrary to our expectations, ammonia availability due to urease activity inP. mirabilisdid not drive this gene expression. AgdhAmutant was growth deficient in minimal medium with citrate as the sole carbon source, and loss ofgdhAresulted in a significant fitness defect in the mouse model of urinary tract infection. UnlikeEscherichia coli, which repressesgdhAand upregulatesglnAin vivoand cannot utilize citrate, the data suggest thatP. mirabilisuses glutamate dehydrogenase to monitor carbon-nitrogen balance, and this ability contributes to the pathogenic potential ofP. mirabilisin the urinary tract.

O-Acetylated peptidoglycan: its occurrence, pathobiological significance, and biosynthesis

1992 ◽  
Vol 38 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Anthony J. Clarke ◽  
Claude Dupont
Keyword(s):  
Cell Walls ◽  
Biological Effects ◽  
Clinical Importance ◽  
Hydroxyl Group ◽  
Human Pathogens ◽  
Structural Units ◽  
Composition And Structure ◽  
And Staphylococcus Aureus

Bacterial cell walls and their structural units, particularly peptidoglycan, induce a vast variety of biological effects in host organisms. The pathobiological effects of peptidoglycan are greatly enhanced by various modifications and substitutions to its basic composition and structure. One such modification is the presence of acetyl moieties at theC-6 hydroxyl group of N-acetylmuramyl residues, and to date, 11 species of eubacteria, including some important human pathogens, such as Neisseria gonorrhoeae, Proteus mirabilis, and Staphylococcus aureus, are known to possess O-acetylated peptidoglycan. This review addresses the influence of O-acetylation of peptidoglycan on its resistance to degradation both in vitro and in vivo, the clinical importance of the modification, and the currently held views on the pathway for its biosynthesis. Key words: peptidoglycan, murein, O-acetylation, lysozyme, arthritis.

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