Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biotyping scheme of Baird-Parker was applied to cultures of Staphylococcus epidermidis from patients. In all, 63.6% of 228 cultures belonged to biotype 1, followed by biotypes 4, 3, and 2 in decreasing order of incidence. When classified according to clinical source of isolation, cultures of S. epidermidis were most frequently isolated from urine, with 39.5% of 228 cultures from this source. Each of the four biotypes was distributed throughout all nine catagories of clinical sources. The production of virulence factors was based on the results of three groups of tests: (i) deoxyribonuclease, urease, gelatinase, caseinase, and lysozyme production; (ii) lipolytic activity on the tweens; and (iii) hemolysin production. Enzymatic activity was highest for organisms in biotypes 1, followed by biotypes 3, 4, and 2 in decreasing order. Of the 228 cultures, 76.3% were lysed by lysostaphin. Resistance to antibiotics was highest for tetracycline, ampicillin, and penicillin, with rates of 54.8, 69.3, and 81.6%, respectively. The role of S. epidermidis as an etiological agent was studied by analyzing the laboratory and clinical data of 80 patients selected at random with bacteriuric S. epidermidis. Organisms in biotype 1 were most commonly associated with urinary tract infection. The significance of certain biotypes of S. epidermidis as opportunistic pathogens among compromised hosts in a hospital environment is discussed.
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PMID:Virulence factors of biotypes of Staphylococcus epidermidis from clinical sources. 117 3

It has been hypothesized that urinary urokinase and sialidase may play a role in urolithiasis. If these theories have substance it is to be expected that microorganisms may also affect these enzymes, since the association between urinary tract infection and renal stone formation is well known. It is generally assumed that Proteus mirabilis and Staphylococcus albus, which produce the urea-splitting enzyme urease, are responsible for stone formation. However, the importance of non-urease-producing microorganisms (Escherichia coli and Enterococcus) in urolithiasis is unclear. Spectrophotometric studies were therefore devised to clarify this problem. Microorganisms associated with infection-induced stones (Proteus mirabilis and Escherichia coli) respectively inhibited the urokinase and stimulated the sialidase activity. In contrast, microorganisms which were not associated with infection stones (Bacillus subtilis) had significantly less effect on urokinase and sialidase activity. This study may explain infection-induced stone formation and could open a completely new line of research.
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PMID:Effects of bacteria involved with the pathogenesis of infection-induced urolithiasis on the urokinase and sialidase (neuraminidase) activity. 146 76

The composition of 3,084 urinary calculi was determined using an infrared spectrophotometer. Mixed calcium oxalate-calcium phosphate stones were most frequently implicated. Of the urinary calculi analyzed 199 were associated with urinary tract infection. Escherichia coli was most frequently isolated (43 strains) and urease-producing organisms, such as Proteus mirabilis, were cultured from 40 patients. The core culture of 20 staghorn calculi yielded 15 isolates from 14 stones. There were 13 identical species isolated from the urine and stone specimens of 13 patients (65%), including 7 strains of P. mirabilis. These results suggest that cultures of urine specimens of urolithiasis patients, especially those with staghorn calculi, may help to elucidate the bacteriology of the stones.
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PMID:Composition of urinary calculi related to urinary tract infection. 150 58

Urinary tract infection with Proteus mirabilis may lead to serious complications, including cystitis, acute pyelonephritis, fever, bacteremia, and death. In addition to the production of hemolysin and the enzyme urease, fimbriae and flagellum-mediated motility have been postulated as virulence factors for this species. We purified mannose-resistant/proteuslike (MR/P) fimbriae and flagella from strains CFT322 and HU2450, respectively. Electron microscopy revealed highly concentrated preparations of fimbriae and flagella. Fimbrial and flagellar structural subunits were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 18.5 and 41 kDa, respectively. N-terminal sequencing revealed that 10 of the first 20 amino acids of the major MR/P subunit matched the sequence of the P. mirabilis uroepithelial cell adhesin N terminus and 11 of 20 amino acids matched the predicted amino acid sequence of the Escherichia coli P fimbriae structural subunit, PapA. In addition, 90 and 80% homologies were found between the first 20 amino acids of P. mirabilis flagellin and those of Salmonella typhimurium phase-1 flagellin and the E. coli hag gene product, respectively. An enzyme-linked immunosorbent assay using purified antigens showed a strong reaction between the MR/P fimbriae or flagella and sera of CBA mice challenged transurethrally with P. mirabilis. A possible role for MR/P fimbriae in the pathogenesis of urinary tract infection is supported by (i) a strong immune response to the antigen in experimentally infected animals, (ii) amino acid sequence similarity to other enteric surface structure, and (iii) our previously reported observation that MR/P fimbriae are expressed preferentially as the sole fimbrial type in human pyelonephritis isolates.
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PMID:Proteus mirabilis flagella and MR/P fimbriae: isolation, purification, N-terminal analysis, and serum antibody response following experimental urinary tract infection. 168 Jan 6

By using our new infection stone model of a rat, we evaluated the effect of a novel urease inhibitor, N-(pivaloyl)glycinohydroxamic acid (P-GHA), on the formation of an infection bladder stone. The oral dosing of P-GHA significantly inhibited the elevation of the urinary ammonia level of rats having the urinary tract infection with Proteus mirabilis. A short term regimen (7 d, 730 +/- 38 mg/kg) with P-GHA significantly inhibited the development of the infection bladder stone. Furthermore, a long term combination regimen (11 d) of P-GHA and aminobenzylpenicillin markedly inhibited the development of the infection bladder stone, and also caused a very slight renal impairment to the rats tested in contrast with the method of Vermeulen et al. Our infection stone model in rats, therefore, seems to be useful for the evaluation of therapeutic agents in long term examinations.
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PMID:Evaluation of effects of novel urease inhibitor, N-(pivaloyl)glycinohydroxamic acid on the formation of an infection bladder stone using a newly designed urolithiasis model in rats. 189 94

Proteus mirabilis, a common agent of nosocomially acquired and catheter-associated urinary tract infection, is the most frequent cause of infection-induced bladder and kidney stones. Urease-catalyzed urea hydrolysis initiates stone formation in urine and can be inhibited by acetohydroxamic acid and other structural analogs of urea. Since P. mirabilis urease is inducible with urea, there has been some concern that urease inhibitors actually induce urease during an active infection, thus compounding the problem of elevated enzyme activity. Quantitating induction by compounds that simultaneously inhibit urease activity has been difficult. Therefore, to study these problems, we constructed a fusion of ureA (a urease subunit gene) and lacZ (the beta-galactosidase gene) within plasmid pMID1010, which encodes an inducible urease of P. mirabilis expressed in E. coli JM103 (Lac-). The fusion protein, predicted to be 117 kDa, was induced by urea and detected on Western blots (immunoblots) with anti-beta-galactosidase antiserum. Peak beta-galactosidase activity of 9.9 mumol of ONPG (o-nitrophenyl-beta-D-galactopyranoside) hydrolyzed per min per mg of protein, quantitated spectrophotometrically, was induced at 200 mM urea. The uninduced rate was 0.2 mumol of ONPG hydrolyzed per min per mg of protein. Induction was specific for urea, as no structural analog of urea (including acetohydroxamic acid, hydroxyurea, thiourea, hippuric acid, flurofamide, or hydroxylamine) induced fusion protein activity. These data suggest that induction by inactivation of UreR, the urease repressor protein that governs regulation of the urease operon, is specific for urea and does not respond to closely related structural analogs.
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PMID:Proteus mirabilis urease: use of a ureA-lacZ fusion demonstrates that induction is highly specific for urea. 189 50

An unusual campylobacter strain, a urease positive thermophilic variant of Campylobacter lari, was isolated from the urine of a patient with urinary tract infection who was hospitalized because of cirrhosis and haemorrhage. The strain was isolated from urine specimens on three separate occasions. A significant serological response to the organism was also detected. This is the first documented case of extra-intestinal infection due to this group of organisms.
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PMID:Isolation of a urease positive thermophilic variant of Campylobacter lari from a patient with urinary tract infection. 207 1

Proteus mirabilis, a common cause of urinary tract infection, can lead to serious complications including pyelonephritis. Adherence factors, urease, and hemolysin may be virulence determinants. These factors were compared for bacteria cultured from 16 patients with acute pyelonephritis and 35 with catheter-associated bacteriuria and for 20 fecal isolates. Pyelonephritis isolates were more likely (P less than .05) to express the mannose-resistant/Proteus-like (MR/P) hemagglutinin in the absence of mannose-resistant/Klebsiella-like (MR/K) hemagglutinin than were catheter-associated or fecal isolates. Pyelonephritis isolates produced urease activity of 63 +/- 27 (mean +/- SD) mumol of NH3/min/mg of protein, not significantly different from catheter-associated or fecal isolates. Hybridization of Southern blots of P. mirabilis chromosomal DNA with two urease gene probes demonstrated that urease gene sequences were conserved in all isolates. Geometric mean of reciprocal hemolytic titers for pyelonephritis isolates was 27.9; for urinary catheter isolates, 18.0; and for fecal isolates, 55.7 (not significantly different, P greater than .1). Although in vivo expression of urease and hemolysin may not be reliable indexes of virulence, MR/P hemagglutination in the absence of MR/K hemagglutination may be necessary for development of pyelonephritis.
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PMID:Hemagglutinin, urease, and hemolysin production by Proteus mirabilis from clinical sources. 217 24

Struvite urolithiasis forms as a consequence of a urinary tract infection by urease-producing species of bacteria such as Proteus mirabilis. Ammonia, produced by the enzymatic hydrolysis of urea, elevates urine pH causing a supersaturation and precipitation of Mg++ as struvite (NH4MgPO4). Calcium often precipitates as well, forming the mineral carbonate-apatite (Ca10(PO4)6CO3). We have developed a procedure based on direct observation by light microscopy whereby struvite crystal growth can be quickly monitored in response to chemical changes in urine. As struvite crystals assume a characteristic shape or crystal habit based on their growth rate, the effect of urine chemistry and the action of various crystallization or urease inhibitors on struvite formation can be quickly shown. In addition preliminary effects of alkaline pH, or the presence of toxic compounds on bacteria can also be shown through their loss of motility.
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PMID:A simple technique for studying struvite crystal growth in vitro. 218 Jan 68

In a group of patients consecutively operated on for renal stones, more than half of the patients had urinary tract infection. In a significant number of the patients with infection stones containing magnesium ammonium phosphate, no urease-producing microorganism could be cultured. Escherichia coli was on the other hand rather frequently cultured from the stone in these patients. This suggests the possibility that E. coli might be involved in stone formation. The correlation between stone and voided urine cultures was incomplete. It is thus important to perform stone cultures. This could be done without loss of accuracy by culturing crushed stones.
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PMID:The bacteriology of operated renal stones. 218 Jul 20


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