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PubMed1998

Enzyme characteristics of beta-D-galactosidase- and beta-D-glucuronidase-positive bacteria and their interference in rapid methods for detection of waterborne coliforms and Escherichia coli.

Bacteria which were beta-D-galactosidase and beta-D-glucuronidase positive or expressed only one of these enzymes were isolated from environmental water samples. The enzymatic activity of these bacteria was measured in 25-min assays by using the fluorogenic substrates 4-methylumbelliferyl-beta-D-galactoside and 4-methylumbelliferyl-beta-D-glucuronide. The enzyme activity, enzyme induction, and enzyme temperature characteristics of target and nontarget bacteria in assays aimed at detecting coliform bacteria and Escherichia coli were investigated. The potential interference of false-positive bacteria was evaluated. Several of the beta-D-galactosidase-positive nontarget bacteria but none of the beta-D-glucuronidase-positive nontarget bacteria contained unstable enzyme at 44.5 degrees C. The activity of target bacteria was highly inducible. Nontarget bacteria were induced much less or were not induced by the inducers used. The results revealed large variations in the enzyme levels of different beta-D-galactosidase- and beta-D-glucuronidase-positive bacteria. The induced and noninduced beta-D-glucuronidase activities of Bacillus spp. and Aerococcus viridans were approximately the same as the activities of induced E. coli. Except for some isolates identified as Aeromonas spp., all of the induced and noninduced beta-D-galactosidase-positive, noncoliform isolates exhibited at least 2 log units less mean beta-D-galactosidase activity than induced E. coli. The noncoliform bacteria must be present in correspondingly higher concentrations than those of target bacteria to interfere in the rapid assay for detection of coliform bacteria.

Enterobacteriaceae↗
PubMed2001

Ancestral divergence, genome diversification, and phylogeographic variation in subpopulations of sorbitol-negative, beta-glucuronidase-negative enterohemorrhagic Escherichia coli O157.

The O157:H7 lineage of enterohemorrhagic Escherichia coli is a geographically disseminated complex of highly related genotypes that share common ancestry. The common clone that is found worldwide carries several markers of events in its evolution, including markers for acquisition of virulence genes and loss of physiological characteristics, such as sorbitol fermentation ability and beta-glucuronidase production. Populations of variants that are distinct with respect to motility and the sorbitol and beta-glucuronidase markers appear to have diverged at several points along the inferred evolutionary pathway. In addition to these variants, distinct subpopulations of the contemporary non-sorbitol-fermenting, beta-glucuronidase-negative O157:H7 clone were recently detected among bovine and human clinical isolates in the United States by using high-resolution genome comparison. In order to determine if these recently described subpopulations were derived from a regional or ancestral divergence event, we used octamer-based genome scanning, marker sorting, and DNA sequence analysis to examine their phylogenetic relationship to populations of non-sorbitol-fermenting, beta-glucuronidase negative O157:H7 and O157:H- strains from Australia. The inferred phylogeny is consistent with the hypothesis that subpopulations on each continent resulted from geographic spread of an ancestral divergence event and subsequent expansion of distinct subpopulations. Marker sorting and DNA sequence analyses identified sets of monophyletic markers consistent with the pattern of divergence and demonstrated that phylogeographic variation occurred through emergence of regional subclones and concentration of regional polymorphisms among distinct subpopulations. DNA sequence analysis of representative polyphyletic markers showed that genome diversity accrued through random drift and bacteriophage-mediated events.

Animals↗
PubMed1984

Detection of beta-glucuronidase in lactose-fermenting members of the family Enterobacteriaceae and its presence in bacterial urine cultures.

Four hundred strains of lactose-fermenting Enterobacteriaceae were tested for hydrolysis of p-nitrophenyl-beta-D-glucopyranosiduronic acid, the chromogenic enzyme substrate of beta-glucuronidase. Escherichia coli was found to be homogeneous with respect to beta-glucuronidase: more than 94% of the examined E. coli strains were positive, whereas none of the other lactose-fermenting strains possessed beta-glucuronidase activity. The qualitative beta-glucuronidase test, as rapid and simple as the o-nitrophenyl-beta-D-galactopyranosidase test, proved to be of diagnostic value, especially in the identification of E. coli in primary urine cultures. No significant differences were observed in the results of experiments in which either substrate-impregnated disks prepared in the laboratory or commercially available tablets were used.

Bacteriuria↗
PubMed1986

Comparison of beta-glucuronidase-based substrate systems for identification of Escherichia coli.

Methods based on the measurement of beta-glucuronidase have been shown to be specific and inexpensive for the identification of Escherichia coli from bacterial colonies within 1 h. Recently, commercial systems incorporating beta-glucuronidase substrates were introduced. Rapid Identification Method E. coli (Austin Biological Laboratories, Curtin Matheson Scientific, Inc., Houston, Tex.) and Rapid Detect E. coli (Organon Teknika, Morris Plains, N.J.) are single-tube test combinations to simultaneously measure beta-glucuronidase (fluorescence at 366 nm), o-nitrophenyl-beta-D-galactopyranoside (yellow), and indole (red). To determine the accuracy and utility of these two systems, we used them to test 169 E. coli and 150 non-E. coli and compared them with conventional substrate tests. The Rapid Detect test was more efficient than the Rapid Identification Method in demonstrating beta-glucuronidase activity, but the commercial systems were equal to each other and to the conventional tests for o-nitrophenyl-beta-D-galactopyranoside and indole. There were no false reactions by either system.

Enterobacteriaceae↗
PubMed1992

Beta-glucuronidase activities of fecal isolates from healthy swine.

Research has shown that various percentages of fecal Escherichia coli isolates obtained from healthy subjects may be beta-glucuronidase negative. The ability to detect beta-glucuronidase activity among fecal E. coli isolates from healthy subjects may be affected by assay conditions. A study was conducted in which agar and broth media containing 4-methylumbelliferyl-beta-D-glucuronide (MUG) were used to examine beta-glucuronidase activities of fecal isolates from healthy swine. Rectal swabs were plated on MacConkey agar plus 100 mg of MUG per liter (MAC-MUG) and incubated at 35 degrees C for 24 h. Each of 986 isolates picked from MAC-MUG was inoculated into duplicate tubes of lauryl tryptose broth plus 50 mg of MUG per liter (LT-MUG). One set of tubes was incubated at 35 degrees C and the other set of tubes was incubated at 44.5 degrees C. Gas production and hydrolysis of MUG, indicated by fluorescence when observed with UV light with a wavelength of 360 nm, were determined after incubation for 24 and 48 h. A higher percentage (P less than 0.01) of isolates was MUG positive at 44.5 degrees C than at 35 degrees C after 24 h of incubation in LT-MUG. A higher percentage (P less than 0.01) of isolates was MUG positive after 48 h than after 24 h of incubation at both 35 and 44.5 degrees C. A lower percentage of isolates (P less than 0.05) was observed to be MUG positive on MAC-MUG agar compared with their MUG reactions in LT-MUG at 35 and 44.5 degrees C. Approximately 89% of the isolates identified were beta-glucuronidase-positive E. coli. The largest proportion of MUG-positive E. coli was detected with LT-MUG at 35 degrees C after 48 h of incubation.

Animals↗
PubMed1991

Evaluation of beta-glucuronidase assay for the detection of Escherichia coli from environmental waters.

The new United States Drinking Water Regulations state that water systems must analyze for Escherichia coli or fecal coliforms on any routine or repeat sample that is positive for total coliforms. The proposed methods for the detection of E. coli are based on beta-glucuronidase activity, using the fluorogenic substrate 4-methylumbelliferyl beta-D-glucuronide (MUG). This study was conducted to determine whether beta-glucuronidase negative E. coli were present in significant numbers in environmental waters. Two hundred and forty E. coli cultures were isolated from 12 water samples collected from different environmental sources. beta-glucuronidase activity was determined using lauryl tryptose broth with MUG, EC broth with MUG, and the Autoanalysis Colilert (AC) procedure. The isolates were also evaluated by the standard EC broth gas fermentation method for fecal coliforms. The results confirm that assaying for the enzyme beta-glucuronidase utilizing the MUG substrate is an accurate method for the detection of E. coli in environmental waters.

Enterobacteriaceae↗
PubMed1992

Breast milk beta-glucuronidase and exaggerated jaundice in the early neonatal period.

Breast-feeding is associated with jaundice in the early neonatal period. Previous work has shown levels of the enzyme beta-glucuronidase in maternal breast milk to be related to infant serum bilirubin on postnatal day 21. Our aim was to establish if there was a correlation between the level of breast milk beta-glucuronidase and the degree of early (first week) neonatal hyperbilirubinaemia. A study of 55 mother and baby pairs showed that breast milk beta-glucuronidase levels had no relationship with the level of infant serum bilirubin between postnatal days 3 and 6. Breast milk beta-glucuronidase does not directly account for the early neonatal jaundice seen in breast-fed babies.

Bilirubin↗
PubMed1980

Studies on beta-glucuronidase of the developing human placenta.

Subfractional activities and some properties of Beta-glucuronidase were studied at different ontogenetic stages of the human placenta. Maximum activity was localized in the 105,000 g supernatant of tissue homogenate. THe enzyme activity in all fractions increased gradually, being maximum in the placentas of 22-26 weeks of gestation. At term, Beta-glucuronidase activity had diminished to a great extent. The enzyme showed considerable stability after heating at 65 C for 10 min. The Km value of this enzyme for p-nitrophenyl-Beta-D-glucuronide was 1.02 mM. EDTA inhibited placental Beta-glucuronidase. Of the cations tested, Ag+, Fe++ and Co++ were stimulatory, while Zn++ was inhibitory to the enzyme. Only one isoenzyme of Beta-glucuronidase was found in human placenta.

Female↗
PubMed1979

Interference of UDP-glucuronyltransferase and beta-glucuronidase activity in rat liver microsomes at pH 7.5 with p-nitrophenol and p-nitrophenylglucuronide as substrates.

Microsomal fraction contains the whole of hepatic UDP-glucuronyltransferase as well as part of beta-glucuronidase. The activities of the two enzymes were assayed under identical conditions using untreated male rat liver microsomes at pH 7.5. In a 30-min incubation with p-nitrophenol and UPD-glucuronic acid, a net glucuronide formation of 0.010 mumol.min-1.g.liver-1 was measured. In the presence of saccharolactone at concentrations selectively blocking beta-glucuronidase, the glucuronidation rate was 0.015 mumol.min-1.g.liver-1. Using the kinetic parameters of beta-glucuronidase (Km = 0.06 mmol/l p-nitrophenylglucuronide, Vm = 0.075 mumol pNP formed.h-1.g.liver-1) determined in the absence of UDP-glucuronic acid, to correct for the beta-glucuronidase's interference on the glucuronidation process, a glucuronide formation of 0.011 mumol.min-1.g.liver-1 was calculated.

Animals↗
PubMed1989

Characterization of the defective beta-glucuronidase activity in canine mucopolysaccharidosis type VII.

Canine mucopolysaccharidosis type VII results from deficient activity of lysosomal beta-glucuronidase. Residual enzymatic activity (0.2-1.7% of normal) was detected in tissue homogenates from affected dogs. In contrast, serum and urine from affected animals had up to 15% residual activity. To further characterize the nature of the defective enzyme, hepatic beta-glucuronidase was partially purified from normal and MPS VII dogs for determination of their physical and kinetic properties. About 65% of the total beta-glucuronidase in normal canine liver required detergent for solubilization (i.e., membrane-associated), whereas only 22% of the residual activity in canine MPS VII liver was membrane-associated. Compared to the normal hepatic enzyme, the Km towards 4-methylumbelliferyl-beta-glucuronide was markedly increased in MPS VII dogs (i.e., 0.48 versus greater than 2.5 mmol/l). In contrast, the thermo-, cryo-, and pH stability properties, as well as the pH optimum (approximately 4.6), were essentially unaffected. In addition, the canine MPS VII hepatic residual activity was unresponsive to sulfhydryl reducing reagents and divalent cations, despite the fact that incubation of normal canine beta-glucuronidase with dithiothreitol and magnesium and/or calcium enhanced the activity more than 15-fold.

Animals↗
PubMed1989

Murine mucopolysaccharidosis type VII. Characterization of a mouse with beta-glucuronidase deficiency.

We have characterized a new mutant mouse that has virtually no beta-glucuronidase activity. This biochemical defect causes a murine lysosomal storage disease that has many interesting similarities to human mucopolysaccharidosis type VII (MPS VII; Sly syndrome; beta-glucuronidase deficiency). Genetic analysis showed that the mutation is inherited as an autosomal recessive that maps to the beta-glucuronidase gene complex, [Gus], on the distal end of chromosome 5. Although there is a greater than 200-fold reduction in the beta-glucuronidase mRNA concentration in mutant tissues, Southern blot analysis failed to detect any abnormalities in the structural gene, Gus-sb, or in 17 kb of 5' flanking and 4 kb of 3' flanking sequences. Surprisingly, a sensitive S1 nuclease assay indicated that the relative level of kidney gusmps mRNA responded normally to androgen induction by increasing approximately 11-fold. Analysis of this mutant mouse may offer valuable information on the pathogenesis of human MPS VII and provide a useful system in which to study bone marrow transplantation and gene transfer methods of therapy.

Alleles↗
PubMed1986

Reduced activity of serum beta-glucuronidase in Marfan syndrome.

Reduced activity of serum beta-glucuronidase (EC 3.2.1.31) was found in three patients with Marfan syndrome, two of whom were siblings. The serum beta-glucuronidase levels in the patients ranged from 294 to 439 micrograms (360.7 +/- 73.2, mean +/- SD) of the released P-nitrophenol/100 ml of serum/hour, whereas those of 7 healthy subjects ranged from 564 to 1445 micrograms (836.4 +/- 287.3). This difference was statistically significant (p less than 0.01). Plasma glycosaminoglycan levels in the patients were lower than those in the healthy subjects, owing mainly to the differences in plasma high-sulfated glycosaminoglycan. The correlation coefficients of serum beta-glucuronidase activity with high-sulfated and total plasma glycosaminoglycans were 0.794 and 0.809, respectively (p less than 0.01 and p less than 0.005, respectively). The results suggest that the decreased plasma high-sulfated glycosaminoglycan levels in Marfan syndrome are due to the reduction of serum beta-glucuronidase, which leads to the decreased degradation of macromolecules and, subsequently, the accumulation of the glycosaminoglycans in the tissues.

Adolescent↗
PubMed1999

Enzyme replacement in murine mucopolysaccharidosis type VII: neuronal and glial response to beta-glucuronidase requires early initiation of enzyme replacement therapy.

We have previously shown that mucopolysaccharidosis type VII (MPS VII) mice receiving six weekly injections of recombinant beta-glucuronidase from birth had improved cognitive ability and reduced central nervous system lysosomal storage. However, a single beta-glucuronidase injection at 5 wk of age did not correct neuronal storage. We define the age at which central nervous system storage in MPS VII mice becomes resistant to beta-glucuronidase therapy and determine the effect of enzyme on other tissues by comparing the histology of mice begun on therapy at various times after birth. MPS VII mice received injections on the day of birth and then weekly for 5 wk with 16,000U/g beta-glucuronidase had reduced lysosomal storage in brain. The same therapy begun on d 14 of life or thereafter failed to correct neuronal storage, even when treatment was continued for six doses. Glial responsiveness or accessibility to enzyme also depended on early treatment. In contrast, leptomeningeal, osteoblast, and retinal pigment epithelial storage reduction depended on enzyme dose rather than age at initiation of therapy. Fixed tissue macrophage storage was reduced in all treated MPS VII mice, even those receiving a single dose. These observations indicate that fixed tissue macrophages in MPS VII mice remain sensitive to enzyme replacement therapy well into adulthood although neurons are responsive or accessible to enzyme therapy early in life. Because early initiation of enzyme replacement is important to achieve a central nervous system response, these studies emphasize the importance of newborn screening for lysosomal storage diseases so that early treatment can maximize the likelihood of a favorable therapeutic response.

Anaphylaxis↗
PubMed1999

Flaxseed and lignans increase cecal beta-glucuronidase activity in rats.

Flaxseed has been shown in previous studies to decrease some early markers of colon cancer risk in part because of its lignans. This study determined whether the intake of flaxseed and lignans is related to the activity of bacterial beta-glucuronidase, an enzyme suggested to increase colon cancer risk. Seven groups of six female rats each were fed, for four weeks, a basal high-fat (20%) diet (BD), BD supplemented with 2.5%, 5.0%, or 10.0% flaxseed, or BD with daily gavage of 0.75, 1.5, or 3.0 mg of secoisolariciresinol diglycoside (SDG), the major mammalian lignan precursor. The specific and total activities of beta-glucuronidase in the cecum were significantly related to the levels of flaxseed (r = 0.539, p < 0.008 and r = 0.599, p < 0.002, respectively) and SDG (r = 0.567, p < 0.007 and r = 0.435, p < 0.04, respectively). The urinary mammalian lignan excretion also increased with increasing flaxseed or SDG levels and thus was significantly related to the specific activity (r = 0.38, p < 0.017) and total activity (r = 0.429, p < 0.007) of beta-glucuronidase. Because flaxseed and lignans are colon cancer protective, it is concluded that, in contrast to other studies, beta-glucuronidase activity may play a beneficial role in their presence by increasing mammalian lignan absorption and enterohepatic circulation.

Animals↗
PubMed1994

Characterization of beta-glucosidase and beta-glucuronidase of alkalotolerant intestinal bacteria.

The number of alkalotolerant intestinal bacteria was 1% of the total flora in humans and 0.8% of those in rats. The beta-glucosidase and beta-glucuronidase activity of these intestinal bacteria was induced by elevating the pH of the medium, but the growth was not changed. The enzyme activity in a medium of pH 7 was 5- to 10-fold higher than that in a medium of pH 6. Isolated bacteria from human and rat feces were cultured in a pH 5 general anaerobic medium (GAM) broth to reach a stationary phase, then the pH of the media was changed from 5 to 8. Both beta-glucosidase and beta-glucuronidase were increased 9.2-12.1-fold. The activity of these enzymes was also increased 2-16-fold by adding substrates (p-nitrophenyl-beta-D-glucuropyranoside or p-nitrophenyl-beta-D-glucuronide). beta-Glucuronidase(s) was inhibited by saccharic acid 1,4-lactone or D-glucuronic acid. However, when lactulose was added to the medium, and then intestinal microflora were inoculated in the medium, the productivity of these enzymes dramatically decreased. We thus contend that the induction of the beta-glucosidase and beta-glucuronidase of intestinal bacteria by a high pH can cause colorectal cancer.

Adult↗
PubMed2000

Effects of glycyrrhizin and glycyrrhetic acid on the growth, glycyrrhizin beta-D-glucuronidase and 3 beta-hydroxysteroid dehydrogenase of human intestinal bacteria.

The peak of glycyrrhizin (GL) beta-D-glucuronidase activity for Ruminococcus sp. PO1-3 and Eubacterium sp. GLH changed to 24 h from 12 h of culture and to 12 h from 48 h, respectively, at almost the same level by the addition of 1.0 mM GL. This enzyme activity was about 20-fold higher in Eubacterium sp. GLH than in Ruminococcus sp. PO1-3. GL beta-D-glucuronidase activity of Ruminococcus sp. PO1-3 with Eubacterium sp. GLH and the intestinal flora showed a maximal peak at 12 h of culture in the presence and absence of 1.0 mM GL. This enzyme activity was about 2.5-fold higher in mixed bacteria than in intestinal flora. 3Beta-hydrosteroid dehydrogenase activity of Ruminococcus sp. PO1-3 and Ruminococcus sp. PO1-3 with Eubacterium sp. GLH was suppressed greater in the presence of GL than without GL. Also, Ruminococcus sp. PO1-3, Eubacterium sp. GLH, and a mixture of both and intestinal flora, metabolized 1.0 mM GL to glycyrrhetic acid (GA) in yields of about 10, 70, 40 and 100%, respectively, with 24 h culture. From the level of GL beta-D-glucuronidase activity, it is considered that the metabolism of GL by intestinal flora is due to both enzymatic and non-enzymatic reactions. Moreover, GA at a concentration of 1.0 mM suppressed growth of Ruminococcus sp. PO1-3, Eubacterium sp. GLH, and the mixture of both and intestinal flora, which metabolized 1.0 mM GA to a negligible amount of 3-oxo-glycyrrhetic acid, indicating the accumulation of unchanged GA. GL beta-D-glucuronidase activity of intestinal flora was enhanced by GA, which stimulated bacteria possessing particular this characteristic.

3-Hydroxysteroid Dehydrogenases↗
PubMed1997

The role of microsomal beta-glucuronidase in ascorbic acid biosynthesis stimulated by xenobiotics in rats.

We (Horio et al., 1993) have reported that the stimulation of the expression of the UDPglucuronosyltransferase (UDPGT) gene played a key role in the ascorbic acid biosynthesis induced by xenobiotics, such as 3-methylcholanthrene (3MC) and phenobarbital (PB). beta-Glucuronidase catalyzes the hydrolysis of glucuronide formed by UDPGT. The role of microsomal beta-glucuronidase in ascorbic acid biosynthesis induced by xenobiotics was investigated using homozygous and heterozygous EHBRs (Eisai hyperbilirubinuria rats) which are deficient in microsomal beta-glucuronidase. Homozygous EHBRs, heterozygous EHBRs, and Sprague Dawley (SD) rats were injected intraperitoneally once with 3MC (20 mg/kg body weight), or once a day for 2 d with PB (100 mg/day kg body weight). In these three strains of rats, the hepatic level of xenobiotics-inducible UDPGT mRNA was elevated similarly by the treatment with xenobiotics. The increases of the hepatic concentration of ascorbic acid and the urinary excretion of ascorbic acid by the treatment with 3MC or PB were markedly suppressed in both EHBRs compared with those in the control SD rats. These results indicate that the microsomal beta-glucuronidase has an important role in the hepatic ascorbic acid biosynthesis induced by xenobiotics.

Animals↗
PubMed2006

Optimization of an enzymatic method for the determination of lysosomal N-acetyl-beta-D-hexosaminidase and beta-glucuronidase in synovial fluid.

BACKGROUND: Our goal was to develop a suitably sensitive assay for N-acetyl-beta-D-hexosaminidase (HEX) and beta-glucuronidase to allow their use as markers of joint diseases. METHODS: We optimized a spectrophotometric method for the determination of lysosomally derived HEX and beta-glucuronidase in synovial fluid on a microplate reader to improve its utility. HEX and beta-glucuronidase act on the 4-nitrophenyl derivatives N-acetyl-beta-glucosamine and beta-D-glucuronide, respectively, to produce 4-nitrophenol, which can be measured at 405 nm on a microplate reader. RESULTS: Maximum enzyme activity was observed at pH 4.7 in a citrate-phosphate buffer for HEX and at pH 4.5 in an acetate buffer for beta-glucuronidase. A 10-microL sample with 30 microL of substrate solution and 40 microL of appropriate buffer produced measurable amounts of 4-nitrophenol after incubation for 60 min at 37 degrees Celsius. Reactions were terminated by the addition of 200 microL of 200 mM borate buffer (pH 9.8). CONCLUSIONS: The assay is sufficiently sensitive for small volumes of synovial fluid, and is useful for the clinical diagnosis of joint diseases.

Aged↗