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 results of the in vitro metronidazole resistance on Helicobacter pylori (H. pylori) eradication have been inconclusive. Metronidazole resistance varies among different geographical locations and a previous study from Thailand reported an in vitro metronidazole resistance of H. pylori of 51 per cent. This study was designed to investigate further the effect of the in vitro metronidazole resistance on the outcome of eradication of H. pylori in the Thai population. Fifty two patients with active gastric ulcer (GU) and duodenal ulcer (DU) who had positive culture for H. pylori were studied. All of these patients had positive rapid urease test (CLO test, Delta West, Australia) using gastric biopsy specimens from the antrum and body taken at the time of initial upper endoscopy. In vitro antimicrobial susceptibility test was performed using Epsilometer test (AB Biodisk, Solna, Sweden). All patients received a one-week triple regimen consisting of omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, metronidazole 500 mg twice daily. Patients with GU continued with another five weeks of omeprazole 20 mg twice daily and patients with DU received another three weeks of omeprazole 20 mg twice daily. Upper endoscopy was repeated at four weeks after the end of the treatment. Three antral and two body biopsy specimens were obtained for identification of H. pylori using CLO test, histology (modified Giemsa stain) and culture. All of these tests had to be negative to confirm a successful eradication. Metronidazole-resistant (MR) strains with MIC > or = 32 mg/l were identified in 27 of the 52 patients (51.92%), whereas, metronidazole-susceptible (MS) strains were isolated from 25 patients (48.08%). Five patients were lost to follow-up and one patient had drug allergy. Successful eradication as defined by negative CLO test, histology and culture was attained in 17/23 (73.91%) patients (GU = 6, DU = 16, GU and DU = 1) with MR strains. 20 out of 23 (86.96%) patients (GU = 9, DU = 12 GU and DU = 2) who had MS strains. The difference was not statistically significant in both groups (P > 0.05). The ulcer healing was, however, highly achieved in both groups (MS = 95.65%, MR = 91.30%, P > 0.05). In vitro metronidazole resistance was high in this population group although this does not predict the outcome of eradication in patients with GU and DU.
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PMID:Eradication rates of Helicobacter pylori between metronidazole-sensitive and metronidazole-resistant strains with metronidazole containing regimen in Thai patients with peptic ulcer disease. 1152 78

Strains of Escherichia coli causing enterohemorrhagic colitis belonging to the O157:H7 lineage are reported to be highly related. Fifteen strains of E. coli O157:H7 and 1 strain of E. coli O46:H(-) (nonflagellated) were examined for the presence of potassium tellurite resistance (Te(r)). Te(r) genes comprising terABCDEF were shown previously to be part of a pathogenicity island also containing integrase, phage, and urease genes. PCR analysis, both conventional and light cycler based, demonstrated that about one-half of the Te(r) E. coli O157:H7 strains (6 of 15), including the Sakai strain, which has been sequenced, carried a single copy of the Te(r) genes. Five of the strains, including EDL933, which has also been sequenced, contained two copies. Three other O157:H7 strains and the O46:H(-) strain did not contain the Te(r) genes. In strains containing two copies, the Te(r) genes were associated with the serW and serX tRNA genes. Five O157:H7 strains resembled the O157 Sakai strain whose sequence contained one copy, close to serX, whereas in one isolate the single copy was associated with serW. There was no correlation between Te(r) and the ability to produce Shiga toxin ST1 or ST2. The Te(r) MIC for most strains, containing either one or two copies, was 1,024 micro g/ml, although for a few the MIC was intermediate, 64 to 128 micro g/ml, which could be increased to 512 micro g/ml by pregrowth of strains in subinhibitory concentrations of potassium tellurite. Reverse transcriptase PCR analysis confirmed that in most strains Te(r) was constitutive but that in the rest it was inducible and involved induction of terB and terC genes. Only the terB, -C, -D, and -E genes are required for Te(r). The considerable degree of homology between the ter genes on IncH12 plasmid R478, which originated in Serratia marcescens, and pTE53, from an E. coli clinical isolate, suggests that the pathogenicity island was acquired from a plasmid. This work demonstrates diversity among E. coli O157:H7 isolates, at least as far as the presence of Te(r) genes is concerned.
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PMID:Genomic variability of O islands encoding tellurite resistance in enterohemorrhagic Escherichia coli O157:H7 isolates. 1216 92

Flavonoids, which are main constituents of herbal medicines, have been reported to inhibit the growth of Helicobacter pylori (HP). Therefore, to evaluate the anti-HP activity of some flavonoids (flavanols, flavones, flavonols and isoflavonoids), their effects on the growth and vacuolation of HP as well as the infective properties of HP against HeLa cells were investigated. Catechins, quercetin and naringenin weakly inhibited the growth of HP, but all tested compounds did not inhibit HP infection into KATO III cells and HP urease activity. Quercetin and naringenin inhibited HP VacA vacuolation in HeLa cells with IC (50) values of 0.046 and 0.36 mM, respectively. Quercetin also inhibited procaspase-3 activation to caspase-3 in HeLa cells induced by HP VacA toxin, which may induce cell death via the proteolytic activation of a cascade of caspases. However, quercetin did not affect Bax and Bcl-2 protein levels. Based on these findings, quercetin may improve gastric cell death by inhibiting apoptotic signaling by HP VacA toxin. Abbreviations. HP: Helicobacter pyloriBSA:bovine serum albumin ESL:enhanced chemiluminescence MIC:minimum inhibitory concentration MTT:methylthiazolyldiphenyl-tetrazolium bromide PBS:phosphate-buffered saline VacA:Vacuolating cytotoxin.
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PMID:In vitro inhibitory effect of flavonoids on growth, infection and vacuolation of Helicobacter pylori. 1577 May 37

This study characterised non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA) isolates from Kuwait hospitals to ascertain whether they were community-acquired MRSA (CA-MRSA). Forty-two nmMRSA isolates obtained between July 2001 and October 2003 were analysed by staphylococcal cassette chromosome mec (SCCmec) typing, bacteriophage typing, production of Panton-Valentine leukocidin (PVL), urease and staphylococcal enterotoxins A, B, C and D, TSST-1, and by pulsed-field gel electrophoresis (PFGE). Forty-one isolates were SCCmec type IV, and one isolate was SCCmec type III. The isolates belonged to six PFGE patterns, with two types, A and D, distributed in six and four hospitals, respectively. Most (n = 26; 61.9%) isolates produced urease. These isolates were mainly from wound and skin infections, showed low-level methicillin resistance (MIC 8-48 mg/L), and nine carried genes for PVL. These characteristics, together with their carriage of the type-IV SCCmec, identified the isolates as CA-MRSA. Ten of the 16 urease-negative isolates produced staphylococal enterotoxin C; 12 reacted weakly with phage 75, and were resistant to clindamycin and/or erythromycin, which are characteristics of EMRSA-15. Thus, this study identified the co-existence of two types of nmMRSA, i.e., CA-MRSA and EMRSA-15, in Kuwait hospitals.
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PMID:Characterisation of non-multiresistant methicillin-resistant Staphylococcus aureus (including EMRSA-15) in Kuwait Hospitals. 1645 14

The anti-H. pylori activity of Pterocarpus santalinus (PS), a traditional herb, has been assessed and compared with that of bismuth subcitrate, through in vitro studies employing rat gastric epithelial cell cultures and H. pylori isolates from gastric mucosal biopsy patients. The MIC of PS was found to be 20 microg/mL. H. pylori was co-cultivated with rat gastric epithelial cells in the presence/absence of PS at its MIC. A reduction in the activity of urease, a normal appearance of the epithelial cells on electron microscopic examination, a decrease in lipid peroxidation and lactate dehydrogenase suggests the possible anti-H. pylori activity of PS.
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PMID:Pterocarpus santalinus: an In Vitro study on its anti-Helicobacter pylori effect. 1712 31

Hopeanolin (1), an unusual resveratral trimer with an ortho-quinone nucleus, was isolated and characterized from the stem bark of Hopea exalata. Also obtained were six known stibenoids, shoreaphenol (2), vaticanol G (3), alpha-viniferin (4), pauciflorol A (5), vaticanol A (6), and trans-3,5,4'-trihydroxystilbene 2-C-glucoside (7). The structure of 1 was determined by spectroscopic data interpretation. Compounds 1-7 were tested for antifungal activity and inhibitory effects against jack bean urease. Hopeanolin (1) demonstrated antifungal activity in the MIC value range 0.1-22.5 microg/mL.
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PMID:Bioactive oligostilbenoids from the stem bark of Hopea exalata. 1719 Apr 64

Organogermanium compounds have been used as pharmacological agents. However, very few reports are available on the synthesis and antibacterial activities of lactones containing organogermaniums. The purpose of the present investigation was to determine the effects of different lactone-substituted organogermaniums on bacterial growth and their urease activity. We report synthesis of 12 germa-gamma-lactones (GeL) and their antimicrobial activities against several bacterial pathogens. Antibacterial action of all GeL was highly selective against Gram-negative bacilli, particularly Proteus mirabilis, an important pathogen infecting the urinary tract. Furthermore, our data indicate that 8-quinoline derivatives were more potent against P. mirabilis than 2-methyl-8-quinoline. For example, the beta-(o-methylphenyl)-gamma,gamma-bis(8-quinolinoxy)germa-gamma-lactone and beta-(o-methoxyphenyl)-gamma,gamma-bis(8-quinolinoxy)germa-gamma-lactone were maximally active with MIC(90) of 61 and 94 microM, respectively. In vitro studies demonstrated a linear correlation between antibacterial activity and inhibition of P. mirabilis urease enzyme. Further kinetic analyses revealed that inhibition occurred in a noncompetitive and concentration-dependent manner with the minimum IC(50) of 31 microM for beta-(o-methoxyphenyl)-gamma,gamma-bis(8-quinolinoxy)germa-gamma-lactone. In conclusion, these findings suggest that GeL have potential to be developed as antimicrobial agents against P. mirabilis infection.
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PMID:Germa-gamma-lactones as novel inhibitors of bacterial urease activity. 1736 56

The antibacterial activity of an oil extract of Chamomilla recutita flowers against Helicobacter pylori (H. pylori) was evaluated by the agar dilution method using Colombia agar with 10% sheep blood, an inoculum of McFarland 0.5 and incubation in an anaerobic atmosphere at 37 degrees C for 3 days. The oil extract was prepared by olive oil extraction of Chamomilla recutita flowers using rotary pulsation. The MIC(90) (minimal inhibitory concentration) and MIC(50) were 125 mg/mL and 62.5 mg/mL, respectively. It was shown that the Chamomilla recutita oil extract inhibited the production of urease by H. pylori. In addition, it was found that the morphological and fermentative properties of H. pylori were affected by application of the Chamomilla recutita oil extract.
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PMID:Antibacterial activity of Chamomilla recutita oil extract against Helicobacter pylori. 1772 68

Helicobacter pylori (H. pylori) infection is now established as the major pathogenic factor in chronic gastritis and peptic ulcer disease. In addition, there is accumulating evidence thatH. pylori plays an important role in the process of gastric carcinogenesis. On the other hand, oriental traditional medicines have been used for stomach disease for thousands of years. In the present study, methanol extract from the stem bark ofMagnolia sieboldii (M. sieboldii) and its components were investigated on their inhibitory effects against urease activity and growth ofH. pylori in vitro. The methanol extract ofM. sieboldii significantly inhibited the growth ofH. pylori ATCC 43504 at 5 mg/ml. From the further fractionation, the chloroform fraction inhibited the bacterial growth dose-dependently. Among four fractions separated from the chloroform fraction by silica gel column chromatography, MS-C-2 was the most potent. Costunolide was isolated from the MS-C-2 subfraction by preparative TLC and recrystallization using n-hexane. Anti-H. pylori effect of costunolide was investigated using one commercial strain (H. pylori ATCC 43504) and three clinical strains (H. pylori 4, 43, 82548). Costunolide exhibited potent anti-H. pylori activity, and the MIC was around 100-200 mug/ml. However, costunolide had no inhibitory effect ofH. pylori urease activity at the concentration used for the growth inhibition assay. From these results, we conclude that costunolide inhibits the growth ofH. pylori by the independent manner ofH. pylori urease inhibition.
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PMID:Anti-Helicobacter pylori effect of costunolide isolated from the stem bark ofMagnolia sieboldii. 1897 64

This study investigated the microbiological characteristics of 100 clinical isolates of Cryptococcus neoformans species complex, including serotypes, mating types, molecular types, antifungal susceptibility and virulence. The isolates were collected at National Taiwan University Hospital from 1999 to 2004. Eight isolates of C. neoformans from pigeon droppings were also evaluated. Among these isolates, 99 were C. neoformans var. grubii serotype A and one was C. neoformans var. gattii serotype B. All of these isolates were alpha mating types. PCR fingerprinting, generated by primers M13 and (GACA)(4), and URA5 gene restriction fragment length polymorphism analysis revealed that C. neoformans var. grubii isolates belonged to the VNI (98 isolates) and the VNII (one isolate) types, and the single C. neoformans var. gattii was VGI type. The similar profiles of clinical and environmental isolates suggest that patients might acquire these yeasts from the environment. The MIC(90) for fluconazole, itraconazole, 5-flucytosine, voriconazole and amphotericin B against all C. neoformans isolates were 8, 0.5, 4, 0.125 and 0.5 mg/L, respectively. All clinical isolates produced urease, phospholipase, capsule and melanin, but these activities varied with individual isolates. Analysis of six clinical and two environmental isolates with various levels of phospholipase activity indicated a correlation between phospholipase activity and the ability to adhere to the lung epithelial cell line, A549. The extent of cell damage, as indicated by lactate dehydrogenase release, also paralleled the phospholipase activity of these isolates. In addition, production of melanin contributed significant protection against amphotericin B killing of the isolates tested.
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PMID:Microbiological characteristics of clinical isolates of Cryptococcus neoformans in Taiwan: serotypes, mating types, molecular types, virulence factors, and antifungal susceptibility. 1969 65


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