In vitro inhibition of Helicobacter pylori urease with non and semi fermented Camellia sinensis

Purpose: Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori. Methods: Minimum inhibitory concentrations of nonfermented and semifermented C. sinensis methanol: water extracts were assessed by broth dilution method. Examination of the urease function was performed by Mc Laren method, and urease production was detected on 12% SDS polyacrylamide gel electrophoresis from whole cell and membrane bound proteins. Results: Both extracts had inhibitory effects against H. pylori and urease production. At a concentration of 2.5 mg/ml of nonfermented extract and 3.5 mg/ml of semifermented extract the production of Ure A and Ure B subunits of the urease enzyme were inhibited completely. A concentration of 4 mg/ml of nonfermented and 5.5 mg/ml of semifermented extract were bactericidal for H. pylori. Conclusions: C. sinensis extracts, especially the nonfermented, could reduce H. pylori population and inhibit urease production at lower concentrations. The superior effect of nonfermented extract is due to its rich polyphenolic compounds and catechin contents

Virulence increasing of salmonella typhimurium in Balb/c Mice after heat-stress induction of phage shock protein A

View at Publisher| Export | Download | Add to List | More... Current Microbiology Volume 59, Issue 4, October 2009, Pages 446-450 Virulence increasing of salmonella typhimurium in Balb/c Mice after heat-stress induction of phage shock protein A (Article) Hassani, A.S.ab, Amirmozafari, N.c, Ghaemi, A.bd a Department of Microbiology, Fars Science and Research Branch of IAU, Shiraz, Fars, Iran b Young Researchers Club (YRC) of Science and Research Branch, Islamic Azad University, Tehran, Iran c Department of Microbiology, Iran University of Medical Sciences, Tehran, Iran View additional affiliations View references (39) Abstract Salmonella typhimurium is a potentially intracellular pathogen and is responsible for thousands of reported cases of acute gastroenteritis and diarrhea each year. Although many successful physiological and genetic approaches have been taken to conclude the key virulence determinants encoded by this organism, the total number of uncharacterized reading frames observed within the S. typhimurium genome suggests that many virulence factors remain to be discovered. This study was conducted to evaluate the role of heat induced phage shock protein A (PspA), in the pathogenicity of S. typhimurium. The stress proteins detected on sodium dodecyl sulfate-polyacrylamide gel electrophoresis were identified specifically by immunoblotting with polyclonal antibody against PspA. PspA was produced in response to heat stress at 45°C and it was over-expressed at 65°C. At this temperature, the stressed bacterial cells producing PspA were more virulent (16 folds greater) to female 6-8 week-old Balb/c mice. Correspondency between decrease in LD50 and increase in PspA production during heat stress and lower pathogenicity in non-producing cells that emerged during stress at 55°C represents PspA as an important virulence factor in heat stressed S. typhimurium. © 2009 Springer Science+Business Media, LLC

Prevalence of Chlamydia trachomatis infections in symptomatic women by polymerase chain reaction (PCR) immunofluorescence and Giemsa stain

Chlamydia trachomatis is a ubiquitous human pathogen that is responsible for the most prevalent bacterial sexually transmitted disease worldwide. Studies show that polymerase chain reaction (PCR) is more sensitive than cellular culture for detection of C. trachomatis infections. The aim of this study is to compare different laboratory methods, including Giemsa staining, direct immunofluorescence assay (DFA) and PCR for detection of C. trachomatis in women with urethral symptoms. In this study, 130 women with urethral symptoms admitted in the gynecology clinic, were used and specimens were obtained with endocervical swab for Giemsa staining, DFA and PCR. All the cases underwent these three techniques. Demographic data and the medical history of patients were obtained by direct interview; however, the mean age of cases was 33.8±9.06. Clinical symptoms included abnormal vaginal discharge in 101 cases (77.7%), spotting in 14 cases (10.8%), dysmenorrheal in 7 cases (5.4%), irritation in 6 cases (4.6%) and dysuria in 2 cases (1.5%). In DFA technique, 5 cases (3.8%) were positive and 3 (2.3%) were suspicious, while in the PCR technique, 6 cases (4.6%) were positive for C. trachomatis. However, 3 suspicious cases with DFA were negative in PCR. There was no positive case for C. trachomatis in Giemsa staining. In conclusion, C. trachomatis was not frequent in this study and it can be concluded that this infection was not a major hygienic problem in the same populations that were previously studied. Consequently, the causes that necessitate monogamy could be related to religious causes. Frequency of Chlamydia detection of DFA and PCR was same in the two groups. Nonetheless, Giemsa staining is not a reliable method for evaluating C. trachomatis.Key words: Chlamydia trachomatis, polymerase chain reaction (PCR), direct immunofluorescence assay (DFA)

Purification and characterization of &#945-galactosidase from Lactobacillus acidofillus

α−Galactosidase (α-D-galactoside galactohydrolase [EC 3.2.1.22]) was obtained from Lactobacillus acidofillus which was grown in modified de Man, Rogosa and Sharpe (MRS) medium, supplemented with raffinose. α-Galactosidase was released from the cells by ultrasonic treatment, then precipitated by ammonium-sulfate and further purified with Sephadex G-200 and DEAE cellulose chromatography with a 18.5-fold increase in specific activity and 28% recovery. Km and Vmax for this enzyme was determined by p-nitrophenyl-α-D-galactoside as substrate, to be about 0.47 mM, and 17.54 μmol/min per mg of protein, respectively. Maximum enzymatic activity occurred at pH 5.5 and temperature at 45°C. The enzymatic activity was retained at least for 30 min, at temperatures of 25 - 55°C, but there was inactive temperature at about 60°C. Galactose was able to decrease the enzyme activity by a factor of 63%. Among the sugars tested, fructose, glucose, sucrose, lactose and mannose reduced the enzyme activity only slightly (less than 10% of the control). A strong inhibition of α-galactosidase activity was found in the presence of 0.1 mM HgCl.Key words: α-Galactosidase, enzyme purification, Lactobacillus acidofillus, kinetic studies

Volatile components of Camellia sinensis inhibit growth and biofilm formation of oral streptococci in vitro

This study aimed to evaluate the efficacy of semi fermented and non fermented Camellia sinensis extracts (Black and Green tea) and comparison between them against Streptococcus mutans ATCC 25175, S. mitis ATCC 9811 and S. sanguis ATCC 10556 that are responsible for dental caries and bacteremias following dental manipulations. Minimum inhibitory concentrations of both tea extracts were assessed by Well diffusion and Broth dilution methods and examination of cell adherence (Biofilm inhibitory concentrations) was observed on glass slides under phase contrast microscope and colony counts from glass beads. Concentration of 1 mg mL-1 of semi fermented tea extract was completely biofilm inhibitor but biofilm formation by these bacteria was seen 7 days after treatment with 1 mg mL-1 of non fermented Camellia sinensis on glass beads and BIC for oral streptococci treated with this extract was 1.5, 2.5 mg mL-1 of semi fermented and 3 mg mL-1 of non fermented extracts had bactericidal effect on these bacteria. Semi fermented and non fermented Camellia sinensis extracts were able to prevent growth of oral streptococci. Therefore dental caries significantly reduce and the efficiency of semi fermented tea was higher due to rich content of volatile components rather than non fermented extracts. © 2008 Asian Network for Scientific Information

Phage shock protein g, a novel ethanol-induced stress protein in salmonella typhimurium

Exposure to ethanol is a stress condition that Salmonella typhimurium often encounters during its life cycle. Food, beverage, drugs, and cosmetics have a long history of using alcohols to control pathogens. Ethanol is also commonly used for disinfecting medical instruments. This study was conducted to evaluate the ethanol stress variations on the protein profile, cell structure, and serologic features of S. typhimurium. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the phage shock protein G (pspG), a new ethanol-induced stress protein in cells adapted to 10% ethanol. The result was confirmed by liquid chromatography-mass spectrometry. The maximum quantity of this 9.02-kDa protein was produced in 12.5% (v/v) of ethanol-treated cultures. Scanning electron microscopy has demonstrated new phenotypic characteristics in bacterial structure. The cells were unable to undergo binary fission. This phenomenon explains the tight attachment of bacteria in a colony. Overall, ethanol extreme stress induced expression of new proteins like PspG and repression of some other proteins in S. typhimurium. These induction and repression processes have inflicted dramatic changes on Salmonella behaviors. © 2008 Springer Science+Business Media, LLC

Evaluation of virulence factors and plasmid-related transmissibility among different isolates of Enterococci

The incidence of virulence factors among 114 Enterococcus faecalis and 35 Enterococcus faecium strains from different clinical specimens were compared with those isolated from control groups. A few of the isolates expressed two or more of the following traits simultaneously: hemolysin, aggregation substance, gelatinase, DNase, hemagglutinin and antibiotic resistance. The frequencies of hemolysin, aggregation substance, and gelatinase production in E. faecalis were much higher than those in E. faecium. However, no statistically significant differences were detected in the other traits. Two of the isolates showed total resistance to all of the antibiotics tested, and others displayed varied degrees of resistance pattern. The frequency of plasmid transfer was shown to be 10 -4- 10 -7 per donor among the isolated strains. The plasmid profile of the bacteria indicated that most of the isolates contained one or more plasmids with molecular weight ranging in 2 to 42 Mda regions. Resistance to gentamicin and tetracycline was the most observed antibiotic resistance pattern, and had the property of efficient inter-enterococcal spp. transfer by mating

Association between single nucleotide polymorphism of apoVLDL-II gene with growth and body composition traits in Iranian commercial broiler line

Very low density apolipoprotein-II (apoVLDL-II) is a major polypeptide component of avian VLDL. The function of apoVLDL-II is the transport of neutral lipids (triacylglycerol) in the form of VLDL in the plasma. The apoVLDLII gene is dormant in embryos, chicks and roosters but can be activated by estrogen. The current study was designed to investigate the association of an apoVLDL-II gene polymorphism on chicken growth and body composition traits. Genomic DNAs were extracted from 400chickens from four different commercial broiler lines. Genotyping for the apoVLDL-II gene by using PCR-RFLP method and SfcI restriction endonuclease showed a mutation in 492-bp fragment located on the first intron. Polymorphism in apoVLDL-II gene was significantly (P < 0.05) associated with body weight at 6 week (BW6), carcass weight (CW), breast muscle weight (BMW), drumstick weight (DW) and wing weight (WINW). No significant difference was observed in the back weight (BAKW) and abdominal fat weight (AFW). This research suggests that apoVLDL-II gene could be a candidate gene that can affect some growth traits in chickens

Nitazoxanide and doxycycline sensitivity among metronidazole resistant helicobacter pylori isolates from patients with gastritis

Background: Antibiotic therapy should be done based on resistance characteristics of Helicobacter pylori strains to commonly prescribed antibiotics in areas with higher resistance rates. Objectives: This study examined antibacterial activity of nitazoxanide and doxycycline against clinical H. pylori isolates showing different metronidazole resistance levels. Methods: A total of 122 patients, who underwent endoscopy were enrolled in this study from 3 hospitals of Tehran, during November 2014 to July 2015. Helicobacter pylori isolates were obtained from gastric biopsies of the patients after culture in specific culture medium and characterization by both biochemical and molecular methods. Antimicrobial susceptibility to metronidazole was detected using the agar dilution method and minimum inhibitory concentrations of nitazoxanide and doxycycline were determined for metronidazole resistant strains. Results: From a total of 122 gastric biopsy specimens, 55 H. pylori strains were recovered (45). Thirty-three of these strains (60.0) were resistance to metronidazole. MIC50 and MIC90 values for metronidazole were 32 and 64 µg/mL, respectively. MIC50 and MIC90 values for doxycycline and nitazoxanide were measured as 4 and �8 µg/mL, and 8 and �32 µg/mL, respectively. Conclusions: Dominance of high level metronidazole resistance H. pylori strains among the studied patients questioned its usefulness for first-line therapy in Iran. Nitazoxanide and doxycycline showed superior activity against H. pylori strains in comparison to metronidazole, which should be considered for alternative therapies. © 2018, Kowsar Medical Publishing Company. All rights reserved

Isolation and identification of anionic surfactant degrading bacteria from activated sludge

Background: Linear alkylbenzene sulfonate (LABS) is an anionic surfactant widely used all over the world. They will eventually end-up and accumulate in household or industrial sewage. Due to their high foaming capabilities which can cause numerous problems in sewage treatment facilities as well as direct toxic effects on many different organisms in ecosystem; they are generally considered as serious pollutants. Many reports have indicated that common bacteria can readily degrade LABS. Methods: In this survey, two different bacteria were isolated from Tehran municipal active sludge that showed the ability to degrade LABS rapidly and actively upon using it as their sole source of carbon. Biochemical tests as well as 16S rRNA gene sequencing performed. Results: Results have indicated the two isolates to be Acinetobacter johnsoni and Pseudomonas beteli. After experiments to optimize the pH and temperature for growth of the two bacterial isolates, the extent of LABS, utilization was evaluated by HPLC method. The Pseudomonas beteli and Acinetobacter johnsoni isolates were able to degrade 96.4 and 97.2 of the original LABS levels after 10 days of growth, respectively. Mixed culture of the two isolates did not significantly increase LABS utilization (97.6). Conclusion: Our study showed the ability of two isolated steains to rapidly biodegrade LABS under aerobic conditions