Recent Submissions

  • Activities of garlic oil, garlic powder, and their diallyl constituents against Helicobacter pylori.

    O'Gara, Elizabeth A.; Hill, David J.; Maslin, David J. (American Society for Microbiology, 2000)
    Chronic Helicobacter pylori disease is reduced with Allium vegetable intake. This study was designed to assess the in vivo anti-H. pylori potential of a variety of garlic substances. The garlic materials all showed substantial but widely differing anti-H. pylori effects against all strains and isolates tested. The MICs (range, 8 to 32 microg/ml) and minimum bactericidal concentrations (MBCs) (range, 16 to 32 microg/ml) of undiluted garlic oil (GO) were smaller than those of garlic powder (GP) (MIC range, 250 to 500 microg/ml; MBC range, 250 to 500 microg/ml) but greater than the MIC of allicin (4. 0 microg/ml) (Table 2) present in GP. Allicin (MIC, 6 microg/ml; MBC, 6 microg/ml) was more potent than diallyl disulfide (MIC range, 100 to 200 microg/ml; MBC range, 100 to 200 microg/ml), its corresponding sulfide, but of a strength similar to that of diallyl tetrasulfide (MIC range, 3 to 6 microg/ml; MBC range, 3 to 6 microg/ml). Antimicrobial activity of the diallyl sulfides increased with the number of sulfur atoms. Time course viability studies and microscopy showed dose-dependent anti-H. pylori effects with undiluted GO, GP, allicin, and diallyl trisulfide after a lag phase of ca. 1 to 2 h. Substantial in vitro anti-H. pylori effects of pure GO and GP and their diallyl sulfur components exist, suggesting their potential for in vivo clinical use against H. pylori infections.
  • The effect of simulated gastric environments on the anti-Helicobacter activity of garlic oil.

    O'Gara, Elizabeth A.; Maslin, David J.; Nevill, Alan M.; Hill, David J. (Blackwell Synergy, 2008)
    AIMS: To investigate the effects of simulated gastric conditions upon the anti-Helicobacter pylori effects of garlic oil (GO). METHODS AND RESULTS: Time course viability experiments assessed the anti-H. pylori activity of GO (16 and 32 microg ml(-1)) in simulated gastric environments. Rapid anti-H. pylori action of GO was observed in artificial gastric juice. Mucus (1-5%) was strongly protective of H. pylori both alone and in the presence of GO, but its protective effect was antagonized by GO. Peptone (5-15 g l(-1)) caused a dose-dependent reduction in the anti-H. pylori activity of GO. Rapeseed oil (5.7-17 g l(-1)) greatly diminished the anti-H. pylori activity of GO. Dextrin (44 and 133 g l(-1)) exhibited direct anti-H. pylori effects and added to those of GO. Simulated meal mixtures decreased but did not eliminate the anti-H. pylori activity of 32 mug ml(-1) GO. CONCLUSIONS: The anti-H. pylori activity of GO was noticeably affected by food materials and mucin. However, substantial activity remained under simulated gastric conditions. Further investigation of the therapeutic potential of GO against H. pylori is therefore warranted. SIGNIFICANCE AND IMPACT OF THE STUDY: Garlic oil may be useful as an alternative treatment against H. pylori, a major cause of gastrointestinal infections in humans.
  • A pilot study to determine the effectiveness of garlic oil capsules in the treatment of dyspeptic patients with Helicobacter pylori.

    McNulty, Cliodna A. M.; Wilson, Melanie P.; Havinga, Wouter; Johnston, Belinda; O'Gara, Elizabeth A.; Maslin, David J. (Wiley InterScience, 2001)
    BACKGROUND: Resistance of Helicobacter pylori to clarithromycin and metronidazole is now found worldwide. Steam-distilled garlic oil has in vitro activity against H. pylori and may be a useful alternative treatment strategy. MATERIALS AND METHODS: In this pilot study dyspeptic patients with positive serology for H. pylori confirmed by 13C urea breath test (UBT), at 0 and 2 weeks, were enrolled. Treatment consisted of one 4 mg garlic oil capsule with a meal four times per day for 14 days. H. pylori eradication was defined as a negative UBT at both follow-up appointments. Suppression was defined as a 50% fall in 13C excess between baseline and follow-up 1. RESULTS: Five patients completed the study. There was no evidence of either eradication or suppression of H. pylori or symptom improvement whilst taking garlic oil. CONCLUSION: These negative results show that, within the gastric milieu, garlic oil at this dose does not inhibit H. pylori. A higher dose administered for a longer time-period may be effective. Antibiotics are usually combined with a proton-pump inhibitor or bismuth salt, as the only antibiotic with any in vivo activity against H. pylori in monotherapy is clarithromycin. A proton pump inhibitor raises gastric pH and, by increasing bacterial division, may increase the in vivo activity of garlic oil. This may be worth pursuing in a future trial.
  • Survival of Escherichia coli O157:H7 in traditional African yoghurt fermentation.

    Ogwaro, B.A.; Gibson, Hazel; Whitehead, Michael P.; Hill, David J. (Elsevier Science Direct, 2002)
    Growth and survival of a nontoxigenic strain of Escherichia coli O157:H7 (ATCC 43888) was determined in traditionally fermented pasteurized milk. Preheated milk was inoculated with 1% (v/v) of a mixed culture of Lactobacillus delbrueckii ssp. bulgaricus (NCIMB 11778) and Streptococcus salivarius ssp. thermophilus (NCIMB 110368) and incubated at 25, 30, 37 or 43 degrees C for 24 h. E. coli O157:H7 (10(5) CFU/ml) were introduced into the milk pre- and post-fermentation. Fermented milk samples were subsequently stored at either 4 degrees C (refrigerator temperature) or 25 degrees C (to mimic African ambient temperature) for 5 days. After 24 h of fermentation, the pH of the samples fermented at the higher temperatures of 37-43 degrees C decreased from 6.8 to 4.4-4.0 ( +/- 0.2) whereas at the lower temperature of 25 degrees C, the pH decreased to pH 5.0 +/- 0.1. During this period, viable counts for E. coli O157:H7 increased from 10(5) to 10(8) - 10(9) CFU/ml except in milk fermented at 43 degrees C wherein viability declined to 10(4) CFU/ml. In fermented (25-30 degrees C) milk stored at 4 degrees C for 5 days, E. coli O157:H7 viability decreased from 10(8-9) to 10(6-7) CFU/ml whereas milk fermented at 43 degrees C resulted in loss of detectable cells. In contrast, storage of fermented milk samples at 25 degrees C for 5 days eventually resulted in complete loss of viability irrespective of fermentation temperature. Stationary phase E. coli O157:H7 inoculated post-fermentation (25 and 43 degrees C) survived during 4 degrees C storage, but not 25 degrees C storage. Fermentation temperature and subsequent storage temperature are critical to the growth and survival of E. coli O157:H7 in traditional fermented products involving yoghurt starter cultures.
  • Culturability, injury and morphological dynamics of thermophilic Campylobacter spp. within a laboratory-based aquatic model system.

    Thomas, C.; Hill, David J.; Mabey, M. (Wiley InterScience, 2002)
    AIMS: To study the survival processes of thermophilic Campylobacter spp. within a modelled aquatic system and particularly the involvement and survival potential of viable but non-culturable forms. METHODS AND RESULTS: The survival and morphological characteristics of populations of thermophilic Campylobacter species exposed to simulated aquatic conditions were examined using a combination of cultural and microscopic techniques. Populations underwent progressive decay when exposed to simulated aquatic conditions. The rates of population decay were observed to be significantly greater at the higher temperature (20 degrees C) with a rapid transition of the dominant sub-populations from non-stressed to dead cells occurred within 3 days. At 10 degrees C the rate of culturability loss was much reduced with substantial development (approx. 80% of total population) of viable but non-culturable (VBNC) populations by all species within 3 days, declining to represent approximately 5-25% of the total population at day 60. Significant differences (P < 0.001) were identified between decay rates as a consequence of different species, sub-populations and temperature but not between sub-populations of different species. Morphological variants including spiral, elongated spirals and rods, short rods and coccoid forms were identified. The endpoints of morphological transition were temperature-independent and isolate-specific yet the rate of morphological transition was directly related to temperature and approximately equivalent between species. CONCLUSION: The VBNC state is a transitory stage in the degeneration of Campylobacter population within the aquatic environments simulated during this study. SIGNIFICANCE AND IMPACT OF THE STUDY: VBNC cells form the most persistent, viable, potentially pathogenic sub-population of Campylobacter populations exposed to aquatic stress conditions.
  • Anti-beta2GPI-antibody-induced endothelial cell gene expression profiling reveals induction of novel pro-inflammatory genes potentially involved in primary antiphospholipid syndrome.

    Hamid, Colleen G.; Norgate, K.; D'Cruz, D.P.; Khamashta, M.A.; Arno, M.; Pearson, J.D.; Frampton, Geoffrey; Murphy, John J. (BMJ Publishing & European League Against Rheumatism, 2007)
    OBJECTIVE: To determine the effects of primary antiphospholipid syndrome (PAPS)-derived anti-beta(2)GPI antibodies on gene expression in human umbilical vein endothelial cells (HUVEC) by gene profiling using microarrays. METHODS: Anti-beta(2)GPI antibodies purified from sera of patients with PAPS or control IgG isolated from normal subjects were incubated with HUVEC for 4 h before isolation of RNA and processing for hybridisation to Affymetrix Human Genome U133A-2.0 arrays. Data were analysed using a combination of the MAS 5.0 (Affymetrix) and GeneSpring (Agilent) software programmes. For selected genes microarray data were confirmed by real-time PCR analysis or at the protein level by ELISA. RESULTS: A total of 101 genes were found to be upregulated and 14 genes were downregulated twofold or more in response to anti-beta(2)GPI antibodies. A number of novel genes not previously associated with APS were induced, including chemokines CCL20, CXCL3, CX3CL1, CXCL5, CXCL2 and CXCL1, the receptors Tenascin C, OLR1, IL-18 receptor 1, and growth factors CSF2, CSF3 IL-6, IL1beta and FGF18. The majority of downregulated genes were transcription factors/signalling molecules including ID2. Quantitative real-time RT-PCR analysis confirmed the microarray results for selected genes (CSF3, CX3CL1, FGF18, ID2, SOD2, Tenascin C). CONCLUSIONS: This study reveals a complex gene expression response in HUVEC to anti-beta(2)GPI antibodies with multiple chemokines, pro-inflammatory cytokines, pro-thrombotic and pro-adhesive genes regulated by these antibodies in vitro. Some of these newly identified anti-beta(2)GPI antibody-regulated genes could contribute to the vasculopathy associated with this disease.
  • Antimicrobial properties of garlic oil against human enteric bacteria: evaluation of methodologies and comparisons with garlic oil sulfides and garlic powder.

    Ross, Z.M.; O'Gara, Elizabeth A.; Hill, David J.; Sleightholme, H.V.; Maslin, David J. (American Society for Microbiology., 2001)
    The antimicrobial effects of aqueous garlic extracts are well established but those of garlic oil (GO) are little known. Methodologies for estimating the antimicrobial activity of GO were assessed and GO, GO sulfide constituents, and garlic powder (GP) were compared in tests against human enteric bacteria. Test methodologies were identified as capable of producing underestimates of GO activity. Antimicrobial activity was greater in media lacking tryptone or cysteine, suggesting that, as for allicin, GO effects may involve sulfhydryl reactivity. All bacteria tested, which included both gram-negative and -positive bacteria and pathogenic forms, were susceptible to garlic materials. On a weight-of-product basis, 24 h MICs for GO (0.02 to 5.5 mg/ml, 62 enteric isolates) and dimethyl trisulfide (0.02 to 0.31 mg/ml, 6 enteric isolates) were lower than those for a mixture of diallyl sulfides (0.63 to 25 mg/ml, 6 enteric isolates) and for GP, which also exhibited a smaller MIC range (6.25 to 12.5 mg/ml, 29 enteric isolates). Viability time studies of GO and GP against Enterobacter aerogenes showed time- and dose-dependent effects. Based upon its thiosulfinate content, GP was more active than GO against most bacteria, although some properties of GO are identified as offering greater therapeutic potential. Further exploration of the potential of GP and GO in enteric disease control appears warranted.
  • Integration of digital video sequences and supportive interactive animations into the Level 1 module Introductory Microbiology, to enhance the delivery and effectiveness of experimental microbiology.

    Protheroe, Roy; Sunderland, Duncan (University of Wolverhampton, 2004)
    From a previous innovations project during 2002/2003, the feasibility of producing and editing digital video of experimental microbiological procedures was established. The digital video was produced for eventual use on the Level 1 Introductory Microbiology within the University of Wolverhampton virtual learning environment (WOLF), to improve an understanding of the principles and practice of experimental procedures encountered on the module. In addition to the video sequences, supportive animations of the practical exercises were produced, to be viewed eventually by students in association with the video also via WOLF. The end of the previous project had produced several video and animation sequences, although these had not, at that time, been added to the WOLF topic. To provide an effective package of video and animation sequences to fully support the practical component of the module, more sequences were required, together with refinement of existing material. In addition, following integration into the WOLF topic, an analysis of the effectiveness of the sequences, in supporting an understanding of the theory and practice of the experimental exercises, was considered to be of value.
  • Lecture substitution by technology supported learning (WOLF) - an investigation of effectiveness on the module Introductory Microbiology

    Protheroe, Roy; Hill, David J. (University of Wolverhampton, 2004)
    The Introductory Microbiology topic within the Wolverhampton Online Learning Framework (WOLF) has been developed over a number of years. The topic contains the whole of the module syllabus in an interactive form, including lecture material, tutorials and laboratory practical support. The topic also contains tests for student self-assessment. The material has traditionally been used as a student support mechanism, although in recent times it has also been used as a direct substitution of a proportion of formal lectures. This project was devised to determine the effectiveness of this strategy in relation to student performance and to integrate the University pilot of computer assisted assessment (QMark), since multiple choice testing is used on the module.