Anti-Helicobacter pylori activities were determined by agar dilution, confocal laser scanning microscopy, and cell proliferation assays following treatment with various grape extracts. Muscadine grape skin possessed the strongest activity, followed by grape synergy (skin and seed) and seed, suggesting that higher phenolic levels do not necessarily determine overall anti-H. pylori efficacy.Helicobacter pylori is considered the etiological agent of peptic ulcers and gastritis and is associated with mucosa-associated lymphoid tissue lymphoma and gastric cancer (4). Although treatment is usually effective, it can result in side effects, such as antibiotic resistance development (14) and relapse due to low compliance (2). Therefore, alternative methods should be explored to treat H. pylori infection.Studies have reported many natural plant extracts with anti-H. pylori activity, including garlic, broccoli, cranberries, and green tea (5,12,16,26). Grapes (Vitis vinifera), well known for their high levels of antioxidants and polyphenols, have also shown promise as novel antimicrobial agents. A few studies have already reported the anti-H. pylori activities of grape seed and wine, including an active chemical constituent (e.g., resveratrol, a stilbene from red wine) (13). However, no effort has been made to evaluate the grape skin or different grape types (e.g., table and muscadine grapes). For example, muscadines (Vitis rotundifolia) contain significantly higher levels of phenolics than commercial table grapes in addition to possessing some unique forms of these compounds (23). However, little is currently known about the antibacterial properties these fruits possess, making them prime candidates for study. In addition, it is believed that the high complexity of bioactive compounds present in these products and their broad range of activity over a number of microorganisms may make it difficult for microbes to acquire resistance during treatment (26).The objectives of this study were to investigate the effects of various grape extracts against H. pylori and to determine any correlations between anti-H. pylori activity and extract phenolic content.Five H. pylori strains (G2-1, 26695, WV 99, NB2-1, and 1324P-1) were obtained from Douglas Berg (Washington University, St. Louis, MO), and five clinical H. pylori isolates (D5251, D5131, D5178, D5136, and D5135) were obtained from Ben Gold (Emory University and Centers for Disease Control and Prevention, Atlanta, GA). H. pylori P1pDH80, a green fluorescent protein (GFP)-labeled strain, was provided by Rainer Haas (Max von Pettenkofer Institut fur Hygiene und Medizinische Mikrobiologie, Munchen, Germany). H. pylori SS1, a mouse-adapted strain, was provided by Kathryn Eaton (Department of Veterinary Biosciences, Ohio State University, Columbus, OH). For the entire study, bacteria were grown on brain heart infusion agar (Difco Laboratories, Detroit, MI) (pH 7.4 Ϯ 0.2) supplemented with 10% horse serum (HS) (Sigma Chemical Co., St. Louis, MO) at 37°C for 72 h under microaerophilic ...

Research progress into mechanisms of the anaerobe Clostridium perfringens and associated diseases has been frustrated by the lack of reliable infection models. Wax moth larvae ( Galleria mellonella ) have emerged as a viable alternative to other models of infection since they are economic, survive at 37°C and require no specialist equipment. This study aims to establish to what extent G. mellonella larvae can be used to study the virulence of C. perfringens strains and its suitability for studying novel treatment strategies by an improved time-lapse approach to data collection. Mortality and morbidity rates of larvae challenged with 10 5 CFU of C. perfringens isolates from various sources were observed over 72 h and dose response data obtained. Phenoloxidase enzyme activity was investigated as a marker for immune response and tissue burden assessed by histopathological techniques. Results demonstrate that C. perfringens is pathogenic toward G. mellonella although potency varies dramatically between C. perfringens isolates and the reference strain ATCC 13124 was shown to be avirulent. Infection with C. perfringens strains activated the melanisation pathway resulting in melanin deposition but no increase in enzyme activity was observed. Efficacy of antibiotic therapy (penicillin G, bacitracin, neomycin, and tetracycline) administered parenterally to some extent correlates with that of in vitro analysis. The findings suggest G. mellonella might be a useful in vivo model of infection and convenient as a pre-screening assay for virulence of C. perfringens strains or as a simple, cheap and rapid in vivo assay in the first stage development of novel therapeutics against anaerobes. HIGHLIGHTS Potential novel in vivo model for the study of Clostridium perfringens infection. Novel time-lapse approach to data collection. First report of the pathogenicity of C. perfringens toward G. mellonella . First report of the efficacy of antibiotic therapy in response to C. perfringens infection in G. mellonella .

Hoechst dyes are well known DNA binders that non-selectively inhibit the function of mammalian topoisomerase I and II. Herein, we show that Hoechst 33258 based bisbenzimidazoles (DPA 151–154), containing a terminal alkyne, are effective and selective inhibitors of E. coli. topoisomerase I. These bisbenzimidazoles displayed topoisomerase I inhibition much better than Hoechst 33342 or Hoechst 33258 with IC50 values in the range of 2.47–6.63 μM. Bisbenzimidazoles DPA 151-154 also display selective inhibition of E. coli. topoisomerase I over DNA gyrase and Human topoisomerases I and II, and effectively inhibit bacterial growth.

The objective of this study was to determine the prevalence of antibiotic-resistant bacteria in various herbal products. Twenty-nine herbal supplements (18 traditional and 11 organic products) were purchased from stores and analyzed microbiologically. Total bacterial counts were determined by pour plate and surface spreading on tryptic soy agar (TSA). Antibiotic-resistant bacteria were enumerated on TSA supplemented with ceftriaxone (64 microg/ml) or tetracycline (16 microg/ml). Total bacterial counts ranged from <5 to 2.9 x 10(5) CFU/g. Ceftriaxone- and tetracycline-resistant bacteria were detected in ground garlic samples at 1.1 x 10(2) CFU/g and 3.0 x 102 CFU/g, respectively. Traditional and organic onion powder samples contained tetracycline-resistant bacteria at 17 and 28 CFU/g and ceftriaxone-resistant bacteria at 35 and 2.0 x 10(3) CFU/g, respectively. Other products such as ginger, rosemary, mustard, and goldenseal contained low levels of resistant bacteria. Fifty-two isolates were further evaluated against nine antibiotics, and the prevalence of antibiotic resistance was in the following order: ampicillin, nalidixic acid, trimethoprim, ceftriaxone, and streptomycin. Resistant bacteria were identified as Bacillus spp., Erwinia spp., and Ewingella americana. Staphylococcus spp., Enterobacter cloacae, and Stenotrophomonas maltophilia also were isolated. The presence of antibiotic-resistant bacteria and pathogens in these herbal products suggests that production and use of these products may need further evaluation.

Aims: To identify active phenolic constituents in muscadine grape skin (MGS) extracts and determine interactions among compounds while further exploring their anti-Helicobacter pylori potential in vitro. Methods and Results: The inhibitory effects of quercetin and resveratrol, active polyphenols identified in MGS extracts, against H. pylori were investigated. Quercetin and resveratrol significantly (P < 0Á05) reduced H. pylori counts regardless of pH with minimal bactericidal concentrations of 256 and 128 lg ml À1 , respectively. MGS extracts displayed the highest efficacy, suggesting additional unidentified compounds not determined in this study. Time-course viability experiments showed a dose-dependent anti-H. pylori response to quercetin and resveratrol. Interestingly, neither quercetin nor resveratrol affected H. pylori outer membrane (OM) integrity as determined by 1-N-phenylnaphthylamine (NPN) uptake assays. However, treatment with MGS extract did increase NPN uptake, indicating OM destabilization possibly by additional unknown components. Furthermore, quercetin was found to enter H. pylori as measured by HPLC supporting intracellular drug accumulation. Conclusions: Quercetin and resveratrol possess strong anti-H. pylori activity in vitro and are independent of pH. Our results also suggest that these compounds do not affect H. pylori OM integrity as previously hypothesized and that the primary antimicrobial activity of quercetin may be linked to interactions with intracellular components. Significance and Impact of the Study: The anti-H. pylori effects of quercetin and resveratrol suggest that these compounds may be useful in the dietary prevention and/or treatment of H. pylori infection.