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BACKGROUND: In this study, efficacy and consistency of disc diffusion (DD) and agar dilution (AD) methods in determining Helicobacter pylori susceptibility to antibiotics were evaluated using Brucella blood agar (BBA) in both methods and tetrazolium egg yolk agar (TEYA) in AD. METHODS: Twenty H. pylori isolates were tested for susceptibility to nine antibiotics; metronidazole (MTZ), clarithromycin (CLR), amoxicillin (AMX), tetracycline (TET), ofloxacin (OFX), levofloxacin (LVX), ciprofloxacin (CIP), furazolidone (FRZ), and rifampin (RIF). Antibiotics solutions were impregnated into blank paper disks on BBA in the DD method or added to BBA (ADB) or TEYA (ADT) media in the AD method. Suspensions of H. pylori isolates were surface or spot inoculated on solid media. Plates were incubated in CO2 incubator at 37°C for 5-7 days. RESULTS: The highest rate of susceptibility to MTZ (65%) was determined by DD method compared with AD method (ADB: 40%, ADT: 30%). Both methods showed similar CLR (85%) and AMX (100%) susceptibility rates. Susceptibility to remaining antibiotics, determined by DD and ADB/ADT media were in respective order as 95%, 75% / 75% for TET, 100%, 95% / 85% for FRZ, 85%, 85% / 75% for OFX, 90%, 95% / 85% for LVX, 90%, 85% / 85% for CIP, and 100%, 85% / 75% for RIF. CONCLUSION: DD and AD methods showed consistency in determining 161 (89.4%) susceptibility and resistance and inconsistency in determining 19 (10.6%) susceptibility and resistance (P < 0.05). DD is recommended as a cheap and easy method with the efficacy and precision comparable to the AD method in determining H. pylori susceptibility to antibiotics.

BACKGROUND Sugar-rich foods are of the main components of daily human meals. These foods with high sugar and low water content kill bacteria. However, osmotolerant yeasts survive and multiply. The aim of this study was to examine the occurrence of intracellular Helicobacter pylori(H. pylori) and Staphylococcus spp. in yeast isolates from sugar-rich foods. METHODS Thirty-two yeast isolates from fresh fruits, dried fruits, commercial foods, and miscellaneous foods were identified by the sequencing of amplified products of 26S rDNA. Fluorescence microscopy and LIVE/DEAD bacterial viability kit were used to examine the occurrence of live bacteria inside the yeast’s vacuole. Immunofluorescence assay was used to confirm the identity of intracellular bacteria as H. pylori and Staphylococcus. Polymerase chain reaction (PCR) was used for the detection of 16S rDNA of H. pylori and Staphylococcus in the total DNA of yeasts. RESULTS Yeasts were identified as members of seven genera; Candida, Saccharomyces, Zygosaccharomyces, Pichia, Meyerozyma, Metschnikowia, and Wickerhamomyces. Intravacuolar bacteria were stained green with a bacterial viability kit, revealing that they were alive. Immunofluorescence assay confirmed the identity of intracellular H. pylori and Staphylococcus spp. PCR results revealed that among the 32 isolated yeasts, 53% were H. pylori-positive, 6% were Staphylococcus-positive, 18.7% were positive for both, and 21.8% were negative for both. CONCLUSION Detection of H. pylori- and Staphylococcus-16S rDNA in yeast isolates from dried fruits, and commercial foods showed the occurrence of more than one kind of endosymbiotic bacterium in yeasts’ vacuoles. While the establishment of H. pylori and Staphylococcus in yeast is a sophisticated survival strategy, yeast serves as a potent bacterial reservoir.

Background: Denture stomatitis is a very common oral mucosal lesion, affecting approximately 50% of denture wearers in some populations. More recently there is an increased interest to use natural antimicrobial compounds, like plant extracts of medicinal plants. Objectives: The aim of the present study was to evaluate the efficacy of green tea extract compared with nystatin drop in the treatment of denture stomatitis. Patients and Methods: This was a clinical trial study with 30 patients in two parallel groups, 15 patients received nystatin drop and the other ones green tea extract. The patients in two weeks were recommended to use mouthwash 4 times a day each time 15 - 20 drops for 2 - 3 minutes and after that they should avoid eating and drinking for 30 minutes; patients in the two groups were suggested to use the drug at a specific time. Amount of inflammation and erythema were recorded in each session and measured with a graded blade and recorded according to a 6-point scale. At each visit, mycological samples were taken from the palatal mucosa for culture. Results: Age and sex differences between the groups were not significant. The erythema surface of the palatal was significantly reduced in the both groups at follow-up visits compared with the pretreatment condition. No significant difference was seen between the two groups at the same visits in erythema surface and colony counts of the palatal mucosa (P > 0.05). Conclusions: This study indicated that green tea extract can be effective in reducing the number of Candida colonies and erythematic area comparable to nystatin drop in the management of denture stomatitis.