Wee Tee

Antibody response to campylobacter pylori in diverse ethnic groups

Antibody response to Campylobacter pylori was measured in ethnic groups of Vietnamese, El Salvadorean and Ethiopian origin. The results were compared with the previously reported antibody titres found in sera of culture positive and culture negative patients, patients suffering from duodenal ulcer, white Australian blood donors and Australian Aboriginals. While in Vietnamese the prevalence of serologically positive sera was found to be similar to the white Australian population, numbers of serologically positive sera in El Salvadorean and Ethiopian ethnic groups was found to be very high. The high incidence of serologically positive sera in the Ethiopians correlated with the reported high incidence of duodenal ulcer in this population.

Bacteremia due to Leptotrichia trevisanii sp. nov.

Abstract. A thin, filamentous, non-motile, aerotolerant, anaerobic, gram-negative bacterium was isolated from the blood of a 46-year-old man who was diagnosed as having acute myeloid leukemia. The organism had a positive catalase reaction but was negative in indole and oxidase tests. A commercially available system failed to identify the bacterium, but 16S rRNA gene sequencing showed it to be most closely related (97% similarity) to a recently isolated Leptotrichia sp. The DNA base composition was 29.7% mol G+C, and the organism produced lactate as the sole end-product of glucose fermentation. These data indicate the isolate is a new species of Leptotrichia for which the name Leptotrichia trevisanii sp. nov. is proposed.

In vitro synergy between ranitidine bismuth citrate and tetracycline or clarithromycin against resistant strains of Helicobacter pylori

Treatment of Helicobacter pylori infection in peptic ulcer disease continues to be problematic despite the availability of several therapeutic options. Bismuthbased classical triple therapy (bismuth/ metronidazole/ amoxicillin or tetracycline) was the cornerstone of treatment for Helicobacter pylori infections before proton pump inhibitor-based regimens became available, but it is hampered by poor patient compliance, side effects and the influence of antibiotic resistance on cure [1, 2]. Of particular concern is the increasing antimicrobial resistance reported in Helicobacter pylori worldwide [3]. Resistance to nitroimidazoles, macrolides and, recently, tetracycline has been described [4]. No resistance to bismuth compounds has been reported for Helicobacter pylori, which makes these agents useful in anti-Helicobacter pylori therapies. Future treatment of Helicobacter pylori infection needs to be simple, safe, well tolerated and effective regardless of the level of antibiotic resistance. The in vitro study reported here investigated the effects of combining ranitidine bismuth citrate (RBC) with the antibiotics tetracycline and clarithromycin against susceptible and resistant isolates of Helicobacter pylori. Time-kill kinetic studies were performed to investigate the bactericidal activity of each drug and whether synergy, additive effects or antagonism occurred with the drug combinations.

A Member of the Delta Subgroup of Proteobacteria from a Pyogenic Liver Abscess Is a Typical Sulfate Reducer of the Genus Desulfovibrio

ABSTRACT Strain FH26001/95 (ATCC 700045) was previously isolated from a pyogenic liver abscess from a human. Comparative 16S rRNA gene sequence analysis showed that this strain is related to members of the delta subgroup of the proteobacteria, within a cluster of sulfate-reducing bacteria (Desulfovibrio spp.) and non-sulfate-reducing bacteria (Bilophila wadsworthia and Lawsoniaspp.). The phenotype of strain FH26001/95 was found to be typical of members of the genus Desulfovibrio. Growth and substrate transformations were possible at oxygen concentrations of 2 to 5% (vol/vol) but not at oxygen concentrations of 21% (vol/vol) in air. Its isolation from an infection in a human suggests that some members of the genus Desulfovibrio can be considered opportunistic pathogens.