In Vitro Antimicrobial Susceptibility Testing of Helicobacter felis, H. bizzozeronii, and H. salomonis

The susceptibilities of Helicobacter felis (15 strains), H. bizzozeronii (7 strains), and H. salomonis (3 strains) to 10 antimicrobial agents were investigated by determination of the MIC using the agar dilution method. No consistent differences were noticed between the different Helicobacter species, which were all highly susceptible to ampicillin, clarithromycin, tetracycline, tylosin, enrofloxacin, gentamicin, and neomycin, as demonstrated by low MICs. Higher MICs were obtained for lincomycin (up to 8 μg/ml) and spectinomycin (up to 4 μg/ml). Two H. felis strains showed a MIC of 16 μg/ml for metronidazole, suggesting acquired resistance to this antimicrobial agent

Helicobacter baculiformis sp nov., isolated from feline stomach mucosa

A Gram-negative, microaerophilic slender rod, measuring approximately 10 mu m long and approximately 1 mu m wide, isolated from the gastric mucosa of a cat and designated strain M50(T), was subjected to a polyphasic taxonomic study. Despite its apparent lack of helical coils, the organism showed a corkscrew-like motion by means of multiple sheathed flagella located at both ends of the cell and by a periplasmic fibril coiled around the body. Strain M50T grew preferably on biphasic culture plates or on very moist agar. Coccoid forms predominatecl in cultures older than 4 days as well as in growth obtained on dry agar plates. The strain grew at 37 degrees C, but not at 25 or 42 degrees C and exhibited urease, oxidase and catalase activities. On the basis of 16S rRNA gene sequence analysis, the novel isolate was identified as a member of the genus Helicobacter and showed about 98 to 99% sequence similarity to Helicobacter felis, Helicobacter bizzozeronii, Helicobacter salomonis, Helicobacter cynogastricus and 'Candidatus Helicobacter heilmannii', five highly related species previously detected in the feline or canine gastric mucosa. Protein profiling of strain M50(T) using SDS-PAGE revealed a pattern different from those of other Helicobacter species of mammalian gastric origin. Additionally, the urease and HSP60 gene sequences of strain M50(T) were different from those of H. felis, H. bizzozeronii, H. salomonis, H. cynogastricus and 'Ca. H. heilmannii'. It is thus proposed that strain M50(T) (=LMG T 23839 =CCUG 53816(T)) represents a novel species within this genus, for which the name Helicobacter baculiformis sp. nov. is proposed

Growth, cysts and kinetics of Borrelia garinii (Spirochaetales: Spirochaetacea) in different culture media

The aim of the present paper was to evaluate cyst formation and growth parameters of Borrelia garinii in a range of media differing in formulation and cost. A qualitative assessment of morphology and motility of B. garinii was conducted. All media were prepared aseptically and used in test tubes or Petri dishes. For each medium, the initial spirochete concentration was standardized to 10³ spirochets/mL. The following culture media were suitable to grow B. garinii: Barbour-Stoenner-Kelly, brain heart infusion and PMR. Growth was minimal at six weeks post-inoculation and maximum spirochete density was observed between 9-12 weeks. Often, the cultures developed cysts of different sizes, isolated or in groups, with a spiraled portion of variable sizes, mainly in unfavorable culture media. Brazilian Lyme disease-like illness, also known as Baggio-Yoshinari syndrome (BYS), is a new and interesting emerging tick-borne disease, caused by Borrelia burgdorferi sensu lato spirochetes, only during its cystic forms. It has been assumed that the peculiar clinical and laboratory features of BYS are consequential to the absence of a human sucker Ixodes ricinus complex tick at risk areas in Brazil, supporting the concept that the borrelia phenotypic expression pattern is modified as it is transmitted through the host