Nutritional Requirements and Antibiotic Resistance Patterns ofHelicobacterSpecies in Chemically Defined Media

The growth of the gastric pathogenHelicobacter pylori in the absence of serum remains challenging, and nutritional requirements have only partially been defined, while almost nothing is known about nutritional requirements of otherHelicobacter spp. Although previous data showed thatH. pylori grows in the chemically defined medium F-12, but not in other tissue culture media examined, the specific components responsible for growth were not entirely understood. Here we describe the optimization of amino acids, metals, and sodium chloride forH. pylori . Iron, zinc, and magnesium were critical for growth; copper was not required. Optimization of sodium chloride was further beneficial. Nutritional requirements and antibiotic resistance patterns of several otherHelicobacter spp. revealed that all exceptH. felis grew in serum-free, unsupplemented F-12. AllHelicobacter spp. were resistant to at least six antimicrobial agents when cultured in the presence of serum. However, in the absence of serum,H. pylori ,H. mustelae , andH. muridarum became sensitive to polymyxin B and/or trimethoprim. Much of the data were obtained using a convenient ATP assay to quantify growth.H. pylori has surprisingly few absolute requirements for growth: 9 amino acids, sodium and potassium chloride, thiamine, iron, zinc, magnesium, hypoxanthine, and pyruvate. These data suggest thatH. pylori and otherHelicobacter spp. are not as fastidious as previously thought. The data also suggest that chemically defined media described herein could yield the growth of a wide range ofHelicobacter spp., allowing a more detailed characterization ofHelicobacter physiology and interactions with host cells.