Amino acid requirements of a Chlamydia trachomatis genital strain in McCoy cell cultures

The amino acid requirements of Chlamydia trachomatis were defined in McCoy cell monolayer cultures, depleted of their nutrient reserves by maintenance in Earle balanced salt solution for at least 2 days, and then treated at infection with 1 μg of cycloheximide per ml, an inhibitor of host cell protein and deoxyribonucleic acid synthesis. Serum-free Waymouth MB 752/1 medium lacking one amino acid or a group of related amino acids was added to depleted cultures before infection. Eight of the amino acids normally present in MB 752/1 were essential for chlamydial growth, six were advantageous for growth, and five were nonessential.