Increased recovery of Legionella micdadei and Legionella bozemanii on buffered charcoal yeast extract agar supplemented with albumin

Abstract

The recovery of Legionella micdadei and L. bozemanii serogroups 1 and 2 from infected guinea pig spleens was evaluated by using two culture media: buffered charcoal yeast extract agar with 0.1% α-ketoglutarate (BCYEα) and the same medium supplemented with 1% bovine serum albumin (ABCYEα). At the lowest dilution of spleen tissue (10-1), recovery of all strains of L. micdadei and L. bozemanii was more efficient on ABCYEα than on BCYEα. L. micdadei strains had higher recovery rates on ABCYEα after another 10-fold dilution, but recoveries of L. bozemanii were similar on both media. Recovery rates for most test strains were comparable on BCYEα and ABCYEα at the highest dilution (10-3) of tissue tested. The presence of albumin in BCYEα increased the recovery rate of L. micdadei more than that of L. bozemanii. The use of ABCYEα medium in place of BCYEα may improve the recovery of L. micdadei and L. bozemanii from clinical specimens. Preliminary studies indicate that this medium also enhances recovery of certain Legionella spp. from environmental samples.