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Unculturable bacteria--the uncharacterized organisms that cause oral infections

2002; SAGE Publishing; Volume: 95; Issue: 2 Linguagem: Inglês

10.1258/jrsm.95.2.81

1758-1095

William G. Wade,

Enterobacteriaceae and Cronobacter Research

The first bacterial culture media were broths made either by infusion or by enzymatic digestion of meat from various sources. Originally developed by Spallanzani in the 18th century and then refined by Pasteur in the 19th century, these allowed the recovery of bacteria from human disease sites1,2. However, it was quickly realized that such broths would be likely to contain mixtures of micro-organisms, and Robert Koch saw the need for development of solid culture media that would allow the physical separation of bacterial colonies. He first tried aseptically divided potatoes. Material taken from infected lesions was spread across the potato and then incubated at body temperature. Following incubation, bacterial colonies were seen which could be subcultured to further potatoes to give pure cultures. Although successful, Koch observed that only a limited number of the micro-organisms present in the sample grew on the potato. This was probably the first recognition of the phenomenon of unculturability in vitro. Nevertheless, the success of the technique led to the use of solidifying agents such as gelatin and agar to create solid media from the broths developed by Pasteur and others. This advance led to the golden age of medical microbiology, in the last quarter of the 19th century, when many of the bacteria causing serious infections in man were identified. This tremendous success, however, probably led microbiologists to become complacent simply because so many important pathogenic bacteria could be cultured in vitro in this way.