Haemophilus influenzae

Haemophilus influenzae holds a unique place in biological history: it was the first free-living organism to have its complete genome sequenced, in 1995. This achievement revealed the extent of horizontal gene transfer in bacterial evolution—analysis showed that roughly 20% of H. influenzae genes appeared to have been acquired from other species. The bacterium also demonstrated natural competence, actively importing DNA from its environment in a regulated process that increases when nutrients become limiting.

H. influenzae's competence system shows remarkable specificity. The bacterium preferentially takes up DNA containing a specific 9-base uptake signal sequence, which appears nearly 1,500 times in its own genome—far more than expected by chance. This means H. influenzae efficiently imports DNA from its own species or close relatives while largely ignoring foreign DNA. The system creates a genetic commons among H. influenzae strains while maintaining species boundaries. It's selective openness: receptive to relevant innovations while filtering out noise.

The bacterium's lifestyle illustrates the power of strategic dependency. H. influenzae requires growth factors (X and V factors) found in blood, making it dependent on host environments. Rather than maintaining the full metabolic machinery to synthesize these factors—as E. coli does—H. influenzae deleted these pathways and committed to environments where the factors are available. This streamlining reduced genome size and metabolic costs while restricting ecological range. The tradeoff between autonomy and efficiency echoes throughout business strategy: specialized dependence on specific resources or relationships can enable superior performance in narrow contexts.