Infections due to organisms of the genus Herellea. B5W and B. anitratum.

The common bacterial infections have, until relatively recently, been caused by bacteria that were not indigenous to the host but rather were acquired by the host from external sources. The decline in prevalence of the common communicable infections such as tuberculosis, diphtheria, etc., has occurred steadily during the latter decades of the 19th century and the early decades of the 20th. This decline was perhaps accelerated by the development of specific prophylactic and therapeutic agents, although the evidence that these agents were critical to this declining pattern is far from secure. However, accompanying the decline in the prevalence of the commonest infections of other decades has been an increase in infections due to bacteria that are indigenous to the host. The latter organisms are from genera that are usually ordinary inhabitants of the host, and, perhaps because of the widespread use of antibacterial agents, these organisms are often already resistant