“…An increasing incidence of Gram-negative infection in hospital practice is now a well-recognized phenomenon and antibiotics undoubtedly contribute to this. The increased incidence of Gram-negative bacillaemias since the introduction of antibacterial agents is reported by Denton et al (1957) and Finland, Jones, and Barnes (1959) while others have recorded rapid Gram-negative colonization of various sites (Redman and Lockey, 1967;Mummery, Bradley, and Jeffries, 1971;Devetski, Tillman, Norsen, and Lepper, 1963;Montgomerie, Doak, Taylor, and North, 1970). The resistance of the patient influences the type of organism.…”