1940

Eward Abraham and Ernst Chain report first instance of antibiotic resistance: a strain of E. coli that inactivated penicillin by producing the enzyme penicillinase. (The mechanism of deactivation: beta-lactamase enzymes hydrolyze [break down with water] the beta-lactam rings of the penicillins and, in another variant, cephalosporins [Lin, et al.] . The spread of this resistance was documented by 1942, when four strains of Staphylococcus aureus, which inactivated penicillin among hospitalized patients. The spread was temporarily halted in the 1960s with introduction of the semi- synthetic methicillin, but methicillin-resistant strains of S. aureus shortly emerged, and it was only in 1981 that the mechanism of resistance was unraveled. By then strains of pneumococcus had also proven penicillin-resistant (beginning in 1967) and in 1976 beta lactamase-producing gonococci were isolated in England and the U.S., followed by rapid spread of gonococcal penicillin-resistant strains, esp. in Asia (Lobanova & Pilla).