In 1967 a penicillin-resistant pneumonia, caused by streptococcus pneumoniae and called pneumococcus, surfaced in a remote village in papua, new guinea. at about the same time american military personnel in southeast asia were acquiring penicillin-resistant gonorrhea from prostitutes. by 1976, when the soldiers had come home, they brought the new strain of gonorrhea with them and physicians had to find new drugs to treat it. in 1983 a hospital-acquired intestinal infection caused by the bacterium enterococcus faecium joined the list of bacteria that could not be killed by penicillin. which of these best describes why certain bacteria have become resistant to penicillin?