Milk from before antibiotic era were resistant to antibiotic tetracycline
The researchers started with 50 samples collected from 1941 to 1947, and they found that the samples contained seven different Streptococcus species, including two subspecies of S. dysgalactiae. Interestingly, the researchers found some of the samples were resistant to the antibiotic tetracycline and did not carry antibiotic resistance genes typically seen in today's antibiotic-resistant bacterial strains. Since these samples were collected prior to the antibiotic era, the results add to a growing body of literature showing that antibiotic resistance occurred naturally before humans discovered...
Source: sciencedaily.com
