title: A sudden decline in ampicillin resistance in Salmonella typhimurium.
abstract: Starting in 1975, an abrupt decline in ampicillin resistance of Salmonella typhimurium (the most common and antibiotic-resistant serotype) occurred in New York City. The present lower rate of 5% to 7.9% at our hospitals represents a return to the 1965 level. At the same time, the ampicillin resistance in S typhimurium from calves and other farm animals from upper New York State, which has been rising since 1972, has reached 75%. Substantial differences between levels of resistance in Escherichia coli from animals and humans were also noted. The divergence of the trends in S typhimurium from these two sources in New York State suggests a substantial degree of separation of the respective reservoirs of Salmonella and of antibiotic resistance.
mesh_terms: D000667:Ampicillin / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002417:Cattle / Q000382:microbiology*; D004197:Disease Reservoirs / Q000662:veterinary; D006801:Humans; D009518:New York; D009519:New York City; D010403:Penicillin Resistance; D012481:Salmonella Infections, Animal / Q000382:microbiology / Q000635:transmission; D012486:Salmonella typhimurium / Q000145:classification / Q000187:drug effects*
chemical_list: D000667:Ampicillin