Janet, Remember, it is not the person who is resistant to the antibiotic, it is the germs that the person harbors. Resistance is most likely when someone takes the drug for a few days, feels better, then discontinues it. Then the stronger (more antibiotic resistant) germs reproduce. Do this a few times and you have multidrug resistant bugs. Was your mastitis hospital aquired? Hospitals are the source of some of the "best" germs, due to the constant selective pressure of antibiotics and germicides. If even one resistant germ is left behind, it can have millions of babies by tomorrow.... Just another one of my 'pet peeves', Catherine Watson Genna, IBCLC NYC [log in to unmask]