31.   Resistant strains are going to stay there?

32.   Researchers suspect that people may have picked up the resistant strain from food.

33.   Saliba noted that the over-prescribing of antibiotics has become a grave public health concern, with the emergence of resistant strains of bacteria.

34.   Scientists have learned that HIV strains resistant to AZT and some protease inhibitors existed before the drugs were ever given to AIDS patients.

35.   Some highly resistant strains of infectious bacteria are now all but untreatable because they are resistant to virtually all classes of antibiotics.

36.   Such resistance occurs inevitably over time as an antibiotic kills off susceptible strains of a germ and leaves only the more resistant strains to proliferate.

37.   The authors said the result was often treatment failure or the circulation of substandard drugs, which contributed to the development of resistant strains of microbes.

38.   The researchers found that the AIDS virus, which mutates easily, produces so many molecular variations of itself that it can almost instantly generate resistant strains.

39.   The rising tide of resistant strains is complicating efforts to control the disease.

40.   There is the ancient torment, malaria, present now in strains resistant to the commonly used drugs.