A student streaks an agar plate with two strains of streptococcus aureus. *
The agar plate contains the antibiotic streptomycin. After 48 hrs of
incubation at room temperature the agar plate shows no growth. What is
the best explanation for this result?
both strains of bacteria are resistant to the antibiotic
both strains of bacteria are sensitive to the antibiotic
there was an error in plate preparation
bacterial conjugation has occurred