Methods are described for determining whether a subject suffering from, or suspected of suffering from, an infectious disease caused by a microbe is infected with a strain of the microbe that is susceptible to an antimicrobial agent, where there exist different strains of the microbe that are resistant to the antimicrobial agent. The methods comprise determining whether nucleic acid of the strain of the microbe infecting the subject comprises wild-type nucleotide sequence at a conserved nucleotide position at which mutation is associated with resistance to the antimicrobial agent in nucleic acid of the different resistant strains. The methods are particularly applicable for determining whether a subject suffering from, or suspected of suffering from, Gonorrhoea is infected with a strain of Neisseria gonorrhoeae that is susceptible to an antimicrobial agent. Kits for use in the methods are described, as well as methods for treatment of infectious disease. Methods for reducing the prevalence of resistance of microbes causing infectious disease to antimicrobial agents are also described.
