By Karolos Grohmann RIO DE JANEIRO, Aug 18 (Reuters) - Bronze medallist weightlifter Izzat Artykov on Thursday became the first athlete to be stripped of a Rio Olympics medal, testing positive for drugs as doping moved into the spotlight with the Games entering the final stretch. The International Olympic Committee (IOC) had executed the most extensive pre-Games drugs testing plan while also re-testing hundreds of samples from the previous two Olympics in London and Beijing in an effort to root out cheats. Despite discovering 98 positive samples in the re-tests and banning those athletes from Rio and dozens more in targeted pre-competition tests, several more athletes were caught at the Games. More...