To determine the epidemiological relationship between pneumococci of serotype 9V, with reduced susceptibility to ciprofloxacin, penicillin and erythromycin, referred to the Reference Laboratory during 1997-2001.
Antibiotic Resistance Monitoring and Reference Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, Colindale, London NW9 5HT, UK. alan.johnson@hpa.org.uk
