CHARACTERIZATION OF NEISSERIA-MENINGITIDI S ISOLATED DURING SYSTEMIC INFECTIONS IN CHILE - 1992-1993

Background: In Chile, all systemic infections caused by Neisseria meni ngitidis must be reported and the bacterial strain must be sent to a R eference Laboratory at the Instituto de Salud Publica de Chile (ISP). Aim: to report the characterization of strains of N. meningitidis isol ated during systemic infections in Chile during the years 1992 and 199 3. Methods: the serogroup, serotype, subtype and antimicrobial suscept ibility of every strain of N. meningitidis received at the ISP during 1992 and 1993 was studied. Results: six hundred twenty eight strains o f N. meningitidis were confirmed during 1992 and 1993. B serogroup was responsible of 91.1% and 94.7% of confirmed cases during 1992 and 199 3 respectively. Serotypes and subtypes most frequently associated to B serogroup were B: 15: P1.3 (63.2% in 1992 and 51.8% in 1993) and B:NT :P1.3 (11.7% in 1992 and 21.3% in 1993). In 1992, all strains were sus ceptible to penicillin, chloramphenicol, ceftriaxone and rifampicin. D uring 1993, 7 (2%) strains were found, for the first time in Chile, mo derately susceptible to penicillin and rifampicin MIC90 increased four fold in respect of 1992, although all strains continued to be suscepti ble to this antimicrobial. Conclusions: the increasing frequency of NT (non typified strains) isolation will demand the use of molecular bio logy techniques for their identification. The appearance of penicillin resistant strains in our country is worrisome.