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Biomedical subjects

M E Valenzuela

Publications and source records attributed to M E Valenzuela.

9 recordsLinked to original sources

Development of highly specific monoclonal antibodies for the diagnosis of Vibrio cholerae 01.

We report here the development of two monoclonal antibodies, termed 5G8 and 5C12, belonging to the IgM and IgG1 class, respectively, suitable for the identification of Vibrio cholerae 01 in clinical and environmental samples. The specificities of the monoclonals were evaluated by ELISA and indirect immunofluorescent microscopy of microorganisms normally present in stool samples and with two bacterial panels. One panel included 72 potentially antigenically related bacterial strains and the second panel included 20 pathogenic bacterial strains involved in diarrhea cases. The results of these extensive analyses indicate that monoclonal antibodies 5G8 and 5C12 are highly specific and suitable for the clinical diagnosis of Vibrio cholerae 01 in human stool samples by indirect immunofluorescent microscopy. Although the antigenic sites recognized by these antibodies were not identified in this study, the observation of Western blot patterns suggested that 5G8 and 5C12 monoclonal antibodies bind to LPS epitopes, a good structural marker for the detection of V. cholerae 01 because it is present in all bacterial cell walls.

Animals

[Characterization of Neisseria meningitidis isolated fron systemic infections. Chile, 1992-1993].

BACKGROUND: in Chile, all systemic infections caused by Neisseria meningitidis must be reported and the bacterial strain must be sent to a Reference Laboratory at the Instituto de Salud Pública de Chile (ISP). AIM: to report the characterization of strains of N. meningitidis isolated during systemic infections in Chile during the years 1992 and 1993. METHODS: the serogroup, serotype, subtype and antimicrobial susceptibility of every strain of N. meningitidis received at the ISP during 1992 and 1993 was studied. RESULTS: six hundred twenty eight strains of N. meningitidis were confirmed during 1992 and 1993. B serogroup was responsible of 91.1% and 94.7% of confirmed cases during 1992 and 1993 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 susceptible to penicillin, chloramphenicol, ceftriaxone and rifampicin. During 1993, 7 (2%) strains were found, for the first time in Chile, moderately susceptible to penicillin and rifampicin MIC90 increased fourfold in respect of 1992, although all strains continued to be susceptible to this antimicrobial. CONCLUSIONS: the increasing frequency of NT (non typified strains) isolation will demand the use of molecular biology techniques for their identification. The appearance of penicillin resistant strains in our country is worrisome.

Chile