Caracterización molecular de aislamientos invasores colombianos de Streptococcus pneumoniae serotipo 5 recuperados entre 1994 y 2004.

Abstract

Introducción. Streptococcus pneumoniae serotipo 5 es causa importante de enfermedad invasora en Colombia, donde se ha demostrado la circulación del clon 19-Colombia 5 susceptible a penicilina pero resistente a tetraciclina y a cloranfenicol. Objetivo. Establecer las relaciones genéticas de aislamientos invasores colombianos de S. pneumoniae serotipo 5 recuperados entre 1994 y 2004 con el clon 19-Colombia 5 . Materiales y métodos. Se estudiaron 83 aislamientos que tenían datos de susceptibilidad a penicilina, vancomicina, ceftriaxona, eritromicina, trimetoprim sulfametoxazol, cloranfenicol y tetraciclina, de los cuales 29 fueron obtenidos de niños menores de cinco años. El patrón de restricción del ADN se determinó por electroforesis en gel de campo pulsado, usando la enzima Sma I. La similitud genética entre los aislamientos y el clon se estableció según los criterios de Tenover y utilizando el programa Fingerprinting II. Resultados. Todos los aislamientos se relacionaron con el clon 19-Colombia 5 y se agruparon en el patrón electroforético A con 17 subtipos. El patrón A se estableció en 32 aislamientos (38,6%), el A8 en 18 (21,7%) y el A5 en 10 (12%), los 15 patrones restantes agruparon los otros 23 aislamientos. Los 34 aislamientos resistentes a tetraciclina y cloranfenicol mostraron relación con los patrones electroforéticos A (n = 32), A16 (n = 1) y A28 (n = 1), caracterizados, al igual que el clon, por presentar una banda de 340 Kb. Conclusión. Estos resultados muestran la circulación continua en el país de aislamientos de S. pneumoniae serotipo 5 genéticamente relacionados con el clon 19-Colombia 5 .Palabras clave: Streptococcus pneumoniae, meningitis, neumonía, electroforesis en gel de campo pulsado, resistencia a la tetraciclina, resistencia a cloranfenicol. Molecular characterization of Colombian invasive serotype 5 Streptococcus pneumoniae isolates recovered between 1994 and 2004Background. Streptococcus pneumoniae serotype 5 is an important cause of invasive disease in Colombia where the circulation of the clone Colombia 5 -19, penicillin susceptible but tetracycline and chloramphenicol resistant, has been demonstrated. Objective. To establish the genetic relatedness among Colombian invasive S. pneumoniae serotype 5 isolates, recovered between 1994 and 2004, and the clone Colombia 5 -19. Materials and methods. Eighty three isolates with penicillin, vancomycin, ceftriaxone, erythromycin, trimethoprim-sulfametoxazole, chloramphenicol and tetracycline susceptibility patterns were studied. Of these isolates, 29 were recovered from children less than 5 years of age. DNA restriction patterns of all isolates were determined for pulsed field gel electrophoresis, using the SmaI enzyme. Genetic similarity among isolates and the clone Colombia 5 -19 was established according to Tenover's criteria and the Fingerprintingä II program. Results. All isolates were related with the Colombia 5 -19 clone and belonged to the electrophoretic pattern A, of which 17 subtypes were derived. Most of the isolates belonged to pat...

Circulation of Streptococcus pneumoniae clone Colombia5 ST289 in nine Latin American countries

“…According to the PFGE band patterns, all isolates identified across 15 Latin American countries in this study and in previous studies (11,16) had a genetic similarity higher than 78.5% ( Figure 2), which indicates that all of them belong to the same clonal group. Based on the results of this study and the previous studies mentioned above, a map of the geographic distribution of the main electrophoretic subtypes identified thus far in the 15 countries was elaborated (Figure 3).…”

“…For this reason, the low frequency of tetracycline-resistant isolates found in this study (9.1%) can be explained by the fact that isolates were recovered from children less than 5 years of age, in whom tetracycline is not a recommended treatment (17). In Colombia, tetracycline is used in the treatment of pneumonia in adults (18,19), and it has been reported that 55.6% of S. pneumoniae isolates recovered from patients older than 5 years of age are resistant (16). The proportion of isolates in this study that were resistant to TMP-SMX (68.2%) was lower than the overall resistance (80.8%) reported by Argentina, Brazil, Colombia, Mexico, and Uruguay (11).…”

“…Table 2 shows the 13 subtypes identified as derived of pattern A among the 44 isolates. Subtypes A5, A6, A8, A13, and A27, originally identified in previous studies (11,16), comprised 61.4% of the isolates. In contrast, subtypes A28 to A35 were recognized for the first time in this study and included 38.6% of the isolates.…”

“…Tetracycline and chloramphenicol resistance of the Nicaragua isolates (subtypes A, A31, A32, and A33) was associated with an approximately 340-kb fragment restriction that has been related to this type of resistance in the A pattern of the Colombia 5 ST289 clone (10) as well as some other subtypes, including A1, A3, A16, and A28 (11,16). Tetracycline resistance can be attributed to the selec- tive pressure generated by the use of this antibiotic as treatment for pneumococcal diseases (1,5).…”

“…The electrophoretic patterns identified in the current study were compared with those previously determined in Colombia and other Latin American countries (11,16) to determine if the same patterns are present in different countries of the region.…”