[National surveillance of clinical isolates of Enterococcus faecalis resistant to linezolid carrying the optrA gene in Colombia, 2014-2019]. / Vigilancia nacional de aislamientos clínicos de Enterococcus faecalis resistentes al linezolid portadores del gen optrA en Colombia, 2014-2019.

OBJECTIVE: To describe the epidemiological, phenotypical and genetic characteristics of clinical isolates carrying the optrA gene identified in antimicrobial resistance surveillance by the laboratory of the National Institute of Health of Colombia. METHODS: Between October 2014 and February 2019, 25 isolates of Enterococcus spp. resistant to linezolid were received. Antimicrobial identification and sensitivity were determined using Vitek 2 and the minimum inhibitory concentration (MIC) to linezolid was established with E-test. The optrA gene was detected by PCR, and the genetic diversity of optrA-positive isolates was tested with Diversilab®. Six isolates were selected to perform whole genome sequencing. RESULTS: The optrA gene was confirmed in 23/25 isolates of E. faecalis from seven departments in Colombia. The isolates presented a MIC to linezolid between 8 and >256µg/mL. Typing by Diversilab® showed a wide genetic variability. All the isolates analyzed by whole genome sequencing showed the resistance genes fexA, ermB, lsaA, tet(M), tet(L) and dfrG in addition to optrA and were negative for other mechanisms of resistance to linezolid. Three type sequences and three optrA variants were identified: ST16 (optrA-2), ST476 (optrA-5) and ST618 (optrA-6). The genetic environment of the optrA-2 (ST16) isolates presented the impB, fex, optrA segment, associated with plasmid, while in two isolates (optrA-6 and optrA-5) the transferable chromosomal element Tn6674-like was found. CONCLUSION: OptrA-positive clinical isolates present a high genetic diversity, with different optrA clones and variants related to two types of structures and different mobile genetic elements.

Vigilancia nacional de aislamientos clínicos de Enterococcus faecalis resistentes al linezolid portadores del gen optrA en Colombia, 2014-2019

Objetivo. Describir las características epidemiológicas, fenotípicas y genéticas de aislamientos clínicos portadores de optrA identificados en la vigilancia de resistencia antimicrobiana por el laboratorio del Instituto Nacional de Salud de Colombia. Métodos. Entre octubre de 2014 y febrero 2019, se recibieron 25 aislamientos de Enterococcus spp. resistentes al linezolid. La identificación y sensibilidad antimicrobiana se determinó con Vitek 2 y la concentración inhibitoria mínima (CIM) al linezolid se estableció con E-test. El gen optrA se detectó mediante PCR. La diversidad genética de aislamientos positivos para optrA se analizó con Diversilab®. Se seleccionaron seis aislamientos para llevar a cabo la secuenciación del genoma completo. Resultados. Se confirmó el gen optrA en 23/25 aislamientos de E. faecalis de siete departamentos de Colombia. Los aislamientos presentaron una CIM al linezolid entre 8 y >256μg/mL. La tipificación por Diversilab® indicó una amplia variabilidad genética. Todos los aislamientos analizados mediante secuenciación del genoma completo, presentaron genes de resistencia fexA, ermB, lsaA, tet(M), tet(L) y dfrG además de optrA y fueron negativos para otros mecanismos de resistencia al linezolid. Se identificaron tres secuencias tipos y tres variantes de optrA: ST16 (optrA-2), ST476 (optrA-5) y ST618 (optrA-6). El entorno genético de los aislamientos optrA-2 (ST16) presentó el segmento impB, fex, optrA, asociado a plásmido, mientras que en dos aislamientos (optrA-6 y optrA-5) se encontró el elemento cromosómico transferible Tn6674-like. Conclusión. Los aislamientos clínicos positivos para optrA presentan una alta diversidad genética, con diferentes clones y variantes de optrA relacionados con dos tipos de estructuras y diferentes elementos genéticos móviles.

Objective. To describe the epidemiological, phenotypical and genetic characteristics of clinical isolates carrying the optrA gene identified in antimicrobial resistance surveillance by the laboratory of the National Institute of Health of Colombia. Methods. Between October 2014 and February 2019, 25 isolates of Enterococcus spp. resistant to linezolid were received. Antimicrobial identification and sensitivity were determined using Vitek 2 and the minimum inhibitory concentration (MIC) to linezolid was established with E-test. The optrA gene was detected by PCR, and the genetic diversity of optrA-positive isolates was tested with Diversilab®. Six isolates were selected to perform whole genome sequencing. Results. The optrA gene was confirmed in 23/25 isolates of E. faecalis from seven departments in Colombia. The isolates presented a MIC to linezolid between 8 and >256μg/mL. Typing by Diversilab® showed a wide genetic variability. All the isolates analyzed by whole genome sequencing showed the resistance genes fexA, ermB, lsaA, tet(M), tet(L) and dfrG in addition to optrA and were negative for other mechanisms of resistance to linezolid. Three type sequences and three optrA variants were identified: ST16 (optrA-2), ST476 (optrA-5) and ST618 (optrA-6). The genetic environment of the optrA-2 (ST16) isolates presented the impB, fex, optrA segment, associated with plasmid, while in two isolates (optrA-6 and optrA-5) the transferable chromosomal element Tn6674-like was found. Conclusion. OptrA-positive clinical isolates present a high genetic diversity, with different optrA clones and variants related to two types of structures and different mobile genetic elements.

Aislamientos invasivos de Haemophilus influenzae en menores de 5 años: distribución de los serotipos y de la sensibilidad antimicrobiana, SIREVA II Colombia 2002-2013 / Invasive Haemophilus influenzae isolates in children younger than 5 years: Distribution of serotypes and antimicrobial sensitivity, SIREVA II Colombia 2002-2013

Objetivo: Analizar del 2002 al 2013 los datos de la vigilancia de los serotipos y sensibilidad antimicrobiana de los aislamientos invasivos de Haemophilus influenzae ( H. influenzae ) en niños menores de 60 meses. Materiales y métodos: Se analizaron los datos demográficos, fuente y enfermedad asociada de los aislamientos invasivos de H. influenzae recibidos entre 2002 y 2013. Todos los aislamientos habían sido confirmados bacteriológicamente, tenían el dato del serotipo, el cual fue determinado por el método de aglutinación en lámina y PCR y los patrones de sensibilidad antimicrobiana por concentración inhibitoria mínima a ampicilina, SXT, cloranfenicol, cefuroxima y ceftriaxona. El análisis se realizó por periodos de 3 años. Resultados: Por enfermedad invasiva el 50,5% eran de pacientes con meningitis, 23,5% de neumonías, 19,5% de sepsis y bacteriemia, 2,0% de otros y 4,5% sin dato. Por procedencia se recibieron de Bogotá y Antioquia 55 aislamientos de cada uno, de Risaralda 24, de Valle 15, de Santander 11 y 40 de 14 departamentos. El serotipo predominante fue el Hib (40,5%), seguido de HiNT (38,0%), Hia (17,5%), Hid (2,0%), Hif (1,5%) y Hie (0,5%). Del total de los aislamientos, 12,0% eran resistentes a ampicilina; 16,5% a SXT; 1,0% a cloranfenicol y 0,5% a ceftriaxona. Todos los aislamientos fueron sensibles a cefuroxima y a rifampicina. Conclusiones: La vigilancia por el laboratorio es una vigilancia pasiva voluntaria pero, no obstante el número reducido de aislamientos, permite determinar que Hib continúa circulando en esta población y que hay otros serotipos de H. influenzae que causan enfermedad invasiva. Por tanto es necesario mantener y fortalecer la vigilancia de este patógeno.

Objective: To analyze 2002-2013 surveillance data on the serotypes and antimicrobial sensitivity of invasive Haemophilus influenzae ( H. influenzae ) isolates in children younger than 60 months. Materials and methods: We analyzed the demographic data, source and associated diseases ofinvasive HI isolates from cases recorded from 2002-2013. All isolates had been bacteriologically confirmed and had data on their serotype, which was determined by the slide agglutination method and polymerase chain reaction. The antimicrobial sensitivity patterns were determined by minimum inhibitory concentration of ampicillin, trimethoprim-sulfamethoxazole, chloramp-henicol, cefuroxime and ceftriaxone. The analysis was conducted in 3-year periods. Results: According to invasive disease, 50.5% of patients had meningitis, 23.5% had pneumonia,19.5% had sepsis and bacteremia, 2.0% had other diseases and 4.5% lacked data. By origin, 55 isolates each were received from Bogota and Antioquia, 24 were from Risaralda, 15 were from Valle, 11 were from Santander and 40 came from 14 departments. The predominant serotype was Hib (40.5%), followed by HiNT (38.0%), Hia (17.5%), Hid (2.0%), Hif (1.5%) and Hie (0.5%). Ofthe total isolates, 12.0% were resistant to ampicillin; 16.5% to trimethoprim-sulfamethoxazole,1.0% to chloramphenicol and 0.5% to ceftriaxone. All isolates were sensitive to cefuroxime andrifampicin. Conclusions: Laboratory surveillance is a voluntary passive surveillance; however, the low number of isolates helped determine that Hib continues to circulate in this population and that there are other H. influenzae serotypes that cause invasive disease. Therefore, surveillance of this pathogen needs to be maintained and reinforced.