Nueva Delhi metalo--ß--lactamasa en especies de Enterobacteriaceae aisladas de pacientes hospitalizados, Managua, Nicaragua / New Delhi Metallo--ß-lactamase in Enterobacteriaceae species isolated from hospitalized patients, Managua Nicaragua

Resumen Objetivo: determinar la frecuencia de metalo-β lactamasa tipo Nueva Delhi (NDM), en aislados de enterobacterias provenientes de pacientes hospitalizados con diferentes procesos infecciosos. Método: se realizó una investigación descriptiva transversal, agosto 2015 - octubre 2016, en el Hospital Alemán Nicaragüense. Se estudiaron 249 cepas en vigilancia activa a los carbapenémicos. La identificación y perfil de resistencia se efectuó en Vitek2; la sospecha de resistencia a los carbapenémicos se tomó cuando la CMI de Imipenem y Meropenem 2-4 μg/mL y Ertapenem 2 μg/mL, se determinó mediante Kirby Bauer, el test de sinergia triple disco (carbapenémicos y EDTA 10µg); se hizo la reacción en cadena de la polimerasa para metalo-β-lactamasa Nueva Delhi. Resultados: se analizaron 249 cepas, entre estas se identificó 45 cepas resistentes a los carbapenémicos, correspondiendo al 18%. De estas cepas, 43 dieron positivo para el test de sinergia con EDTA; 21 portaban el gen de Nueva Delhi. El 66% de metalo-β-lactamasa Nueva Delhi se encontró en aislamientos de Klebsiella pneumoniae, seguida de Escherichia vulneris en un 14%, Escherichia coli en un 5%, Providencia rettgeri en un 5%, Pantoea agglomerans en un 5% y Kluyvera cryocrescens en un 5%.19 Conclusiones: el hallazgo del presente estudio es una advertencia clara sobre la circulación de cepas de metalo-β-lactamasa tipo Nueva Delhi que codifican la resistencia a los carbapenémicos en el hospital analizado.

Abstract Objective: to determine the frequency of New Delhi-type metallo-β-lactamase (NDM) in isolates of enterobacteria from patients hospitalized with different infectious processes. Method: a cross-sectional descriptive study was carried out between August 2015 and October 2016 at Alemán Nicaragüense Hospital. A total of 249 strains were studied in active surveillance of carbapenems resistance. The identification and resistance profile was carried out in Vitek2. Suspected resistance to carbapenems was considered when the MIC of Imipenem and Meropenem was 2-4 μg/mL and for Ertapenem of 2 μg/mL, determined by Kirby Bauer, the triple disc synergy test (carbapenems and EDTA 10μg). A polymerase chain reaction test was made to determinate New Delhi metallo-β lactamase. Results: a total of 249 strains were analyzed, among which 45 strains resistant to carbapenems were identified, corresponding to 18%. Of these strains, 43 were positive for the synergy test with EDTA; 21 carried the New Delhi gene. Of the New Delhi metallo-β lactamase. 66% were found in isolates of Klebsiella pneumoniae, followed by Escherichia vulneris in 6 isolates, Escherichia coli in 2, Providencia rettgeri in 2, Pantoea agglomerans in 2 and Kluyvera cryocrescens by 2. Conclusions: the results of the present study are a clear warning about the circulation of New Delhi-type metallo-β-lactamase strains that codify for the resistance to carbapenems in the hospital analyzed.

Hb Presbyterian (HBB: c.327C>G) in a Nicaraguan Family.

Hemoglobin (Hb) is the protein responsible for oxygen transportation. It is a tetrameric protein comprising two α- and two ß-globin subunits. In the literature, a large number of mutations in the α- and ß-globin genes have been documented. Among these mutations, Hb Presbyterian (HBB: c.327 C>G), is a naturally occurring mutant exerting low oxygen affinity. The C to G exchange (AAC>AAG) at codon 108 of the ß-globin gene results in the substitution of asparagine by lysine. Here, we document the identification of HBB: c.327 C>G in a 6-year-old female patient and her father from Nicaragua and Cuba, respectively. The presence of the abnormal Hb was confirmed by cellulose acetate electrophoresis, high performance liquid chromatography (HPLC) and genomic DNA sequencing. The ß-globin gene sequences for both, father and daughter, disclosed the heterozygous mutation at codon 108 to be Hb Presbyterian or HBB: c.327 C>G. The mutant Hb was previously reported in four families from North America, Germany, Japan and Spain, respectively. This is the fifth family carrying HBB: c.327 C>G described to date and the first report from Latin America.