RESUMEN
BACKGROUND: Macrolide and lincosamide resistance in Streptococcus pyogenes is due to the acquisition of mef, ermB and ermA genes, which confer different resistance phenotypes, namely M, MLSBconstitutive and MLSBinducible respectively. The last report of resistance in Chile was done in the period 1990-1998, in which resistance to macrolides was 5.4%, with M phenotype as the predominant one. AIM: To characterize the evolution of erythromycin and clindamycin resistance and their associated genes in S. pyogenes strains isolated from patients with invasive and non-invasive infections in the period 1996 to 2005. MATERIAL AND METHODS: Resistance to erythromycin and clindamycin was determined in 1,282 clinical isolates using the disk diffusion test. Resistant isolates were analyzed by polymerase chain reaction (PCR) for the presence of the above mentioned resistance genes. RESULTS: Global resistance to erythromycin and clindamycin was 3.5 and 0.7% respectively. Eighty percent of the resistant strains possessed the M. phenotype. CONCLUSIONS: Resistance levels of S. pyogenes have decreased in Chile in the last years. Most resistant strains have M phenotype in contrast to many countries in which the MLSB constitutive phenotype is the predominant one.
Asunto(s)
Antibacterianos/farmacología , Clindamicina/farmacología , Farmacorresistencia Bacteriana/genética , Eritromicina/farmacología , Faringitis/microbiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/efectos de los fármacos , Proteínas Bacterianas/genética , Chile/epidemiología , Farmacorresistencia Bacteriana/efectos de los fármacos , Genotipo , Humanos , Proteínas de la Membrana/genética , Metiltransferasas/genética , Faringitis/tratamiento farmacológico , Fenotipo , Distribución de Poisson , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus pyogenes/genéticaRESUMEN
OBJECTIVES: To describe risk factors for acquired infection during neonatal extracorporeal membrane oxygenation and to examine the predictive value of inflammatory markers in the diagnosis of infection. METHODS: A retrospective study was conducted with data for patients under 30 days supported with extracorporeal membrane oxygenation from 2003 to April 2016, in a neonatal intensive care unit. RESULTS: Our study included 160 neonatal patients, the average age of connection was 8.5 days and the duration of extracorporeal membrane oxygenation support was 9.7 days. The incidence of confirmed infection was 23%. Patients with confirmed infection present more frequently: vaginal delivery, lower birth weight, female sex, diagnosis of congenital diaphragmatic hernia, and longer duration of extracorporeal membrane oxygenation. When comparing the group of patients with confirmed infection and suspicion of infection, there were no significant differences in the inflammatory markers. When calculating the slope for each one, the difference in white blood cell count slope 72 h before the infection is significant; in patients with confirmed infection, the count of white blood cell increases (slope: 0.25), versus the group of patients with suspected infection in whom the count decreases (slope: -0.39). No differences were found in other variables. CONCLUSION: Our study describes that the factors that increase the risk of infection are lower birth weight, vaginal birth, duration of extracorporeal membrane oxygenation, and a positive trend of white blood cell 72 h prior to infection/suspicion. Further studies are necessary to include or definitively rule out the use of these factors and the biomarkers as predictors of infection in neonatal patients supported with extracorporeal membrane oxygenation.
RESUMEN
Background: Macrolide and lincosamide resistance in Streptococcus pyogenes is due to the acquisition of mef, ermB and ermA genes, which confer different resistance phenotypes, namely M, MLSBconstitutive and MLSBinducible respectively. The last report of resistance in Chile was done in the period 1990-1998, in which resistance to macrolides was 5.4 percent, with M phenotype as the predominant one. Aim: To characterize the evolution of erythromycin and clindamycin resistance and their associated genes in S. pyogenes strains isolated from patients with invasive and non-invasive infections in the period 1996 to 2005. Material and Methods: Resistance to erythromycin and clindamycin was determined in 1,282 clinical isolates using the disk diffusion test. Resistant isolates were analyzed by polymerase chain reaction (PCR) for the presence of the above mentioned resistance genes. Results: Global resistance to erythromycin and clindamycin was 3.5 and 0.7 percent respectively. Eighty percent of the resistant strains possessed the M. phenotype. Conclusions: Resistance levels of S. pyogenes have decreased in Chile in the last years. Most resistant strains have M phenotype in contrast to many countries in which the MLSB constitutive phenotype is the predominant one.