RESUMEN
We report the case of a catheter-related bloodstream infection caused by Chryseobacterium indologenes, an uncommon and multi-resistant pathogen, in a pediatric patient with a long-term vascular access device placed for chemotherapy treatment. The infection was successfully treated with ciprofloxacin antibiotic-lock therapy. This is the first report on successful salvage of a long-term device colonized by multi-resistant Chryseobacterium indologenes.
Asunto(s)
Bacteriemia/microbiología , Infecciones Relacionadas con Catéteres/microbiología , Catéteres Venosos Centrales/microbiología , Chryseobacterium/aislamiento & purificación , Infecciones por Flavobacteriaceae/microbiología , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Infecciones Relacionadas con Catéteres/tratamiento farmacológico , Niño , Chryseobacterium/efectos de los fármacos , Ciprofloxacina/uso terapéutico , Infecciones por Flavobacteriaceae/tratamiento farmacológico , Humanos , Masculino , Sarcoma de Ewing/complicaciones , Sarcoma de Ewing/tratamiento farmacológico , Resultado del TratamientoRESUMEN
We describe three cases of bloodstream infection caused by colistin-resistant Escherichia coli in patients in a tertiary hospital in Italy, between August 2016 and January 2017. Whole genome sequencing detected the mcr-1 gene in three isolated strains belonging to different sequence types (STs). This occurrence of three cases with mcr-1-positive E. coli belonging to different STs in six months suggests a widespread problem in settings where high multidrug resistance is endemic such as in Italy.
Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Escherichia coli/tratamiento farmacológico , Proteínas de Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Tienamicinas/uso terapéutico , Anciano , Anciano de 80 o más Años , Farmacorresistencia Bacteriana/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/microbiología , Femenino , Humanos , Italia , Meropenem , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Análisis de Secuencia de ADN , Resultado del TratamientoRESUMEN
Klebsiella pneumoniae is at the forefront of antimicrobial resistance for Gram-negative pathogenic bacteria, as strains resistant to third-generation cephalosporins and carbapenems are widely reported. The worldwide diffusion of these strains is of great concern due to the high morbidity and mortality often associated with K. pneumoniae infections in nosocomial environments. We sequenced the genomes of 89 K. pneumoniae strains isolated in six Italian hospitals. Strains were selected based on antibiotypes, regardless of multilocus sequence type, to obtain a picture of the epidemiology of K. pneumoniae in Italy. Thirty-one strains were carbapenem-resistant K. pneumoniae carbapenemase producers, 29 were resistant to third-generation cephalosporins, and 29 were susceptible to the aforementioned antibiotics. The genomes were compared to all of the sequences available in the databases, obtaining a data set of 319 genomes spanning the known diversity of K. pneumoniae worldwide. Bioinformatic analyses of this global data set allowed us to construct a whole-species phylogeny, to detect patterns of antibiotic resistance distribution, and to date the differentiation between specific clades of interest. Finally, we detected an â¼ 1.3-Mb recombination that characterizes all of the isolates of clonal complex 258, the most widespread carbapenem-resistant group of K. pneumoniae. The evolution of this complex was modeled, dating the newly detected and the previously reported recombination events. The present study contributes to the understanding of K. pneumoniae evolution, providing novel insights into its global genomic characteristics and drawing a dated epidemiological scenario for this pathogen in Italy.
Asunto(s)
Antibacterianos/uso terapéutico , Carbapenémicos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/genética , Técnicas de Tipificación Bacteriana , Secuencia de Bases , Infección Hospitalaria/microbiología , ADN Bacteriano/genética , Evolución Molecular , Humanos , Italia/epidemiología , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADN , beta-Lactamasas/genéticaRESUMEN
The aim of this study was to evaluate the antibacterial activity and cytotoxic effect of the compound SIAB-GV3, a new formulation presenting as an aqueous suspension of silicon dioxide (SiO2) functionalized with silver (Ag+) nanoparticles and benzalkonium. The product is formulated as an adjuvant for the treatment of inflammatory diseases of the oral cavity. This study demonstrates that SIAB-GV3 possesses strong antimicrobial activity against most of the common oral pathogens, in particular against Streptococcus pyogenes, Porphyromonas gingivalis and Aggregatibacter actinimycetemcomitans. The cytotoxic effect against human embryo lung fibroblasts (HELF cells) was evaluated at different times, from 1 h to 168 h, using concentrations of SIAB-GV3 ranging from 50 mg/ml to 0.0008 mg/ml. At the concentration of 10 mg/ml, commonly used in clinical practice, the compound results cyto- toxic after about 2 hours, this time being much longer than the typical time of local application, which is no more than 10 minutes. In conclusion, our findings suggest that SIAB-GV3 has a good antibacterial activity against the most common oral pathogens even at very low concentrations and a low cytotoxic activity, thanks to the synergistic effects of Ag nanoparticles, silicon dioxide and benzalkonium.