RESUMEN
A Gram-stain-negative strain, designated BR102T, isolated from a soil sample in Brazil was characterized by a polyphasic approach. Comparative 16S rRNA gene sequences indicated that strain BR102T belonged to the genus Citrobacter. The recN- and whole-genome-based phylogeny, and multilocus sequence analysis based on concatenated partial fusA, leuS, pyrG and rpoB sequences strongly supported a clade encompassing strain BR102T and a strain from public database that was distinct from currently recognized species of the genus Citrobacter. Average nucleotide identity and digital DNA-DNA hybridization values between strain BR102T and the closest relative Citrobacter freundii ATCC 8090T were 91.8 and 48.8â%, respectively. The ability to metabolize different compounds further discriminated strain BR102T from other closely related species of the genus Citrobacter. The novel variants bla CMY-179 and qnrB97, which encoded a CMY-2-like ß-lactamase and a QnrB-type protein, respectively, were identified in strain BR102T. BR102T was resistant to ampicillin, amoxicillin/clavulanate and cefoxitin. The DNA G+C content of strain BR102T is 51.3âmol%. Based on these results, strain BR102T represents a novel species of the genus Citrobacter, for which the name Citrobacter meridianamericanus sp. nov. is proposed. The type strain is BR102T (=MUM 22.55T=IMI 507229T).
Asunto(s)
Citrobacter , Genes Bacterianos , Análisis de Secuencia de ADN , ARN Ribosómico 16S/genética , Ácidos Grasos/química , ADN Bacteriano/genética , Filogenia , Composición de Base , Técnicas de Tipificación Bacteriana , SueloAsunto(s)
Antibacterianos/farmacología , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/genética , Resistencia a la Vancomicina/efectos de los fármacos , Resistencia a la Vancomicina/genética , Proteínas Bacterianas/genética , Brasil , Ligasas de Carbono-Oxígeno/genética , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Análisis de SecuenciaRESUMEN
We performed a single-month snapshot study of the population diversity of multidrug resistant (MDR) Klebsiella pneumoniae isolates producing carbapenemases and/or extended-spectrum ß-lactamases from four major hospitals in Brazil. Isolates produced diverse ESBL (CTX-M-2, -8, -15, SHV-2), KPC-2 or both (CTX-M-2 and KPC-2), linked to specific genetic backgrounds and plasmids from a few families (IncR, IncFIIk, IncL/M) that were shared among clonal lineages within and between hospitals. A high clonal diversity was identified, among isolates from the same ST (ST11, ST15, ST101 or ST340). Diverse capsular types (n=13 K-types) were identified, most of which linked to specific ST (ST11 and K27 or K64, ST101 and K17, ST340 and KL151, ST15 and K24 or ST17 and KL112). Isolates shared a common set of virulence genes (ureA, fimH, uge, wabG, mrkD, entB) and occasionally ybtS (42%) and kfuBC (18%). Our data suggest intra- and inter-hospital spread of common genetic structures and international MDR K. pneumoniae clones.
Asunto(s)
Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Klebsiella , Klebsiella pneumoniae , Plásmidos/genética , beta-Lactamasas/genética , Brasil/epidemiología , Monitoreo Epidemiológico , Hospitales , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidad , Epidemiología Molecular , Virulencia/genéticaRESUMEN
We analyse the diversity of extended-spectrum beta-lactamases (ESBLs), antibiotic resistance genes, and plasmid content among Escherichia coli from a community and a hospital setting in Rio de Janeiro, Brazil. ESBL producers (CTX-M-2, CTX-M-9, CTX-M-59) belonged to different phylogroups/sequence types, and bla(CTX-M) were identified in IncA/C plasmids, reinforcing the possible intraplasmid evolution of bla(CTX-M-59) from bla(CTX-M-2) and the implication of IncA/C on bla(CTX-M) spread.
Asunto(s)
Antibacterianos/farmacología , Infecciones por Escherichia coli/microbiología , Escherichia coli/aislamiento & purificación , Plásmidos/análisis , beta-Lactamasas/metabolismo , Brasil , Análisis por Conglomerados , Infecciones Comunitarias Adquiridas/microbiología , Infección Hospitalaria/microbiología , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/genética , Variación Genética , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Fenotipo , Filogenia , beta-Lactamasas/genéticaRESUMEN
OBJECTIVES: this study focused on the population structure of OXA-23-producing Acinetobacter baumannii clinical isolates from Rio de Janeiro, Brazil. METHODS: the analysis included several genomic typing methods, including PFGE, two multilocus sequence typing (MLST) schemes, sequence group (SG) determination and bla(OXA-51-like) sequencing. The genomic context of the bla(OXA-23) gene was also evaluated using I-CeuI hybridizations and PCR assays. RESULTS: congruent clustering was obtained revealing four lineages. In accordance, four new sequence types (STs) (ST131, ST132, ST133 and ST134) were obtained with the MLST-OD scheme (associated with the Oxford Database) and four (ST79, ST15 and two new allelic profiles) with the MLST-IP scheme (developed by the Institute Pasteur). Four SGs (SG1, SG4 and two new profiles) were identified, allowing the association of 70% of the isolates with European clone II. bla(OXA-51-like) sequencing revealed the presence of bla(OXA-66), bla(OXA-69), bla(OXA-95) and bla(OXA-132). CONCLUSIONS: identification of new STs together with new SG profiles are findings suggestive of a local diversity hotspot that is worth exploring.