RESUMO
In Enterobacteriaceae, the blaOXA-48-like genes have been identified on plasmids in different regions of the world. The OXA-370 is a plasmid-encoded OXA-48-like enzyme reported in two distinct regions of Brazil. Recently, we demonstrate that the blaOXA-370 gene is disseminated among several Enterobacteriaceae species and clones, indicating a high potential for dissemination. In this work, we described for the first time the complete nucleotide sequence of six plasmids harboring the blaOXA-370 gene. Complete DNA sequencing using the Illumina platform and annotation of the plasmids showed that they belonged to incompatibility groups IncX and had in average 70 kbp. The blaOXA-370 gene is located in a composite transposon containing four genes encoding transposases, named Tn6435. In this study, highly similar plasmids were detected in different Enterobacteriaceae genera.
Assuntos
Elementos de DNA Transponíveis , Plasmídeos/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Biologia Computacional/métodos , Conjugação Genética , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Transformação BacterianaAssuntos
Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/isolamento & purificação , Proteínas de Bactérias/genética , beta-Lactamases/genética , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Antibacterianos/uso terapêutico , Brasil , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Testes de Sensibilidade MicrobianaRESUMO
BKC-1 is a new class A serine carbapenemase that was recently identified in Klebsiella pneumoniae clinical isolates. The principal objective of this study was to evaluate the frequency of blaBKC-1 by testing a collection of Klebsiella isolates. Only 2 of 635 Klebsiella isolates (0.3%) carried blaBKC-1 The two BKC-1-producing isolates belonged to clonal complex 442 and possessed identical pulsed-field gel electrophoresis patterns. The blaBKC-1 gene was inserted into a 10-kb plasmid that was identical to the previously reported plasmid, p60136. The BKC-producing K. pneumoniae isolates presented also possessed other mechanisms for beta-lactam resistance, such as genes encoding extended-spectrum beta-lactamases and mutations in the genes ompK35 and ompK36, encoding the major porins.
Assuntos
Proteínas de Bactérias/metabolismo , Klebsiella/efeitos dos fármacos , Klebsiella/enzimologia , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Eletroforese em Gel de Campo Pulsado , Klebsiella/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Mutação/genética , Plasmídeos/genética , beta-Lactamases/genéticaRESUMO
The expression of flagella correlates with different aspects of bacterial pathogenicity, ranging from adherence to host cells to activation of inflammatory responses by the innate immune system. In the present study, we investigated the role of flagella in the adherence of an atypical enteropathogenic Escherichia coli (aEPEC) strain (serotype O51:H40) to human enterocytes. Accordingly, isogenic mutants deficient in flagellin (FliC), the flagellar structural subunit; the flagellar cap protein (FliD); or the MotAB proteins, involved in the control of flagellar motion, were generated and tested for binding to differentiated Caco-2 cells. Binding of the aEPEC strain to enterocytes was significantly impaired in strains with the fliCa nd fliD genes deleted, both of which could not form flagella on the bacterial surface. A nonmotile but flagellated MotAB mutant also showed impaired adhesion to Caco-2 cells. In accordance with these observations, adhesion of a EPEC strain 1711-4 to Caco-2 cells was drastically reduced after the treatment of Caco-2 cells with purified FliD. In addition, incubation of a EPEC bacteria with specific anti-FliD serum impaired binding to Caco-2 cells. Finally, incubation of Caco-2 cells with purified FliD, followed by immunolabeling, showed that the protein was specifically bound to the microvillus tips of differentiated Caco-2 cells. The a EPEC FliD or anti-FliD serum also reduced the adherence of prototype typical enteropathogenic, enterohemorrhagic, and enterotoxigenic E. coli strains to Caco-2 cells. In conclusion, our findings further strengthened the role of flagella in the adherence of a EPEC to human enterocytes and disclosed the relevant structural and functional involvement of FliD in the adhesion process.
Assuntos
Aderência Bacteriana/fisiologia , Proteínas de Bactérias/metabolismo , Enterócitos/microbiologia , Escherichia coli Enteropatogênica/fisiologia , Microvilosidades/fisiologia , Animais , Anticorpos , Proteínas de Bactérias/genética , Células CACO-2 , Enterócitos/fisiologia , Escherichia coli Enteropatogênica/genética , Humanos , Imuno-Histoquímica , Camundongos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Mutação , Coelhos , Proteínas RecombinantesRESUMO
Pseudomonas aeruginosa is an important cause of infection, especially in immunocompromised patients. In this regard, strains producing carbapenemases, mainly metallo-ß-lactamases (MBLs), have become a significant public health concern. Here, we present the complete annotated genome sequence (65.7 kb) of an F8-related lytic myovirus (Pbunalikevirus genus) that infects MBL-producing P. aeruginosa strains.