RESUMO
Changes in Kluyvera taxonomy may clarify each species contribution for recruitment and dissemination of their relevant ß-lactamases. The CTX-M-2 subgroup is linked to Kluyvera ascorbata, KLUC to Kluyvera cryocrescens, and CTX-M-25 to Kluyvera georgiana. The CTX-M-8 subgroup can be linked to Kluyvera genomospecies 3 and CTX-M-9 to Kluyvera genomospecies 2. Kluyvera sichuanensis and Kluyvera genomospecies 1 harbor new subgroups. The CTX-M-1 subgroup has a direct counterpart in an isolate proposed as a new genomospecies 5.
Assuntos
Kluyvera , Kluyvera/genética , beta-Lactamases/genéticaAssuntos
Antibacterianos/uso terapêutico , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Klebsiella/tratamento farmacológico , beta-Lactamases/genética , Adulto , Ductos Biliares/cirurgia , Brasil , Carbapenêmicos , Infecção Hospitalar/tratamento farmacológico , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Kluyvera/efeitos dos fármacos , Kluyvera/genética , Kluyvera/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , beta-Lactamases/isolamento & purificaçãoRESUMO
A putative fosA gene in Kluyvera georgiana 14751 showed 99% nucleotide identity with plasmid-encoded fosA4 Due to a single-nucleotide insertion translating to a truncated protein, K. georgiana 14751 fosA does not confer fosfomycin resistance. However, analysis of another genome deposit (Kluyvera ascorbata WCH1410) that could be recategorized as K. georgiana after phylogenetic analysis revealed a fosA gene 100% identical to the plasmid-borne fosA4 gene. We suggest that Kluyvera georgiana represents the most probable origin of fosA4.
Assuntos
Antibacterianos/farmacologia , Kluyvera/efeitos dos fármacos , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Fosfomicina/farmacologia , Kluyvera/genética , Testes de Sensibilidade Microbiana , Filogenia , Plasmídeos/genéticaRESUMO
Carbapenemase-producing bacteria cause difficult-to-treat infections related to increased mortality in health care settings. Their occurrence has been reported in raw sewage, sewage-impacted rivers, and polluted coastal waters, which may indicate their spread to the community. We assessed the variety and concentration of carbapenemase producers in coastal waters with distinct pollution levels for 1 year. We describe various bacterial species producing distinct carbapenemases not only in unsuitable waters but also in waters considered suitable for primary contact.
Assuntos
Proteínas de Bactérias/genética , Klebsiella pneumoniae/genética , Água do Mar/microbiologia , Microbiologia da Água , beta-Lactamases/genética , Acinetobacter/enzimologia , Acinetobacter/genética , Acinetobacter/isolamento & purificação , Aeromonas/enzimologia , Aeromonas/genética , Aeromonas/isolamento & purificação , Proteínas de Bactérias/classificação , Proteínas de Bactérias/metabolismo , Brasil , Citrobacter/enzimologia , Citrobacter/genética , Citrobacter/isolamento & purificação , Enterobacter/enzimologia , Enterobacter/genética , Enterobacter/isolamento & purificação , Expressão Gênica , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , Kluyvera/enzimologia , Kluyvera/genética , Kluyvera/isolamento & purificação , Pseudomonas/enzimologia , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Recreação , Serratia/enzimologia , Serratia/genética , Serratia/isolamento & purificação , beta-Lactamases/classificação , beta-Lactamases/metabolismoRESUMO
Kluyveromyces aestuarii was found in sediments from 7 of 8 mangroves in Rio de Janeiro; and absent only at one site with heavy plastic bag pollution. Its presence suggests influence in other habitats from a mangrove and its absence in a mangrove suggests some non-fecal pollution or other habitat alteration.
Assuntos
Sequência de Bases , Indicadores Ambientais , Microbiologia Ambiental , Kluyvera/genética , Kluyvera/isolamento & purificação , Kluyveromyces/genética , Kluyveromyces/isolamento & purificação , Áreas Alagadas , Métodos , MétodosRESUMO
This study characterised the genetic environment of the chromosomally encoded bla(KLUA-9) gene from a clinical Kluyvera ascorbata isolate and performed a kinetic characterisation of KLUA-9. Purified KLUA-9 showed the highest catalytic efficacies towards benzylpenicillin, ampicillin, piperacillin, first-generation cephalosporins, cefuroxime and cefoperazone; like other 'cefotaximases', it showed a much higher rate of hydrolysis of cefotaxime than ceftazidime, whilst dicloxacillin, cefoxitin and imipenem behaved as poor substrates. A 9kb insert from K. ascorbata was cloned (Escherichia coli KK68C1) and sequenced. bla(KLUA-9) and its 266bp upstream flanking region (almost identical to the integron-associated bla(CTX-M-2)) are preceded by an aspat variant, a ypdABC-like operon and two open reading frames with unknown functions. Unlike ISCR1-associated bla(CTX-M-2) genes, we failed to detect the putative orf513 recombination sites. Instead, we were able to localise the 5bp target sites for insertion of ISEcp1B, suggesting that this element could be responsible for future (or still undetected) mobilisation of bla(KLUA-9) to more efficiently transferred elements.
Assuntos
Cefalosporinas/farmacologia , Kluyvera/enzimologia , Kluyvera/genética , beta-Lactamases/genética , Sequência de Bases , Resistência às Cefalosporinas/genética , Cefalosporinas/metabolismo , DNA Bacteriano/genética , Farmacorresistência Bacteriana/genética , Infecções por Enterobacteriaceae/microbiologia , Evolução Molecular , Genes Bacterianos , Humanos , Técnicas In Vitro , Cinética , Kluyvera/efeitos dos fármacos , Kluyvera/isolamento & purificação , Dados de Sequência Molecular , Plasmídeos/genética , beta-Lactamases/metabolismoRESUMO
Chromosomal beta-lactamase genes (bla(KLUY)) from six Kluyvera georgiana strains isolated in Guyana were cloned and expressed in Escherichia coli. KLUY-1 exhibited 100% amino acid identity with the extended-spectrum beta-lactamase CTX-M-14. We also show that a 2.7-kb Kluyvera chromosomal region exhibits 99% nucleotide identity to a portion of In60 that includes bla(CTX-M-9).
Assuntos
Proteínas de Escherichia coli/genética , Kluyvera/enzimologia , Kluyvera/genética , beta-Lactamases/genética , Sequência de Aminoácidos , Antibacterianos/farmacologia , Cromossomos Bacterianos/genética , Clonagem Molecular , Desoxirribonuclease EcoRI/química , Escherichia coli/genética , Guiana , Humanos , Kluyvera/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Dados de Sequência MolecularRESUMO
In order to assess the relationship between the genus Kluyvera and other members of the family Enterobacteriaceae, the 16S rRNA genes of type strains of the recognized Kluyvera species, Kluyvera georgiana, Kluyvera cochleae, Kluyvera ascorbata and Kluyvera cryocrescens, were sequenced. A comparative phylogenetic analysis based on these 16S rRNA gene sequences and those available for strains belonging to several genera of the family Enterobacteriaceae showed that members of the genus Kluyvera form a cluster that contains all the known Kluyvera species. However, the type strain of Enterobacter intermedius (ATCC 33110T) was included within this cluster in a very close relationship with the type strain of K. cochleae (ATCC 51609T). In addition to the phylogenetic evidence, biochemical and DNA-DNA hybridization analyses of species within this cluster indicated that the type strain of E. intermedius is in fact a member of the genus Kluyvera and, within it, of the species Kluyvera cochleae. Therefore, following the current rules for bacterial nomenclature and classification, the transfer of E. intermedius to the genus Kluyvera as Kluyvera intermedia comb. nov. is proposed (type strain, ATCC 33110T=CIP 79.27T=LMG 2785T=CCUG 14183T). Biochemical analysis of four E. intermedius strains and one K. cochleae strain independent of the respective type strains further indicated that E. intermedius and K. cochleae represent the same species and are therefore heterotypic synonyms. Nomenclatural priority goes to the oldest legitimate epithet. Consequently, Kluyvera cochleae Muller et al. 1996 is a later synonym of Kluyvera intermedia (Izard et al. 1980) Pavan et al. 2005.
Assuntos
Enterobacter/classificação , Kluyvera/classificação , Filogenia , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , DNA Ribossômico/análise , Enterobacter/genética , Enterobacter/metabolismo , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/metabolismo , Kluyvera/genética , Kluyvera/metabolismo , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fenótipo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Terminologia como AssuntoRESUMO
A gene identical to plasmid-borne bla(CTX-M-3) is present in the chromosome of one Kluyvera ascorbata strain. It is associated with a structure including an inverted repeat right and an open reading frame 477-like gene probably involved in the mobilization of bla(CTX-M-3). Two other K. ascorbata strains rendered the previously described bla(KLUA-9) gene.