RESUMO
Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged the brucellae with the primarily free-living, phylogenetically related Ochrobactrum spp. in the genus Brucella. This change, founded only on global genomic analysis and the fortuitous isolation of some opportunistic Ochrobactrum spp. from medically compromised patients, has been automatically included in culture collections and databases. We argue that clinical and environmental microbiologists should not accept this nomenclature, and we advise against its use because (i) it was presented without in-depth phylogenetic analyses and did not consider alternative taxonomic solutions; (ii) it was launched without the input of experts in brucellosis or Ochrobactrum; (iii) it applies a non-consensus genus concept that disregards taxonomically relevant differences in structure, physiology, population structure, core-pangenome assemblies, genome structure, genomic traits, clinical features, treatment, prevention, diagnosis, genus description rules, and, above all, pathogenicity; and (iv) placing these two bacterial groups in the same genus creates risks for veterinarians, medical doctors, clinical laboratories, health authorities, and legislators who deal with brucellosis, a disease that is particularly relevant in low- and middle-income countries. Based on all this information, we urge microbiologists, bacterial collections, genomic databases, journals, and public health boards to keep the Brucella and Ochrobactrum genera separate to avoid further bewilderment and harm.
Assuntos
Brucella , Ochrobactrum , Ochrobactrum/classificação , Ochrobactrum/genética , Ochrobactrum/patogenicidade , Ochrobactrum/fisiologia , Brucella/classificação , Brucella/genética , Brucella/patogenicidade , Brucella/fisiologia , Terminologia como Assunto , Filogenia , Brucelose/tratamento farmacológico , Brucelose/microbiologia , Humanos , Infecções Oportunistas/microbiologiaRESUMO
The intracellular pathogens of the genus Brucella are phylogenetically close to Ochrobactrum, a diverse group of free-living bacteria with a few species occasionally infecting medically compromised patients. A group of taxonomists recently included all Ochrobactrum organisms in the genus Brucella based on global genome analyses and alleged equivalences with genera such as Mycobacterium. Here, we demonstrate that such equivalencies are incorrect because they overlook the complexities of pathogenicity. By summarizing Brucella and Ochrobactrum divergences in lifestyle, structure, physiology, population, closed versus open pangenomes, genomic traits, and pathogenicity, we show that when they are adequately understood, they are highly relevant in taxonomy and not unidimensional quantitative characters. Thus, the Ochrobactrum and Brucella differences are not limited to their assignments to different "risk-groups", a biologically (and hence, taxonomically) oversimplified description that, moreover, does not support ignoring the nomen periculosum rule, as proposed. Since the epidemiology, prophylaxis, diagnosis, and treatment are thoroughly unrelated, merging free-living Ochrobactrum organisms with highly pathogenic Brucella organisms brings evident risks for veterinarians, medical doctors, and public health authorities who confront brucellosis, a significant zoonosis worldwide. Therefore, from taxonomical and practical standpoints, the Brucella and Ochrobactrum genera must be maintained apart. Consequently, we urge researchers, culture collections, and databases to keep their canonical nomenclature.
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Brucella intermedia/Ochrobactrum intermedium strain DF13 was isolated from Brazilian soil and is able to degrade 2,4-dichlorophenoxyacetic acid (2,4-D). Here, we report on its genome sequence, with 4,570,268 bp and a 57.8% G+C content.
RESUMO
The genus Brucella, described by Meyer and Shaw in 1920, comprises bacterial pathogens of veterinary and public health relevance. For 36 years, the genus came to include three species that caused brucellosis in livestock and humans. In the second half of the 20th century, bacteriologists discovered five new species and several 'atypical' strains in domestic animals and wildlife. In 1990, the Brucella species were recognized as part of the Class Alphaproteobacteria, clustering with pathogens and endosymbionts of animals and plants such as Bartonella, Agrobacterium and Ochrobactrum; all bacteria that live in close association with eukaryotic cells. Comparisons with Alphaproteobacteria contributed to identify virulence factors and to establish evolutionary relationships. Brucella members have two circular chromosomes, are devoid of plasmids, and display close genetic relatedness. A proposal, asserting that all brucellae belong to a single species with several subspecies debated for over 70 years, was ultimately rejected in 2006 by the subcommittee of taxonomy, based on scientific, practical, and biosafety considerations. Following this, the nomenclature of having multiples Brucella species prevailed and defined according to their molecular characteristics, host preference, and virulence. The 100-year history of the genus corresponds to the chronicle of scientific efforts and the struggle for understanding brucellosis.
Assuntos
Brucella/classificação , Brucelose/microbiologia , Animais , Brucella/genética , Brucella/patogenicidade , Especificidade de Hospedeiro , Humanos , Terminologia como Assunto , Fatores de Virulência/genéticaRESUMO
RESEARCH BACKGROUND: In recent decades, laccases (p-diphenol-dioxygen oxidoreductases; EC 1.10.3.2) have attracted the attention of researchers due to their wide range of biotechnological and industrial applications. Laccases can oxidize a variety of organic and inorganic compounds, making them suitable as biocatalysts in biotechnological processes. Even though the most traditionally used laccases in the industry are of fungal origin, bacterial laccases have shown an enormous potential given their ability to act on several substrates and in multiple conditions. The present study aims to characterize a plasmid-encoded laccase-like multicopper oxidase (LMCO) from Ochrobactrum sp. BF15, a bacterial strain previously isolated from polluted soil. EXPERIMENTAL APPROACH: We used in silico profile hidden Markov models to identify novel laccase-like genes in Ochrobactrum sp. BF15. For laccase characterization, we performed heterologous expression in Escherichia coli, purification and activity measurement on typical laccase substrates. RESULTS AND CONCLUSIONS: Profile hidden Markov models allowed us to identify a novel LMCO, named Lac80. In silico analysis of Lac80 revealed the presence of three conserved copper oxidase domains characteristic of three-domain laccases. We successfully expressed Lac80 heterologously in E. coli, allowing us to purify the protein for further activity evaluation. Of thirteen typical laccase substrates tested, Lac80 showed lower activity on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), pyrocatechol, pyrogallol and vanillic acid, and higher activity on 2,6-dimethoxyphenol. NOVELTY AND SCIENTIFIC CONTRIBUTION: Our results show Lac80 as a promising laccase for use in industrial applications. The present work shows the relevance of bacterial laccases and highlights the importance of environmental plasmids as valuable sources of new genes encoding enzymes with potential use in biotechnological processes.
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We report here on a high-quality draft genome sequence of Ochrobactrum haematophilum strain P6BS-III (DSM 106071), a Gram negative, non-sporulating bacterium isolated from a pastureland (Buenos Aires province, Argentina) which had been chronically exposed to the herbicide glyphosate. The genome of 5.25 Mb with a DNA G+C content of 56.63% size was estimated to contain 5,291 protein coding genes and 57 RNA genes. Genome analysis revealed the presence of the phn operon, which is involved in the phosphonate degradation pathway, and a class II 5-enolpyruvylshikimate-3-phosphate synthase (EPSP) that confers tolerance to glyphosate. Genes related to plant growth promotion traits are also present, and include genes for phosphorus metabolism, calcium phosphate and phytate solubilization, siderophore production, organic acid biosynthesis and indole acetic acid (IAA) production.
RESUMO
Entomopathogenic nematodes (EPNs) form specific mutualistic associations with bioluminescent enterobacteria. In Heterorhabditidis indica, Ochrobactrum spp. was identified beside the symbiont Photorhabdus luminescens but its involvement in the symbiotic association in the EPNs remains unclear. This study describe the population structure and the diversity in Ochrobactrum natural populations isolated from EPNs in the Caribbean basin in order to question the existence of EPN-specialized clones and to gain a better insight into Ochrobactrum-EPNs relationships. EPN-associated Ochrobactrum and Photorhabdus strains were characterized by multi-locus sequence typing, Pulsed-Field Gel Electrophoresis fingerprinting and phenotypic traits. Population study showed the absence of EPN-specialized clones in O. intermedium and O. anthropi but suggested the success of some particular lineages. A low level of genetic and genomic diversification of Ochrobactrum isolated from the natural population of Caribbean nematodes was observed comparatively to the diversity of human-associated Ochrobactrum strains. Correspondences between Ochrobactrum and P. luminescens PFGE clusters have been observed, particularly in the case of nematodes from Dominican Republic and Puerto Rico. O. intermedium and O. anthropi associated to EPNs formed less biofilm than human-associated strains. These results evoke interactions between Ochrobactrum and the EPN symbiotic system rather than transient contamination. The main hypothesis to investigate is a toxic/antitoxic relationship because of the ability of Ochrobactrum to resist to antimicrobial and toxic compounds produced by Photorhabdus.
Assuntos
Nematoides/microbiologia , Ochrobactrum/genética , Animais , Região do Caribe/epidemiologia , República Dominicana/epidemiologia , Genética Populacional , Humanos , Tipagem de Sequências Multilocus , Photorhabdus , Filogenia , Porto Rico/epidemiologia , SimbioseRESUMO
Ochrobactrum anthropi, a rare human pathogen, has been isolated predominantly from patients with catheter-related bacteraemia and rarely from other infections. In 2016, six cases of pseudo-bacteraemia caused by carbapenem-resistant O. anthropi isolates were recovered from an Argentinian hospital. The resistant phenotype exposed by the isolates caught our attention and led to an extensive epidemiologic investigation. Here we describe the characterization of a carbapenem-resistant O. anthropi outbreak whose probable cause was by contaminated collection tubes. The genome analysis of one strain revealed the presence of various resistant determinants. Among them, a metal-dependent hydrolase of the ß-lactamase superfamily I, phnP, was found. Lately the recovery of unusual multidrug-resistant pathogens in the clinical setting has increased, thus emphasizing the need to implement standardized infection control practice and epidemiologic investigation to identify the real cause of hospital outbreaks.
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Introducción: El semen es una mezcla compleja de fluidos y células que posee las condiciones adecuadas para albergar microorganismos, especialmente bacterias. Objetivo: Evaluar la presencia de bacterias en el semen de individuos normozoospérmicos asintomáticos para infecciones urogenitales. Métodos: Se realizó una secuenciación estándar posterior a la amplificación por PCR con el uso de los cebadores universales 27F y 1492R para identificación de bacterias, en 10 muestras de semen de voluntarios normozoospérmicos asintomáticos para infecciones urogenitales. Resultados: Se identificó a Ochrobactrum anthropi en 8 de las 10 muestras seminales evaluadas y a Haemophilus paraurethrae o Escherichia coli en los dos restantes. O. anthropi es una bacteria comensal, ampliamente distribuida en la naturaleza, especialmente en las fuentes de agua que, a pesar de su baja virulencia, ocasionalmente causa infecciones en individuos inmunocomprometidos. Conclusión: La alta frecuencia de O. anthropi en las muestras de semen de individuos normozoospérmicos asintomáticos para infecciones urogenitales puede asociarse a procesos de contaminación durante la recolección de la muestra, debido a la amplia distribución de esta bacteria, especialmente en las fuentes de agua(AU)
Introduction: Semen is a complex combination of fluids and cells that can harbor microorganisms, especially bacteria. Objective: To assess the presence of bacteria in semen samples from asymptomatic normozoospermic individuals, for urogenital infections. Methods: Standard sequencing after PCR amplification was performed with the use of the universal primers 27F and 1492R for bacterial identification, in 10 semen samples of asymptomatic normozoospermic volunteers for urogenital infections. Results: Thisidentified Ochrobactrum anthropi in 8 out of 10 samples assessed. In the remaining two samples, we identified Haemophilus paraurethrae and Escherichia coli. O. anthropi is a commensal bacterium, widely spread in nature, especially in water sources that, despite its low virulence, occasionally cause infections in immune compromised individuals. Conclusion: The high frequency of O. anthropi in semen samples from asymptomatic normozoospermic individuals, for urogenital infections can be associated with contamination during the collection of the sample, due to the wide distribution of this bacterium, especially in water sources(AU)
Assuntos
Humanos , Masculino , Adulto , Sêmen/microbiologia , Infecções Bacterianas/microbiologia , Reação em Cadeia da Polimerase/métodos , Ochrobactrum anthropi/isolamento & purificação , Poluição da Água/efeitos adversosRESUMO
The present report describes the misidentification of Brucella spp. from a positive blood culture using traditional microbiology tests. A molecular test identified the bacterium as Ochrobactrum anthropi. According to the information available, this report is the first to include this type of case in Mexico.
RESUMO
OBJECTIVES: Bacteria belonging to the genera Ochrobactrum and Achromobacter are bacteria considered opportunistic, causing infections mainly in immunocompromised patients. ß-lactamases are the main cause of resistance to ß-lactam antibiotics. This study aimed to investigate the antimicrobial resistance profile and the presence of ß-lactamases encoding genes in Ochrobactrum sp. and Achromobacter sp. isolated from Brazilian soils. METHODS: Soil samples from the five regions of Brazil were collected for the isolation of bacteria, which were identified molecularly and then, the minimum inhibitory concentration and detection of ß-lactamases encoding genes were performed. RESULTS: High-level of resistance to ß-lactam antibiotics and different ß-lactamases encoding genes were found (blaCTX-M-Gp1, blaSHV, blaOXA-1-like and blaKPC), including the first report of the presence of blaKPC in bacteria belonging to the genera Ochrobactrum and Achromobacter. CONCLUSION: The results showed that the bacteria from this study, belonging to genera Ochrobactrum and Achromobacter isolated from soil, harbor different ß-lactamases encoding genes and can act as a reservoir of these genes.
Assuntos
Achromobacter/isolamento & purificação , Ochrobactrum/isolamento & purificação , beta-Lactamases/genética , beta-Lactamas/farmacologia , Achromobacter/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Brasil , Testes de Sensibilidade Microbiana , Ochrobactrum/genética , Microbiologia do Solo , Resistência beta-LactâmicaRESUMO
Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found to have the potential to form silver nanoparticles intracellularly at room temperature within 24 h. The biosynthesized silver nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and scanning electron microscope (SEM). The UV-visible spectrum of the aqueous medium containing silver nanoparticles showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. The SEM and TEM micrographs revealed that the synthesized silver nanoparticles were spherical in shape with a size range from 38 nm - 85 nm. The silver nanoparticles synthesized by the isolate were also used to explore its antibacterial potential against pathogens like Salmonella Typhi, Salmonella Paratyphi, Vibrio cholerae and Staphylococcus aureus.
Assuntos
Antibacterianos/farmacologia , Nanopartículas/metabolismo , Ochrobactrum/metabolismo , Prata/farmacologia , Antibacterianos/metabolismo , Organismos Aquáticos/classificação , Organismos Aquáticos/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Ribossômico/química , Bactérias Gram-Negativas/efeitos dos fármacos , Microscopia Eletrônica , Nanopartículas/química , Ochrobactrum/classificação , FilogeniaRESUMO
Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found to have the potential to form silver nanoparticles intracellularly at room temperature within 24 h. The biosynthesized silver nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and scanning electron microscope (SEM). The UV-visible spectrum of the aqueous medium containing silver nanoparticles showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. The SEM and TEM micrographs revealed that the synthesized silver nanoparticles were spherical in shape with a size range from 38 nm - 85 nm. The silver nanoparticles synthesized by the isolate were also used to explore its antibacterial potential against pathogens like Salmonella Typhi, Salmonella Paratyphi, Vibrio cholerae and Staphylococcus aureus.
Assuntos
Antibacterianos/farmacologia , Nanopartículas/metabolismo , Ochrobactrum/metabolismo , Prata/farmacologia , Antibacterianos/metabolismo , Organismos Aquáticos/classificação , Organismos Aquáticos/genética , Organismos Aquáticos/isolamento & purificação , Organismos Aquáticos/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bactérias Gram-Negativas/efeitos dos fármacos , Microscopia Eletrônica , Nanopartículas/química , Nanopartículas/ultraestrutura , Ochrobactrum/classificação , Ochrobactrum/genética , Ochrobactrum/isolamento & purificação , Filogenia , /genética , Análise de Sequência de DNA , Análise Espectral , Prata/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Fatores de TempoRESUMO
Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found to have the potential to form silver nanoparticles intracellularly at room temperature within 24 h. The biosynthesized silver nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and scanning electron microscope (SEM). The UV-visible spectrum of the aqueous medium containing silver nanoparticles showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. The SEM and TEM micrographs revealed that the synthesized silver nanoparticles were spherical in shape with a size range from 38 nm - 85 nm. The silver nanoparticles synthesized by the isolate were also used to explore its antibacterial potential against pathogens like Salmonella Typhi, Salmonella Paratyphi, Vibrio cholerae and Staphylococcus aureus.
Assuntos
Antibacterianos/farmacologia , Nanopartículas/metabolismo , Ochrobactrum/metabolismo , Prata/farmacologia , Antibacterianos/metabolismo , Organismos Aquáticos/classificação , Organismos Aquáticos/genética , Organismos Aquáticos/isolamento & purificação , Organismos Aquáticos/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bactérias Gram-Negativas/efeitos dos fármacos , Microscopia Eletrônica , Nanopartículas/química , Nanopartículas/ultraestrutura , Ochrobactrum/classificação , Ochrobactrum/genética , Ochrobactrum/isolamento & purificação , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Prata/metabolismo , Análise Espectral , Staphylococcus aureus/efeitos dos fármacos , Temperatura , Fatores de TempoRESUMO
Ochrobactrum anthropi is a rare pathogen in humans that is usually related to infections in inmunocompromised patients or people with indwelling medical devices. There are very few reported cases of O. anthropi bacteremia in patients on hemodialysis. We report a 19-year-old female on hemodialysis through a jugular catheter, with fever and malaise lasting one month. The catheter was withdrawn and Ochrobactrum anthropi was isolated from it and from blood cultures. The patient was successfully treated with levofloxacin.
Assuntos
Feminino , Humanos , Adulto Jovem , Bacteriemia/microbiologia , Infecções Relacionadas a Cateter/microbiologia , Cateteres de Demora/efeitos adversos , Infecções por Bactérias Gram-Negativas/microbiologia , Ochrobactrum anthropi/isolamento & purificação , Diálise Renal/efeitos adversosRESUMO
Ochrobactrum anthtropi es un bacilo gram negativo aeróbico, no fermentador de la glucosa, anteriormente conocido como Achromobacter sp o CDC grupo Vd. Ha sido aislado del medio ambiente y de infecciones en seres humanos que generalmente presentaban algún tipo de inmunocompromiso. Las infecciones por este microorganismo fueron bacteriemias relacionadas a catéteres y en ocasiones endoftalmitis, infecciones urinarias, meningitis, endocarditis, absceso hepático, osteocondritis, absceso pelviano y absceso pancreático. Se presenta el caso de un paciente de sexo masculino, de 69 años de edad, que consultó a la guardia por hipotensión sostenida y síndrome febril de cuatro días de evolución, escalofrío, sudoración profusa y deterioro del sensorio. El paciente tenía diabetes de tipo 2 y antecedente de accidente cerebrovascular. Debido a insuficiencia renal crónica presentaba un catéter de doble lumen para la diálisis. Se documentó una bacteriemia relacionada a catéter por cultivo de sangre a través de catéter y de vena periférica, utilizando el sistema automatizado de hemocultivos Bact-Alert y la metodología de tiempo diferencial (>120min). La confirmación se realizó, una vez removido el catéter, por la técnica semicuantitativa de Maki (> 15 UFC). El microorganismo fue identificado por API 20NE y Vitek 1 como Ochrobactrum anthropi.
Ochrobactrum anthropi is a non-glucose fermentative, aerobic gram-negative bacillus, formerly known as Achromobacter sp or CDC group Vd. It has been isolated from the environment and from infections in usually immunocompromised human beings. The documented infections frequently involved catheter related bacteremia whereas endophthalmitis, urinary infections, meningitis, endocarditis, hepatic abscess, osteochondritis, pelvic abscess and pancreatic abscess were rarely involved. Here it is presented the case of a male patient aged 69 years with sustained hypotension, four day febrile syndrome, chill, lavish perspiration and sensorium deterioration. He had type 2 diabetes and antecedent of cerebrovascular accident. A double-lumen dialysis catheter was present due to chronic renal insufficiency. An episode of catheter-related bloodstream infection was documented by using Bact-Alert Blood Culture System and Differential-Time-to-Positivity Method for central venous catheter versus peripheral blood cultures (>120 min). Once removed, it was confirmed through Maki semi quantitative technique (>15 FCU). The microorganism was identified by API 20NE and Vitek 1 as Ochrobactrum anthropi.