Assuntos
Infecções por Burkholderia , Burkholderia , Fibrose Cística , Microbiota , Humanos , Fibrose Cística/complicações , PulmãoRESUMO
We have sequenced the whole genome of Streptomyces sp. 6(4) isolated from tomato roots that presents antifungal activity against phytopathogenic fungi, mainly Bipolaris sorokiniana. The genome has almost 7 Mb and 3368 hypothetical proteins that were analysed and characterized in Uniprot with the emphasis on biological compounds. Multilocus sequence typing (MLST) analyses were performed in an effort to characterize and identify this isolate, resulting in a new sequence type (ST), classified as ST64. Phenetic and phylogenetic trees were constructed to investigate Streptomyces sp. 6(4) evolution and sequence similarity, and the isolate is a strain closer to Streptomyces prasinus and Streptomyces viridosporus . It is known that the genus Streptomyces possess huge metabolic capacity with the presence of cryptic genes. These genes are usually present in clusters, which are responsible for the production of diverse natural products, mainly antibiotics. In addition, 6(4) showed 11 biosynthetic gene clusters through antiSMASH, including 3 polyketide synthase (PKS) and non-ribosomal peptide synthase (NRPS) type clusters.
RESUMO
The gut microbiota is a complex community composed by several microorganisms that interact in the maintenance of homeostasis and contribute to physiological processes, including brain function. The relationship of the taxonomic composition of the gut microbiota with neurological diseases such as autism, Parkinson's, Alzheimer's, anxiety, and depression is widely recognized. The immune system is an important intermediary between the gut microbiota and the central nervous system, being one of the communication routes of the gut-brain axis. Although the complexity of the relationship between inflammation and epilepsy has not yet been elucidated, inflammatory processes are similar in many ways to the consequences of dysbiosis and contribute to disease progression. This study aimed to analyze the taxonomic composition of the gut microbiota of rats treated with prednisolone in a kindling model of epilepsy. Male Wistar rats (90 days, n = 24) divided into four experimental groups: sodium chloride solution 0.9 g%, diazepam 2 mg/kg, prednisolone 1 mg/kg, and prednisolone 5 mg/kg administered intraperitoneally (i.p.) for 14 days. The kindling model was induced by pentylenetetrazole (PTZ) 25 mg/kg i.p. on alternate days. The taxonomic profile was established by applying metagenomic DNA sequencing. There was no change in alpha diversity, and the composition of the gut microbiota between prednisolone and diazepam was similar. The significant increase in Verrucomicrobia, Saccharibacteria, and Actinobacteria may be related to the protective activity against seizures and inflammatory processes that cause some cases of epilepsy. Further studies are needed to investigate the functional influence that these species have on epilepsy and the inflammatory processes that trigger it.
Assuntos
Microbioma Gastrointestinal , Pentilenotetrazol , Animais , Masculino , Prednisolona , Ratos , Ratos Wistar , Convulsões/induzido quimicamenteRESUMO
OBJECTIVES: The aim of this study was to evaluate the relationship between antimicrobial susceptibility and genotype of a Mycobacterium abscessus subsp. massiliense isolate obtained from the respiratory tract of a patient in southern Brazil. METHODS: The isolate (named Myco1POA) was submitted to whole-genome sequencing using an Illumina MiSeq platform. Data were analysed using Trim Galore!, SPAdes Genome Assembler, Geneious and BioEdit software. Multilocus sequence typing (MLST) was performed by in silico analysis of seven housekeeping genes according to the Institut Pasteur database. The antimicrobial susceptibility profile was determined by broth microdilution according to Clinical and Laboratory Standards Institute (CLSI) guidelines. RESULTS: Several mutations in genes related to antimicrobial resistance were identified in Myco1POA. MLST indicated that the isolate belonged to a novel sequence type (ST), which was designated ST262. Phenotypic susceptibility and genotypic findings were concordant, except for clarithromycin [erm(41) and rrl genes]. CONCLUSION: Here we describe the genome sequence of M. abscessus subsp. massiliense Myco1POA identified as a novel sequence type (ST262) and indicate possible new gene mutations leading to clarithromycin resistance.
Assuntos
Claritromicina , Mycobacterium abscessus , Antibacterianos/farmacologia , Brasil , Claritromicina/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Mutação , Mycobacterium abscessus/genéticaRESUMO
Broth microdilution (BMD), the reference method to determine bacterial susceptibility to polymyxins, is a laborious and time-consuming technique. Policimbac® is a commercial test panel which uses lyophilized polymyxin B to determine the minimum inhibitory concentration for Gram-negative isolates. This study evaluated the performance of Policimbac® in comparison with BMD for 110 isolates. Although the Policimbac® presented a very low essential agreement, the categorical agreement with BMD was optimal. Policimbac® is an alternative approach to BMD for evaluating the susceptibility to polymyxin B.
Assuntos
Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/métodos , Polimixina B/farmacologia , Farmacorresistência Bacteriana , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana/instrumentaçãoRESUMO
BACKGROUND: Clostridium (Clostridioides) difficile infection (CDI) is recognized worldwide as a public health concern, related mainly with hypervirulent strains. In Brazil there are few studies about molecular epidemiology of C. difficile, for this reason, we aimed to characterize C. difficile isolates from a large cohort study of three different Brazilian states to identify virulence and resistance genes, specifically genes related to metronidazole and vancomycin resistance. METHODS: All 153 fecal samples were submitted to C. difficile culture in CM0601 broth. Identification of suspected colonies was confirmed by matrix-assisted laser desorption/ionization (MALDI-TOF/MS, Brucker Daltonics, Germany). The tcdA and tcdB toxin were searched by PCR. The sequence type (ST) was determinate by multilocus sequencing typing (MLST) and susceptibility profile was performed by agar dilution method. RESULTS: Among the 16 isolates, we identified fourteen different STs, five belonging to Clade 1, one to Clade 2 and eight news STs with high similarity levels. Resistance (ermB, tetM, VanW and nimB) and virulence genes (cwp84, cwp66, cwp2, fbpA and secA) were found in toxigenic strains. CONCLUSION: Differently from other studies, we found high levels of resistance to vancomycin. These results suggest that the main circulating strains in Brazil belong to Clade 1 and have high pathogenicity and resistance profile.
Assuntos
Toxinas Bacterianas , Clostridioides difficile , Infecções por Clostridium , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Brasil , Clostridioides difficile/genética , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/epidemiologia , Estudos de Coortes , Farmacorresistência Bacteriana , Alemanha , Humanos , Tipagem de Sequências Multilocus , Fatores de Virulência/genéticaRESUMO
Recently it was developed the Colistin Broth Disk Elution test which uses colistin disks as a source of these antibiotics. The aim of this study was to evaluate the performance of protocols that used diminished volumes of the reagents: the Colistin Broth Microelution (CBM) (1â¯mL) and the Microelution-Plates Test (MPT) (200⯵L), as well as the Colistin Susceptibility Test Tube (CSTT), which uses only one colistin disk added to a tube containing broth. The tests were performed with 85 Gram-negative isolates collected from surveillance studies. The CBM, MPT, and CSTT tests presented a good Categorical Agreement (CA), Essential Agreement (EA), sensitivity and specificity to Enterobacterales isolates, however the ME and VME were less satisfactory. The results for non-fermentative isolates were not satisfactory. In conclusion, the proposed methods, mainly the CSTT, can be used as screening tests to detect colistin resistant among Enterobacterales, as they are an easy and inexpensive option to the reference method.
Assuntos
Antibacterianos/farmacologia , Técnicas de Química Analítica/normas , Colistina/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Sensibilidade e EspecificidadeRESUMO
The mcr-1 gene has been identified in bacterial isolates obtained from humans, animals, environment, and food, including Salmonella spp., which is one of the major foodborne pathogens worldwide. The aim of this study was to evaluate the presence of mcr-1 gene in Salmonella spp. from food produced in Brazil and to characterize the isolates harboring this gene. A total of 490 Salmonella spp. isolates from the Brazilian National Program for the Control of Foodborne Pathogens were screened for the presence of mcr-1 gene by polymerase chain reaction (PCR). Whole genome sequencing (WGS) was performed in positive isolates to characterize the sequence type (ST), plasmid families and resistance genes. Antimicrobial susceptibility tests were performed by broth microdilution. Selected isolates were submitted to conjugation experiments using the Escherichia coli J53 as a receptor. We detected eight isolates harboring the mcr-1 gene; seven belonged to Salmonella enterica serovar Typhimurium and its monophasic variant 4,[5],12:i:-, and one belonged to serovar Saintpaul. Seven of the mcr-1 positive isolates displayed a high rate of resistance to other antibiotics in addition to colistin. Analysis of the WGS indicated that the ST 19 was the most common ST among the mcr-1 positive isolates. The mcr-1 gene was located in an IncX4 plasmid of â¼33 kb, with no additional resistance genes and with high identity with a plasmid obtained from a clinical isolate of E. coli mcr-1 positive in Brazil. All plasmids harboring the mcr-1 gene were able to conjugate. Our results suggest the spread of a single plasmid type in Brazil harboring the mcr-1 among Salmonella spp. The horizontal transfer of this mobile element has been contributing to the spread of the colistin resistance in the country.
Assuntos
Contaminação de Alimentos , Microbiologia de Alimentos , Sequências Repetitivas Dispersas , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Conjugação Genética , DNA Bacteriano , Farmacorresistência Bacteriana , Escherichia coli/genética , Microbiologia de Alimentos/métodos , Genes Bacterianos , Testes de Sensibilidade Microbiana , Filogenia , Reação em Cadeia da Polimerase , Carne de Porco/microbiologia , Aves Domésticas/microbiologia , Salmonella enterica/isolamento & purificação , Salmonella typhimurium/classificação , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/isolamento & purificação , Perus/microbiologia , Sequenciamento Completo do GenomaRESUMO
Two hundred isolates of Enterobacterales were tested by Rapid Polymyxins NP for the detection of polymyxin resistance and compared to the reference test broth microdilution (BMD). The sensitivity and specificity of the NP test were 98% and the results are faster than the BMD, decreasing from approximately 24 to 2 h.