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1.
BMC Infect Dis ; 20(1): 15, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906936

RESUMO

BACKGROUND: Bacillus cereus sometimes causes central nervous system infection, especially in compromised hosts. In cases of meningitis arising during neutropenia, CSF abnormalities tend to be subtle and can be easily overlooked, and mortality rate is high. We report a survived case of B. cereus meningitis/brain abscess in severe neutropenia, presenting as immune reconstitution syndrome. CASE PRESENTATION: A 54-year-old Japanese female with acute myelogenous leukemia developed B. cereus bacteremia and meningitis during consolidation chemotherapy. At the onset, she presented with mild meningism. She had marked leukocytopenia (WBC <100/µL, neutrophils 0/µL) and lumbar puncture yielded only mild pleocytosis. She was transferred to intensive care unit, and meropenem, linezolid and vancomycin was started. With intensive therapy, she recovered and once became afebrile. On day 19, however, her fever, meningism and consciousness level dramatically worsened despite recovery of bone marrow function. The antimicrobial chemotherapy was continued and finally she was cured with no complications. CONCLUSIONS: With early diagnosis and prompt initiation and of antibiotics, the case was successfully treated without any sequelae. It is important to remember that, even under optimal antimicrobial therapy, bone marrow recovery can cause transient reaggravation of the disease. In such cases, timely and appropriate evaluation should be done to make the clinical decision to change, continue, or intensify treatment.


Assuntos
Bacteriemia/complicações , Abscesso Encefálico/complicações , Neutropenia Febril Induzida por Quimioterapia/complicações , Síndrome Inflamatória da Reconstituição Imune/complicações , Meningites Bacterianas/complicações , Antibacterianos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bacillus cereus/isolamento & purificação , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/microbiologia , Feminino , Humanos , Síndrome Inflamatória da Reconstituição Imune/tratamento farmacológico , Síndrome Inflamatória da Reconstituição Imune/microbiologia , Leucemia Mieloide Aguda/tratamento farmacológico , Meningites Bacterianas/tratamento farmacológico , Meningites Bacterianas/microbiologia , Pessoa de Meia-Idade , Resultado do Tratamento
2.
Carbohydr Polym ; 227: 115369, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590875

RESUMO

The isolation, screening, and identification of multi-metal resistant (Cd, Cu, Pb, and Zn) bacteria from polluted coastal sediment samples were performed. In this study, the isolates S2-2 and S3-2 had higher multi-metal resistance and were identified as Pseudomonas pachastrellae KMS2-2 and Bacillus cereus KMS3-1, respectively. One-variable-at-a time approach suggested that optimum conditions for exopolysaccharides (EPS) production were pH 7.0, incubation time 120 h, 5 g/L sucrose, and 10 g/L yeast extract. Further, optimization by central composite design revealed that the optimum concentrations of sucrose and yeast extract for higher EPS production (8.9 g/L) were 5 g/L, and 30 g/L, respectively. Heteropolysaccharide nature of EPS determined by FTIR, TLC, and HPLC analysis, consist of mannose, rhamnose, glucose, and xylose. In addition, EPS showed strong emulsifying and flocculation activity. Results suggested the potential EPS-producing multi-metal resistant Bacillus cereus KMS3-1 could be used in biotechnological and industrial application, especially metal removal.


Assuntos
Bacillus cereus/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/isolamento & purificação , Emulsões , Floculação , Sedimentos Geológicos/microbiologia , Metais Pesados/farmacologia , Pseudomonas/isolamento & purificação
3.
BMC Infect Dis ; 19(1): 959, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31711418

RESUMO

BACKGROUND: An infected aneurysm of the thoracic aorta is a rare clinical condition with significant morbidity and mortality. Patients with fast-growing aortic aneurysms show a high incidence of rupture. Gram-positive organisms, such as the Staphylococcus and Enterococcus species, are the most common cause of infection. CASE PRESENTATION: A 91-year-old man presented at our facility with high grade fever and tachypnea, which he had experienced for the previous two days. He had a history of end-stage renal disease and had been undergoing regular chest computed tomography (CT) follow-up for a left lower lung nodule. CT imaging with intravenous contrast media showed a thoracic aortic aneurysm with hemothorax. Rupture of the aneurysm was suspected. CT imaging performed a year ago showed a normal aorta. Blood samples showed a Bacillus cereus infection. The patient was successfully treated for a mycotic aortic aneurysm secondary to Bacillus cereus bacteremia. CONCLUSIONS: Here, we report a rare of an infected aneurysm of the thoracic aorta probably caused by Bacillus cereus. Although infected aneurysms have been described well before, an aneurysm infected with Bacillus cereus is rare. Bacillus cereus, a gram-positive spore-building bacterium, can produce biofilms, which attach to catheters. It has recently emerged as a new organism that can cause serious infection.


Assuntos
Aneurisma Infectado/microbiologia , Aorta Torácica/microbiologia , Aorta Torácica/patologia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Bacillus cereus/isolamento & purificação , Administração Intravenosa , Administração Oral , Idoso de 80 Anos ou mais , Aneurisma Infectado/tratamento farmacológico , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Fluoroquinolonas/administração & dosagem , Fluoroquinolonas/uso terapêutico , Hemotórax/diagnóstico por imagem , Humanos , Masculino , Insuficiência Respiratória , Choque Séptico/tratamento farmacológico , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Vancomicina/administração & dosagem , Vancomicina/uso terapêutico
4.
World J Microbiol Biotechnol ; 35(11): 173, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673794

RESUMO

Neutral proteases have broad application as additives in modern laundry detergents and therefore, thermostability is an integral parameter for effective production of protein crystals. To improve thermostability, the contribution of individual residues of Bacillus cereus neutral protease was examined by site-directed mutagenesis. The Lys11Arg and Lys211Arg mutants clearly possessed improved thermostabilities (Tm were 63 and 61 °C respectively) compared to the wild-type (Tm was 60 °C). MD simulations further revealed that the mutants had low RMSD and RMSF values compared to wild-type BCN indicating increased stability of the protein structure. Lys11Arg mutant particularly possessed the lowest RMSD values due to increased residue interactions, which resulted in enhanced thermostability. The mutants also displayed strong stability to most inhibitors, organic solvents and surfactants after incubation for 1 h. This study demonstrated Lys-Arg mutation enhanced thermostability of BCN and thus provides insight for engineering stabilizing mutations with improved thermostability for related proteins.


Assuntos
Bacillus cereus/enzimologia , Bacillus cereus/genética , Dipeptídeos/genética , Estabilidade Enzimática , Mutação , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Sequência de Aminoácidos , Bacillus cereus/classificação , Bacillus cereus/isolamento & purificação , Proteínas de Bactérias/genética , Sequência de Bases , Clonagem Molecular , Regulação Bacteriana da Expressão Gênica , Cinética , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Peptídeo Hidrolases/química , Peptídeo Hidrolases/isolamento & purificação , Filogenia , Conformação Proteica , Engenharia de Proteínas , Proteínas Recombinantes , Alinhamento de Sequência , Temperatura Ambiente
5.
BMC Infect Dis ; 19(1): 910, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664944

RESUMO

BACKGROUND: On September 4, 2018, a boarding school in the Shunyi District of Beijing, China reported an outbreak of acute gastroenteritis. At least 209 suspected students caused of diarrhea and vomiting. The case was investigated, and control measures were taken to prevent further spread. METHODS: A retrospective cohort study was conducted among the school students and staff in order to test hypothesis that high risk of food served at the school canteen. We collected information on demographics, refectory records, person to person transmission by uniform epidemiological questionnaire. Risk ratios (RR) and 95% confidence intervals (CI) were calculated. Stool specimens of cases and canteen employees, retained food, water, and environmental swabs were investigated by laboratory analysis. RESULTS: We identified 209 cases (including 28 laboratory-confirmed cases) which occurred from August 29 to September 10. All cases were students, and the average age was 20, 52% were male. The outbreak lasted for 13 days, and peaked on September 5. Consumption of Drinks stall and Rice flour stall on September 1 (RR:3.4, 95%CI:1.5-7.8, and RR:7.6, 95%CI:2.8-20.2), Rice flour stall and Fish meal stall on September 2 (RR:4.0, 95%CI:1.2-13.6, and RR:4.6, 95%CI:1.7-12.5), muslim meal stall on September 4 (RR:2.7, 95%CI:1.3-5.4), Barbeque stall on September 5 (RR:3.0, 95%CI:1.2-7.0) were independently associated with increased risk of disease within the following 2 days. Among 35 specimens of rectal swabs or feces from students, 28 specimens were positive. Norovirus GI.6 alone was detected in 23 specimens, Bacillus cereus alone in 3 specimens and both norovirus GI.6 and Bacillus cereus in 2 specimens. Ten specimens of rectal swabs from canteen employees were positive for norovirus GI, and 2 specimens were positive for Bacillus cereus. Four retained food specimens were positive for Bacillus cereus, and environmental samples were negative for any viruses or bacteria. CONCLUSION: Our investigation indicated that canteen employees were infected by two pathogens (norovirus and Bacillus cereus) and transmission may have been possible due to unhygienic practices. Student consumption of food or drink at high-risk stalls was determined as the probable cause of the outbreak.


Assuntos
Bacillus cereus/isolamento & purificação , Infecções por Caliciviridae/epidemiologia , Surtos de Doenças , Doenças Transmitidas por Alimentos/microbiologia , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , Adolescente , Pequim/epidemiologia , Infecções por Caliciviridae/complicações , Diarreia/complicações , Fezes/microbiologia , Fezes/virologia , Feminino , Contaminação de Alimentos , Doenças Transmitidas por Alimentos/virologia , Gastroenterite/complicações , Higiene das Mãos , Humanos , Masculino , Razão de Chances , Estudos Retrospectivos , Inquéritos e Questionários , Universidades , Vômito/complicações , Adulto Jovem
6.
Medicine (Baltimore) ; 98(43): e17609, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31651871

RESUMO

RATIONALE: Bacillus cereus (B cereus) is an aerobic or facultative anaerobic gram-positive, spore-forming bacterium. It can cause fatal disease and generally manifests as 3 distinct syndromes: food intoxication, localized infection, and systemic infection. It is a rare infection that can occur in immunocompetent persons with osteolytic and high-titer anti-IFN-γ autoantibodies. PATIENT CONCERNS: We reported a case of an HIV-negative 24-year old man with an interrupted fever and a 20-day history of progressive ache in the right thigh and high-titer anti-IFN-γ autoantibodies. Magnetic resonance imaging, X-radiography, high-resolution computed tomography, and 3-dimensional reconstruction of the bone showed multiple lucent defects with moth-eaten destruction of the bone and cortical substance of bone in the right femur. Emission CT showed significantly increased uptake in the femur. DIAGNOSIS AND INTERVENTIONS: The patient was originally misdiagnosed with osteosarcoma; acute osteomyelitis was also considered. He received intravenous piperacillin, sulbactam, and levofloxacin during hospitalization; however, he did not respond to the 3-week antibiotic course and his condition worsened. After cultures from incisional biopsy specimens were obtained from the femoral cavity, B cereus-induced osteomyelitis was diagnosed. He received intravenous injections of moxifloxacin 400 mg qd for 4 weeks and oral moxifloxacin 400 mg qd for 8 weeks. OUTCOMES: The patient's symptoms and signs improved. His X-radiography, HRCT, MRI, and 3-dimensional reconstruction of the bone showed absolute absorption in the right femur. However, the anti-IFN-γ autoantibody titer was still high. No recurrence was observed after 24 months of follow-up. He is still undergoing follow-up at this time. LESSONS: This is the first case involving a patient with B cereus infection showing a high titer of anti-IFN-γ autoantibodies. B cereus infection can involve the bone, leading to osteolysis in HIV-negative individuals. Although this patient was HIV-negative and had no other comorbidities, the presence of high titer anti-IFN-γ autoantibodies may be the primary reason for B cereus infection. Clinicians should pay more attention to the identification of osteolytic destruction caused by tumor and infection.


Assuntos
Anticorpos Antibacterianos/sangue , Autoanticorpos/sangue , Bacillus cereus/isolamento & purificação , Interferon gama/imunologia , Osteólise/sangue , Antibacterianos/administração & dosagem , Bacillus cereus/imunologia , Osso e Ossos/imunologia , Humanos , Masculino , Moxifloxacina/administração & dosagem , Osteólise/tratamento farmacológico , Osteólise/microbiologia , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-31522662

RESUMO

A cluster of gastrointestinal illness was detected following receipt of a complaint of becoming ill after a multi-course dinner at a restaurant in Canberra, Australian Capital Territory (ACT), Australia. The complaint led to an investigation by ACT Health. Food samples retained by the restaurant for microbiological analysis returned an unsatisfactory level of Bacillus cereus in beef (19,000 colony forming units/gram [cfu/g]) and a satisfactory level in arancini (50 cfu/g). These positive samples underwent whole genome sequencing and genes encoding diarrhoeal toxins were detected with no laboratory evidence of the emetic toxin. No stool specimens were collected. A cohort study was undertaken and 80% (33/41) of patrons took part in a structured interview. There was no significant difference in age or sex between those ill and not ill. Due to universal exposure most foods were unable to be statistically analysed and no significant results were found from the food history. The ill cohort diverged into two distinct groups based on incubation period and symptoms suggesting this outbreak involved B. cereus intoxication with both diarrhoeal and potentially emetic toxins. Some hygiene practices during food preparation were noted to be inadequate and heating and cooling procedures were unverified when questioned. A combination of the incubation periods and symptom profile, food laboratory evidence, and genomic sequencing of the B. cereus diarrhoeal gene suggest a probable aetiology of B. cereus intoxication. Public health action included the restaurant rectifying hygiene practices and documenting heating/cooling procedures.


Assuntos
Bacillus cereus/isolamento & purificação , Toxinas Bacterianas/toxicidade , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Gastroenterite/epidemiologia , Carne Vermelha/microbiologia , Animais , Território da Capital Australiana/epidemiologia , Bacillus cereus/genética , Bovinos , Estudos de Coortes , Diarreia/epidemiologia , Diarreia/microbiologia , Diarreia/mortalidade , Eméticos , Feminino , Contaminação de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/mortalidade , Gastroenterite/microbiologia , Gastroenterite/mortalidade , Humanos , Masculino , Restaurantes , Estudos Retrospectivos , Inquéritos e Questionários
8.
Food Chem Toxicol ; 133: 110729, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31381944

RESUMO

The present study aimed to develop a consortium of nutritive fermented food products, supplemented with phytochemicals, with reduced toxicological contents. We developed new flavored Doenjang products (protein rich) fermented with lotus, ginkgo, and garlic plant extract-based Meju (termed as EMD) as the starter culture and by using traditional Meju (termed as TMD), where these plant extracts were added later during the fermentation process. Fermented Doenjang samples were analyzed for reduced levels of biogenic amines (BAs), aflatoxins, and microbial hazards, (including Bacillus cereus) as well as for their nutritive contents and antioxidant potential, after varying periods of fermentation (0, 3, 6, 9 and 12 months). All Doenjang samples prepared using plant extracts and their mixtures (1% and 10%) showed desired reduction in B. cereus counts, BAs, aflatoxins, and other foodborne pathogens as well as showed potent antioxidant abilities, including phenolic/flavonoid contents. Based on the higher efficiency in reducing various toxicants, Ginkgo biloba leaf extract added TMD samples were selected for the development of Doenjang products as an innovative approach, with great potential to improve the quality and safety of soybean fermented products in the Korean market, offering enhanced health benefits and reduced risks of toxicity.


Assuntos
Aflatoxinas/análise , Carga Bacteriana , Aminas Biogênicas/análise , Extratos Vegetais/análise , Alimentos de Soja/análise , Bacillus cereus/isolamento & purificação , Linhagem Celular , Cor , Fermentação , Microbiologia de Alimentos/métodos , Qualidade dos Alimentos , Depuradores de Radicais Livres/análise , Alho/química , Ginkgo biloba/química , Humanos , Concentração de Íons de Hidrogênio , Coreia (Geográfico) , Lotus/química , Alimentos de Soja/microbiologia , Soja/química , Soja/microbiologia
9.
Anal Chim Acta ; 1080: 162-169, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31409466

RESUMO

Driven by a bright prospect for rapid, portable and cost-effective point-of-care testing, an assembled Pasteur pipette device to integrate nucleic acid extraction, amplification and detection was developed to detect B. cereus in a sample-to-answer format. Denaturation Bubble-mediated Strand Exchange Amplification (SEA) was chosen to perform isothermal amplification because it requires only a pair of primers and one Bst DNA polymerase. The established SEA can detect as low as 1.0 × 10-13 M genomic DNA of B. cereus, which was comparable with the previously reported method for B. cereus detection. The assembled Pasteur pipette allows sample-to-answer diagnostic in a simple, low-cost, portable, and disposable format. The inherent function of Pasteur pipette enables direct liquid handling without the need of extra pipettes, syringes or pumps. Visual readout was achieved by using a pH sensitive dye, further simplifying result judgment process. The detection limit for B. cereus is 1.0 × 104 CFU/mL in pure cultures, while the detection limit in artificially contaminated milk is 1.0 × 105 CFU/mL without enrichment and 1.0 × 100 CFU/mL following 12 h enrichment. Considering that typical cell counts in food samples associated to food poisoning are 1.0 × 105 to 1.0 × 108 CFU per gram/milliliter B. cereus, our Pasteur pipette is enough sensitive for answer-to-sample diagnosis of B. cereus even directly from foods without enrichment. The whole diagnostic procedure could be completed within 50 min, dramatically decreasing the detection time. In a word, the assembled Pasteur pipette device, combined with a homemade metal bath, possesses great potential for sample-to-answer application in resource-limited settings.


Assuntos
Bacillus cereus/isolamento & purificação , Carga Bacteriana/métodos , Colorimetria/métodos , DNA Bacteriano/análise , Animais , Carga Bacteriana/instrumentação , Proteínas de Bactérias/química , Colorimetria/instrumentação , Corantes/química , DNA Polimerase Dirigida por DNA/química , Contaminação de Alimentos/análise , Geobacillus stearothermophilus/enzimologia , Limite de Detecção , Leite/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Papel
10.
Curr Microbiol ; 76(11): 1355-1360, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31324956

RESUMO

Bacillus cereus not only has adverse effects on the nutrition and shelf life of dairy products but also seriously endanger people's health. This study was conducted to reveal the prevalence and genetic diversity of B. cereus strains isolated from raw milk and cattle farm environments. A total 56 of B. cereus strains were detected from 300 environmental samples (soil, water, fodder, air, milk pails, milking machines, cowsheds, bedding, excrement, cow surfaces, udders, overalls, soles, and staff hand samples) and 50 raw milk samples, and divided into 18 sequence types (STs) using multilocus sequence typing method. These STs included ST27, ST61, ST92, ST142, ST168, ST208, ST378, ST427, ST766, ST 857, ST1098, ST1140, ST1194, ST1236, ST1336, ST1339, ST1341, and ST1348, among them, ST857 (7/56, 12.5%) was the dominant ST, and were detected from air, cowsheds, bedding, excrement, and raw milk samples. Our findings could reveal the distribution and genetic diversity of B. cereus strains in raw milk and cattle farm environments, and provide a theoretical basis for controlling the potential harm of this pathogenic bacteria in dairy products.


Assuntos
Bacillus cereus/genética , Bacillus cereus/isolamento & purificação , Leite/microbiologia , Microbiologia do Ar , Criação de Animais Domésticos/instrumentação , Animais , Bacillus cereus/classificação , Bovinos/microbiologia , Fazendas , Feminino , Variação Genética , Tipagem de Sequências Multilocus , Filogenia , Microbiologia do Solo , Microbiologia da Água
11.
Talanta ; 204: 44-49, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357318

RESUMO

Bacillus cereus, a common soil bacterium, has been shown to act as a biogeochemical indicator for concealed mineralisations, e.g., vein-type Au deposits. Field and cultivation-free detection of Bacillus cereus in the presence of Au3+ and other metal ions is significantly important but still almost blank in current biogeochemical prospecting of gold mine system. Herein, a self-established simple approach was slightly improved to make silver nanoparticles (Ag NPs) rapidly concentrated on every bacterial cell, and highly strong and distinct surface-enhanced Raman scattering (SERS) signals of Bacillus cereus free from any native fluorescence have been obtained in a so called 'mixing-and-measuring' manner. Furthermore, SERS was used for the first time to our knowledge to investigate the impacts of different concentrations of metal ions on Bacillus cereus, and successfully utilized for distinguishing Au3+ ions from other species. A more convincing multi-Raman criterion based on Raman bands, and further the entire Raman spectrum in combination with statistical analysis (e.g., principal component analysis (PCA)) were found capable of detecting spectral differences of Bacillus cereus in the presence of metal ions (Au3+, Ag+, Cu2+ and Zn2+) with different concentrations. An interesting phenomenon has been found that except for Au3+ ions, the highest permissive concentration of other metal ions for the detected Bacillus cereus is up to 10 µg/mL possibly due to their resistance to Au. The results also indicate that an effective biogeochemical exploration technique of SERS spectral response may be developed, where Bacillus cereus spore counts are measured in the field and used as a pre-screening method to target areas useful for further sampling and complete geochemical analysis.


Assuntos
Bacillus cereus/isolamento & purificação , Carga Bacteriana/métodos , Ouro/farmacologia , Bacillus cereus/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ouro/química , Ouro/toxicidade , Nanopartículas Metálicas/química , Mineração/métodos , Análise de Componente Principal , Prata/química , Análise Espectral Raman/métodos , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/isolamento & purificação
12.
Arch Microbiol ; 201(9): 1195-1205, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31172252

RESUMO

Awareness of the consumer has increased the demand of safe and chemical-free foods, and consequently it has increased the demand of antibacterial bioactive compounds. In the present study, antibacterial compound produced by a local bacterial isolate NSD MTCC 10072, showing antagonistic activity against six human pathogens, was isolated, partially purified and characterized. Maximum production of antibacterial compound was observed between 51 and 60 h after seeding. The antibacterial activity of the compound was found to be thermostable up to 80 °C for 60 min and its efficacy was very good between pH 4 and 12. Minimum inhibitory concentration (25.84 µg/µl) of the antibacterial compound was observed against Streptococcus aureus NICM 2901. GC-MS analysis of the bacterium secreted chemical compound (C11H18N2O2) was used to identify the antimicrobial compound as Pyrrolo(1,2-a) pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl). In Silico studies showed that the antimicrobial compound is non-toxic, non-irritating and followed Lipinski-type properties which suggested that the compound could be used as potential drug against different human pathogens.


Assuntos
Antibacterianos/farmacologia , Bacillus cereus/metabolismo , Proteínas de Bactérias/farmacologia , Agentes de Controle Biológico/farmacologia , Antibacterianos/metabolismo , Bacillus cereus/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Agentes de Controle Biológico/metabolismo , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium/efeitos dos fármacos , Pirróis/química , Pirróis/farmacologia , Staphylococcus aureus/efeitos dos fármacos
13.
Pak J Pharm Sci ; 32(2 (Supplementary)): 889-894, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31103988

RESUMO

Amylases are enzymes that catalyze the hydrolysis of starch into highly valuable products of economic significance. Amylases are used extensively in various industrial sectors. Microbial sources particularly Bacillus species are well known for the cost effective commercial production of amylase enzyme. Present study focuses on the enhancement of amylase enzyme production from an indigenously isolated Bacillus cereus AS2 strain via one variable at a time (OVAT) optimization of different physical and chemical factors. Purposely, eight parameters possibly affecting the amylase production including temperature, pH, incubation time, inoculum size, substrate concentration, metal ions, carbon and nitrogen sources were investigated. According to the results, amylase production was significantly boosted at maximum when the Bacillus cereus AS2 was grown at 45°C on pH 7.0 for 72 hours in the medium supplemented with 4% starch and 0.5% glycine. Among the different metal ions tested, CaCl2 (0.05%) was found significant to accelerate extracellular amylase production.


Assuntos
Amilases/biossíntese , Bacillus cereus/química , Bacillus cereus/metabolismo , Meios de Cultura/química , Bacillus cereus/genética , Bacillus cereus/isolamento & purificação , Carbono/metabolismo , Glicina/química , Concentração de Íons de Hidrogênio , Metais , Microbiologia do Solo , Amido , Temperatura Ambiente
14.
PLoS One ; 14(5): e0217021, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31107885

RESUMO

Spores of several Bacillus species have long history of consumption and safe use as probiotics and a variety of formulations containing these organisms are available in the global market. Considering the difficulties in the identification of Bacillus species and the poor microbiological quality of many probiotic formulations, we used three up-to-date methodological approaches for analyzing the content of ten formulations marketed in Italy and labeled to contain Bacillus spores. We compared the performance of biochemical tests based on the BCL Vitek2 card and MALDI-TOF mass spectrometry, using 16S rDNA sequencing as the reference technique. The BCL card performed well in identifying all Bacillus probiotic strains as well as the Bruker's MALDI Biotyper. Nevertheless, the MALDI score values were sometimes lower than those indicated by the manufacturer for correct species identification. Contaminant bacteria (Lysinibacillus fusiformis, Acinetobacter baumannii, Bacillus cereus, Brevibacillus choshinensis, Bacillus licheniformis, Bacillus badius) were detected in some formulations. Characterization of the B. cereus contaminant showed the potential pathogenicity of this strain. Microbial enumeration performed by the plate count method revealed that the number of viable cells contained in many of the analyzed products differed from the labeled amount. Overall, our data show that only two of the ten analyzed formulations qualitatively and quantitatively respect what is on the label. Since probiotic properties are most often strain specific, molecular typing of isolates of the two most common Bacillus species, B. clausii and B. coagulans, was also performed. In conclusion, the majority of the analyzed products do not comply with quality requirements, most likely leading to reduced/absent efficacy of the preparation and representing a potential infective risk for consumers.


Assuntos
Bacillus/classificação , Probióticos/análise , Acinetobacter baumannii/isolamento & purificação , Bacillaceae/isolamento & purificação , Bacillus/isolamento & purificação , Bacillus cereus/isolamento & purificação , Bacillus licheniformis/isolamento & purificação , Brevibacillus/isolamento & purificação , DNA Bacteriano/genética , Contaminação de Medicamentos , Itália , Fenótipo , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/isolamento & purificação , Especificidade da Espécie , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Virulência
15.
Analyst ; 144(10): 3289-3296, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-30949633

RESUMO

Bacillus spp. are spore-forming bacteria, and some of them, including Bacillus cereus and Bacillus anthracis, are pathogens. Dipicolinic acid (DPA) has been recognized as a biomarker for spore-forming bacteria. Thus, developing rapid sensing methods to spot the presence of DPA in suspicious samples is significant. In this study, we employ complexes of glutathione-capped gold nanoclusters (Au@GSH NCs) with Cu2+ as sensing probes against DPA. Au@GSH NCs possess orange-reddish fluorescence. However, their fluorescence is significantly quenched in the presence of Cu2+. In the presence of DPA, the fluorescence of Au@GSH NCs can be restored because DPA can easily remove Cu2+ on the NCs through chelation based on the high formation constant (log K = 7.97) between Cu2+ and DPA. Therefore, on the basis of this fact, Au@GSH NC-Cu2+ complexes are used as turn-on fluorescence probes against DPA. Unlike most of the existing sensing methods, the developed Au@GSH-Cu2+-based sensing method is not affected by the presence of phosphates, which can be commonly found in real samples. The limit of detection of using the developed sensing method toward DPA can reach as low as ∼19 nM. In addition, we also demonstrate the feasibility of using the developed sensing method for detection and quantification of DPA in soil samples and B. cereus spore lysates.


Assuntos
Corantes Fluorescentes/química , Ouro/química , Nanopartículas Metálicas/química , Ácidos Picolínicos/análise , Espectrometria de Fluorescência/métodos , Bacillus cereus/isolamento & purificação , Biomarcadores/análise , Quelantes/análise , Quelantes/química , Cobre/química , Fluorescência , Glutationa/química , Limite de Detecção , Ácidos Picolínicos/química , Solo/química
16.
Biofouling ; 35(2): 204-216, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30950292

RESUMO

Formation of bacterial biofilms is a risk with many in situ medical devices. Biofilm-forming Bacillus species are associated with potentially life-threatening catheter-related blood stream infections in immunocompromised patients. Here, bacteria were isolated from biofilm-like structures within the lumen of central venous catheters (CVCs) from two patients admitted to cardiac hospital wards. Isolates belonged to the Bacillus cereus group, exhibited strong biofilm formation propensity, and mapped phylogenetically close to the B. cereus emetic cluster. Together, whole genome sequencing and quantitative PCR confirmed that the isolates constituted the same strain and possessed a range of genes important for and up-regulated during biofilm formation. Antimicrobial susceptibility testing demonstrated resistance to trimethoprim-sulphamethoxazole, clindamycin, penicillin and ampicillin. Inspection of the genome revealed several chromosomal ß-lactamase genes and a sulphonamide resistant variant of folP. This study clearly shows that B. cereus persisting in hospital ward environments may constitute a risk factor from repeated contamination of CVCs.


Assuntos
Bacillus cereus/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Cateteres Venosos Centrais/microbiologia , Antibacterianos/farmacologia , Bacillus cereus/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Infecções Relacionadas a Cateter/microbiologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Contaminação de Equipamentos , Equipamentos e Provisões Hospitalares , Humanos , Testes de Sensibilidade Microbiana
18.
BMC Infect Dis ; 19(1): 197, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30813918

RESUMO

BACKGROUND: Bacillus cereus is a gram-positive rod bacterium that is responsible for food poisoning. It is naturally widely distributed, and thus often contaminates cultures. Although it is rarely considered responsible, it can cause serious infections under certain conditions. However, lethal infections, especially in immunocompetent patients, are rare. CASE PRESENTATION: A healthy 60-year-old man developed community-acquired B. cereus pneumonia and alveolar hemorrhage unveiled by abrupt chest pain and hemoptysis with no other advance symptoms. B. cereus induced silent alveolar destruction without any local or systemic inflammatory response. Although the lesion resembled lung anthrax, there was no evidence of Bacillus anthracis toxin. CONCLUSIONS: Some isolates of B. cereus can cause anthrax-like fulminant necrotizing pneumonia in immunocompetent patients. If this type of B. cereus were used as a means of bioterrorism, it may be quite difficult to recognize as bioterrorism. We should keep B. cereus in mind as a potential pathogen of fulminant human infectious disease.


Assuntos
Infecções por Bacillaceae/etiologia , Bacillus cereus/patogenicidade , Infecções Comunitárias Adquiridas/microbiologia , Pneumonia Bacteriana/etiologia , Antraz/microbiologia , Infecções por Bacillaceae/microbiologia , Bacillus anthracis/isolamento & purificação , Bacillus anthracis/patogenicidade , Bacillus cereus/isolamento & purificação , Infecções Comunitárias Adquiridas/diagnóstico por imagem , Humanos , Imunocompetência , Masculino , Pessoa de Meia-Idade , Pneumonia Bacteriana/diagnóstico por imagem , Pneumonia Bacteriana/microbiologia , Infecções Respiratórias/microbiologia
19.
Int J Food Microbiol ; 296: 21-30, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-30826539

RESUMO

The microbial risk involved with natural food fermentation is largely unknown. Here, we report the prevalence of enteric bacterial pathogens in the traditional fermented foods marketed in Northeast region of India. A total of 682 samples of 39 food types (broadly categorized into fermented soybean, bamboo shoot, fish, milk and pork products) collected over four different seasons from seven states of India were analyzed in this study. Cultivation-independent analysis by MiSeq amplicon sequencing of V4-V5 region of the 16S rRNA gene showed the bacterial community structure in the foods. Among the WHO prioritized foodborne bacterial pathogens, we detected the prevalence of phylotypes related to Clostridium botulinum, Bacillus cereus, Staphylococcus aureus, Clostridium perfringens, Listeria monocytogenes, and Escherichia coli in these ethnic foods. We also observed the occurrence of other well known human enteric pathogens like Proteus mirabilis, Clostridium difficile, and Yersinia enterocolitica. Further pathogen-specific qPCR assays confirmed a higher population (>107 cells/g) of B. cereus, P. mirabilis, and a C. botulinum related phylotype in the fermented soybean, fish, and pork products. We noticed a general trend of higher pathogen occurrence during the colder months without any seasonal variation of total bacterial load in the fermented foods. Further qPCR analysis on toxigenic and pathogenic potential, and toxins production by immunoassays showed that all the soybean samples and the isolated B. cereus cultures were positive for diarrheal toxins (Nhe and Hb1), and nearly half of the samples were positive for emetic toxin (cereulide). Similarly, the food samples and associated swarming P. mirabilis cultures were positive with the pathogenic factors like hemolysin (hpm), urease (ure) and multidrug resistance. However, we could not confirm the presence of botulinum neurotoxin (toxins A, B, E, and F) in the C. botulinum positive food samples. This is the first baseline data of the enteric bacterial pathogens prevalent in the traditional fermented foods of India, which will support the sustained effort of WHO to estimate the global foodborne disease burden. The unusual presence of P. mirabilis in the fermented foods marketed in the Indian region with high incidence of urolithiasis cases is a concern. Our study emphasizes the need of the hour to have a coordinated action to control and prevent the spread of enteric bacterial pathogens through fermented foods marketed in India. Moreover, replacing the indigenous process with a defined starter culture based controlled fermentation will enhance the safety of Indian fermented foods.


Assuntos
Bacillus cereus/isolamento & purificação , Enterobacteriaceae/isolamento & purificação , Microbiologia de Alimentos/métodos , Inocuidade dos Alimentos/métodos , Listeria monocytogenes/isolamento & purificação , Animais , Bacillus cereus/genética , Bacillus cereus/patogenicidade , Carga Bacteriana , Reatores Biológicos/microbiologia , Depsipeptídeos/análise , Enterobacteriaceae/genética , Enterobacteriaceae/patogenicidade , Fermentação , Peixes/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Proteínas Hemolisinas/análise , Humanos , Índia , Listeria monocytogenes/genética , Listeria monocytogenes/patogenicidade , Leite/microbiologia , Prevalência , RNA Ribossômico 16S/genética , Carne Vermelha/microbiologia , Sasa/microbiologia , Soja/microbiologia , Urease/análise
20.
Arch Microbiol ; 201(6): 769-785, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30843087

RESUMO

The present study was aimed to investigate the effects of plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGRs) on the physiology and yield of wheat grown in less fertile sandy soil. The isolated PGPR strains were identified by 16S-rRNA gene sequencing as Planomicrobium chinense (P1), Bacillus cereus (P2) and Pseudomonas fluorescens (P3). Wheat varieties (Galaxy-13 and Pak-2013) differing in sensitivity to drought were soaked in fresh cultures of bacterial isolates and the PGRs (salicylic acid and putrescine) were sprayed at 150 mg/L on seedlings at three leaf stage. PGPR and PGRs treated plants showed significant increase in the contents of chlorophyll, sugar and protein even under harsh environmental conditions. Drought stress enhanced the production of proline, antioxidant enzymes and lipid peroxidation but a decrease was noted in the biochemical content (i.e. chlorophyll, protein and sugar) of inoculated plants. PGPR inoculation also significantly enhanced the yield parameters (i.e. plant height, spike length, grain yield and weight) and improved the fertility status of sandy soil. The accumulation of macronutrient, total NO3-N and P concentration and soil moisture content of rhizosphere soil was also enhanced by PGPRs inoculation. It is concluded that the combined effects of PGPR and PGRs have profound effects on the biochemical responses and drought tolerance of wheat grown in sandy soils.


Assuntos
Bacillus cereus/isolamento & purificação , Planococáceas/fisiologia , Reguladores de Crescimento de Planta/farmacologia , Pseudomonas fluorescens/fisiologia , Triticum/microbiologia , Bacillus cereus/genética , Clorofila/metabolismo , Secas , Planococáceas/genética , Planococáceas/isolamento & purificação , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/isolamento & purificação , Putrescina/farmacologia , Ácido Salicílico/farmacologia , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Plântula/microbiologia , Solo/química , Microbiologia do Solo , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
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