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1.
Ecotoxicol Environ Saf ; 187: 109850, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31677569

RESUMO

Soil fumigation is currently the most effective method for controlling soil-borne pests and diseases in high-value crops. To better understand the effect of chloropicrin (CP), dazomet (DZ), dimethyl disulfide (DMDS), allyl isothiocyanate (AITC) and 1,3-dichloropropene (1,3-D) fumigants on soil microorganisms, this study monitored changes in the diversity and community composition of soil bacteria involved in denitrification using real-time PCR and high-throughput gene sequencing techniques. These five fumigants significantly decreased the bacterial population size in some phyla including Proteobacteria, Chloroflexi and Acidobacteria, and increased the bacterial population size in other phyla such as Firmicutes, Gemmatimonadetes, Actinobacteria, Verrucomicrobia, Saccharibacteria and Parcubacteria. Although bacterial diversity declined after CP fumigation, it was briefly stimulated by the other four fumigants. Meanwhile, all five fumigants temporarily decreased populations of denitrifying bacteria containing the napA, narG, nirS or nirK enzyme-encoding genes. Denitrifiers bearing the cnorB, qnorB or nosZ genes were relatively stable following DZ and DMDS fumigation. However, cnorB and nosZ decreased initially following CP, AITC and 1,3-D fumigation. Simultaneously, the abundance of qnorB significantly increased in AITC and 1,3-D fumigated soils. These results showed that soil fumigation significantly shifted the abundance and community structure of denitrifying bacteria. This study will help to predict the response of different phyla of denitrifying bacteria to soil fumigation.


Assuntos
Bactérias Anaeróbias/efeitos dos fármacos , Fumigação , Microbiota/efeitos dos fármacos , Resíduos de Praguicidas/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/crescimento & desenvolvimento , Biodiversidade , Desnitrificação , Microbiota/genética , Solo/química
2.
Sci Total Environ ; 692: 602-612, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539968

RESUMO

In this study, an anaerobic ammonium oxidation (anammox) reactor, which was inhibited by a salinity of 50 g NaCl L-1 during a long-term experiment, was rapidly restarted by decreasing the salinity to 20 g NaCl L-1 and adding biomass. The effects of exposure time and shock concentrations on the anammox reactor indicate that anammox granular sludge has a high tolerance to salinity and strong ability for self-recovery. The nitrogen removal efficiency was higher than 50% after exposure to 50 g NaCl L-1 for 66 h. To shorten the time taken for effluent nitrogen concentrations to attain national standards (GB18918-2002) after the anammox reactor was shocked with NaCl, reactor performance (i.e., recovery) after the addition of K+, glycine betaine, Fe2+, and hydroxylamine were compared after the reactor was inhibited by 80 g NaCl L-1. The results indicate that hydroxylamine was the best reversal agent. The recovery time of the anammox reactor could be shortened by 50% following the addition of hydroxylamine. The most favorable NH2OH-N/NO2--N concentration ratio for improving nitrogen removal of anammox was 1:11. The abundances of Planctomycetes and its genera Candidatus Kuenenia and Brocadiaceae_g_unclassified increased after repeated salinity shock-recovery phases, indicating that Candidatus Kuenenia and Brocadiaceae_g_unclassified are able to adapt to NaCl shocking and recovery.


Assuntos
Amônia/metabolismo , Bactérias Anaeróbias/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Cloreto de Sódio/toxicidade , Eliminação de Resíduos Líquidos , Bactérias Anaeróbias/metabolismo , Microbiota/fisiologia , Oxirredução , Estresse Fisiológico
3.
Ecotoxicology ; 28(8): 1003-1008, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31471821

RESUMO

Anaerobic ammonium-oxidizing (anammox) bacteria can play an important role in nitrogen elimination in the environment. However, the effect of heavy metals on anammox bacteria in aquatic ecosystem remains largely unknown. The present study investigated the variability of anammox bacterial community in a freshwater reservoir after a severe heavy metal spill. The richness (Chao1 richness estimator = 2-18), diversity (Shannon index = 0.26-2.04) and community structure of anammox bacteria changed considerably with sampling date, while anammox bacterial abundance (from 1.38 × 105 to 3.09 × 105 anammox bacterial 16S rRNA gene copies per gram dry sediment) was less responsive to metal spill. Anammox bacterial communities were mainly composed of Brocadia- and Anammoxoglobus-like bacteria as well as novel phylotype, however, there relative abundance varied among sampling dates. This work could add the knowledge of the response of anammox bacteria to heavy metal contamination.


Assuntos
Compostos de Amônio/efeitos adversos , Bactérias Anaeróbias/efeitos dos fármacos , Sedimentos Geológicos/química , Metais Pesados/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Bactérias Anaeróbias/fisiologia , Biodiversidade , Sedimentos Geológicos/microbiologia , Oxirredução , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
4.
Endodoncia (Madr.) ; 37(2): 30-38, sept. 2019. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-186297

RESUMO

Objetivo: El objetivo de este estudio ha sido valorar cómo el hidróxido de calcio y la pasta triantibiótica (3-ATB) con agua destilada o propilenglicol actúan frente a una de las principales bacterias anaerobias facultativas presentes en dientes permanentes jóvenes con pulpa necrótica. Material y Método: Se llevó a cabo la siembra de la cepa bacteriana E.Coli (ATCC(R) 25922) en placas Petri para probar la susceptibilidad de los materiales mediante el método de difusión en agar. Se realizó la lectura de los resultados a las 48 horas mediante la medición de los halos de inhibición (mm) presentes en las placas. Resultados: La pasta tri-antibiótica mostró mayor inhibición que el hidróxido de calcio. Respecto a los solventes, la pasta 3-ATB ofreció mejor resultado combinada con propilenglicol, mientras que la respuesta del hidróxido de calcio fue más favorable al mezclar con agua destilada. Conclusiones: La pasta 3-ATB es más efectiva contra microorganismos anaerobios facultativos que el hidróxido de calcio, independientemente del solvente utilizado. En cuanto al solvente, el propilenglicol es más efectivo con pasta tri-antibiótica y el hidróxido de calcio lo es con agua destilada


Objective: The objective of this study was to assess how calcium hydroxide and triple antibiotic paste (3-ATB) with distilled water or propylene glycol act against one of the main facultative anaerobic bacteria present in young permanent teeth with necoritc pulp. Material and Methods: The seeding of the E.Coli (ATCC(R) 25922) was carried out in Petri dishes to test the susceptibility of the materials by the agar diffusion method. The results were read at 48 hours by measuring the inhibition zones (mm) present in the plates. Results: 3-ATB paste showed greater inhibition than calcium hydroxide. Regarding the solvents, 3-ATB paste offered better re-sults with propylene glycol, while the calcium hydroxide response was more favorable mixed with distilled water. Conclusions: 3-ATB paste is more effective against facultative anaerobic microorganisms than calcium hydroxide, regardless of the solvent used. As for the solvent, propylene glycol is more effective with 3-ATB paste while calcium hydroxide with distilled water


Assuntos
Humanos , Anti-Infecciosos/uso terapêutico , Hidróxido de Cálcio/metabolismo , Pomadas/uso terapêutico , Bactérias Anaeróbias/efeitos dos fármacos , Dentição Permanente , Propilenoglicol/uso terapêutico , Água Destilada , Espectrofotometria , Análise de Variância , Análise Estatística
5.
J Infect Chemother ; 25(11): 837-844, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31427200

RESUMO

Obligate anaerobes exist as resident flora in various sites in humans, but they are also emphasized as endogenous causative microorganism of infections. We performed surveillance to understand the trend of drug susceptibility in obligate anaerobic bacteria in the Kinki area of Japan. In the experiment, we used 156 obligate anaerobe isolates collected from 13 institutions that participated in the Study of Bacterial Resistance Kinki Region of Japan. MALDI Biotyper was used to identify the collected strains, and among the 156 test strains, those that could be identified with an accuracy of Score Value 2.0 or more included 6 genera, 30 species, and 144 strains (Bacteroides spp. 77 strains, Parabacteroides sp. 2 strains, Prevotella spp. 29 strains, Fusobacterium spp. 14 strains, Porphyromonas spp. 2 strains, and Clostridioides difficile 20 strains), and they were assigned as subject strains for drug susceptibility testing. The drug susceptibility test was carried out by broth microdilution method using Kyokuto Opt Panel MP ANA (Kyokuto Pharmaceutical Industrial Co., Ltd., Tokyo, Japan) and judged according to CLSI criteria. As a result, Bacteroides and Parabacteroides species showed good sensitivities to tazobactam-piperacillin, imipenem, metronidazole and chloramphenicol, and low sensitivities to ampicillin, cefoperazone and vancomycin. Prevotella species showed good sensitivities to sulbactam-ampicillin, tazobactam-piperacillin, cefmetazole, imipenem, doripenem and metronidazole. Susceptibility rates to other drugs were slightly different depending on the bacterial species. Both Fusobacterium spp. and Porphyromonas spp. showed high sensitivities to many drugs. C. difficile was highly sensitive to vancomycin and metronidazole, having MIC90s of 0.5 µg/mL and ≤2 µg/mL, respectively.


Assuntos
Anti-Infecciosos/uso terapêutico , Bactérias Anaeróbias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Japão , Testes de Sensibilidade Microbiana
6.
Future Microbiol ; 14: 1055-1064, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31469008

RESUMO

Multidrug resistance (MDR) in anaerobes is not a well-known topic. Bacteroides fragilis group isolates have numerous resistance determinants such as multidrug efflux pumps, cfiA and nimB genes and activating insertion sequences, and some isolates exhibited extensive drug-resistant patterns. MDR rates in B. fragilis group were from 1.5 to >18% and up to >71% in cfiA and nimB positive isolates carrying insertion sequences. MDR was present in >1/2 of Clostridioides difficile isolates, most often in epidemic/hypervirulent strains and unusually high metronidazole or vancomycin resistance has been reported in single studies. MDR was found in Prevotella spp. (in ≤10% of isolates), Finegoldia magna, Veillonella spp. and Cutibacterium acnes. Resistance in the anaerobes tends to be less predictable and anaerobic microbiology is required in more laboratories. New hopes may be new antibiotics such as eravacycline, cadazolid, surotomycin, ridinilazol or C. difficile toxoid vaccines; however, more efforts are needed to track the MDR in anaerobes.


Assuntos
Antibacterianos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Infecções Bacterianas/epidemiologia , Farmacorresistência Bacteriana Múltipla , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/isolamento & purificação , Infecções Bacterianas/microbiologia , Genes Bacterianos , Humanos , Prevalência
7.
Eur J Clin Microbiol Infect Dis ; 38(10): 1787-1794, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31175478

RESUMO

Complicated intra-abdominal infections (cIAIs) are commonly associated with multimicroorganisms and treatment choices are becoming narrower due to developing resistance, especially in the gram-negative Enterobacteriaceae species. Eravacycline is a newly developed, fully synthetic tetracycline derivative that has shown potent broad-spectrum activity against a wide variety of microorganisms, including those such as extended spectrum ß-lactamase producing Enterobacteriaceae and Acinetobacter. Eravacycline has shown activity against many gram-positive organisms such as methicillin-resistant S. aureus and vancomycin resistant Enterococcus faecalis and Enterococcus faecium (VRE), gram-negative organisms such as Escherichia coli, and anaerobic species of microorganisms such as Bacteroides. This fluorocycline has been compared to ertapenem and meropenem for the treatment of complicated intra-abdominal infections and levofloxacin for the treatment of complicated urinary tract infections. Eravacycline was shown to be noninferior to ertapenem but did not meet noninferiority criteria in comparison to levofloxacin. Oral and IV formulations on eravacycline were tested in clinical trials, but at this time, only the IV formulation is FDA approved. Eravacycline has been noted to have a half-life of 20 h with protein binding around 80%; AUC over minimum inhibitory concentration (MIC) has also been shown to be eravacycline's best predictor of efficacy. Of note, eravacycline does not require any renal dose adjustments, as the majority of its clearance is by nonrenal pathways.


Assuntos
Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Infecções Intra-Abdominais/tratamento farmacológico , Tetraciclinas/farmacologia , Tetraciclinas/uso terapêutico , Administração Intravenosa , Administração Oral , Bactérias Anaeróbias/efeitos dos fármacos , Ensaios Clínicos como Assunto , Coinfecção/tratamento farmacológico , Aprovação de Drogas , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana , Resultado do Tratamento
8.
Anaerobe ; 59: 49-53, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31103531

RESUMO

The objectives of this study were to report on the antimicrobial susceptibility of 276 clinically significant anaerobic bacteria belonging to the major genera isolated between May 2017 and November 2018 in a tertiary hospital in Granada (Spain) and to describe key clinical features of the patients. Species identification was performed by MALDI-TOF MS. Antimicrobial susceptibility tests were performed against penicillin, amoxicillin-clavulanic, imipenem, meropenem, moxifloxacin, clindamycin, metronidazole, vancomycin, and piperacillin-tazobactam using the gradient diffusion technique and EUCAST breakpoints (except for moxifloxacin). The most frequent anaerobes were Bacteroides (29.7%; n = 82), Clostridioides difficile (15.9%, n = 44), Prevotella (10.8%, n = 30), and Propionibacterium (10.7%, n = 25). Metronidazole was not universally active against all genera tested, and some isolates showed resistance to this drug. Almost all tested anaerobes were susceptible to carbapenems and amoxicillin-clavulanate except for Clostridioides difficile (resistance rate of 94%) and Bacteroides (19%), respectively. High overall resistance rates to clindamycin were observed, especially for genera Finegoldia (54%), Bacteroides (49%), and Prevotella (40%). Resistance rates to carbapenems and amoxicillin-clavulanate were very low for the majority of tested genera but were high for Clostridioides difficile and Bacteroides spp., respectively. Resistance to clindamycin was very high, especially for Bacteroides, Finegoldia magna, Prevotella and Peptoniphilus. Routine antimicrobial susceptibility testing for anaerobes contributes information on the global situation and allows empirical therapies to be selected in accordance with local data on resistant strains.


Assuntos
Antibacterianos/farmacologia , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/isolamento & purificação , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Farmacorresistência Bacteriana , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias Anaeróbias/efeitos dos fármacos , Infecções Bacterianas/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Espanha/epidemiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Centros de Atenção Terciária , Adulto Jovem
9.
Int J Cancer ; 145(10): 2701-2711, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30980680

RESUMO

Overuse of antibiotic drugs alters the composition of gut microbiota and has detrimental effects on the host. In our study, we investigated association of gut flora and antibiotics in the prognosis of patients with liver cancer who have undergone chemotherapy by analyzing two independent clinical studies. We retrospectively subanalyzed a previously reported randomized controlled trial (RCT) on hepatic arterial infusion chemotherapy in patients with hepatocellular carcinoma (HCC) to investigate the association between use of antibiotics and prognosis. In the other study, we prospectively determined the abundance of specific bacterial genus in patients with HCC by sequencing 16S ribosomal RNA and assessed its association with survival. Subanalysis of the RCT data showed that, of 26 types of antibiotics used, administration of carbapenem before or during chemotherapy was associated with poor progression-free survival (PFS) and overall survival (OS) of patients with HCC (carbapenem + vs. -; median PFS, 78 days vs. 154 days, p = 0.0053; median OS, 177 days vs. 475 days, p = 0.0003). Multivariate analysis revealed that antianaerobic drug use is an independent predictor of poor prognosis. In the prospective study, the abundance of Blautia in fecal microbiota correlated positively with both PFS and OS of patients with HCC who underwent chemotherapy. Use of antibiotics targeting anaerobes is associated with a poor prognosis in patients with HCC who have undergone chemotherapy, whereas the intestinal anaerobic bacteria, Blautia is associated with a good prognosis. These findings might indicate the need for caution regarding overuse of broad-spectrum antibiotics targeting anaerobes in patients with HCC.


Assuntos
Antibacterianos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bactérias Anaeróbias/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Idoso , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/isolamento & purificação , Carcinoma Hepatocelular/microbiologia , Carcinoma Hepatocelular/mortalidade , Ensaios Clínicos Fase II como Assunto , DNA Bacteriano/isolamento & purificação , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Humanos , Infusões Intra-Arteriais , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/microbiologia , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Intervalo Livre de Progressão , Estudos Prospectivos , RNA Ribossômico 16S/genética , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos
10.
Anaerobe ; 57: 86-89, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30951830

RESUMO

Aspiration pneumonia is an infectious disease of the lungs caused by inhalation of saliva or foods, associated with swallowing dysfunction. Therefore, the major causative organisms are oral or gastric bacteria. In this study, we evaluated the antimicrobial susceptibility patterns of the anaerobic bacteria which can cause aspiration pneumonia, Fusobacterium spp., Finegoldia magna, Bacteroides fragilis, Peptostreptococcus spp., Prevotella spp., and Streptococcus milleri group to ceftriaxone, cefmetazole, flomoxef, ampicillin/sulbactam, and ampicillin. We also tested the ß-lactamase activities of each of the bacterial strains. Fusobacterium spp. and Finegoldia magna were susceptible to all of the tested antimicrobial drugs, except ampicillin, and showed no ß-lactamase activity. The Streptococcus milleri group, Bacteroides fragilis, and Peptostreptococcus spp. showed decreased susceptibility to cefmetazole or flomoxef as compared to the susceptibility levels documented in a previous report. There was one strain of Peptostreptococcus anaerobius which was not susceptible to ampicillin/sulbactam, but also showed no ß-lactamase activity, suggesting that this strain harbored a mechanism of resistance other than the production of ß-lactamase. The susceptibility of Prevotella spp. to ceftriaxone was also decreased as compared to the susceptibility level documented in a previous report. Furthermore, ß-lactamase-positive strains were found even among ceftriaxone-susceptible strains. Elderly persons with swallowing dysfunction carry a risk of recurrent episodes of aspiration pneumonia and repeated use of antibiotics increases the risk of development of antibiotic resistance. In the present study, the antibiotic susceptibilities of some of organisms which can cause aspiration pneumonia were found to be decreased as compared to the susceptibility levels documented in a previous report. Therefore, surveillance of the antimicrobial susceptibility patterns of these bacteria is recommended to prevent the development of resistance.


Assuntos
Antibacterianos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/isolamento & purificação , Infecções Bacterianas/microbiologia , Testes de Sensibilidade Microbiana , Pneumonia Aspirativa/microbiologia , Humanos
11.
Environ Pollut ; 248: 743-755, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30851584

RESUMO

Two laboratory-scale anaerobic membrane bioreactor (AnMBRs) were built to investigate the effect of zinc oxide nanoparticles (ZnO-NPs) on their performance, and the recovery phase was also examined. Results showed that the addition of ZnO-NPs with 0.4 mg/L caused significant deteriorations of AnMBR performance, including decrements of chemical oxygen demand (COD) removal efficiency from 96.4% to 81.5% and biogas production from 0.36 to 0 L/g COD removal within 40 days. A significant increment from 13.2 to 52.1 mg/L in soluble microbial products (SMP) was obtained, while no obvious effect on colloids was observed except an increased fluctuation of colloid concentration. Additionally, gas chromatography-mass spectrometry (GC-MS) analysis revealed remarkable changes of compounds in effluent with exposure to ZnO-NPs, and some new alkanes and esters were produced, such as Cyclobutane, 1,2-diethyl-, trans-, Tetradecane, Cyclopropane, octyl-, and Butanoic acid, methyl ester. The microbial community was compared using high-throughput sequencing, clearly showing the changes in both bacteria and archaea communities. Furthermore, results for recovery phase indicated that the AnMBR performance can be recovered within around 60 days after stopping ZnO-NPs addition, accompanied by the decrement of zinc concentration mainly adsorbed by sludge.


Assuntos
Reatores Biológicos/microbiologia , Membranas Artificiais , Microbiota/efeitos dos fármacos , Nanopartículas/toxicidade , Poluentes Químicos da Água/análise , Óxido de Zinco/toxicidade , Anaerobiose , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/crescimento & desenvolvimento , Biocombustíveis/análise , Análise da Demanda Biológica de Oxigênio , Biomassa , Nanopartículas/química , Esgotos/química , Purificação da Água/métodos , Óxido de Zinco/química
12.
Anaerobe ; 56: 61-65, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30753898

RESUMO

The CDC recommended outpatient treatment of pelvic inflammatory disease (PID) is an intramuscular dose of ceftriaxone plus 14 days of doxycycline, with or without metronidazole. European guidelines (2017) include moxifloxacin plus ceftriaxone as a first line regimen, particularly for women with Mycoplasma genitalium-associated PID. However, the susceptibility of bacteria recovered from the endometrium of women with PID to moxifloxacin is unknown. The in vitro antibiotic susceptibility of facultative and anaerobic bacteria recovered from endometrial biopsy samples were evaluated from 105 women having symptomatic PID and/or histologically confirmed endometritis. A total of 342 endometrial isolates from enrollment visits were identified using a combination of biochemical tests and sequencing. Isolates were tested for antimicrobial susceptibility using agar dilution against ceftriaxone, clindamycin, doxycycline, metronidazole and moxifloxacin according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Neisseria gonorrhoeae was susceptible to ceftriaxone with all isolates having an MIC of 0.03 µg/mL. All the other endometrial isolates were susceptible to ceftriaxone, except for Prevotella species, only half of which were susceptible. The in vitro susceptibility profile for BV-associated bacteria (Gardnerella vaginalis, Atopobium vaginae, Prevotella species, Porphyromonas species and anaerobic gram-positive cocci) revealed greater susceptibility to moxifloxacin compared to doxycycline. Moxifloxacin was superior to metronidazole for G. vaginalis and A. vaginae, and either metronidazole or moxifloxacin was needed to cover Prevotella species. Based on in vitro susceptibility testing, the combination of ceftriaxone plus moxifloxacin provides similar coverage of facultative and anaerobic pathogens compared to the combination of ceftriaxone, metronidazole and doxycycline. Head to head clinical studies of these treatment regimens are needed to evaluate clinical efficacy and eradication of endometrial pathogens following treatment.


Assuntos
Antibacterianos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/isolamento & purificação , Infecções Bacterianas/microbiologia , Endometrite/microbiologia , Endométrio/microbiologia , Doença Inflamatória Pélvica/microbiologia , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Técnicas de Tipagem Bacteriana , Feminino , Humanos , Testes de Sensibilidade Microbiana , Análise de Sequência de DNA
13.
Clin Microbiol Infect ; 25(6): 760.e1-760.e6, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30217761

RESUMO

OBJECTIVES: Gram-positive, anaerobic cocci (GPAC) can cause infections in humans. Only a few cases of bacteraemia with GPAC have been reported. We describe the clinical and microbiological characteristics of GPAC bacteraemia. METHODS: A retrospective population-based study of GPAC bacteraemia 2012-2016 in southern Sweden was performed. GPAC were identified using matrix-associated laser desorption ionization time-of-flight mass spectrometry or 16S rRNA gene sequencing. Etests were used to determine antibiotic susceptibilities. Data on patient and infection characteristics, treatment, and outcome were collected from the medical records. RESULTS: A total of 226 episodes of GPAC bacteraemia in adults were studied; this corresponds to an annual incidence of 3.4 cases per 100,000 persons per year. The bacteria identified were Anaerococcus spp. (n = 43), Atopobium spp. (n = 7), Blautia spp. (n = 1), Finegoldia spp. (n = 15), Parvimonas spp. (n = 100), Peptoniphilus spp. (n = 52), Peptostreptococcus spp. (n = 2), and Ruminococcus spp. (n = 9) of which 200 isolates were identified to the species level. Resistance to imipenem and piperacillin was not identified, whereas resistance among the 229 isolates to penicillin was detected in four, to metronidazole in six, and clindamycin in 16 isolates. The median age of patients was 73 years (55-83, IQR), 57% were male and comorbidities were common. Fifty-one per cent of infections were polymicrobial. In 60% of cases a focus of infection was identified. Forty per cent of patients had either organ dysfunction or shock. The 30-day mortality was 11%, and nosocomial infections were over-represented among the deceased. CONCLUSIONS: GPAC bacteraemia is much more common than previously reported. GPAC-bacteraemia is a condition with significant mortality mainly affecting elderly persons with comorbidities.


Assuntos
Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Bactérias Anaeróbias/isolamento & purificação , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Cocos Gram-Positivos/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Bacteriemia/patologia , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/genética , Criança , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Feminino , Infecções por Bactérias Gram-Positivas/patologia , Cocos Gram-Positivos/classificação , Cocos Gram-Positivos/efeitos dos fármacos , Cocos Gram-Positivos/genética , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Ribossômico 16S/genética , Estudos Retrospectivos , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Suécia/epidemiologia , Adulto Jovem
14.
Sci Total Environ ; 650(Pt 1): 604-615, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30208346

RESUMO

Aquatic macrophytes play a significant role in the nutrient cycle of freshwater ecosystems. However, nutrients from plant debris release into both sediments and overlying water if not timely harvested. To date, minimal information is available regarding nutrient release and its subsequent influences on bacterial communities with decaying debris. In this study, Potamogeton crispus was used as a model plant. Debris biomass levels of 0 g (control, J-CK), 10 g dry weight (DW) (100 g DW/m2, J-10 g), 40 g DW (400 g DW/m2, J-40 g) and 80 g DW (800 g DW/m2, J-80 g) were used to simulate the different biomass densities of P. crispus in field. The physicochemical parameters of overlying water and sediment samples were analysed. The community composition of anammox bacteria in the sediment was also analysed using 16S rRNA genes as markers. The results showed that dissolved oxygen and pH dramatically decreased, whereas total nitrogen (TN) and NH4+-N concentrations increased in the overlying water in the initial stage of P. crispus decomposition. However, NO3--N concentration changes in the overlying water were more complicated. The concentrations of organic matter, TN and NH4+-N in the sediment all increased, but the rate of increase varied among the groups with different initial biomass levels, indicating that these physicochemical properties in sediment are significantly affected by debris biomass level and decay time. In addition, the order of anammox bacteria abundance was J-40 g > J-CK > J-80 g > J-10 g. Moreover, the community structure of anammox bacteria were simpler compared to that of J-CK as debris biomass level increased. The results demonstrate that P. crispus debris decomposition could affect the ecological distribution of anammox bacteria. Such influence clearly varies with varying amounts of P. crispus biomass debris. This information could be useful for the management of aquatic macrophytes in freshwater ecosystems.


Assuntos
Bactérias Anaeróbias/efeitos dos fármacos , Água Doce , Sedimentos Geológicos , Nitrogênio/metabolismo , Nitrogênio/farmacologia , Potamogetonaceae/metabolismo , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Biomassa , Ecossistema , Monitoramento Ambiental , Água Doce/química , Água Doce/microbiologia , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Concentração de Íons de Hidrogênio , Metagenoma/genética , Nitrogênio/análise , Oxigênio/análise , Filogenia , RNA Ribossômico 16S/genética , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/farmacologia
15.
Anaerobe ; 55: 40-53, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30316817

RESUMO

Acquired resistance to metronidazole, a 5-nitroimidazole drug largely used worldwide in the empirical treatment of infections caused by anaerobes, is worrisome, especially since such resistance has been described in multidrug-resistant anaerobic bacteria. In anaerobes, acquired resistance to metronidazole may be due to a combination of various and complex mechanisms. Among them, nim genes, possibly located on mobile genetic elements, encode nitro-imidazole-reductases responsible for drug inactivation. Since the first description of Nim proteins about 25 years ago, more nim genes have been identified; currently 11 nim genes are known (nimA to nimK). Mostly reported in Bacteroides fragilis group isolates, nim genes are now described in a variety of anaerobic genera encompassing the 4 main groups of Gram-negative and Gram-positive bacilli and cocci, with variable expression ranging from phenotypically silent to low-level or high-level resistance to metronidazole. This review describes the trends of metronidazole resistance rates among anaerobes over the past 20 years and summarizes current knowledge on mechanisms involved in this resistance. It also provides an update on the phylogenetic and geographical distribution of nim genes, the mechanisms involved in their expression and regulation, and their role in metronidazole resistance.


Assuntos
Anti-Infecciosos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Farmacorresistência Bacteriana , Metronidazol/farmacologia , Bactérias Anaeróbias/enzimologia , Bactérias Anaeróbias/genética , Variação Genética , Nitroimidazóis/metabolismo , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo
16.
J Infect Chemother ; 25(4): 311-313, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30287186

RESUMO

INTRODUCTION: Solithromycin is a novel fluoroketolide developed to treat pneumonia. But, few studies evaluating its antimicrobial activity against S. pneumoniae in a mixed-infection model with anaerobes are available, while community-acquired pneumonia can involve mixed-infection of Streptococcus pneumoniae and anaerobic bacteria. This study evaluated the antimicrobial activity of solithromycin against macrolide-resistant S. pneumoniae and anaerobic bacteria with a murine pneumonia mixed-infection model. MATERIAL AND METHODS: We evaluated antimicrobial activity of solithromycin (10 and 20 mg/kg) and levofloxacin (126 mg/kg) against S. pneumoniae with a three-point mutation in penicillin-binding protein and an ermB gene, and Parvimonas micra. Antimicrobial efficacy was calculated for each isolate as the change in bacterial count (Δlog10 CFU/mL) obtained in the treated mice after 24 h compared with the count in the starting control animals. RESULTS: The solithromycin and levofloxacin minimum inhibitory concentrations (MICs) for S. pneumoniae were 0.03 and 0.5 µg/mL, respectively. The solithromycin and levofloxacin MICs for P. micra were 0.015 and 0.12 µg/mL, respectively. In a mixed-infection model, solithromycin showed significantly higher antimicrobial activity against S. pneumoniae than levofloxacin (solithromycin 20 mg/kg; -2.87 ± 1.33 log10 CFU/mL vs. levofloxacin; -1.35 ± 0.37 log10 CFU/mL, p = 0.0397). Similarly, solithromycin showed significantly higher antimicrobial activity against P. micra than levofloxacin (solithromycin 20 mg/kg; -2.78 ± 0.98 log10 CFU/mL vs. levofloxacin; -1.57 ± 0.47 log10 CFU/mL, p = 0.0400). DISCUSSION: Solithromycin showed higher antimicrobial activities against macrolide-resistant S. pneumoniae and P. micra than levofloxacin, even though they were coexisted in murine lung tissue. Our results suggest that solithromycin could be effective for pneumonia patients due to S. pneumoniae to reduce bacterial density in lung tissue.


Assuntos
Antibacterianos/uso terapêutico , Bactérias Anaeróbias/efeitos dos fármacos , Coinfecção/tratamento farmacológico , Levofloxacino/farmacologia , Macrolídeos/farmacologia , Streptococcus pneumoniae/efeitos dos fármacos , Triazóis/farmacologia , Animais , Antibacterianos/farmacologia , Bactérias Anaeróbias/patogenicidade , Coinfecção/microbiologia , Modelos Animais de Doenças , Farmacorresistência Bacteriana , Feminino , Humanos , Levofloxacino/uso terapêutico , Macrolídeos/uso terapêutico , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Organismos Livres de Patógenos Específicos , Streptococcus pneumoniae/patogenicidade , Resultado do Tratamento , Triazóis/uso terapêutico
17.
Ann Lab Med ; 39(2): 190-199, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30430782

RESUMO

BACKGROUND: Anaerobic bacterial resistance trends may vary across regions or institutions. Regional susceptibility patterns are pivotal in the empirical treatment of anaerobic infections. We determined the antimicrobial resistance patterns of clinically important anaerobic bacteria, including recently named or renamed anaerobes. METHODS: A total of 521 non-duplicated clinical isolates of anaerobic bacteria were collected from a tertiary-care hospital in Korea between 2014 and 2016. Anaerobes were isolated from blood, body fluids, and abscess specimens. Each isolate was identified by conventional methods and by Bruker biotyper mass spectrometry (Bruker Daltonics, Leipzig, Germany) or VITEK matrix-assisted laser desorption ionization time-of-flight mass spectrometry (bioMérieux, Marcy-l'Étoile, France). Antimicrobial susceptibility was tested using the agar dilution method according to the CLSI guidelines. The following antimicrobials were tested: piperacillin-tazobactam, cefoxitin, cefotetan, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, tetracycline, and metronidazole. RESULTS: Most Bacteroides fragilis isolates were susceptible to piperacillin-tazobactam, imipenem, and meropenem. The non-fragilis Bacteroides group (including B. intestinalis, B. nordii, B. pyogenes, B. stercoris, B. salyersiae, and B. cellulosilyticus) was resistant to meropenem (14%) and cefotetan (71%), and Parabacteroides distasonis was resistant to imipenem (11%) and cefotetan (95%). Overall, the Prevotella and Fusobacterium isolates were more susceptible to antimicrobial agents than the B. fragilis group isolates. Anaerobic gram-positive cocci exhibited various resistance rates to tetracycline (6-86%). Clostridioides difficile was highly resistant to penicillin, cefoxitin, imipenem, clindamycin, and moxifloxacin. CONCLUSIONS: Piperacillin-tazobactam, cefoxitin, and carbapenems are highly active ß-lactam agents against most anaerobes, including recently named or renamed species.


Assuntos
Antibacterianos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Abscesso/microbiologia , Antibacterianos/química , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/isolamento & purificação , Infecções Bacterianas/patologia , Bacteroides/efeitos dos fármacos , Bacteroides/isolamento & purificação , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Espectrometria de Massas , Testes de Sensibilidade Microbiana , República da Coreia , Centros de Atenção Terciária
18.
J Antibiot (Tokyo) ; 72(2): 111-113, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30367175

RESUMO

Curvulaide A (1), a new bicyclic polyketide, together with its known congener preussilide D, were produced by solid-state fermentation with Curvularia sp. IFB-Z10. The structure of 1 was elucidated using a combination of spectral methods, including extensive one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) data, high resolution electrospray ionization mass spectrometry (HRESIMS), experimental and calculated electronic circular dichroism (ECD) spectra. Curvulaide A (1) exhibited moderate anti-anaerobic bacteria activity against periodontal pathogen Porphyromonas gingivalis with the MIC value of 62.5 µM, and showed moderate cytotoxicity against human hepatoma cell lines BEL7402/5-Fu with IC50 values of 12.46 µM.


Assuntos
Antineoplásicos/farmacologia , Ascomicetos/metabolismo , Bactérias Anaeróbias/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Policetídeos/química , Policetídeos/farmacologia , Porphyromonas gingivalis/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Ressonância Magnética Nuclear Biomolecular
19.
Anaerobe ; 55: 107-111, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30423437

RESUMO

It has been reported that sub-minimal inhibitory concentrations (sub-MICs) of antibiotics are capable of altering bacterial surface properties and phenotype. In this study, the effects of sub-MICs of certain antibiotics on surface hydrophobicity, cell morphology, and protein profile were ascertained using Fusobacterium nucleatum, Porphyromonas gingivalis and Treponema denticola strains, which are pathogenic bacterial species in periodontal diseases. The MICs of antibiotics were determined by culturing bacteria in media supplemented with serially diluted antibiotic solutions, and sub-MIC of antibiotics was used. The effect of sub-MIC of antibiotics on cell morphology was determined by scanning electron microscopy. Microscopic observation of F. nucleatum and P. gingivalis grown at a sub-MIC of amoxicillin revealed cell enlargement. T. denticola grown at a sub-MIC of doxycycline also showed cell elongation. The relative surface hydrophobicity determined by measuring the ability of the bacteria to absorb n-hexadecane revealed an increase in surface hydrophobicity of F. nucleatum grown at sub-MIC of penicillin and amoxicillin, but a decrease with metronidazole; whereas increased hydrophobicity was observed in T. denticola grown at sub-MIC of doxycycline, metronidazole and tetracycline. The surface hydrophobicity of P. gingivalis increased only when grown in sub-MIC of metronidazole. The protein expression profile of the treated bacteria differed from their respective controls. These results confirmed that sub-MIC concentrations of antibiotics can affect the phenotype, surface properties and morphology of periodontal pathogenic anaerobic bacteria.


Assuntos
Antibacterianos/farmacologia , Fusobacterium nucleatum/efeitos dos fármacos , Porphyromonas gingivalis/efeitos dos fármacos , Propriedades de Superfície/efeitos dos fármacos , Treponema denticola/efeitos dos fármacos , Bactérias Anaeróbias/química , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/ultraestrutura , Fusobacterium nucleatum/química , Fusobacterium nucleatum/ultraestrutura , Humanos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Porphyromonas gingivalis/química , Porphyromonas gingivalis/ultraestrutura , Proteoma/análise , Treponema denticola/química , Treponema denticola/ultraestrutura
20.
Anaerobe ; 55: 96-102, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30447394

RESUMO

Exposure to environmental pollutants is associated with a greater risk for metabolic diseases including cardiovascular disease. Pollutant exposure can also alter gut microbial populations that may contribute to metabolic effects and progression of inflammatory diseases. Short-chain fatty acids (SCFAs), produced from gut fermentation of dietary carbohydrates, such as inulin, exert numerous effects on host energy metabolism and are linked to a reduced risk of diseases. The hypothesis was that exposure to dioxin-like pollutants modulate gut microbial viability and/or fermentation processes. An inulin-utilizing isolate was collected from murine feces, characterized and used in subsequent experiments. Exposure to polychlorinated biphenyl, PCB 126 impeded bacterial viability of the isolate at concentrations of 20 and 200 µM. PCB 126 exposure also resulted in a significant loss of intracellular potassium following exposure, indicating cell membrane disruption of the isolate. Furthermore, total fecal microbe samples from mice were harvested, resuspended and incubated for 24 h in anaerobic media containing inulin with or without PCB 126. HPLC analysis of supernatants revealed that PCB 126 exposure reduced succinic acid production, but increased propionate production, both of which can influence host glucose and lipid metabolism. Overall, the presented evidence supports the idea that pollutant exposure may contribute to alterations in host metabolism through gut microbiota-dependent mechanisms, specifically through bacterial fermentation processes or membrane disruption.


Assuntos
Anti-Infecciosos/farmacologia , Poluentes Ambientais/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Inulina/metabolismo , Metabolismo/efeitos dos fármacos , Prebióticos , Aerobiose , Anaerobiose , Animais , Bactérias Anaeróbias/efeitos dos fármacos , Ácidos Graxos Voláteis/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Bifenilos Policlorados/farmacologia
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