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1.
Bol. latinoam. Caribe plantas med. aromát ; 20(3): 260-269, may. 2021. tab
Article in English | LILACS | ID: biblio-1342820

ABSTRACT

The aim of this study was to undertake a screening experiment on essential oils (EO) of Myrcia lundiana, Ocimum basilicum and Lippia alba against six food-spoiling pathogenic bacteria. Seventy-two (72) samples were initially analyzed fo antimicrobial activity based on the agar diffusion test. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations were determined for the 12 samples which showed greatest antimicrobial potential in this stage. Two samples of L. alba, three samples of M. lundiana and seven samples of O. basilicum showed a MIC of 0.12-125 µL/mL for the six tested bacteria. Of these, the EO of O. basilicum cultivar Maria Bonita stood out with the lowest MIC and MBC. Thus, a mixture simulating this essential oil was prepared from commercial standards of the compounds (±)-linalool, geraniol and 1,8-cineole. Significantly higher MIC and MBC were detected in the simulation compared to the respective EO, suggesting a synergistic effect between compounds.


El objetivo de este estudio fue realizar un experimento de detección en aceites esenciales (AE) de Myrcia lundiana, Ocimum basilicum y Lippia alba contra seis bacterias patógenas que estropean los alimentos. Setenta y dos (72) muestras fueron analizadas inicialmente para la actividad antimicrobiana basada en la prueba de difusión en agar. Se determinaron las concentraciones mínimas inhibitoria (CMI) y bactericida (CMB) para las 12 muestras que mostraron el mayor potencial antimicrobiano en esta etapa. Dos muestras de L. alba, tres muestras de M. lundiana y siete muestras de O. basilicum mostraron un CMI de 0.12-125 µL/mL para las seis bacterias analizadas. De estos, el AE de O. basilicum cultivar Maria Bonita se destacó con el CMI y CMB más bajos. Por lo tanto, se preparó una mezcla que simula este aceite esencial a partir de los estándares comerciales de los compuestos de (±)-linalol, geraniol y 1,8-cineol. Se detectaron CMI y CMB significativamente más altos en la simulación en comparación con el AE respectivo, lo que sugiere un efecto sinérgico entre los compuestos.


Subject(s)
Bacteria/drug effects , Oils, Volatile/pharmacology , Ocimum basilicum/chemistry , Myrtaceae/chemistry , Lippia/chemistry , Anti-Bacterial Agents/pharmacology , Sesquiterpenes/analysis , Oils, Volatile/chemistry , Microbial Sensitivity Tests , Food , Anti-Bacterial Agents/chemistry
2.
Electron. j. biotechnol ; 50: 16-22, Mar. 2021. ilus, tab
Article in English | LILACS | ID: biblio-1292419

ABSTRACT

BACKGROUND: Cecropin P1, acting as an antimicrobial, has a broad-spectrum antibacterial activity with some antiviral and antifungal properties. It is a promising natural alternative to antibiotics which is originally isolated from the pig intestinal parasitic nematode Ascaris suum. Many studies have shown that Cecropin P1 is helpful for the prevention or treatment of clinical diseases. Therefore, it is very necessary to establish a safe, nontoxic, and efficient expression method of Cecropin P1. RESULTS: The results indicated that the recombinant protein was about 5.5 kDa showed by Tricine­SDS­ PAGE and Western blot. And Cecropin P1 was efficiently secreted and expressed after 12 h of induction, with an increasing yield over the course of the induction. Its maximum concentration was 7.83 mg/L after concentration and purification. In addition, in vitro experiments demonstrated that Cecropin P1 not only exerted a strong inhibitory effect on Escherichia coli, Salmonella sp., Shigella sp., and Pasteurella sp., but also displayed an antiviral activity against PRRSV NADC30-Like strain. CONCLUSIONS: Collectively, the strategy of expressing Cecropin P1 in Saccharomyces cerevisiae is harmless, efficient, and safe for cells. In addition, the expressed Cecropin P1 has antiviral and antibacterial properties concurrently.


Subject(s)
Peptides/pharmacology , Saccharomyces cerevisiae/drug effects , Anti-Bacterial Agents/pharmacology , Antiviral Agents/pharmacology , Peptides/chemistry , In Vitro Techniques , Recombinant Proteins , Microbial Sensitivity Tests , Blotting, Western
3.
Med. infant ; 28(1): 38-42, Marzo 2021. Tab
Article in Spanish | LILACS, BINACIS, UNISALUD | ID: biblio-1283476

ABSTRACT

Últimamente, se están detectando mutaciones en las proteínas ligadoras de penicilina (PBP) de los estreptococos beta-hemolíticos que corresponden a sitios que en Streptococcus pneumoniae han determinado sensibilidad disminuida a los antibióticos beta-lactámicos. Primero, se describieron cepas con sensibilidad intermedia a penicilina en Streptococcus agalactiae (estreptococos del grupo B), luego en Streptococcus dysgalactiae subsp. equisimilis (mayormente grupos C y G) y, más recientemente, cepas con sensibilidad disminuida a aminopenicilinas y cefalosporinas de tercera generación en Streptococcus pyogenes (grupo A). El costo biológico de estas modificaciones nos permite pensar que los niveles de resistencia no han de ser tan elevados como para comprometer por ahora la efectividad clínica de los beta-lactámicos (AU)


Recently, mutations in penicillin-binding proteins (PBPs) of beta-hemolytic streptococci have been detected corresponding to sites that in Streptococcus pneumoniae have been determined to have decreased sensitivity to beta-lactam antibiotics. First, strains with intermediate sensitivity to penicillin were described in Streptococcus agalactiae (group B streptococci), subsequently in Streptococcus dysgalactiae subsp. equisimilis (mainly groups C and G) and, more recently, strains with decreased sensitivity to third-generation aminopenicillins and cephalosporins were found in Streptococcus pyogenes (group A). The biological cost of these modifications suggests that, for now, resistance levels are not high enough to compromise the clinical effectiveness of beta-lactams (AU)


Subject(s)
Streptococcus agalactiae/drug effects , Streptococcus pyogenes/drug effects , Penicillin Resistance , Microbial Sensitivity Tests , beta-Lactam Resistance , beta-Lactams/pharmacology , Anti-Bacterial Agents/pharmacology
4.
Rev. Soc. Bras. Med. Trop ; 54: e02622020, 2021.
Article in English | LILACS, ColecionaSUS, SES-SP | ID: biblio-1143877

ABSTRACT

Abstract INTRODUCTION: Carbapenemase-resistant enterobacteria that produce the bla NDM gene are found worldwide. However, this is the first report of blaNDM in Klebsiella aerogenes in Brazil. METHODS: The identification of bacterial species was performed using anautomated system and confirmed by biochemical tests, 16S rRNA gene sequencing, and detection of resistance genes. RESULTS: The clinical isolate showed minimum inhibitory concentration resistance to meropenem and polymyxin B at 8mg/L and 4mg/L, respectively. Only the blaNDM gene was detected. CONCLUSIONS: The current report of the blaNDM gene in isolated MDR enterobacteria indicates that this gene can spread silently in a hospital setting.


Subject(s)
Enterobacter aerogenes/genetics , Bacterial Proteins , beta-Lactamases/genetics , Brazil , RNA, Ribosomal, 16S , Microbial Sensitivity Tests , Drug Resistance, Multiple, Bacterial/genetics , Enterobacteriaceae , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology
5.
Rev. Soc. Bras. Med. Trop ; 54: e20190524, 2021. tab, graf
Article in English | LILACS, ColecionaSUS, SES-SP | ID: biblio-1136925

ABSTRACT

Abstract INTRODUCTION: The aac(6')-Ib-cr and bla KPC genes are spreading among Enterobacteriaceae species, including Providencia stuartii, in some countries of world. METHODS: These genes were investigated in 28 P. stuartii isolates from a public hospital in Recife, Pernambuco, Brazil, by PCR and sequencing. RESULTS: The aac(6')-Ib-cr gene was detected in 16 resistant isolates, and the bla KPC gene was seen in 14. CONCLUSIONS: The presence of these genes in P. stuartii multi- and extensively drug-resistant isolates indicates that the resistance arsenal of this species is increasing, thus limiting the therapeutic options.


Subject(s)
Humans , Enterobacteriaceae Infections , Plasmids , beta-Lactamases/genetics , Brazil , Microbial Sensitivity Tests , Providencia , Drug Resistance, Multiple, Bacterial , Anti-Bacterial Agents/pharmacology
6.
Rev. Soc. Bras. Med. Trop ; 54: e20200087, 2021. tab, graf
Article in English | LILACS, ColecionaSUS, SES-SP | ID: biblio-1136920

ABSTRACT

Abstract INTRODUCTION: In this study, we report a clonal dissemination of carbapenem resistant Acinetobacter baumannii isolates due to the acquisition of blaOXA-23 in a regional hospital located in Brazilian Amazon Region. METHODS: The isolates were identified by MALDI-TOF and the carbapenemase-encoding genes were detected by multiplex-PCR. The genetic similarity was investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: Only 10 (55.6%) isolates harbored the gene bla OXA-23. PFGE analysis revealed that these isolates belong to a single clone. CONCLUSIONS: This dissemination strategy indicates the need for surveillance, adoption of control procedures defined in guidelines, and the careful administration of antimicrobials should be reinforced.


Subject(s)
Humans , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Bacterial Proteins/genetics , beta-Lactamases/genetics , Brazil/epidemiology , Drug Resistance , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Molecular Epidemiology , Hospitals , Anti-Bacterial Agents/pharmacology
7.
Braz. j. med. biol. res ; 54(2): e10099, 2021. tab
Article in English | LILACS, ColecionaSUS | ID: biblio-1142582

ABSTRACT

The objective of this study was to analyze the infection rate and drug resistance of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) in the genitourinary tract of Chinese patients. From December 2018 to June 2019, vaginal secretion or urinary secretion of outpatients in our hospital were selected for culture and drug sensitivity analysis of Ureaplasma urealyticum and Mycoplasma hominis. In 4082 Chinese samples, 1567 Mycoplasma were detected, a detection rate of 38.39%, among which 1366 cases were UU single positive, accounting for 33.47%, 15 cases were MH single positive, accounting for 0.36%, 186 cases were UU and MH mixed positive, accounting for 4.56%. The most affected age groups were 21-30 years and 31-40 years, accounting for 19.09 and 15.05%, respectively. The results of drug sensitivity showed that doxycycline, minocycline, josamycin, clarithromycin, and roxithromycin were more sensitive to mycoplasma infection. The distribution of Ureaplasma urealyticum and Mycoplasma hominis in the human genitourinary system and their sensitivity to antibiotics is different for sex and age groups.


Subject(s)
Humans , Male , Female , Adult , Young Adult , Ureaplasma urealyticum/drug effects , Ureaplasma Infections/microbiology , Mycoplasma hominis/drug effects , Microbial Sensitivity Tests , China , Ureaplasma urealyticum/isolation & purification , Mycoplasma hominis/isolation & purification , Asian Continental Ancestry Group , Anti-Bacterial Agents/pharmacology
8.
Article in Chinese | WPRIM | ID: wpr-880448

ABSTRACT

Biliary stent has been widely used in the treatment of biliary stricture and obstruction, it can relieve the pain of patients effectively, but bacterial infection and stent obstruction are still troublesome after surgery. We introduce the mechanism of infection and stent blockage caused by bacterial invasion after biliary stent implantation, and expound the formation mechanism of bacterial biofilm and bile sludge in this review. Antibacterial biliary stent is an effective way to inhibit biliary tract infection, the literatures on antibacterial modification of biliary stent with different antibacterial methods in domestic and abroad are reviewed, and the research prospect of antibacterial biliary stent is summarized and prospected.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bile , Biliary Tract , Cholestasis , Humans , Stents
9.
Mem. Inst. Oswaldo Cruz ; 116: e200587, 2021. tab, graf
Article in English | LILACS | ID: biblio-1287343

ABSTRACT

BACKGROUND The inappropriate use of antibiotics has led to the accelerated growth of resistance to antibiotics. The search for new therapeutic strategies (i.e., antimicrobial peptides-AMPs) has thus become a pressing need. OBJECTIVE Characterising and evaluating Sarconesiopsis magellanica larval fat body-derived AMPs. METHODS Fat body extracts were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC); mass spectrometry was used for characterising the primary structure of the AMPs so found. ProtParam (Expasy) was used for analysing the AMPs' physico-chemical properties. Synthetic AMPs' antibacterial activity was evaluated. FINDINGS Four new AMPs were obtained and called sarconesin III, IV, V and VI. Sarconesin III had an α-helix structure and sarconesins IV, V and VI had linear formations. Oligomer prediction highlighted peptide-peptide interactions, suggesting that sarconesins III, V and VI could form self-aggregations when in contact with the microbial membrane. AMPs synthesised from their native molecules' sequences had potent activity against Gram-positive bacteria and, to a lesser extent, against Gram-negative and drug-resistant bacteria. Sarconesin VI was the most efficient AMP. None of the four synthetic AMPs had a cytotoxic effect. MAIN CONCLUSIONS S. magellanica larval fat body-derived antimicrobial peptides are an important source of AMPs and could be used in different antimicrobial therapies and overcoming bacterial resistance.


Subject(s)
Animals , Diptera , Fat Body , Microbial Sensitivity Tests , Pore Forming Cytotoxic Proteins , Calliphoridae , Larva , Anti-Bacterial Agents/pharmacology
10.
Rev. Soc. Bras. Med. Trop ; 54: e05992020, 2021. tab
Article in English | LILACS | ID: biblio-1155526

ABSTRACT

Abstract INTRODUCTION: This study aimed to determine the role of genes encoding aminoglycoside-modifying enzymes (AMEs) and 16S rRNA methylase (ArmA) in Acinetobacter baumannii clinical isolates. METHODS: We collected 100 clinical isolates of A. baumannii and identified and confirmed them using microbiological tests and assessment of the OXA-51 gene. Antibiotic susceptibility testing was carried out using disk agar diffusion and micro-broth dilution methods. The presence of AME genes and ArmA was detected by PCR and multiplex PCR. RESULTS: The most and least effective antibiotics in this study were netilmicin and ciprofloxacin with 68% and 100% resistance rates, respectively. According to the minimum inhibitory concentration test, 94% of the isolates were resistant to gentamicin, tobramycin, and streptomycin, while the highest susceptibility (20%) was observed against netilmicin. The proportion of strains harboring the aminoglycoside resistance genes was as follows: APH(3′)-VIa (aphA6) (77%), ANT(2")-Ia (aadB) (73%), ANT(3")-Ia (aadA1) (33%), AAC(6′)-Ib (aacA4) (33%), ArmA (22%), and AAC(3)-IIa (aacC2) (19%). Among the 22 gene profiles detected in this study, the most prevalent profiles included APH(3′)-VIa + ANT(2")-Ia (39 isolates, 100% of which were kanamycin-resistant), and AAC(3)-IIa + AAC(6′)-Ib + ANT(3")-Ia + APH(3′)-VIa + ANT(2")-Ia (14 isolates, all of which were resistant to gentamicin, kanamycin, and streptomycin). CONCLUSIONS: High minimum inhibitory concentration of aminoglycosides in isolates with the simultaneous presence of AME- and ArmA-encoding genes indicated the importance of these genes in resistance to aminoglycosides. However, control of their spread could be effective in the treatment of infections caused by A. baumannii.


Subject(s)
Acinetobacter baumannii/genetics , Bacterial Proteins , RNA, Ribosomal, 16S/genetics , Microbial Sensitivity Tests , Drug Resistance, Bacterial/genetics , Aminoglycosides/pharmacology , Methyltransferases , Anti-Bacterial Agents/pharmacology
11.
Braz. j. med. biol. res ; 54(7): e10889, 2021. tab, graf
Article in English | LILACS | ID: biblio-1249311

ABSTRACT

Utilization of plant resources for treatment of Helicobacter pylori infections is one of the appealing approaches as rapid emergence of antibiotic-resistant strains is occurring throughout the world. Ethanol extract and its fractions from Hibiscus rosa-sinensis red flower were assessed for antibacterial and urease inhibitory activities towards forty-three clinical strains and two reference strains of H. pylori. The ethyl acetate fraction exhibited the most potent bacteriostatic activity with minimum inhibitory concentrations (MICs) of 0.2-0.25 mg/mL and minimum bactericidal concentrations (MBCs) of 1.25-1.5 mg/mL against all test strains, including forty-three strains resistant to one to four antibiotics, azithromycin (MICs, 8-256 µg/mL), erythromycin (MICs, 8-128 µg/mL), levofloxacin (MICs, 8-256 µg/mL), and/or metronidazole (MICs, 8-256 µg/mL). The fraction had similar antibacterial activities toward these test strains suggesting the preparation and the antibiotics do not have a common mechanism of anti-H. pylori activity. The fraction also had stronger effects on biofilm formation, morphological conversion, and urease activity of H. pylori than the other fractions and the ethanol extract. These flower preparations were non-toxic to three human cell lines, and nine compounds were also isolated and identified from the ethyl acetate fraction. In vivo research needs to be conducted to confirm the potential usefulness of H. rosa-sinensis flower and its constituents for effective prevention and treatment of H. pylori disease.


Subject(s)
Humans , Helicobacter pylori , Helicobacter Infections/drug therapy , Rosa , Hibiscus , Plant Extracts/pharmacology , Microbial Sensitivity Tests , Flowers , Anti-Bacterial Agents/pharmacology
12.
Article in Chinese | WPRIM | ID: wpr-879015

ABSTRACT

The volatile oil from Mastiche and Olibanum medicinal materials was extracted by steam distillation, and the chemical components of the volatile oil were analyzed by GC-MS technology. The differences of the volatile oil components were compared and study on the Helicobacter pylori in vitro antimicrobial activitiy was conducted. The results showed that the yields of the volatile oil from Mastiche and Olibanum were 11.93% and 2.40%, respectively. A total of 46 compounds(91.31%) were identified from the volatile oil from Mastiche annd 35 compounds(92.49%) from Olibanum. The classification and comparison study of the components showed that the content of monoterpenes in the volatile oil from Mastiche was the highest(40.69%), followed by alcohols(28.48%); while the content of alcohols in the volatile oil from Olibanum was the highest(35.81%), followed by esters(24.92%). There were significant differences in the components of volatile oil from Mastiche and Olibanum, which might be one of the reasons for the difference in efficacy and application. In vitro bacteriostatic experiments showed that the minimum inhibitory concentration(MIC) of the volatile oil from Mastiche against H. pylori was 1 mg·mL~(-1), and the MIC of the volatile oil from Olibanum against H. pylori was more than 1 mg·mL~(-1). In combination with the results of the oil yield experiment, Mastiche had the advantage of inhibiting H. pylori activity. The research results provide scientific basis for the rational application of Mastiche and Olibanum.


Subject(s)
Anti-Bacterial Agents/pharmacology , Frankincense , Gas Chromatography-Mass Spectrometry , Helicobacter pylori , Monoterpenes/analysis , Oils, Volatile/pharmacology
13.
Article in Chinese | WPRIM | ID: wpr-879000

ABSTRACT

Due to worldwide abuse of chemical antibiotics and continuous emergence of "superbugs", the harm of bacterial drug resistance to human beings has become more and more serious. Therefore, it is of great significance to look for green antibiotics with a wide range of sources, broad antibacterial spectrum, non-toxicity or low toxicity, environmentally friendliness, diverse active components and low drug resistance. The volatile oil of traditional Chinese medicine is a kind of volatile oily liquid that exists in plants and can be distilled with steam and immiscible with water. Because of its good potential to resist drug-resistant pathogens, it is widely used in food, medicine and other fields. This paper summarized the antibacterial advantages and characteristics of volatile oil of traditional Chinese medicine, and the antibacterial effect and antibacterial mechanism of combined application of volatile oil of traditional Chinese medicine, in order to provide some theoretical basis and study ideas for solving the problem of bacterial drug resistance and developing natural and green antibiotics.


Subject(s)
Anti-Bacterial Agents/pharmacology , Anti-Infective Agents , Drugs, Chinese Herbal/pharmacology , Humans , Medicine, Chinese Traditional , Oils, Volatile/pharmacology
14.
Chinese Journal of Biotechnology ; (12): 1092-1106, 2021.
Article in Chinese | WPRIM | ID: wpr-878616

ABSTRACT

Antibiotic resistance is a major global concern and challenge in the 21st century. Enterobacteriaceae are one of the important pathogens of hospital-acquired infections. With the increasing use of antibiotics in clinical practice, a variety of drug-resistant Enterobacteriaceae, especially multidrug-resistant Enterobacteriaceae have emerged, posing an increasingly serious threat to human health. Bacteria can acquire antibiotic resistance by mutation or horizontal transfer of antibiotic resistance genes, and it is often possible to predict the corresponding resistance phenotype from known mechanism. However, recent findings suggest that genetic background and environmental factors could alter the expression of specific resistance genes and that a given genotype does not always generate the expected resistance phenotype. The genotype-phenotype segregation greatly hampers our ability to predict antibiotic resistance phenotype from a genetic perspective. In this review, we explore the genetic and environmental regulation of the expression of antibiotic resistance genes in a variety of Enterobacteriaceae, with the aim to provide scientific evidence for genetic prediction of antibiotic resistance phenotype and clinical guidance on drug use.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria , Cross Infection , Drug Resistance, Microbial , Enterobacteriaceae/genetics , Humans
15.
Arq. bras. oftalmol ; 83(6): 463-472, Nov.-Dec. 2020. tab, graf
Article in English | LILACS | ID: biblio-1153079

ABSTRACT

ABSTRACT Purpose: The aims of this study were to characterize alpha-hemolytic streptococci among isolates from cases of infectious endophthalmitis and keratitis and to determine their distributions. Methods: The sample included 27 and 35 nonduplicated isolates of alpha-hemolytic streptococci recovered from patients with infectious endophthalmitis (2002-2013) and keratitis (2008-2013), respectively. Isolates were identified by the optochin susceptibility and bile solubility tests, using a biochemical identification system. The minimum inhibitory concentration was determined by the broth microdilution method. Molecular identification was performed by analyses of three constitutive genes and the complementary multilocus sequence. The molecular epidemiology of Streptococcus pneumoniae was investigated using multilocus sequence typing, and the presence of the capsular polysaccharide-encoding gene was assessed using conventional polymerase chain reaction. Outcomes were evaluated using the patients' medical records. Results: Phenotypic tests differentiated S. pneumoniae from other alpha-hemolytic streptococci, consistent with later molecular identifications. Streptococcus oralis was significantly prevalent among the endophthalmitis isolates, as was S. pneumoniae in the keratitis isolates. High levels of susceptibility to antibiotics were observed, including vancomycin, cephalosporins, and fluoroquinolones. High genetic variability was detected among the 19 S. pneumoniae strains, with 15 predicted to be encapsulated. The medical records of patients with infectious endophthalmitis were reviewed (n=15/27; 56%), and final visual acuity was assessed in 12 cases (44%). Many patients progressed to a final visual acuity state of "no light perception" (6/12; 50%), "light perception" (3/12; 25%), or "hand motion" (1/12; 8%). The medical records of patients with infectious keratitis were also reviewed (n=24/35; 69%), and final visual acuity was assessed in 18 cases (51%). Similarly, most patients progressed to a final visual acuity state of "no light perception" (6/18; 33%), "light perception" (1/18; 6%), or "hand motion" (6/18; 33%). Overall, the majority of patients progressed to a final visual acuity state of "no light perception" (12/30), "light perception" (4/30), or "hand motion" (7/30). Conclusions: The distribution of alpha-hemolytic streptococci in ocular infections suggested the presence of a species-specific tissue tropism. The prognoses of patients with ocular streptococcal infections were highly unfavorable, and antibiotic resistance did not contribute to the unfavorable clinical progressions and poor outcomes.


RESUMO Objetivo: O objetivo deste estudo foi caracterizar os estreptococos alfa-hemolíticos isolados de endoftalmite infecciosa e ceratite e determinar sua distribuição. Métodos: A amostra incluiu 27 e 35 isolados não-duplicados de estreptococos alfa-hemolíticos recuperados de pacientes com endoftalmite infecciosa (2002-2013) e ceratite (2008-2013), respectivamente. Os isolados foram identificados pelos testes de suscetibilidade à optoquina e bile solubilidade, utilizando um sistema de identificação bioquímica. A concentração inibitória mínima foi determinada pelo método de microdiluição em caldo. A identificação molecular foi realizada pela análise de três genes constitutivos e análise complementar de sequências multilocus. A epidemiologia molecular do Streptococcus pneumoniae foi investigada por tipagem de sequência multilocus, e a presença do gene codificador do polissacarídeo capsular foi avaliada por reação em cadeia da polymerase convencional. Os resultados foram avaliados utilizando os prontuários médicos dos pacientes. Resultados: Os testes fenotípicos diferenciaram S. pneumoniae dos outros estreptococos alpha-hemolíticos, consistentes com identificações moleculares posteriores. S. oralis foi significativamente prevalente entre os isolados de endoftalmite, assim como S. pneumoniae nos isolados de ceratite. Foram observados altos níveis de suscetibilidade a antibióticos, incluindo vancomicina, cefalosporinas e fluoroquinolonas. Alta variabilidade genética foi detectada entre as 19 cepas de S. pneumoniae, com 15 previstas para serem encapsuladas. Os prontuários médicos dos pacientes com endoftalmite infecciosa foram revisados (n=15/27; 56%), e a acuidade visual final foi avaliada em 12 casos (44%). Muitos pacientes evoluiram para um estado final de acuidade visual de "sem percepção luminosa" (6/12; 50%), "percepção luminosa" (3/12; 25%) ou "movimentos de mãos" (1/12; 8%). Também foram revisados os prontuários médicos dos pacientes com ceratite infecciosa (n=24/35; 69%), e a acuidade visual final foi avaliada em 18 casos (51%). Da mesma foram, a maioria dos pacientes evoluiu para um estado final de acuidade visual de "sem percepção luminosa" (6/18; 33%), "percepção luminosa" (1/18; 6%) ou "movimentos de mãos" (6/18; 33%). No geral, a maioria dos pacientes evoluiu para um estado final de acuidade visual de "sem percepção luminosa" (12/30), "percepção luminosa" (4/30) ou "movimentos de mãos" (7/30). Conclusões: A distribuição de estreptococos alfa-hemolíticos nas infecções oculares sugeriu a presença de um tropismo de tecido específico da espécie. Os prognósticos dos pacientes com infeções oculares por estreptococos foram altamente desfavoráveis e a resistência a antibióticos contribuiu não para as progressões clínicas des­favoráveis e os maus resultados.


Subject(s)
Humans , Endophthalmitis , Endophthalmitis/drug therapy , Endophthalmitis/epidemiology , Keratitis , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Streptococcus pneumoniae , Microbial Sensitivity Tests , Keratitis/drug therapy , Keratitis/epidemiology
16.
Dental press j. orthod. (Impr.) ; 25(6): 43-48, Nov.-Dec. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1154053

ABSTRACT

ABSTRACT Objective: To evaluate different concentrations of Galla chinensis extract (GCE) added to poly(methyl methacrylate) (PMMA), which is widely used for fabrication of removable orthodontic appliances, regarding the effectiveness of this herbal extract on antimicrobial effect and flexural strength of PMMA. Methods: Acrylic resin samples containing 0.4%, 0.8% and 1.6% GCE were prepared. Flexural strength was investigated via three-point flexural strength test for the 15 acrylic resin blocks of each concentration. Disk diffusion test was used to evaluate antibacterial effects of incorporating the same concentrations of GCE into acrylic resin. All these three groups were compared with the control group, with no added GCE, regarding flexural strength and antibacterial properties. Results: Comparison of flexural strength between the three study groups and the control group showed significant differences between the groups (P=0.018). However, there was no significant difference between the groups containing GCE. There were significant differences in antimicrobial activity between the four groups (P=0.026). Conclusion: Within the limitations of this study, it is suggested that incorporation of GCE into PMMA would be beneficial for antimicrobial activity and flexural strength of PMMA, but further studies on other physical properties and antimicrobial effects on other bacterial strain would be beneficial prior to clinical investigations.


RESUMO Objetivo: Avaliar se diferentes concentrações de extrato de Galla chinensis (EGC) adicionado ao polimetilmetacrilato (PMMA), que é amplamente utilizado para a fabricação de aparelhos ortodônticos removíveis, interferem no efeito antimicrobiano desse extrato e na resistência à flexão do PMMA. Métodos: Foram preparadas amostras de resina acrílica com concentrações de 0,4%, 0,8% e 1,6% de EGC. Para a avaliação da resistência à flexão, utilizou-se o teste de flexão em três pontos para as 15 amostras de resina em cada concentração. O teste de disco-difusão foi utilizado para avaliar os efeitos antibacterianos da incorporação das mesmas concentrações de EGC na resina acrílica. Esses três grupos foram comparados ao grupo controle, sem adição do EGC, em relação à resistência à flexão e quanto às propriedades antimicrobianas. Resultados: As comparações dos três grupos com o grupo controle mostraram diferenças significativas (p=0,018) para a resistência à flexão. Entretanto, não houve diferença significativa entre os grupos contendo EGC. Foram encontradas diferenças significativas na atividade antimicrobiana entre os quatro grupos (p=0,026). Conclusão: Dentro das limitações desse estudo, parece que a incorporação de EGC no PMMA seria benéfica para a atividade antimicrobiana e a resistência à flexão do PMMA. Porém, estudos adicionais sobre outras propriedades físicas e sobre os efeitos antimicrobianos contra diferentes cepas de bactérias seriam interessantes antes de se fazer pesquisas clínicas.


Subject(s)
Acrylic Resins , Denture Bases , Flexural Strength , Anti-Infective Agents , Anti-Bacterial Agents/pharmacology , Materials Testing , Plant Extracts/pharmacology
17.
Braz. dent. j ; 31(6): 611-616, Nov.-Dec. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132345

ABSTRACT

Abstract The aim of this study was to evaluate the antibacterial potential of a calcium silicate-based sealer (Bio-C Sealer, Angelus) against common bacteria in primary and secondary endodontic infections. Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus mutans were exposed to fresh Bio-C Sealer for 24 h by the agar diffusion method (n=5). Additionally, the antibacterial activity was investigated against E. faecalis and S. mutans biofilms (48 h old) grown in discs with 4 mm in diameter and 2 mm in height. (n=3) of set discs of Bio-C Sealer (Angelus), EndoFill (Dentsply-Mallefer), Sealer 26 (Dentsply), AH Plus (Dentsply), Sealapex (Sybron-Endo) and EndoSequence BC Sealer (Brasseler). The antibacterial activity was evaluated by colony forming unity (CFU) counting using ImageJ software. Data were compared by one-way ANOVA followed by Holm-Sidak test (a=5%). Fresh Bio-C Sealer exhibited antimicrobial activity against all bacteria evaluated by agar diffusion method, except for S. mutans. Set discs of all endodontic sealers tested showed similar CFU values for E. faecalis (p>0.05). S. mutans in biofilms showed higher susceptibility to EndoFill compared with the other sealers (p<0.05). In conclusion, the results indicate that fresh Bio-C Sealer does not inhibit S. mutans growth, but exhibits antibacterial activity against E. faecalis, S. aureus, P. aeruginosa and E. coli. After setting, the Bio-C Sealer exhibits an antimicrobial potential comparable to that of the other sealers evaluated in E. faecalis biofilm, but lower than that of EndoFill for S. mutans biofilm.


Resumo O objetivo deste estudo foi avaliar o potencial antibacteriano do novo cimento biocerâmico (Bio-C Sealer, Angelus) contra bactérias comuns em infecções endodônticas primárias e secundárias. Culturas de Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus e Streptococcus mutans foram expostos a amostras frescas do Bio-C sealer durante 24 h pelo método de difusão em agar (n=5). A atividade antibacteriana de amostras dos cimentos Bio-C Sealer (Angelus), EndoFill (Dentsply-Mallefer), Sealer 26 (Dentsply), AH Plus (Dentsply), Sealapex (Sybron-Endo) e EndoSequence BC Sealer (Brasseler) após a presa também foi investigada em biofilmes de 48 h das bactérias E. faecalis e S. mutans, crescidos em discos com 4 mm de diâmetro e 2 mm de altura. A atividade antibacteriana foi avaliada por contagem das unidades formadoras de colônias (UFC) utilizando o software ImageJ. Os dados foram comparados por ANOVA a um critério seguido pelo pós-teste Holm-Sidak (a=5%). Amostras frescas do Bio-C Sealer exibiram atividade antimicrobiana contra todas as bactérias avaliadas pelo método de difusão em ágar, exceto para S. mutans. A análise da formação de biofilme mostrou que todos os cimentos endodônticos testados apresentaram valores similares de UFC para E. faecalis (p> 0,05), enquanto biofilmes de S. mutans foram mais suscetíveis ao EndoFill em comparação com os demais cimentos (p<0,05). Conclui-se que o cimento Bio-C Sealer fresco exibe atividade antibacteriana para E. faecalis, S. aureus, P. aeruginosa e E. coli, mas não inibe o crescimento de S. mutans. Após a presa, o cimento Bio-C Sealer exibe potencial antimicrobiano similar ao dos demais cimentos avaliados em biofilme de E. faecalis, mas inferior ao do EndoFill para S. mutans.


Subject(s)
Root Canal Filling Materials/pharmacology , Epoxy Resins , Staphylococcus aureus , Materials Testing , Enterococcus faecalis , Silicates/pharmacology , Calcium Compounds , Escherichia coli , Anti-Bacterial Agents/pharmacology
18.
Braz. dent. j ; 31(5): 485-492, Sept.-Oct. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132341

ABSTRACT

Abstract Green chemistry has been applied in different areas due to the growing demands for renewable processes and one of them is nanotechnology. The aim of this study was to characterize a formulation containing silver nanoparticles (AgNPs) produced by a green synthesis and to evaluate its antimicrobial activity. The formulation will be used as an intracanal dressing exploiting the AgNPs' antimicrobial properties, which are crucial to prevent infections and bacterial reinfections that can compromise endodontic treatments. In the green synthesis, silver nitrate was employed as the precursor salt, maltose as a reducing agent, and gelatin as a stabilizing agent. The formulation was prepared mixing 50 % of a liquid containing the AgNPs and 50 % of hydroxyethylcellulose gel at 1.5 % with proper evaluation of the process inherent parameters. Techniques such as molecular absorption spectrometry and dynamic light scattering were used in characterization step. The antimicrobial activity of the AgNPs against Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 25175 was verified according to National Comittee for Clinical Laboratory Standards (NCCLS) by determining minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The obtained results indicated the formulation containing AgNPs produced by a green synthesis was properly characterized by the selected techniques. Furthermore, the formulation assessment proved that it is suitable for the proposal as well as it has potential to be used as an intracanal dressing since presented antimicrobial activity against all bacterial strains evaluated.


Resumo A química verde tem sido aplicada em diferentes áreas devido à crescente demanda por processos renováveis e uma delas é a nanotecnologia. O objetivo deste estudo foi caracterizar uma formulação contendo nanopartículas de prata (AgNPs) produzidas por meio de síntese verde e avaliar sua atividade antimicrobiana. A formulação será usada como curativo intracanal explorando as propriedades antimicrobianas das AgNPs que são cruciais para prevenir infecções e reinfecções bacterianas que podem comprometer os tratamentos endodônticos. Na síntese verde, nitrato de prata foi empregado como sal precursor, maltose como agente redutor e gelatina como agente estabilizador. A formulação foi preparada misturando-se 50% do líquido contendo as AgNPs e 50% de gel de hidroxietilcelulose a 1,5% com avaliação adequada dos parâmetros inerentes ao processo. Técnicas como espectrometria de absorção molecular e espalhamento dinâmico de luz foram usadas na etapa de caracterização. A atividade antimicrobiana das AgNPs contra Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 e Streptococcus mutans ATCC 25175 foi verificada de acordo com o National Comittee for Clinical Laboratory Standards (NCCLS), determinando-se a concentração inibitória mínima (MIC) e a concentração bactericida mínima (MBC). Os resultados obtidos indicaram que a formulação contendo AgNPs produzidas por meio de síntese verde foi devidamente caracterizada pelas técnicas selecionadas. Além disso, a avaliação da formulação provou que ela é adequada para a proposta, bem como tem potencial para ser utilizada como curativo intracanal já que apresentou atividade antimicrobiana contra todas as cepas bacterianas avaliadas.


Subject(s)
Metal Nanoparticles , Anti-Infective Agents/pharmacology , Silver/pharmacology , Bandages , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology
19.
Dental press j. orthod. (Impr.) ; 25(4): 51-58, July-Aug. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1133680

ABSTRACT

ABSTRACT Objective: To investigate the effect of ZnO nanocoating on mechanical properties of NiTi orthodontic wires and antibacterial activity. Methods: 0.016 x 0.022-in NiTi orthodontic wires were coated with ZnO nanoparticles using an electrochemical deposition method with three electrodes system in 0.1M Zn(NO3)2. Mechanical properties and frictional resistance of the coated wires were investigated using an universal testing machine. Antibacterial effect of ZnO coating was also investigated. Results: A stable adhered ZnO nanocoating on NiTi wires was obtained. The coated wires have a significant antibacterial activity against S. aureus, S. pyogens and E. coli, and a reduction of frictional forces by 34%. Conclusion: ZnO nanocoating may improve the antibacterial effects of NiTi wires and reduce the frictional resistance. Coating may be implanted in orthodontic practice for faster and safer treatment.


RESUMO Objetivos: Avaliar o efeito do nanorrevestimento de óxido de zinco (ZnO) sobre as propriedades mecânicas e propriedades antibacterianas de fios ortodônticos de NiTi. Métodos: Fios 0,016" x 0,022" de NiTi foram revestidos com nanopartículas de ZnO por meio de um método de deposição eletroquímica com um sistema de três eletrodos a 0,1M Zn(NO3)2. Uma máquina universal de testes foi utilizada para avaliar as propriedades mecânicas e a resistência friccional dos fios revestidos. Além disso, também foram analisadas as propriedades antibacterianas do revestimento de ZnO. Resultados: Obteve-se uma aderência estável das nanopartículas de ZnO sobre os fios NiTi. Os fios revestidos apresentaram atividade antibacteriana significativa contra S. aureus, S. pyogens e E. coli, e apresentaram uma redução de 34% na força de atrito. Conclusão: O revestimento com nanopartículas de óxido de zinco pode melhorar as propriedades antibacterianas e reduzir a resistência friccional dos fios de NiTi. Assim, o revestimento dos fios pode ser utilizado na Ortodontia visando tratamentos mais rápidos e seguros.


Subject(s)
Zinc Oxide/pharmacology , Orthodontic Wires , Staphylococcus aureus , Surface Properties , Titanium/pharmacology , Zinc , Materials Testing , Dental Alloys , Escherichia coli , Anti-Bacterial Agents/pharmacology , Nickel
20.
Rev. chil. infectol ; 37(4): 362-370, ago. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1138560

ABSTRACT

Resumen Introducción: Las enterobacterias son una causa principal de infecciones del torrente sanguíneo y su resistencia antimicrobiana se encuentra en aumento. Esto lleva a un incremento de la morbilidad-mortalidad y de los costos en la salud pública. Las enterobacterias resistentes a carbapenems representan un grave desafío a nivel global ya que existen escasas opciones terapéuticas disponibles. Objetivo: Caracterización clínico/microbiológica de las bacteriemias resistentes a carbapenémicos observadas en un período de 4 años. Material y Método: Estudio retrospectivo, observacional y descriptivo, sobre las bacteriemias por enterobacterias resistentes y sensibles a carbapenems. Resultados: Se analizó un total de 84 pacientes con bacteriemia por enterobacterias resistentes y sensibles a carbapenems. Entre las resistentes, observamos una mayor proporción de: tratamiento antimicrobiano previo, hospitalización en unidad de terapia intensiva (UTI), inicio de la bacteriemia en UTI y antecedentes de β-lactamasas de espectro extendido. Además, se detectó un amplio predominio de Klebsiella pneumoniae productor de KPC y una mortalidad atribuible de 52,4%. Discusión: El estudio posibilitó profundizar el conocimiento de una enfermedad emergente de elevada mortalidad, en vistas al diseño y aplicación de estrategias de control de infecciones y de esquemas de tratamiento efectivos adaptados a la epidemiologia local.


Abstract Background: Enterobacteriaceae are a major cause of bloodstream infections and their antimicrobial resistance continues to increase. This leads to higher morbidity-mortality rates and public health costs. Carbapenem-resistant Enterobacteriaceae represent a serious challenge globally, since there are few therapeutic options available. Aim: Clinical/microbiological characterization of the carbapenem-resistant bacteremia observed over a period of 4 years. Methods: Retrospective, observational and descriptive study about bacteremia caused by carbapenem-resistant and susceptible Enterobacteriaceae. Results: A total of 84 patients with bacteremia including carbapenem-resistant and susceptible Enterobacteriaceae were analyzed. We found that patients infected with carbapenem-resistant strains presented a higher proportion of: previous antibiotic treatment, hospitalization in intensive care unit (ICU), onset of the bacteremia during hospitalization in ICU and previous infection with extended-spectrum-beta-lactamase producing Enterobacteriaceae. Additionally, we observed a predominance of KPC-producing Klebsiella pneumoniae and an attributable mortality rate of 52.4%. Discussion: This study allowed for a better understanding of an emerging problem with high mortality, which in turn is useful for the design and adoption of infection control strategies and effective treatment regimens adapted to our local epidemiology.


Subject(s)
Humans , Klebsiella Infections/drug therapy , Klebsiella Infections/epidemiology , Bacteremia/drug therapy , Bacteremia/epidemiology , Argentina/epidemiology , beta-Lactamases , Microbial Sensitivity Tests , Carbapenems/pharmacology , Retrospective Studies , Drug Resistance, Bacterial , Enterobacteriaceae , Klebsiella pneumoniae , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology
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