scholarly journals Método alternativo e sustentável para a realização de coloração bacteriana de Gram e Wirtz-Conklin: Relevância ambiental e econômica no ensino prático da microbiologia

2021 ◽  
Vol 10 (9) ◽  
pp. e9510917585
Author(s):  
Fabricio Ueda Reine ◽  
Lorena Aparecida Bianchi de Souza ◽  
Jéssica Lima de Menezes ◽  
Rosana Ferreira Carli Cangussu Gomes ◽  
Aline Campos Reis de Souza ◽  
...  

As preparações coradas são os exames microscópicos mais comumente empregados em microbiologia, pois proporcionam uma melhor visualização dos microrganismos. Tendo em vista que as técnicas de coloração de Gram e Wirtz-Conklin são comumente utilizadas na rotina de laboratórios de microbiologia e nas aulas de microscopias coradas, este projeto teve como objetivo comparar a técnica padrão de coloração em superfície das lâminas, com a técnica por imersão, que por sua vez pode evitar o desperdício de corantes, impacto ambiental e diminuir custos laboratoriais e no ensino. Dessa forma, foram feitos esfregaços bacterianos (Escherichia coli; Staphylococcus aureus; Alicyclobacillus acidoterrestris e Bacillus subtilis) em lâmina, seguidos de fixação em chama. Após esse procedimento as lâminas foram submetidas à coloração pela técnica de superfície e pela técnica de imersão. Posteriormente as lâminas foram visualizadas em microscópio óptico comum e a resolução das imagens e características tintoriais foram avaliadas e registradas. A técnica de coloração por imersão, tanto para a coloração de Gram quanto para Wirtz-Conklin, evitou desperdício dos corantes utilizados nas técnicas, bem como, a saturação das soluções após muitas passagens de lâminas. Assim, a técnica de coloração por imersão é favorável para o uso nas aulas ou nos laboratórios de microbiologia. A aplicação dessa técnica mostrou resultados significativos para a diminuição do desperdício e, consequentemente, os impactos ao meio ambiente e à economia das instituições de ensino.

2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.


2018 ◽  
Vol 42 (10) ◽  
pp. 512-514
Author(s):  
Rui-bo Xu ◽  
Xiao-tian Yang ◽  
Hai-nan Li ◽  
Peng-cheng Zhao ◽  
Jiao-jiao Li ◽  
...  

Two new bis-Schiff bases containing a piperazine ring, N,N‘-bis(4-chlorobenzylidene)- and N,N‘-bis(4-cyanobenzylidene)-1,4-bis(3-aminopropyl)piperazine, were prepared by the reaction of N,N‘-bis(3-aminopropyl)piperazine with 4-chloro- and 4-cyanobenzaldehyde, respectively. The dichloro compound was fully identified by X-ray crystallography and it exhibited good antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis.


Author(s):  
Nur Aishah Abdul Wahab ◽  
Hairul Shahril Muhamad ◽  
Nabilah Ahmad Alhadi ◽  
Salina Mat Radzi ◽  
Maryam Mohamed Rehan ◽  
...  

Combination effects between Cymbopogon flexuosus and Cymbopogon nardus essential oils were studied to determine whether the combination could emerge as better and more powerful antimicrobial agents against six selected bacteria includes Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis. This combination study exhibited 40.67% additive, 28.67% antagonistic, 16.00% indifferent and 14.66% synergistic effects. C. flexuosus and C. nardus essential oils in combination showed a high inhibitory activity against S. aureus with 16% synergistic, 64% additive and 20% indifferent effects.


2020 ◽  
Vol 39 (03) ◽  
Author(s):  
VĂN HỒNG THIỆN ◽  
LÊ BÍCH TRÂM ◽  
NGUYỄN THANH LAN ◽  
HỒ NGUYỄN HOÀNG YẾN ◽  
LƯU HỒNG TRƯỜNG ◽  
...  

Nghiên cứu này đã xác định được mẫu nghiên cứu thu tại Vườn quốc gia Phú Quốc là loài Homalomena pierreana. Thông qua kỹ thuật sắc ký ghép khối phổ, 10 hợp chất thuộc nhóm sesquiterpene có trong cao chiết ethanol của thân rễ loài H. pierreana đã được xác định. Ngoài ra, cao chiết ethanol từ mẫu nghiên cứu cũng cho thấy khả năng kháng lại 6 chủng vi khuẩn kiểm định là Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis và Salmonella typhimurium.


Author(s):  
LUCIANA HELENA MAIA PORTE ◽  
MARIA HELENA MIGUEZ ROCHA LEÃO ◽  
ALEXANDRE PORTE

Lactoferrina bovina (bLF), proveniente do soro de leite, foimicroencapsulada pela técnica de spray drying. Microcápsulascontendo 20 % de bLF foram produzidas, utilizando-se comomaterial de parede dextrina: amido octenilsuccinato (OSA) emdiferentes proporções: 100:00, 75:25, 50:50, 25:75 e 0:100 %.Foram avaliadas a cor e a estabilidade de cor das microcápsulassob armazenamento em ambientes com diferentes umidadesrelativas e a atividade antimicrobiana da lactoferrina liberadadas microcápsulas. As microcápsulas apresentaram cor clara etenderam a escurecer sob armazenamento em ambiente com altaumidade relativa. Verifi cou-se atividade inibitória das microcápsulasde bLF produzidas para diferentes bactérias Gram positivas(Bacillus subtilis CCT 2576, Staphylococcus aureus CCT 2740,Micrococcus luteus CCT 2692, Enterococcus faecium CCT 5079,Streptococcus faecium ATCC 10541, Rhodococcus equi CCT0541), Gram negativas (Pseudomonas aeruginosa ATCC 13388,Salmonella choleraesius CCT 4296, Escherichia coli CCT 0547) elevedura (Candida albicans ATCC 10231). A concentração inibitóriamínima (MIC) das microcápsulas variou de acordo com o microorganismotestado (MIC entre 2,5-100 mg.mL-1). Com exceção deB. subtilis (MIC entre 50-100 mg.mL-1 para as microcápsulas), aconcentração de bLF contida nas microcápsulas necessária parainibir o crescimento dos micro-organismos foi menor do que a bLFnativa. Esses resultados sugerem efeito de potencialização daatividade antimicrobiana da bLF após o processamento por spraydrying.


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Daniyar Sadyrbekov ◽  
Timur Saliev ◽  
Yuri Gatilov ◽  
Ivan Kulakov ◽  
Roza Seidakhmetova ◽  
...  

A cyclopropane derivative of limonene, (1 S, 4 S, 6 R)-7,7-dichloro-4-[(1 S)-2,2-dichloro-1-methylcyclopropyl]-1-methylbicyclo [4.1.0] heptane (compound 2), was synthesized and its structure was determined by NMR and X-ray crystallographic methods. In addition, an antimicrobial activity of the compound against Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli, Pseudomonas aeruginosa) bacterial strains was also scrutinized.


2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Corina Danciu ◽  
Florin Borcan ◽  
Codruta Soica ◽  
Istvan Zupko ◽  
Erzsébet Csányi ◽  
...  

In recent years polyurethane microstructures (PM) have gained increasing attention in the pharmaceutical field due to the importance of their practical application. Since finding that such a formulation with genistein could improve its applications, we have conducted a preliminary study regarding the in vitro antiproliferative (MCF7, MDA-MB-231 and T47D) and antimicrobial ( Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis (D), Bacillus subtilis, B. cereus, and Candida albicans) activity in order to test whether polyurethane micro structuresre present a good option for further modulation of genistein's bioavailability. It was concluded that the polyurethane micro structures are a bad in vitro partner for the isoflavone genistein.


2012 ◽  
Vol 534 ◽  
pp. 78-81
Author(s):  
Ting Wei Hu ◽  
Shao Yun Shan ◽  
Shi Mei Yang ◽  
Li Hong Jiang ◽  
Ya Ming Wang ◽  
...  

Polyaniline(PANI)/TiO2 nanocomposites are successful synthesized by one step-interfacial polymerization method. Morphologies and structures of the nanocomposites are characterized using SEM, FTIR, and XRD. The antibacterial properties of PANI/TiO2 nanocomposites on Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Bacillus megateriu and Bacillus cereus are tested. The effect of molar ratio of aniline and tetrabutyl titanate on structures and antibacterial properties are also been explored. The results show that the content of tetrabutyl titanate has a obvious influence on structure and morphologies of the nanocomposites. PANI/TiO2 nanocomposites have antibacterial properties especially on Staphylococcus aureus and Escherichia coli, which shows a best antibacterial property when the molar ratio of aniline to tetrabutyl titanate is 3:2.


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