Antifungal Activity, Antibiofilm and Association Studies with O-Alkylamidoximes against Cryptococcus spp.

This is the first study that describes the antifungal and anti-biofilm potential of O-alkylamidoximes against strains of Cryptococcus neoformans and Cryptococcus gattii. In vitro tests have shown that O-alkylamidoximes are capable of inhibiting fungal growth and biofilm formation of the C. neoformans and C. gattii strains, suggesting, from molecular docking, the potential for interaction with the Hsp90. The associations between O-alkylamidoximes and amphotericin B were beneficial. Therefore, O-alkylamidoximes can be a useful alternative to contribute to the limited arsenal of drugs, since they showed a powerful action against the primary agents of Cryptococcosis.

Patulin inhibits LPS-induced nitric oxide production by suppressing MAPKs signaling pathway.

Patulin (PAT) is a natural product isolated from several species of fungi. Here, we evaluated the effect of PAT (62.5-4,000 ng/ml) in lipopolysaccharide (LPS)-activated murine peritoneal macrophages. Cell viability assay showed that PAT at concentrations up to 250 ng/ml did not affect macrophage viability. PAT (250 ng/ml) significantly reduced LPS-induced nitric oxide production (by 98.4%), inducible nitric oxide synthase (iNOS) expression (by 83.5%), and iNOS messenger ribonucleic acid expression (by 100.0%). Moreover, PAT significantly reduced LPS-induced interleukin-1ß (by 80.6%), cluster of differentiation (CD) 69 (by 63.1%), and Toll-like receptor (TLR) 4 (by 91.9%) protein expression. Finally, PAT significantly reduced LPS-triggered phosphorylation of all mitogen-activated protein kinases (MAPK) assessed: extracellular signal-regulated kinase (ERK; by 89.5%), c-Jun N-terminal kinase (JNK; by 77.5%), and p38 (by 72.3%). Taken together, these data suggest that PAT downregulates acute inflammatory response, inhibiting nitric oxide production by suppressing CD69-TLR4/ERK-JNK-p38 MAPKs/Nos2/iNOS signaling pathway.

Multi-purpose Disinfecting Solutions only Partially Inhibit the Development of Ocular Microbes Biofilms in Contact Lens Storage Cases.

PURPOSE: Certain ocular resident or pathogenic microbes may remain viable in the presence of multi-purpose disinfectant solutions (MPDSs), subsequently developing biofilms inside contact lens storage cases (CLSCs) which pose a risk of infection to wearers. This study evaluated the formation of ocular microbiota biofilms exposed to three top selling MPDS. METHODS: Crystal violet assay was carried out for the verification of biofilm formation. The in vitro assays evaluated Pseudomonas aeruginosa UFPEDA 416 and Staphylococcus aureus UFPEDA 02 exposure of 48 h to MPDS, as well as the use of 40 KHz ultrasound at the beginning and with 24 h immersion in the MPDS. Subsequently, in vivo assays evaluated the formation of microbial biofilms on the CLSC walls containing silicone-hydrogel contact lenses immersed in MPDS from 15 healthy volunteer patients, who had been wearing the lenses for 7 days. RESULTS: Biofilms were inhibited by 26%-98% in the in vitro assays, with a statistically significant difference only for P. aeruginosa UFPEDA 416 exposed to diluted MPDS. Most inhibitions occurred moderately and weakly. In addition, adherent cells were detected in more than 90% of the tests. Biofilm was not inhibited in more than one third of the results, nor was it disturbed, especially with the ultrasound treatments. The average of obtained optical densities at 590 nm was between 0.6 and 0.8 in the in vivo assays. The results were similar between the CLSC right and left wells. There was a correlation between microbial biofilm formation and the type of MPDS tested, with statistical difference between the three treatments. CONCLUSION: MPDS promoted a partial inhibition of microbial biofilm formation but only one MPDS proved to be more effective in vitro and in vivo. This study, however, could not distinguish the effect of possible errors in the good hygiene practices of the users.

Colour Me Blue: The History and the Biotechnological Potential of Pyocyanin.

Pyocyanin was the first natural phenazine described. The molecule is synthesized by about 95% of the strains of Pseudomonas aeruginosa. From discovery up to now, pyocyanin has been characterised by a very rich and avant-garde history, which includes its use in antimicrobial therapy, even before the discovery of penicillin opened the era of antibiotic therapy, as well as its use in electric current generation. Exhibiting an exuberant blue colour and being easy to obtain, this pigment is the subject of the present review, aiming to narrate its history as well as to unveil its mechanisms and suggest new horizons for applications in different areas of engineering, biology and biotechnology.

Avaliação bacteriológica do gelo em pacote comercializado em Recife, PE / Bacteriological evaluation of packaged ice commercialized in Recife, PE

O gelo é um produto resultante do congelamento da água potável e é comumente utilizado para conservação de alimentos e consumo. Sua avaliação bacteriológica após fusão pode demonstrar se houve contaminação por microrganismos patógenos durante o processo de fabricação. Considerando o gelo como fonte potencial de transmissão de doenças, este trabalho objetivou verificar a qualidade bacteriológica do produto comercializado em Recife-PE. Baseado na legislação vigente no país para água potável, foram pesquisados coliformes totais e termotolerantes após fusão dos cubos de gelo, em condições assépticas. Foram analisadas 27 amostras do produto comercializado em pacotes de 3 kg, de nove diferentes marcas. Ensaios presuntivos e confirmativos para coliformes totais e termotolerantes foram realizados pela Técnica da Presença e Ausência. Do total de amostras, 15 estavam em desacordo com a legislação vigente e 14 delas eram positivas para coliformes termotolerantes, tendo sido identificada a bactéria Klebsiella pneumoniae como predominante no teste de termotolerância.

Ocurrence of chlorine resistant strains of Pseudomonas aeruginosa from different water sources - DOI: 10.4025/actascibiolsci.v29i3.488 / Ocorrência de linhagens de Pseudomonas aeruginosa cloro resistentes em águas de diferentes origens - DOI: 10.4025/actascibiolsci.v29i3.488

The nutritional versatility and the adaptability of Pseudomonas aeruginosa to different environments, including water, are well known. Chlorine and other chlorine agents are used as water disinfecting all around the world. The aim of this work was to evaluate the possible chlorine resistance amongst P. aeruginosa strains isolated from different aquatic sources by using different contact time (1, 5, 10, 20, 30 and 40 minutes) in solutions with known chlorine concentrations according current legislation in the country to potable water: 0.5; 1.0 and 2.0 ppm. The chlorine resistance test was done by direct exposure of P. aeruginosa under a solution with known chlorine concentration. Results showed that P. aeruginosa strains isolated from different aquatic sources are able to survive in different chlorine concentrations. At 1 ppm, most of them were not inhibited. It was also observed that the most resistant strains were antibiotic multiresistant.

Pseudomonas aeruginosa é conhecida por sua versatilidade metabólica e extrema capacidade de adaptação a diferentes ambientes, inclusive aquáticos. Para desinfecção de águas, o cloro e agentes que contêm cloro continuam sendo os mais usados no mundo. O objetivo deste trabalho foi avaliar a resistência ao cloro de linhagens de P. aeruginosa, isoladas de amostras de águas de diversos ambientes. Foram testados diferentes tempos de contato (1, 5, 10, 20, 30 e 40 minutos) e soluções aquosas de cloro, com concentrações definidas com base na legislação vigente no país para água potável: 0,5; 1,0 e 2,0 ppm. O teste de resistência ao cloro foi desenvolvido por meio da exposição direta das bactérias às soluções. Os resultados revelaram que P. aeruginosa, isoladas de diferentes fontes de água, têm a habilidade de sobreviver a diferentes concentrações de cloro. Na concentração de 1 ppm, a maioria das linhagens não foi inibida. As linhagens mais resistentes ao cloro também apresentaram relação de multirresistência à maioria dos antibióticos testados.

Antibiogramas de linhagens de Pseudomonas aeruginosa isoladas de diferentes ambientes aquáticos / Antibiograms of Pseudomonas aeruginosa strains isolated from different aquatic environments

Neste estudo, foram investigadas 13 linhagens de Pseudomonas aeruginosa oriundas de diferentes fontes de ambientes aquáticos em Recife-PE: poços de cemitérios, água mineral, água tratada do sistema de abastecimento e efluentes de aterro sanitário. Foram empregadas as classes de antibióticos mais utilizadas no tratamento contra P.aeruginosa: agentes beta-lactâmicos, aminoglicosídeos, carbepenemas e quinolonas. Todas as linhagens selvagens mostraram-se sensíveis aos antibióticos testados.

Evidência do antagonismo entre Pseudomonas aeruginosa e bactérias indicadoras de contaminação fecal em água / Evidence of the antagonism between Pseudomonas aeruginosa and indicating bacteria of fecal contamination in water

Sabe-se que a bactéria Pseudomonas aeruginosa (PA) pode interferir em análises colimétricas. Apesar disto, sua enumeração é questionada neste tipo de análise, por ser considerado um microrganismo oportunista, não habitante do trato intestinal de animais de sangue quente. No Brasil, a bactéria é padrão de potabilidade em águas minerais. Por conta da sua grande versatilidade metabólica, a bactéria teria vantagens sobre os demais microrganismos na água. No presente trabalho, 16 linhagens de PA foram investigadas como o objetivo de evidenciar o antagonismo contra dois representantes do grupo coliforme: Escherichia coli (EC) e Enterobacter aerogenes (EA). O teste foi realizado utilizando a técnica dos blocos de gel de agarose modificada. Todas as linhagens de PA apresentaram atividades antimicrobiana contra EA eEC, formando halos de inibição de até 29mm de diâmetro. O fenômeno do antagonismo foi evidenciado quando a piocianina estava presente.

Evidência do antagonismo entre Pseudomonas aeruginosa e bactérias indicadoras de contaminação fecal em água / Evidence of the antagonism between Pseudomonas aeruginosa and indicating bacteria of fecal contamination in water

Sabe-se que a bactéria Pseudomonas aeruginosa (PA) pode interferir em análises colimétricas. Apesar disto, sua enumeração é questionada neste tipo de análise, por ser considerado um microrganismo oportunista, não habitante do trato intestinal de animais de sangue quente. No Brasil, a bactéria é padrão de potabilidade em águas minerais. Por conta da sua grande versatilidade metabólica, a bactéria teria vantagens sobre os demais microrganismos na água. No presente trabalho, 16 linhagens de PA foram investigadas como o objetivo de evidenciar o antagonismo contra dois representantes do grupo coliforme: Escherichia coli (EC) e Enterobacter aerogenes (EA). O teste foi realizado utilizando a técnica dos blocos de gel de agarose modificada. Todas as linhagens de PA apresentaram atividades antimicrobiana contra EA eEC, formando halos de inibição de até 29mm de diâmetro. O fenômeno do antagonismo foi evidenciado quando a piocianina estava presente.

The Pseudomonas aeruginosa (PA) interference towards the coliform group is known in water analysis. Its enumeration has been questioned through the years because it is considered an opportunistic pathogen not inhabitant of intestinal tract of warm-blooded animaIs. In Brazil, PA is indicator only in mineral waters. Due to its metabolic versatility, it would have advantages under other organisms in water. The aim of this work was to evidence the antagonistic phenomenon. It was investigated 16 strains of PA towards Escherichia coli (EC) e Enterobacter aerogenes(EA). Tests were done by using the modified agarose disks technique. All PA strains had antagonistic activity. The event were more evidenced when pyocyanin were present.