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1.
J Microbiol Immunol Infect ; 57(3): 385-395, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38453541

RESUMO

BACKGROUND: Copper plays a role in urinary tract infection (UTI) and urinary copper content is increased during Proteus mirabilis UTI. We therefore investigated the effect of copper on uropathogenic P. mirabilis and the underlying mechanisms, focusing on the virulence associated aspects. METHODS: Mouse colonization, swarming/swimming assays, measurement of cell length, flagellin level and urease activity, adhesion/invasion assay, biofilm formation, killing by macrophages, oxidative stress susceptibility, OMPs analysis, determination of MICs and persister cell formation, RT-PCR and transcriptional reporter assay were performed. RESULTS: We found that copper-supplemented mice were more resistant to be colonized in the urinary tract, together with decreased swarming/swimming, ureases activity, expression of type VI secretion system and adhesion/invasion to urothelial cells and increased killing by macrophages of P. mirabilis at a sublethal copper level. However, bacterial biofilm formation and resistance to oxidative stress were enhanced under the same copper level. Of note, the presence of copper led to increased ciprofloxacin MIC and more persister cell formation against ampicillin. In addition, the presence of copper altered the outer membrane protein profile and triggered expression of RcsB response regulator. For the first time, we unveiled the pleiotropic effects of copper on uropathogenic P. mirabilis, especially for induction of bacterial two-component signaling system regulating fitness and virulence. CONCLUSION: The finding of copper-mediated virulence and fitness reinforced the importance of copper for prevention and therapeutic interventions against P. mirabilis infections. As such, this study could facilitate the copper-based strategies against UTI by P. mirabilis.


Assuntos
Biofilmes , Cobre , Testes de Sensibilidade Microbiana , Infecções por Proteus , Proteus mirabilis , Infecções Urinárias , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/patogenicidade , Proteus mirabilis/fisiologia , Proteus mirabilis/genética , Animais , Infecções Urinárias/microbiologia , Cobre/farmacologia , Camundongos , Virulência , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Infecções por Proteus/microbiologia , Feminino , Fenótipo , Antibacterianos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Macrófagos/microbiologia , Aderência Bacteriana/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
2.
Waste Manag ; 137: 158-167, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34775289

RESUMO

Along the line that "Leave No Litter" (LNL) in protected areas is promoted globally, Hong Kong launched its LNL campaign in 2016. The success of the campaign is critically dependent on the compliance of the park visitors. Because behavioral intention is influenced by determinants of different domains, this study adopted a multilevel perspective to examine how demographic, psychological, and situational variables affected LNL intention using a voluntary response sample of 374 hikers in Hong Kong. The results indicated that attitude, perceived behavioral control, and preparedness were significant predictors of LNL intention, indicating the direct associations between them. Furthermore, preparedness mediated the effects of attitude, subjective norm, and perceived behavioral control on LNL intention. The findings of this paper may contribute to the body of knowledge on pro-environmental behavior of recreationists by providing a novel understanding of LNL intention of Hong Kong hikers. Furthermore, this study may cast light on the sustainable management of protected areas in Hong Kong as well as cities around the world.


Assuntos
Atitude , Intenção , Hong Kong , Análise Multinível , Teoria Psicológica , Inquéritos e Questionários
3.
Chest ; 158(5): 2130-2135, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32710891
4.
PLoS One ; 13(6): e0198930, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29883473

RESUMO

There is an interest in identifying Anaphase Promoting-Complex/Cyclosome (APC/C) inhibitors that lead to sensitivity to microtubule poisons as a strategy for targeting cancer cells. Using budding yeast Saccharomyces cerevisiae, peptides derived from the Mitotic Arrest Deficient 2 (Mad2)-binding motif of Cell Division Cycle 20 (Cdc20) were observed to inhibit both Cdc20- and CDC20 Homology 1 (Cdh1)-dependent APC/C activity. Over expression of peptides in vivo led to sensitivity to a microtubule poison and, in a recovery from a microtubule poison arrest, delayed degradation of yeast Securin protein Precocious Dissociation of Sisters 1 (Pds1). Peptides with mutations in the Cdc20 activating KILR-motif still bound APC/C, but lost the ability to inhibit APC/C in vitro and lost the ability to induce sensitivity to a microtubule poison in vivo. Thus, an APC/C binding and activation motif that promotes mitotic progression, namely the Cdc20 KILR-motif, can also function as an APC/C inhibitor when present in excess. Another activator for mitotic progression after recovery from microtubule poison is p31comet, where a yeast predicted open-reading frame YBR296C-A encoding a 39 amino acid predicted protein was identified by homology to p31comet, and named Tiny Yeast Comet 1 (TYC1). Tyc1 over expression resulted in sensitivity to microtubule poison. Tyc1 inhibited both APC/CCdc20 and APC/CCdh1 activities in vitro and bound to APC/C. A homologous peptide derived from human p31comet bound to and inhibited yeast APC/C demonstrating evolutionary retention of these biochemical activities. Cdc20 Mad2-binding motif peptides and Tyc1 disrupted the ability of the co-factors Cdc20 and Cdh1 to bind to APC/C, and co-over expression of both together in vivo resulted in an increased sensitivity to microtubule poison. We hypothesize that Cdc20 Mad2-binding motif peptides, Tyc1 and human hp31 peptide can serve as novel molecular tools for investigating APC/C inhibition that leads to sensitivity to microtubule poison in vivo.


Assuntos
Ciclossomo-Complexo Promotor de Anáfase/antagonistas & inibidores , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Peptídeos/farmacologia , Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Antineoplásicos/uso terapêutico , Proteínas Cdc20/metabolismo , Proteínas Cdh1/metabolismo , Ensaios Enzimáticos , Inibidores Enzimáticos/metabolismo , Humanos , Proteínas Mad2/metabolismo , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Mitose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Peptídeos/metabolismo , Peptídeos/uso terapêutico , Domínios e Motivos de Interação entre Proteínas , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Moduladores de Tubulina/farmacologia , Moduladores de Tubulina/uso terapêutico
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