In Vitro Bactericidal Activity of Biogenic Copper Oxide Nanoparticles for Neisseria gonorrhoeae with Enhanced Compatibility for Human Cells.

Resistance to antibiotics and antimicrobial compounds is a significant problem for human and animal health globally. The development and introduction of new antimicrobial compounds are urgently needed, and copper oxide nanoparticles (CuO NPs) have found widespread application across various sectors including biomedicine, pharmacy, catalysis, cosmetics, and many others. What makes them particularly attractive is the possibility of their synthesis through biogenic routes. In this study, we synthesized biogenic green tea (GT, Camellia sinensis)-derived CuO NPs (GT CuO NPs) and examined their biophysical properties, in vitro toxicity for mammalian cells in culture, and then tested them against Neisseria gonorrhoeae, an exemplar Gram-negative bacterium from the World Health Organization's Priority Pathogen List. We compared our synthesized GT CuOP NPs with commercial CuO NPs (Com CuO NPs). Com CuO NPs were significantly more cytotoxic to mammalian cells (IC50 of 7.32 µg/mL) than GT CuO NPs (IC50 of 106.1 µg/mL). GT CuO NPs showed no significant increase in bax, bcl2, il6, and il1ß mRNA expression from mammalian cells, whereas there were notable rises after treatment with Com CuO NPs. GT-CuO NPs required concentrations of 0.625 and 3.125 µg/mL to kill 50 and 100% of bacteria, respectively, whereas Com-CuO NPs needed concentrations of 15.625 and 30 µg/mL to kill 50 and 100% of bacteria, and the antibiotic ceftriaxone killed 50 and 100% with 3.125 and 30 µg/mL. Gonococci could be killed within 30 min of exposure to GT CuO NPs and the NPs could kill up to 107 within 1 h. In summary, this is the first report to our knowledge that describes the bioactivity of biogenic CuO NPs against N. gonorrhoeae. Our data suggest that biogenic nanoparticle synthesis has significant advantages over traditional chemical routes of synthesis and highlights the potential of GT-CuO NPs in addressing the challenges posed by multidrug-resistant Neisseria gonorrhoeae infections.

Antimicrobial activity of compounds identifed by artifcial intelligence discovery engine targeting enzymes involved in Neisseria gonorrhoeae peptidoglycan metabolism

Background Neisseria gonorrhoeae (Ng) causes the sexually transmitted disease gonorrhoea. There are no vaccines and infections are treated principally with antibiotics. However, gonococci rapidly develop resistance to every anti biotic class used and there is a need for developing new antimicrobial treatments. In this study we focused on two gonococcal enzymes as potential antimicrobial targets, namely the serine protease L,D-carboxypeptidase LdcA (NgO1274/NEIS1546) and the lytic transglycosylase LtgD (NgO0626/NEIS1212). To identify compounds that could interact with these enzymes as potential antimicrobials, we used the AtomNet virtual high-throughput screening technology. We then did a computational modelling study to examine the interactions of the most bioactive com pounds with their target enzymes. The identifed compounds were tested against gonococci to determine minimum inhibitory and bactericidal concentrations (MIC/MBC), specifcity, and compound toxicity in vitro. Results AtomNet identifed 74 compounds that could potentially interact with Ng-LdcA and 84 compounds that could potentially interact with Ng-LtgD. Through MIC and MBC assays, we selected the three best performing compounds for both enzymes. Compound 16 was the most active against Ng-LdcA, with a MIC50 value<1.56 µM and MBC50/90 values between 0.195 and 0.39 µM. In general, the Ng-LdcA compounds showed higher activ ity than the compounds directed against Ng-LtgD, of which compound 45 had MIC50 values of 1.56–3.125 µM and MBC50/90 values between 3.125 and 6.25 µM. The compounds were specifc for gonococci and did not kill other bacteria. They were also non-toxic for human conjunctival epithelial cells as judged by a resazurin assay. To support our biological data, in-depth computational modelling study detailed the interactions of the compounds with their target enzymes. Protein models were generated in silico and validated, the active binding sites and amino acids involved elucidated, and the interactions of the compounds interacting with the enzymes visualised through molecu lar docking and Molecular Dynamics Simulations for 50 ns and Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA). Conclusions We have identifed bioactive compounds that appear to target the N. gonorrhoeae LdcA and LtgD enzymes. By using a reductionist approach involving biological and computational data, we propose that compound Ng-LdcA-16 and Ng-LtgD-45 are promising anti-gonococcal compounds for further development

Saturated iso-type fatty acids from the marine bacterium Mesoflavibacter zeaxanthinifaciens with anti-Trypanosomal potential

Chagas disease is a Neglected Tropical Disease with limited and ineffective therapy. In a search for new anti-trypanosomal compounds, we investigated the potential of the metabolites from the bacteria living in the corals and sediments of the southeastern Brazilian coast. Three corals, Tubastraea coccinea, Mussismilia hispida, Madracis decactis, and sediments yielded 11 bacterial strains that were fully identified by MALDI-ToF/MS or gene sequencing, resulting in six genera—Vibrio, Shewanella, Mesoflavibacter, Halomonas, Bacillus, and Alteromonas. To conduct this study, EtOAc extracts were prepared and tested against Trypanosoma cruzi. The crude extracts showed IC50 values ranging from 15 to 51 μg/mL against the trypomastigotes. The bacterium Mesoflavibacter zeaxanthinifaciens was selected for fractionation, resulting in an active fraction (FII) with IC50 values of 17.7 μg/mL and 23.8 μg/mL against the trypomastigotes and amastigotes, respectively, with neither mammalian cytotoxicity nor hemolytic activity. Using an NMR and ESI-HRMS analysis, the FII revealed the presence of unsaturated iso-type fatty acids. Its lethal action was investigated, leading to a protein spectral profile of the parasite altered after treatment. The FII also induced a rapid permeabilization of the plasma membrane of the parasite, leading to cell death. These findings demonstrate that these unsaturated iso-type fatty acids are possible new hits against T. cruzi.

Protótipos microbianos como candidatos a fármacos para protozooses negligenciadas / Microbial prototypes as drug candidates for neglected protozoa

Doenças tropicais negligenciadas atingem cerca de 1,7 bilhões de pessoas, gerando um forte impacto na economia e problemas na Saúde Pública. Dentre as endemias mais negligenciadas, encontra-se a doença de Chagas, que afeta cerca de 6 milhões de pessoas, e no Brasil, dispõe-se de apenas de um fármaco altamente tóxico contra a infecção. Sendo assim, existe uma necessidade urgente para novos tratamentos. A exploração farmacológica de compostos produzidos por microrganismos é de longa data e contribuiu até hoje, com diversos fármacos aprovados. O presente projeto avaliou o potencial anti-Trypanosoma cruzi de metabólitos de espécies bacterianas marinhas encontradas no litoral paulista. Para isto, foram coletados invertebrados e sedimentos marinhos e isoladas 32 espécies bacterianas, resultando em 12 microrganismos identificados por MALDI-TOF/MS ou sequenciamento genético. Os extratos orgânicos, contendo os metabólitos microbianos, foram avaliados quanto ao potencial anti-T. cruzi em tripomastigotas, apresentando valores de Concentração Efetiva 50% (CE50) entre 1,5 e 59,0 µg/mL. Duas cepas foram submetidas à abordagem One Strain Many Compounds (OSMAC), porém, não se observou aumento da potência antiparasitária. O pré-fracionamento do extrato da Olleya marilimosa, resultou em uma fração (FII) ativa contra os tripomastigotas (CE50 23 µg/mL), com ausência de citotoxicidade em fibroblastos e hemácias até 200 µg/mL. A análise em ressonância magnética nuclear (RMN 1H) e espectrometria de massas de alta resolução, demonstrou a presença de 4 ácidos graxos de cadeia iso, 1 (C19H37O2), 2 (C20H39O2), 3 (C21H41O2) e 4 (C22H43O2)...(AU)

Neglected tropical diseases affects about 1.7 billion people, generating a strong impact on the economy and problems in Public Health. Among the most neglected endemic diseases is Chagas disease, which affects about 6 million people, and in Brazil, only one highly toxic drug is available against it. Therefore, there is an urgent need for new treatments. The pharmacological exploitation of compounds produced by microorganisms is long-standing and has contributed to several approved drugs. The present project evaluated the anti-Trypanosoma cruzi potential of metabolites of marine bacterial species found on the coast of São Paulo. For this, invertebrates and marine sediments were collected and 32 bacterial species were isolated, resulting in 12 microorganisms identified by MALDI-TOF/MS or genetic sequencing. The organic extracts containing the microbial metabolites were evaluated for antiT. cruzi potential. crossed in trypomastigotes, presenting Effective Concentration 50% (EC50) between 1.5 and 59.0 µg/mL. Two strains were submitted to the One Strain Many Compounds (OSMAC) approach, however, there was no increase in antiparasitic potency. Prefractionation of Olleya marilimosa extract resulted in an active fraction (FII) against trypanomastigotes (EC50 23 µg/mL), with no cytotoxicity in fibroblasts or red blood cells up to 200 µg/mL. Nuclear Magnetic Resonance analysis (NMR 1H) and High-Resolution Mass Spectrometry demonstrated the presence of 4 iso chain fatty acids, 1 (C19H37O2), 2 (C20H39O2), 3 (C21H41O2) and 4 (C22H43O2). Using spectrofluorimetry, it was observed that FII induced a change in the permeability of the plasma membrane of the parasite. Analysis in mass spectrometry (MALDI-TOF/MS) also demonstrated changes in the protein profile of parasites after treatment. This study presented in an unprecedented way, the anti-T. cruzi potential metabolites of the marine bacteria studied. The isolation and characterization of these compounds may contribute to new pharmaceutical prototypes for Chagas disease. (AU)