Marine macroalga-associated heterotrophic Bacillus velezensis: a novel antimicrobial agent with siderophore mode of action against drug-resistant nosocomial pathogens

2021 ◽  
Vol 203 (9) ◽  
pp. 5561-5575
Author(s):  
Kajal Chakraborty ◽  
Aneetta Francis ◽  
Rekha Devi Chakraborty ◽  
Sumayya Asharaf ◽  
Vinaya Kizhakkepatt Kizhakkekalam ◽  
...  
2003 ◽  
Vol 4 (6) ◽  
pp. 1457-1465 ◽  
Author(s):  
Entsar I. Rabea ◽  
Mohamed E.-T. Badawy ◽  
Christian V. Stevens ◽  
Guy Smagghe ◽  
Walter Steurbaut

2009 ◽  
Vol 278 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Kai-rong Wang ◽  
Jie-xi Yan ◽  
Bang-zhi Zhang ◽  
Jing-jing Song ◽  
Peng-fei Jia ◽  
...  

2014 ◽  
Vol 56 (6) ◽  
pp. 461-467 ◽  
Author(s):  
Ruth Estela Gravato Rowlands ◽  
Christiane Asturiano Ristori ◽  
Alice A. Ikuno ◽  
Maria Luisa Barbosa ◽  
Miyoko Jakabi ◽  
...  

Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.


Author(s):  
Alka Rani ◽  
Khem Chand Saini ◽  
Felix Bast ◽  
Sunita Varjani ◽  
Sanjeet Mehariya ◽  
...  

Microorganisms including actinomycetes, archaea, bacteria, fungi, yeast, and micro algae are the auspicious source of vital bioactive compounds. In this review, the existing state of the art re-garding antimicrobial molecules from microorganisms has been summarized. The potential an-timicrobial compounds from actinomycetes, particularly Streptomyces sp.; archaea; fungi including endophytic and marine-derived fungi, mushroom; yeast, and microalgae were briefly described. Furthermore, this review briefly summarized the activity and mode of action of bacteriocins, a ribosomally synthesized antimicrobial peptides product of Eurotium sp., Streptomyces parvulus, S. thermophiles, Lactococcus lactis, etc. Bacteriocins have inherent properties such as targeting multi-ple-drug resistant pathogens, which allows them to be considered next-generation antibiotics. Similarly, Glarea lozoyensis derived antifungal lipohexpeptides i.e., pneumocandins, inhibits 1,3-β-glucan synthase of the fungal cell wall and acts as a precursor for the synthesis of caspo-fungin, is also elaborated. In conclusion, this review highlights the possibility of using microor-ganisms as an antimicrobial resource for biotechnological, nutraceutical, and pharmaceutical ap-plications. However, more investigations are still required to separate, purify, and characterize these bioactive compounds and transfer these primary drugs into clinically approved antibiotics.


Science ◽  
2020 ◽  
Vol 370 (6519) ◽  
pp. 974-978 ◽  
Author(s):  
Fan Zhang ◽  
Miao Zhao ◽  
Doug R. Braun ◽  
Spencer S. Ericksen ◽  
Jeff S. Piotrowski ◽  
...  

New antifungal drugs are urgently needed to address the emergence and transcontinental spread of fungal infectious diseases, such as pandrug-resistant Candida auris. Leveraging the microbiomes of marine animals and cutting-edge metabolomics and genomic tools, we identified encouraging lead antifungal molecules with in vivo efficacy. The most promising lead, turbinmicin, displays potent in vitro and mouse-model efficacy toward multiple-drug–resistant fungal pathogens, exhibits a wide safety index, and functions through a fungal-specific mode of action, targeting Sec14 of the vesicular trafficking pathway. The efficacy, safety, and mode of action distinct from other antifungal drugs make turbinmicin a highly promising antifungal drug lead to help address devastating global fungal pathogens such as C. auris.


Parasitology ◽  
2016 ◽  
Vol 143 (11) ◽  
pp. 1469-1478 ◽  
Author(s):  
CRISTINA FONSECA-BERZAL ◽  
CRISTIANE FRANÇA DA SILVA ◽  
RUBEM F. S. MENNA-BARRETO ◽  
MARCOS MEUSER BATISTA ◽  
JOSÉ A. ESCARIO ◽  
...  

SUMMARYThe phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruzi prototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50 value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in this in vitro assay on BT, both compounds triggered important damages in T. cruzi that lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 on T. cruzi trypomastigotes.


ChemMedChem ◽  
2021 ◽  
Author(s):  
Parichita Chakraborty ◽  
Dorenda Oosterhuis ◽  
Riccardo Bonsignore ◽  
Angela Casini ◽  
Peter Olinga ◽  
...  

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