The potentials of secondary metabolites from Bacillus cereus SN7 and Vagococcus fluvialis CT21 against fish pathogenic bacteria

2021 ◽  
pp. 105062
Author(s):  
Feli Feliatra ◽  
Ummi Mardhiah Batubara ◽  
Yuana Nurulita ◽  
Iesje Lukistyowati ◽  
Jarot Setiaji
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.


2021 ◽  
Vol 12 (1) ◽  
pp. 85-93
Author(s):  
Wallapat Phongtang ◽  
Ekachai Chukeatirote

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 787
Author(s):  
Tshikala Eddie Lulamba ◽  
Ezekiel Green ◽  
Mahloro Hope Serepa-Dlamini

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.


1970 ◽  
Vol 18 ◽  
pp. 16-20
Author(s):  
BA Omogbai ◽  
FA Eze

Context: Plant based antimicrobial represent a vast untapped source for medicines and further exploration of plant antimicrobial neeto occur. Evolvulus alsinoides (L) (Convolvulaceae) is a perennial herb is used in traditional medicine in East Asia, India, Africa and Philippines to cure fever, cough, cold, venereal diseases, azoospermia, adenitis and dementia.   Objective: The objective of this research was to evaluate the antimicrobial activity of the extracts of E. alsinoides on some clinical microbial isolates.   Materials and Methods: The ed thanolic and aqueous extracts of the whole plant (leaves and twigs) were analysed for alkanoids, tannins, glycosides, steroids, flavonoids, saponins, volatile oil and resins. The determination of antibacterial activity was done using the agar well diffusion technique. Pure cultures of pathogenic bacteria such as Bacillus cereus, Staphylococcus aureus, Micrococcus leutus, Klebsiella Pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi were used for antibacterial activity assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).   Results: The ethanolic extract of the plant had MIC values ranging from 16 mg/ml to 512.5 mg/ml. The least MIC was 16mg-ml against Salmonella typhi while Bacillus cereus and Staphylococcus aureus showed the highest MIC of 512.5 mg-ml. In the aqueous extract the MIC ranged between 512.5 to >1025 mg/ml. Salmonella typhi, Micrococcus luteus and Staphylococcus aureus were not inhibited by the water extract. Phytochemical result showed ethanol to be a better solvent for the extraction of the bioactive agents in this plant which include: glycosides, alkaloids, saponins, tannins, flavonoids and volatile oil.   Conclusion: In this study the gram-negative organisms had the lowest MICs and MBCs. This suggests their higher susceptibility to the extract of this plant. On the basis of the result obtained in this investigation it can be concluded that ethanol extract of Evolvulus alsinoides had significant in vitro broad spectrum antimicrobial activity.   Keywords: Evolvulus alsinoides; Phytochemical screening; Antibacterial activity. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8769 JBS 2010; 18(0): 16-20


Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 270
Author(s):  
Ilhem Saadouli ◽  
Imène Zendah El Euch ◽  
Emna Trabelsi ◽  
Amor Mosbah ◽  
Alaeddine Redissi ◽  
...  

Streptomyces is the most frequently described genus of Actinomycetes, a producer of biologically active secondary metabolites. Indeed, the Streptomyces species produces about 70% of antibiotics and 60% of antifungal molecules used in agriculture. Our study was carried out with the goal of isolating and identifying antimicrobial secondary metabolites from Streptomyces misionensis V16R3Y1 isolated from the date palm rhizosphere (southern Tunisia). This strain presented a broad range of antifungal activity against Fusarium oxysporum, Aspergillus flavus, Penicillium expansum, Aspergillus niger, Candida albicans, Candida metapsilosis, and Candida parapsilosis and antibacterial activity against human pathogenic bacteria, including Escherichia fergusonii, Staphylococcus aureus, Salmonella enterica, Enterococcus faecalis, Bacillus cereus and Pseudomonas aeruginosa. The purification procedure entailed ethyl acetate extract, silica gel column, and thin layer chromatography. Based on 1H NMR metabolomic procedure application, also supported by the GC-MS analysis, cyclic dipeptide (l-Leucyl-l-Proline) was identified as the major compound in the bioactive fraction. In order to confirm the identity of the active compound and to have a large quantity thereof, a chemical synthesis of the cyclic dipeptide was performed. The synthetic compound was obtained with a very good yield (50%) and presented almost the same effect compared to the extracted fraction. This study indicates for the first time that Streptomyces misionensis V16R3Y1 exhibits a broad spectrum of antimicrobial activities, produced cyclic dipeptide (l-Leucyl-l-Proline) and might have potential use as a natural agent for pharmaceutical and agri-food applications.


2015 ◽  
Vol 78 (5) ◽  
pp. 954-962 ◽  
Author(s):  
XUETONG FAN ◽  
PETER FELKER ◽  
KIMBERLY J. SOKORAI

Mesquite pod flour produced from nitrogen-fixing trees of the Prosopis species has a unique aroma and flavor that is preferred by some consumers. Due to the presence of wildlife, grazing domestic animals, and insects, the pods have a high potential of being contaminated with human pathogenic bacteria, such as Bacillus cereus. Nonthermal processing technologies are helpful to reduce the population of microorganisms in the flour because heating deteriorates the characteristic flavor. A study was conducted to investigate the efficacy of ionizing radiation in decontaminating two types of mesquite pod flours (Prosopis alba and Prosopis pallida) naturally contaminated with B. cereus and the effects of irradiation on the formation of furan, a possible human carcinogen. Results showed that the populations of B. cereus were 3.8 and 5.4 log CFU/g in nonirradiated P. alba and P. pallida flours, respectively, and populations of microflora, mesophilic spores, B. cereus, and B. cereus spores decreased with increasing radiation doses. At 6 kGy, the populations fell below 1 log CFU/g. Irradiation at 6 kGy had no significant effect on the fructose, glucose, or sucrose content of the flour. Nonirradiated P. alba and P. pallida flours contained 13.0 and 3.1 ng/g of furan, respectively. Furan levels increased with irradiation doses at rates of 2.3 and 2.4 ng/g/kGy in the two flours. The level of 3-methylbutanal was reduced or not affected by irradiation, while the hexanal level was increased. Our results suggested that irradiation was effective in decontaminating contaminated mesquite flour. The significance of furan formation and possible changes in flavor due to irradiation may need to be further examined.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Priya Srivastava ◽  
D. K. Upreti ◽  
T. N. Dhole ◽  
Apurva K. Srivastava ◽  
Meghanand T. Nayak

Context.Usnea ghattensisG. Awasthi (Usneaceae) endemic fruticose lichen found growing luxuriantly in Northern Western Ghats of India, it also contains Usnic acid as a major chemical and tested against some human pathogenic bacteria.Objective. To explore antimicrobial properties ofUsnea ghattensisagainst some human pathogenic bacteria.Materials and Methods. The lichen was extracted in acetone, methanol, and ethanol.In vitroantimicrobial activity was tested initially byKirby-Bauertechnique of disc diffusion method and was confirmed by minimum inhibitory concentration using Broth microdilution method according to the NCCLS guidelines.Results. Ethanol extract was most effective againstBacillus cereusandPseudomonas aeruginosawith a zone of inhibition 29.8 ± 0.6 mm and 12.3 ± 0.5 mm diameters at a concentration of 0.2 mg/mL. Acetone and methanol extract demonstrated almost similar activity againstStaphylococcus aureusand the zone of inhibition was 24.6 ± 0.5 and 24.7 ± 0.4 mm. Only methanol extract was showing activity againstStreptococcus faecaliswith a 13.5 ± 0.8 mm zone. MIC value noted againstStaphylococcus aureusandStreptococcus faecaliswas 6.25 μg/mL and 25 μg/mL, whereas againstBacillus cereusandPseudomonas aeruginosa, MIC calculated was 3.125 μg/mL and 200 μg/mL, respectively.Conclusion. The present study demonstrates the relatively higher activity of this lichen against not only gram (+) but significantly also against gram (−) bacteria. This indicates that this lichen might be a rich source of effective antimicrobial agents.


2021 ◽  
Vol 15 (3) ◽  
pp. 143-153
Author(s):  
Zara Nomentsoa Razafiarimanga ◽  
Lovarintsoa Judicael ◽  
Randriamampianina ◽  
Hanitra Ranjana Randrianarivo ◽  
Saïd M’bae Sadam ◽  
...  

The present work aimed to study the composition and antimicrobial properties of the essential oil of Helichrysum ibityense leaves (HIEO). HIEO was extracted by hydrodistillation from fresh leaves with a yield of 1.9%. It had a relative density of 0.9247 at 20℃, a refractive index of 1.4706, an optical rotation of -0°33, an acid index of 2.10 and an ester index of 54. Gas chromatography analysis/flame ionisation detection of HIEO had identified 17 components, representing more than 99.54% of the overall composition of the HIEO including 1.8-cineole (69.46%) the major component, α-terpinene (4.62%), β-caryophyllene (4.39%), α-pinene (4.13%), β-pinene (2.96%), p-cymene (2.39%) and γ-terpinene (2.16%). The HIEO antimicrobial activity was tested against nine pathogenic bacteria including Staphylococcus aureus, Staphylococcus pneumoniae, Streptococcus pyogenes, Clostridium perfringens, Bacillus cereus, Pseudomonas aeruginosa, Enterobacter cloacae, Enterobacter aerogenes, Yersinia enterocolitica, and Candida albicans using the Disc diffusion and the Microdilution assays. HIEO exhibited broad activity spectrum and high microbial activity with inhibition zones (IZ) ranging from 12 to 35 mm. On Bacillus cereus, the most sensitive bacterium, its Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were 9.37 mg/ml and 13.22 mg/ml respectively. With an MBC/MIC ratio of 1.41, HIEO exerted a bactericidal action on Bacillus cereus. When administered orally to mice at 1000 mg/kg body weight, HIEO caused symptoms of intoxication which disappeared after 24 h. These preliminary results revealed HIEO could be used to treat different infectious diseases if its safety will be confirmed.


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