In vitro Assessment of Bacterial Strains Associated with Microalgae as Potential Probiotics

Bacteria and microalgae are essential elements in the aquatic ecosystem, co-existing and having constant interactions with each other which help microalgae to exert its beneficial effect as probiotics in aquaculture. This research aims to isolate and identify potential probiotics from different species of microalgae and to evaluate their antimicrobial activity against pathogenic Vibrio spp. via series of in vitro assays; disc diffusion, well diffusion, and co-culture assays. A total of 18 bacterial strains were isolated from five species of microalgae; Chlorella sp., Nannochloropsis sp., Amphora sp., Chaetoceros sp., and Spirulina sp.. The isolated strains were tested in in vitro antagonistic assay against four Vibrio spp. (Vibrio harveyi, Vibrio alginolyticus, Vibrio vulnificus, and Vibrio parahaemolyticus). Seventeen strains demonstrated antimicrobial activity with the highest inhibition was observed by strain SPS11 against V. parahaemolyticus (12.6 ± 0.36 mm) in disc diffusion assay and strain NAS32 showed 13.2 ± 0.45 mm clear zone against V. vulnificus in well diffusion assay. In co-culture assay, both the SPS11 and NAS32 were able to reduce the growth of V. parahaemolyticus and V. harveyi at concentration of 106 and 108 CFU mL-1, respectively. Strains SPS11 and NAS32 were characterized as gram positive bacteria with rod shape and further identified as Lysinibacillus fusiformis (SPS11) and Lysinibacillus sphaericus (NAS32) using 16s rRNA. These two strains should be further studied in in vivo challenged experiments in fish and shellfish to explore their probiotic effects.

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In vitro and in vivo antimicrobial activity of Ulva lactuca Linn. (Green algae) associated endophytic bacterial Strains

Journal of Applied Pharmaceutical Science ◽

10.7324/japs.2016.601019 ◽

2016 ◽

pp. 138-146 ◽

Cited By ~ 2

Author(s):

Prasanna Habbu ◽

Vijayanand Warad ◽

Rajesh Shastri ◽

Chetan Savant ◽

Smita Madagundi ◽

...

Keyword(s):

Antimicrobial Activity ◽

Green Algae ◽

Ulva Lactuca ◽

Bacterial Strains

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Lactococcosis a Re-Emerging Disease in Aquaculture: Disease Significant and Phytotherapy

Veterinary Sciences ◽

10.3390/vetsci8090181 ◽

2021 ◽

Vol 8 (9) ◽

pp. 181

Author(s):

Mehdi Soltani ◽

Bernardo Baldisserotto ◽

Seyed Pezhman Hosseini Shekarabi ◽

Shafigh Shafiei ◽

Masoumeh Bashiri

Keyword(s):

Antibacterial Activity ◽

Essential Oils ◽

Medicinal Herbs ◽

In Vitro Assays ◽

Bacterial Disease ◽

Bacterial Strains ◽

Immune Parameters ◽

Aquaculture Industry

Lactococcosis, particularly that caused by Lactococcus garvieae, is a major re-emerging bacterial disease seriously affecting the sustainability of aquaculture industry. Medicinal herbs and plants do not have very much in vitro antagonism and in vivo disease resistance towards lactococcosis agents in aquaculture. Most in vitro studies with herbal extractives were performed against L. garvieae with no strong antibacterial activity, but essential oils, especially those that contain thymol or carvacrol, are more effective. The differences exhibited by the bacteriostatic and bactericidal functions for a specific extractive in different studies could be due to different bacterial strains or parts of chemotypes of the same plant. Despite essential oils being shown to have the best anti-L. garvieae activity in in vitro assays, the in vivo bioassays required further study. The extracts tested under in vivo conditions presented moderate efficacy, causing a decrease in mortality in infected animals, probably because they improved immune parameters before challenging tests. This review addressed the efficacy of medicinal herbs to lactococcosis and discussed the presented gaps.

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Antimicrobial Activity of Extracts from the Humiria balsamifera (Aubl)

Plants ◽

10.3390/plants10071479 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1479

Author(s):

Edelson de J. S. Dias ◽

Antônio J. Cantanhede Filho ◽

Fernando J. C. Carneiro ◽

Cláudia Q. da Rocha ◽

Luís Cláudio N. da Silva ◽

...

Keyword(s):

Antimicrobial Activity ◽

Ethyl Acetate ◽

High Performance ◽

Stem Bark ◽

Bacterial Strains ◽

Leaf Extracts ◽

Polarity Index ◽

New Treatments

Humiria balsamifera (Aubl), commonly known as “mirim”, is a plant of the Humiriaceae family, which consists of 39 species divided between eight genera: Duckesia, Endopleura, Humiria, Humiriastrum, Hylocara, Sacoglottis, Schistostemon, and Vantenea. This study aimed to characterize H. balsamifera extracts by LC-MS/MS and evaluate their antimicrobial potential through in vitro and in vivo assays. The leaves and stem bark of H. balsamifera were collected and dried at room temperature and then ground in a knife mill. The extracts were prepared with organic solvents in order to increase the polarity index (hexane, ethyl acetate, and methanol). The antimicrobial effects of these extracts were evaluated against the following bacterial strains: Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 15313, Salmonella enterica Typhimurium ATCC 14028, and Staphylococcus aureus ATCC 6538. The best activity was observed in the ethyl acetate (EALE = 780 µg/mL), methanol (MLE = 780 µg/mL), and hexane (HLE = 1560 µg/mL) leaf extracts against S. aureus. Considering the results for both antimicrobial and antibiofilm activities, the EALE extract was chosen to proceed to the infection assays, which used Tenebrio molitor larvae. The EALE treatment was able to extend the average lifespan of the larvae (6.5 days) in comparison to S. aureus-infected larvae (1 day). Next, the samples were characterized by High-Performance Liquid Chromatography coupled to a mass spectrometer, allowing the identification of 11 substances, including seven flavonoids, substances whose antimicrobial activity is already well-reported in the literature. The number of bioactive compounds found in the chemical composition of H. balsamifera emphasizes its significance in both traditional medicine and scientific research that studies new treatments based on substances from the Brazilian flora.

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Antimicrobial Activity of Essential Oil from Pinus yunnanensis Franch.var tenuifolia Growing in China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.430-432.438 ◽

2012 ◽

Vol 430-432 ◽

pp. 438-442 ◽

Cited By ~ 1

Author(s):

Yu Hong Tian ◽

Zi Li ◽

Shi Hua Wu ◽

Qiong Huang

Keyword(s):

Antimicrobial Activity ◽

Essential Oil ◽

Gas Chromatography Mass Spectrometry ◽

Disc Diffusion ◽

Bacterial Strains ◽

Antibacterial And Antifungal Activities ◽

Pinus Yunnanensis ◽

Agar Dilution ◽

Antibacterial And Antifungal

The in vitro antimicrobial activity of the essential oil from needles of Pinus yunnanensis Franch.var tenuifolia was investigated. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography-mass spectrometry (GC-MS) method. The major compound of the essential oil was α-pinene (22.542%), followed by β-caryophyllene (16.636%), 1,2,4a,5,8,8a-hexahydro-4,7-dimethyl-1-(1-methylethyl)-naphthalene (5.085%), β-cubebene (4.779%), elixene (4.442%), α-cadinol (3.528%),α-caryophyllene (3.459%) and limonene (3.428%). The antimicrobial activity of oil was evaluated by using disc diffusion and agar dilution methods, respectively. The results indicated that the essential oil held moderate antimicrobial activity against tested microorganisms. The essential oil did not differ remarkably in its antibacterial and antifungal activities. The minimum inhibitory concentrations (MICs) were 40 ml/l for bacterial strains, and 80 ml/l for fungal strains.

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Interferences bacteriennes au niveau cutane chez la souris «hairless» dixénique

Canadian Journal of Microbiology ◽

10.1139/m86-136 ◽

1986 ◽

Vol 32 (9) ◽

pp. 751-755 ◽

Cited By ~ 1

Author(s):

M. C. Barc ◽

P. Bourlioux ◽

H. Boureau ◽

F. Nerbone ◽

E. Wasconcellos da Costa

Keyword(s):

Staphylococcus Aureus ◽

Pseudomonas Aeruginosa ◽

Antimicrobial Activity ◽

Digestive Tract ◽

Staphylococcus Epidermidis ◽

Bacteriocin Production ◽

In Vitro Assays ◽

Adherence Inhibition

Bacterial colonizaion of the digestive tract and the skin was studied over a 3-week period in a group of 10 germfree HRS mice using Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa. Sequential utilization of two strains allowed us to carry out six assays and to show the presence of interference phenomena during colonization of the skin. When P. aeruginosa was given after challenge with S. aureus or S. epidermidis, it did not colonize the skin. If the first challenge was done with P. aeruginosa, this bacteria was eliminated within 10 days by S. aureus and S. epidermidis on the skin, but it succeeded in colonizing the digestive tract. When the first challenge was done with S. aureus, colonization of the skin and the digestive tract with S. epidermidis was prevented, whereas these two species were found in association when S. aureus was given in second place. None of the in vitro assays (mixed culture, bacteriocin production, adherence inhibition, antimicrobial activity) could explain the in vivo observations.

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Novel 3-Acetyl-2,5-disubstituted-1,3,4-oxadiazolines: Synthesis and Biological Activity

Molecules ◽

10.3390/molecules25245844 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5844

Author(s):

Kinga Paruch ◽

Łukasz Popiołek ◽

Anna Biernasiuk ◽

Anna Hordyjewska ◽

Anna Malm ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Aromatic Aldehydes ◽

Bactericidal Effect ◽

In Vitro Assays ◽

Bacterial Strains ◽

Stage Synthesis ◽

Low Cytotoxicity ◽

Staphylococcus Spp

The aim of our study was the two-stage synthesis of 1,3,4-oxadiazole derivatives. The first step was the synthesis of hydrazide–hydrazones from 3-methyl-4-nitrobenzhydrazide and the corresponding substituted aromatic aldehydes. Then, the synthesized hydrazide–hydrazones were cyclized with acetic anhydride to obtain new 3-acetyl-2,3-disubstituted-1,3,4-oxadiazolines. All of obtained compounds were tested in in vitro assays to establish their potential antimicrobial activity and cytotoxicity. Our results indicated that few of the newly synthesized compounds had some antimicrobial activity, mainly compounds 20 and 37 towards all used reference bacterial strains (except Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa) and fungi. These substances showed a strong or powerful bactericidal effect, especially against Staphylococcus spp. belonging to Gram-positive bacteria. Compound 37 was active against Staphylococcus epidermidis at minimal inhibitory concentration (MIC) = 0.48 µg/mL and was characterized by low cytotoxicity. This compound possessed quinolin-4-yl substituent in the second position of 1,3,4-oxadiazole ring and 3-methyl-4-nitrophenyl in position 5. High effectiveness and safety of these derivatives make them promising candidates as antimicrobial agents. Whereas the compound 20 with the 5-iodofurane substituent in position 2 of the 1,3,4-oxadiazole ring showed the greatest activity against S. epidermidis at MIC = 1.95 µg/mL.

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In Vivo Growth of Pseudomonas aeruginosa Strains PAO1 and PA14 and the Hypervirulent Strain LESB58 in a Rat Model of Chronic Lung Infection

Journal of Bacteriology ◽

10.1128/jb.01572-07 ◽

2007 ◽

Vol 190 (8) ◽

pp. 2804-2813 ◽

Cited By ~ 61

Author(s):

Irena Kukavica-Ibrulj ◽

Alessandra Bragonzi ◽

Moira Paroni ◽

Craig Winstanley ◽

François Sanschagrin ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Rat Model ◽

Growth Curves ◽

Lung Infection ◽

In Vitro Assays ◽

Bacterial Strains ◽

In Vivo Growth ◽

Chronic Lung Infection

ABSTRACT Pseudomonas aeruginosa chronic lung infections are the major cause of morbidity and mortality in cystic fibrosis (CF) patients. The P. aeruginosa strains PAO1 and PA14 were compared with the Liverpool epidemic strain LESB58 to assess in vivo growth, infection kinetics, and bacterial persistence and localization within tissues in a rat model of chronic lung infection. The three P. aeruginosa strains demonstrated similar growth curves in vivo but differences in tissue distribution. The LESB58 strain persisted in the bronchial lumen, while the PAO1 and PA14 strains were found localized in the alveolar regions and grew as macrocolonies after day 7 postinfection. Bacterial strains were compared for swimming and twitching motility and for the production of biofilm. The P. aeruginosa LESB58 strain produced more biofilm than PAO1 and PA14. Competitive index (CI) analysis of PAO1, PA14, and LESB58 in vivo indicated CI values of 0.002, 0.0002, and 0.14 between PAO1-PA14, PAO1-LESB58, and LESB58-PA14, respectively. CI analysis comparing the in vivo growth of the PAO1 ΔPA5441 mutant and four PA14 surface attachment-defective (sad) mutants gave CI values 10 to 1,000 times lower in competitions with their respective wild-type strains PAO1 and PA14. P. aeruginosa strains studied in the rat model of chronic lung infection demonstrated similar in vivo growth but differences in virulence as shown with a competitive in vivo assay. These differences were further confirmed with biofilm and motility in vitro assays, where strain LESB58 produced more biofilm but had less capacity for motility than PAO1 and PA14.

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Assessment of Antidiarrheal, Antispasmodic and Antimicrobial Activities of Methanolic Seeds Extract of Peganum harmala L. (Nitrariaceae)

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2020/v32i2430812 ◽

2020 ◽

pp. 74-82

Author(s):

Mohd Nazam Ansari

Keyword(s):

Castor Oil ◽

Antimicrobial Activities ◽

Positive Control ◽

In Vitro Assays ◽

Klebsiella Pneumonia ◽

Bacterial Strains ◽

Peganum Harmala ◽

Control Drug

Background: Many plants and herbs have been shown to possess antidiarrheal, antispasmodic, and antimicrobial activities. The present study was developed to determine the possible antidiarrheal and antispasmodic effects of methanolic extract of Peganum harmala L. (MEPH) in diarrhea and hyperactive gut. Methodology: The crude MEPH was studied using the in-vivo castor oil-induced diarrhea model in mice, while isolated rat ileum was used in the in-vitro studies. Antimicrobial efficacy of MEPH was tested against different bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia), Yeast (Candida albicans) and Fungus (Aspergillus niger) using in-vitro assays. Results: In the castor oil-induced diarrhea, MEPH at 100 and 200 mg/kg showed 40% and 80% protection in mice while positive control drug, loperamide showed 100% protection. In the in-vitro experiments, MEPH dose-dependently (0.01 to 0.3 mg/mL) inhibited carbachol and high K+-induced contractions at comparable EC50 values similar to papaverine, a phosphodiesterase (PDE) inhibitor. The PDE inhibitory like effect was further confirmed when pre-incubated ileum tissues with MEPH (0.1 and 0.3 mg/mL) shift the isoprenaline-mediated inhibitory CRCs against carbachol to the left, similar to papaverine. In antibacterial assay, MEPH showed efficacy against two Gram positive bacteria (S. aureus, and B. subtilis) and one Gram negative bacteria (E. coli). But extract didn’t show any effect against K. pneumoniae. The MEPH also showed efficacy against fungal strain (A. niger) and yeast strain (C. albicans). Conclusions: MEPH shows antidiarrheal and antispasmodic effects because of its antimotility effect which were possibly due to the inhibition of PDE enzyme. The study has shown an optimal antimicrobial activity of MEPH as all bacteria, yeast and fungal strains were found sensitive except K. pneumoniae. MEPH proved efficacy against both enteric and non-enteric pathogens causing diarrhea, thus confirming its role in both the infectious and non-infectious diarrhea.

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Cetylpyridinium-chloride (CPC) and Miramistin (MST) compared to established antiseptics under protein challenge in-vitro - evaluating alternative agents for wound cleansing

10.21203/rs.2.9330/v1 ◽

2019 ◽

Author(s):

Julian-Dario Rembe ◽

Vivian-Denise Thompson ◽

Nina Hauer ◽

Ewa Klara Klara Stuermer

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Chronic Wounds ◽

Cetylpyridinium Chloride ◽

High Protein ◽

Test Method ◽

In Vitro Assays ◽

Clinical Value

Abstract Background: Due to rising numbers microbial resistance to established antibiotics and first described tolerance developments for local wound antimicrobials a continuous need for alternative antimicrobial agents exists. Due to complex conditions in the microenvironment of especially chronic wounds, such as high protein levels, novel antimicrobials need to meet advanced requirements. Aim: Compare the antimicrobial efficacy of Cetylpiridinium-chloride (CPC) and miramistin (MST) to established antimicrobials under protein-challenge in-vitro. Methods: Antimicrobial activity of octenidin-dihydrochloride, povidon-iodine, polyhexamethylene-biguanide hydrochloride, chlorhexidine, cetylpiridinium-chloride and Miramistin after 0.5, 1, 3, 5 and 10 min of exposure against S. aureus, P. aeruginosa, E. coli, E. faecium and C. albicans was tested, using a quantitative suspension method with either 0.3% or 3% bovine albumin challenge, based on DIN EN 13727 (‘Chemical disinfectants and antiseptics - Quantitative suspension test for the evaluation of bactericidal activity in the medical area - Test method and requirements (phase 2, step 1)’). Results: CPC and MST demonstrated no inferiority to the established agents in-vitro. Especially CPC showed equal reduction rates as octenidin and povidon-iodine and achieved significantly higher reduction rates within shorter exposure times than polyhexanide and chlorhexidine (p ≤ 0.01) for S. aureus, P. aeruginosa, E. faecium and C. albicans. Both agents demonstrated no significant loss of efficacy under high protein-challenge (3% albumin). Conclusion: In terms of antimicrobial activity cetylpyridinium-chloride and miramistin proved to be at least equally effective as established agents. No protein error was detected in the tested concentrations. More complex in-vitro assays and comprehensive in-vivo and clinical studies will be needed to determine their clinical value.

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