Probiotic Potential Analysis and Safety Evaluation of Enterococcus durans A8-1 Isolated From a Healthy Chinese Infant

To evaluate the probiotic characteristics and safety of Enterococcus durans isolate A8-1 from a fecal sample of a healthy Chinese infant, we determined the tolerance to low pH, survival in bile salts and NaCl, adhesion ability, biofilm formation, antimicrobial activity, toxin gene distribution, hemolysis, gelatinase activity, antibiotic resistance, and virulence to Galleria mellonella and interpreted the characters by genome resequencing. Phenotypically, E. durans A8-1 survived at pH 5.0 in 7.0% NaCl and 3% bile salt under aerobic and anaerobic condition. The bacterium had higher adhesion ability toward mucin, collagen, and Bovine Serum Albumin (BSA) in vitro and showed high hydrophobicity (79.2% in chloroform, 49.2% in xylene), auto-aggregation activity (51.7%), and could co-aggregate (66.2%) with Salmonella typhimurium. It had adhesion capability to intestinal epithelial Caco-2 cells (38.74%) with moderate biofilm production and antimicrobial activity against several Gram-positive pathogenic bacteria. A8-1 can antagonize the adhesion of S. typhimurium ATCC14028 on Caco-2 cells to protect the integrity of the cell membrane by detection of lactate dehydrogenase (LDH) and AKP activities. A8-1 also helps the cell relieve the inflammation induced by lipopolysaccharide by reducing the expression of cytokine IL-8 (P = 0.002) and TNF-α (P > 0.05), and increasing the IL-10 (P < 0.001). For the safety evaluation, A8-1 showed no hemolytic activity, no gelatinase activity, and had only asa1 positive in the seven detected virulence genes in polymerase chain reaction (PCR), whereas it was not predicted in the genome sequence. It was susceptible to benzylpenicillin, ampicillin, ciprofloxacin, levofloxacin, moxifloxacin, tigecycline, nitrofurantoin, linezolid, vancomycin, erythromycin, and quinupristin/dalofopine except clindamycin, which was verified by the predicted lasA, lmrB, lmrC, and lmrD genes contributing to the clindamycin resistance. The virulence test of G. mellonella showed that it had toxicity lower than 10% at 1 × 107 CFU. According to the results of these evaluated attributes, E. durans strain A8-1 could be a promising probiotic candidate for applications.

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Assessment of Safety and Probiotic Traits of Enterococcus durans OSY-EGY, Isolated From Egyptian Artisanal Cheese, Using Comparative Genomics and Phenotypic Analyses

Frontiers in Microbiology ◽

10.3389/fmicb.2020.608314 ◽

2020 ◽

Vol 11 ◽

Author(s):

Walaa E. Hussein ◽

Ahmed G. Abdelhamid ◽

Diana Rocha-Mendoza ◽

Israel García-Cano ◽

Ahmed E. Yousef

Keyword(s):

Antimicrobial Activity ◽

Bile Salts ◽

Pathogenic Bacteria ◽

Genomic Analysis ◽

Essential Amino Acids ◽

Industrial Applications ◽

Comparative Genomic ◽

Gelatinase Activity ◽

Enterococcus Durans ◽

Dpph Scavenging

An Enterococcus durans strain, designated OSY-EGY, was previously isolated from artisanal cheese. In this work, comparative genomic and phenotypic analyses were utilized to assess the safety characteristics and probiotic traits of the bacterium. The comparative genomic analysis revealed that the strain is distantly related to potentially pathogenic Enterococcus spp. The genome was devoid of genes encoding acquired antibiotic resistance or marker virulence factors associated with Enterococcus spp. Phenotypically, the bacterium is susceptible to vancomycin, ampicillin, tetracycline, chloramphenicol, and aminoglycosides and does not have any hemolytic or gelatinase activity, or cytotoxic effect on Caco-2 cells. Altogether, these findings confirm the lack of hazardous traits in E. durans OSY-EGY. Mining E. durans OSY-EGY genome, for probiotic-related sequences, revealed genes associated with acid and bile salts tolerance, adhesion, competitiveness, antioxidant activitiy, antimicrobial activity, essential amino acids production, and vitamins biosynthesis. Phenotypically, E. durans OSY-EGY was tolerant to acidic pH (3.0), and presence of 0.3% bile salts. The bacterium showed adhesion capability to Caco-2 cells, cholesterol-lowering effect, DPPH scavenging activity, and antimicrobial activity against several Gram-positive pathogenic bacteria. Based on the current work, we propose that E. durans OSY-EGY is a potentially safe strain with desirable probiotic and antimicrobial traits. Thus, the investigated strain could be a promising candidate for several industrial applications.

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In vitro and in vivo efficacy of the combination of colistin and endolysins against clinical strains of Multi-Drug Resistant (MDR) pathogens

10.1101/662460 ◽

2019 ◽

Author(s):

L. Blasco ◽

A. Ambroa ◽

R. Trastoy ◽

E. Perez-Nadales ◽

F. Fernández-Cuenca ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Activity ◽

Klebsiella Pneumoniae ◽

Acinetobacter Baumannii ◽

Bactericidal Activity ◽

Pathogenic Bacteria ◽

Galleria Mellonella ◽

Clinical Strain

ABSTRACTThe multidrug resistance (MDR) among pathogenic bacteria is jeopardizing the worth of antimicrobials, which had previously changed medical sciences. In this study, we used bioinformatic tools to identify the endolysins ElyA1 and ElyA2 (GH108-PG3 family) present in the genome of bacteriophages Ab1051Φ and Ab1052Φ, respectively. The muralytic activity of these endolysins over MDR clinical isolates (Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae) was tested using the turbidity reduction assay. The minimal inhibitory concentrations (MICs) of endolysin, colistin and their combination were determined using the microdilution checkerboard method. The antimicrobial activity of the combinations was confirmed by time kill curves and in vivo assays in larvae of Galleria mellonella. Our results showed that ElyA1 displayed activity against all 25 strains of A. baumannii and P. aeruginosa tested and against 13 out of 17 strains of K. pneumoniae. No activity was detected when assays were done with endolysin ElyA2. The combined antimicrobial activity of colistin and endolysin ElyA1 yielded a reduction in the colistin MIC for all strains studied, except K. pneumoniae. These results were confirmed in vivo in G. mellonella survival assays. In conclusion, the combination of colistin with new endolysins such as ElyA1 could increase the bactericidal activity and reduce the MIC of the antibiotic, thus also reducing the associated toxicity.IMPORTANCEThe development of multiresistance by pathogen bacteria increases the necessity of the development of new antimicrobial strategies. In this work, we combined the effect of the colistin with a new endolysin, ElyA1, from a bacteriophage present in the clinical strain of Acinetobacter baumannii Ab105. ElyA1 is a lysozyme-like family (GH108-GP3), whose antimicrobial activity was described for first time in this work. Also, another endolysin, ElyA2, with the same origin and family, was characterized but in this case no activity was detected. ElyA1 presented lytic activity over a broad spectrum of strains from A. baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. When colistin was combined with ElyA1 an increase of the antimicrobial activity was observed with a reduced concentration of colistin, and this observation was also confirmed in vivo in Galleria mellonella larvae. The combination of colistin with new endolysins as ElyA1 could increase the bactericidal activity and lowering the MIC of the antibiotic, thus also reducing the associated toxicity.

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Phytochemical composition and in vitro screening of the antimicrobial activity of essential oils on oral pathogenic bacteria

Natural Product Research ◽

10.1080/14786419.2017.1329730 ◽

2017 ◽

Vol 32 (5) ◽

pp. 544-551 ◽

Cited By ~ 27

Author(s):

Roberta Tardugno ◽

Federica Pellati ◽

Ramona Iseppi ◽

Moreno Bondi ◽

Giacomo Bruzzesi ◽

...

Keyword(s):

Antimicrobial Activity ◽

Essential Oils ◽

Pathogenic Bacteria ◽

In Vitro Screening ◽

Phytochemical Composition

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Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

NeuroQuantology ◽

10.14704/nq.2021.19.9.nq21135 ◽

2021 ◽

Vol 19 (9) ◽

pp. 38-45

Author(s):

Hussein H. Al-Turnachy ◽

Fadhilk. alibraheemi ◽

Ahmed Abd Alreda Madhloom ◽

Zahraa Yosif Motaweq ◽

Nibras Yahya Abdulla

Keyword(s):

Antimicrobial Activity ◽

Silver Nanoparticles ◽

Biological Activity ◽

Pathogenic Bacteria ◽

Punica Granatum ◽

Gram Positive ◽

Gram Negative ◽

Inhibition Zones ◽

Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

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Apis andreniformis associated Actinomycetes show antimicrobial activity against black rot pathogen (Xanthomonas campestris pv. campestris)

PeerJ ◽

10.7717/peerj.12097 ◽

2021 ◽

Vol 9 ◽

pp. e12097

Author(s):

Yaowanoot Promnuan ◽

Saran Promsai ◽

Wasu Pathom-aree ◽

Sujinan Meelai

Keyword(s):

Antimicrobial Activity ◽

16S Rrna ◽

16S Rrna Gene ◽

Honey Bee ◽

Pseudomonas Syringae ◽

Xanthomonas Campestris ◽

Pathogenic Bacteria ◽

Rrna Gene ◽

Apis Andreniformis

This study aimed to investigate cultivable actinomycetes associated with rare honey bee species in Thailand and their antagonistic activity against plant pathogenic bacteria. Actinomycetes were selectively isolated from the black dwarf honey bee (Apis andreniformis). A total of 64 actinomycete isolates were obtained with Streptomyces as the predominant genus (84.4%) followed by Micromonospora (7.8%), Nonomuraea (4.7%) and Actinomadura (3.1%). All isolates were screened for antimicrobial activity against Xanthomonas campestris pv. campestris, Pectobacterium carotovorum and Pseudomonas syringae pv. sesame. Three isolates inhibited the growth of X. campestris pv. campestris during in vitro screening. The crude extracts of two isolates (ASC3-2 and ASC5-7P) had a minimum inhibitory concentration (MIC) of 128 mg L−1against X. campestris pv. campestris. For isolate ACZ2-27, its crude extract showed stronger inhibitory effect with a lower MIC value of 64 mg L−1 against X. campestris pv. campestris. These three active isolates were identified as members of the genus Streptomyces based on their 16S rRNA gene sequences. Phylogenetic analysis based on the maximum likelihood algorithm showed that isolate ACZ2-27, ASC3-2 and ASC5-7P were closely related to Streptomyces misionensis NBRC 13063T (99.71%), Streptomyces cacaoi subsp. cacaoi NBRC 12748T (100%) and Streptomyces puniceus NBRC 12811T (100%), respectively. In addition, representative isolates from non-Streptomyces groups were identified by 16S rRNA gene sequence analysis. High similarities were found with members of the genera Actinomadura, Micromonospora and Nonomuraea. Our study provides evidence of actinomycetes associated with the black dwarf honey bee including members of rare genera. Antimicrobial potential of these insect associated Streptomyces was also demonstrated especially the antibacterial activity against phytopathogenic bacteria.

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Chemical characterization and in vitro antimicrobial activity of honeybee propolis and Scaptotrigona jujuyensis geopropolis against tomato pathogenic bacteria

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n5p1799 ◽

2020 ◽

Vol 42 (5) ◽

pp. 1799-1808

Author(s):

Irene Laura Cibanal ◽

◽

Leticia Andrea Fernández ◽

Giovanni Galietta Positano ◽

Lucía Bóffano Chebataroff ◽

...

Keyword(s):

Antimicrobial Activity ◽

Pathogenic Bacteria ◽

Chemical Characterization ◽

In Vitro Antimicrobial Activity

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Genome-Wide Sensitivity Analysis of the MicrosymbiontSinorhizobium melilotito Symbiotically Important, Defensin-Like Host Peptides

mBio ◽

10.1128/mbio.01060-17 ◽

2017 ◽

Vol 8 (4) ◽

Cited By ~ 19

Author(s):

Markus F. F. Arnold ◽

Mohammed Shabab ◽

Jon Penterman ◽

Kevin L. Boehme ◽

Joel S. Griffitts ◽

...

Keyword(s):

Antimicrobial Activity ◽

Associated Factors ◽

Pathogenic Bacteria ◽

High Throughput Sequencing ◽

Bacterial Resistance ◽

Outer Membrane Proteins ◽

Effector Proteins ◽

Symbiotic Interaction ◽

Model Legume

ABSTRACTThe model legume speciesMedicago truncatulaexpresses more than 700 nodule-specific cysteine-rich (NCR) signaling peptides that mediate the differentiation ofSinorhizobium melilotibacteria into nitrogen-fixing bacteroids. NCR peptides are essential for a successful symbiosis in legume plants of the inverted-repeat-lacking clade (IRLC) and show similarity to mammalian defensins. In addition to signaling functions, many NCR peptides exhibit antimicrobial activityin vitroandin vivo. Bacterial resistance to these antimicrobial activities is likely to be important for symbiosis. However, the mechanisms used byS. melilotito resist antimicrobial activity of plant peptides are poorly understood. To address this, we applied a global genetic approach using transposon mutagenesis followed by high-throughput sequencing (Tn-seq) to identifyS. melilotigenes and pathways that increase or decrease bacterial competitiveness during exposure to the well-studied cationic NCR247 peptide and also to the unrelated model antimicrobial peptide polymyxin B. We identified 78 genes and several diverse pathways whose interruption altersS. melilotiresistance to NCR247. These genes encode the following: (i) cell envelope polysaccharide biosynthesis and modification proteins, (ii) inner and outer membrane proteins, (iii) peptidoglycan (PG) effector proteins, and (iv) non-membrane-associated factors such as transcriptional regulators and ribosome-associated factors. We describe a previously uncharacterized yet highly conserved peptidase, which protectsS. melilotifrom NCR247 and increases competitiveness during symbiosis. Additionally, we highlight a considerable number of uncharacterized genes that provide the basis for future studies to investigate the molecular basis of symbiotic development as well as chronic pathogenic interactions.IMPORTANCESoil rhizobial bacteria enter into an ecologically and economically important symbiotic interaction with legumes, in which they differentiate into physiologically distinct bacteroids that provide essential ammonia to the plant in return for carbon sources. Plant signal peptides are essential and specific to achieve these physiological changes. These peptides show similarity to mammalian defensin peptides which are part of the first line of defense to control invading bacterial populations. A number of these legume peptides are indeed known to possess antimicrobial activity, and so far, only the bacterial BacA protein is known to protect rhizobial bacteria against their antimicrobial action. This study identified numerous additional bacterial factors that mediate protection and belong to diverse biological pathways. Our results significantly contribute to our understanding of the molecular roles of bacterial factors during legume symbioses and, second, provide insights into the mechanisms that pathogenic bacteria may use to resist the antimicrobial effects of defensins during infections.

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The synthetic synergistic cinnamon oil CIN-102 is active against Madurella mycetomatis, the most common causative agent of mycetoma

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009488 ◽

2021 ◽

Vol 15 (6) ◽

pp. e0009488

Author(s):

Mickey Konings ◽

Kimberly Eadie ◽

Wilson Lim ◽

Ahmed H. Fahal ◽

Johan Mouton ◽

...

Keyword(s):

Pathogenic Bacteria ◽

Galleria Mellonella ◽

Subcutaneous Tissue ◽

Larval Survival ◽

Success Rates ◽

Cinnamon Oil ◽

Novel Treatments ◽

Madurella Mycetomatis

Mycetoma is a devastating neglected tropical infection of the subcutaneous tissue and most commonly caused by the fungus Madurella mycetomatis. Treatment of mycetoma consists of a combination of a long term antifungal treatment with itraconazole and surgery. However, treatment is associated with low success rates. Therefore, there is a need to identify novel treatments for mycetoma. CIN-102 is a synthetic partial copy of cinnamon oils with activity against many pathogenic bacteria and fungi. In this study we determined the in vitro activity of CIN-102 against 21 M. mycetomatis isolates and its in vivo efficacy in a M. mycetomatis infected Galleria mellonella larval model. In vitro, CIN-102 was active against M. mycetomatis with MICs ranging from 32 μg/mL to 512 μg/mL. 128 μg/mL was needed to inhibit the growth in 50% of tested isolated. In vivo, concentrations below the MIC of 40 mg/kg and 80 mg/kg CIN-102 prolonged larval survival, but higher concentrations of CIN-102 did not.

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In-vitro Antioxidant Activity and Antimicrobial Activity of Hydroalcoholic Extracts of Vernonia cinerea

Journal of Drug Delivery and Therapeutics ◽

10.22270/jddt.v9i1.2226 ◽

2019 ◽

Vol 9 (1) ◽

pp. 225-228

Author(s):

Jaswinder Mehta ◽

Peenu Mahendra Joshi ◽

Priyanka Kushwaha ◽

Geeta Parkhe

Keyword(s):

Antimicrobial Activity ◽

Antioxidant Activity ◽

Free Radicals ◽

Pathogenic Bacteria ◽

Radical Scavenging ◽

Diffusion Method ◽

Dependent Manner ◽

Hydroalcoholic Extract ◽

Vernonia Cinerea

The aim of present study was to estimate the in vitro antioxidant potential and antimicrobial activity of hydroalcoholic extract of Vernonia cinerea. Antioxidant activity was assessed by using 2, 2- diphenyl-1-picryl-hydrazyl (DPPH) assay using ascorbic acid as standard antioxidant. The extract was found to scavenge effectively the free radicals. The total flavonoid contents were determined by established methods and were found to be 0.547 mg/100mg in quercitin equivalents. Antimicrobial activity was performed against 2 stains of human pathogenic bacteria by well diffusion method. Hydroalcoholic extract of Vernonia cinerea showed good antimicrobial activity against gram positive bacteria. The antioxidant activities may be attributed to the presence of significant amounts of flavonoid compounds. Results indicated that hydroalcoholic extract of Vernonia cinerea possess significant antioxidant effect in dose dependent manner, followed by the hydroalcoholic extract of Vernonia cinerea possessed good antimicrobial activity. Keywords: Antioxidant activity, Radical scavenging activity, Free radicals, Antimicrobial activity.

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