Evaluation of Antimicrobial-Antibiofilm Activity of a Hydrogen Peroxide Decontaminating System Used in Dental Unit Water Lines

A dental unit water line (DUWL) equipped with a device designed to automatically and continually flush a bacteriostatic solution of hydrogen peroxide (WHE) and a discontinuous disinfecting system (BIOSTER) was evaluated. In the first instance a preliminary sensitivity test on a large number of microorganisms (bacteria and fungi) was tried with a H2O2 range from 100 to 800 ppm. The bacteria frequently reported in DUWL (including Pseudomonas spp, Streptococcus spp., Staphylococcus spp., E. coli) and some periodontal pathogens showed a minimum inhibitory concentration from 100 to 300 H2O2 ppm (also including M. marinum and C. albicans). However, H2O2 did not show any inhibitory effects against: A. actinomycetemcomitans, C. glabrata C. parapsilos, F. nucleatum, M. micros. In a second step, the DUWL was experimentally infected with S. faecalis, E. coli, P. aeruginosa, S. aureus. After disinfection steps with 3% H2O2, the inhibitory effect on planktonic forms and on sessile biofilm was measured. In a third step, the count of 16S rRNA gene copies by real time PCR at different points of the DUWL described an accrue of bacterial slime in “hot spot” regions characterized by irregular/slow water flux (valves, elbows). However these results suggest that hydrogen peroxide is not only able to inhibit bursts of planktonic bacteria inside the DUWL, but that it could also be effective against sessile biofilm containing heterotrophic microorganisms derived from domestic water line contamination. In addition some oral pathogens could be contaminating and surviving in DUWL.

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The Anti-biofilm Activity of Nanometric Zinc doped Bioactive Glass against Putative Periodontal Pathogens: An in vitro Study

Biomedical glasses ◽

10.1515/bglass-2018-0009 ◽

2018 ◽

Vol 4 (1) ◽

pp. 95-107

Author(s):

Nasrin Esfahanizadeh ◽

Mohammad Reza Nourani ◽

Abbas Bahador ◽

Nasrin Akhondi ◽

Mostafa Montazeri

Keyword(s):

Biofilm Formation ◽

Sol Gel ◽

Antimicrobial Properties ◽

In Vitro Study ◽

Inhibitory Effect ◽

Antibiofilm Activity ◽

Periodontal Pathogens ◽

Microplate Reader ◽

45S5 Bioglass

Abstract Colonization of periodontal pathogens on the surgical sites is one of the primary reasons for the failure of regenerative periodontal therapies. Bioactive glasses (BGs) owing to their favorable structural and antimicrobial properties have been proposed as promising materials for the reconstruction of periodontal and peri-implant bone defects. This study aimed to investigate the antibiofilm activity of zinc-doped BG (Zn/BG) compared with 45S5 Bioglass® (BG®) on putative periodontal pathogens. In this in vitro experimental study, the nano BG doped with 5-mol% zinc and BG® were synthesized by sol-gel method. Mono-species biofilms of Aggregatibacter actinomycetemcomitans (A. a), Porphyromonas gingivalis (P. g), and Prevotella intermedia (P. i)were prepared separately in a well-containing microplate. After 48 hours of exposure to generated materials at 37°C, the anti-biofilm potential of the samples was studied by measuring the optical density (OD) at 570nm wavelengths with a microplate reader. Two-way ANOVA then analyzed the results. Both Zn/BG and BG® significantly reduced the biofilm formation ability of all examined strains after 48 hours of incubation (P=0.0001). Moreover, the anti-biofilm activity of Zn/BG was significantly stronger than BG® (P=0.0001), which resulted in the formation of a weak biofilm (OD<1) compared with a moderately adhered biofilm observed with BG® (1<OD<2). Zn/BG showed a significant inhibitory effect on the biofilm formation of all examined periodontal pathogens. Given the enhanced regenerative and anti-biofilm properties of this novel biomaterial, further investigations are required for its implementation in clinical situations.

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Isolation, screening and identification of microorganisms having antimicrobial activity isolated from samples collected on seabed of Northeast Vietnam

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/14/3/9871 ◽

2016 ◽

Vol 14 (3) ◽

pp. 539-547

Author(s):

Lê Thị Hồng Minh ◽

Vũ Thị Quyên ◽

Nguyễn Mai Anh ◽

Đoàn Thị Mai Hương ◽

Brian T Murphy ◽

...

Keyword(s):

Secondary Compounds ◽

Inhibitory Effect ◽

Rrna Gene ◽

Bioactive Substances ◽

E Coli ◽

Gram Positive Bacteria ◽

Chemical Structures ◽

Screening And Identification ◽

Fermentation Broths ◽

Reference Strains

Microorganisms are especially interested in due to the ability to produce secondary compounds with high-value applications. Plenty of novel and diverse chemical structures have been found in the bioactive substances of microorganisms. In this study, we isolated 143 strains of bacteria and actinomycetes from 161 samples including: sediments, sponges, soft corals, echinoderms and starfish collected from three sea areas of Viet Nam: Ha Long - Cat Ba; Co To - ThanhLan; Bai Tu Long. The strains were fermented in A1 medium and then fermentation broths were extracted 5 times with ethyl acetate. The extraction residue screening test using 7 reference strains isolated 15 target strains with the highest biological activity. Most of these strains have dramatic inhibition on Gram positive bacteria: Enterococcus faecalis ATCC29212; Bacillus cereus ATCC13245 and Candida albicans ATCC10231 with MIC values less than or equal to the MIC value of the reference antibiotic. In particular, strain G057 was active against S. enterica ATCC 13076 and G002 inhibited E. coli ATCC25922 with respective values MICG057 = 8 µg/ ml, MICG002 = 256µg/ ml; and three strains G115, G119, G120 showed the inhibitory effect towards P. aeruginosa ATCC27853 with respective values MICG115 = 64 µg/ ml, MICG119 = 32 µg/ ml and MICG120 = 32 µg/ ml. All 15 strains were then subjected to morphological and phylogenetic investigations based on 16S rRNA gene sequences. The results showed that 9 of 15 strains G016, G017, G019, G043, G044, G047, G068, G119 and G120 belonged to Genus Micromonospora; strains G039 and G065 were identified as Genus Stretomyces; G002 was identified as Bacillus; G057 was identified as Nocardiopsis; G115 was in Photobacterium and G121 belonged Oceanisphaera.

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Antagonistic Action of Lactobacillus acidophilus Toward Intestinal and Foodborne Pathogens in Associative Cultures1

Journal of Food Protection ◽

10.4315/0362-028x-40.12.820 ◽

1977 ◽

Vol 40 (12) ◽

pp. 820-823 ◽

Cited By ~ 171

Author(s):

S. E. GILLILAND ◽

M. L. SPECK

Keyword(s):

Escherichia Coli ◽

Hydrogen Peroxide ◽

Staphylococcus Aureus ◽

Foodborne Pathogens ◽

Lactobacillus Acidophilus ◽

Inhibitory Effect ◽

Enteropathogenic Escherichia Coli ◽

Anaerobic Conditions ◽

Antagonistic Action ◽

E Coli

Lactobacillus acidophilus exerted antagonistic actions on growth of Staphylococcus aureus, Salmonella typhimurium, enteropathogenic Escherichia coli, and Clostridium perfringens when grown with each in associative cultures. S. aureus and C. perfringens were more sensitive to the inhibition than were S. typhimurium and E. coli. The amount of the antagonism produced varied among strains of L. acidophilus and could not be directly related to amounts of acid produced; hydrogen peroxide produced by the lactobacilli appeared to be partially responsible for the antagonistic interaction. The inhibitory effect was produced also under anaerobic conditions in a pre-reduced medium.

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Fate of CMY-2-Encoding Plasmids Introduced into the Human Fecal Microbiota by Exogenous Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02528-18 ◽

2019 ◽

Vol 63 (5) ◽

Cited By ~ 6

Author(s):

Mehreen Anjum ◽

Jonas Stenløkke Madsen ◽

Joseph Nesme ◽

Bimal Jana ◽

Maria Wiese ◽

...

Keyword(s):

Escherichia Coli ◽

Fluorescent Protein ◽

Hot Spot ◽

Fecal Microbiota ◽

Plasmid Transfer ◽

Poultry Meat ◽

Animal Origin ◽

Rrna Gene ◽

Content Type ◽

E Coli

ABSTRACT The gut is a hot spot for transfer of antibiotic resistance genes from ingested exogenous bacteria to the indigenous microbiota. The objective of this study was to determine the fate of two nearly identical blaCMY-2-harboring plasmids introduced into the human fecal microbiota by two Escherichia coli strains isolated from a human and from poultry meat. The chromosome and the CMY-2-encoding plasmid of both strains were labeled with distinct fluorescent markers (mCherry and green fluorescent protein [GFP]), allowing fluorescence-activated cell sorting (FACS)-based tracking of the strain and the resident bacteria that have acquired its plasmid. Each strain was introduced into an established in vitro gut model (CoMiniGut) inoculated with individual feces from ten healthy volunteers. Fecal samples collected 2, 6, and 24 h after strain inoculation were analyzed by FACS and plate counts. Although the human strain survived better than the poultry meat strain, both strains transferred their plasmids to the fecal microbiota at concentrations as low as 102 CFU/ml. Strain survival and plasmid transfer varied significantly depending on inoculum concentration and individual fecal microbiota. Identification of transconjugants by 16S rRNA gene sequencing and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) revealed that the plasmids were predominantly acquired by Enterobacteriaceae species, such as E. coli and Hafnia alvei. Our experimental data demonstrate that exogenous E. coli of human or animal origin can readily transfer CMY-2-encoding IncI1 plasmids to the human fecal microbiota. Small amounts of the exogenous strain are sufficient to ensure plasmid transfer if the strain is able to survive the gastric environment.

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Evolution of Pig Fecal Microbiota Composition and Diversity in Response to Enterotoxigenic Escherichia coli Infection and Colistin Treatment in Weaned Piglets

Microorganisms ◽

10.3390/microorganisms9071459 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1459

Author(s):

Mohamed Rhouma ◽

Charlotte Braley ◽

William Thériault ◽

Alexandre Thibodeau ◽

Sylvain Quessy ◽

...

Keyword(s):

Oral Treatment ◽

Fecal Microbiota ◽

Enterotoxigenic Escherichia Coli ◽

Rrna Gene ◽

Weaned Piglets ◽

E Coli ◽

Escherichia Coli Infection ◽

Pig Health ◽

Microbiota Diversity ◽

Sampling Times

The intestinal microbiota plays several important roles in pig health and growth. The aim of the current study was to characterize the changes in the fecal microbiota diversity and composition of weaned piglets following an oral challenge with an ETEC: F4 strain and/or a treatment with colistin sulfate (CS). Twenty-eight piglets were used in this experiment and were divided into four groups: challenged untreated, challenged treated, unchallenged treated, and unchallenged untreated. Rectal swab samples were collected at five sampling times throughout the study. Total genomic DNA was used to assess the fecal microbiota diversity and composition using the V4 region of the 16S rRNA gene. The relative abundance, the composition, and the community structure of piglet fecal microbiota was highly affected by the ETEC: F4 challenge throughout the experiment, while the oral treatment with CS, a narrow spectrum antibiotic, resulted in a significant decrease of E. coli/Shigella populations during the treatment period only. This study was the first to identify some gut microbiota subgroups (e.g., Streptococcus, Lachnospiraceae) that are associated with healthy piglets as compared to ETEC: F4 challenged animals. These key findings might contribute to the development of alternative strategies to reduce the use of antimicrobials in the control of post-weaning diarrhea in pigs.

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A novel bis(pyrazolyl)methane compound as a potential agent against Gram-positive bacteria

Scientific Reports ◽

10.1038/s41598-021-95609-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Pedro Seguí ◽

John J. Aguilera-Correa ◽

Elena Domínguez-Jurado ◽

Christian M. Sánchez-López ◽

Ramón Pérez-Tanoira ◽

...

Keyword(s):

Antibacterial Activity ◽

Inhibitory Effect ◽

Eukaryotic Cell ◽

Liver Carcinoma ◽

Gram Positive ◽

Minimal Inhibitory Concentrations ◽

E Coli ◽

Gram Positive Bacteria ◽

Therapeutic Compounds ◽

Toxic Concentrations

AbstractThis study was designed to propose alternative therapeutic compounds to fight against bacterial pathogens. Thus, a library of nitrogen-based compounds bis(triazolyl)methane (1T–7T) and bis(pyrazolyl)methane (1P–11P) was synthesised following previously reported methodologies and their antibacterial activity was tested using the collection strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Moreover, the novel compound 2P was fully characterized by IR, UV–Vis and NMR spectroscopy. To evaluate antibacterial activity, minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), minimum biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) assays were carried out at different concentrations (2–2000 µg/mL). The MTT assay and Resazurin viability assays were performed in both human liver carcinoma HepG2 and human colorectal adenocarcinoma Caco-2 cell lines at 48 h. Of all the synthesised compounds, 2P had an inhibitory effect on Gram-positive strains, especially against S. aureus. The MIC and MBC of 2P were 62.5 and 2000 µg/mL against S. aureus, and 250 and 2000 µg/mL against E. faecalis, respectively. However, these values were > 2000 µg/mL against E. coli and P. aeruginosa. In addition, the MBICs and MBECs of 2P against S. aureus were 125 and > 2000 µg/mL, respectively, whereas these values were > 2000 µg/mL against E. faecalis, E. coli, and P. aeruginosa. On the other hand, concentrations up to 250 µg/mL of 2P were non-toxic doses for eukaryotic cell cultures. Thus, according to the obtained results, the 2P nitrogen-based compound showed a promising anti-Gram-positive effect (especially against S. aureus) both on planktonic state and biofilm, at non-toxic concentrations.

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Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Molecules ◽

10.3390/molecules26061773 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1773

Author(s):

Patchima Sithisarn ◽

Piyanuch Rojsanga ◽

Pongtip Sithisarn

Keyword(s):

Antibacterial Activities ◽

Inhibitory Effect ◽

Total Flavonoid ◽

Total Phenolic ◽

Antibacterial Effects ◽

E Coli ◽

Young Fruit ◽

Oroxylum Indicum ◽

Zoonotic Bacteria

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

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Developing Lactic Acid Bacteria as an Oral Healthy Food

Life ◽

10.3390/life11040268 ◽

2021 ◽

Vol 11 (4) ◽

pp. 268

Author(s):

Wei-Kuang Lai ◽

Ying-Chen Lu ◽

Chun-Ren Hsieh ◽

Chien-Kei Wei ◽

Yi-Hong Tsai ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Inhibitory Effect ◽

Periodontal Pathogen ◽

Periodontal Pathogens ◽

Health Food ◽

Pocket Depth ◽

Oral Tablet ◽

Strong Inhibitory Effect ◽

Oral Pathogens

Lactic acid bacteria have functions in immunoregulation, antagonism, and pathogen inhibition. The purpose of this study was to evaluate the effectiveness of lactic acid bacteria (LAB) in countering oral pathogens and develop related products. After a series of assays to 450 LAB strains, 8 heat-inactivated strains showed a strong inhibitory effect on a caries pathogen, Streptococcus mutans, and 308 heat-inactivated LAB strains showed a strong inhibitory effect on a periodontal pathogen, Porphyromonas gingivalis. The key reasons for inhibiting oral pathogens were bacteriocins produced by LAB and the coaggregation effect of the inactivated cells. We selected Lacticaseibacillus (Lb) paracasei 111 and Lb.paracasei 141, which had the strongest inhibitory effects on the above pathogens, was the main oral health food source. The optimal cultural conditions of Lb. paracasei 111 and Lb. paracasei 141 were studied. An oral tablet with a shelf life of 446 days made of the above strains was developed. A 40 volunteers’ clinical study (CSMUH IRB number: CS05065) was conducted with this tablet in the Periodontological Department of the Stomatology Research Center, Affiliated Hospital of Chung Shan Medical University (Taiwan). After 8 weeks of testing, 95% and 78.9% of patients showed an effect on reducing periodontal pathogens and improving probing pocket depth, respectively, in the oral tablet group.

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Inocybe brijunica sp. nov., a New Ectomycorrhizal Fungus from Mediterranean Croatia Revealed by Morphology and Multilocus Phylogenetic Analysis

Journal of Fungi ◽

10.3390/jof7030199 ◽

2021 ◽

Vol 7 (3) ◽

pp. 199

Author(s):

Armin Mešić ◽

Danny Haelewaters ◽

Zdenko Tkalčec ◽

Jingyu Liu ◽

Ivana Kušan ◽

...

Keyword(s):

Rna Polymerase Ii ◽

National Park ◽

Hot Spot ◽

Phylogenetic Reconstruction ◽

Ectomycorrhizal Fungus ◽

Alkaline Solutions ◽

Rrna Gene ◽

28S Rrna ◽

Internal Transcribed Spacer Region ◽

Biogeographical Region

A new ectomycorrhizal species was discovered during the first survey of fungal diversity at Brijuni National Park (Croatia), which consists of 14 islands and islets. The National Park is located in the Mediterranean Biogeographical Region, a prominent climate change hot-spot. Inocybe brijunica sp. nov., from sect. Hysterices (Agaricales, Inocybaceae), is described based on morphology and multilocus phylogenetic data. The holotype collection was found at the edge between grassland and Quercus ilex forest with a few planted Pinus pinea trees, on Veli Brijun Island, the largest island of the archipelago. It is easily recognized by a conspicuous orange to orange–red–brown membranaceous surface layer located at or just above the basal part of the stipe. Other distinctive features of I. brijunica are the medium brown, radially fibrillose to rimose pileus; pale to medium brown stipe with fugacious cortina; relatively small, amygdaliform to phaseoliform, and smooth basidiospores, measuring ca. 6.5–9 × 4–5.5 µm; thick-walled, utriform, lageniform or fusiform pleurocystidia (lamprocystidia) with crystals and mostly not yellowing in alkaline solutions; cheilocystidia of two types (lamprocystidia and leptocystidia); and the presence of abundant caulocystidia only in the upper 2–3 mm of the stipe. Phylogenetic reconstruction of a concatenated dataset of the internal transcribed spacer region (ITS), the nuclear 28S rRNA gene (nrLSU), and the second largest subunit of RNA polymerase II (rpb2) resolved I. brijunica and I. glabripes as sister species.

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The Phytochemical Analysis of Vinca L. Species Leaf Extracts Is Correlated with the Antioxidant, Antibacterial, and Antitumor Effects

Molecules ◽

10.3390/molecules26103040 ◽

2021 ◽

Vol 26 (10) ◽

pp. 3040

Author(s):

Alexandra Ciorîță ◽

Cezara Zăgrean-Tuza ◽

Augustin C. Moț ◽

Rahela Carpa ◽

Marcel Pârvu

Keyword(s):

Bacterial Infections ◽

Inhibitory Effect ◽

Total Phenolic ◽

Phytochemical Analysis ◽

Leaf Extracts ◽

Antitumor Effects ◽

Cytotoxic Effects ◽

E Coli ◽

Lactate Dehydrogenase Release ◽

Nitric Oxide Concentration

The phytochemical analysis of Vinca minor, V. herbacea, V. major, and V. major var. variegata leaf extracts showed species-dependent antioxidant, antibacterial, and cytotoxic effects correlated with the identified phytoconstituents. Vincamine was present in V. minor, V. major, and V. major var. variegata, while V. minor had the richest alkaloid content, followed by V. herbacea. V. major var. variegata was richest in flavonoids and the highest total phenolic content was found in V. herbacea which also had elevated levels of rutin. Consequently, V. herbacea had the highest antioxidant activity followed by V. major var. variegata. Whereas, the lowest one was of V. major. The V. minor extract showed the most efficient inhibitory effect against both Staphylococcus aureus and E. coli. On the other hand, V. herbacea had a good anti-bacterial potential only against S. aureus, which was most affected at morphological levels, as indicated by scanning electron microscopy. The Vinca extracts acted in a dose-depended manner against HaCaT keratinocytes and A375 melanoma cells and moreover, with effects on the ultrastructure, nitric oxide concentration, and lactate dehydrogenase release. Therefore, the Vinca species could be exploited further for the development of alternative treatments in bacterial infections or as anticancer adjuvants.

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