Antimicrobial activities and in vitro properties of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes of high latitude water areas in Xinjiang, China

Abstract Background There are still a large variety of microorganisms among aquatic animals, especially probiotic lactic acid bacteria in cold water fishes at high latitudes have not been fully developed. Hence, the present study aims to evaluate the probiotic potential of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes (Xinjiang) and select candidates to be used as new food preservative agents and/or probiotic additives in feeding of aquaculture. Results A total of 43 Lactobacillus spp. were isolated from 16 kinds of intestinal tract of cold-water fishes. They were characterized by phenotypic methods, identified using Rep-PCR and 16S rRNA gene sequencing as four species: Lactobacillus sakei (22 isolates), Lactobacillus plantarum (16 isolates), Lactobacillus casei (4 isolates) and Lactobacillus paracasei (1 isolate). The in vitro tests included survival in low pH and bile, antimicrobial activity (against Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica, Listeria monocytogenes, and Listeria innocua), resistance to 15 antibiotics and hemolytic tests. Among all 43 lactobacilli isolates, the 22 isolates showed a wide range of antimicrobial activity against 6 different pathogenic strains. There were twenty isolates growing at optimal temperature ranging 16~20 °C, which were initially considered to be cold-adapted strains. Two (2) Lb. sakei strains and 2 Lb. plantarum strains demonstrated the highest survivability after 4 h of exposure at pH 2.0. Most of the tested strains cannot be cultured after exposed into 0.5% bile solution for 4 h, while 2 Lb. plantarum strains (E-HLM-3, CQ-CGC-2) and 1 Lb. sakei strain M-DGM-2 survived even at 2% bile concentration. In addition, the safety assessment showed that 22 strains without any detectable hemolytic activity and resistant to glycopeptides (vancomycin, teicoplanin), levofloxacin, aztreonam, amikacin and oxacillin, while all the studied lactobacilli showed sensitivity to or semi-tolerant to other antibiotics. Conclusions Based on all the experiments, 3 strains, including E-HLM-3, CQ-CGC-2, and M-DGM-2 might be a candidate of choice for using in the food preservative agents and/or probiotic additives in feeding of aquaculture.

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Antimicrobial activities and in vitro properties of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes of high latitude water areas in Xinjiang, China

10.21203/rs.2.12860/v2 ◽

2019 ◽

Author(s):

Xiaojing Wei ◽

Yan Zhang ◽

Hong Zhou ◽

Fengwei Tian ◽

Yongqing Ni

Keyword(s):

Antimicrobial Activity ◽

Salmonella Enterica ◽

Intestinal Tract ◽

Cold Water ◽

In Vitro Tests ◽

Rrna Gene ◽

Food Preservative ◽

Cold Adapted ◽

Wide Range

Abstract Background There are still a large variety of microorganisms among aquatic animals, especially probiotic lactic acid bacteria in cold water fishes at high latitudes have not been fully developed. Hence, the present study aims to evaluate the probiotic potential of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes (Xinjiang) and select candidates to be used as new food preservative agents and/or probiotic additives in feeding of aquaculture. Results A total of 43 Lactobacillus spp. were isolated from 16 kinds of intestinal tract of cold-water fishes. They were characterized by phenotypic methods, identified using Rep-PCR and 16S rRNA gene sequencing as four species: Lactobacillus sakei (22 isolates), Lactobacillus plantarum (16 isolates), Lactobacillus casei (4 isolates) and Lactobacillus paracasei (1 isolate). The in vitro tests included survival in low pH and bile, antimicrobial activity (against Escherichia coli , Salmonella enterica subsp. enterica serovar Typhimurium , Salmonella enterica subsp. enterica , Listeria monocytogenes , and Listeria innocua ), resistance to 15 antibiotics and hemolytic tests. Among all 43 lactobacilli isolates, the 22 isolates showed a wide range of antimicrobial activity against 6 different pathogenic strains. There were twenty isolates growing at a optimal temperature ranging 16~20°C, which were initially considered to be cold-adapted strains. Two (2) Lb. sakei strains and 2 Lb. plantarum strains demonstrated the highest survivability after 4 h of exposure at pH 2.0. Most of the tested strains cannot be cultured after exposed into 0.5% bile solution for 4 h, while 2 Lb. plantarum strains (E-HLM-3, CQ-CGC-2) and 1 Lb. sakei strain M-DGM-2 survived even at 2% bile concentration. In addition, the safety assessment showed that 22 strains without any detectable hemolytic activity and resistant to glycopeptides (vancomycin, teicoplanin), levofloxacin, aztreonam, amikacin and oxacillin, while all the studied lactobacilli showed sensitivity to or semi-tolerant to other antibiotics. Conclusions Based on all the experiments, 3 strains, including E-HLM-3, CQ-CGC-2, and M-DGM-2 might be a candidate of choice for using in the food preservative agents and/or probiotic additives in feeding of aquaculture.

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Antimicrobial activities and in vitro properties of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes of high latitude water areas in Xinjiang, China

10.21203/rs.2.12860/v1 ◽

2019 ◽

Author(s):

Xiaojing Wei ◽

Yan Zhang ◽

Hong Zhou ◽

Fengwei Tian ◽

Yongqing Ni

Keyword(s):

Antimicrobial Activity ◽

Salmonella Enterica ◽

Intestinal Tract ◽

Cold Water ◽

In Vitro Tests ◽

Rrna Gene ◽

Food Preservative ◽

Cold Adapted ◽

Wide Range

Abstract Background There are still a large variety of microorganisms among aquatic animals, especially probiotic lactic acid bacteria in cold water fishes at high latitudes have not been fully developed. Hence, the present study aims to evaluate the probiotic potential of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes (Xinjiang) and select candidates to be used as new food preservative agents and/or probiotic additives in feeding of aquaculture. Results A total of 43 Lactobacillus spp. were isolated from 16 kinds of intestinal tract of cold-water fishes. They were characterized by phenotypic methods, identified using rep-PCR and 16S rRNA gene sequencing as four species: Lactobacillus sakei (22 isolates), Lactobacillus plantarum (16 isolates), Lactobacillus casei (4 isolates) and Lactobacillus paracasei (1 isolate). The in vitro tests included survival in low pH and bile, antimicrobial activity (against Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica, Listeria monocytogenes, and Listeria innocua), resistance to 15 antibiotics and hemolytic tests. Among all 43 lactobacilli iaolates, the 22 isolates showed a wide range of antimicrobial activity against 6 different pathogenic strains. There were twenty isolates growing at a optimal temperature ranging 16~20°C, which were initially considered to be cold-adapted strains. Two (2) Lb. sakei strains and 2 Lb. plantarum strains demonstrated the highest survivability after 4 h of exposure at pH 2.0. Most of the tested strains cannot be cultrued after exposed into 0.5% bile solution for 4 h, while 2 Lb. plantarum strains (E-HLM-3, CQ-CGC-2) and 1 Lb. sakei strain M-DGM-2 survived even at 2% bile concentration. In addition, the safety assessment showed that 22 strains without any detectable hemolytic activity and resistant to glycopeptides (vancomycin, teicoplanin), levofloxacin, aztreonam, amikacin and oxacillin, while all the studied lactobacilli showed sensitivity to or semi-tolerant to other antibiotics. Conclusions In conclusion, based on all the experiments, 3 strains, including E-HLM-3, CQ-CGC-2, and M-DGM-2 might be a candidate of choice for using in the food preservative agents and/or probiotic additives in feeding of aquaculture.

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Carvacrol Prodrugs with Antimicrobial Activity Loaded on Clay Nanocomposites

Materials ◽

10.3390/ma13071793 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1793 ◽

Cited By ~ 2

Author(s):

Piera Eusepi ◽

Lisa Marinelli ◽

Fátima García-Villén ◽

Ana Borrego-Sánchez ◽

Ivana Cacciatore ◽

...

Keyword(s):

Antimicrobial Activity ◽

Intestinal Tract ◽

In Vitro Release ◽

Water Soluble ◽

Clay Nanocomposites ◽

X Ray ◽

Release Studies ◽

Wide Range ◽

Vitro Release

Background: Carvacrol, an essential oil with antimicrobial activity against a wide range of pathogens, and its water soluble carvacrol prodrugs (WSCP1-3) were intercalated into montmorillonite (VHS) interlayers to improve their stability in physiological media and promote their absorption in the intestine. Methods: Intercalation of prodrugs by cation exchange with montmorillonite interlayer counterions was verified by X-ray powder diffraction and confirmed by Fourier transform infrared spectroscopy and thermal analysis. Results: In vitro release studies demonstrated that montmorillonite successfully controlled the release of the adsorbed prodrugs and promoted their bioactivation only in the intestinal tract where carvacrol could develop its maximum antimicrobial activity. The amount of WSCP1, WSCP2, and WSCP3 released from VHS were 38%, 54%, and 45% at acid pH in 120 min, and 65%, 78%, and 44% at pH 6.8 in 240 min, respectively. Conclusions: The resultant hybrids successfully controlled conversion of the prodrugs to carvacrol, avoiding premature degradation of the drug.

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Probiotic potential of Lactobacillus fermentum G-4 originating from the meconium of newborns

Journal of the Serbian Chemical Society ◽

10.2298/jsc181105015z ◽

2019 ◽

Vol 84 (4) ◽

pp. 365-376

Author(s):

Gordana Zavisic ◽

Sasa Petricevic ◽

Slavica Ristic ◽

Milena Rikalovic ◽

Natasa Jovanovic-Ljeskovic ◽

...

Keyword(s):

Antimicrobial Activity ◽

Bacterial Translocation ◽

Hemolytic Activity ◽

Lactobacillus Fermentum ◽

In Vitro Tests ◽

Rrna Gene ◽

Probiotic Properties ◽

Probiotic Potential

The present study was dedicated to determining probiotic potential of a human isolate G-4, originated from meconium. The isolate was identified using morphological, physiological and biochemical assays and molecular method based on 16S rRNA gene sequencing. In order to evaluate its probiotic properties in vitro tests were performed: the survival in simulated gastrointestinal conditions, adhesion to hexadecane, and antimicrobial activity. Safety aspects of the isolate were examined by testing toxicity, gastrointestinal tolerance and bacterial translocation in vivo, as well as hemolytic activity in vitro. The isolate G-4, identified as Lactobacillus fermentum, showed viability in artificial gastric and intestinal juice (low degree of cell viability reduction for 0.69 and 1.30 logCFU mL-1 units, respectively), moderate adhesion to hexadecane (39?2.1 %), and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype Abony and Clostridium sporogenes, due to production of lactic acid (9.80 g L-1). No signs of toxicity, bacterial translocation, hemolytic activity, were observed.

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Subinhibitory Antimicrobial Concentrations: A Review of In Vitro and In Vivo Data

Canadian Journal of Infectious Diseases ◽

10.1155/1992/793607 ◽

1992 ◽

Vol 3 (4) ◽

pp. 193-201 ◽

Cited By ~ 14

Author(s):

George G Zhanel ◽

Daryl J Hoban ◽

Godfrey KM Harding

Keyword(s):

Antimicrobial Activity ◽

Animal Studies ◽

Molecular Level ◽

Bacterial Virulence ◽

Antibacterial Effects ◽

Wide Range ◽

Immune Defences

Antimicrobial activity is not an ‘all or none’ effect. An increase in the rate and extent of antimicrobial action is usually observed over a wide range of antimicrobial concentrations. Subinhibitory antimicrobial concentrations are well known to produce significant antibacterial effects, and various antimicrobials at subinhibitory concentrations have been reported to inhibit the rate of bacterial growth. Bacterial virulence may be increased or decreased by subinhibitory antimicrobial concentrations by changes in the ability of bacteria to adhere to epithelial cells or by alterations in bacterial susceptibility to host immune defences. Animal studies performed in rats, hamsters and rabbits demonstrate decreased bacterial adherence, reduced infectivity and increased survival of animals treated with subinhibitory antimicrobial concentrations compared to untreated controls. The major future role of investigation of subinhibitory antimicrobial concentrations will be to define more fully, at a molecular level, how antimicrobials exert their antibacterial effects.

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In vitro antimicrobial activity of the organic extract of Cladonia substellata Vainio and usnic acid against Staphylococcus spp. obtained from cats and dogs

Pesquisa Veterinária Brasileira ◽

10.1590/s0100-736x2017000400011 ◽

2017 ◽

Vol 37 (4) ◽

pp. 368-378 ◽

Cited By ~ 6

Author(s):

Jusciêne B. Moura ◽

Agueda C. de Vargas ◽

Gisele V. Gouveia ◽

João J. de S. Gouveia ◽

Juracy C. Ramos-Júnior ◽

...

Keyword(s):

Antimicrobial Activity ◽

Biological Activities ◽

Meca Gene ◽

Usnic Acid ◽

Organic Extract ◽

In Vitro Antimicrobial Activity ◽

Low Concentrations ◽

Wide Range ◽

Staphylococcus Spp

ABSTRACT: Cladonia substellata Vainio is a lichen found in different regions of the world, including the Northeast of Brazil. It contains several secondary metabolites with biological activity, including usnic acid, which has exhibited a wide range of biological activities. The aim of this study was to evaluate the in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid. Initially, Staphylococcus spp., derived from samples of skin and ears of dogs and cats with suspected pyoderma and otitis, were isolated and analyzed. In antimicrobial susceptibility testing against Staphylococcus spp., 77% (105/136) of the isolates were resistant to the antimicrobials tested. In the assessment of biofilm production, 83% (113/136) were classified as producing biofilm. In genetic characterization, 32% (44/136) were positive for blaZ, no isolate (0/136) was positive for the mecA gene, and 2% (3/136) were positive for the icaD gene. The in vitro antimicrobial activity of the organic extract of C. substellata and purified usnic acid against Staphylococcus spp. ranged from 0.25mg/mL to 0.0019mg/mL, inhibiting bacterial growth at low concentrations. The substances were more effective against biofilm-producing bacteria (0.65mg/mL-0.42mg/mL) when compared to non-biofilm producing bacteria (2.52mg/mL-2.71mg/mL). Usnic acid and the organic extract of C. substellata can be effective in the treatment of pyoderma and otitis in dogs and cats caused by Staphylococcus spp.

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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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In Vitro Antifungal Activities of a Series of Dication-Substituted Carbazoles, Furans, and Benzimidazoles

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.10.2503 ◽

1998 ◽

Vol 42 (10) ◽

pp. 2503-2510 ◽

Cited By ~ 58

Author(s):

Maurizio Del Poeta ◽

Wiley A. Schell ◽

Christine C. Dykstra ◽

Susan K. Jones ◽

Richard R. Tidwell ◽

...

Keyword(s):

Antimicrobial Activity ◽

Candida Albicans ◽

Fusarium Solani ◽

Antifungal Agents ◽

Antifungal Drugs ◽

Inhibitory Compounds ◽

Wide Range ◽

Fluconazole Resistant ◽

Resistant Strains

ABSTRACT Aromatic dicationic compounds possess antimicrobial activity against a wide range of eucaryotic pathogens, and in the present study an examination of the structures-functions of a series of compounds against fungi was performed. Sixty-seven dicationic molecules were screened for their inhibitory and fungicidal activities againstCandida albicans and Cryptococcus neoformans. The MICs of a large number of compounds were comparable to those of the standard antifungal drugs amphotericin B and fluconazole. Unlike fluconazole, potent inhibitory compounds in this series were found to have excellent fungicidal activities. The MIC of one of the most potent compounds against C. albicans was 0.39 μg/ml, and it was the most potent compound against C. neoformans (MIC, ≤0.09 μg/ml). Selected compounds were also found to be active againstAspergillus fumigatus, Fusarium solani,Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. Since some of these compounds have been safely given to animals, these classes of molecules have the potential to be developed as antifungal agents.

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Evaluating In Vitro Antimicrobial Activity of Thymol toward Hygiene-Indicating and Pathogenic Bacteria

Journal of Food Protection ◽

10.4315/0362-028x-70.2.425 ◽

2007 ◽

Vol 70 (2) ◽

pp. 425-431 ◽

Cited By ~ 19

Author(s):

PASQUALE M. FALCONE ◽

MARIANNA MASTROMATTEO ◽

MATTEO A. DEL NOBILE ◽

MARIA R. CORBO ◽

MILENA SINIGAGLIA

Keyword(s):

Antimicrobial Activity ◽

Stationary Phase ◽

Growth Kinetics ◽

Active Compound ◽

Quantitative Description ◽

Lag Time ◽

Growth Cycle ◽

Microbial Response ◽

Wide Range

Results of a study of the kinetics of bacterial inhibition by thymol in order to develop appropriate applications for the compound in food systems are presented. A modeling-based approach was used to provide a quantitative description of the antimicrobial activity of thymol toward some foodborne pathogens and hygiene-indicating bacteria, which could be postprocessing contaminants of ready-to-eat meat products. The effect of the active compound on the bacterial growth was assessed from growth kinetics curves and dose-response profiles in a wide range of thymol concentrations, i.e., from 50 to 1,000 ppm. Inhibitory data were produced using a macrodilution methodology based on a turbidimetric technique. Microbial response was discussed in terms of Gompertz's parameters as well as in terms of the active concentration of thymol affecting the growth status of microbial suspension (noninhibitory concentration and MIC). Results suggested that thymol can be successfully used as an alternative antimicrobial to increase the lag time as well as to decrease the maximum value of the growth index as reached in the stationary phase of the growth cycle for all investigated bacteria. Due to their high sensitivity to the antimicrobial stress as observed at sub-MIC, it is arguably a potential use of thymol for assurance of food safety and hygiene in combination with other preservative technologies. A quantitative evaluation of the antimicrobial properties of the active compound was performed using a macrodilution methodology based on a turbidimetric technique to produce inhibitory data. Both the growth kinetics and inhibition profile in a wide range of thymol concentrations were obtained for each test bacterium, mathematically modeled, and analyzed. Noninhibitory concentration and MIC were determined to investigate both the microbial sensibility and resistance toward thymol, and Gompertz's parameters were evaluated to assess the microbial response at each phase of growth cycle. The in vitro–obtained results suggested that thymol may be successfully used as a alternative preservative to increase the lag time as well as to decrease the maximum cell load reached in the stationary phase of growth cycle for all investigated bacteria.

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Fungal Colonization and Biodeterioration of Plasticized Polyvinyl Chloride

Applied and Environmental Microbiology ◽

10.1128/aem.66.8.3194-3200.2000 ◽

2000 ◽

Vol 66 (8) ◽

pp. 3194-3200 ◽

Cited By ~ 88

Author(s):

Jeremy S. Webb ◽

Marianne Nixon ◽

Ian M. Eastwood ◽

Malcolm Greenhalgh ◽

Geoffrey D. Robson ◽

...

Keyword(s):

Bacterial Colonization ◽

Morphological Characteristics ◽

Sole Source ◽

Dioctyl Phthalate ◽

Microbial Colonization ◽

Fungal Colonization ◽

In Vitro Tests ◽

Rrna Gene ◽

Microbial Succession

ABSTRACT Significant substratum damage can occur when plasticized PVC (pPVC) is colonized by microorganisms. We investigated microbial colonization of pPVC in an in situ, longitudinal study. Pieces of pPVC containing the plasticizers dioctyl phthalate and dioctyl adipate (DOA) were exposed to the atmosphere for up to 2 years. Fungal and bacterial populations were quantified, and colonizing fungi were identified by rRNA gene sequencing and morphological characteristics.Aureobasidium pullulans was the principal colonizing fungus, establishing itself on the pPVC between 25 and 40 weeks of exposure. A group of yeasts and yeast-like fungi, includingRhodotorula aurantiaca and Kluyveromyces spp., established themselves on the pPVC much later (after 80 weeks of exposure). Numerically, these organisms dominated A. pullulans after 95 weeks, with a mean viable count ± standard error of 1,000 ± 200 yeast CFU cm−2, compared to 390 ± 50 A. pullulans CFU cm−2. No bacterial colonization was observed. We also used in vitro tests to characterize the deteriogenic properties of fungi isolated from the pPVC. All strains of A. pullulans tested could grow with the intact pPVC formulation as the sole source of carbon, degrade the plasticizer DOA, produce extracellular esterase, and cause weight loss of the substratum during growth in vitro. In contrast, several yeast isolates could not grow on pPVC or degrade DOA. These results suggest that microbial succession may occur during the colonization of pPVC and that A. pullulans is critical to the establishment of a microbial community on pPVC.

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