Antioxidant Properties and Antibacterial Effects of Eucalyptus camaldulensis Ethanolic Leaf Extract on Biofilm Formation, Motility, Hemolysin Production, and Cell Membrane of the Foodborne Pathogen Listeria monocytogenes

2019 ◽  
Vol 16 (8) ◽  
pp. 581-589 ◽  
Author(s):  
Ozioma Forstinus Nwabor ◽  
Kitiya Vongkamjan ◽  
Supayang Piyawan Voravuthikunchai
Keyword(s):  
Listeria Monocytogenes ◽  
Cell Membrane ◽  
Biofilm Formation ◽  
Leaf Extract ◽  
Antioxidant Properties ◽  
Foodborne Pathogen ◽  
Eucalyptus Camaldulensis ◽  
Antibacterial Effects ◽  
Ethanolic Leaf Extract

scholarly journals Dimethylnitrosamine (DMN) pre-treated rats and protective effect of Vernonia amygdalina post-treatment on liver function

2016 ◽  
Vol 4 (1) ◽  
pp. 74
Author(s):  
Usunomena Usunobun ◽  
Gabriel Anyanwu
Keyword(s):  
Total Protein ◽  
Leaf Extract ◽  
Total Bilirubin ◽  
Antioxidant Properties ◽  
Ethanolic Extract ◽  
Post Treatment ◽  
Vernonia Amygdalina ◽  
Male Wistar Rats ◽  
Drug Treatments ◽  
Ethanolic Leaf Extract

Background: Liver disease and toxicity is common, especially with many drug treatments. The effect of Vernonia amygdalina ethanolic leaf extract post-treatment on rats pre-treated with dimethylnitrosamine (DMN) was evaluated.Methods: Male wistar rats were orally administered DMN (single dose of 25 mg/kg) on first day and thereafter post-treated with 100 and 200mg/kg ethanolic leaf extract of Vernonia amygdalina for seven days. Analysis of serum concentrations of albumin, total protein, total bilirubin and glucose were carried out.Results: Administration of DMN alone to rats significantly increased glucose and total bilirubin concentration (P < 0.05) in the serum while it significantly reduced (P<0.05) serum total protein and albumin concentrations when compared with controls. However, post-treatment of DMN administered rats with 100 and 200 mg/kg ethanolic extract leaf of Vernonia amygdalina significantly (P<0.05) reversed these changes in a concentration dependent manner.Conclusion: In conclusion ethanolic leaf extract of Vernonia amygdalina have a potent hypoglycaemic and hepatoprotective action against dimethylnitrosamine-induced liver damage in rats may be due to its antioxidant properties.

scholarly journals EVALUATION OF ANTIDIABETIC AND ANTIOXIDANT EFFECTS OF ETHANOLIC LEAF EXTRACT OF ERYTHRINA ABBYSINICA LAM, EX DC

2018 ◽  
Vol 11 (8) ◽  
pp. 300
Author(s):  
Kamadyaapa Davie Rexon ◽  
Gondwe Mavuto Masopera ◽  
Shauli Mathulo ◽  
Sewani Rusike Constance ◽  
Nkeh Chungag Benedicta
Keyword(s):  
Blood Glucose ◽  
Leaf Extract ◽  
Antioxidant Properties ◽  
Diabetic Rats ◽  
Control Group ◽  
Oral Glucose ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Ethanolic Leaf Extract ◽  
Antioxidant Effects

  Objective: This study was conducted to scientifically evaluate the antidiabetic and antioxidant effects of ethanolic leaf extract of Erythrina abbysinica (EEA).Methods: Acute and sub-chronic effects of EEA at 100, 200, and 400 mg/kg/bwt and glibenclamide (GL) at 5 mg/kg/bwt. were evaluated in both normal and streptozotocin (STZ)-induced diabetic male Wistar rats (250–300 g). The acute studies were performed using oral glucose tolerance test (OGTT). In sub-chronic studies, animals were orally administered with EEA and GL daily for 6 w. Brine shrimp assay was used to determine the toxicity of EEA. 1, 1-diphenyl-2-picrylhydrazyl, ferric reducing capacity of plasma, and thiobarbituric acid reactive substances assays were used to determine antioxidant properties of EEA.Results: Following OGTT, EEA significantly (p<0.05) and dose-dependently (100, 200, and 400 mg/kg/bwt) decreased blood glucose levels in both normal and STZ-induced diabetic rats when compared with positive and negative control counterparts at all-time points, whereas GL significantly (p<0.05) decreased blood glucose only in normal rats but not in diabetic rats. Daily, oral administration of EEA for 6 w significantly (p<0.05) and dose-dependently (100, 200, and 400 mg/kg/bwt) decreased blood glucose levels in STZ-induced diabetic rats when compared with the diabetic control group. EEA revealed weak toxicity with a lethal concentration50 value of 997 μg/ml). Furthermore, EEA showed significant free radical scavenging, total antioxidant, and anti-lipid peroxidative capacities.Conclusion: The study has shed more light on the scientific basis for the use of E. abbysinica in management of diabetes in some communities of Eastern Cape of South Africa.

scholarly journals Novel Cadmium Resistance Determinant in Listeria monocytogenes

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Cameron Parsons ◽  
Sangmi Lee ◽  
Victor Jayeola ◽  
Sophia Kathariou
Keyword(s):  
Heavy Metals ◽  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Foodborne Pathogen ◽  
Whole Genome ◽  
Cadmium Resistance ◽  
Content Type ◽  
Content Model ◽  
Tolerance To Cadmium

ABSTRACT Listeria monocytogenes is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. It is ubiquitous in the environment and often exhibits resistance to heavy metals. One of the determinants that enables Listeria to tolerate exposure to cadmium is the cadAC efflux system, with CadA being a P-type ATPase. Three different cadA genes (designated cadA1 to cadA3) were previously characterized in L. monocytogenes. A novel putative cadmium resistance gene (cadA4) was recently identified through whole-genome sequencing, but experimental confirmation for its involvement in cadmium resistance is lacking. In this study, we characterized cadA4 in L. monocytogenes strain F8027, a cadmium-resistant strain of serotype 4b. By screening a mariner-based transposon library of this strain, we identified a mutant with reduced tolerance to cadmium and that harbored a single transposon insertion in cadA4. The tolerance to cadmium was restored by genetic complementation with the cadmium resistance cassette (cadA4C), and enhanced cadmium tolerance was conferred to two unrelated cadmium-sensitive strains via heterologous complementation with cadA4C. Cadmium exposure induced cadA4 expression, even at noninhibitory levels. Virulence assessments in the Galleria mellonella model suggested that a functional cadA4 suppressed virulence, potentially promoting commensal colonization of the insect larvae. Biofilm assays suggested that cadA4 inactivation reduced biofilm formation. These data not only confirm cadA4 as a novel cadmium resistance determinant in L. monocytogenes but also provide evidence for roles in virulence and biofilm formation. IMPORTANCE Listeria monocytogenes is an intracellular foodborne pathogen causing the disease listeriosis, which is responsible for numerous hospitalizations and deaths every year. Among the adaptations that enable the survival of Listeria in the environment are the abilities to persist in biofilms, grow in the cold, and tolerate toxic compounds, such as heavy metals. Here, we characterized a novel determinant that was recently identified on a larger mobile genetic island through whole-genome sequencing. This gene (cadA4) was found to be responsible for cadmium detoxification and to be a divergent member of the Cad family of cadmium efflux pumps. Virulence assessments in a Galleria mellonella model suggested that cadA4 may suppress virulence. Additionally, cadA4 may be involved in the ability of Listeria to form biofilms. Beyond the role in cadmium detoxification, the involvement of cadA4 in other cellular functions potentially explains its retention and wide distribution in L. monocytogenes.

Removal of Listeria monocytogenes Biofilms with Bacteriophage P100†

2010 ◽  
Vol 73 (8) ◽  
pp. 1519-1524 ◽  
Author(s):  
KAMLESH A. SONI ◽  
RAMAKRISHNA NANNAPANENI
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biofilm Formation ◽  
Foodborne Pathogen ◽  
Growth Conditions ◽  
Cell Populations ◽  
Wide Range ◽  
Serotype 1 ◽  
Stainless Steel Coupon ◽  
Steel Coupon

Listeria monocytogenes is an important foodborne pathogen with a persistent ability to form biofilm matrices in the food processing environments. In this study, we have determined the ability of bacteriophage P100 to reduce L. monocytogenes cell populations under biofilm conditions by using 21 L. monocytogenes strains representing 13 different serotypes. There were considerable differences in the ability of various strains of L. monocytogenes to form biofilms, with strains of serotype 1/2a showing maximum biofilm formation. Irrespective of the serotype, growth conditions, or biofilm levels, the phage P100 treatment significantly reduced L. monocytogenes cell populations under biofilm conditions. On the stainless steel coupon surface, there was a 3.5- to 5.4-log/cm2 reduction in L. monocytogenes cells by phage treatment. These findings illustrate that phage P100 is active against a wide range of L. monocytogenes strains in biofilm conditions.

Biofilm Formation Ability of Listeria monocytogenes Isolates from Raw Ready-to-Eat Seafood

2009 ◽  
Vol 72 (7) ◽  
pp. 1476-1480 ◽  
Author(s):  
HAJIME TAKAHASHI ◽  
SATOKO MIYA ◽  
KAZUNORI IGARASHI ◽  
TAKAYUKI SUDA ◽  
SHINTARO KURAMOTO ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Factors ◽  
Biofilm Formation ◽  
Foodborne Pathogen ◽  
Microtiter Plate ◽  
Processing Plant ◽  
High Incidence ◽  
Sporadic Cases ◽  
Different Levels

Listeria monocytogenes is of great concern as a foodborne pathogen. Many ready-to-eat foods are widely contaminated with this organism and have caused listeriosis outbreaks and sporadic cases in many countries. In Japan, there is a high incidence of L. monocytogenes contamination, specifically in raw ready-to-eat seafood. Identical L. monocytogenes subtypes have been isolated repeatedly from samples of food manufactured at a given store or processing plant, and researchers suspected that certain L. monocytogenes isolates have formed biofilms at these sites. A microtiter plate biofilm formation assay was conducted, and all raw ready-to-eat seafood isolates tested were able to form biofilms to various degrees. Biofilm formation by L. monocytogenes isolates of lineage I was significantly greater (P = 0.000) than that by isolates of lineage II. However, isolates of clonal lineages formed different levels of biofilms, indicating that the ability to form a biofilm is affected positively or negatively by environmental factors.

scholarly journals Listeria monocytogenes DNA Glycosylase AdlP Affects Flagellar Motility, Biofilm Formation, Virulence, and Stress Responses

2016 ◽  
Vol 82 (17) ◽  
pp. 5144-5152 ◽  
Author(s):  
Ting Zhang ◽  
Dongryeoul Bae ◽  
Chinling Wang
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Responses ◽  
Transcriptional Repression ◽  
Biofilm Formation ◽  
Foodborne Pathogen ◽  
Dna Glycosylase ◽  
Flagellar Motility ◽  
Temperature Dependent ◽  
Bifunctional Protein ◽  
Content Type

ABSTRACTThe temperature-dependent alteration of flagellar motility gene expression is critical for the foodborne pathogenListeria monocytogenesto respond to a changing environment. In this study, a genetic determinant,L. monocytogenesf2365_0220(lmof2365_0220), encoding a putative protein that is structurally similar to theBacillus cereusalkyl base DNA glycosylase (AlkD), was identified. This determinant was involved in the transcriptional repression of flagellar motility genes and was namedadlP(encoding anAlkD-likeprotein [AdlP]). Deletion ofadlPactivated the expression of flagellar motility genes at 37°C and disrupted the temperature-dependent inhibition ofL. monocytogenesmotility. TheadlPnull strains demonstrated decreased survival in murine macrophage-like RAW264.7 cells and less virulence in mice. Furthermore, the deletion ofadlPsignificantly decreased biofilm formation and impaired the survival of bacteria under several stress conditions, including the presence of a DNA alkylation compound (methyl methanesulfonate), an oxidative agent (H2O2), and aminoglycoside antibiotics. Our findings strongly suggest thatadlPmay encode a bifunctional protein that transcriptionally represses the expression of flagellar motility genes and influences stress responses through its DNA glycosylase activity.IMPORTANCEWe discovered a novel protein that we namedAlkD-likeprotein (AdlP). This protein affected flagellar motility, biofilm formation, and virulence. Our data suggest that AdlP may be a bifunctional protein that represses flagellar motility genes and influences stress responses through its DNA glycosylase activity.

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