scholarly journals Enterococcus faecium isolated from healthy dogs for potential use as probiotics

2020 ◽  
Vol 23 (2) ◽  
pp. 197-205
Author(s):  
K. A. Abd El-Razik ◽  
E. S. Ibrahim ◽  
A. M. Younes ◽  
A. A. Arafa ◽  
A. S. M. Abuelnaga ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Molecular Identification ◽  
Enterococcus Faecium ◽  
Virulence Genes ◽  
Pcr Amplification ◽  
Virulence Determinants ◽  
Specific Pcr ◽  
Healthy Dogs ◽  
Potential Use

This study aimed to isolate and identify enterococci obtained from fresh faecal swabs of 16 healthy dogs. Following molecular identification, all isolates were screened against the most critical virulence factors as well as enterocin (bacteriocin) determinants to confirm that the isolated enterococcus was safe to be used as host-specific probiotic. Enterococcus faecium was isolated and confirmed in 8 out of the 16 samples. Regarding the assessment of the virulence determinants, E. faecium strains were negative for tested (gelE and esp) virulence genes. Furthermore, the genome was evaluated for the incidence of five known enterocin genes by specific PCR amplification. Four strains encoding entAS-48 gene were found, while only one strain harboured the entL50A/B gene. Based on these results, five of the E. faecium isolated in this study were considered as promising probiotic candidates for dogs.

Genes Encoding Bacteriocins and Their Expression and Potential Virulence Factors of Enterococci Isolated from Wood Pigeons (Columba palumbus)

2006 ◽  
Vol 69 (3) ◽  
pp. 520-531 ◽  
Author(s):  
MARÍA MARTÍN ◽  
JORGE GUTIÉRREZ ◽  
RAQUEL CRIADO ◽  
CARMEN HERRANZ ◽  
LUIS M. CINTAS ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Pcr Amplification ◽  
Virulence Gene ◽  
Antagonistic Activity ◽  
Mass Spectrometry Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virulence Determinants ◽  
Spectrometry Analysis

Samples of the intestinal content and carcasses of wood pigeons (Columba palumbus) were evaluated for enterococci with antimicrobial activity. Enterococcus faecium comprised the largest enterococcal species with antagonistic activity, followed by Enterococcus faecalis and Enterococcus columbae. PCR amplification of genes coding bacteriocins and determination of their nucleotide sequence, and the use of specific antipeptide bacteriocin antibodies and a noncompetitive indirect enzyme-linked immunosorbent assay, permitted characterization of enterococci coding that described bacteriocins and their expression. The efaAfm determinant was the only virulence gene detected in E. faecium, whereas E. faecalis showed a larger number of virulence determinants, and E. columbae did not carry any of the virulence genes examined. Although all E. faecalis isolates manifested a potent direct antimicrobial activity, no activity was detected in supernatants of producer cells. Purification of the antagonistic activity of E. columbae PLCH2 showed multiple chromatographic fragments after matrix-assisted laser desorption–ionization time-of-flight mass spectrometry analysis, suggesting the active peptide(s) had not yet purified to homogeneity. Bacteriocinogenic E. faecium and E. columbae isolates may be considered hygienic for production of enterocins and potentially safe due to their low incidence of potential virulence genes and susceptibility of most relevant clinical antibiotics. However, the presence among the enterococci of E. faecalis strains with a potent antagonistic activity and multiple virulence factors is an issue that must be considered further.

scholarly journals Virulence factors and antibiotic resistance in enterococci isolated from food-stuffs

2011 ◽  
Vol 56 (No. 7) ◽  
pp. 352-357 ◽  
Author(s):  
K. Trivedi ◽  
S. Cupakova ◽  
R. Karpiskova
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Diffusion Method ◽  
Haemolytic Activity ◽  
Virulence Determinants ◽  
Disk Diffusion Method ◽  
Specific Pcr ◽  
Virulence Potential ◽  
Enterococcal Species ◽  
Species Specific

A collection of 250 enterococci isolated from various food-stuffs were used to investigate seven virulence determinants and the microbial susceptibility of eight antibiotics. Species-specific PCR revealed the presence of E. faecalis (127 isolates), E. faecium (77 isolates), E. casseliflavus (21 isolates), E. mundtii (19 isolates) and E. durans (six isolates). Multiplex PCR for virulence factors showed that from a total 250 isolates, 221 (88.4%) carried one or more virulence-encoding genes. β-Haemolytic activity was also evident in enterococcal species other than E. faecalis and E. faecium. Species other than E. faecalis and E. faecium isolated from food are also seen to harbour the potential for virulence. Antimicrobial susceptibility testing using the disk diffusion method showed that of the total 250 isolates, 114 (46%) were resistant to cephalothin and 94 (38%) to ofloxacin. Lower antibiotic resistance was seen with ampicillin, chloramphenicol, gentamicin and teicoplanin. None of the isolates was found to be resistant to vancomycin. The results of this study show that food can play an important role in the spread of enterococci with virulence potential through the food chain to the human population.

scholarly journals Incidence of virulence determinants in clinical Enterococcus faecium and Enterococcus faecalis isolates collected in Sardinia (Italy)

2003 ◽  
Vol 52 (6) ◽  
pp. 491-498 ◽  
Author(s):  
I. Duprè ◽  
S. Zanetti ◽  
A. M. Schito ◽  
G. Fadda ◽  
L. A. Sechi
Keyword(s):  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Virulence Genes ◽  
Protein Gene ◽  
Surface Protein ◽  
Virulence Determinants ◽  
Colonization Factor ◽  
Aggregation Substance ◽  
Epithelial Cell Lines ◽  
Surface Protein Gene

Enterococci are widely distributed in the environment; within the human body, they are normal commensals of the oral cavity, gastrointestinal tract and vagina. In recent years, enterococci have become one of the most frequent causes of acquired nosocomial infections worldwide. The molecular mechanism of virulence of these bacteria is still not completely understood. The aims of this work were to characterize phenotypically 47 isolates of Enterococcus faecalis and Enterococcus faecium collected in Sardinia (Italy) by their abilities to adhere to different epithelial cell lines (Vero and Caco-2 cells) and to associate their phenotypes with the presence of known virulence genes detected within their genomes by PCR. The following genes were amplified: AS (aggregation substance), esp (surface protein gene), ace (accessory colonization factor), efaA (E. faecalis endocarditis antigen) and gelE (gelatinase). The virulence genes were detected in E. faecalis isolates only, with the exception of esp, which was found in both species. The phenotypic and genotypic results were also compared with the susceptibility of isolates to various antibiotics.

scholarly journals Incidence of Virulence Factors and Antibiotic Resistance among Enterococci Isolated from Food

2001 ◽  
Vol 67 (9) ◽  
pp. 4385-4389 ◽  
Author(s):  
Charles M. A. P. Franz ◽  
Albrecht B. Muscholl-Silberhorn ◽  
Nuha M. K. Yousif ◽  
Marc Vancanneyt ◽  
Jean Swings ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Enterococcus Faecalis ◽  
Virulence Factors ◽  
Enterococcus Faecium ◽  
Antibiotic Susceptibility ◽  
Virulence Determinants ◽  
Virulence Traits

ABSTRACT The incidence of virulence factors among 48 Enterococcus faecium and 47 Enterococcus faecalis strains from foods and their antibiotic susceptibility were investigated. No strain was resistant to all antibiotics, and for some strains, multiple resistances were observed. Of E. faecium strains, 10.4% were positive for one or more virulence determinants, compared to 78.7% of E. faecalis strains. Strains exhibiting virulence traits were not necessarily positive for all traits; thus, the incidence of virulence factors may be considered to be strain specific.

Detection of virulence factors in high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium isolates from a Tunisian hospital

2007 ◽  
Vol 53 (3) ◽  
pp. 372-379 ◽  
Author(s):  
N. Klibi ◽  
K. Ben Slama ◽  
Y. Sáenz ◽  
A. Masmoudi ◽  
S. Zanetti ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Virulence Factors ◽  
Enterococcus Faecium ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Gelatinase Activity ◽  
Genes Encoding ◽  
High Level

Phenotypic and genotypic determination of virulence factors were carried out in 46 high-level gentamicin-resistant (HLGR) clinical Enterococcus faecalis (n = 34) and Enterococcus faecium (n = 12) isolates recovered from different patients in La Rabta Hospital in Tunis, Tunisia, between 2000 and 2003 (all these isolates harboured the aac(6′)–aph(2″) gene). The genes encoding virulence factors (agg, gelE, ace, cylLLS, esp, cpd, and fsrB) were analysed by PCR and sequencing. The production of gelatinase and hemolysin, the adherence to caco-2 and hep-2 cells, and the capacity for biofilm formation were investigated in all 46 HLGR enterococci. The percentages of E. faecalis isolates harbouring virulence genes were as follows: gelE, cpd, and ace (100%); fsrB (62%); agg (56%); cylLLS (41.2%); and esp (26.5%). The only virulence gene detected among the 12 HLGR E. faecium isolates was esp (58%). Gelatinase activity was detected in 22 of the 34 E. faecalis isolates (65%, most of them with the gelE+–fsrB+ genotype); the remaining 12 isolates were gelatinase-negative (with the gelE+–fsrB– genotype and the deletion of a 23.9 kb fragment of the fsr locus). Overall, 64% of the cylLLS-containing E. faecalis isolates showed β-hemolysis. A high proportion of our HLGR E. faecalis isolates, in contrast to E. faecium, showed moderate or strong biofilm formation or adherence to caco-2 and hep-2 cells.

Use of virulence determinants and seropathotypes to distinguish high- and low-riskEscherichia coliO157 and non-O157 isolates from Europe

2013 ◽  
Vol 142 (5) ◽  
pp. 1019-1028 ◽  
Author(s):  
M. F. ANJUM ◽  
E. JONES ◽  
V. MORRISON ◽  
R. TOZZOLI ◽  
S. MORABITO ◽  
...  
Keyword(s):  
High Risk ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Virulence Determinants ◽  
Chain Reaction ◽  
E Coli ◽  
Specific Pcr ◽  
Polymerase Chain ◽  
Production Strain

SUMMARYThe presence of 10 virulence genes was examined using polymerase chain reaction (PCR) in 365 European O157 and non-O157Escherichia coliisolates associated with verotoxin production. Strain-specific PCR data were analysed using hierarchical clustering. The resulting dendrogram clearly separated O157 from non-O157 strains. The former clustered typical high-risk seropathotype (SPT) A strains from all regions, including Sweden and Spain, which were homogenous by Cramer'sVstatistic, and strains with less typical O157 features mostly from Hungary. The non-O157 strains divided into a high-risk SPTB harbouring O26, O111 and O103 strains, a group pathogenic to pigs, and a group with few virulence genes other than for verotoxin. The data demonstrate SPT designation and selected PCR separated verotoxigenicE. coliof high and low risk to humans; although more virulence genes or pulsed-field gel electrophoresis will need to be included to separate high-risk strains further for epidemiological tracing.

scholarly journals Silkworm model for Bacillus anthracis infection and virulence determination

2021 ◽  
Author(s):  
Atmika Paudel ◽  
Yoshikazu Furuta ◽  
Hideaki Higashi
Keyword(s):  
Bacillus Anthracis ◽  
Virulence Factors ◽  
Large Scale ◽  
Virulence Genes ◽  
Lethal Dose ◽  
Infection Model ◽  
Virulence Determinants ◽  
Silkworm Hemolymph ◽  
Effective Doses ◽  
Obligate Pathogen

Bacillus anthracis is an obligate pathogen and a causative agent of anthrax. Its major virulence factors are plasmid-coded; however, recent studies have revealed chromosome-encoded virulence factors, indicating that the current understanding of its virulence mechanism is elusive and needs further investigation. In this study, we established a silkworm (Bombyx mori) infection model of B. anthracis Sterne. We showed that silkworms were killed by B. anthracis and cured of the infection when administered with antibiotics. We quantitatively determined the lethal dose of the bacteria that kills 50% larvae and effective doses of antibiotics that cure 50% infected larvae. Furthermore, we demonstrated that B. anthracis mutants with disruption in virulence genes such as pagA, lef, and atxA had attenuated silkworm-killing ability and reduced colonization in silkworm hemolymph. The silkworm infection model established in this study can be utilized in large-scale infection experiments to identify novel virulence determinants and develop novel therapeutic options against B. anthracis infections.

scholarly journals Virulence Determinants of Colistin-Resistant K. pneumoniae High-Risk Clones

Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 436
Author(s):  
Ozlem Dogan ◽  
Cansel Vatansever ◽  
Nazli Atac ◽  
Ozgur Albayrak ◽  
Sercin Karahuseyinoglu ◽  
...  
Keyword(s):  
High Risk ◽  
Virulence Factors ◽  
Median Survival ◽  
Iron Uptake ◽  
Virulence Genes ◽  
Virulence Determinants ◽  
Neutrophil Activity ◽  
Biosynthesis Gene ◽  
Survival Capacity ◽  
Neutrophil Response

We proposed the hypothesis that high-risk clones of colistin-resistant K. pneumoniae (ColR-Kp) possesses a high number of virulence factors and has enhanced survival capacity against the neutrophil activity. We studied virulence genes of ColR-Kp isolates and neutrophil response in 142 patients with invasive ColR-Kp infections. The ST101 and ST395 ColR-Kp infections had higher 30-day mortality (58%, p = 0.005 and 75%, p = 0.003). The presence of yersiniabactin biosynthesis gene (ybtS) and ferric uptake operon associated gene (kfu) were significantly higher in ST101 (99%, p ≤ 0.001) and ST395 (94%, p < 0.012). Being in ICU (OR: 7.9; CI: 1.43–55.98; p = 0.024), kfu (OR:27.0; CI: 5.67–179.65; p < 0.001) and ST101 (OR: 17.2; CI: 2.45–350.40; p = 0.01) were found to be predictors of 30-day mortality. Even the neutrophil uptake of kfu+-ybtS+ ColR-Kp was significantly higher than kfu--ybtS- ColR-Kp (phagocytosis rate: 78% vs. 65%, p < 0.001), and the kfu+-ybtS+ ColR-Kp survived more than kfu--ybtS- ColR-Kp (median survival index: 7.90 vs. 4.22; p = 0.001). The kfu+-ybtS+ ColR-Kp stimulated excessive NET formation. Iron uptake systems in high-risk clones of colistin-resistant K. pneumoniae enhance the success of survival against the neutrophil phagocytic defense and stimulate excessive NET formation. The drugs targeted to iron uptake systems would be a promising approach for the treatment of colistin-resistant high-risk clones of K. pneumoniae infections.

scholarly journals Low Occurrence of Virulence Determinants in Vancomycin-Resistant Enterococcus from Clinical Samples in Southwest Nigeria

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Folasade Muibat Adeyemi ◽  
Nana-Aishat Yusuf ◽  
Rashidat Ronke Adeboye ◽  
Omotayo Opemipo Oyedara
Keyword(s):  
Virulence Factors ◽  
Molecular Identification ◽  
Resistance Genes ◽  
Clinical Samples ◽  
Screening Methods ◽  
Vancomycin Resistant Enterococcus ◽  
Virulence Determinants ◽  
Southwest Nigeria ◽  
Vancomycin Resistant ◽  
Polymerase Chain

Background: The virulence factors of enterococci play a major role in the pathogenicity of enterococcal strains. Objectives: This study aimed to evaluate virulence factors and detect selected virulence and resistance genes in vancomycin-resistant Enterococcus (VRE) from clinical samples from southwest Nigeria. Methods: The VRE isolates (n = 85) recovered from clinical samples were characterized using conventional microbiology techniques, and molecular identification was made with ddlE primers. Phenotypic screening for five virulence determinants and detection of virulence and resistance genes using a polymerase chain reaction were carried out. Results: Phenotypic identification revealed 61 Enterococcus faecium and 24 Enterococcus faecalis. All the isolates hydrolyzed bile. Moreover, 88.2% of the isolates produced biofilm; however, 72.9% of the isolates produced gelatinase enzyme. Altogether, six isolates (7%) produced all five virulence factors. The least virulence factor expressed by the two species E. faecium and E. faecalis was DNase at 21.3% and 29.2% followed by cytolysin at 27.9% and 41.7%, respectively. Only 25 isolates (29.4%), including 23 E. faecium (37.7%) and only 2 (8.3%) E. faecalis isolates, revealed bands with molecular identification. Additionally, VRE isolates showed bands for asa1 (16%); only 1 (4%) isolate had the hyl gene and vanB gene, respectively. Conclusions: The absence of vanA and low detection of vanB resistance genes suggest the possible presence of other van types and emphasizes the need for further investigations on the incidence of other van genes using molecular screening methods in enterococci isolates in Nigeria for surveillance purposes. Moreover, the low occurrence of virulence genes implies that there might be other mediators of pathogenicity involved in Enterococcus virulence traits.

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