Virulence factors, antibiotic resistance, and bacteriocins in enterococci from artisan foods of animal origin

Valenzuela, Antonio Sánchez; Omar, Nabil Ben; Abriouel, Hikmate; López, Rosario Lucas; Veljović, Katarina; Martı́nez-Cañamero, Magdalena; Topisirovic, Milan Kojic Ljubisa; Gálvez, Antonio

doi:10.1016/j.foodcont.2008.06.004

Cited by 101 publications

(74 citation statements)

References 43 publications

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“…In this study, both antioxidant and antimicrobial activities were investigated in culture supernatants and cell free extracts of lactic acid bacteria isolated from regional dairy and meat products. The selected isolates were identified as Enterococcus faecium, which is a Gram-positive, catalase-negative cocci that share many characteristics with the genera Lactococcus and Streptococcus (Valenzuela et al, 2009). The enterococci are a complex and important group of bacteria that can be found in a variety of food products, such as milk and cheese, meat and vegetables (De Vuyst et al, 2003;Gomes et al, 2008).…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products

et al. 2015

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Lactic acid bacteria (LAB) have an important role in a great variety of fermented foods. In addition to their contribution to sensory characteristics, they enhance food preservation and can be used as probiotics. In this study, the antimicrobial and antioxidant activities of culture supernatants and cell free extracts of 16 LAB isolated from meat and dairy products were investigated. The bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to Enterococcus faecium species. Antimicrobial activity against the indicator microorganism (Listeria monocytogenes) was observed at 11 culture supernatants and 4 cell free extracts. The sensibility of culture supernatant was evaluated by proteinase K and trypsin and it was observed that activity of antimicrobial substance was completely lost after the treatment. All of the isolates showed antioxidant activity as determined by the Thiobarbituric Acid Reactive Substances (TBARS) method with both types of extracts. When the antioxidant capacity was investigated using ABTS •+ method (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH method (2,2-diphenyl-1-picrylhydrazyl) it was observed that only culture supernatants showed antioxidant capacity. These bacteria could particularly help to reduce or inhibit pathogenic microorganisms as well as oxidative spoilage in foods and feed.Keywords: antimicrobial activity, antioxidant, Enterococcus, lactic acid bacteria, molecular characterization.Atividade antimicrobiana e antioxidante de espécies de Enterococcus isoladas de carne e produtos lácteos ResumoAs bactérias ácido láticas (BAL) têm um papel importante em uma grande variedade de alimentos fermentados. Em adição à sua contribuição para as características sensoriais, estes microorganismos melhoram a conservação de alimentos e podem ser utilizados como probióticos. Neste estudo, as atividades antimicrobiana e antioxidante do sobrenadante e dos extratos livres de células de 16 isolados de LAB de carne e produtos lácteos foram investigadas. Os isolados foram identificados pelo sequenciamento da região 16S do rRNA. Após a comparação das sequências obtidas com aquelas disponíveis na base de dados GenBank, observou-e que todos os isolados foram pertencentes à espécie Enterococcus faecium. A atividade antimicrobiana contra o microrganismo indicador (Listeria monocytogenes) foi observada no sobrenadante das culturas em 11 isolados, e nos extratos livres de células por 4 isolados. A sensibilidade da cultura sobrenadante foi avaliada pela proteinase K e tripsina e observou-se que a atividade da substância antimicrobiana foi completamente perdida após o tratamento com as enzimas proteolíticas. Todos os isolados apresentaram atividade antioxidante, como determinado pelo método do ácido tiobarbitúrico de substâncias reativas (TBARS) com ambos os tipos de extratos. Quando a capacidade antioxidante foi investigada usando o método do ABTS (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) e o método de DPPH (2,2-di...

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Section: Discussionmentioning

confidence: 99%

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products

et al. 2015

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“…DNA molecular weight marker 100 bp was used as the standard and gels were photographed under a UV light transilluminator [ALLIANCE 4.7; Merton (a molecular imager gel documentation system)]. Mannu et al, 2003;Valenzuela et al, 2009) -were used to screen the isolates. The reactions were performed in a total volume of 25 µl using 5 µl DNA, 1 µl of 10 pM of each primer, 12.5 µl PCR Dream Taq Master Mix (Thermo Scientific), and water of PCR grade to make up the volume.…”

Section: Methodsmentioning

confidence: 99%

“…The isolates were screened for the presence of virulence factors previously described among enterococci. Specific primers that allow for the detection of the following six virulence genes that have been reported to aid in the colonization and establishment of infections within the host: ace, efaA, cylA, gelE, esp and hylE, as previously described in the literature (Shankar et al, 1999;Mannu et al, 2003;Valenzuela et al, 2009) -were used to screen the isolates. The reactions were performed in a total volume of 25 µl using 5 µl DNA, 1 µl of 10 pM of each primer, 12.5 µl PCR Dream Taq Master Mix (Thermo Scientific), and water of PCR grade to make up the volume.…”

Section: Methodsmentioning

confidence: 99%

Macrolide, glycopeptide resistance and virulence genes in Enterococcus species isolates from dairy cattle

Iweriebor

Chikwelu

Okoh

2016

Journal of Medical Microbiology

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The genus Enterococcus is known to possess the capacity to acquire and disseminate antimicrobial resistant determinants alongside the ability to produce various virulence genes that enables it to establish infections. We assessed the prevalence and antibiogram profiles of Enterococcus spp. in faecal samples of dairy cattle. Faecal swab samples were collected from 400 dairy cattle from two commercial cattle farms in two rural communities in the Eastern Cape, South Africa. Confirmation of enterococci isolates was carried out by PCR targeting of the tuf gene. Species delineation was by species-specific primers targeting the superoxide dismutase (sodA) gene in a multiplex PCR assay. Isolates were screened for the presence of the following virulence genes (ace, gelE, esp, efaA, cylA and hylE) and antimicrobial resistance determinants to erythromycin, vancomycin and streptomycin were evaluated molecularly. A total of 340 isolates were confirmed as belonging to the genus Enterococcus. Species distribution among the isolates consisted of Enterococcus faecium (52.94 %) and Enterococcus durans (23.53 %) in preponderance compared to the three other species, namely Enterococcus faecalis (8.8 %), Enterococcus hirae (8.6 %) and Enterococcus casseliflavus (5.9 %). All were resistant to vancomycin, while 99 % showed resistance to aminoglycoside and 94 % to macrolide. Three virulence genes (ace, gelE and esp) were detected in almost all the confirmed isolates. The resistance determinants vanB (19.7 %), vanC1 (25 %), vanC2/3 (26.3 %) ermB (40.29 %) and strA (50.88 %) were detected among the isolates. A high prevalence of multidrug-resistant enterococci isolates was detected in this study and the genetic repertoire to survive in the presence of antimicrobial agents was present in these organisms. INTRODUCTIONMembers of the genus Enterococcus are known to be abundantly present in the intestinal tracts of humans and warmblooded animals, as well as in water and soil environments. These bacteria have become notorious recently because of their ability to cause nosocomial infections, especially among both immunocompromised patients and elderly people. Pathogenic enterococci have been reported to harbour a pathogenicity island that encodes for aggregation substance (AS), gelatinase, extracellular surface proteins (esp), cytolysin, hyaluronidase and other proteins (Giridhara Upadhyaya et al., 2009;Shankar et al., 2002). These virulence factors enable enterococci to cause tissue damage and inflammation.Besides their possession of several virulence factors, members of the genus Enterococcus also have inherent capacity to accumulate and disseminate antimicrobial resistance determinants. Enterococci, like other bacteria are capable of developing strategies to enhance their survival in adverse situations (Garcia-Migura et al., 2005). They have emerged as an important opportunistic pathogen causing life-threatening infections in patients, alongside the fact that they have developed remarkable resistance to a battery of antimicrobial agents belo...

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“…In addition, an earlier study showed that entAS-48 was widely distributed throughout E. faecalis (Joosten, Rodríguez, & Nuñez, 1997). On the contrary, no equivalence in results was found with other authors, who detected the presence of genes encoding for ent1071 A-B and P in E. faecalis, whereas they never detected genes for entAS-48 (Martín-Platero, Valdivia, Maqueda, & Martínez-Bueno, 2009;Valenzuela et al, 2009). Moreover, a correlation can be established between the gene distribution and the strain origin, since four of the six positive strains were isolated from the same cheese (Valtellina Casera).…”

Section: Detection Of Enterocin Structural Genesmentioning

confidence: 72%

Biopreservation potential ofEnterococcus faecalisisolated from Italian traditional raw milk cheeses

Silvetti

Morandi

Brasca

2013

CyTA - Journal of Food

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Enterococcus faecalis is frequently associated with raw milk cheeses of Mediterranean area. The genetic diversity of 38 E. faecalis obtained from raw milk products in Italy was assessed through Randomly Amplified Polymorphic DNA PCR (RAPD-PCR) and repetitive extragenic palindromic PCR (rep-PCR). The strains were screened for their antimicrobial activity against 5 food-borne spoilage and pathogenic bacteria and 13 lactic acid bacteria (LAB), commonly used as starter cultures. Investigation was made to identify the bacteriocinogenic potential by searching for bacteriocin-encoding genes. Inhibitory effects against undesirable bacteria, including Bacillus cereus (44.7% of strains), Escherichia coli (18.4%), Listeria monocytogenes (15.8%), Staphylococcus aureus (2.6%), and Clostridium sporogenes (21.1%), were detected. Moderate antagonism towards LAB was found. One strain producing enterocin AS-48 was identified, suggesting that the antimicrobial activity of the phenotypically positive isolates should be necessarily due to another non-enterocin factor. A deeper insight into biopreservation potential of dairy E. faecalis was provided, highlighting the influence of this species on cheese microbial community.Keywords: Enterococcus faecalis; biopreservation; enterocins; raw milk cheeses; rep-PCR; RAPD-PCR Frecuentemente, el Enterococcus faecalis es asociado con los quesos de leche cruda de la región mediterránea. En el presente estudio se valoró la diversidad genética de 38 E. faecalis obtenidos de productos de leche cruda de Italia, mediante RAPD-PCR y rep-PCR. Se estudió la actividad antimicrobiana de las cepas a partir de cinco bacterias patógenas y saprófitas de origen alimentario y de 13 bacterias de ácido láctico (BAL) utilizadas comúnmente como cultivos iniciadores. Con el objetivo de identificar el potencial bacteriocinagénico mediante la búsqueda de genes de codificación de bacteriocinas, se realizaron investigaciones, detectándose efectos inhibitorios contra bacterias indeseables, entre las que se incluyen Bacillus cereus (44.7% de las cepas), Escherichia coli (18.4%), Listeria monocytogenes (15.8%), Staphylococcus aureus (2.6%) y Clostridium sporogenes (21.1%). Asimismo, se constató un moderado antagonismo contra las BAL y se identificó una cepa que produce enterocina AS-48, lo cual sugiere que la actividad antimicrobiana de los aislados fenotípicamente positivos es consecuencia de otro factor diferente a la enterocina. El estudio arrojó una comprensión más profunda sobre el potencial de biopreservación de E. faecalis en lácteos, destacándose la influencia de esta especie dentro de la comunidad microbiana de los quesos.

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Virulence factors, antibiotic resistance, and bacteriocins in enterococci from artisan foods of animal origin

Cited by 101 publications

References 43 publications

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products

Macrolide, glycopeptide resistance and virulence genes in Enterococcus species isolates from dairy cattle

Biopreservation potential ofEnterococcus faecalisisolated from Italian traditional raw milk cheeses

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