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1.
Braz J Microbiol ; 55(2): 1131-1138, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38319530

RESUMEN

Pathogenic bacterial biofilms present significant challenges, particularly in food safety and material deterioration. Therefore, using Enterococcus mundtii A2, known for its antagonistic activity against pathogen adhesion, could serve as a novel strategy to reduce pathogenic colonization within the food sector. This study aimed to investigate the biofilm-forming ability of E. mundtii A2, isolated from camel milk, on two widely used stainless steels within the agri-food domain and to assess its anti-adhesive properties against various pathogens, especially on stainless steel 316L. Additionally, investigations into auto-aggregation and co-aggregation were also conducted. Plate count methodologies revealed increased biofilm formation by E. mundtii A2 on 316L, followed by 304L. Scanning electron microscopy (SEM) analysis revealed a dense yet thin biofilm layer, playing a critical role in reducing the adhesion of L. monocytogenes CECT 4032 and Staphylococcus aureus CECT 976, with a significant reduction of ≈ 2 Log CFU/cm2. However, Gram-negative strains, P. aeruginosa ATCC 27853 and E. coli ATCC 25922, exhibit modest adhesion reduction (~ 0.7 Log CFU/cm2). The findings demonstrate the potential of applying E. mundtii A2 biofilms as an effective strategy to reduce the adhesion and propagation of potentially pathogenic bacterial species on stainless steel 316L.


Asunto(s)
Adhesión Bacteriana , Biopelículas , Enterococcus , Acero Inoxidable , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Adhesión Bacteriana/efectos de los fármacos , Enterococcus/fisiología , Enterococcus/efectos de los fármacos , Animales , Microbiología de Alimentos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Antibiosis , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/fisiología , Listeria monocytogenes/crecimiento & desarrollo , Leche/microbiología
2.
Int J Food Microbiol ; 299: 33-38, 2019 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-30952015

RESUMEN

In order to determine the microbial safety of produce, conventional fecal indicator bacteria (CFIB) such as Escherichia coli and Enterococcus are quantified as a standard practice. Bacteroidales are also fecal indicators mostly used for water samples; however, their use and persistence in foods has been rarely studied. In this study, persistence of both CFIB and genetic markers of host-specific Bacteroidales was determined in artificially contaminated materials and vegetables with different textured surfaces under different storage conditions. Sterile feces were contaminated with E. coli, E. faecalis, Bacteroidesthetaiotaomicron (human origin), and Bacteroidales from porcine and bovine origin. Feces were applied to filters of mixed cellulose esters and tomatoes (smooth surface) and flat cork coupons and melons (rough surface) and stored at 10 °C/95% relative humidity (RH) and 25 °C/65%RH for up to 25 days. Bacteroidales markers were analyzed by real-time polymerase chain reaction (qPCR), whereas CFIB were plated onto selective agars. CFIB detection on filters and cork surfaces declined over time. E. coli decreased 2.9 log CFU and 1.2 log CFU per filter and cork, respectively, at 10 °C/95%RH and 5.8 log CFU and 1.8 log CFU per filter and cork, respectively, at 25 °C/65%RH. E. faecalis decreased 1.9 log CFU on filters and 1.3 log CFU on cork at 10 °C/95%RH and 2.6 log CFU/filter and cork under both storage conditions. Although E. coli levels in tomatoes slightly increased during storage, the levels decreased by the end of the assays. However, CFIB levels in melons stored at 10 °C/95%RH increased after 20 days; when stored at 25 °C/65%RH, these levels increased after five days. Bacteroidales levels (universal and host-specific markers) in inanimated material and produce did not show significant differences (P ≤ 0.01) over time. Stability and persistence of Bacteroidales genetic markers make them superior to CFIB as markers and are alternatives for determining the risk of exposure to feces-contaminated produce.


Asunto(s)
Bacteroidetes/fisiología , Enterococcus/fisiología , Escherichia coli/fisiología , Microbiología de Alimentos/métodos , Frutas/microbiología , Animales , Bacteroidetes/genética , Bovinos , Cucurbitaceae/microbiología , Enterococcus/genética , Escherichia coli/genética , Marcadores Genéticos/genética , Humanos , Solanum lycopersicum/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa , Porcinos
3.
Br Poult Sci ; 58(1): 76-82, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27845560

RESUMEN

Poultry fed on wheat-based diets regularly ingest wheat germ agglutinin (WGA) that has toxic effects in vitro on intestinal epithelial cells (IEC) obtained from 14-d-old broilers. Cytotoxicity and the potential role of 14 intestinal bacterial strains in the removal of bound lectins in epithelial cell cultures were investigated. Cytotoxicity was dependent on time and lectin concentration; the lethal dose (LD50) was 8.36 µg/ml for IEC exposed for 2 h to WGA. Complementary sugars to WGA were detected on the surface of one Enterococcus and 9 Lactobacillus strains isolated from poultry. These strains were evaluated as a lectin removal tool for cytotoxicity prevention. Incubation of lactic acid bacteria with WGA before IEC-lectin interaction caused a substantial reduction in the percentage of cell deaths. The protection was attributed to the amount of lectin bound to the bacterial surfaces and was strain-dependent. L. salivarius LET 201 and L. reuteri LET 210 were more efficient than the other lactic acid bacteria assayed. These results provide a basis for the development of probiotic supplements or cell-wall preparations of selected lactic acid bacteria intended to avoid harmful effects of a natural constituent of the grain in wheat-based diets.


Asunto(s)
Pollos/microbiología , Enterococcus/fisiología , Enterocitos/efectos de los fármacos , Lactobacillus/fisiología , Enfermedades de las Aves de Corral/prevención & control , Aglutininas del Germen de Trigo/toxicidad , Animales , Dieta/efectos adversos , Dieta/veterinaria , Enterococcus/aislamiento & purificación , Intestinos/citología , Intestinos/microbiología , Lactobacillus/aislamiento & purificación , Aves de Corral/microbiología , Enfermedades de las Aves de Corral/inducido químicamente , Probióticos , Especificidad de la Especie
4.
Braz. j. microbiol ; Braz. j. microbiol;47(3): 691-696, July-Sept. 2016. tab
Artículo en Inglés | LILACS | ID: lil-788958

RESUMEN

ABSTRACT This study highlights the prevalence of aminoglycoside-modifying enzyme genes and virulence determinants among clinical enterococci with high-level aminoglycoside resistance in Inner Mongolia, China. Screening for high-level aminoglycoside resistance against 117 enterococcal clinical isolates was performed using the agar-screening method. Out of the 117 enterococcal isolates, 46 were selected for further detection and determination of the distribution of aminoglycoside-modifying enzyme-encoding genes and virulence determinants using polymerase chain reaction -based methods. Enterococcus faecium and Enterococcus faecalis were identified as the species of greatest clinical importance. The aac(6')-Ie-aph(2")-Ia and ant(6')-Ia genes were found to be the most common aminoglycoside-modifying enzyme genes among high-level gentamicin resistance and high-level streptomycin resistance isolates, respectively. Moreover, gelE was the most common virulence gene among high-level aminoglycoside resistance isolates. Compared to Enterococcus faecium, Enterococcus faecalis harbored multiple virulence determinants. The results further indicated no correlation between aminoglycoside-modifying enzyme gene profiles and the distribution of virulence genes among the enterococcal isolates with high-level gentamicin resistance or high-level streptomycin resistance evaluated in our study.


Asunto(s)
Masculino , Femenino , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Enterococcus/efectos de los fármacos , Enterococcus/fisiología , Farmacorresistencia Bacteriana , Aminoglicósidos/metabolismo , Aminoglicósidos/farmacología , Virulencia/genética , Pruebas de Sensibilidad Microbiana , China/epidemiología , Prevalencia , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/epidemiología , Enterococcus/metabolismo , Genes Bacterianos , Antibacterianos/metabolismo
5.
Braz J Microbiol ; 47(3): 691-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27268115

RESUMEN

This study highlights the prevalence of aminoglycoside-modifying enzyme genes and virulence determinants among clinical enterococci with high-level aminoglycoside resistance in Inner Mongolia, China. Screening for high-level aminoglycoside resistance against 117 enterococcal clinical isolates was performed using the agar-screening method. Out of the 117 enterococcal isolates, 46 were selected for further detection and determination of the distribution of aminoglycoside-modifying enzyme-encoding genes and virulence determinants using polymerase chain reaction -based methods. Enterococcus faecium and Enterococcus faecalis were identified as the species of greatest clinical importance. The aac(6')-Ie-aph(2″)-Ia and ant(6')-Ia genes were found to be the most common aminoglycoside-modifying enzyme genes among high-level gentamicin resistance and high-level streptomycin resistance isolates, respectively. Moreover, gelE was the most common virulence gene among high-level aminoglycoside resistance isolates. Compared to Enterococcus faecium, Enterococcus faecalis harbored multiple virulence determinants. The results further indicated no correlation between aminoglycoside-modifying enzyme gene profiles and the distribution of virulence genes among the enterococcal isolates with high-level gentamicin resistance or high-level streptomycin resistance evaluated in our study.


Asunto(s)
Aminoglicósidos/metabolismo , Aminoglicósidos/farmacología , Farmacorresistencia Bacteriana , Enterococcus/efectos de los fármacos , Enterococcus/fisiología , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Antibacterianos/farmacología , China/epidemiología , Enterococcus/aislamiento & purificación , Femenino , Genes Bacterianos , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Prevalencia , Virulencia/genética
6.
J Microbiol Biotechnol ; 26(6): 1026-34, 2016 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-26907753

RESUMEN

In the current study, a total of 135 enterococci strains from different sources were screened for the presence of the enterocin-encoding genes entA, entP, entB, entL50A, and entL50B. The enterocin genes were present at different frequencies, with entA occurring the most frequently, followed by entP and entB; entL50A and L50B were not detected. The occurrence of single enterocin genes was higher than the occurrence of multiple enterocin gene combinations. The 80 isolates that harbor at least one enterocin-encoding gene (denoted "Gene(+) strains") were screened for antimicrobial activity. A total of 82.5% of the Gene(+) strains inhibited at least one of the indicator strains, and the isolates harboring multiple enterocin-encoding genes inhibited a larger number of indicator strains than isolates harboring a single gene. The indicator strains that exhibited growth inhibition included Listeria innocua strain CLIP 12612 (ATCC BAA-680), Listeria monocytogenes strain CDC 4555, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, S. aureus ATCC 29213, S. aureus ATCC 6538, Salmonella enteritidis ATCC 13076, Salmonella typhimurium strain UK-1 (ATCC 68169), and Escherichia coli BAC 49LT ETEC. Inhibition due to either bacteriophage lysis or cytolysin activity was excluded. The growth inhibition of antilisterial Gene+ strains was further tested under different culture conditions. Among the culture media formulations, the MRS agar medium supplemented with 2% (w/v) yeast extract was the best solidified medium for enterocin production. Our findings extend the current knowledge of enterocin-producing enterococci, which may have potential applications as biopreservatives in the food industry due to their capability of controlling food spoilage pathogens.


Asunto(s)
Antibacterianos/farmacología , Antibiosis , Enterococcus/genética , Genes Bacterianos , Listeria/fisiología , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Bacteriófagos/fisiología , Hidrocarburos Aromáticos con Puentes/metabolismo , Hidrocarburos Aromáticos con Puentes/farmacología , Medios de Cultivo/química , Enterococcus/crecimiento & desarrollo , Enterococcus/fisiología , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/fisiología , Genotipo , Listeria/crecimiento & desarrollo , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/fisiología , Perforina/genética , Reacción en Cadena de la Polimerasa
7.
Rev. med. interna Guatem ; 20(supl. 1): 46-49, 2016. ilus
Artículo en Español | LILACS | ID: biblio-987522

RESUMEN

La endocarditis infecciosa por Enterococcus gallinarum no es muy común, actualmente se reportan pocos casos. Los Enterococcus spp. son bacterias que se encuentran en el tracto intestinal de humanos, mamíferos y aves; así como el tracto genital femenino de los seres humanos. Encontrar éstos microorganismos en sangre puede indicar la presencia de contaminación, en particular si tomamos en cuenta que sobreviven a condiciones extremas de clima (temperatura y pH).1 Enterococcus gallinarum es parte de la microbiota normal del tracto gastrointestinal, pero también puede encontrarse en enfermos hospitalizados, particularmente por periodos prolongados así como en alimentos. La bacteriemia causada por éstos afectan generalmente a pacientes inmunocomprometidos o con enfermedades crónicas debilitantes y/o degenerativas.2 La bacteriemia se define como la presencia de microorganismos en sangre, comprobado por 2 o más hemocultivos; una higiene oral inadecuada puede conllevar a inflamación y ulceración gingival; así mismo la manipulación de procedimientos odontológicos que impliquen procedimientos invasivos de mucosa gingival o lesiones en la misma como un cepillado dental que cause sangrado de la mucosa oral.3 Usualmente la infección de E. gallinarum se acompaña de una infección polimicrobiana. Últimamente se ha visto un aumento de enfermedades adquiridas en la comunidad de especies de Enterococcos spp resistentes hacia distintos fármacos, pero en especial a la Vancomicina, debido al uso indiscriminado de la avoparcina, un antimicrobiano del grupo de los glicopéptidos, que se usa en la industria y crianza de animales de granja.1 (AU)


Asunto(s)
Humanos , Femenino , Adulto , Infecciones Bacterianas/tratamiento farmacológico , Enterococcus/fisiología , Bacteriemia/diagnóstico , Endocarditis Bacteriana/microbiología , Guatemala , Antiinfecciosos/efectos adversos
8.
Artículo en Inglés | MEDLINE | ID: mdl-26513931

RESUMEN

Nosocomial infections are one of the leading causes of morbidity and mortality. This study determined both prevalence and antimicrobial susceptibility of microorganisms identified during January to December 2012 at a tertiary public hospital, Sao Paulo, Brazil. Data, hospital length of stay, age, identity of microorganisms, and antimicrobial susceptibilities were obtained from patients' records. A total of 724 positive strains were obtained from different body sites. Gram-negative microorganisms are significantly more prevalent than gram-positive microorganisms (p = 0.001). In all clinics analyzed, coagulase-negative Staphylococcus (CoNS) was the most prevalent microorganism isolated (21.6%), followed by Pseudomonas aeruginosa (12.4%). Extended spectrum ß-lactamase Klebsiella pneumoniae was present in 62.7% of the strains and 18.9% were resistant to carbapenem/meropenem. Acinetobacter baumannii showed multidrug resistance. The majority of Escherichia coli isolates were obtained from positive urinary tract cultures (63.4%), with 27.5% resistant against cefepime. Elderly patients, long periods of hospital stay and continuous usage of a single antibiotic should be kept in mind of possible causes for infection of A. baumannii, ESBL and carbapenem-resistant K. pneumoniae and the worrisome E. coli with increased resistance to cefepime. The data allowed us to implement monitoring programs as part of the prevention strategy against pathogens prevalence and antibiotic resistance burden at Ipiranga Hospital, Sao Paulo, Brazil.


Asunto(s)
Antibacterianos , Infecciones Bacterianas/epidemiología , Infección Hospitalaria/epidemiología , Farmacorresistencia Bacteriana , Hospitales Públicos , Centros de Atención Terciaria , Infecciones por Acinetobacter/epidemiología , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/aislamiento & purificación , Acinetobacter baumannii/fisiología , Infecciones Bacterianas/microbiología , Brasil/epidemiología , Estudios de Cohortes , Infección Hospitalaria/microbiología , Enterococcus/aislamiento & purificación , Enterococcus/fisiología , Escherichia coli/aislamiento & purificación , Escherichia coli/fisiología , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/fisiología , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas/epidemiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/aislamiento & purificación , Pseudomonas aeruginosa/fisiología , Estudios Retrospectivos , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus/aislamiento & purificación , Staphylococcus/fisiología
9.
Braz J Microbiol ; 45(1): 111-5, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24948921

RESUMEN

We evaluated the frequency of enterococci from food and found 95.2% of positivity, being E. faecium and E. faecalis the most frequent species. High-level streptomycin resistance was observed, as well as gelatinase and hemolysis activity, showing the potential role of environmental strains as reservoir of virulence and resistance traits.


Asunto(s)
Enterococcus/clasificación , Enterococcus/aislamiento & purificación , Contaminación de Alimentos , Microbiología de Alimentos , Brasil , Farmacorresistencia Bacteriana , Enterococcus/fisiología , Gelatinasas/análisis , Hemólisis , Prevalencia , Factores de Virulencia/análisis
10.
J Dairy Sci ; 97(2): 789-97, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24359825

RESUMEN

Bovine Enterococcus mundtii CRL1656 (Centro de Referencia para Lactobacilos Culture Collection) produces an anti-Listeria and anti-Streptococcus dysgalactiae bacteriocin identified as mundticin CRL1656. The strain and its bacteriocin are candidates to be included in a beneficial product to prevent bovine mastitis as an alternative to antimicrobial agents. To optimize the production of biomass and mundticin CRL1656 by E. mundtii CRL1656, a complete 3 × 2(4) factorial design was applied. The effect of culture medium, initial pH, inoculum size, incubation temperature, and agitation conditions on biomass and bacteriocin production was evaluated simultaneously. Growth parameters were determined using the modified Gompertz model. A nonlinear model was used to estimate the effects of the variables on growth parameters. Bacteriocin production was analyzed using a linear mixed model. Optimal biomass and mundticin CRL1656 production by E. mundtii CRL1656 were obtained in different conditions. Maximal growth was recorded in autolyzed yeast, peptone, tryptone, Tween 80, and glucose or M17 broths, pH 6.5, 5.0% inoculum, 30 °C, with agitation. However, bacteriocin titers were higher in autolyzed yeast, peptone, tryptone, Tween 80, and glucose or de Man-Rogosa-Sharpe (MRS) broths, pH 6.5, 30°C, both with or without agitation. Knowledge of the optimum conditions for growth and bacteriocin production of E. mundtii CRL1656 will allow the obtainment of high levels of biomass and mundticin CRL1656 as bioingredients of potential products to prevent bovine mastitis.


Asunto(s)
Bacteriocinas/metabolismo , Biomasa , Bovinos/microbiología , Medios de Cultivo/química , Enterococcus/fisiología , Animales , Bovinos/fisiología , Femenino , Probióticos/química
11.
Braz. j. microbiol ; Braz. j. microbiol;45(1): 111-115, 2014. tab
Artículo en Inglés | LILACS | ID: lil-709493

RESUMEN

We evaluated the frequency of enterococci from food and found 95.2% of positivity, being E. faecium and E. faecalis the most frequent species. High-level streptomycin resistance was observed, as well as gelatinase and hemolysis activity, showing the potential role of environmental strains as reservoir of virulence and resistance traits.


Asunto(s)
Enterococcus/clasificación , Enterococcus/aislamiento & purificación , Contaminación de Alimentos , Microbiología de Alimentos , Brasil , Farmacorresistencia Bacteriana , Enterococcus/fisiología , Gelatinasas/análisis , Hemólisis , Prevalencia , Factores de Virulencia/análisis
12.
Braz. J. Microbiol. ; 45(1): 111-115, 2014. tab
Artículo en Inglés | VETINDEX | ID: vti-745895

RESUMEN

We evaluated the frequency of enterococci from food and found 95.2% of positivity, being E. faecium and E. faecalis the most frequent species. High-level streptomycin resistance was observed, as well as gelatinase and hemolysis activity, showing the potential role of environmental strains as reservoir of virulence and resistance traits.(AU)


Asunto(s)
Enterococcus/clasificación , Enterococcus/aislamiento & purificación , Contaminación de Alimentos , Microbiología de Alimentos , Brasil , Farmacorresistencia Bacteriana , Enterococcus/fisiología , Gelatinasas/análisis , Hemólisis , Prevalencia , Factores de Virulencia/análisis
13.
Benef Microbes ; 4(3): 267-75, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23538205

RESUMEN

Lactic acid bacteria were isolated and identified in the faeces of Chinese Crested and Yorkshire terrier pups and their probiotic features were investigated in vitro. Thirty seven isolates were identified as Lactobacillus or Enterococcus. Out of these isolates, 31 were lactic acid bacteria (LAB) and belonged to the species Lactobacillus reuteri (16/37; 43.3%), Lactobacillus animalis (7/37; 18.9%), Lactobacillus acidophilus (3/37; 8.1%), Lactobacillus sanfranciscensis (2/37; 5.4%), Lactobacillus murinus (2/37; 5.4%), and Lactobacillus paraplantarum (1/37; 2.7%), while six other LAB isolates were Enterococcus spp. (6/37; 16.2%). Strains were tested for resistance to gastric acidity (pH 2.5 for 3 h) and bile salts (0.3% ox gall), cell surface hydrophobicity by microbial adhesion to solvents, antagonism against pathogenic bacteria (Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica serovar Typhimurium and Listeria monocytogenes), production of hydrogen peroxide, and antibiotic susceptibility. Thirty four strains were highly resistant to acidic conditions with slight (18 strains) to moderate (16 strains) growth inhibition by bile salts. Seven isolates had highly hydrophobic cellular surfaces and 28 strains exhibited strong antagonism against the bacterial pathogens tested, although 8 isolates tested against Leptospira interrogans had no effect on pathogen growth. All isolates produced low rates of hydrogen peroxide. Based on these results, two Lactobacillus strains showed promising probiotic-related features and merit investigation as probiotics for dogs.


Asunto(s)
Perros , Enterococcus/aislamiento & purificación , Enterococcus/fisiología , Heces/microbiología , Lactobacillus/aislamiento & purificación , Lactobacillus/fisiología , Probióticos/aislamiento & purificación , Animales , Antibiosis , Farmacorresistencia Bacteriana , Enterococcus/clasificación , Enterococcus/efectos de los fármacos , Peróxido de Hidrógeno/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Lactobacillus/clasificación , Lactobacillus/efectos de los fármacos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Estrés Fisiológico
14.
Microbiol Res ; 166(1): 1-13, 2011 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-20116222

RESUMEN

Eight strains belonging to Lactobacillus spp. and five to Enterococcus spp. were isolated from the gut of worker Apis mellifera L. bees. Studies based on 16S rRNA sequencing revealed that AJ5, IG9, A15 and CRL1647 strains had a 99% identity with Lactobacillus johnsonii, while SM21 showed a 99% similarity with Enterococcus faecium. L. johnsonii CRL1647, AJ5 and IG9 were high lactic acid producers (values were between 177 and 275 mM), and in vitro they inhibited different human food-borne pathogens and Paenibacillus larvae, the American foulbrood agent. This bacterium was the most sensitive to the lactic acid effect being inhibited by 44 mM of this metabolite. L. johnsonii CRL1647, AJ5 and IG9 also presented important surface properties. These cells showed between 77% and 93% of auto-aggregation. The preliminary study of the chemical nature of the aggregating factors revealed that the molecules involved in the surface of each L. johnsonii strain were quite complex; and something of a peptidic nature was mainly involved. E. faecium SM21 produced bacteriocin-like compounds with anti-Listeria effects. Furthermore, a band close to 6.0-7.5 kDA was detected by SDS-PAGE studies, and the entA, B and P structural genes were amplified by PCR reactions. For the first time, bee-gut associated L. johnsonii and E. faecium strains have been isolated, identified, cultivated and some of their functional properties reported.


Asunto(s)
Antibacterianos/farmacología , Bacteriocinas/farmacología , Abejas/microbiología , Enterococcus/clasificación , Enterococcus/fisiología , Ácido Láctico/biosíntesis , Lactobacillus/clasificación , Lactobacillus/fisiología , Animales , Antibiosis , Bacteriocinas/biosíntesis , Biodiversidad , ADN Bacteriano/análisis , Enterococcus/química , Enterococcus/genética , Enterococcus/aislamiento & purificación , Enterococcus faecium/genética , Genotipo , Intestinos/microbiología , Lactobacillus/química , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Listeria/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Paenibacillus/efectos de los fármacos , Fenotipo , Filogenia , ARN Ribosómico 16S/genética , Propiedades de Superficie
15.
Fish Physiol Biochem ; 35(1): 219-22, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18777139

RESUMEN

This study evaluated the total and differential leukocyte counting and the phagocytic activity in Nile tilapia Oreochromis niloticus experimentally injected with Enterococcus sp. in the swim bladder. Fish were distributed in four treatments in triplicates of non-injected fish, fish injected with 1 ml of sterile saline solution 0.65%, and fish injected with 1 x 10(3) and 1 x 10(6) colony-forming units (CFU) of Enterococcus diluted in 1 ml sterile saline. Twenty-four hours after injection, the fish were anesthetized and the blood collected for white blood cell (WBC) counts, differential counting of WBC, and phagocytic activity of blood leukocytes. The increased numbers of WBC and lymphocytes were followed by decreased number of monocyte after infection. The percentages of phagocytic activities in the blood were 55.3 and 55.9%, respectively, in tilapia injected with 1 x 10(3) and 1 x 10(6) CFU/ml.


Asunto(s)
Cíclidos/inmunología , Enterococcus/fisiología , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/microbiología , Infecciones por Bacterias Grampositivas/veterinaria , Leucocitos/inmunología , Fagocitosis/inmunología , Animales , Infecciones por Bacterias Grampositivas/inmunología , Infecciones por Bacterias Grampositivas/microbiología , Recuento de Leucocitos
16.
Mar Pollut Bull ; 58(1): 45-54, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18952244

RESUMEN

Human fecal contamination of coral reefs is a major cause of concern. Conventional methods used to monitor microbial water quality cannot be used to discriminate between different fecal pollution sources. Fecal coliforms, enterococci, and human-specific Bacteroides (HF183, HF134), general Bacteroides-Prevotella (GB32), and Clostridium coccoides group (CP) 16S rDNA PCR assays were used to test for the presence of non-point source fecal contamination across the southwestern Puerto Rico shelf. Inshore waters were highly turbid, consistently receiving fecal pollution from variable sources, and showing the highest frequency of positive molecular marker signals. Signals were also detected at offshore waters in compliance with existing microbiological quality regulations. Phylogenetic analysis showed that most isolates were of human fecal origin. The geographic extent of non-point source fecal pollution was large and impacted extensive coral reef systems. This could have deleterious long-term impacts on public health, local fisheries and in tourism potential if not adequately addressed.


Asunto(s)
Antozoos/microbiología , Microbiología Ambiental , Monitoreo del Ambiente/métodos , Heces/microbiología , Reacción en Cadena de la Polimerasa/métodos , Contaminantes del Agua/análisis , Animales , Antozoos/fisiología , Bacteroides/aislamiento & purificación , Bacteroides/fisiología , Biomarcadores , Recuento de Colonia Microbiana , Enterococcus/aislamiento & purificación , Enterococcus/fisiología , Escherichia coli/aislamiento & purificación , Escherichia coli/fisiología , Humanos , Océanos y Mares , Filogenia , Puerto Rico , Análisis de Regresión , Agua de Mar/química
17.
Food Microbiol ; 25(5): 668-75, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18541165

RESUMEN

Enterococci can be used in the food industry as starter or probiotic cultures. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, the prevalence of enterococci in selected Brazilian foodstuffs (raw and pasteurized milk, meat products, cheeses and vegetables) was evaluated. Phenotypic and PCR protocols were used for species identification. Tests for production of gelatinase, haemolysin, bacteriocin and bile salt hydrolysis were done with all enterococci isolates, whereas molecular determination of virulence markers (genes esp, gel, ace, as, efaA, hyl and cylA) and antibiotic resistance was checked only for Enterococcus faecium and Enterococcus faecalis isolates. The antibiotic-resistant isolates were assayed for biofilm formation and adhesion to mammalian cells. From the 120 food samples analyzed, 52.5% were positive for enterococci, meat and cheese being the most contaminated. E. faecium was the predominant species, followed by E. faecalis, E. casseliflavus and Enterococcus gallinarum. Phenotypic tests indicated that 67.7% of isolates hydrolyzed bile salts, 15.2% produced bacteriocin, 12.0% were beta-hemolytic and 18.2% produced gelatinase. Antibiotic resistance (gentamicin, tetracycline and erythromycin) and genes encoding for virulence traits were more frequent in E. faecalis than in E. faecium. Three E. faecium isolates were resistant to vancomycin. Among antibiotic-resistant isolates, 72.4% of E. faecalis were able to form biofilm and 13.8% to adhere to Caco-2 cells. Antibiotic-resistant E. faecalis and E. faecium isolates were grouped by RAPD-PCR and a scattered distribution was noted, indicating that resistance was not related to a particular clone. The spread of virulence/resistance traits in isolates of the two species and different RAPD-types suggest the pathogenic potential of both species. By contrast, the recovery of bacteriocinogenic E. faecium isolates with no virulence traits suggests their potential for biotechnological applications. In conclusion, our results showed that enterococci from Brazilian foods present important dualist aspects for food safety.


Asunto(s)
Seguridad de Productos para el Consumidor , Farmacorresistencia Bacteriana , Enterococcus , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Antibacterianos/farmacología , Adhesión Bacteriana , Biopelículas/crecimiento & desarrollo , Brasil/epidemiología , Células CACO-2 , Queso/microbiología , Recuento de Colonia Microbiana , ADN Bacteriano/química , ADN Bacteriano/genética , Enterococcus/efectos de los fármacos , Enterococcus/aislamiento & purificación , Enterococcus/patogenicidad , Enterococcus/fisiología , Humanos , Carne/microbiología , Pruebas de Sensibilidad Microbiana , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia , Especificidad de la Especie , Factores de Virulencia/genética
18.
Can Vet J ; 49(10): 991-4, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19119367

RESUMEN

The concentrations of lactic acid bacteria (LAB) in 42 vaginal samples from healthy and ill bitches were determined. Eight isolates belonging to the genera Lactobacillus and Enterococcus were selected and identified and their in vitro antimicrobial activity against canine pathogens and their ability to adhere to canine vaginal epithelial cells were determined. There was no correlation between the concentrations of vaginal LAB and clinical status, body temperature, vaginal pH, or age. Although the animals were either well or suffering from various illnesses, LAB were found in almost every sample, and the selected isolates showed promising probiotic-related features. These findings are significant for the design of strategies for the modulation of vaginal microbiota by vaginal LAB isolates.


Asunto(s)
Antibiosis , Adhesión Bacteriana/fisiología , Enfermedades de los Perros/microbiología , Enterococcus/fisiología , Lactobacillus/fisiología , Probióticos , Vagina/microbiología , Animales , Recuento de Colonia Microbiana/veterinaria , Perros , Enterococcus/aislamiento & purificación , Células Epiteliales/microbiología , Escherichia coli/crecimiento & desarrollo , Femenino , Lactobacillus/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/veterinaria , Pseudomonas/crecimiento & desarrollo , Staphylococcus aureus/crecimiento & desarrollo
19.
J Appl Microbiol ; 100(1): 123-34, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16405692

RESUMEN

AIMS: To assess the inhibitory activity on Gram-positive and Gram-negative bacteria of several species of enterococci recovered from a natural corn silage. METHODS AND RESULTS: The inhibitory activity of strains of Enterococcus faecalis (58), Enterococcus faecium (35), Enterococcus gallinarum (3) and Enterococcus casseliflavus (4) were studied employing indicator strains from various sources (clinical, food and ATCC). Enterococcus faecalis MR99, the only strain with inhibitory activity, inhibited other enterococci, Listeria spp., Staphylococcus aureus, Clostridium spp., Bacillus spp., Escherichia coli, Shigella sonnei and Shigella flexneri. The bacterium contained only one conjugative pheromone-responsive plasmid. The partially chromatography-purified MR99 enterocin (PPE) had a molecular weight of approx. 5000 Da and a pI of 6.2, was sensitive to proteolytic enzymes and could be extracted in benzene and butanol. It appeared stable to adjustment of pH 4.0, 5.0, 6.0, 7.0 and 8.0 and was resistant to heat. Inactivation was at 15 min at 121 degrees C. Enterocin MR99 was bactericidal on strains of Listeria monocytogenes, Staph. aureus, and bovine mastitis agents, it was bacteriostatic on E. coli. Although enterocins MR99 and AS48 have inhibitory activity on Gram-negative bacilli, PCR studies demonstrated a lack of relationship between them. CONCLUSIONS: The active component had a protein nature, was resistant to heat and presented a wide inhibitory spectrum. SIGNIFICANCE AND IMPACT OF THE STUDY: The biological properties of Ent. faecalis MR99 suggest that this strain merits further investigations so it can be applied in human and veterinary health programmes.


Asunto(s)
Bacteriocinas/farmacología , Enterococcus/fisiología , Microbiología de Alimentos , Ensilaje/microbiología , Zea mays/microbiología , Bacillus/efectos de los fármacos , Hidrocarburos Aromáticos con Puentes/análisis , Hidrocarburos Aromáticos con Puentes/farmacología , Clostridium/efectos de los fármacos , Medios de Cultivo , Electroforesis en Gel de Poliacrilamida/métodos , Enterococcus faecalis/fisiología , Enterococcus faecium/fisiología , Escherichia coli/efectos de los fármacos , Focalización Isoeléctrica/métodos , Listeria/efectos de los fármacos , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/ultraestructura , Microscopía Electrónica/métodos , Plásmidos/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Shigella/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/ultraestructura
20.
Reprod Nutr Dev ; 44(5): 397-405, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15636159

RESUMEN

In order to determine probiotic properties, 137 strains of lactic acid bacteria from the feces of Creole goats were screened, only six were resistant to pH 2.0 and bile salts (0.3%). Three strains identified as Lactobacillus and two as Enterococcus showed agglutination with the treated yeast. Between them, Lactobacillus DDL17, DDL19, DDL48 and Enterococcus DDE39 demonstrated high specificity in this test because the correspondent agglutination was inhibited by one sugar, suggesting the presence of a lectin-like structure in their cell walls, which could be due to adhesion ability. Another Enterococcus strain (DDE55) showed low affinity because five sugars inhibited the agglutination of the treated yeasts. The results of hydrophobic properties showed that the strains who were able to agglutinate yeasts presented similar hydrophobic characteristics as hexadecane, xylene and toluene, but high specificity was not related to a high hydrophobicity. Only two strains (Lactobacillus DDL19 and DDL48) showed aggregation with the lowest concentration of ammonium sulfate, complementing the hydrophobicity assay. Only one strain, Lactobacillus DDL48, showed an inhibition against an enteric indicator strain (Salmonella Typhimurium and Escherichia coli O111). This inhibitory action was not affected by the addition of catalase and no inhibition was detected after neutralizing the supernatant culture fluid. These strains could be pre-selected in order to complete studies focused on designing a probiotic for use in goat feed.


Asunto(s)
Enterococcus/fisiología , Cabras , Lactobacillus/fisiología , Probióticos/administración & dosificación , Salmonella typhimurium/crecimiento & desarrollo , Pruebas de Aglutinación , Animales , Antibiosis , Adhesión Bacteriana , Enterococcus/aislamiento & purificación , Enterococcus/metabolismo , Heces/microbiología , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Lactobacillus/aislamiento & purificación , Lactobacillus/metabolismo
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