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1.
Braz. j. microbiol ; 48(3): 576-586, July-Sept. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-889141

RESUMO

Abstract The present work discusses the technological and new selection criteria that should be included for selecting lactic acid bacteria for production of fermented meat. Lactic acid bacteria isolated from Bulgarian traditional fermented "lulanka" salami was studied regarding some positive technological parameters (growth at different temperature, pH, and proteolytic activity). The presence of genes related to the virulence factors, production of biogenic amines, and vancomycin resistance were presented in low frequency in the studied lactic acid bacteria. On the other hand, production of antimicrobial peptides and high spread of bacteriocin genes were broadly presented. Very strong activity against L. monocytogenes was detected in some of the studied lactic acid bacteria. In addition, the studied strains did not present any antimicrobial activity against tested closely related bacteria such as Lactobacillus spp., Lactococcus spp., Enterococcus spp. or Pediococcus spp. To our knowledge this is the first study on the safety and antimicrobial properties of lactic acid bacteria isolated from Bulgarian lukanka obtained by spontaneous fermentation.


Assuntos
Animais , Lactobacillales/isolamento & purificação , Lactobacillales/metabolismo , Produtos da Carne/microbiologia , Suínos , Aminas Biogênicas/metabolismo , Lactobacillales/efeitos dos fármacos , Lactobacillales/genética , Fermentação , Inocuidade dos Alimentos , Microbiologia de Alimentos , Antibacterianos/farmacologia
2.
Vitae (Medellín) ; 23(3): 167-172, 2016. Ilustraciones
Artigo em Inglês | LILACS, COLNAL | ID: biblio-988486

RESUMO

Background: Ready to eat sliced-cooked-meat-products (RTE) are popular convenience foods. Slicing of such products at retail point is a common practice in supermarkets. Due to handling, as well as the supermarket environment, it has been suggested that the counts and presence of specific lactic acid bacteria (LAB) in these products may be associated with their rapid deterioration and short shelf life. Objectives: The aim was to quantify and identify LAB in commercial sliced cooked ham. Methods: Thirty samples of sliced cooked ham were collected from five supermarkets. Each sample was analyzed in terms of: Lactobacillus on De Man Rogosa, Sharpe agar (30°C), mesophilic (30°C) and thermophilic (37ºC) Streptococcus on M17 agar containing 1% lactose, Lactococcus on LM17 agar containing 100 µg per liter of cycloheximide (25°C) and Enterococci on Kanamicin Aesculin Azide agar containing kanamycin (37°C), all under anaerobic conditions (Gas-Pack System®, BBL) for 48-72h. Twenty-one colonies were randomly picked and physiologically and biochemically characterized. Results: No difference was observed in genuses between supermarkets; however, significant differences were observed between microbial genuses. Enterococci showed the lowest count (2.34 ± 0.05 log10 CFU/g) and Lactobacilli had the highest counts (5.98 ± 0.04 log10 CFU/g). Of the strains isolated 23.8% were identified as thermophillic Lactobacillus, 23.8% mesophilic Lactobacillus, 28.6% Enterococcus, 14.3% Lactococcus and 9.5% Streptococcus. From these, only six could be characterized to species level; one was L.lactis subsp. lactis and five were L. amylolyticus. Conclusions: High LAB counts are a common cause of spoilage in RTE meat products, since these are commonly found in meat environments. Therefore a study on the processing, distribution and in-site handling of RTE meat products at supermarkets may be necessary in order to increase its shelf life.


Antecedentes: Los productos cárnicos rebanados cocidos listos para el consumo (RTE) son alimentos populares de conveniencia. El rebanado de este tipo de productos es una práctica común en los supermercados. Debido a la manipulación, así como al entorno del supermercado, se ha sugerido que los recuentos y la presencia de bacterias ácido lácticas (LAB) en estos productos pueden estar asociados con su rápido deterioro y corta vida en anaquel. Objetivo: El objetivo de este trabajo fue cuantificar e identificar LAB en jamón cocido rebanado en el supermercado. Métodos: se recolectaron 30 muestras de jamón cocido rebanado de cinco supermercados. Cada muestra se analizó en términos de: Lactobacillus en agar De Man Rogosa, Sharpe (30°C), Streptococcus mesofílicos (30°C) y termofílicos (37°C) en agar M17 conteniendo 1% de lactosa, Lactococcus en agar LM17 contiendo 100 µg por litro de ciclohexamida (25°C), y Enterococci en agar Kanamicin Aesculin Azide conteniendo kanamicina (37°C), todos bajo condiciones anaeróbicas (Gas-Pack System®, BBL) por 48-72h. Veintiún colonias seleccionadas al azar fueron fisiológica y bioquímicamente caracterizadas. Resultados: No se observaron diferencias en el género entre los supermercados; sin embargo, se observaron diferencias significativas entre género microbiano. Los enterococos mostraron los recuentos más bajos (2,34 ± 0,05 log10 CFU/g) y los lactobacilos los más altos (5,98 ± 0,04 log10 CFU/g). De las cepas aisladas 23,8% fueron identificados como Lactobacillus termófilos, 23,8% Lactobacillus mesófilos, 28,6% Enterococcus, 14,3% Lactococcus y 9,5% Streptococcus. De éstos, sólo seis pudieron caracterizarse a nivel de especie; uno fue L.lactis subsp lactis y cinco fueron L. amylolyticus. Conclusiones: Conteos altos de LAB son una causa común del deterioro de los productos cárnicos listos para el consumo, ya que estos se encuentran comúnmente en los entornos donde se maneja carne. Por lo tanto, es necesario llevar a cabo un estudio sobre el procesamiento, distribución y manejo de productos cárnicos listos para el consumo en los supermercados con el fin de aumentar su vida en anaquel.


Assuntos
Humanos , Lactobacillales , Produtos da Carne , Prazo de Validade de Produtos , Lactobacillus
3.
Braz. j. microbiol ; 46(1): 173-181, 05/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-748235

RESUMO

The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc/Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus, following by Lactobacillus sakei and Leuconostoc mesentereoides; the Enterococcus sp. was not present in the samples.


Assuntos
Carga Bacteriana , Microbiologia de Alimentos , Lactobacillales/classificação , Lactobacillales/isolamento & purificação , Embalagem de Alimentos , Temperatura , Fatores de Tempo , Vácuo
4.
Braz. j. microbiol ; 45(1): 25-33, 2014. ilus, tab
Artigo em Inglês | LILACS | ID: lil-709475

RESUMO

A total of 244 lactic acid bacteria (LAB) strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7%) followed by Streptococcus spp. (65, 36.1%) and Lactococcus spp. (27, 15%). Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast) were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus,8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M) and/or erm(B)]. PCR assays shows that some resistant strains harbor tet(M) and/or erm(B) resistance genes.


Assuntos
Humanos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Laticínios/microbiologia , Lactobacillales/efeitos dos fármacos , Lactobacillales/isolamento & purificação , Preparações Farmacêuticas , DNA Bacteriano/genética , Egito , Genes Bacterianos , Lactobacillales/classificação , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase
5.
Braz. j. microbiol ; 44(2): 407-415, 2013. tab
Artigo em Inglês | LILACS | ID: lil-688578

RESUMO

The influences of fish infusion decarboxylase broth (IDB) on biogenic amines (BA) formation by lactic acid bacteria (LAB) were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream) IDB. The result of the study showed that significant differences in ammonia (AMN) and BA production were observed among the LAB strains in fish IDB (p < 0.05). The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM), dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L) and mackerel (100.84 mg/L) IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L) in sardine IDB.


Assuntos
Aminas Biogênicas/metabolismo , Meios de Cultura/química , Lactobacillales/metabolismo , Amônia/metabolismo , Ácido Láctico/metabolismo , Lactobacillales/crescimento & desenvolvimento
6.
J. appl. oral sci ; 18(4): 426-431, July-Aug. 2010. graf, tab
Artigo em Inglês | LILACS | ID: lil-557116

RESUMO

OBJECTIVE: The aim of this study was to detect the prevalence of selected bacterial species in intraoral sites of patients with chronic periodontitis (CP) using multiplex polymerase chain reaction (PCR). METHODOLOGY: Samples were collected from the tongue dorsum, buccal mucosa, supragingival and subgingival plaque and saliva of 30 patients with untreated CP. Multiplex PCR was used to determine prevalence rates, which were then compared using a chi-square test. Significance level was set at p<0.05. Mean and standard deviation values were used to evaluate variations in prevalence according to site. RESULTS: The prevalence of S. mutans was 70 percent in saliva; 60 percent in samples collected from the tongue dorsum; 50 percent in samples collected from the buccal mucosa; 56.5 percent in the supragingival plaque; and 53.5 percent in the subgingival plaque. The prevalence of E. faecalis ranged from 3.5 percent to 13.5 percent in all intraoral microenvironment. The highest prevalence of P. gingivalis was found in subgingival plaque (53.5 percent), and of P. intermedia in supragingival plaque (33.5 percent), subgingival plaque (30 percent) and tongue dorsum (33.5 percent). The prevalence of bacteria did not vary significantly among the intraoral sites. CONCLUSIONS: All studied bacteria were identified in intraoral sites. S. mutans, P. gingivalis and P. intermedia had high prevalence rates, but the prevalence of E. faecalis was low. Multiplex PCR proved to be an adequate method for epidemiological studies.


Assuntos
Adulto , Feminino , Humanos , Masculino , Bacteroidaceae/classificação , Periodontite Crônica/microbiologia , Lactobacillales/classificação , Reação em Cadeia da Polimerase/métodos , Bochecha/microbiologia , Periodontite Crônica/classificação , Placa Dentária/microbiologia , Enterococcus faecalis/isolamento & purificação , Gengiva/microbiologia , Hemorragia Gengival/classificação , Mucosa Bucal/microbiologia , Bolsa Periodontal/classificação , Porphyromonas gingivalis/isolamento & purificação , Prevotella intermedia/isolamento & purificação , Saliva/microbiologia , Streptococcus mutans/isolamento & purificação , Língua/microbiologia
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