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1.
Arq. bras. med. vet. zootec. (Online) ; 71(5): 1686-1694, set.-out. 2019. tab
Article in Portuguese | VETINDEX, LILACS | ID: biblio-1038671

ABSTRACT

O objetivo deste trabalho foi avaliar a pastagem, o desempenho, o conforto térmico e os parâmetros hematológicos de bovinos Nelore na fase de terminação em sistemas integrados de produção agropecuária com duas densidades de árvores (ILPF-1L= 196 árvores ha-1 e ILPF-3L=448 árvores ha-1) e em pleno sol (ILP). Foram avaliados a massa e a composição morfológica da forragem, o ganho médio diário, o ganho de peso por área e a taxa de lotação no verão e no outono, bem como as variáveis climáticas dos sistemas em três horários e parâmetros hematológicos dos animais (n=60). A massa de forragem foi superior no tratamento ILP e no verão (P<0,05). Porém, a redução da massa de forragem nos sistemas ILPFs não interferiu no desempenho dos animais (P>0,05). A temperatura ambiente, a temperatura do globo e o índice de temperatura e umidade foram melhores nos tratamentos com sombreamento e no período da manhã, proporcionando maior conforto aos animais, sendo ainda confirmado pelo menor volume globular dos bovinos em ILP (P<0,05). Conclui-se que os sistemas com componente arbóreo diminuem a massa de forragem, mas essa redução não altera o desempenho dos animais na fase de terminação. Além disso, os sistemas ILPFs melhoram o conforto térmico, entretanto essa melhora não foi suficiente para favorecer o desempenho.(AU)


The objective of this work was to evaluate pasture, performace, thermal comfort, and haematological parameters of Nellore cattle in the finishing phase in integrated crop-livestock systems with two tree densities (ICLF-1L= 196 ha -1 trees and ICLF-3L= 448 ha -1 trees) and in full sun (ICL). The forage mass morphological composition of the pasture average daily gain, weight gain per area, stocking rate of the animals were evaluated in summer and autumn, and the climatic variables of systems we evaluated at three different times, and haematological parameters of the animals (n= 60). The forage mass was higher in the ICL treatment and summer (P<0.05). However, the reduction of the forage mass in the ILPFs systems did not interfere with the performance of the animals (P>0.05). Ambient temperature, globe temperature and temperature and humidity index were better in shade treatments and in the morning, providing greater comfort to the animals, and was also confirmed by the lower globular volume of the bovines in ICL (P<0.05). It is concluded that the systems with trees reduce the forage mass but this reduction does not alter the animals' performance in the finishing phase. In addition, ICLFs improve the thermal comfort of the animals, however, this improvement was not enough to favor their performance.(AU)


Subject(s)
Animals , Cattle , Animal Welfare , Weight Gain , Pasture/methods , Heat-Shock Response , Pinus taeda , Poaceae/anatomy & histology , Animal Husbandry/methods
2.
Arq. bras. med. vet. zootec. (Online) ; 71(1): 274-280, jan.-fev. 2019. tab, graf
Article in Portuguese | LILACS, VETINDEX | ID: biblio-989375

ABSTRACT

Objetivou-se estimar herdabilidades e correlações de características ponderais com 36.505 animais, da Associação Brasileira de Criadores Zebu. O modelo incluiu efeito genético direto, materno, ambiente permanente, residual - aleatórios e efeitos de grupos contemporâneos - fixos. Os parâmetros foram estimados pelo método de máxima verossimilhança restrita (REML), utilizando-se software Wombat. Os resultados das herdabilidades variaram de 0,20 a 0,25 peso à desmama e ao sobreano; 0,16 a 0,20 peso metabólico não ajustado e ajustado à desmama, 0,21 a 0,25 peso metabólico ajustado à desmama e metabólico ajustado ao sobreano. As correlações genéticas entre peso à desmama e peso metabólico não ajustado à desmama, peso à desmama e peso metabólico ajustado à desmama são, respectivamente 0,76 e 1,00. A correlação genética entre peso ao sobreano e metabólico ao sobreano não ajustado, peso ao sobreano com metabólico sobreano ajustado foram 0,97 e 1,00. Correlação genética entre peso à desmama e ao sobreano foi 0,72, peso metabólico não ajustado à desmama e metabólico não ajustado ao sobreano 0,54, peso metabólico ajustado à desmama e metabólico ajustado ao sobreano foi 0,71. Correlações genéticas entre peso à desmama e metabólico ajustado à desmama e peso ano com metabólico ano ajustado foram 1,00 e 1,00. Portanto, utilização de peso metabólico sem ajuste de idade pode viesar estimativas de parâmetros genéticos.(AU)


The objective of this study was to estimate heritability and correlations of 36,505 animals, belonging to the Brazilian Association of Zebu Breeders. They were estimated by Restricted Maximum Likelihood method (REML) using Wombat software. The model included the direct additive genetic effect, maternal, permanent maternal environment and residual as random and fixed effects of contemporary group. The results of heritability ranged from 0,20 to 0,25 for weaning weight and yearling; 0,16 to 0,20 for real metabolic weaning, 0,21 to 0,25 for metabolic adjusted weight at weaning and yearling metabolic adjusted. The genetic correlations between weaning weight with metabolic real, weaning weight adjusted with metabolic are respectively 0,76 and 1,00. The genetic correlation between yearling weight and metabolic real, yearling weight adjusted metabolic were 0,97 and 1,00. Genetic correlations between weaning weight and yearling was 0,72, real metabolic weight at weaning and yearling real metabolic was 0,54, adjusted metabolic weight at weaning and yearling metabolic adjusted was 0,71. Genetic correlations between weight at weaning and adjusted metabolic and weight-adjusted metabolic year were 1,00 and 1,00. Therefore, the use of metabolic weight without age adjustment can warn the estimates.(AU)


Subject(s)
Animals , Body Weight , Cattle/genetics , Cattle/microbiology
3.
Arq. bras. med. vet. zootec. (Online) ; 71(1): 353-356, jan.-fev. 2019. ilus
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1038587

ABSTRACT

The objective of this study was to characterize the displacement patterns of Nellore cattle in areas of crop livestock and crop livestock forest integration systems with density of 196 and 448 eucalyptus ha-1. Paddock maps were drawn from satellite images of the experimental area. In each evaluated system there was one trained observer, that on the paddock map recorded the place the animals stayed every 10 minutes. The exploration of the area by the animals was observed for 12 hours, starting at 6 a.m. and ending at 6 p.m. The displacement of the animals in the ILP system during the evaluation was bigger than the ILPFs systems, resulting in greater exploration of the area, this fact was due the presence of trees that, for the animals resembled fences, limiting the exploration of the paddock in ILPFs. In the ILPF with higher density of trees, this behavior was more evident. In the period from 10:10 a.m. to 14:00 p.m. the displacement of the animals was decrease by the high temperatures in all systems, although it was more effective in the ILP system. It is concluded that the displacement of cattle is influenced by the presence and density of arboreal component integrated crop livestock system.(AU)


Subject(s)
Animals , Cattle , Behavior, Animal , Pasture , Forests , Eucalyptus , Animal Husbandry/methods
4.
Arq. bras. med. vet. zootec. (Online) ; 70(2): 517-524, mar.-abr. 2018. tab
Article in English | LILACS, VETINDEX | ID: biblio-910689

ABSTRACT

The objective this paper was to evaluate the effect of two categories of beef finished in pasture with supplementation with two herbage allowance on performance, carcass and meat characteristics. Thirty-six Guzera cattle were used, 18 steers and 18 heifers with an initial age of 20 months. There was significant difference in daily weight gain for animal category and the herbage allowance, which were higher in males and animals submitted to high herbage allowance. Steers showed higher final weight, carcass weight and forequarter yield compared with the heifers, although the hindquarter yield was higher in the heifers, however the herbage allowance did not influence these characteristics. There were not statistical differences for carcass yield, ribeye area, backfat thickness and marbling score for the animal categories and herbage allowance. The meat chemical composition of the steers did not differ of the heifers, however, the animals submitted to high herbage allowance was increase in ether extract and pH, decrease in protein percentage. It was concluded that the animal category and the herbage allowance changed the animal performance, improving performance in males and cattle submitted to high herbage allowance.(AU)


O objetivo do presente trabalho foi avaliar o efeito de duas categorias de bovinos terminados em pastagem com suplementação em duas ofertas de forragem no desempenho, na qualidade da carcaça e da carne. Foram utilizados 36 bovinos Guzerá, 18 novilhos e 18 novilhas, com idade inicial de 20 meses de idade. Observou-se diferença significativa no ganho de peso diário para categoria animal e ofertas de forragem, que foram superiores nos machos e nos animais submetidos à oferta alta de forragem. Os novilhos apresentaram maior peso final, peso de carcaça e rendimento de dianteiro em comparação com as novilhas, embora o rendimento do traseiro tenha sido maior para as novilhas, entretanto as ofertas de forragem não influenciaram essas características. Não houve diferenças estatísticas para rendimento de carcaça, área de olho de lombo, espessura de gordura subcutânea e marmorização para categorias de animais e ofertas de forragem. Quanto à composição química, a carne de novilhos não diferiu das novilhas. Os animais submetidos à alta oferta de forragem tiveram aumento no extrato etéreo e pH, redução na porcentagem de proteína. Conclui-se que a categoria animal e os níveis de forragem alteram o desempenho animal, melhorando, assim, o desempenho nos machos e nos bovinos submetidos à alta oferta de forragem.(AU)


Subject(s)
Animals , Cattle , Infant Nutritional Physiological Phenomena , Meat/classification , Pasture/analysis , Cattle , Weight Gain
5.
Avian Pathol ; 41(6): 579-88, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23237371

ABSTRACT

Genetic variability and genotypic antimicrobial resistance (AMR) of Campylobacter jejuni and Campylobacter coli from commercial broiler farms were investigated in this study. Campylobacter isolates were genetically characterized by random amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR) and flaA-SVR and flaB-SVR sequence-based typing. Eight RAPD types were identified in C. jejuni and three in C. coli, while 16 fla profiles were detected among all isolates. Further, 13 flaA-SVR and 13 flaB-SVR alleles were identified. Both typing methods detected a high level of genetic diversity, but fla-SVR typing showed a higher discriminatory power. Indeed, Simpson's index of fla typing (D=0.920) was higher than that of RAPD typing (D=0.814). Moreover, the association of flaA-SVR and flaB-SVR sequence analysis showed a higher discriminatory power compared with the sequence analysis of single loci. Isolates were also analysed by the mismatch amplification mutation assay PCR test and the detection of cmeB gene to determine the occurrence of genetic determinants of AMR to macrolides and fluoroquinolones and multidrug resistance. The A2074C and A2075G mutations in the 23S rRNA gene, the C257T mutation in the gyrA gene, and the cmeB gene were higher in C. coli (19.0%, 67.0%, 100.0% and 100.0%, respectively) than in C. jejuni (0.0%, 3.1%, 48.3% and 48.3%, respectively). This study showed a high degree of genetic diversity and a high prevalence of genetic determinants of macrolide resistance, fluoroquinolone resistance and multidrug resistance among C. jejuni and C. coli isolates from Italian commercial broiler farms.


Subject(s)
Campylobacter Infections/veterinary , Campylobacter coli/genetics , Campylobacter jejuni/genetics , Chickens/microbiology , Poultry Diseases/microbiology , Animals , Anti-Infective Agents/pharmacology , Bacterial Typing Techniques/veterinary , Campylobacter Infections/epidemiology , Campylobacter Infections/microbiology , Campylobacter coli/drug effects , Campylobacter coli/isolation & purification , Campylobacter jejuni/drug effects , Campylobacter jejuni/isolation & purification , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Drug Resistance, Bacterial/genetics , Flagellin/genetics , Genetic Loci , Genetic Variation , Genotype , Italy/epidemiology , Macrolides/pharmacology , Poultry Diseases/epidemiology , Random Amplified Polymorphic DNA Technique/veterinary , Sequence Analysis, DNA/veterinary
6.
Res Vet Sci ; 88(3): 427-35, 2010 Jun.
Article in English | MEDLINE | ID: mdl-19926103

ABSTRACT

The study concerns 130 Staphylococcus aureus strains isolated from different raw-milk dairy products (122 isolates) and human samples (eight isolates). Four different typing techniques were applied: biochemical profiles (Biolog GP), restriction fragment length polymorphism of coagulase gene (coaRFLP), random amplified polymorphic DNA (RAPD) and multilocus variable number tandem repeat analysis (MLVA). Moreover multiplex-PCR was used to study the distribution of genes encoding staphylococcal enterotoxins. The results of this study reveal marked genomic and phenotypic variability among the tested S. aureus. The considered techniques were all found useful for strain typing, but, based on discriminatory power as the key parameter of the typing system, MLVA and Biolog GP were found to be the most powerful techniques. The methods showed little concordance in terms of discerning the clusters of related strains.


Subject(s)
Bacterial Typing Techniques/methods , Dairy Products/microbiology , Polymorphism, Restriction Fragment Length , Staphylococcus aureus/genetics , Animals , Cattle , Coagulase/genetics , DNA Fingerprinting/methods , Female , Humans , Milk/microbiology , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment Length/genetics , Random Amplified Polymorphic DNA Technique/methods , Restriction Mapping/methods , Sheep , Sheep Diseases/microbiology , Staphylococcal Infections/diagnosis , Staphylococcal Infections/veterinary , Staphylococcus aureus/enzymology , Staphylococcus aureus/isolation & purification , Tandem Repeat Sequences/genetics
7.
Int J Food Microbiol ; 109(1-2): 109-20, 2006 May 25.
Article in English | MEDLINE | ID: mdl-16529834

ABSTRACT

This study investigated the genotypic and phenotypic diversity in 34 isolates of enterococci obtained during ripening of Batzos cheese from raw goat milk and characterized phenotypically as Enterococcus durans. RAPD-PCR, plasmid profiling and PFGE were used to study the genetic variability and distinguish closely related isolates. Species recognition by means of RAPD-PCR was in agreement with the phenotypic identification for 29 strains. One strain was characterized as Lactococcus lactis subsp. lactis by RAPD-PCR and four strains were grouped with the Enterococcus faecium reference strain. All strains were vancomycin sensitive, while 10 strains showed beta-haemolytic reaction on human blood and the majority of them (88.9%) showed decarboxylase activity on tyramine. All strains exhibited antagonistic activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli and Listeria monocytogenes and the majority inhibited Enterococcus faecalis. Isolates displayed weak acidifying ability and low proteolytic activities when grown in milk for 24h. However, their caseinolytic activity after growth in milk for seven days was significant with preference for alphas-casein degradation.


Subject(s)
Cheese/microbiology , Enterococcus/classification , Enterococcus/genetics , Enterococcus/isolation & purification , Phylogeny , Animals , Electrophoresis, Agar Gel/methods , Food Microbiology , Genotype , Goats , Milk/microbiology , Phenotype , Plasmids , Random Amplified Polymorphic DNA Technique/methods , Species Specificity , Vancomycin Resistance
8.
Lett Appl Microbiol ; 38(5): 400-5, 2004.
Article in English | MEDLINE | ID: mdl-15059211

ABSTRACT

AIMS: This work was carried out in order to evaluate the microbial diversity of whey cultures collected from different Grana Padano cheese plants in Veneto region (north-east Italy) by means of RAPD-PCR and Temporal Temperature Gradient Gel Electrophoresis (TTGE) analysis. METHODS AND RESULTS: Lactobacillus helveticus was the dominant species among isolated thermophilic lactobacilli. RAPD-PCR with primers M13 and D8635 resulted a suitable method for typing Lact. helveticus at strain level. Thirteen different Lact. helveticus biotypes were detected in the seven whey cultures studied with one biotype present in all the whey cultures. Besides Lact. helveticus, Lact. delbrueckii subsp. lactis was the main microbial species detected by TTGE. CONCLUSIONS: RAPD-PCR resulted very useful in studying Lact. helveticus biodiversity; furthermore, TTGE analysis allowed to detect the dominant thermophilic microflora characteristic of Grana Padano cheese whey cultures. IMPACT OF THE STUDY: By the combined used of RAPD-PCR and TTGE it could be possible to follow the behaviour in strain or species composition of whey cultures during time.


Subject(s)
Cheese/microbiology , Electrophoresis, Polyacrylamide Gel/methods , Lactobacillus/classification , Random Amplified Polymorphic DNA Technique/methods , Bacterial Typing Techniques , Biodiversity , Culture Media , DNA, Bacterial/analysis , Lactobacillus/genetics , Lactobacillus/growth & development
9.
Int J Food Microbiol ; 91(2): 129-39, 2004 Mar 01.
Article in English | MEDLINE | ID: mdl-14996456

ABSTRACT

Eighty-nine strains of Lactobacillus delbrueckii subsp. lactis isolated from Italian hard and semi-hard cheeses and artisan starter cultures were characterised by phenotypic and genotypic methods. Phenotypic diversity was evaluated by studying biochemical characteristics (i.e. acidifying and peptidase activities) of technological interest. Genotypic diversity was evidenced by RAPD-PCR and pulsed field gel electrophoresis (PFGE). Phenotypic characterisation indicated a wide variability of the acidifying activity within Lact. delbrueckii subsp. lactis. Although the data was variable, it allowed us to evidence groups of strains with different acidifying properties, especially in terms of acidification intensity. Concerning peptidase activity, Lact. delbrueckii subsp. lactis showed a homogeneously high x-prolil-dipeptidil-aminopeptidase activity and a considerable but more heterogeneous lysil-aminopeptidase activity. The increased resolution obtained by the use of two molecular typing techniques, i.e. RAPD-PCR and PFGE, allowed to widen the level of strain heterogeneity. Technological and ecological pressures are determinant in selecting Lact. delbrueckii subsp. lactis sub-populations which are more functional to the different cheese technologies.


Subject(s)
Cheese/microbiology , DNA, Bacterial/analysis , Food Microbiology , Genetic Variation , Lactobacillus/genetics , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field/methods , Genotype , Hydrogen-Ion Concentration , Lactobacillus/classification , Lactobacillus/enzymology , Peptide Hydrolases/metabolism , Phenotype , Phylogeny , Random Amplified Polymorphic DNA Technique/methods
10.
FEMS Microbiol Lett ; 225(1): 143-8, 2003 Aug 08.
Article in English | MEDLINE | ID: mdl-12900033

ABSTRACT

Samples of sourdoughs obtained from 13 artisanal bakeries located in the Molise and Campania regions were analysed. The sourdoughs were produced with the exclusive use of Triticum aestivum wheat flour. pH values of sourdoughs from Molise were generally lower than those from Campania. The number of yeasts in the samples of sourdoughs from Molise was generally higher than in those from Campania, which in two cases evidenced counts about 2 log cfu x g(-1). By utilising and comparing traditional and biomolecular techniques of identification a complete picture of the isolates was obtained: 58 strains were identified as Saccharomyces cerevisiae, five as Candida colliculosa, four as C. lambica, three as C. krusei, three as C. valida and two as C. glabrata.


Subject(s)
Bread/microbiology , Yeasts/isolation & purification , Candida/genetics , Candida/isolation & purification , DNA, Fungal/genetics , Hydrogen-Ion Concentration , Italy , Random Amplified Polymorphic DNA Technique , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/isolation & purification , Triticum/microbiology , Yeasts/classification , Yeasts/genetics
11.
Int J Food Microbiol ; 69(1-2): 125-33, 2001 Sep 19.
Article in English | MEDLINE | ID: mdl-11589551

ABSTRACT

Yeast isolates from infant faeces and Feta cheese were characterized to species level by phenotypic criteria, Randomly Amplified Polymorphic DNA (RAPD)-PCR and mitochondrial DNA (mt-DNA) restriction analysis. Results suggested that there is a good agreement between phenotypic characterization of yeasts and RAPD-PCR at species level; in addition, RAPD-PCR as well as mt-DNA restriction analysis provided good discrimination at strain level. Some technological and probiotic properties of selected strains were also investigated. The test strains exhibited lipolytic and proteolytic activities. They also tolerated low pH and survived satisfactory in gastric juice in vitro as well as in the presence of bile. In general, the isolates from faeces were more resistant to low pH and bile than those from Feta cheese. Selected strains could be used as starter supplements for industrial fermentations.


Subject(s)
Cheese/microbiology , DNA, Mitochondrial/genetics , Feces/microbiology , Yeasts/genetics , Cluster Analysis , DNA Fingerprinting , Fermentation , Humans , Hydrogen-Ion Concentration , Infant , Probiotics/classification , Probiotics/metabolism , Random Amplified Polymorphic DNA Technique , Temperature , Yeasts/classification , Yeasts/metabolism
12.
Int J Food Microbiol ; 69(1-2): 69-77, 2001 Sep 19.
Article in English | MEDLINE | ID: mdl-11589562

ABSTRACT

This work studied the qualitative and quantitative proteolytic and lipolytic activities of Yarrowia lipolytica strains isolated from two cheese types. Randomly amplified polymorphic DNA-PCR (RAPD-PCR) analysis was used to compare the cheese strains of Y. lipolytica with strains isolated from other food products and with the type strain of the species in order to investigate the genetic diversity and occurrence of specific environmental groups. Diversity of proteolytic and especially lipolytic activity within Y. lipolytica strains isolated from dairy products was observed. In particular, the degree of specificity for saturated or unsaturated fatty acids as well as for even- or odd-numbered carbon free fatty acids (FFAs) varied among the strains. The RAPD-PCR profiles showed low genetic relatedness between many of the food isolates and the type strain of the species. Such genetic variability needs to be further evaluated. Most of the Y. lipolytica strains appeared to be specific to the particular environment from which they were isolated. However, phenotypic characteristics having technological importance in dairy products and, particularly, lipolytic activities did not correspond to the genetic differences observed by RAPD-PCR analysis.


Subject(s)
Cheese/microbiology , DNA, Fungal/analysis , Fatty Acids/metabolism , Saccharomycetales/genetics , Saccharomycetales/metabolism , Chromatography, Gas , Food Microbiology , Polymerase Chain Reaction , Polymorphism, Genetic/genetics , Random Amplified Polymorphic DNA Technique/methods , Saccharomycetales/enzymology , Temperature , Time Factors
13.
J Microbiol Methods ; 47(1): 35-40, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11566225

ABSTRACT

Species-specific PCR assays with primers targeted to D-alanine:D-alanine ligase (ddl) encoding genes were developed for the identification of Enterococcus durans and E. hirae. The specificity of the primers was validated in a multiplex PCR on well characterised E. durans (n=30) and E. hirae (n=16) strains, all of which were identified correctly. This PCR procedure offers a reliable and rapid alternative to conventional phenotypic methods for speciation of these enterococci of growing clinical importance.


Subject(s)
Enterococcus/classification , Enterococcus/genetics , Peptide Synthases/genetics , Polymerase Chain Reaction/methods , Bacterial Typing Techniques , DNA Primers , Enterococcus/enzymology , Humans , Species Specificity , Time Factors
14.
J Dairy Res ; 68(2): 303-16, 2001 May.
Article in English | MEDLINE | ID: mdl-11504393

ABSTRACT

In the present study, 124 enterococcal strains, isolated from traditional Italian cow, goat and buffalo cheeses, were characterized using phenotypic features and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). The RAPD-PCR profiles obtained with four primers and five different amplification conditions were compared by numerical analysis and allowed an inter- and intraspecific differentiation of the isolates. Whole cell protein analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used as a reference method for species identification. The strains were identified as Enterococcus faecalis (82 strains), E. faecium (27 strains), E. durans (nine strains), E. gallinarum (four strains) and E. hirae (two strains). Species recognition by means of RAPD-PCR was in agreement with the SDS-PAGE results except for eight strains of E. faecium that clustered in separated groups. On the other hand, phenotypic identification based on carbohydrate fermentation profiles, using the rapid ID 32 STREP galleries, gave different results from SDS-PAGE in 12.1% of the cases. The majority of the strains had weak acidifying and proteolytic activities in milk. One E. faecium strain showed vanA (vancomycin resistance) genotype while four strains showed a beta-haemolytic reaction on human blood. Several strains showed antagonistic activity towards indicator strains of Listeria innocua, Clostridium tyrobutyricam and Propionibacterium freudenreichii subsp. shermanii.


Subject(s)
Cheese/microbiology , Enterococcus/classification , Enterococcus/genetics , Animals , Buffaloes , Cattle , Electrophoresis, Polyacrylamide Gel/veterinary , Enterococcus/drug effects , Genotype , Goats , Italy , Phenotype , Phylogeny , Random Amplified Polymorphic DNA Technique/methods , Random Amplified Polymorphic DNA Technique/veterinary , Species Specificity , Vancomycin Resistance
15.
Lett Appl Microbiol ; 33(1): 26-30, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11442810

ABSTRACT

AIMS: The study was carried out to evaluate the use of randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) as a method for the identification of lactobacilli isolated from meat products. METHODS AND RESULTS: RAPD-PCR with primers M13 and D8635 was applied to the identification and intraspecific differentiation of 53 lactobacilli isolates originating from traditional fermented sausages and artisanal meat plants of the Veneto region (Italy). Most of the isolates were assigned to the species Lactobacillus sakei and Lact. curvatus; differentiation of groups of strains within the species was also possible. CONCLUSION: RAPD-PCR could be applied to the identification of lactobacilli species most commonly found in meat products. SIGNIFICANCE AND IMPACT OF THE STUDY: The method, which is easy and rapid to perform, could be useful for the study of the lactobacilli populations present in fermented sausages, and could help in the selection of candidate strains to use as starter cultures in meat fermentation.


Subject(s)
Bacterial Typing Techniques , Lactobacillus/classification , Meat Products/microbiology , Random Amplified Polymorphic DNA Technique , DNA, Bacterial/analysis , DNA, Bacterial/isolation & purification , Fermentation , Italy , Lactobacillus/genetics , Lactobacillus/isolation & purification , Meat-Packing Industry
16.
FEMS Yeast Res ; 1(2): 161-7, 2001 Jul.
Article in English | MEDLINE | ID: mdl-12702361

ABSTRACT

The evolution of the yeast population during manufacturing and ripening of 'salsiccia sotto sugna', a typical salami of the Lucania region (southern Italy), was investigated. Four different batches, produced in four farms in Lucania, were studied. Each batch showed a specific yeast population, and the most frequently isolated yeasts belonged to Debaryomyces hansenii and its anamorph Candida famata, and Rhodotorula mucilaginosa. Yarrowia lipolytica was isolated from three sausage batches. The Y. lipolytica isolates were further characterised, in particular for their lipolytic activity on pork fat. Lipolytic activity was maximal at pH 5.5, with oleic and palmitic acids as major free fatty acids produced. The use of randomly amplified polymorphic DNA-polymerase chain reaction allowed the detection of a high genetic heterogeneity among the isolates phenotypically assigned to the species Y. lipolytica.


Subject(s)
Meat Products/microbiology , Yeasts/classification , Animals , Candida/classification , Candida/isolation & purification , Fermentation , Food Handling/methods , Italy , Lipase/metabolism , Mycological Typing Techniques , Random Amplified Polymorphic DNA Technique , Rhodotorula/classification , Rhodotorula/isolation & purification , Saccharomycetales/classification , Saccharomycetales/isolation & purification , Swine , Yarrowia/classification , Yarrowia/genetics , Yarrowia/isolation & purification , Yeasts/genetics , Yeasts/isolation & purification
17.
J Appl Microbiol ; 89(2): 267-74, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10971758

ABSTRACT

Enterococci were isolated from semicotto caprino cheese, a traditional cheese produced in Southern Italy: they were a significant part of the microbial population of this cheese, confirming the importance of the presence of these micro-organisms during cheese-making and ripening. They were also identified and studied for their phenotypic and genotypic characteristics: Enterococcus faecalis and Ent. faecium were the most frequently isolated species, followed by Ent. durans, Ent. hirae and Ent. gallinarum. None of the isolates showed lipolytic activity, whereas they were characterized by a relevant proteolytic activity as well as an antagonistic activity towards Listeria innocua. One strain of Ent. gallinarum showed a low-level resistance to vancomycin, while six out of the 79 Ent. faecalis strains possessed beta-haemolysis reaction. The highest acidifying potential in skim milk was obtained by Ent. faecalis isolates. Thirty enterococcal strains representative of the different species at different ripening times were analysed by means of RAPD-PCR, and revealed species-specific profiles for all the considered species.


Subject(s)
Cheese/microbiology , Enterococcus/isolation & purification , Enterococcus/metabolism , Animals , Enterococcus/classification , Enterococcus/genetics , Goats , Hydrogen-Ion Concentration , Italy , Peptide Hydrolases/metabolism , Polymerase Chain Reaction , Random Amplified Polymorphic DNA Technique
18.
Lett Appl Microbiol ; 30(1): 5-9, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10728551

ABSTRACT

In the present work randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) with primers M13 and RF2 was applied to the identification at species level of yeast strains isolated from cheeses. RAPD-PCR analysis of the type strains of different yeast species gave distinctive band profiles that allowed a clear differentiation of all the considered species. Forty-two of the 48 dairy associated yeasts were clearly assigned to the species Saccharomyces cerevisiae, Kluyveromyces marxianus (anamorph Candida kefyr), Kluyveromyces lactis (anamorph Candida sphaerica), Debaryomyces hansenii (anamorph Candida famata), Yarrowia lipolytica and Torulaspora delbrueckii (anamorph Candida colliculosa). The method, which is rapid and easy to perform, could be a useful tool for the identification of yeasts present in dairy products.


Subject(s)
Cheese/microbiology , DNA, Fungal/analysis , Food Microbiology , Polymerase Chain Reaction/methods , Yeasts/classification , Base Sequence , DNA Primers/genetics , Electrophoresis , Molecular Sequence Data , Polymorphism, Genetic/genetics , Sequence Analysis, DNA , Species Specificity , Yeasts/genetics
19.
J Appl Microbiol ; 88(1): 117-23, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10735250

ABSTRACT

Water-buffalo Mozzarella (WBM) cheese is one of the several 'pasta filata' or stretched curd cheeses that originated in southern Italy, traditionally manufactured from raw milk employing natural whey starter cultures. Lactose- and galactose-fermenting yeasts isolated from WBM were studied to evaluate their role in the ripening of this cheese. The kinetic parameters of the growth of the yeasts as well as their principal metabolic end-products showed a great variability depending on the species. Moreover, the genetic polymorphism of the yeasts was studied for their differentiation at species level by means of the polymerase chain reaction (PCR) fingerprinting and mitochondrial DNA (mtDNA) restriction analysis. While the differentiation based on metabolic traits was not able to discriminate Kluyveromyces marxianus, Candida kefyr and C. sphaerica, the PCR analysis with primers M13 and RF2 resulted in a reliable and rapid method for differentiating at species level Saccharomyces cerevisiae, K. marxianus, K. lactis and their anamorphic species. Furthermore, mtDNA analysis proved to be more discriminating at strain level.


Subject(s)
Cheese/microbiology , Food Microbiology , Genetic Variation , Yeasts/classification , Animals , Buffaloes , Cattle , DNA Fingerprinting , DNA, Fungal/analysis , DNA, Mitochondrial/analysis , Milk/metabolism , Milk/microbiology , Phenotype , Phylogeny , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Yeasts/genetics , Yeasts/growth & development
20.
Res Microbiol ; 149(9): 631-43, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9826919

ABSTRACT

Twenty-five strains of thermophilic lactobacilli isolated from yoghurt and from semi-hard and hard cheeses (in parallel with nine type or reference strains) were identified and grouped according to their genetic relatedness. Strains were identified by sugar fermentation patterns using the "API 50 CHL" galleries, by species-specific DNA probes in dot-blot hybridization experiments, by amplification and restriction analysis of the 16S rRNA gene (ARDRA) and by polymerase chain reaction (PCR) using species-specific oligonucleotide primers. Strains were classified as Lactobacillus delbrueckii subsp. lactis and subsp. bulgaricus, L. helveticus, and L. acidophilus. Strains which were atypical by sugar fermentation patterns were also identified. Most of the strains could not be grouped using carbohydrate fermentation profiles. PCR fingerprinting was used to identify DNA profiles for the 25 lactobacilli. Experimentally obtained PCR profiles enabled discrimination of all strains, which were grouped according to the similarities in their combined patterns. In general, the clustering of the strains corresponded well with species delineation obtained by molecular identification. The dendrogram of genetic relatedness enabled the unambiguous identification of most of the strains which were shown to be atypical by the sugar fermentation profile, except for a discrepancy in one L. delbrueckii subsp. lactis strain and one atypical Lactobacillus sp. strain.


Subject(s)
Bacterial Typing Techniques , Carbohydrate Metabolism , Dairy Products/microbiology , Lactobacillus/classification , Lactobacillus/genetics , Cheese/microbiology , Cluster Analysis , DNA Probes , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Fermentation , Genes, rRNA , Genotype , Lactobacillus/isolation & purification , Lactobacillus/metabolism , Nucleic Acid Hybridization , Phenotype , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Restriction Mapping , Species Specificity , Temperature , Yogurt/microbiology
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