RESUMO
Dairy propionibacteria are used as ripening cultures for the production of Swiss-type cheeses, and some strains have potential for use as probiotics. This study investigated the biodiversity of wild dairy Propionibacteria isolates in dairy farms that produce Swiss-type cheeses in Minas Gerais State, Brazil. RAPD and PFGE were used for molecular typing of strains and MLST was applied for phylogenetic analysis of strains of Propionibacterium freudenreichii. The results showed considerable genetic diversity of the wild dairy propionibacteria, since three of the main species were observed to be randomly distributed among the samples collected from different farms in different biotopes (raw milk, sillage, soil and pasture). Isolates from different farms showed distinct genetic profiles, suggesting that each location represented a specific niche. Furthermore, the STs identified for the strains of P. freudenreichii by MLST were not related to any specific origin. The environment of dairy farms and milk production proved to be a reservoir for Propionibacterium strains, which are important for future use as possible starter cultures or probiotics, as well as in the study of prevention of cheese defects.
Assuntos
Biodiversidade , Microbiologia de Alimentos , Propionibacterium/genética , Animais , Brasil , Queijo/microbiologia , Microbiologia Ambiental , Variação Genética , Leite/microbiologia , Tipagem de Sequências Multilocus , Filogenia , Probióticos/isolamento & purificação , Propionibacterium/classificação , Propionibacterium/isolamento & purificação , Técnica de Amplificação ao Acaso de DNA PolimórficoRESUMO
The prevention and control of pathogens colonization through probiotics administration in poultry feeding is of increasing interest. The genus Propionibacterium is an attractive candidate for the development of probiotic cultures as they produce short chain fatty acids (SCFA) by carbohydrates fermentation. The presence of strains of this genus in hens of conventional production systems and backyard hens was investigated. Propionibacteria were isolated from the intestine and identified by physiological and biochemical tests. PCR amplification of the 16S rRNA gene of the isolates was performed and products were compared with sequences from databases. The presence of the genus Propionibacterium was demonstrated in 26% of hens and Propionibacterium acidipropionici and Propionibacterium avidum were the identified species. A comparative study of their physiological and functional characteristics was performed. P. acidipropionici strains were the most resistant to in vitro gastrointestinal digestion, but the adhesion to intestinal tissue was strain dependent. Some differences were found between both species with respect to their growth and SCFA production in an in vitro cecal water model, but all the strains were metabolically active. The production of SCFA in cecal slurries inoculated with the strain P. acidipropionici LET 105 was 30% higher than in non-inoculated samples. SCFA concentrations obtained were high enough to inhibit Salmonella enterica serovar Enteritidis when assayed in a cecal water model. P. acidipropionici LET 105 was also able to compete with Salmonella for adhesion sites on the intestinal mucosa in ex vivo assays. Results contribute to the knowledge of the species diversity of the genus Propionibacterium in the intestine of poultry and provide evidence of their potential for probiotics products development.
Assuntos
Ácidos Graxos Voláteis/metabolismo , Aves Domésticas/microbiologia , Probióticos/isolamento & purificação , Propionibacterium/isolamento & purificação , Propionibacterium/fisiologia , Animais , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Aderência Bacteriana , Análise por Conglomerados , Ácidos Graxos Voláteis/farmacologia , Dados de Sequência Molecular , Filogenia , Propionibacterium/classificação , Propionibacterium/genética , RNA Ribossômico 16S/genética , Salmonella enteritidis/efeitos dos fármacos , Salmonella enteritidis/crescimento & desenvolvimento , Análise de Sequência de DNARESUMO
OBJECTIVE: In this study, we aimed to investigate the occurrence of several microbial species in cases of failed endodontic therapy by means of the polymerase chain reaction (PCR). Study design Root canal samples were taken from 22 root-filled teeth with persistent periradicular lesions selected for re-treatment. DNA was extracted from the samples and analyzed for the presence of 19 microbial taxa by using the polymerase chain reaction. RESULTS: All samples were positive for at least 1 of the target microbial species. Enterococcus faecalis was the most prevalent species-detected in 77% of the cases. The other most prevalent species were Pseudoramibacter alactolyticus (52%), Propionibacterium propionicum (52%), Dialister pneumosintes (48%), and Filifactor alocis (48%). Candida albicans was found in 9% of the samples. The mean number of species in samples filled up to 2 mm short of the radiographic apex was 3 (range, 1-5), whereas cases in which the filling was greater than 2 mm from the apex yielded a mean of 5 species (range, 2-11). This difference was statistically significant (P <.05). CONCLUSIONS: Microorganisms occurred in all cases of root-filled teeth associated with periradicular lesions, which lends strong support to the assertion that treatment failures are rather of infectious etiology, caused by persistent or secondary intraradicular infections. E faecalis was the most prevalent species, followed by 4 other anaerobic species: P. alactolyticus, P. propionicum, D. pneumosintes, and F. alocis. All examined samples harbored at least 1 of the following gram-positive bacterial species: E. faecalis, P. alactolyticus, or P. propionicum.
Assuntos
Bactérias/classificação , Cavidade Pulpar/microbiologia , Tratamento do Canal Radicular , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida albicans/classificação , Enterococcus faecalis/classificação , Eubacterium/classificação , Feminino , Fusobacterium/classificação , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/classificação , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Periapicais/microbiologia , Doenças Periapicais/terapia , Reação em Cadeia da Polimerase , Propionibacterium/classificação , Retratamento , Materiais Restauradores do Canal Radicular/uso terapêutico , Ápice Dentário/microbiologia , Falha de TratamentoRESUMO
OBJECTIVE: Propionibacterium propionicus and the recently described species Actinomyces radicidentis have been isolated from infections of endodontic origin; nevertheless, the possibility exists that their actual prevalence may have been underestimated by culture. The purpose of our study was to assess the occurrence of these 2 species in different types of endodontic infections by using the sensitive 16S rDNA-based nested polymerase chain reaction approach. STUDY DESIGN: To detect these 2 species, nested polymerase chain reaction was performed directly in samples taken from primary endodontic infections associated with asymptomatic periradicular lesions, acute apical periodontitis, or acute periradicular abscesses and in samples from patients in whom endodontic therapy had failed. DNA was extracted from the samples and initially amplified by using universal 16S rDNA primers. In the second round of amplification, the first polymerase chain reaction products were used to detect a specific 16S rDNA fragment of either P propionicus or A radicidentis. RESULTS: P propionicus was detected in 6/21 (29%) root canal samples from teeth with chronic periradicular lesions, in 5/10 (50%) cases diagnosed as acute apical periodontitis, and in 7/19 (37%) pus samples aspirated from acute periradicular abscesses. Overall, this species was found in 18/50 (36%) samples taken from primary endodontic infections. Of the root canal samples obtained from root-filled teeth with chronic periradicular lesions, P propionicus was detected in 7/12 (58%) cases. A radicidentis was detected in 1/21 (5%) root canal samples from teeth with chronic periradicular lesions and in 1/10 (10%) cases of acute apical periodontitis. No pus sample yielded this species. In general, A radicidentis was detected in 2/50 (4%) samples taken from primary endodontic infections and in 1/12 (8%) root canal samples taken from patients in whom endodontic treatment had failed. CONCLUSIONS: P propionicus was found in a relatively large number of patients with primary and persistent endodontic infections. This strengthens the assumption that this bacterial species is an endodontic pathogen associated with different forms of periradicular diseases. In contrast, A radicidentis was only occasionally detected in the patients examined. The role played by this species in endodontic infections remains to be clarified.
Assuntos
Actinomyces/classificação , Actinomicose/microbiologia , Doenças da Polpa Dentária/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Propionibacterium/classificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA Bacteriano/análise , Cavidade Pulpar/microbiologia , Humanos , Pessoa de Meia-Idade , Abscesso Periapical/microbiologia , Doenças Periapicais/microbiologia , Periodontite Periapical/microbiologia , Reação em Cadeia da Polimerase , RNA Ribossômico 16SRESUMO
There are many methods to identify anaerobic nonsporeforming bacilli: histological, bacteriological (biochemical test, microsystem API 20 A), serological, cell wall composition analysis, molecular methods and gas-liquid chromatography (GLC). A comparison between biochemical tests and gas-liquid chromatography was made in this study for the identification of this group of microorganisms. GLC conditions were established with the aid of reference strains. These conditions were then applied to ten strains which were previously identified by biochemical tests. Strains were grown in PYG broth and fermentation end products were analyzed, volatile and non volatile fatty acids. Their qualitative determination was made by comparing the retention time of known standards and the chromatographic pattern of reference strains. In addition, a semiquantitative analysis was made. The results of identification by biochemical tests were: five strains belonged to Actinomyces genus; three were Propionibacterium acnes; one Propionibacterium granulosum and one P. propionicum. By the GLC only seven strains were identified: four were Actinomyces and three P. acnes. Only six strains showed identification correlation by both biochemical tests and GLC. GLC is a presumptive identification method that can be used along with other complementary tests for a definitive identification at genus level.
Assuntos
Técnicas de Tipagem Bacteriana/métodos , Cromatografia Gasosa/métodos , Bacilos Gram-Positivos Asporogênicos/classificação , Ácidos/análise , Actinomyces/química , Actinomyces/classificação , Actinomyces/isolamento & purificação , Anaerobiose , Parede Celular/química , Bacilos Gram-Positivos Asporogênicos/química , Bacilos Gram-Positivos Asporogênicos/isolamento & purificação , Propionibacterium/química , Propionibacterium/classificação , Propionibacterium/isolamento & purificação , Propionibacterium acnes/química , Propionibacterium acnes/classificação , Propionibacterium acnes/isolamento & purificaçãoRESUMO
Numerical Taxonomy's techniques were employed on twenty one anaerobic Gram positive bacilli strains taking account of eighty morphologic and biochemical features. Two methods of coding (weighted and non weighted) and four clustering methods (unweighted pair-group method using arithmetic averages; weighted pair-group method using arithmetic averages; single linkage and complete linkage) were used. Eight dendrograms were obtained and they showed that C. haemolyticum (strains 1, 2, 4, 7); C. subterminale (strains 8, 19); C. botulinum (strain 14) and C. sporogenes (strain 15) belong to a different group than the other strains. Another group would be formed with C. perfringens (strains 3, 5, 6, 12, 16, 21) and C. paraperfringens (strains 9, 10, 11). Of the remaining strains the two classified as Propionibacterium acnes (strains 17, 18) have a very high degree of agreement. C. histolyticum (strain 20) adjoins at a very low level, while C. butyricum (strain 13) shows a unfixed behaviour. The dendrograms display a disposition according with Classical Taxonomy.