ABSTRACT
Resumen Se aislaron del contenido intestinal del mejillón patagónico dos cepas de bacterias ácido lácticas y se caracterizaron por pruebas fenotípicas y moleculares. Los aislamientos se identificaron como Enterococcus hirae y fueron denominados E. hirae 463Me y 471Me. Por técnicas de PCR se identificó el gen de la enterocina P en ambas cepas, mientras que solamente en la cepa 471Me se detectó la enterocina hiracin JM79. Ambas cepas resultaron sensibles a los antibióticos clínicamente importantes y entre los rasgos de virulencia investigados mediante amplificación por PCR solo se pudieron detectar los genes cylL l y cylL s , sin embargo, no se observó actividad hemolítica en la prueba de agar sangre. Los sobrenadantes libres de células resultaron activos contra todas las cepas de Listeria y Enterococcus ensayadas, contra Lactobacillus plantarum TwLb 5 y contra Vibrio anguilarum V10. En óptimas condiciones de crecimiento, ambas cepas mostraron actividad inhibitoria contra Listeria innocua ATCC 33090 después de 2h de incubación. E. hirae 471Me alcanzó una actividad inhibitoria máxima de 163.840UA/ml después de 6h de incubación, mientras que el mismo valor se registró para E. hirae 463Me después de 8h. En ambos casos, la actividad antagonista alcanzó su máximo antes de lograr la fase estacionaria y permaneció estable hasta las 24h de incubación. En nuestro conocimiento, este es el primer informe de aislamiento de cepas bacteriocinogénicas de E. hirae de mejillón patagónico. La alta actividad inhibitoria y la ausencia de rasgos de virulencia indican que estos microorganismos podrían aplicarse en áreas biotecnológicas como la biopreservación de alimentos o las formulaciones probióticas.
Abstract Two bacteriocin-producing lactic acid bacterial strains were isolated from the intestinal content of the Patagonian mussel and characterized by phenotypic and molecular tests. The isolates were identified as Enterococcus hirae and named E. hirae 463Me and 471Me. The presence of the enterocin P gene was identified in both strains by PCR techniques, while enterocin hiracin JM79 was detected only in the 471Me strain. Both strains were sensitive to clinically important antibiotics and among the virulence traits investigated by PCR amplification, only cylL l and cylL s could be detected; however, no hemolytic activity was observed in the blood agar test. Cell free supernatants were active against all Listeria and Enterococcus strains tested, Lactobacillus plantarum TwLb 5 and Vibrio anguilarum V10. Under optimal growth conditions, both strains displayed inhibitory activity against Listeria innocua ATCC 33090 after 2h of incubation. E. hirae 471Me achieved a maximum activity of 163840AU/ml after 6h of incubation, while the same value was recorded for E. hirae 463Me after 8h. In both cases, the antagonist activity reached its maximum before the growth achieved the stationary phase and remained stable up to 24h of incubation. To our knowledge, this is first report of the isolation of bacteriocinogenic E. hirae strains from the Patagonian mussel. The high inhibitory activity and the absence of virulence traits indicate that they could be applied in different biotechnological areas such as food biopreservation or probiotic formulations.
Subject(s)
Animals , Bacteriocins/biosynthesis , Mytilus edulis/microbiology , Enterococcus hirae/isolation & purification , Enterococcus hirae/metabolism , Gastrointestinal Contents/microbiology , Enterococcus hirae/physiologyABSTRACT
In this paper, an investigation on lactic acid bacterial isolates from ethnic goat raw milk samples were examined for their probiotic potential and safety parameters. For this purpose, isolated bacterial cultures were screened based on certain parameters viz., sugar fermentation, tolerance to temperature, salt, low pH, bile salts, and phenol resistance. After that, these bacterial cultures were more estimated in vitro for auto-aggregation, cell surface hydrophobicity, response to simulated stomach duodenum channel, antibiotic resistance, and antimicrobial activity. Besides, probiotic traits show the absence of gelatinase and hemolytic activity supports its safety. The isolate G24 showed good viability at different pH, bile concentration, phenol resistance and response to simulated stomach duodenum passage but it did not show gelatinase and hemolytic activities. Isolate G24 was susceptible to amikacin, carbenicillin, kanamycin, ciprofloxacin, co-trimazine, nitrofurantoin, streptomycin, and tetracycline. Isolate G24 also exhibited antimicrobial action against five common pathogenic bacteria, such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogens, and Salmonella typhimurium. It displayed the maximum auto-aggregation, cell surface hydrophobicity to different hydrocarbons. Following molecular characterization the isolate G24 was identified as Enterococcus hirae with 16S rRNA gene sequencing and phylogeny. E. hirae G24 bears the excellent properties of probiotics.
ABSTRACT
Objective This study was to understand the structure characteristics of prophages in the genome of Enterococcus hirae R17,and also to analyze their interaction relationships with the host bacterium.Methods The gene distribution and gene encoding characteristics of prophages in the genome of Enterococcus hirae R17 were identified using the PHAST software.The virulence gene,antimicrobial resistance genes,and environmental resistance genes in the prophages were also analyzed.Results Three prophages were found on the chromosome of Enterococcus hirae,including two incomplete prophage elements (Prophage-1 and Prophage-2) and one complete prophage (Prophage-3).Some function genes of bacteria were found in the sequence of three prophages,including nucleotide transportation and metabolism related genes.One incomplete prophage carrying erythromycin-and bacitracin-resistance genes was identified in the plasmid,which suggested that prophage induced gene horizontal transfer caused erythromycin-and bacitracin-resistance of Enterococcus hirae R17.Conclusion This study laid a solid foundation for the diversity analysis of prophages of Enterococcus hirae.Prophages played an important role in promotion of antimicrobial resistance of enterococci.Scientists should pay more attention to the spread of antimicrobial resistance and pathogenicity induced by prophages.
ABSTRACT
Selective intestinal decontamination (SID) with norfloxacin has been widely used for the prophylaxis of spontaneous bacterial peritonitis (SBP) because of a high recurrence rate and preventive effect of SID for SBP. However, it does select resistant gut flora and may lead to SBP caused by unusual pathogens such as quinolone-resistant gram-negative bacilli or gram-positive cocci. Enterococcus hirae is known to cause infections mainly in animals, but is rarely encountered in humans. We report the first case of SBP by E. hirae in a cirrhotic patient who have previously received an oral administration of norfloxacin against SBP caused by Klebsiella pneumoniae and presented in septic shock.
Subject(s)
Humans , Male , Middle Aged , Administration, Oral , Ampicillin/therapeutic use , Anti-Bacterial Agents/therapeutic use , Ascitic Fluid/microbiology , Enterococcus/isolation & purification , Gram-Positive Bacterial Infections/complications , Microbial Sensitivity Tests , Peritonitis/diagnosis , Sepsis/etiologyABSTRACT
Enterococcus hirae infection is rare in humans. We describe a case of pyelonephritis that was caused by Enterococcus hirae in a 57-year-old woman. E. hirae was isolated from both blood and urine. This is the 2nd case report on bacteremia caused by E. hirae in Korea.
Subject(s)
Female , Humans , Middle Aged , Bacteremia , Enterococcus , Korea , PyelonephritisABSTRACT
Enterococcus hirae infection is rare in humans. We describe a case of pyelonephritis that was caused by Enterococcus hirae in a 57-year-old woman. E. hirae was isolated from both blood and urine. This is the 2nd case report on bacteremia caused by E. hirae in Korea.
Subject(s)
Female , Humans , Middle Aged , Bacteremia , Enterococcus , Korea , PyelonephritisABSTRACT
Enterococcus hirae is a member of the Enterococcus genus and is known to cause infections in animals, but it is uncommonly encountered in clinical isolates from humans. We isolated E. hirae from blood of a patient with acute pyelonephritis and sepsis. This is the first case report of bacteremia caused by E. hirae in Korea.
Subject(s)
Animals , Humans , Bacteremia , Enterococcus , Korea , Pyelonephritis , SepsisABSTRACT
Enterococcus hirae is a member of the Enterococcus genus and is known to cause infections in animals, but it is uncommonly encountered in clinical isolates from humans. We isolated E. hirae from blood of a patient with acute pyelonephritis and sepsis. This is the first case report of bacteremia caused by E. hirae in Korea.