The characteristics of a strain of Bacillus amyloliquefaciens isolated from the intestine of Arapaima gigas, selected for its ability to generate inhibition of multiple pathogenic bacteria of fishes were analyzed by using molecular tools such as PCR and mass spectrometry - MALDI TOF / TOFM. The results showed through PCR that this strain has key genes for the generation of antimicrobial peptides such as bmyB (bacillomycin L synthetase B), fenD (fengycin synthetase), srfAA (subunit 1 surfactin synthetase), bacA (bacilysin biosynthesis protein) and iturin (iturin A). In addition, by mass spectrometry analysis were detected bacteriocins (plipastatin, gramicidin, fengycin, surfactin), intestine binding proteins (like-enolase), antimicrobial peptide transport proteins (ABC-transporters) and immune system stimulation proteins like flagelin. Collagenase, chitinases and xylose-isomerases protein...

Se analizaron las características de una cepa de Bacillus amyloliquefaciens aislada del intestino de Arapaima gigas, seleccionada por su capacidad para generar inhibición de múltiples bacterias patógenas de peces, mediante el uso de herramientas moleculares como PCR y espectrometría de masas - MALDI TOF/TOF. Los resultados mostraron a través de PCR que esta cepa cuenta con genes claves para la generación de péptidos antimicrobianos como bmyB (bacillomycin L synthetase B), fenD (fengycin sintetasa), srfAA (subunidad 1 surfactin sintetasa), bacA (proteína de biosíntesis de bacilysin) e iturin (iturin A). Además, mediante el análisis por espectrometría de masas se detectaron bacteriocinas (plipastatin, gramicidin, fengycin, surfactin), proteínas de fijación al intestino (like-enolase), proteinas transportadoras de péptidos antimicrobianos (ABC-transporters) y proteínas de e...

The production of tilapia (Oreochromis sp) is being affected by outbreaks of lake tilapia virus (TiLV) with high mortality in the main breeding regions in Peru. The aim of this study was to determine the presence of TiLV in two tilapia fish farms in Piura and San Martín, which presented mortalities greater than 60%. Samples (liver and brain) were taken from 70 fish from different stages of culture that showed lethargy, loss of appetite, eye lesions and skin erosions. The detection and confirmation of TiLV was determined by semi-nested RT-PCR and subsequent sequencing of the amplified product of segment 3 of the virus. Products of the expected weight (250 bp) corresponding to samples from the two production centres were found. The phylogenetic analysis showed a high homology among the isolates and an identity greater than 90% with the Israeli reference strain (KU751816.1).

The production of tilapia (Oreochromis sp) is being affected by outbreaks of lake tilapia virus (TiLV) with high mortality in the main breeding regions in Peru. The aim of this study was to determine the presence of TiLV in two tilapia fish farms in Piura and San Martín, which presented mortalities greater than 60%. Samples (liver and brain) were taken from 70 fish from different stages of culture that showed lethargy, loss of appetite, eye lesions and skin erosions. The detection and confirmation of TiLV was determined by semi-nested RT-PCR and subsequent sequencing of the amplified product of segment 3 of the virus. Products of the expected weight (250 bp) corresponding to samples from the two production centres were found. The phylogenetic analysis showed a high homology among the isolates and an identity greater than 90% with the Israeli reference strain (KU751816.1).

Probiotic bacteria in aquaculture represent a control alternative and prevention of pathogens, in addition, reduce the use of antibiotics. However, it is necessary to search for other groups of bacteria with similar or better properties, obtained even from the same source. The aim of the study was to identify molecularly lactic acid bacteria with probiotic properties isolated from the posterior intestine of Nile tilapia (Oreochromis niloticus). The study was carried out from November 2017 to March 2018 evaluating the antagonistic, proteolytic, amylolytic, and antibiotic sensitivity activities, and antagonistic to the following pathogens: Aeromonas hydrophila, Aeromonas veronii, Pseudomonas aeruginosa, Pseudomonas putida and Plesiomonas shigelloides. It was identified by sequencing the 16S rRNA gene that Enterococcus faecium (IP5-2a) and Pedioc...

Probiotic bacteria in aquaculture represent a control alternative and prevention of pathogens, in addition, reduce the use of antibiotics. However, it is necessary to search for other groups of bacteria with similar or better properties, obtained even from the same source. The aim of the study was to identify molecularly lactic acid bacteria with probiotic properties isolated from the posterior intestine of Nile tilapia (Oreochromis niloticus). The study was carried out from November 2017 to March 2018 evaluating the antagonistic, proteolytic, amylolytic, and antibiotic sensitivity activities, and antagonistic to the following pathogens: Aeromonas hydrophila, Aeromonas veronii, Pseudomonas aeruginosa, Pseudomonas putida and Plesiomonas shigelloides. It was identified by sequencing the 16S rRNA gene that Enterococcus faecium (IP5-2a) and Pedioc...

Probiotic bacteria in aquaculture represent a control alternative and prevention of pathogens, in addition, reduce the use of antibiotics. However, it is necessary to search for other groups of bacteria with similar or better properties, obtained even from the same source. The aim of the study was to identify molecularly lactic acid bacteria with probiotic properties isolated from the posterior intestine of Nile tilapia (Oreochromis niloticus). The study was carried out from November 2017 to March 2018 evaluating the antagonistic, proteolytic, amylolytic, and antibiotic sensitivity activities, and antagonistic to the following pathogens: Aeromonas hydrophila, Aeromonas veronii, Pseudomonas aeruginosa, Pseudomonas putida and Plesiomonas shigelloides. It was identified by sequencing the 16S rRNA gene that Enterococcus faecium (IP5-2a) and Pedioc...

Probiotic bacteria in aquaculture represent a control alternative and prevention of pathogens, in addition, reduce the use of antibiotics. However, it is necessary to search for other groups of bacteria with similar or better properties, obtained even from the same source. The aim of the study was to identify molecularly lactic acid bacteria with probiotic properties isolated from the posterior intestine of Nile tilapia (Oreochromis niloticus). The study was carried out from November 2017 to March 2018 evaluating the antagonistic, proteolytic, amylolytic, and antibiotic sensitivity activities, and antagonistic to the following pathogens: Aeromonas hydrophila, Aeromonas veronii, Pseudomonas aeruginosa, Pseudomonas putida and Plesiomonas shigelloides. It was identified by sequencing the 16S rRNA gene that Enterococcus faecium (IP5-2a) and Pedioc...

Antimicrobial peptides are small molecules that exhibit strong antagonistic activity against pathogenic microorganisms and are synthesized by a wide variety or organisms, including probiotic bacteria. The aim of the study was to identify peptides with antimicrobial activity in the Enterococcus faecium IP5-2a strain previously isolated from the intestinal tract of Nile tilapia (Oreochromis niloticus). Cellular and extracelullar proteins extraction was performed, followed by 1D SDS-PAGE gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The results revealed peptides with antimicrobial activity, including P54 (SagA) protein, a bacteriocin-like protein and a lantibiotic. These proteins play an important role in the antagonistic capacity of the E. faecium IP52a strain, allowing it to be considered as a potential probiotic in the aquaculture industry.