Bacteriocin-like inhibitory substance in aquaculture: a classic method of protein precipitation for a new aplicability / Substância inibidora tipo bacteriocina na aquicultura: método clássico de precipitação de proteínas para novas aplicações

Techniques to decrease losses from bacterial diseases are always important to improve the fish production. The use of antagonistic substances (bacteriocins) has been proven to be a viable option. The aim of this study was to evaluate different methods of purification for bacteriocin like inhibitory substances (BLIS). For the purification process, we isolated and used two Gram-positive bacilli that produce antagonistic substances for pathogens in aquaculture. Tests for detection of interfering factors were also performed. After the confirmation that the antagonistic action was due the BLIS activity, we carried out the purification methods. The methods tested were: cell free supernatant, acid extraction and ammonium sulfate precipitation at two concentrations (20 and 50%). Salmonella Tiphy CFP/IAL1472 and Aeromonas hydrophila (isolated in a tilapia production environment) were used as indicators of the efficiency of extracts in controlling pathogenic potentials. Ammonium sulfate precipitation at 50% was the most appropriate for purifying the antagonistic substance for both indicators. The extracts of the two isolates remained active for 22 days at 25ºC. These are promising results regarding the water and fish health without the use of antibiotics, in this manner being a safer environmental practice.

Técnicas para diminuir as perdas causadas por doenças bacterianas são importantes para melhorar continuamente a produção de pescado. O uso de substâncias antagônicas (bacteriocinas) tem-se mostrado uma opção viável. O objetivo do trabalho foi avaliar diferentes métodos de purificação de bacteriocinas como substâncias inibidoras (BLIS). Dois bacilos Gram-positivos, produtores de substâncias antagonistas para agentes patogênicos da aquicultura, foram utilizados em processos de purificação. Depois de confirmada a ação antagônica pela atividade de BLIS, os métodos de purificação foram realizados. Os métodos testados foram: células livres de sobrenadante, extração ácida e precipitação por sulfato de amônia em duas concentrações (20 e 50%). Salmonella Typhi PCP/IAL1472 e Aeromonas hydrophila (isolada de um ambiente de tilapicultura) foram utilizadas como indicadores de eficiência dos extratos. O precipitado por sulfato de amônio a 50% foi o mais adequado para purificar a substância antagonista para ambos os isolados indicadores. Os extratos dos dois isolados permaneceram ativos por 22 dias em 25ºC. Estes resultados são promissores do ponto de vista da manutenção da sanidade da água e dos peixes, sem uso de antibióticos, constituindo uma prática ambientalmente mais segura.

Comparación bacteriana de 30 piezas de alta velocidad antes y después de ser utilizadas en la facultad de odontología, Región Veracruz / Bacterial comparison of 30 high speed handpieces before and after being used at the school of dentistry, Veracruz Region

Introducción: en los procedimientos odontológicos se está expuestoa gran cantidad de microorganismos y las intervenciones clínicas provocan un contacto directo o indirecto con éstos, ya sea a través del instrumental, equipo odontológico contaminado con saliva, sangre, exudados, etcétera. Por esta razón debe tomarse en cuenta el tipo de contaminación de las piezas de mano por ser parte del equipo de uso cotidiano para realizar tratamientos odontológicos. Objetivos generales:Determinar la carga bacteriana en las piezas de alta velocidad antes y después de su uso en diferentes clínicas de la Facultad de Odontologíade la UV Región Veracruz. Metodología: Investigación transversal, descriptiva y observacional. Material y métodos: Se seleccionaron al azar 30 piezas de mano de los estudiantes de la Universidad Veracruzana Facultad de Odontología Región Veracruz, a las cuales se tomó una muestra con un hisopo de algodón antes y después de su uso en la práctica dental. Se realizaron cultivos con las muestras obtenidas que se observaron durante tres días seguidos bajo microscopio para comprobar la presencia de colonias bacterianas. Resultados: De las30 piezas antes de ser utilizadas se detectó Bacillus grampositivos en24 por ciento de las muestras; en 20 por ciento Bacillus gramnegativos, en 6 por ciento Streptobacillus gram-positivos; en 20 por ciento Staphylococcus grampositivos; en 3 por ciento Cocobacillus gramnegativos y en 22 por ciento Actinomyces gramnegativos. El restante 2 por ciento no reveló unidades formadoras de colonias (UFC). En un segundo muestreo, 33 por ciento desarrolló Bacillus grampositivos, 10 por cientoBacillus gramnegativos, 20 por ciento adquirió Sthapylococcus grampositivos, 3 por ciento Sthapylococcus gramnegativo y 34 por ciento no reveló UFC. Conclusión:En el primer muestreo se detectaron microorganismos en 98% de laspiezas de mano, mientras que en el segundo muestreo 66% se contaminócon microorganismos y en 34% no se observó contaminación.

Introduction: dental activity is exposed to a lot of microorganisms,and clinical interventions have a direct or indirect contact with them.Whether through the instruments, dental equipment contaminatedwith saliva, blood, etc; so you should take into account the type ofcontamination of handpieces for being the most widely used equipmentfor dental treatment. General Objectives: Determine the bacterialload in high-speed parts before and after being used in diff erentclinical uses in Dentistry School at UV, Veracruz. Methodology:Cross-sectional, descriptive and observational research. Materialand methods: 30 pieces of students from the Universidad VeracruzanaSchool of Dentistry, Veracruz region, which a sample was takenwith a swab to pieces before and after use in dental practice wererandomly selected. Cultures with samples obtained observedduring three days in a row microscope to determine the presenceof bacterial colonies were made. Results: Of the 30 pieces beforebeing used 24% of Bacillus Gram-positive samples were found; 20%Bacillus Gram-negative, Gram-positive Streptobacillus 6%; 20%Gram-positive Staphylococcus, 3% developed Coccobacillus Gramnegativeand 22% Gram negative Actinomyces. The remaining 2%no colony forming units development (UFC). In a second sampling;33% developed Bacillus Gram-positive, Gram-negative Bacillus10%, 20% obtained Sthapylococcus Gram-positive, Gram-negativeSthapylococcus 3% and 34% did not develop colony forming unit(CFU). Conclusion: In the first sampling 98% of the pieces were microorganism growth, while in the second 66% and the presence ofmicroorganisms obtained 34% no development.

Thermophilic bacteria in Moroccan hot springs, salt marshes and desert soils

The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.

Results of the 1997 SENTRY Antimicrobial Surveillance Program in three Brazilian medical centers

The SENTRY Antimicrobial Surveillance Program began in January, 1997, and is designed to monitor nosocomial and selected community acquired infections via a worldwide surveillance network of sentinel hospitals distributed equally by geographic location and size. Three sites in Brazil - Rio de Janeiro, Florianópolis, and Säo Paulo - participated in the SENTRY Antimicrobial Surveillance Program stet. Rank order of occurrence and antimicrobial susceptibillity of pathogenic species causing bloodstream infections, pneumonia, wound or skin and soft tissue infections, and urinary tract infections (UTI) in hospitalized patients were determined by collecting consecutive isolates over a specified period of time. Antimicrobial susceptibilities of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis obtained from outpatients with respiratory tract infections were also evaluated. The isolates for the evaluated infections were: 1) bloodstream - 20 consecutive isolates in each calendar month during a 12-month period; 2) pneumonia - 100 consecutive isolates over a 6 month period; 3) wound or skin and soft tissue - 50 consecutive isolates over a 3 month period; and 4) UTI - 50 consecutive isolates over a 3 month period. Each hospital also contributed, over a 6 month period, consecutive clinically significant outpatient isolates (one isolate per patient) of S. pneumoniae, H. influenzae, and M. catarrhalis that were considered pathogens in respiratory tract infections. Data collected for each isolate included species identification, antimicrobial susceptibility profile, data of isolation, and specimen type. Molecular studies were performed on selected isolates. A total of 1,241 bacterial strains were obtained; the majority were cultured from hospitalized patients, while 139 were fastidious organisms from community acquired respiratory tract infections. Gram-negative bacilli and S. aureus were the predominant pathogens, and Enterobacter spp. was a significant pathogen. The predominance of P. aeruginosa and Acinetobacter spp. and the significant levels of resistence to most agents are of major concern, as is the epidemic rate of ESBL-producing strains of Klebsiella spp. and E. coli in Brazil, which is much higher than rates seen in other areas of the world. Resistance among P. aeruginosa and the Enterobacteriaceae to fluoroquinolones, oxacillin-resistant S. aureus, and penicillin- and trimethoprim-sulfamethoxazole-resistant pneumococci were other...