Isolation and therapeutic efficacy of enteropathogenic E. coli phage cocktail against colibacillosis in neonatal goats

Phage based therapeutics have shown promising results against the infections caused by the drug resistant bacteria. To combat the problem of antibiotic resistance posed by diarrhoeagenic E. coli, here, we identified and characterized 38 E. coli phages which were isolated from 70 solid sources (goat-faeces and soil). The in vitro lytic range of phage isolates (n=38) against 439 isolates of E. coli was found between 16 and 53%. Three phage isolates with highest host range showed lytic efficacy against 53, 48 and 46% of E. coli isolates, respectively. A preparation with above three phages was developed, and the phages of the preparation were found stable at wide range of temperature, pH and chloroform treatment. Endotoxin content of the preparation was found below the threshold level and it also passed safety and sterility tests. a total of 40 diarrheic goat kids were administered orally with the therapeutic phage preparation for two days twice daily. Total 21 diarrheic goat-kids were successfully treated using the therapeutic phage preparation, whereas 19 kids could not be treated (success rate: 52.5%; 21/40). The results of the current study provide insight for using lytic bacteriophages for therapeutic interventions against drug resistant E. coli responsible for colibacillosis in neonatal goat kids

Construction of a broad host range expression plasmid vector by Golden Gate cloning

Aims@#Expression of recombinant proteins across a range of different host organisms has profound contribution to the advancement in biotechnology. In this study, we aimed to construct a highly versatile broad host range (BHR) expression vector, designated as pYL101C.@*Methodology and results@#The Golden Gate cloning approach was used to construct pYL101C. Key features of pYL101C include a strong integron promoter (PINTc), a BHR pBBR1 origin of replication (ori), gentamycin resistance gene (GmR) as a selectable marker and a multiple cloning site (MCS) downstream of the promoter for easy-cloning purpose. To verify the functionality of pYL101C, we cloned the superfolder green fluorescent protein (sfGFP) reporter gene into pYL101C and transferred the resultant recombinant plasmid pYL101C::sfGFP into various Gram-negative bacteria. Transformants obtained stably expressed strong green fluorescence under blue light excitation even without selection after four passages. @*Conclusion, significance and impact of study@#The constructed BHR expression vector, pYL101C and recombinant pYL101C::sfGFP are stable and can be used to monitor the presence of Gram-negative bacteria, such as endophytes and pathogens in their hosts and environment.

Los vectores virales y su relación con la bioseguridad en el laboratorio / Viral vectors and their relationship with biosafety in the laboratory / Vetores virais e sua relação com a biossegurança no laboratório

Los vectores virales constituyen un amplio grupo de agentes usados en los laboratorios de biología molecular y microbiología, para transferir ácido nucleico externo dentro de una célula "blanco". Estos laboratorios requieren medidas de bioseguridad para proteger al personal, el ambiente de trabajo y la población en general de exposiciones no intencionales a estos agentes biológicos. Esta revisión incluye definiciones y generalidades sobre los vectores más usados, así como consideraciones sobre los niveles de bioseguridad necesarios, teniendo en cuenta tanto la constitución genética del vector original, como el tipo de inserto que se quiera clonar y expresar en una determinada célula. Además se describen diferentes propiedades de los vectores como el tropismo, las distintas formas de transmisión, la estabilidad del agente viral y su persistencia, que resultan claves para determinar el grupo de riesgo. Dentro de las condiciones de trabajo adecuadas se incluyen medidas de contención, ensayos de riesgo ambiental y una breve descripción de la biocustodia. Finalmente se destaca el papel de los Comités de Bioseguridad Institucional, como elemento crítico en las actividades necesarias para impedir las exposiciones y proteger al personal del laboratorio y al medio ambiente.

Viral vectors are a broad group of agents used in molecular biology and microbiology laboratories to transfer exogen nucleic acid. These labs require biosafety measures designed to protect their staff, the population and the environment that may be unintentionally exposed to hazardous organisms. This review includes general properties of known vectors, variations in biosafety levels in relation to original vector genetics and the type of insert to be cloned and expressed in a determined cell. It is also important to consider other issues such as transmission, stability and persistence to determine the vector risk group. Under adequate working conditions, containment measures, risk assays and a short description on biosecurity are included. Finally the function of Institutional Biosafety Committees is a critical element to advise on measures needed to prevent exposures and protect laboratory workers and the environment.

Os vetores virais constituem um amplo grupo de agentes utilizados nos laboratórios de biologia molecular e microbiologia para transferir ácido nucleico externo para uma célula "alvo". Esses laboratórios exigem medidas de biossegurança para proteger o pessoal, o ambiente de trabalho e a população em geral de exposições não intencionais a esses agentes biológicos. Esta revisão inclui definições e generalidades sobre os vetores mais comumente usados, bem como considerações sobre os níveis de biossegurança necessários, levando em consideração a constituição genética do vetor original e o tipo de enxerto a ser clonado e expresso numa célula específica. Além disso, são descritas diferentes propriedades dos vetores, como o tropismo, as diferentes formas de transmissão, a estabilidade do agente viral e a sua persistência, dados-chave para a determinação do grupo de risco. As condições de trabalho adequadas incluem medidas de contenção, testes de risco ambiental e uma breve descrição da biocustódia. Finalmente, o papel das Comissões Institucionais de Biossegurança é destacado como um elemento crítico nas atividades necessárias para prevenir exposições e para proteger o pessoal de laboratório e o meio ambiente.

Aphid parasitoids (Hymenoptera, Braconidae, Aphidiinae) and their associations related to biological control in Brazil

This study evaluated the parasitoid-aphid-plant associations in Brazil with the objective of developing a useful research database for further studies of aphid parasitoid ecology and aphid management. The original material was obtained from collections made in Paraná, Rio Grande do Sul, Minas Gerais, and São Paulo states. The published information on the Aphidiinae in Brazil is revised. The general features of the target parasitoid fauna of Central and South America is summarized and promising biological control programs of some aphid species in Brazil is discussed.

Este trabalho avaliou as interações parasitóides-pulgão-planta no Brasil, com o objetivo de desenvolver um banco útil de dados para estudos subseqüentes em ecologia de parasitóides de afídeos e manejo de pulgões. O material original foi obtido de coletas nos estados do Paraná, Rio Grande do Sul, Minas Gerais e São Paulo, sendo revisadas as informações sobre Aphidiinae publicadas no Brasil. Foram também sumarizadas as caracteristicas gerais da fauna de parasitóides das Américas Central e do Sul e discutidos os programas potenciais de controle biológico de algumas espécies de pulgões no Brasil.

Biological Characteristics of Escherichia coli Bacteriophage f_2 in Comparison with Its Broad Host Range Phage / 中华医院感染学杂志

OBJECTIVE Through investigation of the changes in biological characteristics of an E scherichia coli bacteriophage with broad host range,to study the mechanism of phage-host specificity and the bactericidal efficacy on sewage water samples.METHODS In this study,one strain of E.coli bacteriophages with broad host range was screened from natural environment using the E.coli 285.Then,in order to analyze the difference of biologic effects before and after the host range changed,we made a comparison of biological properties between the phage with broad host range and the phage f2.RESULTS The ultrastructure under electron microscope showed that the two phages were round-shaped particles,but phage XY′s diameter between 20-90 nm,short-tailed and occasionally visible;the anti-serum K value of phages f2 and XY was 30.1 and 41.5,respectively;whereas,between phages XY and f2,there was a low correlativity(K value