ABSTRACT
Background: Escherichia coliis able to produce different infections in humans. It pathogenicity in the female genital tract is unknown. Objective:To determine the presence of virulence genes (VG) in E. colistrains isolated from the female genital tract. Material and Methods:146 E. colistrains isolated as monomicrobial cultures from vaginal infections were genetically characterized by search of hly, iucC, afa, fimH, neuC, sfa/foc, cnF1, papC, usp,and ibeAVG. Studies were performed by means PFGE and PCR. Results:Genetic analysis of the strains showed two groups with a similarity of approximately 80%. The similarity genetic intragroup was approximately 95%. The results showed strains with a high number of VG and the most common were cnf1andfimH.The afagene was not detected. Were identified eight VG combinations and the most common was papC+ hly+ iucC+ afa- neuC- fimH+ sfa/foc+ cnf1+ usp+ ibeA-. Discussion:The studied strains are concentrated in two genetic groups. Most of the strains contain a great number of VG present in E. coliisolated from extraintestinal infections. Conclusion:It is important to develop new research strategies in this area, to deepen the phylogenetic knowledge of these strains and confirm their true role in vaginal infection.
Introducción: Escherichia colies capaz de producir diferentes cuadros infecciosos en el ser humano. Su patogenicidad en el tracto genital femenino es discutible. Objetivo:Determinar la presencia de genes de virulencia (GV) en cepas de E. colide procedencia vaginal. Material y Métodos:146 cepas de E. coliaisladas desde infecciones vaginales a partir de cultivos monomicrobianos fueron estudiadas mediante EGCP y RPC. Los genes investigados fueron: papC, hly, iucC, afa, fimH, neuC, sfa/foc, cnf1, usp,e ibeA. Resultados:El análisis genético de las cepas demostró dos grupos con una similitud aproximada a 80% según Dice. La similitud genética intra-grupo fue aproximadamente de 95%. Los resultados mostraron cepas con un alto número de GV, siendo más comunes cnf1 y fimH.El gen afano fue detectado. Se determinaron ocho combinaciones de GV siendo la más común papC+ hly+ iucC+ afa- neuC- fimH+ sfa/foc+ cnf1+ usp+ibeA-. Discusión:las cepas estudiadas se concentran en dos grupos genéticos característicos y la mayoría de las cepas analizadas concentra un importante número de GV presentes en E. coliaisladas de infecciones extra-intestinales. Conclusión:Es importante desarrollar nuevas estrategias de investigación en esta área, que permitan profundizar el conocimiento filogenético de estas cepas y confirmar su verdadero rol en la infección vaginal.
Subject(s)
Female , Humans , Escherichia coli Infections/microbiology , Escherichia coli/genetics , Escherichia coli/pathogenicity , Vaginosis, Bacterial/microbiology , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Escherichia coli/isolation & purification , Genes, Bacterial/genetics , Phylogeny , Polymerase Chain Reaction , Virulence/geneticsABSTRACT
Staphylococcus aureus, a recognized human and animal pathogen is capable of producing various exoproteins, a process mediated by the mechanism of quorum sensing. This organism is screened in processed foods, and can produce food poisons. S. aureus is known for its ability to produce antimicrobial substances (bacteriocins) active against Listeria monocytogenes is the major pathogen in contamination of processed food and responsible of listeriosis. The aim of this research was to detect, purify and characterize partially an antimicrobial substance produced by S. aureus strain active against L. monocytogenes. In this investigation 46 S. aureus strains isolated from processed foods were studied. Activity was determined against L. monocytogenes by agar diffusion techniques. The partial purification and and characterization of antimicrobial substance was realized by molecular exclusion chromatography and polyacrylamide gel electrophoresis under denaturing and nondenaturing condictions. The antimicrobial substance that showed a molecular weight of 3.5 kDa approximately was resistant to different temperatures and wide pHs range. The antimicrobial substance could be classified as bacteriocins type II, subclass IIa. Future studies could be contributed to the possible use of the antimicrobial substance as food biopreservant.