RESUMO
The enterocin CRL35 biosynthetic gene cluster was cloned and sequenced. The sequence was revealed to be highly identical to that of the mundticin KS gene cluster (S. Kawamoto, J. Shima, R. Sato, T. Eguchi, S. Ohmomo, J. Shibato, N. Horikoshi, K. Takeshita, and T. Sameshima, Appl. Environ. Microbiol. 68:3830-3840, 2002). Short synthetic peptides were designed based on the bacteriocin sequence and were evaluated in antimicrobial competitive assays. The peptide KYYGNGVSCNKKGCS produced an enhancement of enterocin CRL35 antimicrobial activity in a buffer system.
Assuntos
Bacteriocinas/farmacologia , Peptídeos/farmacologia , Sequência de Aminoácidos , Bacteriocinas/química , Bacteriocinas/genética , Primers do DNA , Sinergismo Farmacológico , Enterococcus/genética , Listeria/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Peptídeos/síntese química , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The replication of herpes simplex virus (HSV) type 1 and 2 in Vero cells is inhibited in the presence of enterocin CRL35 (ECRL), a bacteriocin produced by Enterococcus faecium CRL35. Attempts to resolve the mode of action of ECRL indicate that virus adsorption and penetration are not affected. Instead, a late step of virus multiplication is hindered since the addition of 100 microg/ml of ECRL at 8h post infection still causes a 90% inhibition of virus release. The effect of ECRL on HSV antigen expression was studied by immunofluorescence using a polyclonal serum and a monoclonal antibody against glycoprotein D (gamma protein). These studies indicated that ECRL impeded the second round of infection, apparently as a consequence of the inhibition of glycoprotein D expression. The replication of syncytial mutants of HSV-1 was significantly inhibited at a ECRL concentration of 25 microg/ml. Both the percentage of fused cells and the polykaryocyte size were affected. Studies on the effect of ECRL on viral protein synthesis showed that in the presence of ECRL, HSV late gamma proteins were not synthesized. From these findings, it is concluded that inhibition of HSV spreading by ECRL is due to the prevention of mainly late glycoprotein synthesis.
Assuntos
Antivirais/farmacologia , Bacteriocinas/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Animais , Chlorocebus aethiops , Testes Imunológicos de Citotoxicidade , Técnica Indireta de Fluorescência para Anticorpo , Células Gigantes/metabolismo , Glicoproteínas/metabolismo , Herpesvirus Humano 1/fisiologia , Herpesvirus Humano 2/fisiologia , Humanos , Células Vero , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Changes in microbial flora during the manufacture and maturation of Argentine Tafí cheese was examined. The microbial flora was found to be predominantly mesophilic streptococci, leuconostocs and homofermentative lactobacilli. Streptococcus lactis predominated on the surface and in the internal portion of the cheese after pressing. Streptococcus cremoris reached its maximum population after salting. The main microbial types during maturation were Lactobacillus casei and Lactobacillus plantarum . Pathogenic microorganisms were not detected in any of the samples analyzed.