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1.
Braz J Biol ; 83: e248746, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495165

RESUMO

Colorectal cancer (CRC) is one of the most common cancers leading to comorbidities and mortalities globally. The rational of current study was to evaluate the combined epigallocatechin gallate and quercetin as a potent antitumor agent as commentary agent for therapeutic protocol. The present study investigated the effect of epigallocatechin Gallate (EGCG) (150mg) and quercetin (200mg) at different proportions on proliferation and induction of apoptosis in human colon cancer cells (HCT-116). Cell growth, colonogenic, Annexin V in addition cell cycle were detected in response to phytomolecules. Data obtained showed that, the colony formation was inhibited significantly in CRC starting from the lowest concentration tested of 10 µg/mL resulting in no colonies as visualized by a phase-contrast microscope. Data showed a significant elevation in the annexin V at 100 µg/mL EGCG(25.85%) and 150 µg/mL quercetin (48.35%). Moreover, cell cycle analysis showed that this combination caused cell cycle arrest at the G1 phase at concentration of 100 µg/mL (72.7%) and 150 µg/mL (75.25%). The combined effect of epigallocatechin Gallate and quercetin exert antiproliferative activity against CRC, it is promising in alternative conventional chemotherapeutic agent.


Assuntos
Catequina , Neoplasias Colorretais , Anexina A5 , Catequina/análogos & derivados , Catequina/farmacologia , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/tratamento farmacológico , Humanos , Quercetina/farmacologia
3.
J Appl Microbiol ; 118(3): 583-91, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25529022

RESUMO

AIM: To control eight most predominant Eimeria spp. involved in the economic disease of coccidiosis in broiler chicken, by a chemically characterized essential oil of eucalyptus and peppermint. METHODS AND RESULTS: The experimental design consisted of 160 day-old-broiler chicks, divided into four equal groups (G1 , G2 , G3 and G4 ), with 40 birds per group. Each group was divided into four equal subgroups. Birds in G1 were deprived of essential oil treatment and of Eimeria challenge. Birds in G2 were unchallenged, and administered the essential oil in drinking water at 0.69 ml kg(-1) body weight. Birds in G3 were untreated with essential oil, and each of its four subgroups was challenged at a different age (14, 21, 28 and 35 days). Birds in G4 were treated with essential oil, and challenged in the same manner as for G3 . Equal number of birds from all subgroups (n = 10) were sacrificed at the sixth day after the time allocated for each challenge. The 6 day incubation period post challenge resulted in respective mean per cent weight increase in G2 and G1 birds equivalent to 57.8 and 53.1% (P < 0.05). In addition, the essential oil improved the per cent weight increase in challenged birds (54.6%) compared to the challenged-untreated birds (18.6%) (P < 0.05). The mean feed conversion, mortality, intestinal lesion scores and oocyst counts were significantly reduced in the challenged-treated birds compared to the challenged-untreated birds (P < 0.05). CONCLUSIONS: The results support the hypothesis of using the essential oils of eucalyptus and peppermint to control the most prevalent Eimeria spp. involved in coccidiosis of broiler chicken, helping in improvement of their production, alleviation of lesions and reduction in intestinal oocyst counts. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides information about the possibility of using this blend of essential oil as a coccidiostat for the protection of broiler chickens against the prevalent eight Eimeria spp. of coccidiosis.


Assuntos
Galinhas/parasitologia , Coccidiose/veterinária , Coccidiostáticos/uso terapêutico , Óleos Voláteis/uso terapêutico , Doenças das Aves Domésticas/prevenção & controle , Animais , Peso Corporal/efeitos dos fármacos , Galinhas/crescimento & desenvolvimento , Coccidiose/parasitologia , Coccidiose/patologia , Coccidiose/prevenção & controle , Coccidiostáticos/química , Eimeria/crescimento & desenvolvimento , Intestinos/parasitologia , Intestinos/patologia , Óleos Voláteis/química , Oocistos , Doenças das Aves Domésticas/parasitologia , Doenças das Aves Domésticas/patologia , Ganho de Peso
4.
J Appl Microbiol ; 115(6): 1278-86, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24033981

RESUMO

AIM: To evaluate the impact of Eucalyptus and peppermint essential oils on immune modulation and production of broiler chicken challenged with a molecularly characterized velogenic NewCastle disease virus (vNDV). METHODS AND RESULTS: The experimental design included five treatments with three replicate pens/treatment comprised of 12-day-old broilers chicks/replicate. The five treatments included a positive challenge control (non-NDV vaccinated/nonessential oil treated/challenged) (NNEOC), a negative challenge control (NDV vaccinated/essential oil treated/unchallenged) (VEOU), a non-NDV vaccinated/essential oil treated/challenged (NEOC), a NDV vaccinated/nonessential oil treated/challenged (VNEOC) and a NDV vaccinated/essential oil treated/challenged (VEOC). The lowest mean survival rate (0·0%) and lowest production performance were obtained by the positive challenge control, while the best mean survival (93·3%) and average body weight (2649 g) were obtained by the negative challenge controls (P < 0·05). Among the three others challenged treatments, the best mean survival (79·2%), highest mean body weight at 42 days of age (2445 g), the lowest feed conversion ratio (1·60) and the highest serum conversion immunopotentiation at 35 days of age determined by ELISA and hemagglutination titres were obtained by the VEOC birds compared with respective means obtained by birds of the NEOC and VNEOC treatments (P < 0·05). CONCLUSIONS: The results supported the possibility of using the essential oils of Eucalyptus and Peppermint in broilers to immunopotentiate the response to vaccination against velogenic NDV, helping in significant improvement of survival and production. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides information about the potential use of essential oils of eucalyptus and peppermint that can be exploited as commercial immunopotentiators for the protection of NDV-vaccinated broiler chickens against economic velogenic NDV.

5.
East Mediterr Health J ; 16(12): 1221-5, 2012 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-24988395

RESUMO

The study evaluated the antimicrobial resistance of molecularly characterized strains of Staphylococcus aureus and S. saprophyticus isolated from 3 Lebanese dairy-based food products that are sometimes consumed raw: kishk, shanklish and baladi cheese. Suspected Staphylococcus isolates were identified initially using standard biochemical tests, then strains that were confirmed by polymerase chain reaction (29 S. aureus and 17 S. saprophyticus) were evaluated for their susceptibility to different antimicrobials. The highest levels of contamination with staphylococci were in baladi cheese. Resistance rates ranged from 67% to gentamicin to 94% to oxacillin and clindamycin. The results suggest that these locally made dairy-based foods may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus spp.

6.
Ann Trop Med Parasitol ; 103(1): 39-52, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19173775

RESUMO

In a recent study, bacteria have been isolated from popular Lebanese dairy products, which had been collected in the Beqaa Valley, in north-eastern Lebanon. The foods investigated were two cheeses (shankleesh and baladi) and a dried fermented mixture of yogurt and wheat grains (kishk). Bacterial colonies on McConkey and sorbitol-McConkey agar that showed the morphology of Escherichia coli were biochemically tested and then classified, using PCR-based assays, into the various strains of pathogenic and non-pathogenic E. coli. Some of the confirmed E. coli isolates were proven to be pathogenic, including two identified as E. coli O157:H7. When the pathogenic isolates were tested for their susceptibility to 10 different antibiotics (all commonly used, by clinicians and veterinarians, for the treatment of infections with Gram-negative bacteria), each tested isolate was found to be highly resistant to at least one antibiotic. It therefore appears that, in Lebanon, some popular dairy products pose a public-health hazard, acting as vehicles for the transmission of drug-resistant pathogens.


Assuntos
Antibacterianos/farmacologia , Laticínios/microbiologia , Farmacorresistência Bacteriana , Escherichia coli , Animais , Bovinos , Contagem de Colônia Microbiana , Indústria de Laticínios , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/genética , Escherichia coli O157/patogenicidade , Humanos , Líbano , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Estatística como Assunto
7.
Med Oncol ; 25(1): 30-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18188712

RESUMO

The objective of this study is to evaluate the efficacy of epigallocatechin gallate against ATL cells. The anti-proliferative and pro-apoptotic effects of EGCG were evaluated in HTLV-1-positive and -negative cells. EGCG exhibited a marked decrease in proliferation of ATL cells at 96 h of treatment. The results indicated that TGF-alpha was down-regulated whereas levels of TGF-beta2 increased. Cell cycle distribution analysis revealed an increase in cells in the pre-G(1) phase which was confirmed by ELISA. The results on proteins showed an up-regulation of p53, Bax and p21 protein levels while the levels of Bcl-2alpha were down-regulated.


Assuntos
Apoptose/efeitos dos fármacos , Catequina/análogos & derivados , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Catequina/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Leucemia-Linfoma de Células T do Adulto/patologia , Leucemia-Linfoma de Células T do Adulto/virologia , RNA Mensageiro/análise , Fatores de Crescimento Transformadores/genética
8.
Chem Biol Interact ; 164(1-2): 102-14, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17049505

RESUMO

The retrovirus human T-cell lymphotrophic virus type-1 (HTLV-1) causes adult T-cell leukemia (ATL), which remains with no cure. This study evaluates the effects of l-lysine on proliferation and induction of apoptosis using non-cytotoxic concentrations of the test compound against HTLV-1 positive and negative malignant cell lines. The anti-proliferative effect of lysine was established and confirmed by studying the effects of the test compound on the expression of TGF mRNA expression by RT-PCR. To investigate the effect of l-lysine on the induction of apoptosis, DNA flow cytometry analyses was done and the results verified by cell death ELISA. The results indicated that a significant increase in the preG(1) phase and a decrease in the S phase of the cell cycle in all of the ATL cells tested. l-Lysine up-regulated p53, p21, and Bax protein levels and a down-regulation of Bcl-2alpha in all the cell lines tested. l-Lysine was found to exert its effect through the NF-kappaB pathway by inhibiting the p65 subunit specifically. Also l-lysine caused a decrease in the levels MMP-2 and MMP-9 as well as their enzymatic activity.


Assuntos
Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Lisina/toxicidade , Adulto , Sequência de Bases , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , DNA/metabolismo , Relação Dose-Resposta a Droga , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , NF-kappa B/metabolismo , RNA Mensageiro/metabolismo , Fator de Transcrição RelA/antagonistas & inibidores , Fatores de Crescimento Transformadores/genética , Fatores de Crescimento Transformadores/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo
9.
Leuk Res ; 30(7): 869-81, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16427125

RESUMO

The effects of a novel nutrient formulation Epican Forte (EF) were evaluated on proliferation and induction of apoptosis using non-cytotoxic concentrations against HTLV-1 positive (HuT-102 & C91-PL) and negative (CEM & Jurkat) cells. EF showed anti-proliferative effect as determined by MTT assay and TGF mRNA protein expression using RT-PCR. EF resulted in the down-regulation of TGF-alpha and an up-regulation in TGF-beta2. EF caused a significant increase in apoptotic cells in the preG1 phase. These results were confirmed using Cell Death ELISA and Annexin V-FITC. Induction of apoptosis was caused by an up-regulation of p53, p21 and Bax protein levels and a down-regulation of Bcl-2alpha protein expression level.


Assuntos
Acetilcisteína/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Arginina/farmacologia , Ácido Ascórbico/farmacologia , Catequina/análogos & derivados , Cobre/farmacologia , Vírus Linfotrópico T Tipo 1 Humano/efeitos dos fármacos , Lisina/farmacologia , Manganês/farmacologia , Prolina/farmacologia , Selênio/farmacologia , Linfócitos T/efeitos dos fármacos , Catequina/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA/análise , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Ensaio de Imunoadsorção Enzimática/métodos , Citometria de Fluxo , Perfilação da Expressão Gênica , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade , Relação Estrutura-Atividade , Linfócitos T/virologia , Fatores de Crescimento Transformadores/genética
11.
J Dairy Sci ; 85(5): 1023-30, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12086035

RESUMO

Strained yogurt, labneh, produced by straining cow's milk set yogurt in cloth bags, was stored at 5, 15, and 25 degrees C, and changes in microbial counts, pH, titratable acidity, percentage of free whey, and sensory attributes were monitored during storage. Counts of total aerobes, psychrotrophic yeasts, yeasts and molds, and lactic acid bacteria, except in samples stored at 25 degrees C, increased irrespective of storage temperature. The pH of samples decreased, titratable acidity and percentage of free whey increased, and texture defects were detected at a later stage than flavor changes during storage. Shelf-life data of labneh was adequately described by the Weibull distribution. The nominal shelf life determined using sensory changes and yeast counts as failure criteria ranged from 8.5 to 10.5, 4.7 to 5.8 and 2.3 to 2.7 d at 5, 15 and 25 degrees C, respectively. Q10 (shelf life at T degrees C/shelf life at T+10 degrees C) for flavor quality loss was 1.98 at 5 degrees C, and the corresponding activation energy was 11.3 kcal/mol.


Assuntos
Manipulação de Alimentos/métodos , Conservação de Alimentos , Iogurte , Adulto , Animais , Bovinos , Fenômenos Químicos , Físico-Química , Contagem de Colônia Microbiana , Cor , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Odorantes , Sensação , Paladar , Temperatura , Termodinâmica , Fatores de Tempo , Leveduras/crescimento & desenvolvimento , Iogurte/microbiologia
12.
AIDS Res Hum Retroviruses ; 13(3): 235-9, 1997 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-9115810

RESUMO

Ascorbic acid (ascorbate or vitamin C) has been shown to suppress the induction of HIV in latently infected T lymphocytic cells following stimulation with a tumor promoter (PMA) and inflammatory cytokine (TNF-alpha). To assess whether this inhibition was mediated via modulation of the cellular transcription factor, NF-kappa B, we carried out gel shift analysis on nuclear extracts prepared under different conditions of cell stimulation in the presence or absence of ascorbate, N-acetylcysteine (NAC), or zidovudine (AZT). Pretreatment of ACH-2 T cells by NAC followed by stimulation with PMA, TNF-alpha, or hydrogen peroxide (H2O2) resulted in strong suppression of NF-kappa B activation. In contrast, neither ascorbate nor AZT affected NF-kappa B activity under all three induction conditions in the ACH-2 cell line. Ascorbate and AZT also had no effect on NF-kappa B activation following TNF-alpha- or PMA-induced stimulation of U1 promonocytic cells. These results suggest that the molecular mechanism of HIV inhibition by ascorbate is not mediated via NF-kappa B inhibition, unlike that seen with other antioxidants.


Assuntos
Ácido Ascórbico/farmacologia , HIV/efeitos dos fármacos , NF-kappa B/metabolismo , Replicação Viral/efeitos dos fármacos , Acetilcisteína/farmacologia , Linhagem Celular , HIV/fisiologia , Humanos , Peróxido de Hidrogênio/farmacologia , Linfócitos T/virologia , Acetato de Tetradecanoilforbol/farmacologia , Transcrição Genética/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Latência Viral
14.
Nutrition ; 11(5 Suppl): 684-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8748252

RESUMO

We have recently shown that ascorbic acid (AA) suppresses the production of HIV in a latently infected T-lymphocytic cell line (ACH-2) following stimulation with the tumor promoter, PMA. To evaluate the effect of ascorbic acid on virus activation following treatment with inflammatory cytokine, we tested tumor necrosis factor alpha (TNF-alpha) whose levels are elevated in patients with HIV/AIDS. ACH-2 cultures, pretreated with various nontoxic concentrations of ascorbate or AZT were stimulated for 2 h with TNF-alpha, and incubated further with fresh supplements of ascorbate or AZT. At 24 to 48 h post-treatment, the RT activity released into culture supernatant was determined. Results showed that TNF-alpha alone caused approximately 13- to 16-fold stimulation in the level of extracellular RT. Pretreatment with ascorbic acid at 200 micrograms/ml caused a little more than about 2- to 4-fold reduction in extracellular RT levels. Most remarkably, exposure to 300 micrograms/ml ascorbate resulted in approximately 5- to 10-fold lowering of the extra-cellular RT titer. In contrast, no significant suppression in extracellular RT levels was seen with concentrations of AZT in the range of 1-5 micrograms/ml.


Assuntos
Ácido Ascórbico/farmacologia , HIV/efeitos dos fármacos , HIV/fisiologia , Fator de Necrose Tumoral alfa/farmacologia , Linhagem Celular , Humanos , DNA Polimerase Dirigida por RNA/metabolismo , Linfócitos T/virologia , Acetato de Tetradecanoilforbol/farmacologia , Zidovudina/farmacologia
15.
Chem Biol Interact ; 91(2-3): 207-15, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7514961

RESUMO

We have investigated the molecular basis of the inhibitory effect of ascorbate (vitamin C) on human immunodeficiency virus (HIV) expression in unstimulated chronically infected and reporter cell lines. Comparison of intracellular HIV RNA and protein patterns of ascorbate-treated cells with corresponding patterns of untreated controls, did not show significant differences in the synthesis or processing of individual viral RNA and polypeptides, indicating that the inhibitory effect of ascorbate is not directed at steps of viral transcription or translation. Enzyme assays on cell extracts showed that the activity of an HIV LTR-directed reporter protein made in ascorbate-treated cells was reduced to approximately 11% relative to that of untreated control. These results, combined with previous observations on the suppression of HIV RT activity, are consistent with a mechanism of action in which ascorbate exerts a posttranslational inhibitory effect on HIV by causing impairment of enzymatic activity.


Assuntos
Ácido Ascórbico/farmacologia , HIV/efeitos dos fármacos , Northern Blotting , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Genes Reporter , HIV/genética , HIV/metabolismo , Repetição Terminal Longa de HIV/efeitos dos fármacos , Humanos , Biossíntese de Proteínas/efeitos dos fármacos , RNA Viral/biossíntese , Inibidores da Transcriptase Reversa , Transcrição Genética/efeitos dos fármacos , Proteínas Virais/biossíntese , beta-Galactosidase/biossíntese
16.
Am J Clin Nutr ; 54(6 Suppl): 1231S-1235S, 1991 12.
Artigo em Inglês | MEDLINE | ID: mdl-1720598

RESUMO

To elucidate the action of vitamin C on pathogenic human retroviruses, we investigated and compared the effects of noncytoxic concentrations of ascorbic acid (AA), its calcium salt (Ca-ascorbate), and two thiol-based reducing agents [glutathione (GSH) and N-acetyl-L-cysteine (NAC)] against human immunodeficiency virus (HIV)-1 replication in chronically infected T lymphocytes. Ca-ascorbate reduced extracellular HIV reverse transcriptase (RT) activity by about the same magnitude as the equivalent dose of AA. Long-term experiments showed that continuous presence of ascorbate was necessary for HIV suppression. NAC (10 mmol/L) caused less than twofold inhibition of HIV RT and conferred a synergistic effect (approximately eightfold inhibition) when tested simultaneously with AA (0.426 mmol/L). In contrast, nonesterified GSH (less than or equal to 1.838 mmol/L) had no effect on RT concentrations and did not potentiate the anti-HIV effect of AA. These results further support the potent antiviral activity of ascorbate and suggest its therapeutic value in controlling HIV infection in combination with thiols.


Assuntos
Acetilcisteína/farmacologia , Ácido Ascórbico/farmacologia , Glutationa/farmacologia , HIV/efeitos dos fármacos , Compostos de Sulfidrila/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , HIV/crescimento & desenvolvimento , HIV/metabolismo , Humanos , DNA Polimerase Dirigida por RNA/biossíntese
17.
Proc Natl Acad Sci U S A ; 87(18): 7245-9, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1698293

RESUMO

We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions.


Assuntos
Antivirais , Ácido Ascórbico/farmacologia , HIV-1/fisiologia , Replicação Viral/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Transformação Celular Viral/efeitos dos fármacos , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Cinética , Biossíntese de Proteínas , DNA Polimerase Dirigida por RNA/metabolismo , Linfócitos T
18.
J Appl Bacteriol ; 67(2): 209-12, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2808187

RESUMO

From studies based on batch culture, it has been postulated that the expression of the virulence-associated proteins of Yersinia spp. is controlled by temperature and Ca2+, such that these proteins are synthesized only at the higher temperature (37 degrees C) and calcium-scarce conditions of the intracellular environment. It was found, however, that in Yersinia enterocolitica one of these proteins (140 kDa) is not synthesized at submaximal growth rates under any of the relevant conditions, and that another of the implicated proteins (34 kDa), is synthesized even at 28 degrees C during nutrient-limited growth. Thus, temperature and Ca2+ influence the synthesis of these proteins differently under growth conditions that better approximate the natural environments than do batch cultures.


Assuntos
Proteínas da Membrana Bacteriana Externa/biossíntese , Cálcio/farmacologia , Yersinia enterocolitica/metabolismo , Eletroforese em Gel de Poliacrilamida , Temperatura , Yersinia enterocolitica/efeitos dos fármacos , Yersinia enterocolitica/crescimento & desenvolvimento , Yersinia enterocolitica/patogenicidade
19.
J Appl Bacteriol ; 64(5): 459-63, 1988 May.
Artigo em Inglês | MEDLINE | ID: mdl-3049506

RESUMO

The bacteriocidal efficacy of Purogene, a stabilized aqueous solution of chlorine dioxide (ClO2) was examined using bacteria of concern to public health. The organisms tested were: Escherichia coli, Pseudomonas aeruginosa, Yersinia enterocolitica, Klebsiella pneumoniae, Streptococcus pyogenes Group A, Salmonella typhimurium and Bacillus subtilis. The test organisms responded differently to inactivation by Purogene. At least a 4 log reduction in bacterial counts was noted when Purogene was applied at a concentration of 0.75 mg/l. Since Purogene is a stabilized complex, it was necessary to provide a chemical environment suitable for the release of ClO2 in this solution. This was done by varying the pH of Purogene from 3.5 to 8.6 (pH of Purogene is 8.6) while keeping the pH of the experimental medium constant (pH 7.0). The results showed that Purogene was most efficacious at the lowest pH tested (pH 3.5). This indicates that as chlorine dioxide solutions were reduced to chlorite (which predominates at pH 8.6), their bacteriocidal efficacy was reduced, suggesting free chlorine dioxide as the active disinfecting species.


Assuntos
Bactérias/efeitos dos fármacos , Compostos Clorados , Cloro/farmacologia , Desinfetantes/farmacologia , Óxidos/farmacologia , Bactérias/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Cinética , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/crescimento & desenvolvimento
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