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1.
Braz J Biol ; 84: e281448, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38695423

RESUMO

Bacterial contamination causes irreparable losses in the performance of alcoholic fermentation. Antibiotics are used to control these microorganisms, but they generate residues and cause microbial resistance. Today the only commercial product used by the mills is hops, but it is very expensive. As an alternative, the objective of this work was to evaluate the feasibility of using extracts from plants grown in the Cerrado for antimicrobial control during an alcoholic fermentation to replace antibiotics. Hydraethanolic extracts of leaves and essential oil of the following species were tested: Schinus terebinthifolius Raddi, Serjania erecta, Serjania marginata, Campomanesia adamantium and Syzygium cumini. Only the extract of Serjania marginata did not show any activity against the bacterium Bacillus sp. Both the essential oils as well as the hydroalcoholic extracts of S. terebinthifolius and C. adamantium and the extract of S. erecta showed antibacterial activity without harming the yeast, with potential to replace the hops.


Assuntos
Fermentação , Extratos Vegetais , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Bacillus , Óleos Voláteis/farmacologia , Testes de Sensibilidade Microbiana , Bactérias/efeitos dos fármacos
2.
Arch. Soc. Esp. Oftalmol ; 98(6): 338-343, jun. 2023. ilus, graf
Artigo em Espanhol | IBECS | ID: ibc-221225

RESUMO

Objetivo Evaluar la eficacia bactericida de varios compuestos utilizados en el tratamiento de la blefaritis anterior estafilocócica crónica mediante un estudio in vitro. Materiales y métodos Se cultivaron cepas comerciales estándar de Staphylococcus aureus (SAu) (ATCC 25923 Culti-Loops) y Staphylococcus coagulasa-negativo (CoNS) (ATCC 12228 Culti-Loops). Se realizaron pruebas de sensibilidad a vancomicina 30μg, netilmicina 30μg, ácido hipocloroso (HOCl) al 0,01% (Ocudox™, Brill®), aceite de hoja de Melaleuca alternifolia (MeAl) (Navyblef® Cuidado diario, NOVAX®) y digluconato de clorhexidina al 1% (DGCH) (Cristalmina™, Salvat®) mediante el método de difusión en disco de agar (Rosco Neo-Sensitabs™). A las 24horas se midieron los halos inducidos con calibradores automáticos. Los resultados se analizaron con las guías EUCAST- y CLSI potency Neo-Sensitabs™. Resultados La vancomicina indujo un halo de 22,37mm y 21,81mm en SAu y CoNS, respectivamente. La netilmicina produjo halos de 24,45mm en SAu y de 32,49mm en CoNS. MeAl indujo halos de 12,65mm en SAu y de 15,83mm en CoNS. Se encontró un halo de 12,11mm en SAu y un halo de 18,38mm en CoNS utilizando HOCl. DGCH produjo halos de 26,55mm y 23,12mm en SAu y CoNS, respectivamente. Conclusión La netilmicina y la vancomicina demostraron actividad antibiótica frente a ambos patógenos, por lo que pueden ser terapias alternativas de rescate para tratar la blefaritis estafilocócica crónica. El DGCH presenta una eficacia frente a ambos comparable a los antibióticos, mientras que el HOCl y la MeAl demuestran menor eficacia (AU)


Objective To evaluate the bactericidal efficacy of several compounds used in the treatment of chronic staphylococcal anterior blepharitis through an in vitro study. Materials and methods Standard commercial strains of Staphylococcus aureus (SAu) (ATCC 25923 Culti-Loops) and coagulase-negative Staphylococcus (CoNS) (ATCC 12228 Culti-Loops) were cultured. Susceptibility tests were performed to vancomycin 30μg, netilmicin 30μg, hypochlorous acid (HOCl) 0.01% (Ocudox™, Brill®), Melaleuca alternifolia leaf oil (MeAl) (Navyblef® Daily Care, NOVAX®) and 1% chlorhexidine digluconate (DGCH) (Cristalmina™, Salvat®) using the agar disk diffusion method (Rosco Neo-Sensitabs®). After 24hours, the induced halos were measured with automatic calipers. The results were analyzed using the EUCAST- and CLSI potency Neo-Sensitabs® guidelines. Results Vancomycin induced a halo of 22.37mm and 21.81mm in SAu and CoNS, respectively. Netilmicin produced halos of 24.45mm in SAu and 32.49mm in CoNS. MeAl induced halos of 12.65mm in SAu and 15.83mm in CoNS. A 12.11mm halo was found in SAu and an 18.38mm halo in CoNS using HOCl. DGCH produced halos of 26.55mm and 23.12mm in SAu and CoNS, respectively. Conclusion Netilmicin and vancomycin demonstrated antibiotic activity against both pathogens, so they can be alternative rescue therapies to treat chronic staphylococcal blepharitis. DGCH has efficacy against both comparable to antibiotics, while HOCl and MeAl show less efficacy (AU)


Assuntos
Humanos , Antibacterianos/uso terapêutico , Blefarite/tratamento farmacológico , Blefarite/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Doença Crônica
3.
Arch Soc Esp Oftalmol (Engl Ed) ; 98(6): 338-343, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37209719

RESUMO

OBJECTIVE: To evaluate the bactericidal efficacy of several compounds used in the treatment of chronic staphylococcal anterior blepharitis through an in vitro study. MATERIALS AND METHODS: Standard commercial strains of Staphylococcus aureus (SAu) (ATCC 25923 Culti-Loops) and coagulase-negative Staphylococcus (CoNS) (ATCC 12228 Culti-Loops) were cultured. Susceptibility tests were performed to vancomycin 30 µg, netilmicin 30 µg, hypochlorous acid (HOCl) 0.01% (Ocudox™, Brill®), Melaleuca alternifolia leaf oil (MeAl) (Navyblef® Daily Care, NOVAX®) and 1% chlorhexidine digluconate (DGCH) (Cristalmina™, Salvat®) using the agar disk diffusion method (Rosco Neo-Sensitabs®). After 24 h, the induced halos were measured with automatic calipers. The results were analyzed using the EUCAST- and CLSI potency Neo-Sensitabs® guidelines. RESULTS: Vancomycin induced a halo of 22.37 mm and 21.81 mm in SAu and CoNS, respectively. Netilmicin produced halos of 24.45 mm in SAu and 32.49 mm in CoNS. MeAl induced halos of 12.65 mm in SAu and 15.83 mm in CoNS. A 12.11 mm halo was found in SAu and an 18.38 mm halo in CoNS using HOCl. DGCH produced halos of 26.55 mm and 23.12 mm in SAu and CoNS, respectively. CONCLUSION: Netilmicin and vancomycin demonstrated antibiotic activity against both pathogens, so they can be alternative rescue therapies to treat chronic staphylococcal blepharitis. DGCH has efficacy against both comparable to antibiotics, while HOCl and MeAl show less efficacy.


Assuntos
Blefarite , Infecções Estafilocócicas , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Vancomicina/farmacologia , Vancomicina/uso terapêutico , Netilmicina , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus , Staphylococcus aureus , Blefarite/tratamento farmacológico , Blefarite/microbiologia
4.
PLoS One ; 14(3): e0212524, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30861002

RESUMO

PURPOSE: Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency. Limbal cells can be harvested from either a healthy part of the patient's eye or the eye of a donor. Small explants are less likely to inflict injury to the donor site. We investigated the effects of limbal explant size on multiple characteristics known to be important for transplant function. METHODS: Human limbal epithelial cells were expanded from large versus small explants (3 versus 1 mm of the corneal circumference) for 3 weeks and characterized by light microscopy, immunohistochemistry, and transmission electron microscopy. Epithelial thickness, stratification, outgrowth, ultrastructure and phenotype were assessed. RESULTS: Epithelial thickness and stratification were similar between the groups. Outgrowth size correlated positively with explant size (r = 0.37; P = 0.01), whereas fold growth correlated negatively with explant size (r = -0.55; P < 0.0001). Percentage of cells expressing the limbal epithelial cell marker K19 was higher in cells derived from large explants (99.1±1.2%) compared to cells derived from small explants (93.2±13.6%, P = 0.024). The percentage of cells expressing ABCG2, integrin ß1, p63, and p63α that are markers suggestive of an immature phenotype; Keratin 3, Connexin 43, and E-Cadherin that are markers of differentiation; and Ki67 and PCNA that indicate cell proliferation were equal in both groups. Desmosome and hemidesmosome densities were equal between the groups. CONCLUSION: For donor- and culture conditions used in the present study, large explants are preferable to small in terms of outgrowth area. As regards limbal epithelial cell thickness, stratification, mechanical strength, and the attainment of a predominantly immature phenotype, both large and small explants are sufficient.


Assuntos
Proliferação de Células , Células Epiteliais , Epitélio Corneano , Limbo da Córnea , Células-Tronco , Antígenos de Diferenciação/biossíntese , Técnicas de Cultura de Células , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Epitélio Corneano/metabolismo , Epitélio Corneano/ultraestrutura , Feminino , Humanos , Limbo da Córnea/metabolismo , Limbo da Córnea/ultraestrutura , Masculino , Células-Tronco/metabolismo , Células-Tronco/ultraestrutura
5.
Sci Rep ; 8(1): 10502, 2018 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30002380

RESUMO

Limbal stem cell deficiency can be treated with transplantation of cultured human limbal epithelial cells (LEC). It can be advantageous to produce LEC in centralized labs and thereafter ship them to eye clinics. The present study used transport simulations of LEC to determine if vigorous shaking during transport altered the viability, morphology and phenotype during a 4 day-long storage of LEC with a previously described serum-free storage method. Inserts with LEC cultured on amniotic membranes were sutured to caps inside air-tight containers with generous amounts of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)-buffered minimal essential medium (MEM). The containers were distributed among the following testing conditions: 6 hours with full containers, 36 hours with full containers, 36 hours with container three quarters full of medium, and 36 hours with container full of medium containing a shear-protecting agent (Pluronic-F68). Compared to stored, but non-transported controls, no statistically significant changes in viability and immunohistochemical staining were observed. The epithelial sheets remained intact. However, an air-liquid interface in the containers reduced the number of desmosomes and hemi-desmosomes compared to the controls. In conclusion, cultured LEC sheets appear to endure vigorous shaking for at least 36 hours if the container is full.


Assuntos
Doenças da Córnea/cirurgia , Epitélio Corneano/transplante , Limbo da Córnea/patologia , Transplante de Células-Tronco/métodos , Meios de Transporte , Idoso , Idoso de 80 Anos ou mais , Adesão Celular , Sobrevivência Celular , Células Cultivadas/transplante , Células Cultivadas/ultraestrutura , Doenças da Córnea/patologia , Epitélio Corneano/citologia , Humanos , Limbo da Córnea/citologia , Masculino , Microscopia Eletrônica de Transmissão , Células-Tronco/patologia , Células-Tronco/ultraestrutura
6.
Arch Soc Esp Oftalmol ; 91(7): 320-6, 2016 Jul.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26810961

RESUMO

OBJECTIVE: To study the relationship between treatment with diode laser transscleral cyclophotocoagulation and development a neurotrophic keratitis due to the damage of the sensitive corneal innervation. METHODS: A study was conducted on 5 eyes of 5 patients who were treated with diode laser transscleral cyclophotocoagulation and soon developed neurotrophic ulcers. Personal characteristics of the patients were collected, as well as refraction and risk factors for corneal hypoesthesia, and the parameters of the laser used in the surgery. RESULTS: It was found that the 5 patients had predisposing factors of corneal hypoesthesia prior to surgery (chronic use of topical beta blockers, surgery with corneal incisions, diabetes mellitus, or corneal dystrophies); however none had developed neurotrophic keratitis until the cyclophotocoagulation was performed. It also showed that 4 of them were highly myopic, and they all were treated with high laser parameters (with an average of 2880 mW for 3s at an average surface of 275°), triggering neurotrophic ulcers between 10 and 35 days after surgery. CONCLUSION: Neurotrophic keratitis is a rare complication that can occur after diode laser transscleral cyclophotocoagulation, secondary to the damage of the long ciliary nerves. The emergence of this disorder can be triggered by the existence of previous risk factors, including high myopia, thus it is important to respect the recommended treatment parameters to prevent the development of this disorder.


Assuntos
Úlcera da Córnea/etiologia , Fotocoagulação a Laser/efeitos adversos , Nervo Oftálmico/lesões , Complicações Pós-Operatórias/etiologia , Lesões por Radiação/etiologia , Adulto , Idoso , Córnea/inervação , Opacidade da Córnea/etiologia , Feminino , Glaucoma de Ângulo Aberto/cirurgia , Humanos , Fotocoagulação a Laser/instrumentação , Fotocoagulação a Laser/métodos , Lasers Semicondutores , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Nervo Oftálmico/efeitos da radiação , Estudos Retrospectivos
7.
Arch Soc Esp Oftalmol ; 89(3): 127-9, 2014 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-24269394

RESUMO

CLINICAL CASE: A 22-year-old woman patient, diagnosed with an inclusion cyst of the conjunctiva in the nasal sector of the left eye, who after 2 shot/needle injections in the lesion came to our clinic with a dense subconjunctival hemorrhage in four quadrants and with severe pain. After excision biopsy, a capillary hemangioma of the conjunctiva was diagnosed. DISCUSSION: Conjunctival capillary hemangioma is mainly a benign lesion, asymptomatic and mostly congenital in origin, its progression or de novo growth is rare in adulthood.


Assuntos
Neoplasias da Túnica Conjuntiva/patologia , Hemangioma Capilar/patologia , Fatores Etários , Neoplasias da Túnica Conjuntiva/etiologia , Feminino , Hemangioma Capilar/etiologia , Humanos , Adulto Jovem
8.
Arch Soc Esp Oftalmol ; 88(2): 56-63, 2013 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-23433193

RESUMO

OBJECTIVE: To describe the visual outcome of patients who underwent Boston type 1 keratoprosthesis (KPro1) implantation, and describe serious sight-threatening post-operative complications. METHODS: We performed an analysis of the clinical records of all patients who underwent Boston keratoprosthesis implantation (BKI)in our institution from May 2006 to February 2011. RESULTS: A total of 41 eyes of 37 patients were included in the final analysis, of whom 22 (59.45%) were male and 15 were (40.54%) female. The mean age was 56.44 years (range 2-90). The most frequent diagnoses were bullous keratopathy, autoimmune diseases, such as Stevens-Johnson syndrome (SJS)/Lyell syndrome (LS), and aniridic keratopathy. The mean number of previous keratoplasties (PK) was 2.36 (range 0-8), the mean number of previous non-PK surgeries was 1.58 (range 0-9). The mean follow-up time was 22.17 months (range 3-46). The mean best corrected visual acuity (BCVA) logMAR before surgery was 2.05 (range 1.10-2.52), and the mean best corrected visual acuity achieved after surgery was 1.16 (range 0.08- 2.70). The most frequent complication was the formation of retroprosthetic membrane (RPM) which appeared in 22 (53.65%) eyes. Of these, 6 (27.27%) appeared after another surgery. Fourteen (63.63%) RPM required treatment, an average of 1.71 (range 1-4) laser YAG applications were performed, and surgical membranectomy was performed in 3 patients. Eleven (26.82%) eyes showed chorioretinal adhesion problems, 6 (14.63%) of which occurred after follow-up of BKI surgery. Infectious complications occurred in 7 (17.07%) cases; 2 (4.87%) patients had infectious keratitis and 5 (12.19%) endophthalmitis. CONCLUSIONS: Visual function improved in most patients. Those with prior multiple ocular surgeries and alterations of systemic immunity such as SJS, LS, and diabetes mellitus are at increased risk for serious sight-threatening complications, such as RPM, chorioretinal detachment and infection. Nevertheless, we consider KPro as an effective alternative in patients with multiple ocular pathology and imminent risk of rejection of a new KP.


Assuntos
Transplante de Córnea , Próteses e Implantes/efeitos adversos , Transtornos da Visão/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Próteses e Implantes/classificação , Desenho de Prótese , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
9.
Arch Soc Esp Oftalmol ; 86(3): 89-92, 2011 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-21511104

RESUMO

CASE REPORT: A 68 year-old male with idiopathic choroidal polypoidal vasculopathy received seven intravitreal injections of bevacizumab in the supero-nasal quadrant. He later developed a localized limbal stem cell deficiency which required limbal transplantation from the same eye. Two months after surgery, a slight improvement of visual acuity was noted, along with an intact ocular surface, clear cornea and decreased inflammation. DISCUSSION: Repeated surgical trauma on the limbus and surrounding areas may damage the limbal stem cells, giving rise to a corneal epitheliopathy due to iatrogenic limbal deficiency. Repeated intravitreal injections may be considered as one of the possible causes.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Anticorpos Monoclonais/administração & dosagem , Neovascularização de Coroide/tratamento farmacológico , Doenças da Córnea/etiologia , Epitélio Corneano/patologia , Injeções Intravítreas/efeitos adversos , Limbo da Córnea/lesões , Células-Tronco/patologia , Idoso , Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Bevacizumab , Terapia Combinada , Doenças da Córnea/patologia , Doenças da Córnea/cirurgia , Transplante de Córnea , Epitélio Corneano/diagnóstico por imagem , Humanos , Limbo da Córnea/patologia , Masculino , Microscopia Acústica , Fototerapia , Transplante Autólogo
10.
J Chemother ; 21(5): 550-7, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19933047

RESUMO

Plitidepsin (Aplidin) is a novel antitumor agent, derived from the mediterranean tunicate Aplidium albicans, and is currently in phase ii clinical trials with evidence of activity in heavily pretreated multiple myeloma, renal cell carcinoma, melanoma and neuroblastoma patients. As compared to its parental compound didemnin B, plitidepsin has shown a better therapeutic index with less bone marrow toxicity, cardiotoxicity and neurotoxicity in patients and a more potent cytotoxic effect in several tumor cell lines. As sensitivity to the drug varies between cell lines and fresh leukemia samples, we performed studies on transport of plitidepsin in leukemia and lymphoma cell lines to determine the mechanism of uptake. The drug is taken up by an active transport process, i.e. the process is temperature and energy dependent, and has a high-affinity binding site with Kt =212 nM and Vmax = 15 pmoles/min. Importantly, once inside the cell, efflux of plitidepsin is minimum, suggesting that the drug is bound to intracellular macromolecules. Further work showed that plitidepsin binds to G-Protein Coupled Receptors (GPCRs), since GPCR and GRK (GPCR kinases) inhibitors suramin and heparin respectively, markedly reduce the drug uptake and its cytotoxic activity. Signaling via Jak/Stat pathway is inhibited by pharmacological concentrations of plitidepsin, further confirming the relationship between plitidepsin and GPCRs.


Assuntos
Depsipeptídeos/metabolismo , Heparina/farmacologia , Microdomínios da Membrana/metabolismo , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Suramina/farmacologia , 4-Aminopiridina/farmacologia , Trifosfato de Adenosina/metabolismo , Antimetabólitos Antineoplásicos/farmacologia , Transporte Biológico Ativo , Proliferação de Células , Citarabina/farmacologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Peptídeos Cíclicos , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio/efeitos dos fármacos , Receptores Acoplados a Proteínas G/metabolismo , Fatores de Transcrição STAT/antagonistas & inibidores , Fatores de Transcrição STAT/metabolismo , Frações Subcelulares , Fatores de Tempo , Células Tumorais Cultivadas/metabolismo
11.
Oncogene ; 25(29): 4116-21, 2006 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-16491118

RESUMO

Colorectal cancer is a major cause of cancer death worldwide. A number of key oncogenes and tumor suppressor genes have been proposed to drive progression from healthy colonic epithelia to malignant tumors, including members of the Wnt/beta-catenin pathway. Recently, CpG island promoter hypermethylation was shown to cause inactivation of two extracellular Wnt inhibitors in colon cancer: secreted frizzled-related proteins (sFRPs) and Wnt inhibitory factor-1 (WIF-1). Here, we show for the first time that another extracellular Wnt inhibitor, the DICKKOPF-1 (DKK-1) gene, is transcriptionally silenced by CpG island promoter hypermethylation in colon cancer cell lines (n=9), whereas treatment with the DNA-demethylating agent 5-aza-2-deoxycytidine restored DKK-1 expression. Restoration of DKK-1 function in non-expressing cells bearing a truncated APC (Adenomatous Polyposis Coli) gene had no effect on beta-catenin/T-cell factor-dependent transcription, but induced tumor suppressor-like features such as reduced colony formation density and tumor growth inhibition in nude mice. These results suggest additional functions for DKK-1 other than inhibiting canonical Wnt signaling. In primary colorectal tumors, DKK-1 was found hypermethylated in 17% (nine of 54) of cases. Furthermore, while for both SFRP-1 and WIF-1 methylation-associated silencing occurred across the whole spectrum of colorectal tumorigenesis, DKK-1 promoter was selectively hypermethylated in advanced colorectal neoplasms (Duke's C and D tumors).


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias Colorretais/genética , Epigênese Genética , Genes Supressores de Tumor , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas Wnt/genética , Proteínas Adaptadoras de Transdução de Sinal , Proteína da Polipose Adenomatosa do Colo/genética , Proteína da Polipose Adenomatosa do Colo/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Colo/metabolismo , Colo/patologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Ilhas de CpG/genética , Metilação de DNA , Decitabina , Epitélio/metabolismo , Epitélio/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Camundongos , Camundongos Nus , Transplante de Neoplasias , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transplante Heterólogo , Proteínas Wnt/antagonistas & inibidores , Proteínas Wnt/metabolismo
12.
Bioch. eng. j ; 23(3): 231-240, May 1,2005.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP, SESSP-IBACERVO | ID: biblio-1060795

RESUMO

Serogroup C polysaccharide from Neisseria. meningitidis constitutes the antigen for the vaccine against the disease caused by this bacterium. Aiming at enhancing the final polysaccharide concentration as well as the overall yield factor (polysaccharide/biomass), 20 cultivations were carried out in Frantz medium in a 13 L bioreactor at 35°C, 0.5 atm, 400 rpm and air flowrate of 2 L/min. A series of nine batch experiments was carried out under three different conditions (with control of dissolved oxygen at 10%, with control of pH at 6.5 and without dissolved oxygen and pH controls). Another set of runs consisted of 11 fed-batch cultivations without dissolved oxygen control, varying glucose concentration from less than 1.0-3.0 g/L, four of which performed controlling the pH at 6.5, and four under partial fed-batch conditions. The highest polysaccharide concentration (0.26 g/L) and the overall yield (0.16 g/g), were obtained in batch and partial fed-batch experiments when glucose concentration was maintained below 1.0 g/L. An empirical relation is proposed to relate the specific production rate of polysaccharide to glucose concentration during the stationary growth phase of the fed-batch runs. The obtained polysaccharide satisfies the molecular weight criterion, being a suitable antigen for vaccine production.


Assuntos
Neisseria meningitidis Sorogrupo C/genética , Neisseria meningitidis Sorogrupo C/imunologia , Neisseria meningitidis Sorogrupo C/metabolismo , Vacinas Meningocócicas/análise , Vacinas Meningocócicas/biossíntese , Vacinas Meningocócicas/provisão & distribuição , Polissacarídeo-Liases/isolamento & purificação
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