Spiramyin-loaded PLGA implants for the treatment of ocular toxoplasmosis: development, characterization, biocompatibility, and anti-toxoplasma activity.

Ocular toxoplasmosis is the major cause of infectious posterior uveitis worldwide, inducing visual field defect and/or blindness. Despite the severity of this disease, an effective treatment is still lacking. In this study, spiramycin-loaded PLGA implants were developed aiming at the treatment of ocular toxoplasmosis. Implants were manufactured by a hot-molding technique, characterized by Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, Differential Scanning Calorimetry, Scanning Electron Microscopy; evaluated in terms of ocular biocompatibility by immunofluorescence, flow cytometry, cell migration, Hen's egg test-chorioallantoic membrane (HET-CAM) irritation test; and investigated in terms of in vitro efficacy against Toxoplasma gondii . Characterization techniques indicated that spiramycin was dispersed into the polymeric chains and both substances preserved their physical structures in implants. The HET-CAM test indicated that implants did not induce hemorrhage or coagulation, being non-irritant to the CAM. ARPE-19 cells showed viability by MTT assay, and normality in cell cycle kinetics and morphology, without stimulating cell death by apoptosis. Finally, they were highly effective against intracellular parasites without inducing human retinal pigment epithelial cell death. In conclusion, spiramycin-loaded PLGA implants represent a promising therapeutic alternative for the local treatment of ocular toxoplasmosis.

Condução da toxoplasmose gestacional / Management of gestational toxoplasmosis

A toxoplasmose é uma doença proveniente do Toxoplasma gondii, um protozoário que tem os felinos como seu hospedeiro definitivo e os mamíferos e aves como seu hospedeiro intermediário. Tem um curso benigno e autolimitado quando acomete um indivíduo imunocompetente, no entanto a infecção durante a gestação acarreta até 50% de chance de toxoplasmose congênita, podendo causar danos severos ao feto. A virulência dos genótipos encontrados nas Américas Central e do Sul é a mais alta, comparada a Europa e América do Norte, tendo a doença um comportamento mais agressivo. Os estudos relatam a diminuição da infecção fetal em até 60% com o uso da espiramicina, usada ainda na profilaxia. Este artigo discute sobre a triagem materna pré-natal e sua necessidade, a profilaxia e o tratamento da infecção fetal ainda intraútero, com o objetivo de diminuir a transmissão vertical e as sequelas neonatais com suas implicações ao longo da vida.(AU)

Toxoplasmosis it is a disease originating from Toxoplasma gondii, a protozoan that has felines at as ultimate host and mammals and birds at as intermediate host. Has a benign and self-limiting course when affects immunocompetent individual, however, infection during pregnancy leads 50% chance of congenital toxoplasmosis and can cause severe damage to the fetus. The virulence of genotypes found in Central and South America is the highest compared to Europe and North America, having the disease a more aggressive behavior. Studies report a reduction in fetal infection 60% with the use spiramycin still used for prophylaxis. This article discusses prenatal maternal screening, prophylaxis and treatment of fetal infection still in utero with the objective of decreasing vertical transmission and neonatal sequelae with their lifelong implications.(AU)

Toxoplasmosis congénita, una mirada en la actualidad del tratamiento; revisión de la literatura / Congenital toxoplasmosis, a look at contemporary treatment; literature review / Toxoplasmose congênita, um olhar atual no tratamento; revisão de literatura

Introducción. La Toxoplasmosis congénita constituye una causa significativa de morbi-mortalidad neonatal en países de bajos ingresos como Colombia. Puede originar prematuridad, secuelas patológicas y pérdida fetal. El tamizaje en las gestantes y, a su vez, un tratamiento oportuno y adecuado disminuye la transmisión vertical y sus nefastas secuelas. El objetivo es presentar evidencia científica actualizada sobre el tratamiento farmacológico de la Toxoplasmosis Congénita. Metodología. Se realizó una búsqueda no sistemática en bases de datos: Pubmed, Medline, Clinical Key y Springer. Se incluyeron artículos originales y de revisión de tema publicados desde enero de 2014 hasta abril de 2019. División de los temas tratados. se abordan la fisiopatología y clínica, el abordaje diagnóstico, alternativas de prevención y tratamiento. Conclusiones. En la actualidad la terapia farmacológica es limitada, los esquemas de manejos se basan en espiramicina o la combinación de sulfadiazina/pirimetamina y ácido folínico; estas moléculas no son del todo bien toleradas y presentan un amplio espectro de reacciones adversas secundario a sus efectos tóxicos; resulta necesario la ejecución de estudios aleatorizados para evaluar su efectividad. Cómo citar: Rueda-Paez YS, Valbuena-Ruiz L, Quintero-Pimiento N, Pinilla-Plata A, Sayago-Silva J. Toxoplasmosis congénita, una mirada en la actualidad del tratamiento; revisión de la literatura. MedUNAB. 2019;22(1):51-63. doi: 10.29375/01237047.2612

Introduction. Congenital Toxoplasmosis constitutes a significant cause of neonatal morbimortality in underdeveloped countries like Colombia. It can cause prematurity, pathological after-effects and fetal loss. Screening expectant mothers and in turn, a timely and adequate treatment, reduce vertical transmission and its devastating effects. The objective is to present up-to-date scientific evidence about the pharmacological treatment of Congenital Toxoplasmosis. Methodology. A non-systematic search of databases was conducted: Pubmed, Medline, Clinical Key and Springer. Original and topic review articles were included dating from January 2014 to April 2019. Division of topics covered. Physiopathology and clinical pathology, diagnostic approach, prevention and treatment alternatives were addressed. Conclusions. At this time, pharmacological therapy is limited, management schemes are based on spiramycin or a combination of sulfadiazine/pyrimethamine and folinic acid; these molecules are not very well tolerated and exhibit a wide spectrum of adverse reactions apart from their toxic effects, thus it is necessary to conduct randomized studies to evaluate its effectiveness. Cómo citar: Rueda-Paez YS, Valbuena-Ruiz L, Quintero-Pimiento N, Pinilla-Plata A, Sayago-Silva J. Toxoplasmosis congénita, una mirada en la actualidad del tratamiento; revisión de la literatura. MedUNAB. 2019;22(1):51-63. doi: 10.29375/01237047.2612

Introdução. A toxoplasmose congênita é uma causa significativa de morbidade e mortalidade neonatal em países de baixa renda, como a Colômbia. Pode causar prematuridade, sequelas patológicas e perda fetal. A triagem em gestantes e, por sua vez, um tratamento oportuno e adequado diminui a transmissão vertical e suas consequências desastrosas. O objetivo é apresentar evidências científicas atualizadas sobre o tratamento farmacológico da Toxoplasmose Congênita. Metodologia. Foi realizada uma revisão não sistemática nas bases de dados: Pubmed, Medline, Clinical Key e Springer. Foram incluídos tanto artigos originais, quanto revisões de tópicos publicados de janeiro de 2014 até abril de 2019. Divisão dos tópicos discutidos. foram abordadas a fisiopatologia e a clínica, a abordagem diagnóstica, alternativas para prevenção e tratamento. Conclusões. Atualmente, a terapia farmacológica é limitada, os esquemas terapéuticos baseiam-se na espiramicina ou na combinação de sulfadiazina/pirimetamina e ácido folínico; estas moléculas não são totalmente toleradas e apresentam um amplo espectro de reações adversas secundárias aos seus efeitos tóxicos. É necessário realizar estudos randomizados para avaliar sua eficácia. Cómo citar: Rueda-Paez YS, Valbuena-Ruiz L, Quintero-Pimiento N, Pinilla-Plata A, Sayago-Silva J. Toxoplasmosis congénita, una mirada en la actualidad del tratamiento; revisión de la literatura. MedUNAB. 2019;22(1):51-63. doi: 10.29375/01237047.2612

TeleCondutas: toxoplasmose na gestação / TeleGuides: toxoplasmosis during pregnancy

A toxoplasmose, causada pelo protozoário Toxoplasma gondii, apresenta complicações graves quando adquirida no período gestacional. No Brasil, a incidência de toxoplasmose congênita varia entre 4 a 10 casos para cada 10 mil nascidos vivos, com apresentação clínica variável, incluindo alterações oculares (como coriorretinite), neurológicas (como encefalite, microcefalia e macrocefalia), sistêmicas (hepatomegalia, icterícia) e óbito fetal/neonatal. O risco de transmissão e a gravidade das complicações têm comportamentos inversos em relação à idade gestacional. A taxa de transmissão ao feto é 14% no primeiro trimestre e 60% no terceiro trimestre. Já a gravidade, tende a ser maior nas infecções adquiridas no começo da gestação. A taxa de transmissão varia entre 50% a 60% em mães não tratadas e 20% a 30% nas que receberam tratamento durante a gestação. Por isso, a prevenção da infecção, rastreamento e diagnóstico precoce são fundamentais para evitar as complicações da toxoplasmose congênita. Esta guia apresenta informação que orienta a conduta para casos de toxoplasmose na gestação no contexto da Atenção Primária à Saúde, incluindo: Rastreamento, Transmissão e prevenção, Manifestações clínicas, Gestação após infecção aguda, Diagnóstico na gestante, Conduta durante o pré-natal na APS, Tratamento da gestante, Diagnóstico de infecção fetal, Diagnóstico de infecção congênita, Encaminhamento para serviço especializado.

Azithromycin treatment is able to control the infection by two genotypes of Toxoplasma gondii in human trophoblast BeWo cells.

Trophoblast infection by Toxoplasma gondii plays a pivotal role in the vertical transmission of toxoplasmosis. Here, we investigate whether the antibiotic therapy with azithromycin, spiramycin and sulfadiazine/pyrimethamine are effective to control trophoblast infection by two Brazilian T. gondii genotypes, TgChBrUD1 or TgChBrUD2. Two antibiotic protocols were evaluated, as follow: i) pre-treatment of T. gondii-tachyzoites with selected antibiotics prior trophoblast infection and ii) post-treatment of infected trophoblasts. The infection index/replication and the impact of the antibiotic therapy on the cytokine milieu were characterized. It was observed that TgChBrUD2 infection induced lower infection index/replication as compared to TgChBrUD1. Regardless the therapeutic protocol, azithromycin was more effective to control the trophoblast infection with both genotypes when compared to conventional antibiotics. Azithromycin induced higher IL-12 production in TgChBrUD1-infected cells that may synergize the anti-parasitic effect. In contrast, the effectiveness of azithromycin to control the TgChBrUD2-infection was not associated with the IL-12 production. BeWo-trophoblasts display distinct susceptibility to T. gondii genotypes and the azithromycin treatment showed to be more effective than conventional antibiotics to control the T. gondii infection/replication regardless the parasite genotype.

[Effect of antenatal spiramycin treatment on the frequency of retinochoroiditis due to congenital toxoplasmosis in a Colombian cohort].

INTRODUCTION: Gestational toxoplasmosis is frequent and severe. There is still debate about the benefits of treatment against ocular manifestations in the newborn. Spiramycin treatment is used for this purpose, unfortunately prenatal diagnosis is sometimes delayed and pregnant women are not treated. OBJECTIVE: To describe the relationship between treatment with spiramycin during pregnancy in mothers with gestational toxoplasmosis and development of ocular toxoplasmosis in newborns. MATERIALS AND METHODS: We conducted a descriptive study of a case series. We evaluated a prospective cohort of patients diagnosed with gestational toxoplasmosis during three years at the Retinology Service at the Clínica Universitaria Bolivariana in Medellín. RESULTS: Gestational toxoplasmosis was found in 23 mothers; 15 (65%) were treated during pregnancy with 3 g per day of spiramycin, eight (35%) patients were untreated. In the treated group just one newborn developed ocular toxoplasmosis (6.6%), in contrast with five (62.5%) of the eight patients who did not receive treatment. These results suggest that pregnancy treatment reduces the relative risk of ocular toxoplasmosis in the newborn by 96% (95% CI: 33 - 100%). Only two (14%) of the patients who were evaluated, had nervous system involvement related to toxoplasmosis in CT scan or cerebral ultrasound. These two patients also developed ocular pathology and were diagnosed at the time of birth, so they did not received antenatal treatment. CONCLUSIONS: A protective effect was found against the ocular involvement in patients whose mother received treatment with spiramycin (OR=0.04;95% CI: 0.00-0.67), p<0.01 (Fisher's Exact Test).

Efecto del tratamiento prenatal con espiramicina en la frecuencia de retinocoroiditis por toxoplasmosis congénita en una cohorte colombiana / Effect of antenatal spiramycin treatment on the frequency of retinochoroiditis due to congenital toxoplasmosis in a Colombian cohort

Resumen Introducción. La toxoplasmosis de la gestación es frecuente y grave. Hasta ahora no hay consenso sobre la utilidad del tratamiento para prevenir complicaciones oculares en el neonato. En la actualidad, uno de los medicamentos utilizados en las madres diagnosticadas es la espiramicina oral. Infortunadamente, en algunas mujeres gestantes no se hace el diagnóstico prenatal y, por esta u otras razones, no reciben el tratamiento. Objetivo. Describir la relación entre el tratamiento con espiramicina durante el embarazo en madres con toxoplasmosis de la gestación y la presentación de toxoplasmosis ocular en los recién nacidos. Materiales y métodos. Se llevó a cabo un estudio observacional descriptivo de serie de casos. Se evaluó una serie prospectiva de pacientes con toxoplasmosis de la gestación durante tres años de seguimiento en el Servicio de Retinología de la Clínica Universitaria Bolivariana de Medellín. Resultados. Se registraron 23 madres con diagnóstico de toxoplasmosis de la gestación. Quince de ellas (65 %) recibieron durante la gestación tratamiento con espiramicina en dosis de 3 g al día; uno de los neonatos (6,6 %) presentó toxoplasmosis ocular. De las ocho (35 %) pacientes que no recibieron tratamiento, cinco (62,5 %) tuvieron hijos con compromiso ocular por toxoplasma. La razón de momios (odds ratio, OR) del efecto protector contra dicho compromiso en los pacientes cuyas madres recibieron tratamiento fue de 0,04 (IC95% 0,00-0,67), con valor de p menor de 0,01 en la prueba exacta de Fisher. Solo se evidenció compromiso del sistema nervioso central por toxoplasmosis mediante las imágenes de tomografía o ecografía cerebral en dos (14 %) pacientes de las 14 en quienes se hicieron estos estudios. Los dos pacientes presentaron, además, compromiso ocular; ambos fueron diagnosticados en el momento del nacimiento y sus madres no habían recibido tratamiento prenatal. Conclusiones. Estos resultados evidencian que el tratamiento con espiramicina durante el embarazo en la toxoplasmosis de la gestación redujo en 96 % (IC95% 33-100 %) el riesgo relativo de presentar la enfermedad en el recién nacido.

Abstrat Introduction: Gestational toxoplasmosis is frequent and severe. There is still debate about the benefits of treatment against ocular manifestations in the newborn. Spiramycin treatment is used for this purpose, unfortunately prenatal diagnosis is sometimes delayed and pregnant women are not treated. Objective: To describe the relationship between treatment with spiramycin during pregnancy in mothers with gestational toxoplasmosis and development of ocular toxoplasmosis in newborns. Materials and methods: We conducted a descriptive study of a case series. We evaluated a prospective cohort of patients diagnosed with gestational toxoplasmosis during three years at the Retinology Service at the Clínica Universitaria Bolivariana in Medellín. Results: Gestational toxoplasmosis was found in 23 mothers; 15 (65%) were treated during pregnancy with 3 g per day of spiramycin, eight (35%) patients were untreated. In the treated group just one newborn developed ocular toxoplasmosis (6.6%), in contrast with five (62.5%) of the eight patients who did not receive treatment. These results suggest that pregnancy treatment reduces the relative risk of ocular toxoplasmosis in the newborn by 96% (95% CI: 33 - 100%). Only two (14%) of the patients who were evaluated, had nervous system involvement related to toxoplasmosis in CT scan or cerebral ultrasound. These two patients also developed ocular pathology and were diagnosed at the time of birth, so they did not received antenatal treatment. Conclusions: A protective effect was found against the ocular involvement in patients whose mother received treatment with spiramycin (OR=0.04;95% CI: 0.00-0.67), p<0.01 (Fisher's Exact Test).

The prevalence of genotypes that determine resistance to macrolides, lincosamides, and streptogramins B compared with spiramycin susceptibility among erythromycin-resistant Staphylococcus epidermidis.

Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, can be regarded as potential reservoirs of resistance genes for pathogenic strains, e.g., Staphylococcus aureus. The aim of this study was to assess the prevalence of different resistance phenotypes to macrolide, lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant S. epidermidis, together with the evaluation of genes promoting the following different types of MLSB resistance:ermA, ermB, ermC,msrA, mphC, and linA/A'. Susceptibility to spiramycin was also examined. Among 75 erythromycin-resistantS. epidermidis isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of inhibition around the clindamycin disc near the spiramycin disc was found for some spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of resistance to clindamycin by this 16-membered macrolide. The most frequently isolated gene was ermC, irrespective of the MLSB resistance phenotype, whereas the most often noted gene combination wasermC, mphC, linA/A'. The results obtained showed that the genes responsible for different mechanisms of MLSB resistance in S. epidermidis generally coexist, often without the phenotypic expression of each of them.

The prevalence of genotypes that determine resistance to macrolides, lincosamides, and streptogramins B compared with spiramycin susceptibility among erythromycin-resistant Staphylococcus epidermidis

Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, can be regarded as potential reservoirs of resistance genes for pathogenic strains, e.g., Staphylococcus aureus. The aim of this study was to assess the prevalence of different resistance phenotypes to macrolide, lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant S. epidermidis, together with the evaluation of genes promoting the following different types of MLSB resistance:ermA, ermB, ermC,msrA, mphC, and linA/A’. Susceptibility to spiramycin was also examined. Among 75 erythromycin-resistantS. epidermidis isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of inhibition around the clindamycin disc near the spiramycin disc was found for some spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of resistance to clindamycin by this 16-membered macrolide. The most frequently isolated gene was ermC, irrespective of the MLSB resistance phenotype, whereas the most often noted gene combination wasermC, mphC, linA/A’. The results obtained showed that the genes responsible for different mechanisms of MLSB resistance in S. epidermidis generally coexist, often without the phenotypic expression of each of them.

First isolation and molecular characterization of Toxoplasma gondii from a human placenta in Argentina.

Blood sample and placenta were taken from a 37-week pregnant woman; serologic results indicated acute toxoplasmosis. Placenta was inoculated into mice. Seropositive mice were sacrificed and tissue cysts from brain were inoculated into new mice. Specific DNA was detected by PCR, and the isolate was characterized as Type II by nPCR-RFLP for nSAG2, SAG3, BTUB, GRA6, c29-2, c22-8, L358, PK1 and Apico markers. This is the first isolation and molecular characterization of Toxoplasma gondii from humans in Argentina.

Congenital toxoplasmosis and prenatal care state programs.

BACKGROUND: Control programs have been executed in an attempt to reduce vertical transmission and the severity of congenital infection in regions with a high incidence of toxoplasmosis in pregnant women. We aimed to evaluate whether treatment of pregnant women with spiramycin associated with a lack of monitoring for toxoplasmosis seroconversion affects the prognosis of patients. METHODS: We performed a prospective cohort study with 246 newborns (NB) at risk for congenital toxoplasmosis in Goiânia (Brazil) between October 2003 and October 2011. We analyzed the efficacy of maternal treatment with spiramycin. RESULTS: A total of 40.7% (66/162) of the neonates were born seriously infected. Vertical transmission associated with reactivation during pregnancy occurred in 5.5% (9/162) of the NB, with one showing severe infection (systemic). The presence of specific immunoglobulins (fetal IgM and NB IgA) suggested the worst prognosis. Treatment of pregnant women by spiramycin resulted in reduced vertical transmission. When infected pregnant women did not undergo proper treatment, the risk of severe infection (neural-optical) in NB was significantly increased. Fetal IgM was associated with ocular impairment in 48.0% (12/25) of the fetuses and neonatal IgA-specific was related to the neuro-ophthalmologic and systemic forms of the disease. When acute toxoplasmosis was identified in the postpartum period, a lack of monitoring of seronegative pregnant women resulted in a higher risk of severe congenital infection. CONCLUSION: Treatment of pregnant women with spiramycin reduces the possibility of transmission of infection to the fetus. However, a lack of proper treatment is associated with the onset of the neural-optical form of congenital infection. Primary preventive measures should be increased for all pregnant women during the prenatal period and secondary prophylaxis through surveillance of seroconversion in seronegative pregnant woman should be introduced to reduce the severity of congenital infection in the environment.

The effect of spiramycin on Porphyromonas gingivalis and other "classic" periopathogens.

In clinical trials, Spiramycin has shown additional benefit overscaling and root planing on pocket depth reduction, but its effect on periodontal microbiota was evaluated only by darkfield microscopy. Therefore, this study was conducted to determine the effect of Spiramycin administration on Porphyromonas gingivalis and other periodontopathic bacteria using 16S rARN PCR technique. Thirty two non-smoker adults with untreated periodontitis and pocket depth > or = 7 mm. were evaluated to participate in this randomized placebo-controlled clinical trial. Clinical measurements were performed on day -15, 15, 30 and 90 from baseline. Subgingival samples were analyzed for detection of Porphyromonas gingivalis (Pg), Tannerella forsythia (TJ), Treponema denticola (Td) and Aggregatibacter actinomycetemcomitans (Aa) on days -15, 30 and 90. On day 0, 25 Pg positive subjects were randomly assigned to receive either systemically administered Spiramycinfor 7 days (Test group SP) or identical placebo tablets (Placebo group PL). After Spiramycin administration Pg, Tf and Td were suppressed showingstatistically significant difference (p<0.05) with the Placebo group. None of the groups showed changes in Aa detection. These data indicate that bacteria currently associated with advanced periodontitis (Pg, Tf and Td) are suppressed after 7 days of systemic administration of Spiramycin.

Azithromycin and spiramycin induce anti-inflammatory response in human trophoblastic (BeWo) cells infected by Toxoplasma gondii but are able to control infection.

Toxoplasma gondii is an important pathogen which may cause fetal infection if primary infection. Our previous studies have used human choriocarcinoma trophoblastic cells (BeWo cell line) as experimental model of T. gondii infection involving placental microenvironment. This study aimed to examine the effects of azithromycin and spiramycin against T. gondii infection in BeWo cells. Cells were treated with different concentrations of the macrolide antibiotics and analyzed first for cell viability using thiazolyl blue tetrazole (MTT) assay. As cell viability was significantly decreased with drug concentrations higher than 400 µg/mL, the concentration range used in further experiments was from 50 to 400 µg/mL. The number of infected cells and intracellular replication of T. gondii decreased after treatment with each drug. The infection induced up-regulation of the macrophage migration inhibitory factor (MIF), which was also enhanced in infected cells after treatment with azithromycin, but not with spiramycin. Analysis of the cytokine profile showed increase TNF-α, IL-10 and IL-4 production, but decreased IFN-γ levels, were detected in infected cells and treated with each drug. In conclusion, treatment of human trophoblastic BeWo cells with with azithromycin or spiramycin is able to control the infection and replication of T. gondii. In addition, treatment with these macrolides, especially with azityromycin induces an anti-inflammatory response and high MIF production, which can be important for the establishment and maintenance of a viable pregnancy during T. gondii infection.

Unresolved questions about the most successful known parasite.

Every 3 years, the International Congress on Congenital Toxoplasmosis meeting gathers experts with different backgrounds who are involved in congenital toxoplasmosis: gynecologists, pediatricians, ophthalmologists, microbiologists, epidemiologists and research scientists. Most attendees come from the Americas and Europe, where substantial work has been performed to better understand this disease. Two presentations that stressed major current issues in the field of toxoplasmosis are summarized here.

The effect of spiramycin on Porphyromonas gingivalis and other classic periopathogens

Los estudios clínicos indican un efecto adicional beneficioso de la espiramicina cuando se la utiliza junto con el raspaje y alisado radicular. Hasta el presente, su efecto sobre la microbiota periodontal ha sido estudiado sólo con microscopio de campo oscuro. El objetivo del presente estudio fue evaluar el efecto de la espiramicina sobre Porphyromonas gingivalis y otros patógenos periodontales "clásicos", con la técnica de PCR, utilizando el gen 16S del ARNr. Participaron de este estudio clínico controlado randomizado 32 sujeros adultos, no fumadores, con enfermedad periodontal no tratada, con bolsas periodontales >- a 7mm. Se registraron parámetros clínicos en el día -15, 15, 30 y 90 de iniciado el estudio. Se analizó el biofilm periodontal subgingival con PCR, identificándose Prophyromonas gingivalis (Pg), Tannarella forsythia (Tf), Treponema denticola (Td) y Aggregatibacter actinomycetemcomitans (Aa) en el día 30 y 90. En el día 0, 25 sujetos positivos para Porphyromonas gingivalis se dividieron aleatoriamente en dos grupos: grupo Test (Espiramicina 7 días) y grupo control (Placebo 7 días). La espiramicina fue efectiva sobre Pg, Tf, Td. Hubo diferencias (p<0,05) con el grupo control. Ninguno de los grupos mostró diferencias para Aa. Estos datos indicarían que la Espiramicina fue efectiva sobre las bacterias que actualmente se asocian con periodontitis severas (Pg, Tf, Td) luego de la administración sistémica durante 7 días.

Effect of branched-chain amino acids, valine, isoleucine and leucine on the biosythesis of bitespiramycin 4"-O-acylspiramycins

Bitespiramycin, a group of 4"-O-acylated spiramycins with 4"-O-isovalerylspiramycins as the major components, was produced by recombinantspiramycin-producing strain Streptomyces spiramyceticus harboring a 4"-O-acyltransferase gene. The experiment was initially performed in synthetic medium with 0.5 g l-1 Valine, Isoleucine or Leucine feeding at 36 h cultivation. When valine was fed, the biological titer of bitespiramycin was 45.3 percent higher than that of the control group, but the relative content of total isovalerylspiramycin components decreased by 22.5 percent. In the case of ilecine, the biological titer of bitespiramycin and the total isovalerylspiramycins alone were 85 percent and 72.1 percent of the control group, respectively. In contrast, the relative content of other acylated spiramycins increased by 54.41 percent. However, leucine feeding increased the relative content of total isovalerylspiramycins by 41.9 percent while the biological titer of bitespiramycin was nearly equal to that of the control group. The improvement effect of leucine on the biosynthesis of isovalerylspiramycins was further confirmed by feeding of 2.0 g l-1 leucine to the culture with complex medium. After batch feeding with a total amount of 2.0 g l-1 leucine to the culture from 70 h to 90 h, the biological titer of bitespiramycin was almost unreduced, and the final relative content of total isovalerylspiramycins increased from 31.1 percent to 46.9 percent.

Azithromycin inhibits vertical transmission of Toxoplasma gondii in Calomys callosus (Rodentia: Cricetidae).

Toxoplasma gondii infection during pregnancy may cause severe consequences to the embryo. Current toxoplasmosis treatment for pregnant women is based on the administration of spiramycin or a drug combination as sulphadiazine-pyrimethamine-folinic acid (SPFA) in cases of confirmed fetal infection. However, these drugs are few tolerated and present many disadvantages due to their toxic effects to the host. The aim of this study was to evaluate the effectiveness of different treatments on the vertical transmission of T. gondii, including azithromycin, Artemisia annua infusion, spiramycin and SPFA in Calomys callosus as model of congenital toxoplasmosis. C. callosus females were perorally infected with 20 cysts of T. gondii ME49 strain at the day that a vaginal plug was observed (1st day of pregnancy - dop). Treatment with azithromycin, A. annua infusion, and spiramycin started at the 4th dop, while the treatment with SPFA started at the 14th dop. Placenta and embryonic tissues were collected for morphological and immunohistochemical analyses, mouse bioassay and PCR from the 15th to 20th dop. No morphological changes were seen in the placenta and embryonic tissues from females treated with azithromycin, spiramycin and SPFA, but embryonic atrophy was observed in animals treated with A. annua infusion. Parasites were found in the placenta and fetal (brain and liver) tissues of animals treated with SPFA, A. annua infusion and spiramycin, although the number of parasites was lower than in non-treated animals. Parasites were also observed in the placenta of animals treated with azithromycin, but not in their embryos. Bioassay and PCR results confirmed the immunohistochemical data. Also, bradyzoite immunostaining was observed only in placental and fetal tissues of animals treated with SPFA. In conclusion, the treatment with azithromycin showed to be more effective, since it was capable to inhibit the vertical transmission of T. gondii in this model of congenital toxoplasmosis.

Options for clinical trials of pre and post-natal treatments for congenital toxoplasmosis.

Clinical trials comparing different drug regimens and strategies for the treatment of congenital toxoplasmosis and its clinical manifestations in the liveborn child in different clinical settings should aim at formally evaluating the net benefit of existing treatments and at developing new therapeutic options. Currently, there is no ideal drug for congenital toxoplasmosis; future research should focus on the screening of new active drugs and on their pre-clinical and early clinical development, with a focus on pharmacokinetic/dynamic studies and teratogenicity. For the prenatal treatment of congenital toxoplasmosis, a trial comparing spiramycine to pyrimethamine-sulphadiazine and placebo would allow a formal estimation of the effect of both drugs in infected pregnant women. In newborn children, the net benefit of pyrimethamine-sulphadiazine should also be formally assessed. These trials will be implemented in settings where prenatal screening for Toxoplasma gondii is currently implemented. Trials should be carefully designed to allow for translation to other settings and modelling tools like cost-effectiveness analysis should be used to provide clinicians and founders with the best available evidence to establish recommendations.