In vitro and in vivo evaluation of Bacillus clausii against Schistosoma mansoni.

Experimental studies and clinical trials have been showing that probiotics are promising in the prevention and control of parasite infections. B. clausii, obtained from Enterogermina®, was cultured to obtain cell-free culture supernatant (CFS) and spores to evaluate its schistosomicidal effect in vitro and in vivo against Schistosoma mansoni, respectively. For in vitro and in vivo analysis mice were infected with 120 and 50 cercariae, respectively. Couples of adult worms, recovered on day 45 of infection, were exposed to CFS. The in vivo assay was performed for 100 days, where all animals were infected on the 30th day. Four experimental groups were formed, as follows: G1 - Saline solution from the 1st until the 100th day; G2 - B. clausii from the 1st until the 100th day; G3 - B. clausii from the 68th day (onset of oviposition) until the 100th day and G4 - PZQ (50 mg/Kg) from the 75th until the 79th day. In vitro, CFS of B. clausii does not caused mortality nor changed the motility on S. mansoni adult worms. G2 and G3 showed reduction of the 68.58 and 44.25% in the number of eggs eliminated in the feces and 34.29 and 53.6% and 22.8 and 48.49% the number of eggs trapped in the liver and intestine, respectively. Furthermore, in both therapeutic regimens G2 and G3, B. clausii increased the percentage of dead eggs in the intestinal tissue. B. clausii CFS, in vitro, does not showed action against S. mansoni and that treatment with B. clausii spores modulates favorably the parasitological parameters in the experimental infection of S. mansoni.

Ultrastructural analysis of ß-lapachone-induced surface membrane damage in male adult Schistosoma mansoni BH strain worms.

The present study provides, for the first time, conclusions on the in vitro schistosomicidal properties of ß-lap. Adult male Schistosoma mansoni worms of the BH strain were used for the study. Motility, mortality, cell viability and alterations in the tegument were employed as schistosomicidal parameters. Alterations in motility were observed 6h after incubation in concentrations of 50 and 100 µM. ß-lap decreased significantly the worm viability, reducing the formation of formazan in 17.7%, 27.4% and 54.8% at concentrations of 25, 50 and 100 µM, respectively. Mortality in concentrations of 50 and 100 µM was of 67% and 100%, respectively, after 24h. The death of the parasite was preceded by progressive surface membrane damage, characterized by tegument peeling, spine reduction and erosion, blister formation and rupture, and the emergence of holes. In addition to this, in the anterior portion, intense general edema, areas of cracking with a wrinkled surface, furrows and a fibrous appearance were also observed. The results of the present study thus provide a sound basis for further in-depth studies of the schistosomicidal properties of ß-lap, both in the laboratory and in the field.

ß-Lapachone: a naphthoquinone with promising antischistosomal properties in mice.

The activity of ß-lapachone (3,4-dihydro-2,2-dimethyl-2H-naphthol[1,2-b]pyran-5,6-dione, ß-lap) against different stages of Schistosoma mansoni was investigated in mice. Mice infected with 50 cercariae (BH strain) were intraperitoneally treated at a dose of 50 mg/kg for 5 consecutive days, starting on the 1st, 14th, 28th and 45th days after infection, to evaluate the effect of ß-lap on skin schistosomula, lung schistosomula, young worms (before oviposition) and adult worms (after oviposition), respectively. All animals were euthanized 60 days after infection. ß-Lap significantly reduced (p<0.001) the number of worms in 29.78%, 37.2%, 24.2% and 40.22% when administered during the phases of skin schistosomula, lung schistosomula, young worms and adult worms, respectively. Significant reduction was also achieved in terms of female burden. In all groups, there was significant reduction in the number of eggs and granulomas in the hepatic tissue. When the intervention was performed during the phase of adult worms, ß-lap reduced the size of hepatic granulomas and changed the oogram pattern, lowering the percentage of immature eggs and increasing the percentage of mature and dead eggs. Our data indicate that ß-lap has moderate antischistosomal properties. Its molecule may also be used as a prototype for synthesis of new naphthoquinone derivatives with potential schistosomicidal properties. Further studies with different formulations containing ß-lap are needed to clearly establish the best dose and route of administration and its mechanism of action against schistosomes.

Interventions for wound healing among diabetic patients infected with Staphylococcus aureus: a systematic review.

CONTEXT AND OBJECTIVE: Staphylococcus aureus is the most frequent agent isolated in diabetic foot infections and may be associated with changes to wound healing times. The aim of this study was to perform a systematic review of the literature, including studies that assessed the efficacy of any clinical or surgical intervention, as well as oral or topical therapy for diabetic ulcers infected with S. aureus. DESIGN AND SETTING: Systematic review with a search conducted in databases. METHODS: We conducted a systematic review with a comprehensive search in the Lilacs, SciELO, PubMed/Medline, Old Medline, Embase and Cochrane Library databases, for articles published from 1966 to 2010. The articles selected were limited to studies on diabetic patients with wounds infected with S. aureus for whom their healing was followed up, with the use of either antibiotics or experimental treatments. Animal studies and those that did not report the wound healing, as well as review articles, were excluded. RESULTS: Five studies that met the inclusion and exclusion criteria were analyzed. CONCLUSIONS: There are few studies reporting the healing of wounds infected with S. aureus in diabetic patients, although this is the most commonly found pathogen in this type of wound and it frequently consists of methicillin-resistant S. aureus (MRSA). There is insufficient evidence to support early use of broad-spectrum antibiotics against MRSA to promote healing of diabetic ulcers, since antibiotic resistance may develop from such treatment. This highlights the need for further studies on the subject.

Interventions for wound healing among diabetic patients infected with Staphylococcus aureus: a systematic review / Intervenções para a cicatrização de feridas de pacientes diabéticos infectados com Staphylococcus aureus: uma revisão sistemática

CONTEXT AND OBJECTIVE: Staphylococcus aureus is the most frequent agent isolated in diabetic foot infections and may be associated with changes to wound healing times. The aim of this study was to perform a systematic review of the literature, including studies that assessed the efficacy of any clinical or surgical intervention, as well as oral or topical therapy for diabetic ulcers infected with S. aureus. DESIGN AND SETTING: Systematic review with a search conducted in databases. METHODS: We conducted a systematic review with a comprehensive search in the Lilacs, SciELO, PubMed/Medline, Old Medline, Embase and Cochrane Library databases, for articles published from 1966 to 2010. The articles selected were limited to studies on diabetic patients with wounds infected with S. aureus for whom their healing was followed up, with the use of either antibiotics or experimental treatments. Animal studies and those that did not report the wound healing, as well as review articles, were excluded. RESULTS: Five studies that met the inclusion and exclusion criteria were analyzed. CONCLUSIONS: There are few studies reporting the healing of wounds infected with S. aureus in diabetic patients, although this is the most commonly found pathogen in this type of wound and it frequently consists of methicillin-resistant S. aureus (MRSA). There is insufficient evidence to support early use of broad-spectrum antibiotics against MRSA to promote healing of diabetic ulcers, since antibiotic resistance may develop from such treatment. This highlights the need for further studies on the subject.

CONTEXTO: Staphylococcus aureus é o agente mais frequentemente isolado nas infecções de pé em pacientes diabéticos e pode estar associado a mudança no tempo de cicatrização de feridas. O objetivo deste estudo foi realizar uma revisão sistemática da literatura, incluindo estudos que avaliaram a eficácia de qualquer intervenção clínica, cirúrgica, bem como terapia oral ou tópica para o tratamento de úlceras diabéticas infectadas com o S. aureus. TIPO DE ESTUDO E LOCAL: Revisão sistemática com busca realizada em bancos de dados. MÉTODOS: Realizamos uma revisão sistemática com uma busca abrangente nos bancos de dados Lilacs, SciELO, PubMed/Medline, Old Medline, Embase e no banco de dados da biblioteca Cochrane, publicados entre 1966 e 2010. Os artigos selecionados foram limitados aos estudos com feridas infectadas por S. aureus de pacientes diabéticos, que tiveram cicatrização relatada, quer pela utilização de antibióticos ou por substâncias experimentais. Foram excluídos os estudos com animais e os que não relataram a cicatrização das feridas, bem como artigos de revisão. RESULTADOS: Foram analisados cinco estudos que obedeceram aos critérios de inclusão e exclusão. CONCLUSÕES: Raros estudos relataram cicatrização de feridas infectadas com S. aureus em pacientes diabéticos, embora este seja o patógeno mais comumente encontrado neste tipo de ferida, sendo frequentemente resistente à meticilina MRSA (methicillin-resistant S. aureus). Não há evidências suficientes que suportem a utilização precoce de antibióticos de amplo espectro contra MRSA para promoção da cicatrização de úlceras diabéticas, uma vez que o desenvolvimento de resistência a antibióticos pode decorrer desse tipo de tratamento. Isso evidencia a necessidade de novos estudos sobre o assunto.