The susceptibility of Escherichia coli and Helicobacter pylori to pH and the effect of pepsinmediated proteolysis were investigated. This was to establish the relative importance of their bacterial killing properties in gastric juice. Solutions in the pH range 1?5-7?4 with or without pig pepsin A were used, together with seven gastric juice samples obtained from patients undergoing routine gastric collection. Escherichia coli C690 (a capsulate strain), E. coli K-12 (a rough mutant) and Helicobacter pylori E5 were selected as the test organisms. Suspensions of bacteria (1610 6 E. coli ml "1 and 1610 8 H. pylori ml) were pre-incubated with test solutions at 37 6C for up to 2 h, and then cultured to establish the effect on subsequent growth. Survival of bacteria was diminished at pHs of less than 3?5, whereas killing required a pH of less than 2?5. Preincubation with pig pepsin at 0?5, 1?0 and 2?0 mg ml "1 at pH 3?5 reduced viable counts by 100 % for E. coli 690 and E. coli K-12 after 100 min incubation. With H. pylori, the viable counts decreased to 50 % of the control after 20 min incubation in 1 mg pepsin ml "1 at pH 2?5, 3?0 and 3?5. The gastric juices showed bactericidal activity at pH 3?5, and the rate of killing was juice dependent, with complete death of E. coli 690 occurring between 5 and 40 min post-incubation. Thus, killing of E. coli and H. pylori occurs optimally at pHs of less than 2?5. At pH 3?5, little effect is observed, whereas addition of pepsin alone or in gastric juice causes a marked increase in bacterial susceptibility, suggesting an important role for proteolysis in the killing of bacteria.

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is a Myrtaceae plant whose medicinal properties are recognized in several locations. The use of teas and tinctures prepared from their leaves has been used to combat infections caused by fungi of the genus . In this study, aqueous extracts of leaves and hydroethanolic were tested to verify the antifungal potential and its chemical composition has been investigated. The microbiological assays were performed by broth microdilution to determine the minimum inhibitory concentration (MIC) and from these the minimum fungicidal concentration was performed (MFC) by subculturing on solid media. A cell viability curve was obtained for demonstration of inhibition of fungal growth of strains of and . Tests to check morphological changes by the action of the extracts were performed in microcultive cameras depleted environment at concentrations of MIC/2, MIC and MIC × 2. Extracts analyzed by high performance liquid chromatography demonstrated flavonoids and phenolic acids. The extracts showed fungistatic effect and no fungicide with MIC>8192 μg/mL, MFC above 8192 μg/mL. The IC was calculated ranging from 1803.02 to 5623.41 μg/mL. It has been found that the extracts affect the morphological transition capability, preventing the formation of pseudohyphae and hyphae. Teas and tinctures, therefore, have the potential antifungal, by direct contact, causing inhibition of fungal multiplication and its virulence factor, the cell dimorphism, preventing tissue invasion. Further studies are needed to elucidate the biochemical pathways and genes assets involved in these processes.

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We present data on pulmonary infection rates by parasites in the lizards Tropidurus hispidus Spix, 1825 and T. semitaeniatus (Spix, 1825) living sympatrically in the Chapada do Araripe mountain Range, northeastern Brazil. We found no parasite pulmonary infection in T. semitaeniatus. However, two pulmonary parasite species were found in the T. hispidus hosts, the pentastomid Raillietiella mottae Almeida, Freire and Lopes, 2008 and the nematode Rhabdias sp. Overall prevalence was 5%. Prevalence of R. mottae was 2.5% and corresponded to only one parasite on each infected host. Prevalence of Rhabdias sp. was 2.5% and the range of infection was 1-2 parasites per host. This represents the first record of Rhabdias infecting lizards of the family Tropiduridae in the Neotropical region. Furthermore, we present a comparison of parameters of infection by pulmonary parasites including some recent studies in Brazil.Keywords: Raillietiella, Rhabdias, Pentastomida, neotropical region. Taxas de infecção pulmonar em duas espécies simpátricas de lagartos Tropiduridae por pentastomídeos e nematódeos na região Nordeste do Brasil ResumoApresentamos dados sobre taxas de infecção pulmonar por parasitas nos lagartos Tropidurus hispidus e T. semitaeniatus que vivem simpatricamente na encosta da Chapada do Araripe, situada na região Nordeste do Brasil. Não encontramos infecção parasitária nos pulmões dos espécimes de T. semitaeniatus. Entretanto, foram encontradas duas espécies de parasitas nos hospedeiros T. hispidus, os pentastomídeos Raillietiella mottae e os nematódeos Rhabdias sp. A prevalência geral de infecção foi de 5%. A prevalência de infecção de R. mottae foi de 2,5% correspondendo a apenas um parasita por hospedeiro. A prevalência de infecção de Rhabdias sp. foi de 2,5% e a amplitude de infecção de 1-2 parasitas por hospedeiros. Esses resultados compreendem o primeiro registro de Rhabdias infectando lagartos da família Tropiduridae em toda a região Neotropical. Apresentamos também uma comparação com os parâmetros de infecção pulmonar por parasitas incluindo os estudos mais recentes no Brasil.Palavras-chave: Raillietiella, Rhabdias, Pentastomida, região neotropical.

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Objectives: The present work examined the antimicrobial actions of the extracted oils from the body fat of R. jimi (ORJ) against fungi and standard and multi-resistant lines of bacteria, as well as their effects when combined with aminoglycosides. Materials and methods: The toads were collected in the municipality of Exu in Pernambuco State, Brazil, and their body fat oils extracted in a Soxhlet apparatus using hexane. A gas chromatograph coupled to a mass spectrometer was used to identify the fatty acids, based on their methyl esters. The antimicrobial activities of the oil were analyzed against standard and multi-resistant lines of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, as well as against fungal lines of Candida albicans and Candida krusei using the broth microdilution method. Results: The minimum inhibitory concentrations (MIC) of ORJ were 512 mg/mL for Candida krusei and !1024 mg/mL for the other microorganisms. When associated with amikacin, ORJ demonstrated an increase in its ability to inhibit E. coli growth (from 156.25 to 39.06 mg/mL), indicating synergistic interaction. In the same way, when allied with amikacin, gentamicin, and neomycin, the ORJ reduced the MICs meaningly, against P. aeruginosa. Conclusions: These data will enable searches to be made to obtain new products in combination with antibiotics, enhancing the efficacy of these drugs against drug-resistant microorganisms.