The mineralogy and chemistry of the German and Portuguese tiles used to face a historic building in the Amazon region and their natural susceptibility to tropical weathering

During the 19th century, the most prominent buildings of the city of Belém were faced entirely with tiles manufactured in Portugal and Germany, which now exhibit distinct degrees of degradation. The Pinho mansion is one of the most important of these buildings and was selected for the investigation of the action of the tropical Amazonian climate on the degradation of the tiles. To achieve this objective, the tiles were mapped for organic and inorganic degradation, and samples were collected for analysis. The minerals were determined by XRD, the chemical composition by classical wet methods and SEM/EDS, and the microorganisms under the microscope. The results show that the German and Portuguese tiles are quite different in their composition. While both ceramic bodies are composed of SiO2 and Al2O3, CaO was found only in the Portuguese tile. The low Na2O and K2O contents indicate the addition of materials to reduce the fusion temperature. SiO2 and PbO are the main constituents of the glaze, with CoO and FeO being added as pigment. The ceramic body of the German tiles is constituted of quartz, mullite, and cristobalite, in contrast with the Portuguese tiles, which are made of quartz, gehlenite, diopside, calcite, and feldspars. The glazes are XRD-amorphous. The chemical and mineralogical differences between the German and Portuguese tiles indicate that they were produced from different raw materials under distinct thermal processes. The most prominent weathering-related modifications are the thin layers (German tiles), oxidation stains, dark stains, the detachment of the tile (Portuguese tiles), loss of the glaze and powdering of the ceramic body (Portuguese tiles) through the establishment of Cyanophyta and Bacillariophyta.. The distinct degradation patterns of the tiles exposed to the tropical Amazon climate are a consequence of their distinct mineralogy and chemistry.

DEFB1 polymorphisms are involved in susceptibility to human papillomavirus infection in Brazilian gynaecological patients

The human beta defensin 1 (hBD-1) antimicrobial peptide is a member of the innate immune system known to act in the first line of defence against microorganisms, including viruses such as human papillomavirus (HPV). In this study, five functional polymorphisms (namely g-52G>A, g-44C>G and g-20G>A in the 5’UTR and c.*5G>A and c.*87A>G in the 3’UTR) in the DEFB1 gene encoding for hBD-1 were analysed to investigate the possible involvement of these genetic variants in susceptibility to HPV infection and in the development of HPV-associated lesions in a population of Brazilian women. The DEFB1 g-52G>A and c.*5G>A single-nucleotide polymorphisms (SNPs) and the GCAAA haplotype showed associations with HPV-negative status; in particular, the c.*5G>A SNP was significantly associated after multiple test corrections. These findings suggest a possible role for the constitutively expressed beta defensin-1 peptide as a natural defence against HPV in the genital tract mucosa.

A novel ABCG-like transporter of Trypanosoma cruziis involved in natural resistance to benznidazole

Benznidazole (BZ) is one of the two drugs used for Chagas disease treatment. Nevertheless therapeutic failures of BZ have been reported, which were mostly attributed to variable drug susceptibility among Trypanosoma cruzistrains. ATP-binding cassette (ABC) transporters are involved in a variety of translocation processes and some members have been implicated in drug resistance. Here we report the characterisation of the first T. cruzi ABCG transporter gene, named TcABCG1, which is over-expressed in parasite strains naturally resistant to BZ. Comparison ofTcABCG1 gene sequence of two TcI BZ-resistant strains with CL Brener BZ-susceptible strain showed several single nucleotide polymorphisms, which determined 11 amino acid changes. CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene. Only in the parasites transfected with TcI genes there was 2-2.6-fold increased abundance of TcABCG1transporter protein. The analysis in wild type strains also suggests that the level of TcABCG1transporter is related to BZ natural resistance. The characteristics of untranslated regions of TcABCG1genes of BZ-susceptible and resistant strains were investigated by computational tools.

Association of the solute carrier family 11 member 1 gene polymorphisms with susceptibility to leprosy in a Brazilian sample

Natural resistance-associated macrophage protein 1/solute carrier family 11 member 1 gene (Nramp1/Slc11a1) is a gene that controls the susceptibility of inbred mice to intracellular pathogens. Polymorphisms in the human Slc11a1/Nramp1 gene have been associated with host susceptibility to leprosy. This study has evaluated nine polymorphisms of the Slc11a1/Nramp1 gene [(GT)n, 274C/T, 469+14G/C, 577-18G/A, 823C/T, 1029 C/T, 1465-85G/A, 1703G/A, and 1729+55del4] in 86 leprosy patients (67 and 19 patients had the multibacillary and the paucibacillary clinical forms of the disease, respectively), and 239 healthy controls matched by age, gender, and ethnicity. The frequency of allele 2 of the (GT)n polymorphism was higher in leprosy patients [p = 0.04, odds ratio (OR) = 1.49], whereas the frequency of allele 3 was higher in the control group (p = 0.03; OR = 0.66). Patients carrying the 274T allele (p = 0.04; OR = 1.49) and TT homozygosis (p = 0.02; OR = 2.46), such as the 469+14C allele (p = 0.03; OR = 1.53) of the 274C/T and 469+14G/C polymorphisms, respectively, were more frequent in the leprosy group. The leprosy and control groups had similar frequency of the 577-18G/A, 823C/T, 1029C/T, 1465-85G/A, 1703G/A, and 1729+55del4 polymorphisms. The 274C/T polymorphism in exon 3 and the 469+14G/C polymorphism in intron 4 were associated with susceptibility to leprosy, while the allele 2 and 3 of the (GT)n polymorphism in the promoter region were associated with susceptibility and protection to leprosy, respectively.

Radiometric detection of metabolic activity of Paracoccidioides brasiliensis and its susceptibility to amphotericin B and diethylstilbestrol

Paracoccidioidomycosis (South American blastomycosis) is a systemic disease, strikingly more frequent in males, caused by the dimorphic fungus Paracoccidioides brasiliensis. A radiometric assay system has been applied to study the metabolic activity and the effect of drugs on this fungus "in vitro". The Y form of the yeast, grown in liquid Sabouraud medium was inoculated into sterile reaction vials containing the 6B aerobic medium along with 2.0 μCi of 14C-substrates. Control vials, prepared in the same way, contained autoclaved fungi. To study the effects of amphotericin B (AB) (0.1 and 10 μg/ml) and diethylstilbestrol (DSB) (1.0, 5.0 and 10 μg/ml) extra controls with live fungi and no drug were used. All vials were incubated at 35°C and metabolism measured daily with a Bactec instrument. 14CO2 production by P. brasiliensis was slow and could be followed for as long as 50 days. AB at 10mg/ml and DSB at 5 μg/ml inhibited the metabolism and had a cidal effect on this fungus. The results with DSB might explain the low incidence of the disease in females. This technique shows promise for studying metabolic pathways, investi gating more convenient 14C-substrates to expedite radiometric detection and for monitoring the effects of other drugs and factors on the metabolism of P. brasiliensis "in vitro".

In vitro susceptibility to antifungal agents of clinical and environmental Cryptococcus neoformans isolated in Southern of Brazil

The purpose of the present study was to compare the susceptibility to four antifungal agents of 69 Cryptococcus neoformans strains isolated from AIDS patients with that of 13 C. neoformans strains isolated from the environment. Based on the NCCLS M27-A methodology the Minimal Inhibitory Concentrations (MICs) obtained for amphotericin B, itraconazole and ketoconazole were very similar for clinical and environmental isolates. Clinical isolates were less susceptible to fluconazole than environmental isolates. The significance of these findings and aspects concerning the importance, role and difficulties of C. neoformans susceptibility testing are also discussed.

Biomphalaria tenagophila (Orbigny, 1835) (Mollusca): adaptation to desiccation and susceptibility to infection with Schistosoma mansoni Sambon, 1907

Experiments were carried out to test the susceptibility of Biomphalaria tenagophila to the infection with strain SJ of Schistosoma mansoni in the F1, F2 and non-selected parental generation. The potential adaptation of B. tenagophila to desiccation, in healthy mollusks and those exposed to the larvae of S. mansoni of the F1, F2 and non-selected parental generations was also studied. The presence of mucus and soil, at the shell opening, protected the snails against desiccation, favoring survival. The healthy mollusks performed more attempts against desiccation than those exposed to the larvae of the parasite. The mortality rate, during desiccation, was higher among mollusks that remained buried and with the shell opening unobstructed. During the desiccation period the stage of development of the parasite was influenced by the weight loss and the survival of the snails. The longer the period of desiccation, the greater was the weight loss observed, abbreviating survival. The non-selected parental generation was more sensitive to desiccation than the F1 and F2 generations, both in healthy mollusks and in those exposed to S. mansoni larvae. Healthy mollusks were more resistant to desiccation than those exposed to the larvae of the S. mansoni. Desiccation did not interrupt the development of S. mansoni larvae in mollusks, causing a delay in the cercariae elimination. The susceptibility of B. tenagophila to the SJ strain of S. mansoni, in mollusks maintained in water during the larvae incubation period, was similar in all three generations.

HYPOXIC STRESS, HEPATOCYTES AND CACO-2 VIABILITY AND SUSCEPTIBILITY TO Shigella flexneri INVASION

SUMMARY Inflammation due to Shigella flexneri can cause damage to the colonic mucosa and cell death by necrosis and apoptosis. This bacteria can reach the bloodstream in this way, and the liver through portal veins. Hypoxia is a condition present in many human diseases, and it may induce bacterial translocation from intestinal lumen. We studied the ability of S. flexneri to invade rat hepatocytes and Caco-2 cells both in normoxic and hypoxic microenvironments, as well as morphological and physiological alterations in these cells after infection under hypoxia. We used the primary culture of rat hepatocytes as a model of study. We analyzed the following parameters in normoxic and hypoxic conditions: morphology, cell viability, bacterial recovery and lactate dehydrogenase (LDH) released. The results showed that there were fewer bacteria within the Caco-2 cells than in hepatocytes in normoxic and hypoxic conditions. We observed that the higher the multiplicity of infection (MOI) the greater the bacterial recovery in hepatocytes. The hypoxic condition decreased the bacterial recovery in hepatocytes. The cytotoxicity evaluated by LDH released by cells was significantly higher in cells submitted to hypoxia than normoxia. Caco-2 cells in normoxia released 63% more LDH than hepatocytes. LDH increased 164% when hepatocytes were submitted to hypoxia and just 21% when Caco-2 cells were in the same condition. The apoptosis evaluated by Tunel was significantly higher in cells submitted to hypoxia than normoxia. When comparing hypoxic cells, we obtained more apoptotic hepatocytes than apoptotic Caco-2 cells. Concluding our results contribute to a better knowledge of interactions between studied cells and Shigella flexneri. These data may be useful in the future to define strategies to combat this virulent pathogen.

SUSCEPTIBILITY TO ANTIBIOTICS IN URINARY TRACT INFECTIONS IN A SECONDARY CARE SETTING FROM 2005-2006 AND 2010-2011, IN SÃO PAULO, BRAZIL: DATA FROM 11,943 URINE CULTURES

Introduction: Urinary tract infection (UTI) has a high incidence and recurrence, therefore, treatment is empirical in the majority of cases. Objectives: The aim of this study was to analyze the urine cultures performed at a secondary hospital, during two periods, 2005-2006 and 2010-2011, and to estimate the microbial resistance. Patients and methods: We analyzed 11,943 aerobic urine cultures according to basic demographic data and susceptibility to antibiotics in accordance with the Clinical and Laboratory Standards Institute (CLSI) for Vitek 1 and 2. Results: Most of our cohort consisted of young adult females that were seen at the Emergency Department. E. coli was the most frequent (70.2%) among the 75 species isolated. Resistance of all isolates was ≥ 20% for trimethoprim/sulfamethoxazole (TMP/SMX), norfloxacin, nitrofurantoin, cefazolin and nalidixic acid. Although E. coli was more susceptible (resistance ≥ 20% for TMP/SMX and nalidixic acid) among all of the isolates, when classified by the number and percentage of antibiotic resistance. Global resistance to fluoroquinolones was approximately 12%. Risk factors for E. coli were female gender and an age less than 65 years. Men and patients older than 65 years of age, presented more resistant isolates. Extended spectrum beta-lactamases (ESBL) were identified in 173 out of 5,722 Gram-negative isolates (3.0%) between 2010 and 2011. Conclusion: E. coli was the most frequent microbe isolated in the urine cultures analyzed in this study. There was a significant evolution of bacterial resistance between the two periods studied. In particular, the rise of bacterial resistance to fluoroquinolones was concerning.

Trypanosoma cruzi: susceptibility to chemotherapy with benznidazole of clones isolated from the highly resistant Colombian strain

The present investigation was performed to evaluate the susceptibility of seven clones isolated from the highly resistant Colombian strains, prototype of Biodeme Type III. Seven clones previously obtained, showed a phenotypic homogeneity and high similarity with the parental strain. Eight groups of 30 mice were inoculated with one of seven clones or the parental strain; 20 were treated with benznidazole (100mg/kg/day) and 10 were untreated controls. Cure evaluations were done by parasitological and serological tests and PCR. Cure rates varied from 0% (null) to 16.7%. Correlation between positivity of parasitological and serological tests with positive PCR reached 37%. The results demonstrated the high resistance of the clones, suggesting the predominance of a highly resistant principal clone in this strain. The findings apparently indicate that the possibility of cure is minimal for patients infected with this biodeme; a fact that could affect the control of Chagas' disease through treatment of chronically infected people.

Aedes aegypti and Aedes albopictus (Diptera: Culicidae): coexistence and susceptibility to temephos, in municipalities with occurrence of dengue and differentiated characteristics of urbanization

INTRODUCTION: The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paraná and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS: The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion). Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS: Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paraná. CONCLUSIONS: All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paraná and Santa Catarina) presented survival when exposed to the organophosphate temephos.

Susceptibility to amphotericin B of Candida spp. strains isolated in Ceará, Northeastern Brazil

IntroductionAmphotericin B (AMB) is an antifungal agent used extensively in clinical medicine, yet resistance remains low. This study aims to evaluate the susceptibility of Candida spp. against AMB.MethodsFor broth microdilution susceptibility testing, 77 strains of Candida spp. were selected (32 C. albicans, 33 C. tropicalis, and 12 C. parapsilosis). The strains were considered susceptible when they exhibited MIC≤1.0µg/ml.ResultsNone of the strains showed an MIC greater than 0.25µg/ml.ConclusionsFurther works are necessary, with a higher number of strains, to assess the validity of the results used in this study.

Variability of susceptibility to deltamethrin in peridomestic Triatoma sordida from Triângulo Mineiro, State of Minas Gerais, Brazil

AbstractINTRODUCTION:Despite chemical and physical vector control strategies, persistent infestations of Triatoma sordida have been reported in a large part of Minas Gerais, Brazil, and the cause for this is little investigated. We aimed to characterize the deltamethrin toxicological profile in peridomestic T. sordidapopulations from Triângulo Mineiro area of Minas Gerais.METHODS:Susceptibility to deltamethrin was assessed in seventeen peridomestic T. sordida populations. Serial dilutions of deltamethrin in acetone (0.2µL) were topically applied on the first instar nymphs (F1; five days old; fasting weight, 1.2 ± 0.2mg). Dose response results were analyzed using Probit software, and the lethal doses, slope and resistance ratios were determined. Qualitative tests were also performed.RESULTS:The deltamethrin susceptibility profile of T. sordida populations revealed resistance ratios ranging from 0.84 to 2.8. The percentage mortality in response to a diagnostic dose was 100.0% in all populations.CONCLUSIONS:From our results, the lack of resistance to insecticides but persistent T. sordida infestations in the Triângulo Mineiro area may be because of: 1) environmental degradation facilitating dispersion of T. sordida , allowing colonization in artificial ecotopes; 2) operational failures; and 3) complexity of the peridomicile in the study area.These variables are being investigated.

Anopheles darlingi and Anopheles marajoara (Diptera: Culicidae) susceptibility to pyrethroids in an endemic area of the Brazilian Amazon

Abstract: INTRODUCTION: This study aimed to evaluate the susceptibility of Anopheles darlingi Root (1926) and Anopheles marajoara Galvão & Damasceno (1942) to pyrethroids used by the National Malaria Control Program in Brazil. METHODS: Mosquitoes from Amapá, Brazilian Amazon, were assessed for resistance to cypermethrin, deltamethrin, and alpha-cypermethrin. Insecticide-impregnated bottles were used as suggested by the CDC/Atlanta. RESULTS: Diagnostic dose for Anopheles darlingi was 12.5µg/bottle during 30 min of exposure. Concentrations for Anopheles marajoara were 20µg/bottle of cypermethrin and deltamethrin and 12.5µg/bottle of alpha-cypermethrin. CONCLUSIONS : No resistance was recorded for Anopheles darlingi , but Anopheles marajoara requires attention.