Unravelling the fungal darkness in a tropical cave: richness and the description of one new genus and six new species.

Caves are special environments that harbour an incredible diversity of life, including fungal species. Brazilian caves have been demonstrated to be biodiversity hotspots for known and unknown fungal species. We investigated the richness of culturable fungi in a tropical cave in Brazil by isolating these microorganisms from the sediment and air. The fungal abundance of colony-forming units (CFUs) was 3 178 in sediment and 526 in air. We used morphological features and phylogenetic analyses of actin (actA), calmodulin (cmdA), internal transcribed spacer regions and intervening 5.8S rRNA (ITS), large subunit (LSU) rDNA, RNA polymerase II second largest subunit (rpb2), translation elongation factor 1-alpha (tef1), and ß-tubulin (tub2) genes to identify these isolates. Forty-one species belonging to 17 genera of Ascomycota and two of Basidiomycota were identified, and the genus Aspergillus was most commonly observed in the cave (13 taxa). Twenty-four species were found in sediment (16 exclusives) and 25 species were found in air (17 exclusives). In this study, we introduced a new genus (Pseudolecanicillium gen. nov.) in the family Cordycipitaceae and six new species (14 % of the total taxa identified) of fungal isolates obtained from sediment and air: Aspergillus lebretii sp. nov., Malbranchea cavernosa sp. nov., Pseudohumicola cecavii sp. nov., Pseudolecanicillium caatingaense sp. nov., Talaromyces cavernicola sp. nov., and Tritirachium brasiliense sp. nov. In addition, we built a checklist of the fungal taxa reported from Brazilian caves. Our results highlight the contribution of Brazilian caves to the estimation of national and global fungal diversity. Citation: Alves VCS, Lira RA, Lima JMS, Barbosa RN, Bento DM, Barbier E, Bernard E, Souza-Motta CM, Bezerra JDP (2022). Unravelling the fungal darkness in a tropical cave: richness and the description of one new genus and six new species. Fungal Systematics and Evolution 10: 139-167. doi: 10.3114/fuse.2022.10.06.

Association of chitosan and aluminium as a new adjuvant strategy for improved vaccination.

The use of particulate adjuvants offers an interesting possibility to enhance and modulate the immune responses elicited by vaccines. Aluminium salts have been extensively used as vaccine adjuvants, but they lack the capacity to induce a strong cellular and mucosal immune response. Taking this into consideration, in this study we designed a new antigen delivery system combining aluminium salts with chitosan. Chitosan-aluminium nanoparticles (CH-Al NPs) exhibited a mean diameter of 280nm and a positive surface charge. The newly developed CH-Al NPs are more stable at physiological environment than classical CH NPs, showing no cytotoxic effects and revealing potential as a delivery system for a wide range of model antigens. In vivo studies showed that mice immunized with hepatitis B surface antigen (HBsAg)-containing CH NPs display high anti-HBsAg IgG titers in the serum, as well as the highest antigen-specific IgG on vaginal washes. Furthermore, in contrast to mice receiving antigen alone, mice immunized with the particulate adjuvant were able to elicit IgG2c antibody titers and exhibited higher antigen-specific IFN-γ levels in splenocytes. In conclusion, we established that CH-Al NPs, combining two immunostimulants to enhance both humoral and cellular immune responses, are a safe and promising system for antigen delivery. Our findings point towards their potential in future vaccination approaches.

Development of a novel adjuvanted nasal vaccine: C48/80 associated with chitosan nanoparticles as a path to enhance mucosal immunity.

In a time in which mucosal vaccines development has been delayed by the lack of safe and effective mucosal adjuvants, the combination of adjuvants has started to be explored as a strategy to obtain potent vaccine formulations. This study describes a novel adjuvant combination as an effective approach for a nasal vaccine - the association of the mast cell activator compound 48/80 with chitosan based nanoparticles. It was hypothesized that mucoadhesive nanoparticles would promote the cellular uptake and prolong the antigen residence time on nasal cavity. Simultaneously, mast cell activation would promote a local microenvironment favorable to the development of an immune response. To test this hypothesis, two different C48/80 loaded nanoparticles (NPs) were prepared: Chitosan-C48/80 NP (Chi-C48/80 NP) and Chitosan/Alginate-C48/80 NP (Chi/Alg-C48/80 NP). The potential as a vaccine adjuvant of the two delivery systems was evaluated and directly compared. Both formulations had a mean size near 500nm and a positive charge; however, Chi-C48/80 NP was a more effective adjuvant delivery system when compared with Chi/Alg-C48/80 NP or C48/80 alone. Chi-C48/80 NP activated mast cells at a greater extent, were better internalized by antigen presenting cells than Chi/Alg-C48/80 NP and successfully enhanced the nasal residence time of a model antigen. Superiority of Chi-C48/80 NP as adjuvant was also observed in vivo. Therefore, nasal immunization of mice with Bacillus anthracis protective antigen (PA) adsorbed on Chi-C48/80 NP elicited high levels of serum anti-PA neutralizing antibodies and a more balanced Th1/Th2 profile than C48/80 in solution or Chi/Alg-C48/80 NP. The incorporation of C48/80 within Chi NP also promoted a mucosal immunity greater than all the other adjuvanted groups tested, showing that the combination of a mast cell activator and chitosan NP could be a promising strategy for nasal immunization.

Oxidative stress in mice treated with antileishmanial meglumine antimoniate.

In order to improve the understanding of the toxicity of pentavalent antimony (Sb(V)), we investigated the acute effects of meglumine antimoniate (MA) on the oxidative stress in heart, liver, kidney, spleen and brain tissue of mice. Levels of lipoperoxidation and protein carbonylation were measured to evaluate the oxidative status, whereas superoxide dismutase/catalase activity and glutathione levels were recorded to examine the antioxidative status. We observed that MA caused significant protein carbonylation in the heart, spleen and brain tissue. Increased lipoperoxidation was found in the liver and brain tissue. An imbalance between superoxide dismutase and catalase activities could be observed in heart, liver, spleen and brain tissue. Our results suggest that MA causes oxidative stress in several vital organs of mice. This indicates that the production of highly reactive oxygen and nitrogen species induced by MA might be involved in some of its toxic adverse effects.

Unusual coexistence of opportunistic lung infections in a human immunodeficiency virus positive patient suffering from persistent Pneumocystis jirovecii pneumonia: a case report.

It is well established that HIV patients are at high risk of opportunistic infections (OI), like the ones caused by Pneumocystis jirovecii, a worldwide pathogen implicated in interstitial pneumonia (PcP). We present a case of a newly diagnosed HIV-1 patient with multiple OI, including a persistent form of PcP, an invasive aspergillosis (IA), cytomegalovirus and Mycobacterium xenopi lung infection. We describe the combination of laboratorial screening, surgery and antimicrobial therapy that were crucial for patient recovery.

Study of L-arginine in intestinal lesions caused by ischemia-reperfusion in rats.

To examine whether treatment with L-arginine (ARG), a substrate of nitric oxide biosynthesis, attenuated intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rats with ARG (100 mg/kg intravenously) or saline solution (SS) before 60 minutes of I produced by occlusion of the superior mesenteric artery and/or during 120 minutes of R. After I or I/R, we isolated 2-cm jejunal segments for mounting in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl with the use of a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Jejunal contractions were similar in the sham and I+ARG, but reduced in I+SS, I/R+SS, and I/R+ARG groups. Jejunal enteric nerves were damaged in I+SS, IR+SS, and IR+ARG, but not in the I+ARG group, suggesting that ARG attenuate intestinal dysfunctions due to I but not to R.

[Prevalence of markers of hepatitis B infection in the adult population of the district of Coimbra]. / Prevalência dos marcadores de infecção pelo vírus da hepatite B na população adulta do distrito de Coimbra.

AIM: To assess the prevalence of hepatitis B markers in the adult population of the Coimbra district, in the central region of Portugal. METHODS: The study included 657 subjects chosen aleatorily from 4 characteristic councils of the Coimbra district. They were questioned regarding risk factors and blood samples were taken for HBsAg, anti-HBs and anti-HBc testing. Anti-HCV was previously determined and it was positive in 0.45% of the cases. RESULTS: HBsAg was found in 0.91%. Anti-HBs and anti-HBc were both positive in 6.08%, anti-HBc without anti-HBs was found in 1.82% and anti-HBs without anti-HBc was found in 1.67% (11 cases, 8 vaccinated). The general prevalence of hepatitis B markers was 9.3%. Higher prevalences were found in the subjects over 50 years of age, 13.5% (p < 0.05), and in the urban area, 13.2% (p < 0.05). CONCLUSIONS: 1. The HBsAg prevalence in our region is 0.9%; 2. The general prevalence of hepatitis B markers is 9.3%; 3. HBsAg prevalence is higher than anti-HCV prevalence calculated in the same sample; 4. The prevalence of hepatitis B markers in our region is lower than in other Southern European countries.

[The developmental cycle of Rhodnius nasutus Stal, 1859 studied in the laboratory]. / Estudo do ciclo evolutivo do Rhodnius nasutus Stal, 1859, em laboratório.

The biological cycle of Rhodnius nasutus was studied from november 1985 to September 1986 under laboratory conditions. The temperature ranged from 28.0 +/- 2 degrees C to 22.0 +/- 2 degrees C and 59.2 to 70.4% of humidity. Chickens were used as a blood meal source. The complete biological cycle was achieved with an average of 209.4 days of the 16 remaining insects from initial colony of the 30 Katomines. The average incubation period lasted 11.1 days and those for the following nymphal stages were: 17.6 days for the first; 16.1 days for the second; 30.1 days for the third; 71.2 days for the fourth and 79.9 days for the fifth nymphal stage.

Epidemiology of hepatitis C in central Portugal. Prevalence of anti-HCV in the population of the Coimbra District.

Anti-hepatitis C virus antibody (anti-HCV) screening was performed in a sample of the adult population of the Coimbra District. 657 persons were included (267 male and 390 female, mean age of 42.7 + 13.1 years), aleatorily chosen from four characteristic regions. Anti-HCV was detected using an ELISA-2 test and all positive sera were also tested with RIBA-2. General prevalence of anti-HCV was 0.46%. All positive patients live in urban areas and presented risk factors for HCV infection. Anti-HCV was found in 33.3% of intravenous drug abusers, in 1.8% of transfused individuals, in 1.33% of alcoholics (higher than 80 g/d alcohol ingestion), in 1% of cases with history of surgical operations, and in 0.65% of persons who lived in risk regions for hepatitis B. We conclude that anti-HCV prevalence is low in our region. We think it is important to perform other studies on larger samples of general population and to study risk groups.

[Hepatitis C epidemiology in the central area of Portugal. Prevalence of anti-HCV in the population of the district of Coimbra]. / Epidemiologia da hepatite C na região centro de Portugal. Prevalência do anti-VHC na população do distrito de Coimbra.

Anti-hepatitis C virus antibody (anti-HCV) screening was performed in a sample of the adult population of the Coimbra District. 657 persons were included (267 male and 390 female, mean age of 42.7 +/- 13.1 years), aleatorily chosen from four characteristic councils. Anti-HCV was detected using an ELISA-2 test and all positive sera were also tested with RIBA-2. General prevalence of anti-HCV was 0.46%. All positive patients live in urban areas and presented risk factors for HCV infection. Anti-HCV was found in 33.3% of intravenous drug abusers, in 1.8% of transfused individuals, in 1.33% of alcoholics (higher than 80 g/d alcohol ingestion), in 1% of cases with history of surgical operations, and in 0.65% of persons who lived in risk regions for hepatitis B. We conclude that anti-HCV prevalence is low in our region. We think it is important to perform other studies in larger samples of general population and to study risk groups.

[The epidemiology of Chagas' disease in a rural area of the city of Teresina, Piauí, Brazil]. / Epidemiologia da doença de Chagas na zona rural do município de Teresina-Piauí, Brasil.

In the rural areas of Teresina, 129 triatomines were captured distributed in (a) artificial ecotopes; a house with one Triatoma brasiliensis, one Panstrongylus geniculatus, Rhodnius pictipes, and one Rhodnius prolixus and in a uninhabited chicken house (7 Rhodnius nasutus). (b) Natural ecotopes; Pahus Orbignya martiana (41 Rhodnius neglectus, 33 Rhodnius prolixus and 41 Rhodnius nasutus) and Copernicia cerifera (3 Rhodnius neglectus). The 22.6% of captured triatomines were infected by flagellates similar to Trypanosoma cruzi. Twenty-eight sylvatic mammals were captured and examined. Seven Didelphia albiventris, 2 Rattus rattus and a Tamandua tetradactyla were infected with flagellates. The flagellates found in both triatomines and mammals were morphologically indistinguishable from Trypanosoma cruzi. Serology by the indirect immunofluorescence test for Chagas disease revealed two positive seroreactions of positivity among 123 inhabitants examined.

Epidemiological survey of Trypanosoma cruzi infection in North-Eastern Brazil using different diagnostic methods

A prevalencia da infeccao pelo Trypanosoma cruzi foi pesquisada em Oitis, uma pequena comunidade do Estado do Piaui. Duzentos e sessenta e cinco individuos foram investigados pelos seguintes metodos: pesquisa direta, hemocultura, imunofluorescencia indireta (IFA), teste imunoabsorvente ligado a enzima (ELISA), e ELISA de competicao (C-ELISA) com a utilizacao do anticorpo monoclonal TCF87 contra um antigeno do T.cruzi com 25kd. A IFA foi positiva em 14,3 por cento dos individuos, ELISA em 14,7 por cento e C-ELISA em 13,2 por cento. Este ultimo teste mostrou-se aplicavel no diagnostico sorologico da Doenca de Chagas.

Epidemiological survey of Trypanosoma cruzi infection in north-eastern Brazil using different diagnostic methods.

A survey of the prevalence of Trypanosoma cruzi infection was carried out in Oitis, a small community in the State of Piaui, Brazil. Two hundred and sixty five individuals were screened by microscopic examination, hemoculture, indirect immunofluorescence (IFA), enzyme-linked immunosorbent assay (ELISA), and competitive enzyme-linked immunosorbent assay (C-ELISA) using the monoclonal antibody TCF87 against to a 25kd T. cruzi antigen. Seropositivity was 14.3% by the IFA test, 14.7% by ELISA, and 13.2% by C-ELISA. The C-ELISA using the TCF87 monoclonal antibody seems to be applicable in serodiagnosis of Chagas' disease.

[Epidemiology of Chagas disease in the municipalities of Castelo do Piaui and Pedro II, state of Piaui, Brazil]. / Epidemiologia da doença de Chagas nos municípios de Castelo do Piauí e Pedro II, estado do Piauí, Brasil.

Triatoma brasiliensis, Triatoma pseudomaculata and Rhodnius nasutus were captured in artificial and natural echotopes in ten localities situated in rural areas of Castelo do Piauí and Pedro II, State of Piauí, Brazil. Nymphal instars predominated and birds were the main blood meal source for triatomines. T. brasiliensis was the only triatomine captured inside the houses searched, harbouring flagellates morphologically and biologically indistinguishable from Trypanosoma (Schizotrypanum) cruzi. Specific serology against T. cruzi by indirect immunofluorescence (IFI) test showed 21.7% positive reactions among 566 inhabitants examined. The results suggest that in these localities the active transmission of Chagas' disease occurs.