The isolation and characterization of virulence factors of Cryptococcus spp. from saprophytic sources in the city of Ribeirão Preto, São Paulo, Brazil

Yeasts of the Cryptococcus genus are distributed in nature associated to animal and vegetal organic residues. Occasionally, species other than C. neoformans may be responsible for infectious diseases in human and animals. This study aims to determine the occurrence of Cryptococcus species in the atmosphere and bird droppings in the city of Ribeir?o Preto, S?o Paulo, Brazil, and to evaluate three virulence factors: capsule formation, growth at 37 degrees C and melanin production. We analyzed 86 environmental samples (54 droppings and 32 air). Of the 41 strains isolated, 15 were C. neoformans var. neoformans (12 droppings and 3 air), 15 C. albidus (12 droppings and 3 air), 9 C. laurentii (7 droppings and 2 air) and 2 C. uniguttulatus (from droppings). Capsules were produced by 93.3% of C. neoformans var. neoformans, 66.7% of C. albidus, 88.9% of C. laurentii and 50% (1/2) of C. uniguttulatus. All strains of C. neoformans, 20% of C. albidus and 44.4% of C. laurentii were able to grow at 37 degrees C. The melanin production on DOPA agar was verified in C. neoformans (93.3%), C. albidus (26.7%) and C. laurentii (66.7%). We concluded that different Cryptococcus species coexist in the same ecological niche and they are able to produce virulence factors.     

In vitro susceptibility to antifungal agents of environmental Cryptococcus spp. isolated in the city of Ribeirão Preto, São Paulo, Brazil

Infections by Cryptococcus strains other than C. neoformans have been detected in immunocompromised patients. Of these strains, three are considered human pathogens: C. albidus, C. laurenttii, and C. uniguttulatus. This study deals with the in vitro susceptibility of Cryptococcus to drugs such as amphotericin B, itraconazole, fluconazole, and 5-fluorocytosine. Environmental Cryptococcus isolates (50) distributed as follows: C. neoformans var. neoformans (16), C. albidus (17), C. laurentii (14), and C. uniguttulatus (3) were evaluated by the micro and macrodilution techniques, according to EUCAST and NCCLS recommendations, respectively. Considering both methodologies the respective minimal inhibitory concentrations (MIC) were 0.125 and 2 microg/ml for amphotericin B, 0.06 and 8 microg/ml for itraconazole, and 0.5 and more than 64 microg/ml for fluconazole and 5-fluorocytosine. Agreement percentages for the two methodologies were 100% for amphotericin B and fluconazole for all the strains tested. For itraconazole, the agreement percentage was 81.3% in the C. neoformans strain and 100% for all the others. All species had a agreement percentage of 94.1 to 100% when susceptibility to 5-fluorocytosine was tested. It is concluded that environmental isolates of C. neoformans var. neoformans, C. albidus, C. laurentii, and C. uniguttulatus may show high MICs against certain drugs, suggesting in vitro primary resistance to the antifungals tested.     

BF integrase genes of HIV-1 circulating in São Paulo, Brazil, with a recurrent recombination region

Although some studies have shown diversity in HIV integrase (IN) genes, none has focused particularly on the gene evolving in epidemics in the context of recombination. The IN gene in 157 HIV-1 integrase inhibitor-na?ve patients from the S?o Paulo State, Brazil, were sequenced tallying 128 of subtype B (23 of which were found in non-B genomes), 17 of subtype F (8 of which were found in recombinant genomes), 11 integrases were BF recombinants, and 1 from subtype C. Crucially, we found that 4 BF recombinant viruses shared a recurrent recombination breakpoint region between positions 4900 and 4924 (relative to the HXB2) that includes 2 gRNA loops, where the RT may stutter. Since these recombinants had independent phylogenetic origin, we argue that these results suggest a possible recombination hotspot not observed so far in BF CRF in particular, or in any other HIV-1 CRF in general. Additionally, 40% of the drug-na?ve and 45% of the drug-treated patients had at least 1 raltegravir (RAL) or elvitegravir (EVG) resistance-associated amino acid change, but no major resistance mutations were found, in line with other studies. Importantly, V151I was the most common minor resistance mutation among B, F, and BF IN genes. Most codon sites of the IN genes had higher rates of synonymous substitutions (dS) indicative of a strong negative selection. Nevertheless, several codon sites mainly in the subtype B were found under positive selection. Consequently, we observed a higher genetic diversity in the B portions of the mosaics, possibly due to the more recent introduction of subtype F on top of an ongoing subtype B epidemics and a fast spread of subtype F alleles among the B population.     

Incidence of Tinea capitis in São Paulo, Brazil

To determine the incidence of tinea capitis in São Paulo, Brazil, an investigation was performed in Private and Public Pediatrics Service involving 4,500 children from 0 to 15 years old during 5 years (1996–2000). Samples were taken from 132 children with suspected fungal infection of the scalp, for direct microscopy and culture. Tinea of scalp was mycologically confirmed in 112 patients (85%). Males were more affected than females in all age groups. Children below 8 years old accounted for more than 75% of the occurrences. Only three cases of tinea capitis were diagnosed in children from 12 to 15 years of age. Tinea capitis was prevalent in 103 cases (91.96%); inflammatory kerion type lesions were diagnosed in 9 patients (8.04%). Microsporum canis (70.5%) and Trichophyton tonsurans (23.2%) were the most common agents followed by T. mentagrophytes (3.6%), M. gypseum (1.8%) and T. rubrum (0.9%).     

Carnivore mammals in a fragmented landscape in northeast of São Paulo State,Brazil

São Paulo is the most developed state in Brazil and little of its native vegetation remains. In Luiz Antonio and Santa Rita do Passa Quatro municipalities, only small fragments of cerrado (Brazilian savanna) physiognomies (cerradão, cerrado sensu stricto) and of semideciduous forest have been left, surrounded by eucalyptus silviculture and sugar-cane agriculture. However, that vegetation mosaic still shelters large mammals, including several carnivore species. To detect the carnivores present in such a mosaic area (50,000 ha), and to find out how they use the landscape, we recorded them through 21 camera traps and 21 track plots, during 18 months. Species richness, diversity and relative frequency were evaluated according to the habitat. Ten species were recorded, some of them locally threatened to extinction (Puma concolor, Leopardus pardalis, Chrysocyon brachyurus). Species diversity did not significantly differ among fragments, and although most species preferred one or another habitat, the carnivore community as a whole explored all the study area regardless of the vegetation cover; eucalyptus plantations were as used by the carnivores as the native fragments. Therefore, it seems possible to maintain such animals in agricultural landscapes, where some large native fragments are left and the matrix is permeable to native fauna.     

Environmental variables and intertidal beach annelids of São Sebastião Channel (State of São Paulo,Brazil)

Benthic annelid communities were studied during a one-year period (August/95 to July/96) in two sectors of the beaches Engenho d'Agua and S?o Francisco, S?o Sebasti?o Channel (S?o Paulo, Brazil), where the substrate is composed by a mixture of sand and rock fragments. Abiotic parameters such as salinity of interstitial water and sediment properties were used to characterize the environment. The polychaetes were well represented in the two sectors and their distribution was related with sediment type. The density of individuals and the number of taxa was higher at S?o Francisco, while the diversity and the evenness were higher at Engenho d'Agua. This difference can be a consequence of organic enrichment caused by domestic input, and of the lower and more variable salinity at S?o Francisco. Due to these factors, the high density of opportunistic species, like Capitella capitata ssp., Scolelepis squamata, Laeonereis acuta and several oligochaetes, represented 75.5% of total abundance at this sector.     

Clinical, epidemiological and molecular features of the HIV-1 subtype C and recombinant forms that are circulating in the city of São Paulo, Brazil

ABSTRACT: BACKGROUND: The city of Sao Paulo has the highest AIDS case rate, with nearly 60% in Brazil. Despite,several studies involving molecular epidemiology, lack of data regarding a large cohort studyhas not been published from this city.ObjectivesThis study aimed to describe the HIV-1 subtypes, recombinant forms and drug resistancemutations, according to subtype, with emphasis on subtype C and BC recombinants in thecity of S?o Paulo, Brazil.Study designRNA was extracted from the plasma samples of 302 HIV-1-seropositive subjects, of which211 were drug-naive and 82 were exposed to ART. HIV-1 partial pol region sequences wereused in phylogenetic analyses for subtyping and identification of drug resistance mutations.The envelope gene of subtype C and BC samples was also sequenced. RESULTS: From partial pol gene analyses, 239 samples (79.1%) were assigned as subtype B, 23 (7.6%)were F1, 16 (5.3%) were subtype C and 24 (8%) were mosaics (3 CRF28/CRF29-like). Thesubtype C and BC recombinants were mainly identified in drug-na?ve patients (72.7%) andthe heterosexual risk exposure category (86.3%), whereas for subtype B, these values were69.9% and 57.3%, respectively (p = 0.97 and p = 0.015, respectively). An increasing trend ofsubtype C and BC recombinants was observed (p < 0.01). CONCLUSION: The HIV-1 subtype C and CRFs seem to have emerged over the last few years in the city ofS?o Paulo, principally among the heterosexual population. These findings may have animpact on preventive measures and vaccine development in Brazil.     

Food habits of three carnivores in a mosaic landscape of São Paulo state,Brazil

São Paulo is the most developed state in Brazil, but despite intense land use changes, some mammal species still inhabit remnant fragments of native vegetation of the state. We used fecal analyses to investigate prey diversity, trophic niche breadth, and trophic niche overlap of pumas, ocelots, and maned wolves in protected and non-protected areas in São Paulo state. During 18 months, we inspected more than 10,000 km of roads and trails and collected 233 fecal samples. Maned wolves showed generalist food habit, ocelots were predominantly carnivores, and pumas were strict carnivores. The European hare, an exotic species which had not yet been reported in the study area, was identified in the feces of a puma. Trophic niche breadth was the lowest for maned wolves (BA?=?0.339) and the highest for pumas (BA?=?0.723). Trophic niche overlap was high between maned wolves and ocelots (O_jk?=?0.765) and between pumas and ocelots (O_jk?=?0.639). Significantly different diets of maned wolves and ocelots were observed between dry and rainy seasons. Our findings indicate that these three species may adapt their diets to the disturbed landscapes. This is the second study characterizing food habits of ocelots in Cerrado areas but the first considering a large number of samples.     

Leishmania infection in humans, dogs and sandflies in a visceral leishmaniasis endemic area in Maranhão, Brazil

Leishmania infection in humans, dogs and sandflies was examined in the endemic visceral leishmaniasis (VL) municipality of Raposa, state of Maranh?o, Brazil. In this study, we examined Leishmania chagasi infection in the blood serum of both humans and Canis familiaris and the natural Leishmania sp. infection rate in the sandfly vector, Lutzomyia longipalpis. Enzyme-linked immunosorbent assay, indirect immunofluorescence reaction and polymerase chain reaction were performed to detect Leishmania infections in humans, dogs and sandflies, respectively. Overall, 186 out of 986 studied human beings were infected with L. chagasi parasites, representing an infection prevalence of 18.9%. An even higher infection rate was detected in dogs, where 66 (47.8%) out of 138 were infected. Among all Lu. longipalpis captured (n = 1,881), only 26.7% were females. The Leishmania infection frequency for the vector Lu. longipalpis was 1.56%. Remarkably, all infected sandflies were found in the peridomiciliary area. Furthermore, a high incidence of asymptomatic forms of VL in the human and canine populations was observed. The results of this study suggest autochthonous transmission of L. chagasi in this endemic area for visceral leishmaniasis because infection by Leishmania sp. was identified in all important elements of the transmission chain.     

Yeasts isolated from blood and catheter in children from a Public Hospital of São Paulo,Brazil

The great majority of nosocomial fungal infections, especially fungemias, are caused by yeasts, mostly of the genus Candida. In addition, such infections may be associated with intravascular catheters. In this study, 80 yeast strains were isolated from hospitalized children, being 59 from blood cultures and 21 from vascular catheter cultures. The prevalent species in both blood and catheter was C. parapsilosis (32.2% and 48.9%, respectively), followed by C. albicans (16.9% and 28.6%, respectively). Concerning enzyme production, 78.8% of the 80 isolates presented strong proteolytic activity but 78.8% showed no phospholipase activity. We also detected two prevalent killer biotypes: 511 and 888. Additionally, in five patients, it was possible to observe that the yeast species, killer biotype and proteolytic and phospholipase activity of blood and catheter were similar. In view of this, we suggest a transmission of nosocomial yeast infection from catheter to blood.This revised version was published online in October 2005 with corrections to the Cover Date.     

The impact of climate on Leptospirosis in São Paulo,Brazil

In this work, we correlate the daily number of human leptospirosis cases with several climatic factors. We used a negative binomial model that considers hospital daily admissions due to leptospirosis as the dependent variable, and the climatic variables of daily precipitation pattern, and maximum and minimum temperature as independent variables. We calculated the monthly leptospirosis admission probabilities from the precipitation and maximum temperature variables. The month of February showed the highest probability, although values were also high during the spring months. The month of February also showed the highest number of hospital admissions. Another interesting result is that, for every 20 mm precipitation, there was an average increase of 31.5% in hospital admissions. Additionally, the relative risk of leptospirosis varied from 1.1 to 2.0 when the precipitation varied from 20 to 140 mm.     

BF Integrase Genes of HIV-1 Circulating in S?o Paulo,Brazil, with a Recurrent Recombination Region

Although some studies have shown diversity in HIV integrase (IN) genes, none has focused particularly on the gene evolving in epidemics in the context of recombination. The IN gene in 157 HIV-1 integrase inhibitor-naïve patients from the São Paulo State, Brazil, were sequenced tallying 128 of subtype B (23 of which were found in non-B genomes), 17 of subtype F (8 of which were found in recombinant genomes), 11 integrases were BF recombinants, and 1 from subtype C. Crucially, we found that 4 BF recombinant viruses shared a recurrent recombination breakpoint region between positions 4900 and 4924 (relative to the HXB2) that includes 2 gRNA loops, where the RT may stutter. Since these recombinants had independent phylogenetic origin, we argue that these results suggest a possible recombination hotspot not observed so far in BF CRF in particular, or in any other HIV-1 CRF in general. Additionally, 40% of the drug-naïve and 45% of the drug-treated patients had at least 1 raltegravir (RAL) or elvitegravir (EVG) resistance-associated amino acid change, but no major resistance mutations were found, in line with other studies. Importantly, V151I was the most common minor resistance mutation among B, F, and BF IN genes. Most codon sites of the IN genes had higher rates of synonymous substitutions (dS) indicative of a strong negative selection. Nevertheless, several codon sites mainly in the subtype B were found under positive selection. Consequently, we observed a higher genetic diversity in the B portions of the mosaics, possibly due to the more recent introduction of subtype F on top of an ongoing subtype B epidemics and a fast spread of subtype F alleles among the B population.     

Biochemical studies in a eunicid (polychaete) of the littoral of São Paulo,Brazil

• 1.1. The sodium, potassium, chloride, calcium, magnesium, phosphorus, sulphur, copper, iron, total carbon dioxide, uric acid, creatinine, urea, glucose, erythrocruoin, nitrogen, total iodine, protein-bound iodine, total lipids, triglycerides, alkaline phosphatase activity, acid phosphatase activity and copper oxidase activity contents of the blood of the giant Polychaete, Eunice sp., were determined.
• 2.2. The osmolarity of the blood was 997 mOsm/1 and the pH was 6·49, a very low value. The bicarbonate concentration estimated by the Henderson-Hasselbach equation was 4·70 mM/1.
• 3.3. The values of the sea water, sediments, water contained in the tube, tube, cuticle, muscle and faeces are also given.
• 4.4. The chemical composition of the mucus was determined.

     

α1Proteinase inhibitor regulates CD4+ lymphocyte levels and is rate limiting in HIV-1 disease

Background

The regulation of adult stem cell migration through human hematopoietic tissue involves the chemokine CXCL12 (SDF-1) and its receptor CXCR4 (CD184). In addition, human leukocyte elastase (HLE) plays a key role. When HLE is located on the cell surface (HLE_CS), it acts not as a proteinase, but as a receptor for α₁proteinase inhibitor (α₁PI, α₁antitrypsin, SerpinA1). Binding of α₁PI to HLE_CS forms a motogenic complex. We previously demonstrated that α₁PI deficiency attends HIV-1 disease and that α₁PI augmentation produces increased numbers of immunocompetent circulating CD4⁺ lymphocytes. Herein we investigated the mechanism underlying the α₁PI deficiency that attends HIV-1 infection.

Methods and Findings

Active α₁PI in HIV-1 subjects (median 17 µM, n = 35) was significantly below normal (median 36 µM, p<0.001, n = 30). In HIV-1 uninfected subjects, CD4⁺ lymphocytes were correlated with the combined factors α₁PI, HLE_CS ⁺ lymphocytes, and CXCR4⁺ lymphocytes (r² = 0.91, p<0.001, n = 30), but not CXCL12. In contrast, in HIV-1 subjects with >220 CD4 cells/µl, CD4⁺ lymphocytes were correlated solely with active α₁PI (r² = 0.93, p<0.0001, n = 26). The monoclonal anti-HIV-1 gp120 antibody 3F5 present in HIV-1 patient blood is shown to bind and inactivate human α₁PI. Chimpanzee α₁PI differs from human α₁PI by a single amino acid within the 3F5-binding epitope. Unlike human α₁PI, chimpanzee α₁PI did not bind 3F5 or become depleted following HIV-1 challenge, consistent with the normal CD4⁺ lymphocyte levels and benign syndrome of HIV-1 infected chimpanzees. The presence of IgG-α₁PI immune complexes correlated with decreased CD4⁺ lymphocytes in HIV-1 subjects.

Conclusions

This report identifies an autoimmune component of HIV-1 disease that can be overcome therapeutically. Importantly, results identify an achievable vaccine modification with the novel objective to protect against AIDS as opposed to the current objective to protect against HIV-1 infection.     

Evaluation of IgG, IgM, and IgA antibodies to mycoplasma penetrans detected by ELISA and immunoblot in HIV-1-infected and STD patients, in São Paulo, Prazil

The aim of the present study was to determine the frequency of IgG, IgA, and IgM antibodies to Mycoplasma penetrans in HIV-1-infected patients and in patients with sexually transmitted diseases. We tested serum samples from 106 HIV-1-positive patients and 110 individuals with clinical symptoms of urethritis. ELISA and the immunoblot test were performed using M. penetrans lipid associated membrane proteins as antigen. By ELISA, we found a higher frequency (P < 0.05) of IgG against M. penetrans in HIV-1-infected and STD patients (25.5 and 17.3%) than in controls (1.2%), as well as a higher frequency of IgA (P < 0.05) (15.1 and 17.3% compared to 1.2%). For IgM, no differences were observed (P >/= 0.05) (3.8, 9.1, and 5. 8%, respectively). When the frequencies of IgG, IgM, and IgA antibodies of the HIV-1-infected patients were compared taking into account the CD4/CD8 cell ratios < 0.3 and >/= 0.3, no significant differences were observed between the two groups (13.3, 10, and 20%, compared to 20, 0, and 5%, respectively) (P > 0.05), possibly due to the low number of samples on which we could perform T-cell counts (53/106). The M. penetrans peptide of 38 kDa, considered immunodominant, was recognized in immunoblot by 51.8% of positive sera by ELISA for IgG, 50.0% for IgM, and 75% for IgA in the AIDS patients group, and by 47.4, 60.0, and 75.0%, respectively, in the sexually transmitted disease group. Cross-reactions in immunoblot for IgG were observed in sera from individuals infected with Mycoplasma pneumoniae and Mycoplasma hominis, and cross-reactions in immunoblot for IgA were observed in sera from individuals infected with M. hominis; all of them were ELISA negative to M. penetrans.     

Coexistence of antibodies to tick-borne agents of babesiosis and Lyme borreliosis in patients from Cotia county,State of São Paulo,Brazil

This paper reports a case of coinfection caused by pathogens of Lyme disease and babesiosis in brothers. This was the first case of borreliosis in Brazil, acquired in Cotia County, State of S o Paulo, Brazil. Both children had tick bite history, presented erythema migrans, fever, arthralgia, mialgia, and developed positive serology (ELISA and Western-blotting) directed to Borrelia burgdorferi G 39/40 and Babesia bovis antigens, mainly of IgM class antibodies, suggestive of acute disease. Also, high frequencies of antibodies to B. bovis was observed in a group of 59 Brazilian patients with Lyme borreliosis (25.4%), when compared with that obtained in a normal control group (10.2%) (chi-square = 5.6; p < 0.05). Interestingly, both children presented the highest titers for IgM antibodies directed to both infective diseases, among all patients with Lyme borreliosis.     

Prevalence of Toxocara infection in schoolchildren from the Butantã region,São Paulo,Brazil

Visceral larva migrans syndrome by Toxocara affects mainly children between 2 and 5 years of age, it is generally asymptomatic, and the seroprevalence varies from 3 to 86% in different countries. A total of 399 schoolchildren from 14 public schools of the Butant? region, S?o Paulo city, Brazil, were evaluated by Toxocara serology (enzyme-linked immunosorbent assay). Epidemiological data to the Toxocara infection obtained from a protocol were submitted to multiple logistic regression analysis for a risk profile definition. Blood was collected on filter paper by finger puncture, with all samples tested in duplicate. Considering titers > or = 1/160 as positive, the seroprevalence obtained was 38.8%. Among infected children, the mean age was 9.4 years, with a similar distribution between genders. A significant association was observed with the presence of onychophagia, residence with a dirty backyard, living in a slum, previous wheezing episodes, school attended, and family income (p < 0.05). All data, except "living in a slum", were considered to be determinant of a risk profile for the acquisition of Toxocara infection. A monthly income > or = 5 minimum salaries represented a protective factor, although of low relevance. Toxocara eggs were found in at least one of the soil samples obtained from five schools, with high prevalence of Toxocara infections, indicating the frequent soil contamination by this agent.