Experimental transmission of the parasitic flagellates Trypanosoma cruzi and Trypanosoma rangeli between triatomine bugs or mice and captive neotropical bats

Trypanosoma cruzi and Trypanosoma rangeli-like trypanosomes have been found in a variety of neotropical bat species. In this study, bats (Artibeus lituratus, Carollia perspicillata, Desmodus rotundus, Glossophaga soricina, Molossus molossus, Phyllostomus hastatus) were maintained under controlled conditions, and experiments were conducted to determine how they might become infected naturally with trypanosomes. All bats were first screened for existing infections by hemoculture and the examination of blood smears, and only apparently uninfected animals were then used in the experiments. Proof was obtained that the triatomine bug Rhodnius prolixus would readily feed upon some of the bats, and two species became infected after being bitten by bugs infected with T. rangeli. Some bats also became infected by ingesting R. prolixus carrying T. cruzi, or following subcutaneous or intragastic inoculation with fecal suspensions of R. prolixus containing T. cruzi. P. hastatus became infected after ingesting mice carrying T. cruzi. All of the bats studied inhabit roosts that may be occupied by triatomine bugs and, with the exception of D. rotundus, all also feed to at least some extent upon insects. These findings provide further evidence of how bats may play significant roles in the epidemiology of T. cruzi and T. rangeli in the New World tropics.

Chagas disease in Andean countries

The Andean Countries' Initiative (ACI) for controlling Chagas disease was officially created in 1997 within the framework of the Hipolito Unanue Agreement (UNANUE) between the Ministries of Health of Colombia, Ecuador, Peru, and Venezuela. Its objective was to interrupt transmission via vector and transfusion in the region, taking into account that there are 12.5 million people at risk in the four Andean countries forming the initiative in the area and around 3 million people are infected by Trypanosoma cruzi. The progress of control activities for the vector species present in the Andean sub-region, for different reasons, has been slow and control interventions have still not been installed in all geographical areas occupied by the target species. This has been partly due to lack of knowledge about these vector populations' biological characteristics, and consequent uncertainty about which are the appropriate control measures and strategies to be implemented in the region. The main vector species present important similarities in Venezuela and Colombia and in Ecuador and Northern Peru and they can be approached in a similar way throughout the whole regions, basing approaches on and adapting them to the current strategies being developed in Venezuela during the 1960s which have been progressively adopted in the Southern Cone and Central-American region. Additional measures are needed for keeping endemic areas free from Rhodnius prolixus silvatic populations, widely spread in the Orinoco region in Colombia and Venezuela. Regarding aetiological treatment, it is worth mentioning that (with the exception of Colombia) none of the other countries forming the ACI have registered medicaments available for treating infected young people. There are no suitable follow-up programmes in the sub-region or for treating cases of congenital Chagas disease. An integral and integrated programme encompassing all the aspects including transmission by transfusion which seems to have achieved extremely encouraging results in all countries, are urgently needed.

Characterization of Shigella spp. by antimicrobial resistance and PCR detection of ipa genes in an infantile population from Porto Velho (Western Amazon region), Brazil

The incidence of Shigella spp. was assessed in 877 infants from the public hospital in Rondônia (Western Amazon region, Brazil) where Shigella represents the fourth cause of diarrhea. Twenty-five isolates were identified: 18 were Shigella flexneri, three Shigella sonnei, three Shigella boydii and one Shigella dysenteriae. With the exception of S. dysenteriae, all Shigella spp. isolated from children with diarrhea acquired multiple antibiotic resistances. PCR detection of ipa virulence genes and invasion assays of bloody diarrhea and fever (colitis) were compared among 25 patients testing positive for Shigella. The ipaH and ipaBCD genes were detected in almost all isolates and, unsurprisingly, all Shigella isolates associated with colitis were able to invade HeLa cells. This work alerts for multiple antibiotic resistant Shigella in the region and characterizes presence of ipa virulence genes and invasion phenotypesin dysenteric shigellosis.

Toxoplasma gondii: 1908-2008, homage to Nicolle, Manceaux and Splendore

The discovery of Toxoplasma gondii independently by Nicolle and Manceaux (1908) and Splendore (1908) was to open a "Pandora's Box" that has led research on this parasite into a number of scientific disciplines. In the 100 years since its discovery, the mystery surrounding T. gondii and its inter-relationship with humans has continued to provide a stimulating source of material in many areas of research, resulting in the publication of almost 20,000 papers and a number of books. This flood of diverse information shows no sign of abating, with an average of 10 papers per week appearing in PubMed. Herein, it is impossible to do more than provide a very superficial comment on what has become a massive body of scientific information. T. gondii has many unique features and seems to be the "exception to almost every rule" thus acting as a focus for research in disciplines from epidemiology to immunology to human behaviour to cell biology to human disease. In this review a number of the historical advances will be mentioned and combined with a description of the basic biology of the parasite.

The Anopheles albitarsis complex with the recognition of Anopheles oryzalimnetes Wilkerson and Motoki, n. sp. and Anopheles janconnae Wilkerson and Sallum, n. sp. (Diptera: Culicidae)

The Anopheles (Nyssorhynchus) albitarsis complex includes six species: An. albitarsis, Anopheles oryzalimnetes Wilkerson and Motoki, n. sp., Anopheles marajoara, Anopheles deaneorum, Anopheles janconnae Wilkerson and Sallum, n. sp. and An. albitarsis F. Except for An. deaneorum, species of the complex are indistinguishable when only using morphology. The problematic distinction among species of the complex has made study of malaria transmission and ecology of An. albitarsis s.l. difficult. Consequently, involvement of species of the An. albitarsis complex in human Plasmodium transmission is not clear throughout its distribution range. With the aim of clarifying the taxonomy of the above species, with the exception of An. albitarsis F, we present comparative morphological and morphometric analyses, morphological redescriptions of three species and description of two new species using individuals from populations in Brazil, Paraguay, Argentina and Venezuela. The study included characters from adult females, males, fourth-instar larvae, pupae and male genitalia of An. albitarsis, An. marajoara, An. deaneorum and An. oryzalimnetes n. sp. For An. janconnae n. sp. only characters of the female, male and male genitalia were analyzed. Fourth-instar larvae, pupae and male genitalia characteristics of all five species are illustrated. Bionomics and distribution data are given based on published literature records.

Helicobacter pylori cagA and vacA genotypes in Cuban and Venezuelan populations

The aim of this study was to determine the presence of Helicobacter pylori cytotoxin-associated gene (cagA)/vacuolating cytotoxin gene (vacA) among patients with chronic gastritis in Cuba and Venezuela. Gastric antrum biopsies were taken for culture, DNA extraction and PCR analysis. Amplification of vacA and cagA segments was performed using two regions of cagA: 349 bp were amplified with the F1/B1 primers and the remaining 335 bp were amplified with the B7629/B7628 primers. The VA1-F/VA1-R set of primers was used to amplify the 259-bp (s1) or 286-bp (s2) product and the VAG-R/VAG-F set of primers was used to amplify the 567-bp (m1) or 642-bp (m2) regions of vacA. cagA was detected in 87% of the antral samples from Cuban patients and 80.3% of those from Venezuelan patients. All possible combinations of vacA regions were found, with the exception of s2/m1. The predominant combination found in both countries was s1/m1. The percentage of cagA+ strains was increased by the use of a second set of primers and a greater number of strains was amplified with the B7629/B7628 primers in the Cuban patients (p = 0.0001). There was no significant difference between the presence of the allelic variants of vacA and cagA in both populations. The predominant genotype was cagA+/s1m1 in both countries. The results support the necessary investigation of isolates circulating among the human population in each region.

Analysis of membrane protein genes in a Brazilian isolate of Anaplasma marginale

The sequencing of the complete genome of Anaplasma marginale has enabled the identification of several genes that encode membrane proteins, thereby increasing the chances of identifying candidate immunogens. Little is known regarding the genetic variability of genes that encode membrane proteins in A. marginale isolates. The aim of the present study was to determine the degree of conservation of the predicted amino acid sequences of OMP1, OMP4, OMP5, OMP7, OMP8, OMP10, OMP14, OMP15, SODb, OPAG1, OPAG3, VirB3, VirB9-1, PepA, EF-Tu and AM854 proteins in a Brazilian isolate of A. marginale compared to other isolates. Hence, primers were used to amplify these genes: omp1, omp4, omp5, omp7, omp8, omp10, omp14, omp15, sodb, opag1, opag3, virb3, VirB9-1, pepA, ef-tu and am854. After polimerase chain reaction amplification, the products were cloned and sequenced using the Sanger method and the predicted amino acid sequence were multi-aligned using the CLUSTALW and MEGA 4 programs, comparing the predicted sequences between the Brazilian, Saint Maries, Florida and A. marginale centrale isolates. With the exception of outer membrane protein (OMP) 7, all proteins exhibited 92-100% homology to the other A. marginale isolates. However, only OMP1, OMP5, EF-Tu, VirB3, SODb and VirB9-1 were selected as potential immunogens capable of promoting cross-protection between isolates due to the high degree of homology (over 72%) also found with A. (centrale) marginale.

Biological and genetic aspects of crosses between species of the genus Meccus (Hemiptera: Reduviidae Triatominae)

The degree of reproductive isolation between Meccus phyllosomus and the remaining five species of the genus Meccus, as well as between Meccus bassolsae and Meccus pallidipennis, Meccus longipennis and Meccus picturatus, was examined. Fertility and the segregation of morphological characteristics were examined in two generations of hybrids from crosses between these species. The percentage of couples with offspring (fertile) was high in the vast majority of sets of crosses, with the exception of that between ♀M. phyllosomus and ♂Meccus mazzottii. In sets of crosses involving M. bassolsae specimens, no first-generation (F1) individuals were morphologically similar to M. bassolsae, but instead shared the morphology of the other parental species. A similar phenomenon was observed in most sets of crosses involving M. phyllosomus. These results indicated that different degrees of reproductive isolation exist among the species of Meccus involved in this study. The biological evidence obtained in this study does not support the proposal that M. bassolsae is a full species. It could indicate that, on the contrary, it should be considered a subspecies of a single polytypic species. The biological evidence does support the proposal that M. phyllosomus is a full species.

Cellular characterisation of Candida tropicalis presenting fluconazole-related trailing growth

We assessed fluconazole susceptibility in 52 Candida tropicalis clinical strains using seven antifungal susceptibility methods, including broth microdilution (BMD) [standard M27 A3 (with neutral and acid pH), ATB Fungus 3, Vitek 2 system and flow cytometric analysis] and agar-based methods (disk diffusion and E-test). Trailing growth, detection of cell-associated secreted aspartic proteases (Saps) and morphological and ultrastructural traits of these clinical strains were also examined. The ranges of fluconazole 24 h-minimum inhibitory concentration (MIC) values were similar among all methods. The essential agreement among the methods used for MIC determinations was excellent and all methods categorised all strains as susceptible, except for one strain that showed a minor error. The presence of the trailing effect was assessed by six methods. Trailing positivity was observed for 86.5-100% of the strains. The exception was the BMD-Ac method where trailing growth was not observed. Morphological and ultrastructural alterations were detected in C. tropicalis trailing cells, including mitochondrial swelling and cell walls with irregular shapes. We tested the production of Saps in 13 C. tropicalis strains expressing trailing growth through flow cytometry. Our results showed that all of the C. tropicalis strains up-regulated surface Sap expression after 24 h or 48 h of exposure to fluconazole, which was not observed in untreated yeast strains. We concluded that C. tropicalis strains expressing trailing growth presented some particular features on both biological and ultrastructural levels.

Emergence and characterisation of vanB vancomycin-resistant Enterococcus faecalis in Rio de Janeiro, Brazil

Here we describe the detection and characterisation of three isolates of vancomycin-resistant VanB-type Enterococcus faecalis. Sequence analysis suggested that these isolates harboured the vanB1 gene. The isolates were susceptible to the majority of antimicrobial agents tested, with the exception of chloramphenicol, erythromycin and vancomycin, and showed distinct profiles of high-level resistance to aminoglycosides. Analysis of the clonal relatedness of the vanB E. faecalis isolates showed similar pulsed-field gel electrophoresis profiles. To our knowledge, this is the first report of the occurrence of enterococcal strains carrying vanB genes in Brazil.

Brazilian clinical trial of uniform multidrug therapy for leprosy patients: the correlation between clinical disease types and adverse effects

This study sought to verify the correlation between leprosy types and the adverse effects of treatment drugs. This quantitative, prospective, nested study was developed at the Dona Libânia Dermatology Centre in Fortaleza, Brazil. Data were collected from November 2007-November 2008. During this period, 818 leprosy patients were diagnosed and began treatment. Forty patients with tuberculoid leprosy (TT) were selected. Twenty patients followed a standard therapy of dapsone and rifampicin and 20 were administered dapsone, rifampicin and clofazimine (U-MDT). Twenty patients with borderline lepromatous (BL) and lepromatous leprosy (LL) were also selected and treated with U-MDT. All of the subjects received six doses. With the exception of haemolytic anaemia, there was a low incidence of adverse effects in all the groups. We did not observe any differences in the incidence of haemolytic anaemia or other side effects across groups of patients with TT, BL or LL treated with U-MDT.

Identification of blood meal sources of Lutzomyia longipalpis using polymerase chain reaction-restriction fragment length polymorphism analysis of the cytochrome B gene

An analysis of the dietary content of haematophagous insects can provide important information about the transmission networks of certain zoonoses. The present study evaluated the potential of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome B (cytb) gene to differentiate between vertebrate species that were identified as possible sources of sandfly meals. The complete cytb gene sequences of 11 vertebrate species available in the National Center for Biotechnology Information database were digested with Aci I, Alu I, Hae III and Rsa I restriction enzymes in silico using Restriction Mapper software. The cytb gene fragment (358 bp) was amplified from tissue samples of vertebrate species and the dietary contents of sandflies and digested with restriction enzymes. Vertebrate species presented a restriction fragment profile that differed from that of other species, with the exception of Canis familiaris and Cerdocyon thous. The 358 bp fragment was identified in 76 sandflies. Of these, 10 were evaluated using the restriction enzymes and the food sources were predicted for four: Homo sapiens (1), Bos taurus (1) and Equus caballus (2). Thus, the PCR-RFLP technique could be a potential method for identifying the food sources of arthropods. However, some points must be clarified regarding the applicability of the method, such as the extent of DNA degradation through intestinal digestion, the potential for multiple sources of blood meals and the need for greater knowledge regarding intraspecific variations in mtDNA.

Assessment of primary health care: health professionals’ perspective

Objective To assess primary health care attributes of access to a first contact, comprehensiveness, coordination, continuity, family guidance and community orientation. Method An evaluative, quantitative and cross-sectional study with 35 professional teams in the Family Health Program of the Alfenas region, Minas Gerais, Brazil. Data collection was done with the Primary Care Assessment Tool - Brazil, professional version. Results Results revealed a low percentage of medical experts among the participants who evaluated the attributes with high scores, with the exception of access to a first contact. Data analysis revealed needs for improvement: hours of service; forms of communication between clients and healthcare services and between clients and professionals; the mechanism of counter-referral. Conclusion It was concluded that there is a mismatch between the provision of services and the needs of the population, which compromises the quality of primary health care.




Phlebotomines (Diptera, Psychodidae) in caves of the Serra da Bodoquena, Mato Grosso do Sul State, Brazil

The present paper deals with the phlebotomine species captured during the period from January 1998 to June 2000 in 12 caves located in the Serra da Bodoquena, situated in the south central region of Mato Grosso do Sul State, Brazil. Three of the caves are situated further north (in Bodoquena county), seven in the central area (Bonito county) and two in the south (Jardim county). These last two caves and three of those in Bonito are located at the west side of the ridge. Eighteen species of phlebotomines were captured within the caves: Brumptomyia avellari (Costa Lima, 1932), Brumptomyia brumpti (Larrousse, 1920), Brumptomyia cunhai (Mangabeira, 1942), Brumptomyia galindoi (Fairchild & Hertig, 1947), Evandromyia corumbaensis (Galati, Nunes, Oshiro & Rego, 1989), Lutzomyia almerioi Galati & Nunes, 1999, Lutzomyia longipalpis (Lutz & Neiva, 1912), Martinsmyia oliveirai (Martins, Falcão & Silva, 1970), Micropygomyia acanthopharynx (Martins, Falcão & Silva, 1962), Micropygomyia peresi (Mangabeira, 1942), Micropygomyia quinquefer (Dyar, 1929), Nyssomyia whitmani (Antunes & Coutinho, 1939), Psathyromyia campograndensis (Oliveira, Andrade-Filho, Falcão & Brazil, 2001), Psathyromyia punctigeniculata (Floch & Abonnenc, 1944), Psathyromyia shannoni (Dyar, 1929), Pintomyia kuscheli (Le Pont, Martinez, Torrez-Espejo & Dujardin, 1998), Sciopemyia sordellii (Shannon & Del Ponte, 1927) and Sciopemyia sp. A total of 29,599 phlebotomine sandflies was obtained. Lutzomyia almerioi was absolutely predominant (91.5%) over the other species on both sides of the Bodoquena ridge, with the exception of the southern caves in which it was absent. It presents summer predominance, with nocturnal and diurnal activities. The species breeds in the caves and was captured during daytime both in the dark area and in the mouth of the caves. Martinsmyia oliveirai, the second most frequent sandfly, also presents a summer peak and only predominated over the other species in one cave, in which there were human residues.0

Dynamics of 14C-labeled glucose and ammonium in saline arable soils

Organic matter dynamics and nutrient availability in saline agricultural soils of the State of Guanajuato might provide information for remediation strategies. 14C labeled glucose with or without 200 mg kg-1 of NH4+-N soil was added to two clayey agricultural soils with different electrolytic conductivity (EC), i.e. 0.94 dS m-1 (low EC; LEC) and 6.72 dS m-1 (high EC; HEC), to investigate the effect of N availability and salt content on organic material decomposition. Inorganic N dynamics and production of CO2 and 14CO2 were monitored. Approximately 60 % of the glucose-14C added to LEC soil evolved as 14CO2, but only 20 % in HEC soil after the incubation period of 21 days. After one day, < 200 mg 14C was extractable from LEC soil, but > 500 mg 14C from HEC soil. No N mineralization occurred in the LEC and HEC soils and glucose addition reduced the concentrations of inorganic N in unamended soil and soil amended with NH4+-N. The NO2- and NO3- concentrations were on average higher in LEC than in HEC soil, with exception of NO2- in HEC amended with NH4+-N. It was concluded that increases in soil EC reduced mineralization of the easily decomposable C substrate and resulted in N-depleted soil.