Increased resistance to first-line agents among bacterial pathogens isolated from urinary tract infections in Latin America: time for local guidelines?

Emerging resistance phenotypes and antimicrobial resistance rates among pathogens recovered from community-acquired urinary tract infections (CA-UTI) is an increasing problem in specific regions, limiting therapeutic options. As part of the SENTRY Antimicrobial Surveillance Program, a total of 611 isolates were collected in 2003 from patients with CA-UTI presenting at Latin American medical centers. Each strain was tested in a central laboratory using Clinical Laboratory Standard Institute (CLSI) broth microdilution methods with appropriate controls. Escherichia coli was the leading pathogen (66%), followed by Klebsiella spp. (7%), Proteus mirabilis (6.4%), Enterococcus spp. (5.6%), and Pseudomonas aeruginosa (4.6%). Surprisingly high resistance rates were recorded for E. coli against first-line orally administered agents for CA-UTI, such as ampicillin (53.6%), TMP/SMX (40.4%), ciprofloxacin (21.6%), and gatifloxacin (17.1%). Decreased susceptibility rates to TMP/SMX and ciprofloxacin were also documented for Klebsiella spp. (79.1 and 81.4%, respectively), and P. mirabilis (71.8 and 84.6%, respectively). For Enterococcus spp., susceptibility rates to ampicillin, chloramphenicol, ciprofloxacin, and vancomycin were 88.2, 85.3, 55.9, and 97.1%, respectively. High-level resistance to gentamicin was detected in 24% of Enterococcus spp. Bacteria isolated from patients with CA-UTI in Latin America showed limited susceptibility to orally administered antimicrobials, especially for TMP/SMX and fluoroquinolones. Our results highlight the need for developing specific CA-UTI guidelines in geographic regions where elevated resistance to new and old compounds may influence prescribing decisions.

Hitchhiking Trypanosoma cruzi minicircle DNA affects gene expression in human host cells via LINE-1 retrotransposon

The horizontal transfer of Trypanosoma cruzi mitochondrial minicircle DNA to the genomes of naturally infected humans may play an important role in the pathogenesis of Chagas disease. Minicircle integrations within LINE-1 elements create the potential for foreign DNA mobility within the host genome via the machinery associated with this retrotransposon. Here we document integration of minicircle DNA fragments in clonal human macrophage cell lines and their mobilization over time. The movement of an integration event in a clonal transfected cell line was tracked at three months and three years post-infection. The minicircle sequence integrated into a LINE-1 retrotransposon; one such foreign fragment subsequently relocated to another genomic location in association with associated LINE-1 elements. The p15 locus was altered at three years as a direct effect of minicircle/LINE-1 acquisition, resulting in elimination of p15 mRNA. Here we show for the first time a molecular pathology stemming from mobilization of a kDNA/LINE-1 mutation. These genomic changes and detected transcript variations are consistent with our hypothesis that minicircle integration is a causal component of parasite-independent, autoimmune-driven lesions seen in the heart and other target tissues associated with Chagas disease.

Comparative recognition by human IgG antibodies of recombinant proteins representing three asexual erythrocytic stage vaccine candidates of Plasmodium vivax

In previous immuno-epidemiological studies of the naturally acquired antibody responses to merozoite surface protein-1 (MSP-1) of Plasmodium vivax, we had evidence that the responses to distinct erythrocytic stage antigens could be differentially regulated. The present study was designed to compare the antibody response to three asexual erythrocytic stage antigens vaccine candidates of P. vivax. Recombinant proteins representing the 19 kDa C-terminal region of MSP-1(PvMSP19), apical membrane antigen n-1 ectodomain (PvAMA-1), and the region II of duffy binding protein (PvDBP-RII) were compared in their ability to bind to IgG antibodies of serum samples collected from 220 individuals from the state of Pará, in the North of Brazil. During patent infection with P. vivax, the frequency of individuals with IgG antibodies to PvMSP1(19), PvAMA-1, and PvDBP-RII were 95, 72.7, and 44.5% respectively. Although the frequency of responders to PvDBP-RII was lower, this frequency increased in individuals following multiple malarial infections. Individually, the specific antibody levels did not decline significantly nine months after treatment, except to PvMSP1(19). Our results further confirm a complex regulation of the immune response to distinct blood stage antigens. The reason for that is presently unknown but it may contribute to the high risk of re-infection in individuals living in the endemic areas.

Susceptibility of Mycobacterium tuberculosis to first-line antimycobacterial agents in a Brazilian hospital: assessing the utility of the tetrazolium (MTT) microplate assay

We conducted a cross-sectional, hospital-based study between January 2006-March 2008 to estimate the resistance of Mycobacterium tuberculosis to first-line drugs in patients with tuberculosis at a Brazilian hospital. We evaluated the performance of the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] (MTT) microplate assay compared with the Bactec-MGIT 960™ system for mycobacteria testing. The prevalence of resistance in M. tuberculosis was 6.7%. Multidrug-resistance [resistance to rifampicin (RMP) and isoniazid (INH)], INH-resistance and streptomycin (SM)-resistance accounted for 1%, 3.8% and 3.8% of all resistance, respectively, and all isolates were susceptible to ethambutol (EM). The resistance was primary in four cases and acquired in three cases and previous treatment was associated with resistance (p = 0.0129). Among the 119 M. tuberculosis isolates, complete concordance of the results for INH and EM was observed between the MTT microplate and Bactec-MGIT 960TM methods. The observed agreement for RMP was 99% (sensitivity: 90%) and 95.8% for SM (sensitivity 90.9%), lower than those for other drugs. The MTT colourimetric method is an accurate, simple and low-cost alternative in settings with limited resources.

Plasmodium falciparum gametocyte carriage, sex ratios and asexual parasite rates in Nigerian children before and after a treatment protocol policy change instituting the use of artemisinin-based combination therapies

The effects of artemisinin-based combination therapies (ACTs) on transmission of Plasmodium falciparum were evaluated after a policy change instituting the use of ACTs in an endemic area. P. falciparum gametocyte carriage, sex ratios and inbreeding rates were examined in 2,585 children at presentation with acute falciparum malaria during a 10-year period from 2001-2010. Asexual parasite rates were also evaluated from 2003-2010 in 10,615 children before and after the policy change. Gametocyte carriage declined significantly from 12.4% in 2001 to 3.6% in 2010 (@@χ² for trend = 44.3, p < 0.0001), but sex ratios and inbreeding rates remained unchanged. Additionally, overall parasite rates remained unchanged before and after the policy change (47.2% vs. 45.4%), but these rates declined significantly from 2003-2010 (@@χ² for trend 35.4, p < 0.0001). Chloroquine (CQ) and artemether-lumefantrine (AL) were used as prototype drugs before and after the policy change, respectively. AL significantly shortened the duration of male gametocyte carriage in individual patients after treatment began compared with CQ (log rank statistic = 7.92, p = 0.005). ACTs reduced the rate of gametocyte carriage in children with acute falciparum infections at presentation and shortened the duration of male gametocyte carriage after treatment. However, parasite population sex ratios, inbreeding rates and overall parasite rate were unaffected.

Progress with schistosome transgenesis

Genome sequences for Schistosoma japonicum and Schistosoma mansoni are now available. The schistosome genome encodes ~13,000 protein encoding genes for which the function of only a minority is understood. There is a valuable role for transgenesis in functional genomic investigations of these new schistosome gene sequences. In gain-of-function approaches, transgenesis can lead to integration of transgenes into the schistosome genome which can facilitate insertional mutagenesis screens. By contrast, transgene driven, vector-based RNA interference (RNAi) offers powerful loss-of-function manipulations. Our laboratory has focused on development of tools to facilitate schistosome transgenesis. We have investigated the utility of retroviruses and transposons to transduce schistosomes. Vesicular stomatitis virus glycoprotein (VSVG) pseudotyped murine leukemia virus (MLV) can transduce developmental stages of S. mansoni including eggs. We have also observed that the piggyBac transposon is transpositionally active in schistosomes. Approaches with both VSVG-MLV and piggyBac have resulted in somatic transgenesis and have lead to integration of active reporter transgenes into schistosome chromosomes. These findings provided the first reports of integration of reporter transgenes into schistosome chromosomes. Experience with these systems is reviewed herewith, along with findings with transgene mediated RNAi and germ line transgenesis, in addition to pioneering and earlier reports of gene manipulation for schistosomes.

Establishment and characterisation of a new cell line derived from Culex quinquefasciatus (Diptera: Culicidae)

Insect cell cultures are an important biotechnological tool for basic and applied studies. The objective of this work was to establish and characterise a new cell line from Culex quinquefasciatus embryonic tissues. Embryonated eggs were taken as a source of tissue to make explants that were seeded in L-15, Grace's, Grace's/L-15, MM/VP12, Schneider's and DMEM culture media with a pH range from 6.7-6.9 and incubated at 28ºC. The morphological, cytogenetic, biochemical and molecular characteristics of the cell cultures were examined by observing the cell shapes, obtaining the karyotypes, using a cellulose-acetate electrophoretic system and performing random amplified polymorphic DNA-polymerase chain reaction analysis, respectively. The Grace's/L-15 medium provided the optimal nutritional conditions for cell adhesion and proliferation. Approximately 40-60 days following the explant procedure, a confluent monolayer was formed. Cellular morphology in the primary cultures and the subcultures was heterogeneous, but in the monolayer the epithelioid morphology type predominated. A karyotype with a diploid number of six chromosomes (2n = 6) was observed. Isoenzymatic and molecular patterns of the mosquito cell cultures matched those obtained from the immature and adult forms of the same species. Eighteen subcultures were generated. These cell cultures potentially constitute a useful tool for use in biomedical applications.

A population-based study of first and second-line drug-resistant tuberculosis in a high-burden area of the Mexico/United States border

The resistance of 139 Mycobacterium tuberculosis (MTB) isolates from the city of Monterrey, Northeast Mexico, to first and second-line anti-TB drugs was analysed. A total of 73 isolates were susceptible and 66 were resistant to anti-TB drugs. Monoresistance to streptomycin, isoniazid (INH) and ethambutol was observed in 29 cases. Resistance to INH was found in 52 cases and in 29 cases INH resistance was combined with resistance to two or three drugs. A total of 24 isolates were multidrug-resistant (MDR) resistant to at least INH and rifampicin and 11 MDR cases were resistant to five drugs. The proportion of MDR-TB among new TB cases in our target population was 0.72% (1/139 cases). The proportion of MDR-TB among previously treated cases was 25.18% (35/139 cases). The 13 polyresistant and 24 MDR isolates were assayed against the following seven second-line drugs: amikacin (AMK), kanamycin (KAN), capreomycin (CAP), clofazimine (CLF), ethionamide (ETH), ofloxacin (OFL) and cycloserine (CLS). Resistance to CLF, OFL or CLS was not observed. Resistance was detected to ETH (10.80%) and to AMK (2.70%), KAN (2.70%) and CAP (2.70%). One isolate of MDR with primary resistance was also resistant to three second-line drugs. Monterrey has a high prevalence of MDR-TB among previously treated cases and extensively drug-resistant-MTB strains may soon appear.

A human astrocytoma cell line is highly susceptible to infection with Trypanosoma cruzi

Astrocytes play a vital role in neuronal protection, homeostasis, vascular interchange and the local immune response. Some viruses and parasites can cross the blood-brain barrier and infect glia. Trypanosoma cruzi, the aetiological agent of Chagas disease, can seriously compromise the central nervous system, mainly in immune-suppressed individuals, but also during the acute phase of the infection. In this report, the infective capacity of T. cruzi in a human astrocyte tumour-derived cell line was studied. Astrocytes exposed to trypomastigotes (1:10 ratio) produced intracellular amastigotes and new trypomastigotes emerged by day 4 post-infection (p.i.). At day 6 p.i., 93% of the cells were infected. Using flow cytometry, changes were observed in both the expression of major histocompatibility complex class I and II molecules and the chemokine secretion pattern of astrocytes exposed to the parasite. Blocking the low-density lipoprotein receptor on astrocytes did not reduce parasite intracellular infection. Thus, T. cruzi can infect astrocytes and modulate the immune response during central nervous system infection.

Um estudo sobre os aspectos que contribuem para a adoção do canal on-line para compra de livros, CDs e DVDs

O objetivo neste estudo foi identificar os fatores relevantes na adoção do canal on-line para a realização de compras, tendo como principais referências os modelos Unified Theory of Acceptance and Use of Technology (UTAUT), de Venkatesh et al. (2003), de Heijden, Verhagen e Creemers (2003) e de Bramall, Schoefer e McKechnie (2004). Além da revisão da literatura dos assuntos pertinentes, foi realizada uma pesquisa de campo descritiva, de natureza quantitativa com uma amostra de 172 pessoas residentes na cidade de São Paulo, pertencentes às classes socioeconômicas A, B e C (critério Brasil), compradores de livros, CDs ou DVDs no canal off-line. Os dados coletados foram analisados com o uso de técnicas estatísticas nos contextos uni, bi e multivariado. Aplicou-se a técnica de modelagem de equações estruturais (MEE ou Structural Equation Modeling - SEM) para serem identificadas relações de dependência entre construtos e a contribuição de cada um deles na estimação das intenções de adoção da compra pela Internet. Entre os principais resultados encontrados, a atitude em relação ao uso da tecnologia, a confiança e a expectativa de desempenho figuraram como os aspectos mais relevantes para uma possível adoção do canal on-line.

Desenvolvimento de um curso on-line sobre o tema administração de medicamentos

O estudo descreveu o desenvolvimento de um curso on-line sobre o processo da administração de medicamentos - vias. Para tanto se utilizou o World Wide Web Course Tools (WebCT), que é um software que fornece várias ferramentas a supervisores e acesso a estudantes providos de uma senha a diversos ambientes. O material do curso foi subdivido em oito tópicos ilustrados: administração de medicamentos por via oral, sublingual, via parenteral, intradérmica, subcutânea, intramuscular, endovenosa e aplicação tópica e instilação, além das questões para avaliação de conhecimentos. Uma amostra de alunos de graduação da Escola de Enfermagem de Ribeirão Preto - USP avaliou positivamente o curso. Pretende-se agora inseri-lo em disciplina curricular do ensino de graduação, como um recurso adicional à aprendizagem dos alunos.

Panorama brasileiro do ensino de Enfermagem On-line

O objetivo deste estudo foi identificar os cursos de Ensino Superior Nacional de EAD por área de concentração, região geográfica, nível de formação e os cursos de EAD no ensino superior de Enfermagem. O método adotado foi um estudo exploratório descritivo em que foi realizado um levantamento nos sites e portais governamentais e não-governamentais relacionados à educação nacional e EAD das Instituições de Ensino Superior (IES) que praticam EAD. Nos resultados foram identificados apenas dois cursos de pós-graduação lato sensu oferecidos especificamente em Enfermagem. Assim, há necessidade de maior investimento das IES de Enfermagem na criação e avaliação de cursos de EAD, bem como de infra-estrutura e de implementação de uma política de capacitação tecnológica.

Desenvolvimento do curso de gerenciamento em enfermagem on-line: experiência exitosa entre Brasil e Portugal

RESUMO Objetivo Descrever a experiência no planejamento e desenvolvimento de um Curso de Atualização On-Line em Gerenciamento em Enfermagem destinado a enfermeiros nos contextos Brasil e Portugal. Método O desenho instrucional do Curso fundamentou-se na Teoria da Aprendizagem Significativa, na Andragogia e na Metodologia Dialética, valorizando a interação entre os atores e privilegiando os cenários de prática e a aplicação dos conceitos abordados. Resultados O Curso está estruturado em nove unidades teóricas, quatro estudos de caso e prova dissertativa. Foi avaliado positivamente pelos participantes, os quais referiram oportunidades de aquisição de novos conhecimentos; interação e intercâmbio de experiência; motivação em estudar os temas e autoaprendizagem. Conclusão Espera-se que a experiência descrita estimule a proposição de novos cursos e programas na modalidade de Educação a Distância, incrementando os processos de ensino e de aprendizagem para subsidiar análises futuras do seu impacto no desenvolvimento e no aprimoramento de competências gerenciais em enfermagem.

Caste polymorphism of apterous line of the Neotropical termite Nasutitermes corniger (Motschulsky) (Isoptera, Termitidae)

Termite societies are structured by individuals that can be grouped into castes and instars. The development of these instars in most species occurs in irregular patterns and sometimes is distinguished subcastes in physical systems that originate polymorphic soldiers and workers. In this study, we characterized the morphological diversity of castes of apterous in Nasutitermes corniger. We collected four colonies of N. corniger, one every three months between May 2011 and February 2012. Individuals of the nest were separated into groups: larval stages, workers and presoldiers and soldiers. A morphometric analysis was performed on individuals from each group based on head width, metatibia, antenna, and thorax length. The data were submitted to discriminant analysis to confirm different morphological types inside these groups. The apterous line of N. corniger is composed of one first larval instar and two second larval instar. The workers caste has two lines of development with four instars in a larger line and three instars in a lower line. Two morphological types were identified in presoldiers and soldiers. The pattern of castes was similar to other species of the genus, in which bifurcation into two lines of workers, one smaller and one larger occurs after the first molt.

Dicionários disponíveis on-line para aprendizes de inglês: estruturação e recursos

O artigo descreve a estrutura e as formas de acesso características dos dicionários eletrônicos do tipo on-line disponíveis ao aprendiz de língua inglesa, comparando o conteúdo e os recursos de dois dicionários monolíngues e dois dicionários bilíngües - o Cambridge Advanced Learner's Dictionary (CALD, 2009), o Merriam-Webster Learner's Dictionary (MWLD, 2009), o Reverso Dictionary English/Portuguese (RDEP, 2008) e o Wiktionary Inglês/Português (WIP, 2009). Discute-se a funcionalidade desses instrumentos em relação às demandas do aprendiz.