We examined strains of Trypanosoma cruzi isolated from patients with acute Chagas disease that had been acquired by oral transmission in the state of Santa Catarina, Brazil (2005) and two isolates that had been obtained from a marsupial (Didelphis aurita) and a vector (Triatoma tibiamaculata). These strains were characterised through their biological behaviour and isoenzymic profiles and genotyped according to the new Taxonomy Consensus (2009) based on the discrete typing unities, that is, T. cruzi genotypes I-VI. All strains exhibited the biological behaviour of biodeme type II. In six isolates, late peaks of parasitaemia, beyond the 20th day, suggested a double infection with biodemes II + III. Isoenzymes revealed Z2 or mixed Z1 and Z2 profiles. Genotyping was performed using three polymorphic genes (cytochrome oxidase II, spliced leader intergenic region and 24Sα rRNA) and the restriction fragment length polymorphism of the kDNA minicircles. Based on these markers, all but four isolates were characterised as T. cruzi II genotypes. Four mixed populations were identified: SC90, SC93 and SC97 (T. cruzi I + T. cruzi II) and SC95 (T. cruzi I + T. cruzi VI). Comparison of the results obtained by different methods was essential for the correct identification of the mixed populations and major lineages involved indicating that characterisation by different methods can provide new insights into the relationship between phenotypic and genotypic aspects of parasite behaviour.

INTRODUÇÃO: O isolamento de Pseudomonas aeruginosa resistente aos carbapenêmicos (PARC) tem sido cada vez mais frequente nos hospitais brasileiros. O presente estudo investigou a concentração inibitória mínina (CIM), a presença de metalo-β-lactamases (MβL), e uma possível relação clonal entre PARC isoladas entre junho de 2003 a junho de 2005, em um hospital escola na cidade de Florianópolis, Brasil. MÉTODOS: O estudo incluiu 29 PARC e sete isolados com suscetibilidade reduzida. A CIM foi determinada por diluição em ágar. A detecção de MβL foi realizada por sinergismo de duplo disco (SDD) e disco combinado (DC). Genes para MβL foram pesquisados por PCR e confirmados pela análise da sequência de nucleotídeos. A tipagem epidemiológica foi realizada por gel de eletroforese em campo pulsátil. RESULTADOS: Entre os 29 isolados resistentes aos carbapenêmicos, 100% apresentaram suscetibilidade a polimixina B, e 96,7% a piperacilina/tazobactam. Dezessete (62%) destes isolados pertenciam a um mesmo clone (clone A); entre estes, seis isolados apresentaram testes fenotípicos positivos para MβL e carreavam o gene blaSPM-1. O primeiro isolado PARC não foi relacionado ao clone A, carreava o gene blaIMP-16 e foi fenotipicamente positivo somente por DC. CONCLUSÕES: A propagação de um clone com alto nível de resistência sugere a transmissão cruzada como um importante mecanismo de disseminação e tem contribuído para o aumento nos níveis de resistência aos carbapenêmicos. Este estudo enfatiza a necessidade de vigilância contínua e melhoramento nas estratégias de controle de infecção nesta instituição.

INTRODUCTION: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has been isolated with increasing frequency in Brazilian hospitals. Since June 2003, its detection in a teaching hospital in the city of Florianópolis, Brazil, has increased. This study aimed to investigate the minimal inhibitory concentration (MIC), presence of Metallo-β-lactamase (MβL) and a possible clonal relationship among the isolates. METHODS: The study included 29 CRPA and seven isolates with reduced susceptibility. The MIC was determined by agar-dilution. Detection of MβL was performed by Double Disk Sinergism (DDS) and Combined Disk (CD). The MβL gene was verified by PCR and nucleotide sequence analysis. Epidemiological typing was performed by pulsed-field gel electrophoresis. RESULTS: Among the 29 carbapenem-resistant isolates, polymyxin B presented 100% susceptibility and piperacillin/tazobactam 96.7%. Seventeen (62%) strains were verified as clonal (A clone) and among these, six isolates indicated phenotypically positive tests for MβL and harbored the blaSPM-1 gene. The first CRPA isolates were unrelated to clone A, harbored blaIMP-16 and were phenotypically positive only by CD. CONCLUSIONS: The spread of a high-level of resistance clone suggests cross transmission as an important dissemination mechanism and has contributed to the increased rate of resistance to carbapenems. This study emphasizes the need for continuous surveillance and improved strategies.

Large-scale trials of a trapping system designed to collect silvatic Triatominae are reported. Live-baited adhesive traps were tested in various ecosystems and different triatomine habitats (arboreal and terrestrial). The trials were always successful, with a rate of positive habitats generally over 20% and reaching 48.4% for palm trees of the Amazon basin. Eleven species of Triatominae belonging to the three genera of public health importance (Triatoma, Rhodnius and Panstrongylus) were captured. This trapping system provides an effective way to detect the presence of triatomines in terrestrial and arboreal silvatic habitats and represents a promising tool for ecological studies. Various lines of research are contemplated to improve the performance of this trapping system.

Tetratrichomonas didelphidis (Hegner and Ratcliffe, 1927) Andersen and Reilly, 1965 is a flagellate protozoan from the intestine, cecum, and colon of Didelphis marsupialis Linnaeus, 1758. The parasite was found and isolated in the rectal glands in Pavlova starch-containing media in Florianópolis, SC, Brasil from D.

Thirty-five Trypanosoma cruzi strains were isolated from chronic chagasic patients, triatomines and opossums from different municipalities of the State of Rio Grande do Sul. Parasites were characterized by means of mice infectivity, enzyme electrophoresis and randomly amplified polymorphic DNA (RAPD) analysis. Twenty-nine strains were isolated from chagasic patients, 4 from triatomines (2 from Triatoma infestans and 2 from Panstrongylus megistus) and 2 from opossums Didelphis albiventris. Thirty-three T. cruzi strains were of low and 2 strains of high virulence in mice. Both virulent strains were isolated from P. megistus. Isoenzyme analysis of the strains showed 3 different zymodemes. Eleven strains isolated from chagasic patients and 2 from D. albiventris were Z2. Eighteen strains from patients and 2 from T. infestans were ZB and 2 T. cruzi strains isolated from P. megistus were Z1. RAPD profiles obtained with 4 random primers showed a high genetic heterogeneity of the T. cruzi strains. Zymodeme 2 and ZB strains were the more polymorphic. A band sharing analysis of the RAPD profiles of Z2 and ZB strains using 3 primers, showed a very low percentage of shared bands, 20% among 13 ZB strains and 14% among 13 Z2 strains. According to the isoenzyme results, 3 T. cruzi populations were present in State of Rio Grande do Sul. Zymodeme 2 and ZB strains were found infecting man (domiciliar transmission cycle) whereas Z1 strains were found infecting the sylvatic vector P. megistus