Caracterização de duas diferentes subunidades do antígeno B de Echinococcus granulosus e avaliação sorológica de antígenos recombinantes

Duas diferentes subunidades (AgB8/1 e AgB8/2) do antígeno B de Echinococcus granulosus foram caracterizadas e a estrutura dos genes que codificam essas proteínas foram comparadas. As seqüências de DNA foram expressas em Escherichia coli e o valor diagnóstico dos antígenos foi determinado. A seqüência genômica do AgB8/1 apresenta um íntron de 92 pb na posição correspondente ao aminoácido 16 e a seqüência genômica do AgB8/2 apresenta um íntron de 68 pb na posição correspondente ao aminoácido 20. Ambos os íntrons estão localizados entre a porção N-terminal hidrofóbica e a proteína secretada. O potencial diagnóstico dos antígenos recombinantes AgB8/1, AgB8/2, Ag4, Ag5, Ag8t e Ag8c foi testado em ELISA frente a uma soroteca de 211 soros. O antígeno recombinante AgB8/2 mostrou uma sensibilidade média de 86,95% e uma especificidade de 96,72% em ELISA, apresentando portanto, uma melhor performance para diagnóstico da hidatidose cística do que os demais recombinantes testados no presente trabalho. Entre os antígenos recombinantes testados o AgB8/1 e o AgB8/2 não apresentaram reações cruzadas com soros de pacientes com cisticercose e o recombinante AgB8/2 mostrou ser espécie-específico com o painel de soros utilizado. Testes com o peptídeo sintético GU4 mostraram sua mais baixa performance diagnóstica em ELISA, quando comparada com o antígeno recombinante AgB8/2 cuja porção e-terminal ele mimetiza.Two different Echinococcus granulosus antigen B subunits (AgB8/1 and AgB8/2) were characterized and the structure of the genes encoding these two proteins were compared. DNA sequences were expressed in Echerichia coli and the antigens diagnostic value was then assessed. The genomic sequences of AgB8/1 has a 92 bp intron in the position corresponding to amino acid 16; the AgB8/2 genomic sequence presents a 68 bp intron in the position corresponding to amino acid 20. Either introns is located between the putative N-terminal hydrophobic sequence and the secreted protein. The diagnostic performance of the recombinants AgB8/1, AgB8/2, Ag4, Ag5, Ag8t and Ag8c was tested in ELISA with 211 sera. The recombinant antigen AgB8/2 showed a sensitivity of 86,95% and a specificity of 96,72% in ELISA, showing the best diagnostic performance in ELISA among all recombinants tested in this work. The two recombinant antigens (AgB8/1 and AgB8/2) did not show cross-reaction with cysticercosis patient sera and the recombinant AgB8/2 was species-specific. The GU4 synthetic peptide showed lower diagnostic performance than the recombinant AgB8/2 which e-terminal portion it mimics

Occurrence of Acanthamoeba in hospitals: a literature review

Acanthamoeba are among the most prevalent environmental protozoans and have a cosmopolitan distribution. The main concern for public health purposes is that they can also be isolated from contact lenses, storage cases and cleaning solutions, ventilation and air conditioning systems, dental treatment units, dialysis units, emergency showers and eyewash stations. These genera include a diversity of pathogenic microorganisms that leads to infectious diseases inside the hospital environment, and it is of the utmost importance to carry out the surveillance, considering mainly the immunocompromised patients, which are more susceptible to these diseases. The level of human health risk and its associations in the hospital environment is unknown, and part of this problem is potentially the lack of correlation between protozoan exposure and symptom onset, which each patient can develop at different periods in time. Studies on the ecology and distribution of non-enteric pathogens in the hospital environment are necessary to understand their potential threat to human health. Thus, this review presents a current overview of the presence of Acanthamoeba spp. in hospital environments aiming to verify their presence in these environments, and look for effective ways to control their presence through disinfection and monitoring measures

Esparganose ocular humana no sul do Brasil

Registra-se o primeiro caso de esparganose ocular humana no estado de Santa Catarina, sul do Brasil a partir de paciente adulta que apresentou três massas inflamatórias móveis perioculares, localizadas no olho direito, durante dois anos. Com a excisão cirúrgica o material foi para a biópsia e um estágio larval de helminto foi identificado como espargano. Dados clínicos, laboratoriais e epidemioógicos são apresentados neste trabalho.We report the first case of human ocular sparganosis in the state of Santa Catarina, southern Brazil. A young female patient presented with three periocular moveable inflammatory masses in her right eye, during two years. By surgical excisional biopsy, a helminth larval stage was removed and identified as sparganum. Clinical, laboratory and epidemiological data on this parasite are presented

First report of free-living amoebae in sewage treatment plants in Porto Alegre, southern Brazil

Free-living amoebae (FLA) are amphizoic protozoans with a cosmopolitan distribution. Some strains of species are associated with infections in humans. They feed on microorganisms by phagocytosis; however, some of these can become endocytobionts by resisting this process and taking shelter inside the amoeba. The whole world is experiencing increasing shortage of water, and sewage is being reused, so the study of this environment is important in public health context. The objective of this work was to identify FLA present in sewage treatment plants in Porto Alegre, Brazil. About 1 L samples were collected from eight stations (raw and treated sewage) in January, February, July, and August 2022. The samples were sown in monoxenic culture, and the isolated amoebae were subjected to morphological and molecular identifi- cation. Polymerase chain reaction results indicated the presence of the genus Acanthamoeba in 100% of the samples. Gene sequencing showed the presence of Acanthamoeba lenticulata and Acanthamoeba polyphaga - T5 and T4 genotypes - respectively, which are related to pathogenicity. The environment where the sewage is released can be used in recreational activities, exposing individuals to potential interactions with these amoebae and their potential endocytobionts, which may pose risks to public health

Sistema e processo de desinfecção solar de fluido em fluxo contínuo

Universidade Federal do Rio Grande do SulCiências Básicas da SaúdePesquisas HidráulicasDepositad

First report of free-living amoebae in watercourses in southern Brazil : molecular diagnosis and phylogenetic analysis of Vermamoeba vermiformis, Naegleria gruberi, and Acanthamoeba spp.

Free-living amoebae (FLA) are protozoa dispersed in different environments and are responsible for different infections caused to humans and other animals. Microorganisms such as Acanthamoeba spp., Vermamoeba sp., and Naegleria sp. are associated with diseases that affect the central nervous system, in addition to skin infections and keratitis, as occurs in the genus Acanthamoeba and with Vermamoeba vermiformis. Due to the concerns of these FLA in anthropogenic aquatic environments, this work aimed to identify these microorganisms present in waters of Porto Alegre, Brazil. One litre sample was collected in two watercourses during the summer of 2022 and inoculated onto non-nutrient agar plates containing heat-inactivated Escherichia coli. Polymerase chain reaction results indicated the presence of FLA of the genera Acanthamoeba, Vermamoeba, and Naegleria in the study areas. Genetic sequencing indicated the presence of V. vermiformis and Naegleria gruberi. These aquatic and anthropogenic environments can serve as a means of spread and contamination by FLA, which gives valuable information on public health in the city

Susceptibility of Acanthamoeba to multipurpose lens-cleaning solutions

The present study investigated the susceptibility of Acanthamoeba spp. trophozoites to two multipurpose systems for cleaning and maintenance of contact lenses. Three strains of trophozoites from the ATCC (A. castellani T4, A. castellani Neff, and A. polyphaga) and two Acanthamoeba isolates obtained from swimming pools (PT5 and PO1) were placed in monoxenic culture. To test their survival in cleaning solutions for contact lenses, the trophozoites were exposed for 4 and 24 h to two multipurpose solutions (A and B), and were then inoculated into a new monoxenic culture. Amoebic growth on the plates was observed after 72 h of incubation. Trophozoites from all three ATCC strains and one isolate from a swimming pool (PO1) grew in all plates after 4 h of exposure to solutions A and B. After 24 h, the ATCC strains and the PO1 isolate showed growth in most of the plates treated. Only the PT5 isolate showed susceptibility to both solutions over the time intervals tested. The two solutions were not completely effective against most strains and isolates over the time intervals tested. These results are important, since species of Acanthamoeba are widely distributed in the environment and are potential agents of eye pathologies

Estudo parasitológico das areias utilizadas para recreação em 3 parques públicos do município de Porto Alegre-RS

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Virulent T4 Acanthamoeba causing keratitis in a patient after swimming while wearing contact lenses in Southern Brazil

Several strains of free-living amoebae belonging to the genus Acanthamoeba can cause a painful sight-threatening disease of the cornea known as Acanthamoeba keratitis (AK). The numbers of AK cases keep rising worldwide mainly due to an increase in contact lens wearers and lack of hygiene in the maintenance of contact lenses and their cases. We report a case of AK in a healthy young woman admitted to the Hospital de Clinicas in Porto Alegre, southern Brazil. Corneal scrapings were examined for the presence of Acanthamoeba strains. The initial isolate was characterized by morphological and genotypic properties. The isolate belonged to group III according to Pussard and Pons’ cyst morphology. Analysis of its 18S rDNA sequence identified the isolate as genotype T4. The T4 genotype is the most commonly reported among keratitis isolates and the most common in environmental samples