Eimeria proteins: order amidst disorder.

Apicomplexans are important pathogens that cause severe infections in humans and animals. The biology and pathogeneses of these parasites have shown that proteins are intrinsically modulated during developmental transitions, physiological processes and disease progression. Also, proteins are integral components of parasite structural elements and organelles. Among apicomplexan parasites, Eimeria species are an important disease aetiology for economically important animals wherein identification and characterisation of proteins have been long-winded. Nonetheless, this review seeks to give a comprehensive overview of constitutively expressed Eimeria proteins. These molecules are discussed across developmental stages, organelles and sub-cellular components vis-à-vis their biological functions. In addition, hindsight and suggestions are offered with intention to summarise the existing trend of eimerian protein characterisation and to provide a baseline for future studies.

The effect of iron on Trichomonas vaginalis TvCP2: a cysteine proteinase found in vaginal secretions of trichomoniasis patients.

Trichomonas vaginalis (Tv) induces host cell damage through cysteine proteinases (CPs) modulated by iron. An immunoproteomic analysis showed that trichomoniasis patient sera recognize various CPs, also some of them are present in vaginal washes (VWs). Thus, the goal of this work was to determine whether TvCP2 is expressed during infection and to assess the effect of iron on TvCP2 expression, localization and contribution to in vitro cellular damage. Western-blotting (WB) assays using TvCP2r and vaginitis patient serum samples showed that 6/9 Tv (+) but none of the Tv (-) patient sera recognized TvCP2r. WB using an anti-TvCP2r antibody and VWs from the same patients showed that in all of the Tv (+) but none of the Tv (-) VWs, the anti-TvCP2r antibody detected a 27 kDa protein band that corresponded to the mature TvCP2, which was confirmed by mass spectrometry analysis. Iron decreased the amount of TvCP2 mRNA and the protein localized on the parasite surface and cytoplasmic vesicles concomitant with the cytotoxic effect of TvCP2 on HeLa cells. Parasites pretreated with the anti-TvCP2r antibody also showed reduced levels of cytotoxicity and apoptosis induction in HeLa cell monolayers. In conclusion, these results show that TvCP2 is expressed during trichomonal infection and plays an important role in the in vitro HeLa cell cytotoxic damage under iron-restricted conditions.

Signaling Cascades Governing Entry into and Exit from Host Cells by Toxoplasma gondii.

The Apicomplexa phylum includes a large group of obligate intracellular protozoan parasites responsible for important diseases in humans and animals. Toxoplasma gondii is a widespread parasite with considerable versatility, and it is capable of infecting virtually any warm-blooded animal, including humans. This outstanding success can be attributed at least in part to an efficient and continuous sensing of the environment, with a ready-to-adapt strategy. This review updates the current understanding of the signals governing the lytic cycle of T. gondii, with particular focus on egress from infected cells, a key step for balancing survival, multiplication, and spreading in the host. We cover the recent advances in the conceptual framework of regulation of microneme exocytosis that ensures egress, motility, and invasion. Particular emphasis is given to the trigger molecules and signaling cascades regulating exit from host cells.

Towards a noninvasive approach to malaria diagnosis: detection of parasite DNA in body secretions and surface mucosa.

Invasive procedures for diagnostic or therapeutic purposes bear a relative risk of transmission of serious blood-borne infectious disease. In this study, a noninvasive approach to malaria diagnosis using polymerase chain reaction (PCR) for the detection of parasite DNA in saliva, buccal mucosa and urine (alternative samples) was examined. Saliva, buccal mucosa and urine samples were collected simultaneously with blood samples from 93 patients with microscopically confirmed Plasmodium falciparum infection. Species-specific primers detected the parasite DNA only in blood samples. However, when the PCR analysis was repeated using MSP1 and MSP2 primers in a subgroup of 21 complete sets of samples, the parasite DNA was detected in all except 3 samples, which were found to be negative with the MSP2 primers. Parasite density, body temperature or patient age did not influence the PCR results. In conclusion, P. falciparum parasite DNA was detected equally in saliva, buccal mucosa and urine of malaria patients, regardless of their ages, body temperatures or parasite density. Surprisingly, the parasite DNA was not amplified by species-specific primers in the alternative samples whereas it was in the blood samples.

Hallazgo simultáneo de microsporidios en secreciones respiratorias y heces de niños de corta edad / Simultaneous detection of microsporian spores in respiratory secretions and in stool specimens of toddlers

Se efectuó un estudio prospectivo de 70 niños de 1 a 24 meses de edad, con baja probabilidad de infección por HIV, 35 con patologías respiratorias infecciosas y 35 sin ellas. Estuvo dirigido a detectar ocurrencia contemporánea de esporas de microsporidios en secreciones respiratorias (SR) y heces (H), empleando métodos desarrollados para microscopía óptica (coloraciones de Weber modificado por Kokoskin y de Ziehl-Neelsen Acid-Fast modificado por los autores). En el primer grupo fueron positivos en SR 11/35 niños (31,4 por ciento), de los cuales 7/11 (63,6 por ciento) también mostraron esporas en H. En el segundo grupo fueron positivos en SR 8/35 (22,9 por ciento), de los cuales 5/8 (62,5 por ciento) lo fueron en H. En ambos grupos la prevalencia de microsporidios en SR fue importante, sin diferencia estadística significativa entre ellos, y fue destacada la simultaneidad de hallazgos en SR y H en ambos grupos. Conclusiones: 1) una de las especies de microsporidios, o quizás más, probablemente son parásitos naturales y habituales del aparato respiratorio de seres humanos inmunológicamente sanos, como acontece para el aparato digestivo y 2) cuando está presente una infección respiratoria por microsporidios en éstos sujetos, sería un hecho común que simultáneamente se detecten esporas de éstos organismos en sus heces (AU)

Filamentous fungi from aids patient secretions and from the environmental air in hospital

Mediante la toma de muestras de secreciones orofaringeas, nasales y del oído externo de 50 pacientes con sindrome de inmunodeficiencia adquirida (SIDA-AIDS) y del aire de las salas de tratamiento de los mismos, se obtuvieron 238 muestras: 87 de las secreciones y 151 del aire. Se aislaron 29 spp. de hongos filamentosos de los especímenes clínicos y 38 del aire. En las secreciones de los pacientes, el grupo forma: mycelia sterilia, y fusarium oxysporum, f. lateritium, aspergillus parasiticus, fueron los hyphomycetes más representativos y los géneros aspergillus y fusarium constituyeron el 47 porciento de los aislamientos en proporciones semejantes. En el ambiente hospitalario, el grupo forma mycelia sterilia y las especies c. sphaerospermum, aspergillus sydowii y c. cladosporioides fueron los hyphomycetes más representativos y los géneros aspergillus y penicillium constituyeron el 47,7 porciento de los aislamientos. Los taxa más comunes que se presentaron al mismo tiempo en los pacientes como en su ambiente fueron: mycelia sterilia, c. sphaerospermum, a. sydowii, a. restrictus y p. implicatum