Caracterización molecular y fenotípica de aislamientos clínicos de Salmonella Typhimurium variante monofásica (1, 4, [5],12: i: -) recuperados en Colombia / Molecular and phenotypic characterization of Salmonella Typhimurium monophasic variant (1, 4, [5],12: i: -) from Colombian clinical isolates

Resumen: Introducción. La variante monofásica (1,4,[5],12:i:-) de Salmonella Typhimurium ocupa los primeros lugares en los programas de vigilancia de Salmonella a nivel mundial. En Colombia, Salmonella enterica variante monofásica alcanza el cuarto lugar en cuanto a los aislamientos clínicos recuperados por medio de la vigilancia por laboratorio del Grupo de Microbiología del Instituto Nacional de Salud, pero se desconoce si dichos aislamientos están relacionados con la variante monofásica de Typhimurium que circula a nivel global, y con sus características genéticas y fenotípicas. Objetivo. Caracterizar los aislamientos de Salmonella monofásica recuperados en Colombia entre el 2015 y el 2018 por el Grupo de Microbiología del Instituto Nacional de Salud. Materiales y métodos. Se analizaron 286 aislamientos clínicos de Salmonella enterica variante monofásica mediante PCR o secuenciación del genoma completo (Whole Genome Sequencing, WGS) para confirmar si correspondían a Salmonella Typhimurium variante monofásica, en tanto que, en 54 aislamientos, se determinó la estructura genética del operón que codifica la segunda fase flagelar y, en 23, se evaluó la motilidad, el crecimiento y la expresión de las proteínas de membrana externa. Resultados. El 61 % (n=174) de los aislamientos de Salmonella monofásica correspondió a Salmonella Typhimurium serovar monofásico. El 64,8 % (n=35/54) se relacionó con el clon europeo-español y, el 13 % (n=7/54), con el estadounidense. En dos aislamientos de orina se encontró una diferencia significativa en la motilidad y el crecimiento, así como ausencia de la porina OmpD en medio mínimo M9. Conclusiones. En el periodo de estudio, circuló en Colombia la variante monofásica de Salmonella Typhimurium relacionada con el clon europeo-español, y se registró ausencia total del operón fljAB. Los resultados evidenciaron cambios fenotípicos en los aislamientos provenientes de muestras de orina que sugieren adaptación en procesos invasivos.

Abstract: Introduction. The Salmonella Typhimurium monophasic variant (1,4,[5],12:i:-) is currently the most commonly detected variant in Salmonella surveillance programs worldwide. In Colombia, the Salmonella enterica monophasic variant is the fourth most common clinical isolate recovered through the laboratory surveillance of the Grupo de Microbiología from the Instituto Nacional de Salud; however, it is unknown whether these isolates are closely related to the monophasic Typhimurium variant, which circulates globally, and their genetic and phenotypic characteristics have not been reported. Objective. To characterize monophasic Salmonella enterica isolates identified in Colombia from 2015 to 2018 by the Instituto Nacional de Salud. Materials and methods. Two hundred eighty-six clinical isolates of the monophasic Salmonella enterica variant were analyzed by PCR or whole-genome sequencing to confirm whether they corresponded to the Salmonella Typhimurium monophasic variant while the genetic structure of the operon encoding the second flagellar phase was determined in 54 isolates. Motility, growth, and expression of the outer membrane proteins were evaluated in 23 isolates. Results. During the study period in Colombia, 61% (n=174) of Salmonella monophasic isolates belonged to Salmonella Typhimurium serovar monophasic (1,4,[5],12:i-). Of these, 64.8% (n=35/54) were related to the European/Spanish clone and 13% (n=7/54) to the U.S. clone. Two isolates recovered from urine samples showed differences in motility, growth, and the absence of the OmpD porin in M9 minimal medium. Conclusions. Most of the monophasic Salmonella Typhimurium variants that have circulated in Colombia since 2015 lacked the second phase of operon fljAB, which is related to the European/Spanish clone. The results evidenced phenotypic changes in urine samples suggesting bacterial adaptation in the case of these invasive samples.

Contribution of flagella and motility to gut colonisation and pathogenicity of Salmonella Enteritidis in the chicken

ABSTRACT Salmonella Enteritidis causes fowl paratyphoid in poultry and is frequently associated to outbreaks of food-borne diseases in humans. The role of flagella and flagella-mediated motility into host-pathogen interplay is not fully understood and requires further investigation. In this study, one-day-old chickens were challenged orally with a wild-type strain Salmonella Enteritidis, a non-motile but fully flagellated (SE ΔmotB) or non-flagellated (SE ΔfliC) strain to evaluate their ability to colonise the intestine and spread systemically and also of eliciting gross and histopathological changes. SE ΔmotB and SE ΔfliC were recovered in significantly lower numbers from caecal contents in comparison with Salmonella Enteritidis at early stages of infection (3 and 5 dpi). The SE ΔmotB strain, which synthesises paralysed flagella, showed poorer intestinal colonisation ability than the non-flagellated SE ΔfliC. Histopathological analyses demonstrated that the flagellated strains induced more intense lymphoid reactivity in liver, ileum and caeca. Thus, in the present study the flagellar structure and motility seemed to play a role in the early stages of the intestinal colonisation by Salmonella Enteritidis in the chicken.

Are Aedes aegypti mosquitoes potential vectors for leishmaniasis? ­ Case report / Mosquitos Aedes aegypti são vetores potenciais de leishmaniose? ­ Relato de caso

In Brazil dipters of the Lutzomyia genus are the main vectors of leishmaniasis for humans and animals. However, other hematophagous insects such as ticks, fleas, and horse flies may also be considered potential vectors of this protozoon. This paper, regarding an endemic area for visceral leishmaniasis, is the the first description of the Leishmania spp. presence in Aedes aegypti mosquitoes. Two A. aegypti mosquitoes were captured: one of them was feeding on a polysymptomatic dog with leishmaniasis, confirmed by parasitic demonstration and positive PCR for Leishmania spp., and the other was collected in the environment where the dog was isolated. The mosquito engorged with dog's blood was crushed between two microscopic slides and the other one was processed by the polymerase chain reaction assay (PCR) searching for the presence of Leishmania spp. DNA. Amastigote forms of Leishmania sp, were observed in the smear prepared from one mosquito by microscopic examination, as well as other protozoa's flagellated forms. In the other insect it was observed Leishmania DNA amplification. This observation reinforces the role of dogs as sources of infection of Leishmania spp. even to other potential vector species.(AU)

No Brasil, os dípteros do gênero Lutzomyia são os principais vetores da leishmaniose para humanos e animais. No entanto, tem sido constatado que outras espécies de invertebrados hematófagos, como carrapatos, pulgas e mutucas, também podem ser vetores desse protozoário. Este trabalho, realizado em uma área endêmica de leishmaniose visceral, é a primeira descrição da presença de Leishmania spp. em mosquitos da espécie A. aegypti. Dois mosquitos A. aegypti foram capturados no local onde estava isolado um cão polissintomático acometido por leishmaniose visceral, confirmada pela demonstração do parasita em biópsias de órgãos e por resultado positivo na prova de PCR para Leishmania spp. Um dos mosquitos estava sugando o sangue do cão e o outro estava livre no ambiente. O mosquito ingurgitado com o sangue do animal foi esmagado entre duas lâminas de microscopia e o outro foi processado por meio da reação em cadeia pela polimerase (PCR) aplicada à pesquisa do ADN de Leishmania spp. Ao exame microscópico do esfregaço preparado com o mosquito que estava parasitando o cão foram observadas formas amastigotas de Leishmania spp., bem como formas flageladas de outra espécie de protozoário. No outro inseto foi detectada amplificação de ADN do gênero Leishmania. Esta constatação reforça o papel dos cães como fontes de infecção de Leishmania spp. até mesmo para outras espécies de vetores potenciais.(AU)

JVG9, a benzimidazole derivative, alters the surface and cytoskeleton of Trypanosoma cruzi bloodstream trypomastigotes

Trypanosoma cruzi has a particular cytoskeleton that consists of a subpellicular network of microtubules and actin microfilaments. Therefore, it is an excellent target for the development of new anti-parasitic drugs. Benzimidazole 2-carbamates, a class of well-known broad-spectrum anthelmintics, have been shown to inhibit the in vitro growth of many protozoa. Therefore, to find efficient anti-trypanosomal (trypanocidal) drugs, our group has designed and synthesised several benzimidazole derivatives. One, named JVG9 (5-chloro-1H-benzimidazole-2-thiol), has been found to be effective against T. cruzi bloodstream trypomastigotes under both in vitro and in vivo conditions. Here, we present the in vitro effects observed by laser scanning confocal and scanning electron microscopy on T. cruzi trypomastigotes. Changes in the surface and the distribution of the cytoskeletal proteins are consistent with the hypothesis that the trypanocidal activity of JVG9 involves the cytoskeleton as a target.

Protozoans bacterivory in a subtropical environment during a dry/cold and a rainy/warm season

In aquatic ecosystems, bacteria are controlled by several organisms in the food chain, such as protozoa, that use them as food source. This study aimed to quantify the ingestion and clearance rates of bacteria by ciliates and heterotrophic nanoflagellates (HNF) in a subtropical freshwater reservoir (Monjolinho reservoir -São Carlos -Brazil) during one year period, in order to verify their importance as consumers and controllers of bacteria in two seasons, a dry/cold and a rainy/warm one. For this purpose, in situ bacterivory experiments were carried out bimonthly using fluorescently labeled bacteria with 5-(4,6 diclorotriazin-2yl) aminofluorescein (DTAF). Although ciliates have shown the highest individual ingestion and clearance rates, bacterivory was dominated by HNF, who showed higher population ingestion rates (mean of 9,140 bacteria h-1mL-1) when compared to ciliates (mean of 492 bacteria h-1mL-1). The greater predation impact on bacterial communities was caused mainly by the small HNF (< 5 µm) population, especially in the rainy season, probably due to the abundances of these organisms, the precipitation, trophic index state and water temperature that were higher in this period. Thus, the protozoan densities together with environmental variables were extremely relevant in determining the seasonal pattern of bacterivory in Monjolinho reservoir.

Rapid and sensitive detection of Bordetella bronchiseptica by loop-mediated isothermal amplification (LAMP)

Bordetella bronchiseptica causes acute and chronic respiratory infections in diverse animal species and occasionally in humans. In this study, we described the establishment of a simple, sensitive and cost-efficient loop-mediated isothermal amplification (LAMP) assay for the detection of B. bronchiseptica. A set of primers towards a 235 bp region within the flagellum gene of B. bronchiseptica was designed with online software.. The specificity of the LAMP assay was examined by using 6 porcine pathogens and 100 nasal swabs collected from healthy pigs and suspect infected pigs. The results indicated that positive reactions were confirmed for all B. bronchiseptica and no cross-reactivity was observed from other non-B. bronchiseptica. In sensitivity evaluations, the technique successfully detected a serial dilutions of extracted B. bronchiseptica DNA with a detection limit of 9 copies, which was 10 times more sensitive than that of PCR. Compared with conventional PCR, the higher sensitivity of LAMP method and no need for the complex instrumentation make this LAMP assay a promising alternative for the diagnosis of B. bronchiseptica in rural areas and developing countries where there lacks of complex laboratory services.

Structural analysis of flagellar axonemes from inner arm dynein knockdown strains of Trypanosoma brucei

Trypanosoma brucei is a protozoan flagellate that causes African sleeping sickness. Flagellar function in this organism is critical for life cycle progression and pathogenesis, however the regulation of flagellar motility is not well understood. The flagellar axoneme produces a complex beat through the precisely coordinated firing of many proteins, including multiple dynein motors. These motors are found in the inner arm and outer arm complexes. We are studying one of the inner arm dynein motors in the T. brucei flagellum: dynein-f. RNAi knockdown of genes for two components of dynein-f: DNAH10, the a heavy chain, and IC138, an intermediate chain, cause severe motility defects including immotility. To determine if motility defects result from structural disruption of the axoneme, we used two different flagellar preparations to carefully examine axoneme structure in these strains using transmission electron microscopy (TEM). Our analysis showed that inner arm dynein size, axoneme structural integrity and fixed central pair orientation are not significantly different in either knockdown culture when compared to control cultures. These results support the idea that immotility in knockdowns affecting DNAH10 or IC138 results from loss of dynein-f function rather than from obvious structural defects in the axoneme.

Trypanosoma rangeli protein tyrosine phosphatase is associated with the parasite's flagellum

Protein tyrosine phosphatases (PTPs) play an essential role in the regulation of cell differentiation in pathogenic trypanosomatids. In this study, we describe a PTP expressed by the non-pathogenic protozoan Trypanosoma rangeli (TrPTP2). The gene for this PTP is orthologous to the T. brucei TbPTP1 and Trypanosoma cruzi (TcPTP2) genes. Cloning and expression of the TrPTP2 and TcPTP2 proteins allowed anti-PTP2 monoclonal antibodies to be generated in BALB/c mice. When expressed by T. rangeli epimastigotes and trypomastigotes, native TrPTP2 is detected as a ~65 kDa protein associated with the parasite's flagellum. Given that the flagellum is an important structure for cell differentiation in trypanosomatids, the presence of a protein responsible for tyrosine dephosphorylation in the T. rangeli flagellum could represent an interesting mechanism of regulation in this structure.

Secondary zoospores in the algal endoparasite Maullinia ectocarpii (Plasmodiophoromycota)

The present paper deals with the ultrastructure of zoospores produced by the plasmodiophorid Maullinia ectocarpii, living in the marine algal host Ectocarpus siliculosus. The zoospores described here are very similar to secondary zoospores of Polymyxa graminis and Phagomyxa sp. (the latter an algal endoparasite, also). Our results indicate that M. ectocarpii produces two types of plasmodia, and suggest that is a species with a complete life cycle, as it is known for all the Plasmodiophormycota that have been studied. Sporogenic and sporangial plasmodia produce, respectively, primary zoospores with parallel flagella within thick walled resting sporangia, and secondary zoospores with opposite flagella within thin walled sporangia.

Proliferation and bystander suppression induced by membrane and flagellar antigens of Trypanosoma cruzi

We have studied, in vitro, proliferation induced by flagella (FE) and membrane (ME) antigenic fractions of T. cruzi epimastigotes, as well as their regulatory effect on the proliferative response to PPD (Protein Purified Derivative). Crude flagella as well as bands from Western blots of flagella and membrane of epimastigotes were tested. Crude flagella elicited higher proliferation in mononuclear cells from patients with Chagasic cardiomyopathy (CDM) than in patients with no evidence of cardiac pathology (INF). Fractionated antigens induced a lower proliferative response, in intensity as well as in frequency, than the crude extracts. With FE, bands between 150 and 24.3 kDa (B3 to B18 with the exception of B4 and B13) induced higher CPM (Counts Per Minute) in CDM. In INF only bands B7 (87.3 to 80.1 kDa), 9 (69.8 to 64.6 kDa) and 13 (45.4 to 41.5 kDa) had high CPM. ME bands also elicited higher proliferation in CDM. However, only 5 out of 14 bands gave CPM higher than 1000 in CDM and none in INF. The mean down regulation (DR) of most bands was similar in both groups. But the frequency of relevant DR elicited by FE was significantly higher in CDM. In contrast the frequency of up regulation (UR) was higher in INF. Bands 13 and 14 of ME did not induce DR in most INF. The discordance between the frequency of relevant DR in CDM and INF was more evident with ME than with FE. The frequency of (UR) was 50% or higher with all ME bands in INF, but, lower than 12% in CDM. The higher UR in INF and of DR in CDM, suggest the presence of some balance or interaction in INF that is lost in CDM. In ME there might be antigens that could be relevant for the immunoprofilaxis of Chagas' disease. The difference in the clinical status of the two groups seems to be associated with the recognition of different groups of antigens together with variations in the nature of the regulation of the response of mononuclear cells to these antigens.

Hemos estudiado, in vitro, la respuesta proliferativa de células mononucleares a antígenos de Flagelo (FE) y Membrana (ME) de epimastigotes de T. cruzi, así como su efecto regulador en la respuesta proliferativa a PPD (Protein Purified derivative). Fue evaluada tanto la respuesta a Flagelo crudo como a las bandas de Western blots de FE y ME. El flagelo crudo indujo una proliferación de las células mononucleares más intensa en los pacientes con cardiomiopatía (CDM) que en los pacientes sin evidencia de patología cardiaca (INF). Los antígenos fraccionados causaron una menor respuesta proliferativa, tanto en intensidad como en frecuencia, que los antígenos crudos. Las bandas de FE, entre 150 y 24,3 kDa (B3 a B18 con la excepción de B4 y B13), indujeron CPM mas altas en CDM. En INF solo las bandas B7 (87,3 a 80,1 kDa), 9 (69,8 a 64,6 kDa) y 13 (45,4 a 41,5 kDa) causaron CPM (Cuentas Por Minuto) altas. Las bandas de ME también indujeron una proliferación mayor en CDM. Sin embargo, solo 5 de 14 bandas tuvieron CPM promedio mayores de 1000 en INF. La mayor parte de las bandas causaron una baja regulación (BR) que fue similar en ambos grupos. Sin embargo, la frecuencia de BR relevante producida por FE fue significativamente mayor en CDM. Por el contrario la sobre regulación (SB) fue mayor en INF. Las bandas 13 y 14 de ME no indujeron BR en la mayor parte de los INF. La discordancia entre la frecuencia de BR relevante en CDM e INF fue mas evidente con ME que con FE. La frecuencia de SB fue 50% o mas con todas las bandas de ME en INF, pero menor que 12% en los CDM. El predominio de SB en INF y de BR en CDM sugiere la presencia, en los INF, de algún tipo de equilibrio o interacción que esta ausente en los CDM. En ME pudieran estar presente antígenos relevantes para la inmunoprofilaxis de la enfermedad de Chagas. En conjunto nuestros resultados sugieren que las diferencias en los cuadros clínicos pudieran tener relación con la respuesta observada a los diferentes...

Actin-interacting and flagellar proteins in Leishmania spp: bioinformatics predictions to functional assignments in phagosome formation

Several motile processes are responsible for the movement of proteins into and within the flagellar membrane, but little is known about the process by which specific proteins (either actin-associated or not) are targeted to protozoan flagellar membranes. Actin is a major cytoskeleton protein, while polymerization and depolymerization of parasite actin and actin-interacting proteins (AIPs) during both processes of motility and host cell entry might be key events for successful infection. For a better understanding the eukaryotic flagellar dynamics, we have surveyed genomes, transcriptomes and proteomes of pathogenic Leishmania spp. to identify pertinent genes/proteins and to build in silico models to properly address their putative roles in trypanosomatid virulence. In a search for AIPs involved in flagellar activities, we applied computational biology and proteomic tools to infer from the biological meaning of coronins and Arp2/3, two important elements in phagosome formation after parasite phagocytosis by macrophages. Results presented here provide the first report of Leishmania coronin and Arp2/3 as flagellar proteins that also might be involved in phagosome formation through actin polymerization within the flagellar environment. This is an issue worthy of further in vitro examination that remains now as a direct, positive bioinformatics-derived inference to be presented.

Intraflagellar transport complex in Leishmania spp. In silico genome-wide screening and annotation of gene function

Flagella are constructed and maintained through the highly conserved process of intraflagellar transport (IFT), which is a rapid movement of particles along the axonemal microtubules of cilia/flagella. Particles that are transported by IFT are composed of several protein subunits comprising two complexes (A and B), which are conserved among green algae, nematodes, and vertebrates. To determine whether or not homologues to members of the IFT complex proteins are conserved in Leishmania spp, we scanned genomes, transcriptomes and proteomes of Leishmania species in a search for putative IFT factors, which were then identified in silico, compared, cataloged, and characterized. Since a large proportion of newly identified genes in L. major remain unclassified, with many of these being potentially Leishmania- (or kinetoplastid-) specific, there is a need for detailed analyses of homologs/orthologs that could help us understand the functional assignment of these gene products. We used a combination of integrated bioinformatics tools in a pathogenomics approach to contribute to the annotation of Leishmania genomes, particularly regarding flagellar genes and their roles in pathogenesis. This resulted in the formal in silico identification of eight of these homologs in Leishmania (IFT subunits, 20, 27, 46, 52, 57, 88, 140, and 172), along with others (IFTs 71, 74/72, and 81), as well as sequence comparisons and structural predictions. IFT, an important flagellar pathway in Leishmania, begins to be revealed through screening of trypanosomatid genomes; this information could also be used to better understand fundamental processes in Leishmania, such as motility and pathogenesis.

Chemotaxis and flagellar genes of Chromobacterium violaceum

The availability of the complete genome of the Gram-negative beta-proteobacterium Chromobacterium violaceum has increasingly impacted our understanding of this microorganism. This review focuses on the genomic organization and structural analysis of the deduced proteins of the chemosensory adaptation system of C. violaceum. C. violaceum has multiple homologues of most chemotaxis genes, organized mostly in clusters in the bacterial genome. We found at least 67 genes, distributed in 10 gene clusters, involved in the chemotaxis of C. violaceum. A close examination of the chemoreceptors methyl-accepting chemotaxis proteins (MCPs), and the deduced sequences of the members of the two-component signaling system revealed canonical motifs, described as essential for the function of the deduced proteins. The chemoreceptors found in C. violaceum include the complete repertoire of such genes described in bacteria, designated as tsr, tar, trg, and tap; 41 MCP loci were found in the C. violaceum genome. Also, the C. violaceum genome includes a large repertoire of the proteins of the chemosensory transducer system. Multiple homologues of bacterial chemotaxis genes, including CheA, CheB, CheD, CheR, CheV, CheY, CheZ, and CheW, were found in the C. violaceum genome

Sperm ultrastructure and spermatogenesis in the lizard, Tropidurus itambere

Spermatogenesis, with emphasis on spermiogenesis, is described for the lizard, Tropidurus itambere, using light microscopy, phase contrast and epifluorescence, as well as scanning and transmission electron microscopy. Cellular differentiation involves events of chromatin condensation, nuclear elongation and the formation of structural complexes, such as the acrosomal and axonemal ones. Other new characteristics, exclusive for this species, include various aspects of the subacrosomal granule, the insertion of the pro-acrosomal vesicle and the development of these structures to participate in the acrosomal complex. Radial projections occurjust above the nuclear shoulders, which have been recognized already from the beginning of cellular elongation. The development of the midpiece, the dense bodies, formation of the flagellum and elimination of residual cytoplasm result in the final characterization of the mature spermatozoon. Comparisons between Tropiduridae and other lizard families are made.

Morphological study of the spermatogenesis in the teleost Piaractus mesopotamicus

The spermatogenesis of Piaractus mesopotamicus was investigated under light and transmission electron microscopy. The specimens were captured from their natural environment (Rio Miranda and Rio Aquidauana, Pantanal Matogrossense, Brazil) during April and September. The results were compared with the spermatogenic data of specimens under captivity condition. In both conditions, P. mesopotamicus presented the typical spermatogenesis pattern of the teleost fishes, showing no significative differences. The spermatozoon was classified as type I, which has a globular head without acrosome, a short middle piece and a long tail constituted only by the flagellum. This type of spermatozoon is considered the basic type in fishes.

Perspective of a new diagnostic for human trichomonosis

Several diagnostic techniques have been employed for the detection of Trichomonas vaginalis. Microtubules constitute the cytoskeleton in eukaryotic cells and are sensitive to antimitotic drugs, such as Taxol (paclitaxel). We used FLUTAX a fluorescent taxoid - to analyze the microtubule distribution in living trophozoites of T. vaginalis in urine and in vaginal discharge. A high intensity of fluorescence was observed in living T. vaginalis, epithelial cells and leukocytes present in urine and vaginal discharge. Our preliminary results show the perspective of a new diagnostic technique for trichomonosis and will contribute to the understanding of the cytoskeleton of T. vaginalis

Immuno and cytochemical localization of Trypanosoma cruzi nitric oxide synthase

The localization and subcellular distribution of Trypanosoma cruzi nitric oxide synthase was investigated in epimastigote cells by immunocytochemistry at electron and light microscope level, using a polyclonal antibody to neuronal nitric oxide synthase, and also, at light microscope level, by the nicotinamide adenine dinucleotide phosphate-diaphorase histochemical reaction. The immunoreactivity was ultrastructurally localized by electron microscopy in the inner surface of cell membranes and in free cytosolic clusters in the body, flagellum and apical extreme. Light microscopy showed that immunoprecipitates, specific for the Trypanosoma cruzi nitric oxide synthase, co-localized with the formazan precipitates generated by the diaphorase reaction in the same areas identified by electron microscopy. These results, taken together with previous finding from our laboratory could help to explain the involvement of the nitric oxide transduction pathway in T. cruzi epimastigote motility.

Expressäo do flagelo em sorotipos imóveis de Escherichia coli enteroinvasora / Expression of the non motile flagellum in enteroinvasive Escherichia coli serotypes

No presente estudo, a observação de dez sorotipos imóveis de EIEC em microscópio eletrônico levou à descoberta de flagelos em todos os sorotipos estudados, em quantidades que variaram de um a cinco filamentos. A produção do flagelo de EIEC (FLIEC) não foi influenciada pela temperatura, mas o nível de expressão dependeu da cepa e do meio. A maioria das cepas foi móvel em meios de cultura com baixa porcentagem de ágar (0,17-02 por cento). A preparação parcialmente purificada contendo FLIEC, identificado pela ME, foi submetida à técnica de SDS-PAGE. Uma banda de 77kDa, que é relativamente maior do que a massa molecular das flagelinas de outras bactérias entéricas, foi encontrada nessa preparação. Essa banda reagiu com vários soros anti-flagelina de diferentes anterobactérias...

Participacion de epitopes flagelares de Campylobacter jejuni en la adhesion celular / Partipation of Campylobacter jejuni flagellar epitopes in cellular adhesion

Utilizando una cepa flagelada (052) y una aflagelada (T-1), se estudió la participación de epítopes flagelares de C. jejuni en la adhesión a células HEp-2 in vitro. La cepa 052 presentó una capacidad de adhesion significativamente mayor que la cepa T-1. Cuando los ensayos de adhesión fueron realizados en presencia de anticuerpos monoclonales dirigidos contra epítopes flagelares, la capacidad de adhesión de la cepa 052 experimentó una inhibición que fluctuó entre 64,3 y 92,9 por ciento. Mediante una prueba de ELISA se comprobó que estos anticuerpos monoclonales eran específicos y estaban dirigidos exclusivamente contra epítopes flagelares de la cepa 052, no reaccionando con la cepa T-1. Estos resultados demuestran que epítopes flagelares de C. jejuni estarían participando en el proceso de adhesión, sugiriendo la intervención del flagelo en la instalación del proceso infeccioso.