Citopatogenicidade de Trichomonas vaginalis: uma via de sinalização carboidrato-dependente / Trichomonas vaginalis' pathogenic effect and cell signaling in a carbohydrate-dependent manner

Trichomonas vaginalis é um agente infectante da microbiota vaginal que vem sendo correlacionado ao câncer cervical. Um receptor denominado alectina-1 (Gal 1) pode ser expresso em células epiteliais cervicais humanas se ligando à glicofosfolipídica (LPG) de T. vaginalis. A interação de T. vaginalis com as células epiteliais é mediada por cadeias galactose e N-acetilglucosamina (LacNac). Gal 1 se liga aos sítios poly-LacNAC e está relacionada com a aderência de T. vaginalis à célula humana. A sinalização ocorre por intermédio de sítios da proteína Src (SH2) que se associam, ocorrendo sob os domínios de PI3K que fosforilam a membrana de lípides fosfatidilinositol (PIP e PIP2). Aderindo-se às membranas citoplasmáticas e secretando enzimas, T. vaginalis pode ocasionar a ruptura do envoltório celular podendo fagocitar células epiteliais em meio vaginal. O núcleo N-acetilactosamina de Gal 1 pode mediar a regulação do crescimento celular com a ajuda da proteína GRB2; entretanto, Gal 1 pode contribuir para a supressão da inflamação por meio da indução de apoptose pelas células T ativadas. (AU)

Trichomonas vaginalis is an infectious agent of the vaginal flora which has been associated with cervical cancer. Galectin-1 (Gal 1) is a cell receptor expressed in cervical epithelial cells binding T. vaginalis? lipophosphoglican (LPG). Interaction between T. vaginalis and the epithelial cell is mediated by poly-LacNac domains (galactoside and acetil-lactosamin) and is related to cell adherence as well. Cell signaling occurs by the time Src (SH2) domains are correlated with this interaction and PI3K phosphorilation brings up phosphatidil inositol lipid membranes (PIP and PIP2). T. vaginalis adheres to cytoplasm membrane and secrets specific enzymes that probably lead to membrane rupture. Moreover this parasite may phagocyte epithelial cells in vaginal discharge. Gal 1 nucleus called N-acetil-lactosamin can mediate growth development through GRB2 protein and may contribute to inflammation suppression owing to apoptosis induction of activated T cells.(AU)

The Dimension of Trichomonas vaginalis as Measured by Scanning Electron Microscopy

It is known that physicochemical conditions (e.g., pH, temperature, and ionic strength) affect the size of trichomonads. In this study, the sizes of 4 isolates of Trichomonas vaginalis cultured for more than a year (called "old T") and 3 isolates freshly isolated from vaginitis cases (called "fresh T") were compared by scanning electron microscopy. Although the fresh T had shorter body length, body width, and flagellar length than old T, total length (about 26 microm), including body length, flagella length, and axostyle length was almost the same in the 2 groups. A striking difference was observed between the axostyles of the 2 groups; the axostyle length of the fresh T (8.2 microm) was more than twice as long as that of the old T (4.0 microm). However, in several parasitology textbooks, the length of T. vaginalis is said to vary widely from 7 to 32 microm, and its undulating membrane is said to extend about half way (53.5%) to the posterior end of the body. On the other hand, in our study, the undulating membrane was observed to extend more than 3/4 of the body length (72.1%) in old T, whereas in fresh T it could not be measured. Taken together, we suggest that T. vaginalis averages 26 (21-32) microm in total length, with 9.5 (7.4-11.4) microm of body length and 6.8 (5.3-7.7) microm of width, and its undulating membrane extending 3/4 of its body length. Therefore, these findings may provide useful information for morphological characteristics of T. vaginalis.

Trichomonas vaginalis and trichomoniasis in the Republic of Korea

Vaginal trichomoniasis, caused by Trichomonas vaginalis, is the most common sexually transmitted disease. More than 170 million people worldwide are annually infected by this protozoan. In the Republic of Korea, 10.4% of women complaining of vaginal symptoms and signs were found to be infected with T. vaginalis. However, despite its high prevalence, the pathogenesis of T. vaginalis infection has not been clearly characterized although neutrophil infiltration is considered to be primarily responsible for the cytologic changes associated with this infection. We hypothesized that trichomonads in the vagina sometime after an acute infection secrete proteins like excretorysecretory product that have a chemotactic effect on neutrophils, and that these neutrophils are further stimulated by T. vaginalis to produce chemokines like IL-8 and GRO-alpha, which further promote neutrophil recruitment and chemotaxis. Thus, neutrophil accumulation is believed to maintain or aggravate inflammation. However, enhanced neutrophil apoptosis induced by live T. vaginalis could contribute to resolution of inflammation. Macrophages may constitute an important component of host defense against T. vaginalis infection. For example, mouse macrophages alone and those activated by lymphokines or nitric oxide are known to be involved in the extracellular killing of T. vaginalis. In the host, T. vaginalis uses a capping phenomenon to cleave host immunoglobulins with proteinases and thus escape from host immune responses. Recently, we developed a highly sensitive and specific diagnostic polymerase chain reaction (PCR) technique using primers based on a repetitive sequence cloned from T. vaginalis (TV-E650), and found that the method enables the detection of T. vaginalis at concentrations as low as 1 cell per PCR mixture.

Frecuencia de tricomonas vaginalis detectadas mediante papanicolaou en cuatro servicios de salud, 1997-2002 / Frequency of Tricomonas vaginalis detected by means of Papanicolaou in four Services of Health, 1997-2002

La tricomonosis es una de las infecciones de transmisión sexual más frecuentes en el mundo. El Papanicolaou (PAP) no constituye el examen de elección para su diagnóstico, sin embargo, es frecuente el hallazgo del parásito en muestras obtenidas de población en control ginecológico. Para establecer la frecuencia de Tricomonas vaginalis en los PAP procedentes de los Servicios de Salud de Atacama, Metropolitano Norte, Oriente y Bío-Bío se realizó un análisis retrospectivo de 504.638 muestras entre los años 1997 y 2002. Los resultados demostraron la presencia del parásito en 20.270 muestras, (4,0 por ciento). En los 5 años estudiados se observó una tendencia a la disminución de la frecuencia de T. vaginalis de 4,96 por ciento a 3,31 por ciento en todos los Servicios de Salud. El grupo etario de 30-39 años fue el más afectado. Se discute la utilidad del PAP como método diagnóstico, los factores que pudieran incidir en la tendencia observada y las diferencias encontradas entre los servicios. Se concluye que la frecuencia de T. vaginalis disminuyó en los Servicios de Salud estudiados, y que la técnica de Papanicolaou permitió identificar a T. vaginalis, como también efectuar estudios de prevalencia y tratar los casos pesquisados.

Strategies by which some pathogenic trichomonads integrate diverse signals in the decision-marking process

The interaction between each one of Trichomonas vaginalis and Tritrichomonas foetus with their hosts is a complex process in which components associated to the cell surfaces of both parasites and host epithelial cells, and also to soluble components found in vaginal/urethral secretions, are involved. Either cytoadhesion or the cytotoxicity exerted by parasites to host cells can be dictated by virulence factors such as adhesins, cysteine proteinases, laminin-binding proteins, integrins, integrin-like molecules, a cell detachment factor, a pore-forming protein, and glycosidases among others. How trichomonads manipulate informations from the extracellular medium, transduce such informations, and respond to them by stimulating the activities of some surface molecules and/or releasing enzymes are the aspects concerning trichomonal virulence which are here briefly reviewed and discussed.

Prevalência de vaginites específicas e inespecíficas em mulheres na pós-menopausa / Prevalence of non-specific and specific vaginitis in postmenopause women

O climatério é o período da vida feminina caracterizada pelo esgotamento dos folículos ovarianos, tendo como consequência à diminuiçäo dos níveis de estrogênio e progesterona, resultando em alteraçöes fisiológicas sobre a pele, mucosas, ossos e metabolismo lipoprotéico, sendo a menopausa um episódio dentro do climatério que representa a última menstruaçäo da vida da mulher. Com deficiência estrogênica, o epitélio vaginal torna-se atrófico e de pequena espessura, levando consequentemente a uma diminuiçäo da produçäo de glicogênio e baixo teor de acidez, favorecendo o surgimento de vaginites, as quais poderäo ser de origem específica ou inespecífica. Este trabalho teve como objetivo analisar a prevalência de vaginites específicas e inespecíficas em mulheres na pós-menopausa. Foram analisadas 533 mulheres de faixa etária compreendida entre 40 e 65 anos de idade, cujas amostras foram obtidas através de colheita tríplice (ectocérvice, endocérvice e fundo de saco vaginal), com posterior coloraçäo pela técnica de Papanicolaou. Os resultados demonstraram que das 533 mulheres examinadas, houve predomínio de vaginites inespecíficas determinadas por flora mista, em 44,5 porcento das pacientes, seguida por infecçöes ocasionadas pela Gardnerella vaginalis em 10 porcento das pacientes. As vaginites específicas por sua vez tiveram como predomínio às infecçöes provocadas pela Candida sp em 156 casos (27,3 porcento) seguidas pelo Trichomonas vaginalis observada em 72 pacientes (12,6 porcento), tendo sido observada uma maior incidência destes agentes em mulheres com faixa etária variando entre 40 a 49 anos, seguidas por aquela com idade variando entre 50 a 59 anos de idade. Estes dados chamam a atençäo para uma análise cuidadosa de esfregaço vaginal em mulheres na pós-menopausa em especial naquelas com sinais e sintomas de vaginites

Frecuencia de trichomonas vaginalis en citologías procedentes de diferentes centros de salud: Costa Rica 1986-1990 / Trichomonas vaginalis in cytologies of different health centers. Costa Rica 1986-1990

Se realiza una revisión de 72.859 citologías recibidas durante un período de 3 años (1989,1990,1991) en el Servicio de Anatomía Patológica del Hospital México procedentes de 15 diferentes Centros de Salud con el propósito de determinar el porcentaje de casos por Trichomonas vaginalis en esa población; encontrándose un 2.9 percent de citologías con este flagelado. La presencia de T. vaginalis en las preparaciones citológicas puede conllevar a diagnósticos erróneos o a enmascarar lesiones displásicas y neoplásicas por lo que su hallazgo en este material requiere de un análisis cuidadoso

Comparative in vitro sensitivity to metronidazole of Trichomonas vaginalis with isolates and clones.

Isolates of Trichomonas vaginalis from a group of Thai women in Khon Kaen, Thailand were studies for their in vitro sensitivity to metronidazole. Forty-five isolates of T. vaginalis and further 226 laboratory clones of these isolates were examined for drug sensitivity under anaerobic conditions using the CPLM (Cysteine-Peptone-Liver infusion Maltose) medium. The in vitro sensitivity of T. vaginalis to metronidazole, recorded as MLC values revealed highly variable sensitivity profiles Greater than 90% of the trichomonads studies were susceptible to relatively low concentrations of metronidazole in the range of 1-10 micrograms/ml. The remaining fraction of trichomonads, appeared to be less sensitive and required higher concentration of drug to attain the MLCs. The highest recorded MLC was 60 micrograms/ml. The geometric mean MLC of the 45 isolates was 7.99 micrograms/ml while that of The influence of the individual clones of subpopulations of T. vaginalis on the observed sensitivity of the isolate was also examined. A positive linear relationship was observed between the MLC of the isolated and the MLC of the least sensitive clone of the same isolate (p less than 0.05). This suggests that the most resistant clone present within an isolate of T. vaginalis plays an important role in determining the overall drug sensitivity of the isolate.