Made available in DSpace on 2014-12-17T14:16:31Z (GMT). No. of bitstreams: 1
MarianaAPM_DISSERT.pdf: 2606420 bytes, checksum: 97be52d447dc533f85354f32faddd0ad (MD5)
Previous issue date: 2013-03-27 / Funda??o de Apoio ? Pesquisa do Estado do Rio Grande do Norte / Vulvovaginal candidiasis (VVC) is one of the most common
causes of vaginitis and affects about 75% of women of reproductive age. The
majority of cases (80 to 90%) are due to C. albicans, the most virulent species
of the genus Candida. Virulence attributes are scarcely investigated and the
source of infection remains uncertain. Objective: This study aimed to evaluate
the virulence factors and genotypes of clinical isolates of C. albicans
sequentially obtained from the anus and vagina of patients with sporadic and
recurrent VVC. Materials and methods: We analyzed 62 clinical isolates of C.
albicans (36 vaginal and 26 anal strains). Direct examination of vaginal and anal
samples and colony forming units (CFU) counts were performed. Yeasts were
identified using the chromogenic media CHROMagar Candida? and by classical
methodology, and phenotypically characterized regarding to virulence factors,
including the ability to adhere to epithelial cells, proteinase activity,
morphogenesis and biofilm formation. The genotypes of the strains were
investigated with ABC genotyping, microsatellite genotyping with primer M13
and RAPD. Results: We found 100% agreement between direct examination
and culture of vaginal samples. Filamentous forms were present in most of the
samples of vaginal secretion, which presented CFU counts significantly higher
than the samples of anal secretion. There was no statistically significant
difference between virulence factors of infecting vaginal isolates and those
presented by colonizing anal isolates; as well as for the comparison of the
vaginal isolates from patients with different clinical conditions (sporadic or
recurrent VVC). There was a decrease in the ability to adhere to HBEC,
morphogenesis and biofilm formation of the vaginal isolates during the progress
of infection. There was an association between the ability to express different
virulence factors and the clinical manifestations presented by the patients.
Genotype A was the most prevalent (93.6%), followed by genotype C (6.4%).
We found maintenance of the same ABC genotype and greater prevalence of
microevolution for the vaginal strains of C. albicans sequentially obtained.
Vaginal and anal isolates of C. albicans obtained simultaneously from the same
patient presented the same ABC genotype and high genetic relatedness.
Conclusion: It is noteworthy that the proliferation of yeast and bud-to-hypha
transition are important for the establishment of CVV. The expression of
virulence factors is important for the pathogenesis of VVC, although it does not
seem to be determinant in the transition from colonization to infection or to the
installation of recurrent condition. Genotype A seems to be dominant over the
others in both vaginal and anal isolates of patients with VVC. The most common
scenario was microevolution of the strains of C. albicans in the vaginal
environment. It is suggested that the anal reservoir constituted a possible
source of vaginal infection, in most cases assessed / Candid?ase vulvovaginal (CVV) ? uma das causas mais comuns
de vaginite e acomete cerca de 75% das mulheres em idade reprodutiva, sendo
a maioria dos casos (80 a 90%) devido ? C. albicans, esp?cie mais virulenta do
g?nero. Atributos de virul?ncia em CVV s?o pouco investigados, bem como a
fonte da infec??o permanece incerta. Objetivo: Este trabalho teve por
finalidade avaliar os fatores de virul?ncia e gen?tipos de isolados cl?nicos de C.
albicans sequencialmente obtidos do ?nus e da vagina de pacientes com CVV
espor?dica e recorrente. Material e m?todos: Foram analisados 62 isolados
cl?nicos de C. albicans (36 isolados vaginais e 26 isolados anais). Realizou-se o
exame direto das amostras de secre??o vaginal e anal e contagem de
unidades formadoras de col?nia (UFC); as leveduras foram identificadas por
meio cromog?nico CHROMagar Candida? e por metodologia cl?ssica e
caracterizadas fenotipicamente quanto a fatores de virul?ncia, incluindo a
capacidade de ader?ncia a CEBH, a atividade de proteinase, a morfog?nese e
a forma??o de biofilme. Para a avalia??o da variabilidade genot?pica,
empregou-se a t?cnica de genotipagem ABC, al?m da genotipagem por
microssat?lites e RAPD. Resultados: Verificou-se 100% de concord?ncia entre
o exame direto e a cultura de amostras vaginais, observando-se a presen?a de
formas filamentosas na maioria das amostras de secre??o vaginal, as quais
apresentaram contagem de UFC significativamente superior ?quela
apresentada pelas amostras de secre??o anal. N?o se observou diferen?a
estatisticamente significativa quando se comparou os fatores de virul?ncia dos
isolados vaginais infectantes com aqueles apresentados pelos isolados anais
colonizantes; bem como comparando-se os isolados vaginais de C. albicans
obtidos de grupos de pacientes com diferentes condi??es cl?nicas (CVV
espor?dica e com CVVR). Observa-se uma tend?ncia ? diminui??o da
capacidade de ader?ncia, morfog?nese e forma??o de biofilme do isolado
vaginal infectante ao longo do tempo e sugere-se associa??o entre a
capacidade de expressar os diferentes fatores de virul?ncia estudados e as
manifesta??es cl?nicas apresentadas pelas pacientes. O gen?tipo A foi o mais
prevalente (93,6%), seguido do gen?tipo C (6,4%). Houve manuten??o do
mesmo gen?tipo ABC e maior preval?ncia de microevolu??o das cepas
vaginais de C. albicans obtidas sequencialmente, bem como se observou o
mesmo gen?tipo ABC e alta similaridade gen?tica entre isolados vaginais e
anais de C. albicans obtidos simultaneamente da mesma paciente. Conclus?o:
Ressalta-se que a prolifera??o da levedura e a transi??o levedura-hifa s?o
importantes no estabelecimento da CVV. A express?o dos fatores de virul?ncia
? importante na patog?nese de CVV, contudo n?o parece ser determinante na
transi??o de coloniza??o para infec??o nem na instala??o de quadro recorrente
de CVV. O gen?tipo A demonstra ser dominante em rela??o aos demais tanto
em isolados vaginais quanto em isolados anais de pacientes com CVV.
Verifica-se a ocorr?ncia de microevolu??o das cepas de C. albicans no
ambiente vaginal como cen?rio mais comum. Sugere-se que o reservat?rio
anal constituiu uma poss?vel fonte da infec??o vaginal, na grande maioria dos
casos avaliados
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/13481 |
| Date | 27 March 2013 |
| Creators | Medeiros, Mariana Ara?jo Paulo de |
| Contributors | http://lattes.cnpq.br/1463249528959656, Milan, Eveline Pipolo, CPF:70337950415, http://lattes.cnpq.br/2501015206371302, Neves, Rejane Pereira, CPF:21401365434, http://lattes.cnpq.br/0360951033804105, Chaves, Guilherme Maranh?o |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncias Farmac?uticas, UFRN, BR, Bioan?lises e Medicamentos |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0027 seconds