Caracterização fenotípica e genotípica de Staphylococcus aureus resistentes à meticilina isolados na cidade do Natal/RN

Staphylococcus aureus resistente à meticilina (MRSA) é um dos principais agentes de infecções associadas a serviços de saúde em todo o mundo. No Brasil, há a predominância de um clone de MRSA multirresistente denominando clone epidêmico brasileiro (CEB). Entretanto, novos clones nãomultirresistentes com alta virulência têm sido descritos em infecções comunitárias e hospitalares. O objetivo desse estudo foi realizar a caracterização fenotípica e genotípica de cepas de MRSA isoladas na cidade do Natal/RN. Inicialmente avaliamos 60 amostras de S. aureus quanto a resistência à meticilina através de diferentes técnicas fenotípicas, utilizando a detecção do gene mecA por PCR como padrão. O antibiograma de todas as cepas foi realizado utilizando 12 antimicrobianos conforme descrito pelo CLSI. As cepas de MRSA foram caracterizadas geneticamente através da tipagem do cassete cromossômico estafilocócico mec (SCCmec) e da eletroforese em campo elétrico alternado (PFGE). Dos 60 S. aureus estudados, 45 foram resistentes à meticilina. Observamos que para algumas cepas de MRSA os testes de triagem em ágar com 6μg/mL de oxacilina e difusão em meio sólido com oxacilina-1μg apresentaram dificuldades na sua interpretação. No entanto, todas as 45 amostras de MRSA, foram facilmente detectadas pelos testes com o disco de cefoxitina-30μg e pesquisa da PBP2a. A análise molecular das cepas de MRSA mostrou 8 padrões distintos de PFGE (A-H), com predominância do padrão A (73%), relacionado ao CEB. Estas carreavam o SCCmec tipo IIIA, e apresentaram uma considerável variedade de subtipos (A1-A16). Cinco cepas de MRSA portando SCCmec IV também foram xiv identificadas, três delas relacionadas geneticamente ao clone USA800 (Padrão B). Destas cinco, três (2 padrão F e 1 padrão B) foram altamente susceptíveis as drogas testadas, entretanto, dois outros isolados, padrão B, apresentaram multirresistência. As amostras restantes pertenciam a padrões de PFGE distintos dos clones internacionais predominantes em nosso continente. Para realização deste projeto de pesquisa, a metodologia exigiu a interação com pesquisadores de áreas como: infectologia, microbiologia e biologia molecular. Portanto, esta dissertação apresentou um caráter de multidisciplinaridade e transdiciplinaridade no seu desenvolvimento

Estudo dos genes do complexo do antígeno leucocitário humano (hla) associados à susceptibilidade ao diabetes mellitus tipo 1

Of all of the genes associated with the development of Diabetes mellitus type 1 (T1D), the largest contribution comes from the genes in the Human Leukocyte Antigen (HLA) region, mostly the class II DR e DQ genes. Specific combinations of alleles DRB1, DQA1 and DQB1 constituting haplotypes, and further, a combination of more than one haplotype, providing multilocus genotypes are associated with susceptibility, protection and neutrality to DM1. Thus, the aim of present study was to verified the association of polymorphisms of HLA genes class II with susceptibility to type 1 diabetes mellitus (T1D). Ninety-two patients with T1D and 100 individuals normoglycemics (NG) aged between 6 and 20 years were studied. Genomic DNA was obtained from peripheral whole blood, collected in EDTA tube, using the extraction kit Illustra Triple Prep®, GE Healthcare. For HLA typing was used DNA LABType system by One Lambda kit applying Luminex® technology to the method of PCRSSO typing reverse. The alleles DRB1*03:01, *04:05, *04:01, *04:02, DQA1*03:01g, *05:01g, DQB1*02:01g, *03:02, the haplotypes DRB1*03:01-DQA1*05:01-DQB1*02:01, DRB1*04:05-DQA1*03:01g-DQB1*03:02, DRB1*04:02-DQA1*03:01g-DQB1*03:02, DRB1*04:01-DQA1*03:01g-DQB1*03:02 and DR3-DQ2/DR4-DQ8 genotype were significantly associated with the chance of developing T1D. The alleles DRB1*11:01, *15:03, *15:01, *13:01, DQA1*01:02, *04:01g, *01:03, DQB1*06:02, *03:01g, *06:03, *04:02, the haplotypes DRB1*11:01-DQA1*05:01-DQB1*03:01, DRB1*13:01-DQA1*01:03-DQB1*06:03 and DRX-DQX/DRX-DQX genotype, formed by other than the DR3-DQ2 or DR4-DQ8 haplotypes, were significantly associated with T1D protection Despite the major racial Brazilian, even at the regional level, these results are similar to the majority of alleles, genotypes and haplotypes of HLA class II-related susceptibility or resistance to T1D, extensively described in the literature for Caucasian population. Children with age at diagnosis less than 5 years of age had significantly higher frequency of the heterozygous genotype DR3-DQ2/DR4-DQ8 compared to children with age at diagnosis than 5 years old. These results also demonstrate strong association of the genetic profile of the class II HLA for this age group, possibly associated with the severity and rapid progression to the onset of T1D. The knowledge of HLA class II genes may be useful in genetic screens that allow the prediction of T1D

Estudo da detecção do DNA do papiloma vírus humano (HPV) e da expressão imuno-histoquímica de proteína do ciclo celular no carcinoma epidermóide oral

Oral squamous cell carcinoma (OSCC) is the most common malignancy in oral cavity and human papillomavirus (HPV) may have an important role in its development. The aim of this experiment was to investigate the HPV DNA and viral types in 90 cases of OSCC. Moreover, a comparative analysis between the cases of OSSC with and without HPV DNA was performed by using cell cycle markers p21 and pRb in order to detect a possible correlation of these proteins and HPV infection. DNA was extracted from paraffin embedded tissue and amplified by PCR (polymerase chain reaction) with primers PCO3+ e PCO4+ for a fragment of human β-globin gene. After this procedure, PCR for HPV DNA detection was realized using a pair of generic primers GP5+ e GP6+. Immunohistochemical study was performed by streptoavidin-biotin technique and antibodies against p21 and pRb proteins were employed. Eighty-eight cases were positive for human β-globin gene and HPV DNA was found in 26 (29.5%) of then. It could not be detected significant correlation between HPV and age, sex and anatomical sites of the lesion. The most prevalent viral type was HPV 18 (80.8%). Regarding the immunohistochemical analysis, it was detected significant association between HPV presence and pRb immunoexpression (p=0,044), nevertheless, the same was not observed in relation to p21 protein (p =0,416). It can be concluded that the low detection of HPV DNA in OSCC by the present experiment suggests a possible role of the virus in the development and progression in just a subset of this disease

Co-circulação dos vírus dengue tipo 1, 2 e 4 nos Estados do Rio Grande do Norte e Paraíba, 2013

Dengue is a viral disease transmitted by female mosquitoes from genus Aedes, the principal urban vector is Aedes aegypti. Actually dengue has caused, in global scale, substantial morbidity and mortality. Four serotypes (antigenically distinct) are known: DENV-1, DENV-2, DENV-3 and DENV-4. The objective of this study was described the epidemiological profile dengue in the states of Rio Grande do Norte (RN) and Paraíba (PB), 2013. For that, suspected cases of dengue were studied, received for Laboratory of Molecular Biology of infectious disease and cancer (LADIC-UFRN) from different Health Units from RN and PB between January and December of 2013. The viral RNA was obtained from serum samples of patient from health units from RN and PB. It were studied 478 suspected cases of dengue , 252 (52,7%) from Rio Grande do Norte and 226 (47,3%) from Paraíba, showeds a global rate of infection global prevalence of 29,7% (142/478). The co-circulation of three serotypes was observed: DENV-1 (9,8% [14/142]), DENV-2 (3,5% [5/142]) and DENV-4 (86,7% [123/142]). People between 21-30 years old were the most affected by the disease during all the period of the study, representing 63,7% of the cases in both states. The genus most affected was female, representing 63,3% of cases in both states. Pau dos Ferros, Rio Grande do Norte, had the highest circulation of disease, with 8,2% (8/97) of cases. In Paraíba, the city most affected was João Pessoa, with (80% (36/45) of cases. The months with the biggest viral circulation in RN and PB were March and August, respectively. These results are very important to understanding the dengue viral activity in RN and PB, providing data that can guide control actions of this disease in support to local control programs

Epidemiologia e caracterização molecular dos vírus Dengue circulantes no Rio Grande do Norte, 2013-2014

Dengue is an acute infectious disease, usually transmitted by Aedes aegypti mosquitoes. The etiologic agents belong to the family Flaviviridae, genus Flavivirus, and occur as four antigenically related but distinct serotypes designated DENV-1, 2, 3, and 4. In Brazil, the disease represents a national public health problem. The purpose of the present study was to describe epidemiological aspects of dengue in the State of Rio Grande do Norte, from 2013 to 2014. A total of 483 blood or serum samples, collected from January 2013 to December 2014, were studied by RT-PCR for viral detection and typing. The infection was confirmed in 36.44% (176/483) of the cases studied. This study detected the circulation of three serotypes of dengue virus in Rio Grande do Norte, DENV-1, 2, and 4. The predominant serotype in 2013-2014 was the DENV-4, representing 83.51% (81/97) and 68.35% (54/79) of the positive cases, respectively. Regarding the spatial distribution, most of the cases occurred in Natal and Caicó, with 9.28% (9/97) and 18.99% (15/79), respectively. The months with the biggest viral circulation in RN were March 2013 and May 2014. The female gender was the most affected, representing 69.07% (67/97) in 2013 and 54.43% (43/79) in 2014. The most affected age groups were 21-30 years (2013) and 11-20 years (2014) with 25.77% (25/97) and 20.25% (16/79) positive cases, respectively. Phylogenetic analysis indicated that genotype V (DENV-1) and genotype II (DENV-4) circulated in the State. Our results provide information about the dynamics of DENV in the Rio Grande do Norte, important for the development of disease control strategies.