Rosely de Vasconcellos Meissner

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) widespread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications.

Prevalence of HPV infection by cervical cytologic status in Brazil

To assess the prevalence of human papillomavirus (HPV) infection according to cervical cytologic status in northeastern Brazil; identify other risk factors for low‐ and high‐grade squamous intraepithelial lesions (LSILs and HSILs); and identify the most prevalent HPV genotypes associated with the lesions.

Herpes simplex virus type 1 is the main cause of genital herpes in women of Natal, Brazil

OBJECTIVES The purpose of this study was to assess the prevalence of HSV-1 and HSV-2 in sexually active women who participated in the cervical cancer screening program in Natal, Brazil. STUDY DESIGN The study included 261 sexually active women resident in the metropolitan area of Natal, Brazil and attending a public clinic for cervical screening. From each participant, a sample of exfoliated uterine cervical cells was collected, using a cytobrush which was conditioned in a tube containing a preserving solution (PBS+vancomycin+nystatin) and sent to a laboratory where it was processed for DNA extraction. The samples were analyzed for the presence of HSV-1 and HSV-2 DNA in separate reactions by PCRs using specific primers. RESULTS HSV-1 in genital infection is four times more prevalent than HSV-2 in the population analyzed. The highest prevalence rates for both viruses were found in women aged 31-39years. We did not observe any association between the presence of both virus serotypes and socio-demographic characteristics in the population studied, nor with some classical risk factors for sexually transmitted diseases. CONCLUSIONS HSV-1 was the major cause of genital infection by Herpes simplex virus in the women included in this study. No association was found between HSV infection and the socio-demographic characteristics or some classical risk factors for sexually transmitted diseases.

Prevalence of human papillomavirus in archival samples obtained from patients with cervical pre-malignant and malignant lesions from Northeast Brazil.

BackgroundHuman Papillomavirus (HPV) is considered as a necessary, but not sufficient, cause of cervical cancer. In this study, we aimed to assess the prevalence of HPV in a series of pre-malignant and malignant cervical lesion cases, to identify the virus genotypes, and to assess their distribution pattern according to lesion type, age range, and other considered variables. The samples were submitted to histopathological revision examination and analysed by polymerase chain reaction (PCR) for the presence of HPV DNA, followed by HPV typing by dot blot hybridisation.FindingsOf the analysed samples, 53.7% showed pre-malignant cervical lesions, and 46.3% presented with cervical cancer. Most cancer samples (84.1%) were classified as invasive carcinoma. The mean age of these cancer patients was 47.3 years. The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cancer patients. HPV 16 was the most prevalent type, followed by HPV 18 and 58, including both single and double infections. Double infection was detected in 11.6% of the samples, and the most common combination was HPV 16+18.ConclusionsCervical cancer appears to occur in women in a lower age range in the studied area, compared to the situation in other Brazilian regions. Furthermore, among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.FindingsThe overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cervical cancer patients from Northeast Brazil. HPV 16 was the most prevalent type, followed by HPV 18 and 58. The most common double infection was HPV 16+18. Cervical cancer appears to occur in women in a lower age range in the Northeast Brazil. Among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.

Human papillomavirus infection in women attended at a cervical cancer screening service in Natal, Brazil

We analyzed cervical specimens of 202 women, aged 15 to 64 years, attended at Luis Antonio Hospital, Natal, Brazil, to determine the prevalence of HPV and identify the more frequent genotypes and risk factors for HPV infection in women attended at a cervical cancer screening service. Two specimens were collected from each patient: one for cytological examination and the other to detect HPV DNA by PCR, and typing by dot blot hybridization. A total of 54.5% of the sample had normal cytology and 45.5% had cytological alterations. HPV was detected in 24.5% of the cytologically normal women and in 59.8% of those with altered cytology. Both single and double HPV infection increased the likelihood of cytological alterations. Thirteen types of HPV were identified, most of which were high risk. HPV 16 was the most prevalent single-type infection, followed by HPV 58. The most frequent double infection was the association between HPV 56 and 57. The prevalence of HPV in cytologically normal women was greater than that reported for countries on all the continents except Africa. The inverse was observed in women with cytological alterations. The distribution of HPV types was similar to that described for the Americas, with some differences. Multiple sexual partners was the only risk factor showing an association with the presence of HPV infection.

Comparação de três protocolos de extração de DNA a partir de tecido fixado em formol e incluído em parafina

OBJECTIVE: To set up a method for DNA extraction from paraffin embedded cervical cancer specimens, previously formalin-fixed, aiming to accomplish retrospective analysis. METHODS: Sixty specimens were submitted to DNA extraction by three different methods. All of them involved digestion of the tissues by proteinase K, followed by DNA purification, based in three different approaches: protocol A used a DNA isolation kit, GlassMax (Gibco/BRL); protocol B was performed with the kit GFXTM Amersham Pharmacia Biotech; and protocol C was based on the method proposed by Banerjee et al.(2), with modifications. To evaluate the integrity and sufficiency of the DNA, the samples were submitted to a in vitro amplification of a segment of the human b-globin gene, and the PCR products were analyzed by electrophoresis on 7% polyacrylamide gels, followed by silver staining. Results: Among 60 analyzed samples, 45 showed positive results when submitted to the three protocols. In six samples, PCR fragments were obtained with DNAs extracted through protocols A e C; in three samples, DNA extraction was achieved with protocol A only; and in two samples the DNA was successfully extracted only through protocol C. CONCLUSIONS: Protocols A and C generated similar results. Although protocol C is more labor-intensive and time consuming, it does not require a commercial kit and therefore has a lower cost. Furthermore, it does not require the use of organic solvents and may be considered a good alternative for DNA extraction from paraffin embedded tissues.

Human papillomavirus prevalence in women with normal cytology and with cervical cancer in Natal, Brazil

This study analyzed the prevalence of human papillomavirus (HPV) in cervical specimens obtained from women with normal cytology and with cervical cancer, in order to evaluate their correlation with health status and demographic characteristics, as well as sexual and reproductive activity in women treated at a cancer reference hospital in Natal, Northeast Brazil. A total of 158 women were divided into 2 groups according to their health status: group I comprised 110 women with normal cytology, and group II comprised 48 women with cervical cancer. Cervical smears were analyzed by cytological or histopathological examination for the detection of cytological alterations, and by PCR for HPV DNA detection using MY09/11 primers, followed by HPV genotyping by dot blot hybridization. Results showed overall HPV prevalence to be 24.5% in group I, with 19.1% of patients having single infection and 5.4% double infection. The HPV prevalence in group II was 85.4%, with 79.2% of patients having single and 6.2% double infection. We identified 10 different HPV genotypes, most with high oncogenic potential. HPV 16 was the most prevalent genotype in the two studied groups, followed by HPV 58 and HPV 18. High-risk HPV genital infection, chronological age, ethnicity, early onset of sexual and reproductive activities, multiple sexual partners and smoking increased the risk for cervical cancer.