Fernanda Almeida

Homeobox genes: a molecular link between development and cancer

Homeobox genes are regulatory genes encoding nuclear proteins that act as transcription factors, regulating aspects of morphogenesis and cell differentiation during normal embryonic development of several animals. Vertebrate homeobox genes can be divided in two subfamilies: clustered, or HOX genes, and nonclustered, or divergent, homeobox genes. During the last decades, several homeobox genes, clustered and nonclustered ones, were identified in normal tissue, in malignant cells, and in different diseases and metabolic alterations. Homeobox genes are involved in the normal teeth development and in familial teeth agenesis. Normal development and cancer have a great deal in common, as both processes involve shifts between cell proliferation and differentiation. The literature is accumulating evidences that homeobox genes play an important role in oncogenesis. Many cancers exhibit expression of or alteration in homeobox genes. Those include leukemias, colon, skin, prostate, breast and ovarian cancers, among others. This review is aimed at introducing readers to some of the homeobox family functions in normal tissues and especially in cancer.

Molecular epidemiology and virulence markers of Salmonella Infantis isolated over 25 years in São Paulo State, Brazil.

Infection of humans and animals caused by Salmonella is a major public health problem worldwide. Among the more than 2500 serovars, S. Infantis has been one of the 15 most isolated serovars in the world. Despite its clinical importance, little is known about the molecular characteristics of S. Infantis strains from Brazil. The aims of this study were to type S. Infantis isolates of this country and to assess their pathogenic potential. The molecular epidemiology of 35 S. Infantis strains, isolated from human sources (25) and food items (10) between 1984 and 2009 in São Paulo State, Brazil, were investigated using ERIC-PCR, PFGE and MLST. Furthermore, the presence of some virulence markers from Salmonella pathogenicity islands (SPIs) SPI-1 and SPI-2 and from the virulence plasmid was assessed by PCR. Using ERIC-PCR, 34 S. Infantis strains exhibited a high genetic similarity (≥ 93.7%) and using PFGE, 32 strains exhibited a similarity ≥ 80.6%. Additionally, MLST showed a high clonal similarity among strains that all presented the same ST32. Thirty-two isolates under investigation contained the virulence markers invA, sopB, sopD, sipA, sipD, ssaR, sifA, flgK, fljB and flgL. In conclusion, the S. Infantis strains studied were genetically similar, suggesting that a prevalent subtype has been causing disease and food contamination during a 25year period in São Paulo State, an important metropolitan region in Brazil. Furthermore, the contamination between strains from food items and sick humans indicates that better control measures for S. Infantis may be needed in this country.

Molecular characterization of Salmonella Typhimurium isolated in Brazil by CRISPR-MVLST

CRISPR-multi-locus virulence sequence typing (CRISPR-MVLST) was performed to type 92 S. Typhimurium strains isolated from humans and food sources between 1983 and 2013 in Brazil and assess the suitability of this methodology comparing it with PFGE already used for subtyping the same strains. Among the 92 S. Typhimurium strains studied, we identified 25 CRISPR1 alleles, 27 CRISPR2 alleles, 2 fimH alleles and 3 sseL alleles showing that the genetic variability is much higher in the CRISPRs loci than in the virulence genes. The CRISPR-MVLST analysis provided similar results to the PFGE previously published used to type the same set of strains, demonstrating that CRISPR-MVLST is a very efficient approach for subtyping S. Typhimurium serovar and can be used to complement and validate results obtained by the PFGE methodology.

Genotypic diversity, pathogenic potential and the resistance profile of Salmonella Typhimurium strains isolated from humans and food from 1983 to 2013 in Brazil

Salmonella enterica subsp. enterica serovar Typhimurium is one of the leading serovars that causes salmonellosis worldwide. However, few studies have molecularly characterized S. Typhimurium strains in Brazil. In this study, we genotyped 92 S. Typhimurium strains isolated from humans (43) and food (49) between 1983 and 2013 in Brazil using PFGE, multiple-locus variable number of tandem repeats analysis (MLVA) and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Moreover, we assessed the frequency of 12 virulence markers by PCR and the resistance profile against 12 antimicrobials. More than 85.8% of the strains studied carried 11 of the virulence markers or more. Thirty-three strains (25%) were multidrug resistant (MDR). The 92 S. Typhimurium studied were grouped by PFGE as PFGE-A, PFGE-B1 and PFGE-B2; by MLVA as MLVA-A, MLVA-B1 and MLVA-B2; and, finally, by ERIC-PCR as ERIC-A and ERIC-B. The strains isolated from humans before the mid-1990s were allocated to all clusters. The strains isolated from humans after the mid-1990s were distributed in the PFGE-B1, MLVA-B1, MLVA-B2 and ERIC-A clusters. The strains isolated from food were distributed in all clusters, except in PFGE-B2. All typing results suggested that the S. Typhimurium strains of human clinical origin isolated before the mid-1990s were genetically more diverse, which might indicate the selection of a more adapted S. Typhimurium subtype after Salmonella Enteritidis became the most prevalent serovar in Brazil. Regarding strains isolated from food, the results suggest the current circulation of more than one subtype. Furthermore, the high frequency of virulence genes and the presence of MDR strains reinforces their potential hazard for humans and the risk of their presence in foods in Brazil.

Virulence-associated genes, antimicrobial resistance and molecular typing of Salmonella Typhimurium strains isolated from swine from 2000 to 2012 in Brazil

The aims of this study were to assess the pathogenic potential, antimicrobial resistance and genotypic diversity of Salmonella Typhimurium strains isolated in Brazil from swine (22) and the surrounding swine environment (5) from 2000 to 2012 and compare them to the profiles of 43 human strains isolated from 1983 to 2010, which had been previously studied.

Occurrence of enterotoxigenic and nonenterotoxigenic Bacteroides fragilis in calves and evaluation of their antimicrobial susceptibility

Abstract Bacteroides fragilis is considered an important clinical pathogen and the most common anaerobe isolated from human and animal clinical specimens; enterotoxigenic strains produce diarrhea. The presence of enterotoxigenic (ETBF) and nonenterotoxigenic B. fragilis in stool samples from calves with or without acute diarrhea and the antimicrobial susceptibility of the strains were evaluated. The stool samples were plated onto a selective B. fragilis–bile–esculin agar, and incubated anaerobically (10% CO2/90% N2), at 37°C, for 72 h. Species of the B. fragilis group were identified by using the API 32‐A kit. Enterotoxigenic strains were detected by PCR and the cytotoxic assay. From 54 diarrhea and 54 nondiarrhea stools, 124 and 92 members of the B. fragilis group, respectively, were recovered. Only two ETBF strains were isolated from two different diarrhea samples and the bft gene was detected in both. Moreover, the bft gene was detected in DNA from four different diarrheal stools samples but no ETBF strain was recovered. All the bacteria were susceptible to chloramphenicol, imipenem, moxifloxacin, piperacillin/tazobactam, metronidazole and tigecycline. Most of the isolates from both calves with and without diarrhea were resistant to all metals. Our results are of concern, and suggest the need to increase the surveillance of antibiotic and metal resistance of this microbial group isolated from animal production such as calves.

FATORES PROGNÓSTICOS NO CÂNCER DE BOCA

Objective: The present work aimed to present a brief review of literature on the most relevant prognostic factors to the clinical prognosis of patients with oral cancer considering the experience with clinical cases treated at our Oral Center. Method: An analytic and thematic literature review was performed through the PubMed and SciELO database articles. Texts were searched in the English and Portuguese medical literature, which were published from 1980 to 2009. The following key-words were used: prognostic factors, prognostic indicators, oral cancer prognosis, and oral cancer recurrence. Were included articles that addressed squamous cell carcinoma, since it is the most prevalent oral cancer, as well as clinical features, imaging procedures, clinical stage, recurrence rates, and aggressive behavior related to the most significant prognostic factors such as patient age, tumor location, tumor thickness and TNM classification. Were excluded articles whose approaches were related to laboratorial and experimental tests and involving tumor markers or molecular indicators of oral cancer. Results: From a total of 15.542 articles, twenty-three were selected after criteria application, and it was observed that lesions located in areas with difficult surgical access and with greater blood or lymphatic circulation (such as the tongue) have a worse prognosis; greater tumor thickness and TNM staging are associated with worst outcomes. Conclusion: Therefore, each member of the multidisciplinary group which assists OSCC patients must comprehend this pathology and its prognostic factors in order to become able to prevent, recognize and control the oral cancer. DESCRIPTORS: Oral Cancer. Prognostic. Diagnosis.

Hibridização in situ com sonda não-radioativa para mRNA: princípios e aplicações em patologia

A tecnica de hibridizacao in situ (ISH) tem sido usada para identificar mRNA (ou DNA) em amostras de tecido de material humano e animal. Embora uma serie de protocolos para essa tecnica seja utilizada, as descricoes nao sao bem detalhadas. O objetivo deste trabalho e descrever a reacao de hibridizacao in situ em tecido fresco e sua aplicacao em patologia, tornando mais compreensivel essa tecnica tao importante, que possibilita observar a localizacao tecidual e a expressao temporal e espacial dos transcritos de um determinado gene (mRNA). Resultados de reacoes com as ribossondas PITX1, SHH e WNT-5A, realizadas em amostras de tecido congelado, sao apresentados.

Draft Genome Sequences of 40 Salmonella enterica Serovar Typhimurium Strains Isolated from Humans and Food in Brazil

ABSTRACT Salmonellosis is an important health problem worldwide and Salmonella enterica serovar Typhimurium is one of the most common isolated serovars. Here, we reported the draft genomes of 40 S. Typhimurium strains isolated from humans and food in Brazil. These draft genomes will improve phylogenetic analysis and will help enhance our understanding of strains of this serovar isolated in Brazil.

New rehabilitation protocol for oral sinus communications in BRONJ patients.

Sir, The management of bisphosphonate-related osteonecrosis jaw (BRONJ) is challenging because most surgical and medical interventions may not eradicate it. More alarming is performing prosthetic rehabilitation of these patients, subject not enough discussed in the literature. The demand of BRONJ patients in need of prosthetic rehabilitation has being dramatically increased in Brazil. We believe that this is also a huge problem in others countries too. The professionals are concerned about the possible induction of new lesions due to trauma caused by the fabrication and use of prostheses. However, the oral rehabilitation of BRONJ patients is of paramount importance for their quality of life. For circumvent this problem our research group in the School of Dentistry of the University of São Paulo developed a new protocol for obtaining prosthesis with chemical and mechanical characteristics conferring an atraumatic and atoxic pattern (Table 1). After more than 4 years of follow-up there is no recurrence of the BRONJ lesions. There is a lack of information on the use of osseointegrated implants in these patients, thus, due to the long half-life of BFs in the patients, or because patient will be still using BFs, new BRONJ lesions can occur, particularly in areas subject to trauma, our group opted for a denture fabrication based on those indicated for patients irradiated for head and neck cancer. Several parameters were considered for the construction of such prosthesis, including resin type, polymerization cycle, prosthesis finishing and internal adaptation, as described in the chart below. We believe that oral health professionals and their BRONJ patients worldwide will be beneficiated with this prosthetic rehabilitation protocol. We hope to have more discussion about this subject for now on.