Juliana Pfrimer Falcão
University of São Paulo
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Featured researches published by Juliana Pfrimer Falcão.
Proceedings of the National Academy of Sciences of the United States of America | 2014
Sandra Reuter; Thomas Richard Connor; Lars Barquist; Danielle Walker; Theresa Feltwell; Simon R. Harris; Maria Fookes; Miquette Hall; Nicola K. Petty; Thilo M. Fuchs; Jukka Corander; Muriel Dufour; Tamara Ringwood; Cyril Savin; Christiane Bouchier; Liliane Martin; Minna Miettinen; Mikhail Shubin; Julia M. Riehm; Riikka Laukkanen-Ninios; Leila M. Sihvonen; Anja Siitonen; Mikael Skurnik; Juliana Pfrimer Falcão; Hiroshi Fukushima; Holger C. Scholz; Michael B. Prentice; Brendan W. Wren; Julian Parkhill; Elisabeth Carniel
Significance Our past understanding of pathogen evolution has been fragmented because of tendencies to study human clinical isolates. To understand the evolutionary trends of pathogenic bacteria though, we need the context of their nonpathogenic relatives. Our unique and detailed dataset allows description of the parallel evolution of two key human pathogens: the causative agents of plague and Yersinia diarrhea. The analysis reveals an emerging pattern where few virulence-related functions are found in all pathogenic lineages, representing key “foothold” moments that mark the emergence of these pathogens. Functional gene loss and metabolic streamlining are equally complementing the evolution of Yersinia across the pathogenic spectrum. The genus Yersinia has been used as a model system to study pathogen evolution. Using whole-genome sequencing of all Yersinia species, we delineate the gene complement of the whole genus and define patterns of virulence evolution. Multiple distinct ecological specializations appear to have split pathogenic strains from environmental, nonpathogenic lineages. This split demonstrates that contrary to hypotheses that all pathogenic Yersinia species share a recent common pathogenic ancestor, they have evolved independently but followed parallel evolutionary paths in acquiring the same virulence determinants as well as becoming progressively more limited metabolically. Shared virulence determinants are limited to the virulence plasmid pYV and the attachment invasion locus ail. These acquisitions, together with genomic variations in metabolic pathways, have resulted in the parallel emergence of related pathogens displaying an increasingly specialized lifestyle with a spectrum of virulence potential, an emerging theme in the evolution of other important human pathogens.
Environmental Microbiology | 2011
Riikka Laukkanen-Ninios; Xavier Didelot; Keith A. Jolley; Giovanna Morelli; Vartul Sangal; Paula Kristo; Carina Brehony; Priscilla F. M. Imori; Hiroshi Fukushima; Anja Siitonen; Galina Tseneva; Ekaterina Voskressenskaya; Juliana Pfrimer Falcão; Hannu Korkeala; Martin C. J. Maiden; Camilla Mazzoni; Elisabeth Carniel; Mikael Skurnik; Mark Achtman
Multilocus sequence analysis of 417 strains of Yersinia pseudotuberculosis revealed that it is a complex of four populations, three of which have been previously assigned species status [Y. pseudotuberculosis sensu stricto (s.s.), Yersinia pestis and Yersinia similis] and a fourth population, which we refer to as the Korean group, which may be in the process of speciation. We detected clear signs of recombination within Y. pseudotuberculosis s.s. as well as imports from Y. similis and the Korean group. The sources of genetic diversification within Y. pseudotuberculosis s.s. were approximately equally divided between recombination and mutation, whereas recombination has not yet been demonstrated in Y. pestis, which is also much more genetically monomorphic than is Y. pseudotuberculosis s.s. Most Y. pseudotuberculosis s.s. belong to a diffuse group of sequence types lacking clear population structure, although this species contains a melibiose-negative clade that is present globally in domesticated animals. Yersinia similis corresponds to the previously identified Y. pseudotuberculosis genetic type G4, which is probably not pathogenic because it lacks the virulence factors that are typical for Y. pseudotuberculosis s.s. In contrast, Y. pseudotuberculosis s.s., the Korean group and Y. pestis can all cause disease in humans.
Food Microbiology | 2012
Fábio Campioni; Alzira Maria Moratto Bergamini; Juliana Pfrimer Falcão
Salmonellosis is a major health problem worldwide. Serovar Enteritidis has been a primary cause of Salmonella outbreaks in many countries. In Brazil, few molecular typing studies have been performed. The aims of this study were to molecularly type Salmonella Enteritidis strains isolated in Brazil in order to determine the genetic relationship between strains of food and human origin, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 128 S. Enteritidis strains isolated from human feces (67) and food (61) between 1986 and 2010 were studied. The genotypic diversity was assessed by ERIC-PCR and PFGE using XbaI, the antimicrobial resistance by the disc-diffusion assay and the presence of the SPI-1, SPI-2 and pSTV virulence genes assessed by PCR. The ERIC-PCR results revealed that 112 strains exhibited a similarity of >85.4% and the PFGE that 96 strains exhibited a similarity of >80.0%. Almost all strains (97.6%) harbored all 13 virulence genes investigated. Thirty-six strains (28.12%) were resistant to nalidixic acid. In conclusion, the nalidixic acid resistance observed after 1996 is indicative of an increase in the use of this drug. It may be suggested that these 128 strains might have descended from a common ancestor that differed little over 24 years and has been both contaminating food and humans and causing disease for more than two decades in Brazil.
International Journal of Food Microbiology | 2014
Giovana Verginia Barancelli; Tarsila Mendes de Camargo; Natália G. Gagliardi; Ernani Porto; Roberto A. Souza; Fábio Campioni; Juliana Pfrimer Falcão; Ernesto Hofer; Adriano G. Cruz; Carlos Augusto Fernandes de Oliveira
This study aimed to evaluate the occurrence of Listeria monocytogenes in cheese and in the environment of three small-scale dairy plants (A, B, C) located in the Northern region state of São Paulo, Brazil, and to characterize the isolates using conventional serotyping and PFGE. A total of 393 samples were collected and analyzed from October 2008 to September 2009. From these, 136 came from dairy plant A, where only L. seeligeri was isolated. In dairy plant B, 136 samples were analyzed, and L. innocua, L. seeligeri and L. welshimeri were isolated together with L. monocytogenes. In dairy plant C, 121 samples were analyzed, and L. monocytogenes and L. innocua were isolated. Cheese from dairy plants B and C were contaminated with Listeria spp, with L. innocua being found in Minas frescal cheese from both dairy plants, and L. innocua and L. monocytogenes in Prato cheese from dairy plant C. A total of 85 L. monocytogenes isolates were classified in 3 serotypes: 1/2b, 1/2c, and 4b, with predominance of serotype 4b in both dairy plants. The 85 isolates found in the dairy plants were characterized by genomic macrorestriction using ApaI and AscI with Pulsed Field Gel Electrophoresis (PFGE). Macrorestriction yielded 30 different pulsotypes. The presence of indistinguishable profiles repeatedly isolated during a 12-month period indicated the persistence of L. monocytogenes in dairy plants B and C, which were more than 100 km away from each other. Brine used in dairy plant C contained more than one L. monocytogenes lineage. The routes of contamination were identified in plants B and C, and highlighted the importance of using molecular techniques and serotyping to track L. monocytogenes sources of contamination, distribution, and routes of contamination in dairy plants, and to develop improved control strategies for L. monocytogenes in dairy plants and dairy products.
BMC Microbiology | 2010
Nalu T.A. Peres; Pablo R. Sanches; Juliana Pfrimer Falcão; Henrique C.S. Silveira; Fernanda G. Paião; Fernanda C.A. Maranhão; Diana E. Gras; Fernando Segato; Rodrigo A. Cazzaniga; Mendelson Mazucato; Jeny Rachid Cursino-Santos; Roseli Aquino-Ferreira; Antonio Rossi; Nilce M. Martinez-Rossi
BackgroundCutaneous mycoses are common human infections among healthy and immunocompromised hosts, and the anthropophilic fungus Trichophyton rubrum is the most prevalent microorganism isolated from such clinical cases worldwide. The aim of this study was to determine the transcriptional profile of T. rubrum exposed to various stimuli in order to obtain insights into the responses of this pathogen to different environmental challenges. Therefore, we generated an expressed sequence tag (EST) collection by constructing one cDNA library and nine suppression subtractive hybridization libraries.ResultsThe 1388 unigenes identified in this study were functionally classified based on the Munich Information Center for Protein Sequences (MIPS) categories. The identified proteins were involved in transcriptional regulation, cellular defense and stress, protein degradation, signaling, transport, and secretion, among other functions. Analysis of these unigenes revealed 575 T. rubrum sequences that had not been previously deposited in public databases.ConclusionIn this study, we identified novel T. rubrum genes that will be useful for ORF prediction in genome sequencing and facilitating functional genome analysis. Annotation of these expressed genes revealed metabolic adaptations of T. rubrum to carbon sources, ambient pH shifts, and various antifungal drugs used in medical practice. Furthermore, challenging T. rubrum with cytotoxic drugs and ambient pH shifts extended our understanding of the molecular events possibly involved in the infectious process and resistance to antifungal drugs.
Apmis | 2014
Fábio Campioni; Juliana Pfrimer Falcão
Yersinia enterocolitica biotype 1A (B1A) strains are considered as non‐pathogenic; however, some reports have identified some strains as the causal agents of infection. In South America, few studies molecularly characterized the strains of this biotype. This work typed 51 B1A strains isolated from clinical and non‐clinical sources from Brazil and Chile by Enterobacterial Repetitive Intergenic Consensus‐PCR (ERIC‐PCR) to elucidate their genotypic diversity, and verify the distribution of 11 virulence markers by PCR. The strains were divided into two groups, ERIC‐A and ERIC‐B, clustered independently of their clinical or non‐clinical origin. No differences were observed in the frequencies of the virulence markers between clinical and non‐clinical strains. However, the genes ystB, hreP and myfA occurred exclusively in the strains of the group ERIC‐A. Some clinical and non‐clinical strains were clustered in the same genetic group and presented the same number of virulence markers, which might suggest the role of the environment and food as a potential source of infection for humans and animals. The results corroborate with the hypothesis that B1A strains are divided into two main clusters that differ in the frequency of some virulence markers, a fact observed for the first time in South American strains.
Journal of Microbiological Methods | 2010
Roberto A. Souza; André Pitondo-Silva; Deise Pasetto Falcão; Juliana Pfrimer Falcão
In the last few decades, molecular typing has become an important tool in taxonomic, phylogenetic and identification studies of numerous groups of bacteria, including the yersiniae. In this study, Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR), Pulsed-Field Gel Electrophoresis (PFGE), 16S rRNA gene sequencing and Multilocus Sequence Analysis (MLSA) were performed to determine the ability of these techniques to be used in taxonomy and identification of Yersinia strains. A total of 60 Yersinia strains were genotyped by ERIC-PCR and PFGE. Moreover, an in silico analysis was carried out for 16S rRNA gene sequencing and MLSA, using 68 and 49 Yersinia strains, respectively. A phylogenetic tree constructed from the ERIC-PCR, 16S rRNA gene sequencing and MLSA data grouped most of the Yersinia species into distinct species-specific clusters. In the PFGE assay these clusters were not observed. On this basis, ERIC-PCR, 16S rRNA gene sequencing and MLSA seem to be valuable techniques for use in taxonomic and identification studies of the genus Yersinia, whereas PFGE does not. Furthermore, ERIC-PCR has the advantage of being a cheaper, easier and faster assay than 16S rRNA gene sequencing or MLSA, and for these reasons can be considerate an alternative tool in taxonomic studies of yersiniae.
Apmis | 2014
Vinicius Vicente Martins; André Pitondo-Silva; Luisa de Melo Manço; Juliana Pfrimer Falcão; Sueli dos Santos Freitas; Wanderley Dias da Silveira; Eliana Guedes Stehling
The aim of this study was to investigate the occurrence of virulence genes among clinical and environmental isolates of Pseudomonas aeruginosa and to establish their genetic relationships by Enterobacterial Repetitive Intergenic Consensus PCR (ERIC‐PCR). A total of 60 P. aeruginosa isolates from environmental and clinical sources were studied. Of these, 20 bacterial isolates were from soil, 20 from water, and 20 from patients with cystic fibrosis. Analysis of ERIC‐PCR demonstrated that the isolates of P. aeruginosa showed a considerable genetic variability, regardless of their habitat. Numerous virulence genes were detected in both clinical and environmental isolates, reinforcing the possible pathogenic potential of soil and water isolates. The results showed that the environmental P. aeruginosa has all the apparatus needed to cause disease in humans and animals.
International Journal of Food Microbiology | 2013
Fábio Campioni; Margaret A. Davis; Marta Inês Cazentini Medeiros; Juliana Pfrimer Falcão; Devendra H. Shah
Salmonella Enteritidis (S. Enteritidis) is a major causative agent of food-borne gastroenteritis associated with the consumption of contaminated poultry products. In this study we used multilocus variable number of tandem repeats (VNTRs) analysis (MLVA) to discriminate a total of 188 S. Enteritidis strains recovered from human (n=67), food (n=61) and chickens (n=60) during a 24 year period (1986 through 2010) in Brazil. MLVA profiles of the 188 strains from Brazil were compared to the MLVA profiles of 100 human clinical (n=52) and poultry-associated (n=48) strains isolated in North America between 1986 and 2008. MLVA typing led to classification of the 288 strains from Brazil and North America into two major clusters named A and B with 35% of similarity. Cluster A consisted of a vast majority of strains isolated from North America (n=71) and only three strains isolated from Brazil which included two pre-pandemic strains (SE5 and SE4). In contrast, cluster B consisted of all of the post-pandemic strains isolated from Brazil (n=185) and fewer strains isolated from North America (n=29). In general, MLVA typing showed that the North American strains were more genetically diverse whereas Brazilian strains were more genetically clonal. The clustering of pre-pandemic strains from Brazil with the North American strains suggests the possibility that the pre-pandemic strains were more likely genetically diverse; however after 1993 a new and prevalent subtype of S. Enteritidis was introduced in this country. This is the first study describing MLVA genotyping of the S. Enteritidis strains isolated from Brazil.
Infection, Genetics and Evolution | 2013
Fernanda Almeida; André Pitondo-Silva; Maria Aparecida de Oliveira; Juliana Pfrimer Falcão
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.