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1.  Phenotypic and Genotypic Characterization of Group B Streptococcal Isolates in Southern Brazil ▿  
Journal of Clinical Microbiology  2010;48(12):4397-4403.
One-hundred sixty-eight group B streptococcal (GBS) isolates from a Brazilian hospital were phenotypically and genotypically characterized. Isolates were recovered from human sources from April 2006 to May 2008 and classified as either invasive, noninvasive, or colonizing isolates. Classical methods for serotyping and antibiotic resistance profiling were employed. Clonal groups were also defined by pulsed-field gel electrophoresis (PFGE). Results showed that susceptibility to beta-lactam antimicrobials was predominant among the isolates. Only 4.7% were resistant to erythromycin and clindamycin. The erm(B) gene was widely detected in our GBS isolates, according to our phenotypic results (constitutive macrolide-lincosamide-streptogramin B [cMLSB] resistance phenotype), and the erm(A) gene was also detected in some isolates. MLSB resistance was restricted to strains isolated from patients with noninvasive infections and carriers. Serotype Ia was predominant (38.1%), serotype IV isolates were found at a high frequency (13.1%), and few isolates of serotype III were identified (3%). Pulsed-field gel electrophoresis results revealed a variety of types, reflecting the substantial genetic diversity among GBS strains, although a great number of isolates could be clustered into two major groups with a high degree of genetic relatedness. Three main PFGE clonal groups were found, and isolates sharing the same PFGE type were grouped into different serotypes. Furthermore, in a few cases, isolates from the same patients and possessing the same PFGE type were of different serotypes. These findings could be related to the occurrence of capsular switching by horizontal transfer of capsular genes.
doi:10.1128/JCM.00419-10
PMCID: PMC3008495  PMID: 20881175
2.  The type III secretion system is necessary for the development of a pathogenic and endophytic interaction between Herbaspirillum rubrisubalbicans and Poaceae 
BMC Microbiology  2012;12:98.
Background
Herbaspirillum rubrisubalbicans was first identified as a bacterial plant pathogen, causing the mottled stripe disease in sugarcane. H. rubrisubalbicans can also associate with various plants of economic interest in a non pathogenic manner.
Results
A 21 kb DNA region of the H. rubrisubalbicans genome contains a cluster of 26 hrp/hrc genes encoding for the type three secretion system (T3SS) proteins. To investigate the contribution of T3SS to the plant-bacterial interaction process we generated mutant strains of H. rubrisubalbicans M1 carrying a Tn5 insertion in both the hrcN and hrpE genes. H. rubrisulbalbicans hrpE and hrcN mutant strains of the T3SS system failed to cause the mottled stripe disease in the sugarcane susceptible variety B-4362. These mutant strains also did not produce lesions on Vigna unguiculata leaves. Oryza sativa and Zea mays colonization experiments showed that mutations in hrpE and hrcN genes reduced the capacity of H. rubrisulbalbicans to colonize these plants, suggesting that hrpE and hrcN genes are involved in the endophytic colonization.
Conclusions
Our results indicate that the T3SS of H. rubrisubalbicans is necessary for the development of the mottled stripe disease and endophytic colonization of rice.
doi:10.1186/1471-2180-12-98
PMCID: PMC3487950  PMID: 22672506
3.  Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses 
Pedrosa, Fábio O. | Monteiro, Rose Adele | Wassem, Roseli | Cruz, Leonardo M. | Ayub, Ricardo A. | Colauto, Nelson B. | Fernandez, Maria Aparecida | Fungaro, Maria Helena P. | Grisard, Edmundo C. | Hungria, Mariangela | Madeira, Humberto M. F. | Nodari, Rubens O. | Osaku, Clarice A. | Petzl-Erler, Maria Luiza | Terenzi, Hernán | Vieira, Luiz G. E. | Steffens, Maria Berenice R. | Weiss, Vinicius A. | Pereira, Luiz F. P. | Almeida, Marina I. M. | Alves, Lysangela R. | Marin, Anelis | Araujo, Luiza Maria | Balsanelli, Eduardo | Baura, Valter A. | Chubatsu, Leda S. | Faoro, Helisson | Favetti, Augusto | Friedermann, Geraldo | Glienke, Chirlei | Karp, Susan | Kava-Cordeiro, Vanessa | Raittz, Roberto T. | Ramos, Humberto J. O. | Ribeiro, Enilze Maria S. F. | Rigo, Liu Un | Rocha, Saul N. | Schwab, Stefan | Silva, Anilda G. | Souza, Eliel M. | Tadra-Sfeir, Michelle Z. | Torres, Rodrigo A. | Dabul, Audrei N. G. | Soares, Maria Albertina M. | Gasques, Luciano S. | Gimenes, Ciela C. T. | Valle, Juliana S. | Ciferri, Ricardo R. | Correa, Luiz C. | Murace, Norma K. | Pamphile, João A. | Patussi, Eliana Valéria | Prioli, Alberto J. | Prioli, Sonia Maria A. | Rocha, Carmem Lúcia M. S. C. | Arantes, Olívia Márcia N. | Furlaneto, Márcia Cristina | Godoy, Leandro P. | Oliveira, Carlos E. C. | Satori, Daniele | Vilas-Boas, Laurival A. | Watanabe, Maria Angélica E. | Dambros, Bibiana Paula | Guerra, Miguel P. | Mathioni, Sandra Marisa | Santos, Karine Louise | Steindel, Mario | Vernal, Javier | Barcellos, Fernando G. | Campo, Rubens J. | Chueire, Ligia Maria O. | Nicolás, Marisa Fabiana | Pereira-Ferrari, Lilian | da Conceição Silva, José L. | Gioppo, Nereida M. R. | Margarido, Vladimir P. | Menck-Soares, Maria Amélia | Pinto, Fabiana Gisele S. | Simão, Rita de Cássia G. | Takahashi, Elizabete K. | Yates, Marshall G. | Souza, Emanuel M. | Richardson, Paul M.
PLoS Genetics  2011;7(5):e1002064.
The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.
Author Summary
In this work we describe the genome of H. seropedicae SmR1, a bacterium capable of fixing nitrogen and promoting the growth of important plant crops such as maize, rice, and sugar cane. Several investigations have shown that H. seropedicae supplies fixed nitrogen to the associated plant and increases grain productivity up to 50%. In the genome of H. seropedicae, we identified all the genes involved in the nitrogen fixation process and its regulation and, in addition, genes potentially involved in the establishment of efficient interaction with the host plant. Our analyses also revealed that this bacterium has a highly versatile metabolism capable of synthesizing and degrading a large number of organic and inorganic compounds. We believe that the knowledge of the genome of this bacterium will direct research to a better understanding of this important endophytic organism and allow the construction of new strains with enhanced agronomic efficiency.
doi:10.1371/journal.pgen.1002064
PMCID: PMC3093359  PMID: 21589895

Results 1-3 (3)