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BioMed Research International
Volume 2014, Article ID 151405, 13 pages
Research Article

Phylogenetic Analysis of Stenotrophomonas spp. Isolates Contributes to the Identification of Nosocomial and Community-Acquired Infections

1Departamento de Pediatria, Faculdade de Medicina da Universidade de São Paulo, Avenida Dr. Enéas Carvalho Aguiar, 647-5° Andar, 05403-900 São Paulo, SP, Brazil
2Hospital Israelita Albert Einstein, 05652-900 São Paulo, SP, Brazil
3Laboratório de Bacteriologia , Instituto Butantan, 05503-900 São Paulo, SP, Brazil

Received 6 February 2014; Accepted 17 March 2014; Published 10 April 2014

Academic Editor: Ana Lucia Nascimento

Copyright © 2014 Vinicius Godoy Cerezer et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Stenotrophomonas ssp. has a wide environmental distribution and is also found as an opportunistic pathogen, causing nosocomial or community-acquired infections. One species, S. maltophilia, presents multidrug resistance and has been associated with serious infections in pediatric and immunocompromised patients. Therefore, it is relevant to conduct resistance profile and phylogenetic studies in clinical isolates for identifying infection origins and isolates with augmented pathogenic potential. Here, multilocus sequence typing was performed for phylogenetic analysis of nosocomial isolates of Stenotrophomonas spp. and, environmental and clinical strains of S. maltophilia. Biochemical and multidrug resistance profiles of nosocomial and clinical strains were determined. The inferred phylogenetic profile showed high clonal variability, what correlates with the adaptability process of Stenotrophomonas to different habitats. Two clinical isolates subgroups of S. maltophilia sharing high phylogenetic homogeneity presented intergroup recombination, thus indicating the high permittivity to horizontal gene transfer, a mechanism involved in the acquisition of antibiotic resistance and expression of virulence factors. For most of the clinical strains, phylogenetic inference was made using only partial ppsA gene sequence. Therefore, the sequencing of just one specific fragment of this gene would allow, in many cases, determining whether the infection with S. maltophilia was nosocomial or community-acquired.