INVESTIGADORES
QUIROGA Maria Paula
artículos
Título:
Class 1 integrons in environments with different degrees of urbanization
Autor/es:
NARDELLI MAXIMILIANO; SCALZO PAULA MARINA; RAMÍREZ MARÍA SOLEDAD; QUIROGA MARÍA PAULA; CASSINI MARCELO HERNÁN; CENTRÓN DANIELA
Revista:
PLOS ONE
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2012 vol. 7 p. 1 - 13
ISSN:
1932-6203
Resumen:
Background: Class 1 integrons are
one of the most successful elements in the acquisition, expression and spread
of antimicrobial resistance genes (ARG) among clinical isolates. Little is
known about the gene flow of the components of the genetic platforms of class 1
integrons within and between bacterial communities. Thus it is important to
better understand the interactions among "environmental" intI1, its genetic platforms and its
distribution with human activities.
Methodology/Principal Findings: An evaluation of two
types of genetic determinants, ARG (sul1
and qacE1/qacEΔ1 genes) and lateral
genetic elements (LGE) (intI1, ISCR1 and tniC genes) in a model of a culture-based method without antibiotic
selection was conducted in a gradient of anthropogenic disturbances in a
Patagonian island recognized as being one of the last regions containing wild
areas. The intI1, ISCR1 genes and intI1 pseudogenes that were found widespread throughout natural
communities were not associated with urbanization (p>0.05). Each ARG that is
embedded in the most common genetic platform of clinical class 1 integrons,
showed different ecological and molecular behaviours in environmental samples.
While the sul1 gene frequency was associated
with urbanization, the qacE1/qacEΔ1
gene showed an adaptive role to several habitats.
Conclusions/Significance: The high frequency of
intI1 pseudogenes suggests that,
although intI1 has a deleterious
impact within several genomes, it can easily be disseminated among natural
bacterial communities. The widespread occurrence of ISCR1 and intI1 throughout
Patagonian sites with different degree of urbanization, and within different
taxa, could be one of the causes of the increasing frequency of
multidrug-resistant isolates that have characterized Argentina for decades. The
flow of ARG and LGE between natural and clinical communities cannot be
explained with a single general process but is a direct consequence of the
interaction of multiple factors operating at molecular, ecological,
phylogenetic and historical levels.