[High-risk clonal complexes CC2 and CC9 are widely distributed among Enterococcus faecalis hospital isolates recovered in Spain].
ABSTRACT Our previously described multilocus sequence typing (MLST) scheme for Enterococcus faecalis has provided insight into the population structure and global epidemiology of this organism. Two high-risk complexes, CC2 and CC9, especially adapted to the hospital environment and widely distributed in Europe and America, were identified. The purpose of this study was to define the presence of CC2 and CC9 among E. faecalis strains isolated in Spain.
A total of 81 E. faecalis isolates recovered from several sources and geographic areas of Spain were characterized using MLST. Because of their clinical and epidemiological interest, strains were included from each of the vancomycin-resistant E. faecalis hospital outbreaks described in Spain.
Among the isolates, CC2 and CC9 were detected in the hospital setting. Included in these CC were the vancomycin-resistant E. faecalis isolates causing hospital outbreaks in La Coruña, Palma de Mallorca and Valencia, as well as vancomycin-susceptible hospital isolates. The Index of Association (Ia), which measures linkage disequilibrium between alleles, revealed an epidemic population structure on a background of high recombination rates.
High-risk complexes (CC2 and CC9) particularly adapted to the hospital environment were detected in Spain. Evolution of these CC in different areas depended on the local gene pool. Future infection control policies should be orientated to detect high-risk CC with the aim of predicting potential trends toward acquisition of specific resistance, such as to vancomycin.
Article: Essential role of Phox2b-expressing ventrolateral brainstem neurons in the chemosensory control of inspiration and expiration.[show abstract] [hide abstract]
ABSTRACT: Phox2b-expressing neurons of the retrotrapezoid nucleus (RTN), located in the ventrolateral brainstem, are sensitive to changes in PCO(2)/pH, have excitatory projections to the central respiratory rhythm/pattern generator, and their activation enhances central respiratory drive. Using in vivo (conscious and anesthetized rats) and in situ (arterially perfused rat brainstem-spinal cord preparations) models, we evaluated the functional significance of this neuronal population for both resting respiratory activity and the CO(2)-evoked respiratory responses by reversibly inhibiting these neurons using the insect peptide allatostatin following transduction with a lentiviral construct to express the G-protein-coupled Drosophila allatostatin receptor. Selective inhibition of the Phox2b-expressing neurons in the ventrolateral brainstem, including the RTN, using allatostatin was without effect on resting respiratory activity in conscious rats, but decreased the amplitude of the phrenic nerve discharge in anesthetized rats and the in situ rat preparations. Postinspiratory activity was also reduced in situ. In the absence or presence of the peripheral chemoreceptor input, inhibiting the Phox2b-expressing neurons during hypercapnia abolished the CO(2)-evoked abdominal expiratory activity in anesthetized rats and in situ preparations. Inspiratory responses evoked by rising levels of CO(2) in the breathing air were also reduced in anesthetized rats with denervated carotid bodies and conscious rats with peripheral chemoreceptors intact (by 28% and 60%, respectively). These data indicate a crucial dependence of central expiratory drive upon Phox2b-expressing neurons of the ventrolateral brainstem and support the hypothesis that these neurons contribute in a significant manner to CO(2)-evoked increases of inspiratory activity.Journal of Neuroscience 09/2010; 30(37):12466-73. · 7.11 Impact Factor