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Andrée-Anne Lachance Jean-Denis Dutil Richard Larocque Gaétan Daigle 《Environmental Biology of Fishes》2010,88(3):207-215
Laboratory experiments were conducted to assess shelter use and behaviour of juvenile Spotted Wolffish, Anarhichas minor, using time-lapse video. Information about the behaviour of Spotted Wolffish and its habitat utilization is sparse due to
the great depth at which this species lives. Four experiments were conducted using one or two fish per tank, with and without
a shelter. The positions and movements of fish in the tanks and interactions between fish were monitored over 24-h periods.
In experiments in which no shelter was available, Spotted Wolffish spent very little time exploring the water column. They
did not show fidelity to a particular area on the bottom of the tank and exhibited few signs of aggressiveness to each other.
When a shelter was made available, fish spent most of their time in the shelter or close to the shelter. The presence of a
single shelter did not enhance aggressive behaviours in fish kept in pairs. When day and night observations were compared,
no clear diel pattern emerged. The Canadian recovery plan for Spotted Wolffish calls for research aimed at describing their
use of demersal habitats. The present study suggests that shelter availability might be an important feature of the habitat
requirements of juvenile Spotted Wolffish. 相似文献
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H. Lemieux J.-D. Dutil H. Guderley R. Larocque 《Marine and Freshwater Behaviour and Physiology》2013,45(4):287-294
Muscle protein decreases only during prolonged starvation of Atlantic cod (Gadus morhua, Gadidae), but in the absence of protein renewal, muscle metabolic capacities may decrease before marked loss of muscle protein. This study aimed at elucidating the threshold at which decreases in growth and condition reduce muscle metabolic capacities, as well as identifying the indicators that best explain changes in metabolic capacities. To generate a wide spectrum of individual growth rates, condition factors and proximate compositions, cod showing different initial condition were fed or starved for different periods of time. The relationships between muscle proteins and metabolic enzyme activities (LDH and CCO) on one hand, and growth rate, condition factor, hepato- and gonadosomatic index and muscle and liver water and energy contents, on the other hand, were examined through linear regression models. Multiple linear regressions explained a large proportion of the observed variability in proteins and enzyme activities. Changes in LDH and CCO activities were not driven by changes in growth rate. Muscle water was the only significant correlate for both enzymes. Enzyme activities decreased as soon as muscle water began to rise. Increases in water content from 79 to 92% resulted in a 10-fold decrease in LDH and CCO activities. 相似文献
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Julianne V. Kus Manal Tadros Andrew Simor Donald E. Low Allison J. McGeer Barbara M. Willey Cindy Larocque Karen Pike Iris-Ann Edwards Helen Dedier Roberto Melano David A. Boyd Michael R. Mulvey Lisa Louie Christopher Okeahialam Mark Bayley Cynthia Whitehead Denyse Richardson Lesley Carr Fatema Jinnah Susan M. Poutanen 《CMAJ》2011,183(11):1257-1261
New Delhi metallo-β-lactamase-1 (NDM-1) is a recently identified metallo-β-lactamase that confers resistance to carbapenems and all other β-lactam antibiotics, with the exception of aztreonam. NDM-1 is also associated with resistance to many other classes of antibiotics. The enzyme was first identified in organisms isolated from a patient in Sweden who had previously received medical treatment in India, but it is now recognized as endemic throughout India and Pakistan and has spread worldwide. The gene encoding NDM-1 has been found predominantly in Escherichia coli and Klebsiella pneumoniae. We describe the isolation NDM-1–producing organisms from two patients in Toronto, Ontario. To the best of our knowledge, this is the first report of an organism producing NDM-1 that was locally acquired in Canada. We also discuss the evidence that NDM-1 can affect bacterial species other than E. coli and K. pneumoniae, the limited options for treatment and the difficulty laboratories face in detecting organisms that produce NDM-1.New Delhi metallo-β-lactamase-1 (NDM-1) is a metallo-β-lactamase that confers resistance to carbapenems and all other β-lactam antibiotics, with the exception of aztreonam. It is predominantly found in the Enterobacteriaeceae. It was first identified in Escherichia coli and Klebsiella pneumoniae isolated from a patient in Sweden who had previously received medical treatment in India. It is now recognized as endemic throughout India and Pakistan and has spread worldwide due to travel, “medical tourism” and the ability of the genetic element encoding the enzyme to transfer between bacteria.1–3 Three reports of organisms producing NDM-1 in Canada have been published to date. In each instance, the organisms were isolated from the urinary tracts of patients who had recently been admitted to hospitals in India. Two of the isolates were strains of K. pneumoniae and one was a strain of E. coli.4–6 Additional reports of isolation of organisms producing NDM-1 from patients in Canada have been presented in the lay press.Organisms that produce NDM-1 have been associated with resistance to classes of antibiotics other than the β-lactams, thus severely limiting options for treatment.2 Infection control guidance regarding the management of colonization by or infection with organisms that produce carbapenemases, such as NDM-1, have recently been published by Canadian and European authorities.7–9 An essential component of these recommendations is the rapid and accurate identification of the organisms in a clinical microbiology laboratory. The Clinical Laboratory Standards Institute (CLSI) and the United States Centers for Disease Control and Prevention (CDC) recommend screening for the production of carbapenemase using the Modified Hodge Test.10,11 If the result of that test is positive, then the presence and type of carbapenemase can be confirmed by polymerase chain reaction.4Herein, we summarize two additional instances in which organisms producing NDM-1 were isolated from patients in Canada and the first where the organism appears to have been acquired in Canada. 相似文献
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Meeting cholera's challenge to Haiti and the world: a joint statement on cholera prevention and care
Farmer P Almazor CP Bahnsen ET Barry D Bazile J Bloom BR Bose N Brewer T Calderwood SB Clemens JD Cravioto A Eustache E Jérôme G Gupta N Harris JB Hiatt HH Holstein C Hotez PJ Ivers LC Kerry VB Koenig SP Larocque RC Léandre F Lambert W Lyon E Mekalanos JJ Mukherjee JS Oswald C Pape JW Gretchko Prosper A Rabinovich R Raymonville M Réjouit JR Ronan LJ Rosenberg ML Ryan ET Sachs JD Sack DA Surena C Suri AA Ternier R Waldor MK Walton D Weigel JL 《PLoS neglected tropical diseases》2011,5(5):e1145
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Altman E Chandan V Larocque S Aubry A Logan SM Vinogradov E Li J 《FEMS immunology and medical microbiology》2008,53(2):204-213
The outer core region of Helicobacter pylori lipopolysaccharide of the majority of isolates contains an alpha-1,6-glucan polymer synthesized by the product of the HP0159 ORF. Structural studies carried out on HP0159 lipopolysaccharide mutants by a combination of chemical methods, mass spectrometry and nuclear magnetic resonance spectroscopy confirmed that insertional inactivation of HP0159 gene in H. pylori strains 26695 and SS1 resulted in formation of a truncated lipopolysaccharide molecule characterized by the presence of a terminal dd-heptose residue in the side-chain outer core fragment and maintaining an inner core backbone structure compared with the wild-type Lewis antigen-expressing strains. Colonization studies with HP0159 mutants of two mouse-colonizing strains, SS1 and M6, confirmed their inability to successfully colonize the murine stomach. 相似文献
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Analysis of the relative abundance of different types of bacteria capable of toluene degradation in a compost biofilter 总被引:16,自引:0,他引:16
A microbial community of a compost biofilter treating toluene vapors was investigated using serum-bottle assays and mineral-agar
plates. Toluene was not consumed in the absence of oxygen. However, filter-bed extracts exposed to toluene vapor as the only
carbon source produced distinct colony types (phenotypic groups) that were counted separately. Strains from each group were
isolated and checked for toluene-degradation activity in serum bottles. Only 15% of colonies were true toluene degraders.
This population was divided into 11 genotypic groups based on DNA fingerprints. Identification of a member of each group using
16S rRNA gene-sequence comparison showed that they belonged to seven genera: Acinetobacter, Azoarcus, Mycobacterium, Nevskia, Pseudomonas, Pseudonocardia and Rhodococcus. Together, members of the genera Pseudonocardia and Rhodococcus were 34 times more numerous than all the others. We hypothesized that these two organisms are K-strategists (adapted to a resource-restricted and crowded environment) and that the compost biofilter is a K-environment. This would explain why they are not outnumbered by faster growers like Pseudomonas or Acinetobacter species, which would be r-strategists (adapted to a resource-abundant and uncrowded environment).
Received: 11 March 1999 / Received revision: 24 June 1999 / Accepted: 1 August 1999 相似文献