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De Luca DG, Alexander DC, Dingle TC, Dufresne PJ, Hoang LM, Kus JV, Schwartz IS, Mulvey MR, Bharat A. Four genomic clades of Candida auris identified in Canada, 2012-2019. Med Mycol 2021; 60:6462910. [PMID: 34910140 DOI: 10.1093/mmy/myab079] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/29/2021] [Accepted: 12/13/2021] [Indexed: 11/14/2022] Open
Abstract
Candida auris is an emerging yeast that is associated with antifungal resistance and healthcare-associated outbreaks. From 2012-2019, there were 24 known cases of C. auris colonization or infection in Canada. Isolates were from axilla/groin (n = 6), ear (n = 5), blood (n = 4), toe (n = 2), and a variety of other sites (n = 7). Canadian isolates belonged to the four main genomic clades: Clade I (formerly called South Asian clade, n = 12), Clade II (East Asian, n = 3), Clade III (African, n = 4), and Clade IV (South American, n = 5). Isolates within each clade were clonal, however, whole genome sequencing may be helpful in identifying clusters within healthcare facilities.
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Affiliation(s)
- Domenica G De Luca
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg MB, Canada.,University of Manitoba, Winnipeg, MB, Canada
| | | | - Tanis C Dingle
- Alberta Precision Laboratories, Edmonton, AB, Canada.,University of Alberta, Edmonton, AB, Canada
| | - Philippe J Dufresne
- Laboratoire de santé publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada
| | - Linda M Hoang
- BC Centre for Disease Control, Vancouver, BC, Canada
| | | | | | - Michael R Mulvey
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg MB, Canada.,University of Manitoba, Winnipeg, MB, Canada
| | - Amrita Bharat
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg MB, Canada.,University of Manitoba, Winnipeg, MB, Canada
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Croxen MA, Lee TD, Azana R, Hoang LM. Use of genomics to design a diagnostic assay to discriminate between Streptococcus pneumoniae and Streptococcus pseudopneumoniae. Microb Genom 2018; 4:e000175. [PMID: 29629856 PMCID: PMC6113875 DOI: 10.1099/mgen.0.000175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/29/2018] [Indexed: 12/20/2022] Open
Abstract
Distinuishing the species of mitis group streptococci is challenging due to ambiguous phenotypic characteristics and high degree of genetic similarity. This has been particularly true for resolving atypical Streptococcus pneumoniae and Streptococcus pseudopneumoniae. We used phylogenetic clustering to demonstrate specific and separate clades for both S. pneumoniae and S. pseudopneumoniae genomes. The genomes that clustered within these defined clades were used to extract species-specific genes from the pan-genome. The S. pneumoniae marker was detected in 8027 out of 8051 (>99.7 %) S. pneumoniae genomes. The S. pseudopneumoniae marker was specific for all genomes that clustered in the S. pseudopneumoniae clade, including unresolved species of the genus Streptococcus sequenced by the BC Centre for Disease Control Public Health Laboratory that previously could not be distinguished by other methods. Other than the presence of the S. pseudopneumoniae marker in six of 8051 (<0.08 %) S. pneumoniae genomes, both the S. pneumoniae and S. pseudopneumoniae markers showed little to no detectable cross-reactivity to the genomes of any other species of the genus Streptococcus or to a panel of over 46 000 genomes from viral, fungal, bacterial pathogens and microbiota commonly found in the respiratory tract. A real-time PCR assay was designed targeting these two markers. Genomics provides a useful technique for PCR assay design and development.
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Affiliation(s)
- Matthew A. Croxen
- BC Centre for Disease Control Public Health Laboratory, Vancouver, Canada
- Provincial Laboratory for Public Health (ProvLab), University of Alberta Hospital, Edmonton, Alberta, Canada
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
- Present address: Provincial Laboratory for Public Health, Edmonton, Canada
- Present address: Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, Canada
| | - Tracy D. Lee
- BC Centre for Disease Control Public Health Laboratory, Vancouver, Canada
| | - Robert Azana
- BC Centre for Disease Control Public Health Laboratory, Vancouver, Canada
| | - Linda M. Hoang
- BC Centre for Disease Control Public Health Laboratory, Vancouver, Canada
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, Canada
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Hoang LM, Stiver G. Association between cephalosporin therapy and subsequent nosocomial enterococcal colonization in surgical patients. Proc West Pharmacol Soc 2000; 42:103-4. [PMID: 10697706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- L M Hoang
- Department of Medicine, University of British Columbia, Vancouver, Canada
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Hoang LM, Mathers DA. Internally applied endotoxin and the activation of BK channels in cerebral artery smooth muscle via a nitric oxide-like pathway. Br J Pharmacol 1998; 123:5-12. [PMID: 9484848 PMCID: PMC1565131 DOI: 10.1038/sj.bjp.0701570] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
1. In this study the role of nitric oxide synthase (NOS) in the acute activation of large conductance, Ca2+-activated K+ channels (BK channels) by internally applied E. coli lipopolysaccharide (LPS, endotoxin) was examined in vascular smooth muscle cells. 2. Cerebrovascular smooth muscle cells (CVSMCs) were enzymatically dispersed from the middle, posterior communicating and posterior cerebral arteries of adult Wistar rats and maintained at 4 degrees C for 2-4 days before recording with standard patch-clamp techniques. 3. Acute application of LPS (100 microg ml(-1)) to inside-out patches of CVSMC membrane isolated in a cell-free environment rapidly and reversibly increased the open probability, Po of BK channels in these patches by 3.3+/-0.30 fold. 4. Acute application of the nitric oxide (NO) donor sodium nitroprusside (SNP, 100 microM) to inside-out patches of CVSMC membrane, studied in the presence of intact cells, also reversibly increased Po, by some 1.8+/-0.2 fold over control. 5. Kinetic analysis showed that both LPS and SNP increased Po by accelerating the rate of BK channel reopening, rather than by retarding the closure of open channels. 6. Neither LPS nor SNP altered the reversal potential or conductance of BK channels. 7. The NOS substrate L-arginine (1 microM) potentiated the acute activation of BK channels by LPS, while the synthetic enantiomer D-arginine (1 microM) inhibited the action of LPS on BK channels. 8. The acute activation of BK channels by LPS was suppressed by pre-incubation of cells with N(omega)-nitro-L-arginine (50 microM) or N(omega)-nitro-L-arginine methyl ester (1 mM), two competitive antagonists of nitric oxide synthases. N(omega)-nitro-D-arginine (50 microM), a poor inhibitor of NOS in in vitro assays, had no effect on BK channel activation by LPS. 9. These results indicate that excised, inside-out patches of CVSMC membrane exhibit a NOS-like activity which is acutely activated when LPS is present at the cytoplasmic membrane surface. Possible relationships between this novel mechanism and the properties of known isoforms of nitric oxide synthase are discussed.
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Affiliation(s)
- L M Hoang
- Department of Physiology, University of British Columbia, Vancouver, Canada
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Hoang LM, Chen C, Mathers DA. Lipopolysaccharide rapidly activates K+ channels at the intracellular membrane face of rat cerebral artery smooth muscle cells. Neurosci Lett 1997; 231:25-8. [PMID: 9280159 DOI: 10.1016/s0304-3940(97)00519-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lipopolysaccharide (LPS) may accumulate inside mammalian cells through endocytotic uptake or during the replication in invasive bacterial strains. However, the effects of intracellular LPS on cell function remain unknown. This study therefore examined the action of intracellularly applied E. coli LPS on large-conductance, Ca2+-dependent K+ channels (BK channels) in the membrane of rat cerebrovascular smooth muscle cells (CVSMCs). LPS (10-100 microg/ml) rapidly increased the open probability of BK channels when applied to the cytoplasmic face of CVSMC membrane patches. This response was reversible, dose-dependent and reflected an enhanced rate of channel opening in the presence of LPS. These results show for the first time that LPS can alter the gating behavior of ionic channels when applied to the cytoplasmic face of a eukaryotic cell membrane.
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Affiliation(s)
- L M Hoang
- Department of Physiology, Faculty of Medicine, University of British Columbia, Vancouver, Canada
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