Publications by authors named "Melody Dazas"
Microbial pathogenesis is mediated by the expression of virulence genes. However, as microbes with identical virulence gene content can differ in their pathogenic potential, other virulence determinants must be involved. Here, by combining comparative genomics and transcriptomics of a large collection of isolates of the model pathogen Listeria monocytogenes, time-lapse microscopy, in vitro evolution and in vivo experiments, we show that the individual stress responsiveness of L.
View Article and Find Full Text PDFBackground: WHO considers ESBL- and carbapenemase-producing Klebsiella pneumoniae a major global concern. In animals, ESBL- and carbapenemase-producing K. pneumoniae of human-related ST11, ST15 and ST307 have been reported, but not in the context of large WGS-based One Health investigations.
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- Corynebacterium diphtheriae, which causes diphtheria, shows significant genetic diversity and emerging antimicrobial resistance, particularly against penicillin.
- This study analyzed 247 strains collected worldwide to examine their antimicrobial susceptibility, toxin production, and genetic features, finding distinct sublineages linked to toxin presence.
- Key findings include that 17.2% of isolates were resistant to penicillin and that multidrug resistance was present in 10.4% of the tested strains, with genetic factors such as the PBP2m protein and a newly identified multiresistance plasmid playing roles in this resistance evolution.
Healthcare-associated infections (HAIs) are often overlooked in veterinary medicine. Serratia marcescens isolates were recovered over a ten-year period from companion animals in a French veterinary hospital. The pets were sampled either for diagnostic purposes or to monitor colonization.
View Article and Find Full Text PDFA group of six clinical isolates previously identified as Corynebacterium diphtheriae biovar Belfanti, isolated from human cutaneous or peritoneum infections and from one dog, were characterized by genomic sequencing, biochemical analysis and MALDI-TOF mass spectrometry. The six isolates were negative for the diphtheria toxin gene. Phylogenetic analyses showed that the six isolates (including FRC0190) are clearly demarcated from C.
View Article and Find Full Text PDFClinical isolates belonging to Corynebacterium diphtheriae biovar Belfanti were characterized by genomic sequencing and biochemical and chemotaxonomic analyses. Phylogenetic analyses indicated that biovar Belfanti represents a branch that is clearly demarcated from C. diphtheriae strains of biovars Mitis and Gravis.
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- Bordetella pertussis is the bacterium responsible for whooping cough, a contagious respiratory illness that is resurging in several regions worldwide.
- The emergence of antigen-deficient strains poses a risk to the effectiveness of existing acellular vaccines, highlighting the need for better strain transmission tracking.
- Researchers have developed a core genome multilocus sequence typing method that categorizes strains into 2,038 loci, allowing for detailed local and international epidemiological comparisons through a publicly accessible database.
and are the causal agents of whooping cough in humans. They produce diverse virulence factors, including adenylate cyclase-hemolysin (AC-Hly), a secreted toxin of the repeat in toxins (RTX) family with cyclase, pore-forming, and hemolytic activities. Post-translational modifications (PTMs) are essential for the biological activities of the toxin produced by .
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