Management of unexpected laboratory exposure to Burkholderia pseudomallei.

Burkholderia pseudomallei is a Gram-negative saprophytic bacillus that causes melioidosis. The infection is endemic in South-East of Asia and Northern Australia. B.

Population dynamics of plague vector fleas in an endemic focus: implications for plague surveillance.

Plague is a zoonotic vector-borne disease caused by the bacterium Yersinia pestis. In Madagascar, it persists in identified foci, where it is a threat to public health generally from September to April. A more complete understanding of how the disease persists could guide control strategies.

New Bacteriophages with Podoviridal Morphotypes Active against : Characterization and Application Potential.

Phages of highly pathogenic bacteria represent an area of growing interest for bacterial detection and identification and subspecies typing, as well as for phage therapy and environmental decontamination. Eight new phages-YpEc56, YpEc56D, YpEc57, YpEe58, YpEc1, YpEc2, YpEc11, and YpYeO9-expressing lytic activity towards revealed a virion morphology consistent with the morphotype. These phages lyse all 68 strains from 2 different sets of isolates, thus limiting their potential application for subtyping of strains but making them rather promising in terms of infection control.

Assessment of calcium hypochlorite for Bacillus anthracis spore surface's decontamination.

Contamination with microorganisms occurs in laboratories but is also of high concern in the context of bioterrorism. Decontamination is a cornerstone that promotes good laboratory practices and occupational health and safety. Among the most resistant structures formed by microorganisms are spores, produced notably by Clostridium and Bacillus species.

Analysis of Ancient Microbial DNA.

The development of next-generation sequencing has led to a breakthrough in the analysis of ancient genomes, and the subsequent genomic analyses of ancient human skeletal remains have revolutionized our understanding of human evolution. This research led to the discovery of a new hominin lineage, and demonstrated multiple admixture events with more distantly related archaic human populations such as Neandertals and Denisovans over the last 100,000 years. Moreover, it has also yielded novel insights into the evolution of ancient pathogens.

Tecovirimat is effective against human monkeypox virus in vitro at nanomolar concentrations.

The ongoing monkeypox virus (MPXV) outbreak is the largest ever recorded outside of Africa. We isolated and sequenced a virus from the first clinical MPXV case diagnosed in France (May 2022). We report that tecovirimat (ST-246), a US Food and Drug Administration approved drug, is efficacious against this isolate in vitro at nanomolar concentrations, whereas cidofovir is only effective at micromolar concentrations.

Origin and mobility of Iron Age Gaulish groups in present-day France revealed through archaeogenomics.

The Iron Age period occupies an important place in French history because the Gauls are regularly presented as the direct ancestors of the extant French population. We documented here the genomic diversity of Iron Age communities originating from six French regions. The 49 acquired genomes permitted us to highlight an absence of discontinuity between Bronze Age and Iron Age groups in France, lending support to a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups.

Rodent control to fight plague: field assessment of methods based on rat density reduction.

Rodents represent a serious threat to food security and public health. The extent to which rodent control can mitigate the risk from rodent-borne disease depends on both the effectiveness of control in reducing rodent abundance and the impact on disease epidemiology. Focusing on a plague-endemic region of Madagascar, this study compared the effectiveness of 3 methods: live-traps, snap-traps, and rodenticides.

Tolerance engineering in Deinococcus geothermalis by heterologous efflux pumps.

Producing industrially significant compounds with more environmentally friendly represents a challenging task. The large-scale production of an exogenous molecule in a host microfactory can quickly cause toxic effects, forcing the cell to inhibit production to survive. The key point to counter these toxic effects is to promote a gain of tolerance in the host, for instance, by inducing a constant flux of the neo-synthetized compound out of the producing cells.

Genomic and RT-qPCR analysis of trimethoprim-sulfamethoxazole and meropenem resistance in Burkholderia pseudomallei clinical isolates.

Background: Melioidosis is an endemic disease in southeast Asia and northern Australia caused by the saprophytic bacteria Burkholderia pseudomallei, with a high mortality rate. The clinical presentation is multifaceted, with symptoms ranging from acute septicemia to multiple chronic abscesses. Here, we report a chronic case of melioidosis in a patient who lived in Malaysia in the 70s and was suspected of contracting tuberculosis.

Differential serological and neutralizing antibody dynamics after an infection by a single SARS-CoV-2 strain.

Background: We report here the case of two coworkers infected by the same SARS-CoV-2 strain, presenting two different immunological outcomes.

Case: One patient presented a strong IgG anti-receptor-binding domain immune response correlated with a low and rapidly decreasing titer of neutralizing antibodies. The other patient had a similar strong IgG anti-receptor-binding domain immune response but high neutralizing antibody titers.

Case Report of an Injectional Anthrax in France, 2012.

(1) Background: is a spore-forming, Gram-positive bacterium causing anthrax, a zoonosis affecting mainly livestock. When occasionally infecting humans, provokes three different clinical forms: cutaneous, digestive and inhalational anthrax. More recently, an injectional anthrax form has been described in intravenous drug users.

Three New Cases of Melioidosis, Guadeloupe, French West Indies.

Melioidosis has been detected in the Caribbean, and an increasing number of cases has been reported in the past few decades, but only 2 cases were reported in Guadeloupe during the past 20 years. We describe 3 more cases that occurred during 2016-2017 and examine arguments for increasing endemicity.

Polyamino-Isoprenyl Derivatives as Antibiotic Adjuvants and Motility Inhibitors for Porcine Pulmonary Infection Treatment.

The spreading of multidrug-resistant bacteria and the lack of novel antibiotic molecules leave clinicians and veterinarians with very limited options to treat bacterial infections, especially those caused by Gram-negative pathogens. To reduce the selection of antibiotic resistance mechanisms and their transfer to human pathogens, veterinary pharmaceutical companies have dramatically decreased the number of antibiotics used. Among all the investigated alternate solutions, chemosensitizers, which decrease the amount of the used drugs, appear to be one of the most promising strategies.

Transcriptomic studies and assessment of Yersinia pestis reference genes in various conditions.

Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) is a very sensitive widespread technique considered as the gold standard to explore transcriptional variations. While a particular methodology has to be followed to provide accurate results many published studies are likely to misinterpret results due to lack of minimal quality requirements. Yersinia pestis is a highly pathogenic bacterium responsible for plague.

Analysis of Ancient DNA in Microbial Ecology.

The development of next-generation sequencing has led to a breakthrough in the analysis of ancient genomes, and the subsequent genomic analyses of the skeletal remains of ancient humans have revolutionized the knowledge of the evolution of our species, including the discovery of a new hominin, and demonstrated admixtures with more distantly related archaic populations such as Neandertals and Denisovans. Moreover, it has also yielded novel insights into the evolution of ancient pathogens. The analysis of ancient microbial genomes allows the study of their recent evolution, presently over the last several millennia.

A New High-Throughput Approach to Genotype Ancient Human Gastrointestinal Parasites.

Human gastrointestinal parasites are good indicators for hygienic conditions and health status of past and present individuals and communities. While microscopic analysis of eggs in sediments of archeological sites often allows their taxonomic identification, this method is rarely effective at the species level, and requires both the survival of intact eggs and their proper identification. Genotyping via PCR-based approaches has the potential to achieve a precise species-level taxonomic determination.

Generation of a CRISPR database for Yersinia pseudotuberculosis complex and role of CRISPR-based immunity in conjugation.

The clustered regularly interspaced short palindromic repeat - CRISPR-associated genes (CRISPR-Cas) system is used by bacteria and archaea against invading conjugative plasmids or bacteriophages. Central to this immunity system are genomic CRISPR loci that contain fragments of invading DNA. These are maintained as spacers in the CRISPR loci between direct repeats and the spacer composition in any bacterium reflects its evolutionary history.

Clostridium botulinum group I strain genotyping by 15-locus multilocus variable-number tandem-repeat analysis.

Clostridium botulinum is a taxonomic designation that encompasses a broad variety of spore-forming, Gram-positive bacteria producing the botulinum neurotoxin (BoNT). C. botulinum is the etiologic agent of botulism, a rare but severe neuroparalytic disease.

Insight into microevolution of Yersinia pestis by clustered regularly interspaced short palindromic repeats.

Background: Yersinia pestis, the pathogen of plague, has greatly influenced human history on a global scale. Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR), an element participating in immunity against phages' invasion, is composed of short repeated sequences separated by unique spacers and provides the basis of the spoligotyping technology. In the present research, three CRISPR loci were analyzed in 125 strains of Y.

Selection and validation of a multilocus variable-number tandem-repeat analysis panel for typing Shigella spp.

The Shigella genus has historically been separated into four species, based on biochemical assays. The classification within each species relies on serotyping. Recently, genome sequencing and DNA assays, in particular the multilocus sequence typing (MLST) approach, greatly improved the current knowledge of the origin and phylogenetic evolution of Shigella spp.

Analysis of the three Yersinia pestis CRISPR loci provides new tools for phylogenetic studies and possibly for the investigation of ancient DNA.

The precise nature of the pathogen having caused early plague pandemics is uncertain. Although Yersinia pestis is a likely candidate for all three plague pandemics, the very rare direct evidence that can be deduced from ancient DNA (aDNA) analysis is controversial. Moreover, which of the three biovars, Antiqua, Medievalis or Orientalis, was associated with these pandemics is still debated.

Genotyping of Bacillus anthracis strains based on automated capillary 25-loci multiple locus variable-number tandem repeats analysis.

Background: The genome of Bacillus anthracis, the etiological agent of anthrax, is highly monomorphic which makes differentiation between strains difficult. A Multiple Locus Variable-number tandem repeats (VNTR) Analysis (MLVA) assay based on 20 markers was previously described. It has considerable discrimination power, reproducibility, and low cost, especially since the markers proposed can be typed by agarose-gel electrophoresis.