Comparative Analysis of Commercially Available Typhoid Point-of-Care Tests: Results of a Prospective and Hybrid Retrospective Multicenter Diagnostic Accuracy Study in Kenya and Pakistan.

Blood and bone marrow cultures are considered the gold standard for the diagnosis of typhoid, but these methods require infrastructure and skilled staff that are not always available in low- and middle-income countries where typhoid is endemic. The objective of the study is to evaluate the sensitivity and specificity of nine commercially available Salmonella Typhi rapid diagnostic tests (RDTs) using blood culture as a reference standard in a multicenter study. This was a prospective and retrospective multicenter diagnostic accuracy study conducted in two geographically distant areas where typhoid is endemic (Pakistan and Kenya; NCT04801602).

Diagnostic tools used in the evaluation of acute febrile illness in South India: a scoping review.

Background: Acute febrile illness (AFI) is characterized by malaise, myalgia and a raised temperature that is a nonspecific manifestation of infectious diseases in the tropics. The lack of appropriate diagnostics for the evaluation of AFI leads to increased morbidity and mortality in resource-limited settings, specifically low-income countries like India. The review aimed to identify the number, type and quality of diagnostics used for AFI evaluation during passive case detection at health care centres in South India.

Guidance for Studies Evaluating the Accuracy of Rapid Tuberculosis Drug-Susceptibility Tests.

The development and implementation of rapid molecular diagnostics for tuberculosis (TB) drug-susceptibility testing is critical to inform treatment of patients and to prevent the emergence and spread of resistance. Optimal trial planning for existing tests and those in development will be critical to rapidly gather the evidence necessary to inform World Health Organization review and to support potential policy recommendations. The evidence necessary includes an assessment of the performance for TB and resistance detection as well as an assessment of the operational characteristics of these platforms.

Mycobacterium marinum antagonistically induces an autophagic response while repressing the autophagic flux in a TORC1- and ESX-1-dependent manner.

Autophagy is a eukaryotic catabolic process also participating in cell-autonomous defence. Infected host cells generate double-membrane autophagosomes that mature in autolysosomes to engulf, kill and digest cytoplasmic pathogens. However, several bacteria subvert autophagy and benefit from its machinery and functions.

Setting up and monitoring an infection of Dictyostelium discoideum with mycobacteria.

Mycobacterium marinum is the causative agent of fish and amphibian tuberculosis in the wild. It is a genetically close cousin of Mycobacterium tuberculosis, and thereby the infection process remarkably shares many of the hallmarks of M. tuberculosis infection in human, at both the cellular and organism levels.

An iron-regulated LysR-type element mediates antimicrobial peptide resistance and virulence in Yersinia pseudotuberculosis.

During the course of its infection of the mammalian digestive tract, the entero-invasive, Gram-negative bacterium Yersinia pseudotuberculosis must overcome various hostile living conditions (notably, iron starvation and the presence of antimicrobial compounds produced in situ). We have previously reported that in vitro bacterial growth during iron deprivation raises resistance to the antimicrobial peptide polymyxin B; here, we show that this phenotype is mediated by a chromosomal gene (YPTB0333) encoding a transcriptional regulator from the LysR family. We determined that the product of YPTB0333 is a pleiotropic regulator which controls (in addition to its own expression) genes encoding the Yfe iron-uptake system and polymyxin B resistance.

Two-component system regulon plasticity in bacteria: a concept emerging from phenotypic analysis of Yersinia pseudotuberculosis response regulator mutants.

In bacteria, the most rapid and efficient means of adapting gene transcription to extracellular stresses often involves sophisticated systems referred to as two-component systems (2CSs). Although highly conserved throughout the bacterial world, some of these systems may control distinct cell events and have differing contributions to virulence, depending on the species considered. This chapter summarizes the work performed by our group--from the initial PhoP-PhoQ and PmrA-PmrB studies to the most recent genome-scale preliminary analyses--in an attempt to highlight the contribution of 2CS regulon plasticity to the acquisition of some of Yersinia pseudotuberculosis' specific features.

Phenotypic analysis of Yersinia pseudotuberculosis 32777 response regulator mutants: new insights into two-component system regulon plasticity in bacteria.

Two-component regulatory systems (2CSs) typically comprise a sensor kinase and a response regulator that, in concert, monitor the concentration of particular extracellular factors and mediate the transcription of specific genes accordingly. As such, 2CSs play an important role in the regulation of bacterial pathogenesis. On the basis of genome-wide in silico analysis, the Gram-negative enteropathogenic bacterium Yersinia pseudotuberculosis is thought to encode 24 complete 2CSs.