François Signorino-Gelo

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Dynamic persistence of UPEC intracellular bacterial communities in a human bladder-chip model of urinary tract infection

Neeraj Dhar, John McKinney, Kunal Sharma, François Signorino-Gelo, Thomas Marie Simonet, Vivek Vijay Thacker

Uropathogenic Escherichia coli (UPEC) proliferate within superficial bladder umbrella cells to form intracellular bacterial communities (IBCs) during early stages of urinary tract infections. However, the dynamic responses of IBCs to host stresses and antibiotic therapy are difficult to assess in situ. We develop a human bladder-chip model wherein umbrella cells and bladder microvascular endothelial cells are co-cultured under flow in urine and nutritive media respectively, and bladder filling and voiding mimicked mechanically by application and release of linear strain. Using time-lapse microscopy, we show that rapid recruitment of neutrophils from the vascular channel to sites of infection leads to swarm and neutrophil extracellular trap formation but does not prevent IBC formation. Subsequently, we tracked bacterial growth dynamics in individual IBCs through two cycles of antibiotic administration interspersed with recovery periods which revealed that the elimination of bacteria within IBCs by the antibiotic was delayed, and in some instances, did not occur at all. During the recovery period, rapid proliferation in a significant fraction of IBCs reseeded new foci of infection through bacterial shedding and host cell exfoliation. These insights reinforce a dynamic role for IBCs as harbours of bacterial persistence, with significant consequences for non-compliance with antibiotic regimens.

2021

Identification of aminopyrimidine-sulfonamides as potent modulators of Wag31-mediated cell elongation in mycobacteria

Stewart Cole, Neeraj Dhar, Ruben Hartkoorn, Kai Johnsson, Graham Knott, Gaëlle Séraphine Kolly, John McKinney, Monica Rengifo Gonzalez, Jan Lars Rybniker, Isabella Santi, François Signorino-Gelo, Edina Rita Székely, Anthony Vocat

There is an urgent need to discover new antitubercular agents with novel mechanisms of action in order to tackle the scourge of drug-resistant tuberculosis. Here, we report the identification of such a molecule - an AminoPYrimidine-Sulfonamide (APYS1) that has potent, bactericidal activity against M. tuberculosis. Mutations in APYS1-resistant M. tuberculosis mapped exclusively to wag31, a gene that encodes a scaffolding protein thought to orchestrate cell elongation. Recombineering confirmed that a Gln201Arg mutation in Wag31 was sufficient to cause resistance to APYS1, however, neither overexpression nor conditional depletion of wag31 impacted M. tuberculosis susceptibility to this compound. In contrast, expression of the wildtype allele of wag31 in APYS1-resistant M. tuberculosis was dominant and restored susceptibility to APYS1 to wildtype levels. Time-lapse imaging and scanning electron microscopy revealed that APYS1 caused gross malformation of the old pole of M. tuberculosis, with eventual lysis. These effects resembled the morphological changes observed following transcriptional silencing of wag31 in M. tuberculosis. These data show that Wag31 is likely not the direct target of APYS1, but the striking phenotypic similarity between APYS1 exposure and genetic depletion of Wag31 in M. tuberculosis suggests that APYS1 might indirectly affect Wag31 through an as yet unknown mechanism.

Wiley-Blackwell2017

Dynamic persistence of UPEC intracellular bacterial communities in a human bladder-chip model of urinary tract infection

Early invasion of the bladder wall by solitary bacteria protects UPEC from antibiotics and neutrophil swarms in an organoid model

Identification of aminopyrimidine-sulfonamides as potent modulators of Wag31-mediated cell elongation in mycobacteria

Dynamic persistence of UPEC intracellular bacterial communities in a human bladder-chip model of urinary tract infection

Early invasion of the bladder wall by solitary bacteria protects UPEC from antibiotics and neutrophil swarms in an organoid model

Identification of aminopyrimidine-sulfonamides as potent modulators of Wag31-mediated cell elongation in mycobacteria