An in vitro platform for elucidating the molecular genetics of S. aureus invasion of the osteocyte lacuno-canalicular network during chronic osteomyelitis

Masters, Elysia A; Salminen, Alec T.; Begolo, Stefano; Luke, Emma; Barrett, Sydney C; Overby, Clyde; Gill, Ann Lindley; Bentley, Karen L. de Mesy; Awad, Hani A.; Gill, Steven R.; Schwarz, Edward M.; McGrath, James L.

doi:10.1016/j.nano.2019.102039

Cited by 36 publications

(55 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additional mutant strains identified in the genetic screen, agrC and sasC, were also evaluated for changes in cell morphology and growth rate (S1 Fig). SEM results confirmed an expected cell clumping phenotype of the agrC mutant [25], as well as a slightly increased mean cell diameter and hindered growth during stationary phase. SasC mutant cells were statistically similar to WT in cell size and in growth rate.…”

Section: Resultssupporting

confidence: 66%

“…To validate the results of the genetic screen, which used pools of transposon insertion mutants, monoculture μSiM-CA nanopore propagation experiments were performed. It is known that WT S. aureus readily propagates through the 0.5 μm pores within 6 hours ( Fig 3A) [25]. In contrast, a pbp4 deletion mutant of S. aureus, USA300 Δpbp4, was incapable of propagating through the nanopores ( Fig 3B).…”

Section: Resultsmentioning

confidence: 97%

“…PBP4 is Critical for S. aureus Invasion of OLCN in Bone pathogenic process is inconsistent with the established dogma of S. aureus as a non-motile coc-cus~1 μm in diameter, the elucidation of the genes involved in invasion and colonization of the OLCN will provide greater insights into this deadly human pathogen. Previously we have validated the utility of the μSiM-CA platform to distinguish the phenotype of S. aureus strains based on propagation through nanopores [25]. Here we expand on this work by screening a target mutant library, assembled from NTML transposon insertion mutant strains, of S. aureus genes hypothesized to contribute to OLCN invasion through changes in cell wall structure, cell division and cell shape.…”

Section: Plos Pathogensmentioning

confidence: 91%

“…OLCN invasion represents a novel class of antibiotic targets for the prevention and treatment of chronic osteomyelitis. To this end, we developed and characterized the Microfluidic-Silicon Membrane-Canalicular Array (μSiM-CA), which is an in vitro model designed to mimic the dimensions and rigidity of canaliculi using a silicon membrane with spatially pattered 0.5 μm pores [25]. Here we describe a hypothesis-driven genetic screen in which 24 S. aureus mutants with transposon disruptions in genes hypothesized to be involved in OLCN invasion, based on their known function, were assessed for their ability to propagate through the μSiM-CA ( Fig 1A).…”

Section: Plos Pathogensmentioning

confidence: 99%

“…On the other hand, agrC was likely identified as a false positive in the genetic screen due to its aggregation phenotype and increased cell diameter. Indeed, foundational work using the μSiM-CA found that the accessory gene regulator (agr) of S. aureus is not required for bacterial propagation through nanopores in vitro, nor invasion of the OLCN in vivo [25].…”

Section: Plos Pathogensmentioning

confidence: 99%

See 4 more Smart Citations

Identification of Penicillin Binding Protein 4 (PBP4) as a critical factor for Staphylococcus aureus bone invasion during osteomyelitis in mice

et al. 2020

Self Cite

View full text Add to dashboard Cite

Staphylococcus aureus infection of bone is challenging to treat because it colonizes the osteocyte lacuno-canalicular network (OLCN) of cortical bone. To elucidate factors involved in OLCN invasion and identify novel drug targets, we completed a hypothesis-driven screen of 24 S. aureus transposon insertion mutant strains for their ability to propagate through 0.5 μm-sized pores in the Microfluidic Silicon Membrane Canalicular Arrays (μSiM-CA), developed to model S. aureus invasion of the OLCN. This screen identified the uncanonical S. aureus transpeptidase, penicillin binding protein 4 (PBP4), as a necessary gene for S. aureus deformation and propagation through nanopores. In vivo studies revealed that Δpbp4 infected tibiae treated with vancomycin showed a significant 12-fold reduction in bacterial load compared to WT infected tibiae treated with vancomycin (p<0.05). Additionally, Δpbp4 infected tibiae displayed a remarkable decrease in pathogenic bone-loss at the implant site with and without vancomycin therapy. Most importantly, Δpbp4 S. aureus failed to invade and colonize the OLCN despite high bacterial loads on the implant and in adjacent tissues. Together, these results demonstrate that PBP4 is required for S. aureus colonization of the OLCN and suggest that inhibitors may be synergistic with standard of care antibiotics ineffective against bacteria within the OLCN.

show abstract

Section: Resultssupporting

confidence: 66%

Section: Resultsmentioning

confidence: 97%

Section: Plos Pathogensmentioning

confidence: 91%

Section: Plos Pathogensmentioning

confidence: 99%

Section: Plos Pathogensmentioning

confidence: 99%

See 3 more Smart Citations

Identification of Penicillin Binding Protein 4 (PBP4) as a critical factor for Staphylococcus aureus bone invasion during osteomyelitis in mice

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

The Modular µSiM: A Mass Produced, Rapidly Assembled, and Reconfigurable Platform for the Study of Barrier Tissue Models In Vitro

McCloskey

Kasap

Ahmad

et al. 2022

Adv Healthcare Materials

Self Cite

View full text Add to dashboard Cite

Advanced in vitro tissue chip models can reduce and replace animal experimentation and may eventually support “on‐chip” clinical trials. To realize this potential, however, tissue chip platforms must be both mass‐produced and reconfigurable to allow for customized design. To address these unmet needs, an extension of the µSiM (microdevice featuring a silicon‐nitride membrane) platform is introduced. The modular µSiM (m‐µSiM) uses mass‐produced components to enable rapid assembly and reconfiguration by laboratories without knowledge of microfabrication. The utility of the m‐µSiM is demonstrated by establishing an hiPSC‐derived blood–brain barrier (BBB) in bioengineering and nonengineering, brain barriers focused laboratories. In situ and sampling‐based assays of small molecule diffusion are developed and validated as a measure of barrier function. BBB properties show excellent interlaboratory agreement and match expectations from literature, validating the m‐µSiM as a platform for barrier models and demonstrating successful dissemination of components and protocols. The ability to quickly reconfigure the m‐µSiM for coculture and immune cell transmigration studies through addition of accessories and/or quick exchange of components is then demonstrated. Because the development of modified components and accessories is easily achieved, custom designs of the m‐µSiM shall be accessible to any laboratory desiring a barrier‐style tissue chip platform.

show abstract

Bacterial toxins in musculoskeletal infections

Saeed

Sendi

Arnold

et al. 2020

Journal Orthopaedic Research

View full text Add to dashboard Cite

Musculoskeletal infections (MSKIs) remain a major health burden in orthopaedics. Bacterial toxins are foundational to pathogenesis in MSKI, but poorly understood by the community of providers that care for patients with MSKI, inducing an international group of microbiologists, infectious diseases specialists, orthopaedic surgeons and biofilm scientists to review the literature in this field to identify key topics and compile the current knowledge on the role of toxins in MSKI, with the goal of illuminating potential impact on biofilm formation and dispersal as well as therapeutic strategies. The group concluded that further research is needed to maximize our understanding of the effect of toxins on MSKIs, including: further research to identify the roles of bacterial toxins in MSKIs, establish the understanding of the importance of environmental and host factors and in vivo expression of toxins throughout the course of an infection, establish the principles of drug‐ability of antitoxins as antimicrobial agents in MSKIs, have well‐defined metrics of success for antitoxins as antiinfective drugs, design a cocktail of antitoxins against specific pathogens to (a) inhibit biofilm formation and (b) inhibit toxin release. The applicability of antitoxins as potential antimicrobials in the era of rising antibiotic resistance could meet the needs of day‐to‐day clinicians.

show abstract

An in vitro platform for elucidating the molecular genetics of S. aureus invasion of the osteocyte lacuno-canalicular network during chronic osteomyelitis

Cited by 36 publications

References 45 publications

Identification of Penicillin Binding Protein 4 (PBP4) as a critical factor for Staphylococcus aureus bone invasion during osteomyelitis in mice

Identification of Penicillin Binding Protein 4 (PBP4) as a critical factor for Staphylococcus aureus bone invasion during osteomyelitis in mice

The Modular µSiM: A Mass Produced, Rapidly Assembled, and Reconfigurable Platform for the Study of Barrier Tissue Models In Vitro

Bacterial toxins in musculoskeletal infections

Contact Info

Product

Resources

About