Pathogenesis and in vivo interactions of human Streptococcus agalactiae isolates in the Galleria mellonella invertebrate model

Streptococcus agalactiae cadD Is Critical for Pathogenesis in the Invertebrate Galleria mellonella Model

“…Melanin induces hemocyte aggregation into nodules that function as traps for invading microbes, where they are killed by antimicrobial peptides and reactive oxygen species. , Thus, melanin production is a critical function of the G. mellonella innate immune system response to bacterial infection. Additionally, other published work has shown that S. agalactiae infection of G. mellonella induced larval melanization, as well as vacuolation and depletion of innate immune cells . Our work demonstrates that GBS requires expression of cadD for full induction of the innate immune response, melanin production.…”

“…G. mellonella has also gained appreciation as an important model for studying streptococcal pathogenesis. ,,,, G. mellonella has been used to model host–pathogen interactions with Group A Streptococcus, S. pneumoniae , and S. mutans . , For example, S. mutans strains harboring deletions within the individual genes within the lytST and dltAD coding regions exhibited diminished systemic infection and killing of G. mellonella compared to parental strains, results that were also validated in a rat model of disease . Additionally, the G. mellonella model has proven highly effective at discerning differences between colonizing strains and hypervirulent strains of GBS, demonstrating its utility as a tool for studying GBS pathogenesis and virulence.…”

“…G. mellonella has been used to study GBS virulence, and results indicate hypervirulent strains ST17 and ST283 that cause invasive disease in humans also exhibit enhanced virulence in the invertebrate model . Recent work by Crespo-Ortiz and colleagues demonstrated that G. mellonella could be used to model GBS-host interactions in the context of temperature, pH, and secreted factors by commensal bacteria such as Lactobacillus . Invasive strains of GBS induce killing, melanization, and changes in hemocyte morphology in G. mellonella .…”

“…Recent work by Crespo-Ortiz and colleagues demonstrated that G. mellonella could be used to model GBS-host interactions in the context of temperature, pH, and secreted factors by commensal bacteria such as Lactobacillus . Invasive strains of GBS induce killing, melanization, and changes in hemocyte morphology in G. mellonella . However, isogenic mutants of GBS have not been used in this model to study specific virulence factors in the context of GBS pathogenesis.…”

Efficient Inhibition of Streptococcus agalactiae by AIEgen-Based Fluorescent Nanomaterials

“…We further studied the antibacterial effect of TBP-1 based on its good ability of ROS production after light irradiation (4.2 mW cm −2 ). GBS, a prominent co-pathogenic bacterium ( Crespo-Ortiz et al, 2020 ), was chosen as the subject bacteria attributed to its serious harm to human, animal, and aquatic products. The antibacterial efficiency of different TBP-1 concentrations (0, 2, 4, 6, 8, and 10 µM) on GBS under the light as a function of time was measured using plate counting ( Figure 3 ).…”