Tag Archives: Staphylococcus aureus

Micromotors Deliver Oral Vaccines

Researchers are working on new generations of oral vaccines for infectious diseases. But to be effective, oral vaccines must survive digestion and reach immune cells within the intestinal wall. As a step in this direction, UC San Diego nanoengineering researchers have developed oral vaccines powered by micromotors that target the mucus layer of the intestine.

The work appears in the ACS journal Nano Letters. It’s a collaboration between the labs of nanoengineering professors Joseph Wang and Liangfang Zhang at the UC San Diego Jacobs School of Engineering.

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The lack of needles is one reason oral vaccines are attractive. Another reason: oral vaccines can generate a broad immune response by stimulating immune cells within the mucus layer of the intestine to produce a special class of antibody called immunoglobulin A (IgA). The NanoLetters paper documents the team’s efforts to use magnesium particles as tiny motors to deliver an oral vaccine against the bacterial pathogen Staphylococcus aureus. When coated over most of their surfaces with titanium dioxide, magnesium microparticles use water as fuel to generate hydrogen bubbles that power their propulsion.

To develop the oral vaccine, the researchers coated magnesium micromotors with red blood cell membranes that displayed the Staphylococcal α-toxin, along with a layer of chitosan to help them stick to the intestinal mucus. Then, they added an enteric coating that protects drugs from the acidic conditions of the stomach.

The micromotors safely passed through the stomach to the intestine, at which point the enteric coating dissolved, activating the motors. Imaging of mice that had been given the vaccine showed that the micromotors accumulated in the intestinal wall much better than non-motorized particles. The micromotors also stimulated the production of about ten times more IgA antibodies against the Staphylococcal α-toxin than the static particles.

Source: http://jacobsschool.ucsd.edu/

New Combination To Eradicate Staph Aureus

CF-301 is a bacteriophage-derived lysin with potent activity against Staphylococcus aureus (“Staph aureus”) bloodstream infections. CF-301 is the first and only lysin to enter human clinical trials in the US and has recently completed a Phase 1 trial in healthy volunteers. This compound is being developed for the treatment of Staph aureus bloodstream infections (BSI; bacteremia), including endocarditis, caused by methicillin-resistant and susceptible Staphaureus (MRSA and MSSA) strains.

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New drug-resistant strains of Staph aureus have been identified which demonstrate resistance against vancomycin and daptomycin, the only two standard-of-care (SOC) antibiotics indicated for the treatment of MRSA BSI in the US. CF-301 has the potential to be a first-in-class, new treatment for Staph aureus bacteremia. CF-301 has specific and rapid bactericidal activity against Staph aureus. Combinations of CF-301 with vancomycin or daptomycin increased survival significantly in animal models of disease when compared to treatment with SOC antibiotics or CF-301 alone. CF-301 targets a highly conserved region of the cell wall that is vital to bacteria, thus making resistance less likely to develop. When used in combination with SOC antibiotics, the result is a novel combination therapy that has the potential to combat the high unmet clinical need of Staph aureus infections.

Advantages are important:

  • Combination with antibiotics offers a superior treatment approach based on animal models
  • Act at least 12x faster than current antibiotics
  • Specifically kills Staph aureus and spares good bacteria
  • Clears biofilm

Source: https://www.contrafect.com/