Microbiology
Pseudomonas aeruginosa: The Opportunistic Pathogen That Thrives Where Medicine Is Weakest
Pseudomonas aeruginosa is a gram-negative, rod-shaped bacterium that rarely sickens healthy people but becomes a dangerous opportunistic pathogen in those with weakened defenses — burn victims, cystic fibrosis patients, and hospitalized or immunocompromised patients. A member of the ESKAPE group of drug-resistant microbes, it combines intrinsic multidrug resistance, protective biofilms, and a deep toolkit of virulence factors (including the blue pigment pyocyanin), which together make its chronic infections notoriously hard to cure.
Staphylococcus aureus: Skin Commensal, Hospital Killer, and the Toxin Cooking Can't Destroy
Staphylococcus aureus is a gram-positive coccus that lives harmlessly on the skin and in the nose of roughly a third of people, yet turns opportunistic pathogen to cause skin abscesses, sepsis, pneumonia, and toxic shock. Its rapid evolution of antibiotic resistance produced MRSA, and one strain trait makes it a distinct food-safety hazard: it secretes heat-stable enterotoxins that survive cooking even after the bacteria are killed.
Weizmannia coagulans: The Spore-Forming Probiotic Formerly Called Bacillus coagulans
Reclassified from Bacillus coagulans in a 2020 taxonomic revision, so both names appear in the literature. Its endospores give it room-temperature shelf stability, survival of gastric acid, and tolerance of processing heat — advantages over the vegetative Lactobacillus and Bifidobacterium strains that dominate the category. It was the genus that measurably increased in the 2024 UC San Diego kombucha trial.