You can’t see them, but they’re everywhere. Microbes, single-celled organisms too tiny to be detected by the naked eye, are found covering virtually every surface on the planet. When we think of microbes, we typically think of bacteria or viruses; we also tend to think of them in terms of their capability to make us sick. However, despite being the most abundant life form on Earth, only a handful of germs can really knock you over. Here are five common microbes that can cause illness:
E. coli – This one is a major headline-maker when restaurants or food distributors accidently spread it about. E. coli is a common intestinal bacteria. Most of the time encounters with this germ are harmless. One particular strain, however, contains a special endotoxin in its cell membrane that acts as a sort of microscopic landmine when the membrane is destroyed. The cell membrane of a bacterium is a popular target for both antibiotics and our own immune system. When a large number of the microbes are destroyed all at once, the endotoxins are unleashed. This often results in vomiting, diarrhea, and sometimes, a trip to the emergency room.
Staphylococcus – Like E. coli, staphylococcus is found everywhere, especially in soil and on the skin of people and animals. It’s considered part of what is known as “normal flora”, microorganisms that are usually found occupying the skin, generally without consequences. Staph art opportunistic, though, and when they invade an open wound, they can turn into pathogenic nightmares. This is particularly true of the mutant form know as MRSA, or methicillin-resistant Staphylococcus aureus, a subspecies that has wreaked havoc in healthcare facilities for about twenty years now.
Streptococcus – Strep is another common contaminant of skin, soil, doorknobs, you name it. Normally your immune system and other normal microbiota keep its effects in check, but when it sees a window of opportunity, strep can become deadly. Certain strains of streptococcus can cause necrotizing fasciitis, often reported by the news as “flesh-eating bacteria”. This type of strep infection invades deep tissue wounds and releases its own endotoxins, which cause a wave of tissue necrosis around the colony. “Strep throat”, that horribly painful throat infection that loves to sweep through entire school classrooms, can harbor much more serious implications; if left untreated, strep throat can progress to an autoimmune condition called rheumatic fever, which can lead to permanent heart valve damage. So finish that course of antibiotics, folks.
Salmonella – This intestinal bug has plagued humanity for millennia. It is found in raw poultry, eggs, and pork, or can be spread through fertilizers produced with contaminated manure. Like most gastrointestinal infections, the symptoms include abdominal pain, fever, and diarrhea. Most of the time people pass it on their own, but salmonella infections may take a few days of rolling around on the bathroom floor to clear. Not fun.
Influenza – Influenza is no laughing matter. Before the advent of vaccination, the annual arrival of this respiratory virus meant death for millions upon millions worldwide. The pandemic in 1918 caused by a Spanish flu strain killed 50 million people in that year alone, and even now approximately 36,000 Americans succumb to flu complications every year. Flu viruses replicate in a fashion that makes their virulence shift from mild to deadly in an unpredictable pattern, which makes vaccine preparation challenging. Even imperfect vaccines provide some cross-protection, though, so always go for that annual poke in the arm.