Category Archives: bacteria

Believe it or Not

Believe it or Not

By Michael Pickering

Praying Mantis

As a culture, we are obsessed with bugs.  We view all bugs, insects, beetles, and especially spiders as being nefarious.  The only general exceptions that come to mind are butterflies and ladybugs.  Even people who do not know the diet of the larvae and the beetles think they are cute.  But in this world view, the bug daddy of all of our fears is bacteria.  With the constant reminder of bacteria-contaminated food recalls and drug-resistant bacteria, we freak out.  Fungus is relegated to a minor role because most people think it only infects milk, cheese, and bread where the result is unsavory but not dangerous.  If your feet itch or you have a yeast infection, you consider it a treatable nuisance.

This is a skewed thought balance.  The crawly, multi-legged creatures fall into several categories: pernicious (usually economic damage), beneficial (usually predators of the former), symbiotic, etc.  One of the least populated categories is dangerous.  Similarly, most bacteria are benign or beneficial.  The rare, dangerous bacteria are mostly selected for by our overuse of antibiotics in medicine and more importantly in animal husbandry, where a pound is used for every gram used in medicine.  The devastation caused by fungus is mostly known to farmers, ranchers, and premature neonates, where it is the leading cause of death.

roach fossil
Cockroaches have been around for millions of years. Image from

We despise flies, maggots, and cockroaches.  Cockroach larvae would also be reviled and feared, if ever seen.  This abhorrence is based on the notion that they spread germs.  Everyone knows that flies land on poop and on rotting things where maggots are subsequently found, and that cockroaches come from sewers.  They are very germy, very fungal places indeed.  However, that is exactly why the fly spends ground time where it does, and why the roach travels in sewers.  They and their larvae’s principal diet consists of bacteria and fungi.  Just as pigs to truffles, flies and roaches are attracted by smells.  Because the bacteria and fungi spores arrive airborne, they arrive long before the scent attracts the predators, so their colonies are well-established.

Flies lay eggs on rotting things for the abundance of food available for their larvae.  Not the fruit or vegetation, nor the poop, but the bugs feeding on the substrate.  Flies and roaches don’t transport germs, they eat them.  Aside:  With high sugar vegetation such as fruit, the fungus also causes fermentation, making ethanol.  Fruit flies that have been attacked by a wasp have been observed to self-medicate by moving to a “higher proof” fruit, because the wasp larvae implanted in them cannot tolerate the alcohol as well as the flies, thus killing the majority of the intruders.

Bacteria yet remain the scariest to us.  We are so phobic that we try to sterilize everything, including our mouths, our skin, our dwellings and especially our hospitals.  The truth is that we need bacteria to be healthy.  The biome needs bacteria to exist.  The reason hospital bacteria are so virulent and life-threatening is because the antibiotic cleaning agents we use kill 99% of the germs.  The one percent is the territory of the resistant bacteria.  The price the drug resistant bacteria pay for that property renders them non-competitive with the wild-type.  Without the 99% around, they can proliferate.  Aside:  That’s why, when you have a bacterial infection, the doctor insists that you take ALL of the pills.  Most of the unpleasant symptoms are gone after one or two pills, yet you still have a jar of pills.  The doctor is taking care of the one-percenters, the “hells angels” too.

Our mouths, intestines and skin would be dysfunctional were it not for our unique bacterial symbiotes.  Perhaps you have heard the popular parlor question, “what is the germiest part of the human body?”  Most people guess the nether regions, like the anus, or the feet.  In fact, it is the mouth.  Unheard of new strains of bacteria are yet being discovered in the human mouth.  Although healthy urine is sterile, a large part of normal stool is composed of living and dead bacteria.  Manure is always involved in produce recalls due to the presence of dangerous E. coli.  The most difficult type of “food” poisoning to remedy are the ones caused by bacterial invaders that displace the symbiotes in our lower intestine.  Eccrine sweat, which the body produces to regulate temperature and is most abundantly produced on the palms/soles and scalp, includes an antibiotic peptide that protects the resident bacteria.  So it is my opinion that we should use bactericidal cleaning agents sparingly and judiciously.  Don’t use antibacterial mouth washes daily – just when you have an infection like swollen gums or a sore on your cheek.  Do not try to sterilize your skin – use mild, high-fat soap when washing hands and bathing.  Our skin is hydrophobic; don’t make it dysfunctional with strong cleansers and detergents.  I believe that a large percentage of body odor issues and general skin health problems are created by misguided, overly-aggressive cleaning practices and bactericidal-spiked deodorants.

Back to cockroaches, whose presence I think make cities habitable.  Besides micromanaging the microbes in our cities, they are a balanced, healthy diet for mammals and so are a popular food in many parts of the world.  Rats and domestic cats find them irresistible too.  I’m reminded of a conversation with a visitor to our booth at the Pittsburg Conference one year.  He introduced himself as the “head shit chemist” of his state and city.  He mused about why he wasted state money on buying sophisticated, expensive air monitoring equipment for his sewer workers.  The workers had an inviolate rule about entering sewers, no matter what the expensive device reported about the quality of the air – no roaches = no entry!

Photo Credit: Cory Doctorow

Maggots are also beneficial.  Their merits have been praised in the medical literature as far back as the Greek physician Galen, during wars and for the victims in serious accidents involving exposed wounds.  An exposed wound on an immobile person is an ideal host for bacteria and fungi.  The flies eventually arrive, delivering the maggot “maids” who clean the wound, including the dead flesh, and leave the healthy parts intact.  Their metabolic heat helps to keep the patient warm if exposed to cold weather.  When I was in high school, there was an article in the LA Times about a lady who had plunged into a canyon in the Angeles Crest Mountains during winter and was not discovered for several days.  She was pinned in the car and had serious lacerations on her face, as her head had broken the door window.  Her survival was attributed to the maggots on her face – no germs or rotting flesh present, and enough heat generated to prevent hypothermia.

When observing nature, your senses, your beliefs and your emotions are all involved.  Adjust your dials accordingly.

Ripley did not care whether his writers’ submissions were true or not.  They just had to “sound good, ring true.”

Believe it or not.

Persistent Food Myth No. 2: Wood Bad, Plastic Good, by Michael Pickering

In the early 1970’s, the USDA recommended that meat handlers such as butchers and restaurants replace wood cutting boards with plastic. The recommendation was heard as a categorical “MUST”. The assumption was that plastic cutting surfaces were less likely to transfer pathogens. No scientific evidence existed to support their opinion. Years later, researches decided to eliminate the information void by challenging the plastic and wood surfaces with E. coli O157:77, Salmonella, et al. Results indicated that new plastic and wood surfaces were comparable in cleaning and disinfecting properties.

It was discovered that bacteria were not recoverable from wood surfaces a short time after application. Bacteria did migrate into the interior of the wood, however they 1) did no multiply, 2) were not transferable, and 3) eventually died. The same bacterial concentrations on the plastic were transferable, but both surfaces were easily cleaned. Blade damaged plastic surfaces are very different.

Here is the rub: Blade damaged plastic surfaces are very different. First, plastic suffers much greater damage than wood under similar use. More importantly, damaged plastic surfaces proved difficult or impossible to decontaminate while the marred wood behaved much like new wood.

The plastic smoothness factor has reach the street according to my friend Brad Daley, Partner and General Manager at one of my favorite haunts, Cascal, a popular tapas restaurant and bar in Mountain View. He said the Health Department inspectors tell him when the plastic cutting surfaces need sanding. If the surface is visually scarred or discolored, they are told to replace or sand them; no other specifications. I’ll bet there’s an assumption hiding there. Another dangling end is that plastic surfaces vary greatly in chemical properties compared to close-grained wood, and only a few polymers have been tested.

In 1999, the USDA Meat & Poultry inspection manual (official regulations) and the US FDA Food Code (recommendations for restaurants, etc.) permitted the use of close-grained hardwoods, like maple, for cutting boards. Neither has a recommendation for the type of polymer that is acceptable nor do they specify how the plastic surfaces must be maintained. That’s a Gilda Radner “Never mind” to me.