A biofilm is a structured community of microorganisms encapsulated within a self-developed polymeric matrix and adherent to a living or inert surface. Biofilms are also often characterized by surface attachment, structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of polymeric substances.
Single-celled organisms generally exhibit two distinct modes of behavior. The first is the familiar free floating, or planktonic, form in which single cells float or swim independently in some liquid medium. The second is an attached state in which cells are closely packed and firmly attached to each other and usually form a solid surface. A change in behavior is triggered by many factors, including quorum sensing, as well as other mechanisms that vary between species. When a cell switches modes, it undergoes a phenotypic shift in behavior in which large suites of genes are up- and down- regulated. Read more »
Believe it or not, this article was published ten years ago, and we’re still worrying about this everso-easy-to-kill bug!
July 1998 a The following excepts from the upcoming PPOA Pumproom Press are written for professional swimming-pool operators, not for academicians or epidemiologists. They are intended to provoke serious thought and initiate serious action regarding the maintenance of sanitary and safe conditions in the public pools of this country.
Jumping, or should we say leaping, to sensational conclusions is the common modus of the American news media, creating “fact” in the observers’ minds from augmented circumstantial situations. The best example is the current, protracted hysteria in the water-park community regarding E.Coli. No doubt you’ve read our argument in the Pumproom Press Extra, Summer 98, asserting great statistical and logical improbability that contamination actually could have originated and/or sustained itself in the particular pool in question – or in any treated body of water, for that matter. We also hope you’ll concur that the collective reaction of the pool world is somewhat absurd. Read more »
At stupid o’ clock in the morning a BA jumbo disgorges me onto the tarmac at Abuja airport, Nigeria bathing me in an perverse temperature of 24 degrees exacerbated by 90% relative humidity, making me understand why our American cousins refer to it as the discomfort index.
But talking of Americans (another seamless subject change) Abuja airport is already in my opinion far superior to Tom Bradley LAX as the non-local queue, (four of us) passes through passport control in seconds (LAX 64 mins. personal best) making me uniquely the first person at the carousel to await my two cases. Wonder of wonder, one of my cases is the first one to appear. This is the one full of testers both titration and photometric, TDS meters, bio luminescence kit, the works.
So where’s the other one I query? the one with all my clothes in! Gradually other travellers clear customs and jostle for position around the carousel in time honoured fashion, peering intently at cases that appear virtually indistinguishable. By now I’m starting to panic, I’m out here for two weeks and my other pair of underpants is in that case. Wow! Relief, finally, here it is, relief, not just for me, but also for others that I will have to work with over the next two weeks. Read more »
1500 BC Records show public baths in use, (further records show numerous complaints in Latin about pool water temperature)
100 BC The first heated swimming pool is believed to have been built by Gaius Maecenas who was a rich Roman and patron of arts. He supported the poets Horace, Virgil, and Propertius, allowing them to live and write without fear of poverty but sadly instilled in them the fear of drowning.
79 AD Research indicates there were swimming facilities in Pompeii and begs the question; Did nitrogen trichloride contribute to the fall of Pompeii?
1st century Britain Romans build thermal pool at Bath Somerset lined with 45 sheets of lead and fed with warm spa water. Remind me again what is ‘plumbo solvency’ the Latin for?
14th century Britain Public facilities in some English cities, but condemned as places of ill repute, (yep! I’ve swum there!)
16th century Britain Public bathing condemned by puritans as evil (get a life!)
17th century Italy The first known illustration of sand filters by the Italian physician Lucas Antonius, which details a multiple sand filter.
18th century Sweden Chlorine was discovered by chemist Carl Wilhelm Scheele. Possibly whilst messing with his Mother’s bottles of Domestos and Harpic Read more »
