10_Coming clean about dirt – the battle on bacteria

Coming clean about dirt – the battle on bacteria A As a society we are now more hygienic than ever.Previous generations bathed once a week and usedvinegar to clean their homes, whereas today mostof us shower on a daily basis and use a range ofextra-strong household cleaning products. We aretaking cleanliness seriously in order to preventthe spread of viral pandemics like H1N1 (swineflu). The benefit of all this is a reduction in theamount of 1pathogens we are exposed to, but many2microbiologists believe that our obsession withhygiene is detrimental to our health.B Not only are our bodies and homes cleanedmore often than ever, but the detergents andshower gels we use often contain powerful3disinfectants. Antibacterial agents also end upin food via products like pre-washed lettuceand the antibiotics used as 4growth-promotersin farm animals. In addition, we take antibioticdrugs too frequently, often for minor illnesses.The cumulative effect of our war on germs is thatcommon bacteria such as salmonella are mutatingto develop strains resistant to antibiotics. Doctorsare finding that, as bacteria become more resistant,formerly treatable conditions such as tuberculosisare becoming harder to treat and, in some cases,lethal. Overuse of antibiotics like penicillin canalso kill the friendly bacteria living in our digestivesystem, allowing other more harmful bacteria tomultiplyand cause infection. Antibiotic abuse is becomingsuch a big problem that some governments havelaunched public-health campaigns to educatepatients about the issue.C Another consequence of our obsession with germsis a huge increase in allergies such as asthma andeczema in recent years. Exposure to microbesat a young age (such as those from faeces or theenvironment) helps regulate the immune system,reducing the body’s tendency to develop allergicreactions against substances such as dust. Thismeans that children who grow up in very 5sterileenvironments may later develop severe immuneresponses when they eventually come into contactwith these agents. Evidence supporting thishypothesis is that children growing up on animalfarms or in the developing world have very lowinstances of asthma and other allergies becausethey are exposed to more diseases and germs.D It’s important to realize that medical experts arenot suggesting we put an end to washing or that wemove to Africa; in fact, they stress the importanceof regular hand-washing in these times of globalpandemic. What is clear, though, is that we needto find a balance between our high standards ofhygiene and the unnecessary use of antibiotics andantibacterial products. So, if your little brother orsister asks for a pet, perhaps it’s not such a badidea! 1 Taking antibiotics … a has been banned by some governments. b can be harmful when you don’t have abacterial infection. c causes bacteria to mutate. d is harmful to your intestines. 2 Coming into contact with germs when you are achild … a can cause swine flu. b should be avoided. c helps strengthen your immune system. d can be avoided by having pets. 3 Doctors suggest we … a clean our homes less. b have pets at home to get exposure to germs. c stop taking antibiotics and wash our handsmore. d only use antibacterial products when it’sreally necessary. 2 Match words 1–5 in the text to definitions a–e. a substances which help farm animals to produce more meat growth-promoters b agents such as bacteria or a virus that cause disease pathogens c extremely clean, with no bacteria sterile d specialists in dealing with extremely small organisms microbiologists e chemical products used to kill bacteria disinfectants 3 Find words or phrases in the text that meanthe same as … 1 caused by a virus. viral2 becoming different as a result of a genetic change. mutating3 types. strains4 tiny organisms (often pathogenic). microbes5 the group of organs and cells that defends the body against disease. immune system