Can we fight “bad” bacteria without harming “good” bacteria?By Guy Tsafnat - September 21, 2015, 4 PM
At any given moment, there are billions of bacteria living on each of us – on our skins, in our guts, noses, ears, mouths and anywhere else they manage to survive. Most of the time these bacteria are harmless or even beneficial, for example, by keeping harmful bacteria at bay. However, some have specific properties that make them able to turn pathogenic and make us sick and to resist antibiotics. Whether a bacteria is pathogenic or not depends largely on the genes that they carry.
Are there really no new antibiotics?By Guy Tsafnat - August 24, 2015, 4 PM
Global health organisations such as the Centers for Disease Control and Prevention (CDC) and the World Health Organisation (WHO) often broadcast that antibiotics are losing efficacy because bacteria grow resistant to them and there are no new antibiotics. However, this list shows that new antibiotics are steadily being released even today. So are there really no new antibiotics?
What superbugs are there?By Guy Tsafnat - July 20, 2015, 4 PM
“Superbug” is a nickname given to infections for which there are no antibiotics because they can resist any antibiotic we have to fight them. Usually, this is because the bacteria are resistant to the antibiotic drug. Bacteria resist antibiotics in a variety of forms such as having walls that don’t allow the drug into them and producing enzymes that break down the drug before it can damage them. To do that, the bacteria need to have specific genes. Sometimes, combinations of genes make the bacteria resistant to more than one antibiotic and even all known ones. MRSA (AKA “golden staph”) is a common example. Usually this infection is acquired in a hospital and especially in intensive care units. It is the oldest and most widely spread superbug of the species staphylococcus aureus.
Mitigation Strategies for Antibiotic ResistanceBy Guy Tsafnat - June 15, 2015, 4 PM
The World Health Organisation warnsthat we are facing a post-antibiotics era in which diseases commonly and effectively treated by antibiotics could become untreatable and deadly. Common conditions such as urinary tract infections and infected wounds (from accidents or surgery) will become risky. There are already 9 known superbug strains and more are emerging. Elective surgery and cancer treatments will become too risky to perform. In order to understand what we can do to delay or even avoid this future, we first need to look at what forces are driving it.
Why horizontal gene transfer (and mobile genetic elements) are clinically importantBy Guy Tsafnat - May 18, 2015, 4 PM
Antibiotic resistance is conferred to bacteria cells from genes (called antibiotic resistance genes, or sometimes just resistance genes) they carry in their DNA. Darwinian evolution (spontaneous random mutation and selection) can account for some of the resistances we see, but does not explain how bacteria can simultaneously resist a number of man-made antibiotics. Bacteria’s ability to share genes between cells (“horizontally”) makes it possible for organisms to develop resistance much faster and is the reason antibiotic resistance is on the rise.
Strictly speaking, horizontal gene transfer is the movement of DNA between bacteria cells, even of different species. There are several biochemical processes by which this can occur but the result is that phenotypes (including resistance to antibiotics) can spread even if the infection that originally carried them is wiped out.
Antibiotics can accelerate the emergence of resistance genes by killing off the susceptible cells that compete for food. Over time, and increased exposure to multiple antibiotics, a microbial ecosystem becomes richer in “superbugs” – bacteria that resist “last resort” antibiotics such as carbapenems and methicillin.