The Mölnlycke O.R. blog
A rendezvous with Ms Carbapenem resistance
I once had a midwife tell me that an expectant mother in the labour ward wanted to name her newborn daughter “Chlamydia” because she thought it was a nice name! Amused, I asked, “Why?” The midwife replied, “The lady had heard the term often among teenagers, and just liked the sound of it.” The woman was totally unaware what “Chlamydia” was associated with, of course. I felt a bit sorry for the midwife who had the onerous task of telling the lady why she really should not be naming her new baby “Chlamydia”. Stepping back a bit from the discussion, I thought about it and realised that if I didn’t know that Chlamydia was a bacteria that caused a sexually transmitted infection, I might have thought it was a nice name, too, much as I think “carbapenem” is – but more on that later.
This leads me to a more general question: How aware are we of the bacteria all around us – both good and bad bacteria – and what we can or should do to make sure the bad bacteria do not win the battle of survival? The first bacteria date back to nearly 3,000 million years ago. To put it into context, the first hominin (human-like creature) appeared approximately six million years ago. Given how many changes we find between our ancestors from the recent past (geologically speaking) – say 500 years – we can imagine the extent to which bacteria have evolved through these many years.
Fast forward to 1928, and we know penicillin, the first antibiotic, was discovered serendipitously in a laboratory in London. By the early 1940s we had the first stable antibiotic ready for use to treat deadly bacterial diseases like tuberculosis, syphilis, diphtheria, typhoid and many other fatal infections. The pre-antibiotic era was one that most of us have no recollection of but history is littered with records of the scourge of infectious diseases that are so much better controlled now, at least in parts of the world where antibiotics are available and affordable. What followed was a golden era for antibiotics while more and more sophisticated antibiotics were isolated. However, bacteria turned this situation around very quickly and started changing their defence mechanisms, giving rise to widespread resistance to antibiotics, as illustrated in the figure below1. The year each antibiotic was deployed is depicted above the timeline, and the year resistance to each antibiotic was observed is depicted below the timeline. Antibiotic resistance developed through several mechanisms and with every new antibiotic that was discovered resistance shortly followed. Globally, resistant strains of bacteria are low only where antibiotic availability is low because of cost and availability reasons, for example in very poor countries.
1. Nature Chemical Biology; 2007; 3: 541-548.
Not mentioned in the figure above is the isolation of a class of antibiotics referred to as carbapenems in 1976 that came into full use after nearly ten more years of work trying to make stable derivatives. Carbapenems possess a broad spectrum of activity and have high potency against several resistant strains of Gram-positive and Gram-negative bacteria. They are often considered the last line of defence in antibiotic therapy, particularly for those infections caused by Gram negatives. Resistance to this class of antibiotics happened within a decade of their discovery. An encounter with carbapenem-resistant, Gram-negative bacteria, such as Klebsiella pneumonia, Pseudomonas aeruginosa, Acinetobacter spp. and Escherichia coli can cause bloodstream infections, urinary tract infections, post-operative wound infections and intra-abdominal infections, which can prove to be fatal. Carbapenem resistance has now become a huge global public health threat and requires targeted infection control measures amongst others. The situation is worsened by the fact that global travel is increasing – including the growing trend of medical tourism. Both lead to a free ride for resistant bacteria from one part of the world to another. Antibiotic resistance is a public health problem of epidemic proportions and it is increasingly apparent that unless something is done about it very soon the problem will not be far from what it was before 1928.
Increasing awareness about these highly resistant microorganisms commonly encountered in hospitals as well as out in the community is vitally important. Preventing spread is important before carbapenem-resistant bacteria get a foothold in more hospitals or in the community. A raft of precautionary measures besides appropriate antibiotic usage is required, including active case detection and contact precautions for colonised or infected patients, cohorting of patients and staff, and communication about infections when patients are transferred. Hand hygiene and disinfection of medical devices around the affected patient is equally crucial in preventing spread2. Measures to reduce resistance must include factors other than just antimicrobial stewardship programs alone3. Besides corollary measures, a great deal more effort needs to be put into developing new antibiotics by pharmaceutical companies with increased research input from academia. Educating the public about infectious diseases and what and how antibiotics should be used should also help in increasing global awareness about the microbial world, including ‘Ms Carbapenem resistance’.
2. Morbidity and Mortality Weekly Report; 2013; 62: 165-170.
3. Infection Control Hospital Epidemiology; 2011; 32: 584-90.