New Bugs, Old Drugs: How Old Antibiotics Can Help Fight New Infections

A new study shows that older antibiotics are equally or more effective in fighting MRSA and shouldn't be overlooked.

MRSA is the most well-known and widespread of the 'superbugs,' infections usually found in hospital settings and prone to causing post-surgical infections that don't respond to the usual drugs for that infection.

All of this would be of much less importance if Staphylococcus wasn't so versatile. Many people carry MRSA where they would have carried MSSA (Methicillin Sensitive Staphylococcus Aureus) before the advent of resistance: in their nasal passages and throats. It's not uncommon to carry MRSA without symptoms for periods of time that range from a few days to several years. 

But MRSA can colonize open wounds of any kind, and can lead to a range of outcomes including truly terrifying results like necrotizing fasciitis and necrotizing pneumonia. In both cases, 'necrotizing' means 'making dead.' These are the 'flesh eating superbugs' beloved of tabloid scaremongers. 

At present, no-one knows how some people can catch MRSA and recover, while others die within a few days of a similar initial infection by the same organism.

When MRSA initially presents you're looking at rough, red skin with raised bumps like spider bites or nettle stings, pimples or boils. Within 72 hours these have usually gotten a lot worse and often become open boils, deep and pus-filled, accompanied by fever and a rash.

It's not something you'd exactly want, but neither is it all that hard to treat. The big problem with MRSA is something else.

In some cases of community-acquired MRSA (sometimes written CA-MRSA, this just means it was picked up outside a hospital or institution), the infection spreads. In these rare cases the infection is actually more serious than a hospital acquired MRSA infection, and can cause multiorgan dysfunction, sepsis and pneumonia. Why these infections are even more virulent than hospital-acquired ones is still something that we haven't really figured out, but it's thought to be due to toxins produced by some strains of the pathogen.

See Also: The Fight Against Antibiotic-Resistant Infections Is On!

In hospitals, nursing homes and even military institutions and prisons, the story is a little different. MRSA is more or less the same as any other staph infection apart from the fact that it's resistant to the main drug that's used to treat staph infections. That means it likes crowded places with lots of skin-on-skin contact, like prisons and military facilities, and it loves a crowded place with lots of open wounds, intrusive surgical appliances and compromised immune systems. That means hospitals and nursing homes are also prime places to find MRSA, where it's referred to as HA-MRSA (Hospital-Acquired MRSA). 

Who Is At Risk Of MRSA?

There are individual risk factors too. MRSA is more likely to affect you if you're a diabetic, if you're a woman who suffers frequent urinary tract infections, if you're an intravenous drug user or if your immune system is compromised by HIV or by a preexisting infection, or by treatment for cancer or post-transplant immunosuppressant drugs.

The infection rate amongst football players is 16 times the national average, while in prison ordinary staph infections lay the groundwork for MRSA infection - the most reliable guide to whether a prisoner will get MRSA is if he or she has had ordinary staph already.

So now we know what it is and where we're likely to get it. What can be done about it?

First of all, MRSA isn't necessarily more virulent than ordinary staph, apart from its drug resistance. That's important to remember.

The next thing is that basic hygiene is the best way to stop MRSA spreading. In hospitals it spreads on healthcare providers' hands and clothing, towels and curtains, flat surfaces and paper gowns. It's poor cleaning, handwashing and garbage disposal that's making an epidemic out of it, and the most successful large-scale attempt to eradicate MRSA has involved advising healthcare providers to wash their hands and making it easier to do it. 

The best substances are chlorhexadine and Povidone iodine, both of which can be got from chemists. Chlorhexadine is available as a mouthwash, which is effective as an antiseptic for wounds too.

Unfortunately, you can't put chlorhexadine into the bones or lungs of people with deep, persistent MRSA infections. So what can you do?

Currently, doctors are looking at using vancomycin. It's the main treatment for MRSA and it's still the go-to treatment because it remains safe and effective. That's the verdict from a University of Nebraska study published this October in the Journal of the American Medical Association. Study leader Dr Andre Kalil, who's an infectious diseases expert, said, 'even though vancomycin is an older drug, it's still killing staph very effectively,' and there's no need for doctors to switch to using a newer drug.

See Also: Is Your Doctor Prescribing Antibiotics You Don't Need?

If doctors did want to switch to a newer drug, there are plenty available. Vancomycin faces competition from new discoveries like Oritavancin, which promises to be a 'single-shot' cure for the disease, as well as other skin infections. The risk of antibiotic resistance developing is going to be serious as long as there are reservoirs of MRSA in hospitals, prisons and nursing homes as well as in the general population, and the biggest - and oldest - treatment option is still the best: really good basic hygiene.