CRE bacteria
Carbapenem-resistant Enterobacteriaceae (CRE) bacteria Reuters

Nearly 180 people at a Los Angeles hospital may have been exposed to'nightmare' strain of bacteria from the use of contaminated medical equipment.

The deaths of two people at Ronald Reagan UCLA Medical Center have been linked to the outbreak of Carbapenem-Resistant Enterobacteriaceae, while seven others are being treated.

A total of 179 patients at the hospital were exposed to CRE during endoscopic procedures between October and January. A similar outbreak was reported in Seattle, linked to the deaths of 11 patients.

Although national figures on the bacteria are not available, the US Centers for Disease Control and Prevention said 47 states have seen cases of the superbug.

What are CRE?

Carbapenem-resistant Enterobacteriaceae are a family of bacteria which have the potential to kill half the patients who contract them. The family has developed a high resistance to antibiotics, which is why they are so deadly.

Carbapenem are a class of broad-spectrum antibiotics often used as a final treatment against bacterial infection, but the name "Carbapenem-resistant" suggests that they can fail to treat CRE.

Klebsiella species and Escherichia coli (E. coli) are examples of Enterobacteriaceae, a normal part of the human gut bacteria, that can become carbapenem-resistant. Some CRE create an enzyme called klebsiella pneumoniae carbapenemase, first discovered in 2001, that can destroy stronger antibiotics.

How are CRE spread?

CRE are only transmitted by direct contact between an infected wound or bodily fluid and an open wound. The bacteria can also be spread from other invasive medical equipment such as catheters.

Although there is little information on CRE bacterial transmission from animals to humans, it has been observed in some cases with multi-drug-resistant bacteria. The food industry has been identified as a potential source of antibiotic-resistant Enterobacteriaceae.

How are they treated?

Some antiobiotics do work against CRE, but can cause damage to internal organs such as kidneys and some doctors believe antibiotics should not be administered too quickly. Fosfomycin, Tigecycline, nitrofurantoin, pivmecillinam, and co-amoxiclav are sometimes prescribed, although it depends on the infection.

A person's CRE resistance depends upon a number of factors, such as the health of the patient, whether the patient has recently undergone a transplant, risk of co-infection and use of multiple antibiotics.