What is acinetobacter baumannii?

Acinetobacter Baumannii Infection

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Medically reviewed by Drugs.com. Last updated on Sep 24, 2019.

  • Care Notes

What causes an Acinetobacter baumannii infection?

An Acinetobacter baumannii infection is caused by the Acinetobacter baumannii bacteria. It can cause serious infections in the lungs, blood, and brain. It may also cause urinary tract and wound infections. It can be spread by direct contact and may be found on skin or in food, water, or soil. It may also be found in hospitals. Acinetobacter baumannii is highly contagious.

What increases my risk of an Acinetobacter baumannii infection?

Anyone can get an Acinetobacter baumannii infection. You are more likely to get an infection from Acinetobacter baumannii if you have a disease such as diabetes or COPD. You are also at higher risk of getting this infection if:

  • You have a weak immune system. Your immune system helps protect you from getting sick. It may be weak because of you are ill or have had recent surgery.
  • You use poor hygiene. This includes not washing your hands well or long enough.
  • You have been in the intensive care unit (ICU) or have been on a ventilator (breathing machine).
  • You have had a recent surgery or procedure. You are also at higher risk if you have open wounds caused by an accident or injury.
  • You have been near someone who has Acinetobacter baumannii.
  • You have taken antibiotic medicine recently.
  • You have a catheter. This may include a Foley or central venous catheter.

What problems can an Acinetobacter baumannii infection cause?

Acinetobacter baumannii can cause serious and sometimes life-threatening infections. You may not know that you have an Acinetobacter infection until you get sick with one of the following:

  • Pneumonia: Pneumonia is an infection of the lungs. Acinetobacter baumannii can get into your lungs through your mouth or nose. It may cause pneumonia if you have been in the ICU or if you are on a ventilator.
  • Blood infection: A blood infection may occur if the germ enters through a catheter placed in your vein. It can also happen when an infection from another place in your body spreads to your blood.
  • Meningitis: Meningitis is an infection of the brain or spinal cord. This may happen after surgery that was done on your brain or spine. It may also happen if you have a shunt or drain in your head.
  • Urinary tract infection: A urinary tract infection (UTI) is an infection of the kidneys, ureters, or bladder. This may happen when the germ enters your body where you urinate. It may also enter through a catheter that is used to drain your urine.
  • Skin or wound infection: Any skin opening or wound can get infected with the germ.

What are the signs and symptoms of an Acinetobacter baumannii infection?

  • Fever
  • Red, swollen, warm, or painful skin areas or wounds
  • An area of orange, bumpy skin with blisters
  • Cough, chest pain, or trouble breathing
  • Burning feeling while you urinate
  • Sleepiness, headaches, or a stiff neck

How is an Acinetobacter baumannii infection diagnosed?

Healthcare providers will examine you. They may use one or more of the following tests to learn more about your infection:

  • Culture: A sample of your blood, urine, or tissue is sent to the lab. A culture may show which germ is causing your infection.
  • Chest x-ray: A chest x-ray is a picture of your lungs and heart. Your healthcare provider may use an x-ray to look for signs of pneumonia or other infections.
  • Lumbar puncture: Healthcare providers collect a sample of fluid from around your spinal cord using a needle. The fluid is sent to a lab for tests. This test may be done to check for infection, bleeding around your spinal cord, and other problems.

How is an Acinetobacter baumannii infection treated?

Your treatment will depend on where the infection is in your body.

  • Antibiotic medicines: Antibiotic (germ-killing) medicine will be used to treat your infection. Your healthcare provider may give you more than one antibiotic medicine to take at a time. He also may need to change your medicine over time.
  • Pain medicine: You may need medicine to take away or decrease pain.
    • Learn how to take your medicine. Ask what medicine and how much you should take. Be sure you know how, when, and how often to take it.
    • Do not wait until the pain is severe before you take your medicine. Tell your healthcare provider if your pain does not decrease.
    • Pain medicine can make you dizzy or sleepy. Prevent falls by calling someone when you get out of bed or if you need help.
  • Antipyretics: This medicine is given to decrease a fever.

How do I prevent the spread of Acinetobacter baumannii?

  • Wash your hands: Use soap and water to wash your hands after you use the bathroom, before you touch food, and after you cough or sneeze. You may use germ-killing hand cleaner if you do not have water. Always wash your hands when they are dirty.
  • Keep wounds covered: Keep any wounds clean and covered with a bandage until they are healed.
  • Always follow your healthcare provider’s instructions when you take antibiotic medicines: Finish all of your medicine, even if you feel better. Germs may become resistant (harder to kill) if you do not do this. Do not take antibiotics unless your healthcare provider tells you to.

When should I contact my healthcare provider?

Contact your healthcare provider if:

  • You have a fever.
  • You have chills or a cough or feel weak and achy.
  • You have new or more pain, redness, or swelling in the area of a wound.
  • Your urine is dark in color, or you are urinating less or less often than usual.
  • You have questions or concerns about your infection, treatment, or care.

When should I seek immediate care?

Seek help immediately or call 911 if:

  • You have sudden or new chest pain or a fast heartbeat.
  • You have sudden trouble breathing.
  • Your lips and fingernails turn blue.
  • You are sleepy, confused, and have trouble answering simple questions.
  • You have sudden numbness or weakness in your arms or legs.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Learn more about Acinetobacter Baumannii Infection

Associated drugs

  • CNS Infection
  • Infection
  • Sepsis

IBM Watson Micromedex

  • Bacterial Meningitis
  • Bacterial Meningitis in Children
  • Sepsis
  • Sepsis in Children

What Is Acinetobacter Baumannii?

The Acinetobacter superbug can cause diseases such as pneumonia and meningitis.

Acinetobacter baumannii is a bacterium that can cause a range of diseases.

It typically infects people inside a healthcare facility — doctors refer to these as “nosocomial” infections.

There are many different species of Acinetobacter that can cause disease, but A. baumannii accounts for about 80 percent of reported Acinetobacter infections in the United States, according to the Centers for Disease Control and Prevention (CDC).

Acinetobacter Risks

Healthy people have a very low risk of getting an A. baumannii infection, according to the CDC.

The following factors increase the risk of infection:

  • Having a weakened immune system
  • Chronic lung disease
  • Diabetes
  • Lengthy hospital stays
  • Illnesses that require the use of a hospital ventilator
  • Having an open wound treated in the hospital
  • Treatments requiring invasive devices like urinary catheters

Acinetobacter bacteria are not airborne, but can be spread through direct contact with surfaces, objects, or the skin of people that are contaminated with A. baumannii.

Acinetobacter Symptoms

Acinetobacter is an opportunistic bacterium that causes a variety of different diseases with different symptoms.

Types of possible A. baumannii infections include:

  • Pneumonia
  • Bloodstream infections (bacteremia and sepsis)
  • Meningitis (an infection or inflammation of the meninges, the membranes covering the brain and spinal cord)
  • Wound and surgical site infections, including the “flesh-eating” bacterium necrotizing fasciitis
  • Urinary tract infections (UTI)

Symptoms of A. baumannii infections are often clinically indistinguishable from those of infections caused by other opportunistic bacteria, such as Klebsiella pneumoniae and Streptococcus pneumoniae.

Bloodstream infections often initially cause symptoms like fever and chills, rash, and confusion or other altered mental states, and are often associated with an elevated lactic acid level that’s found with severe sepsis.

UTIs typically cause various urinary symptoms, including pain or burning sensations while urinating, foul-smelling urine that may be cloudy or bloody, and a strong urge to urinate frequently.

Meningitis may cause a number of flu-like symptoms, including fever, headache, confusion, sensitivity to bright light, and nausea (with or without vomiting).

Pneumonia may cause a range of symptoms, including but not limited to:

  • Chills
  • Fever
  • Headache
  • Breathing problems
  • Muscle pain and chest pain
  • Cough, sometimes with yellow, green, or bloody mucus

In some cases, A. baumannii may colonize a site, such as an open wound or a tracheostomy site, without causing any infection or symptoms.

Acinetobacter Treatment and ‘Superbug’ Antibiotic Resistance

The CDC considers Acinetobacter, including A. baumannii, a serious public health threat because it’s often resistant to multiple antibiotics.

In fact, 63 percent of Acinetobacter strains are multidrug-resistant, the CDC notes.

Before the 1970s, A. baumannii infections could be treated with a range of different antibiotics, such as aminoglycosides, β-lactams, and tetracyclines, according to a report in the journal Clinical Microbiology Reviews.

Today, however, some strains of A. baumannii are resistant to most antibiotics, including first-line antibiotics and carbapenems, which are often used only as a last resort.

Treating an A. baumannii infection generally requires drug susceptibility tests, which check for antibiotics that are still effective against the particular strain of bacteria.

In some cases, sulbactam and polymyxin antimicrobial drugs still work against A. baumannii when other antibiotics fail.

Editor’s Selection IconA. baumannii does not mess around. As opportunistic pathogens go it’s pretty out there. An aerobic, gram negative, almost entirely antibiotic resistant (largely through passive mechanisms) bacterium that’s developing such a terrible reputation that it has picked up the nickname ‘Iraqibacter’, but that’s mostly because of the high proportion of A. baumannii infections in returned American troops.

The real problem with these bacteria is that it is a jack-of-all-trades. If it gets in your lungs it can cause pneumonia. If it gets in your skin it can cause necrotising fasciitis (flesh eating disease). If it gets in your urinary tract you get a nasty urinary tract infection. Basically, if it’s a moist surface A. baumannii will stick there and develop into an infection. Importantly though it seems that you have to already be a little sick for it to take hold. This in itself presents a problem as doctors and nurses are able to act as asymbiotic transmitters between all the sick people they care for.

“What do you think? Have we made this patient sick enough yet? What does the chart say?”. Credit: Seattle Municipal Archives

In fact, transmission by other patients, doctors and nurses is resulting in A. baumnanii being one of the fastest growing sources of hospital-acquired infection with hospital-acquired pneumonia being a particularly bad problem. Many commentators are predicting this bacterium will be ‘the next big thing’ in infectious disease, if it isn’t already.

All this is made worse by the observation that antibiotics simply do not work as effectively against A. baumannii. A. baumannii contains a number of drug efflux pumps which allow it to remove its cellular contents when under stress, antibiotic stress for example. It also seems to be able to readily pick up DNA from its environment and occasionally incorporate it into a usable form. This mechanism is thought to be responsible for the increasing prevalence in antibiotic resistance generally and in A. baumannii it is predicted to have resulted in a drop from ~90% of clinical isolates being susceptible to ampicillin-sulbactam in 2003 dropping to only ~40% by 2008.

So why bring this bacterium up? A paper came out (a while ago now but I came up with this idea when the paper emerged in 2010) suggesting a very novel means of controlling this nasty bacterium and it all comes back to its name.

The word “Acinetobacter” comes from some interesting Roman and Greek roots. The Greek for non-motile is apparently ακινητο- which when translated into English would normally come out as akinetic- but original transliterations instead gave us akineto- or acineto-. Bacter just means bacteria shaped, so rod.

Funny story, this non-motile bacteria that is so non-motile that its name literally means non-moving rod is actually quite the little mover. Whilst A. baumannii lacks a flagellum it is a very efficient swarming bacterium that moves via twitching motility.

So back to this paper. A recent discovery has found that light may be able to stop the swarming of the bacterium. Yeah, light. Blue light specifically.

Potent antibiotic, apparently. Credit: Kapungo

The researchers found that swarming was most active in the dark but when exposed to blue light the colonies stopped their swarming activity.

What is happening here?

The researchers went back and found a protein in A. baumannii called BlsA (Blue light sensing protein A) that contained a BLUF (blue light sensing using flavin) domain. They mutated blsA and the light sensitivity disappeared but the real question is what is it doing there in the first place?

At this stage there seems to be no answer, all we know is that blue light seems to really mess with this bacteria. Blue light is able to disrupt the formation of biofilms and pellicles, which are particularly relevant in the development of human disease.

Could it be possible that a bacterium that is so difficult to treat, in part due to its inherent resistance to most antibiotics, could be inhibited by a blue light? Time will tell but as was expertly written at the bottom of the commentary in the Journal of Bacteriology “microbiologists open their incubators and let the sun shine in. The results may be illuminating.”

Mmmm. Punny goodness.

In what I hope will be the first of many collaborative cross-posts between Lab Rat and myself (and perhaps other SciAm bloggers) you can click here to find Lab Rat’s in depth look at the blue light inhibition of A. baumannii swarming story. Enjoy!


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