Outbreaks of Acinetobacter baumannii typically occur in intensive care units and healthcare settings with very ill patients. The superbug can cause life-threatening lung and bloodstream infections that are often resistant to many commonly prescribed antibiotics. But a new study has unlocked a key step in how one Acinetobacter bacterium is transmitted to another, shedding light on how antibiotic resistance spreads.
Researchers at the Washington University School of Medicine mutated plasmids within Acinetobacter strains to determine how Acinetobacter reproduces. Plasmids, small loops of DNA, promote drug resistance by invading nearby bacteria with resistance genes, to reproduce and infect more bacteria. Still, plasmids require close contact among bacteria to spread and Acinetobacter baumannii doesn’t mingle well. The bacteria protect itself by injecting lethal proteins into unrelated bacteria that approach too closely. If that’s the case, how does Acinetobacter bacterium spread?
The researchers determined that plasmids within Acinetobacter strains disable the bacterium’s internal self-defense system so that plasmids in neighboring bacteria aren’t killed before they can be injected with copies of Acinetobacter bacterium.
As next steps, the researchers suggest that preventing the spread of antibiotic resistance may begin with preventing plasmid spread. They’re seeking to develop compounds that will prevent plasmids from disrupting bacterial inner defense systems. They assert that such therapies, which aim to prevent bacteria from becoming drug resistant, will be much more effective than trying to develop new antibiotics, which will eventually become resistant.
In the meantime, at least 2 million patients in the U.S. continue to be infected with antibiotic-resistant bacteria, and at least 23,000 people die each year as a result. To prevent the threat of superbugs in hospitals and other healthcare settings, the U.S. Centers for Disease Control and Prevention (CDC) recommends that healthcare providers take these precautions:
- Identify patients by asking about any recent travel or health care. Those who have received care at another facility or in another country are at greatest risk for antibiotic resistance.
- Prescribe an antibiotic only when it’s likely to benefit a patient.
- Encourage patients to use a prescribed antibiotic only as directed.
- Practice good hygiene by handwashing or using alcohol-based hand sanitizer to keep.
- Prescribe an antibiotic that targets the bacteria that is most likely causing their patient’s illness when an antibiotic is likely to provide benefit.
- Prevent infections related to surgery and/or catheter placement and improving antibiotic use through stewardships.
- In hospital settings, place patients with unusual resistance on contact precautions and assess and enhance infection control.
- Be prepared. Plan for usual unusual resistance in your facility and work with the health department to screen others.
- Communicate about resistance status when patients are transferred to another facility and ask colleagues to use an infection control transfer form.
- If an outbreak occurs, continue infection control assessments and colonization screenings until the spread is controlled.
For more information about preventing antibiotic resistance, visit the CDC’s Antibiotic Resistance Solutions Initiative.