In bacterial infections, antibiotics form an essential part of the treatment regimen. One unwanted side effect of antibiotics is the disruption of the body’s microbial flora. This disruption can make the body more susceptible to certain types of infections, including pneumonia caused by the bacterium Pseudomonas aeruginosa. Under the leadership of Prof. Dr. Bastian Opitz of the Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, the research team studied the mechanisms underlying the enhanced susceptibility to P. aeruginosa lung infection following antibiotic therapies. They showed that the antibiotic-induced disruption of the microbial flora resulted in a depletion of certain antibodies in the lungs. Known as ‘IgA’, these antibodies represent an important weapon in the body’s arsenal against infections. By weakening the lung’s immune system, antibiotics are making it easier for Pseudomonas bacteria to infect lungs. The researchers were able to demonstrate the same effect during an observational study involving ICU patients.
Using an animal model, the researchers succeeded in reducing susceptibility to Pseudomonas lung infection. They achieved this by administering specially produced IgA antibodies. The team is planning to conduct additional studies. “We are hoping to further increase our understanding of how antibiotics affect the body’s microbial flora and antimicrobial immune responses, in particular those in the lung” explains Prof. Opitz. He adds: “We also want to study how IgA antibodies could be used to prevent subsequent infections in patients requiring antibiotic therapies.”
*Robak OH, et al.: Antibiotic treatment-induced secondary IgA deficiency enhances susceptibility to Pseudomonas aeruginosa pneumonia. The Journal of Clinical Investigation 2018 May 17. DOI: 10.1172/JCI97065.
Prof. Dr. Bastian Opitz
Medical Department, Division of Infectiology and Pneumonology
Charité – Universitätsmedizin Berlin
t: +49 30 450 553 501