Deadly pneumonia enzyme zmpB may silently damage patients' hearts, study warns

A bacterial enzyme linked to pneumonia may also cause serious heart health damage, new research reveals. Scientists have identified zmpB, produced by Streptococcus pneumoniae, as a key factor in cardiac complications during infections. The findings could lead to better monitoring and treatment for vulnerable patients.

Pneumonia remains a major global health threat, causing over 1.2 million emergency visits and 41,000 adult deaths in the US each year. Worldwide, it claims more than a million children's lives annually. Among the leading causes is Streptococcus pneumoniae, a bacterium known to trigger severe complications, including heart failure, arrhythmias, and heart attacks.

A study published in Cell Reports pinpointed zmpB as the enzyme responsible for much of this damage. Researchers from the University of Maryland School of Medicine (UMSOM) and the University of Alabama at Birmingham (UAB) found that mice infected with normal S. pneumoniae strains developed cardiac microlesions and cell death. However, those exposed to a strain without zmpB showed little to no heart damage.

The team, led by Dr Carlos J. Orihuela, also tested heart organoids against different bacterial strains. Those with zmpB and an additional feature called FIVAR domains caused significantly more cell death and bacterial invasion. Patients with heart failure were more likely to carry this specific version of the bacterium.

The discovery suggests that a simple genetic test could help identify high-risk S. pneumoniae strains early in an infection. This would allow doctors to monitor patients more closely or adjust treatments to reduce heart damage. Understanding these molecular mechanisms may ultimately improve outcomes for those at risk of severe pneumonia complications.