TB bacteria's growth behavior unraveled, paving way for better treatments
In a groundbreaking study, researchers at Tufts University School of Medicine have found that the tuberculosis (TB) bacterium, the leading cause of infectious disease deaths globally, grows at a constant rate throughout its life cycle. The discovery, published in Nature Microbiology, goes against the basic principles of bacterial cell biology. It also sheds light on why this deadly pathogen easily evades our immune system and antibiotics.
TB bacteria's unique growth pattern
Bree Aldridge, a professor of molecular biology and microbiology at Tufts and one of the study's co-senior authors, said that the TB pathogen follows a unique set of rules than other bacteria. This unconventional behavior allows some parts of the infection to rapidly adapt within their host, permitting these outliers to evade detection or resist treatment. The team believes gaps in our understanding of this basic biology have been impeding the development of more effective treatments.
Extensive research on TB bacteria's growth
The research required postdoctoral fellow Christin (Eun Seon) Chung to observe individual TB cells for three years. Since TB bacteria double slowly (about once every 24 hours), new microscopy techniques were developed to observe the microbe over weeks. Chung painstakingly analyzed the footage and manually tracked each TB bacterium and their offspring, uncovering that their growth rates remain constant, irrespective of their size or stage in the cell cycle.
Challenging the fundamental biology
Chung said this is the first reported organism that can maintain consistent growth rates, irrespective of its size or stage in the cell cycle. This behavior defies the basic tenets of bacterial biology, as it has long been believed that ribosomes drive cell growth rates. However, their work indicates something else may be happening in TB bacteria, raising new questions about its growth control.
Unexpected growth behavior shown
The study also found that TB bacteria can start growing from either end after being born, a behavior not observed in related bacteria. This finding further highlights the unique growth patterns of TB microbes and their ability to increase variability among their offspring. Aldridge believes these observations will help in devising more effective treatments against this deadly pathogen.
