However, this condition can also occur independent of cystic fibrosis. A new clinic at Baylor College of Medicine is now offering evaluation and treatment for patients with non-cystic fibrosis
“Bronchiectasis obstructs airflow and can make it difficult to clear the airways,” said Dr. Tara Barto, assistant professor of medicine in the section of pulmonary, critical care and sleep medicine at BCM.
There are many causes of bronchiectasis; it can be related to severe reflux disease with aspiration (reflux of liquid into the lungs), rheumatologic conditions, immune deficiencies, or alpha-1-antitrypsin deficiency, to name a few examples. Approximately 30 percent of the time, there is no specific cause.
Symptoms include shortness of breath, fever, cough, mucus production and chest pain. Often times these patients are diagnosed with recurrent or chronic bronchitis (occurring multiple times per year). The condition is definitively diagnosed by a CT scan of the chest. The mainstay of therapy focuses on airway clearance strategies and suppression of infection.
“Small changes to therapy can make big changes in the life of someone who is suffering from this,” said Barto.
She works with patients to customize a treatment plan to help manage the condition and prevent progression. Usually, she recommends a treatment therapy that patients must follow two times a day, which includes a combination of medications taken in a specific order to open the airways, thin out the secretion and then clear the airways. Her clinic is unique in that it is multidisciplinary with a dedicated respiratory therapist to provide education and assistance with inhaled therapies and airway clearance devices.
Barto recommends talking to your primary care physician and getting a chest x-ray before consulting with a pulmonologist.
Barto is seeing patients for this condition in her clinic on the first and third Tuesdays of the month from 1-5 p.m. For more information or to make an appointment, call 713-798-2400.
BOSTON — A study published today in the journal Nature reports that a viral predator of the cholera bacteria has stolen the functional immune system of bacteria and is using it against its bacterial host. The study provides the first evidence that this type of virus, the bacteriophage (“phage” for short), can acquire a wholly functional and adaptive immune system.
The phage used the stolen immune system to disable – and thus overcome – the cholera bacteria’s defense system against phages. Therefore, the phage can kill the cholera bacteria and multiply to produce more phage offspring, which can then kill more cholera bacteria. The study has dramatic implications for phage therapy, which is the use of phages to treat bacterial diseases. Developing phage therapy is particularly important because some bacteria, called superbugs, are resistant to most or all current antibiotics.
Until now, scientists thought phages existed only as primitive particles of DNA or RNA and therefore lacked the sophistication of an adaptive immune system, which is a system that can respond rapidly to a nearly infinite variety of new challenges. Phages are viruses that prey exclusively on bacteria and each phage is parasitically mated to a specific type of bacteria. This study focused on a phage that attacks Vibrio cholerae, the bacterium responsible for cholera epidemics in humans.
Howard Hughes Medical Institute investigator Andrew Camilli, Ph.D., of Tufts University School of Medicine led the research team responsible for the surprising discovery.
First author Kimberley D. Seed, Ph.D., a postdoctoral fellow in Camilli’s lab, was analyzing DNA sequences of phages taken from stool samples from patients with cholera in Bangladesh when she identified genes for a functional immune system previously found only in some bacteria (and most Archaea, a separate domain of single-celled microorganisms).
To verify the findings, the researchers used phage lacking the adaptive immune system to infect a new strain of cholera bacteria that is naturally resistant to the phage. The phage were unable to adapt to and kill the cholera strain. They next infected the same strain of cholera bacteria with phage harboring the immune system, and observed that the phage rapidly adapted and thus gained the ability to kill the cholera bacteria. This work demonstrates that the immune system harbored by the phage is fully functional and adaptive.
“Virtually all bacteria can be infected by phages. About half of the world’s known bacteria have this adaptive immune system, called CRISPR/Cas, which is used primarily to provide immunity against phages. Although this immune system was commandeered by the phage, its origin remains unknown because the cholera bacterium itself currently lacks this system. What is really remarkable is that the immune system is being used by the phage to adapt to and overcome the defense systems of the cholera bacteria. Finding a CRISPR/Cas system in a phage shows that there is gene flow between the phage and bacteria even for something as large and complex as the genes for an adaptive immune system,” said Seed.
“The study lends credence to the controversial idea that viruses are living creatures, and bolsters the possibility of using phage therapy to treat bacterial infections, especially those that are resistant to antibiotic treatment,” said Camilli, professor of Molecular Biology & Microbiology at Tufts University School of Medicine and member of the Molecular Microbiology program faculty at the Sackler School of Graduate Biomedical Sciences at Tufts University.
Camilli’s previous research established that phages are highly prevalent in stool samples from patients with cholera, implying that phage therapy is happening naturally and could be made more effective. In addition, a study published by Camilli in 2008 determined that phage therapy works in a mouse model of cholera intestinal infection.
The team is currently working on a study to understand precisely how the phage immune system disables the defense systems of the cholera bacteria. This new knowledge will be important for understanding whether the phage’s immune system could overcome newly acquired or evolved phage defense systems of the cholera bacteria, and thus has implications for designing an effective and stable phage therapy to combat cholera.
Additional authors are David W. Lazinski, Ph.D., senior research associate in the Camilli lab at Tufts University School of Medicine, and Stephen B. Calderwood, M.D., Morton N. Swartz, M.D. academy professor of medicine at Harvard Medical School, and chief, division of infectious disease and vice-chair, department of medicine at Massachusetts General Hospital.
Research reported in this publication was supported by the National Institute of Allergies and Infectious Diseases of the National Institutes of Health under award numbers R01AI55058, R01AI045746, and R01AI058935.
Seed, K.D., Lazinski, D.W., Calderwood, S.B., and Camilli, A. (2013). A bacteriophage encodes its own CRISPR/Cas adaptive response to evade host innate immunity. Nature, vol 494, issue 7438, pp 489–491; DOI: 10.1038/nature11927
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