Navigation Links
Research shows how pathogenic bacteria hide inside host cells
Date:1/26/2011

A new study into Staphylococcus aureus, the bacterium which is responsible for severe chronic infections worldwide, reveals how bacteria have developed a strategy of hiding within host cells to escape the immune system as well as many antibacterial treatments. The research, published by EMBO Molecular Medicine, demonstrates how 'phenotype switching' enables bacteria to adapt to their environmental conditions, lie dormant inside host cells and become a reservoir for relapsing infections.

Staphylococcus aureus is a major human pathogen which can be carried by up to 70% of healthy people, and can lead to conditions such as deep tissue infections, osteomyelitis, and chronic lung infections, which are often hard to treat with antibiotics. A key characteristic of these infections is that relapses can occur months or years after an apparent cure.

These relapses, Dr. Bettina Lffler and her team from the Institut fr Medizinische Mikrobiologie in Mnster, Germany, believe are due to phenotype switching, a change in the bacterial behaviour. After infection and invasion of the patient's host cells, the bacteria form small colony variants (SCVs), tiny bacterial subpopulations that can evade the immune system as well as many antibiotics and grow slowly.

"For the microbiologist, it is difficult to detect SCVs in clinical specimens as they grow slowly, often needing several days to form and so can be easily overlooked in diagnosis," said Lffler. "Our study asked two questions: Is the development of SCVs an integral part of the infection process and what are the dynamics of SCV formation?"

The team performed long-term infection studies with Staphylococcus aureus in cell culture systems and also analysed tissue samples from subacute and chronic human infections.

The research revealed that in all infection models, the bacteria were able to persist within the host for several weeks after the infection, leading to the formation of SCV colonies. This showed that SCVs began to appear following infection, after the immune system response was overcome and that this persistence led to a larger phenotypic diversity of bacteria.

"These studies demonstrate that S. aureus are extreme versatile microorganisms that continuously sense their environmental conditions and can rapidly alter to reflect them," said Lffler. "The formation of SCV colonies is a bacterial phenotype switching strategy which is an integral part of the infection process."

This process enables the bacteria to hide inside host cells without provoking an inflammatory response from the host's immune system. In addition, they might be efficiently protected from antibiotic treatment.

"This strategy means that SCVs can be considered as 'dormant forms' of infections which can rapidly regain their full virulence and cause a patient to relapse," concluded Lffler. "This has important clinical implications as it means that targeting phenotype switching could prevent the bacteria from hiding, making the infection more vulnerable to host response and treatment."


'/>"/>

Contact: Ben Norman
Lifesciencenews@wiley.com
44-012-437-70375
Wiley-Blackwell
Source:Eurekalert

Related medicine news :

1. Embedded Mobile & M2M Device revenues to Rise to Almost $19 Billion Globally by 2014, Says Juniper Research
2. 2010 HSR Impact Award recognizes surgical safety research
3. MSU launches first anti-counterfeiting research program
4. Researchers map all the fragile sites of the yeast Saccharomyces cerevisiaes genome
5. UH Case Medical Center researchers publish promising findings for advanced cervical cancer
6. Researchers discover new way to kill pediatric brain tumors
7. Family Research Council: Planned Parenthood Report Oversexualizes Ten-Year-Olds, Undermines Parental Authority
8. Michael J. Fox Foundation Awards $1 Million to Drive Critical New Research Tools and Technologies in Parkinsons Drug Development
9. Luth Researchs IndicatorEDG(TM) Study Finds Americans Hopes of Achieving Their Dreams Are Fading
10. International Diabetes Federation awards $2 million to 9 global diabetes research projects
11. Gladstones Robert Mahley to receive Research!America advocacy award
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/25/2017)... ... 25, 2017 , ... Dr. Donna Bergman, professor of education ... published an article in the medical science journal Physical Medicine and Rehabilitation titled ... and the research that helped produce it, were written and conducted in collaboration ...
(Date:7/25/2017)... ... July 25, 2017 , ... Dr. Gina ... Negrette has more than a decade of experience in psychiatry, treating clients in ... fighting addictions, eating disorders, psychotic and manic conditions, as well as those who ...
(Date:7/25/2017)... , ... July 25, 2017 , ... ... for its Product Innovation in the prestigious CEO World Awards®. The coveted annual ... new products and services, CEO case studies, corporate social responsibility, and milestones from ...
(Date:7/24/2017)... ... July 24, 2017 , ... Engineers at the University of Maryland have invented ... kind of electrical energy that the body uses. , In ordinary batteries the ... of electrons out of the battery is generated by moving positive ions from one ...
(Date:7/24/2017)... ... July 24, 2017 , ... Cheerag D. Upadhyaya , M.D., ... Bloch Neuroscience Institute (SLMBNI), part of Saint Luke’s Health System . Dr. ... Cheerag D. Upadhyaya, MD. M.Sc., FAANS joins Stanley P. Fisher, M.D., who ...
Breaking Medicine News(10 mins):
(Date:7/13/2017)... 2017  New York City-based market research firm Kalorama Information ... aware of.  From new products to new costs, to the ... recently completed study, Potential Pipeline Disruptors . ... 1.  Age-Driven Growth - True Impact Moment Arriving ... the impact the growing population and, to a more extreme ...
(Date:7/12/2017)... , July 12, 2017  Eli Lilly and Company (NYSE: ... with generic companies to resolve pending patent litigation in the ... Virginia regarding the Cialis ® (tadalafil) unit ... April 26, 2020. As part of the agreement, Cialis exclusivity ... 27, 2018. "The unit dose patent for Cialis ...
(Date:7/11/2017)... , July 11, 2017  Bayer has awarded grants totaling ... as part of its prestigious Bayer Hemophilia Awards Program (BHAP). ... Philadelphia and Uniformed Services University of ... among the winners. Grant recipients were announced last night during ... (ISTH) 2017 Congress, Berlin, Germany . ...
Breaking Medicine Technology: