Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Insect Antibiotics - Resistance is Futile!

07.02.2003


Insect Antibiotic, Cecropin A, Bypasses Outer Defenses to Kill Bacteria From The Inside

For antibiotics, the best way to beat bacterial defenses may be to avoid them altogether. Researchers at University of Pennsylvania School of Medicine have discovered that Cecropin A, a member of a family of antibiotic proteins produced by insects, may kill bacteria and avoid resistance by entering bacterial cells and taking control of their genetic machinery.

While most antibiotics kill bacteria by attacking critical enzyme systems, Cecropin A somehow slips inside the bacteria and turns specific genes on and off. The findings challenge conventional thinking on how these antibiotics function, and may aid in turning antimicrobial peptides like Cecropin A into therapeutic agents.



"For decades, researchers have studied Cecropin A and focused on its obvious effects against bacterial cell walls and membranes. These antibiotics certainly do disrupt outer structures of the bacterial cell, but there’s much more to the story," said Paul H. Axelsen, M.D., an associate professor in the Department of Pharmacology and Division of Infectious Diseases at Penn. "Before the bacterial cell dies, Cecropin A enters the cell and alters the way its genes are regulated. It’s like sneaking over the castle wall and opening the gates from the inside. We need to understand this mechanism of action because it may explain why bacteria are unable to develop resistance to this family of antibiotics."

Axelsen’s findings were described in the January issue of the Antimicrobial Agents and Chemotherapy, a publication of the American Society for Microbiology. In their study, Axelsen and his colleagues treated E. coli with small doses of Cecropin A - not enough to kill the bacteria, but enough to see what genes are affected when bacteria are exposed to the antibiotic. They found that transcript levels for 26 genes are affected, 11 of which code for proteins whose functions are unknown. Even more surprising for the researchers, the genes are not the same as the ones affected when bacteria experience nutritional, thermal, osmotic, or oxidative stress.

"It is a whole different mechanism by which to kill bacteria, and one that we still have yet to completely figure out," said Axelsen. "How Cecropin A turns these genes on and, indeed, how it gets inside E. coli in the first place, is still something of a mystery."

Despite years of research, there remains much to know about the antibiotics produced by insects. Cecropin A was discovered in the Cecropia moth, also known as the silkworm moth, the largest moth in North America. Since insects do not have an immune system as humans do, they rely on polypeptide antibiotics like Cecropin A to fight off infections. These proteins are highly selective - they readily kill bacteria, but are harmless to human and other animal cells. Moreover, bacteria that are susceptible initially stay susceptible - researchers have not seen bacteria develop resistance to their action. For this reason, these antibiotics offer a potentially invaluable model for new therapeutic agents.

"We’re engaged in an arms race against infectious bacteria. With each new antibiotic, bacteria have found a way to evolve resistance - primarily by slightly altering cellular enzymes," said Axelsen. "Bacteria may be unable to alter their genetic machinery, and this may explain why strains of bacteria resistant to Cecropin A do not arise."

Funding for this research was supported by grants from the National Institutes of Health and the American Heart Association, and from Affymetrix’s generous donation of E. coli GeneChip Microarrays.

Greg Lester | University of Pennsylvania Medic
Further information:
http://health.upenn.edu/News/News_Releases/feb03/Insects.html

More articles from Life Sciences:

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

nachricht Self-assembled nanostructures hit their target
23.09.2016 | King Abdullah University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>