Research shows novel way in which Salmonella can resist antibiotics and antibacterial soaps

July 24, 2013

Salmonella bacteria – most frequently spread to humans by infected food – that develop a resistance to one group of antibiotics are also less susceptible to killing by other, unrelated antibiotics and a biocide used in common household items, including soap and washing up liquid, new research from the University of Birmingham has shown.

The researchers, Professor Laura Piddock and Dr Mark Webber, from the Antimicrobials Research Group at the University of Birmingham have discovered that a common mutation in Salmonella, which makes it resistant to fluoroquinolones, an important class of antibiotics, also allows survival of bacteria in the presence of other antibiotics or the biocide, triclosan. Triclosan is an antibacterial and antifungal agent found in toothpastes, and soaps.

In a paper published today, they have demonstrated that a mutation which changes DNA gyrase – the target of fluoroquinolones – in Salmonella alters the structure of bacterial DNA by changing the tightness of chromosome coiling. These changes induce stress responses, which protect the bacterium and allow survival in the presence of numerous unrelated antibiotics including .

Prof Piddock said: "This study shows that use of a common antibiotic confers fundamental changes allowing bacteria to survive exposure to several antibiotics plus an antimicrobial found in products commonly used in the home."

The study explored the effects of substituting two specific within DNA gyrase to recreate common changes seen in isolated from patients. Although both mutants were resistant to quinolone antibiotics, one substitution also resulted in a significant increase in survival when exposed to 25 other drugs. These data indicate that the nature of the mutation is important in surviving exposure to antibiotics.

The research also showed that the change in gyrase altered susceptibility to the range of antibiotics by changing supercoiling of the chromosome rather than influencing how much drug was accumulated within the bacterium or other changes to cellular metabolism including the generation of reactive oxygen species.

The study demonstrates that a common mechanism of resistance to one group of antibiotics provides protection against other types of antibiotic. This suggests that such bacteria will survive better in the presence of many antimicrobials including biocides, and gives scientists more vital information in the fight against antibiotic resistance and the development of new drugs.

Dr Webber said: "Our work has helped understand how developing antibiotic resistance can change the biology of bacteria in a profound way. Identifying the conditions which select for resistant bacteria and promote their survival will help use current drugs in better ways"

Explore further: New hypothesis: Why bacteria are becoming increasingly more resistant to antibiotics

Related Stories

New hypothesis: Why bacteria are becoming increasingly more resistant to antibiotics

March 7, 2013
According to his theory, bacteria that are non-resistant to antibiotics acquire said resistance accidentally because they take up the DNA of others that are resistant, due to the stress to which they are subjected.

Bacterial contamination rife in retail store ground turkey

May 3, 2013
(HealthDay)—Ground turkey from retail stores is often contaminated with fecal bacteria, and in many cases the bacteria are resistant to antibiotics, according to a report published in the June issue of Consumer Reports.

Getting better without antibiotics

May 30, 2013
Given the option, many women with symptoms of urinary tract infections are choosing to avoid antibiotics and give their bodies a chance to heal naturally, finds research in BioMed Central's open access journal BMC Family ...

Antibiotics: Change route of delivery to mitigate resistance

June 26, 2013
New research suggests that the rapid rise of antibiotic resistance correlates with oral ingestion of antibiotics, raising the possibility that other routes of administration could reduce the spread of resistance. The manuscript ...

Recommended for you

Molecular hitchhiker on human protein signals tumors to self-destruct

July 24, 2017
Powerful molecules can hitch rides on a plentiful human protein and signal tumors to self-destruct, a team of Vanderbilt University engineers found.

Researchers develop new method to generate human antibodies

July 24, 2017
An international team of scientists has developed a method to rapidly produce specific human antibodies in the laboratory. The technique, which will be described in a paper to be published July 24 in The Journal of Experimental ...

New vaccine production could improve flu shot accuracy

July 24, 2017
A new way of producing the seasonal flu vaccine could speed up the process and provide better protection against infection.

A sodium surprise: Engineers find unexpected result during cardiac research

July 20, 2017
Irregular heartbeat—or arrhythmia—can have sudden and often fatal consequences. A biomedical engineering team at Washington University in St. Louis examining molecular behavior in cardiac tissue recently made a surprising ...

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.