CONTACT: JENNIFER CRONIN
2130 Medical Laboratories
Iowa City IA 52242
(319) 335-9917; fax (319) 335-8034
Release: Nov. 17, 1999
UI antibiotic resistance investigations indicate both
good, bad news
IOWA CITY, Iowa The University of Iowa is reporting
both good news and bad news on the war against antibiotic-resistant bacteria.
Although one UI Health Care study shows there may be a potent, new drug to
combat bacteria resistant to existing antibiotics, another investigation reveals
that some strains of Staphylococcus aureus (S. aureus) have become antibiotic-resistant
globe trotters, spreading throughout the world. S. aureus is the most common
bacterial cause of human diseases, including infections of the lung, bloodstream,
heart valves, skin and those infections caused by surgical wounds.
According to UI findings, a novel synthetic drug linezolid
was universally active against all tested forms of staphylococci regardless
of resistance patterns to other antibiotics. The new drug also inhibited all
enterococci and was 100 percent effective against streptococci.
"Linezolid appears to be a very promising new antimicrobial
agent," said Ronald Jones, M.D., UI professor of pathology. "We have not found
any documented cases where the drug has not been effective."
Jones and Michael Pfaller, M.D., UI professor of pathology
and public health, will present their findings at the 37th annual meeting
of the Infectious Diseases Society of America to be held Nov. 18-21 in Philadelphia.
The UI investigative team is the first, besides the manufacturer Pharmacia
& Upjohn, to test the effectiveness of the drug.
"One of the most exciting potential uses for this
new agent is the management of resistant Gram-positive infections," Pfaller
That potential may be even more important considering
the findings that UI colleague Daniel Diekema, M.D., a UI pathology fellow
and infectious diseases staff physician, will report at the same meeting.
According to the UI study led by Diekema, Pfaller
and Jones, similar and sometimes identical antibiotic-resistant strains of
S. aureus are popping up hundreds and thousands of miles apart, even across
"We demonstrated that there are numerous instances
where bacterial strains were present at many different hospitals in the same
region and at hospitals on different continents," Diekema explained.
The medical community has been using antibiotics to
treat bacterial infections for more than
60 years. However, many bacterial strains have become
immune to most of the available drugs meant to destroy the organisms. Much
of this immunity, or resistance, is due to overuse of the drugs themselves.
In the study Diekema will present, the UI investigators
wanted to find out the genetic relatedness of antibiotic resistant S. aureus
strains in various areas of the world. The UI researchers also wanted to identify
places where resistance was the highest. To conduct the probe, the UI team
relied on the global network of 72 medical centers that participate in the
SENTRY Antimicrobial Surveillance Program sponsored by Bristol-Myers Squibb.
SENTRY is a joint effort between the UI and the Women's and Children's Hospital,
Adelaide, Australia. The program is the first and only worldwide monitoring
system for the spread, over time, of bacteria resistant to antibiotics.
"We did this particular study because it is very important
to understand how these resistant strains are being spread around the world,"
The findings, which showed that many of the resistant
strains cross national borders and that the biggest resistance problem areas
are located in Central and South America and in Asian-Pacific countries, are
important as infectious disease control specialists attempt to combat the
resistance, Diekema stressed.
"If resistance emerges within an individual hospital
because of antibiotic use, then the best way to control that resistance is
to crack down on antibiotic use," he said. "However, if very resistant strains
are being spread widely between hospitals, then the best approach is to emphasize
infection control practices. In the case of S. aureus, it looks like these
resistant strains are very easily spread in hospitals, among hospitals and
even across continents. What that means to us is that even though antibiotic
control is important for this bacteria, even more important probably are good
infection control practices."
University of Iowa Health Care describes the partnership
between the UI College of Medicine and the UI Hospitals and Clinics and the
patient care, medical education and research programs and services they provide.