Chemical & Engineering News Digital Edition - Institute of Materia ...

WHEN THE POPULAR PRESS writes
about the emergence of “superbugs,” bacteria
that resist all of the weapons in the
antibiotic arsenal, public enemy number
one is always methicillin-resistant Staphylococcus
aureus (MRSA).
The gram-positive bug lends itself to
sensational headlines given the thousands of
cases of infection reported each year, including
those of otherwise healthy young people.
But industry observers say a bigger problem
of antibiotic resistance lies in gram-negative
organisms, which tend to strike the very old,
the very young, and the very sick.
“These are people who are in the hospital
and have a lot of other things wrong
with them,” says George Talbot, who has
worked on the development of infectious
disease drugs at both big and small pharmaceutical
companies and now serves as
a consultant to the industry. What is making
doctors nervous is the woefully thin
pipeline of drugs to treat these infections
versus the comparatively robust cache of
drugs to treat gram-positive organisms.
The epidemiology of hospital infections
has a natural cycle. Decades ago, when
COVER STORY
IMMINENT THREAT
As GRAM-NEGATIVE BACTERIA become resistant to current
antibiotics, the search for new drugs accelerates
LISA M. JARVIS, C&EN NORTHEAST NEWS BUREAU
Talbot was doing his residency and internship
in the University of Pennsylvania
hospital system, doctors were concerned
that some types of gram-negative
bacteria were showing resistance
to available medicines. Big pharma
responded, new drugs were developed,
and their fears gradually
subsided.
Subsequently, gram-positive
bacteria moved to the forefront,
Talbot says. Resistant strains
emerged as more antibiotics
were prescribed and artificial
implants—places where grampositive
bacteria love to dwell—
became more common.
Several strains of gram-positive
organisms are, indeed, showing
resistance to some agents in the
U.S., but an adequate stream of
drugs flowing through the pipeline
should address future need, says Robert
C. Moellering Jr., professor of medical research
at Harvard Medical School. As such,
he notes that the urgency for new drugs is
probably somewhat overstated by news
reports. An “it could happen to you” perception
exists for MRSA that has probably
reinforced fears, Talbot adds.
The pipeline of new drugs for treating
gram-negative bacteria, on the other hand,
carries just a trickle. “While we all had our
attention focused on
MRSA, these other
gram-negative bugs
started to rear their ugly
heads,” says Paul Miller,
head of antibacterials
research at Pfizer.
PESKY BUG
Virulent strains
of Pseudomonas
aeruginosa worry
scientists.
Although few people have died because
of untreatable gram-negative infections,
“the fact that we’re seeing any of these is a
concern,” Moellering says.
Stuart Levy, cofounder of Paratek Phar-
ROCHE