Subject: A Firefly Gene May Light Way To Gains on TB 
Date: Published: 5/7/93 (78 lines)
Source: Wall Street Journal. Copyright Dow Jones & Co. Inc.

    Technology & Health:
    A Firefly Gene
    May Light Way
    To Gains on TB
    ----
    By Elyse Tanouye
    Staff Reporter of The Wall Street Journal

    The gene that makes fireflies glow may some day speed physicians'
 diagnoses and treatments of patients infected with drug-resistant
 strains of tuberculosis.
    A team of researchers, led by William R. Jacobs Jr. and Barry R. 
 Bloom of the Albert Einstein College of Medicine in New York's Bronx
 borough, developed tools to insert the firefly gene into TB
 bacteria, taken from a patient's sputum sample, that had been
 exposed to an antibiotic.  If the antibiotic didn't work, the
 bacteria emitted a dim, yellowish-green light, indicating they were
 still alive and resistant to that particular drug.  If a light didn't
 appear after the firefly gene was inserted, the researchers knew the
 antibiotic was effective because the bacteria were dead.
    The new test will halve the time needed to diagnose
 drug-resistant TB in patients, according to the researchers.  Current
 TB tests take as long as 13 weeks -- three to eight weeks to grow
 the billions of bacteria needed to conduct the test, and another
 five weeks to see if one of the dozen or so antibiotics used to
 treat the disease kills them.
    Meanwhile, the patient can continue to spread the disease by
 coughing or sneezing.  Health-care workers are particularly at risk:
 Anecdotal reports indicate that as many as 30% of nurses, doctors
 and other health-care workers at some hospitals have been infected
 with the TB bacteria in the past year.  The problem is particularly
 worrisome in urban areas such as New York, where a recent study
 showed a third of the patients with TB had drug-resistant varieties.
    In today's Science journal, the researchers describe their
 technique of creating a genetically engineered phage, a virus that
 infects bacteria, to carry the gene that produces the luciferase
 enzyme that makes fireflies glow.  As it penetrates the TB bacterium,
 the phage inserts the luciferase gene.
    The researchers are working on improving the phages to reduce the
 time needed to obtain a test result to less than a week.  They are
 also seeking to boost the light intensity so it can be seen in a
 dark room or on film, rather than having to use a light detector.
 Years Away The test may also help pharmaceutical companies find new
 TB drugs.  Time is money in drug discovery, and the firefly TB test
 could greatly increase research productivity, says Barry I. 
 Eisenstein, vice president at Eli Lilly & Co. 's Lilly Research
 Laboratories.  Moreover, many drugs are unstable and break down over
 a period of weeks, making it difficult to gauge results, he says.
 Eli Lilly and Bristol-Myers Squibb Co. are negotiating to use the
 test eventually.  A form of the test for use in hospitals is still
 several years away, Dr. Jacobs says.
    Besides reducing the spread of the disease, earlier diagnoses of
 active TB may save lives.  In one New York case, Dr. Jacobs recounts,
 a patient who was also infected with the AIDS virus was treated for
 TB with the standard three drugs.  One month later, he was doing
 worse and was started on three different antibiotics.  Two months
 later, he was dead.
    Two weeks later, his TB test result came in.  He was infected with
 organisms resistant to seven different antibiotics.  "Had we known in
 the first week what to treat him with, we might have saved his life
 and prevented the spread of multiple-drug-resistant TB to
 health-care workers and other patients," Dr. Jacobs says.
    Many hospitals are considering spending millions of dollars on
 special ventilation systems and masks to reduce their staffs'
 exposure to TB, says George DiFerdinando Jr., medical director of
 New York state's TB-control program.  But, he says, "the best way to
 protect health-care workers isn't masks or ventilation."  He adds:
 "The best way is by rapidly diagnosing and accurately treating
 patients.  And Dr. Jacobs's test helps with that."

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