Health Scan: Defeating disease

New antibiotic approach outsmarts bacteria that 'play possum.'

By JUDY SIEGEL-ITZKOVICH
bacteria 88 (photo credit: )
bacteria 88
(photo credit: )
New ways to kill bacteria that have become resistant to antibiotics have been developed by researchers at the Hebrew University of Jerusalem. Although antibiotics are the most preferred treatment against bacterial infection and disease, it has become apparent that some diseases can't be treated simply by giving antibiotics. Sub-populations of some bacteria can avoid the lethal antibiotics by slowing their metabolism, remaining dormant for days and waiting for the opportunity to strike again. The researchers studied these dormant bacteria and found that they can be killed either by subjecting the bacteria to a fresh dose of nutrients together with the antibiotic treatment, or by infecting them bacteria with phages (viruses that attack bacteria). In both cases the population of these dormant bacteria was significantly reduced. Biophysicist Dr. Nathalie Balaban at HU's Racah Institute of Physics, doctoral student Orit Gefen and master's degree student Sivan Pearl recently reported their findings in Proceedings of the [US] National Academy of Sciences and PLoS Biology. "These results might lead to new phage therapies for fighting infections that persist despite antibiotics," Balaban said. Their research shows that sub-populations of E. Coli survive antibiotic treatments by shutting down their activity, which was measured by following the production of fluorescent proteins in bacteria trapped on micro-chips. The team discovered that protein production does occur in dormant bacteria, immediately after exiting the stationary phase. By exposing the entire bacteria population to antibiotics during this timeframe, the team significantly reduced the number of dormant bacteria that survived. These results offer a potentially new way to tackle dormant bacteria - which are the main reason for failure of antibiotic treatments against diseases such as tuberculosis, which often requires months or years of antibiotic treatment. Also, the results challenge current views as to bacterial dormancy and suggest an alternative model for the transformation of normal bacterial cells into dormant ones. Working with Prof. Amos Oppenheim from the Hebrew University-Hadassah Medical School, the team also studied the interaction between dormant bacteria and phages. They tried to determine whether dormancy evolved as a protection against phage attack, thus allowing the bacteria to survive stressful environments. The team showed that the existence of dormant bacteria provides an advantage when the population is attacked by lysogenic phage (a phage that may reside inside bacteria for generations and only then multiply and attack). Nevertheless, dormancy provided no protection when the bacteria were attacked by lytic phage that reproduces and kills immediately. OXYGEN TREATMENT SENDS FENCER TO BEIJING A 26-year-old Israeli fencer, Dalila Hatuel, accepted to Israel's Olympic team, almost lost her chance to participate in the Beijing games because of torn ligaments in her knee, surgery and the resulting edema (swelling). But she was allowed to go after undergoing treatment in the hyperbaric oxygen chamber at Assaf Harofeh Medical Center in Tzrifin, said Dr. Shai Efrati, the chamber director. After Israel Olympic Team experts observed her fencing, she was allowed to remain on the team and sent for seven more treatments before she flew to China. Exposure to oxygen under high pressure, said Efrati, is very effective in the treatment of wounds and trauma, as the gas speeds up the natural healing process. Sports injuries usually heal, but a hyperbaric chamber speeds it up, as white cells that fight pathogens increase in number, along with collagen cells that rebuild bone. Hyperbaric chambers look like submarines Inside, the oxygen and other gases are at a higher concentration than in ordinary air. Assaf Harofeh's chamber is the largest in the Middle East, and is used to treat not only injuries but also carbon monoxide poisoning and smke inhalation, diabetic skin ulcers on the feet and diving accidents MUSIC RELAXES BLOOD PRESSURE Listening to just 30 minutes of rhythmically homogeneous music daily can significantly reduce high blood pressure, according to Italian researchers who lectured at the American Society of Hypertension's recent annual scientific meeting. In the first study to examine the antihypertensive effect of music on ambulatory blood pressure (ABP), the findings show that patients with mild hypertension who listened to just half an hour of classical, Celtic or Indian raga music a day for a month experienced significant reductions in 24-hour ABP. Hypertension is a common disorder in which blood pressure remains at 140/90 mm Hg or greater, and is responsible for causing at least five million premature deaths each year . "Listening to music is soothing and has often been associated with controlling patient-reported pain or anxiety and acutely reducing blood pressure," said study investigator, University of Florence internal medicine Prof. Pietro Modesti. "But for the first time, our results clearly illustrate the impact that daily music listening has. We are excited about the positive implications for both patients and physicians, who can now confidently explore music listening as a safe, effective, non-pharmacological treatment option or a complement to therapy." A total of 48 patients between 45 and 70, all with mild hypertension and taking pills for it, took part in the study. Of these, 28 aged between 45 and 69 listened to 30 minutes of classical, Celtic and raga music per day while conducting slow breathing exercises. Twenty patients of comparable age, blood pressure and antihypertensive treatment served as the control group. All patients underwent ABP monitoring to set a baseline and one and four weeks after treatment. The study results revealed a significant systolic ABP reduction in those patients who had been listening to music daily. Only small, non-significant BP reductions were revealed via 24-hour monitoring of the control group.