One answer to MRSA may be growing on trees

One answer to MRSA may be growing on trees

Eucalyptus leaves show power over pathogen

Sherry E, Boeck AU, Warnke PH. (Correspondence) Topical application of a new formulation of eucalyptus oil phytochemical clears methicillin-resistant Staphylococcus aureus infection Am J Infect Control 2001; 29(5):346.

If this one gets marketed, a koala bear may be on the label. Have Australian researchers found a natural enemy to a nosocomial scourge in the humble eucalyptus tree? It appears so, but larger clinical trials will be needed to confirm two intriguing cases. "We are all aware that the increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections is associated with increasing mortality rates, increased hospitalization rates, and longer treatment-to-discharge times," they wrote. "Antibiotics seem to have failed us."

So they suggested clinicians take a break from the lab and look around in Australia, where 70% of the plants are eucalyptus trees (over 500 species). These also are called gum trees and tea-tree plants. "Our original inhabitants, the aboriginal people, knew of the medicinal benefits of its leaf oil (eucalyptus oil)," they noted. "Now we do as well."

They presented two case studies showing the topical use of eucalyptus leaf oil extract (PT) formulation of phytochemicals derived directly from the plant eucalyptus globulus, together with bioethanol. Its effective components are Eucalyptus, Melaleuca (tea-tree), Thymus (thyme), Syzygium (clove), and citrus extracts for the treatment of MRSA infection of bone.

Case 1: A 17-year-old man injured in a car accident required open reduction and internal fixation of fractures of the pelvis and femur, followed later by intramedullary nailing of the femur. Chronic postoperative osteomyelitis of the right femur with a draining sinus failed to respond to ciprofloxacin and rifampicin during two years of antibiotic therapy. MRSA was isolated. Removal of the intramedullary nail and wiping of the infection site with PT was followed by application of PT cream (1 g daily) to the sinus for five days. No antibiotics were used during this period. Inflammation subsided markedly over two to three days; the sinus was dry at seven days, with healthy granulation evident. The wound had fully healed at two weeks. No evidence existed of infection after 32 weeks.

Case 2: A 42-year-old man injured by a machine that fell on him in a work accident sustained a foot fracture and dislocation. After open-reduction and internal fixation with k-wires and 3.5 mm screws, the wound healed. The hardware was removed at eight weeks. Infection at the site of the injury then became apparent, and MRSA was confirmed by culture. The infected tissue was surgically debrided. PT liquid (0.5 g daily) was applied to the wound with a cotton bud for three weeks. No antibiotic was used. Marked improvement in the general condition of the patient and reduction of inflammation at the infection site were evident five days after commencement of PT treatment. The wound had closed by 21 days, and cultures at this time showed no MRSA. The patient was still clear of infection at 12 weeks.

"Our findings suggest that formal clinical trials of eucalyptus oil may be warranted in view of the in vitro data known," they concluded.