Some 30 percent of all positive hospital blood culture samples are discarded every day because they’re “contaminated” - they reflect the presence of skin germs instead of specific disease-causing bacteria.
Rather than toss these compromised samples into the trash, clinicians may be able to use the resistance profiles of skin bacteria identified by these tests to treat patients with antibiotics appropriate to their ailment, Tel Aviv University researchers say. Dr. Gidi Stein and Dr. Danny Alon of TAU’s Sackler Faculty of Medicine and the Department of Internal Medicine B. at Beilinson Hospital, Rabin Medical Center, and Prof. Lilach Hadany and Uri Obolski of the Department of Molecular Biology and Ecology of Plants at TAU’s Faculty of Life Sciences conducted a retrospective study on more than 2,500 patients. Their test results demonstrate the unique diagnostic value of “erroneous” cultures.
The study showed the immediate effects on both public health questions and the treatment of individuals whose blood has been contaminated. The results were published in the Journal of Antimicrobial Chemotherapy.
Think before you toss
The more resistant the skin germs, the higher the risk of the infecting bacteria to be resistant, the researchers found. “These results can certainly be used for on-site clinical decisions. Once a contaminated sample has been found to be highly resistant, it is likely that the blood-borne pathogens will have a similar resistance pattern. Thus antibiotic treatment may be better targeted for the actual pathogens,” says Prof. Hadany.