We have investigated the distribution of the various core types (Rl, R2, R3, in 138 Escherichia coli isolates obtained from positive blood cultures. Rabbit antisera, raised against five rough strains expressing the respective core types, were made monospecific by extensive absorption. The reactivity of the antisera was tested in ELISA with bacterial cells that had been autoclaved for full exposure of core epitopes. One hundred and thirty strains could be typed directly, while eight strains required prior digestion with proteinase K for removal of cross-reactions. Ninety-four of the strains (68 %) expressed the R1 type, and 9 (6*5%), 12 (8*7%), 7 (5.1 %) and 3 (202%) strains expressed the R2, R3, R4 and K-12 core types, respectively. An R1R4 mixed core type, hitherto not yet described, was found in 13 (9.4%) strains. Results obtained with polyclonal antisera were in agreement with those obtained with monoclonal antibodies to the R1, R2 and R3 core types. Core typing may serve as an additional serological marker next to conventional typing of 0-, H-and K-antigens.
Microbiology andUnit, Vrije Universiteit, van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
General international agreement has emerged that acupuncture appears to be effective for postoperative dental pain, postoperative nausea and vomiting, and chemotherapy-related nausea and vomiting. For migraine, low-back pain, and temporomandibular disorders the results are considered positive by some and difficult to interpret by others. For a number of conditions such as fibromyalgia, osteoarthritis of the knee, and tennis elbow the evidence is considered promising, but more and better quality research is needed. For conditions such as chronic pain, neck pain, asthma, and drug addiction the evidence is considered inconclusive and difficult to interpret. For smoking cessation, tinnitus, and weight loss the evidence is usually regarded as negative. Reviews have concluded that while not free from serious adverse events, they are rare and that acupuncture is a relatively safe procedure.
BackgroundBlood cultures remain the gold standard for detecting bacteremia despite their limitations. The current practice of blood culture collection is still inefficient with low yields. Limited focus has been given to the association between timing of specimen collection at different time points during admission and their yield.MethodsWe carried out a retrospective observational study by analyzing all 3,890 sets of cultures collected from the 1,962 admitted patients over the seven-month period of this study. We compared the blood culture yield between the early group (≤24 hours after admission) and the late group (> 24 hours of admission). We also investigated the effect of prehospital oral antibiotics and pre-analytical time on the first cultures in the emergency department. Epidemiology and efficiency of blood cultures were studied for each medical specialty.ResultsIn total, 3,349(86.1%) blood cultures were negative and 541(13.9%) were positive for one or more microorganisms. After correcting for contamination, the overall yield was 290 (7.5%). The early group (n = 1,490) yielded significantly more true-positive cultures (10.1% versus 5.8%, P<0.001) than the late group (n = 2,400). The emergency department had a significantly higher yield than general wards, 11.2% versus 5.7% (p<0.001). Prehospital oral antibiotic use and pre-analytical time did not affect the yield of first cultures at the emergency department (p = 0.735 and 0.816 respectively). The number of tests needed to obtain one true-positive culture varied between departments, ranging from 7 to 45.ConclusionThis study showed that blood cultures are inefficient in detecting bacteremia. Cultures collected during 24 hours after admission yielded more positive results than those collected later. Significant variations in blood culture epidemiology and efficiency per specialty suggest that guidelines should be reevaluated. Future studies should aim at improving blood culture yield, implementing educational programs to reduce contamination and cost-effective application of modern molecular diagnostic technologies.
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