Manual Culture

Preparation of patient: Collect specimens before antimicrobial therapy where possible.

Precautions: Blood culture bottles (1 aerobic and 1 anaerobic bottle) should be received in the laboratory within four hours of sampling. Blood cultures received outside this time, but still received on the same day as sampling will still be processed, however such samples will have a laboratory comment added to the final report to alert you to the risk of false negative results with samples that have had a delay in processing. Blood cultures not received on the same day as sampling are not suitable for analysis. Blood cultures should remain at ambient temperature until delivered for testing. For the majority of patients, two blood culture sets are recommended. A second or third set taken from a different site not only increases yield but also allows recognition of contamination. In most conditions other than endocarditis, bacteraemia is intermittent, being related to the fevers and rigors which occur30-60 minutes after the entry of organisms to the bloodstream. Samples should be taken as soon as possible after a spike of fever. However, some work has shown little difference in isolation rates between blood drawn at intervals and simultaneously with fever spikes. Certainly, the timing is less important for continuous bacteraemia, as seen in infective endocarditis. The patient’s skin should be disinfected prior to sample collection in order to minimise the risk of contamination. When filling the bottles, the aerobic bottle may be filled first.

PLEASE NOTE: Samples and accompanying relevant patient/ isolate data maybe referred for confirmatory or further laboratory testing to Reference laboratories. Relevant Public Health departments may also be notified IF a notifiable disease is identified under the Infectious Diseases (Amendment)Regulations 2020 (S.I. No. 53/2020).