Impact of delayed processing of positive blood cultures on organism detection: a prospective multi-centre study

Background Blood cultures remain the gold standard investigation for the diagnosis of bloodstream infections. In many locations, quality-assured processing of positive blood cultures is not possible. One solution is to incubate blood cultures locally, and then transport bottles that flag positive to a central reference laboratory for organism identification and antimicrobial susceptibility testing. However, the impact of delay between the bottle flagging positive and subsequent sub-culture on the viability of the isolate has received little attention. Methods This study evaluated the impact of delays to sub-culture (22 h to seven days) in three different temperature conditions (2–8 °C, 22–27 °C and 35 ± 2 °C) for bottles that had flagged positive in automated detection systems using a mixture of spiked and routine clinical specimens. Ninety spiked samples for five common bacterial causes of sepsis (Escherichia coli, Haemophilus influenzae, Staphylococcus aureus, Streptococcus agalactiae and Streptococcus pneumoniae) and 125 consecutive positive clinical blood cultures were evaluated at four laboratories located in Cambodia, Lao PDR and Thailand. In addition, the utility of transport swabs for preserving organism viability was investigated. Results All organisms were recoverable from all sub-cultures in all temperature conditions with the exception of S. pneumoniae, which was less likely to be recoverable after longer delays (> 46–50 h), when stored in hotter temperatures (35 °C), and from BacT/ALERT when compared with BACTEC blood culture bottles. Storage of positive blood culture bottles in cooler temperatures (22–27 °C or below) and the use of Amies bacterial transport swabs helped preserve viability of S. pneumoniae. Conclusions These results have practical implications for the optimal workflow for blood culture bottles that have flagged positive in automated detection systems located remotely from a central processing laboratory, particularly in tropical resource-constrained contexts

Adapting the Green Revolution for Laos

Initial efforts to introduce Green Revolution practices met obstacles in Laos due to the Vietnam War, early attempt to collectivise agricultural production, and limited investment in agricultural research. Faced with ongoing food shortages, the government embraced agricultural modernisation but lacked the resources to implement it. From 1990 to 2007, the International Rice Research Institute (IRRI) and the Government of Laos built the nation’s capacity in rice research and developed improved varieties suitable to Lao farming conditions. The program has been credited with bringing the Green Revolution to Laos, supporting increases in rice production to levels of national self-sufficiency, and building national research capacity. This chapter traces the history and processes that have seen the development, use, and spread of improved rice varieties throughout Laos, particularly in the lowlands of the Central and Southern Regions. This history represents a departure from the Green Revolution narratives of other Southeast Asian countries, where the development and use of improved varieties was predicated on access to irrigation and fertiliser and favoured yield over other qualities like taste or aroma. Instead, efforts to improve rice production in Laos emphasised plant breeding based on local conditions and preferences—low input, rainfed production of sticky rice—and built the capacity of Lao institutions and researchers to continue rice breeding after formal project efforts ceased