van der Vyver Jenna A, Thomas Teena
Department of Clinical Microbiology and Infectious Diseases, Faculty of Health Science, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
Infection Control Services Laboratory, National Health Laboratory Services, Johannesburg, South Africa.
S Afr J Infect Dis. 2024 Nov 29;39(1):684. doi: 10.4102/sajid.v39i1.684. eCollection 2024.
Microbiological testing of peritoneal dialysis bags for peritonitis often yields culture-negative results. Culture-negative samples should not exceed > 15% according to the International Society for Peritoneal Dialysis. To reduce this issue, the addition of a blood culture bottle incubation step to the culture process was introduced at the Infection Control Services Laboratory (ICSL) of the National Health Laboratory Services (NHLS).
The aim of the study was to ascertain if the change in methodology increased the culture-positivity yield and reduced the culture-negative percentage.
Data from the NHLS Central Data Warehouse (CDW) were analysed to compare the culture-positive results over two periods: June-December 2022 when the non-blood culture (B/C) bottle method was used and January-July 2023 when the B/C bottle method was implemented.
The non-B/C culture method yielded a 23% culture-positivity yield, whereas the B/C bottle-based method yielded a 51% culture-positivity yield. However, the culture-negative yield for the B/C bottle-based method was high at 49%.
The change in dialysis bag processing in 2023 led to a more than doubling in culture-positivity yield. However, the culture-negative percentage remained high. As a result, further modifications to the methodology are needed.
The study findings illustrate that the addition of the B/C bottle incubation step significantly improved peritoneal dialysis bag culture yields which directly impacts patient management.
用于腹膜炎检测的腹膜透析袋微生物检测结果往往为培养阴性。根据国际腹膜透析协会的规定，培养阴性样本不应超过15%。为减少这一问题，国家卫生实验室服务局（NHLS）的感染控制服务实验室（ICSL）在培养过程中增加了血培养瓶孵育步骤。
本研究旨在确定方法的改变是否提高了培养阳性率并降低了培养阴性率。
对NHLS中央数据仓库（CDW）的数据进行分析，以比较两个时期的培养阳性结果：2022年6月至12月使用非血培养（B/C）瓶法时，以及2023年1月至7月实施B/C瓶法时。
非B/C培养法的培养阳性率为23%，而基于B/C瓶的方法的培养阳性率为51%。然而，基于B/C瓶的方法的培养阴性率高达49%。
2023年透析袋处理方法的改变使培养阳性率提高了一倍多。然而，培养阴性率仍然很高。因此，需要对方法进行进一步修改。
研究结果表明，增加B/C瓶孵育步骤显著提高了腹膜透析袋培养率，这直接影响患者管理。
