Concordance between IDEXX Legiolert® (liquid culture assay) and plate culture (ISO 11731:2017) for the detection and quantification of Legionella pneumophila in water samples

IF 3.9 3区医学 Q1 INFECTIOUS DISEASES

Journal of Hospital Infection Pub Date : 2024-08-01 DOI:10.1016/j.jhin.2023.10.019

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引用次数: 0

Abstract

Background

Legionella pneumophila is a water-borne bacterium that can cause Legionnaires' disease. Legiolert® (IDEXX, USA) is a low-labour liquid culture assay for the detection and enumeration of L. pneumophila (SG1-15) from water.

Aim

To analyse concordance between Legiolert and ISO 11731:2017 plate culture method (membrane filtration and culture on selective agars) using hospital water samples (N = 100).

Methods

Incubation was at 39 °C and 36 °C, respectively, for seven days, followed by most-probable enumeration for Legiolert and subculturing and serogrouping of suspected Legionella colonies, with plate culture.

Findings

L. pneumophila (SG1-15) was isolated from 25 out of 100 samples when using Legiolert or plate culture. Fourteen additional Legiolert samples tested positive for L. pneumophila; analysis of the same samples by plate culture was negative (12 out of 14) or yielded only Legionella rubrilucens (two out of 14; confirmed via matrix-assisted ionization/desorption time-of-flight mass spectrometry). L. pneumophila was not captured from Quanti-Tray/Legiolert pouch wells of these positive samples after subculture of puncture aliquots on buffered charcoal yeast-extract agar. Both methods in concordance did not detect L. pneumophila in 61 out of 100 samples.

Conclusion

Legiolert and plate culture are both satisfactory methods to detect L. pneumophila from water samples, and both to detect isolated L. pneumophila in 25% of the sample population. Legiolert provides a faster time to result, and is less resource-demanding and labour-intensive; however, there may be a low risk of cross-reactivity with other organisms. Both methods are suitable for the analysis of water in healthcare settings, where the monitoring of L. pneumophila is imperative in preventing cases of Legionnaires' disease.

查看原文本刊更多论文

IDEXX Legiolert®（液体培养法）和平板培养法（ISO 11731:2017）在检测和定量水样中嗜肺军团菌方面的一致性。

背景：嗜肺军团菌是一种可引起军团病的水传播细菌。在医疗环境中监测这种生物对于保护弱势群体至关重要。Legiolert®（美国IDEXX）是一种低产程液体培养法，用于从水中检测和计数嗜肺乳杆菌（SG1-15），只需最少的操作员培训，并在7天内提供确认结果。目的：使用Legiolert®和ISO 11731:2017平板培养法（膜过滤和选择性琼脂培养）对医院水样（n=100）进行处理，以分析程序之间的一致性。方法：分别在39°C和36°C下培养7天，然后对Legiolert®进行最可能的计数，并用平板培养法对疑似军团菌菌落进行亚培养和血清分组。结果：当使用Legiollert®或平板培养时，从25/100个样本中分离出嗜肺乳杆菌（SG1-15）。另外14份Legiolert®样本的嗜肺乳杆菌检测呈阳性；通过平板培养对相同样品的分析为阴性（12/14）或仅产生红色军团菌（2/14；通过MALDI ToF MS确认）。在BCYE琼脂上继代培养穿刺等分试样后，未从这些阳性样品的Quanti Tray/Legiolert®袋孔中捕获嗜肺乳杆菌。两种方法一致，在61/100份样本中未检测到嗜肺乳杆菌。结论：Legiolert®和平板培养都是从水样中检测嗜肺乳杆菌的令人满意的方法，并且都在25%的样本群体中分离出嗜肺乳球菌。Legiolert®提供了更快的结果时间、更少的资源需求和劳动密集型。尽管如此，与其他生物体发生交叉反应的风险可能很低。这两种方法都适用于医疗环境中的水分析，在医疗环境中，对嗜肺乳杆菌的监测对于预防军团病病例至关重要。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Hospital Infection 医学-传染病学

CiteScore

12.70

自引率

5.80%

发文量

271

审稿时长

19 days

期刊介绍： The Journal of Hospital Infection is the editorially independent scientific publication of the Healthcare Infection Society. The aim of the Journal is to publish high quality research and information relating to infection prevention and control that is relevant to an international audience. The Journal welcomes submissions that relate to all aspects of infection prevention and control in healthcare settings. This includes submissions that: provide new insight into the epidemiology, surveillance, or prevention and control of healthcare-associated infections and antimicrobial resistance in healthcare settings; provide new insight into cleaning, disinfection and decontamination; provide new insight into the design of healthcare premises; describe novel aspects of outbreaks of infection; throw light on techniques for effective antimicrobial stewardship; describe novel techniques (laboratory-based or point of care) for the detection of infection or antimicrobial resistance in the healthcare setting, particularly if these can be used to facilitate infection prevention and control; improve understanding of the motivations of safe healthcare behaviour, or describe techniques for achieving behavioural and cultural change; improve understanding of the use of IT systems in infection surveillance and prevention and control.