Komatsu Shoko, Tanaka Shinobu, Nakanishi Noriko
Department of Infectious Diseases, Kobe Institute of Health, Japan.
Jpn J Infect Dis. 2023 Jan 24;76(1):77-79. doi: 10.7883/yoken.JJID.2022.397. Epub 2022 Aug 31.
Legionella pneumophila, the primary causative agent of Legionnaires' disease, is classified into at least 15 serogroups (SGs). Before genotyping, serotyping is first performed to limit the sources of L. pneumophila infections that caused an outbreak. In addition to conventional assays using monoclonal or polyclonal antisera, serotyping using multiplex polymerase chain reaction (M-PCR) was recently developed for L. pneumophila. In this study, we applied the M-PCR system to 41 strains that remained to be SGUT (untypable) by slide agglutination tests among the 220 L. pneumophila strains isolated from bath water in Kobe City during 2016-2020, to determine SG-genotypes (SGg) by PCR amplification of the specific target gene of the SGs. Among the 41 SGUT strains, SGg4/10/14 was the most predominant (24/41, 58.5%), followed by SGg1 (7/41, 17.1%). Seven strains, except for the strains determined as SGg1, were identified as belonging to a single SGg by M-PCR serotyping (SGg5 [3/41, 7.3%], SGg8 [3/41, 7.3%], and SGg7 [1/41, 2.4%]). Furthermore, we found that the seven strains identified as SGg1 harbored particular genotypes. In conclusion, the M-PCR serotyping assay will be helpful for investigating the distribution of L. pneumophila in environmental and clinical settings.
嗜肺军团菌是军团病的主要病原体，至少可分为15个血清群（SGs）。在进行基因分型之前，首先进行血清分型以限制导致疫情爆发的嗜肺军团菌感染源。除了使用单克隆或多克隆抗血清的传统检测方法外，最近还开发了用于嗜肺军团菌的多重聚合酶链反应（M-PCR）血清分型方法。在本研究中，我们将M-PCR系统应用于2016 - 2020年从神户市洗浴水中分离的220株嗜肺军团菌中，通过玻片凝集试验仍无法分型（SGUT）的41株菌株，通过PCR扩增血清群的特异性靶基因来确定血清群基因型（SGg）。在41株SGUT菌株中，SGg4/10/14最为常见（24/41，58.5%），其次是SGg1（7/41，17.1%）。除了确定为SGg1的菌株外，7株菌株通过M-PCR血清分型被鉴定为属于单一血清群基因型（SGg5 [3/41，7.3%]、SGg8 [3/41，7.3%]和SGg7 [1/41，2.4%]）。此外，我们发现确定为SGg1的7株菌株具有特定的基因型。总之，M-PCR血清分型检测将有助于调查嗜肺军团菌在环境和临床环境中的分布情况。
