渗透压选择性裂解法在MALDI-TOF MS直接鉴定血培养阳性标本中的应用

摘要：目的?采用渗透压选择性裂解法联合基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)直接鉴定阳性血培养瓶中病原菌，为临床早期诊断和治疗提供可靠依据。方法?收集2018年12月至2019年3月杭州迪安医学检验中心微生物室送检的阳性血培养瓶179例，采用渗透压选择性裂解法直接进行MALDI-TOF MS检测。结果?血培养阳性标本经裂解离心、甲酸萃取后得到的谱峰丰度最高，鉴定分值最优；174份单种菌血培养的种、属水平鉴定的符合率分别是67.8%(118/174)、85.1%(148/174)。革兰阴性杆菌的种、属水平鉴定的符合率是74.7%(62/83)、91.6%(76/83)，革兰阳性球菌的种、属水平的鉴定符合率是69.4%(50/72)、80.6%(58/72)，革兰阳性杆菌鉴定种水平的准确率显著低于革兰阴性杆菌(P<0.05)和革兰阳性球菌(P<0.05)。结论?MALDI-TOF MS采用渗透压裂解法对血培养阳性标本直接鉴定，具有简单、快速的优点，但其对菌种鉴定的准确性以及前处理步骤优化方面仍然需要进一步研究。     

革兰染色与MALDI-TOF MS在快速鉴定儿童阳性血培养病原菌种类中的应用

目的 分析革兰染色与基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）在快速鉴定儿童阳性血培养病原菌种类中的应用价值,为儿童血流感染诊断提供快速、准确的实验室依据。方法 收集2019年2月—2020年10月首都医科大学附属北京儿童医院临床送检的儿童阳性血培养瓶,同时进行革兰染色镜检、MALDI-TOF MS快速鉴定和转种培养,以转种培养后的鉴定结果为标准,对革兰染色镜检和MALDI-TOF MS快速鉴定结果进行比较。结果 共收集166例儿童阳性血培养样本,其中单一菌样本占97.6%(162/166),2种菌样本占2.4%(4/166)。以转种培养后的鉴定结果为标准,162例单一菌样本革兰染色镜检结果符合率为97.5%(158/162),其中革兰阳性菌符合率为97.9%(93/95),革兰阴性菌符合率为96.8%(61/63),酵母样真菌符合率为100.0%(4/4);MALDI-TOF MS快速鉴定结果符合率为85.2%(138/162),其中革兰阳性菌符合率为81.1%(77/95),革兰阴性菌符合率为92.1%(58/63),酵母样真菌符合率为75.0%(3/4)。4例2...     

MALDI-TOF MS直接鉴定阳性厌氧血培养瓶中细菌的研究

目的探讨基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)直接鉴定阳性厌氧血培养瓶中细菌的可行性和准确性,评价不同前处理方法用于质谱快速鉴定的临床应用价值。方法收集2017年8月至2018年8月临床非重复阳性厌氧血培养瓶,经革兰染色镜检确认均有菌生长。利用分离胶促凝管法和0.5%十二烷基硫酸钠(SDS)法处理阳性厌氧血培养瓶并用MALDI-TOF MS直接鉴定,与转种后菌落鉴定结果相比较,分析鉴定准确率和一致性。结果共收集阳性厌氧血培养瓶240瓶,包括单菌阳性234瓶,混合菌6瓶,平均报阳时间为(16.87±13.12)h;218瓶(90.83%)可用MALDI-TOF MS直接鉴定,4瓶(1.67%)混合菌生长仅鉴定其中一种菌或无可靠鉴定结果。SDS法和分离胶法对革兰阴性菌的鉴定准确率(94.81%、94.16%)显著高于革兰阳性菌(87.50%、81.25%),差异有统计学意义(χ2=3.96、9.53,P0.05);SDS法和分离胶法直接鉴定与菌落鉴定结果的一致率分别为92.31%、89.74%。SDS法前处理鉴定的准确率和鉴定分值≥2.0的比例(94.17%、69.23%)均高于分离胶法(90.83%、65.81%);SDS法厌氧菌的鉴定分值≥2.0的比例(83.33%)明显高于分离胶法(58.33%)。结论 MALDI-TOF MS可应用于临床常见厌氧血培养阳性菌的鉴定,SDS法前处理对厌氧菌的快速鉴定有较高的准确率。     

MALDI-TOF MS直接涂靶法快速鉴定丝状真菌的临床应用

目的评价基质辅助激光解吸电离飞行时间质谱直接涂靶法（质谱直涂法）快速鉴定丝状真菌的临床应用价值。方法对2010年1月至2017年12月首都医科大学附属北京同仁医院临床标本中分离的133株丝状真菌分别进行形态学、基因序列分析及质谱直涂法鉴定，并将鉴定结果进行分析比较。 采用SPSS 16.0软件进行统计分析，计数资料采用χ2检验。结果以基因序列分析结合形态学鉴定的结果为标准，将133株丝状真菌鉴定到种、复合群和属的鉴定率:质谱直涂法分别为64.66%、79.70%和96.24%，基因序列分析则分别为69.17%、83.46%和99.25%，而形态学鉴定分别为68.42%、84.21%和93.23%。 质谱直涂法与另外两种方法的种、复合群和属的鉴定率的差异无统计学意义（χ2值分别为0.611、0.625、2.728和0.516、0.915、1.206，P值均＞0.05）。 质谱直涂法将77株曲霉属中61.04%、88.31%和98.70%的菌株分别鉴定到种、复合群和属，将14株青霉属中64.29%和92.86%的菌株分别鉴定到种和属，还将42株其他丝状真菌中的71.43%和92.86%的菌株分别鉴定到种和属；因数据库中真菌种类不足，致3.76%（5/133）的真菌无效鉴定。结论MALDI-TOF MS直接涂靶法鉴定丝状真菌的能力可与形态学鉴定和基因序列分析相媲美，因其快速且操作简便，临床应用值得推广。     

优化差速离心法在血培养报警瓶MALDI-TOF MS细菌鉴定中的应用

目的评价用于血培养报警瓶基质辅助激光解吸电离飞行时间质谱(matrix assisted laser desorptionionization-time of flight mass spectrometry,MALDI-TOF MS)细菌直接鉴定的前处理方法。方法建立优化差速离心法流程。收集首都医科大学附属北京同仁医院2015年10月至12月外周血培养报警标本100例(均为单一菌),以转种培养后菌落MALDI-TOF MS鉴定为金标准,对比差速离心法优化前后、BRUKER SEPSITYPER试剂盒(简称试剂盒法)鉴定结果,评价优化差速离心法的准确率。收集2016年1月至10月外周血及体液培养报警标本516例(经革兰染色确认为细菌),对优化差速离心法进行大样本应用研究。结果优化的差速离心法、试剂盒法及优化前的差速离心法鉴定准确率分别为97%、94%及92%,差异无统计学意义;优化的差速离心法鉴定分值2.0的例数则多于其他两种方法,与优化前相比差异具有统计学意义(χ~2=3.916,P=0.048)。516例样本单一菌486例,混合菌30例。优化的差速离心法鉴定准确率为92.2%(476/516)。外周血及其他体液样本鉴定准确率分别为96.5%(179/289)、86.8%(197/227),差异有统计学意义(χ~2=16.92,P0.01)。单一菌鉴定准确率为97.1%(472/486),其中革兰阳性球菌和阴性杆菌分别为96.9%、99.1%,均明显高于阳性杆菌(55.6%),差异有统计学意义(χ~2=25.329,P0.01;χ~2=48.526,P0.01)。混合菌鉴定准确率为13.3%(4/30)。体液样本混合菌比例为11%(25/227),显著高于外周血[1.7%(5/289),χ~2=20.008,P0.01]。结论优化差速离心法鉴定率高、成本低、易操作,优于试剂盒法,对单一细菌MALDI-TOF MS血培养报警直接鉴定更具临床应用价值。     

MALDI-TOF MS在临床微生物样本直接检测中的应用

基质辅助激光解吸电离飞行时间质谱（ MALDI-TOF MS）是近年来发展起来的一项新兴的微生物鉴定技术,与传统的生化表型鉴定方法和分子生物学方法相比,MALDI-TOF MS具有操作简单、快速、准确和经济的特点。鉴于其对培养出的纯菌落鉴定的准确性和稳定性,MALDI-TOF MS也可被应用于临床样本的直接检测,包括阳性血培养瓶、中段尿、脑脊液等。本文主要就MALDI-TOF MS用于直接检测临床样本的原理、流程、鉴定效能及其研究进展等方面做一综述。     

MALDI-TOF MS在短期培养后胸腹腔积液中细菌快速鉴定的应用

目的 对临床胸腹腔积液样本进行短期培养,使用基质辅助激光解析电离飞行时间质谱仪(MALDI-TOF MS)进行细菌鉴定,以建立可用于胸腹腔积液的快速细菌检测方法。方法 收集360例细菌感染的胸腹腔积液(胸腔积液163例、腹腔积液197例),所有样本分为三份:一份常规培养并使用微生物鉴定仪检测; 第二份直接离心集菌后用MALDI-TOF MS鉴定; 第三份与营养肉汤混合并短期培养2 h,离心洗涤后用MALDI-TOF MS鉴定。以微生物鉴定仪结果作为金标准,评估MALDI-TOF MS对短期培养后胸腹腔积液中致病菌的鉴定效能。结果 MALDI-TOF MS对短期培养后两种样本的正确检出率分别为94.5%和90.9%,总的未检出率只有7.5%; 单一细菌生长的样本鉴定结果与常规方法符合率达到94.1%; 能从混合细菌生长的样本中准确鉴定优势菌。结论 经过短期培养后的胸腹腔积液样本,MALDI-TOF MS检出率高,结果可靠; 所需时间比常规培养缩短至少12 h,可为临床准确快速提供病原菌报告。     

SDS和SAP前处理联合MALDI-TOF MS在报阳血培养样本快速病原菌鉴定中的价值

目的 评估十二烷基硫酸钠(SDS)和皂甙(SAP)前处理联合基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)对报阳血培养样本进行快速病原菌鉴定的应用价值.方法 收集2018年4月—2019年4月上海交通大学医学院附属新华医院阳性血培养样本296例,分别采用SDS和SAP对阳性血培养样本进行前处理,获取菌体沉...     

分离胶促凝管联合MALDI-TOF MS直接检测血培养阳性细菌

目的建立用分离胶促凝管联合基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)直接检测血培养阳性待测菌的方法并评估其鉴定符合率。方法共收集阳性血培养491例,利用分离胶促凝管直接从血培养瓶中富集并提纯菌体,采用MALDI-TOF MS对待测菌进行菌种鉴定,同时对报阳性血培养瓶进行转种培养,纯菌落用Vitek 2 Compact全自动微生物分析系统(简称Vitek 2 Compact)进行鉴定。若两者鉴定结果不一致,则以基因测序结果予以确证。结果 491例阳性血培养瓶鉴定出的待测菌包括30个属和64个种。在462例单菌株感染血培养瓶中,菌株的种、属鉴定符合率分别为73.6%和3.7%。其中175例革兰阴性菌的种、属鉴定率分别为84.0%(147例)和2.9%(5例);251例革兰阳性菌的种、属鉴定率分别为75.3%(189例)和4.4%(11例);36例念珠菌的种、属鉴定率分别为19.4%(7例)和2.8%(1例)。在29例复数菌感染血瓶中,鉴定出其中一种细菌的种、属鉴定率分别为79.3%(23例)和10.3%(3例)。血流感染中常见病原菌的菌种鉴定符合率达83.3%~96.9%。结论本研究建立了分离胶促凝管联合MALDI-TOF MS直接检测血培养阳性待测菌的方法,与传统的培养鉴定方法相比,对血流感染中主要病原菌的鉴定符合率较高,且方法快速、简便,成本低廉,适合在临床微生物实验室中推广应用。     

Early adjustment of empirical antibiotic therapy of bloodstream infections on the basis of direct identification of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and Gram staining results

IntroductionTo assess the potential added value of rapid MALDI-TOF MS-based identification of bacteria in positive blood cultures to the information provided by Gram staining for adequate empirical antibiotic treatment adjustments in patients with bloodstream infections (BSI).MethodsWe conducted a retrospective, single-center, pre-post quasi-experimental study. In the pre-MALDI-TOF MS phase of the study antibiotic adjustments were made on the basis of Gram stain results, whereas in the MALDI-TOF MS phase they were based on information provided by Gram staining and MALDI-TOF MS results. No antimicrobial stewardship program for BSI was in place within the study period. Antibiotic regimens were categorized as correct, improvable or incorrect.ResultsCohorts were matched for demographics, clinical characteristics of patients and bacterial species involved. Enterobacteriales were the most represented in both study periods (67%), followed by Non-fermenting Gram-negative bacilli and Gram-positive cocci. The number of patients receiving correct, improvable and incorrect empirical antibiotic treatments was comparable for both study periods (P = 0.45, P = 0.57, P = 0.87, respectively). The percentage of patients who ended up receiving correct treatment following modified empirical antibiotic regimens was significantly higher (P = 0.008) in the MALDI-TOF MS phase (27 patients/38.6%) than in the pre-MALDI-TOF MS phase of the study (11 patients/15.7%), although overall adequate coverage of the bacteria causing the infection was comparable across the study periods (90%).ConclusionGram stain results offer valuable information for early adjustment of empirical antibiotic therapies for BSI. Nevertheless, rapid identification of bacteria involved in BSI by MALDI-TOF MS provides added value to achieve this aim.     

Comparison of the ASTA MicroIDSys and VITEK MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems for identification of clinical bacteria and yeasts

The ASTA MicroIDSys system (ASTA, Suwon, Korea) is a newly developed Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system for identification of microorganisms. We compared the performance of the ASTA MicroIDSys system with that of the VITEK MS system (bioMérieux, Marcy l’Etoile, France) for identifying clinical microorganisms. A total 2055 isolates including 1910 bacteria and 145 yeasts were tested. Among them, the VITEK MS correctly identified 1999 (97.3%) isolates to species level and 26 (1.3%) to the genus level. The ASTA MicroIDSys correctly identified 1988 (96.7%) isolates to species level and 28 (1.4%) to the genus level. The VITEK MS and ASTA MicroIDSys misidentified one isolate and four (0.2%) isolates, respectively, and provided no identification for 29 (1.4%) and 35 (1.7%) isolates, respectively. The performance of the ASTA MicroIDSys was comparable to that of the VITEK MS for identification of clinically relevant bacterial and yeast isolates.     

基质辅助激光解吸电离飞行时间质谱微生物鉴定系统性能验证方案的建立

目的建立基质辅助激光解吸电离飞行时间质谱系统(MALDI-TOF MS)在常规临床微生物鉴定中的性能验证方法,指导临床实验室规范微生物鉴定程序。方法选取标准菌株、质控菌株和临床菌株共115株,包含革兰阳/阴性球菌30株、革兰阳/阴性杆菌31株、真菌30株,厌氧菌、苛养菌各12株,所有菌株均经Vitek Compact鉴定和/或细菌16S r DNA、真菌ITS DNA测序分析验证。任意选择3种MALDI-TOF MS微生物鉴定系统厦门质谱、布鲁克质谱、安图质谱,采用检测系统推荐方法进行菌株鉴定,进行准确度验证试验。精密度验证:选取标准菌株和临床菌株10株,1位操作者使用3个检测系统对10株菌株分别进行质谱鉴定3次,连续鉴定3 d; 3位操作者使用3个检测系统对10株菌株每d分别进行质谱鉴定3次,连续鉴定3 d,从而验证鉴定结果的重复性。结果厦门质谱、布鲁克质谱、安图质谱对标准/质控菌株(除外厌氧菌)的鉴定符合率为100%;对临床菌株的属水平鉴定符合率为100%;对革兰阴/阳性杆菌的种水平鉴定符合率分别为100%、100%、96.77%;对革兰阳性球菌的种水平鉴定符合率分别为96.67%、96.67%、100%;对真菌的种水平鉴定符合率均为90%一致;对苛养菌的种水平鉴定符合率均为100%;对厌氧菌鉴定符合率为91.67%种水平一致。精密度验证试验结果重复性100%。结论 3种MALDI-TOF MS系统在革兰阳/阴性球菌、革兰阳/阴性杆菌、真菌、苛养菌鉴定的准确度和精密度符合要求,验证通过。本文建立的微生物鉴定质谱仪性能验证方案可满足综合性医院临床微生物实验室常规鉴定基本要求。     

Clinical utility of direct application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry and rapid disk diffusion test in presumptive antimicrobial therapy for bacteremia

Objective

To study how and to what degree the rapid pathogen identification by MALDI-TOF MS coupled with rapid disk diffusion test improve the current clinical practice of patients with bacteremia in a tertiary teaching hospital with full-time ID consultation service.

MALDI-TOF MS技术在鲍曼不动杆菌鉴定及同源性分析中的应用

目的评价基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)技术对我院鲍曼不动杆菌属的鉴定及同源性分析的能力。方法对2014年9月至2015年2月我院29株经PhoneixTM100全自动微生物鉴定仪鉴定为鲍曼不动杆菌属的菌株进行MALDI-TOF MS鉴定,用MALDI-Biotyper软件进行同源性分析,并用16S rRNA基因测序进行验证。结果 MALDI-TOF MS鉴定结果为鲍曼不动杆菌(Acinetobacter baumannii)26株,院内不动杆菌(Acinetobacter nosocomialis)3株。MALDI-TOF MS鉴定为院内不动杆菌的3株菌株的16S rRNA基因测序结果显示,2株为院内不动杆菌,1株为鲍曼不动杆菌。26株质谱鉴定为鲍曼不动杆菌的菌株分为2大簇(Ⅰ型,Ⅱ型),Ⅱ型又分为2小簇(Ⅱa、Ⅱb)。Ⅰ型、Ⅱ型分布在我院4个病区。结论MALDI-TOF MS技术鉴定鲍曼不动杆菌精准,可以鉴别鲍曼不动杆菌和院内不动杆菌。MALDI-Biotyper数据库软件进行同源性分析十分快捷。     

基质辅助激光解吸电离飞行时间质谱在临床病原菌鉴定中的应用

目的探讨基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption ionization-time of flight mass spectrometry,MALDI-TOF MS)系统用于快速鉴定临床分离菌的可靠性和实用性。方法收集南京军区南京总医院2013年7~10月自临床标本分离的非重复细菌1 061株,分别使用MALDI-TOF MS和Vitek 2 Compact全自动细菌鉴定仪系统进行鉴定,结果不一致的菌株采用16S r DNA测序验证。结果 1 061株临床分离菌中1 058株(99.7%)经MALDI-TOF MS系统正确鉴定到属水平,1 016株(95.8%)正确鉴定到种,其余3株(0.3%)未给出鉴定结果。5株鉴定结果不一致的菌株经16S r DNA测序确认,结果与MALDI-TOF MS和Vitek 2 Compact鉴定符合率分别为40.0%(2/5)和0(0/5)。结论 MALDI-TOF MS可以作为一个快速、准确和价廉的工具应用于临床分离菌的鉴定。     

不同基质辅助激光解吸电离飞行时间质谱系统对链球菌鉴定性能的比较

目的了解基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)对链球菌属临床菌株的鉴定能力。方法收集2015-2019年同济大学附属东方医院临床分离的链球菌,16SrRNA基因测序确定细菌种类。采用直接涂抹法平行使用Autof MS1000型质谱仪、VITEK MS质谱鉴定系统及Bruker Biotyper系统对菌株进行质谱鉴定。结果134株链球菌属细菌中,3套质谱鉴定系统对无乳链球菌、化脓链球菌、解没食子酸链球菌、戈登链球菌及变异链球菌的准确鉴定率均为100%。Bruker Biotyper和Autof MS1000型质谱仪对21株停乳链球菌及14株星座链球菌未能鉴定到亚种,5株缓症链球菌鉴定为口腔链球菌,肺炎链球菌和咽峡炎链球菌各有1株鉴定错误;Autof MS1000型质谱仪鉴定链球菌种水平置信度高于Bruker Biotyper系统。VITEK MS质谱鉴定系统可鉴定停乳链球菌的部分亚种,但14株星座链球菌未能鉴定到亚种,7株缓症链球菌鉴定为缓症链球菌/口腔链球菌,2株咽峡炎链球菌分别鉴定为星座链球菌和肺炎链球菌。结论3套质谱鉴定系统对链球菌属中临床常见的无乳链球菌、化脓链球菌可准确鉴定、直接报告,但是对一些种类菌株鉴定结果有误或不能鉴别亚种,需要DNA序列分析或结合血清学或其他补充实验来准确鉴定。     

Rapid detection of twenty-nine common Chinese glucose-6-phosphate dehydrogenase variants using a matrix-assisted laser desorption/ionization-time of flight mass spectrometry assay on dried blood spots

BackgroundGlucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common inherited disease. Current neonatal screening methods for G6PD deficiency primarily rely on the use of biochemical tests. However, only 15%–20% of female carriers were estimated to have been detected using these tests. As a better alternative, DNA-based tests could be used for G6PD deficiency screening. We aimed to develop a matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) assay for G6PD variant detection.MethodsA MALDI-TOF MS assay with multiprimer extension (multi-PEX) was developed to rapidly and accurately detect the 29 common G6PD variants in the Chinese population using a dried blood spot as a template. A parallel study screening 571 unrelated neonatal samples using the MALDI-TOF MS and fluorescence quantitative enzymatic assays was performed. All results were confirmed by Sanger sequencing in a blind study.ResultsIn 571 unrelated neonatal samples, 34 positive samples, including 26 samples from hemizygous males and eight samples from heterozygous females, were correctly identified, yielding a clinical sensitivity of 100%. The results were validated using Sanger sequencing with 100% concordance. In contrast, the fluorescence quantitative enzymatic assay had a 75% false negative and 88.8% false positive rate for the detection of heterozygous G6PD deficient females.ConclusionsWe established a reliable MALDI-TOF MS assay for G6PD deficiency screening in the Chinese population maximizing the chance of detection of heterozygous G6PD deficient females and reducing the false negative and false positive rates associated with routinely used newborn screening procedures.     

Phenotype determination of hemoglobinopathies by mass spectrometry

Objectives

Nowadays, nearly 1000 hemoglobin (Hb) variants are known. The standard biochemical techniques used in Hb analysis are mainly: isoelectric focusing, cation-exchange liquid chromatography (LC) and reversed-phase LC. In addition to this approach, a protein analysis is achieved by mass spectrometry (MS) and additional DNA studies are performed. The aim of this review is to emphasize the significance of MS methods applied to Hb variants analysis.

Results and perspectives

To perform Hb studies, different MS techniques are currently used such as electrospray ionization (ESI), matrix-assisted laser desorption ionization (MALDI) and tandem mass spectrometry (MS/MS). As shown here, MS is an efficient tool for identification of all types of variants (substitution of a single amino acid residue, several substitutions in the same globin chain, insertions/deletions, fusion Hbs). The use of MS in neonatal screening of Hb variants is also presented.

Conclusions

MS is a powerful technique for Hb analysis. It appears as being an important additional method in the set of biochemical techniques.     

Lactococcus lactis cholangitis and bacteremia identified by MALDI-TOF mass spectrometry: A case report and review of the literature on Lactococcus lactis infection

Lactococcus lactis is a rare causative organism in humans. Cases of L. lactis infection have only rarely been reported. However, because it is often difficult to identify by conventional commercially available methods, its incidence may be underestimated. We herein report the case of a 70-year-old man with cholangiocarcinoma who developed L. lactis cholangitis and review previously reported cases of L. lactis infection. Our case was confirmed by matrix-assisted desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This case shows L. lactis is a potential causative pathogen of cholangitis and that MALDI-TOF MS can be useful for the rapid and accurate identification of L. lactis infection. We searched the literature for published case reports on cholangitis and any other infections caused by L. lactis, and thereby identified 36 cases, including our case. At least 66.7% (n = 24) of the cases had significant underlying conditions; 15 of the cases involved patients with an immunocompromised status. At least 41.7% (n = 15) had a significant food consumption history, such as the consumption of unpasteurized dairy products. The clinical sources of L. lactis were diverse and endocarditis was the most common diagnosis (n = 8), followed by hepatobiliary infection (n = 6), central nervous system infection (n = 5), and peritonitis (n = 4). The prognosis was favorable in most cases.