Lepuschitz Sarah, Hauser Kathrin, Schriebl Agnes, Schlagenhaufen Claudia, Stöger Anna, Chakeri Ali, Vötsch Kornelia, Pekard-Amenitsch Shiva, Springer Burkhard, Allerberger Franz, Ruppitsch Werner
Austrian Agency for Health and Food Safety, Institute of Medical Microbiology and Hygiene, Graz, Austria.
Front Microbiol. 2020 Nov 24;11:581081. doi: 10.3389/fmicb.2020.581081. eCollection 2020.
The complex comprises several closely related entities, which are ubiquitous in the natural environment, including in plants, animals, and humans. is the major species within this complex. strains are opportunistic pathogens and a common cause of healthcare-associated infections. can colonize the human gastrointestinal tract, which may become a reservoir for infection. The aim of this study was to investigate the fecal carriage in six healthy individuals during a 1 year period. Stool samples were obtained once a week. Using direct and pre-enriched cultures streaked on ampicillin-supplemented agar plates, up to eight individual colonies per positive sample were selected for further characterization. Whole genome sequencing (WGS) was performed for strain characterization. Sequence type (ST), core genome complex type (CT), K and O serotypes, virulence traits, antibiotic resistance profiles, and plasmids were extracted from WGS data. In total, 80 isolates were obtained from 48 positive cultures of 278 stool samples from five of the six test subjects. The samples of the five colonized volunteers yielded at most two, three, four (two persons), and five different strains, respectively. These 80 isolates belonged to 60 STs, including nine new STs; they were of 70 CTs, yielded 48 K serotypes, 11 O serotypes, and 39 and 51 alleles. Four of the five subjects harbored serotypes K20 and K47, as well as STs ST37, ST101, ST1265, and ST20, which had previously been linked to high-risk clones. In total, 25 genes conferring antibiotic resistance and 42 virulence genes were detected among all 80 isolates. Plasmids of 15 different types were found among 65 of the isolates. Fecal carriage of individual strains was of short duration: 70 strains were found on a single sampling day only, and 5 strains were isolated in samples collected over two consecutive weeks. Two of the five colonized individuals-working colleagues having meals together-shared identical types four times during the study period. Our findings point toward the potential role of food as a reservoir for in humans.
该复合体由几个密切相关的实体组成，它们在自然环境中普遍存在，包括在植物、动物和人类中。是该复合体中的主要菌种。菌株是机会致病菌，是医疗保健相关感染的常见原因。可在人类胃肠道定植，胃肠道可能成为感染源。本研究的目的是调查6名健康个体在1年期间的粪便携带情况。每周采集一次粪便样本。使用接种在补充氨苄青霉素的琼脂平板上的直接培养和预富集培养，每个阳性样本最多选择8个单菌落进行进一步鉴定。对菌株进行全基因组测序（WGS）以进行特征分析。从WGS数据中提取序列类型（ST）、核心基因组复合体类型（CT）、K和O血清型、毒力特征、抗生素耐药谱和质粒。总共从6名受试对象中5名的278份粪便样本的48次阳性培养物中获得了80株分离株。5名定植志愿者的样本分别最多产生了2株、3株、4株（2人）和5株不同的菌株。这80株分离株属于60种ST，包括9种新的ST；它们属于70种CT，产生了48种K血清型、11种O血清型以及39个和51个等位基因。5名受试者中有4名携带血清型K20和K47，以及ST37、ST101、ST1265和ST20等ST，这些ST先前已与高风险克隆相关联。在所有80株分离株中总共检测到25个赋予抗生素耐药性的基因和42个毒力基因。在65株分离株中发现了15种不同类型的质粒。个体菌株的粪便携带持续时间较短：仅在单个采样日发现70株，在连续两周采集的样本中分离到5株。5名定植个体中有2名——一起用餐的同事——在研究期间4次共享相同的类型。我们的研究结果表明食物作为人类中储存库的潜在作用。
