Blau Khald, Berger Fabian K, Mellmann Alexander, Gallert Claudia
Department of Microbiology-Biotechnology, Faculty of Technology, University of Applied Sciences Emden/Leer, 26723 Emden, Germany.
Institute of Medical Microbiology and Hygiene, Saarland University Medical Center, 66421 Homburg, Germany.
Microorganisms. 2023 Oct 5;11(10):2497. doi: 10.3390/microorganisms11102497.
is the most important pathogen causing antimicrobial-associated diarrhea and has recently been recognized as a cause of community-associated infection (CA-CDI). This study aimed to characterize virulence factors, antimicrobial resistance (AMR), ribotype (RT) distribution and genetic relationship of isolates from diverse fecally contaminated environmental sources. isolates were recovered from different environmental samples in Northern Germany. Antimicrobial susceptibility testing was determined by E-test or disk diffusion method. Toxin genes ( and ), genes coding for binary toxins () and ribotyping were determined by PCR. Furthermore, 166 isolates were subjected to whole genome sequencing (WGS) for core genome multi-locus sequence typing (cgMLST) and extraction of AMR and virulence-encoding genes. Eighty-nine percent (148/166) of isolates were toxigenic, and 51% (76/148) were positive for . Eighteen isolates (11%) were non-toxigenic. Thirty distinct RTs were identified. The most common RTs were RT127, RT126, RT001, RT078, and RT014. MLST identified 32 different sequence types (ST). The dominant STs were ST11, followed by ST2, ST3, and ST109. All isolates were susceptible to vancomycin and metronidazole and displayed a variable rate of resistance to moxifloxacin (14%), clarithromycin (26%) and rifampicin (2%). AMR genes, such as , , -- cassette, , (M), (40), and (P), conferring resistance toward fluoroquinolone, beta-lactam, aminoglycoside, macrolide and tetracycline antimicrobials, were found in 166, 137, 29, 32, 21, 72, 17, and 9 isolates, respectively. Eleven "hypervirulent" RT078 strains were detected, and several isolates belonged to RTs (i.e., RT127, RT126, RT023, RT017, RT001, RT014, RT020, and RT106) associated with CA-CDI, indicating possible transmission between humans and environmental sources pointing out to a zoonotic potential.
是引起抗菌药物相关性腹泻的最重要病原体，最近已被确认为社区获得性感染（CA-CDI）的病因。本研究旨在对来自不同粪便污染环境来源的分离株的毒力因子、抗菌药物耐药性（AMR）、核糖体分型（RT）分布及遗传关系进行特征分析。分离株从德国北部不同环境样本中获得。采用E-test或纸片扩散法进行抗菌药物敏感性试验。通过PCR检测毒素基因（和）、编码二元毒素的基因（）及核糖体分型。此外，对166株分离株进行全基因组测序（WGS），以进行核心基因组多位点序列分型（cgMLST）并提取AMR和毒力编码基因。89%（148/166）的分离株产毒素，其中51%（76/148）检测为阳性。18株（11%）分离株不产毒素。鉴定出30种不同的RTs。最常见的RTs为RT127、RT126、RT001、RT078和RT014。多位点序列分型（MLST）鉴定出32种不同的序列类型（ST）。优势STs为ST11，其次是ST2、ST3和ST109。所有分离株对万古霉素和甲硝唑敏感，对莫西沙星（14%）、克拉霉素（26%）和利福平（2%）的耐药率各不相同。在166株、137株、29株、32株、21株、72株、17株和9株分离株中分别发现了赋予对氟喹诺酮类、β-内酰胺类、氨基糖苷类、大环内酯类和四环素类抗菌药物耐药性的AMR基因，如、、--盒式结构、、（M）、（40）和（P）。检测到11株“高毒力”RT078菌株，且有几株分离株属于与CA-CDI相关的RTs（即RT127、RT126、RT023、RT017、RT001、RT014、RT020和RT106），这表明人和环境来源之间可能存在传播，提示存在人畜共患病潜力。
