Characterization of Clostridium perfringens Causing Liver Abscess Using Whole-Genome Sequencing: A Case Report and Literature Review.

A patient who had previously undergone varicose vein surgery developed persistent postoperative fever. The results of ultrasonography and computed tomography (CT) indicated the possible presence of a liver abscess. Subsequent blood and drainage fluid cultures yielded Gram-positive bacilli exhibiting characteristic hemolytic rings. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) identified both isolates as Clostridium perfringens (C. perfringens), implicating this pathogen as the etiological agent of the liver abscess. The patient was treated empirically with cefuroxime, ornidazole, and cefoperazone-sulbactam, after which the fever gradually resolved and the patient was discharged in stable condition. To further characterize the microbiological features of the isolates, whole-genome sequencing (WGS) was performed. Comparative genomic analysis demonstrated that the similarity between the two strains was higher than 99.99%, indicating a clonal origin. Further genotypic characterization revealed the presence of the major toxin gene plc, along with several accessory toxin genes, including pfoA, colA, and cloSI. In addition, genes encoding neuraminidases and hyaluronidases were identified, suggesting enhanced tissue invasiveness. The strains also harbored multiple antimicrobial resistance-associated genes, including mprF, tetB(P), and cplR. To contextualize these findings, a literature review was conducted to summarize the clinical and etiological characteristics of liver abscesses caused by C. perfringens. Analysis of reported cases indicated that advanced age, male sex, underlying hepatobiliary disease, and diabetes mellitus were common predisposing factors. Among these cases, only six cases were tested for C. perfringens toxin genes: five cases were associated with the plc gene alone, while one case involved concurrent detection of both plc and pfoA. Overall, this study provided important molecular and clinical evidence to support improved diagnosis, risk assessment, and therapeutic management of liver abscesses caused by C. perfringens.