Phenotypic and genetic analyses of two Campylobacter fetus isolates from a patient with relapsed prosthetic valve endocarditis

Abstract

Campylobacter fetus can cause intestinal and systemic disease in humans and are well established veterinary and economic pathogens. We report the complete genomic sequences of two C. fetus subsp. fetus (Cff) isolates recovered in 2017 (CITCf01) and 2018 (CITCf02) from a case of recurrent prosthetic valve endocarditis. Both were capable of growth aerobically. Their genomes were found to be highly conserved and syntenic with 99.97% average nucleotide identity (ANI) while differences in their respective sap loci defined the temporal separation of their genomes. Based on core genome phylogeny and ANI of 83 Cff genomes belonging to the previously described human-associated Cff lineage, CITCf01 and CITCf02 grouped in a clade of eleven sequence type (ST)3 Cff (including the Cff type strain NCTC 10842T). CITCf01 and CITCf02 were marked for their lack of unique genomic features when compared to isolates within the subspecies and the type strain in particular. We identified point mutations in oxidative stress response genes, among others, that may contribute to aerobiosis. We report a case of Cff causing relapsed prosthetic valve endocarditis and we highlight the sap island as a polymorphic site within the genetically stable ST3 lineage, central to pathogenicity.

Prosthetic valve endocarditis caused by Campylobacter fetus: a case report and literature review

“…21 Low MICs for imipenem, meropenem, gentamicin, and erythromycin were also observed in earlier cases of PVE caused by C. fetus. 2,4,6,9 The cause and route of C. fetus infection are still unclear, but this infection is thought to occur after exposure to contaminated food from cattle and sheep, with predisposing factors such as immunosuppression and valve abnormalities. 12 Our patient was immunocompetent; therefore, how he became infected is unclear, and we assume that bacteremia caused by C. fetus contributed to his PVE and worsened systemic condition.…”

“…21 Low MICs for imipenem, meropenem, gentamicin, and erythromycin were also observed in earlier cases of PVE caused by C. fetus . 2,4,6,9…”

“…2 However, PVE caused by C. fetus is extremely rare, with only seven cases reported worldwide and one case reported in Asia (Table 1), all of which occurred in immunocompetent patients. [2][3][4][5][6][7][8][9] The purpose of this report is to present the first case of PVE caused by C. fetus in Korea.…”

Campylobacter fetus Invasive Infections and Risks for Death, France, 2000–2021

“…Disease severity and risk for death from C. fetus systemic infection are of concern for clinicians; fatality rate is ≈15% (4,5). C. fetus is also known to have a predilection for vascular endothelium, causing mycotic aneurysms, thrombophlebitis, endocarditis (including infections of prosthetic heart valves), and multivisceral complications (4)(5)(6)(7)(8)(9)(10)(11). A bactericidal antimicrobial drug treatment based on use of a β-lactam (such as amoxicillin/clavulanic acid or a carbapenem) should be favored (4).…”