Two clinical cases of common variable immunodeficiency (CVID) patients with Campylobacters-associated diarrhoea and repeated bacteraemia over a period of almost 10 years
We compare here two clinical cases of common variable immunodeficiency (CVID) patients with Campylobacters-associated diarrhoea and repeated bacteraemia over a period of almost 10 years. The main goal of this study was to analyse and compare the genome of each isolated strain for both cases during follow-up. For patient “B”, 18 isolates of C. coli (BC) and 17 isolates of C. jejuni (BJ) were sampled between 2014 and 2024. For patient “T”, 10 isolates of C. coli (TC) were sampled between 2019 and 2024. Next-generation sequencing was used to confirm the species and perform molecular antimicrobial resistance identification, MLST typing, core-genome MLST, core-genome SNP (cgSNP) analysis and source attributions. For patient B, we identified two clusters from 2014 and one from 2022-2023. The cgSNP analysis displayed three clusters of C. jejuni and confirmed that each C. coli most likely came from the same initial strain. Additionally, a 16S rDNA mutation in position A1358G associated to gentamicin resistance was found among C. coli from 2022. Recent C. coli were also resistant to ertapenem which is associated to an amino-acids duplication within the PorA protein sequence. For patient T, each C. coli has the same CC, ST (except for TC06) and porcine origin. Isolates from 2023 displayed an A1358G 16S rDNA mutation and one isolate a duplication in PorA sequence. Retrospective analyses of antimicrobial therapy for both patients showed an association between the administration of antibiotics and the appearance of resistance markers, suggesting an in vivo selection pressure. Here, we described two cases of recurrent C. coli and C. jejuni infections among CVID patients, with strains able to escape to successive antimicrobial therapies with specific DNA mutations.