Our findings suggest that the interplay between bacterial virulence factors (e.g. the presence of T4SS, sequence variability in genes encoding collagen-like surface protein (SclA) and mutations in transcriptional regulator RocA) and host immunological deficiencies (e.g. MBL deficiency, low CD19+ lymphocytes) may increase the risk for recurrence. This evidence concerns the gene CD19 and hyperinsulinemic hypoglycemia, familial, 4.