Table 4.

In vivo and ex vivo virulence assays performed with selected strains from previously described lineages and/or clades possessing a pFv-related plasmid.

Lineage/ cladea	Selected strain	Resistance tob		Virulence forc
		TP	HS + Fe	Tilapia
L1-clade A	yb158	+ (5.2 × 103%)	+ (4.0 × 103%)	+ (2.5 × 107)
	V246	+ (1.5 × 103%)	+ (1.6 × 103%)	NT
L3	12	+ (7.1 × 103%)	+ (7.3 × 102%)	+ (1.3 × 107)
L5	V252	+ (9.2 × 102%)	+ (7.7 × 102%)	+ (2.5 × 106)

^aPhylogenetic lineage determined by Roig et al [11]. L3 and L5 are clonal complexes.

^bResistance to tilapia plasma (TP) and iron-overloaded human serum (HS+ 10 μM of FeCl₃ [13]) after 4 h at 28°C (tilapia) or 6 h at 37°C (human) is coded as follow: +, survival ≥100%; -, survival <100%. Data in parentheses correspond to the medium percent survival from three independent experiments.

^cVirulence was determined by immersion challenge. The medium value of 50% lethal dose (LD₅₀) from two different experiments is presented in parentheses as cfu/ml. Results are coded as follows: - (≥10⁸) +(< 10⁸) [10, 24].

NT, non tested.