Table 2.

In vitro phenotype screening of in vivo isolates of B. mallei: representative results

Straina	Biologb		Individual chemical sensitivitiesc								Antimicrobial peptidesc
	No. resistant/total (23)	Change	H2O2: 0.02, 0.1 %	NaCl: 1, 4 %	Nalidixic acid: 5, 50 µg/mL	Niaproof 4: 0.027, 0.10 %	RNI: 2 mM	Cecropin P1	Cecropin A	LL-37	Mastoparan 7	Magainin	Melittin	Histatin 5	Proteolytic activity (mm)
Spleen isolates: Bm FMH aerosols
Bm FMH parent	9d	none	4.5, 4.5	S, S+	S, S+	S+, S+	S	R	R/S	R	R/S	R/S	S	R	1.5
			4, 5	S, S+	S/R, S+	S+, S+	S	S	nd	S	R	S	S	nd	nd
26-2	10	R-nal. acid	NCe	S, S+	R, S	S+, S+	S	nde	R−	nd	S+	R	R	nd	2.5–3
26-3	10	R-nal. acid	4.0, 7	S, S+	R, S	S, S+	S	nd	R−	nd	S+	R	R	nd	2.5
Bm FMH parent	9d		4, 5	S, S+	R/S, S+	S+, S+	S	nd	S	R	S	S	nd	nd
45-7	9, diffs	R-nal.A; S-linco	NC	NC	R/S+	S, S+	NC	nd	NC	NC	S +	NC	NC	nd	nd
45-9	9, diffs	R/S-nal.A; S-Nacl	NC	NC	NC	NC	NC	NC	nd	NC	R	NC	NC	nd	nd
Bm FMH parent	9d	–	4.5, 6	S+, S+	S, S+	S+, S+	S+	nd	S	nd	S+	S	S	nd	nd
60-1	NC	None	4.5, 6	S+, S+	S, S+	S+, S+	S+	nd	R	nd	S	S	R	nd	“
60-3	NC	None	5, 5(haze)	S+, S+	R, S	S+, S+	S	nd	S	nd	S	R	R	nd	“
60-3	NC	None	4.5, 5(haze)	S, S+	R, S	S+, S+	S	nd	R	nd	S	R	R	nd	“

^aIsolates are from spleens of mice infected with Bm FMH. With the exception of the infecting strain (parent), the strains are identified by the day post-inoculation on which spleens were collected from the infected mice and by the isolate number. Responses of the isolates which varied from the parent are bolded (more R) or in bold italics (more S)

^bSensitivities were determined with the GEN III panel of 23 chemicals (Biolog). The Biolog criteria were used for resistance (R, >50 % positive control OD₆₃₀), sensitive (S, <50 % pos. control), and borderline or variable (R/S). “Diffs” indicates that the strain was resistant to the same total no. chemicals as the parent but differed in specific chemical sensitivities

^cSensitivities to specific chemicals and antimicrobial peptides are determined by OD₆₃₀ readings: values >75 % positive control (resistant, R), >50 % and <75 % pos. ctrl (borderline, R/S), <50 % (sensitive, S), and <×2 negative control (highly sensitive, S+). For the H₂O₂ plates, the values (mm) are the zones of cleared growth proximal to the H₂O₂ spot

^dIn Biolog experiments, Bm strain FMH was resistant to nine conditions: 1 % NaCl, Na lactate, pH 5 and 6, tetrazolium blue and purple, vancomycin, rifampin, and lincomycin. It was variable but usually sensitive to nalidixic acid in the Biolog and individual assays (low, 5 µg/mL; and high, 50 µg/mL). Bm FMH was generally sensitive to 13 conditions: NaCl (4 % and 8 %), fusidic acid, d-serine, guanidine HCl, Niaproof 4, LiCl, potassium tellurite, aztreonam, Na butyrate, nalidixic acid, Na bromate, and troleandomycin

^eNC = same as parent (no change); nd = not done