A rapid and simple method for routine determination of antibiotic sensitivity to biofilm populations of Pseudomonas aeruginosa

Table 2 Odds ratios with 95% CIs from ordinal mixed effect regression by susceptibility test types for each of the antibiotics based on standardized (Z-score) concentrations

Antimicrobial agents	MIC^a		MBEC-50^b		MBEC-75^c
Antimicrobial agents	OR_z (95% CIs)^d	BFCA (%)^e	OR_z (95% CIs)^d	BFCA (%)^e	OR_z (95% CIs)^d	BFCA (%)^e
Gentamicin	2.31 (0.00132, 0.00406)**	61	11.05 (0.00390, 0.03132)***	65	4.18 (0.00227, 0.00769)***	62
Amikacin	1.75 (0.00108, 0.00284)*	50	5.00 (0.00251, 0.00996)***	64	4.06 (0.00244, 0.00676)***	64
Ciprofloxacin	2.40 (0.00077, 0.00751)	51	3.57 (0.00196, 0.00650)***	58	5.40 (0.00279, 0.01047)***	55
Meropenem	2.49 (0.00135, 0.00459)**	50	2.99 (0.00196, 0.00456)***	58	2.62 (0.00173, 0.00396)***	54
Colistin	8.66 (0.00153, 0.048.96)*	54	7.49 (0.00154, 0.03636)*	58	18.66 (0.00427, 0.08148)***	58
Fosfomycin	61.10 (0.00149, 2.50718)*	54	2.91 (0.00170, 0.00499)***	58	2.84 (0.00182, 0.00444)***	58
Ceftazidime	1.54 (0.00103, 0.00231)*	53	2.20 (0.00145, 0.00333)***	56	3.53 (0.00216, 0.00576)***	55

*P < 0.05; **P < 0.01; ***P < 0.001
^aMinimal inhibitory concentrations (MIC, mg mL⁻¹) of planktonic cells
^bMinimal biofilm eradication concentrations (MBEC, mg mL⁻¹) were categorized as responsive reaching about 50% and 75% of the total nonviable cells within a given antibiotic concentration range
^cOdds ratio with 95% confidence interval
^dBiofilm formation classification accuracy (negative, weak, moderate, or strong)

ISSN: 1476-0711