Table 2.

Biofilm formation and antimicrobial resistance in clinical isolates

		A. baumannii		E. coli		K. pneumoniae		P. aeruginosa		S. aureus
		n=53		n=39		n=54		n=36		n=23
% MDRa		86.7%; 46/53		79.5%; 31/39		100%		77.7%; 28/36		65.2%; 15/23
Antimicrobial		%b	%Biofilm Production	%	% Biofilm Production	%	% Biofilm Production	%	% Biofilm Production	%	% Biofilm Production
Aminoglycosides
Amikacin	R	67	65	10	33	20	83	25	67	ND	ND
	S	33	47	90	15	80	50	75	81	ND	ND
Gentamicin	R	90	89	47	14	93	79	39	75	3	100
	S	10	67	53	19	7	71	61	59	97	90
Tobramycin	R	70	81	53	19	53	81	23	90	ND	ND
	S	30	33	47	14	47	64	77	78	ND	ND
Ansamycins
Rifampin	R	ND	ND	ND	ND	ND	ND	ND	ND	0	92
	S	ND	ND	ND	ND	ND	ND	ND	ND	100	78
Cephalosporins
Cefazolin	R	ND	ND	93	14	90	67	100	80	69	99
	S	ND	ND	7	50	10	0	0	0	31	50
Cefepime	R	ND	ND	77	9	93	82	63	79	ND	ND
	S	ND	ND	23	43	7	56	37	82	ND	ND
Cefoxitin	R	ND	ND	10	67	13	100	100	80	74	95
	S	ND	ND	90	11	87	65	0	0	26	60
Cefotaxime	R	80	63	ND	ND	93	68	ND	ND	ND	ND
	S	20	50	ND	ND	7	100	ND	ND	ND	ND
Ceftazidime	R	53	44	77	13	97	86	67	90	ND	ND
	S	47	93	23	29	3	33	33	60	ND	ND
Ceftriaxone	R	ND	ND	80	13	87	73	100	80	ND	ND
	S	ND	ND	20	33	13	69	0	0	ND	ND
Carbepenems
Imipenem	R	67	85	0	0	0	0	75	86	ND	ND
	S	33	30	100	17	100	70	25	95	ND	ND
Meropenem	R	67	85	0	0	0	0	58	78	ND	ND
	S	33	30	100	17	100	70	42	82	ND	ND
Flouroquinolones
Ciprofloxacin	R	90	85	83	12	63	79	75	80	ND	ND
	S	10	33	17	40	37	45	25	100	ND	ND
Levofloxacin	R	57	71	83	12	50	80	80	92	50	93
	S	43	92	17	40	50	60	20	50	50	80
Penicillins
Ampicillin	R	100	67	97	17	100	70	100	80	100	100
	S	0	0	3	0	0	0	0	0	0	0
Aztreonam	R	100	67	73	9	97	90	73	73	ND	ND
	S	0	0	27	38	3	100	27	100	ND	ND
Oxacillin	R	ND	ND	ND	ND	ND	ND	ND	ND	83	92
	S	ND	ND	ND	ND	ND	ND	ND	ND	17	60
Piperacillin	R	93	71	13	0	30	78	67	75	ND	ND
	S	7	100	87	19	60	61	33	90	ND	ND
Tetracyclines
Tetracycline	R	80	71	67	20	63	58	ND	ND	20	83
	S	20	50	33	10	37	91	ND	ND	80	88
Sulfonamides
Trimeth-Sulfameth	R	90	78	77	17	73	86	100	80	0	0
	S	10	50	23	14	27	50	0	0	1000	87

^a A multidrug-resistant (MDR) organism was defined as any extented spectrum-lactamase (ESBL) producing bacteria, or if resistant to all tested antimicrobials on 3 or more classes of antimicrobial agent.

^b %; indicates the percentage of isolates resistant (R) or sensitive (S) to each antimicrobial agent. Antimicrobial suceptibilities were determined using BD Phoenix™ automated microbiology system and are reflective of clinical breakpoints.