Table 2.

Antibiotic resistance patterns of Cedecea neteri isolated from a patient's catheter (current case) and reported in previous studies.

Antibiotic	Susceptibility (MIC, μg/mL)∗	Reference number	Resistance mechanism encoded in C. neteri SSMD04 genome†
Aminobenzyl-penicillin
Amoxicillin	R (>16)	[12]	AmpC‡, MBL§
Ampicillin	R (>16)	[11], current case	AmpC, MBL
β-Lactam/β-lactamase inhibitors
Amoxicillin-clavulanate	R (8/4)	[12]	AmpC, MBL
Ampicillin-sulbactam	R (>16/8)	Current case	AmpC, MBL
Cephalosporins (1st generation)
Cefazolin	R (>16)	Current case	AmpC, MBL
Cephalothin	R ¶	[11]	AmpC, MBL
Cephalosporins (2nd generation)
Cefoxitin	R (>16)	Current case	AmpC, MBL
Cefuroxime	I (16)	Current case	AmpC, MBL
Polymyxins
Colistin	R ¶	[11]	LPS modification system#

^∗Intermediate (I): likely to respond to high dosage therapy. Resistant (R): unlikely to respond to high dosage therapy. ^†Reference [14]. ^‡Analysis of open reading frame (ORF) JT31_10470 (1149 bp, 382 amino acids) in the C. neteri SSMD04 genome indicated sequence homology to AmpC β-lactamases. AmpC enzymes belong to the class C cephalosporinases (reviewed in [17]). Scrutiny of the deduced amino acid sequence of JT31_10470 revealed the presence of the following conserved sequence elements characteristic of class C β-lactamases: S-X-S-K (positions 85 to 88), Y-A-N (positions 171 to 173), and K-T-G (positions 336 to 338). ^§Metallo-β-lactamase. ^¶Resistance phenotype was determined using the Kirby-Bauer disk method as reported in the cited reference. ^#Components of the LPS modification system (mgrB, phoP, phoQ, and the pmr operon) are present in the annotated genome of C. neteri SSMD04, but these loci do not contain mutations known to confer colistin resistance [18].