Accession ARO:3002676
DefinitioncatB3 is a plasmid or chromosome-encoded variant of the cat gene found in Salmonella typhimurium, Acinetobacter baumannii and Escherichia coli
AMR Gene Familychloramphenicol acetyltransferase (CAT)
Drug Classphenicol antibiotic
Resistance Mechanismantibiotic inactivation
ResistomesAcinetobacter baumanniiwgs, Citrobacter freundiig+p+wgs, Enterobacter asburiaewgs, Enterobacter cloacaep+wgs, Enterobacter hormaecheip+wgs, Enterobacter kobeiwgs, Escherichia colig+p+wgs, Klebsiella aerogenesp, Klebsiella oxytocap+wgs, Klebsiella pneumoniaep+wgs, Morganella morganiip+wgs, Proteus mirabilisg+wgs, Providencia rettgeriwgs, Pseudomonas aeruginosap+wgs, Pseudomonas fluorescenswgs, Raoultella planticolawgs, Salmonella entericag+p+wgs, Serratia marcescenswgs, Shigella flexnerip+wgs, Shigella sonneiwgs
Classification9 ontology terms | Show
Parent Term(s)4 ontology terms | Show
+ chloramphenicol acetyltransferase (CAT) [AMR Gene Family]
+ confers_resistance_to_antibiotic azidamfenicol [Antibiotic]
+ confers_resistance_to_antibiotic chloramphenicol [Antibiotic]
+ confers_resistance_to_antibiotic thiamphenicol [Antibiotic]

Wang M, et al. 2003. Antimicrob Agents Chemother 47(7): 2242-2248. Plasmid-mediated quinolone resistance in clinical isolates of Escherichia coli from Shanghai, China. (PMID 12821475)

Tosini F, et al. 1998. Antimicrob Agents Chemother 42(12): 3053-3058. Class 1 integron-borne multiple-antibiotic resistance carried by IncFI and IncL/M plasmids in Salmonella enterica serotype typhimurium. (PMID 9835490)

Bunny KL, et al. 1995. Antimicrob Agents Chemother 39(3): 686-693. New mobile gene cassettes containing an aminoglycoside resistance gene, aacA7, and a chloramphenicol resistance gene, catB3, in an integron in pBWH301. (PMID 7793874)

Houang ET, et al. 2003. Antimicrob Agents Chemother 47(4): 1382-1390. Epidemiology of rifampin ADP-ribosyltransferase (arr-2) and metallo-beta-lactamase (blaIMP-4) gene cassettes in class 1 integrons in Acinetobacter strains isolated from blood cultures in 1997 to 2000. (PMID 12654674)


Prevalence of catB3 among the sequenced genomes, plasmids, and whole-genome shotgun assemblies available at NCBI for 85 important pathogens (see methodological details and complete list of analyzed pathogens). Values reflect percentage of genomes, plasmids, or whole-genome shotgun assemblies that have at least one hit to the AMR detection model. Default view includes percentages calculated based on Perfect plus Strict RGI hits. Select the checkbox to view percentages based on only Perfect matches to AMR reference sequences curated in CARD (note: this excludes resistance via mutation as references in protein variant models are often wild-type, sensitive sequences).

Prevalence: protein homolog model (view sequences)

SpeciesNCBI ChromosomeNCBI PlasmidNCBI WGS
Achromobacter xylosoxidans75%0%61.64%
Acinetobacter baumannii0%0%0.96%
Citrobacter freundii3.45%1.16%17.83%
Citrobacter koseri0%0%4.17%
Enterobacter asburiae0%0%3.12%
Enterobacter cloacae3.33%5.19%8.13%
Enterobacter hormaechei0%3.6%18.54%
Enterobacter kobei0%0%4.69%
Escherichia coli0.48%0.75%5.51%
Klebsiella aerogenes0%2.56%3.57%
Klebsiella oxytoca0%6.67%3.74%
Klebsiella pneumoniae5.8%2.53%24.58%
Morganella morganii9.09%6.67%14.29%
Proteus mirabilis13.04%0%5.17%
Providencia rettgeri0%0%15.38%
Providencia stuartii0%0%7.69%
Pseudomonas aeruginosa0%4.88%0.83%
Pseudomonas fluorescens0%0%0.73%
Raoultella planticola0%0%5.26%
Salmonella enterica0.27%1.19%0.75%
Serratia marcescens0%3.28%3.46%
Shigella flexneri0%2.13%0.26%
Shigella sonnei0%0%0.78%
Show Perfect Only

Detection Models

Model Type: protein homolog model

Model Definition: The protein homolog model is an AMR detection model. Protein homolog models detect a protein sequence based on its similarity to a curated reference sequence. A protein homolog model has only one parameter: a curated BLASTP bitscore cutoff for determining the strength of a match. Protein homolog model matches to reference sequences are categorized on three criteria: perfect, strict and loose. A perfect match is 100% identical to the reference sequence along its entire length; a strict match is not identical but the bitscore of the matched sequence is greater than the curated BLASTP bitscore cutoff. Loose matches are other sequences with a match bitscore less than the curated BLASTP bitscore.

Bit-score Cut-off (blastP): 350

>gb|AFQ93498.1|+|catB3 [Enterobacter cloacae]

>gb|JX101693.1|+|58201-58833|catB3 [Enterobacter cloacae]