blactx−m−55

extended-spectrum beta-lactamase

Validation StatusSupported

Overview

Mechanism: hydrolyzes beta-lactam antibiotics
Validation Method: PCR and sequencing
Drug Classes: Ceftazidime, Cefotaxime, Cefepime, Aztreonam, Piperacillin/tazobactam, Ceftriaxone, Ampicillin
Organisms: Klebsiella pneumoniae, Salmonella enterica subsp. enterica, Salmonella enterica, Salmonella enterica serovar Montevideo
Geographic Location: China, Shanghai, China, Thailand
Papers: 4
Databases: Reslit

Papers4

Drug Susceptibility and Molecular Epidemiology of Klebsiella pneumoniae Bloodstream Infection in ICU Patients in Shanghai, China.

PMID 34722591 · 2021

The study identified bla CTX-M-14, bla CTX-M-15, bla CTX-M-55, and bla KPC-2 as the most prevalent resistance genes in K. pneumoniae isolates from ICU patients in Shanghai, China.

Gene Information

Gene Name: blactx−m−55
Allele: blaCTX−M−55
Encodes: extended-spectrum beta-lactamase
Source Database: Reslit
Confers Resistance To: CeftazidimeCefotaximeCefepimeAztreonamPiperacillin/tazobactam
Organisms Tested In: • Klebsiella pneumoniae
Geographic Location: Shanghai, China
Validation Method: PCR and sequencing

Comparative genomics analysis of Salmonella Enteritidis isolated from clinical cases associated with chicken.

PMID 39587491 · 2024

Five Salmonella Enteritidis isolates were analyzed, revealing multiple antimicrobial resistance genes and chromosomal mutations. Key resistance genes included bla CTX−M−55, bla TEM−141, bla TEM−1B, aac(6')-Iaa, aph(3’)-IIa, aph(3’’)-Ib, aph(6)-Id, tet(A), floR, fosA3, and sul2. Chromosomal mutations in gyrA (D87G/D87Y) and acrB (F28L/L40P) were also identified, contributing to fluoroquinolone and multidrug resistance.

Gene Information

Gene Name: blactx−m−55
Allele: blaCTX−M−55
Encodes: beta-lactamase
Source Database: Reslit
Mechanism: hydrolyzes beta-lactam antibiotics
Confers Resistance To: CeftazidimeCefotaximeCeftriaxone
Organisms Tested In: • Salmonella enterica subsp. enterica
Geographic Location: China
Validation Method: genomic analysis
Sequence Accession: CP084532.1|CP102669.1|NC_003197.2|NC_003198.1|CP026327.1

Genetic insights into antimicrobial resistance and virulence characteristics of Salmonella enterica isolated from Nile tilapia sourced from retail markets in Thailand.

PMID 41291426 · 2025

The study identified multiple antimicrobial resistance (AMR) genes in Salmonella enterica isolates from Nile tilapia, including beta-lactamases (bla TEM−1B, bla CTX−M−55, bla CTX−M−14, bla LAP−2), quinolone resistance genes (qnrS1, qnrS13), tetracycline resistance genes (tet(A), tet(B), tet(M)), aminoglycoside resistance genes (aadA2, aph(3’’)-Ib, aph(6)-Id, aac(6’)-Ia), sulfonamide resistance genes (sul1, sul2, sul3), florfenicol resistance gene (floR), and efflux pump systems (mdsABC, mdtK).

Gene Information

Gene Name: blactx−m−55
Allele: blaCTX−M−55
Encodes: Beta-lactamase
Source Database: Reslit
Confers Resistance To: AmpicillinCeftazidimeCefotaximeCefepime
Organisms Tested In: • Salmonella enterica
Geographic Location: Thailand
Validation Method: whole genome sequencing

Genomic analysis of multidrug-resistant Salmonellaenterica Serovar Montevideo isolates in China.

PMID 41398904 · 2025

The study identified multiple AMR genes in Chinese S. Montevideo isolates, including beta-lactamases (bla TEM−1B, bla OXA−1, bla LAP−2, bla CTX−M−55, bla CTX−M−65, bla DHA−1), quinolone resistance genes (qnrS2, qnrS1, qnrA1, qnrB6, qnrB4, qepA1), macrolide resistance genes (mphA, mphE, msrE, mphB), tetracycline resistance genes (tetA, tetD, tetB), sulfonamide resistance genes (sul1, sul2, dfrA14, dfrA12, dfrA27, sul3), and chloramphenicol resistance genes (floR, catA2, catB3).

Gene Information

Gene Name: blactx−m−55
Allele: blaCTX−M−55
Encodes: Beta-lactamase
Source Database: Reslit
Confers Resistance To: Cefotaxime
Organisms Tested In: • Salmonella enterica serovar Montevideo
Geographic Location: China
Validation Method: genomic sequencing and antimicrobial susceptibility testing
Sequence Accession: CP007540|NC_047854|NC_010463|NC_006949|NC_013059|NC_047753|NC_018279|NC_005857|JQ071613|CP029039

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blactx−m−55

Gene Information

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