Browse AMR Genes

Explore antimicrobial resistance genes from the literature

porB1b

outer membrane porin

NCBI Pathogen Isolates

Bacterial genomes carrying this gene

NCBI Reference Gene Catalog

Known alleles and reference sequences

Protein entries specific to porB1b

Browse AMR rules for porB1b

Validation StatusSupported

Overview

Mechanism: mutation
Validation Method: sequencing and MIC determination
Drug Classes: Cefixime, Ceftriaxone, Penicillin, Ciprofloxacin, Azithromycin, Tetracycline, Penicillin|Tetracycline, Ceftriaxone|Cefixime, BETA-LACTAM, BETA-LACTAM/TETRACYCLINE, CEPHALOSPORIN/QUINOLONE/TETRACYCLINE
Organisms: Neisseria gonorrhoeae
Geographic Location: Canada|United Kingdom|United States, Kenya, Korea, KwaZulu-Natal, South Africa, New Zealand +2 more
Alleles: 5
Papers: 17
Databases: Reslit
Mutations: 18

Mutations

Protein Change	Nucleotide Change	Mechanism	Organism	Resistance To	Database	Validation Status
G120D	-	major outer membrane protein porin P.IB	Neisseria gonorrhoeae	Penicillin\|TetracyclineBETA-LACTAM	Reference Gene CatalogReslit	Confirmed
G120K	-	decreased permeability of antimicrobials, major outer membrane protein porin P.IB	Neisseria gonorrhoeae	Penicillin\|TetracyclineCeftriaxone\|CefiximeCeftriaxone+2 more	Reference Gene CatalogReslit

Allele Variants5

Allele	Database	Papers	Drug Classes	Organisms	Countries	Years	Sequence Accession	Protein Accession
porB	Reslit	4	Cefixime, Ceftriaxone +2	Neisseria gonorrhoeae	Korea, Northern Territory, Australia, Russia	2010, 2017, 2018, 2019	FJ465093\|FJ465094\|FJ465095	-
PorB	Reslit	1	Azithromycin, Tetracycline	Neisseria gonorrhoeae	Canada\|United Kingdom\|United States	2020	ERR191763\|ERR191769	-
porB1b_G120K	Reslit	1	Penicillin	Neisseria gonorrhoeae	KwaZulu-Natal, South Africa	2021	PRJNA681740	-
porB1b_A121N	Reslit	1	Penicillin	Neisseria gonorrhoeae	KwaZulu-Natal, South Africa	2021	PRJNA681740	-
porB1b	Reslit	2	Ceftriaxone, Cefixime	Neisseria gonorrhoeae	Kenya, New Zealand	2021	PRJNA660404\|SAMN15960547\|SAMN15960548\|SAMN15960549\|SAMN15960550\|SAMN15960551\|SAMN15960552\|SAMN15960553\|SAMN15960554\|SAMN15960555\|CP061491\|CP061490\|CP061498\|CP061488\|CP061487\|CP061486\|CP061492\|CP061485\|CP061484\|CP061483	-

Papers17

1

Various penA mutations together with mtrR, porB and ponA mutations in Neisseria gonorrhoeae isolates with reduced susceptibility to cefixime or ceftriaxone.

PMID 20093260 · 2010

The study identifies various penA mutations, along with mtrR, porB, and ponA mutations, associated with reduced susceptibility to cefixime and ceftriaxone in Neisseria gonorrhoeae isolates.

Gene Information

Gene Name: porB1b
Allele: porB
Encodes: outer membrane porin
Source Database: Reslit
Mechanism: mutation
Confers Resistance To: CefiximeCeftriaxone
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: Korea
Validation Method: sequencing and MIC determination
Sequence Accession: FJ465093|FJ465094|FJ465095

2

Molecular Antimicrobial Resistance Surveillance for Neisseria gonorrhoeae, Northern Territory, Australia.

PMID 28820128 · 2017

The study identified low levels of azithromycin resistance (0.2%) and no ceftriaxone resistance in Neisseria gonorrhoeae in the Northern Territory of Australia. It also found that ciprofloxacin resistance was significantly lower by PCR than by bacterial culture.

Gene Information

Gene Name: porB1b
Allele: porB
Encodes: outer membrane protein
Source Database: Reslit
Confers Resistance To: Penicillin
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: Northern Territory, Australia
Validation Method: PCR testing

3

RNA markers enable phenotypic test of antibiotic susceptibility in Neisseria gonorrhoeae after 10 minutes of ciprofloxacin exposure.

PMID 30072794 · 2018

The study identifies porB and rpmB as RNA markers that can rapidly determine antibiotic susceptibility of Neisseria gonorrhoeae to ciprofloxacin within 10 minutes of exposure.

Gene Information

Gene Name: porB1b
Allele: porB
Encodes: membrane channel forming protein
Source Database: Reslit
Confers Resistance To: Ciprofloxacin
Organisms Tested In: • Neisseria gonorrhoeae
Validation Method: digital PCR
Sequence Accession: SRP150785

4

Resistance of Neisseria gonorrhoeae isolates to beta-lactam antibiotics (benzylpenicillin and ceftriaxone) in Russia, 2015-2017.

PMID 31344102 · 2019

The study identified mutations in penA, ponA, mtrR, and porB genes, as well as the presence of bla TEM plasmids, which contribute to benzylpenicillin resistance in Neisseria gonorrhoeae isolates from Russia.

Gene Information

Gene Name: porB1b
Allele: porB
Encodes: outer membrane porin protein PorB1b
Source Database: Reslit
Confers Resistance To: Penicillin
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: Russia
Validation Method: microarray hybridization and sequencing
Sequence Accession: NC_002098.1

5

Equations To Predict Antimicrobial MICs in Neisseria gonorrhoeae Using Molecular Antimicrobial Resistance Determinants.

PMID 31871081 · 2020

The study identifies several genes and mutations associated with antimicrobial resistance in Neisseria gonorrhoeae, including PenA, mtrR, 23S rRNA, rpsJ, PorB, PonA, GyrA, ParC, and bla. These genetic elements contribute to resistance against various antibiotics such as ceftriaxone, cefixime, azithromycin, tetracycline, ciprofloxacin, and penicillin.

Gene Information

Gene Name: porB1b
Allele: PorB
Encodes: outer membrane porin
Source Database: Reslit
Mechanism: amino acid substitution
Confers Resistance To: AzithromycinTetracycline
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: Canada|United Kingdom|United States
Validation Method: multivariate regression analysis
Sequence Accession: ERR191763|ERR191769

6

Antimicrobial Resistance Mechanisms, Multilocus Sequence Typing, and NG-STAR Sequence Types of Diverse Neisseria gonorrhoeae Isolates in KwaZulu-Natal, South Africa.

PMID 34280016 · 2021

The study identified multiple AMR genes and mutations in Neisseria gonorrhoeae isolates from KwaZulu-Natal, South Africa, including blaTEM, penA_ins346D, ponA_L421P, mtrR_G45D, porB1b_G120K, porB1b_A121N, mtrR_disrupted, tetM, rpsJ_V57M, gyrA_S91F, gyrA_D95G, gyrA_D95A, parC_D86N, S87N, and S87I, which confer resistance to penicillin, tetracycline, and ciprofloxacin.

Gene Information

Gene Name: porB1b
Allele: porB1b_G120K
Encodes: outer membrane protein
Source Database: Reslit
Confers Resistance To: Penicillin
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: KwaZulu-Natal, South Africa
Validation Method: whole-genome sequencing
Sequence Accession: PRJNA681740

7

Antimicrobial Resistance Mechanisms, Multilocus Sequence Typing, and NG-STAR Sequence Types of Diverse Neisseria gonorrhoeae Isolates in KwaZulu-Natal, South Africa.

PMID 34280016 · 2021

The study identified multiple AMR genes and mutations in Neisseria gonorrhoeae isolates from KwaZulu-Natal, South Africa, including blaTEM, penA_ins346D, ponA_L421P, mtrR_G45D, porB1b_G120K, porB1b_A121N, mtrR_disrupted, tetM, rpsJ_V57M, gyrA_S91F, gyrA_D95G, gyrA_D95A, parC_D86N, S87N, and S87I, which confer resistance to penicillin, tetracycline, and ciprofloxacin.

Gene Information

Gene Name: porB1b
Allele: porB1b_A121N
Encodes: outer membrane protein
Source Database: Reslit
Confers Resistance To: Penicillin
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: KwaZulu-Natal, South Africa
Validation Method: whole-genome sequencing
Sequence Accession: PRJNA681740

8

Antimicrobial Resistance Profiling and Phylogenetic Analysis of Neisseria gonorrhoeae Clinical Isolates From Kenya in a Resource-Limited Setting.

PMID 34385981 · 2021

The study identified multiple AMR genes and mutations in Neisseria gonorrhoeae isolates from Kenya, including mutations in gyrA, parC, penA, ponA1, rpsJ, folP, mtrR, rpoB, pilQ, porB1b, and rplD, which confer resistance to fluoroquinolones, penicillins, cephalosporins, tetracyclines, sulfonamides, rifampicin, and macrolides.

Gene Information

Gene Name: porB1b
Allele: porB1b
Encodes: outer membrane porin
Source Database: Reslit
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: Kenya
Validation Method: sequencing and mutation analysis
Sequence Accession: PRJNA660404|SAMN15960547|SAMN15960548|SAMN15960549|SAMN15960550|SAMN15960551|SAMN15960552|SAMN15960553|SAMN15960554|SAMN15960555|CP061491|CP061490|CP061498|CP061488|CP061487|CP061486|CP061492|CP061485|CP061484|CP061483

9

The antimicrobial resistance landscape of Neisseria gonorrhoeae in New Zealand from November 2018 to March 2019 and the role of sexual orientation in transmission.

PMID 34755593 · 2021

The study identified several AMR genes and mutations in Neisseria gonorrhoeae isolates from New Zealand, including blaTEM-1, blaTEM-135, tetM, 23S C2611T, rpsJ V57M, mtrR A39T, mtrR G45D, penA mutations, penB mutations, ponA L421P, gyrA mutations, parC mutations, and norM promoter mutations, which contribute to resistance against various antibiotics such as penicillin, tetracycline, azithromycin, ciprofloxacin, ceftriaxone, and cefixime.

Gene Information

Gene Name: porB1b
Allele: porB1b
Encodes: outer membrane porin
Source Database: Reslit
Confers Resistance To: CeftriaxoneCefixime
Organisms Tested In: • Neisseria gonorrhoeae
Geographic Location: New Zealand
Validation Method: gene detection and MIC testing
Sequence Accession: PRJNA738299