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Inducible cephalosporinase production in clinical isolates of Enterobacter cloacae is controlled by a regulatory gene that has been deleted from Escherichia coli

N. Honoré, M.H. Nicolas, S.T. Cole
1986 EMBO Journal  
We now report the molecular characterization of this new gene, ampR, and show that its product functions in both induction and repression of ampC expression.  ...  In this model, the message would be transduced to ampR leading to increased transcription of ampC, B-lactamase overproduction and relief of the block on peptidoglycan biosynthesis.  ... 
doi:10.1002/j.1460-2075.1986.tb04704.x fatcat:iigxrjgufrbp5a5vycsxgifotm

The Regulatory Repertoire of Pseudomonas aeruginosa AmpC ß-Lactamase Regulator AmpR Includes Virulence Genes

Deepak Balasubramanian, Lisa Schneper, Massimo Merighi, Roger Smith, Giri Narasimhan, Stephen Lory, Kalai Mathee, Pierre Cornelis
2012 PLoS ONE  
In Enterobacteriaceae, the transcriptional regulator AmpR, a member of the LysR family, regulates the expression of a chromosomal b-lactamase AmpC.  ...  Further, using a Caenorhabditis elegans model, we demonstrate that a functional AmpR is required for P. aeruginosa pathogenicity.  ...  ) for help with the initial qPCR analysis, and Hassan Sakhtah and Lars Dietrich (Columbia University) for helpful discussions about phenazine assays and Hansi Kumari (Mathee Lab) for critical reading of  ... 
doi:10.1371/journal.pone.0034067 pmid:22479525 pmcid:PMC3315558 fatcat:haiz3sufw5ae7l4d4griad2j74

The lack of OmpF, but not OmpC, contributes to increased antibiotic resistance in Serratia marcescens

A. Moya-Torres, M. R. Mulvey, A. Kumar, I. J. Oresnik, A. K. C. Brassinga
2014 Microbiology  
The host model Caenorhabditis elegans was used in this study to investigate if porin deficits affected bacterial virulence.  ...  When porin mutants were evaluated in the C. elegans host model, the virulence of the single porin mutant strains increased in comparison to the wild-type.  ...  AmpR initiates expression of chromosomally-encoded molecular class C β-lactamase AmpC.  ... 
doi:10.1099/mic.0.081166-0 pmid:25015362 fatcat:hsh7m6dbxjf3peyjjwvyq3wypy

Epidemiology of β-Lactamase-Producing Pathogens

Karen Bush, Patricia A. Bradford
2020 Clinical Microbiology Reviews  
Major β-lactamase families include plasmid-mediated extended-spectrum β-lactamases (ESBLs), AmpC cephalosporinases, and carbapenemases now appearing globally, with geographic preferences for specific variants  ...  SUMMARY β-Lactam antibiotics have been widely used as therapeutic agents for the past 70 years, resulting in emergence of an abundance of β-lactam-inactivating β-lactamases.  ...  Redefining the role of the beta-lactamase locus in methicillin-resistant Staphylococcus aureus: beta-lactamase regulators disrupt the MecI-mediated strong repression on mecA and optimize the phenotypic  ... 
doi:10.1128/cmr.00047-19 pmid:32102899 pmcid:PMC7048014 fatcat:ldjrgstst5aqxgory2cdds3vj4

Insight into a strategy for attenuating AmpC-mediated β-lactam resistance: Structural basis for selective inhibition of the glycoside hydrolase NagZ

Misty D. Balcewich, Keith A. Stubbs, Yuan He, Terrence W. James, Gideon J. Davies, David J. Vocadlo, Brian L. Mark
2009 Protein Science  
This activity is required for resistance to cephalosporins mediated by inducible AmpC b-lactamase.  ...  AmpC mediated b-lactam resistance.  ...  Attenuation has been achieved in a model system of E. coli harboring a plasmid encoding an ampC-ampR operon, 16 and more recently in the opportunistic pathogen P. aeruginosa. 29 The most selective  ... 
doi:10.1002/pro.137 pmid:19499593 pmcid:PMC2775221 fatcat:ub3oqgu6tvhzrn362ty4yoiioi

A dynamic and intricate regulatory network determines Pseudomonas aeruginosa virulence

Deepak Balasubramanian, Lisa Schneper, Hansi Kumari, Kalai Mathee
2012 Nucleic Acids Research  
The critical traits contributing to the pathogenic potential of P. aeruginosa are the production of a myriad of virulence factors, formation of biofilms and antibiotic resistance.  ...  This review is focused on providing a global picture of virulence gene regulation in P. aeruginosa.  ...  Conflict of interest statement. None declared.  ... 
doi:10.1093/nar/gks1039 pmid:23143271 pmcid:PMC3592444 fatcat:ysiaojq5gze5pjmz7qpmorqoqq

Stenotrophomonas maltophilia: an Emerging Global Opportunistic Pathogen

J. S. Brooke
2012 Clinical Microbiology Reviews  
AmpC expression is activated when AmpR is bound with anhydro-N-acetylmuramylpeptide, and the expression of AmpC is repressed when AmpR is bound with UDP-N-acetylmuramic acid-pentapeptide (374) .  ...  AmpR is a transcriptional regulator of ampC expression. AmpC is associated with the recycling of bacterial cell wall components.  ... 
doi:10.1128/cmr.00019-11 pmid:22232370 pmcid:PMC3255966 fatcat:42inw3a7qrb67mboxkxs755npa

Oxidative Stress Response in Pseudomonas aeruginosa

Waleska Stephanie da Cruz Nizer, Vasily Inkovskiy, Zoya Versey, Nikola Strempel, Edana Cassol, Joerg Overhage
2021 Pathogens  
variety of different environments including hospitals.  ...  The high versatility and pathogenicity of this bacterium is attributed to its genomic complexity, the expression of several virulence factors, and its intrinsic resistance to various antimicrobials.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/pathogens10091187 pmid:34578219 fatcat:w5n5zjc3off4vb273tlrfdthdu

An atlas of the binding specificities of transcription factors in Pseudomonas aeruginosa directs prediction of novel regulators in virulence

Tingting Wang, Wenju Sun, Ligang Fan, Canfeng Hua, Nan Wu, Shaorong Fan, Jilin Zhang, Xin Deng, Jian Yan
2021 eLife  
the binding specificities of 182 TFs.  ...  These results will significantly facilitate future studies on transcriptional regulation in P. aeruginosa and other relevant pathogens, and accelerate to discover effective treatment and prevention strategies  ...  Balasubramanian et al., The regulatory repertoire of Pseudomonas aeruginosa AmpC 797 ss-lactamase regulator AmpR includes virulence genes. PLoS One 7, e34067 (2012). 798 68. J. H. Hammond, E. F.  ... 
doi:10.7554/elife.61885 pmid:33779544 pmcid:PMC8041468 fatcat:bl4uvqo5i5e3bdwsleuxv7nipu

Molecular Epidemiology and Vertical Transmission of ESBL-/AmpC-producing Enterobacteriaceae along the Broiler Production Chain [article]

Michaela Projahn, Universitätsbibliothek Der FU Berlin, Universitätsbibliothek Der FU Berlin
The occurrence of extended-spectrum beta-lactamase (ESBL)-/AmpC betalactamase-producing E. coli in humans and animals is a challenging problem in antibiotic treatment in human and veterinary medicine.  ...  Therefore, high resolution molecular methods like pulsed-field gel-electrophoresis (PFGE) as well as whole genome sequencing (WGS) was applied to the respective isolates to determine their phylogenetic  ...  Acknowledgements The presented study was funded by the Federal Ministry of Education and Research (BMBF) RESETII consortium (grant no.: 01KI1313C,  ... 
doi:10.17169/refubium-258 fatcat:gcn5v36w3nbphg4uuiq47lhrum

The effects of antimicrobial therapy on faecal Escherichia coli and Mucosal Staphylococci in dogs

Vanessa Schmidt
Commensal isolates can be a source of clinical infections and studies reporting the prevalence of AMR and risk factors for such isolates are important.  ...  Furthermore, one of the most significant impacts upon commensal bacterial populations is antimicrobial therapy that may select for pre-existing AMR organisms or transmission of resistance determinants.  ...  AmpC-production may also be chromosomally mediated (Woodford et al., 2007) .  ... 
doi:10.17638/00018715 fatcat:4ycg5ge2qfet7hls2nb6fz7rt4


2020 Nippon Saikingaku Zasshi  
K. aerogenes に注目 したところ,ampC については 2~3 グループ,ampR については 2 グループに分類された。分類された ampCampR それぞれを検出す るプライマーを用いた PCR の結果,2 系統の ampCampR が存在す ることが確認できた。しかし,ボロン酸試験結果との関連はみられな かった。  ...  当所で構 築した薬剤耐性遺伝子基盤データベースを利用し,ampC およびその 上流にある AmpR 遺伝子(ampR)との関連を調べ,これらの遺伝子 を検出するためのプライマーを設計した。 【結果・考察】解析した 7 株とデータベースから抽出した ampC およ び ampR について,それぞれ系統樹を作成した。  ...  Evaluation of antibacterial prunin lauroyl ester on mouse model of experimental periodontitis Structural and functional analysis of autolysin CD24020 catalytic domain of Clostridium difficile blaCTX-M  ... 
doi:10.3412/jsb.75.60 pmid:31969516 fatcat:jd7bagpexrcyvleh7va5yrohxu

Lytic Transglycosylases: Untangling Misconceptions in Bacterial Cell Wall Dynamics

Anna Isabell Weaver
The bacterial cell wall comprises a strong, covalently closed network of peptidoglycan (PG) strands.  ...  One class of autolysin, the lytic transglycosylases (LTGs), cleaves the glycosidic linkages within PG strands.  ...  Acknowledgements We thank Matthew Jorgenson (University of Arkansas for Medical Sciences) and all members of the Dörr lab for helpful discussion.  ... 
doi:10.7298/7qxq-7095 fatcat:rqtrt5zbebdsvakoqge7psfksm

Cyanogenesis in the cystic fibrosis pathogen Pseudomonas aeruginosa

Chandrika Goh Nair, Huw Williams, Jane Davies, Biotechnology And Biological Sciences Research Council (Great Britain)
Here, the overall aims have been to explore the clinical relevance of cyanide production in the CF airway and to improve current understanding of the molecular microbiology of cyanogenesis.  ...  P. aeruginosa is also one of only a few bacterial species capable of producing hydrogen cyanide (HCN).  ...  The regulatory repertoire of Pseudomonas aeruginosa AmpC ß-lactamase regulator AmpR includes virulence genes. PloS one. 7, 3 (Jan. 2012), e34067. Baldini, R.L., Starkey, M. and Rahme, L.G. 2014.  ... 
doi:10.25560/44080 fatcat:5ytx5zuocfgstpmbsk6zoizwwa

Studies towards secondary metabolite formation in myxobacteria : elucidation of biosynthetic pathways and yield optimization [article]

Stefan Müller, Universität Des Saarlandes, Universität Des Saarlandes
AmpR activates ampC (beta lactamase) and CatR or ClcR activates the catBC or clcABD operon, respectively [94;95] , but more recent studies suggest that LysR-like proteins may act as global regulators  ...  Accordingly, these data suggest that the repressive effect of ammonia on chivosazol biosynthesis is directly mediated via the transcriptional regulator NtcA.  ...  Shwan Rachid, generated and characterized all mutant strains used in this study and elaborated the biosynthetic model.  ... 
doi:10.22028/d291-23078 fatcat:4jco2vi7ere4lexvxa5cq4qnla