ArticleThe Journal of antimicrobial chemotherapy2010
Down-regulation of porin M35 in Moraxella catarrhalis by aminopenicillins and environmental factors and its potential contribution to the mechanism of resistance to aminopenicillins.
Article in The Journal of antimicrobial chemotherapy, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.
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Who cites it
12 citing papers in PubMed, 22 citations in OpenAlex.
- A global perspective on the genomics ofMicrobial genomics · 2025Article
- Article
- Development of Nanobodies as Theranostic Agents against CMY-2-Like Class C β-Lactamases.Antimicrobial agents and chemotherapy · 2023Article
- Gene Expression Regulation in Airway Pathogens: Importance for Otitis Media.Frontiers in cellular and infection microbiology · 2022Review
- Expression of the Oligopeptide Permease Operon of Moraxella catarrhalis Is Regulated by Temperature and Nutrient Availability.Infection and immunity · 2015Article
- Moraxella catarrhalis AcrAB-OprM efflux pump contributes to antimicrobial resistance and is enhanced during cold shock response.Antimicrobial agents and chemotherapy · 2015Article
- Identification of an outer membrane lipoprotein involved in nasopharyngeal colonization by Moraxella catarrhalis in an animal model.Infection and immunity · 2014Article
- Panel 5: Microbiology and immunology panel.Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery · 2013Review
- RNA-Seq-based analysis of the physiologic cold shock-induced changes in Moraxella catarrhalis gene expression.PloS one · 2013Article
- Adaptive and mutational resistance: role of porins and efflux pumps in drug resistance.Clinical microbiology reviews · 2012Review
- Physiologic cold shock of Moraxella catarrhalis affects the expression of genes involved in the iron acquisition, serum resistance and immune evasion.BMC microbiology · 2011Article
- Moraxella catarrhalis outer membrane vesicles carry β-lactamase and promote survival of Streptococcus pneumoniae and Haemophilus influenzae by inactivating amoxicillin.Antimicrobial agents and chemotherapy · 2011Article
Corrections and comments
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesThe outer membrane protein M35 of Moraxella catarrhalis is an antigenically conserved porin. Knocking out M35 significantly increases the MICs of aminopenicillins. The aim of this study was to determine the biological mechanism of this potentially new antimicrobial resistance mechanism of M. catarrhalis and the behaviour of M35 in general stress situations.
methodsPCR using m35-specific primers was used to detect the m35 gene in clinical isolates. The m35 mRNA expression of strains 300, O35E and 415 after exposure to amoxicillin and different stress conditions was measured by real-time PCR and normalized in relation to their 16S rRNA expression. The expression of M35 protein was analysed by SDS-PAGE and western blotting.
resultsScreening of 52 middle ear isolates resulted in positive PCR products for all tested strains. The analysis of m35 mRNA expression after amoxicillin treatment showed 24%-85% down-regulation compared with the respective amoxicillin-free controls in all three strains tested. Also, analysis of protein concentrations revealed lower M35 expression after growth with amoxicillin. Investigation of M35 during general stress responses showed down-regulation of the porin with growth at 26°C and 42°C, under hyperosmolar stress and under iron restriction.
conclusionsThe reduced expression of M35 after aminopenicillin exposure indicates a novel resistance mechanism against aminopenicillins in M. catarrhalis, which may be relevant in vivo. The differences in expression after different stress treatments demonstrate that M35 is involved in general stress responses.
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