Related Experiment Video

Updated: Jun 23, 2026

Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice
08:52

Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice

Published on: February 22, 2019

Emergence of quinolone-resistant Bordetella pertussis in Japan

Masayuki Ohtsuka1, Ken Kikuchi, Kenichiro Shimizu

  • 1Department of Infection Control Science, Faculty of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, Japan. kikuti@juntendo.ac.jp

Antimicrobial Agents and Chemotherapy
|May 6, 2009
PubMed

Insights

Six Bordetella pertussis strains in Japan exhibit high resistance to nalidixic acid (NAL) and reduced susceptibility to fluoroquinolones. This resistance is linked to a specific D87G mutation in the gyrA gene.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Bordetella pertussis is a significant cause of respiratory illness worldwide.
  • Antibiotic resistance in B. pertussis poses a growing public health concern.
  • Fluoroquinolones are important antibiotics for treating bacterial infections.

Purpose of the Study:

  • To investigate the antibiotic susceptibility of Bordetella pertussis strains isolated from children in Japan.
  • To identify the genetic basis for nalidixic acid (NAL) resistance in these strains.

Main Methods:

  • Phenotypic characterization of B. pertussis isolates for antibiotic susceptibility testing.
  • Genomic analysis to identify mutations in the gyrA gene.

Main Results:

  • Six B. pertussis strains isolated between 2004 and 2006 demonstrated high-level resistance to nalidixic acid (NAL; MIC >256 microg/ml).
  • These resistant strains also showed decreased susceptibility to other fluoroquinolones.
  • All NAL-resistant strains possessed the identical D87G mutation in the gyrA gene.

Conclusions:

  • The D87G mutation in gyrA is associated with high-level nalidixic acid resistance in Bordetella pertussis.
  • Emergence of fluoroquinolone resistance in B. pertussis warrants continued surveillance.

More Related Videos

Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses12:20

Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses

Published on: December 29, 2015

Related Concept Videos

Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
Diphtheria01:28

Diphtheria

Diphtheria is an acute, toxin-mediated infectious disease that primarily affects the upper respiratory tract. It is caused by Corynebacterium diphtheriae, a Gram-positive, pleomorphic rod that lacks spore-forming capability and exhibits a characteristic club-shaped morphology under microscopic examination. While C. diphtheriae can asymptomatically colonize mucosal surfaces, clinical disease manifests only when the bacterial strain is lysogenized by a specific β-corynephage. This phage...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Inhibitors of Bacterial DNA Synthesis01:28

Inhibitors of Bacterial DNA Synthesis

Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...