Related Experiment Video

Updated: Jul 16, 2026

A Fast and Reliable Pipeline for Bacterial Transcriptome Analysis Case study: Serine-dependent Gene Regulation in Streptococcus pneumoniae
10:18

A Fast and Reliable Pipeline for Bacterial Transcriptome Analysis Case study: Serine-dependent Gene Regulation in Streptococcus pneumoniae

Published on: April 25, 2015

Gene expression profiling of the response of Streptococcus pneumoniae to penicillin

P David Rogers1, Teresa T Liu, Katherine S Barker

  • 1Department of Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA. drogers@utmem.edu

The Journal of Antimicrobial Chemotherapy
|March 7, 2007
PubMed
Abstract

Insights

This study reveals how Streptococcus pneumoniae alters gene expression to survive low penicillin doses. Understanding these changes in bacterial cell wall response may lead to new therapeutic targets against penicillin resistance.

Area of Science:

  • Microbiology
  • Genomics
  • Molecular Biology

Background:

  • Streptococcus pneumoniae is a major human pathogen.
  • Penicillin is a key antibiotic for treating S. pneumoniae infections.
  • Understanding bacterial stress responses is crucial for combating antibiotic resistance.

Purpose of the Study:

  • To investigate gene expression changes in S. pneumoniae exposed to subinhibitory penicillin concentrations.
  • To elucidate the mechanisms of bacterial adaptation to penicillin stress.
  • To identify potential therapeutic targets for enhancing penicillin efficacy.

Main Methods:

  • S. pneumoniae strain D39 was cultured with and without subinhibitory penicillin (0.03 mg/L).
  • Global gene expression profiling was performed using DNA microarrays.
  • Real-time RT-PCR was employed to validate differential gene expression.

Main Results:

  • A total of 386 genes exhibited altered expression in response to penicillin.
  • Upregulated genes included the ciaR-ciaH operon, luxS, and genes involved in cell envelope synthesis and the pst locus.
  • Downregulated genes encompassed those related to competence, capsule biosynthesis, fatty acid elongation, and polyamine transport.

Conclusions:

  • The observed gene expression alterations represent a protective response to penicillin-induced cell wall damage.
  • These responsive genes could serve as novel therapeutic targets to improve penicillin activity.
  • The findings offer insights into previously unknown mechanisms of penicillin resistance in S. pneumoniae.

More Related Videos

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae09:12

Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae

Published on: January 17, 2014

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins06:05

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins

Published on: September 30, 2014

Related Concept Videos

Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Production of Antibiotics01:27

Production of Antibiotics

Penicillin, one of the earliest and most widely used antibiotics, is produced industrially by the filamentous fungus Penicillium chrysogenum. Large stirred-tank bioreactors ranging from tens to hundreds of thousands of liters maintain tightly controlled temperature, pH, and dissolved oxygen conditions to support fungal metabolism and maximize antibiotic yield. Penicillin is a secondary metabolite, synthesized primarily during the stationary growth phase, which requires a carefully managed...
Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
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...
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,...