Related Experiment Videos

Clinical implications of macrolide resistance in community-acquired respiratory tract infections

Daryl J Hoban1, George G Zhanel

  • 1Health Science Centre, Department of Medical Microbiology, MS673 Thorlakson Building, 820, Sherbrook Street, Winnipeg, Manitoba R3A 1R9, Canada. dhoban@hsc.mb.ca

Expert Review of Anti-Infective Therapy
|December 22, 2006
PubMed

Insights

Macrolide resistance in Streptococcus pneumoniae is rising. However, clarithromycin may remain effective for respiratory infections due to its pharmacokinetics, suggesting susceptibility data may underestimate its clinical utility.

Area of Science:

  • Microbiology
  • Pharmacology
  • Infectious Diseases

Background:

  • Increasing macrolide resistance in Streptococcus pneumoniae over 15 years.
  • Need to evaluate clinical relevance of in vitro susceptibility testing for macrolides.

Purpose of the Study:

  • To examine macrolide resistance specifics in Streptococcus pneumoniae.
  • To assess the clinical relevance of in vitro susceptibility testing for azithromycin and clarithromycin.
  • To evaluate the pharmacokinetics and pharmacodynamics of macrolides in respiratory infections.

Main Methods:

  • Review of laboratory surveillance data.
  • Analysis of pharmacokinetic and pharmacodynamic properties of azithromycin and clarithromycin.
  • Comparison of in vitro susceptibility data with clinical efficacy.

Main Results:

  • Macrolide resistance in Streptococcus pneumoniae has significantly increased.
  • Azithromycin and clarithromycin concentrate well in respiratory tissues.
  • In vitro susceptibility testing may underestimate the clinical utility of these macrolides.
  • Clarithromycin shows potential for efficacy against low-level macrolide resistance in pneumococci.

Conclusions:

  • Clarithromycin remains a viable option for empiric treatment of respiratory infections.
  • Pharmacokinetic properties support the clinical utility of macrolides despite in vitro resistance.
  • Susceptibility data should be interpreted cautiously in the context of drug pharmacodynamics.

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...
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...
Microbiota of the Respiratory Tract01:29

Microbiota of the Respiratory Tract

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...
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...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Microbiota Modulation by Antibiotics01:21

Microbiota Modulation by Antibiotics

Antibiotics have revolutionized modern medicine by saving countless lives from bacterial infections. However, their widespread use has inadvertently harmed the delicate balance of the human gut microbiota. The gut microbiota, a complex community of bacteria, archaea, viruses, and fungi, plays a vital role in regulating metabolism, immune responses, and maintaining intestinal health. Antibiotics, especially broad-spectrum types, disrupt this ecosystem by eradicating both harmful and beneficial...