Related Experiment Video
Updated: May 7, 2026

06:06
Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
An unexpected Streptococcus pneumoniae strain.
Journal of Chemotherapy (Florence, Italy)
|October 5, 2013
Summary
A rare multidrug-resistant Streptococcus pneumoniae strain caused bacterial meningitis in Italy, necessitating a switch to linezolid and levofloxacin. This case highlights the importance of considering risk factors for multidrug resistance in pneumococcal infections.
Area of Science:
- Infectious Diseases
- Clinical Microbiology
- Pharmacology
Background:
- Streptococcus pneumoniae is a leading cause of bacterial meningitis.
- Italy typically reports low prevalence of multidrug-resistant (MDR) S. pneumoniae strains.
- Prompt identification and appropriate treatment are crucial for managing pneumococcal meningitis.
Observation:
- An unexpected case of bacterial meningitis caused by an MDR S. pneumoniae strain occurred in Italy.
- Initial treatment with ceftriaxone and dexamethasone was ineffective due to the strain's resistance.
- The patient presented with risk factors including immunosuppression and prior antibiotic therapy.
Findings:
- A second-line treatment regimen including linezolid and levofloxacin was initiated based on susceptibility and pharmacokinetic data.
- The patient showed dramatic clinical improvement following the administration of the new antibiotic regimen.
- Detailed patient history revealed risk factors associated with MDR S. pneumoniae.
Implications:
- This case underscores the emerging threat of MDR S. pneumoniae in regions with previously low prevalence.
- It emphasizes the need for careful consideration of patient risk factors when selecting antibiotic therapy for severe pneumococcal infections.
- Clinicians should maintain a high index of suspicion for MDR strains and adjust treatment strategies accordingly.
Related Concept Videos
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...
Pneumonia I: Introduction
Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...
Pneumonia I: Introduction
Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Bacterial Meningitis I: Introduction
Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...
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...
Pneumonia II: Pathophysiology
The pathophysiology of pneumonia involves the following steps:

