Related Experiment Video

Updated: Oct 7, 2026

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
06:06

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Published on: September 11, 2020

Genotypes of clustered cases of Pneumocystis carinii pneumonia

M Olsson1, B M Eriksson, K Elvin

  • 1Swedish Institute for Infectious Disease Control and Microbiology and Tumor Biology Center, Karolinska Institutet, Stockholm, Sweden.

Scandinavian Journal of Infectious Diseases
|May 10, 2001
PubMed

Insights

Pneumocystis carinii pneumonia (PCP) outbreaks in immunocompromised patients were studied. Genotyping of P. carinii f. hominis isolates suggests person-to-person transmission is not the primary route for this fungal pneumonia.

Area of Science:

  • Medical Mycology
  • Infectious Diseases
  • Immunocompromised Host Research

Background:

  • Outbreaks of Pneumocystis carinii pneumonia (PCP) in immunocompromised patients, including those without human immunodeficiency virus (HIV), have raised questions about person-to-person transmission of P. carinii.
  • Understanding the transmission dynamics of P. carinii is crucial for preventing and managing PCP in vulnerable populations.

Purpose of the Study:

  • To investigate the transmission routes of P. carinii in immunocompromised patients experiencing outbreaks.
  • To determine if person-to-person transmission is the predominant mode of P. carinii spread in these settings.

Main Methods:

  • Genotyping of P. carinii sp. f. hominis mitochondrial large subunit ribosomal RNA gene (mt LSU rRNA) from 17 bronchoalveolar lavage isolates from three distinct PCP outbreaks.
  • Utilized direct sequencing and three distinct allele-specific polymerase chain reaction (PCR) assays for genotyping.
  • Outbreaks involved renal transplant recipients and patients with hematological disorders.

Main Results:

  • Analysis of P. carinii f. hominis genotypes from the studied outbreaks.
  • Limited patient contact data was available for correlation with genotyping results.
  • The detected genotypes did not provide strong evidence supporting person-to-person transmission as the main route of P. carinii spread.

Conclusions:

  • The findings suggest that person-to-person transmission is unlikely to be the predominant transmission route for P. carinii in humans, even during outbreaks.
  • Further research with more extensive contact tracing data is needed to fully elucidate P. carinii transmission pathways.
  • This study contributes to the understanding of P. carinii epidemiology in non-HIV immunocompromised individuals.

Related Concept Videos

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...
Pneumonia I: Introduction01:29

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: Introduction01:30

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...
Pneumonia II: Pathophysiology01:29

Pneumonia II: Pathophysiology

The pathophysiology of pneumonia involves the following steps:
Single Nucleotide Polymorphisms-SNPs01:05

Single Nucleotide Polymorphisms-SNPs

A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes01:28

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...