Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Endoscopic Procedures III: Video Capsule Endoscopy01:28

Endoscopic Procedures III: Video Capsule Endoscopy

837
Capsule endoscopy, or wireless or video capsule endoscopy, is a diagnostic procedure for examining the entire gastrointestinal tract. Patients swallow a capsule about the size of a vitamin tablet. The capsule is equipped with a transmitter, a battery, an LED light source, and a color video camera to capture images throughout the gastrointestinal tract. This procedure is particularly useful for diagnosing conditions such as Crohn's disease, ulcerative colitis, tumors, polyps, ulcers,...
837
What is Gene Expression?01:42

What is Gene Expression?

196.7K
Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
196.7K
Expressing Solution Concentration02:48

Expressing Solution Concentration

67.8K
A solute is a component of a solution that is typically present at a much lower concentration than the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
Concentrations may be quantitatively assessed using a wide variety of measurement units, each convenient for particular applications. Molarity (M) is a useful concentration unit for many applications in chemistry.
67.8K
SN1 Reaction: Stereochemistry02:15

SN1 Reaction: Stereochemistry

10.3K
This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction.
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
10.3K
SN1 Reaction: Kinetics02:05

SN1 Reaction: Kinetics

9.6K
In an SN2 reaction, the reaction rate depends on both the type of nucleophile and the substrate. A hindered tertiary alkyl halide is practically inert to the SN2 mechanism despite using a strong nucleophile.
However, Sir Christopher Ingold and Edward D. Hughes, who studied the kinetics of various nucleophilic substitution reactions, noticed that a tertiary alkyl halide does undergo a nucleophilic substitution reaction in the presence of a weak nucleophile. While studying the substitution...
9.6K
SN1 Reaction: Mechanism02:25

SN1 Reaction: Mechanism

14.3K
Kinetic studies of ionization of a tertiary halide in a protic solvent suggest that only the substrate participates in the rate-determining step (slow step). The nucleophile is involved only after the slowest step. The SN1 reaction takes place in a multiple-step mechanism. 
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a...
14.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Understanding the role of parental decision-making and quality of clinical care in under-5 mortality in Western Kenya: an application of the Three Delays model.

BMC health services research·2026
Same author

Post-mortem characterisation of pathogen-specific causes of infection-related deaths in African and south Asian neonates: a prospective, observational, multicentre study.

The Lancet. Infectious diseases·2026
Same author

Assessing safety in the RTS,S/AS01 malaria vaccine implementation programme: an overview and comparison of methods.

Malaria journal·2026
Same author

Deaths with preceding hospitalisations within 180 days in eight countries in sub-Saharan Africa and South Asia: A secondary descriptive analysis of the Child Health and Mortality Prevention Surveillance (CHAMPS) network.

BMJ open·2026
Same author

lsaC and Tandem lsaE-lnuB Resistance Genes in Invasive Group A Streptococcus.

Emerging infectious diseases·2026
Same author

Country-specific estimates of misclassification rates of computer-coded verbal autopsy algorithms.

BMJ global health·2026

Related Experiment Video

Updated: Jan 31, 2026

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination
09:11

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination

Published on: September 25, 2014

22.6K

Streptococcus mitis Expressing Pneumococcal Serotype 1 Capsule.

Fernanda C Lessa1, Jennifer Milucky2, Nadine G Rouphael3

  • 1Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Atlanta, Georgia, USA. flessa@cdc.gov.

Scientific Reports
|December 21, 2018
PubMed
Summary

Genes for Streptococcus pneumoniae

More Related Videos

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
04:25

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

Published on: February 24, 2014

46.6K
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

2.2K

Related Experiment Videos

Last Updated: Jan 31, 2026

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination
09:11

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination

Published on: September 25, 2014

22.6K
Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
04:25

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

Published on: February 24, 2014

46.6K
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

2.2K

Area of Science:

  • Microbiology
  • Immunology
  • Genetics

Background:

  • The polysaccharide capsule of Streptococcus pneumoniae is a key virulence factor.
  • Vaccine-induced immunity targeting specific capsular polysaccharides prevents pneumococcal disease.
  • Serotype 1 Streptococcus pneumoniae is highly invasive and associated with meningitis outbreaks.

Purpose of the Study:

  • To investigate the presence and characteristics of Streptococcus pneumoniae-like polysaccharide capsule genes in commensal bacteria.
  • To explore the immunological similarity of capsules expressed by commensal streptococci to those of Streptococcus pneumoniae.
  • To understand the genetic relatedness of commensal bacteria expressing these capsule genes.

Main Methods:

  • Polymerase chain reaction (PCR) was used to detect specific genes in upper respiratory tract samples.
  • Oropharyngeal samples were analyzed for the presence and immunological properties of expressed capsules.
  • Whole genome sequencing was performed on identified bacterial clones.

Main Results:

  • Genes for polysaccharide capsules similar to those of Streptococcus pneumoniae were frequently detected in adults not carrying pneumococci.
  • Serotype 1-specific genes were predominantly found.
  • Capsules expressed by serotype 1 genes in Streptococcus mitis were immunologically indistinguishable from pneumococcal capsules.
  • Whole genome sequencing identified three distinct Streptococcus mitis clones with cps1 operons highly similar to the pneumococcal reference.

Conclusions:

  • Commensal streptococci, such as Streptococcus mitis, can harbor genes for Streptococcus pneumoniae-like capsules.
  • These findings suggest a potential role for commensal streptococci in natural immunity against Streptococcus pneumoniae.
  • Further research is needed to elucidate the contribution of commensal bacteria to immunity against pneumococcal infections.