Related Experiment Video
Updated: Jul 30, 2026
10:19
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Colonization and infection of newborn infants caused by bacteriophage-group II Staphylococcus aureus strains
Journal of Clinical Microbiology
|October 1, 1979
Abstract:
A staphylococcal strain which exhibited weak lytic reaction with group II phages was isolated from a newborn infant with a skin infection. Subsequent investigations established that this weakly reacting strain was responsible for an endemic level of infection and colonization within the hospital nursery. The use of consistently appearing weak lytic reactions in the evaluation of this episode is described.
Insights
A staphylococcal strain causing endemic nursery infections was identified by its weak reaction to specific bacteriophages. This finding highlights the diagnostic value of subtle phage typing results in controlling hospital-acquired infections.
Area of Science:
- Microbiology
- Epidemiology
- Infectious Diseases
Background:
- Staphylococcal infections pose a significant risk in neonatal intensive care units.
- Bacteriophage typing is a crucial tool for identifying and tracking bacterial strains.
- Subtle or weak lytic reactions can sometimes be overlooked in routine diagnostics.
Purpose of the Study:
- To investigate a staphylococcal strain causing endemic infections in a hospital nursery.
- To evaluate the utility of weak bacteriophage lytic reactions in identifying and managing outbreaks.
Main Methods:
- Isolation of a staphylococcal strain from a neonate with a skin infection.
- Characterization of the strain's lytic reaction patterns with group II bacteriophages.
- Epidemiological investigation to determine the extent of infection and colonization within the nursery.
Main Results:
- A staphylococcal strain exhibiting a weak lytic reaction with group II phages was isolated.
- This strain was found to be responsible for endemic infection and colonization in the hospital nursery.
- Consistent observation of weak lytic reactions aided in the evaluation of the outbreak.
Conclusions:
- Weak bacteriophage lytic reactions can be indicative of significant epidemiological events.
- Phage typing, including subtle reactions, is valuable for controlling hospital-acquired staphylococcal infections in nurseries.
- Early identification of specific strains through phage typing is essential for effective infection control.
Related Concept Videos
00:43Lysogenic Cycle of Bacteriophages
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
01:28Development of the Oral Microbiota
The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
01:25Colonisation of Pathogens
Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
01:28Regulation of Bacterial Virulence
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
01:29Staphylococcal Skin Infections
Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
01:26Bacterial Meningitis II: Pathophysiology
Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...