Nephritis caused by Streptococcus zooepidemicus (Lancefield group C)

Area of Science:

• Nephrology
• Microbiology
• Epidemiology

Background:

• Poststreptococcal glomerulonephritis (PSGN) is typically associated with Group A Streptococcus.
• The role of non-Group A Streptococcus in PSGN etiology requires further investigation.

Observation:

• Three family members developed nephritis following upper-respiratory-tract infections.
• Streptococcus zooepidemicus (Lancefield group C) was isolated from affected individuals.
• Infection was linked to the consumption of unpasteurized milk from a family dairy farm.

Findings:

• Isolated Streptococcus zooepidemicus produced endostreptosin, a key antigen in PSGN development.
• Patients exhibited elevated and persistent antibody titers to endostreptosin.
• Epidemiological data supported the association between Streptococcus zooepidemicus and nephritis.

Implications:

• This outbreak implicates non-Group A streptococci, specifically Streptococcus zooepidemicus, in the causation of PSGN.
• Highlights the risk of consuming unpasteurized milk for acquiring nephritogenic bacteria.
• Suggests a broader range of streptococcal species involved in PSGN pathogenesis.