Streptococci as urinary pathogens.

Area of Science:

• Clinical Microbiology
• Urology
• Bacteriology

Background:

• Streptococci are common in urine specimens.
• Accurate identification of urinary tract pathogens is crucial for effective treatment.
• Certain fastidious bacteria may be overlooked in routine laboratory settings.

Purpose of the Study:

• To identify catalase-negative gram-positive cocci and coccobacilli from urine specimens.
• To assess the prevalence of non-streptococcal species.
• To propose an improved isolation protocol for clinical laboratories.

Main Methods:

• Prospective study of 11,725 urine specimens over 2 months.
• Isolation and species identification of 242 strains of catalase-negative gram-positive cocci/coccobacilli.
• Use of cysteine-lactose-electrolyte-deficient agar and carbon dioxide incubation.

Main Results:

• 242 strains were isolated, comprising 10% of important isolates.
• 30% of isolates were species other than Streptococcus faecalis and S. agalactiae.
• Gardnerella vaginalis accounted for 20 of 24 coccobacilli isolates; many fastidious species were associated with pyuria.

Conclusions:

• Urinary tract infections involve a broader range of catalase-negative gram-positive cocci and coccobacilli than commonly identified.
• Routine laboratory methods may miss certain fastidious organisms.
• A modified isolation protocol can enhance the detection of these pathogens.