Performance of time-lapsed turbidimetry and agar plating as bacterial quantification methods.

Accurate bacterial quantification is crucial for studying microbial pathogenesis, host-pathogen interactions, and therapeutic interventions. Two widely used methods include agar plating with colony-forming unit (CFU) enumeration and time-lapsed turbidimetry in liquid broth culture. While agar plating remains the gold standard in both IMPORTANCE: Accurate bacterial quantification is fundamental to microbiology research and clinical diagnostics. While agar plating is a widely used method, our study demonstrates that liquid broth turbidimetry provides accurate bacterial quantification, which is fundamental to microbiology research and clinical diagnostics. While agar plating is a widely used method, our study demonstrates that liquid broth turbidimetry provides a highly correlative and more precise approach for quantifying diverse, clinically relevant bacterial pathogens, including when dealing with low bacterial density. The enhanced sensitivity and precision may be valuable for early infection detection, monitoring treatment efficacy, and understanding microbial dynamics in research settings where accurate quantification of even low-density organisms is essential. The findings support considering liquid broth turbidimetry as a complementary or alternative method for bacterial growth quantification.