Urinary tract infections can occur despite sterile standard urine cultures because routine plating methods often miss fastidious organisms, low-count pathogens, or anaerobes that are detectable by advanced molecular testing or enhanced culture techniques.
Multiple clinical studies and reviews demonstrate that standard urine cultures frequently yield false-negative results or fail to detect fastidious organisms, low bacterial counts, anaerobes, and emerging uropathogens in patients with active urinary tract infections. Advanced methods such as expanded quantitative urine cultures (EQUC) and next-generation sequencing (NGS) routinely identify pathogens that standard cultures miss.