New York City medium for enhanced recovery of Mycoplasma pneumoniae from clinical specimens

Abstract

Modified New York City (MNYC) medium and PPLO medium without methylene blue (PPLO agar) were compared for their ability to support the growth of Mycoplasma pneumoniae from clinical specimens. Pharyngeal specimens were collected from 1,070 college students who visited the Syracuse University Student Health Center. Of these patients, 623 were symptomatic for respiratory infection, and the remaining 447 were asymptomatic for respiratory illness. Throat swabs were inoculated into PPLO broths, and these broths were subcultured onto MNYC medium and PPLO agar after 3 and 14 days of incubation. A total of 222 (20.7%) clinical isolates of M. pneumoniae were recovered on these solid media, with the majority of the isolates (196) recovered from symptomatic patients. All isolates grew on MNYC medium, whereas five isolates failed to grow on PPLO agar. All isolates of M. pneumoniae recovered from symptomatic patients were detected on MNYC medium within 1 to 5 days of incubation, whereas 5 to 7 days of incubation were required before mycoplasmal growth was detected on PPLO agar. Over 86% of these mycoplasma isolates were detected on MNYC medium within 3 days of incubation and before the detection of any mycoplasmal growth on PPLO agar. A similar pattern of recovery times was observed for mycoplasmas isolated from asymptomatic patients. The results of this study have shown that MNYC medium is better than PPLO agar in supporting the rapid growth of M. pneumoniae from clinical specimens after 72-h blind subculture in PPLO glucose broth.