Polymerase chain reaction versus culture for detection ofUreaplasma urealyticum andMycoplasma hominis in the urogenital tract of adults and the respiratory tract of newborns

Abstract

The efficiency of the polymerase chain reaction (PCR) was compared with that of culture for detection of Ureaplasma urealyticum and Mycoplasma hominis in 726 clinical specimens comprising 189 gynecological samples, 362 urological samples, and 175 samples from newborn infants. The sensitivity of PCR versus culture was 95% for both organisms, while the sensitivity of culture versus PCR was 91% for Ureaplasma urealyticum and 84% for Mycoplasma hominis. Furthermore, PCR tests were faster than culture tests, allowing the time to diagnosis to be reduced from two to five days to 24 h.

Comparison of Culture With the Polymerase Chain Reaction for Detection of Gennital Mycoplasma

“…Nine patients in our study had a positive culture but a negative PCR assay result. Similar observations have been reported by other investigators (20,22) and have been attributed to degradation of bacterial DNA or inhibitor(s) of the PCR reaction in clinical samples. For example, blood is a poor biologic specimen for PCR-based methods, because hemoglobin can inhibit the PCR reaction.…”

“…The results indicate that the use of a PCR assay for genital mycoplasma (20)(21)(22)(23). This finding is not surprising given the fact that mycoplasmas are liable organisms lacking a cell wall.…”

“…PCR has an advantage in that it can still detect DNA of dead organisms. Although the combined use of liquid and solid media is thought to be the most sensitive culture method available, it has been shown in other studies (20) to detect only 75-80% of samples infected with Mycoplasmas. If in our study the111 positive specimens detected by both culture and PCR represented all infections, then the 59 positive specimens detected by culture represent only 53% of the infected samples, whereas the PCR positive samples represent 91% of them.…”

Comparison of Multiplex PCR Assay with Culture for Detection of Genital Mycoplasmas

“…Enhanced sensitivity for genital mycoplasma detection with PCR is consistent with the literature (2,23,40). This finding is not surprising given the fact that mycoplasmas are labile organisms lacking a cell wall.…”

Frequency of sexually transmitted diseases and main methodological implications

“…Quantificare l'incidenza e la distribuzione di questi patogeni nella popolazione, mediante l'investimento in opportune strategie di controllo e prevenzione, è importante per ridurre la morbilità e la mortalità correlata a questo tipo di infezioni con ricadute, sicuramente, in termini di qualità di vita per i pazienti ma anche in termini di spesa sanitaria più complessa da calcolare. Numerosi sono i test di amplificazione degli acidi nucleici (NAATs) in Real-Time polymerase chain reaction (RT-PCR) per la rivelazione di Chlamydia trachomatis e Neisseria gonorrhoeae (11,23,32,45) mentre poco implementati quelli per la rilevazione di Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum e Ureaplasma parvum, nonostante numerosi studi abbiano dimostrato una maggiore sensibilità delle metodiche RT-PCR (1,2,28,41,44). Diversi sono i laboratori che stanno implementando la diagnostica molecolare e impiegano le metodiche colturali solo quando è necessario l'antibiogramma.…”