Real‐Time PCR and Quantitative Culture for Mycoplasma pneumoniae Load in Pharyngeal Swabs from Children at Preliminary Diagnosis and Discharge

Abstract

Background. Extensive studies have focused on the diagnosis and treatment of Mycoplasma pneumoniae infection; however, rare studies investigated the posttreatment conditions. We analyzed the carrying status of M. pneumoniae in the respiratory tract of children before and after treatment. Methods. Ninety-two children with M. pneumoniae pneumonia were included in this study. Clinical data were obtained from each patient, and pharyngeal swab sampling was performed at preliminary diagnosis and discharge. Real-time PCR and dilution quantitative culture were utilized to determine the DNA quantification and number of viable M. pneumoniae from samples collected upon preliminary diagnosis and discharge. Results. All the 92 cases showed DNA positivity upon preliminary diagnosis, serum IgM antibody was detected in 80 patients, and positivity of M. pneumoniae culture was observed in 82 cases. Upon discharge, the M. pneumoniae nucleotide and culture positivity were detected in 87 and 49 cases, respectively. The content of viable M. pneumoniae was 10–104 CCU/mL and 10–102 CCU/mL in the preliminary diagnosis samples and discharge samples, respectively. Conclusions. Real-time PCR was rapid and effective for the qualitative diagnosis of M. pneumoniae at the early stage, but it cannot be used to evaluate the prognosis of patients with M. pneumoniae infection. Quantitative analysis for M. pneumoniae DNA could not directly reflex the viable strain content.

Absolute quantification of Mycoplasma pneumoniae in infected patients by droplet digital PCR to track disease severity and treatment efficacy

“…Real-time PCR, a well-developed practical method for the detection of infective pathogens, has been widely used for the clinical diagnosis of M. pneumoniae ( Dumke et al, 2007 ; Winchell and Mitchell, 2013 ; Zhao et al, 2020 ). However, it relies on a standard curve to calculate the DNA copy number, which differs among experiments and thus complicates the diagnostic process.…”

Macrolide-resistant Mycoplasma pneumoniae: Do we know the situation in Europe?

“…Debido a las ventajas de tiempos de respuesta cortos, alta sensibilidad y especificidad, y no afectarse por la respuesta inmunológica, la PCR se ha convertido en opción preferida para el diagnóstico temprano de M. pneumoniae en el medio asistencial [ 28 , 29 ]. Sin embargo, tiene algunas limitaciones, la necesidad de muestras de alta calidad, y la posibilidad de que los inhibidores de la PCR conduzcan a resultado falsos negativos [ 30 ].…”

“…Los antibióticos más utilizados para el tratamiento en las neumonías por este microorganismo, sobre todo en niños, son los macrólidos que tienen acción antiinflamatoria además de antibiótica, lo que contribuye a la mejoría del paciente [ 30 ]. Dentro de los macrólidos, la azitromicina, roxitromicina o claritromicina se prefieren a la eritromicina por su mejor tolerancia, su mejor administración y menor duración de tratamiento.…”

Analysis of Clinical Efficacy of Erythromycin Combined with Oseltamivir Phosphate Granules in the Treatment of Mycoplasma Pneumonia in Children

“…Clinically, erythromycin, as the first choice of macrolides, can maintain a high concentration in serum, so as to completely control mycoplasma pneumonia [16] , some studies have found that macrolide antibiotics have significant effect on improving the clinical efficacy of patients with MPP. Moreover, some studies have reported that macrolide resistant children have less inhibitory effect on microorganisms and may not achieve the effect of treating MPP [17] . Since Japan first reported macrolide resistance 1970, the global prevalence of macrolide resistant MP has increased to 10 %-30 %, which will eventually lead to severe refractory MP [18] .…”