Detección de Mycoplasma canadense y Mycoplasma californicum en ganado lechero de Argentina / Detection of Mycoplasma canadense and Mycoplasma californicum in dairy cattle from Argentina

Diferentes especies del género Mycoplasma pueden afectar al ganado bovino y causar varias enfermedades. La técnica de PCR, secuenciación y posterior análisis de la región ITS 16S-23S ARNr ha mostrado que existe una importante variabilidad interespecies entre Mollicutes. Se realizó la amplificación (región ITS 16S-23S ARNr) de 16 aislamientos sospechosos de corresponder a alguna especie de Mycoplasma, que habían sido obtenidos de muestras de leche provenientes de rodeos lecheros. Catorce de esos aislamientos fueron PCR positivos. Para confirmar la identidad de Mycoplasma bovis, dichos aislamientos fueron evaluados por otra PCR especie-específica. Siete aislamientos dieron un resultado positivo. Los productos de la PCR de la ITS 16S-23S ARNr de un aislamiento identificado como M. bovis y de otros dos aislamientos identificados como no-M. bovis fueron seleccionados al azar, secuenciados y analizados. Las tres secuencias (A, B y C) mostraron 100 % de similitud con cepas de M. bovis, Mycoplasma canadense y Mycoplasma californicum, respectivamente

Different species of Mycoplasma can affect bovine cattle, causing several diseases. PCR sequencing and further analysis of the 16S-23S rRNA ITS region have shown a significant interspecies variability among Mollicutes. Sixteen suspected isolates of Mycoplasma spp. obtained from milk samples from dairy herds were amplified (16S-23S rRNA ITS region). Fourteen out of those 16 suspected Mycoplasma spp. isolates were PCR-positive. To confirm the identity of Mycoplasma bovis, these 14 isolates were tested by another species-specific PCR. Seven of the isolates rendered a positive result. The products of 16S-23S rRNA ITS PCR from one isolate that was identified as M. bovis and from two other isolates, identified as non- M. bovis were randomly selected, sequenced and analyzed. The three sequences (A, B and C) showed 100% similarity with M. bovis, Mycoplasma canadense and Mycoplasma californicum respectively

Macrolide Resistance of Mycoplasma pneumoniae and Its Detection Rate by Real-Time PCR in Primary and Tertiary Care Hospitals

BACKGROUND: This study aimed to evaluate the prevalence of Mycoplasma pneumoniae in primary and tertiary care hospitals and its macrolide resistance rate. METHODS: Nasopharyngeal swabs were collected from 195 pediatric patients in primary and tertiary care hospitals from October to November 2010. The AccuPower MP real-time PCR kit (Bioneer, Korea) was used for the detection of M. pneumoniae. Direct amplicon sequencing was performed to detect point mutations conferring resistance to macrolides in the 23S rRNA gene. RESULTS: Among the 195 specimens, 17 (8.7%) were M. pneumoniae positive, and 3 of the strains (17.6%) obtained from these 17 specimens displayed the A2063G mutation in 23S rRNA. Three macrolide-resistant M. pneumoniae isolates were isolated from patients hospitalized at the primary care hospital. The positive rates of M. pneumoniae for the primary and tertiary care hospitals were 12.1% (15/124) and 2.8% (2/71), respectively (P=0.033). CONCLUSIONS: The positive rate of M. pneumoniae in the primary care hospital was higher than that in the tertiary care hospital. Simultaneous detection of M. pneumoniae and macrolide-resistant mutation genes in the 23S rRNA by real-time PCR is needed for rapid diagnosis and therapy of M. pneumoniae infections.

Two Cases of Mycoplasma pneumoniae Pneumonia with A2063G Mutation in the 23S rRNA Gene in Siblings

We describe 2 cases of pneumonia caused by the same macrolide-resistant Mycoplasma pneumoniae in siblings. M. pneumoniae was identified using real-time PCR. Direct sequence analysis of the 23S rRNA gene revealed a point mutation in V domain (A2063G) of the 23S rRNA gene.