Submicron Particle and Cell Concentration in a Closed Chamber Surface Acoustic Wave Microcentrifuge.

Preconcentrating particulate and cellular matter for their isolation or detection is often a necessary and critical sample preparation or purification step in many lab-on-a-chip diagnostic devices. While surface acoustic wave (SAW) microcentrifugation has been demonstrated as a powerful means to drive efficient particle concentration, this has primarily been limited to micron dimension particles. When the particle size is around 1 µm or below, studies on SAW microcentrifugation to date have shown that particle ring-like aggregates can only be obtained in contrast to the localized concentrated clusters that are obtained with larger particles. Considering the importance of submicron particles and bioparticles that are common in many real-world samples, we elucidate why previous studies have not been able to achieve the concentration of these smaller particles to completion, and we present a practical solution involving a novel closed chamber configuration that minimizes sample heating and eliminates evaporation to show that it is indeed possible to drive submicron particle and cell concentration down to 200 nm diameters with SAW microcentrifugation over longer durations.

[Duration of preservation of viable cells, DNA, and antigens of Mycoplasma hominis and ureaplasmas in human serum at 37 degrees C].

How long the viable cells of M. hominis, Ureaplasma spp., U. urealyticum, U. parvum, and their antigens retained in human serum at 37 degrees C was investigated. M. hominis cells were shown to hold their viability within 12 days with a gradual titer drop, the antigens being also detected within 12 days whereas intracellular and extracellular DNAs were seen within 40 days (an observation time). Under the same conditions, Ureaplasma cells died after 24 hours, their antigens were disrupted following 3 days and intracellular and extracellular DNAs of different species were detectable by polymerase chain reaction (PCR) within 17-40 days. The long preservation of extracellular and dead cell DNAs suggests that diagnostic examination of patients by means of PCR may yield false-positive results.

[Cloning and expression of the Mycoplasma hominis ftsZ for a cell division protein]. / Klonirovanie i ékspressiia gena, kodiruiushchego belok deleniia mikoplazmy (ftsZ, Mycoplasma hominis).

A Mycoplasma hominis chromosomal fragment containing the full-length ftsZ gene was cloned and sequenced. Natural expression of this gene was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) with total RNA. The M. hominis FtsZ protein was shown to differ substantially from its counterparts of two other Mycoplasma species, M. genitalium and M. pneumoniae. The possibility of M. hominis ftsZ expression in Escherichia coli was demonstrated with several bacterial strains. The M. hominis FtsZ protein was isolated from E. coli cells transformed with recombinant plasmids carrying the M. hominis ftsZ gene. Complementation between the E. coli and M. hominis FtsZ proteins was observed in transformants.

Micoplasma hominis y Ureaplasma spp en mujeres que consultan por infertilidad / Mycoplasma Hominis and Ureaplasma Spp. in women attending to infertility consultations

RESUMEN Introducción: Las infecciones por micoplasmas y ureaplasmas pueden producir fallos en la reproducción y vincularse con problemas de infertilidad femenina. Objetivo: Determinar la frecuencia de infecciones por Micoplasma hominis y Ureaplasma spp en mujeres que consultan por infertilidad e identificar si existe asociación entre las infecciones detectadas y los antecedentes de infecciones de transmisión sexual y enfermedad inflamatoria pélvica, procederes ginecológicos y síntomas de infecciones. Métodos: Se realizó un estudio descriptivo transversal, para evaluar muestras de exudados endocervicales de 175 mujeres, con edades entre 20 y 45 años, provenientes de la consulta de infertilidad del Instituto Nacional de Endocrinología, entre junio de 2016 y enero de 2017. Para la detección de micoplasmas urogenitales se utilizó el juego de reactivos Myco Well D-One. Se tuvieron en cuenta los aspectos éticos y se utilizó la prueba Chi Cuadrado para evaluar la significación estadística de las posibles asociaciones. Resultados: De las 175 muestras evaluadas, 102 (58,1 por ciento) mostraron la presencia de infecciones, de ellas 65 correspondieron a Ureaplasma spp (37,1 por ciento), 11 a Micoplasma hominis (6,2 por ciento), y 26 a asociaciones de Micoplasma hominis y Ureaplasma spp (14,8 por ciento). Se identificó asociación entre las infecciones detectadas y la presencia de antecedentes de infecciones de transmisión sexual y enfermedad inflamatoria pélvica, no así con relación a los procederes ginecológicos y síntomas de infecciones. Conclusiones: La frecuencia total de infecciones fue relativamente alta y la especie más frecuente el Ureaplasma spp. Las infecciones detectadas estuvieron asociadas a algunos de los factores estudiados(AU)

ABSTRACT Introduction: Infections caused by Mycoplasmas and Ureaplasmas may result in faults in the reproduction process and can be linked to female infertility. Objective: To determine the frequency of infection by Mycoplasma hominis and Ureaplasma spp. in women who attend to infertility consultations and if these are associated with a history of sexually transmitted infections and pelvic inflammatory disease, gynaecological procedures and symptoms of infections. Methods: A descriptive cross-sectional study was conducted to evaluate samples of endocervical swabs of 175 women between the ages of 20 to 45 years, from the Infertility consultation of the National Institute of Endocrinology, during June 2016 to January 2017. For the detection of urogenital mycoplasmas it was used the reagents kit Myco Well D-One. There were taken into account the ethical aspects and it was used the chi-square test to assess the statistical significance of the possible associations. Results: Of the 175 evaluated samples, 102 (58.1 percent) showed the presence of infections, 65 of them corresponded to Ureaplasma spp (37.1 percent), 11 to Mycoplasma hominis (6.2 percent), and 26 associations of Mycoplasma hominis and Ureaplasma spp (14.8 percent). It was identified association between the detected infections and the presence of a history of sexually transmitted infections and pelvic inflammatory disease, but not with the gynaecological procedures and the symptoms of infections. Conclusions: The total frequency of infection was relatively high and the most prevalent specie was the Ureaplasma spp. The detected infections were associated with some of the factors studied(AU)

Long-term survival and intracellular replication of Mycoplasma hominis in Trichomonas vaginalis cells: potential role of the protozoon in transmitting bacterial infection.

The existence of a symbiotic relationship between Trichomonas vaginalis and Mycoplasma hominis, which is the first reported example of symbiosis between two obligate human pathogens, has been recently reported by our research group. In this work, we examined the cellular location of M. hominis in respect to T. vaginalis. By using gentamicin protection assays, double immunofluorescence, and confocal microscopy, we obtained strong evidence that M. hominis is located within protozoan cells. 5-Bromodeoxyuridine incorporation assays showed that intracellularly located mycoplasmas actively synthesize DNA. Our results demonstrate that M. hominis has the capability of entering trichomonad cells and of replicating inside the protozoon. These findings suggest that symbiosis might provide the bacteria, during human infection, with the capability to resist to environmental stresses, such as host defense mechanisms and pharmacological therapies.