ABSTRACT
Objective:To identify and characterize one Spiroplasma strain (designated as DGKH1) isolated from the blood of a patient with sepsis. Methods:The traditional bacterial culture, staining, morphological observation, physiological and biochemical identification, 16S rRNA gene sequencing, phylogenetic analysis, genome sequencing, and the genome-related index analysis were performed to accurately determine the taxonomic status of the strain DGKH1. Antibiotic susceptibility testing was performed using a specific kit for culturing and testing Ureaplasma urealyticum/ Metamycoplasma hominis. Results:The strain DGKH1 could weakly grow on Columbia blood agar, chocolate agar, and Haemophilus chocolate 2 agar. However, it did not grow in liquid culture medium containing tetracycline (4 μg/ml), doxycycline (1 μg/ml), minocycline (1 μg/ml), josamycin (2 μg/ml), roxithromycin (1 μg/ml), clarithromycin (1 μg/ml), or telithromycin (1 μg/ml). DGKH1 resembling Metamycoplasma hominis formed "fried egg-like colonies" on Mycoplasma solid culture medium. DGKH1 could not be stained by Gram staining. When observed under transmission electron microscopy (TEM) using phosphate buffer as the matrix, the bacteria were spiral-shaped. Results of 16S rRNA gene sequence alignment showed that DGKH1 was highly similar (99.85%) to Spiroplasma eriocheiris CCTCC M 207170 T. However, the urea decomposition test was positive, which was different from all of the known Spiroplasma species. The phylogenetic analysis based on whole genome showed that DGKH1 was clustered in a small branch along with Spiroplasma eriocheiris CCTCC M 207170 T. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 94.14% and 56.00%, respectively, both below the threshold for prokaryotic species identification. Conclusions:DGKH1 represented a potential new species of genus Spiroplasma, closely related to Spiroplasma eriocheiris. Some microbiological characteristics of DGKH1 were similar to Mycoplasmas. However, the natural host and epidemiological data of DGKH1 need to be further studied.
ABSTRACT
Objetivo. Determinar la presencia de Spiroplasma penaei en el plancton, bentos y fauna acompañante en 2 fincas comerciales de camarones. Materiales y métodos. Fueron colectadas 200 muestras para identificación de lesiones características de Spiroplasma, a través de la técnica de histología, mientras que para la técnica de PCR se tomaron 326 muestras de plancton, bentos y fauna acompañante. Las muestras colectadas fueron preservadas en tubos estériles con etanol al 95% para análisis de PCR y en solución Davidson para análisis histológicos. Resultados. En los muestreos realizados en las dos fincas camaroneras fue detectada la presencia de Spiroplasma en una muestra de un representante de los dípteros (mosca de agua) a través de la técnica de PCR en tiempo real, el cual arrojo una Tm=84, similar a la del control positivo de Spiroplasma utilizado. Esta muestra fue secuenciada y comparada con secuencias de bacterias almacenadas en el banco de datos GenBank usando el algoritmo BLAST, encontrando 100% de homología con un fragmento de los genes ribosomales 16S de la bacteria Spiroplasma penaei. Conclusiones. La mosca de agua es portadora de Spiroplasma penaei, sin embargo no se puede afirmar que este organismo sea el transmisor de la infección, por lo que se recomienda realizar ensayos de tipo experimental con moscas de agua infectadas con Spiroplasma penaei, en camarones libres de patógenos, para evaluar si en realidad es el vector de infección.
Subject(s)
Animals , Benthic Fauna , Plankton , Polymerase Chain Reaction , SpiroplasmaABSTRACT
Surface serology is an important determinant in Spiroplasma systematics. Reciprocal antigen/antibody reactions between spiroplasmas and individual antisera delineate the 38 described groups and species. However, reciprocal serology is impractical for largescale studies. This report describes a successful, streamlined polyvalent screening approach used to examine isolates from an environmental survey.
A sorologia de superfície é um determinante importante na sistemática de Spiroplasma. Reações antígeno-anticorpo entre spiroplasmas e antisoro individuais delineiam os 38 grupos e espécies descritos. No entanto, reações sorológicas são impraticáveis em estudos em larga-escala. Esse relato descreve uma metodologia de triagem bem sucedida a ser empregada no exame de isolados em levantamentos ambientais.
ABSTRACT
O objetivo deste trabalho foi verificar a eficiência de inseticidas no tratamento de sementes no controle da cigarrinha-do-milho em viveiro telado. Sementes de milho foram tratadas ou não com inseticidas (imidacloprid, thiamethoxan, thiodicarb + zn, thiodicarb, carbofuran, carbofuran + zn e carbosulfan) e semeadas em vasos plásticos. Nas plantas, foram confinadas cigarrinhas sadias e avaliada a eficiência desses inseticidas no controle desse inseto, em diferentes intervalos de tempo e em períodos sucessivos. Os produtos imidacloprid e thiamethoxan foram os mais eficientes no controle da cigarrinha, proporcionando eficiência de controle de adultos de D. maidis igual ou superior a 70 por cento, até o trigésimo dia de avaliação, após 4 a 24h de confinamento das cigarrinhas.
This research was aimed at checking the efficiency of insecticide seed treatment on corn leafhopper control, at greenhouse. Maize seeds were treated with insecticides (imidacloprid, thiamethoxan, thiodicarb + zn, thiodicarb, carbofuran, carbofuran + zn and carbosulfan) and sowed on plastic pots. On those plants healthy leafhoppers were confined, and the efficiency of those insecticides on its control was evaluated, at different intervals of time and in successive periods. The insecticides imidacloprid and thiamethoxan were the most efficient to control the corn leafhoppers, and provided control efficiency of D. maidis adults equal or upper 70 percent until the thirtieth day of evaluation, after 4 to 24h of leafhoppers confining.