Use of Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry for the Identification of Pathogenic Vibrio in Fish.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid, cost-effective method for identification of a broad range of bacterial taxa, but its accuracy for Vibrio spp. from samples of aquatic animal origin is unknown. We used DNA sequence analysis targeting two conserved genes, rpoB and rpoD, as the identification standard for 5 reference strains and 35 Vibrio spp. field isolates obtained from diagnostic aquaculture samples. Overall, MALDI-TOF MS correctly identified 100% of the five reference strains to the genus level and 80% (4 of 5) to the species level. For field isolates, 83% (29 of 35) were correctly identified to the genus level, and 49% (17 of 35) were correctly identified to the species level. Eight (23%) field isolates were incorrectly identified at the species level. The MALDI-TOF MS method produced no identification for 17% (6 of 35) of the field isolates. Using traditional culture identification, 100% of the five reference strains were correctly identified to the species level. All 35 field isolates were correctly identified to the genus level; 51% (18 of 35) of the isolates were identified correctly to the species level, while 29% (10 of 35) were misidentified at the species level. Overall, MALDI-TOF MS was comparable to phenotypic identification, and accuracy will likely improve with enhancement of MALDI-TOF MS database robustness.

In vitro elution of amikacin and vancomycin from impregnated plaster of Paris beads.

OBJECTIVE: To describe in vitro elution characteristics of amikacin and vancomycin from calcium sulfate hemihydrate 98% (plaster of Paris, POP) beads and characterize eluent inhibition of Staphylococcus spp. STUDY DESIGN: Experimental study. METHODS: POP beads were impregnated with amikacin or vancomycin alone or in combination and then incubated alone or in combination for 84 days at 37 degrees C in plastic tubes containing sterile phosphate-buffered saline (PBS). Beads containing no antimicrobial served as negative control. Beads were intermittently moved to a new tube containing drug-free PBS. Antimicrobial was measured in the eluent using a polarized fluorescent immunoassay. Eluent inhibition of Staphylococcus spp. was determined at each time point. RESULTS: Antimicrobial release from beads was characterized by an initial rapid phase then a slower phase. Although antimicrobial release from beads occurred throughout the 84 days, most was in the first 24 hours, except for vancomycin alone. Duration of eluent inhibition of Staphylococcus spp. growth ranged from 0.5 (amikacin alone) to 56 days (vancomycin alone). Control eluent did not inhibit bacterial growth. CONCLUSIONS: Amikacin elution from POP beads was rapid, inhibiting growth for <24 hours with or without vancomycin. Vancomycin elution was slower and inhibited growth for 56 days alone or for 5 days with amikacin. CLINICAL RELEVANCE: Vancomycin-impregnated beads appear to be reasonable as a therapeutic option whereas amikacin-impregnated POP beads and amikacin and vancomycin combinations may require further study before considering as a therapeutic option.

Prevalencia de Anaplasma marginale en bovinos del sector La Piñata, municipio La Cañada de Urdaneta: estado Zulia Venezuela / Prevalence of anaplasma marginale in cattle from La Piñata sector La Cañada de Urdaneta county Zulia state Venezuela

Se realizó un estudio con la finalidad de determinar la prevalencia de Anaplasma marginale en bovinos del sector La Piñata, municipio La Cañada de Urdaneta, estado Zulia, Venezuela. Para ello fueron seleccionadas 12 fincas, con una población de 6.894 bovinos, evaluándose 174 muestras por medio de la técnica de Inmunofluorescencia Indirecta (IFI) y la observación de frotis de capa blanca. A través de la técnica de IFI, se obtuvo una prevalencia de 95,4 por ciento (166 animales positivos) para Anaplasma marginale; mientras que mediante la observación de frotis de capa blanca fue de 56,9 por ciento (99 animales positivos). No se encontraron diferencias significativas con relación a la presencia de Anaplasma marginale y el sexo o la edad de los animales. Todas las fincas incluidas en la investigación mostraron prevalencias de Anaplasma marginale iguales o mayores a 75 por ciento, indicando que la zona estudiada presenta una condición de estabilidad enzootica para este hemoparásito. La técnica de IFI resultó ser más efectiva con relación a la observación de frotis de capa blanca en la detección de animales infectados con Anaplasma marginale