Comparison of the Pour, Spread, and Drop Plate Methods for Enumeration of Rhizobium spp. in Inoculants Made from Presterilized Peat.

NifTAL Project, Department of Agronomy and Soil Science, College of Tropical Agriculture and Human Resources, University of Hawaii, Honolulu, Hawaii 96822.
Applied and Environmental Microbiology (Impact Factor: 3.67). 12/1982; 44(5):1246-7.
Source: PubMed

ABSTRACT Inoculants prepared with presterilized peat were enumerated by the pour, spread, and drop plate techniques. Results indicated that the three plating methods were interchangeable. The drop plate method was preferred because of its economy in materials and labor.

572 Reads
  • Source
    • "Experiments were conducted twice, plating was done in duplicates and in three consecutive dilutions were plated, to achieve measurable bacterial count on the plates; the optimal colony counts in this method are among 15–150. The spread-plate technique [47] was performed on non-selective plate count agar (PCA), contained in 9-cm plastic sterile Petri dishes. The detection limit for undiluted samples is 1 CFU/mL and 10 CFU/ml for the diluted ones [48] [49]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this work, an intensive assessment of solar disinfection of secondary wastewater was elaborated in controlled laboratory conditions. Batch tests of E. coli-spiked synthetic secondary effluent, at nine different constant intensity levels, were followed by a 48-h dark storage. Solar disinfection was monitored in half-hourly intervals demonstrating distinct phases of lag followed by sharp inactivation. The results were fit to a shoulder log-linear and a Weibull distribution model. The solar-driven inactivation, the latency period and the effective disinfection time (for 4-log reduction) were correlated properly with the applied irradiance, resulting in a common, standardized dose for all intensities. Evolution of bacterial response in the dark was monitored for 48 h, and was in each case characterized as growth or decay. Also, the energy threshold, which was able to shift post-irradiation behavior from growth to decay, was analytically studied. In all intensity levels, this standard was approximately constant, as an effective bacteriostatic dose (EBD). Finally, similar dose-related disinfection and regrowth effects were observed, suggesting compliance with the reciprocity law, with minor deviations.
    Chemical Engineering Journal 07/2015; 281. DOI:10.1016/j.cej.2015.06.077 · 4.32 Impact Factor
  • Source
    • "The liver was air exposed by dissection using sterile surgical material and was microbiologically sampled for bacterial counting and V. vulnificus recovery on TSA-plates. Bacterial counts from blood, gills or liver were performed by drop plating on TSA [21]. All the experiments described comply with the guidelines of the European Union Council (2010/63/EU) for the use of laboratory animals and have been approved by the department of environment (reference code 2014/pesca/RGP/028), as well as by the general directorate of agricultural and livestock production of the "
    [Show abstract] [Hide abstract]
    ABSTRACT: Vibrio vulnificus is an aquatic gram-negative bacterium that causes a systemic disease in eels called warm-water vibriosis. Natural disease occurs via water born infection; bacteria attach to the gills (the main portal of entry) and spread to the internal organs through the bloodstream, provoking host death by haemorrhagic septicaemia. V. vulnificus produces a toxin called RtxA13 that hypothetically interferes with the eel immune system facilitating bacterial invasion and subsequent death by septic shock. The aim of this work was to study the early steps of warm-water vibriosis by analysing the expression of three marker mRNA transcripts related to pathogen recognition (tlr2 and tlr5) and inflammation (il-8) in the gills of eels infected by immersion with either the pathogen or a mutant deficient in rtxA13. Results indicate a differential response that is linked to the rtx toxin in the expression levels of the three measured mRNA transcripts. The results suggest that eels are able to distinguish innocuous from harmful microorganisms by the local action of their toxins rather than by surface antigens. Finally, the cells that express these transcripts in the gills are migratory cells primarily located in the second lamellae that re-locate during infection suggesting the activation of a specific immune response to pathogen invasion in the gill. Copyright © 2015. Published by Elsevier Ltd.
    Fish &amp Shellfish Immunology 01/2015; 43(2). DOI:10.1016/j.fsi.2015.01.009 · 2.67 Impact Factor
  • Source
    • "Biofilms were first disrupted by vigorous pipetting. The cell suspension was then serially diluted using BHIG broth and 10 μL of each dilution was plated in four replicates (40 μL in total) on BHI agar plates using the drop plate method described by Hoben and Somasegaran [50] and Herigstad et al. [51]. Colonies on the plates were counted after 72 hours of incubation under anaerobic conditions at 37°C. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Bacterial vaginosis is a common vaginal infection associated with numerous gynecological and obstetric complications. This condition is characterized by the presence of thick adherent vaginal biofilms, composed mainly of Gardnerella vaginalis. This organism is thought to be the primary aetiological cause of the infection paving the way for various opportunists to colonize the niche. Previously, we reported that the natural antimicrobials subtilosin, ε-poly-L-lysine, and lauramide arginine ethyl ester selectively inhibit the growth of this pathogen. In this study, we used plate counts to evaluate the efficacy of these antimicrobials against established biofilms of G. vaginalis. Additionally, we validated and compared two rapid methods (ATP viability and resazurin assays) for the assessment of cell viability in the antimicrobial-treated G. vaginalis biofilms. Out of the tested antimicrobials, lauramide arginine ethyl ester had the strongest bactericidal effect, followed by subtilosin, with clindamycin and polylysine showing the weakest effect. In comparison to plate counts, ATP viability and resazurin assays considerably underestimated the bactericidal effect of some antimicrobials. Our results indicate that these assays should be validated for every new application.
    Infectious Diseases in Obstetrics and Gynecology 09/2012; 2012:284762. DOI:10.1155/2012/284762
Show more


572 Reads
Available from