Russell T. Greene

Comparison of an enzyme-linked immunosorbent assay to an indirect immunofluorescence assay for the detection of antibodies to Borrelia burgdorferi in the dog

An enzyme-linked immunosorbent assay (ELISA) was compared to an indirect immunofluorescence assay (IFA) for detection of IgG antibodies to Borrelia burgdorferi in dog sera. The concordance of the two tests was 93.5% for sera from dogs from Maryland (n = 93), 98.0% for sera from dogs from North Carolina (n = 446), and 97.2% for the combined sample groups (n = 539). Twenty-five of the 27 samples with discordant or low positive results were tested, and showed immunoblot reactions to 1 to 10 different bands. Reaction patterns and intensity of the bands were quite variable, and did not explain a reason for the discordance.

Pseudospirochetes in Animal Blood Being Cultured for Borrelia Burgdorferi

A major advantage of enzyme assay over classical use of immunofluorescence and other serologic procedures for identification of mycoplasmas is that the technical requirements and reagents for preparation and performance of the serologic tests are obviated. Both enzyme assay systems evaluated in this study were simple to conduct and required only 4 hours of incubation before assessment. Although both enzyme assay systems are potentially more convenient than present mycoplasma identification techniques, the requirement for as much as 60 ml of log phase culture renders them impractical for use in most diagnostic and clinical laboratories. A system designed especially for mycoplasmas might require less inoculum and/or less intense color reactions. This adaptation might be accomplished by miniaturization of the test, elimination of substrates for nonreactive enzymes, addition of appropriate substrates for other enzymes, utilization of more sensitive color reactions, and/or adaptation of color reactions to automated evaluation in a microtiter plate enzyme-linked immunosorbent assay reader. With such modifications, identification of mycoplasmas by enzyme assay could become a useful procedure in diagnostic laboratories. References

Evaluation of Four Commercial Anaerobic Systems for Identification of Eubacterium Suis

Four commercial anaerobic systems (CASs) were evaluated for usefulness in identification of Eubacterium suis. Twelve strains were evaluated in each system in triplicate, and results were interpreted independently by 5 individuals. Statistically significant differences (P < 0.01) due to strain variation and reader interpretation accounted for discrepancies encountered. The reactivity, repeatability, and unique profiles generated made both CAS-1 and CAS-2 suitable adjuncts for identification of E. suis when colony morphology and Gram reaction were considered. Limited reactivity in CAS-3 limited its use as an aid in identification. Variability in test observations and the large number of numerical profiles generated precluded use of CAS-4.

The influence of host factors on the outcome of a viral infection.

The clinician confronted with a patient that has an infectious disease, particularly one caused by a virus, faces a series of difficult problems: diagnostic confirmation of the infection, instituting appropriate therapy, duration of treatment, preventing secondary complications, and preventing transmission of the virus to susceptible animals. Yet, it is the complex relationship between the patient, as host to a pathogenic virus, the virus, and the environment that ultimately influences the clinical course of an infection. The ability to accurately prognose the outcome of any infection is, therefore, predicated on the clinicians awareness of biological and environmental variables that apply to the individual patient.