Phenotypic and genotypic characterization of competitive exclusion products for use in poultry

Abstract

Aims: Phenotypic and genotypic bacteria identification methods were compared for their efficacy in determining the composition of competitive exclusion (CE) products. Methods and Results: Phenotypic methods used for bacterial identification were fatty acid methyl ester profiles, biochemical assays and carbohydrate utilization profiles. Genotypic methods were MicroSeq16S rRNA sequence analysis and BLAST searches of the GenBank sequence database. Agreement between phenotypic and genotypic methods for identification of bacteria isolated from the Preempt CE product was 20%. A defined test mixture of bacteria was identified to the species level 100% by BLAST analysis, 64% by MicroSeq and 36% by phenotypic techniques. Conclusions: The wide range of facultative and obligate anaerobic bacteria present in a CE product are more accurately identified with 16S rRNA sequence analyses than with phenotypic identification techniques. Significance and Impact of the Study: These results will provide guidelines for manufacturers of CE products to submit more reliable product information for market approval by regulatory agencies.

Vancomycin-Resistant Lactococcus lactis 1A-1 Isolated from a Competitive Exclusion Product Transfers Vancomycin Resistance Genes to Staphylococcus aureus

“…It is possible that the L. lactis isolate acquired a vancomycin resistance gene from a vancomycin-resistant Enterococcus sp. that was present in the CE product [8]. In the present study, we hypothesize that the vancomycinresistant L. lactis isolate may have the potential to transfer resistance determinants to a S. aureus strain similar to those that normally transit the human GI tract [9].…”

Assessment of a probiotic Containing Bacillus Subtilis on the Performance and Gut Health of Laying Japanese Quails (Coturnix Coturnix Japonica)

“…Hence, the early administration of 'good' bacteria for competitive exclusion has been proposed as a method to prevent undesirable infections. There are several reports on the capacity of live bacterial cultures (Callaway et al, 2008;Corrier et al, 1998;Nisbet et al,1998;Wagner et al, 2003) and probiotic organisms (Higgins et al, 2007;Higgins et al, 2008;Higgins et al, 2010;Patterson & Burkholder, 2003;Vicente et al, 2008) to reduce the colonization of the gastrointestinal tract of poultry by opportunistic pathogens. The current study showed that the dietary inclusion of Bacillus subtilis enhanced the birds' immunity against Newcastle disease and avian influenza.…”

Rapid identification of pathogenic streptococci isolated from moribund red tilapia (Oreochromis spp.)

“…belonging to Lancefield groups B and C failed to be identified with the Rapid Strep system (Watts and Yancey, 1994). Therefore, comparison of the 16S rRNA sequences of investigated bacteria has high discriminatory power to resolve closely related species (Wagner et al, 2003). MicroSeq500 16S rRNA sequencing is an excellent commercial identification assay marketed for the rapid and accurate identification of bacterial pathogens (Woo et al, 2009) via sequencing the first 500 base pairs of the 16S rRNA gene.…”