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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #371970

Research Project: Identification of Disease Mechanisms and Control Strategies for Bacterial Respiratory Pathogens in Ruminants

Location: Ruminant Diseases and Immunology Research

Title: Comparison of two schemes for multilocus sequence typing (MLST) of Mycoplasma bovis and revision of the pubMLST reference method

item Register, Karen
item LYSNYANSKY, INNA - Kimron Veterinary Institute
item JELINSKI, MURRAY - University Of Saskatchewan
item Boatwright, Jr, William
item WALDNER, MATTHEW - University Of Saskatchewan
item Bayles, Darrell
item PILO, PAOLA - University Of Bern
item Alt, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/25/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Background. Mycoplasma bovis is a major pathogen of cattle and bison, causing pneumonia, pharyngitis, otitis, arthritis, mastitis and reproductive disorders. In 2015, a multilocus sequence typing (MLST) scheme comprised of 7 loci was reported for M. bovis, which has since served as the PubMLST reference method. An alternative MLST scheme was subsequently reported (Rosales et al. 2015. J. Clin. Microbiol. 53:789-794) but no direct comparison of the two methods has been undertaken. Although the PubMLST scheme has proven to be highly informative and discriminatory, modification of the scheme is necessary due to the recent identification of isolates missing one of the typing loci, adh-1. The goal of this study was to compare the performance of the two MLST schemes and to identify a revised reference scheme capable of fully typing all isolates. Methods and Results. We evaluated 448 isolates obtained from cattle, bison, deer and a goat that represent geographically distant locations and a variety of anatomic origins and clinical presentations. All isolates were typed using both methods and those isolates missing adh-1 were given an allele assignment of 0 for that locus. The discrimination index for the PubMLST and alternative schemes is 0.909 (91 STs) and 0.842 (77 STs), respectively. Although the PubMLST reference scheme outperformed the alternative scheme, the adh-1 locus must be retired if the PubMLST scheme is to be retained as a reference method. A modified scheme including only the six remaining PubMLST loci is highly informative (DI=0.897, 79 STs), but addition of a seventh locus to further boost discriminatory power was deemed necessary. A comparative analysis of genome sequences from the isolates used in this study identified a locus in the dnaA gene, which is also one of the loci in the alternative scheme, as the optimal choice for replacing the adh-1 locus. This revised scheme has a DI of 0.914 and distinguished 88 STs from the 448 isolates evaluated. Following publication in a peer-reviewed journal, the revised scheme will be implemented as the new reference method on the M. bovis PubMLST site.