Mycoplasma agalactiae: The Sole Cause of Classical Contagious Agalactia?

Sergio Migliore,Roberto Puleio,Robin A. J. Nicholas,Guido R. Loria

doi:10.3390/ani11061782

Abstract

Simple SummaryFor over thirty years, contagious agalactia has been recognized as a mycoplasma disease affecting small ruminants caused by four different pathogens: Mycoplasma agalactiae, Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens which were previously thought to produce clinically similar diseases. Today, with major advances in diagnosis enabling the rapid identification by molecular methods of causative mycoplasmas from infected flocks, it is time to revisit this issue. In this paper, we discuss and argue the reasons to support Mycoplasma agalactiae infection as the sole cause of contagious agalactia.Contagious agalactia (CA) is suspected when small ruminants show all or several of the following clinical signs: mastitis, arthritis, keratoconjunctivitis and occasionally abortion. It is confirmed following mycoplasma isolation or detection. The historical and major cause is Mycoplasma agalactiae which was first isolated from sheep in 1923. Over the last thirty years, three other mycoplasmas (Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens) have been added to the etiology of CA because they can occasionally cause clinically similar outcomes though nearly always in goats. However, only M. agalactiae is subject to animal disease regulations nationally and internationally. Consequently, it makes little sense to list mycoplasmas other than M. agalactiae as causes of the OIE-listed CA when they are not officially reported by the veterinary authorities and unlikely to be so in the future. Indeed, encouraging countries just to report M. agalactiae may bring about a better understanding of the importance of CA. In conclusion, we recommend that CA should only be diagnosed and confirmed when M. agalactiae is detected either by isolation or molecular methods, and that the other three mycoplasmas be removed from the OIE Manual of Diagnostic Tests and Vaccines in Terrestrial Animals and associated sources.

Highlights

Introduction published maps and institutional affilIn 1999, the consensus of the working group on contagious agalactia (CA) of the ECCOST Action 826 on ruminant mycoplasmoses, which met in Toulouse, France, agreed that four mycoplasmas—Mycoplasma agalactiae, M. mycoides subsp. capri, M. capricolum subsp. capricolum and M. putrefaciens—should be recognized as causal agents of Contagious agalactia (CA) because the clinical disease they cause can be similar and includes mastitis, arthritis, keratoconjunctivitis and, occasionally, abortion [1]
The principal objective of this paper is to show that M. agalactiae should be considered the sole cause of classical CA
The main clinical signs of CA caused by M. agalactiae are mastitis which can involve

Summary

Introduction

Introduction published maps and institutional affilIn 1999, the consensus of the working group on contagious agalactia (CA) of the ECCOST Action 826 on ruminant mycoplasmoses, which met in Toulouse, France, agreed that four mycoplasmas—Mycoplasma agalactiae, M. mycoides subsp. capri (previously named M.m. mycoides large colony), M. capricolum subsp. capricolum and M. putrefaciens—should be recognized as causal agents of CA because the clinical disease they cause can be similar and includes mastitis, arthritis, keratoconjunctivitis and, occasionally, abortion [1]. COST Action 826 on ruminant mycoplasmoses, which met in Toulouse, France, agreed that four mycoplasmas—Mycoplasma agalactiae, M. mycoides subsp. Capricolum and M. putrefaciens—should be recognized as causal agents of CA because the clinical disease they cause can be similar and includes mastitis, arthritis, keratoconjunctivitis and, occasionally, abortion [1]. M. mycoides large colony), M. capricolum subsp. This decision followed earlier observations by Perreau in 1979 [2] that clinical signs of infections causing M. agalactiae, the main and historical cause, were sufficiently similar to those of M. m. Lambert, who compiled the chapter on CA, added another mycoplasma, M. putrefaciens, mainly based on a few reports including one from Da Massa et al in 1987 describing a iations.

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