<p>Contagious Agalactia In Sheep And Goats: Current Perspectives</p>

Abstract

Contagious agalactia (CA) is a disease caused equally by four Mycoplasma species, in single or mixed infections. Clinical signs are multiple, including mastitis, arthritis, keratoconjunctivitis, pneumonia, and septicemia, non-specific, and expressed differently depending whether sheep or goats are affected, on causative mycoplasmas as well as type of husbandry. CA has been reported worldwide and its geographic distribution maps to that of small ruminant breeding areas. However, as current diagnostic tests are expensive and difficult to implement, it is certainly underdiagnosed and prevalence data are only available for a few countries. CA control relies on vaccines, chemotherapy and good herd management practices. It requires long-term commitment but is often unsuccessful, with frequent clinical relapses. The persistence of the etiological agents, despite their overall susceptibility to antimicrobials, comes from their genetic plasticity and capacity to escape the host immune response. The existence of asymptomatic carriers and the numerous sources of infections contribute to rapid spread of the disease and complicate the control and prevention efforts. Here we review all these aspects in order to highlight recent progress made and identify gaps in knowledge or tools needed for better disease management. Discussion also underlines the detrimental effect of contagious agalactia on small ruminant welfare.

Addressing the Antimicrobial Resistance of Ruminant Mycoplasmas Using a Clinical Surveillance Network

“…There was a dominance of respiratory signs in cattle (201 samples on average, i.e., 89%) and sheep (65 samples on average, i.e., 81%). In goats, respiratory and mammary signs were the most frequent (both averaging 50 samples, i.e., 30% each), in line with contagious agalactia (CA) syndrome ( 4 ). However, clinical metadata were missing for around 30 goat specimens each year, and so the clinical picture was not fully complete.…”

“…Mycoplasma diseases are mostly controlled using antimicrobials ( 2 ). The ruminants sector is underserved with effective vaccines ( 3 , 4 ), which makes it doubly essential to preserve antimicrobial efficacy. Antimicrobial resistance (AMR) surveillance programs are key to the process, as they provide both early warning about potential emergence and a starting basis for adapting treatments in response to changes in resistance patterns ( 5 , 6 ).…”

Validation of Loop-Mediated Isothermal Amplification (LAMP) Field Tool for Rapid and Sensitive Diagnosis of Contagious Agalactia in Small Ruminants

“…Moreover, the real-time PCR price per test (in euro, excluding Value-Added Tax) was estimated to be 24 € compared to 15 € (excluding Value-Added Tax) of the LAMP test price. Current diagnostic methods, using sheep and goats milk samples, include a variety of M. agalactiae-specific PCR-based assays [20]. In literature, these methods all extensively reported to have a high sensitivity and accuracy with a detection limit between 10 to 350 CFU/ml [6,7,21,22]; a quite high level in comparison to our detection limits for both the methods (real-time PCR and LAMP).…”

Efflux Might Participate in Decreased Susceptibility to Oxytetracycline in Contagious Agalactia-Causative Mycoplasma spp.

“…Contagious agalactia (CA) is an infectious syndrome affecting small ruminants worldwide and especially countries in Southern Europe with large dairy industries. Its main clinical signs are mastitis, keratoconjunctivitis, and arthritis, but others such as pneumonia and septicemia have also been reported [ 1 ]. The negative economic impact of CA comes essentially from milk production loss and morbidity in young animals [ 2 ].…”