Mycoplasma suis infection in suckling pigs on a Belgian farm

Mycoplasma suis (formerly known as Eperythrozoon suis) is an epicellular bacterium that affects porcine red blood cells. M. suis infections occur worldwide and are associated with weakness and anemia in suckling and weaned pigs, and reproductive disorders in sows. The present field report describes the detection of M. suis in anemic piglets originating from a Belgian farrow-to-finish herd. The herd was experiencing increased piglet mortality (16%) in the farrowing unit and had a high percentage of repeat breeders (22%). A control program using antimicrobials and hygienic and sanitary measures significantly decreased the number of clinically anemic piglets and the mortality rate in the farrowing unit. However, it did not have any significant influence on the reproductive failure of the farm. The lack of a significant effect on reproductive failure was probably due to the circulation of porcine reproductive and respiratory syndrome virus (PRRSV) on the farm

Evaluation of amplified rDNA restriction analysis (ARDRA) for the identification of Mycoplasma species

BACKGROUND: Mycoplasmas are present worldwide in a large number of animal hosts. Due to their small genome and parasitic lifestyle, Mycoplasma spp. require complex isolation media. Nevertheless, already over 100 different species have been identified and characterized and their number increases as more hosts are sampled. We studied the applicability of amplified rDNA restriction analysis (ARDRA) for the identification of all 116 acknowledged Mycoplasma species and subspecies. METHODS: Based upon available 16S rDNA sequences, we calculated and compared theoretical ARDRA profiles. To check the validity of these theoretically calculated profiles, we performed ARDRA on 60 strains of 27 different species and subspecies of the genus Mycoplasma. RESULTS: In silico digestion with the restriction endonuclease AluI (AG^CT) was found to be most discriminative and generated from 3 to 13 fragments depending on the Mycoplasma species. Although 73 Mycoplasma species could be differentiated using AluI, other species gave undistinguishable patterns. For these, an additional restriction digestion, typically with BfaI (C^TAG) or HpyF10VI (GCNNNNN^NNGC), was needed for a final identification. All in vitro obtained restriction profiles were in accordance with the calculated fragments based on only one 16S rDNA sequence, except for two isolates of M. columbinum and two isolates of the M. mycoides cluster, for which correct ARDRA profiles were only obtained if the sequences of both rrn operons were taken into account. CONCLUSION: Theoretically, restriction digestion of the amplified rDNA was found to enable differentiation of all described Mycoplasma species and this could be confirmed by application of ARDRA on a total of 27 species and subspecies