Insertion element IS 1296 in Mycoplasma mycoides subsp. mycoides small colony identifies a European clonal line distinct from African and Australian strains

Abstract

Strains of Mycoplasma mycoides subsp. mycoides small colony (SC) type, the agent of contagious bovine pleuropneumonia (CBPP), were analysed with respect to the polymorphism of distribution of a newly discovered insertion element, lS1296, on the chromosome. Analysis of 64 strains isolated from Europe, Africa and Australia, including four vaccine strains and the type strain PG1, revealed ten different IS patterns, forming two main clusters. The European strains originated from outbreaks of CBPP in different countries, and from various other sources such as semen and preputial washings from cattle, lungs from goats and buffalo, and milk from sheep. They showed identical IS1296 patterns, except one strain which had an additional IS1296 element, but the pattern belonged to the same cluster. This shows that the strains from Europe form a clonal lineage. The strains originating from different geographical parts of the African continent and from Australia showed four closely related IS1296 patterns which belong to a separate cluster. This indicates that strains from Africa and Australia form a clonal lineage different from that of the European strains, suggesting that the sporadic cases of CBPP that have re-emerged in Europe almost 15 years after the last declared endemic case in 1967 arose from an established reservoir within Europe rather than being the result of repeated importation from Africa and Australia. While most strains from Africa and Australia had the same IS1296 pattern, all vaccine strains could be distinguished by an individual pattern. The type strain PG1 also had a particular IS1296 pattern which belongs to the cluster of the strains from Africa and Australia. The molecular definition of clonality of M. mycoides subsp. mycoides SC strains with IS1296 represents a rapid and reproducible method for subtyping and differentiation of vaccine strains. It permits at the present time the definition of two main clonal lines, one including the strains from the European continent and a second with strains from Africa and Australia.

Etudes expérimentales sur l'efficacité des souches vaccinales T1 sr et T1/44 de <em>Mycoplasma mycoides</em> spp. <em>mycoides</em> (petite colonie) contre un isolat causant la péripneumonie contagieuse bovine au Kenya - Effet d'une infection de rappel

“…These trials had a precise objective: evaluate the protection afforded by a single injection at the minimum dose required by international standards, i.e., 10 7 viable mycoplasmas per dose (14) for T1sr and T1/44 strains by a contact challenge performed three months after the vaccination. These trials were to be performed in three different African locations, Cameroon, Kenya and Namibia, in order to take into account the genetic variability of the MmmSC strains that could be correlated to a modification of the potency of the vaccine (1,17). In addition, a second protocol was designed in Kenya to assess the protection afforded one year after vaccination.…”

Genotyping ofMycoplasma mycoidessubsp.mycoidesSC by multilocus sequence analysis allows molecular epidemiology of contagious bovine pleuropneumonia

“…The evidence of multiple copies of insertion elements present in the MmmSC genome allowed the development of new typing tools based on Southern blot hybridisation. The use of IS1296 as a probe allowed the clear differentiation of recent European strains from those of African origin [7]. The observed difference was explained later on by the identification of an 8.8 kbp deletion in the genome of most MmmSC strains of European origin [43], resulting in a missing IS1296 band.…”

Antigenic and genetic characterisation of lipoprotein lppC from Mycoplasma mycoides subsp. mycoides SC

“…These reemerging outbreaks in Europe were due to a particular cluster of M. mycoides subsp. mycoides SC strains which were not present on other continents, as observed by IS1296 typing [7]. In this respect, small ruminants have been proposed as possible reservoirs of the pathogen [22,25].…”

“…Mycoplasmal cultures were grown in a standard mycoplasma medium [4] to a density of 10 8 -10 9 cells/mL. Crude lysate preparations with GES buffer (5 M guanidium thiocyanate, 100 mM EDTA, 0.5% N-lauroylsarcosine) and DNA extraction were performed as previously described [7].…”