Abstract
The Bacillus anthracis virulence plasmid pXO2, which encodes for a polypeptide capsule, can be lost during long term laboratory storage. To determine if pXO2 is lost in nature we screened B. anthracis isolates obtained from B. anthracis spores from contaminated animal burial sites in Turkey for their ability to express a capsule upon primary culture. A total of 672 B. anthracis colonies were examined of which ten produced a mixed mucoid (capsule +ve)/non-mucoid (capsule −ve) phenotype and a further one colony yielded non-mucoid colonies upon repeated culture. Screening by PCR using pXO2 specific primers revealed that seven of these isolates had eliminated the plasmid. Of the four colonies which were positive by PCR, one regained the ability to express a capsule upon repeated culture suggesting that the defect was reversible. This is an important observation as capsule expression is a principal marker of virulence and in the absence of PCR serves as a key diagnostic marker. The results of this preliminary study suggest that pXO2 is lost in nature and that further studies are need to determine the mechanisms by which this occurs.
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References
Bellan SE, Turnbull PC, Beyer W et al (2013) Effects of experimental exclusion of scavengers from carcasses of anthrax-infected herbivores on Bacillus anthracis sporulation, survival, and distribution. Appl Environ Microbiol 79:3756–3761. doi:10.1128/AEM.00181-13
Bowen JE, Quinn CP (1999) The native virulence plasmid combination affects the segregational stability of a theta-replicating shuttle vector in Bacillus anthracis var New Hampshire. J Appl Microbiol 87:270–278. doi:10.1046/j.1365-2672.1999.00885.x
Buyuk F, Sahin M, Cooper C et al (2015) The effect of prolonged storage on the virulence of isolates of Bacillus anthracis obtained from environmental and animal sources in the Kars Region of Turkey. FEMS Microbiol Lett 362(13):102. doi:10.1093/femsle/fnv102
Dey R, Hoffman PS, Glomski IJ (2012) Germination and amplification of anthrax spores by soil-dwelling Amoebas. Appl Environ Microbiol 78:8075–8081. doi:10.1128/AEM.02034-12
Dragon DC, Rennie R (1995) The ecology of anthrax spores: tough but not invincible. Can Vet J 36:295–301
Hugh-Jones M, Blackburn J (2009) The ecology of Bacillus anthracis. Mol Asp Med 30:356–367. doi:10.1016/j.mam.2009.08.003
Marston CK, Hoffmaster AR, Wilson KE et al (2005) Effects of long-term storage on plasmid stability in Bacillus anthracis. Appl Environ Microbiol 71:7778–7780. doi:10.1128/AEM.71.12.7778-7780.2005
Saile E, Koehler TM (2006) Bacillus anthracis multiplication, persistence and genetic exchange in the rhizosphere of grass plants. Appl Environ Microbiol 72:1674–3168. doi:10.1128/AEM.72.5.3168-3174.2006
Smith KL, DeVos V, Bryden H et al (2000) Bacillus anthracis diversity in Kruger National Park. J Clin Microbiol 38:3780–3784
Turnbull PCB, Hutson RA, Ward MJ et al (1992) Bacillus anthracis but not always anthrax. J Appl Bacteriol 72:21–28. doi:10.1111/j.1365-2672.1992.tb04876.x
Wang H, Liu X, Feng E et al (2011) Curing the plasmid pXO2 from Bacillus anthracis A16 using plasmid incompatibility. Curr Microbiol 62:703–709
Funding
This work was supported by the Defence Science and Technology Laboratory (DSTLX-1000085195).
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Callum Cooper and Fatih Buyuk are Co-first authors.
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Cooper, C., Buyuk, F., Schelkle, B. et al. Virulence plasmid stability in environmentally occurring Bacillus anthracis from North East Turkey. Antonie van Leeuwenhoek 110, 167–170 (2017). https://doi.org/10.1007/s10482-016-0767-5
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DOI: https://doi.org/10.1007/s10482-016-0767-5