Concepts of macro- and microevolution as related to the problem of origin and global expansion of the plague pathogen Yersinia pestis

Suntsov, V. V.; Suntsova, N. I.

doi:10.1134/s1062359008040018

Cited by 14 publications

(6 citation statements)

References 8 publications

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“…In this study, it was found that the marmot Marmota sibirica and the flea Oropysilla silantiewi comprise subsequent host species for the pseudotuberculosis microbe Yersinia pestis tarbagani . Thermotaxis triggers the parasitic flea to move from the litter (where they usually live) onto the hibernating marmot in response a drop in the host temperature, resulting in the transfer of the microbe (Suntsov & Suntsova 2008). The immuno‐inactive ‘cold’ blood of torpid marmots (5 °C) provides favourable conditions for the optimal reproduction of the microbe (4–8 °C).…”

Section: Discussionmentioning

confidence: 99%

Energetic costs of the immune response and torpor use in a primate

Canale¹,

Henry

2010

Functional Ecology

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Summary1. Resource-limiting conditions impose a change in the energetic distribution between competing physiological processes. Over the past decade there has been increasing interest in trade-offs between the immune system and competing energy-consuming life-history traits. However, the trade-offs with energy saving mechanisms, such as heterothermy, have received limited attention. 2. The goal of this study is to determine how daily heterothermy expression could be adjusted to counterbalance the energetic requirements for the activation of the immune system depending on food availability (ad libitum vs. 40% calorie restriction) in a heterothermic primate, the Grey Mouse Lemur (Microcebus murinus). 3. On the day of the immune challenge, torpor was removed through the onset of fever, inducing a thermogenic cost. On the days following, food-restricted individuals returned to deep torpor (i.e. energy saving) whereas those fed ad libitum continued to skip torpor for at least three additional days. 4. The rapid return to an energy saving state in food restricted individuals raises new questions on the relationship between body temperature and immunocompetence. We suggest that (i) hyperthermia provides the first line of defence against pathogens, which is a trait common to all organisms, (ii) but that hypothermia may also protect the host by inhibiting pathogen proliferation.

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Section: Discussionmentioning

confidence: 99%

Energetic costs of the immune response and torpor use in a primate

Canale¹,

Henry

2010

Functional Ecology

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“…Accordingly, mortality became an essential part of the life cycle of Y. pestis and selective pressure caused by the necessity for lethality has undoubtedly favoured subsequent increases in virulence. As a consequence, plague bacilli became efficient pathogens and have recently disseminated from ancient foci in central Asia to reservoirs throughout the world, where they now cause acute disease in a large number of animal species including man (Suntsov & Suntsova, 2008). The virulence of these potential 'epidemic' isolates contrasts sharply with 'enzootic' strains (including pestoides variants) of Y. pestis that remain contained within the original reservoirs where the species evolved (Anisimov et al, 2004;Martinevskii, 1969).…”

Section: Introductionmentioning

confidence: 99%

Attenuated enzootic (pestoides) isolates of Yersinia pestis express active aspartase

et al. 2009

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It is established that Yersinia pestis, the causative agent of bubonic plague, recently evolved from enteropathogenic Yersinia pseudotuberculosis by undergoing chromosomal degeneration while acquiring two unique plasmids that facilitate tissue invasion (pPCP) and dissemination by fleabite (pMT). Thereafter, plague bacilli spread from central Asia to sylvatic foci throughout the world. These epidemic isolates exhibit a broad host range including man as opposed to enzootic (pestoides) variants that remain in ancient reservoirs where infection is limited to muroid rodents. Cells of Y. pseudotuberculosis are known to express glucose-6-phosphate dehydrogenase (Zwf) and aspartase (AspA); these activities are not detectable in epidemic Y. pestis due to missense mutations (substitution of proline for serine at amino position 155 of Zwf and leucine for valine at position 363 of AspA). In this study, functional Zwf was found in pestoides strains E, F and G but not seven other enzootic isolates; enzymic activity was associated with retention of serine at amino acid position 155. Essentially, full AspA activity occurred in pestoides isolates where valine (pestoides A, B, C and D) or serine (pestoides E, F, G and I) occupied position 363. Reduced activity occurred in strains Angola and A16, which contained phenylalanine at this position. The k cat but not K m of purified AspA from strain Angola was significantly reduced. In this context, aspA of the recently described attenuated enzootic microtus biovar encodes active valine at position 363, further indicating that functional AspA is a biomarker for avirulence of Y. pestis in man.

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“…BEARDEN AND BRUBAKER gens and have now disseminated from ancestral foci in Central Asia and perhaps Africa to reservoirs throughout the world where they cause lethal disease in many animal species, including humans (Suntsov and Suntsova 2008). The virulence of these potential ''epidemic'' isolates contrasts markedly with ''enzootic'' strains of Y. pestis (also termed ''pestoides'' variants) that remain contained within their original reservoirs (Martinevskii 1969, Anisimov et al 2004.…”

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confidence: 98%

Recent Findings Regarding Maintenance of Enzootic Variants ofYersinia pestisin Sylvatic Reservoirs and Their Significance in the Evolution of Epidemic Plague

Bearden

Brubaker

2010

Vector-Borne and Zoonotic Diseases

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Despite the widespread presence of bubonic plague in sylvatic reservoirs throughout the world, the causative agent (Yersinia pestis) evolved in its present form within the last 20,000 years from enteropathogenic Yersinia pseudotuberculosis. Comparison of the genomes from the two species revealed that Y. pestis possesses only a few unique plasmid-encoded genes that contribute to acute disease, whereas this organism has lost about 13% of the chromosomal genes that remain active in Y. pseudotuberculosis. These losses reflect readily detectable additions, deletions, transpositions, inversions, and acquisition of about 70 insertion sequence (IS) inserts, none of which are likely to promote increased virulence. In contrast, major enzymes of intermediary metabolism, including glucose 6-phosphate dehydrogenase (Zwf ) and aspartase, are present but not catalytically functional due to the presence of missense mutations. The latter are generally not detectable by the technology of bioinformatics and, in the case of Y. pestis, result in radical changes in the metabolic flow of carbon. As an important consequence, plague bacilli exhibit a stringent low-calcium response characterized by conversion of L-glutamate (and metabolically related amino acids) to L-aspartate with secretion of the latter into supernatant fluid at 37 degrees C in culture media containing Na(+) but lacking added Ca(2+). This phenomenon also occurs in vivo and likely adversely affects the bioenergetics of host amino acid pools. Curiously, aspartase is functional in all tested enzootic (pestoides) strains of Y. pestis. These isolates are typically restricted to the ancient plague reservoirs of Central Asia and Africa and are fully virulent in members of the rodent Superfamily Muroidea but avirulent in guinea pigs and man. The implications of these findings for the distribution and ecology of Y. pestis could be significant.

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Concepts of macro- and microevolution as related to the problem of origin and global expansion of the plague pathogen Yersinia pestis

Cited by 14 publications

References 8 publications

Energetic costs of the immune response and torpor use in a primate

Energetic costs of the immune response and torpor use in a primate

Attenuated enzootic (pestoides) isolates of Yersinia pestis express active aspartase

Recent Findings Regarding Maintenance of Enzootic Variants ofYersinia pestisin Sylvatic Reservoirs and Their Significance in the Evolution of Epidemic Plague

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