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Amerindian Helicobacter pylori strains go extinct, as european strains expand their host range.

Domínguez-Bello MG, Pérez ME, Bortolini MC, Salzano FM, Pericchi LR, Zambrano-Guzmán O, Linz B - PLoS ONE (2008)

Bottom Line: We found that all strains that had been cultured from Africans were African strains (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos.If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear.This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Puerto Rico, San Juan, Puerto Rico, USA.

ABSTRACT
We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori strains would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes) of 131 strains: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all strains that had been cultured from Africans were African strains (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori strains were hspAmerind. Strains hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination). The lower genetic structure in hpEurope strains is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear. This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts.

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Mosaic structure of the multilocus H. pylori sequences in representative strains.The ancestral source of each polymorphic nucleotide is shown by a vertical line for each of the seven gene fragments in the multilocus analysis of 10 representative strains from each group (see the legend below Mestizo strains). Individual nucleotides were derived from ancestral Europe1 (grey), ancestral Europe2 (green), ancestral Africa1 (blue) and ancestral EastAsia (yellow). Nucleotides not assigned with >50% probability to any one population are indicated by white lines. African and European components can be observed in hpEurope strains from Spaniards and Mestizos, as well as in hpAfrica1 from Mestizos, while African hpAfrica1 strains and Amerindian hspAmerind strains tested were largely homogeneous.
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pone-0003307-g003: Mosaic structure of the multilocus H. pylori sequences in representative strains.The ancestral source of each polymorphic nucleotide is shown by a vertical line for each of the seven gene fragments in the multilocus analysis of 10 representative strains from each group (see the legend below Mestizo strains). Individual nucleotides were derived from ancestral Europe1 (grey), ancestral Europe2 (green), ancestral Africa1 (blue) and ancestral EastAsia (yellow). Nucleotides not assigned with >50% probability to any one population are indicated by white lines. African and European components can be observed in hpEurope strains from Spaniards and Mestizos, as well as in hpAfrica1 from Mestizos, while African hpAfrica1 strains and Amerindian hspAmerind strains tested were largely homogeneous.

Mentions: The bacterial strains were assigned to populations according to their multilocus DNA sequences: those from African hosts yielded only hpAfrica1, those from Spanish yielded hpEurope and those from Koreans yielded hspEAsia (Table 1). However, Huitoto and Guahibo Amerindians yielded both hspAmerind and hpEurope strains, and Mestizos yielded hpEurope and hpAfrica1, but not hspAmerind. The least and most diverse strains of H. pylori populations were hspAmerind and hpEurope, respectively (Figure 2A). Nonetheless, when grouping the strains by host, strain diversity in Amerindians increased to the levels found in Spanish and Mestizo hosts (Figure 2B), consistently with the circulation of mixed strains (Table 1) and with the remarkable mosaicism reflected in the multilocus sequences (Figure 3). As stated previously [7], [26], the ancestry patterns of modern hpEurope strains revealed extensive recombination between the two ancestral populations ancestral Europe1 and ancestral Europe2. Spanish H. pylori (Figure 3) further include components from ancestral hpAfrica1, which possibly reflects the role Africa has played in shaping the Spanish modern human gene pool. Traces of African bacterial ancestry were also detected in strains from Mestizos and Amerindians. The observed mosaicism reflects extensive recombination and results in lower genetic structure.


Amerindian Helicobacter pylori strains go extinct, as european strains expand their host range.

Domínguez-Bello MG, Pérez ME, Bortolini MC, Salzano FM, Pericchi LR, Zambrano-Guzmán O, Linz B - PLoS ONE (2008)

Mosaic structure of the multilocus H. pylori sequences in representative strains.The ancestral source of each polymorphic nucleotide is shown by a vertical line for each of the seven gene fragments in the multilocus analysis of 10 representative strains from each group (see the legend below Mestizo strains). Individual nucleotides were derived from ancestral Europe1 (grey), ancestral Europe2 (green), ancestral Africa1 (blue) and ancestral EastAsia (yellow). Nucleotides not assigned with >50% probability to any one population are indicated by white lines. African and European components can be observed in hpEurope strains from Spaniards and Mestizos, as well as in hpAfrica1 from Mestizos, while African hpAfrica1 strains and Amerindian hspAmerind strains tested were largely homogeneous.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2551748&req=5

pone-0003307-g003: Mosaic structure of the multilocus H. pylori sequences in representative strains.The ancestral source of each polymorphic nucleotide is shown by a vertical line for each of the seven gene fragments in the multilocus analysis of 10 representative strains from each group (see the legend below Mestizo strains). Individual nucleotides were derived from ancestral Europe1 (grey), ancestral Europe2 (green), ancestral Africa1 (blue) and ancestral EastAsia (yellow). Nucleotides not assigned with >50% probability to any one population are indicated by white lines. African and European components can be observed in hpEurope strains from Spaniards and Mestizos, as well as in hpAfrica1 from Mestizos, while African hpAfrica1 strains and Amerindian hspAmerind strains tested were largely homogeneous.
Mentions: The bacterial strains were assigned to populations according to their multilocus DNA sequences: those from African hosts yielded only hpAfrica1, those from Spanish yielded hpEurope and those from Koreans yielded hspEAsia (Table 1). However, Huitoto and Guahibo Amerindians yielded both hspAmerind and hpEurope strains, and Mestizos yielded hpEurope and hpAfrica1, but not hspAmerind. The least and most diverse strains of H. pylori populations were hspAmerind and hpEurope, respectively (Figure 2A). Nonetheless, when grouping the strains by host, strain diversity in Amerindians increased to the levels found in Spanish and Mestizo hosts (Figure 2B), consistently with the circulation of mixed strains (Table 1) and with the remarkable mosaicism reflected in the multilocus sequences (Figure 3). As stated previously [7], [26], the ancestry patterns of modern hpEurope strains revealed extensive recombination between the two ancestral populations ancestral Europe1 and ancestral Europe2. Spanish H. pylori (Figure 3) further include components from ancestral hpAfrica1, which possibly reflects the role Africa has played in shaping the Spanish modern human gene pool. Traces of African bacterial ancestry were also detected in strains from Mestizos and Amerindians. The observed mosaicism reflects extensive recombination and results in lower genetic structure.

Bottom Line: We found that all strains that had been cultured from Africans were African strains (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos.If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear.This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Puerto Rico, San Juan, Puerto Rico, USA.

ABSTRACT
We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori strains would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes) of 131 strains: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all strains that had been cultured from Africans were African strains (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori strains were hspAmerind. Strains hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination). The lower genetic structure in hpEurope strains is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear. This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts.

Show MeSH