Presence of Helicobacter pylori in a Mexican Pre-Columbian Mummy

Abstract

Background: Recent studies showed that Helicobacter pylori existed in the New World prior to the arrival of Columbus. The purpose of the present study was to detect the presence of Helicobacter pylori in pre-Columbian mummies from Northern Mexico.

Methods: Six samples were studied (four samples of gastric remains, tongue-soft palate, and brain remained as negative controls) from two of the six naturally mummified corpses studied (adult male and infant male). Samples were taken from tissues suitable for DNA amplification by Polymerase chain reaction (PCR). DNA was extracted and H. pylori detection was carried out by PCR and hybridized with the pHp probe from 16S rRNA gene. The purified PCR products were cloned and sequenced in both directions. DNA sequences were analyzed with ALIGN and BLAST software. A second amplification was performed using ureB gene by real-time PCR.

Results: From four samples of gastric remnant, only two were H. pylori-positive for amplification of a 109 bp DNA fragment; the remaining two were negative, as were the tongue-soft palate and the brain biopsies as well. These PCR products were hybridized with a pHp probe. Nucleotide sequence analysis showed homology with H. pylori in 98 of 99% when compared with the gene bank nucleotide sequence. Only one sample of gastric remnant H. pylori-positive with 16S rRNA gene was also positive for ureB gene from H. pylori.

Conclusion: This data supported infection with H. pylori in Mexican pre-Columbian mummies dating from approximately 1,350 AC.

Figure 1

Mexican Pre-Columbian mummies. Yellow box showed the mummy that was Helicobacter pylori-positive.

Figure 2

Polymerase chain reaction (PCR) amplification and hybridization of biopsy samples. A) PCR products of the 109-bp fragment of 16S rRNA obtained from H. pylori. Line: 1) gastric remains I; 2) gastric remains II; 3) tongue-soft palate; 4) brain; 5) H. pylori ATCC 43504; 6) H. pylori 84–183, and 7) negative control reaction. M = Molecular weight marker (100-bp DNA ladder). B) Hybridization of PCR products with pHp probe.

Figure 3

Sequence alignment of the 16S rRNA gene obtained from three clones of mummy 2.

Figure 4

Sequence alignment of 16S rRNA gene obtained from mummy 2 compared with H. pylori strain using BLASTN.

Figure 5

ureB gene detection of H. pylori by real-time PCR using Taqman probe. Control positive are a fragment of 97 bp from ureB gene of H. pylori 26695 (ATCC 700392) cloned in pPCR-TOPO 2.1 (Invitrogen). High and low positive control equivalent to approximately 6 × 10⁶ and 60 copies of the ureB gene, respectively.

Figure 6

Histological examinations of gastric remains of a Mexican mummy with hematoxin-eosin stain. A) 4×; B) 10×; C) 40×, and D) 100×.