Evidence of tetracycline use in ancient Nubia

Associating the use of antibiotics primarily with modern medicine, I was intrigued to read a newspaper article which suggested that one of the ancient populations of Nubia had regularly consumed tetracycline, most likely imbibing it in their beer.

Led by George Armelagos, an anthropologist from Atlanta, and Mark Nelson, a medicinal chemist from Boston, the research highlighted in the article was published in the American Journal of Physical Anthropology.

According to this research, evidence for the use of tetracycline goes back almost 2,000 years. Such evidence has been derived over the past 30 years from examination of bone samples from several archaeological sites in Sudanese Nubia, Egypt and Jordan using fluorescent microscopy.

Initial reports of ancient tetracycline use were at first met with scepticism and suggestions that the tetracycline-like fluorescence observed in Nubian bone was the result of post-mortem deterioration by soil bacteria and fungi.

In this latest research, previously recovered bone samples from a cemetery on the West bank of the Nile were subject to a different method in an attempt to provide better evidence for the presence of the antibiotic.

The bones were those of a Nubian population who lived 350–550 years before the Christian era and who cultivated the floodplains of the Nile. This burial site has since been flooded after the latest construction that raised the height of the dam at Aswan.

As in the earlier work, the bone samples were first viewed by fluorescence microscopy. The patterns that emerged were observed to be similar to the patterns found in tetracycline-labelled bone in modern clinical settings.

In addition, the researchers write that the bone chosen was in an excellent state of preservation, possessing no visual evidence of bacterial or fungal contamination either on the surface or internally.

What the researchers did next was to extract and isolate the bone-complexed tetracycline and then chemically characterise it using HPLC-MS (high pressure liquid chromatography coupled with mass spectroscopy).

This analytical technique confirmed the presence of tetracycline in the bones in a concentration that suggested more than just a single accidental exposure to the antibiotic through, for example, a one-time event of bacterial contamination of grain or other foodstuffs.

The researchers think that this ancient Nubian population was skilled in the science of fermentation and that they could have produced gruels or beer fermentations containing Streptomyces or other bacterial species that imparted pharmacological effects.

The concentration of tetracycline detected in the bone samples suggests that these mixtures were produced deliberately using active culture or previous fermentation broth. For example, the tibia and skull belonging to a four-year-old were found to be saturated with tetracycline, suggesting that they may have been giving high doses to the child to try to cure an illness.

The researchers now plan to determine the dosage of tetracycline that the ancient Nubians were using.