On the Origin of American Tuberculosis

Biogeographic Perspectives on Human Genetic Diversification

Modern humans originated in Africa 300,000 yr ago, and before leaving their continent of origin, they underwent a process of intense diversification involving complex demographic dynamics. Upon exiting Africa, different populations emerged on the four other inhabited continents, shaped by the interplay of various evolutionary processes, such as migrations, founder effects, and natural selection. Within each region, continental populations, in turn, diversified and evolved almost independently for millennia. As a backdrop to this diversification, introgressions from archaic species contributed to establishing different patterns of genetic diversity in different geographic regions, reshaping our understanding of our species' variability. With the increasing availability of genomic data, it has become possible to delineate the subcontinental human population structure precisely. However, the bias toward the genomic research focused on populations from the global North has limited our understanding of the real diversity of our species and the processes and events that guided different human groups throughout their evolutionary history. This perspective is part of a series of articles celebrating 40 yr since our journal, Molecular Biology and Evolution, was founded (Russo et al. 2024). The perspective is accompanied by virtual issues, a selection of papers on human diversification published by Genome Biology and Evolution and Molecular Biology and Evolution.

Evidence of Cushing's syndrome in a pre-Columbian Mexican statue?

INTRODUCTION

In the absence of skeletons or written narrations, information about diseases in past societies may be acquired from icono-diagnosis. From the observation of a masterpiece presenting pathological features, we tried to make retrospective diagnosis.

MATERIAL AND METHOD

A pre-Columbian Mexican statuette originating from the Chupicuaro culture and dated 600 BC to 200 AD - conserved in the Louvre Museum in Paris (Section of the quai Branly - Jacques Chirac museum) was examined; it was found to display a huge spinal curvature with excessive dorsal kyphosis and obesity.

RESULTS

The appearance of the figurine with large head, shortened stature and limbs, may suggest a form of dwarfism; however, many statuettes in the Chupicuaro culture were found displaying large head and relatively short limbs, suggesting that these pictorial features are more of an artistic style. On the contrary, uncommon kyphosis and obesity led us to diagnose a case of either Pott disease associated with neuro-endocrine complications, or of Cushing's disease.

CONCLUSION

Although icono-diagnosis could have allowed us to contribute to the health mapping of ancient Americas and propose the presence of complicated tuberculosis in central Mexico between 600 BC and 200 AD, we believe "Choupi" portrays here an individual having suffered from hypercortisolism (Cushing's disease). Even though considerations related to cultural and artistic context may constitute limitations to interpretation, iconotopsy/iconodiagnosis are important for a better description of the natural history of diseases, as a complement to morphological analyses of human remains (paleopathology) and laboratory exams (DNA or immunology testing).

The pathway of tuberculosis in Argentina: Historical (19th and 20th centuries), epidemiological, and paleopathological data

OBJECTIVE

This paper explores the history of TB in Argentina from the pre- Columbian period to recent times in order to evaluate the impact of the industrialization (late 19th and early 20th centuries) on the increasing rates of this disease.

MATERIALS

Historical, paleopathological, and current epidemiological data were reviewed.

METHODS

Data were integrated under a paleopathological approach.

RESULTS

Skeletal evidence suggests the existence of TB before colonization. This is followed by two different periods of increasing TB rates: a probable but unconfirmed first stage, related to the contact between Europeans and natives during the 16th-18th centuries, and a second stage during the Industrial Revolution, from the 1880s to the 1950s, when it was finally controlled with the aid of chemotherapies.

CONCLUSIONS

TB rates increased during industrialization, coincident and probably related to immigration, the disorganized growth of cities, and bad working conditions. Nowadays, TB is under control in the general population, but it remains an important health problem in areas with poor living conditions and in immunocompromised patients.

SIGNIFICANCE

This is the first study that integrates archaeological, historical and epidemiological data to acknowledge the pathway of TB in Argentina.

LIMITATIONS

No skeletal evidence of TB from 19th and 20th centuries and from medical archives from sanatoria are available.

SUGGESTIONS FOR FURTHER RESEARCH

Further research needs to be conducted from these records, in order to improve the current knowledge of TB during the industrialization period in Argentina.

Prior pandemics. looking to the past for insight into the COVID-19 pandemic

COVID-19 is not the world's first pandemic, not its worst, or likely to be its last. In fact, there have been many pandemics throughout history with lessons for the current one. The most destructive pandemic of all time, at least in terms of the number of people killed in the shortest time, was the “Spanish flu“ pandemic of 1918/1919. Why did it happen? What lessons did it teach us? And could it happen again? These questions are addressed in the context of the current COVID-19 pandemic and several other nearly equally devastating pandemics of earlier times

Tuberculosis Genetic Epidemiology: A Latin American Perspective

There are an estimated 10 million new cases of tuberculosis worldwide annually, with 282,000 new or relapsed cases each year reported from the Americas. With improvements in genome sequencing technology, it is now possible to study the genetic diversity of tuberculosis with much greater resolution. Although tuberculosis bacteria do not engage in horizontal gene transfer, the genome is far more variable than previously thought. The study of genome-wide variation in tuberculosis has improved our understanding of the evolutionary origins of tuberculosis, the arrival of tuberculosis in Latin America, the genetic determinants of drug resistance, and lineage-specific associations with important clinical phenotypes. This article reviews what is known about the arrival of tuberculosis in Latin America, the genetic diversity of tuberculosis in Latin America, and the genotypic determinants of clinical phenotypes.

Insights from paleomicrobiology into the indigenous peoples of pre-colonial America - a review

This review investigates ancient infectious diseases in the Americas dated to the pre-colonial period and considers what these findings can tell us about the history of the indigenous peoples of the Americas. It gives an overview, but focuses on four microbial pathogens from this period: Helicobacter pylori, Mycobacterium tuberculosis, Trypanosoma cruzi and Coccidioides immitis, which cause stomach ulceration and gastric cancer, tuberculosis, Chagas disease and valley fever, respectively. These pathogens were selected as H. pylori can give insight into ancient human migrations into the Americas, M. tuberculosis is associated with population density and urban development, T. cruzi can elucidate human living conditions and C. immitis can indicate agricultural development. A range of methods are used to diagnose infectious disease in ancient human remains, with DNA analysis by polymerase chain reaction one of the most reliable, provided strict precautions are taken against cross contamination. The review concludes with a brief summary of the changes that took place after European exploration and colonisation.

Co-evolution of Mycobacterium tuberculosis and Homo sapiens

The causative agent of human tuberculosis (TB), Mycobacterium tuberculosis, is an obligate pathogen that evolved to exclusively persist in human populations. For M. tuberculosis to transmit from person to person, it has to cause pulmonary disease. Therefore, M. tuberculosis virulence has likely been a significant determinant of the association between M. tuberculosis and humans. Indeed, the evolutionary success of some M. tuberculosis genotypes seems at least partially attributable to their increased virulence. The latter possibly evolved as a consequence of human demographic expansions. If co-evolution occurred, humans would have counteracted to minimize the deleterious effects of M. tuberculosis virulence. The fact that human resistance to infection has a strong genetic basis is a likely consequence of such a counter-response. The genetic architecture underlying human resistance to M. tuberculosis remains largely elusive. However, interactions between human genetic polymorphisms and M. tuberculosis genotypes have been reported. Such interactions are consistent with local adaptation and allow for a better understanding of protective immunity in TB. Future 'genome-to-genome' studies, in which locally associated human and M. tuberculosis genotypes are interrogated in conjunction, will help identify new protective antigens for the development of better TB vaccines.

Human and tuberculosis co-evolution: An integrative view

Tuberculosis (TB) ranks as the second cause of death from an infectious disease worldwide after HIV. Archaeogenetics and evolutionary scenario for the Mycobacterium tuberculosis complex (MTBC) are in favor of a long-term interaction between tuberculosis and humans, predating the Neolithic period, contrary to the traditional belief. If tuberculosis evolved as a human pathogen in Africa and has spread outside Africa about more than ten-thousand years ago, its life history traits have been shaped by the immune system. Numerous studies described a variety of human susceptibility factors to TB, suggesting that MTBC strains have evolved different ways to overcome this system. However, the results of these studies reveal some inconsistencies even within populations. The temporally varying history of epidemics and ever-varying genetic diversity of pathogens and strains could easily contribute to blur out signal of selection in our human genome. Palaeomicrobiology gives the opportunity to genotype ancient TB strains circulating in past populations. Accessing ancient human pathogens allows us to a better understanding of infectious agents over a longer time scale and confrontation with the dynamic of modern TB strains. Nevertheless, we have to consider tuberculosis as a multifactorial disorder in which environmental factors interact tightly with human and pathogen genetic.

Mycobacterium tuberculosis complex lipid virulence factors preserved in the 17,000-year-old skeleton of an extinct bison, Bison antiquus

Tracing the evolution of ancient diseases depends on the availability and accessibility of suitable biomarkers in archaeological specimens. DNA is potentially information-rich but it depends on a favourable environment for preservation. In the case of the major mycobacterial pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, robust lipid biomarkers are established as alternatives or complements to DNA analyses. A DNA report, a decade ago, suggested that a 17,000-year-old skeleton of extinct Bison antiquus, from Natural Trap Cave, Wyoming, was the oldest known case of tuberculosis. In the current study, key mycobacterial lipid virulence factor biomarkers were detected in the same two samples from this bison. Fluorescence high-performance liquid chromatography (HPLC) indicated the presence of mycolic acids of the mycobacterial type, but they were degraded and could not be precisely correlated with tuberculosis. However, pristine profiles of C₂₉, C₃₀ and C₃₂ mycocerosates and C₂₇ mycolipenates, typical of the Mycobacterium tuberculosis complex, were recorded by negative ion chemical ionization gas chromatography mass spectrometry of pentafluorobenzyl ester derivatives. These findings were supported by the detection of C₃₄ and C₃₆ phthiocerols, which are usually esterified to the mycocerosates. The existence of Pleistocene tuberculosis in the Americas is confirmed and there are many even older animal bones with well-characterised tuberculous lesions similar to those on the analysed sample. In the absence of any evidence of tuberculosis in human skeletons older than 9,000 years BP, the hypothesis that this disease evolved as a zoonosis, before transfer to humans, is given detailed consideration and discussion.