Armadillo Questions 1. Taking

1)

Mycobacterium leprae, the bacterial cause of leprosy,is almost impossible to culture in a laboratory (Slonczewski,2009). M. leprae is an acid fast gram positive bacillus(Slonczewski, 2009). M. leprae has one of the slowestdoubling times of any pathogen. It takes approximately 14 days forthe cells to divide (Slonczewski, 2009). M. leprae iseasily detected on Fite-Faraco staining (Ooi,2004). M.leprae is from the same genus as Mycobacteriumtuberculosis; the two species have similar physicalcharacteristics and similar genomes.

The genome for M. leprae has been sequenced, and it has been foundthat almost half of the genes are pseudogenes; genes that no longercode for proteins to be transcribed in the cell (Cole, 2001). Manyof these pseudogenes correspond to genes found in Mycobacteriumtuberculosis that are still functional (Cole, 2001). The loss ofthese genes have caused M. leprae to rely on the host cellto survive. The bacteria needs an extremely specific environment tothrive in.

It is extremely difficult to culture Mycobacterium leprae.All attempts to create a medium that the bacteria are able to growin has failed. Scientists have found that the bacteria can onlygrow when acting as a parasite in animals with lower bodytemperature, such as armadillos, genetically immune deficient mice,or the extremities of a human body (Slonczewski 2009). Aramadillosare used predominantly as a host for the bacteria, but the animalsare difficult to work with, thus making animal research onMycobacterium leprae slow and complicated (Wheeler, 2002).Scientists are still attempting to create a media that will supportgrowth of the bacteria to increase the ease of studying it.

M. leprae has plagued mankind since ancient times. Leprosywas one of the most terrifying diseases in history due to the largeopen sores and deformations it caused. Hundreds of thousands ofpeople died each year from leprosy until drugs were found thatcould combat it. Antibiotics have helped to decrease the number ofcases of leprosy, but poorer areas around the world still haveproblems with this disease. In 2004, there were approximately50,000 new cases of infection.

2)

The diagnosis of leprosy is primarily a clinical one. In oneEthiopian study, the following criteria had a sensitivity of 94%with a positive predictive value of 98% in diagnosing leprosy.Diagnosis was based on one or more of three signs:

1. Hypopigmented or reddish skin patches with definite loss ofsensation
2. Thickened peripheral nerves
3. Acid-fast bacilli on skin smears or biopsy material

3)

1895, Hansen and Looft made the initial observation regardingthe possibility of environmental factors involved in thetransmission of leprosy [24]. They suggested that the initial siteof cutaneous lesions often involved sites with direct contact withenvironmental surfaces (e.g., wading in streams and rivers inpatients with lesions in calves). Subsequently, 27 years afterHansen’s description of M. leprae, Sand proposed that thetransmission of leprosy between humans takes place indirectly. Hisfindings were the result of analyzing 1221 patients in theNorwegian leprosarium of Reitgjaerdet in whom the transmissionwithin household was relatively low and most cases occurred in menwho had more contact with environmental sources. He furtherproposed that perhaps a living organism or ground containingdecomposing material were factors involved in the transmissioncycle [25].

Environmental factors such as climate, type of soil and water,environmental degree of acidity [20], etc.; along with spillover ofM. leprae from human cases (e.g., nasal dischargescontaminating soil or water) may facilitate the amplification ofthe transmission cycle in biotopes with existing suitableecological abiotic and biotic determinants (i.e., tropical andsubtropical settings) [34, 35]. In this hypothetical model, we canpostulate that chemoprophylaxis (or preemptive treatment) ofcontacts of multibacillary cases and effective treatment of leprosycases decreases spillage of M. leprae into environmentalreservoirs (soil, water, plants, or free-living amoebas) [24, 25,27]. Preliminary evidence from a leprosy-endemic area in India hasshown that genetic material of M. leprae was detected nearwashing and bathing areas where cases of leprosy were detected andgenetic fingerprinting correlated between human cases and DNAdetected in soil samples [24, 29]. The spillover of M.leprae into soil and water may explain the acquisition of thispathogen by armadillos acting as scavengers, and ultimately linkinga reverse cycle of transmission from armadillos back to humans[32]. Nevertheless, it is possible that there are otherunidentified environmental reservoirs or vectors influencing theoccurrence of new human infections in highly endemic areas.Zoonotic transmission of M. leprae from armadillos in theGolf Coast of the United States contributes to endemic humaninfections detected in this geographic area every year, supportingthe fact that leprosy is not exclusively transmittedperson-to-person .

4) Do people really eat armadillos? It may seemlike an odd question, but the answer is “Yes”. In many areas ofCentral and South America, armadillo meat is oftenused as part of an average diet. Armadillo meat isa traditional ingredient in Oaxaca, Mexico.

The risk of getting leprosy from an armadillois low because most people who get exposed don’t get sick with theancient scourge, known medically as Hansen’s disease and now easilytreatable. … They think it requires frequenthandling of armadillos or eatingtheir meat for leprosy to spread.

Dust armadillo meat in flour, salt, and pepper.Brown on both sides in the butter. Put enough water in pot to coverafter adding remaining vegetables. Cover and simmer until meat istender, about 2 hours

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