Saturday, April 21, 2012

Leishmania mexicana

     Today, I helped a friend attempt to catch woodrats (Neotoma micropus) and sandflies. She is working on her thesis....she's on the hunt for a particular parasite.  This parasite isn't a big problem in this area, but it is a problem in other areas. She's looking to see if it is here...and for good reason. In 2007, dermatologists in Dallas, Texas diagnosed NINE cases of cutaneous leishmaniasis...but we will get to that later. First things first, taxonomy!

L. mexicana Promastigote
     This parasite is a protist withing the excavate clade. Leishmania in the phylum Euglenozoa....which contains the commonly known free-living Euglena; an elegant example of a flagellate often found in pond scum.  Leishmania belongs in class Kinetoplastida and order Trypanosomatida alongside other trypanosomes such as Trypanosoma cruzi (which causes Chagas' disease) and Trypanosoma gambiense (which causes sleeping sickness).  The genus, Leishmania, has many pathogenic species. The Leishmania donovani species complex causes the most terrible form of this disease, which is known as visceral leishmaniasis (a.k.a. "Kala-Azar"). Leishmania braziliensis causes mucocutaneous leishmaniasis. Many other species cause cutaneous leishmaniasis, but only one is found in the new world....this is Leishmania mexicana.

L. mexicana Amastigote (in green)

Life Cycle
     The life cycle of this organism involves two body forms. An infected female sandfly takes a blood meal from an uninfected human. During this feeding, Leishmania mexicana promastigotes make their way into their new host's blood stream. As the body's immune system goes to work, macrophages ingest the promastigotes. While inside of the macrophages, the promastigotes transform into an amastigote form (the green ovoid organism in the picture on the right). The amastigotes reproduce within the macrophages and other cells. Then, along comes an innocent, uninfected female sandfly hungry for a delicious blood meal. As the sandfly sucks the blood of the infected human, she ingests the infected macrophages. Once inside of the sandfly, the amastigotes burst from the macrophages and transform into the promastigote stage within the midgut of the sandfly. Then the promastigotes migrate to the proboscis of the fly, where they await for the fly to have its next blood meal...completing the life cycle.

Cutaneous and Diffused Cutaneous Leishmaniasis
     These forms of leishmaniasis are less dangerous than visceral forms. The cutaneous form manifests as ulcers at the site where the sandfly bites its host. In this form, the amastigotes don't spread to other areas. The ulcers show up anywhere from a few days to a few months post-infection. This form usually heals on its own given time. 

     The diffused form of cutaneous leishmaniasis only manifests after the amastigotes cutaneously spread due to defective immune cells (such as T-cells). This can cause sores and ulcers all over the body that do not respond well to drugs. Penstostam is a drug that is often used in the US to treat this form of leishmaniasis. Penstostam works by inhibiting ATP synthesis.  There is ongoing research into vaccine development that works against the promastigote life stage.
     These diseases are typically only found in Central and South America. However, there have been cases reported right here in Texas. Cases began appearing in South Texas years ago, but it wasn't until the last few years that it was reported further north. In 2007, nine different cases were reported from around the Dallas area. Researchers believe that sandflies infect woodrats as they search for blood meals. These woodrats then become what we call a "reservoir". This means that they are able to serve as a sort of storage space for the propagation of the Leishmania mexicana protozoans without a human host. This keeps the protists circulating in the sandflies, making them potential disease vectors.

Moral of the Story
     There is strong evidence to suggest that if sandflies and woodrats are present, so could be present this parasite. People in rural areas are more at risk despite the sandflies' recent movements into more urban areas. Using insect repellants will reduce the risk of being bitten, so keep that in mind the next time you head out to the boonies! :p


  1. Hi there,

    I'm a grad student working at UT on Leishmania mexicana too! Could you put me in touch with your friend doing the rodent sampling?

    Stavana Strutz

  2. Hey Stavana! I'm sorry I'm just now seeing this comment. The last few months have been pretty crazy and I didn't even think to check for comments until today. (I know, what a crappy excuse!) Anyway, I gave my friend your e-mail address. I hope you hear from her soon! Also, while I have you on here, what are you doing for your research project? is your work going? Thanks for posting! We hope to hear from you again soon!

  3. Ejakulasi dini ialah urusan seksual yg dialami oleh laki laki. Ejakulasi dini yakni keadaan di mana laki-laki menyusun air mani, sebentar sesudah melaksanakan penetrasi ke pada pepek. faktor ini pasti saja, mengadakan ketidakpuasaan seksual terhadap pasangannya.

    satu orang laki laki menggondol ejakulasi dini ditandai dgn terjadinya ejakulasi pada wahid menit sesudah jalankan penetrasi ke vagina.

    Penyebab ejakulasi dini umumnya disebabkan oleh 2 aspek :

    1.Faktor psikologis
    sekian banyak penyigian mengekspresikan, bahwa penyebab penting terjadinya ejakulasi dini disebabkan oleh elemen psikologis. di mana laki laki merasa resah, sebab bimbang tak sanggup menurunkan kepuasaan guna pasangan. Berikut ini yaitu sekian banyak perihal psikologis lain yg bisa memunculkan terjadinya ejakulasi dini:

    2.Disfungsi ereksi
    Disfungsi ereksi umumnya disebabkan lantaran laki-laki merasa khawatir guna sanggup membentengi ereksi sewaktu pertalian seksual. faktor tertera kian dapat mencetak susunan pikir bagi serentak ejakulasi.

    Peringatan : Sekali lagi apabila anda merasa artikel ana belum terang atau ada hal lain, sehingga kamu dapat klik Chat Online, di mana profesional saya dapat menjawab keluhan kamu, atau hubungi nomer (021)-62303060. Klinik Apollo Jakarta mengharapkan mudah-mudahan kamu selalu sembuh.

    Klinik Apollo Andrologi | Pengobatan kulup panjang

    Metode sunat klinik apollo | Sunat modern biaya terjangkau

    Dokter spesialis | Free Chat

  4. Bagaimana mengobati kencing nanah tanpa obat?

    Mengobati kencing nanah tanpa obat mungkin sangat kecil kemungkinan yang bisa dilakukan dengan cara ini. Karena jika anda menderita penyakit maka anda harus melakukan pemeriksaan dan pengobatan dengan dokter yang tentunya akan diberikan obat yang sesuai dengan penyebabnya.
    Apa yang anda rasakan jika anda terkena atau terinfeksi penyakit menular seksual ini?

    1. Stress, Malu, Takut di Kucilkan
    2. Putus asa
    3. Malu untuk melakukan pemeriksaan dengan dokter

    "Jika anda merasakan gejala atau tanda2 kencing nanah, jangan merasa malu untuk melakukan pemeriksaan. segera lakukan pengobatan secepat mungkin untuk membantu anda agar terhindar dari infeksi penyakit lain yang dapat di timbulkan dari penyakit kencing nanah."
    Silahkan konsultasikan keluhan yang anda rasakan pada kami. Klinik apollo merupakan salah satu klinik sepesialis kulit dan klamin terbaik di jakata. Ditunjang tekhnologi modern serta dokter yang sudah berpengalaman dibidangnya, kami dapat membantu memberikan solusi untuk keluhan penyakit kelamin yang anda rasakan.

    Kunjungi halaman facebook kami di : Klinik Spesialis Kelamin Apollo

    Kulup panjang | Kulup bermasalah tidak usah mau sunat

    Ejakulasi dini bisa sembuh | Sunat dewasa di klinik apollo

    Chat | Klini chat