Kusamutsa Majini Molunjika mu Mabakiteriya
Kusamutsa majini mopingasa (HGT) ndi njira yosamutsira zinthu za majini pakati pa zamoyo zomwe sizimachitika kudzera mu cholowa kuchokera kwa kholo kupita kwa ana (choyima), koma m'malo mwake "zimadumphadumpha" pakati pa anthu, ngakhale pakati pa mitundu. Mu mabakiteriya, HGT ndi imodzi mwa njira zofunika kwambiri zosinthira chifukwa imalola mabakiteriya kukhala ndi makhalidwe atsopano mwachangu popanda kudikira nthawi yayitali ya kusintha kwadzidzidzi ndi kusankha kwachilengedwe. Zotsatira zake zimakhala zosiyanasiyana: kuyambira pakuwonekera kwa kukana maantibayotiki, kuwonjezeka kwa mphamvu ya tizilombo toyambitsa matenda, mpaka kuonekera kwa mphamvu zatsopano za kagayidwe kachakudya zothandiza m'malo ovuta kwambiri.
Nchifukwa chiyani HGT ndi yofunika kwambiri mu mabakiteriya?
Mabakiteriya nthawi zambiri amaberekana mosagonana pogwiritsa ntchito kugawanika kwa binary. M'malingaliro, izi zimalola kusintha kwa majini a bakiteriya kudalira kusintha kwa majini. Komabe, kwenikweni, mabakiteriya amatha "kusinthana" majini kudzera mu HGT, zomwe zimapangitsa kuti kusintha kwa majini kuchuluke kwambiri pakapita nthawi yochepa. HGT imathandiza mabakiteriya kuti azitha kusintha momwe zinthu zilili monga kukhalapo kwa maantibayotiki, kusintha kwa zakudya, kuukira kwa chitetezo cha mthupi cha munthuyo, kapena mpikisano ndi tizilombo tina.
Pa mlingo wa anthu ambiri, HGT imalola mabakiteriya kuphatikiza makhalidwe apamwamba ochokera ku magwero osiyanasiyana. Mwachitsanzo, majini omwe amalemba ma enzymes omwe amaphwanya mankhwala oopsa amatha kufalikira pakati pa magulu a mabakiteriya omwe amakhala m'malo oipitsidwa. Pankhani yachipatala, izi zimayambitsa vuto lalikulu chifukwa majini okana maantibayotiki amatha kusamutsa kuchokera ku mabakiteriya omwe si opatsirana kupita ku omwe amafalikira, zomwe zimapangitsa kuti matenda omwe ndi ovuta kuchiza.
Kusiyana pakati pa kusamutsa majini mopingasa ndi mopingasa
Kusamutsa majini olunjika kumachitika majini akamadutsa kuchokera ku maselo a makolo kupita ku maselo aakazi panthawi yogawa maselo. Kapangidwe kake ndi "mtengo wa banja." Mosiyana ndi zimenezi, HGT ili ngati "network" chifukwa majini amatha kusuntha pakati pa mizere yosiyanasiyana. Zotsatira zake, ubale wa phylogenetic pakati pa mabakiteriya nthawi zina umakhala wovuta kudziwa kuchokera ku jini imodzi, chifukwa jiniyo mwina inachokera ku chamoyo china. Ichi ndi chimodzi mwa zifukwa zomwe kusanthula kwa phylogenetic ya mabakiteriya nthawi zambiri kumagwiritsa ntchito majini angapo nthawi imodzi kapena kugwiritsa ntchito majini enaake, osunga nthawi.
Njira zitatu zazikulu za HGT m'mabakiteriya
Kawirikawiri, HGT mwa mabakiteriya imachitika kudzera m'njira zitatu zazikulu: kusintha, kusintha kwa maselo, ndi kulumikizana. Iliyonse ili ndi njira zosiyana, zofunikira, ndi zotsatira za zamoyo.
1. Kusintha: kutenga DNA kuchokera ku chilengedwe
Kusintha ndi njira imene mabakiteriya amatenga DNA yamaliseche kuchokera m'malo awo ndikuyiyika mu genome yawo kapena kuisunga ngati plasmid. DNA yamaliseche iyi nthawi zambiri imachokera ku maselo ena a bakiteriya omwe adafa ndikusinthidwa. Si mabakiteriya onse omwe amatha kusintha; mabakiteriya ayenera kukhala mu mkhalidwe "waluso", mkhalidwe wapadera wa thupi womwe umalola DNA kutengedwa.
Zitsanzo za mabakiteriya omwe angasinthe mwachilengedwe ndi monga Streptococcus pneumoniae, Bacillus subtilis, ndi Neisseria spp. Kusintha kungapereke ubwino wosinthika, monga kupeza majini omwe amapangitsa mabakiteriya kukhala osagonjetsedwa ndi maantibayotiki kapena kulola kugwiritsa ntchito magwero enaake a kaboni. Mu biotechnology, kusintha kumagwiritsidwanso ntchito kuyambitsa ma plasmid obwerezabwereza m'mabakiteriya, monga Escherichia coli, ngakhale nthawi zambiri amagwiritsa ntchito njira zopangira monga kutentha kapena electroporation.
2. Kutumiza: kusamutsa majini kudzera mu bacteriophages
Kupatsa munthu kachilombo kamene kamafalitsa mabakiteriya (bacteriophage) mwangozi kamatenga DNA ya bakiteriya kuchokera ku selo imodzi ya bakiteriya kupita ku ina. Pali mitundu iwiri ikuluikulu ya kupereka munthu kachilomboka:
– Kutumiza kwa majini kwachibadwa: kumachitika pamene phage mu lytic cycle "ikuyika" chidutswa cha DNA ya bakiteriya, m'malo mwa DNA ya phage mwachisawawa. Zotsatira zake, chidutswa chilichonse cha majini a bakiteriya chimakhala ndi kuthekera konyamulidwa.
– Kupereka kwapadera: kumachitika mu ma phage otentha omwe amalumikizana ndi genome ya bakiteriya (prophages). Pamene prophage ituluka (excises) mokwanira, imatha kunyamula majini omwe ali pafupi ndi malo olumikizirana.
Kutumiza mabakiteriya kumachita gawo lofunika kwambiri pakufalikira kwa majini oopsa. Mabakiteriya ambiri odziwika bwino amalembedwa ndi majini omwe amanyamulidwa ndi ma phage, monga poizoni wa diphtheria mu Corynebacterium diphtheriae ndi poizoni wa Shiga m'mitundu ina ya E. coli. Chifukwa chake, matenda a phage amatha "kukweza" mabakiteriya kuti akhale oopsa kwambiri.
3. Kulumikizana: Kusamutsa DNA kudzera mu kukhudzana mwachindunji
Kulumikizana ndi njira ya HGT yomwe imaphatikizapo kukhudzana mwachindunji pakati pa maselo awiri a bakiteriya, nthawi zambiri kudzera mu kapangidwe monga pilus yogonana. Njirayi nthawi zambiri imachitika ndi plasmid yolumikizana, monga F plasmid mu E. coli. Selo lopereka lomwe limanyamula plasmid yolumikizana limatha kupanga mlatho wolumikizana ndikukopera DNA ya plasmid mu selo lolandira. Chochititsa chidwi n'chakuti, kulumikizana sikuti nthawi zonse kumakhala kwa ma plasmid okha; pansi pa mikhalidwe ina, ma plasmid amatha kusonkhanitsa magawo a DNA ya chromosome (monga, mu mitundu ya Hfr, yokhala ndi nthawi yayitali yolumikizana).
Kulumikizana n'kofunika kwambiri pakufalikira kwa kukana mankhwala opha tizilombo chifukwa majini ambiri okana mankhwala amakhala pa ma plasmid omwe amatha kusamutsa mabakiteriya pakati pa mabakiteriya, ngakhale pakati pa mitundu ndi mitundu. Ichi ndi chimodzi mwa zifukwa zazikulu zomwe zimayambitsa kufalikira kwa mabakiteriya osagwiritsa ntchito mankhwala ambiri (MDR) m'zipatala ndi m'malo ozungulira.
Zinthu za majini zoyenda zomwe zimathandiza HGT
Kuwonjezera pa njira zitatu zazikulu zomwe zili pamwambapa, HGT mu mabakiteriya imakhudzidwa kwambiri ndi zinthu za majini zoyenda, monga:
– Ma plasmids: DNA yozungulira ya extra-chromosome yomwe nthawi zambiri imakhala ndi majini okana maantibayotiki, zinthu zomwe zimayambitsa matenda, kapena njira zinazake za kagayidwe kachakudya.
– Transposons: “majini odumphadumpha” omwe amatha kusuntha malo mkati mwa genome kapena pakati pa ma plasmid ndi ma chromosome. Ma Transposons nthawi zambiri amakhala ndi majini okana.
– Ma Integrons: machitidwe omwe amatha kugwira ndi kutulutsa makaseti a majini, nthawi zambiri amakhala ndi majini okana. Ma Integrons amagwira ntchito yayikulu mu mabakiteriya omwe amapatsira matenda.
– Zilumba za genomic: zigawo zazikulu za DNA zomwe zimapezeka kudzera mu HGT ndipo zitha kukhala ndi majini a virulence (zilumba za pathogenicity) kapena mphamvu zapadera za kagayidwe kachakudya.
Zinthu zimenezi zimapangitsa mabakiteriya kuoneka ngati ali ndi "chipangizo chowongolera" chomwe chingawonjezedwe kapena kuchotsedwa malinga ndi zosowa zosinthira.
Zotsatira za HGT: kuyambira pa kusintha kwa zinthu kupita ku thanzi la anthu
Kukana maantibayotiki
Nkhani yofunika kwambiri yokhudzana ndi HGT ndi kufalikira kwa kukana mankhwala opha tizilombo. Majini monga bla (beta-lactamase), mecA (kukana methicillin mu MRSA), kapena majini a mapampu a efflux amatha kufalikira mwachangu kudzera mu plasmids ndi transposons. Pamene maantibayotiki amagwiritsidwa ntchito kwambiri (m'zipatala, ziweto, ndi ulimi), kuthamanga kwa kusankha kumawonjezeka, kotero mabakiteriya omwe amapeza majini okana kudzera mu HGT adzapulumuka ndi kulamulira.
Kachirombo ndi tizilombo toyambitsa matenda atsopano
HGT imayambitsanso kubuka kwa mitundu yatsopano ya tizilombo toyambitsa matenda. Mabakiteriya amatha kupeza majini kuti amamatire, kulowa, poizoni, kapena kutulutsa madzi, zomwe zimathandiza kuti matenda azitha kugwira bwino ntchito. Nthawi zina, mabakiteriya omwe kale anali osavulaza amatha kukhala tizilombo toyambitsa matenda chifukwa cha "phukusi" la majini oopsa ochokera ku zilumba za genomic kapena phages.
Kusintha kwa chilengedwe ndi kukonzanso zachilengedwe
Kupatula mankhwala, HGT ndi yothandiza pa zachilengedwe za tizilombo toyambitsa matenda. Mabakiteriya amatha kukhala ndi mphamvu yowononga ma hydrocarbon, mankhwala ophera tizilombo, kapena zitsulo zolemera, motero zimathandiza njira zokonzanso zinthu. M'malo ovuta kwambiri, HGT imatha kufalitsa majini okhudzana ndi kulekerera kutentha kwambiri, mchere, kapena pH yoopsa.
Kodi asayansi amaphunzira bwanji za HGT?
HGT imaphunziridwa kudzera mu zoyeserera za labotale ndi kusanthula majini. Mwa majini, HGT imatha kuzindikirika pofufuza kusiyana kwa kapangidwe ka maziko (monga kuchuluka kwa GC) komwe kumasiyana ndi majini akuluakulu, kukhalapo kwa majini omwe ali ofanana kwambiri ndi a zamoyo zokhudzana ndi kutali, kapena kukhalapo kwa zinthu zoyenda monga transposases. Kusanthula kwa phylogenetic kungawululenso "zosagwirizana" pamene mtengo wosinthika wa jini sugwirizana ndi mtengo wosinthika wa mtundu wake.
Kutseka
Kusamutsa majini m'mabakiteriya mopingasa ndi injini yamphamvu yosinthira zinthu. Kudzera mu kusintha, kusintha majini, ndi kulumikizana—kothandizidwa ndi ma plasmids, transposons, integrons, ndi zilumba za genomic—mabakiteriya amatha kupeza makhalidwe atsopano mwachangu. Kumbali imodzi, HGT imathandiza mabakiteriya kusintha ndikusunga mphamvu za chilengedwe cha tizilombo toyambitsa matenda. Kumbali ina, HGT imabweretsa vuto lalikulu pa thanzi la anthu pofulumizitsa kufalikira kwa kukana maantibayotiki ndi zinthu zoopsa. Kumvetsetsa njira ndi machitidwe a HGT ndikofunikira kwambiri popanga njira zowongolera matenda, kugwiritsa ntchito bwino maantibayotiki, komanso kupanga njira zatsopano zothanirana ndi kusintha kwa mabakiteriya nthawi zonse.
