Kutamiswa kweMajini Akatsetseka muMabhakitiriya
Kutamisa majini (HGT) inzira yekufambisa majini pakati pezvisikwa zvisingaitike kuburikidza nenhaka kubva kumubereki kuenda kumwana (yakatwasuka), asi "inosvetuka" pakati pevanhu, kunyangwe pakati pemarudzi. Mumabhakitiriya, HGT ndeimwe yenzira dzakakosha dzekushanduka-shanduka nekuti inobvumira mabhakitiriya kukurumidza kuwana hunhu hutsva pasina kumirira nguva refu yekuchinja kwemuviri uye sarudzo yechisikigo. Mhedzisiro yayo yakakura: kubva pakubuda kwekusagona kurwisa mabhakitiriya, kuwedzera kwehutachiona hwehutachiona, kusvika pakubuda kwehunyanzvi hutsva hwemetabolism hunobatsira munzvimbo dzakaoma.
Sei HGT ichikosha mumabhakitiriya?
Mabhakitiriya anowanzo berekana asina kusangana pabonde kuburikidza ne binary fission. Mudzidziso, izvi zvinoita kuti kusiyana kwemajini ebhakitiriya kutsamire pakuchinja kwemajini. Zvisinei, muchokwadi, mabhakitiriya anogona "kuchinjana" majini kuburikidza ne HGT, zvichibvumira kusiyana kwemajini kuwedzera zvakanyanya munguva pfupi. HGT inobatsira mabhakitiriya kugadzirisa kushushikana kwezvakatipoteredza kwakadai sekuvapo kwemishonga inorwisa mabhakitiriya, shanduko mune zvinovaka muviri, kurwiswa nemasoja emuviri wemunhu, kana kukwikwidzana nemamwe mabhakitiriya.
Pahuwandu hwevanhu, HGT inobvumira mabhakitiriya kusanganisa hunhu hwakanaka hunobva kwakasiyana-siyana. Semuenzaniso, majini anogadzira ma enzymes anoputsa mishonga ine chepfu anogona kupararira pakati penharaunda dzemabhakitiriya dzinogara munzvimbo dzakasvibiswa. Mumamiriro ezvinhu ekiriniki, izvi zvinokonzera dambudziko guru nekuti majini asingarwisi mabhakitiriya anogona kutapurirana kubva kumabhakitiriya asina hutachiona kuenda kune ane hutachiona, zvichikonzera hutachiona hwakaoma kurapa.
Musiyano uripo pakati pekufambiswa kwemajini akatwasuka uye akatwasuka
Kutamiswa kwemajini akamira kunoitika kana majini achipfuudzwa kubva kumasero evabereki kuenda kumasero emwanasikana panguva yekupatsanurwa kwemasero. Patani yacho inenge iri "mhuri yemuti." Kusiyana neizvi, HGT yakafanana ne "network" nekuti majini anogona kufamba pakati pemadzinza akasiyana. Nekuda kweizvozvo, hukama hwephylogenetic pakati pemabhakitiriya dzimwe nguva hunonetsa kuziva kubva kujini rimwe chete, sezvo jini racho ringave rakabva kune chimwe chipenyu. Ichi ndicho chimwe chikonzero nei ongororo dzephylogenetic dzemabhakitiriya dzichiwanzoshandisa majini akawanda panguva imwe chete kana kushandisa majini chaiwo, anodzivirira.
Nzira nhatu huru dzeHGT mumabhakitiriya
Kazhinji, HGT mubhakitiriya inoitika kuburikidza nenzira nhatu huru: kushanduka, kuchinjika, uye kubatana. Imwe neimwe ine nzira dzakasiyana, zvinodiwa, uye mhedzisiro yehupenyu.
1. Kuchinja: kutora DNA kubva kunharaunda
Kuchinja-chinja inzira iyo mabhakitiriya anotora DNA isina chinhu kubva munzvimbo yaanogara oiisa mugenome yavo kana kuichengetedza seplasmid. DNA iyi isina chinhu inowanzobva kune mamwe masero ebhakitiriya akafa uye akaongororwa. Haasi mabhakitiriya ese anokwanisa kushanduka; mabhakitiriya anofanira kunge ari mumamiriro "ekugona", mamiriro chaiwo emuviri anobvumira DNA kutorwa.
Mienzaniso yemabhakitiriya anogona kushanduka-shanduka sechisikigo inosanganisira Streptococcus pneumoniae, Bacillus subtilis, uye Neisseria spp. Kushanduka kunogona kupa zvakanakira zvinochinjika, zvakaita sekuwana majini anoita kuti mabhakitiriya asanyanya kurwisa mabhakitiriya kana kubvumira kushandiswa kwezvimwe zvinhu zvine kabhoni. Mu biotechnology, kushanduka kunoshandiswawo kuunza recombinant plasmids mumabhakitiriya, akadai seEscherichia coli, kunyangwe kazhinji uchishandisa nzira dzekugadzira dzakadai sekupisa kana electroporation.
2. Kutapurirana: kutapurirana kwemajini kuburikidza nemabhakitiriya
Kuwedzerwa kweropa kunoitika kana hutachiona hunokanganisa mabhakitiriya (bacteriophage) hukatakura DNA yebhakitiriya netsaona kubva kumasero ebhakitiriya kuenda kune rimwe. Kune nzira mbiri huru dzekuwedzera ropa:
– Kuwedzerwa kwemasero: kunoitika kana phage iri mu lytic cycle "ichibatanidza" nechidimbu cheDNA yebhakitiriya, ichitsiva phage DNA nenzira isina kurongeka. Nekuda kweizvozvo, chero chidimbu chemajini ebhakitiriya chinogona kutakurwa.
– Kuwedzerwa kwemakemikari: kunoitika mumaphage anodziya anobatanidzwa mu genome rebhakitiriya (prophages). Kana prophage ikabuda (excises) isina kukwana, inogona kutakura majini ari pedyo nenzvimbo yekubatanidzwa.
Kuwedzerwa kwehutachiona mumasero eropa kunoita basa guru mukupararira kwemajini ane utachiona. Chepfu dzakawanda dzinozivikanwa dzebhakitiriya dzinonyorwa nemajini anotakurwa nemaphage, akadai sechepfu yediphtheria muCorynebacterium diphtheriae uye chepfu yeShiga mune mamwe marudzi eE. coli. Saka, hutachiona hwephage hunogona "kusimudzira" mabhakitiriya kuti ave nehutachiona hwakawanda.
3. Kubatana: Kutapurirana kweDNA kuburikidza nekubata zvakananga
Kubatana inzira yeHGT inosanganisira kusangana zvakananga pakati pemasero maviri ebhakitiriya, kazhinji kuburikidza nechimiro chakadai sepilus yebonde. Maitiro aya anowanzo tungamirirwa neplasmid inobatana, senge F plasmid muE. coli. Sero remupi rinotakura plasmid inobatana rinogona kugadzira bhiriji rekubatanidza uye kukopa DNA yeplasmid musero rinogamuchirwa. Zvinofadza kuti, kubatana hakungogumiri kumaplasmid chete; pasi pemamwe mamiriro ezvinhu, maplasmid anogona kuunganidza zvikamu zveDNA yechromosome (semuenzaniso, mumhando dzeHfr, nekuwedzera kwekubatana).
Kubatana kwakakosha mukupararira kwekusagona kurwisa mabhakitiriya nekuti majini mazhinji ekusagona kurwisa anowanikwa mumaplasmid anogona kutamira pakati pemabhakitiriya, kunyangwe pakati pemarudzi nemarudzi. Ichi ndicho chimwe chezvikonzero zvikuru zvekubuda kwemabhakitiriya asingashandise mishonga yakawanda (MDR) muzvipatara nenzvimbo dzakatikomberedza.
Zvinhu zvemajini zvinofamba zvinotsigira HGT
Kuwedzera kune nzira nhatu huru dziri pamusoro apa, HGT mumabhakitiriya inobatanidzwa zvakanyanya nezvinhu zvemajini zvinofamba, zvakaita se:
– Plasmids: DNA yakatenderera yekunze kwechromosome inowanzo takura majini ekusagona kurwisa mabhakitiriya, zvinhu zvinokonzera hutachiona, kana nzira dzakati dzekugadzirisa muviri.
– Transposons: "majini anosvetuka" anogona kufambisa nzvimbo mukati me genome kana pakati peplasmids nema chromosomes. Transposons dzinowanzo takura majini ekudzivirira.
– MaIntegrons: masisitimu anokwanisa kubata nekubudisa makaseti emajini, anowanzova nemajini asingapindire. MaIntegrons anoita basa guru mubhakitiriya rinoparira zvirwere.
– Zvitsuwa zveGenomic: zvikamu zvikuru zveDNA zvinowanikwa kuburikidza neHGT uye zvinogona kunge zvine majini ane hutachiona (zvitsuwa zvepathogenicity) kana kugona kwakakosha kwemetabolism.
Zvinhu izvi zvinoita kuti mabhakitiriya aite seane "mudziyo we modular" unogona kuwedzerwa kana kubviswa zvichienderana nezvinodiwa pakugadzirisa.
Mhedzisiro yeHGT: kubva pakushanduka-shanduka kusvika kuhutano hwevanhu
Kusakwanisa kurwisa mabhakitiriya
Nyaya inonyanya kukosha ine chekuita neHGT kupararira kwekusagona kurwisa mabhakitiriya. Majini akadai sebla (beta-lactamase), mecA (kusagona kurwisa methicillin muMRSA), kana majini emapombi emvura anogona kupararira nekukurumidza kuburikidza neplasmids uye transposons. Kana maantibiotics achishandiswa zvakanyanya (mumakiriniki, zvipfuyo, uye kurima), kumanikidzwa kwekusarudza kunowedzera, saka mabhakitiriya anowana majini ekusagona kurwisa kuburikidza neHGT achararama uye achatonga.
Hutachiona nehutachiona hutsva
HGT inokonzerawo kubuda kwemarudzi matsva ezvirwere. Mabhakitiriya anogona kuwana majini ekunamatira, kupinda, chepfu, kana masisitimu ekuburitsa, zvichiita kuti hutachiona hushande zvakanaka. Dzimwe nguva, mabhakitiriya aimbova asina njodzi anogona kuva hutachiona nekuda kwe "package" yemajini ane hutachiona kubva kuzvitsuwa zve genomic kana phages.
Kugadziriswa kwezvakatipoteredza uye kugadziriswa kwezvinhu zvipenyu
Kupfuura mushonga, HGT inobatsira mukuchengetedza hutachiona. Mabhakitiriya anogona kuwana kugona kwekuparadza mahydrocarbon, mishonga yezvipembenene, kana simbi dzinorema, nokudaro zvichibatsira mukugadzirisa zvinhu zvipenyu. Munzvimbo dzakanyanya kuipa, HGT inogona kuparadzira majini ane chekuita nekushivirira tembiricha yakakwira, munyu, kana pH yakanyanyisa.
Masayendisiti anodzidza sei nezveHGT?
HGT inodzidzwa kuburikidza nekuyedza murabhoritari uye ongororo ye genomic. Panyaya ye genomic, HGT inogona kuonekwa nekutsvaga mutsauko mukugadzirwa kwe base (semuenzaniso, GC content) inosiyana kubva ku main genome, kuvapo kwemajini akafanana neaya ezvisikwa zvine hukama huri kure, kana kuvapo kwezvinhu zvinofamba zvakaita se transposases. Kuongorora kwe phylogenetic kunogonawo kuratidza "kusawirirana" kana muti we evolutionary we gene usingaenderane nemuti we evolutionary wemhando yawo.
Penutup
Kutamiswa kwemajini akatambanudzwa mumabhakitiriya injini ine simba yekushanduka-shanduka. Kuburikidza nekushanduka, kuchinjirwa, uye kubatana—kunotsigirwa nemaplasmid, transposons, integrons, uye genomic islands—mabhakitiriya anokwanisa kukurumidza kuwana hunhu hutsva. Kune rumwe rutivi, HGT inobatsira mabhakitiriya kugadzirisa uye kuchengetedza mashandiro ezvisikwa zvehutachiona. Kune rumwe rutivi, HGT inokonzera dambudziko guru kuhutano hwevanhu nekukurumidzisa kupararira kwekusagona kurwisa mabhakitiriya uye zvinhu zvinokuvadza. Kunzwisisa mashandiro nemapatani eHGT kwakakosha pakugadzira nzira dzekudzivirira hutachiona, kushandiswa kwemishonga inorwisa mabhakitiriya zvine hungwaru, uye kugadzirwa kwemishonga mitsva yekugadzirisa hunhu hwebhakitiriya hunoramba huchichinja.
