\nYersinia pestis, bacteria care provoac\u0103 ciuma, a terorizat omenirea de-a lungul secolelor, ucig\u00e2nd peste 200 milioane de persoane pe plan mondial \u015fi duc\u00e2nd la izbucnirea a dou\u0103 epidemii \u00eengrozitoare, \u00een secolele al VI-lea e.n. \u015fi al XIV-lea e.n.<\/p>\n
\n\u00cens\u0103 aceast\u0103 bacterie nu a fost dintotdeauna at\u00e2t de periculoas\u0103. Oamenii de \u015ftiin\u0163\u0103 americani au anun\u0163at, mar\u0163i, c\u0103 o serie de modific\u0103ri genetice minore care s-au produs \u00een urm\u0103 cu multe secole – prin intermediul unei singure gene care a suferit o muta\u0163ie – au transformat aceast\u0103 bacterie \u00eentr-un uciga\u015f \u00een serie.<\/p>\n
\nYersinia pestis a cauzat dou\u0103 dintre cele mai distrug\u0103toare pandemii din istoria omenirii: Ciuma lui Iustinian, din secolul al VI-lea, denumit\u0103 astfel dup\u0103 \u00eemp\u0103ratul bizantin care, de\u015fi s-a \u00eemboln\u0103vit, a reu\u015fit s\u0103 supravie\u0163uiasc\u0103, \u015fi Moartea Neagr\u0103, din secolul al XIV-lea. \u015eobolanii purt\u0103tori de puricii care transportau bacteria uciga\u015f\u0103 au contribuit la r\u0103sp\u00e2ndirea bolii \u00een r\u00e2ndul oamenilor.<\/strong><\/p>\n \nSavan\u0163ii americani au realizat teste pe \u015foareci pentru a retrasa evolu\u0163ia acelor modific\u0103ri genetice ale bacteriei.<\/p>\n \nEi au preluat o form\u0103 ancestral\u0103 a bacteriei care circul\u0103 \u015fi ast\u0103zi \u00een lume – izolat\u0103 la nivelul unui roz\u0103tor din Asia asem\u0103n\u0103tor \u015foarecelui – \u015fi au inserat-o \u00eentr-o gen\u0103 denumit\u0103 Pla, care este implicat\u0103 \u00een dizolvarea cheagurilor sangvine. Aceast\u0103 ad\u0103ugire a ajutat bacteria s\u0103 produc\u0103 infec\u0163ii pulmonare fatale.<\/strong><\/p>\n \nO muta\u0163ie similar\u0103, realizat\u0103 cu multe secole \u00een urm\u0103, au transformat bacteria Yersinia pestis dintr-un agent patogen ce cauza infec\u0163ii gastrointestinale moderate \u00eentr-unul care a provocat o boal\u0103 respiratorie fatal\u0103, denumit\u0103 pest\u0103 pulmonar\u0103.<\/p>\n \nOamenii de \u015ftiin\u0163\u0103 au descoperit, de asemenea, c\u0103 o singur\u0103 muta\u0163ie a aceleia\u015fi gene – o muta\u0163ie prezent\u0103 \u015fi \u00een tulpinile din epoca modern\u0103 ale bacteriei – a permis acesteia s\u0103 se r\u0103sp\u00e2ndeasc\u0103 \u00een organism \u015fi s\u0103 invadeze nodulii limfatici, a\u015fa cum se \u00eent\u00e2mpl\u0103 \u00een cazul ciumei bubonice.<\/p>\n \nCiuma lui Iustinian a ucis \u00eentre 20 de milioane \u015fi 50 de milioane de oameni, iar Moartea Neagr\u0103 a omor\u00e2t cel pu\u0163in 150 de milioane de persoane, spune expertul \u00een microbiologie Wyndham Lathem, de la Universitatea Northwestern din Chicago, coordonatorul acestui studiu ce a fost publicat \u00een revista Nature Communications.<\/p>\n \nSavantul american spune c\u0103 este dificil de identificat cu precizie momentul \u00een care bacteria, care \u015fi-a ad\u0103ugat \u015fi a eliminat diverse gene de-a lungul timpului, a inclus \u00een structura ei gena Pla, dar “aproape sigur acest lucru s-a \u00eent\u00e2mplat \u00een urm\u0103 cu cel pu\u0163in 1.500 de ani”. Astfel, acea includere a genei Pla \u00een genomul bacteriei Yersinia pestis s-ar fi produs cu un secol \u00eenainte de Ciuma lui Iustinian.<\/p>\n","protected":false},"excerpt":{"rendered":" C\u00e2teva modific\u0103ri genetice minore au transformat bacteria Mor\u0163ii Negre – una dintre cele mai grave pandemii din istoria omenirii – dintr-un agent patogen cu o virulen\u0163\u0103 moderat\u0103 \u00eentr-un veritabil uciga\u015f \u00een serie, potrivit unui studiu realizat recent \u00een Statele Unite.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[510],"tags":[22895,40959],"class_list":["post-123888","post","type-post","status-publish","format-standard","hentry","category-actualitate","tag-bacterie","tag-moartea-neagra"],"_links":{"self":[{"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=\/wp\/v2\/posts\/123888","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=123888"}],"version-history":[{"count":0,"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=\/wp\/v2\/posts\/123888\/revisions"}],"wp:attachment":[{"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=123888"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=123888"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bm.dev.synology.me\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=123888"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}