ИЗУЧЕНИЕ ПОПУЛЯЦИЙ ПАТОГЕННЫХ ЛИСТЕРИЙ В

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ÑÅËÜÑÊÎÕÎÇßÉÑÒÂÅÍÍÀß ÁÈÎËÎÃÈß, 2014, ¹ 4, ñ. 30-34
ÓÄÊ 579.64:579.61/.62:579.26
doi: 10.15389/agrobiology.2014.4.30rus
ÈÇÓ×ÅÍÈÅ ÏÎÏÓËßÖÈÉ ÏÀÒÎÃÅÍÍÛÕ ËÈÑÒÅÐÈÉ Â ÎÁÚÅÊÒÀÕ
ÎÊÐÓÆÀÞÙÅÉ ÑÐÅÄÛ Ñ ÈÑÏÎËÜÇÎÂÀÍÈÅÌ ÑÊÀÍÈÐÓÞÙÅÉ
ÝËÅÊÒÐÎÍÍÎÉ ÌÈÊÐÎÑÊÎÏÈÈ
È.Á. ÏÀÂËÎÂÀ, Ä.À. ÁÀÍÍÈÊÎÂÀ, À.Á. ÊÎÍÎÍÅÍÊÎ
 îòíîøåíèè ðÿäà èíôåêöèîííûõ çàáîëåâàíèé, âûçûâàåìûõ ïàòîãåííûìè è óñëîâíîïàòîãåííûìè áàêòåðèÿìè, ïðîèñõîäèò ïîñòåïåííûé ïåðåñìîòð ìåñòà âîçáóäèòåëÿ â ðàçëè÷íûõ
ýêîñèñòåìàõ, àêòóàëüíûìè îñòàþòñÿ âîïðîñû ðàñïðîñòðàíåíèÿ, àäàïòàöèè, ñïîñîáíîñòè èõ æèçíåííûõ ôîðì ê ðàçâèòèþ â ïîïóëÿöèÿõ â ñðåäå îáèòàíèÿ. Èçâåñòíî, ÷òî ëèñòåðèè óñòîé÷èâû ê
âíåøíèì ôàêòîðàì, ïðè ýòîì ñóùåñòâåííî ó÷àñòèëèñü ñëó÷àè ïåðåäà÷è ëèñòåðèîçà ñ ðàñòèòåëüíûìè ïðîäóêòàìè. Îäíàêî äàííûå îá ýêîëîãè÷åñêèõ àñïåêòàõ ñóùåñòâîâàíèÿ âîçáóäèòåëÿ ëèñòåðèîçà îãðàíè÷åíû. Îäíî èç ïåðñïåêòèâíûõ íàïðàâëåíèé â èçó÷åíèè ýêîëîãèè ïàòîãåííûõ áàêòåðèé ― ïîïóëÿöèîííûé ïîäõîä, îñíîâàííûé íà èññëåäîâàíèè êîëîíèé áàêòåðèé, à íå îòäåëüíîé
êëåòêè.  ñòàòüå ïðèâåäåíû äàííûå ýêñïåðèìåíòàëüíûõ èññëåäîâàíèé, ïðîâåäåííûõ ñ ïðèìåíåíèåì ìåòîäà ñêàíèðóþùåé ýëåêòðîííîé ìèêðîñêîïèè, ïîçâîëÿþùèì àíàëèçèðîâàòü êîëîíèè áàêòåðèé áåç íàðóøåíèÿ èõ åñòåñòâåííîé àðõèòåêòîíèêè. Âûïîëíåíî ñðàâíåíèå ìîðôîëîãè÷åñêèõ
îñîáåííîñòåé ïîïóëÿöèé ëèñòåðèé â øèðîêîì äèàïàçîíå òåìïåðàòóð (îò −18 äî 37 °Ñ) â ðàçëè÷íûõ îáúåêòàõ ñðåäû îáèòàíèÿ, òàêèõ êàê ìîëî÷íûå è ìÿñíûå ïðîäóêòû, êîðìà, âîäà, çåëåíûå
ðàñòåíèÿ. Ìîðôîëîãè÷åñêàÿ ïëàñòè÷íîñòü êëåòîê ëèñòåðèé è îñîáåííîñòè ñóùåñòâîâàíèÿ ïîïóëÿöèé ëèñòåðèé â îêðóæàþùåé ñðåäå ïðîäåìîíñòðèðîâàíû íà ïðèâåäåííûõ ñêàíîãðàììàõ. Ïîêàçàíî, ÷òî ëèñòåðèè àäàïòèðóþòñÿ ê ìåíÿþùèìñÿ óñëîâèÿì ñóùåñòâîâàíèÿ, ïðèîáðåòàÿ ñïîñîáíîñòü ïåðåõîäèòü ê ãåòåðîìîðôèçìó ñ ðàçëè÷íûìè ïðîÿâëåíèÿìè L-òðàíñôîðìàöèè, ÷òî îáåñïå÷èâàåò èì äëèòåëüíóþ ïåðñèñòåíöèþ â îêðóæàþùåé ñðåäå. Ïîëó÷åííûå äàííûå ïîçâîëèëè âûÿâèòü îñíîâíûå çàêîíîìåðíîñòè àäàïòàöèîííûõ ìåõàíèçìîâ âûæèâàåìîñòè ó ýòèõ áàêòåðèé. Ê
òàêèì ìåõàíèçìàì, â ÷àñòíîñòè, îòíîñèòñÿ ãåòåðîìîðôèçì ñ ðàçëè÷íûìè ïðîÿâëåíèÿìè L-òðàíñôîðìàöèè; ñïîñîáíîñòü ê ôîðìèðîâàíèþ ìèêðîêîëîíèé è êîëîíèé ïî òèïó ìíîãîêëåòî÷íîãî îðãàíèçìà; öåëîñòíîñòü ïîïóëÿöèè â ïðîöåññå ðàçâèòèÿ çà ñ÷åò âíóòðèïîïóëÿöèîííûõ ñâÿçåé; ñïîñîáíîñòü ïîïóëÿöèè ðåàãèðîâàòü íà âîçäåéñòâèå ñðåäû îáèòàíèÿ.
Êëþ÷åâûå ñëîâà: ïàòîãåííûå áàêòåðèè, ïîïóëÿöèè ëèñòåðèé, ãåòåðîìîðôèçì, Lòðàíñôîðìàöèÿ, îêðóæàþùàÿ ñðåäà, ñàïðîôèòèçì, ñêàíèðóþùàÿ ýëåêòðîííàÿ ìèêðîñêîïèÿ.
Íàêîïëåíèå äàííûõ î ñàïðîôèòè÷åñêîì ñóùåñòâîâàíèè ïàòîãåííûõ
ìèêðîîðãàíèçìîâ ïðèâåëî ê ïåðåñìîòðó ìåñòà âîçáóäèòåëåé ðÿäà èíôåêöèîííûõ çàáîëåâàíèé â ðàçëè÷íûõ ýêîñèñòåìàõ (1-4).  ïîñëåäíåå äåñÿòèëåòèå
ñïåöèàëèñòû ïî ïèùåâûì òîêñèêîèíôåêöèÿì âñå áîëüøå âíèìàíèÿ óäåëÿþò âîçáóäèòåëþ ëèñòåðèîçà, ñëó÷àè ïåðåäà÷è êîòîðîãî ñ ðàñòèòåëüíûìè
ïðîäóêòàìè ñóùåñòâåííî ó÷àñòèëèñü.
Íåñìîòðÿ íà çíà÷èòåëüíîå ÷èñëî ïóáëèêàöèé ïî ýïèçîîòîëîãèè,
ýïèäåìèîëîãèè, ìîëåêóëÿðíîé áèîëîãèè ïàòîãåíà, ôàðìàêîëîãèè, èììóíîëîãèè, ãåíåòèêå è êëèíè÷åñêèì îñîáåííîñòÿì çàáîëåâàíèÿ, ýêîëîãèÿ âîçáóäèòåëÿ ëèñòåðèîçà èçó÷åíà ìàëî (1, 5, 6).  òî æå âðåìÿ èçâåñòíî, ÷òî ëèñòåðèè äîñòàòî÷íî óñòîé÷èâû ê íåáëàãîïðèÿòíûì ôàêòîðàì, ìîãóò ðàñòè
ïðè íèçêèõ çíà÷åíèÿõ ðÍ, âûñîêîé êîíöåíòðàöèè NaCl, ïðîÿâëÿþò ñâîéñòâà ìèêðîàýðîôèëîâ è ïñèõðîôèëîâ. Êàê òèïè÷íûå ïðåäñòàâèòåëè ñàïðîíîçîâ ëèñòåðèè ñïîñîáíû ðàçìíîæàòüñÿ â ïî÷âå, ïåðåìåùàòüñÿ ñ ãðóíòîâûìè âîäàìè è ïîäíèìàòüñÿ â ñëîè ñ âåãåòèðóþùèìè ïîáåãàìè îäíîëåòíèõ
ðàñòåíèé, â òîì ÷èñëå êîðìîâûõ.
Âïåðâûå âîïðîñ î ñóùåñòâîâàíèè ïðèðîäíûõ ðåçåðâóàðîâ âîçáóäèòåëåé èíôåêöèé âî âíåøíåé ñðåäå ïîäíÿë Â.È. Òåðñêèõ (4). Â íàñòîÿùåå
âðåìÿ ïðèçíàåòñÿ, ÷òî èçó÷àòü ôóíäàìåíòàëüíûå è ïðèêëàäíûå àñïåêòû
ýòîé ïðîáëåìû íåîáõîäèìî ñ øèðîêèõ áèîëîãè÷åñêèõ ïîçèöèé íà îñíîâå
ïîïóëÿöèîííî-ýêîëîãè÷åñêèõ ïîäõîäîâ (7, 8). Àäàïòàöèÿ ïàòîãåíîâ ñîïðîâîæäàåòñÿ ãåòåðîìîðôèçìîì è èçìåíåíèåì ôèçèîëîãèè êëåòîê, ñïîñîáñòâóþùèì óìåíüøåíèþ ýíåðãèè ðîñòà (â ÷àñòíîñòè, ñíèæåíèåì ôåðìåíòà30
òèâíîé àêòèâíîñòè â îòíîøåíèè ðÿäà ñóáñòðàòîâ) (9), ÷òî ÷àñòî îñëîæíÿåò èäåíòèôèêàöèþ èçîëÿòîâ.
Ïðè èçó÷åíèè æèçíåííûõ ôîðì ëèñòåðèé â ðàçíûõ ñðåäàõ ìû èñïîëüçîâàëè 48-÷àñîâóþ êóëüòóðó Listeria innocua (10) â S-ôîðìå ñ òèïè÷íûìè êóëüòóðàëüíî-áèîõèìè÷åñêèìè ñâîéñòâàì. Âçàèìîäåéñòâèå ëèñòåðèé ñ
ðàñòåíèÿìè èññëåäîâàëè ïî àâòîðñêîé ìåòîäèêå ìîäåëèðîâàíèÿ ïðîíèêíîâåíèÿ ëèñòåðèé ÷åðåç êîðíåâóþ ñèñòåìó â âåãåòàòèâíûå îðãàíû ñ ïðèìåíåíèåì ìåòîäà ñêàíèðóþùåé ýëåêòðîííîé ìèêðîñêîïèè (ÑÝÌ) è îöåíêîé äèíàìèêè âûæèâàåìîñòè áàêòåðèé (10). CÝÌ ïðîâîäèëè íà ýëåêòðîííîì ìèêðîñêîïå Hitachi-800 ñî ñêàíèðóþùåé ïðèñòàâêîé Hitachi-8010
(ßïîíèÿ) ïðè óñêîðÿþùåì íàïðÿæåíèè 75 ê è èíñòðóìåíòàëüíîì óâåëè÷åíèè ½1-10 òûñ. (10). Ïèùåâûå ïðîäóêòû â ñòåðèëüíûõ åìêîñòÿõ êîíòàìèíèðîâàëè âçâåñüþ ëèñòåðèé (5½108 ÊÎÅ/ìë) è îñòàâëÿëè ïðè êîìíàòíîé òåìïåðàòóðå íà 3 ÷, çàòåì ïîìåùàëè â ðàçíûå òåìïåðàòóðíûå óñëîâèÿ (18-22 °Ñ íà 3 ñóò, 4 °Ñ íà 3 ñóò, −8 è −18 °Ñ íà 10 ñóò), ïîñëå ÷åãî
îòáèðàëè ïðîáû äëÿ áàêòåðèîëîãè÷åñêîãî àíàëèçà è ÑÝÌ.
Î ìîðôîëîãè÷åñêîé ïëàñòè÷íîñòè ëèñòåðèé (ðèñ. 1) ñâèäåòåëüñòâîâàëî íàëè÷èå îâîèäíûõ êëåòîê (òèïè÷íû äëÿ S-êîëîíèé), â ðàçíûõ óñëîâèÿõ ïðåâðàùàþùèõñÿ â ïàëî÷êîâèäíûå, â êëåòêè ïðîòîïëàñòíîãî òèïà, íèòåâèäíûå, ìåëêèå îêðóãëûå (L-ôîðìû), èçâèòûå ôîðìû, ÷òî ïðèñóùå áàêòåðèÿì íà ñòàäèÿõ L-òðàíñôîðìàöèè. Øèðîêàÿ ýêîëîãè÷åñêàÿ òîëåðàíòíîñòü, ñîïðîâîæäàþùàÿñÿ èçìåíåíèåì ìîðôîëîãè÷åñêèõ îñîáåííîñòåé ïîïóëÿöèé, çàòðóäíÿåò ïåðâè÷íóþ èíäèêàöèþ è èäåíòèôèêàöèþ ëèñòåðèé â
îáúåêòàõ âåòåðèíàðíî-ñàíèòàðíîãî íàäçîðà.
Ïðè ïîíèæåííûõ òåìïåðàòóðàõ, óãíåòàþùèõ áîëüøèíñòâî ìåçîôèëüíûõ ïàòîãåíîâ, ëèñòåðèè íå âñòðå÷àþò êîíêóðåíöèè è ìîãóò àêòèâíî
ðàçìíîæàòüñÿ (11). Ïî äàííûì Â.Ñ. Çóåâà ñ ñîàâò. (12), ïðè òåìïåðàòóðå
4-6 °Ñ ó ñàëüìîíåëë â âîäå íàáëþäàåòñÿ L-òðàíñôîðìàöèÿ (12). Ìû îòìå÷àëè (ðèñ. 2, À), ÷òî ëèñòåðèè â âîäå â êîëîíèÿõ è ìèêðîêîëîíèÿõ ñîõðàíÿëè òèïè÷íóþ ïàëî÷êîâèäíóþ ôîðìó è áûëè îáúåäèíåíû ìåæêëåòî÷íûì ìàòðèêñîì, ôîðìèðóþùèì ïîêðîâû, ÷òî ñâèäåòåëüñòâîâàëî î íàëè÷èè ïîëíîöåííîé êëåòî÷íîé ñòåíêè. Îòðèöàòåëüíûå òåìïåðàòóðû (îò −8
äî −18 °Ñ) íå âëèÿëè íà ìîðôîëîãèþ è æèçíåñïîñîáíîñòü ïîïóëÿöèé ëèñòåðèé (13, 14). Îíè ïîääåðæèâàëè æèçíåñïîñîáíîñòü ïðè íèçêèõ ïîëîæèòåëüíûõ è äàæå îòðèöàòåëüíûõ òåìïåðàòóðàõ, ñóùåñòâóÿ â êîëîíèÿõ è
ìèêðîêîëîíèÿõ ñ ïîâåðõíîñòíîé áèîïëåíêîé (ñì. ðèñ. 2, Á, Â), îáðàçîâàííîé âíåêëåòî÷íûìè ïðîäóêòàìè, àíàëîãè÷íûìè êîìïîíåíòàì êëåòî÷íîé
ñòåíêè, ñèíòåçèðóåìûì è ñåêðåòèðóåìûì ïîëíîöåííîé áàêòåðèåé (15). Èçâåñòíî, ÷òî ó ýíòåðîïàòîãåííûõ áàêòåðèé îñíîâó áèîïëåíêè ñîñòàâëÿþò
àäãåçèíû áåëêîâîé è ïîëèñàõàðèäíîé ïðèðîäû (16). Ñòðàòåãèÿ âûæèâàíèÿ
ïîïóëÿöèé ëèñòåðèé â ãîëîäíîé ñðåäå (âîäîïðîâîäíàÿ âîäà) ïðè ðàçíûõ
òåìïåðàòóðàõ îñíîâàíà íà ãåòåðîìîðôèçìå ñ ðàçëè÷íûìè ïðîÿâëåíèÿìè
L-òðàíñôîðìàöèè, ÷òî ðàñøèðÿåò âîçìîæíîñòè ïîääåðæàíèÿ èõ ÷èñëåííîñòè è öèðêóëÿöèè â ìåæýïèäåìèîëîãè÷åñêèå ïåðèîäû (13).
Ñâîéñòâî ëèñòåðèé íå òîëüêî âûæèâàòü, íî è ðàçìíîæàòüñÿ ïðè
ïîíèæåííûõ òåìïåðàòóðàõ îáóñëîâëåíî àäàïòàöèîííûìè ìåõàíèçìàìè,
ïðèñóùèìè ïñèõðîôèëàì.  ïåðâóþ î÷åðåäü, ýòî òàê íàçûâàåìàÿ ãîìåîâÿçêîñòíàÿ àäàïòàöèÿ — èçìåíåíèå ñîñòàâà æèðíûõ êèñëîò â ëèïèäàõ
ìåìáðàí â ñîîòâåòñòâèè ñ òåìïåðàòóðîé îêðóæàþùåé ñðåäû. Ïðè ïîíèæåíèè òåìïåðàòóðû ñîäåðæàíèå íåíàñûùåííûõ æèðíûõ êèñëîò ïîâûøàåòñÿ,
÷åì ïðåäîòâðàùàåòñÿ çàìåðçàíèå ëèïèäîâ è èçáûòî÷íàÿ æåñòêîñòü ìåìáðàí. Ê äðóãèì ïîäîáíûì ôàêòîðàì îòíîñèòñÿ ñïîñîáíîñòü êîìïåíñèðîâàòü ìàëóþ ýôôåêòèâíîñòü ðèáîñîì ïðè íèçêèõ òåìïåðàòóðàõ èõ äîïîëíè31
òåëüíûì îáðàçîâàíèåì, ÷òî ïðîÿâëÿåòñÿ â óâåëè÷åíèè ñîäåðæàíèÿ ÐÍÊ.
Êðîìå òîãî, àäàïòàöèÿ ïñèõðîôèëîâ ñâÿçàíà ñ êîíôîðìàöèîííûìè èçìåíåíèÿìè áåëêîâ ïîä äåéñòâèåì òåðìîëàáèëüíûõ ôåðìåíòîâ (17-19).
Âñå ÷àùå ðåãèñòðèðóþò âñïûøêè ëèñòåðèîçà ïðè óïîòðåáëåíèè â
ïèùó ìÿñíûõ è ìîëî÷íûõ ïðîäóêòîâ (6, 20, 21). Ìû ïîêàçàëè, ÷òî ïîñëå
êîíòàìèíàöèè ëèñòåðèÿìè èõ êîëîíèåîáðàçóþùàÿ àêòèâíîñòü ïðè 4 °Ñ çà
7 ñóò â ñòåðèëèçîâàííîì ìîëîêå óâåëè÷èâàëàñü íà ÷åòûðå ïîðÿäêà, â êèñëîìîëî÷íûõ ïðîäóêòàõ — íà òðè, â ñûðàõ — íà äâà (22). Ñëåäîâàòåëüíî,
íàëè÷èå äàæå íåáîëüøîãî ÷èñëà ëèñòåðèé ñïîñîáíî ïðèâåñòè ê áóðíîìó
ðàçâèòèþ ïîïóëÿöèè äî îïàñíîãî äëÿ çäîðîâüÿ êîëè÷åñòâà.  óñëîâèÿõ
ïîíèæåííûõ òåìïåðàòóð áûëî óñòàíîâëåíî, ÷òî, êàê è â âîäíîé ñðåäå, îäíà ÷àñòü ïîïóëÿöèè ñóùåñòâóåò â êîëîíèÿõ è ìèêðîêîëîíèÿõ ñ ìåæêëåòî÷íûì ìàòðèêñîì, ôîðìèðóþùèì ïîêðîâû (áèîïëåíêè), äðóãàÿ ― íàõîäèòñÿ íà ðàçíûõ ñòàäèÿõ ãåòåðîìîðôèçìà, ÷òî ñâèäåòåëüñòâóåò î ôåíîòèïè÷åñêîé ãåòåðîãåííîñòè ïîïóëÿöèé (ðèñ. 3, À, Á, Â).
Èçó÷åíèå ìîðôîëîãèè è îñîáåííîñòåé ðàçâèòèÿ ëèñòåðèé â ñòåáëÿõ
êîðìîâîãî îâñà ñîðòà Óëîâ (10) ïîçâîëèëî êîíñòàòèðîâàòü, ÷òî ýòè ìèêðîîðãàíèçìû èç ïî÷âû ÷åðåç êîðíåâóþ ñèñòåìó ïðîíèêàþò âíóòðü âåãåòàòèâíûõ îðãàíîâ. Òàê, â ãîìîãåíàòå êîðíåé ÷èñëî ëèñòåðèé áûëî âûøå, ÷åì
â ãîìîãåíàòå ëèñòîâûõ ïëàñòèíîê. Âíóòðè ëèñòîâûõ ïëàñòèíîê íà âñåõ
ñðîêàõ íàáëþäåíèÿ áûë âûÿâëåí ãåòåðîìîðôèçì ëèñòåðèé ñ äåôåêòíîé
êëåòî÷íîé ñòåíêîé (ðèñ. 4, À). Èç ìîðôîëîãè÷åñêèõ âàðèàíòîâ îòìå÷àëè
áàêòåðèè ñ èçìåíåííîé ôîðìîé, íàðóøåííûì ìåõàíèçìîì äåëåíèÿ, ñ ïîòåðåé ñïîñîáíîñòè ê àäãåçèè è êîëîíèçàöèè, ÷òî, êàê èçâåñòíî, âåäåò ê
óòðàòå ïàòîãåííûõ ñâîéñòâ, îáðàçîâàíèå êëåòîê ïðîòîïëàñòíîãî òèïà. Ïðè
áëàãîïðèÿòíûõ óñëîâèÿõ ãåòåðîìîðôíûå êëåòêè ðåâåðñèðîâàëè â èñõîäíóþ
ôîðìó ñ ñîõðàíåíèåì ìîðôîëîãè÷åñêèõ è ôèçèîëîãè÷åñêèõ ñâîéñòâ (10).
Ñòðàòåãèÿ âûæèâàíèÿ ïîïóëÿöèé ëèñòåðèé â ðàñòåíèè îïðåäåëÿåòñÿ êîìïëåêñîì åãî ìåõàíèçìîâ çàùèòû, äåéñòâèå êîòîðûõ âûçûâàåò ðàçðóøåíèå
êëåòî÷íîé ñòåíêè, ÷òî ïðèâîäèò ê ðàçëè÷íûì ïðîÿâëåíèÿì L-òðàíñôîðìàöèè è îáðàçîâàíèþ íåñòàáèëüíûõ L-ôîðì, ñïîñîáíûõ ê ðåâåðñèè â èñõîäíîå ñîñòîÿíèå. Ýòîò ïðîöåññ ðàñøèðÿåò âîçìîæíîñòè âîçáóäèòåëÿ ïîääåðæèâàòü ÷èñëåííîñòü è íàêàïëèâàòüñÿ â çåëåíûõ êîðìàõ (23).
Êîíòàìèíàöèè êîðìîâ ëèñòåðèÿìè òàêæå ñïîñîáñòâóåò àäãåçèÿ è
êîëîíèçàöèÿ òâåðäûõ ÷àñòèö êîðìîâ (24). Ñ èñïîëüçîâàíèåì ÑÝÌ áûëî
ïîêàçàíî, ÷òî ïðè ïîíèæåííûõ òåìïåðàòóðàõ è ïîâûøåííîé âëàæíîñòè â
òå÷åíèå 24 ÷ êëåòêè ïðèêðåïëÿëèñü ê ïîâåðõíîñòè äðîáëåíîãî çåðíà ñ
ïîñëåäóþùèì ôîðìèðîâàíèåì ìèêðîêîëîíèé è êîëîíèé (ñì. ðèñ. 4, Á),
òî åñòü ïðîèñõîäèëî àêòèâíîå ðàçìíîæåíèå ëèñòåðèé. Ïðè ïîâûøåíèè
òåìïåðàòóðû àäãåçèÿ è êîëîíèçàöèÿ çàìåäëÿëèñü âñëåäñòâèå ïñèõðîôèëüíîñòè ýòèõ áàêòåðèé.
Òàêèì îáðàçîì, ïîïóëÿöèè ëèñòåðèé â ðàçíûõ îáúåêòàõ (âîäà, çåëåíûå ðàñòåíèÿ, çåðíî, ïðîäóêòû ïèòàíèÿ) â äèàïàçîíå òåìïåðàòóð îò −18
äî +37 °Ñ àäàïòèðóþòñÿ ê ìåíÿþùèìñÿ óñëîâèÿì, ïðîÿâëÿÿ ãåòåðîìîðôèçì ñ ðàçëè÷íûìè ýëåìåíòàìè L-òðàíñôîðìàöèè, ÷òî îáåñïå÷èâàåò äëèòåëüíóþ ïåðñèñòåíöèþ. L-òðàíñôîðìàöèÿ ñóùåñòâåííî çàòðóäíÿåò èíäèêàöèþ ëèñòåðèé, òàê êàê íåðåäêî âèäèìîãî ðîñòà ïðè êóëüòèâèðîâàíèè
òàêèõ áàêòåðèé íà ïèòàòåëüíûõ ñðåäàõ íå íàáëþäàåòñÿ.
Ñîáñòâåííûå èññëåäîâàíèÿ è àíàëèç äàííûõ ëèòåðàòóðû ïîçâîëèëè
íàì íàçâàòü îñíîâíûå àäàïòàöèîííûå ìåõàíèçìû, îáåñïå÷èâàþùèå ñîõðàíåíèå æèçíåñïîñîáíîñòè ó ëèñòåðèé. Ýòî ôåíîòèïè÷åñêàÿ ãåòåðîãåííîñòü
(ãåòåðîìîðôèçì ñ ðàçëè÷íûìè ïðîÿâëåíèÿìè L-òðàíñôîðìàöèè); âîçìîæíîñòü ôîðìèðîâàòü ìèêðîêîëîíèè è êîëîíèè ïî òèïó ìíîãîêëåòî÷íîãî
32
îðãàíèçìà; öåëîñòíîñòü ïîïóëÿöèè çà ñ÷åò âíóòðèïîïóëÿöèîííûõ ñâÿçåé,
îòñóòñòâóþùèõ ó åäèíè÷íûõ êëåòîê, è åå ñïîñîáíîñòü ðåàãèðîâàòü íà âîçäåéñòâèå ñðåäû îáèòàíèÿ (9).
Èç-çà ñïîñîáíîñòè íåñòàáèëüíûõ L-ôîðì èíèöèèðîâàòü íîâûå êîëîíèé ïîñðåäñòâîì ðåâåðñèè â èñõîäíóþ ôîðìó Â.Ä. Òèìàêîâ è Ã.ß. Êîãàí íàçâàëè ïðîöåññ L-òðàíñôîðìàöèè «òðàíçèòíîé ñèñòåìîé» (25). Òàêîé
àäàïòàöèîííûé ìåõàíèçì, ïðîÿâëÿþùèéñÿ èçìåíåíèåì áèîõèìè÷åñêèõ è
ìîðôîëîãè÷åñêèõ ñâîéñòâ â ïîïóëÿöèÿõ, ñïîñîáñòâóåò âûæèâàíèþ âèäà áàêòåðèé è ñîçäàåò îïàñíîñòü âîçíèêíîâåíèÿ èíôåêöèîííîãî î÷àãà (9).
Èòàê, ñ ïðèìåíåíèåì íåèíâàçèâíîé ñêàíèðóþùåé ýëåêòðîííîé ìèêðîñêîïèè èçó÷åí ãåòåðîìîðôèçì, âîçäåéñòâèå àáèîòè÷åñêèõ è áèîòè÷åñêèõ
ôàêòîðîâ ñðåäû íà ïîïóëÿöèþ, ñïîñîáíîñòü ê ðåâåðñèè, ïðîöåññû àäãåçèè è êîëîíèçàöèè è ïð. ó ëèñòåðèé, ÷òî äàëî îáúåêòèâíóþ èíôîðìàöèþ
îá èõ ïîïóëÿöèÿõ â ñðåäå îáèòàíèÿ è ðàñøèðèëî ïðåäñòàâëåíèå î ñòðóêòóðíî-ôóíêöèîíàëüíûõ îñîáåííîñòÿõ ïàòîãåííûõ îðãàíèçìîâ â öåëîì. Â
øèðîêîì ñìûñëå ýòî ïîçâîëÿåò ïî-íîâîìó ïîäîéòè êî ìíîãèì ïðàêòè÷åñêèì ïðîáëåìàì âîçäåéñòâèÿ íà âîçáóäèòåëåé êàê â ñðåäå îáèòàíèÿ, òàê è
â ìàêðîîðãàíèçìå, â òîì ÷èñëå îáîñíîâàòü ïîäáîð íîâûõ äåçèíôèöèðóþùèõ ñðåäñòâ è ëåêàðñòâåííûõ ïðåïàðàòîâ.
ÃÍÓ Âñåðîññèéñêèé ÍÈÈ âåòåðèíàðíîé
ñàíèòàðèè, ãèãèåíû è ýêîëîãèè Ðîññåëüõîçàêàäåìèè,
Ïîñòóïèëà â ðåäàêöèþ
20 ìàðòà 2013 ãîäà
123022 Ðîññèÿ, ã. Ìîñêâà, Çâåíèãîðîäñêîå ø., 5,
e-mail: sanmicrobio@mail.ru
EXPERIMENTAL STUDY OF POPULATIONS OF PATHOGENIC
Listeria IN ENVIRONMENT USING SCANNING ELECTRON
MICROSCOPY
I.B. Pavlova, D.A. Bannikova, A.B. Kononenko
All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology, Russian Academy of Agricultural Sciences, 5, Zvenigorodskoe sh., Moscow, 123022 Russia, e-mail sanmicrobio@mail.ru
Received March 20, 2013
doi: 10.15389/agrobiology.2014.4.30eng
Abstract
Due to accumulated data, the ideas on existance and the state of pathogenic and opportunistic bacteria in different ecosystems gradually change, while distribution, adaptation, growth and
development of bacterial forms in populations in different media and objects remain relevant. Listeria
are known to be resistant to external factors, and the frequency of their transmission through plant
production increses significantly. At that, the data concerning ecological aspects of living cycle of the
pathogen are still limited. Ecology of the bacteria is one of the substantial sections of biology concerning development, survival and interactions of the microorganisms population and the environment. One of the perspective trends in studying ecology of the pathogenic bacteria is approach on
population level being based on a study of bacterial colonies, and not a separate cell. The date of the
experiments are presented in the paper being carried out with using scanning electron microscopy
method resulting in ability to study bacterial colonier without violation of their natural architectonics. The morphological features of Listeria populations in the different objects of inhabitance medium, e.g. milk and meat products, feeds, water, green plants, in a broad temperature rang (from −18
up to 37 °Ñ) were examined. Morphological plasticity of Listeria cells and the peculiarities of Listeria
populatios existence in the environment were demonstrated on the presental scanogramms. It was
shown that Listeria adapted to the changing conditions of existence acquiring the ability to transform
into heteromorphism with the different manifestations of L-transformation resulting in their prolonged persistence in the environment. The obtained data allowed to reveal the main conformities of
the survival rate of those bacteria. Specifically, heteromorphism concerns such mechanism with the
different manifestations of L-transformation, as well as the ability to form the microcolonies and
colonies by a type of multicellular organism, integrity of a population during a process owing to the
interpopulations bonds, ability of a population to react onto influence of inhabitance medium. The
data etended our ideas on the structure and functions of pathogenic organism. In a broad sense, it
allows to revise a lot of practical problems concerning control of pathogens both in environment and
in macroorganosm, including recommendations on desifectants, medicines, therapy and prophylaxy.
33
Keywords: pathogenic bacteria, Listeria populatios, heteromorphism, L-transformation, environment, saprophytism, scanning electron microscopy.
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