[Influence of mutation L,D-carboxypeptidase-coding gene on dynamics of Listeria infection].
OBJECTIVE
To study the progress of infection caused by mutant Listeria monocytogenes with deletion of Imo0028 gene coding L,D-carboxypeptidase (protein involved in metabolism of peptidoglycan).


METHODS
Deletion of Imo0028 gene was performed with site-specific mutagenesis method using wild-type strain EGDe. Virulence was studied on mice of BALB/c line.


RESULTS
Strain GIMd0028 with deletion of Imo0028 gene did not differ from parent strain on in vitro growth rate, cytotoxicity and production of listeriolysin O and phospholipase PlcA pathogenicity factors. Effective LD50 for wild-type strain EGDe was 1x10(4) CFU/ mouse and 2x10(5) CFU/mouse for intravenous and intraperitoneal inoculation respectively. Deaths of animals were observed after 3 - 7 days. LD50 for mutant strain GIMd0028 was 1x10(5) CFU/mouse for intravenous inoculation. It was not possible to determine LD50 for intraperitoneal inoculation, and infection progressed atypically slowly. For example, deaths of animals were observed during 22 days (time of experiment) starting from day 4 when strain GIMd0028 in dose 10(6) CFU/mouse was used for inoculation. In average, death of 1 - 2 mice out of 75 inoculated was observed. Presence of L. monocytogenes was confirmed by its isolation from liver and brain of dead mice.


CONCLUSIONS
Disruption of function of Imo0028 gene coding L,D-carboxypeptidase protein, which takes part in metabolism of peptidoglycan, changes dynamics of listeriosis.
Iurov
D S
DS
Egorova
I Iu
IIu
Varfolomeev
A F
AF
Kolbasov
D V
DV
Ermolaeva
S A
SA
D000818:Animals; D002268:Carboxypeptidases / Q000235:genetics*; D018450:Disease Progression; D017353:Gene Deletion; D007928:Lethal Dose 50; D008089:Listeria monocytogenes / Q000235:genetics* / Q000472:pathogenicity*; D008088:Listeriosis / Q000382:microbiology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D016297:Mutagenesis, Site-Directed; D014774:Virulence
D002268:Carboxypeptidases; C055587:carboxypeptidase L; C078874:carboxypeptidase D