[Primary investigation on variable but nonculturable-state of enterotoxigenic Escherichia coli in vitro].
OBJECTIVE
7 variable but nonculturable-state strains of Enterotoxigenic Escherichia coli (ETEC) during the routine bacterial subculture were found in our lab and their morphology and antigen studied. Biological features, antigens and pathogenicity of the revertants were also tested and compared to that of the initial strains in order to detect their variations.


METHODS
Biological variations between the variable but nonculturable-state and the revertant of every strain were detected, using the routine gram-staining, reverting the isolates in animal intestinal, reverting their pathogenicity, serological agglutination, biochemical identifications and antibiotic resistance tests.


RESULTS
For the 7 variable but nonculturable-state strains of ETEC,other than the trains that had changed into sphero vegetale cells, there were no other obvious variations found. However, high pathogenicity of these strains still remained.


CONCLUSIONS
The presence of variable but nonculturable-state strains suggested that the routine method of bacteria storage should be changed and more attention should be paid to realize the existence of this kind of bacteria during the routine surveillance of the communicable diseases.
Chen
Dao-li
DL
Departmant of Clinical Laboratory, Center for Diseaae Prevertion and Control of Maan shan City of Anhui Province, Maan shan 243011, China.
Feng
Yu-hua
YH
D000942:Antigens, Bacterial; D024881:Drug Resistance, Bacterial; D054307:Enterotoxigenic Escherichia coli / Q000187:drug effects / Q000276:immunology / Q000472:pathogenicity; D008828:Microbiological Techniques
D000942:Antigens, Bacterial