Appl Microbiol. 1973 December; 26(6): 919–924. Copyright notice Repair and Enumeration of Injured Coliforms in Frozen Foods1 M. Warseck, B. Ray, and M. L. Speck aDepartment of Food Science, North Carolina State University, Raleigh, North Carolina 27607 1 Paper no. 4144 of the Journal Series of the North Carolina State Agricultural Experiment Station, Raleigh, N.C. Two strains of Escherichia coli manifested death and repairable injury after being frozen in water or sterile foods at -20 C. The injured survivors were inhibited from forming colonies on violet red bile agar (VRBA) or deoxycholate lactose agar; this inhibition was greater when enumeration was done by the pour plate method instead of the surface or surface-overlay method. Injured cells repaired rapidly in Trypticase soy broth (TSB), and the repair was about maximum after 1 h at 25 C. When the injured cells were added to different foods and incubated at 25 C, repair also occurred; however, recovery was better and more uniform when the samples were mixed with TSB and incubated 1 h at 25 C. Cell multiplication was not evident until after 90 to 120 min at 25 C. The enumeration of coliforms from commercially frozen foods was increased when the thawed samples were mixed with TSB and the cells were allowed to repair 1 h at 25 C. In some samples, the repair permitted at least a 20-fold increase in the coliform count. The associated flora in the commercially frozen foods gave no evidence of impairing the repair of coliforms, nor did they start multiplication prior to 90 min after being incubated in TSB at 25 C. Generally, the plating gave more reproducible recovery of coliforms than did the most probable number method. Also, a higher number of coliforms were obtained by the surface-overlay method of plating using VRBA. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=379934 Appl Environ Microbiol. 1986 Jan ;51 (1):1-5 3513698 [Cited: 17]    Injured coliforms in drinking water.   [My paper] G A McFeters , J S Kippin , M W LeChevallier Coliforms were enumerated by using m-Endo agar LES and m-T7 agar in 102 routine samples of drinking water from three New England community water systems to investigate the occurrence and significance of injured coliforms. Samples included water collected immediately after conventional treatment, during the backwash cycle, at various points in the distribution system, and 1 week after the break and subsequent repair of a distribution main. Injured coliforms in these samples averaged greater than 95%. m-T7 agar yielded 8- to 38- fold more coliforms than did m-Endo agar LES. The geometric mean of coliforms recovered by m-Endo agar LES was less than 1 confirmed coliform per 100 ml, although m-T7 agar yielded 5.7 to 67.5 confirmed coliforms per 100 ml. In addition, the majority of these samples giving positive results on m-T7 agar produced no detectable counts on m-Endo agar LES. These findings indicated that coliforms were injured and largely undetected by use of accepted analytical media in the systems examined.   Mesh-terms: Bacteriological Techniques; Culture Media; Enterobacteriaceae, isolation & purification; Support, U.S. Gov't, Non-P.H.S.; Water Microbiology; Water Supply, standards;   http://aem.asm.org/cgi/reprint/51/1/1.pdf ENUMERATING INJURED COLIFORMS IN DRINKING WATER The article emphasizes the importance of enumerating injured coliforms in drinking water and reviews the sources of injury, factors influencing the extent of injury, problems in enumerating stressed coliforms, recent advances in enumeration techniques, and the health implications of injured coliforms. Recommendations regarding future research are included.    Additional Information:  Sponsored by Environmental Protection Agency, Cincinnati, OH. Drinking Water Research Div. INJURED COLIFORMS IN DRINKING WATER Coliforms were enumerated by using m-Endo agar LES and m-T7 agar in 102 routine samples of drinking water from three New England community water systems to investigate the occurrence and significance of injured coliforms. Samples included water collected immediately after conventional treatment, during the backwash cycle, at various points in the distribution system, and 1 week after the break and subsequent repair of a distribution main. Injured coliforms in these samples averaged >95%. m-T7 agar yielded 8- to 38-fold more coliforms than did m-Endo agar LES. (Copyright (c) 1986, American Society for Microbiology.)    Additional Information:  Pub. in Applied and Environmental Microbiology, v51 n1 p1-5 Jan 86. repared in cooperation with Salem and Beverly Water Supply Board, Beverly, MA. Sponsored by Environmental Protection Agency, Cincinnati, OH. Water Engineering Research Lab. Water Science and Technology Vol 31 No 5-6 pp 115–118 © IWA Publishing 1995 Investigation of injury of coliforms after chlorination M. du Preez, R. Kfir and P. Coubrough Division of Water Technology, CSIR, P.O. Box 395 Pretoria 0001 South Africa -------------------------------------------------------------------------------- ABSTRACT The extent of coliform injury after chlorination and the relationship between regrowth of injured coliforms and assimilable organic carbon concentrations (AOC) were studied. Seeded (Escherichia coli E25), sterilized tap water (AOC concentration adjusted to 400mg C/l) was incubated for a period of 3 weeks (25-28oC) after chlorination (0.5 and 1mg/l). Bacteria were enumerated using m-Endo agar LES and m-T7 agar. Chlorination resulted in a 3 log reduction in coliform counts within one minute. No viable colonies were found for 27% of the water samples enumerated with m-Endo agar LES. Injured coliforms were enumerated from all the water samples except one and were present in higher numbers than non-injured coliforms in the majority of the water samples. During the second and third weeks of incubation, only injured bacteria were observed in chlorinated samples. Additional AOC contributed little to the survival and regrowth of chlorinated bacteria. http://www.iwaponline.com/wst/03105/wst031050115.htm Effects of Receiving-Water Quality and Wastewater Treatment on Injury, Survival, and Regrowth of Fecal-Indicator Bacteria