Normal serum cytotoxicity for P32-labeled smooth Enterobacteriaceae. I. Loss of label, death, and ultrastructural damage.

Spitznagel, John K. (University of North Carolina, Chapel Hill), and Lawrence A. Wilson. Normal serum cytotoxicity for P(32)-labeled smooth Enterobacteriaceae. I. Loss of label, death, and ultrastructural damage. J. Bacteriol. 91:393-400. 1966.-Metabolically labeled smooth Escherichia coli lost between 10 and 90% of P(32), compared with control suspensions, when suspended for 60 min in normal serum at 37 C. Similar results were obtained with several other genera of Enterobacteriaceae. The structural nature of the cell injury in E. coli was shown by electron microscopic examination of ultrathin sections. Complex injury which included all peripheral cell structures occurred and various degrees of cytoplasmic loss resulted. Injured bacteria retained their essential shape and did not collapse, evidently because sufficient rigid cell wall remained to prevent this. The cell damage was more like that reported with ethylenediaminetetraacetic acid lysozyme than that reported with growth in penicillin. Damage sufficient to cause rupture of peripheral structures was unique in that it involved only localized areas of cell wall and left large sections relatively intact. The loss of P(32) in the fresh normal serum was closely related to bacterial viability loss.