E. coli Serotype D433

Abstract

Summary and Conclusions

A study of the cultural characteristics and sensitivity to antibiotics of E. coli serotype D433 and its occurrence in infants and in patients suffering from various E. coli infections revealed the following: (1) Serotype D433 was recovered from 5 sporadic cases of infantile diarrhea; it was present in the feces of all, in the nasopharynx of 2 and in the throat of 1 of these patients. The presence of this micröorganism in the upper respiratory tract renders air-borne transmission, particularly in nurseries, a distinct possibility. (2) Serotype D433 was found neither in 33 additional patients suffering from diarrheal disease nor in 23 premature normal infants harboring E. coli during the first week of life, nor was it recovered from 28 patients suffering from various E. coli infections of organs other than the intestinal tract. (3) Ingestion of serotype D433 of E. coli resulted in diarrhea and weight loss in a 2-months-old infant, whereas a similar exposure to the patient's own strain of E. coli failed to do so. Terramycin therapy was followed by clinical improvement and the disappearance of E. coli serotype D433. (4) Serotype D433 (4 strains received from England and 5 isolated in this laboratory) were completely or considerably inhibited on SS agar and desoxycholate citrate agar but grew well on Endo agar. Obviously, these selective culture media should not be used exclusively in examinations for the presence of this organism. (5) Serotype D433 (the above-mentioned 9 strains) was found to be highly susceptible to aureomycin, Chloromycetin, terramycin, and polymyxin B (10 μg per ml), but less so to streptomycin. None of the strains were susceptible to bacitracin (100 U per ml) and penicillin (500 U per ml). (6) Treatment with aureomycin of 4 patients resulted in prompt disappearance of serotype D433 and clinical improvement; the fifth patient was treated with sulfadiazine and penicillin and continued to excrete this microorganism in the feces.