A total of 416 samples comprising faecal samples from diarrhoeic cases of man, calves, sheep and goats, and urine samples from patients with urinary tract infections, were examined for the presence of enterobacteria of emerging pathogenic significance. Citrobacter freundii from 20, C. intermedius biotype-a from four, Serratia marcescens (serotype 05:H13, bactericin type 16) from one and Erwinia herbicola from two human stool samples were isolated. Only two urine samples yielded C. freundii. Citrobacter freundii was isolated from 10 and C. intermedius biotype-a from two calves. From sheep and goats, two isolates of C. freundii and three of C. intermedius biotype-a were obtained. None of these samples yielded Edwarsiella tarda or Yersinia enterocolitica. The examination of 99 toads and 145 wall lizards revealed that toads were reservoirs for C. freundii, C. intermedius biotype-a and Salmonella brijbhumi, whereas wall lizards were reservoirs for C. freundii, C. intermedius biotype-a, E. herbicola, Enterobacter cloacae and Salmonella spp. These bacteria were present in the range of 2.0 x 10(6) to 6.0 x 10(11) organisms per gram of intestinal contents. In addition, toads were carriers for Edwardsiella tarda (new serotypes 04167:H1 and 05159: non-motile). None of the toads and wall lizards proved positive for C. intermedius biotype-b (C. koseri), S. marcescens and Y. entercolitica. C. freundii, C. intermedius biotype-a, E. herbicola and S. marcescens were resistant to penicillin and erythromycin whereas E. tarda isolates were also resistant to gentamycin, neomycin, colistin and sulfamethaxazole.