Phenotypic characteristics of 12 paired, Salmonella serotypes isolated from healthy and ill chickens were compared. Variables compared included antibiotic resistance profiles, production of colicins and siderophores, mannose-sensitive hemagglutination of erythrocytes, resistance to serum complement, carbon source utilization, presence and transmissibility of R plasmids, and invasiveness in primary chicken kidney cell culture. Differences were found between pairs for utilization of carbon sources, mannose-sensitive hemagglutination of erythrocytes, and invasiveness in cell culture.

Renal mass was surgically reduced in 78 dogs by uninephrectomy or by combined renal infarction and uninephrectomy. Renal clearance of inulin and renal clearance of exogenous creatinine were determined simultaneously, and the creatinine to inulin clearance (C/I) ratio was calculated. Clearance procedures were performed 2 to 3 months after reduction of renal mass, and were repeated at intervals thereafter. Overall, the C/I ratio was 1.008 +/- 0.007 for 192 determinations, with a highly significant correlation (R2 = 0.994, P < 0.0001) between creatinine clearance and inulin clearance. There was no significant effect of gender of dogs, time after partial renal ablation, or dietary protein intake on C/I ratios. Degree of renal ablation did not affect C/I ratios. The results indicated that exogenous creatinine clearance is a valid measure of glomerular filtration rate in both male and female dogs with reduced renal mass.

Live, avirulent Escherichia coli vaccine strains were constructed and tested for efficacy in preventing colibacillosis in 4-week-old pigs. Either or both of 2 plasmids were inserted into avirulent E coli strain G58-1 (0101:NM). These plasmids were pPMC4, which encodes for LTb subunits of heat-labile enterotoxin, and pDHF1, which encodes for K88ac fimbriae. Litter- and weight-matched pigs were removed from sows when they were 10 days old and vaccinated orally with the constructed strains or with G58-1 (negative control vaccine) when they were 2 weeks old and 5 days later. All pigs were challenge-inoculated with virulent E coli strain 3030-2 (0157:K88, LT+, STb+) 2 weeks after the first vaccination. Only 1 pig vaccinated with G58-1/pPMC4/pDHF1 developed diarrhea and none died following challenge inoculation. Seventeen of 31 control pigs developed diarrhea and 11 died. Of 18 pigs vaccinated with G58-1/pDHF1 then challenge-inoculated with the virulent strain, 5 developed diarrhea and 2 died. Fifteen of 18 litter- and weight-matched controls developed diarrhea and 8 died. When compared with G58-1 (negative control), G58-1/pPMC4 afforded no protection to pigs challenge-inoculated with 3030-2.