Campylobacters in enteric infections of cattle and sheep

The primary aim of this study was to investigate the prevalence of Campylobacters in cattle and sheep and their relationship with enteric diseases. Material obtained from surveys provided epidemiological information and strains to carry out taxonomical and pathological studies.

Campylobacters were isolated from 45*6 Pe^ cent of 693 diarrhoeic and 49*6 per cent 125 non-diarrhoeic cattle and from 33*3 per cent of 24 diarrhoeic and 26.8 per cent 127 non-diarrhoeic sheep. No significant relationship was found between the secretion of different Campylobacter spp and diarrhoea

In cattle C. jejuni was isolated from 22.1 per cent, C. coli from 6 per cent, "C. ??intestinalis" (CHI) from 15.6 per cent and C. fetus from 3.4 per cent of 860 animals examined. Campylobacters were isolated from 88 per cent of the calf neonatal diarrhoea outbreaks investigated, having a higher isolation rate (45*1 per cent) than those of cryptosporidium sp. (32.8 per cent), rotavirus (23.5 per cent), coronavirus (7-6 per cent) and K99+ E. coli (2.6 per cent). Rotavirus was significantly correlated with diarrhoea in most outbreaks, Cryptosporidium sp. in some and K99+ E. coli in a few. apylobacters were isolated more frequently from calves infected with Cryptosporidium, than from animals without a detectable excretion of oocysts. Fewer dairy calves mgre than 1 month old excreted C. jejuni and C. coli than beef animals whilst the secretion rate of CHI and C. fetus and any of the other enteropathogens was similar, means of improved bacteriological procedures 8 per cent of the calves were found to simultaneously excrete 2 or 3 Campylobacter spp.

In sheep C. jejuni was isolated from 14.6 per cent, C. coli from 6 per cent, "C. ??alis" from 8.6 per cent and C. sputorum subsp. bubulus from 2 per cent of 151 animals examined. Lambs may become naturally infected from the 28th day of life and excrete ??ferent Campylobacter spp. for short periods. No relationship was found between Campylobacter spp spp. excretion of dams and their corresponding nursing lambs.

In naturally infected calf faeces stored at +4°C Campylobacters could survive for more m 3 months but the isolation rate obtained from 554 faeces significantly decreased on the 7th day of storage.

Colonial and microscopic morphology, coccal transformation and nalidixic acid (Nal), ??phenyl tetrazolium chloride and cephalothin tolerance were useful to differentiate 3 Camplobacter groups which comprise 2 related species each: jejuni/coli GC (C. pejuni & C. coli), fetus GC (CHI and C. fetus) and "atypical" fetus GC ("C. fecalis" and C. itorum subsp. bubulus). C. jejuni was differentiated from £. coli by hippurate test. fetus, CHI and "atypical" fetus GC by H2S production from FBP (Iron medium) and TSI. C. sputorum subsp. bubulus was differentiated from "C. fecalis" by catalase test. All C bovine isolates were biochemically indistinguishable and 67•9 per cent serologically mutated to strains previously described as porcine CHI or bovine "C. fecalis". "C. calis" and C. sputorum subsp. bubulus were unique in becoming sensitive to Nal in agar itaining Fe^+ or Fe+++. CHI strains produced black pigment in iron containing agar an feet which was increased by exposure of plates to sunlight and inhibited by Nal. capsules were detected in most Campylobacters.

Single enteric infections were studied in gnotobiotic calves and lambs using C. jejuni strains in calves and lambs and C. coli and CHI in lambs. Campylobacters colonized and were maintained in high numbers in the large bowel but in the small intestine the number ??erally decreased with time. A mild disease was produced characterised by mucoid faeces with minor pathological alterations mainly restricted to the ileum and large bowel.