Virulence factors in Escherichia coli strains isolated from Swedish piglets with diarrhea

Abstract

Parenteral vaccination of sows against Escherichia coli diarrhea in their newborn piglets has become more common during the last decade in Sweden, and the vaccination has generally had positive effects. For more than 20 years we have investigated E. coli strains isolated from piglets and wegned pigs with enteric disorders, noting the presence of 0 groups, enterotoxins, and adhesins. There has been a continuous change in`the frequency of these virulence factors. The present study was performed during 1983 and 1984 to follow this change, since such information is essential for the proper choice of vaccines. A total of 856 E. coli strains were obtained from 683 herds divided into three age groups: 1 to 6 days old, 1 to 6 weeks old, and weaned pigs. 0 group 149 still dominated in the last two age groups, while 0 group 101 was, for the first time, the most frequent 0 group in neonatal piglets. AU but four 0149 strains carried the K88 antigen, which was found in only one other strain (0 group 8). K99 antigen was most often found in 0 groups 101 and 64, and among all the K99 strains ST mouse was the most common (44 of 57), followed by ST mouse-ST pig strains (12 of 57). The 987P antigen was demonstrated in 26 strains belonging to 0 groups 141 and OX46 and nontypable strains. Two strains belonging to 0 group 101 were positive for F41 antigen; one of them also carried the K99 antigen. Among ail non-0149 strains, ST mouse was the most common type of enterotoxigenic E. coli (n = 88), followed in decreasing order by ST mouse-ST pig strains (n = 69) and ST pig strains (n = 33). In 114 strains producing enterotoxins no adhesive factor was found. Thus, vaccination of the Swedish sow population for more than 5 years with vaccines containing 0149 and K88 antigens has apparently changed the pattern of enterotoxigenic E. coli in neonatal diarrhea. The frequency of 0149:K88 strains has been reduced, and 0101:K99:ST mouse strains now dominate. However, 0149 strains remain the dominant 0 group in piglets older than 1 'week. In spite of all our diagnostic efforts, no virulence factors were detected in about one third of the piglets and weaned pigs with enteric disorders.

Genotyping of fimbrial adhesins inEscherichia coli strains isolated from slovak piglets suffering from diarrhea

“…We found only five to be positive for F6 (3.1 %). A low prevalence of ETEC strains in isolates from piglets with diarrhea which expressed F6 adherence antigen was reported in Sweden (Soderlind et al 1988) and United Kingdom (Wray et al 1993).…”

Evidence of Protection against Diarrhoea in Suckling Piglets by a Hormone‐like Protein in the Sow's Milk

“…The typing of 0 and K antigens of E. coli strains was performed by Dr. 0. SODERLIND at the National Veterinary Institute, Uppsala, Sweden as previously described (SODERLIND et al, 1988). The heat-stable enterotoxin (ST) from E. coli was tested in infant mice and piglets using heat-treated (80°C, 20min) culture filtrates (OLSSON and SODERLIND, 1980).…”

“…The etiological agents responsible for outbreaks of neonatal diarrhoea in pigs are frequently enteropathogenic strains of E. coli (SODERLIND et al, 1988). The pathogenicity of these strains are dependent on the production of the enterotoxins, LT and ST (SMITH and GYLES, 1970), as well as adhesins such as K 88,987P, K 9 9 and F41 (SMYTH et al, 1981;SODERLIND et al, 1988). Other infectious agents such as rotavirus (BOHL, 1979) and Isosporu suis (STUART et al, 1982) may also be involved, though, in Sweden at least, they are not found in piglets under 2-3 days of age (NILSSON et al, 1984).…”

Development of A Loop-Mediated Isothermal Amplification (LAMP) for the Detection of F5 Fimbriae Gene in Enterotoxigenic Escherichia coli (ETEC)

“…The type of fimbriae is determined by the genes encoding fimbriae protein, thus detection of the genes encoding fimbriae protein can determine the type that the fimbriae has expressed. F5 fimbriae is one of the most common fimbriae antigen, it was established as a transmissible K antigen with adhesive properties in 1975 [17] and encoded on a 58-megadalton plasmid [8].…”