Gene typing of the colonisation factor K88 (F4) in enterotoxigenic Escherichia coli strains isolated from diarrhoeic piglets

Abstract

More than 4 000 E. coli strains isolated from diarrhoeic piglets in 111 pig herds in the Czech Republic during the period 19952000 were examined for serogroup and virulence factors. Gene typing of the K88 marker by polymerase chain reaction (PCR) was used for the examination of 283 enterotoxigenic strains (ETEC) which agglutinated with antisera against K88 or adhered to intestinal brush borders. The K88 gene was detected in 237 strains; among them 232 strains possesed the K88 variant. Genotype K88ab was found in two strains of the serogroup O8 from one herd and the gene K88ad was detected in three strains of the serogroup O8 originating from another herd. The results show that the type K88ac is predominant in ETEC strains with colonisation factors K88 in pig herds in the Czech Republic.

Post‐natal development of the porcine microbiota composition and activities

“…Diarrhoea in suckling and weaned piglets is one of the most important sources of large economic losses in production farms and it has been generally believed to be caused by proliferation of pathogens, including enterotoxigenic strains of E. coli F4 (Alexa et al ., 2001). The fact that this particular strain was detected by real‐time PCR in only 3 out of 10 samples (12‐ and 23‐day‐old piglets) was probably due to the fact that this was not a challenge trial and the piglets were reared under experimental conditions and in comparatively clean facilities.…”

“…A reaction mixture (25 µl) consisted of 12.5 µl of IQ SYBR Green Supermix (Bio‐Rad), 0.2 µM of each primer set and 5 µl of the template DNA. The PCR conditions for the quantification of the three lactobacilli were: an initial DNA denaturation step at 95°C for 3 min, followed by 40 cycles of denaturation at 95°C for 15 s, and primer annealing and extension at 62.5°C for 45 s. Enterotoxigenic E. coli strain F4 was quantified using the following PCR programme: 40 cycles: 92°C for 45 s, 50°C for 45 s, 72°C for 45 s (Alexa et al ., 2001). For the determination of the number of L. sobrius DSM16698 T , L. reuteri DSMZ 20016 T , L. acidophilus DSMZ 20079 T and enterotoxigenic E. coli strain F4 in porcine samples, fluorescent signals detected from two serial dilutions were compared with a standard curve generated with the respective bacterium in the same experiment.…”

Hydrolysable chestnut tannins for reduction of postweaning diarrhea: Efficacy on an experimental ETEC F4 model

“…The native ETEC strain used in this study was isolated from a weaned piglet at the piggery of the research station Agroscope–Posieux (Switzerland); the piglet exhibited acute PWD. The strain was resistant to sulfamethoxazole (smx R ) and harbored the F4 fimbriae gene (K88ac+ subvariant), the heat-labile toxin gene (LT+), and the heat-stable toxin gene (STb+) but not the STa gene, as determined by polymerase chain reaction (PCR; primers are listed in Table 1 [ 20 – 22 ]). In order to obtain a convenient selection marker to retrieve the ETEC strain from feces at the output of the infection model, a spontaneous mutant resistant to rifampicin was searched for and isolated.…”

Intestinal challenge with enterotoxigenic Escherichia coli in pigs, and nutritional intervention to prevent postweaning diarrhea

“…Researchers examined 44 F4 + ETEC isolates from PWD pigs and found that 96% carried the F4ac fimbriae genes and 4% carried the F4ab fimbriae genes ( Choi and Chae, 1999 ). Another study found that 98% of F4 + ETEC from 237 PWD pigs carried F4ac variant ( Alexa et al., 2001 ). The expression of the fimbrial genes is usually affected by environmental factors including temperature, pH, and culture medium ( De Graaf and Mooi, 1986 ).…”