FEMS Microbiology Letters 99 (1992) 131-136 © 1992 Federation of European Microbiological Societies 0378-1097/92/$05.00 Published by Elsevier 131 FEMSLE 05171 Establishment of three categories of P-fimbriated Escherichia coli strains that show different toxic phenotypes and belong to particular O serogroups Jorge Blanco a, M. Pilaf Alonso a,b, Miguel Blanco a, Jesfis E. Blanco a, Enrique A. Gonzfilez a and J. Ignacio Garabal a a Departamento de Microbiolox[a e Parasitolox{a, Facultade de Veterinaria, Unic'ersidade de Santiago, Lugo, Spain and h Unidade de Microbiolox[a, Complexo Ho~pitalario Xeral-Calde, Lugo, Spain Received 31 July 1992 Accepted 14 September 1992 Key words: Escherichia coli; P-fimbriae; Toxins; Virulence 1. SUMMARY Eight hundred and nineteen strains of Escherichia coli isolated in Spain between 1986 and 1991 from extraintestinal infections and feces of healthy controls were investigated for expres- sion of P-fimbriae using a particle agglutination test. Among strains causing urinary tract infec: tions, sepsis and other extraintestinal infections, P-fimbriae were found in 31% (130/420) (P < 0.001), 25% (30/118) (P < 0.001) and 12% (11/92) (P < 0.5) respectively. In contrast, only 7% (14/189) of faecal isolates from healthy indi- viduals carried P-fimbriae. According to two more common toxic markers detected in this study (o~- haemolysin and cytotoxic necrotizing factor type 1), P-fimbriated E. coli strains were grouped into three categories: haemolysin+cytotoxic necrosing factor + (Hly+CNF1 +) (68/185; 37%), haemoly- Correspondence to: J. Blanco, Departamento de Microbiolox@ e Parasitoloxia Facultade de Veterinaria, 27002 Lugo, Spain. sin+cytotoxic necrosing factor- (Hly+CNF1 -) (61/185; 33%) and Hly-CNF1- (56/185; 30%). The 185 P-fimbriated strains belonged to 17 dif- ferent O serogroups. However, 148 (80%) were of one of six serogroups (O1, 02, 04, 06, 07 and O18). The most frequent serogroups determined in the Hly+CNF1 + strains were the 04 and 06 (53/68; 78%), in the Hly+CNF1 - strains it was the O18 (27/61; 44%) and in the Hly-CNF1- strains the O1, 02 and 07 (41/56; 73%). The majority (160/185; 86%) of P-fimbriated E. coli expressed the mannose-resistant haemagglutinin type IVa. 2. INTRODUCTION Escherichia coli is the most common oppor- tunistic pathogen associated with urinary tract infections (UTI), sepsis and other extraintestinal infections [1-3]. The adherence of E. coli to uroepithelial cells is perhaps the most important event in the pathogenesis of UTI and urosepsis Downloaded from https://academic.oup.com/femsle/article-abstract/99/2-3/131/476255 by guest on 27 May 2020