Genetic diversity and virulence profiles of Escherichia coli isolates causing spontaneous bacterial peritonitis and bacteremia in patients with cirrhosis.
Among patients with cirrhosis, infections caused by Escherichia coli organisms that translocate from the gut are a frequent and severe complication. One hundred ten E. coli isolates from 110 cirrhotic patients with spontaneous bacterial peritonitis and/or spontaneous bacteremia were characterized for their phylogenetic group and virulence genotype (34 extraintestinal virulence factor genes). Genetic relatedness was investigated by enterobacterial repetitive intergenic consensus sequence type 2 (ERIC-2) PCR typing and multilocus sequence typing. Phylogenetic groups A, B1, B2, and D accounted for 24%, 4%, 48%, and 24% of the population, respectively. Overall, 68 distinct ERIC-2 profiles were encountered. Eleven clonal groups, represented by multiple isolates (2 to 11) from the same sequence type (ST) or sequence type complex, were identified. These clonal groups accounted for 54 (49%) isolates overall. Membership in one of these clonal groups was more frequent among B2 isolates than non-B2 isolates (67% versus 32%, P < 0.001). The most frequent sequence types were ST95 (n = 13) and ST73 (n = 8), followed by the ST14 and ST10 complexes (n = 7). ST131 and ST69 were represented by three isolates each. Clonal group-associated isolates exhibited a greater prevalence of 11 virulence genes, including pap elements, than the other isolates. However, no association between clonal groups and host factors, type of infection, or mortality was observed. In conclusion, E. coli isolates causing spontaneous bacterial peritonitis and bacteremia in cirrhotic patients are genetically diverse. However, approximately half of the isolates belong to familiar clonal groups and exhibit extensive virulence profiles that may be associated with greater invasive potential.
Bert
Frédéric
F
Service de Microbiologie, Hôpital Beaujon, 100 Boulevard du Général Leclerc, 92110 Clichy, France. frederic.bert@bjn.aphp.fr
Johnson
James R
JR
Ouattara
Bénédicte
B
Leflon-Guibout
Véronique
V
Johnston
Brian
B
Marcon
Estelle
E
Valla
Dominique
D
Moreau
Richard
R
Nicolas-Chanoine
Marie-Hélène
MH
D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000382:microbiology*; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications*; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010538:Peritonitis / Q000382:microbiology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D015995:Prevalence; D017422:Sequence Analysis, DNA; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D037521:Virulence Factors