Characterizing avian pathogenic Escherichia coli (APEC) from colibacillosis cases, 2018

Abstract

Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is a devastating disease of poultry that results in multi-million-dollar losses annually to the poultry industry. Disease syndromes associated with APEC includes colisepticemia, cellulitis, air sac disease, peritonitis, salpingitis, omphalitis, and osteomyelitis among others. A total of 61 APEC isolates collected during the Fall of 2018 (Aug–Dec) from submitted diagnostic cases of poultry diagnosed with colibacillosis were assessed for the presence of 44 virulence-associated genes, 24 antimicrobial resistance genes and 17 plasmid replicon types. Each isolate was also screened for its ability to form biofilm using the crystal violet assay and antimicrobial susceptibility to 14 antimicrobials using the NARMS panel. Overall, the prevalence of virulence genes ranged from 1.6% to >90% with almost all strains harboring genes that are associated with the ColV plasmid—the defining trait of the APEC pathotype. Overall, 58 strains were able to form biofilms and only three strains formed negligible biofilms. Forty isolates displayed resistance to antimicrobials of the NARMS panel ranging from one to nine agents. This study highlights that current APEC causing disease in poultry possess virulence and resistance traits and form biofilms which could potentially lead to challenges in colibacillosis control.

Antimicrobial resistance, virulence associated genes and phylogenetic background versus plasmid replicon types: the possible associations in avian pathogenic Escherichia coli (APEC)

“…Out of them, IncP (47/72, 65.27%), IncI1 (42/72, 58.3%) and IncF group (FIA, FIB, FIC, FIIA, Frep; 39/72, 54.16%) were the most prevalent plasmid types. High prevalence of IncP among the isolates (47/72, 65.27%) differs the current study from previous reports on APEC, as they have recorded lower values or no presence of P replicon type [ 6 , 35 – 37 ]. The IncP plasmids are composed of genes responsible for resistance to a wide variety of antibiotic classes, heavy metals and quaternary ammonium compounds in gram negative bacteria.…”

“…In the present study, variety of patterns for plasmid replicons (50 different [6,[35][36][37]. The IncP plasmids are composed of genes responsible for resistance to a wide variety of antibiotic classes, heavy metals and quaternary ammonium compounds in gram negative bacteria.…”

“…Since there is no single genetic determinant to identify APEC, efforts have been made to identify minimal predictors for diagnostic purposes. Accordingly, panel of five genes including: iroN (salmochelin), iutA or aerJ (aerobactin), ompT (outer membrane protease), iss (serum resistance) and hlyF (toxin) has been widely accepted for APEC virulotyping [ 5 , 6 ].…”

YqeH contributes to avian pathogenic Escherichia coli pathogenicity by regulating motility, biofilm formation, and virulence

“…The bacterial colonization and invasion of host cells are crucial steps in APEC infection process [ 28 , 29 ]. Type 1 fimbriae contribute to bacterial adhesion and invasion of host cells, which create conditions for a series of processes, such as pathogen colonization and infection [ 30 , 31 ].…”

Identification of novel genes involved in the biofilm formation process of Avian Pathogenic Escherichia coli (APEC)

“…The prevalence of 30 selected putative biofilm formation genes was determined in a sample of 109 APEC and 104 avian fecal E . coli (AFEC) isolates collected from previous studies [ 28 ]. AFEC isolates were compared to APEC strains to identify genes more prevalent in the pathogenic strains (APEC) than the commensal fecal strains (AFEC).…”