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. 2019 Aug 15;9(1):11930.
doi: 10.1038/s41598-019-47948-1.

Molecular profiling and antimicrobial resistance of Shiga toxin-producing Escherichia coli O26, O45, O103, O121, O145 and O157 isolates from cattle on cow-calf operations in South Africa

Musafiri Karama  1 , Alfred O Mainga  2 , Beniamino T Cenci-Goga  2   3 , Mogaugedi Malahlela  2 , Saeed El-Ashram  4   5 , Alan Kalake  6
Affiliations

Molecular profiling and antimicrobial resistance of Shiga toxin-producing Escherichia coli O26, O45, O103, O121, O145 and O157 isolates from cattle on cow-calf operations in South Africa

Musafiri Karama et al. Sci Rep. .

Abstract

In this study, 140 cattle STEC isolates belonging to serogroups O157, O26, O145, O121, O103 and O45 were characterized for 38 virulence-associated genes, antimicrobial resistance profiles and genotyped by PFGE. The majority of isolates carried both stx1 and stx2 concurrently, stx2c, and stx2d; plasmid-encoded genes ehxA, espP, subA and saa but lacked katP and etpD and eaeA. Possession of eaeA was significantly associated with the presence of nle genes, katP, etpD, ureC and terC. However, saa and subA, stx1c and stx1d were only detected in eaeA negative isolates. A complete OI-122 and most non-LEE effector genes were detected in only two eaeA positive serotypes, including STEC O157:H7 and O103:H2. The eaeA gene was detected in STEC serotypes that are commonly implicated in severe humans disease and outbreaks including STEC O157:H7, STEC O145:H28 and O103:H2. PFGE revealed that the isolates were highly diverse with very low rates of antimicrobial resistance. In conclusion, only a small number of cattle STEC serotypes that possessed eaeA, had the highest number of virulence-associated genes, indicative of their high virulence. Further characterization of STEC O157:H7, STEC O145:H28 and O103:H2 using whole genome sequencing will be needed to fully understand their virulence potential for humans.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Relationship between plasmid-encoded Virulence Genes and eaeA.
Figure 2
Figure 2
Distribution of pathogenicity island-encoded genes.
Figure 3
Figure 3
PFGE dendograms of serogroups O157 (A) and O121 (B) STEC isolates.
Figure 4
Figure 4
PFGE dendograms of serogroups O145 (A) and O103 (B) STEC isolates.
Figure 5
Figure 5
A PFGE dendogram of serogroup O26 STEC isolates.
Figure 6
Figure 6
A PFGE dendogram of serogroup O45 STEC isolates.
See this image and copyright information in PMC

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