Prevalence and Virulent Gene Profiles of Sorbitol Non-Fermenting Shiga Toxin-Producing Escherichia coli Isolated from Goats in Southern Thailand

Abstract

Shiga toxin-producing Escherichia coli (STEC) is the pathogenic E. coli causing disease in humans via the consumption or handling of animal food products. The high prevalence of these organisms in ruminants has been widely reported. Among STECs, O157 is one of the most lethal serotypes causing serious disease in humans. The present study investigated the prevalence of sorbitol non-fermenting STECs in goats reared in the lower region of southern Thailand and described the virulent factors carried by those isolates. Sorbitol non-fermenting (SNF)-STECs were found in 57 out of 646 goats (8.82%; 95% CI 6.75% to 11.28%). Molecular identification revealed that 0.77% of SNF-STEC isolates were the O157 serotype. Shiga toxin genes (stx₁ and stx₂) and other virulent genes (i.e., eaeA, ehxA, and saa) were detected by molecular techniques. The presence of stx₁ (75.44%) was significantly higher than that of stx₂ (22.81%), whereas 1.75% of the total isolates carried both stx₁ and stx₂. Most of the isolates carried ehxA for 75.44%, followed by saa (42.11%) and eaeA (12.28%). In addition, 21.05% of STEC isolates did not carry any eaeA, ehxA, or saa. The first investigation on SNF-STECs in goat was conducted in the lower region of southern Thailand. The present study revealed that goats could be one of the potential carriers of SNF-STECs in the observing area.

Keywords: goats; sorbitol non-fermenting Shiga toxin-producing Escherichia coli; southern Thailand; virulent genes.

Figure 1

Location of goat farms participating in the present study. A total of 646 goats were selected from 61 goat farms in Narathiwat (n = 10), Pattani (n = 7), Phatthalung (n = 6), Satun (n = 10), Songkhla (n = 18), and Yala (n = 10).