Prevalence and Characteristics of Plasmid-Encoded Serine Protease EspP in Clinical Shiga Toxin-Producing Escherichia coli Strains from Patients in Sweden

• Shiga toxin-producing Escherichia coli (STEC) infection can cause a broad spectrum of symptoms spanning from asymptomatic shedding to mild and bloody diarrhea (BD) and even life-threatening hemolytic-uremic syndrome (HUS). As a member of the serine protease autotransporters of Enterobacteriaceae (SPATE) family, EspP has the ability to degrade human coagulation factor V, leading to mucosal bleeding, and also plays a role in bacteria adhesion to the surface of host cells. Here, we investigated the prevalence and genetic diversity of espP among clinical STEC isolates from patients with mild diarrhea, BD, and HUS, as well as from asymptomatic individuals, and assessed the presence of espP and its subtypes in correlation to disease severity. We found that 130 out of 239 (54.4%) clinical STEC strains were espP positive, and the presence of espP was significantly associated with BD, HUS, and O157:H7 serotype. Eighteen unique espP genotypes (GTs) were identified and categorized into four espP subtypes, i.e., espP alpha (119, 91.5%), espP gamma (5, 3.8%), espP delta (4, 3.1%), and espP epsilon (2, 1.5%). espP alpha was widely distributed, especially in strains from patients with BD and HUS, and correlated with serotype O157:H7. Serogroup O26, O145, O121, and O103 strains carried espP alpha only. Ten GTs were identified in espP alpha, and espP alpha/GT2 was significantly associated with severe disease, i.e., BD and HUS. Additionally, espP was strongly linked to the presence of eae gene, and the coexistence of espP alpha and stx2/stx2a + stx2c was closely related to HUS status. To sum up, our data demonstrated a high prevalence and genetic diversity of the espP gene in clinical STEC strains in Sweden and revealed an association between the presence of espP, espP subtypes, and disease severity. espP, particularly the espP alpha subtype, was prone to be present in more virulent STEC strains, e.g., "top-six" serotypes strains.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

NATURVETENSKAP  -- Biologi -- Mikrobiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Microbiology (hsv//eng)

Nyckelord

Shiga toxin-producing Escherichia coli

espP gene

gene diversity

hemolytic uremic syndrome

clinical significance

Shiga toxin-producing Escherichia coli; espP gene; gene diversity; hemolytic uremic syndrome; clinical significance

Publikations- och innehållstyp

ref (ämneskategori)

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