scholarly journals 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

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Musafiri Karama ◽  
Alfred O. Mainga ◽  
Beniamino T. Cenci-Goga ◽  
Mogaugedi Malahlela ◽  
Saeed El-Ashram ◽  
...  
Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 424 ◽  
Author(s):  
Karama ◽  
Cenci-Goga ◽  
Malahlela ◽  
Smith ◽  
Keddy ◽  
...  

Shiga toxin-producing Escherichia coli (STEC) isolates (N = 38) that were incriminated in human disease from 2006 to 2013 in South Africa were characterized by serotype, virulence-associated genes, antimicrobial resistance and pulsed-field gel electrophoresis (PFGE). The isolates belonged to 11 O:H serotypes. STEC O26:H11 (24%) was the most frequent serotype associated with human disease, followed by O111:H8 (16%), O157:H7 (13%) and O117:H7 (13%). The majority of isolates were positive for key virulence-associated genes including stx1 (84%), eaeA (61%), ehxA (68.4%) and espP (55%), but lacked stx2 (29%), katP (42%), etpD (16%), saa (16%) and subA (3%). stx2 positive isolates carried stx2c (26%) and/or stx2d (26%) subtypes. All pathogenicity island encoded virulence marker genes were detected in all (100%) isolates except nleA (47%), nleC (84%) and nleD (76%). Multidrug resistance was observed in 89% of isolates. PFGE revealed 34 profiles with eight distinct clusters that shared ≥80% intra-serotype similarity, regardless of the year of isolation. In conclusion, STEC isolates that were implicated in human disease between 2006 and 2013 in South Africa were mainly non-O157 strains which possessed virulence genes and markers commonly associated with STEC strains that have been incriminated in mild to severe human disease worldwide. Improved STEC monitoring and surveillance programs are needed in South Africa to control and prevent STEC disease in humans.


2015 ◽  
Vol 35 (9) ◽  
pp. 775-780 ◽  
Author(s):  
Marcos R.A. Ferreira ◽  
Talícia dos S. Silva ◽  
Ariel E. Stella ◽  
Fabricio R. Conceição ◽  
Edésio F. dos Reis ◽  
...  

Abstract: In order to detect virulence factors in Shiga toxin-producing Escherichia coli (STEC) isolates and investigate the antimicrobial resistance profile, rectal swabs were collected from healthy sheep of the races Santa Inês and Dorper. Of the 115 E. coli isolates obtained, 78.3% (90/115) were characterized as STEC, of which 52.2% (47/90) carried stx1 gene, 33.3% (30/90) stx2 and 14.5% (13/90) both genes. In search of virulence factors, 47.7% and 32.2% of the isolates carried the genes saa and cnf1. According to the analysis of the antimicrobial resistance profile, 83.3% (75/90) were resistant to at least one of the antibiotics tested. In phylogenetic classification grouped 24.4% (22/90) in group D (pathogenic), 32.2% (29/90) in group B1 (commensal) and 43.3% (39/90) in group A (commensal). The presence of several virulence factors as well as the high number of multiresistant isolates found in this study support the statement that sheep are potential carriers of pathogens threatening public health.


2021 ◽  
Author(s):  
Libby Obumneke Onyeka ◽  
Abiodun A. Adesiyun ◽  
Karen H. Keddy ◽  
Ayanda Manqele ◽  
Evelyn Madoroba ◽  
...  

2018 ◽  
Vol 82 (1) ◽  
pp. 39-44 ◽  
Author(s):  
BURTON W. BLAIS ◽  
KYLE TAPP ◽  
MARTINE DIXON ◽  
CATHERINE D. CARRILLO

ABSTRACT Next-generation sequencing plays an important role in the characterization of clinical bacterial isolates for source attribution purposes during investigations of foodborne illness outbreaks. Once an illness cluster and a suspect food vehicle have been identified, food testing is initiated for confirmation and to determine the scope of a contamination event so that the implicated lots may be removed from the marketplace. For biochemically diverse families of pathogens such as Shiga toxin–producing Escherichia coli (STEC), the ability to detect specific strains may be hampered by the lack of a universal selective enrichment approach for their recovery against high levels of background microbiota. The availability of whole genome sequence data for a given outbreak STEC strain prior to commencement of food testing may provide food microbiologists an opportunity to customize selective enrichment techniques favoring the recovery of the outbreak strain. Here we demonstrate the advantages of using the publicly available ResFinder tool in the analysis of STEC model strains belonging to serotypes O111 and O157 to determine antimicrobial resistance traits that can be used in formulating strain-specific enrichment media to enhance recovery of these strains from microbiologically complex food samples. The improved recovery from ground beef of model STEC strains with various antimicrobial resistance profiles was demonstrated using three classes of antibiotics as selective agents, suggesting the universal applicability of this new approach in supporting foodborne illness investigations.


2005 ◽  
Vol 156 (7) ◽  
pp. 793-806 ◽  
Author(s):  
Azucena Mora ◽  
Jesús E. Blanco ◽  
Miguel Blanco ◽  
M. Pilar Alonso ◽  
Ghizlane Dhabi ◽  
...  

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