Serotypes and antibiotic resistance of Verotoxigenic (VTEC) and Necrotizing (NTEC) Escherichia coli strains isolated from calves with diarrhoea

Abstract

Serotypes and antibiotic resistance of 51 Verotoxigenic (VTEC) and 33 Necrotizing (NTEC) bovine Escherichia coli strains were determined and compared with those shown by 205 non-VTEC non-NTEC strains isolated from the same batch of calves. E. coli untypable for O-antigen represented 47% of the VTEC, 12% of the NTEC and 8.8% of the non-VTEC non-NTEC. Typable VTEC belonged to serotypes 02:K?, 0103:K-, 0104:K?, 0128:K?, 0153:K- and O157:K-:H7, whereas typable NTEC were of serotypes 08:K87, 015:K14, 015:K-, 054:K?, 076:K-, 078:K(80), 088:K?, 0123:K-, 0139:K- and 0153:K-. Non-VTEC non-NTEC showed a wide variety of serotypes which were generally unrelated to those found in VTEC and NTEC. VTEC were resistant to antibiotics at higher rates than NTEC and non-VTEC non-NTEC, and showed also the highest multidrug-resistant pattern. Our results show that bovine VTEC strains belonged to O-groups usually found in human VTEC causing sporadic diarrhoea, haemorrhagic colitis and/or haemolytic uraemic syndrome, such as 02, 0103, 0104, 0153 and especially 0128 and O157. In contrast, bovine NTEC strains belonged to serotypes different from those previously found in necrotizing E. coli strains of human origin.

Antibiotic Resistance, Virulence Gene, and Molecular Profiles of Shiga Toxin-Producing Escherichia coli Isolates from Diverse Sources in Calcutta, India

“…E. coli O157:H7 is reportedly susceptible to many antibiotics (34,42). However, non-O157 strains isolated from humans and animals have developed antibiotic resistance and many are resistant to multiple antimicrobials commonly used in human and veterinary medicine (12,14,37). Approximately 49.2% of the present strains showed antibiotic resistance to one or more of the antimicrobial agents used in this study.…”

Microbial Source Tracking: Current Methodology and Future Directions

“…Serogrouping of microorganisms based on the presence of different somatic (O) antigenic determinants has been used by several investigators to differentiate E. coli from various sources (17,28). It has been reported that different serotypes of E. coli are associated with different animal sources, although many serotypes are also shared among humans and animals (8,33,55).…”

Identification and Characterization of Integron-Mediated Antibiotic Resistance among Shiga Toxin-Producing Escherichia coli Isolates

“…However, several recent studies have documented antibiotic resistance among E. coli O157:H7 isolates (4,13,19,29). Non-O157 STEC strains isolated from humans and animals also have developed antibiotic resistance, and many are resistant to multiple antimicrobials commonly used in human and veterinary medicine (4,6,29). There is currently a great deal of speculation regarding the role that the therapeutic and subtherapeutic use of antimicrobials in animals has played in accelerating the development and dissemination of antimicrobial-resistant bacterial pathogens (1,33,34).…”