Characterization and antimicrobial susceptibility of <i>Escherichia coli</i> isolated from healthy farm animals in Tunisia

Bessalah, Salma; Fairbrother, John M.; Salhi, Imed; Vanier, Ghyslaine; Khorchani, Touhami; Seddik, Mabrouk-Mouldi; Hammadi, Mohamed

doi:10.1080/10495398.2020.1752702

Cited by 5 publications

(6 citation statements)

References 45 publications

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“…Virulence genes defining EPEC, STEC and ExPEC were tested in both the frozen BPW aliquots (i.e., faecal samples) and in typical colonies on MAC plates (hereafter referred to as isolates) using previously reported multiplex PCR assays at the EcL (Bessalah et al, 2021). The pathotypes and virulence factors of E. coli were selected based on their public health significance and their occurrence in the gastrointestinal tracts of animals.…”

Section: Methodsmentioning

confidence: 99%

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Occurrence and antimicrobial resistance of Salmonella species and potentially pathogenic Escherichia coli in free‐living seals of Canadian Atlantic and eastern Arctic waters

Saab,

Vanier,

Sudlovenick

et al. 2023

Zoonoses and Public Health

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Seal populations in Canadian waters provide sustenance to coastal communities. There is potential for pathogenic and/or antimicrobial‐resistant bacteria to transfer to humans through inadvertent faecal contamination of seal products. The objective of this study was to investigate the occurrence and potential antimicrobial resistance of Salmonella spp., Escherichia coli and Listeria monocytogenes in faecal samples collected from grey seals (Halichoerus grypus) in the Gulf of St. Lawrence and from ringed seals (Pusa hispida) in Frobisher Bay and Eclipse Sound, Nunavut, Canada. Grey seals were harvested during commercial hunts or during scientific sampling; ringed seals were collected by Inuit hunters during subsistence harvests. Virulence genes defining pathogenic E. coli were identified by PCR, and antimicrobial susceptibility testing was performed on recovered isolates. In grey seals, E. coli was detected in 34/44 (77%) samples, and pathogenic E. coli (extraintestinal E. coli [ExPEC], enteropathogenic E. coli [EPEC] or ExPEC/EPEC) was detected in 13/44 (29%) samples. Non‐susceptibility to beta‐lactams and quinolones was observed in isolates from 18 grey seals. In ringed seals from Frobisher Bay, E. coli was detected in 4/45 (9%) samples; neither virulence genes nor antimicrobial resistance was detected in these isolates. In ringed seals from Eclipse Sound, E. coli was detected in 8/50 (16%) samples and pathogenic E. coli (ExPEC and ExPEC/EPEC) in 5/50 (10%) samples. One seal from Eclipse Sound had an E. coli isolate resistant to beta‐lactams. A monophasic Salmonella Typhimurium was recovered from 8/50 (16%) seals from Eclipse Sound. All Salmonella isolates were resistant to ampicillin, streptomycin, sulfisoxazole and tetracycline. L. monocytogenes was not detected in any sample. These findings suggest that seals may act as important sentinel species and as reservoirs or vectors for antimicrobial‐resistant and virulent E. coli and Salmonella species. Further characterization of these isolates would provide additional insights into the source and spread of antimicrobial resistance and virulence genes in these populations of free‐living seals.

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Section: Methodsmentioning

confidence: 99%

Section: Virulence Gene Detection and Pathotyping Of E Colimentioning

confidence: 99%

Occurrence and antimicrobial resistance of Salmonella species and potentially pathogenic Escherichia coli in free‐living seals of Canadian Atlantic and eastern Arctic waters

Saab,

Vanier,

Sudlovenick

et al. 2023

Zoonoses and Public Health

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“…Two microplates were coated overnight at 4 • C with 100 µL per well of each of the purified nanobodies diluted in PBS to a final concentration of 10 µg/mL. Post blocking with 5% skimmed milk in PBS for 2 h at RT, different concentrations (10 4 to 10 9 cells diluted in PBS buffer) of the E. coli F17 strain [23] and the control strain BL-21(DE3) were added and incubated for 1 h at 37 • C. A rabbit anti-F17A polyclonal antibody [12] diluted to 1/1000 was applied for 1 h at 37 • C. An anti-rabbit-HRP conjugated antibody (Invitrogen, Carlsbad, CA, USA) diluted to 1/5000 in PBS was used for detection. Three washes with PBS buffer were performed after each incubation.…”

Section: Vhh Binding By Cell-elisamentioning

confidence: 99%

Nanobody-Based Sandwich Immunoassay for Pathogenic Escherichia coli F17 Strain Detection

et al. 2023

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Rapid and specific detection of pathogenic bacteria in fecal samples is of critical importance for the diagnosis of neonatal diarrhea in veterinary clinics. Nanobodies are a promising tool for the treatment and diagnosis of infectious diseases due to their unique recognition properties. In this study, we report the design of a nanobody-based magnetofluorescent immunoassay for the sensitive detection of pathogenic Escherichia coli F17-positive strains (E. coli F17). For this, a camel was immunized with purified F17A protein from F17 fimbriae and a nanobody library was constructed by phage display. Two specific anti-F17A nanobodies (Nbs) were selected to design the bioassay. The first one (Nb1) was conjugated to magnetic beads (MBs) to form a complex capable of efficiently capturing the target bacteria. A second horseradish peroxidase (HRP)-conjugated nanobody (Nb4) was used for detection by oxidizing o-phenylenediamine (OPD) to fluorescent 2,3-diaminophenazine (DAP). Our results show that the immunoassay recognizes E. coli F17 with high specificity and sensitivity, with a detection limit of 1.8 CFU/mL in only 90 min. Furthermore, we showed that the immunoassay can be applied to fecal samples without pretreatment and remains stable for at least one month when stored at 4 °C.

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“…Rectal swabs of cattle were collected from various organized and unorganized farms in and around Pune district during the period January-March 2015. Rectal swabs were collected from 15 different dairy cattle (cow/buffalo) using the method previously described by Bessalah et al [14]. Drinking water samples from six different farms were also collected and tested for the presence of VTEC.…”

Section: Sample Collectionmentioning

confidence: 99%

“…DNA was extracted using the boiling method as described by Bessalah et al [14] and Blanco et al [16] with few modifications. Briefly, colonies from the SMAC plate were suspended in 1 mL sterile deionized water and placed in a water bath at 100 o C for 10 min.…”

Section: Dna Extractionmentioning

confidence: 99%

Isolation and characterization of Escherichia coli serotype O157:H7 and other verotoxin-producing E. coli in healthy Indian cattle

et al. 2020

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Background and Aim: Cattle are the main reservoir of Escherichia coli O157:H7 and other verotoxigenic E. coli (VTEC); therefore, there is an increased risk of infection to humans by either direct or indirect mode of transmissions. However, the prevalence of E. coli O157:H7 in the healthy cattle population of India is yet to be ascertained. This study aimed to screen the dairy cattle in and around Pune, Maharashtra, India, for verotoxin-producing E. coli O157:H7. Materials and Methods: A total of 257 rectal swabs were collected from 15 different organized and unorganized dairy farms of Pune during the period, January-March 2015. The screening involved enrichment in EC broth followed by differential identification on MacConkey sorbitol agar. The presumptive positive isolates were further confirmed by multiplex polymerase chain reaction (PCR) using primers specific to rfbE (O157), fliC (H7), VT1 (MK1), and VT2 (MK2). Vero-toxicity and antibiotic sensitivity were examined in PCR confirmed isolates. Results: Out of the 257 samples analyzed, 1.9% (2/105) were positive for O157:H7 and 39% (41/105) were positive for VTEC. Two PCR confirmed positive O157:H7 strains and two randomly selected PCR-positive VT strains exhibited in vitro cytopathic effect on Vero cells on day-7 post-inoculation. Antibiotic sensitivity profiling of O157:H7 strains exhibited resistance against penicillin G, kanamycin, ampicillin, tetracycline, gentamycin, cefotaxime, streptomycin, and piperacillin. Conclusion: These findings reveal the presence of pathogenic E. coli O157:H7 in the healthy cattle of Pune; in a situation, wherein regular surveillance for O157:H7 is not a norm. Therefore, the findings presented herein warrant routine surveillance and public awareness to prevent the transfer of such pathogens and manage health risks to the public.

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Characterization and antimicrobial susceptibility of Escherichia coli isolated from healthy farm animals in Tunisia

Cited by 5 publications

References 45 publications

Occurrence and antimicrobial resistance of Salmonella species and potentially pathogenic Escherichia coli in free‐living seals of Canadian Atlantic and eastern Arctic waters

Occurrence and antimicrobial resistance of Salmonella species and potentially pathogenic Escherichia coli in free‐living seals of Canadian Atlantic and eastern Arctic waters

Nanobody-Based Sandwich Immunoassay for Pathogenic Escherichia coli F17 Strain Detection

Isolation and characterization of Escherichia coli serotype O157:H7 and other verotoxin-producing E. coli in healthy Indian cattle

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