Molecular types, virulence profiles and antimicrobial resistance of Escherichia coli causing bovine mastitis

Abstract

BackgroundEscherichia coli is an important aetiological agent of bovine mastitis worldwide.MethodsIn this study, 82 E. coli from bovine mastitis milk samples from 49 farms were analysed for their genetic diversity using phylogenetic grouping and multilocus sequence typing. The isolates were examined by PCR for a selection of virulence factors (VFs). Antimicrobial susceptibility profiles were assessed using the disk diffusion method.ResultsThe most prevalent phylogroups were group B1 (41.5 per cent of the isolates) and group A (30.5 per cent). A variety of 35 different sequence types (STs) were identified, including ST1125 (11 per cent), ST58 (9.8 per cent), ST10 (8.5 per cent) and ST88 (7.3 per cent). Aggregate VF scores (the number of unique VFs detected for each isolate) ranged from 1 to 3 for 63.4 per cent of the isolates and were at least 4 for 12.2 per cent. For 24.4 per cent of the isolates, the score was 0. The three most frequent VFs were traT, fyuA and iutA. The majority (72 per cent) of the isolates harboured traT. The majority (68.3 per cent) of the isolates were fully susceptible to all antimicrobials tested, with 22 per cent resistant to ampicillin and 14.6 per cent to tetracycline. Resistance rates were low for gentamicin (3.7 per cent), amoxicillin/clavulanic acid (2.4 per cent) and ceftiofur (1.2 per cent), respectively.ConclusionAmong the study’s sample population, E. coli strains were genotypically diverse, even in cows from the same farm, although some STs occurred more frequently than others. Susceptibility to clinically relevant compounds remained high.

Witch Hazel Significantly Improves the Efficacy of Commercially Available Teat Dips

“…To test for the antibacterial activity of DIP and WH on Gram-negative bacteria, DIP and WH were tested on Gram-negative bacteria that can be associated with IMIs, such as E. coli and P. aeruginosa [33]. E. coli are usually associated with transient infections but can cause persistent IMIs through enhanced adherence to host tissue and/or production of shiga-like toxins by certain strains [34,35]. Pseudomonas spp., such as P. aeruginosa, are environmental mastitis-causing pathogens that spread through the use of water during milking [36].…”

Characterization of Escherichia coli Strains Derived from Cow Milk of Subclinical and Clinical Cases of Mastitis

“…The majority (68%) of the E. coli isolates from cows with mastitis in Switzerland were fully susceptible to all antimicrobials tested. The authors observed low resistance rates for gentamicin (3.7%), amoxicillin/clavulanic acid (2.4%), and ceftiofur (1.2%) [34]. The low resistance rates were also reported among mastitis E. coli isolates in Denmark with no resistance to gentamicin and ceftiofur [35].…”

International clones of extended‐spectrum β‐lactamase (CTX‐M)‐producingEscherichia coliin peri‐urban wild animals, Brazil

“…coli ST1251, fluoroquinolone-resistant strains have been reported in animal faeces and wastewater (Jamborova et al, 2015;Varela, Macedo, Nunes, & Manaia, 2015), as well as mcr-1-harbouring strains from food animals (Zurfluh et al, 2017). Escherichia coli belonging to ST58 has been globally reported from a variety of sources including food (Ben Said et al, 2015), polluted mangrove (Sacramento et al, 2018), poultry, hospital-and community-acquired infections (Borges et al, 2019;McKinnon, Chowdhury, & Djordjevic, 2018) and bovine mastitis (Nüesch-Inderbinen et al, 2019). Interestingly, ST58/CC155 frequently shares identical antimicrobial resistance patterns in both animal and human populations.…”

“…Nowadays, most ESBL-producing Escherichia coli circulating at the human-animal-environment interface belong to international sequence types (STs) such as ST10, ST38, ST58, ST131, ST212, ST648, ST744, ST1158 and ST1251 (Borges, Tarlton, & Riley, 2019;Cao et al, 2014;Castellanos et al, 2017;Haenni et al, 2018;Nüesch-Inderbinen et al, 2019;Pitout, 2012;Tacão et al, 2017;Tafoukt, Touati, Leangapichart, Bakour, & Rolain, 2017;Vignoli et al, 2016;Zurfluh et al, 2017), suggesting a broad host adaptation of these pathogens. In this study, we report the occurrence of pandemic clones of CTX-M-producing E. coli recovered from a diversity of peri-urban wild animals in Brazil, highlighting the transmission of this sort of bacteria in anthropogenic-shared environments.…”