Comparison of the antibiotic resistance between genetically diverse and toxigenic Bacillus cereus sensu lato from milk, pepper and natural habitats

Abstract

Aims Bacillus cereus sensu lato is a complex group of closely related bacteria, which are commonly present in the natural environment and food products. These organisms may cause food poisoning and spoilage as well as opportunistic infections. Thus far, their resistance to selected antibiotics has been explored only in part, especially in the context of strain source. Therefore, our goal was to compare the resistance of B. cereus sl from milk (environment with the potential impact of antibiotics) with strains from soil and pepper (environment without contact with antibiotics) in relation to their origin, toxicity and phylogenetic relationships. Methods and results Antibiotic resistance of B. cereus sl was assessed by determining their minimal inhibitory concentrations (MICs) followed by statistical analyses. The phylogeny of the bacteria was investigated by multilocus sequence typing, and toxicity was determined with quantitative reverse‐transcription real‐time PCR. We found that the isolates from milk were more often multiresistant and exhibited a common resistance pattern to β‐lactams but a varied sensitivity to the tested macrolides, clindamycin, tetracycline and vancomycin. Moreover they displayed often significantly higher average MICs; however, their resistance did not correlate with phylogeny, toxicity, or in most cases, with taxonomic affiliation. Conclusion We conclude that mainly food matrices may serve as an important reservoir of resistant isolates of B. cereus sl and that the use of antibiotics for the treatment of animal diseases must be carefully monitored as it strongly promotes natural selection for multiresistant strains, even among opportunist pathogens. Significance and Impact of the Study The fact that compared to the isolates from natural habitats, nonpathogenic B. cereus sl isolated from food acquire antibiotic resistance faster, should increase producers and consumers awareness and result in protection of public health.

Re‐Imagining Drug Discovery using Mass Spectrometry

“…Note that ion ratios can be easily calibrated to provide absolute concentrations using an external calibration created with standards of both reactants and products. [32] As expected, no enzymatic activity is observed against meropenem, a third generation β-lactam antibiotic for which Bacillus cereus does not commonly show natural resistance [69,70] (Figure 5C and 5F). This demonstrates the versatility of the label-free DESI-MS approach for rapidly assessing enzymatic activity against multiple substrates without the need for any additional method development.…”

Elucidation of the Bovine Intramammary Bacteriome and Resistome from healthy cows of Swiss dairy farms in the Canton Tessin

“…An important aspect is the high prevalence of bacteria belonging to the Bacillus cereus group in milk samples of healthy cows (9%). This bacterial group, including twelve closely related species, is commonly found in environmental and food products accounting for between 11 to 47% of isolates, particularly in raw milk from cows and buffalo ( Liu Y. et al, 2015 ; Owusu-Kwarteng et al, 2017 ; Baldwin, 2020 ; Radmehr et al, 2020 ; Zhao et al, 2020 ; Bartoszewicz and Czyżewska, 2021 ). Due to heat-resistant spores, these bacteria survive the pasteurization process and could cause spoilage of dairy products and even intoxication of human consumers ( Gopal et al, 2015 ).…”

Midguts of Culex pipiens L. (Diptera: Culicidae) as a potential source of raw milk contamination with pathogens

“…Bacillus cereus group represents the major food contamination sources that may lead to food poisoning which happens in the form of two types of syndromes, the emetic, and/or the diarrheal syndromes 33 . They can produce several enterotoxins: Hemolysin BL (HBL), Non-haemolytic enterotoxin (NHE) and Cytotoxin K (CytK) 34 B. cereus group named also, B. cereus sensu lato includes eight closely related species: B. anthracis, B. cereus sensu stricto , B. cytotoxicus, B. mycoides, B. pseudomycoides, B. thuringiensis, B. toyonensis , and B. weihenstephanensis 35 . However, the most members recognized as pathogenic bacteria among B. cereus group were B .…”