Next Article in Journal
Chickpea Aquafaba-Based Emulsions as a Fat Replacer in Pound Cake: Impact on Cake Properties and Sensory Analysis
Previous Article in Journal
Dietary Supplementation with Sea Buckthorn Berry Puree Alters Plasma Metabolomic Profile and Gut Microbiota Composition in Hypercholesterolemia Population
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Foods
Volume 11
Issue 16
10.3390/foods11162480
foods-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Toxigenic Genes, Pathogenic Potential and Antimicrobial Resistance of Bacillus cereus Group Isolated from Ice Cream and Characterized by Whole Genome Sequencing

by
Rosa Fraccalvieri
1,
Angelica Bianco
1,2,*,
Laura Maria Difato
1,
Loredana Capozzi
1,
Laura Del Sambro
1,
Domenico Simone
1,
Roberta Catanzariti
1,
Marta Caruso
1,
Domenico Galante
1,
Giovanni Normanno
3,
Lucia Palazzo
1,
Maria Tempesta
4 and
Antonio Parisi
1
1
Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZS PB), Via Manfredonia 20, 71121 Foggia, Italy
2
Experimental Zooprophylactic Institute of Apulia and Basilicata, 71121 Foggia, Italy
3
Department of Science of Agriculture, Food and the Environment (SAFE), University of Foggia, 71121 Foggia, Italy
4
Department of Veterinary Medicine, University Aldo Moro of Bari, Strada per Casamassima Km 3, 70010 Valenzano, Italy
*
Author to whom correspondence should be addressed.
Foods 2022, 11(16), 2480; https://doi.org/10.3390/foods11162480
Submission received: 11 July 2022 / Revised: 12 August 2022 / Accepted: 15 August 2022 / Published: 17 August 2022
(This article belongs to the Section Food Microbiology)
Review Reports Versions Notes

Abstract

:
Bacillus cereus is isolated from a variety of foods where it may cause food spoilage and/or food poisoning due to its toxigenic and pathogenic nature. In this study, we identified members of B. cereus groups in 65% of the ice cream samples analyzed, which were characterized based on multi locus variable number tandem repeats analysis (MLVA) and whole genome sequencing (WGS). The MLVA revealed that 36 strains showed different allelic profiles. Analyses of WGS data enabled the identification of three members of the B. cereus group: B. cereus sensu stricto, B. mosaicus and B. thuringiensis. Based on the multi locus sequence typing (MLST) scheme, the strains were classified in 27 sequence types (STs), including ST26 that causes food poisoning. Toxin genes’ detection revealed the presence of the genes encoding nonhemolytic enterotoxin (NHE), hemolysin BL (HBL), cytotoxin K (cytK) and cereulide (ces) in 100%, 44%, 42% and 8% of the strains, respectively. The identification of eleven antimicrobial resistance (AMR) genes predicted the resistance to five different antimicrobials, and the resistance to beta-lactam antibiotics was confirmed with a phenotypic antimicrobial test. Taken together, the results showed that the B. cereus strains isolated from ice cream were a potential hazard for consumer safety.

1. Introduction

The Bacillus cereus (B. cereus) group, named also as B. cereus sensu lato (B. cereus s.l.), is a gram-positive, rod-shaped, spore-forming [1] bacteria. The group includes bioterrorism agent B. anthracis, food-borne pathogen B. cereus sensu stricto (B. cereus s.s.), and biopesticide B. thuringiensis. The members belonging to B. cereus s.l. include genetically closed strains, and a recent study [2] proposed a novel taxonomic nomenclature for the B. cereus group useful to standardize the “genomospecies/subspecies/biovar” nomenclatural framework for more accurate species assignment.
The B. cereus group is widespread in the environment and it can contaminate feedstocks used for food preparation [3]. Their spores, which are able to survive dehydration and pasteurization processes, contaminate food through dehydrated and pasteurized ingredients [3]. Among contaminated foods, raw milk represents a hazard to food and consumer safety because spores can survive pasteurization treatments [4,5]. Other foods that pose the same concern are ready-to-eat products, such as ice cream, wherein B. cereus has been isolated as a pathogen [6].
The B. cereus group produces various types of toxins including insecticidal or pathogenic toxins, which can cause diseases such as diarrhea, vomiting or serious food poisoning and hemolysis, and even death [7,8,9,10]. There is known strong evidence of food-borne outbreaks sustained from B. cereus [3]. Interestingly, in 2019 the typical toxins produced by B. cereus were the agents frequently reported at the EU (European Union) level with a number of FBOs (food-borne outbreaks) that were twice as many as the FBO numbers due to toxins produced by other pathogens, including C. perfringens or S. aureus. Of concern is the association between Bacillus cereus human infection and deaths [11]. The contamination of foods with B. cereus s.l. may lead to food poisoning that usually manifests as emetic syndrome and/or diarrheal syndrome [12]. The former is caused by ingestion of the cereulide toxin, encoded by the ces genes [13,14,15]. The second is caused by three heat-labile enterotoxins: hemolysin BL (HBL), nonhemolytic enterotoxin (NHE) and cytotoxin K (cytK). Hemolysin BL is transcribed from the gene cluster hblABCD [16]. The nonhemolytic enterotoxin is encoded by gene cluster nheABC [17]. The cytotoxin K (cytK) protein, encoded by the genes cytK-1/2, is highly cytotoxic. It is implicated as the primary toxin responsible for diarrhea [8,18]. In the diarrheal syndrome the vegetative cells of B. cereus, present in food, after colonizing the intestine begin to produce the enterotoxins [7].
The distinguishing markers between the species within the B. cereus group are encoded by genes contained in highly mobile genetic elements (plasmids) [5,19,20]. Bacillus thuringiensis carries the plasmid that includes insecticidal toxin genes (e.g., the cry gene encoding d-endotoxins, Vip genes encoding vegetative insecticidal protein or Cyt gene) [2], while B. anthracis harbors two large plasmids: pXO1, encoding the anthrax toxin complex and the virulence regulator AtxA; pXO2, encoding the virulence factor poly-g-D-glutamic acid capsule [21]. Moreover, the genetic determinants of the B. cereus emetic toxin, the gene cluster cesABCD, are located on a large plasmid [5,22,23]. Although food-borne diseases associated with the consumption of B. cereus-contaminated foods do not necessarily require therapeutic treatment, investigating the genes involved in antibiotic resistance may be important. To date, the best strategy for performing typing and the genetic characterization of B. cereus s.l. is conferred by the WGS approach [3].
The aim of this study was to investigate the presence of B. cereus species and their genes encoding toxins in ice cream samples marketed in two southern Italian regions, Apulia and Basilicata. We have described the genetic characterization of the strains and the potential risk based on their genotypic diversity, pathogenic potential and AMR.

2. Materials and Methods

2.1. Isolation of B. cereus Group from Ice Cream Samples

A total of 51 ice cream samples were collected: 24 (24/51; 47%) homemade ice creams, collected from different local pastry shops and 27 (27/51; 53%) commercially produced (packaged) ice creams from 11 different Italian brands purchased from supermarkets in two southern Italian regions, Apulia and Basilicata. The samples were transferred to the laboratory in sterile bags. The detection of presumptive B. cereus was performed in accord to ISO 21871:2006 E [24]. Briefly, 5 g of food were homogenized in 45 mL Buffered Peptone Water (BPW) (BPW, Biolife, Milan, Italy) for 30 s; after, the sample was supplemented with 45 mL of Tryptic Soy Polimixin Broth (TSPB, Biolife, Milan, Italy), homogenized and heated at 30 °C for 48 h. An aliquot (10 μL) from each sample was plated directly onto Agar Mannitol Egg Yolk Polimixin (MYP, Biolife, Milan, Italy) and incubated at 30 °C for 24/48 h. From each plate, up to 5 presumptive strains possessing typical colony morphologies were confirmed as B. cereus using the hemolysis test on sheep blood agar plates. Bacterial strains isolated were stored at −80 °C.

2.2. DNA Extraction

Genomic DNA of each strain was purified using DNeasy Blood & Tissue (Qiagen, Hilden, Germany) following the manufacturer’s instructions. DNA concentration was determined by Qubit Quantitation using Qubit dsDNA HS Assay (Invitrogen, Thermo Fisher Scientific, Waltham, MA, USA).

2.3. Multi Locus VNTR Analysis (MLVA)

Five presumptive B. cereus strains, isolated from each positive sample, were screened by MLVA as previously reported by Valjevac et al., 2005 [25]. The products of polymerase chain reaction (PCR) were visualized by electrophoretic separation using QIAxcel High Resolution Kit on QIAxcel instruments (Qiagen). The different allele profiles identified in isolates derived from the same food source were selected for further characterizations by WGS.

2.4. Whole Genome Sequencing

For each selected B. cereus strain, paired-end genomic libraries and sequencing were processed as previously reported in Bianco et al., 2020 [26]. Draft genomes were submitted to BTyper3 tool [27], which performs in silico analysis to detect: identification of the closest strain, sequence type (ST) and clonal complex, phylogenetic group based on panC gene sequence and the major toxin factors. We used BTyper2 tool (Version 2.3.2; https://github.com/lmc297/BTyper, accessed on 9 July 2022) [28] for antimicrobial (AMR) gene detection.

2.5. Antimicrobial Susceptibility Test

Antimicrobial susceptibility of all B. cereus strains was evaluated using the Kirby–Bauer disk diffusion method according to the Clinical and Laboratory Standards Institute [29] for S. aureus [30]. Twelve antibiotics (Liofilchem®, Roseto degli Abbruzzi, Italy) were tested, including ampicillin (AMP, 10 μg), amoxicillin-clavulanic acid (AUG, 20 μg/10 μg), penicillin (P, 10 U), cephalothin (KF, 30 μg), imipenem (IPM, 10 μg), gentamicin (CN, 10 μg), kanamycin (K, 30 μg), erythromycin (E, 15 μg), vancomycin (VA, 30 μg), chloramphenicol (C, 30 μg), tetracycline (TE, 30 μg), clindamycin (DA, 2 μg). After incubating for 18 h at 36 ± 1 °C, the inhibition zones were measured and interpreted referring to the Clinical and Laboratory Standards Institute (CLSI, 2010) for S. aureus [30]. Staphylococcus aureus ATCC 29,213 and E. coli ATCC 25,922 were used as control strains.

2.6. Nucleotide Sequence Accession Numbers

The draft genomes of the B. cereus identified have been deposited in GenBank as BioProject PRJNA773646. The numbers of BioSample and accession ID are reported in Supplementary Table S1.

2.7. Statistical Analysis

Differences among the percentages of different isolates were compared using the Chi-square test (v2, p < 0.05) with Epi Info 3.3.2 software (Centers for Disease Control and Prevention, Atlanta, GA, USA).

3. Results

The B. cereus colonies showed the typical color morphology, being dull gray and opaque, with a rough matted surface and irregular perimeters. Based on bacterial growth, 65% (33/51) of the ice cream samples analyzed were B. cereus group positive, of which 18 (18/27; 67%) were packaged ice cream and 15 (15/24; 63%) were homemade ice creams (Table 1). No statistically significant difference was observed between the packaged ice cream group and the homemade ice cream group (p > 0.05). Among the 51 ice cream samples, only 4 (2 homemade and 2 packaged) were fruit dairy-free ice cream, and they were all B. cereus group negative; the other samples were prepared using milk as an ingredient. The results of the MLVA performed on five strains isolated from each ice cream (n = 33) that were positive for B. cereus s.l., showed 36 different allelic profiles. Specifically, the strains isolated from 30 ice cream samples showed a unique genetic profile for each source analyzed, whereas the strains isolated from three sources showed two different B. cereus s.l. profiles, respectively (Table 1 and Supplementary Table S2). We selected these 36 strains to perform genetic characterization by WGS. The draft genome sequence of the investigated B. cereus s.l. strains consisted of an average of 146 contigs comprising approximately 5.588.926bp. The average coverage was estimated at ∼92X. The overall G + C content of 36 isolates was 35% (Supplementary Table S3). Bioinformatic analysis performed by the BTyper3 tool confirmed that all strains belonged to the B. cereus group: 12 strains (33%) were identified as B. cereus s.s.; 12 (33%) strains were identified as B. mosaicus; 8 strains (22%) were identified as B. mosaicus subsp. cereus; 3 strains (8%) were identified as B. mosaicus subsp. cereus biovar Emeticus; 1 strain (3%) was identified as B. cereus s.s. biovar Thuringiensis. The MLST analysis identified 27 different STs (Table 1); among these we identified six new STs that were submitted on public database PubMLST (https://pubmlst.org/ accessed on 13 August 2022). Based on panC gene sequences, the strains were distributed among three different phylogenetic groups (Table 1): 17 strains (47%) were attributed to phylogenetic group III; 13 strains (36%) were assigned to phylogenetic group IV; 6 strains (17%) were assigned to phylogenetic group II. The degree of pathogenicity was assessed by searching for toxin- (Table 1) and antibiotic-resistant genes (Table 2). The BTyper3 tool identified the gene cluster nhe (nonhemolytic enterotoxin) and the Sph (sphingomyelinase) and bpsE genes (exo-polysaccharide capsule gene) in all strains analyzed; the gene bpsH (exo-polysaccharide capsule gene) was identified in 47% (17/36) of the strains; the gene cluster encoding diarrheal toxin Hbl was identified in 44% (16/36) of the strains; the gene cytK2 was identified in 42% (15/36) of the strains; the gene cluster cesABCD, encoding the emetic toxin cereulide, was identified in 8% (3/36) of the strains; the Vip4Aa1 gene, encoding vegetative insecticidal proteins, was identified in one strain (3%), which was identified as B. thuringiensis. Additionally, the antimicrobial resistance genes were predicted (Table 2). All strains harbored the genes conferring resistance to beta-lactam and fosfomycin antibiotics. Eighty-six percent (31/36) of the strains carried the vanR-M genes and 31% (11/36) carried the vanZF-Pp; other AMT genes identified with a frequency <25% were: lsa (B), which encoded a protein that confers resistance to clindamycin; vanS-Pt2, vanR-Pt and vanY-Pt2 genes, which encode proteins that confer vancomycin resistance; the tetL gene that confers tetracycline resistance. Additionally, phenotypic antimicrobial susceptibility testing was performed. The results of the antimicrobial tests are presented in Table 3. All B. cereus s.l. strains resulted in being sensitive to imipenem, gentamycin, kanamycin, vancomycin and chloramphenicol. Similarly, as predicted by the BTyper tool, the majority of the isolates were susceptible to erythromycin (89%), clindamycin (97%) and tetracycline (89%) with one exception; these results were in agreement with AMR gene prediction, which identified the tetL gene in the same strain (B. cereus s.s. BC561A). A similar result was obtained for beta-lactam resistance: all strains (100%) were resistant to ampicillin, 97% to penicillin and 94% to amoxicillin/clavulanic acid and cephalothin.

4. Discussion

Spores and vegetative cells of the B. cereus group are ubiquitous in the environment and, therefore, are commonly found in different kinds of unprocessed food [7]. Spores may survive the intense processing of dehydrated foods and the pasteurization temperature [4,5,6,31]. and they can also germinate, and reproduce at low temperatures due to the psychotropic feature [31,32]. These challenges make B. cereus a very important and frequently encountered bacterium in the food industry [31,33]. The presence of B. cereus s.l. and their toxins in foods poses a potential risk for food spoilage and to public health [31,32]. B. cereus s.l. are psychrotolerant microorganisms and their contamination of refrigerated stored foods raises a food safety problem [31,33]. Various studies reported different rates of B. cereus s.l. contamination: in dried food samples of different pulses and cereals 56% [34]; in pasteurized milk 27% to 47% [30,35,36,37]; in milk and dairy products 14% to 70% [38,39,40,41]; in ice cream 30% to 63% [6,31,38,41]. Our study investigated the presence of the B. cereus group in ice creams, which was estimated to be 65% (33/51); a similar prevalence (62.7%) was described in Messelhausser U. et al., 2010 [6]. With the aim of screening the different members of B. cereus s.l. isolated from the samples collected, we performed MLVA that identified 36 different B. cereus s.l. profiles. When we compared the genetic profiles with species identification based on WGS, the correlation was found for 33% (12/36) of strains (Supplementary Table S2). Probably, this result was due to the low number of samples analyzed. However, MLVA analysis allowed the selection of samples for next-generation sequencing. The genetic characterization performed by WGS identified three species among the B. cereus group: B. cereus s.s., B. mosaicus and B. thuringiensis. Interestingly, all B. cereus s.s. and the one B. thuringiensis identified belonged to phylogenetic group IV, whereas the B. mosaicus belonged to both phylogenetic group II and III. Additionally, we identified 27 STs, of which six have not been described previously. The most prevalent ST was ST142, which was identified in 11% (4/36) of the strains, followed by ST26 identified in 8% (3/36) of the strains. This result was in agreement with a previous study that analyzed milk samples [26]. Among the other STs, ST1084, ST126, ST92 and ST98 were identified in two strains, whereas the remaining STs were in one strain. Interestingly, ST26 is known as an ST that causes food poisoning with vomiting and includes clinically isolated strains [42,43], suggesting that the strains belonging to this ST are potentially damaging strains that may be present in ready-to-eat foods. The probable pathogenic power exhibited by the isolated strain was assessed by the detection of the virulence factors and AMR genes. The most common enterotoxin-encoding genes identified were nhe and sph according to previous reports [26,44]. Other major virulence factors were identified, as well as the gene cluster of HBL (hblABCD) encoded for the enterotoxin BL and cytK2 (cytotoxin K) gene; these are genes that encode toxins with a high degree of cytopathogenicity [45,46,47]. Some previous studies reported that 35 to 100% of the strains isolated from various food items harbored hbl and cytK genes [30,35,36,48,49,50,51,52,53]. The cytotoxic effect of enterotoxins and enzymes is determined by their combination and their levels of expression, strictly dependent on the strain [45]. Diarrheal syndrome is probably the result of the combination and synergistic action of different toxins and enzymes. The isolate identified as B. thuringiensis harbored the Vip4Aa1 gene that encoded the vegetative insecticidal proteins but did not harbor the cry gene that encoded δ-cry endotoxins responsible for the pesticidal action. The toxin responsible for the emetic syndrome is the heat stable cereulide protein encoded by the gene cluster cesABCD [13], which we identified in 8% (3/36) of the analyzed isolates. Based on this finding, these strains can be considered potentially responsible for the emetic syndrome. Interestingly, these strains belonged to ST26, typically associated with emetic B. cereus isolates [54]. The finding of the prevalence rate of the gene cesABCD in B. cereus s.l. agreed with previous studies that isolated B. cereus s.l. from milk, dairy products and other sources [35,48,53]. The antibiotic susceptibility of bacteria is a public health concern. We identified genes that were potentially associated with the resistance of five different antibiotics, and we compared this result with the phenotypic test. The Fcyn-fosBx1 gene was identified in all isolates, which could confer Fosfomycin resistance; because there are no available references of phenotypic interpretation about the Fosfomycin resistance, this finding cannot be compared. Thirty-four isolates harbored the genes associated with vancomycin (vanS-Pt2, vanR-M, vanR-Pt, VanZF-Pp, VanR-F and vanY-Pt2) resistance, but all isolates resulted in being susceptible to the phenotypic test. Nine isolates carried the clindamycin (lsaB)-resistant gene, but all isolates were susceptible (except one that presented an intermediate resistance) to the phenotypic test. In one isolate we identified a gene tetL that confers resistance to tetracycline, and this finding was in accordance with the phenotypic test. In all isolates, we identified the genes BLA-1 and BLA-2 associated with the beta-lactam antibiotic; additionally, we found that all isolates were resistant to ampicillin, 94% resistant to amoxicillin-clavulanic acid, 97% resistant to penicillin G and 94% resistant to cephalothin using the phenotypic test. Typically, B. cereus is resistant to penicillin G or other beta-lactam antibiotics [55,56,57]. The ability to resist beta-lactam antibiotics may be conferred by the capability of B. cereus s.l. to synthesize the enzyme involved in the antibiotic degradation [57,58]. In B. cereus s.l., the production of this enzyme can lead to resistance even up to the third generation of cephalosporins [58,59]. Similarly to the results of other studies [30,57,58,60], the isolates tested showed susceptibility to imipenem, gentamicin, kanamycin, erythromycin, chloramphenicol, tetracycline and clindamycin. However, no gene associated with these resistances has been identified. These results highlighted that there is not always correlation between phenotype and genotype; in this study we evaluated the genetic profile of resistance genes, but we did not have any information about the genetic expression. Conversely, not all genes associated with AMR are known; thus, our study was in agreement with the concept reported in [45], which stressed the importance of updating dedicated databases with information derived from comparing AMR genes identified by WGS and antibiotic resistance detected by phenotypic testing.

5. Conclusions

Our study showed that the B. cereus group strains, isolated from ice cream, were potential enterotoxin producers and were also capable of exhibiting antibiotic resistance. B. cereus s.l. is a potential risk for the consumer due to its toxin-forming ability.
Interestingly, we identified three members of the B. cereus group, and the analyses revealed that B. thuringiensis and B. mosaicus can carry similar virulence determinants as B. cereus s.s. This study confirmed the low prevalence rate of emetic toxin gene ces and a high presence of the three heat-labile enterotoxins: hemolysin BL (HBL), nonhemolytic enterotoxin (NHE) and cytotoxin K (cytK). Furthermore, our results highlighted the resistance to penicillin and third-generation cephalosporins and sensitivity to other antibiotics tested.
We suggest that MLVA can be used for the purpose of carrying out a preliminary screening, and the analysis of WGS, followed by appropriate data analysis strategies, could be a highly effective way to evaluate the pathogenic potential of the B. cereus group.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/foods11162480/s1, Table S1: Genome annotation; Table S2: MLVA Analysis. In the table were reported the MLVA allelic profiles and taxon names prediction by MLVA and WGS taxon names; Table S3: Quality Assessment Tool for Genome Assemblies report.

Author Contributions

Conceptualization, M.C., D.G. and A.P.; data curation, R.F., L.M.D., L.C., D.S., R.C., D.G., G.N., M.T. and A.P.; formal analysis, R.F., A.B., L.M.D., L.C., L.D.S., D.S., L.P. and A.P.; funding acquisition, M.C. and A.P.; investigation, A.B., L.M.D., L.C., L.D.S., R.C., M.C., G.N., L.P., M.T. and A.P.; methodology, R.F., A.B., L.M.D., L.C., L.D.S., D.S., M.C. and A.P.; project administration, L.P. and A.P.; resources, A.P.; software, A.P.; supervision, A.P.; validation, R.C. and A.P.; visualization, M.T. and A.P.; writing—original draft, R.F.; writing—review and editing, A.B. and A.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Ministry of Health, Italy (Rome) (Project Code: IZS PB 04/16 RC).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Liu, Y.; Du, J.; Lai, Q.; Zeng, R.; Ye, D.; Xu, J.; Shao, Z. Proposal of Nine Novel Species of the Bacillus cereus Group. Int. J. Syst. Evol. Microbiol. 2017, 67, 2499–2508. [Google Scholar] [CrossRef]
  2. Carroll, L.M.; Wiedmann, M.; Kovac, J. Proposal of a Taxonomic Nomenclature for the Bacillus cereus Group Which Reconciles Genomic Definitions of Bacterial Species with Clinical and Industrial Phenotypes. mBio 2020, 11, e00034-20. [Google Scholar] [CrossRef]
  3. EFSA Panel on Biological Hazards (BIOHAZ). Risks for public health related to the presence of Bacillus cereus and other Bacillus spp. including Bacillus thu-ringiensis in foodstuffs. EFSA J. 2016, 14, e04524. Available online: https://www.efsa.europa.eu/it/efsajournal/pub/4524 (accessed on 11 August 2022).
  4. Larsen, H.D.; Jørgensen, K. Growth of Bacillus cereus in Pasteurized Milk Products. Int. J. Food Microbiol. 1999, 46, 173–176. [Google Scholar] [CrossRef]
  5. Stenfors Arnesen, L.P.; Fagerlund, A.; Granum, P.E. From Soil to Gut: Bacillus cereus and Its Food Poisoning Toxins. FEMS Microbiol. Rev. 2008, 32, 579–606. [Google Scholar] [CrossRef]
  6. Messelhäusser, U.; Kämpf, P.; Fricker, M.; Ehling-Schulz, M.; Zucker, R.; Wagner, B.; Busch, U.; Höller, C. Prevalence of Emetic Bacillus cereus in Different Ice Creams in Bavaria. J. Food Prot. 2010, 73, 395–399. [Google Scholar] [CrossRef] [PubMed]
  7. Granum, P.E.; Lund, T. Bacillus cereus and Its Food Poisoning Toxins. FEMS Microbiol. Lett. 1997, 157, 223–228. [Google Scholar] [CrossRef] [PubMed]
  8. Lund, T.; De Buyser, M.L.; Granum, P.E. A New Cytotoxin from Bacillus cereus That May Cause Necrotic Enteritis. Mol. Microbiol. 2000, 38, 254–261. [Google Scholar] [CrossRef]
  9. Tran, S.-L.; Guillemet, E.; Gohar, M.; Lereclus, D.; Ramarao, N. CwpFM (EntFM) Is a Bacillus cereus Potential Cell Wall Peptidase Implicated in Adhesion, Biofilm Formation, and Virulence. J. Bacteriol. 2010, 192, 2638–2642. [Google Scholar] [CrossRef]
  10. Palma, L.; Muñoz, D.; Berry, C.; Murillo, J.; Caballero, P. Bacillus Thuringiensis Toxins: An Overview of Their Biocidal Activity. Toxins 2014, 6, 3296–3325. [Google Scholar] [CrossRef]
  11. Authority, E.F.S. European Centre for Disease Prevention and Control The European Union One Health 2019 Zoonoses Report. EFSA J. 2021, 19, e06406. [Google Scholar] [CrossRef]
  12. Granum, P.E. Bacillus cereus and Its Toxins. Soc. Appl. Bacteriol. Symp. Ser. 1994, 23, 61S–66S. [Google Scholar]
  13. Agata, N.; Ohta, M.; Yokoyama, K. Production of Bacillus cereus Emetic Toxin (Cereulide) in Various Foods. Int. J. Food Microbiol. 2002, 73, 23–27. [Google Scholar] [CrossRef]
  14. Ehling-Schulz, M.; Vukov, N.; Schulz, A.; Shaheen, R.; Andersson, M.; Märtlbauer, E.; Scherer, S. Identification and Partial Characterization of the Nonribosomal Peptide Synthetase Gene Responsible for Cereulide Production in Emetic Bacillus Cereus. Appl. Environ. Microbiol. 2005, 71, 105–113. [Google Scholar] [CrossRef] [PubMed]
  15. Ehling-Schulz, M.; Fricker, M.; Scherer, S. Identification of Emetic Toxin Producing Bacillus cereus Strains by a Novel Molecular Assay. FEMS Microbiol. Lett. 2004, 232, 189–195. [Google Scholar] [CrossRef]
  16. Beecher, D.J.; Schoeni, J.L.; Wong, A.C. Enterotoxic Activity of Hemolysin BL from Bacillus Cereus. Infect. Immun. 1995, 63, 4423–4428. [Google Scholar] [CrossRef]
  17. Granum, P.E.; O’Sullivan, K.; Lund, T. The Sequence of the Non-Haemolytic Enterotoxin Operon from Bacillus Cereus. FEMS Microbiol. Lett. 1999, 177, 225–229. [Google Scholar] [CrossRef]
  18. Li, F.; Zuo, S.; Yu, P.; Zhou, B.; Wang, L.; Liu, C.; Wei, H.; Xu, H. Distribution and Expression of the Enterotoxin Genes of Bacillus cereus in Food Products from Jiangxi Province, China. Food Control 2016, 67, 155–162. [Google Scholar] [CrossRef]
  19. Thomas, D.J.; Morgan, J.A.; Whipps, J.M.; Saunders, J.R. Plasmid Transfer between the Bacillus Thuringiensis Subspecies Kurstaki and Tenebrionis in Laboratory Culture and Soil and in Lepidopteran and Coleopteran Larvae. Appl. Environ. Microbiol. 2000, 66, 118–124. [Google Scholar] [CrossRef]
  20. Van der Auwera, G.A.; Timmery, S.; Hoton, F.; Mahillon, J. Plasmid Exchanges among Members of the Bacillus cereus Group in Foodstuffs. Int. J. Food Microbiol. 2007, 113, 164–172. [Google Scholar] [CrossRef]
  21. Brézillon, C.; Haustant, M.; Dupke, S.; Corre, J.-P.; Lander, A.; Franz, T.; Monot, M.; Couture-Tosi, E.; Jouvion, G.; Leendertz, F.H.; et al. Capsules, Toxins and AtxA as Virulence Factors of Emerging Bacillus cereus Biovar Anthracis. PLoS Negl. Trop. Dis. 2015, 9, e0003455. [Google Scholar] [CrossRef] [PubMed]
  22. Hoton, F.M.; Andrup, L.; Swiecicka, I.; Mahillon, J. The Cereulide Genetic Determinants of Emetic Bacillus cereus Are Plasmid-Borne. Microbiology 2005, 151, 2121–2124. [Google Scholar] [CrossRef] [PubMed]
  23. Ehling-Schulz, M.; Fricker, M.; Grallert, H.; Rieck, P.; Wagner, M.; Scherer, S. Cereulide Synthetase Gene Cluster from Emetic Bacillus Cereus: Structure and Location on a Mega Virulence Plasmid Related to Bacillus Anthracis Toxin Plasmid PXO1. BMC Microbiol. 2006, 6, 20. [Google Scholar] [CrossRef] [PubMed]
  24. 14:00–17:00 ISO 21871:2006- Microbiology of Food and Animal Feeding Stuffs—Horizontal Method for the Determination of Low Numbers of Presumptive Bacillus Cereus—Most Probable Number Technique and Detection Method. Available online: https://www.iso.org/cms/render/live/en/sites/isoorg/contents/data/standard/03/60/36015.html (accessed on 11 August 2022).
  25. Valjevac, S.; Hilaire, V.; Lisanti, O.; Ramisse, F.; Hernandez, E.; Cavallo, J.-D.; Pourcel, C.; Vergnaud, G. Comparison of Minisatellite Polymorphisms in the Bacillus cereus Complex: A Simple Assay for Large-Scale Screening and Identification of Strains Most Closely Related to Bacillus Anthracis. Appl. Environ. Microbiol. 2005, 71, 6613–6623. [Google Scholar] [CrossRef]
  26. Bianco, A.; Capozzi, L.; Monno, M.R.; Del Sambro, L.; Manzulli, V.; Pesole, G.; Loconsole, D.; Parisi, A. Characterization of Bacillus cereus Group Isolates From Human Bacteremia by Whole-Genome Sequencing. Front. Microbiol. 2020, 11, 599524. [Google Scholar] [CrossRef]
  27. Carroll, L.M.; Cheng, R.A.; Kovac, J. No Assembly Required: Using BTyper3 to Assess the Congruency of a Proposed Taxonomic Framework for the Bacillus cereus Group with Historical Typing Methods. Front. Microbiol. 2020, 11, 580691. [Google Scholar] [CrossRef]
  28. Carroll, L.M.; Kovac, J.; Miller, R.A.; Wiedmann, M. Rapid, High-Throughput Identification of Anthrax-Causing and Emetic Bacillus cereus Group Genome Assemblies via BTyper, a Computational Tool for Virulence-Based Classification of Bacillus cereus Group Isolates by Using Nucleotide Sequencing Data. Appl. Environ. Microbiol. 2017, 83, e01096-17. [Google Scholar] [CrossRef]
  29. M100Ed32|Performance Standards for Antimicrobial Susceptibility Testing, 32nd Edition. Available online: https://clsi.org/standards/products/microbiology/documents/m100/ (accessed on 11 August 2022).
  30. Gao, T.; Ding, Y.; Wu, Q.; Wang, J.; Zhang, J.; Yu, S.; Yu, P.; Liu, C.; Kong, L.; Feng, Z.; et al. Prevalence, Virulence Genes, Antimicrobial Susceptibility, and Genetic Diversity of Bacillus cereus Isolated from Pasteurized Milk in China. Front. Microbiol. 2018, 9, 533. [Google Scholar] [CrossRef]
  31. Cadirci, O.; Gucukoglu, A.; Terzi Gulel, G.; Uyanik, T. Enterotoxigenic Structures of Bacillus cereus Strains Isolated from Ice Creams. J. Food Saf. 2018, 38, e12537. [Google Scholar] [CrossRef]
  32. Hanashiro, A.; Morita, M.; Matté, G.R.; Matté, M.H.; Torres, E.A.F.S. Microbiological Quality of Selected Street Foods from a Restricted Area of São Paulo City, Brazil. Food Control 2005, 16, 439–444. [Google Scholar] [CrossRef]
  33. Anderson Borge, G.I.; Skeie, M.; Sørhaug, T.; Langsrud, T.; Granum, P.E. Growth and Toxin Profiles of Bacillus cereus Isolated from Different Food Sources. Int. J. Food Microbiol. 2001, 69, 237–246. [Google Scholar] [CrossRef]
  34. Blakey, L.J.; Priest, F.G. The Occurrence of Bacillus cereus in Some Dried Foods Including Pulses and Cereals. J. Appl. Bacteriol. 1980, 48, 297–302. [Google Scholar] [CrossRef] [PubMed]
  35. Owusu-Kwarteng, J.; Wuni, A.; Akabanda, F.; Tano-Debrah, K.; Jespersen, L. Prevalence, Virulence Factor Genes and Antibiotic Resistance of Bacillus cereus Sensu Lato Isolated from Dairy Farms and Traditional Dairy Products. BMC Microbiol. 2017, 17, 65. [Google Scholar] [CrossRef] [PubMed]
  36. Reis, A.L.S.; Montanhini, M.T.M.; Bittencourt, J.V.M.; Destro, M.T.; Bersot, L.S. Gene Detection and Toxin Production Evaluation of Hemolysin BL of Bacillus cereus Isolated from Milk and Dairy Products Marketed in Brazil. Braz. J. Microbiol. 2013, 44, 1195–1198. [Google Scholar] [CrossRef] [PubMed]
  37. Yobouet, B.A.; Kouame-Sina, S.M.; Dadie, A.; Makita, K.; Grace, D.; Dje, K.M.; Bonfoh, B. Contamination of Raw Milk with Bacillus cereus from Farm to Retail in Abidjan, Côte d’Ivoire and Possible Health Implications; Dairy Science and Technology: Thrissur, India, 2014. [Google Scholar] [CrossRef]
  38. Ahmed, A.A.-H.; Moustafa, M.K.; Marth, E.H. Incidence of Bacillus cereus in Milk and Some Milk Products. J. Food Prot. 1983, 46, 126–128. [Google Scholar] [CrossRef] [PubMed]
  39. Merzougui, S.; Lkhider, M.; Grosset, N.; Gautier, M.; Cohen, N. Prevalence, PFGE Typing, and Antibiotic Resistance of Bacillus cereus Group Isolated from Food in Morocco. Foodborne Pathog. Dis. 2014, 11, 145–149. [Google Scholar] [CrossRef]
  40. Cosentino, S.; Mulargia, A.F.; Pisano, B.; Tuveri, P.; Palmas, F. Incidence and Biochemical Characteristics of Bacillus Flora in Sardinian Dairy Products. Int. J. Food Microbiol. 1997, 38, 235–238. [Google Scholar] [CrossRef]
  41. Yibar, A.; ÇetïNkaya, F.; SoyutemïZ, E.; Yaman, G. Süt ve Peynirden İzole Edilen Bacillus Cereus’un Prevalansı, Enterokoksin Üretimi ve Antibiyotik Direnci. Kafkas. Univ. Vet. Fak. Derg. 2017, 23, 635–642. [Google Scholar] [CrossRef]
  42. Fricker, M.; Messelhäusser, U.; Busch, U.; Scherer, S.; Ehling-Schulz, M. Diagnostic Real-Time PCR Assays for the Detection of Emetic Bacillus cereus Strains in Foods and Recent Food-Borne Outbreaks. Appl. Environ. Microbiol. 2007, 73, 1892–1898. [Google Scholar] [CrossRef]
  43. Priest, F.G.; Barker, M.; Baillie, L.W.J.; Holmes, E.C.; Maiden, M.C.J. Population Structure and Evolution of the Bacillus cereus Group. J. Bacteriol. 2004, 186, 7959–7970. [Google Scholar] [CrossRef]
  44. Yu, S.; Yu, P.; Wang, J.; Li, C.; Guo, H.; Liu, C.; Kong, L.; Yu, L.; Wu, S.; Lei, T.; et al. A Study on Prevalence and Characterization of Bacillus cereus in Ready-to-Eat Foods in China. Front. Microbiol. 2020, 10, 3043. [Google Scholar] [CrossRef] [PubMed]
  45. Ceuppens, S.; Rajkovic, A.; Heyndrickx, M.; Tsilia, V.; Van De Wiele, T.; Boon, N.; Uyttendaele, M. Regulation of Toxin Production by Bacillus cereus and Its Food Safety Implications. Crit. Rev. Microbiol. 2011, 37, 188–213. [Google Scholar] [CrossRef] [PubMed]
  46. Madeira, J.-P.; Alpha-Bazin, B.; Armengaud, J.; Duport, C. Time Dynamics of the Bacillus cereus Exoproteome Are Shaped by Cellular Oxidation. Front. Microbiol. 2015, 6, 342. [Google Scholar] [CrossRef] [PubMed]
  47. Sergeev, N.; Distler, M.; Vargas, M.; Chizhikov, V.; Herold, K.E.; Rasooly, A. Microarray Analysis of Bacillus cereus Group Virulence Factors. J. Microbiol. Methods 2006, 65, 488–502. [Google Scholar] [CrossRef] [PubMed]
  48. Bianco, A.; Capozzi, L.; Miccolupo, A.; Iannetti, S.; Danzetta, M.L.; Del Sambro, L.; Caruso, M.; Santagada, G.; Parisi, A. Multi-Locus Sequence Typing and Virulence Profile in Bacillus cereus Sensu Lato Strains Isolated from Dairy Products. Ital. J. Food Saf. 2020, 9, 8401. [Google Scholar] [CrossRef]
  49. Chon, J.-W.; Yim, J.-H.; Kim, H.-S.; Kim, D.-H.; Kim, H.; Oh, D.-H.; Kim, S.-K.; Seo, K.-H. Quantitative Prevalence and Toxin Gene Profile of Bacillus cereus from Ready-to-Eat Vegetables in South Korea. Foodborne Pathog. Dis. 2015, 12, 795–799. [Google Scholar] [CrossRef]
  50. Chon, J.-W.; Kim, J.-H.; Lee, S.-J.; Hyeon, J.-Y.; Seo, K.-H. Toxin Profile, Antibiotic Resistance, and Phenotypic and Molecular Characterization of Bacillus cereus in Sunsik. Food Microbiol. 2012, 32, 217–222. [Google Scholar] [CrossRef]
  51. Hwang, J.-Y.; Park, J.-H. Characteristics of Enterotoxin Distribution, Hemolysis, Lecithinase, and Starch Hydrolysis of Bacillus cereus Isolated from Infant Formulas and Ready-to-Eat Foods. J. Dairy Sci. 2015, 98, 1652–1660. [Google Scholar] [CrossRef]
  52. Lee, N.; Sun, J.M.; Kwon, K.Y.; Kim, H.J.; Koo, M.; Chun, H.S. Genetic Diversity, Antimicrobial Resistance, and Toxigenic Profiles of Bacillus cereus Strains Isolated from Sunsik. J. Food Prot. 2012, 75, 225–230. [Google Scholar] [CrossRef]
  53. Yim, J.-H.; Kim, K.-Y.; Chon, J.-W.; Kim, D.-H.; Kim, H.-S.; Choi, D.-S.; Choi, I.-S.; Seo, K.-H. Incidence, Antibiotic Susceptibility, and Toxin Profiles of Bacillus cereus Sensu Lato Isolated from Korean Fermented Soybean Products. J. Food Sci. 2015, 80, M1266–M1270. [Google Scholar] [CrossRef]
  54. Carroll, L.M.; Wiedmann, M.; Mukherjee, M.; Nicholas, D.C.; Mingle, L.A.; Dumas, N.B.; Cole, J.A.; Kovac, J. Characterization of Emetic and Diarrheal Bacillus cereus Strains from a 2016 Foodborne Outbreak Using Whole-Genome Sequencing: Addressing the Microbiological, Epidemiological, and Bioinformatic Challenges. Front. Microbiol. 2019, 10, 144. [Google Scholar] [CrossRef] [PubMed]
  55. Andrews, J.M.; Wise, R. Susceptibility Testing of Bacillus Species. J. Antimicrob. Chemother. 2002, 49, 1040–1042. [Google Scholar] [CrossRef] [PubMed]
  56. Citron, D.M.; Appleman, M.D. In Vitro Activities of Daptomycin, Ciprofloxacin, and Other Antimicrobial Agents against the Cells and Spores of Clinical Isolates of Bacillus Species. J. Clin. Microbiol. 2006, 44, 3814–3818. [Google Scholar] [CrossRef]
  57. Park, Y.-B.; Kim, J.-B.; Shin, S.-W.; Kim, J.-C.; Cho, S.-H.; Lee, B.-K.; Ahn, J.; Kim, J.-M.; Oh, D.-H. Prevalence, Genetic Diversity, and Antibiotic Susceptibility of Bacillus cereus Strains Isolated from Rice and Cereals Collected in Korea. J. Food Prot. 2009, 72, 612–617. [Google Scholar] [CrossRef] [PubMed]
  58. Gdoura-Ben Amor, M.; Jan, S.; Baron, F.; Grosset, N.; Culot, A.; Gdoura, R.; Gautier, M.; Techer, C. Toxigenic Potential and Antimicrobial Susceptibility of Bacillus cereus Group Bacteria Isolated from Tunisian Foodstuffs. BMC Microbiol. 2019, 19, 196. [Google Scholar] [CrossRef]
  59. Ozçelïk, B.; Çitak, S. Evaluation of Antibiotic Resistance of Bacillus cereus Isolates in Ice-Cream Samples Sold in Ankara. Turk. J. Pharm. Sci. 2009, 6, 231–238. [Google Scholar]
  60. Luna, V.A.; King, D.S.; Gulledge, J.; Cannons, A.C.; Amuso, P.T.; Cattani, J. Susceptibility of Bacillus Anthracis, Bacillus cereus, Bacillus mycoides, Bacillus pseudomycoides and Bacillus thuringiensis to 24 Antimicrobials Using Sensititre Automated Microbroth Dilution and Etest Agar Gradient Diffusion Methods. J. Antimicrob. Chemother. 2007, 60, 555–567. [Google Scholar] [CrossRef]
Table
Table 1. Phylogenetic characterization of the 36 isolates of B. cereus s.l. The table shows the data relating to the species identification, phylogenetic cluster, sequence type (ST), clonal complex and major toxin-virulence genes. In grey are indicated the strains isolated from three ice creams that each showed two different B. cereus s.l. profiles. In bold are indicated the new STs identified in the current study. (+): presence; (-): absence.
Table 1. Phylogenetic characterization of the 36 isolates of B. cereus s.l. The table shows the data relating to the species identification, phylogenetic cluster, sequence type (ST), clonal complex and major toxin-virulence genes. In grey are indicated the strains isolated from three ice creams that each showed two different B. cereus s.l. profiles. In bold are indicated the new STs identified in the current study. (+): presence; (-): absence.
SourceSample N. of Positive/N. of Total; Prevalence %ID StrainsTaxon NamespanC GroupPubMLST STClonal ComplexVirulence Factors
cesABCDnheABChblABCDCytKSphBpsEBpsHVip4Aa1
Packaged ice cream18/27; 67%BC56BB. cereus s.s.Group_IV197ST-23-+++++--
BC147AB. mosaicus subsp. cereus; B. cereusGroup_III2663ST-205-+-++++-
BC384AB. mosaicus subsp. cereus biovar EmeticusGroup_III26nd++--++--
BC391AB. cereus s.s.Group_IV142ST-142-+++++--
BC429AB. mosaicusGroup_III127nd-+--+++-
BC430CB. cereus s.s.Group_IV857nd-++++++-
BC430DB. cereus s.s.Group_IV98nd-++++++-
BC431AB. cereus s.s.Group_IV98nd-++++++-
BC431BB. mosaicusGroup_III92nd-+--+++-
BC432CB. mosaicus subsp. cereus biovar EmeticusGroup_III26nd++--+++-
BC433AB. mosaicusGroup_III2681nd-+--+++-
BC433CB. cereus s.s.Group_IV1282ST-142-+-+++--
BC434AB. mosaicusGroup_II2682nd-+--+++-
BC435AB. cereus s.s.Group_IV2683nd-++++++-
BC477AB. mosaicus subsp. cereus; B. cereusGroup_III1084nd-+--++--
BC478AB. mosaicus subsp. cereus; B. cereusGroup_III144nd-+--++--
BC479AB. mosaicus subsp. cereus; B. cereusGroup_III1989ST-205-+-+++--
BC480AB. mosaicusGroup_III120nd-+--++--
BC550AB. mosaicus subsp. cereus; B. cereusGroup_III205ST-205-+--++--
BC559AB. mosaicusGroup_II2727nd-+--+++-
BC571AB. mosaicusGroup_II216nd-++-+++-
Homemade ice cream15/24; 63%BC194CB. cereus s.s.Group_IV142ST-142-+++++--
BC437AB. cereus s.s.Group_IV142ST-142-+++++--
BC514AB. mosaicus subsp. cereus; B. cereusGroup_III1084ST-205-+--++--
BC551AB. mosaicusGroup_II126nd-++-+++-
BC552AB. mosaicus subsp. cereus biovar EmeticusGroup_III26nd++--++--
BC553AB. mosaicusGroup_II126nd-++-+++-
BC557AB. mosaicus subsp. cereus; B. cereusGroup_III2726nd-+--++--
BC558AB. cereus s.s.Group_IV1967nd-++++++-
BC560AB. mosaicus subsp. cereus; B. cereusGroup_III164nd-+--++--
BC561AB. cereus s.s.Group_IV33nd-++++++-
BC563AB. cereus s.s.Group_IV142ST-142-+++++--
BC565AB. cereus s.s. biovar ThuringiensisGroup_IV138ST-18-+++++-+
BC567AB. mosaicusGroup_III92nd-+--+++-
BC568AB. mosaicusGroup_III365ST-365-++-++--
BC569AB. mosaicusGroup_II369nd-+--++--
Table
Table 2. Occurrence of antimicrobial resistance genes identified in the strains of B. cereus s.l. In the table are the AMR genes predicted by the BTyper tool. (+): presence; (-): absence.
Table 2. Occurrence of antimicrobial resistance genes identified in the strains of B. cereus s.l. In the table are the AMR genes predicted by the BTyper tool. (+): presence; (-): absence.
SourceStrainsID StrainsfosBx1BLA2BLA-1lsaBvanS-Pt2vanR-MvanR-PtVanZF-PpVanR-FvanY-Pt2tetL
Packaged ice creamB. cereus s.s.BC56B++++-+-----
B. mosaicus subsp. cereus; B. cereusBC147A+++--+-----
B. mosaicus subsp. cereus biovar EmeticusBC384A+++--+-----
B. cereus s.s.BC391A+++--+-+---
B. mosaicusBC429A+++--+-----
B. cereus s.s.BC430C+++++++----
B. cereus s.s.BC430D+++--+-----
B. cereus s.s.BC431A++++-+-----
B. mosaicusBC431B+++----+---
B. mosaicus subsp. cereus biovar EmeticusBC432C+++--+-----
B. mosaicusBC433A+++----+---
B. cereus s.s.BC433C+++--+-+---
B. mosaicusBC434A+++--+-----
B. cereus s.s.BC435A+++--+-----
B. mosaicus subsp. cereus; B. cereusBC477A+++--+-----
B. mosaicus subsp. cereus; B. cereusBC478A+++--+-----
B. mosaicus subsp. cereus; B. cereusBC479A+++--+-----
B. mosaicusBC480A+++--------
B. mosaicus subsp. cereus; B. cereusBC550A+++--+-+---
B. mosaicusBC559A+++--------
B. mosaicusBC571A++++-+-----
Homemade ice creamB. cereus s.s.BC194C+++--+-+---
B. cereus s.s.BC437A+++--+-+---
B. mosaicus subsp. cereus; B. cereusBC514A+++--+-----
B. mosaicusBC551A+++++++----
B. mosaicus subsp. cereus biovar EmeticusBC552A+++--+-----
B. mosaicusBC553A+++++++----
B. mosaicus subsp. cereus; B. cereusBC557A+++--+-----
B. cereus s.s.BC558A+++--+-+---
B. mosaicus subsp. cereus; B. cereusBC560A+++--+-----
B. cereus s.s.BC561A+++++++--++
B. cereus s.s.BC563A+++--+-+---
B. cereus s.s. biovar ThuringiensisBC565A++++-+-----
B. mosaicusBC567A+++----+---
B. mosaicusBC568A++++++++---
B. mosaicusBC569A+++--+-----
Table
Table 3. Antimicrobial resistance pattern of the B. cereus s.l. strains.
Table 3. Antimicrobial resistance pattern of the B. cereus s.l. strains.
Beta-lactamaseCarbapenemsAminoglycosidesMacrolidesGlycopeptidesAmphenicolsTetracyclinesLincosamides
ID StrainsAMPAUGPKFIMICNKEVACTEDA
BC56BRRRRSSSISSIS
BC147ARRRRSSSISSSS
BC384ARRRSSSSSSSSS
BC391ARRRRSSSSSSSS
BC429ARRRRSSSSSSSS
BC430CRRRRSSSSSSSS
BC430DRRRRSSSSSSSS
BC431ARRRRSSSSSSIS
BC431BRRRRSSSSSSSS
BC432CRRRRSSSSSSSS
BC433ARRRRSSSSSSSS
BC433CRRRRSSSSSSIS
BC434ARRRRSSSSSSSS
BC435ARRRRSSSSSSSS
BC477ARRRRSSSISSSS
BC478ARRRRSSSSSSSS
BC479ARRRRSSSSSSSS
BC480ARRRRSSSSSSSS
BC550ARRRRSSSSSSSS
BC559ARRRRSSSSSSSS
BC571ARRRRSSSSSSSS
BC194CRRRRSSSSSSSS
BC437ARRRRSSSSSSSS
BC514ARSRRSSSSSSSS
BC551ARRRRSSSSSSSS
BC552ARRRRSSSSSSSS
BC553ARSSSSSSSSSSI
BC557ARRRRSSSSSSSS
BC558ARRRRSSSSSSSS
BC560ARRRRSSSSSSSS
BC561ARRRRSSSSSSRS
BC563ARRRRSSSSSSSS
BC565ARRRRSSSSSSSS
BC567ARRRRSSSSSSSS
BC568ARRRRSSSISSSS
BC569ARRRRSSSSSSSS
AMP: ampicillin; AUG: amoxicillin/ac.clav; P: penicillin; KF: cephalothin; IMI: imipenem; CN: gentamicin; K: kanamycin; E: erythromycin; VA: vancomycin; C: chloramphenicol; TE: tetracycline; DA: clindamycin.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Fraccalvieri, R.; Bianco, A.; Difato, L.M.; Capozzi, L.; Del Sambro, L.; Simone, D.; Catanzariti, R.; Caruso, M.; Galante, D.; Normanno, G.; et al. Toxigenic Genes, Pathogenic Potential and Antimicrobial Resistance of Bacillus cereus Group Isolated from Ice Cream and Characterized by Whole Genome Sequencing. Foods 2022, 11, 2480. https://doi.org/10.3390/foods11162480

AMA Style

Fraccalvieri R, Bianco A, Difato LM, Capozzi L, Del Sambro L, Simone D, Catanzariti R, Caruso M, Galante D, Normanno G, et al. Toxigenic Genes, Pathogenic Potential and Antimicrobial Resistance of Bacillus cereus Group Isolated from Ice Cream and Characterized by Whole Genome Sequencing. Foods. 2022; 11(16):2480. https://doi.org/10.3390/foods11162480

Chicago/Turabian Style

Fraccalvieri, Rosa, Angelica Bianco, Laura Maria Difato, Loredana Capozzi, Laura Del Sambro, Domenico Simone, Roberta Catanzariti, Marta Caruso, Domenico Galante, Giovanni Normanno, and et al. 2022. "Toxigenic Genes, Pathogenic Potential and Antimicrobial Resistance of Bacillus cereus Group Isolated from Ice Cream and Characterized by Whole Genome Sequencing" Foods 11, no. 16: 2480. https://doi.org/10.3390/foods11162480

APA Style

Fraccalvieri, R., Bianco, A., Difato, L. M., Capozzi, L., Del Sambro, L., Simone, D., Catanzariti, R., Caruso, M., Galante, D., Normanno, G., Palazzo, L., Tempesta, M., & Parisi, A. (2022). Toxigenic Genes, Pathogenic Potential and Antimicrobial Resistance of Bacillus cereus Group Isolated from Ice Cream and Characterized by Whole Genome Sequencing. Foods, 11(16), 2480. https://doi.org/10.3390/foods11162480

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop