#Antibiotics #resistance and #toxin profiles of #Bacillus cereus-group isolates from fresh #vegetables from #German retail #markets (BMC Microbiol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

BMC Microbiol. 2019 Nov 9;19(1):250. doi: 10.1186/s12866-019-1632-2.

Antibiotics resistance and toxin profiles of Bacillus cereus-group isolates from fresh vegetables from German retail markets.

Fiedler G1, Schneider C2, Igbinosa EO3,4, Kabisch J3, Brinks E3, Becker B2, Stoll DA2, Cho GS3, Huch M2, Franz CMAP3.

Author information: 1 Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103, Kiel, Germany. gregor.fiedler@mri.bund.de. 2 Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Straße 9, 76131, Karlsruhe, Germany. 3 Department of Microbiology and Biotechnology, Hermann-Weigmann-Straße 1, 24103, Kiel, Germany. 4 Present Address: Department of Microbiology, Faculty of Life Sciences, University of Benin, Private Mail Bag 1154, Benin City, 30001, Nigeria.

 

Abstract

BACKGROUND:

This study aimed to evaluate the safety of raw vegetable products present on the German market regarding toxin-producing Bacillus cereus sensu lato (s.l.) group bacteria.

RESULTS:

A total of 147 B. cereus s.l. group strains isolated from cucumbers, carrots, herbs, salad leaves and ready-to-eat mixed salad leaves were analyzed. Their toxinogenic potential was assessed by multiplex PCR targeting the hemolysin BL (hbl) component D (hblD), non-hemolytic enterotoxin (nhe) component A (nheA), cytotoxin K-2 (cytK-2) and the cereulide (ces) toxin genes. In addition, a serological test was used to detect Hbl and Nhe toxins. On the basis of PCR and serological results, none of the strains were positive for the cereulide protein/genes, while 91.2, 83.0 and 37.4% were positive for the Hbl, Nhe and CytK toxins or their genes, respectively. Numerous strains produced multiple toxins. Generally, strains showed resistance against the β-lactam antibiotics such as penicillin G and cefotaxim (100%), as well as amoxicillin/clavulanic acid combination and ampicillin (99.3%). Most strains were susceptible to ciprofloxacin (99.3%), chloramphenicol (98.6%), amikacin (98.0%), imipenem (93.9%), erythromycin (91.8%), gentamicin (88.4%), tetracycline (76.2%) and trimethoprim/sulfamethoxazole combination (52.4%). The genomes of eight selected strains were sequenced. The toxin gene profiles detected by PCR and serological test mostly agreed with those from whole-genome sequence data.

CONCLUSIONS:

Our study showed that B. cereus s.l. strains encoding toxin genes occur in products sold on the German market and that these may pose a health risk to the consumer if present at elevated levels. Furthermore, a small percentage of these strains harbor antibiotic resistance genes. The presence of these bacteria in fresh produce should, therefore, be monitored to guarantee their safety.

KEYWORDS: Antibiotic resistance; Bacillus cereus sensu lato; Food safety; Fresh produce; Toxins; Whole genome sequencing

PMID: 31706266 DOI: 10.1186/s12866-019-1632-2

Keywords: Antibiotics; Drugs Resistance; Bacillus cereus; Food Safety; Germany; Amoxicillin; Cefotaxim; Ampicillin.

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#Toxigenic potential and #antimicrobial susceptibility of #Bacillus cereus group #bacteria isolated from #Tunisian #foodstuffs (BMC Microbiol., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

BMC Microbiol. 2019 Aug 24;19(1):196. doi: 10.1186/s12866-019-1571-y.

Toxigenic potential and antimicrobial susceptibility of Bacillus cereus group bacteria isolated from Tunisian foodstuffs.

Gdoura-Ben Amor M1,2, Jan S3, Baron F3, Grosset N3, Culot A3,4, Gdoura R5, Gautier M3, Techer C4.

Author information: 1 Laboratory Research of Toxicology-Microbiology Environmental and Health LR17ES06, Sciences Faculty of Sfax, University of Sfax, Sfax, Tunisia. marwagdoura50@yahoo.fr. 2 Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l’Œuf, Rennes, France. marwagdoura50@yahoo.fr. 3 Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l’Œuf, Rennes, France. 4 Mixscience, Rue des Courtillons, ZAC Cissé Blossac, 35712, Bruz, France. 5 Laboratory Research of Toxicology-Microbiology Environmental and Health LR17ES06, Sciences Faculty of Sfax, University of Sfax, Sfax, Tunisia.

 

Abstract

BACKGROUND:

Despite the importance of the B. cereus group as major foodborne pathogens that may cause diarrheal and/or emetic syndrome(s), no study in Tunisia has been conducted in order to characterize the pathogenic potential of the B. cereus group. The aim of this study was to assess the sanitary potential risks of 174 B. cereus group strains isolated from different foodstuffs by detecting and profiling virulence genes (hblA, hblB, hblC, hblD, nheA, nheB, nheC, cytK, bceT and ces), testing the isolates cytotoxic activity on Caco-2 cells and antimicrobial susceptibility towards 11 antibiotics.

RESULTS:

The entertoxin genes detected among B. cereus isolates were, in decreasing order, nheA (98.9%), nheC (97.7%) and nheB (86.8%) versus hblC (54.6%), hblD (54.6%), hblA (29.9%) and hblB (14.9%), respectively encoding for Non-hemolytic enterotoxin (NHE) and Hemolysin BL (HBL). The isolates are multi-toxigenic, harbouring at least one gene of each NHE and HBL complexes associated or not to bceT, cytK-2 and ces genes. Based on the incidence of virulence genes, the strains were separated into 12 toxigenic groups. Isolates positive for cytK (37,9%) harbored the cytK-2 variant. The detection rates of bceT and ces genes were 50.6 and 4%, respectively. When bacteria were incubated in BHI-YE at 30 °C for 18 h and for 5 d, 70.7 and 35% of the strains were shown to be cytotoxic to Caco-2 cells, respectively. The cytotoxicity of B. cereus strains depended on the food source of isolation. The presence of virulence factors is not always consistent with cytotoxicity. However, different combinations of enterotoxin genetic determinants are significantly associated to the cytotoxic potential of the bacteria. All strains were fully sensitive to rifampicin, chloramphenicol, ciprofloxacin, and gentamycin. The majority of the isolates were susceptible to streptomycin, kanamycin, erythromycin, vancomycin and tetracycline but showed resistance to ampicillin and novobiocin.

CONCLUSION:

Our results contribute data that are primary to facilitate risk assessments in order to prevent food poisoning due to B. cereus group.

KEYWORDS: Antibiotic resistance; Bacillus cereus; Cytotoxicity; Foodstuffs; Virulence genes

PMID: 31445510 DOI: 10.1186/s12866-019-1571-y

Keywords: Antibiotics; Drugs Resistance; Bacillus cereus; Food Safety; Tunisia.

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Novel #Sequence Type in #Bacillus cereus Strains Associated with #Nosocomial #Infections and #Bacteremia, #Japan (Emerg Infect Dis., abstract)

[Source: US Centers for Disease Control and Prevention (CDC), Emerging Infectious Diseases Journal, full page: (LINK). Abstract, edited.]

Volume 25, Number 5—May 2019 / CME ACTIVITY – Research

Novel Sequence Type in Bacillus cereus Strains Associated with Nosocomial Infections and Bacteremia, Japan

Reiko Akamatsu, Masato Suzuki, Keiji Okinaka, Teppei Sasahara, Kunikazu Yamane, Satowa Suzuki, Daisuke Fujikura1, Yoshikazu Furuta, Naomi Ohnishi2, Minoru Esaki, Keigo Shibayama, and Hideaki Higashi

Author affiliations: Hokkaido University, Sapporo, Japan (R. Akamatsu, D. Fujikura, Y. Furuta, N. Ohnishi, H. Higashi); National Institute of Infectious Diseases, Tokyo, Japan (M. Suzuki, S. Suzuki, K. Shibayama); National Cancer Center Hospital, Tokyo (K. Okinaka, M. Esaki); Jichi Medical University, Tochigi, Japan (T. Sasahara); Yonago Medical Center, Tottori, Japan (K. Yamane)

 

Abstract

Bacillus cereus is associated with foodborne illnesses characterized by vomiting and diarrhea. Although some B. cereus strains that cause severe extraintestinal infections and nosocomial infections are recognized as serious public health threats in healthcare settings, the genetic backgrounds of B. cereus strains causing such infections remain unknown. By conducting pulsed-field gel electrophoresis and multilocus sequence typing, we found that a novel sequence type (ST), newly registered as ST1420, was the dominant ST isolated from the cases of nosocomial infections that occurred in 3 locations in Japan in 2006, 2013, and 2016. Phylogenetic analysis showed that ST1420 strains belonged to the Cereus III lineage, which is much closer to the Anthracis lineage than to other Cereus lineages. Our results suggest that ST1420 is a prevalent ST in B. cereus strains that have caused recent nosocomial infections in Japan.

Keywords: Bacillus cereus; Nosocomial Outbreaks; Bacteremia; Japan.

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