A rare waterborne outbreak of Bacillus paranthracis in Shandong province, China, 2020: epidemiologic survey, genomic insights, and virulence characteristics.

Bacillus paranthracis, a Gram-positive conditional pathogen of Bacillus cereus group species, is capable of causing foodborne and waterborne illnesses, leading to intestinal diseases in humans characterized by diarrhoea and vomiting. However, documented cases of B. paranthracis infection outbreaks are rare in the world, and the genomic background of outbreak strains is seldom characterized. This study retrospectively analyzed strains obtained from an outbreak in schools, as well as from water systems in peri-urban areas, China, in 2020. In total, 28 B. cereus group isolates were retrieved, comprising 6 from stool samples and 22 from water samples. Epidemiological and phylogenetic investigations indicated that the B. paranthracis isolate from drinking water as the causative agent of the outbreak. The genomic comparison revealed a high degree of consistency among 8 outbreak-related strains in terms of antimicrobial resistance gene profiles, virulence gene profiles, genomic content, and multilocus sequence typing (MLST). The strains related to the outbreak show highly similar genomic ring diagrams and close phylogenetic relationships. Additionally, this study shed light on the pathogenic potential and complexity of B. cereus group through its diversity in virulence genes and mice infection model. The findings highlight the usefulness of B. paranthracis genomes in understanding genetic diversity within specific environments and in tracing the source of pathogens during outbreak situations, thereby enabling targeted infection control interventions.

Molecular characterization and toxigenic profiles of Bacillus cereus isolates from foodstuff and food poisoning outbreaks in Brazil.

Bacillus cereus sensu stricto (s.s.) is a well-known foodborne pathogen that produces a range of enterotoxins and is able to cause two different types of foodborne illnesses-the emetic and the diarrheal syndromes. In this study, 54 B. cereus s.s. strains isolated from foodstuff and foods involved in food poisoning outbreaks were characterized according to the presence of toxin-encoding genes, virulence-encoding genes, and panC typing. Most isolates were assigned to panC groups IV (61.1%) and III (25.9%), but members of groups II and V could also be found. Investigation of specific alleles revealed high numbers of isolates carrying toxin and other virulence genes including nheA (100%), nheB (100%), hblA (79.6%), hblC (79.6%), hblD (74.1%), cytK-2 (61.1%), clo (100%), pc-plc (75.9%), sph (68.5%), pi-plc (66.6%), hlyIII (62.9%), and hlyII (24.1%). All isolates were negative for ces and cytK-1. In summary, we detected various enterotoxin and other virulence factor genes associated with diarrheal syndrome in strains analyzed, implicated or not with food poisoning. Furthermore, the most isolates analyzed belong to high-risk phylogenetic groups' panC types III and IV. Our study provides a convenient molecular scheme for characterization of B. cereus s.s. strains responsible for food poisoning outbreaks in order to improve the monitoring and investigation and assess emerging clusters and diversity of strains.

A comparative study on biological activities of different solvent extracts from whole seed, seed coat and cotyledon of two Lathyrus species

Abstract The present study was conducted to assess the phenolic content, and antibacterial and antioxidant activities of Lathyrus L. species. The extraction of phenolic compounds from whole seeds, seed coat and cotyledon of Lathyrus hierosolymitanus Boiss. and Lathyrus annuus L. seeds was performed employing different solvents. Total phenolic content (TPC) was measured by Folin- Ciocalteau assay, while the antioxidant activity was determined by DPPH radical scavenging activity, and reducing power assay. It was found that TPC of extracts ranged from 0.12 mg to 6.53 mg GAE/gdw. For each solvent, seed coat extracts were generally observed to render higher TPC and antioxidant activities. There was a correlation between TPC and antioxidant activity. In addition, all extracts were also examined for their antimicrobial activity against Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. Methanol extracts showed the highest antibacterial activity which is consistent with TPC, but there was no correlation between TPC and antibacterial activity. Solvents were observed to have effects on gallic acid, caffeic acid, and epicatechin extractions. HPLC analysis results of extracts confirmed methanol and ethanol as preferred solvents for phenolic extraction from Lathyrus sp. Phenolic content in the extracts could be suggested to contribute to their antioxidant and antibacterial activity.

Controlling Bacillus cereus adherence to stainless steel with different cleaning and sanitizing procedures used in dairy plants / Controle do processo de adesão de Bacillus cereus ao aço inoxidável após diferentes procedimentos de limpeza e sanitização usados na indústria de laticínios

Bacillus cereus adherence to stainless steel used to milk contact surfaces was observed, depending on the cleaning and sanitizing procedures applied and the physicochemical properties of the surfaces. Numbers of surviving B. cereus after hygiene procedures were affected by temperature, the concentrations of both alkaline and acid washes, and the pH of the chlorine solution. The adhesion of B. cereus to the stainless steel was not thermodynamically favorable, and the adherence of this microorganism occurred in lower number, in accordance to the thermodynamic aspect of adhesion.

Foi observada a adesão de Bacillus cereus em superfície de aço inoxidável em contato com o leite, segundo o procedimento de limpeza, a sanitização e as propriedades físico-químicas da superfície. O número de B. cereus viáveis, após os procedimentos de higienização, foi afetado pela temperatura, pela concentração das soluções alcalinas e ácidas e pelo pH da solução clorada. A adesão de B. cereus em aço inoxidável não foi termodinamicamente favorável, e ocorreu pouca adesão desse microrganismo, de acordo com os aspectos termodinâmicos da adesão.