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Hajiali S, Daneshjou S, Daneshjoo S, Khajeh K. Biosynthesis Optimization of Antibacterial-Magnetic Iron Oxide Nanoparticles from Bacillus megaterium. Biol Trace Elem Res 2024:10.1007/s12011-024-04168-7. [PMID: 38607527 DOI: 10.1007/s12011-024-04168-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/31/2024] [Indexed: 04/13/2024]
Abstract
The occurrence of antibiotic resistance on common bacterial agents and the need to use new generations of antibiotics have led to the use of various strategies for production. Taking inspiration from nature, using bio-imitation patterns, in addition to the low cost of production, is advantageous and highly accurate. In this research, we were able to control the temperature, shake, and synthesis time of the synthesis conditions of Bacillus megaterium bacteria as a model for the synthesis of magnetic iron nanoparticles and optimize the ratio of reducing salt to bacterial regenerating agents as well as the concentration of salt to create iron oxide nanoparticles with more favorable properties and produced with more antibacterial properties. Bacterial growth was investigated by changing the incubation times of pre-culture and overnight culture in the range of the logarithmic phase. The synthesis time, salt ratio, and concentration were optimized to achieve the size, charge, colloidal stability, and magnetic and antibacterial properties of nanoparticles. The amount of the effective substance produced by the bacteria was selected by measuring the amount of the active substance synthesized using the free radical reduction (DPPH) method. With the help of DPPH, the duration of the synthesis was determined to be one week. Characterizations such as UV-vis spectroscopy, FTIR, FESEM, X-ray, and scattering optical dynamics were performed and showed that the nanoparticles synthesized with a salt concentration of 80 mM and a bacterial suspension to salt ratio of 2:1 are smaller in size and have a light scattering index, a PDI index close to 0.1, and a greater amount of reducing salt used in the reaction during one week compared to other samples. Moreover, they had more antibacterial properties than the concentration of 100 mM. As a result, better characteristics and more antibacterial properties than common antibiotics were created on E. coli and Bacillus cereus.
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Affiliation(s)
- Sajedeh Hajiali
- Department of Nanotechnology, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Sara Daneshjou
- Department of Nanobiotechnology, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
| | - Somayeh Daneshjoo
- Department of Medical Nanotechnology, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Khosro Khajeh
- Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran
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2
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Jovanovic A, Paunovic K, Ercegovac M, Popovic D, Davidovic D. Personal stethoscope disinfection practices and bacterial contamination: A cross-sectional study at the University Hospital Emergency Department in Belgrade, Serbia. Am J Infect Control 2024; 52:176-182. [PMID: 37598902 DOI: 10.1016/j.ajic.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/22/2023]
Abstract
BACKGROUND A significant reduction in bacterial growth on stethoscope membranes has been noticed after performing daily disinfection. Nevertheless, disinfection is rarely performed. We aimed to assess self-reported stethoscope disinfection practices among medical doctors, detect bacterial contamination on personal stethoscopes, and estimate the effectiveness of 70% ethanol as a stethoscope disinfecting agent. METHODS To determine stethoscope disinfection practices, participants filled out a questionnaire (N = 47), followed by providing stethoscopes for bacterial analysis. Differences in bacterial contamination were observed through the self-reported frequency and method of stethoscope disinfection. The effect of disinfecting with 70% ethanol was evaluated by comparing the presence of bacterial growth before and after disinfection. RESULTS The presence of bacterial growth was found in 78.7% of the stethoscope samples, with the median (interquartile range) number of colony-forming units at 25 (10-105). The frequency of disinfection greatly impacted the number of colony-forming units, and the method affected the presence of bacterial growth. Disinfection of stethoscope membranes using 70% ethanol resulted in a compelling 97.3% reduction of bacterial growth. CONCLUSIONS Adequate stethoscope disinfection is highly efficient in reducing bacterial contamination and as such should be considered a critical step in hygienic practices.
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Affiliation(s)
- Ana Jovanovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Institute of Hygiene and Medical Ecology, Belgrade, Serbia
| | - Katarina Paunovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Institute of Hygiene and Medical Ecology, Belgrade, Serbia
| | - Marko Ercegovac
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Clinic of Neurology, Clinical Center of Serbia, Belgrade, Serbia
| | - Dusan Popovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Department of Gastroenterology, Clinic for Internal Medicine, Clinical Hospital Center "Dr Dragisa Misovic-Dedinje", Belgrade, Serbia
| | - Dragana Davidovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Institute of Hygiene and Medical Ecology, Belgrade, Serbia.
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Kobayashi A, Higashi H, Shimada T, Suzuki S. Baseline and seasonal trends of Bacillus cereus and Bacillus subtilis from clinical samples in Japan. Infect Prev Pract 2023; 5:100272. [PMID: 36910424 PMCID: PMC9995940 DOI: 10.1016/j.infpip.2023.100272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 02/07/2023] [Indexed: 02/13/2023] Open
Abstract
Background Outbreaks of Bacillus cereus bloodstream infections (BSIs) are a concern in Japanese medical settings. Aim This study determined baseline values for B. cereus detection in clinical samples that are useful as reference values for hospitals when assessing the need for intervention. Method A retrospective analysis of B. cereus detection in the Japan Nosocomial Infections Surveillance data from 2008 to 2014 was performed; it included 950 individual hospitals across the country. Findings Bacillus spp. were detected in 0.54% of the clinical specimens submitted for bacteriological testing. Specimens positive for Bacillus spp. were mainly blood (24.6%), stool (26.5%), and respiratory specimens (23.3%). Identification of Bacillus spp. at the species level (i.e., B. cereus or B. subtilis) was reported in 55.3%, 14.7%, and 15.4% of cases, of which 88.9%, 48.3%, and 33.1% were B. cereus in blood, stool, and respiratory specimens, respectively. Of the 4105 hospital-years, 75.7% had blood specimens with Bacillus spp., with a median of 0.85 blood specimens/100 beds annually (interquartile range, 0.17-2.10). The B. cereus detection showed significant summer seasonality, regardless of specimen type or geographic distribution. The B. subtilis detection did not show seasonality, and its detection remained constant throughout the year. The seasonality of Bacillus spp. reflects the high proportion of B. cereus. Conclusions The increased detection rate of Bacillus spp. during summer should be interpreted as a risk factor for B. cereus BSIs. A post-summer decrease in Bacillus spp. should not be interpreted as an effect of interventions.
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Affiliation(s)
- Ayako Kobayashi
- Field Epidemiology Training Program, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hideaki Higashi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Tomoe Shimada
- Center for Field Epidemiology Intelligence, Research, and Professional Development, National Institute of Infectious Diseases, Tokyo, Japan
| | - Satowa Suzuki
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan
- Corresponding author. Address: Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan. Contact number 81-3-5285-1111(ext. 6310).
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Complete Genome Sequences of 24 Strains of Bacillus cereus Isolated from Nosocomial Infection and Bacteremia Cases in Japan. Microbiol Resour Announc 2022; 11:e0120321. [PMID: 35289651 PMCID: PMC9022585 DOI: 10.1128/mra.01203-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacillus cereus is mainly associated with foodborne illness but sometimes causes nosocomial infections. We previously reported that B. cereus strains of a specific sequence type, ST1420, were associated with nosocomial infection. Here, we determined the complete genome sequences of B. cereus strains isolated from nosocomial infection cases in Japanese hospitals.
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Fatani S, Saito Y, Alarawi M, Gojobori T, Mineta K. Genome sequencing and identification of cellulase genes in Bacillus paralicheniformis strains from the Red Sea. BMC Microbiol 2021; 21:254. [PMID: 34548024 PMCID: PMC8456639 DOI: 10.1186/s12866-021-02316-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 09/08/2021] [Indexed: 11/23/2022] Open
Abstract
Background Cellulolytic microorganisms are considered a key player in the degradation of plant biomass in various environments. These microorganisms can be isolated from various environments, such as soils, the insect gut, the mammalian rumen and oceans. The Red Sea exhibits a unique environment in terms of presenting a high seawater temperature, high salinity, low nutrient levels and high biodiversity. However, there is little information regarding cellulase genes in the Red Sea environment. This study aimed to examine whether the Red Sea can be a resource for the bioprospecting of microbial cellulases by isolating cellulase-producing microorganisms from the Red Sea environment and characterizing cellulase genes. Results Three bacterial strains were successfully isolated from the plankton fraction and the surface of seagrass. The isolated strains were identified as Bacillus paralicheniformis and showed strong cellulase activity. These results suggested that these three isolates secreted active cellulases. By whole genome sequencing, we found 10 cellulase genes from the three isolates. We compared the expression of these cellulase genes under cellulase-inducing and non-inducing conditions and found that most of the cellulase genes were generally upregulated during cellulolysis in the isolates. Our operon structure analysis also showed that cellulase genes form operons with genes involved in various kinds of cellular reactions, such as protein metabolism, which suggests the existence of crosstalk between cellulolysis and other metabolic pathways in the bacterial isolates. These results suggest that multiple cellulases are playing important roles in cellulolysis. Conclusions Our study reports the isolation and characterization of cellulase-producing bacteria from the Red Sea. Our whole-genome sequencing classified our three isolates as Bacillus paralicheniformis, and we revealed the presence of ten cellulase orthologues in each of three isolates’ genomes. Our comparative expression analysis also identified that most of the cellulase genes were upregulated under the inducing conditions in general. Although cellulases have been roughly classified into three enzyme groups of beta-glucosidase, endo-β-1,4-glucanase and exoglucanase, these findings suggest the importance to consider microbial cellulolysis as a more complex reaction with various kinds of cellulase enzymes. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02316-w.
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Affiliation(s)
- Siham Fatani
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Yoshimoto Saito
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.,Marine Open Innovation Institute (MaOI), Shizuoka, Japan
| | - Mohammed Alarawi
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Takashi Gojobori
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
| | - Katsuhiko Mineta
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
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Nakayama T, Yamaguchi T, Jinnai M, Yamamoto S, Li HT, Ngo PT, Tran DNM, Nguyen OTH, Hoang PH, Do Nguyen P, Van Dang C, Kumeda Y, Hase A. Untargeted Phylogenetic Group III of Multi-drug-Resistant Bacillus cereus Isolated Using Fraser Medium from Retail Chickens in Ho Chi Minh City. Curr Microbiol 2021; 78:3115-3123. [PMID: 34173839 DOI: 10.1007/s00284-021-02562-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 05/31/2021] [Indexed: 11/26/2022]
Abstract
The prevalence of food-borne bacteria in developing countries is less well understood than in developed countries. The ISO11290-1 isolation method is commonly used to study Listeria contamination in chicken; however, all isolates are identified as untargeted Bacillus cereus. This study aimed to determine the classification, antibiotic susceptibility, and virulence genes of B. cereus isolated from retail chickens in Vietnam. Bacterial isolation using the ISO11290-1 method yielded 12 strains of B. cereus from seven out of 60 chickens. For determining bacterial diversity, panC and multilocus sequence typing (MLST) analyses were performed. PanC analysis showed that all seven strains belong to the phylogenetic group III, to which the highest risk of foodborne illnesses was associated. MLST analysis showed that most strains contained a ST205 complex; further, all strains were found to be resistant to ampicillin, ciprofloxacin, and tetracycline. Virulence genes were also investigated. ces, a cereulide-related gene, was detected in 50% of the isolated strains, followed by cytK, nheA, and hblA enterotoxins in 41.7%, 16.7%, and 25% of the strains, respectively. In conclusion, B. cereus may be erroneously detected when attempting to detect Listeria in food using the ISO11290-1 method. Further study of the prevalence of B. cereus in Vietnamese food is needed to improve food safety.
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Affiliation(s)
- Tatsuya Nakayama
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan.
- Division of Biomedical Food Research, National Institute of Health Sciences, Kawasaki, Kanagawa, Japan.
| | - Takahiro Yamaguchi
- Department of Microbiology, Osaka Institute of Public Health, Higashinari-ku, Osaka, Japan
| | - Michio Jinnai
- Department of Microbiology, Kanagawa Prefecture Institute of Public Health, Chigasaki, Kanagawa, Japan
| | - Shiori Yamamoto
- Division of Biomedical Food Research, National Institute of Health Sciences, Kawasaki, Kanagawa, Japan
| | - Hien Thi Li
- Ho Chi Minh Institute of Public Health, Ho Chi Minh City, Vietnam
| | - Phong Thanh Ngo
- Ho Chi Minh Institute of Public Health, Ho Chi Minh City, Vietnam
| | | | | | | | - Phuc Do Nguyen
- Ho Chi Minh Institute of Public Health, Ho Chi Minh City, Vietnam
| | - Chinh Van Dang
- Ho Chi Minh Institute of Public Health, Ho Chi Minh City, Vietnam
| | - Yuko Kumeda
- Center for Microorganism Control, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Atsushi Hase
- Faculty of Contemporary Human Life Science, Tezukayama University, Nara, Japan
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Carroll LM, Cheng RA, Wiedmann M, Kovac J. Keeping up with the Bacillus cereus group: taxonomy through the genomics era and beyond. Crit Rev Food Sci Nutr 2021; 62:7677-7702. [PMID: 33939559 DOI: 10.1080/10408398.2021.1916735] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Bacillus cereus group, also known as B. cereus sensu lato (s.l.), is a species complex that contains numerous closely related lineages, which vary in their ability to cause illness in humans and animals. The classification of B. cereus s.l. isolates into species-level taxonomic units is thus essential for informing public health and food safety efforts. However, taxonomic classification of these organisms is challenging. Numerous-often conflicting-taxonomic changes to the group have been proposed over the past two decades, making it difficult to remain up to date. In this review, we discuss the major nomenclatural changes that have accumulated in the B. cereus s.l. taxonomic space prior to 2020, particularly in the genomic sequencing era, and outline the resulting problems. We discuss several contemporary taxonomic frameworks as applied to B. cereus s.l., including (i) phenotypic, (ii) genomic, and (iii) hybrid nomenclatural frameworks, and we discuss the advantages and disadvantages of each. We offer suggestions as to how readers can avoid B. cereus s.l. taxonomic ambiguities, regardless of the nomenclatural framework(s) they choose to employ. Finally, we discuss future directions and open problems in the B. cereus s.l. taxonomic realm, including those that cannot be solved by genomic approaches alone.
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Affiliation(s)
- Laura M Carroll
- Structural and Computational Biology Unit, EMBL, Heidelberg, Germany
| | - Rachel A Cheng
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Jasna Kovac
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
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Cerar Kišek T, Pogačnik N, Godič Torkar K. Genetic diversity and the presence of circular plasmids in Bacillus cereus isolates of clinical and environmental origin. Arch Microbiol 2021; 203:3209-3217. [PMID: 33830284 DOI: 10.1007/s00203-021-02302-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
The diversity of 61 Bacillus cereus strains isolated from different clinical specimens, food including raw milk and milk products, and water was evaluated. PFGE analysis could discriminate 61 distinct pulsotypes with similarity levels from 25 to 82%, which were divided into 13 clonal complexes. The similarity between clonal complexes was at least 40%. Clinical strains were divided into 10 clonal complexes, while the strains, isolated from milk, food and water were included in 9, 6 and 6 clonal complexes, respectively. Three clonal complexes were dominated by clinical isolates, while they were absent in two complexes. Bacterial isolates from food, being a probable source of alimentary toxoinfection, showed low similarity to isolates from stool specimens. The isolates from both sources were classified together in only 4 out of 13 clonal complexes. The large circular and linear plasmids with the sizes between 50 and 200 kb were detected in 24 (39.3%) and 14 (23%) B. cereus strains, respectively. Thirteen (21.3%) strains contained only one plasmid, two plasmids were found in 6 (9.8%) of strains, and three or more plasmids were obtained in 5 (8.2%) of tested strains. The plasmids were confirmed in 30.8% and 40% of isolates from clinical specimens and food and milk samples, respectively. No clear correlation between the PFGE profiles, the source as well as plasmid content among all tested strains was observed.
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Affiliation(s)
- Tjaša Cerar Kišek
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Nežka Pogačnik
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000, Ljubljana, Slovenia
| | - Karmen Godič Torkar
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000, Ljubljana, Slovenia.
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Carroll LM, Cheng RA, 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. [PMID: 33072050 PMCID: PMC7536271 DOI: 10.3389/fmicb.2020.580691] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/25/2020] [Indexed: 12/19/2022] Open
Abstract
The Bacillus cereus group, also known as B. cereus sensu lato (s.l.), is a species complex comprising numerous closely related lineages, which vary in their ability to cause illness in humans and animals. The classification of B. cereus s.l. isolates into species-level taxonomic units is essential for facilitating communication between and among microbiologists, clinicians, public health officials, and industry professionals, but is not always straightforward. A recently proposed genomospecies-subspecies-biovar taxonomic framework aims to provide a standardized nomenclature for this species complex but relies heavily on whole-genome sequencing (WGS). It thus is unclear whether popular, low-cost typing methods (e.g., single- and multi-locus sequence typing) remain congruent with the proposed taxonomy. Here, we characterize 2,231 B. cereus s.l. genomes using a combination of in silico (i) average-nucleotide identity (ANI)-based genomospecies assignment, (ii) ANI-based subspecies assignment, (iii) seven-gene multi-locus sequence typing (MLST), (iv) single-locus panC group assignment, (v) rpoB allelic typing, and (vi) virulence factor detection. We show that sequence types (STs) assigned using MLST can be used for genomospecies assignment, and we provide a comprehensive list of ST/genomospecies associations. For panC group assignment, we show that an adjusted, eight-group framework is largely, albeit not perfectly, congruent with the proposed eight-genomospecies taxonomy, as panC alone may not distinguish (i) B. luti from Group II B. mosaicus and (ii) B. paramycoides from Group VI B. mycoides. We additionally provide a list of loci that capture the topology of the whole-genome B. cereus s.l. phylogeny that may be used in future sequence typing efforts. For researchers with access to WGS, MLST, and/or panC data, we showcase how our recently released software, BTyper3 (https://github.com/lmc297/BTyper3), can be used to assign B. cereus s.l. isolates to taxonomic units within this proposed framework with little-to-no user intervention or domain-specific knowledge of B. cereus s.l. taxonomy. We additionally outline a novel method for assigning B. cereus s.l. genomes to pseudo-gene flow units within proposed genomospecies. The results presented here highlight the backward-compatibility and accessibility of the recently proposed genomospecies-subspecies-biovar taxonomic framework and illustrate that WGS is not a necessity for microbiologists who want to use the proposed nomenclature effectively.
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Affiliation(s)
- Laura M. Carroll
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Rachel A. Cheng
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Jasna Kovac
- Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, PA, United States
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Aoyagi T, Kishihara Y, Ogawa M, Ito Y, Tanaka S, Kobayashi R, Tokuda K, Kaku M. Characterization of Ba813 harbouring Bacillus cereus in patients with haematological malignancy and hospital environments at a medical centre in Japan. J Med Microbiol 2020; 69:999-1004. [PMID: 32530394 DOI: 10.1099/jmm.0.001212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction. Bacillus cereus harbouring Ba813, a specific chromosomal marker of Bacillus anthtacis, is found in patients with severe manifestations and causes nosocomial outbreaks.Aim. We assessed the genetic characteristics and virulence of Ba813(+) B. cereus in a hospital setting.Methodology. Three neutropenic patients with haematological malignancy developed B. cereus bacteraemia within a short period. Fifteen B. cereus were isolated from different sites in a haematology ward. A total of 18 isolates were evaluated for Ba813- and B. anthracis-related virulence, food poisoning-related virulence, genetic diversity, bacteria motility and biofilm formation.Results. Ba813(+) B. cereus was detected in 33 % (1/3) of patients and 66 % (9/15) of the hospital environment. The 18 strains were divided into 2 major clusters (clade 1 and clade 2), and 14 strains were classified into clade 1. All Ba813(+) strains, including four sequence types, were classified into clade 1/the cereus III lineage, which is most closely related to the anthracis lineage. Two strains belonging to clade 1/non-cereus III carried the B. anthracis-associated cap gene, but not Ba813. B. cereus, including Ba813(+) strains, had significantly lower prevalence of enterotoxin genes than clade 2 strains. In clade 1, B. cereus, Ba813(+) strains showed significantly higher swimming motility and biofilm formation ability than Ba813(-) strains.Conclusion. Ba813(+) B. cereus, which are genetically closely related to B. anthracis, were abundant in a haematological ward. Ba813(+) B. cereus with high motility and biofilm formation abilities may spread easily in hospital environments, and could become a hospital-acquired infection.
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Affiliation(s)
- Tetsuji Aoyagi
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aobaku, Sendai, Japan
| | - Yasuhiro Kishihara
- Infection Control Team, National Hospital Organization Kyushu Medical Center, 1-8-1 Jigyohama, Chuo-ku, Fukuoka, Japan
| | - Miho Ogawa
- Department of Bacteriology, BML, Inc., 1361-1, Matoba, Kawagoe, Japan
| | - Yuki Ito
- Infection Control Team, National Hospital Organization Kyushu Medical Center, 1-8-1 Jigyohama, Chuo-ku, Fukuoka, Japan
| | - Sakie Tanaka
- Infection Control Team, National Hospital Organization Kyushu Medical Center, 1-8-1 Jigyohama, Chuo-ku, Fukuoka, Japan
| | - Ryozo Kobayashi
- Infection Control Team, National Hospital Organization Kyushu Medical Center, 1-8-1 Jigyohama, Chuo-ku, Fukuoka, Japan
| | - Koichi Tokuda
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aobaku, Sendai, Japan.,Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aobaku, Sendai, Japan
| | - Mistuo Kaku
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aobaku, Sendai, Japan.,Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aobaku, Sendai, Japan
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11
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Aoyagi T, Oshima K, Endo S, Baba H, Kanamori H, Yoshida M, Tokuda K, Kaku M. Ba813 harboring Bacillus cereus, genetically closely related to Bacillus anthracis, causing nosocomial bloodstream infection: Bacterial virulence factors and clinical outcome. PLoS One 2020; 15:e0235771. [PMID: 32658912 PMCID: PMC7357740 DOI: 10.1371/journal.pone.0235771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022] Open
Abstract
Bacillus cereus commonly causes catheter-related bloodstream infections (BSIs) in hospital settings, and occasionally occurs fatal central nervous system (CNS) complications. B. cereus harboring Ba813, a specific chromosomal marker of Bacillus anthracis, has been found in patients with severe infection and nosocomial BSI. However, the bacteriological profile and clinical feature of Ba813 (+) B. cereus are unclear. Fifty-three patients with B. cereus BSI were examined. Isolates were evaluated for Ba813, B. anthracis-related and food poisoning-related virulence, multilocus sequencing typing, and biofilm formation. Patients’ clinical records were reviewed retrospectively. The 53 isolates were comprised of 29 different sequence types in two distinct clades. Seventeen of the 53 (32%) B. cereus isolates including five sequence types possessed Ba813 and were classified into Clade-1/Cereus-III lineage which is most closely related to Anthracis lineage. No B. cereus possessed B. anthracis-related virulence genes. Ba813 (+) strains showed a lower prevalence of enterotoxin genes than Clade-2 strains (n = 4), but no difference from Clade-1. Ba813 (+) strains showed significantly lower biofilm formation than Clade-1/non-Cereus-III (n = 22) and Clade-2 strains, respectively. Compared to Clade-1/non-Cereus-III and Clade-2 B. cereus, Ba813 (+) strains were isolated more frequently from elderly patients, patients with indwelling central venous catheter rather than peripheral venous catheter, and patients who remained in the hospital for longer before BSI onset. No significant differences in disease severity or mortality were observed. Though two of the ten Ba813 (-) strains in Clade-1/Cereus III were isolated from the patients with CNS complication, no significant difference was observed in the bacterial profile and clinical characteristics among Clade-1/Cereus III strains. In conclusion, our report suggested that Ba813-harboring B. cereus strains, genetically closely related to B. anthracis, were abundant among B. cereus strains in the hospital setting, and might cause catheter-related nosocomial BSI. However, it did not affect the clinical outcomes.
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Affiliation(s)
- Tetsuji Aoyagi
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
| | - Kengo Oshima
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shiro Endo
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroaki Baba
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hajime Kanamori
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Makiko Yoshida
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Koichi Tokuda
- Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Mitsuo Kaku
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Infectious Diseases, Tohoku Medical and Pharmaceutical University, Sendai, Japan
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Phylogenetic Analysis of Bacillus cereus sensu lato Isolates from Commercial Bee Pollen Using tRNA Cys-PCR. Microorganisms 2020; 8:microorganisms8040524. [PMID: 32268545 PMCID: PMC7232370 DOI: 10.3390/microorganisms8040524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/25/2020] [Accepted: 04/03/2020] [Indexed: 01/06/2023] Open
Abstract
Endospore-forming bacteria related to the Bacillus cereus group produce toxins that cause illnesses in organisms from invertebrates to mammals, including foodborne illnesses in humans. As commercial bee pollen can be contaminated with these bacteria, a comprehensive microbiological risk assessment of commercial bee pollen must be incorporated into the relevant regulatory requirements, including those that apply in Mexico. To facilitate detection of members of this group of bacteria, we have developed a PCR strategy that is based on the amplification of the single-copy tRNACys gene and specific genes associated with tRNACys to detect Bacillus cereus sensu lato (B. cereus s.l.). This tRNACys-PCR-based approach was used to examine commercial bee pollen for endospore-forming bacteria. Our analysis revealed that 3% of the endospore-forming colonies isolated from a commercial source of bee pollen were related to B. cereus s.l., and this result was corroborated by phylogenetic analysis, bacterial identification via MALDI-TOF MS, and detection of enterotoxin genes encoding the HBL and NHE complexes. The results show that the isolated colonies are closely related phylogenetically to B. cereus, B. thuringiensis, and B. bombysepticus. Our results indicate that the tRNACys-PCR, combined with other molecular tools, will be a useful approach for identifying B. cereus s.l. and will assist in controlling the spread of potential pathogens.
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Oda M, Yokotani A, Hayashi N, Kamoshida G. Role of Sphingomyelinase in the Pathogenesis of Bacillus cereus Infection. Biol Pharm Bull 2020; 43:250-253. [DOI: 10.1248/bpb.b19-00762] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Masataka Oda
- Department of Microbiology and Infection Control Sciences, Kyoto Pharmaceutical University
| | - Atsushi Yokotani
- Department of Microbiology and Infection Control Sciences, Kyoto Pharmaceutical University
| | - Naoki Hayashi
- Department of Microbiology and Infection Control Sciences, Kyoto Pharmaceutical University
| | - Go Kamoshida
- Department of Microbiology and Infection Control Sciences, Kyoto Pharmaceutical University
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