Characterization of Bacillus cereus Isolates from Raw Soybean Sprouts

2004 ◽  
Vol 67 (5) ◽  
pp. 1031-1035 ◽  
Author(s):  
HYE-JUNG KIM ◽  
DONG SUN LEE ◽  
HYUN-DONG PAIK

Raw soybean sprouts, which are used as ingredients in cook-chilled products, were analyzed to evaluate the incidence of mesophilic aerobic microorganisms, psychrotrophic microorganisms, anaerobic microorganisms, coliforms, and spore-forming microorganisms Bacillus cereus, Clostridium botulinum, and Clostridium perfringens. Mesophilic microorganisms on raw soybean sprouts were present in large populations, 5.5 × 106 to 1.4 × 108 CFU/g, and psychrotrophic microorganisms were found to be more numerous than the other groups. Coliforms accounted for 15% of mesophilic microorganism counts on average, and the average for spore-forming microorganisms was 5.2 × 102 CFU/g. B. cereus was isolated from 12 of 17 soybean sprout samples, whereas C. botulinum and C. perfringens were not isolated. B. cereus was isolated in greater numbers at 30° C compared with other temperatures and was not isolated at 4° C. Of the 55 strains isolated from soybean sprouts, 52 were positive for starch hydrolysis, and only 3 strains did not hydrolyze starch. Among the 55 strains of B. cereus isolates, 53 showed the ability to produce diarrheal enterotoxin by CRET-RPLA.

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 472 ◽  
Author(s):  
Balgabay Maikanov ◽  
Raikhan Mustafina ◽  
Laura Auteleyeva ◽  
Jan Wiśniewski ◽  
Krzysztof Anusz ◽  
...  

The aim of this study was to assess occurrence of Clostridium botulinum and Clostridium perfringens in honey samples from Kazakhstan. Analyses were carried out using a set of PCR methods for identification of anaerobic bacteria, and detection of toxin genes of C. botulinum and C. perfringens. Among 197 samples, C. botulinum was noticed in only one (0.5%). The isolated strain of this pathogen showed the presence of the bont/A and ntnh genes. C. perfringens strains were isolated from 18 (9%) samples, and mPCR (multiplex PCR) analysis led to them all being classified as toxin type A with the ability to produce α toxin. Sequence analysis of 16S rDNA genes showed occurrence in 4 samples of other anaerobes related to C. botulinum, which were C. sporogenes and C. beijerinckii strains. C. botulinum prevalence in honey samples from Kazakhstan in comparison to the prevalence in samples collected from the other regions seems to be less. The highest prevalence of Clostridium sp. was noticed in the East Kazakhstan province. Our study is the first survey on BoNT-producing clostridia and C. perfringens prevalence in Kazakh honey.


2008 ◽  
Vol 71 (6) ◽  
pp. 1178-1185 ◽  
Author(s):  
T. RAHMATI ◽  
R. LABBE

For the period 1990 through 2003, seafood was the most commonly identified food linked to foodborne outbreaks in the United States. Fish as a commodity has rarely been examined for the presence of Bacillus cereus in particular. For the present study, 347 fresh and processed retail seafood samples were examined for the presence of Clostridium botulinum, Clostridium perfringens, and B. cereus. The presence of C. botulinum was not confirmed in any of the isolates, but C. perfringens was confirmed in 17 samples. One of the C. perfringens isolates possessed the enterotoxin gene, as determined by PCR. In contrast, 62 confirmed B. cereus isolates were obtained from separate samples at levels ranging from 3.6 to >1,100 CFU/g. Thirty (48%) of 62 isolates produced both the hemolysin BL (HBL) and nonhemolytic (NHE) enterotoxins, and 58 (94%) and 31 (50%) produced NHE or HBL toxins, respectively. The presence of at least one of the three genes of the NHE complex was detected in 99% of the isolates; 69% of the isolates possessed all three genes. In contrast, 71% of the isolates possessed at least one of the three genes of the HBL complex, and 37% possessed all three HBL gene components. Fifty of the 62 B. cereus isolates were from imported seafood, and 19 (38%) of these samples were at levels >100 CFU/g. Twelve of the 14 highest enterotoxin assay results were from isolates from imported food. Only one B. cereus isolate possessed the cereulide synthetase gene, ces; this isolate also possessed the genes for the three-component HBL and NHE complexes. A majority of enterotoxin-producing isolates were resistant to 2 of 10 antibiotics tested, ceftriaxone and clindamycin. Our results demonstrate the potential of seafood as a vehicle for foodborne illness caused by B. cereus, in particular the enterotoxin-producing genotype.


1982 ◽  
Vol 45 (3) ◽  
pp. 244-248 ◽  
Author(s):  
J. D. KEMP ◽  
B. E. LANGLOIS ◽  
A. E. JOHNSON

Hams were placed in cure after thawing by 3 methods: at 2C, at 16C, and in water at 37C. A fourth group was placed in cure while still frozen. Microbiological populations and fat rancidity tests were determined at various intervals during processing. Sensory scores and tenderness values were determined after 3 months of aging. Clostridium perfringens, Bacillus cereus, Escherichia coli, coliforms and enterococci were not detected after salt equalization. Hams cured without thawing had lower initial bacterial, yeast and mold counts but no differences among thaw groups were observed in counts during aging. Hams thawed in water had lower flavor and overall satisfaction scores than the other groups. Fat breakdown as noted by FFA, TBA and peroxide values increased with aging but were erratic although ham cured without thawing had lower peroxide values. Satisfactory dry-cured aged hams were produced regardless of method of thawing. However, since hams cured without thawing had less weight loss, lower peroxide numbers, lower initial microbial counts and similar final microbial counts and sensory scores, it appears that hams do not need to be thawed to produce dry-cured aged hams.


2011 ◽  
Vol 77 (16) ◽  
pp. 5761-5769 ◽  
Author(s):  
Pablo Soriano-Maldonado ◽  
Ana Isabel Martínez-Gómez ◽  
Montserrat Andújar-Sánchez ◽  
José L. Neira ◽  
Josefa María Clemente-Jiménez ◽  
...  

ABSTRACTFormamidases (EC 3.5.1.49) are poorly characterized proteins. In spite of this scarce knowledge, ammonia has been described as playing a central role in the pathogenesis of human pathogens such asHelicobacter pylori, for which formamidase has been shown to participate in the nitrogen metabolic pathway. Sequence analysis has revealed that at least two different groups of formamidases are classified as EC 3.5.1.49: on the one hand, the derivatives of the FmdA-AmdA superfamily, which are the best studied to date, and on the other hand, the derivatives ofHelicobacter pyloriAmiF. Here we present the cloning, purification, and characterization of a recombinant formamidase fromBacillus cereusCECT 5050T (BceAmiF), the second member of the AmiF subfamily to be characterized, showing new features of the enzyme further supporting its relationship with aliphatic amidases. We also present homology modeling-based mutational studies confirming the importance of the Glu140 and Tyr191 residues in the enzymatic activities of the AmiF family. Moreover, we can conclude that a second glutamate residue is critical in several members of the nitrilase superfamily, meaning that what has consistently been identified as a C-E-K triad is in fact a C-E-E-K tetrad.


1996 ◽  
Vol 59 (2) ◽  
pp. 193-196 ◽  
Author(s):  
GHADA HASSAN ◽  
NASSIM NABBUT

Bacillus cereus clinical isolates recovered from blood, wounds and diarrheal feces as well as natural isolates from normal feces, rice, dehydrated milk, and soil were characterized with respect to their biochemical profiles, antimicrobial susceptibility and enterotoxigenicity. The biochemical profiles of all the isolates were similar regardless of their sources. However, some degree of variability was shown in the Voges-Proskauer, nitrate reduction, and esculin hydrolysis tests and in the ability to grow in the presence of 40% bile. All the isolates were resistant to amoxicillin, oxacillin, and penicillin and susceptible to gentamicin and vancomycin. Susceptibility to cephalothin was variable among the clinical isolates, whereas susceptibility to clindamycin and erythromycin was inconsistent for all of them. The B. cereus clinical isolates recovered from human diarrheal feces were found to be strong producers of diarrheal enterotoxin as revealed by induction of diarrhea in mice and vascular permeability reaction. The clinical isolates recovered from wounds and blood and the natural isolates recovered from rice, milk, and normal feces, on the other hand, were weak producers of diarrheal enterotoxin.


2020 ◽  
Vol 161 (48) ◽  
pp. 2019-2028
Author(s):  
Katalin Eszter Müller ◽  
Ferenc Rozgonyi

Összefoglaló. Az élelmiszer-eredetű megbetegedések igen gyakoriak, bár pontos adatok nem állnak rendelkezésre, mivel az enyhe, gyorsan múló gastrointestinalis tünetekkel a betegek nem fordulnak orvoshoz, vagy nem történik diagnosztikus vizsgálat. Az amerikai Járványügyi és Betegségmegelőzési Központ (CDC) adatai szerint az USA-ban évente 6 lakosból 1 esik át élelmiszer okozta tüneteken. Az ételintoxikációk során a baktérium által termelt toxinok okozzák a tüneteket, közülük a leggyakoribb a Clostridium perfringens, a Staphylococcus aureus és a Bacillus cereus okozta, élelmiszer-eredetű intoxikáció. A nem megfelelően tárolt vagy hőkezelt élelmiszerekben – beleértve a S. aureus által szennyezett anyatejet – ezen baktériumok életképesek maradnak, elszaporodnak, és toxint termelhetnek, illetve toxinjaik megőrzik megbetegítőképességüket. Az étel elfogyasztása után 3–12 órával hányást, hasmenést okoznak. A tünetek többnyire 24 órán belül megszűnnek. A Clostridium botulinum súlyos neurológiai tünetei miatt emelkedik ki a többi toxikoinfekció sorából. C. botulinum okozta tünetekre felnőtteknél házi készítésű konzervek és húskészítmények elfogyasztása után jelentkező gastrointestinalis vagy neurológiai tünetek esetén kell gondolnunk. A Clostridioides difficile szintén a toxinjai révén okoz súlyos, életveszélyes megbetegedést, továbbá az esetek 20–30%-ában számolnunk kell az infekció relapsusával. Növekvő gyakorisága miatt ismernünk érdemes a laboratóriumi és klinikai diagnosztika részleteit és a legmodernebb kezelési lehetőségeket, úgymint megfelelő mintavétel, mintatárolás és -szállítás, tenyésztés, toxinkimutatás, helyes tüneti kezelés, antibiotikumkombinációk, széklettranszplantáció és monoklonálisantitest-kezelés. Orv Hetil. 2020; 161(48): 2019–2028. Summary. Foodborne diseases are quite common, however, accurate data are not available because patients do not visit doctors with mild, rapidly resolving symptoms and diagnostic tests are not performed. The Centers of Disease Control and Prevention (CDC) estimates that, in the USA, 1 in 6 citizens gets food poisoning yearly. Symptoms of intoxication are due to the toxins produced by bacteria, mostly by Clostridium perfringens, Staphylococcus aureus and Bacillus cereus. These bacteria can survive in not properly stored or heated food, including S. aureus contaminated breastmilk. They can multiply and produce toxins causing intoxications. The gastrointestinal symptoms start 3–12 hours after consumption of the contaminated food and resolve in 24 hours. Clostridium botulinum causes severe neurological symptoms that should be suspected after consumption of home-made cans, smoked hams and sausages. The disease caused by Clostridioides difficile is not a foodborne one, but C. difficile causes severe infection via its toxins. Another problem is that C. difficile infection recurs in 20–30% of cases. Due to the increasing incidence of foodborne diseases, it is worth to learn the precise clinical and laboratory diagnostic algorithms including sampling, storage and transportation of samples, cultivation of bacteria and differential diagnosis of these diseases, furthermore the most up-to-date symptomatic and causative treatment options like antibiotic combinations, stool transplantation and monoclonal antibodies. Orv Hetil. 2020; 161(48): 2019–2028.


2006 ◽  
Vol 72 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Luc M. Hornstra ◽  
Ynte P. de Vries ◽  
Marjon H. J. Wells-Bennik ◽  
Willem M. de Vos ◽  
Tjakko Abee

ABSTRACT Specific amino acids, purine ribonucleosides, or a combination of the two is required for efficient germination of endospores of Bacillus cereus ATCC 14579. A survey including 20 different amino acids showed that l-alanine, l-cysteine, l-threonine, and l-glutamine are capable of initiating the germination of endospores of B. cereus ATCC 14579. In addition, the purine ribonucleosides inosine and adenosine can trigger germination of the spores. Advanced annotation of the B. cereus ATCC 14579 genome revealed the presence of seven putative germination (ger) operons, termed gerG, gerI, gerK, gerL, gerQ, gerR, and gerS. To determine the role of the encoded putative receptors in nutrient-induced germination, disruption mutants were constructed by the insertion of pMUTIN4 into each of the seven operons. Four of the seven mutants were affected in the germination response to amino acids or purine ribonucleosides, whereas no phenotype could be attributed to the mutants with disrupted gerK, gerL, and gerS loci. The strain with a disrupted gerR operon was severely hampered in the ability to germinate: germination occurred in response to l-glutamine but not in the presence of any of the other amino acids tested. The gerG mutant showed significantly reduced l-glutamine-induced germination, which points to a role of this receptor in the l-glutamine germination signaling pathway. gerR, gerI, and gerQ mutants showed reduced germination rates in the presence of inosine, suggesting a role for these operons in ribonucleoside signaling. Efficient germination by the combination of l-glutamine and inosine was shown to involve the gerG and gerI operons, since the germination of mutants lacking either one of these receptors was significantly reduced. Germination triggered by the combination of l-phenylalanine and inosine was lost in the gerI mutant, indicating that both molecules are effective at the GerI receptor.


Author(s):  
J. I. Bennetch

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.


1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.


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