We isolated the strain MBL13 with high collagenase productivity from the soil of piled up animal bones. It was identified as Bacillus cereus. We purified and characterized Bacillus cereus collagenase (BCC). The molecular weight of BCC was 38.0 kDa and the optimum temperature and pH for the enzyme activity were 40 degrees C and 8.0 respectively. The enzyme was stable when the temperature was below 50 degrees C, but only retained 10% activity when kept at 60 degrees C for 1 h. The enzyme activity was stable between pH 7.0-8.5. Some metal ions such as Ca2+, Zn2+, Mg2+ enhanced the enzyme activity, and Cu2+ brought the obvious inhibition. In addition, EDTA and EGTA could inhibit the enzyme activity. We suggested that the purified enzyme was a member of the metalloproteases. Based on the experiment of substrate specificity, we found that the purified enzyme was bone collagenolytic protease, and had a much stronger capacity of hydrolysis for type I collagen than that for type II collagen and type III collagen. By BCC hydrolyzing bone collagen, we obtained polypeptides with different chain lengths. The comparative test indicated that the hydrolysis capacity of BBC was higher than that of standard type I collagenase. The results introduced a new strain and a novel collagenolytic protease for industrial enzyme.
Animals ; Bacillus cereus ; enzymology ; isolation & purification ; Bone and Bones ; microbiology ; Collagenases ; biosynthesis ; isolation & purification ; Hydrolysis ; Soil Microbiology

In order to develop a rapid and reliable method for B. cereus genotyping, factors influencing PFGE results, including preparation of bacterial cells embedded in agarose, lysis of embedded cells, enzymatic digestion of intact genomic DNA, and electrophoresis parameters allowing for reproducible and meaningful DNA fragment separation, were controlled. Optimal cellular growth (Luria-Bertani agar plates for 12-18 h) and lysis conditions (4 h incubation with 500 µg/mL lysozyme) produced sharp bands on the gel. Restriction enzyme NotI was chosen as the most suitable. Twenty-two isolates were analyzed by NotI digestion, using three electrophoretic parameters (EPs). The EP-a was optimal for distinguishing between isolates. The optimized protocol could be completed within 40 h which is a significant improvement over the previous methods.
Bacillus cereus ; genetics ; isolation & purification ; Bacteriological Techniques ; DNA, Bacterial ; chemistry ; genetics ; Electrophoresis, Gel, Pulsed-Field ; methods

OBJECTIVETo study clinical characteristics and resistance of wound surface infections, so as to guide clinical diagnosis and rational administration.

METHODSThe clinical setting and laboratory results were collected by analyzing 20 strains of Bacillus cereus isolated from clinical samples in patients from our hospital from October 2011 to June 2012, including 18 males and 2 females,ranging in age from 22 to 67 years old, averaged (47.30 +/- 11.16) years old. The courses of disease ranged from 5 to 20 days. All the patients were treated with nutrition support therapy, debridement and the corresponding antibiotic therapy. The patients had anemia, low protein hyperlipidemia and wound contamination history while Bacillus cereus infected. Thirty people were selected as normal group, including 23 males and 7 females,with an average age of (45.20 +/- 15.05) years old. Infection control condition was assessed by comparing culture for pathogens and patients wound redness or exudation cases before and after treatment. Antimicrobial susceptibility test was conducted by K-B method.

RESULTSA total of 20 stains of Bacillus cereus were isolated from wound surface infections in department of orthopedics of our hospital. Among them,the infections were correlated with the wound contamination (16/20), malnutrition (20/20), and open-fracture (20/20), operation time (15 cases > 3 h). The laboratory blood test showed that the levels of TP [(49.94 +/- 8.24) g/L], ALB [(29.54 +/- 5.45 ) g/L] and Hb [(103.20 +/- 11.79) g/L] in the infection group was lower than those of control group; in the contrast, the levels of WBC [(8.35 +/- 2.31) x 10(9)/L], NEUT [(6.98 +/- 1.99) x 10(9)/L], hs-CRP [(73.60 +/- 55.14) mg/L] and CK [(900.10 +/- 1 259.12) IU/L] were higher in the infection group than those of control group, and the differences were statistically significant (P < 0.01). The diameter of inhibition zone in penicillin, cefazolin, cefuroxime, ceftazidime, cefepime, cotrimoxazole, erythromycin were less than 15 mm, and suggested that Bacillus cereus resisted to these antibiotics. However, the diameter of inhibition zone in clindamycin, vancomycin, gentamicin, ciprofloxacin, imipenem were larger than 20 mm and this data indicated that the bacteria were highly sensitive to these antibiotics.

CONCLUSIONOrthopedic patients who immunocompromised, hypoproteinemia and accompanied by open wounds and contaminated wound susceptible to infect Bacillus cereus; sensitive antimicrobial drugs should be selected on the basis of supplement albumin, symptomatic and supportive treatment.

Adult ; Aged ; Anti-Bacterial Agents ; pharmacology ; Bacillus cereus ; drug effects ; isolation & purification ; Female ; Humans ; Male ; Middle Aged ; Orthopedics ; Wound Infection ; microbiology

Antibiotic dependence in clinical isolates has been reported, albeit rarely, such as vancomycindependent enterococcus and beta-lactam-dependent Staphylococcus saprophyticus. We report herein a clinical isolate of beta-lactam-dependent Bacillus cereus. A 16-yr-old female was admitted on 8 September 2005 with neutropenic fever during chemotherapy following surgical removal of peripheral neuroectodermal tumor. She had had an indwelling chemoport since August 2004 and experienced B. cereus bacteremia three times during the recent 3-month period prior to the admission; the bacteremias were treated with cefepime-based chemotherapy. On hospital days 1 and 3, B. cereus was isolated from blood drawn through the chemoport. The isolates were resistant to penicillin, ceftriaxone, and erythromycin, and susceptible to vancomycin and ciprofloxacin. The isolate of hospital day 3 grew only nearby the beta-lactam disks including penicillin and ceftriaxone on disk diffusion testing. The beta-lactam-dependent isolate required a minimum of 0.064 microgram/mL of penicillin or 0.023 microgram/mL of cefotaxime for growth, which was demonstrated by E test (AB Biodisk, Sweden). Light microscopy and transmission electron microscopy revealed a marked elongation of the dependent strain compared with the non-dependent strain. Prolonged therapy with beta-lactams in the patient with an indwelling intravenous catheter seemed to be a risk factor for the emergence of beta-lactam-dependence in B. cereus.
Adolescent ; Anti-Bacterial Agents/therapeutic use ; Bacillaceae Infections/*drug therapy/microbiology ; Bacillus cereus/cytology/*drug effects/isolation & purification ; Bacteremia/drug therapy/microbiology ; Cephalosporins/*therapeutic use ; Female ; Humans ; Microbial Sensitivity Tests ; Neutropenia/*complications/etiology ; Risk Factors ; *beta-Lactam Resistance

BACKGROUND: The incidence of Bacillus cereus bacteremia is increasing, but the identification of Bacillus species remains difficult. Brilliance Bacillus cereus agar (BBC agar; Oxoid, UK) is a new CHROMagar medium that allows selective isolation and identification of B. cereus; however, its clinical usefulness is seldom studied. We evaluated the usefulness of BBC agar to identify B. cereus isolates recovered from blood cultures. METHODS: We analyzed a total of 53 blood isolates that showed a Bacillus-like morphology on Gram staining. All isolates were identified by using both the API Coryne (bioMerieux, France) and API 50CH/B (bioMerieux) systems. They were subsequently subcultured on BBC agar, incubated for 24 hr, and then examined for characteristic blue-green colonies. The clinical characteristics of patients whose isolates were identified as B. cereus were assessed. RESULTS: Of the 53 isolates, 18 were identified as B. cereus by API 50CH/B. With the API 50CH/B system used as gold standard, the sensitivity and specificity for the identification of B. cereus were 100% (18/18) and 100% (35/35), respectively, using BBC agar, and 67% (12/18) and 100% (35/35), respectively, using the API Coryne system. Of the 18 patients with B. cereus bacteremia, 15 showed infectious signs, and 3 had more than 2 blood cultures positive for B. cereus on separate days. CONCLUSIONS: Our study shows, for the first time, that BBC agar, with its good agreement and ease of use, is a valuable alternative to the API 50CH/B system for the presumptive identification of B. cereus isolates from blood cultures.
Adolescent ; Adult ; Agar/chemistry ; Aged ; Bacillus cereus/*isolation & purification ; Bacteremia/*diagnosis/microbiology ; Child ; Child, Preschool ; Chromogenic Compounds/*chemistry ; Culture Media ; Female ; Gram-Positive Bacterial Infections/*diagnosis/microbiology ; Humans ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

OBJECTIVES: In July 2 2010, a diarrhea outbreak occurred among the workers in a company in Gyeungju city, Korea. An epidemiological investigation was performed to clarify the cause and transmission route of the outbreak. METHODS: We conducted a questionnaire survey among 193 persons, and we examined 21 rectal swabs and 6 environmental specimens. We also delegated the Daegu Bukgu public health center to examine 3 food service employees and 5 environmental specimens from the P buffet which served a buffet on June 30. The patient case was defined as a worker of L Corporation and who participated in the company meal service and who had diarrhea more than one time. We also collected the underground water filter of the company on July 23. RESULTS: The attack rate of diarrhea among the employees was 20.3%. The epidemic curve showed that a single exposure peaked on July 1. The relative risk of attendance and non-attendance by date was highest for the lunch of June 30 (35.62; 95% CI, 2.25 to 574.79). There was no specific food that was statistically regarded as the source of the outbreak. Bacillus cereus was cultured from two of the rectal swabs, two of the preserved foods and the underground water filter. We thought the exposure date was lunch of June 30 according the latency period of B. cereus. CONCLUSIONS: We concluded the route of transmission was infection of dishes, spoons and chopsticks in the lunch buffet of June 30 by the underground water. At the lunch buffet, 50 dishes, 40 spoons, and chopsticks were served as cleaned and wiped with a dishcloth. We thought the underground water contaminated the dishes, spoons, chopsticks and the dishcloth. Those contaminated materials became the cause of this outbreak.
Adult ; Aged ; Bacillus cereus/*isolation & purification ; Diarrhea/etiology ; *Disease Outbreaks ; Female ; Foodborne Diseases/*epidemiology/microbiology ; Fresh Water/microbiology ; Gram-Positive Bacterial Infections/*epidemiology/microbiology ; Humans ; Male ; Middle Aged ; Questionnaires ; Rectum/microbiology

OBJECTIVETo synthesize the ecofriendly nanoparticles, which is viewed as an alternative to the chemical method which initiated the use of microbes like bacteria and fungi in their synthesis.

METHODSThe current study uses the endophytic bacterium Bacillus cereus isolated from the Garcinia xanthochymus to synthesize the silver nanoparticles (AgNPs). The AgNPs were synthesized by reduction of silver nitrate solution by the endophytic bacterium after incubation for 3-5 d at room temperature. The synthesis was initially observed by colour change from pale white to brown which was confirmed by UV-Vis spectroscopy. The AgNPs were further characterized using FTIR, SEM-EDX and TEM analyses.

RESULTSThe synthesized nanoparticles were found to be spherical with the size in the range of 20-40 nm which showed a slight aggregation. The energy-dispersive spectra of the nanoparticle dispersion confirmed the presence of elemental silver. The AgNPs were found to have antibacterial activity against a few pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Klebsiella pneumoniae.

CONCLUSIONSThe endophytic bacteria identified as Bacillus cereus was able to synthesize silver nanoparticles with potential antibacterial activity.

Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacillus cereus ; drug effects ; isolation & purification ; Escherichia coli ; drug effects ; Garcinia ; chemistry ; Klebsiella pneumoniae ; drug effects ; Metal Nanoparticles ; chemistry ; Microbial Sensitivity Tests ; Nanoparticles ; chemistry ; Phytotherapy ; methods ; Plant Extracts ; chemistry ; pharmacology ; Pseudomonas aeruginosa ; drug effects ; Silver ; chemistry ; pharmacology ; Staphylococcus aureus ; drug effects