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

Contamination with sanitary microorganisms from Enterobacteriaceae, Pseudomonadaceae, Staphylococcaceae, Micrococcaceae and Bacillaceae families in flower bee pollen from Bulgaria after one-year vacuum-packed cold storage has been found. Dried flower bee pollens intended for human consumption were with high incidence rate of contamination with Pantoea sp. (P. agglomerans and P. agglomerans bgp6) (100%), Citrobacter freundii (47%), Proteus mirabilis (31.6%), Serratia odorifera (15.8%) and Proteus vulgaris (5.3%). Bee pollens were also positive for the culture of microorganisms from Staphylococcaceae, Micrococcaceae and Bacillaceae families: Staphylococcus hominis subsp hominis, Staphylococcus epidermidis, Arthrobacter globiformis, Bacillus pumilis, Bacillus subtilis and Bacillus amyloliquefaciens. It was concluded that, if consumed directly, the vacuum-packed cold stored dried bee pollen, harvested according hygienic requirements from bee hives in industrial pollution-free areas without intensive crop production, is not problem for healthy human.
Arthrobacter ; Bacillaceae ; Bacillus ; Bacillus subtilis ; Bees* ; Bulgaria ; Citrobacter freundii ; Crop Production ; Enterobacteriaceae ; Flowers* ; Humans ; Incidence ; Micrococcaceae ; Pantoea ; Pollen* ; Proteus mirabilis ; Proteus vulgaris ; Pseudomonadaceae ; Serratia ; Staphylococcaceae ; Staphylococcus epidermidis ; Staphylococcus hominis ; Urticaria ; Vacuum*

Aims: A 2,2-dichloropropionic acid (2,2-DCP) naturally degrading bacterial species, strain SN1 was successfully isolated from cow dung capable of utilizing the substance as the sole carbon source and energy. Methodology and results: Strain SN1 was preferred over other strains (SN2, SN3 and SN4) following observations on its rapid growth in 20 mM 2,2-DCP liquid minimal media. Since strain SN1 clearly exhibited tolerance towards 2,2-DCP, its growth in various concentrations (10 mM, 20 mM, 30 mM and 40 mM) of the substance was evaluated. The study found the bacteria grew particularly well in 20 mM 2,2-DCP with the highest chloride release of 39.5 µmole Cl- /mL while exhibiting a remarkably short doubling time of 3.85 h. In view of such notable characteristics, species identification via Biolog GEN III system and 16S rRNA analysis was performed and established strain SN1 as Bacillus cereus. Conclusion, significance and impact of study: Considering the rapid growth of B. cereus strain SN1 in such medium, its employment as a bioremediation agent to treat 2,2-DCP contaminated soils may prove beneficial. Moreover, this is the first reported case of a Bacillus sp. isolated from cow dung capable of utilizing 2,2-DCP. Therefore, further assessment into its ability to degrade other types of haloalkanoic acids merit special consideration.
Bacillus cereus

Aims: This study was conducted to isolate Bacillus cereus from raw and cooked chicken meat from selected retail shops and wet markets in Kota Bharu and to determine the antimicrobial resistance patterns of B. cereus. Methodology and results: A total of sixty samples (30 from raw and 30 from cooked chicken meat) were tested for presence of B. cereus. Isolation and identification of B. cereus was done by using routine bacterial culture and Polymerase Chain Reaction (PCR). Bacillus cereus was detected in 16.67% (10/60) of the samples tested. All isolates were negative for the enterotoxigenic gene, nhe genes, however, six of the isolates were found to be positive for hbla genes. B. cereus isolates showed 100% resistance towards beta lactam antibiotics. Conclusion, significance and impact study: Although only 60 samples are analysed in the current study, the fact that toxigenic strains of B. cereus were isolated in cooked chicken meat intended for human consumption implies the potential public health risk it might pose. Further study with increased sample size, screening other toxigenic strains of B. cereus and molecular typing is recommended to have a more detailed understanding of the occurrence of the bacteria in chicken meat in Kota Bharu. It is necessary to educate the public on the risks of food contamination by bacteria that may cause food borne illnesses. Some precautions such as routine checking of the freshness of food before consumption, hygienic preparation and proper cooking of food can be implemented to reduce the risks of food borne illnesses related B. cereus and other potentially dangerous bacteria.
Bacillus cereus ; Foodborne Diseases

In our previous studies, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15 have been shown to be antagonistic to Aspergillus flavus in stored rice grains. In this study, the biocontrol activities of these strains were evaluated against Aspergillus candidus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum, which are predominant in stored rice grains. In vitro and in vivo antifungal activities of the bacterial strains were evaluated against the fungi on media and rice grains, respectively. The antifungal activities of the volatiles produced by the strains against fungal development and population were also tested using I-plates. In in vitro tests, the strains produced secondary metabolites capable of reducing conidial germination, germ-tube elongation, and mycelial growth of all the tested fungi. In in vivo tests, the strains significantly inhibited the fungal growth in rice grains. Additionally, in I-plate tests, strains KU143 and AS15 produced volatiles that significantly inhibited not only mycelial growth, sporulation, and conidial germination of the fungi on media but also fungal populations on rice grains. GC-MS analysis of the volatiles by strains KU143 and AS15 identified 12 and 17 compounds, respectively. Among these, the antifungal compound, 5-methyl-2-phenyl-1H-indole, was produced by strain KU143 and the antimicrobial compounds, 2-butyl 1-octanal, dimethyl disulfide, 2-isopropyl-5-methyl-1-heptanol, and 4-trifluoroacetoxyhexadecane, were produced by strain AS15. These results suggest that the tested strains producing extracellular metabolites and/or volatiles may have a broad spectrum of antifungal activities against the grain fungi. In particular, B. megaterium KU143 and P. protegens AS15 may be potential biocontrol agents against Aspergillus and Penicillium spp. during rice grain storage.
Aspergillus flavus ; Aspergillus fumigatus ; Aspergillus* ; Bacillus megaterium* ; Bacillus* ; Fungi ; Germination ; In Vitro Techniques ; Penicillium* ; Pseudomonas*

In our previous study, three bacterial strains, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15, were selected as effective biocontrol agents against Aspergillus flavus on stored rice grains. In this study, we evaluated the inhibitory effects of the volatiles produced by the strains on A. flavus growth and aflatoxin production on stored rice grains. The three strains significantly reduced mycelial growth of A. flavus in dual-culture assays compared with the negative control strain, Sphingomonas aquatilis KU408, and an untreated control. Of these tested strains, volatiles produced by B. megaterium KU143 and P. protegens AS15 markedly inhibited mycelial growth, sporulation, and conidial germination of A. flavus on agar medium and suppressed the fungal populations in rice grains. Moreover, volatiles produced by these two strains significantly reduced aflatoxin production in the rice grains by A. flavus. To our knowledge, this is the first report of the suppression of A. flavus aflatoxin production in rice grains using B. megaterium and P. protegens volatiles.
Aflatoxins* ; Agar ; Aspergillus flavus* ; Aspergillus* ; Bacillus megaterium* ; Bacillus* ; Germination ; Pseudomonas* ; Sphingomonas

Geobacillus thermoglucosidasius is a kind of Gram-positive facultative anaerobic bacteria. The fast growth rate under high temperature and less susceptibility to microbial contamination enable G. thermoglucosidasius to be a desirable producer of biofuels and high-value-added chemicals for the next-generation industrial biotechnology. However, compared with the classical model strain Escherichia coli, the applications of G. thermoglucosidasius are hampered by its low transformation efficiency. This study aimed at obtaining competent cells with high transformation efficiency through inactivating restriction enzymes, adding cell membrane inhibitors and cell wall weakening agents. The results showed that the electro-transformation efficiency achieved 1.2×10⁴ CFU/(μg DNA) by knocking out four genes encoding restriction enzymes. Adding a certain amount of tween 80, dl-threonine and glycine further increased the competent efficiency about 22.5, 44, and 334 times, respectively. The electro-transformation efficiency was enhanced to 4.6×10⁶ CFU/(μg DNA) under the optimized conditions, laying a foundation for genetic manipulation and metabolic engineering of G. thermoglucosidasius.
Electroporation ; Electroporation Therapies ; Bacillaceae ; Cell Membrane ; Escherichia coli/genetics*

ABSTRACT Aims: Dickeya dadantii is a pathogenic bacterium causing bacterial soft rot disease in plants. The bacterium uses a homoserine lactone signal in its quorum sensing process to express the virulence factor genes. Anti-quorum sensing is a new approach to control plant pathogenic bacteria. The aims of this study are to characterize AHL-lactonase enzyme produced by Bacillus thuringiensis SGT3g and to determine its effectiveness in inhibiting virulence of D. dadantii. Methodology and results: Activity of AHL-lactonase was determined using Chromobacterium violaceum as a bacterial biosensor. The crude extract enzymes of AHL-lactonase on both as extracellular and intracellular enzymes were analyzed their enzyme activity of protein precipitation and dialysis products. The optimum activity of AHL-lactonase was found at 30 °C and pH 5-8. Bacillus thuringiensis SGT3g was capable to reduce soft rot symptom disease caused by D. dadantii on Phalaenopsis orchid leaves after 24 h of incubation. Conclusion, significance and impact study: Bacillus thuringiensis SGT3g was capable to degrade AHL signal of C. violaceum and D. dadantii. The activity AHL-lactonase of B. thuringiensis SGT3g had a wide range of pH and temperature. The lactonase could reduce soft rot symptom disease caused by D. dadantii without any growth inhibition of D. dadantii on orchid leaves. Bacillus thuringiensis SGT3g can be used as an alternative biopesticide to control phytopathogenic bacteria due to its capability to suppress bacterial pathogenic virulence.
Bacillus thuringiensis

Bacillus megaterium ; pathogenicity ; Brain Abscess ; diagnosis ; microbiology ; Female ; Humans ; Middle Aged

PURPOSE: Bacillus cereus is an important cause of post-traumatic endophthalmitis. Several different anti-biotics have been used to prevent permanent visual loss. The authors compared the efficacy of intravitreal vancomycin and ciprofloxacin in the treatment of experimental Bacillus cereus endophthalmitis. METHODS: Forty eyes of 20 white rabbits were inoculated with B. cereus organisms. Ten eyes were randomized to receive intravitreal vancomycin (group 1) and 10 eyes ciprofloxacin (group 2) after 12 or 24 hours. Fellow eyes were injected with normal saline as control group. After 48 hours, the eyes were examined and graded for clinical signs of infection and enucleated for histologic examination. RESULTS: There was a statistically significant difference in clinical features between treated groups and control group (p<0.05). There was no significant difference between vancomycin-treated group and ciprofloxacin-treated group. Compared to eyes treated 12 hours after inoculation, eyes treated 24 hours after inoculation showed worse clinical gradings (p<0.05). Histologic examination showed vancomycin or ciprofloxacin-treated groups had significant less inflammation and tissue destruction than control group (p<0.05). There was a statistically significant difference in vitreous and retinal structure between ciprofloxacin-treated after 12 hours inoculation and 24 hours inoculation group (p<0.05). CONCLUSIONS: Ciprofloxacin appeared to be limiting inflammation and tissue destruction in experimental Bacillus endophthalmitis and might effective in substitute vancomycin when necessary.
Bacillus cereus ; Bacillus* ; Ciprofloxacin* ; Endophthalmitis* ; Inflammation ; Rabbits ; Retinaldehyde ; Vancomycin