Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bacillaceae”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources

Comparative bioenergetics of sulfate reduction in Desulfovibrio and Desulfotomaculum spp.

Extracts of Desulfotomaculum nigrificans, Desulfotomaculum orientis, and Desulfotomaculum ruminis exhibit low levels of inorganic pyrophosphatase but were found to have high levels of pyrophosphate:acetate phosphotransferase. Conversely, extracts of Desulfovibrio gigas, Desulfovibrio vulgaris, and Desulfovibrio desulfuricans Norway 4 were shown to have high levels of inorganic pyrophosphatase but negligible amounts of pyrophosphate:acetate phosphotransferase. Both enzymes are reductant activated and appear to have an analogous function in removing pyrophosphate formed during the activation of sulfate. Conservation of the bond energy of pyrophosphate in Desulfotomaculum eliminates the necessity for invoking electron-transfer-coupled phosphorylation to account for the growth of these bacteria on lactate plus sulfate. Relative growth yields of Desulfovibrio vulgaris and Desulfotomaculum orientis on lactate plus sulfate indicate that the latter does not carry out significant electron-transfer-coupled phosphorylation in this mode of growth.

Acetate Kinase↗

Two membrane-associated NiFeS-carbon monoxide dehydrogenases from the anaerobic carbon-monoxide-utilizing eubacterium Carboxydothermus hydrogenoformans.

Two monofunctional NiFeS carbon monoxide (CO) dehydrogenases, designated CODH I and CODH II, were purified to homogeneity from the anaerobic CO-utilizing eubacterium Carboxydothermus hydrogenoformans. Both enzymes differ in their subunit molecular masses, N-terminal sequences, peptide maps, and immunological reactivities. Immunogold labeling of ultrathin sections revealed both CODHs in association with the inner aspect of the cytoplasmic membrane. Both enzymes catalyze the reaction CO + H(2)O --> CO(2) + 2 e(-) + 2 H(+). Oxidized viologen dyes are effective electron acceptors. The specific enzyme activities were 15,756 (CODH I) and 13,828 (CODH II) micromol of CO oxidized min(-1) mg(-1) of protein (methyl viologen, pH 8.0, 70 degrees C). The two enzymes oxidize CO very efficiently, as indicated by k(cat)/K(m) values at 70 degrees C of 1.3. 10(9) M(-1) CO s(-1) (CODH I) and 1.7. 10(9) M(-1) CO s(-1) (CODH II). The apparent K(m) values at pH 8.0 and 70 degrees C are 30 and 18 microM CO for CODH I and CODH II, respectively. Acetyl coenzyme A synthase activity is not associated with the enzymes. CODH I (125 kDa, 62.5-kDa subunit) and CODH II (129 kDa, 64.5-kDa subunit) are homodimers containing 1.3 to 1.4 and 1.7 atoms of Ni, 20 to 22 and 20 to 24 atoms of Fe, and 22 and 19 atoms of acid-labile sulfur, respectively. Electron paramagnetic resonance (EPR) spectroscopy revealed signals indicative of [4Fe-4S] clusters. Ni was EPR silent under any conditions tested. It is proposed that CODH I is involved in energy generation and that CODH II serves in anabolic functions.

Acetate-CoA Ligase↗

Chloride, a new environmental signal molecule involved in gene regulation in a moderately halophilic bacterium, Halobacillus halophilus.

The gram-positive, aerobic, moderately halophilic bacterium Halobacillus halophilus is challenged in its environment by frequently changing salt (NaCl) concentrations. Recently, H. halophilus was shown to be the first prokaryote that is dependent on Cl(-) for growth. In a search for the biological function of Cl(-) in this prokaryote, we identified different Cl(-)-dependent processes, which suggests a more general role for Cl(-) in the metabolism of H. halophilus. To analyze the effect of Cl(-) in more detail, we concentrated on one model system, the Cl(-)-dependent production of flagella, and aimed to identify the molecular basis for the Cl(-) dependence of flagellum production. Here, we report that synthesis of the major subunit of the flagellum, FliC, is dependent on the Cl(-) concentration of the medium, as determined by Western blot analyses. The gene encoding FliC was cloned and sequenced, and Northern blot as well as reverse transcriptase PCR analyses revealed that expression of fliC is Cl(-) dependent. FliC is the first protein of known function demonstrated to be synthesized in a Cl(-)-dependent manner in a prokaryote. Two-dimensional gel electrophoresis of cells grown under different conditions revealed five more Cl(-)-induced proteins; these were identified by N-terminal sequencing and database searches to be orthologs of proteins involved in stress response in Bacillus subtilis. The data indicate that Cl(-) is an important environmental signal in this moderate halophile and regulates protein synthesis and gene expression. Furthermore, the data may suggest that Cl(-) plays a role in the signal transduction involved in salt perception by this bacterium.

Amino Acid Sequence↗

Isolation of glucocardiolipins from Geobacillus stearothermophilus NRS 2004/3a.

Glucose-substituted cardiolipins account for about 4 mol% of total phospholipid extracted from exponentially grown cells of Geobacillus stearothermophilus NRS 2004/3a. Individual glucocardiolipin species exhibited differences in fatty acid substitution, with iso-C(15:0) and anteiso-C(17:0) prevailing. The compounds were purified to homogeneity by a novel protocol and precharacterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Bacillaceae↗

Effect of dimer dissociation on activity and thermostability of the alpha-glucuronidase from Geobacillus stearothermophilus: dissecting the different oligomeric forms of family 67 glycoside hydrolases.

The oligomeric organization of enzymes plays an important role in many biological processes, such as allosteric regulation, conformational stability and thermal stability. alpha-Glucuronidases are family 67 glycosidases that cleave the alpha-1,2-glycosidic bond between 4-O-methyl-D-glucuronic acid and xylose units as part of an array of hemicellulose-hydrolyzing enzymes. Currently, two crystal structures of alpha-glucuronidases are available, those from Geobacillus stearothermophilus (AguA) and from Cellvibrio japonicus (GlcA67A). Both enzymes are homodimeric, but surprisingly their dimeric organization is different, raising questions regarding the significance of dimerization for the enzymes' activity and stability. Structural comparison of the two enzymes suggests several elements that are responsible for the different dimerization organization. Phylogenetic analysis shows that the alpha-glucuronidases AguA and GlcA67A can be classified into two distinct subfamilies of bacterial alpha-glucuronidases, where the dimer-forming residues of each enzyme are conserved only within its own subfamily. It seems that the different dimeric forms of AguA and GlcA67A represent the two alternative dimeric organizations of these subfamilies. To study the biological significance of the dimerization in alpha-glucuronidases, we have constructed a monomeric form of AguA by mutating three of its interface residues (W328E, R329T, and R665N). The activity of the monomer was significantly lower than the activity of the wild-type dimeric AguA, and the optimal temperature for activity of the monomer was around 35 degrees C, compared to 65 degrees C of the wild-type enzyme. Nevertheless, the melting temperature of the monomeric protein, 72.9 degrees C, was almost identical to that of the wild-type, 73.4 degrees C. It appears that the dimerization of AguA is essential for efficient catalysis and that the dissociation into monomers results in subtle conformational changes in the structure which indirectly influence the active site region and reduce the activity. Structural and mechanistic explanations for these effects are discussed.

Amino Acid Sequence↗

Characterization of Bacillus cereus isolates associated with fatal pneumonias: strains are closely related to Bacillus anthracis and harbor B. anthracis virulence genes.

Bacillus cereus is ubiquitous in nature, and while most isolates appear to be harmless, some are associated with food-borne illnesses, periodontal diseases, and other more serious infections. In one such infection, B. cereus G9241 was identified as the causative agent of a severe pneumonia in a Louisiana welder in 1994. This isolate was found to harbor most of the B. anthracis virulence plasmid pXO1 (13). Here we report the characterization of two clinical and one environmental B. cereus isolate collected during an investigation of two fatal pneumonia cases in Texas metal workers. Molecular subtyping revealed that the two cases were not caused by the same strain. However, one of the three isolates was indistinguishable from B. cereus G9241. PCR analysis demonstrated that both clinical isolates contained B. anthracis pXO1 toxin genes. One clinical isolate and the environmental isolate collected from that victim's worksite contained the cap A, B, and C genes required for capsule biosynthesis in B. anthracis. Both clinical isolates expressed a capsule; however, neither was composed of poly-D-glutamic acid. Although most B. cereus isolates are not opportunistic pathogens and only a limited number cause food-borne illnesses, these results demonstrate that some B. cereus strains can cause severe and even fatal infections in patients who appear to be otherwise healthy.

Adult↗

Pneumonia and empyema infection associated with a Bacillus species that resembles B. alvei.

An organism resembling Bacillus alvei was isolated from the lung and pleural fluid of an immunocompetent patient. The isolate differed from the type strain of B. alvei in its ability to reduce nitrate and its inability to produce dihydroxyacetone and acetylmethylcarbinol. The isolate was resistant to ciprofloxacin and showed intermediate susceptibility to vancomycin.

Bacillaceae Infections↗

Bacillus licheniformis prosthetic aortic valve endocarditis.

A 73-year old man developed an acute prosthetic aortic valve dehiscence for which emergent operation was undertaken. The intraoperative evidence of an aortic annular disruption and of a subannular abscess led to the hypothesis that an endocarditis process was involved. The aortic valve was replaced with a stentless porcine bioprosthesis. Cultures taken intraoperatively from the aortic area had a pure growth of aerobic, spore-forming, gram-positive bacilli identified as Bacillus licheniformis. The patient responded to specific antibiotic therapy with no relapse at a 20-month follow-up. The potentiality of B. licheniformis as a pathogen should be reconsidered.

Aged↗

Brain abscess due to Bacillus macerans following a penetrating periorbital injury.

We report a case of a brain abscess due to Bacillus macerans and Clostridium sp. following a penetrating periorbital injury by a wooden branch. Intracranial penetration by and retention of a foreign body were not suspected initially, and neurological symptoms developed only 2.5 months later. Previously reported cases of brain abscesses due to Bacillus species are reviewed.

Bacillaceae Infections↗

Fulminating bacteremia and pneumonia due to Bacillus cereus.

We present two cases of rapidly progressing, fatal pneumonia caused by Bacillus cereus. These cases are interesting in that B. cereus, even from blood or sputum specimens, may often be considered a contaminant and receive inadequate attention. Also of interest was the fact that the two patients resided in the same area of the state, were welders by trade, and became ill within a few days of each other, yet there was no epidemiologic link between them.

Adult↗

Use of pulsed-field gel electrophoresis to investigate a pseudo-outbreak of Bacillus cereus in a pediatric unit.

Bacillus cereus is a well-known cause of food poisoning. It also causes rare systemic infections, usually in immunocompromised patients. Dissemination of this species in hospitals had been reported. Most of these episodes were pseudo-outbreaks and were usually secondary to equipment or environmental contamination. We report here on the use of pulsed-field gel electrophoresis (PFGE) to analyze a pseudo-outbreak of B. cereus in a pediatric unit. Different restriction endonucleases had been tested, and SmaI was found to give the best result for PFGE. Among the 26 clinical isolates of B. cereus and the type strain of the species, 15 distinct PFGE patterns were distinguished. PFGE after DNA macrorestriction with SmaI could clearly differentiate between the epidemiologically related isolates and the unrelated isolates. Because the same epidemic strain of B. cereus was isolated from the settle plates which were exposed near the outlet of the ventilation system, the source of this pseudo-outbreak was suspected to be the unit's air filtration system. This is one of the first reports of the application of PFGE to the study of B. cereus, and this method is useful for epidemiological investigation.

Bacillaceae Infections↗

Bacillus thuringiensis subsp. konkukian (serotype H34) superinfection: case report and experimental evidence of pathogenicity in immunosuppressed mice.

We present a case of severe war wounds infected by Bacillus thuringiensis serotype H34 and describe the experimental protocol used to demonstrate its ability to infect mice after cutaneous inoculation. This case is interesting because B. thuringiensis is considered to be a contaminant in laboratories and receives inadequate attention.

Adult↗

Nosocomial pseudoepidemic caused by Bacillus cereus traced to contaminated ethyl alcohol from a liquor factory.

From September 1990 to October 1990, 15 patients who were admitted to four different departments of the National Taiwan University Hospital, including nine patients in the emergency department, three in the hematology/oncology ward, two in the surgical intensive care unit, and one in a pediatric ward, were found to have positive blood (14 patients) or pleural effusion (1 patient) cultures for Bacillus cereus. After extensive surveillance cultures, 19 additional isolates of B. cereus were recovered from 70% ethyl alcohol that had been used as a skin disinfectant (14 isolates from different locations in the hospital) and from 95% ethyl alcohol (5 isolates from five alcohol tanks in the pharmacy department), and 10 isolates were recovered from 95% ethyl alcohol from the factory which supplied the alcohol to the hospital. In addition to these 44 isolates of B. cereus, 12 epidemiologically unrelated B. cereus isolates, one Bacillus sphaericus isolate from a blood specimen from a patient seen in May 1990, and two B. sphaericus isolates from 95% alcohol in the liquor factory were also studied for their microbiological relatedness. Among these isolates, antibiotypes were determined by using the disk diffusion method and the E test, biotypes were created with the results of the Vitek Bacillus Biochemical Card test, and random amplified polymorphic DNA (RAPD) patterns were generated by arbitrarily primed PCR. Two clones of the 15 B. cereus isolates recovered from patients were identified (clone A from 2 patients and clone B from 13 patients), and all 29 isolates of B. cereus recovered from 70 or 95% ethyl alcohol in the hospital or in the factory belonged to clone B. The antibiotype and RAPD pattern of the B. sphaericus isolate from the patient were different from those of isolates from the factory. Our data show that the pseudoepidemic was caused by a clone (clone B) of B. cereus from contaminated 70% ethyl alcohol used in the hospital, which we successfully traced to preexisting contaminated 95% ethyl alcohol from the supplier, and by another clone (clone A) without an identifiable source.

Anti-Bacterial Agents↗

Outbreak of Bacillus cereus infections in a neonatal intensive care unit traced to balloons used in manual ventilation.

In 1998, an outbreak of systemic infections caused by Bacillus cereus occurred in the Neonatal Intensive Care Unit of the University Hospital Vrije Universiteit, Amsterdam, The Netherlands. Three neonates developed sepsis with positive blood cultures. One neonate died, and the other two neonates recovered. An environmental survey, a prospective surveillance study of neonates, and a case control study were performed, in combination with molecular typing, in order to identify potential sources and transmission routes of infection. Genotypic fingerprinting by amplified-fragment length polymorphism (AFLP) showed that the three infections were caused by a single clonal type of B. cereus. The same strain was found in trachea aspirate specimens of 35 other neonates. The case control study showed mechanical ventilation with a Sensormedics ventilation machine to be a risk factor for colonization and/or infection (odds ratio, 9.8; 95% confidence interval, 1.1 to 88.2). Prospective surveillance showed that colonization with B. cereus occurred exclusively in the respiratory tract of mechanically ventilated neonates. The epidemic strain of B. cereus was found on the hands of nursing staff and in balloons used for manual ventilation. Sterilization of these balloons ended the outbreak. We conclude that B. cereus can cause outbreaks of severe opportunistic infection in neonates. Typing by AFLP proved very useful in the identification of the outbreak and in the analysis of strains recovered from the environment to trace the cause of the epidemic.

Bacillaceae Infections↗

Bacillus cereus bacteremia in a preterm neonate.

Bacillus cereus is an uncommon but potentially serious bacterial pathogen causing infections of the bloodstream, lungs, and central nervous system of preterm neonates. A case of bacteremia caused by B. cereus in a 19-day-old preterm neonate who was successfully treated with vancomycin, tobramycin, meropenem, and clindamycin is described. Implications for the diagnostic laboratory and clinicians when Bacillus species are detected in normally sterile sites are discussed, and the small numbers of infant infections proven to be due to this organism that have been described previously are reviewed.

Anti-Bacterial Agents↗

Identification and in-depth characterization of clinical isolates of Peribacillus frigoritolerans.

UNLABELLED: Peribacillus frigoritolerans is a bacterial species commonly found in the environment and used as a plant-growth promoter and biocontrol agent in agriculture. Recent evidence has proven that Peribacillus spp. are also able to cause severe infections in humans, thus emerging as new human pathogens. In this study, for the first time, 10 P. frigoritolerans strains were isolated from human samples (both superficial and sterile deep body sites) and characterized in terms of morphology, lifestyle, genetics, and virulence. The molecular identification by MALDI-TOF mass spectrometry and 16S rRNA gene sequencing was inconclusive, while whole-genome sequencing was effective in properly identifying isolates within the species P. frigoritolerans. The pangenome analysis provided an overview of the virulence potential of P. frigoritolerans, revealing the presence of genes involved in antibiotic resistance and toxin/exoenzyme production. Phenotypically, the strains displayed different features and behaviors, indicating strain-specific properties and high intra-species variability. A part of the strains exhibited virulence factors, being able to swim and swarm, form biofilms, and produce enzymes and toxins. Antibiotic susceptibility testing revealed resistance to ampicillin for all strains and resistance to erythromycin and clindamycin for some of them. Antimicrobial activity against Gram-positive bacteria and fungi was demonstrated, further corroborating the presence of putative bacteriocin/antimicrobial peptide-encoding genes. An association between the overall virulence potential and infection site/severity was hypothesized. Altogether, these findings highlight the extreme diversity within the species, reveal the strain-dependent pathogenic potential of P. frigoritolerans, and support its role as a candidate human pathogen. IMPORTANCE: This study provides insights into the infectious role of Peribacillus frigoritolerans, an almost unknown bacterial species with agrobiotechnological potential but no history of human infections. This is the first report of P. frigoritolerans isolation from human clinical samples. Ten P. frigorit-olerans strains were herein characterized for their morphology, lifestyle, genetics, and virulence, highlighting an extreme intra-species variability and the potential to act as pathogens in humans. Importantly, this study points out the need for unconventional methods for proper identification of this species, since traditional techniques result inconclusive. Resistance to commonly prescribed antibiotics was also evidenced, confirming the importance of antimicrobial testing on clinical iso-lates. This study lays the foundation for a more in-depth characterization of Peribacillus spp. in the clinical context.

Humans↗

Experimental Bacillus cereus post-traumatic endophthalmitis and treatment with ciprofloxacin.

BACKGROUND: Bacillus species remain an important cause of post-traumatic endophthalmitis, often causing permanent visual loss. METHODS: Twenty two rabbits were used to evaluate the clinical and histological findings of Bacillus cereus experimental post-traumatic endophthalmitis. Eyes that had received a scleral laceration and surgical repair were inoculated with Bacillus cereus. Thirty four other rabbits were used to evaluate the efficacy of intravitreal ciprofloxacin in treating experimental disease. RESULTS: Animals developed a post-traumatic endophthalmitis that closely mimicked human disease, characterised by a rapidly progressive and destructive endophthalmitis. Histological evaluation revealed retinal detachment, retinal necrosis, and the infiltration of inflammatory cells into the subretinal space. Intravitreal ciprofloxacin (100 micrograms) prevented the development of disease when given 1 hour and 6 hours after trauma and inoculation. CONCLUSIONS: Clinical and histological examination of experimental Bacillus cereus post-traumatic endophthalmitis suggests that retinal detachment and retinal necrosis play important roles in visual loss. Ciprofloxacin may be of benefit in the management of certain intraocular infections following penetrating injury.

Animals↗