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Sigma 29-like protein is a common sporulation-specific element in bacteria of the genus Bacillus.

A monoclonal antibody specific for an antigenic determinant on the Bacillus subtilis sporulation-induced sigma factor sigma 29 reacted with proteins similar in size to sigma 29 in extracts of sporulating Bacillus licheniformis, Bacillus amyloliquifaciens, Bacillus cereus, Bacillus natto, and Bacillus pumilus but not in extracts prepared from vegetatively growing cultures of these bacteria. These results indicate that RNA polymerase modifications, initially described for B. subtilis, are likely to be common among sporulating Bacillus spp. and that at least some of the specific modifications that are observed in sporulating B. subtilis are conserved among members of this genus.

Antibodies, Monoclonal↗

Structure and glycosylation of lipoteichoic acids in Bacillus strains.

The occurrence, structure, and glycosylation of lipoteichoic acids were studied in 15 Bacillus strains, including Bacillus cereus (4 strains), Bacillus subtilis (5 strains), Bacillus licheniformis (1 strain), Bacillus polymyxa (2 strains), and Bacillus circulans (3 strains). Whereas in the cells of B. polymyxa and B. circulans neither lipoteichoic acid nor related amphipathic polymer could be detected, the cells of other Bacillus strains were shown to contain lipoteichoic acids built up of poly(glycerol phosphate) backbone chains and hydrophobic anchors [gentiobiosyl(beta 1----1/3)diacylglycerol or monoacylglycerol]. The lipoteichoic acid chains of the B. licheniformis strain and three of the B. subtilis strains had N-acetylglucosamine side branches, but those of the B. cereus strains and the remaining two B. subtilis strains did not. The membranes of the B. licheniformis strain and the first three B. subtilis strains exhibited enzyme activities for the synthesis of beta-N-acetylglucosamine-P-polyprenol and for the transfer of N-acetylglucosamine from this glycolipid to endogenous acceptors presumed to be lipoteichoic acid precursors. In contrast, the membranes of the other strains lacked both or either of these two enzyme activities. The correlation between the occurrence of N-acetylglucosamine-linked lipoteichoic acids and the distribution of these enzymes is consistent with the previously proposed function of beta-N-acetylglucosamine-P-polyprenol as a glycosyl donor in the introduction of alpha-N-acetylglucosamine branches to lipoteichoic acid backbone chains.

Bacillus↗

Rapid Ped-2E9 cell-based cytotoxicity analysis and genotyping of Bacillus species.

Bacillus species causing food-borne disease produce multiple toxins eliciting gastroenteritis. Toxin assays with mammalian cell cultures are reliable but may take 24 to 72 h to complete and also lack sensitivity. Here, a sensitive and rapid assay was developed using a murine hybridoma Ped-2E9 cell model. Bacillus culture supernatants containing toxins were added to a Ped-2E9 cell line and analyzed for cytotoxicity with an alkaline phosphatase release assay. Most Bacillus cereus strains produced positive cytotoxicity results within 1 h, and data were comparable to those obtained with the standard Chinese hamster ovary (CHO)-based cytotoxicity assay, which took about 72 h to complete. Moreover, the Ped-2E9 cell assay had 25- to 58-fold-higher sensitivity than the CHO assay. Enterotoxin-producing Bacillus thuringiensis also gave positive results with Ped-2E9 cells, while several other Bacillus species were negative. Eight isolates from food suspected of Bacillus contamination were also tested, and only one strain, which was later confirmed as B. cereus, gave a positive result. In comparison with two commercial diarrheal toxin assay kits (BDE-VIA and BCET-RPLA), the Ped-2E9 assay performed more reliably. Toxin fractions of >30 kDa showed the highest degree of cytotoxicity effects, and heat treatment significantly reduced the toxin activity, indicating the involvement of a heat-labile high-molecular-weight component in Ped-2E9 cytotoxicity. PCR results, in most cases, were in agreement with the cytotoxic potential of each strain. Ribotyping was used to identify cultures and indicated differences for several previously reported isolates. This Ped-2E9 cell assay could be used as a rapid (approximately 1-h) alternative to current methods for sensitive detection of enterotoxins from Bacillus species.

Animals↗

Transmission experiments of cilia-associated respiratory bacillus in mice, rabbits and guineapigs.

Transmission experiments of cilia-associated respiratory (CAR) bacillus were performed in mice in order to clarify the principal route of the infection, and in rabbits and guineapigs in order to examine their susceptibility. Determination of the infection was evaluated serologically by the indirect immunofluorescence assay (IFA) technique and histologically by the presence of CAR bacillus in the airways. BALB/c mice were intranasally inoculated with the SMR strain of CAR bacillus. The IFA antibody to the bacteria in these mice rose to more than 1:160 at 4 weeks postinoculation (PI) and the mice were utilized as transmitters for the following experiments. One out of 15 uninfected mice kept in intracage contact with infected mice became infected from 4 weeks after contact. Incidence of contact infection increased thereafter. On the other hand, there was no evidence of infection in the uninfected mice housed in the separate cages from the cage in which infected mice were housed throughout the 12-week observation period. The primary method of CAR bacillus transmission seems to be direct contact with infected mice or fomites contaminated by infected mice; airborne transmission appears to be of little importance. Rabbits and guineapigs were also intranasally inoculated with the SMR strain of CAR bacillus. IFA antibodies were positively detected by 4 weeks PI, but no CAR bacillus nor histological changes relating to the infection were observed in the airways of either species. It is suggested that rat origin CAR bacillus can transmit to rabbits and guineapigs, and that the infection can spread to other species of rodents and rabbits.

Animals↗

Effect of heat treatment of milk on activation of Bacillus spores.

The quality and shelf life of fluid milk products are dependent on the amount and type of microorganisms present following pasteurization. This study evaluated the effects of different pasteurization processes on the microbial populations in fluid milk. The objective was to determine whether certain pasteurization processes lead to an increase in the amount of bacteria present in pasteurized milk by activating Bacillus spores. Samples of raw milk were collected on the day of arrival at the dairy plant. The samples were pasteurized at 63 degrees C for 30 min (low temperature, long time), 72 degrees C for 15 s (high temperature, short time), 76 degrees C for 15 s, and 82 degrees C for 30 min. The pasteurized samples were then stored at 6 and 10 degrees C for 14 days. The samples were analyzed for standard plate count and Bacillus count immediately after pasteurization and after 14 days of storage. Pasteurization of milk at 72 and 76 degrees C significantly (P < 0.05) increased the amount of Bacillus spore activation over that of 63 degrees C. There was no detection of Bacillus in initial samples pasteurized at 82 degrees C for 30 min, but Bacillus was present in samples after storage for 14 days, indicating that injury and recovery time preceded growth. The majority of isolates were characterized as Bacillus mycoides and not Bacillus cereus, suggesting that this organism might be more a cause of sweet curdling of fluid milk than previously reported.

Animals↗

[Isolation and identification of Bacillus anthracis in an accidental case].

During June to July 2005, a few farmers in Chengde county of Hebei province were got ill after eating beef of sick cattle. The cattle could be infected with Bacillus anthracis. One beef sample and one soil sample contaminated with cattle blood were collected and used for pathogen isolation and identification in laboratory. Two bacteria strains were isolated from beef and soil sample, respectively, and showed typical morphology of Bacillus anthracis on blood agar and under microscope with Gram stain. The two bacteria strains were also positive to standard positive serum of Bacillus anthracis by slide agglutination test. Biochemical characteristics of the two bacteria were tested using API CHB/E strip and analyzed by API software (version 3.3), result showed that the two isolated bacteria were Bacillus anthracis. Polymerase chain reaction (PCR) was used to further characterize the two isolated bacteria strains. Three pairs of primer were designed and used for PCR, and these primers exactly matched the protective antigen gene, edema factor gene and capsule gene, respectively. By analyzed on agarose gel, PCR products were 423bp, 494bp and 397bp, respectively, and this result showed that the two isolated bacteria contained two plasmids, pX01 and pX02, which encoded anthrax toxin and capsule, respectively. Anthrax toxin and capsule were very important virulent factors for Bacillus anthracis. PCR products were purified and then cloned to T vector, positive clone was chose and sequenced. By BLAST with GenBank, sequence of the three genes of the two bacteria strains had a similarity of 99% with Bacillus anthracis A2012 strain, Ames Ancestor strain and A16R strain. Based on results of colonial morphology, serum test and biochemistry characterization, the two bacteria strains are Bacillus anthracis. They can encode anthrax toxin and capsule, and are virulent to animal and human.

Animals↗

Bacillus species pseudobacteremia following hospital construction.

A 13-fold increase (0.08 to 1.05%) in the isolation rate of Bacillus species from in-patient blood cultures led to the investigation of pseudobacteremia over a four-month period. Data on blood isolates (BACTEC NR 660, bottle types 6A and PEDS) of Bacillus species were compiled between July and October 1993. BACTEC bottles, as well as their plastic lids and rubber septa (representing 20% of stored bottles), and alcohol swabs, iodine preparation pads and butterfly collection systems were cultured. Air plates inside the BACTEC 660 instrument were cultured, as well as swabs of both the BACTEC needles and the interior of the BACTEC handling area. To investigate carry-over contamination, sterile BACTEC bottles were tested immediately following bottles containing Bacillus species. Growth of Bacillus species was obtained from 16% of the plastic lids and 1.3% of the rubber septa. No growth was obtained from other cultures. The outbreak coincide with construction on a driveway of the hospital over the area where BACTEC bottles were stored. Upon completion of construction in November 1993, the isolation of Bacillus species returned to baseline. No pseudobacteremia isolates occurred in areas where the trained intravenous team was assigned. In conclusion, hospital construction leading to airborne spread of Bacillus species may cause Bacillus species pseudobacteremia, and failure to disinfect blood culture bottles adequately may predispose to such an outcome.

Bacillaceae Infections↗

Identification of Bacillus sp. FTU strain and the study of the caa3-type oxidase homology.

The culture, morphology, and genome of alkalo- and halotolerant bacterial strain Bacillus sp. FTU were characterized; the strain is compared to other representatives of genus Bacillus. The DNA-DNA hybridization data indicate that the strains of Bacillus halodurans DSM 497 and DSM 2513 and Bacillus sp. FTU belong to the same species. Bacillus sp. FTU can be renamed to Bacillus halodurans FTU. The N-terminal amino acid fragments of the subunits I and II of the terminal caa3-type cytochrome c oxidase of B. halodurans FTU were sequenced. The N-terminal fragments of this enzyme and of the caa3-type oxidase of alkalophilic Bacillus firmus OF4 are highly homologous (homology of subunits I and II is over 90 and over 96%, respectively). Such high homology of the terminal oxidases of these bacteria might be due to their alkaline medium.

Amino Acid Sequence↗

Demyelination in the central nervous system following a delayed-type hypersensitivity response to bacillus Calmette-Guérin.

We describe here a model of delayed-type hypersensitivity response in the CNS directed against a non-CNS antigen. The results presented in this paper show that bacillus Calmette-Guérin sequestrated behind the blood-brain barrier provokes an immune-mediated assault leading to bystander myelin damage. The delayed-type hypersensitivity response was induced by the intracranial injection of heat-killed bacillus Calmette-Guérin followed by subcutaneous immunization two to six weeks later. A single intracranial injection of bacillus Calmette-Guérin resulted in a rapid myelomonocytic response which persisted for approximately two weeks. By four weeks the inflammatory cells were no longer detected. Serum proteins were also excluded from the CNS parenchyma at this time. However, immunohistochemical staining with anti-bacillus Calmette-Guérin antiserum revealed the presence of bacillus Calmette-Guérin debris at the site of the original intracranial injection, indicating that the inflammatory response failed to clear the mycobacterium fully. Following peripheral sensitization with bacillus Calmette-Guérin in complete Freund's adjuvant, a strong delayed-type hypersensitivity response was detected at the site of bacillus Calmette-Guérin deposits in the CNS. An extensive inflammatory lesion was spread over a large area of the dorsal hippocampus. The lesion was composed predominantly of mononuclear phagocytes and T cells. Staining with anti-myelin basic protein antiserum showed bystander myelin damage. Delayed-type hypersensitivity responses were studied over several months and were still detected in the CNS five months after peripheral immunization.

Animals↗

The effect of ofloxacin on bacillus calmette-guerin induced toxicity in patients with superficial bladder cancer: results of a randomized, prospective, double-blind, placebo controlled, multicenter study.

PURPOSE: We determined whether prophylaxis with ofloxacin could decrease the toxicity of bacillus Calmette-Guerin for transitional cell carcinoma of the bladder. We also investigated the impact of ofloxacin on bacillus Calmette-Guerin antitumor efficacy. MATERIALS AND METHODS: In this randomized, double-blind, multicenter study 115 patients with primary or recurrent superficial bladder cancer (Ta/T1, CIS, G1-G3) and no prior bacillus Calmette-Guerin treatment were randomized to induction treatment with intravesical bacillus Calmette-Guerin (6 plus 3 instillations) plus 200 mg ofloxacin in group 1 or plus placebo in group 2. Adverse events were assessed using a detailed grid of classification for bacillus Calmette-Guerin related adverse events. Mean patient age +/- SD was 65.6 +/- 10.4 years in the 57 group 1 patients and 65.7 +/- 8.7 years in the 58 in group 2. Median followup was 369 and 374 days in groups 1 and 2, respectively. RESULTS: Ofloxacin significantly decreased by 18.5% the incidence of class II or higher moderate and severe adverse events between instillations 4 and 6. The percent of class III adverse events was significantly decreased by ofloxacin between instillations 1 and 9. Although ofloxacin decreased adverse events involving the lower urinary tract, it did not prevent class I adverse events. Compliance with full bacillus Calmette-Guerin treatment was also improved. Of patients in group 1, 80.7% received 9 instillations compared with 65.5% in group 2 (p = 0.092). At 12 months recurrence and progression rates in group 1 and 2 were 12.7% and 17.2%, and 5.5% and 1.7%, respectively. CONCLUSIONS: Prophylactic ofloxacin decreased the incidence of moderate to severe adverse events associated with bacillus Calmette-Guerin intravesical therapy, particularly class III events, which are primarily associated with patient dropout. Compliance with induction and maintenance therapy may be improved by adjuvant ofloxacin therapy. However, long-term comparative studies with other preventive strategies must be done to confirm these initial findings with compliance and recurrence-free survival as the primary end points.

Adjuvants, Immunologic↗

A randomized prospective comparison of oral versus intravesical and percutaneous bacillus Calmette-Guerin for superficial bladder cancer.

Reports of a dramatic decrease in tumor recurrence and regression of muscle invasive disease with oral bacillus Calmette-Guerin prompted us to conduct a randomized prospective comparison of oral bacillus Calmette-Guerin with the standard intravesical plus percutaneous therapy. Oral therapy consisted of 200 mg. Tice bacillus Calmette-Guerin 3 times each week. Intravesical and percutaneous Tice bacillus Calmette-Guerin at a dose of 50 mg. was given weekly for 6 weeks, at 8, 10 and 12 weeks, then at 6 months and every 6 months thereafter. Minimal side effects confirmed the safety of oral bacillus Calmette-Guerin. Tumor recurrence was documented in 21 of 33 oral bacillus Calmette-Guerin patients (64%) and 18 of 55 (33%) who received intravesical plus percutaneous therapy (p less than 0.002, chi-square test). We were unable to demonstrate any antitumor activity of oral bacillus Calmette-Guerin in this study.

Administration, Intravesical↗

Bacillus Calmette-Guerin versus doxorubicin versus thiotepa: a randomized prospective study in 202 patients with superficial bladder cancer.

We report the second interim analysis of data from a randomized prospective trial comparing the prophylactic effect of 15 courses of 50 mg. doxorubicin, 50 mg. thiotepa or 150 mg. bacillus Calmette-Guerin instilled intravesically against recurrences and progression of superficial transitional cell bladder cancer. Of 202 enrolled patients 176 currently are evaluable with a mean follow-up of 3 years (range 3 to 97 months). The number of patients with recurrences was significantly lower in the bacillus Calmette-Guerin arm (9 of 67) compared to the doxorubicin (23 of 53, p equals 0.002) and thiotepa (20 of 56, p equals 0.003) arms. The over-all recurrence index per 100 patient-months also was lower for the bacillus Calmette-Guerin versus the thiotepa and doxorubicin groups (0.53 versus 1.55 and 1.7, respectively). Bacillus Calmette-Guerin also was superior in preventing recurrences and progression of high risk tumors, that is stage T1, grade 3 or multiple growths, associated or not with carcinoma in situ. In the stage T1 category 19 of 32 (60%) tumors recurred under treatment with doxorubicin, 11 of 33 (33%) with thiotepa and 6 of 49 (12%) with bacillus Calmette-Guerin. Toxicity to intravesical bacillus Calmette-Guerin was higher compared to the other drugs but it was not limiting: bladder irritability and malaise occurred in 42% of the patients, granulomatous cystitis in 16.4% and bladder contraction in 1.4% (1 of 64). The latter complication occurred in a patient whose stage T1m grade 2 tumors had recurred 3 times, who underwent 3 transurethral bladder resections within 15 months and who had received thiotepa for 4 months after having been removed from the study 11 months after entry. Three patients in the doxorubicin group (5.6%) underwent radical cystectomy for local urothelial progression. One patient (1.8%) in the same group died of distant progression. Our preliminary results suggest that at the dose, periodicity and duration used in the study bacillus Calmette-Guerin is significantly superior to the chemotherapeutic agents doxorubicin and thiotepa for the prophylaxis of recurrence and retardation of progression in superficial transitional cell bladder tumors.

Administration, Intravesical↗

Isolation and characterization of Bacillus sp. INT005 accumulating polyhydroxyalkanoate (PHA) from gas field soil.

A gram-positive bacterium (designated strain INT005) that accumulated polyhydroxyalkanoate (PHA) was isolated from gas field soil. From its morphological and physiological properties and the partial nucleotide sequence (about 500 bp) of its 16S rDNA, it was suggested that strain INT005 was similar to several species of the genus Bacillus. We confirmed that strain INT005 is a Bacillus sp. The PHA productivities of strain INT005 were higher than those of Bacillus megaterium and Ralstonia eutropha at 37-45 degrees C reported to date, and it was suggested that the PHA synthase of INT005 may exhibit moderate thermostability. The bacterium had the ability to produce poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate-co-3-hydroxyhexanoate), and poly(3-hydroxybutyrate-co-6-hydroxyhexanoate-co-3-hydroxyhexanoate) from the appropriate carbon sources. The PHA synthase from INT005 showed similar substrate specificity to those of class I and III PHA synthases and strain INT005 produced PHAs with various monomer compositions. From the analysis of monomer composition and PHA accumulation in the presence of acrylic acid, it was suggested that de novo fatty acid synthesis and beta-oxidation are involved in the PHA synthesis of Bacillus sp. INT005. Since Bacillus sp. INT005 could synthesize PHA even at 45 degrees C and PHAs with various monomer compositions, and only one report on the cloning of the synthesis-related genes from a Bacillus species (B. megaterium) has been published;Bacillus sp. INT005 is thought to be very valuable source of PHA synthesis-related genes.

Journal Article↗

Antibody and cytokine responses to the cilium-associated respiratory bacillus in BALB/c and C57BL/6 mice.

The cilium-associated respiratory (CAR) bacillus is a gram-negative, gliding bacterium that causes persistent respiratory tract infections in rodents despite histologic and serologic evidence of a marked immune response. To assess humoral immunity and cytokine responses in CAR bacillus disease, 6-week-old female BALB/c and C57BL/6 mice were inoculated intratracheally with 10(5) CAR bacillus organisms. CAR bacillus-specific serum immunoglobulins (immunoglobulin M [IgM], IgG1, IgG2a, IgG2b, IgG3, and IgA) and local pulmonary cytokines (tumor necrosis factor alpha [TNF-alpha], gamma interferon [IFN-gamma], and interleukin-4 [IL-4]) were evaluated by enzyme-linked immunosorbent assay every 7 days for 49 days. BALB/c mice developed CAR bacillus-induced lesions early in the course of disease that became more severe with time. Correlating with increasing disease severity, BALB/c mice had elevations in all antibody isotypes tested, and elevations in pulmonary TNF-alpha, IFN-gamma, and IL-4. C57BL/6 mice developed mild lesions with mild increases in serum IgM, IgG1, IgG2b, and IgG3 levels and minimally detectable IgG2a and IgA. Cytokine perturbations were not detected in C57BL/6 mice. The persistence of infection in BALB/c mice with vigorous serum antibody responses and increased IFN-gamma and IL-4 responses suggests that humoral immunity and T-cell responses are ineffective at preventing CAR bacillus disease. Furthermore, the lackluster antibody responses and undetectable cytokine responses in C57BL/6 mice suggest that humoral immunity and T-cell responses are not critical in resistance to CAR bacillus-induced disease.

Animals↗

Differential interleukin-10 and gamma interferon mRNA expression in lungs of cilium-associated respiratory bacillus-infected mice.

The cilium-associated respiratory (CAR) bacillus is a gram-negative, extracellular bacterium that causes persistent respiratory tract infections in rodents. We have previously demonstrated that BALB/c mice are more susceptible to CAR bacillus-induced disease than resistant C57BL/6 mice, with elevations in pulmonary gamma interferon (IFN-gamma) and interleukin (IL)-4. IL-10 is a type 2 cytokine that can increase host susceptibility to bacterial diseases through its anti-inflammatory effects, including suppression of macrophage function. The purpose of this study was to further describe the cytokine profiles associated with histologic lesions in CAR bacillus-infected mice and to assess the effects of cytokine depletion on the pathogenesis of disease. Six-week-old female BALB/c and C57BL/6 mice and mice with targeted mutations in IFN-gamma and IL-4 were inoculated intratracheally with 10(5) CAR bacillus organisms, and samples were collected at 6 to 7 weeks postinoculation. Lung samples were collected for histopathologic examination and analysis of cytokine mRNA. IFN-gamma, IL-10, and IL-4 mRNA levels in the lungs of infected mice were semiquantitatively measured using a reverse transcriptase-mediated PCR assay and compared to those in uninfected control animals of each strain. BALB/c mice infected with CAR bacillus had a median lung lesion score of 6 and IL-10 and IL-4 mRNA levels were significantly elevated. The majority of C57BL/6 mice were resistant to disease characterized by lung lesions scores of 2 or less and a dominant IFN-gamma mRNA cytokine profile. A few C57BL/6 mice with lesions scores of 5 or greater had elevations in all three cytokines and were susceptible to disease. C57BL/6 IFN-gamma knockout mice had increased disease with elevations in IL-10 and IL-4 mRNA, while BALB/c IL-4 knockout mice infected with CAR bacillus had a mild decrease in lesion severity and an attenuated IL-10 mRNA expression compared to wild-type BALB/c mice. These data indicate that IL-10 and IL-4 predominate in CAR bacillus-induced histologic lesions in mice, while IFN-gamma may play a role in resistance to disease.

Animals↗

Specificity of translation of spore polypeptides in bacillus in vitro systems.

Cell free extracts prepared from exponentially growing Escherichia coli and Bacillus cereus as well as from Bacillus cereus at the end of exponential growth were optimized for various factors required for amino acid incorporation when programmed with Bacillus ribonucleic acid. All three preparations synthesized glutamine synthetase antigen when ribonucleic acid from a Bacillus subtilis strain that overproduces glutamine synthetase was added. The post exponential Bacillus cereus extract, however, was most active for the synthesis of Bacillus cereus sport coat antigen when supplemented with the appropriate ribonucleic acid. There appears to be some specificity in the translation of at least this sporulation messenger RNA.

Bacillus cereus↗

The aggregation-mediated conjugation system of Bacillus thuringiensis subsp. israelensis: host range and kinetics of transfer.

The aggregation-mediated conjugation system in Bacillus thuringiensis subsp. israelensis encoded on the plasmid pXO16 is characterized by the formation of aggregates when Agr+ and Agr- cells are socialized in exponential growth. Using the aggregation phenotypes, we have identified potential recipients of the aggregation-plasmid pXO16 among Bacillus cereus, Bacillus subtilis, Bacillus megaterium, Bacillus sphaericus, and 24 subspecies of B. thuringiensis. We found 14 Agr- strains, i.e., potential recipients of the aggregation system encoded by plasmid pXO16. Five strains contained a conjugative apparatus of their own and were excluded from further examinations. To monitor the transfer of plasmid pXO16, we constructed a transposon insertion of the plasmid with Tn5401. The study of the plasmid transfer of pXO16::Tn5401 indicated the secretion of bacteriocins from both donor strain and recipient strains. Only one out of the nine strains examined was unable to receive the aggregation-plasmid pXO16 and express the aggregation phenotype and the conjugative abilities. It was found that the transfer of plasmid pXO16 to Bacillus thuringiensis subsp. israelensis Agr- strains was 100%. All recipients had acquired the aggregation-plasmid pXO16 and converted to the Agr+ phenotype.

Anti-Bacterial Agents↗

Clinical significance of Bacillus species isolated from blood cultures.

To determine the clinical significance of blood isolates of Bacillus, we reviewed all blood cultures obtained at North Carolina Memorial Hospital between 1981 and 1985. Over the five-year study period the number of patients (incidence per 10,000 hospital admissions) from whom Bacillus was isolated increased from 4.97 in 1981 to 12.5 in 1985. The incidence per 1,000 blood cultures also increased from 1.12 in 1981 to 2.33 in 1985. Review of the medical records of 78 of the 95 patients (82%) with positive cultures allowed retrospective classification of five isolates (6.4%) as clinically significant, 33 isolates (42.3%) as possibly significant, and 40 isolates (51.3%) as nonsignificant. Underlying diseases in patients with clinically significant Bacillus bacteremia included burn trauma in two, leukemia in one, carcinoma in one, and gastrointestinal hemorrhage in one. All isolates judged to be clinically significant and the majority of possibly significant isolates were B cereus. We conclude that the isolation of Bacillus species from blood cultures is clinically significant in 5% to 10% of cases, that the incidence of Bacillus bacteremia is increasing, and that burn trauma should be added to the list of conditions known to predispose to clinically significant Bacillus bacteremia.

Adolescent↗