scholarly journals The intracerebral infection of mice with Bordetella pertussis

1961 ◽  
Vol 59 (2) ◽  
pp. 205-216 ◽  
Author(s):  
Jean M. Dolby ◽  
A. F. B. Standfast
Keyword(s):  
Bordetella Pertussis ◽  
Viable Count ◽  
Lethal Level ◽  
Virulent Strains ◽  
Single Organism ◽  
Striking Change ◽  
Circulating Antibodies ◽  
Intracerebral Infection

The growth of virulent strains of Bordetella pertussis in the brains of mice was studied by carrying out viable counts on mice killed at various times during the infection. The results suggested that this system conformed to the general model which postulates that the organisms causing death multiply in vivo at a rate which is constant for all doses and that death is certain to occur when the number of organisms reaches a certain constant figure.Perhaps the most important factor in this route of infection is the lodgement of the parasite in the host, for if this is accomplished a single organism grows until the lethal level is reached. There is no sublethal infection.In actively and passively protected mice, the growth of the organism is approximately the same as in unprotected controls for the first 4–5 days. At this time there is a striking change in protected animals and the viable count falls rapidly and progressively and the animals survive. At the same time the blood-brain barrier becomes permeable and circulating antibodies diffuse into the brain. In vitro, specific antisera plus complement are highly bactericidal.

scholarly journals A comparison between the intranasal and intracerebral infection of mice with Bordetella pertussis

1961 ◽  
Vol 59 (2) ◽  
pp. 217-229 ◽  
Author(s):  
A. F. B. Standfast ◽  
Jean M. Dolby
Keyword(s):  
Blood Brain Barrier ◽  
Bordetella Pertussis ◽  
Critical Level ◽  
Viable Count ◽  
Brain Barrier ◽  
Blood Brain ◽  
Virulent Strains ◽  
Lethal Infection ◽  
Intracerebral Infection ◽  
The Brain

1. The main differences between intracerebral and intranasal infections in mice with virulent strains of Bordetella pertussis are in: (1) the responses to small in fecting doses (< 1 LD 50); (2) the action of antisera in controlling infection; (3) the action of toxin on brain and lung; and (4) the rates of increase of the viable count. The two infections can run concurrently in the same mouse without any demonstrable interference.2. The terminal viable count in the lung and brain is c. 108 organisms.3. In the brain there is no sublethal infection with virulent strains; probably even single organisms can grow up to the critical level and kill the mouse. In the lung sublethal infections are found in which the count rises to a figure below the critical level and then declines.4. The action of ‘intranasal’ antiserum is to reduce a lethal infection to a sublethal one in the lung but there is no effect in the brain. ‘Intracerebral’ antisera cannot act until the blood-brain barrier becomes leaky, when they are able to reduce the viable count and eventually sterilize the brain. In the lung ‘intracerebral’ sera have no action against lethal infections but can control small infections (<I LD 50). The sublethal intranasal test measures this effect but it also measures the action of ‘intranasal’ sera and so cannot be used to distinguish the two types of sera and hence the two antigens.

Papaya shoot tip associated endophytic bacteria isolated from in vitro cultures and host–endophyte interaction in vitro and in vivo

2007 ◽  
Vol 53 (3) ◽  
pp. 380-390 ◽  
Author(s):  
Pious Thomas ◽  
Sima Kumari ◽  
Ganiga K. Swarna ◽  
T.K.S. Gowda
Keyword(s):  
Culture Medium ◽  
Carica Papaya ◽  
In Vitro Cultures ◽  
Dependent Manner ◽  
16S Rdna Sequence ◽  
16S Rdna Sequence Analysis ◽  
Single Organism ◽  
Dose Dependent

Fourteen distinct bacterial clones were isolated from surface-sterilized shoot tips (~1 cm) of papaya (Carica papaya L. ‘Surya’) planted on Murashige and Skoog (MS)-based papaya culture medium (23/50 nos.) during the 2–4 week period following in vitro culturing. These isolates were ascribed to six Gram-negative genera, namely Pantoea ( P. ananatis ), Enterobacter ( E. cloacae ), Brevundimonas ( B. aurantiaca ), Sphingomonas , Methylobacterium ( M. rhodesianum ), and Agrobacterium ( A. tumefaciens ) or two Gram-positive genera, Microbacterium ( M. esteraromaticum ) and Bacillus ( B. benzoevorans ) based on 16S rDNA sequence analysis. Pantoea ananatis was the most frequently isolated organism (70% of the cultures) followed by B. benzoevorans (13%), while others were isolated from single stocks. Bacteria-harboring in vitro cultures often showed a single organism. Pantoea, Enterobacter, and Agrobacterium spp. grew actively on MS-based normal papaya medium, while Microbacterium, Brevundimonas, Bacillus, Sphingomonas, and Methylobacterium spp. failed to grow in the absence of host tissue. Supplying MS medium with tissue extract enhanced the growth of all the organisms in a dose-dependent manner, indicating reliance of the endophyte on its host. Inoculation of papaya seeds with the endophytes (20 h at OD550 = 0.5) led to delayed germination or slow seedling growth initially. However, the inhibition was overcome by 3 months and the seedlings inoculated with Pantoea, Microbacterium, or Sphingomonas spp. displayed significantly better root and shoot growths.

scholarly journals Effects of Bordetella pertussis infection on human respiratory epithelium in vivo and in vitro.

1991 ◽  
Vol 59 (1) ◽  
pp. 337-345 ◽  
Author(s):  
R Wilson ◽  
R Read ◽  
M Thomas ◽  
A Rutman ◽  
K Harrison ◽  
...  
Keyword(s):  
Bordetella Pertussis ◽  
Respiratory Epithelium ◽  
Pertussis Infection

scholarly journals Efficacy of BB-83698, a Novel Peptide Deformylase Inhibitor, in a Mouse Model of Pneumococcal Pneumonia

2004 ◽  
Vol 48 (1) ◽  
pp. 80-85 ◽  
Author(s):  
E. Azoulay-Dupuis ◽  
J. Mohler ◽  
J. P. Bédos
Keyword(s):  
Mouse Model ◽  
Lung Tissue ◽  
Resistant Strain ◽  
Peptide Deformylase ◽  
In Vitro Activity ◽  
Wild Type ◽  
Virulent Strains ◽  
Resistant Strains

ABSTRACT The efficacy of BB-83698, a novel potent peptide deformylase inhibitor, was evaluated in a mouse model of acute pneumonia. The Streptococcus pneumoniae isolates tested included four virulent strains (one penicillin-susceptible wild-type strain, one macrolide-resistant strain, and two quinolone-resistant mutants [a mutant carrying mutations in ParC and GyrA and an efflux mutant] isogenic to the wild type) and two poorly virulent penicillin-resistant strains. Pneumonia was induced by intratracheal inoculation of 105 CFU (virulent strains) into immunocompetent mice or 107 CFU (less virulent strains) into leukopenic mice. Animals received three or six subcutaneous injections of antibiotics at 12- or 24-h intervals, with antibiotic treatment initiated at 3, 6, 12, or 18 h postinfection (p.i.). BB-83698 showed potent in vitro activity against all strains (MICs, 0.06 to 0.25 μg/ml). In the in vivo model, all control animals died within 2 to 5 days of infection. BB-83698 (80 mg/kg of body weight twice daily or 160 mg/kg once daily) protected 70 to 100% of the animals, as measured 10 days p.i., regardless of the preexisting resistance mechanisms. In contrast, the survival rates for animals treated with the comparator antibiotics were 30% for animals treated with erythromycin (100 mg/kg) and infected with the macrolide-resistant strain, 34% for animals treated with amoxicillin (200 mg/kg every 8 h) and infected with the penicillin-resistant strain, and 0 and 78% for animals treated with ciprofloxacin (250 mg/kg) and infected with the ParC and GyrA mutant and the efflux mutant, respectively. At 80 mg/kg, BB-83698 generated a peak concentration in lung tissue of 61.9 μg/ml within 1 h and areas under the concentration-times curves of 57.4 and 229.4 μg · h/ml for plasma and lung tissue, respectively. The emergence of S. pneumoniae isolates with reduced susceptibilities to BB-83698 was not observed following treatment with a suboptimal dosing regimen. In conclusion, the potent in vitro activity of BB-83698 against S. pneumoniae, including resistant strains, translates into good in vivo efficacy in a mouse pneumonia model.

scholarly journals T-2307 Shows Efficacy in a Murine Model of Candida glabrata Infection despite In Vitro Trailing Growth Phenomena

2010 ◽  
Vol 54 (9) ◽  
pp. 3630-3634 ◽  
Author(s):  
Eio Yamada ◽  
Hiroshi Nishikawa ◽  
Nobuhiko Nomura ◽  
Junichi Mitsuyama
Keyword(s):  
Murine Model ◽  
Candida Glabrata ◽  
Viable Count ◽  
Control Group ◽  
Alamar Blue ◽  
Inhibition Of Growth ◽  
Mitochondrial Functions ◽  
Clinically Significant

ABSTRACT T-2307, a novel arylamidine, has been shown to exhibit broad-spectrum in vitro and in vivo antifungal activities against clinically significant pathogens. In our preliminary studies, Candida glabrata exhibited significant trailing growth (partial inhibition of growth over an extended range of antifungal concentrations) in the presence of T-2307 when it was tested using the Clinical and Laboratory Standards Institute (CLSI) guidelines with 0.2% glucose and 48 h of incubation, making reading of the MIC difficult. In the present study, we attempted to attenuate trailing growth to avoid misreading of the MIC. On the basis of the hypothesis that T-2307 may inhibit the mitochondrial functions of cells, the carbon source or the glucose concentration in the medium was changed. The trailing growth of C. glabrata ATCC 90030 in the presence of T-2307 was attenuated as the concentration of glucose in the medium decreased to 0.1% or lower, and trailing growth was completely inhibited when glycerol was used. A susceptibility test using Alamar blue was performed to facilitate reading of the MIC without changing the composition of the medium and provided a clear MIC endpoint at 24 h. To investigate if T-2307 shows efficacy against trailing isolates in vivo, we evaluated the efficacy of T-2307 in a murine model of disseminated candidiasis caused by C. glabrata. T-2307 at 0.05 mg/kg of body weight/day significantly decreased the viable count in the kidneys compared to that for the control group (P < 0.05). It would be better to test the susceptibility of C. glabrata to T-2307 using modified media or Alamar blue to avoid misreading of the MIC due to the significant trailing growth.

scholarly journals The effects of humoral, cellular and non-specific immunity on intracerebralBordetella pertussisinfections in mice

1975 ◽  
Vol 74 (1) ◽  
pp. 85-102 ◽  
Author(s):  
Jean M. Dolby ◽  
D. E. Dolby ◽  
Caroline J. Bronne-Shanbury
Keyword(s):  
Bordetella Pertussis ◽  
Cell Mass ◽  
Bactericidal Effect ◽  
Suppressive Effect ◽  
Repeated Doses ◽  
Intracerebral Infection ◽  
The Brain ◽  
Infecting Organisms ◽  
Do So

When mice were injected intracerebrally with doses ofBordetella pertussisvaccine greater than 5 ImD50 and challenged intracerebrally 14 days later with virulentB. pertussisthere was an immediate reduction in the numbers of organisms. An analysis of thisin vivobactericidal effect has shown that large doses of an unrelated vaccine,Salmonella typhosa, equivalent in cell mass to about 50 ImD 50 ofB. pertussisvaccine can achieve this effect, so for such doses the effect must be partly non-specific. This action is not maintained and so is not ultimately protective. Local immunoglobulin was also demonstrable 14 days after 300 ImD 50 ofB. pertussisvaccine but following smaller doses of 10–20 ImD 50 it could not be found until after the mice had been infected and the blood–brain barrier impaired.A similar immediate reduction in the numbers of infecting organisms inoculated 1 day after vaccination has been shown to follow very small, non-protective doses of vaccines unrelated toB. pertussisand to be achieved with lipopolysaccharide and endotoxin isolated fromB. pertussis.Brains were not sterilized and only in mice receiving protectiveB. pertussisvaccine was the lowering of infection maintained beyond 2 days and the brains eventually sterilized.The antibody passively protecting mice against intracerebral infection was found in the 19 S and 11 S globulin fractions of the serum of once-vaccinated mice and in the 11 S and 7 S fractions of the serum of rabbits and ascitic fluid of mice receiving repeated doses of vaccine. The IgM probably eliminated infections by immediate sterilization but had to be present locally to do so since it was unable to pass from the circulation into the brain, and was therefore inactive when injected intraperitoneally. The IgA and IgG were not so restricted and both the 11 S and 7 S globulins were capable of exerting an immediate suppressive effect on infecting organisms. The 7 S globulin was also capable of a maintained or delayed suppressive effect.Lymphocytes from fully protected once-vaccinated mice, transferred 2–3 weeks after intraperitoneal vaccination, were able to confer some protection when injected intraperitoneally or intracerebrally into recipient mice infected 2 weeks after transfer. Homologous, non-concentrated antiserum from once-vaccinated mice, injected intraperitoneally 1 hr. before infection sometimes augmented the transferred immunity, whereas alone it was inactive.

scholarly journals The effect of the antigen which elicits the bactericidal antibody and of the mouse-protective antiǵen on the growth of Bordetella pertussis in the mouse brain

1975 ◽  
Vol 74 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Jean M. Dolby ◽  
J. P. Ackers ◽  
D. E. Dolby
Keyword(s):  
Bordetella Pertussis ◽  
Protective Antigen ◽  
Passive Immunity ◽  
Cell Vaccine ◽  
Potency Assay ◽  
Whole Cell ◽  
Protective Antibody ◽  
Bactericidal Antibody

SUMMARYThe effect of antigens of Bordetella pertussis and their antibodies on brain infections by B. pertussis in mice are suppression of an infection immediately, so that the initial 90 % loss due to leakage from the brain is maintained or the numbers of bacteria are reduced even further, sometimes with complete sterilization particularly after a small lethal challenge of 10 LD 50 (mechanism 1), and a delayed antibacterial activity in vivo which does not begin until 3 days after challenge (mechanism 2). The first, immediate reaction is over in 2–3 days; the second is maintained from 3–4 days onwards, and results in elimination of the bacteria and protection of mice.The parts played in vivo in overcoming infection in these two ways by two antigens and their respective antibodies have been investigated. These antigens are a lipopolysaccharide capable of eliciting an antibody which is bactericidal in vitro in the presence of complement called the ‘bactericidal antigen’, and the mouse protective antigen.Considering first passive immunity, bactericidal antibody elicited by isolated antigen, and of high titre in vitro, is only very weakly active by mechanism (1) in vivo. Brains are seldom sterilized and mice not therefore protected. Antisera to whole cell vaccines whether they contain the ‘bactericidal antigen’ or not, or the protective antigen or not can more easily reduce infections by mechanism (1), eliminating small lethal challenges in some mice which are protected. A passive, intracerebrally protective antibody (PIPA) different from other known antibodies, has been postulated to account for this. Antisera to whole cell vaccine which is protective as denned in the potency assay, can, in additon to this, protect mice by mechanism (2) not only against 10 LD 50 but also 100 LD 50 challenge, and is the only antibody which can do this.These antibodies have been investigated by injecting them with the challenging organisms. The antibody effects described above are given by antisera stimulated by several injections and also by the concentrated serum immunoglobulins of once vaccinated mice. The antibody, which is bactericidal in vitro only, is in the 7 S globulin fraction of the serum of once vaccinated mice. The protective antibody capable of overcoming small and large challenges is in the 19 S and 11 S globulins. The antibody, PIPA, protecting against small lethal challenges only is in the fraction A2 containing mainly 11 S globulin.In active immunization experiments the suppression of infection which immediately follows intracerebral vaccination, but which only lasts 2–3 days (mechanism 1), is not dependent on either ‘bactericidal’ or protective antigens but on a component present in all our whole cell vaccines. Vaccines which also had protective antigen eliminated the remaining infection at 4–6 days after challenge by mechanism (2).As in passive immunity, only the protective antigen can completely overcome 100 LD 50. Suppression of a small, lethal, intracerebral infection given 14 days after intraperitoneal vaccination by mechanism (1) may however be correlated with protective antigen.

scholarly journals Analysis of bvgR Expression in Bordetella pertussis

2003 ◽  
Vol 185 (23) ◽  
pp. 6902-6912 ◽  
Author(s):  
Tod J. Merkel ◽  
Philip E. Boucher ◽  
Scott Stibitz ◽  
Vanessa K. Grippe
Keyword(s):  
Bordetella Pertussis ◽  
Transcriptional Activation ◽  
Northern Blot Analysis ◽  
Whooping Cough ◽  
Transmembrane Protein ◽  
In Vitro Transcription ◽  
Environmental Signals ◽  
Transcription System

ABSTRACT Bordetella pertussis, the causative agent of whooping cough, produces a wide array of factors that are associated with its ability to cause disease. The expression and regulation of these virulence factors are dependent upon the bvg locus, which encodes three proteins: BvgA, a 23-kDa cytoplasmic protein; BvgS, a 135-kDa transmembrane protein; and BvgR, a 32-kDa protein. It is hypothesized that BvgS responds to environmental signals and interacts with BvgA, a transcriptional regulator, which upon modification by BvgS binds to specific promoters and activates transcription. An additional class of genes is repressed by the products of the bvg locus. The repression of these genes is dependent upon the third gene, bvgR. Expression of bvgR is dependent upon the function of BvgA and BvgS. This led to the hypothesis that the binding of phosphorylated BvgA to the bvgR promoter activates the expression of bvgR. We undertook an analysis of the transcriptional activation of bvgR expression. We identified the bvgR transcript by Northern blot analysis and identified the start site of transcription by primer extension. We determined that transcriptional activation of the bvgR promoter in an in vitro transcription system requires the addition of phosphorylated BvgA. Additionally, we have identified cis-acting regions that are required for BvgA activation of the bvgR promoter by in vitro footprinting and in vivo deletion and linker scanning analyses. A model of BvgA binding to the bvgR promoter is presented.

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