scholarly journals Transient Intestinal Colonization by a Live-Attenuated Oral Cholera Vaccine Induces Protective Immune Responses in Streptomycin-Treated Mice

2020 ◽  
Vol 202 (24) ◽  
Author(s):  
Bolutife Fakoya ◽  
Brandon Sit ◽  
Matthew K. Waldor
Keyword(s):  
Single Dose ◽  
Antibiotic Treatment ◽  
Treatment Protocol ◽  
Small Animal ◽  
Intestinal Colonization ◽  
Content Type ◽  
Immune Correlates ◽  
Adult Mice ◽  
Clearance Kinetics ◽  
Cholera Vaccines

ABSTRACT Current mouse models for evaluating the efficacy of live oral cholera vaccines (OCVs) have important limitations. Conventionally raised adult mice are resistant to intestinal colonization by Vibrio cholerae, but germfree mice can be colonized and have been used to study OCV immunogenicity. However, germfree animals have impaired immune systems and intestinal physiology; also, live OCVs colonize germfree mice for many months, which does not mimic the clearance kinetics of live OCVs in humans. In this study, we leveraged antibiotic-treated, conventionally raised adult mice to study the effects of transient intestinal colonization by a live OCV V. cholerae strain. In a single-dose vaccination regimen, we found that HaitiV, a live-attenuated OCV candidate, was cleared by streptomycin-treated adult mice within 2 weeks after oral inoculation. This transient colonization elicited far stronger adaptive immune correlates of protection against cholera than did inactivated whole-cell HaitiV. Infant mice from HaitiV-vaccinated dams were also significantly more protected from choleric disease than pups from inactivated-HaitiV-vaccinated dams. Our findings establish the benefits of antibiotic-treated mice for live-OCV studies as well as their limitations and underscore the immunogenicity of HaitiV. IMPORTANCE Oral cholera vaccines (OCVs) are being deployed to combat cholera, but current killed OCVs require multiple doses and show little efficacy in young children. Live OCVs have the potential to overcome these limitations, but small-animal models for testing OCVs have shortcomings. We used an antibiotic treatment protocol for conventional adult mice to study the effects of short-term colonization by a single dose of HaitiV, a live-OCV candidate. Vaccinated mice developed vibriocidal antibodies against V. cholerae and delivered pups that were resistant to cholera, whereas mice vaccinated with inactivated HaitiV did not. These findings demonstrate HaitiV’s immunogenicity and suggest that this antibiotic treatment protocol will be useful for evaluating the efficacy of live OCVs.

scholarly journals Transient intestinal colonization by a live-attenuated oral cholera vaccine induces protective immune responses in streptomycin-treated mice

2020 ◽  
Author(s):  
Bolutife Fakoya ◽  
Brandon Sit ◽  
Matthew K. Waldor
Keyword(s):  
Single Dose ◽  
Antibiotic Treatment ◽  
Treatment Protocol ◽  
Small Animal ◽  
Intestinal Colonization ◽  
Germ Free ◽  
Immune Correlates ◽  
Adult Mice ◽  
Clearance Kinetics ◽  
Cholera Vaccines

AbstractCurrent mouse models for evaluating the efficacy of live oral cholera vaccines (OCVs) have important limitations. Conventionally raised adult mice are resistant to intestinal colonization by Vibrio cholerae, but germ-free mice can be colonized and have been used to study OCV immunogenicity. However, germ free animals have impaired immune systems and intestinal physiology; also, live OCVs colonize germ free mice for many months, which does not mimic the clearance kinetics of live OCVs in humans. Here, we leverage antibiotic-treated, conventionally raised adult mice to study the effects of transient intestinal colonization by a live OCV V. cholerae strain. In a single dose vaccination regimen, we found that HaitiV, a live-attenuated OCV candidate, was cleared by streptomycin treated adult mice within a week after oral inoculation. This transient colonization elicited far stronger adaptive immune correlates of protection against cholera than did inactivated whole-cell HaitiV. Infant mice from HaitiV vaccinated dams were also significantly protected from choleric disease than pups from inactivated-HaitiV dams. Our findings establish the benefits of antibiotic treated mice for live OCV studies as well as its limitations and underscore the immunogenicity of HaitiV.ImportanceOral cholera vaccines (OCVs) are being deployed to combat cholera but current killed OCVs require multiple doses and show little efficacy in young children. Live OCVs have the potential to overcome these limitations but small animal models for testing OCVs have shortcomings. We used an antibiotic treatment protocol for conventional adult mice to study the effects of short-term colonization by a single dose of HaitiV, a live OCV candidate. Vaccinated mice developed vibriocidal antibodies against V. cholerae and delivered pups that were resistant to cholera, whereas mice vaccinated with inactivated HaitiV did not. These findings demonstrate HaitiV’s immunogenicity and suggest that this antibiotic treatment protocol will be useful for evaluating the efficacy of live OCVs.

scholarly journals Profound Alterations of Intestinal Microbiota following a Single Dose of Clindamycin Results in Sustained Susceptibility to Clostridium difficile-Induced Colitis

2011 ◽  
Vol 80 (1) ◽  
pp. 62-73 ◽  
Author(s):  
Charlie G. Buffie ◽  
Irene Jarchum ◽  
Michele Equinda ◽  
Lauren Lipuma ◽  
Asia Gobourne ◽  
...  
Keyword(s):  
Single Dose ◽  
Clostridium Difficile ◽  
Antibiotic Treatment ◽  
Intestinal Microbiota ◽  
Rapid Development ◽  
Acute Stage ◽  
Rrna Gene ◽  
Content Type ◽  
Intestinal Pathogen ◽  
Induced Changes

ABSTRACTAntibiotic-induced changes in the intestinal microbiota predispose mammalian hosts to infection with antibiotic-resistant pathogens.Clostridium difficileis a Gram-positive intestinal pathogen that causes colitis and diarrhea in patients following antibiotic treatment. Clindamycin predisposes patients toC. difficilecolitis. Here, we have used Roche-454 16S rRNA gene pyrosequencing to longitudinally characterize the intestinal microbiota of mice following clindamycin treatment in the presence or absence ofC. difficileinfection. We show that a single dose of clindamycin markedly reduces the diversity of the intestinal microbiota for at least 28 days, with an enduring loss of ca. 90% of normal microbial taxa from the cecum. Loss of microbial complexity results in dramatic sequential expansion and contraction of a subset of bacterial taxa that are minor contributors to the microbial consortium prior to antibiotic treatment. Inoculation of clindamycin-treated mice withC. difficile(VPI 10463) spores results in rapid development of diarrhea and colitis, with a 4- to 5-day period of profound weight loss and an associated 40 to 50% mortality rate. Recovering mice resolve diarrhea and regain weight but remain highly infected with toxin-producing vegetativeC. difficilebacteria and, in comparison to the acute stage of infection, have persistent, albeit ameliorated cecal and colonic inflammation. The microbiota of “recovered” mice remains highly restricted, and mice remain susceptible toC. difficileinfection at least 10 days following clindamycin, suggesting that resolution of diarrhea and weight gain may result from the activation of mucosal immune defenses.

scholarly journals Oral Immunization with Cholera Toxin Provides Protection against Campylobacter jejuni in an Adult Mouse Intestinal Colonization Model

mBio ◽  
2013 ◽  
Vol 4 (3) ◽  
Author(s):  
M. John Albert ◽  
Abu Salim Mustafa ◽  
Anjum Islam ◽  
Shilpa Haridas
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Cholera Toxin ◽  
Campylobacter Jejuni ◽  
Adult Mouse ◽  
Outer Membrane Proteins ◽  
Cross Reaction ◽  
Intestinal Colonization ◽  
Content Type ◽  
Cholera Vaccines

ABSTRACTImmunity toCampylobacter jejuni, a major diarrheal pathogen, is largely Penner serotype specific. For broad protection, a vaccine should be based on a common antigen(s) present in all strains. In our previous study (M. J. Albert, S. Haridas, D. Steer, G. S. Dhaunsi, A. I. Smith, and B. Adler, Infect. Immun. 75:3070–3073, 2007), we demonstrated that antibody to cholera toxin (CT) cross-reacted with the major outer membrane proteins (MOMPs) of allCampylobacter jejunistrains tested. In the current study, we investigated whether immunization with CT protects against intestinal colonization byC. jejuniin an adult mouse model and whether the nontoxic subunit of CT (CT-B) is the portion mediating cross-reaction. Mice were orally immunized with CT and later challenged withC. jejunistrains (48, 75, and 111) of different serotypes. Control animals were immunized with phosphate-buffered saline. Fecal shedding of challenge organisms was studied daily for 9 days. Serum and fecal antibody responses were studied by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. The cross-reactivity of rabbit CT-B antibody to MOMP was studied by immunoblotting. The reactivity of 21 overlapping 30-mer oligopeptides (based on MOMP’s sequence) against rabbit CT antibody was tested by ELISA. Test animals produced antibodies to CT and MMP in serum and feces and showed resistance to colonization, the vaccine efficacies being 49% (for strain 48), 37% (for strain 75), and 34% (for strain 111) (P, ≤0.05 to ≤0.001). One peptide corresponding to a variable region of MOMP showed significant reactivity. CT-B antibody cross-reacted with MOMP. Since CT-B is a component of oral cholera vaccines, it might be possible to controlC. jejunidiarrhea with these vaccines.IMPORTANCECampylobacter jejuniis a major cause of diarrhea worldwide. Patients who recover fromC. jejunidiarrhea develop immunity to the infecting serotype and remain susceptible to infection with other serotypes. A vaccine based on a common protective antigen(s) present in allC. jejuniserotypes is expected to provide broad protection. In our previous study, we showed that antibody to cholera toxin (CT) reacted with the major outer membrane proteins (MOMPs) from different strains ofC. jejuni. We assumed that the B subunit of the toxin (CT-B), which is nontoxic and a component of licensed oral cholera vaccines, might be the component that cross-reacts with MOMP. In the current study, we showed that orally immunizing mice with CT protected them against colonization upon challenge with different serotypes ofC. jejuni. We also showed that CT-B is the component mediating cross-reaction. Therefore, it might be possible to use cholera vaccines to preventC. jejunidiarrhea. This could result in significant savings in vaccine development and treatment of the disease.

scholarly journals Effect of Antibiotic Treatment on Establishment and Elimination of Intestinal Colonization by KPC-Producing Klebsiella pneumoniae in Mice

2011 ◽  
Vol 55 (6) ◽  
pp. 2585-2589 ◽  
Author(s):  
Federico Perez ◽  
Michael J. Pultz ◽  
Andrea Endimiani ◽  
Robert A. Bonomo ◽  
Curtis J. Donskey
Keyword(s):  
Klebsiella Pneumoniae ◽  
Antibiotic Treatment ◽  
Test Strain ◽  
Moderate Activity ◽  
Significant Activity ◽  
Intestinal Colonization ◽  
Oral Antibiotics ◽  
Content Type ◽  
Polymyxin E ◽  
The Impact

ABSTRACTAn understanding of the impact of antibiotics on the intestinal reservoir of KPC carbapenemase-producingKlebsiella pneumoniae(KPC-Kp) is important to prevent its emergence. We used a mouse model to examine the effect of antibiotic treatment on the establishment and elimination of intestinal colonization with KPC-Kp. Mice (10 per group) received subcutaneous antibiotics daily for 8 days. On day 3 of treatment, 103CFU of KPC-Kp was given orogastrically, and concentrations of KPC-Kp in stool were monitored. Additional experiments assessed the effects of antibiotic treatment on concentrations of total anaerobes andBacteroidesspp. in stool and the efficacy of orogastric gentamicin and polymyxin E in suppressing KPC-Kp colonization. Of four antibiotics with minimal activity against the KPC-Kp test strain (MIC ≥ 16 μg/ml), those that suppressed total anaerobes and bacteroides (i.e., clindamycin and piperacillin-tazobactam) promoted colonization by KPC-Kp (P< 0.001), whereas agents that did not suppress total anaerobes or bacteroides (i.e., ciprofloxacin and cefepime) did not (P= 0.35). Of two agents with moderate activity against the KPC-Kp test strain, ertapenem (MIC, 4 μg/ml) did not promote colonization by KPC-Kp, whereas tigecycline (MIC, 3 μg/ml) did (P< 0.001), despite not reducing levels of total anaerobes or bacteroides. Orogastric treatment with gentamicin and polymyxin E suppressed KPC-Kp to undetectable levels in the majority of mice. These data suggest that antibiotics that disturb the intestinal anaerobic microflora and lack significant activity against KPC-Kp promote colonization by this organism. The administration of nonabsorbed oral antibiotics may be an effective strategy to suppress colonization with KPC-Kp.

scholarly journals Effect of Parenteral Antibiotic Administration on Establishment of Intestinal Colonization by Candida glabrata in Adult Mice

2005 ◽  
Vol 49 (1) ◽  
pp. 438-440 ◽  
Author(s):  
Nicole J. Pultz ◽  
Usha Stiefel ◽  
Mahmoud Ghannoum ◽  
Marion S. Helfand ◽  
Curtis J. Donskey
Keyword(s):  
Antibiotic Treatment ◽  
Candida Glabrata ◽  
Antibiotic Administration ◽  
Intestinal Colonization ◽  
Parenteral Antibiotic ◽  
Adult Mice

ABSTRACT We examined the effect of antibiotic treatment on establishment of intestinal colonization by Candida glabrata in adult mice. Subcutaneous ceftriaxone, piperacillin-tazobactam, clindamycin, and metronidazole promoted increased density of stool colonization, whereas cefepime, levofloxacin, and aztreonam did not. These findings suggest that antibiotics that inhibit intestinal anaerobes promote C. glabrata colonization.

scholarly journals An Oral Inoculation Infant Rabbit Model for Shigella Infection

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Carole J. Kuehl ◽  
Jonathan D. D’Gama ◽  
Alyson R. Warr ◽  
Matthew K. Waldor
Keyword(s):  
Type Iii Secretion ◽  
Diarrheal Disease ◽  
Small Animal ◽  
Oral Route ◽  
Oral Infection ◽  
Secretion System ◽  
Colonic Epithelium ◽  
Intestinal Colonization ◽  
Content Type ◽  
Small Animal Models

ABSTRACT Shigella species cause diarrheal disease globally. Shigellosis is typically characterized by bloody stools and colitis with mucosal damage and is the leading bacterial cause of diarrheal death worldwide. After the pathogen is orally ingested, it invades and replicates within the colonic epithelium through mechanisms that rely on its type III secretion system (T3SS). Currently, oral infection-based small animal models to study the pathogenesis of shigellosis are lacking. Here, we found that orogastric inoculation of infant rabbits with Shigella flexneri resulted in diarrhea and colonic pathology resembling that found in human shigellosis. Fasting animals prior to S. flexneri inoculation increased the frequency of disease. The pathogen colonized the colon, where both luminal and intraepithelial foci were observed. The intraepithelial foci likely arise through S. flexneri spreading from cell to cell. Robust S. flexneri intestinal colonization, invasion of the colonic epithelium, and epithelial sloughing all required the T3SS as well as IcsA, a factor required for bacterial spreading and adhesion in vitro. Expression of the proinflammatory chemokine interleukin 8 (IL-8), detected with in situ mRNA labeling, was higher in animals infected with wild-type S. flexneri versus mutant strains deficient in icsA or T3SS, suggesting that epithelial invasion promotes expression of this chemokine. Collectively, our findings suggest that oral infection of infant rabbits offers a useful experimental model for studies of the pathogenesis of shigellosis and for testing of new therapeutics. IMPORTANCE Shigella species are the leading bacterial cause of diarrheal death globally. The pathogen causes bacillary dysentery, a bloody diarrheal disease characterized by damage to the colonic mucosa and is usually spread through the fecal-oral route. Small animal models of shigellosis that rely on the oral route of infection are lacking. Here, we found that orogastric inoculation of infant rabbits with S. flexneri led to a diarrheal disease and colonic pathology reminiscent of human shigellosis. Diarrhea, intestinal colonization, and pathology in this model were dependent on the S. flexneri type III secretion system and IcsA, canonical Shigella virulence factors. Thus, oral infection of infant rabbits offers a feasible model to study the pathogenesis of shigellosis and to develop and test new therapeutics.

Safety and efficacy of stereotactic radiosurgery for tumors of the spine

2004 ◽  
pp. 413-418 ◽  
Author(s):  
Deborah L. Benzil ◽  
Mehran Saboori ◽  
Alon Y. Mogilner ◽  
Ronald Rocchio ◽  
Chitti R. Moorthy
Keyword(s):  
Spinal Cord ◽  
Single Dose ◽  
Pain Relief ◽  
Total Dose ◽  
Stereotactic Radiosurgery ◽  
Medical Center ◽  
Primary Tumors ◽  
Content Type ◽  
Increased Risk ◽  
Fine Print

Object. The extension of stereotactic radiosurgery treatment of tumors of the spine has the potential to benefit many patients. As in the early days of cranial stereotactic radiosurgery, however, dose-related efficacy and toxicity are not well understood. The authors report their initial experience with stereotactic radiosurgery of the spine with attention to dose, efficacy, and toxicity. Methods. All patients who underwent stereotactic radiosurgery of the spine were treated using the Novalis unit at Westchester Medical Center between December 2001 and January 2004 are included in a database consisting of demographics on disease, dose, outcome, and complications. A total of 31 patients (12 men, 19 women; mean age 61 years, median age 63 years) received treatment for 35 tumors. Tumor types included 26 metastases (12 lung, nine breast, five other) and nine primary tumors (four intradural, five extradural). Thoracic tumors were most common (17 metastases and four primary) followed by lumbar tumors (four metastases and four primary). Lesions were treated to the 85 to 90% isodose line with spinal cord doses being less than 50%. The dose per fraction and total dose were selected on the basis of previous treatment (particularly radiation exposure), size of lesion, and proximity to critical structures. Conclusions. Rapid and significant pain relief was achieved after stereotactic radiosurgery in 32 of 34 treated tumors. In patients treated for metastases, pain was relieved within 72 hours and remained reduced 3 months later. Pain relief was achieved with a single dose as low as 500 cGy. Spinal cord isodoses were less than 50% in all patients except those with intradural tumors (mean single dose to spinal cord 268 cGy and mean total dose to spinal cord 689 cGy). Two patients experienced transient radiculitis (both with a biological equivalent dose (BED) > 60 Gy). One patient who suffered multiple recurrences of a conus ependymoma had permanent neurological deterioration after initial improvement. Pathological evaluation of this lesion at surgery revealed radiation necrosis with some residual/recurrent tumor. No patient experienced other organ toxicity. Stereotactic radiosurgery of the spine is safe at the doses used and provides effective pain relief. In this study, BEDs greater than 60 Gy were associated with an increased risk of radiculitis.

scholarly journals MetR-Regulated Vibrio cholerae Metabolism Is Required for Virulence

mBio ◽  
2012 ◽  
Vol 3 (5) ◽  
Author(s):  
Ryan W. Bogard ◽  
Bryan W. Davies ◽  
John J. Mekalanos
Keyword(s):  
Amino Acid ◽  
Vibrio Cholerae ◽  
Virulence Factor ◽  
Current Knowledge ◽  
Intestinal Colonization ◽  
Wild Type ◽  
Pathogenic Potential ◽  
Content Type ◽  
Mouse Intestine

ABSTRACTLysR-type transcriptional regulators (LTTRs) are the largest, most diverse family of prokaryotic transcription factors, with regulatory roles spanning metabolism, cell growth and division, and pathogenesis. Using a sequence-defined transposon mutant library, we screened a panel ofV. choleraeEl Tor mutants to identify LTTRs required for host intestinal colonization. Surprisingly, out of 38 LTTRs, only one severely affected intestinal colonization in the suckling mouse model of cholera: the methionine metabolism regulator, MetR. Genetic analysis of genes influenced by MetR revealed thatglyA1andmetJwere also required for intestinal colonization. Chromatin immunoprecipitation of MetR and quantitative reverse transcription-PCR (qRT-PCR) confirmed interaction with and regulation ofglyA1, indicating that misregulation ofglyA1is likely responsible for the colonization defect observed in themetRmutant. TheglyA1mutant was auxotrophic for glycine but exhibited wild-type trimethoprim sensitivity, making folate deficiency an unlikely cause of its colonization defect. MetJ regulatory mutants are not auxotrophic but are likely altered in the regulation of amino acid-biosynthetic pathways, including those for methionine, glycine, and serine, and this misregulation likely explains its colonization defect. However, mutants defective in methionine, serine, and cysteine biosynthesis exhibited wild-type virulence, suggesting that these amino acids can be scavenged in vivo. Taken together, our results suggest that glycine biosynthesis may be required to alleviate an in vivo nutritional restriction in the mouse intestine; however, additional roles for glycine may exist. Irrespective of the precise nature of this requirement, this study illustrates the importance of pathogen metabolism, and the regulation thereof, as a virulence factor.IMPORTANCEVibrio choleraecontinues to be a severe cause of morbidity and mortality in developing countries. Identification ofV. choleraefactors critical to disease progression offers the potential to develop or improve upon therapeutics and prevention strategies. To increase the efficiency of virulence factor discovery, we employed a regulator-centric approach to multiplex our in vivo screening capabilities and allow whole regulons inV. choleraeto be interrogated for pathogenic potential. We identified MetR as a new virulence regulator and serine hydroxymethyltransferase GlyA1 as a new MetR-regulated virulence factor, both required byV. choleraeto colonize the infant mouse intestine. Bacterial metabolism is a prerequisite to virulence, and current knowledge of in vivo metabolism of pathogens is limited. Here, we expand the known role of amino acid metabolism and regulation in virulence and offer new insights into the in vivo metabolic requirements ofV. choleraewithin the mouse intestine.

scholarly journals Antibiotic treatment with one single dose of gentamicin at admittance in addition to a β-lactam antibiotic in the treatment of community-acquired bloodstream infection with sepsis

PLoS ONE ◽  
2020 ◽  
Vol 15 (7) ◽  
pp. e0236864 ◽  
Author(s):  
Karolina Liljedahl Prytz ◽  
Mårten Prag ◽  
Hans Fredlund ◽  
Anders Magnuson ◽  
Martin Sundqvist ◽  
...  
Keyword(s):  
Single Dose ◽  
Bloodstream Infection ◽  
Antibiotic Treatment ◽  
Lactam Antibiotic

scholarly journals Protection against Streptococcus pneumoniae Invasive Pathogenesis by a Protein-Based Vaccine Is Achieved by Suppression of Nasopharyngeal Bacterial Density during Influenza A Virus Coinfection

2016 ◽  
Vol 85 (2) ◽  
Author(s):  
M. Nadeem Khan ◽  
Qingfu Xu ◽  
Michael E. Pichichero
Keyword(s):  
T Cells ◽  
Streptococcus Pneumoniae ◽  
Influenza A Virus ◽  
Influenza A ◽  
Passive Transfer ◽  
Bacterial Density ◽  
Content Type ◽  
Adult Mice ◽  
Significant Difference ◽  
Colonization Density

ABSTRACTAn increase inStreptococcus pneumoniaenasopharynx (NP) colonization density during a viral coinfection initiates pathogenesis. To mimic naturalS. pneumoniaepathogenesis, we commensally colonized the NPs of adult C57BL/6 mice withS. pneumoniaeserotype (ST) 6A or 8 and then coinfected them with mouse-adapted H1N1 influenza A virus (PR/8/34).S. pneumoniaeestablished effective commensal colonization, and influenza virus coinfection causedS. pneumoniaeNP density to increase, resulting in bacteremia and mortality. We then studied histidine triad protein D (PhtD), anS. pneumoniaeadhesin vaccine candidate, for its ability to prevent invasiveS. pneumoniaedisease in adult and infant mice. In adult mice, the efficacy of PhtD vaccination was compared with that of PCV13. Vaccination with PCV13 led to a greater reduction ofS. pneumoniaeNP density (>2.5 log units) than PhtD vaccination (∼1-log-unit reduction). However, no significant difference was observed with regard to the prevention ofS. pneumoniaebacteremia, and there was no difference in mortality. Depletion of CD4+T cells in PhtD-vaccinated adult mice, but not PCV13-vaccinated mice, caused a loss of vaccine-induced protection. In infant mice, passive transfer of antisera or CD4+T cells from PhtD-vaccinated adult mice led to a nonsignificant reduction in NP colonization density, whereas passive transfer of antisera and CD4+T cells was needed to cause a significant reduction in NP colonization density. For the first time, these data show an outcome with regard to prevention of invasiveS. pneumoniaepathogenesis with a protein vaccine similar to that which occurs with a glycoconjugate vaccine despite a less robust reduction in NP bacterial density.

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