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1.
BMC Gastroenterol ; 24(1): 157, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720287

RESUMO

BACKGROUND: At present, eradication regimens for non-Helicobacter pylori Helicobacter (NHPH) have not been established yet. We investigated effectiveness of the standard triple-drug combination therapy for Helicobacter pylori eradication and of a proton pump inhibitor (PPI) monotherapy in eradication of NHPH. METHODS: Subjects were the patients who were diagnosed with NHPH-infected gastritis based on microscopic findings, helical-shaped organisms obviously larger than Helicobacter pylori, in the gastric mucosal specimens using Giemsa staining at Kenwakai Hospital between November 2010 and September 2021, whose NHPH species were identified by polymerase chain reaction (PCR) analysis of urease genes in endoscopically-biopsied samples, and who consented to NHPH eradication with either the triple-drug combination therapy for one week or a PPI monotherapy for six months. Six months after the completion of eradication, its result was determined with esophagogastroduodenoscopy, microscopic examination, and PCR analysis. In cases of unsuccessful eradication, a second eradication with the other therapy was suggested to the patient. RESULTS: PCR analysis detected NHPH in 38 patients: 36 as Helicobacter suis and two as Helicobacter heilmannii/Helicobacter ailurogastricus. Fourteen Helicobacter suis-infected and one Helicobacter heilmannii/Helicobacter ailurogastricus-infected patients requested eradication therapy. The triple-drug combination therapy succeeded in four of five patients, while the PPI monotherapy succeeded in five of 10 patients. Three of five patients who had been unsuccessful with the latter therapy requested the triple-drug combination therapy as the second eradication and all three were successful. In total, the triple-drug combination therapy succeeded in seven out of eight (87.5%) attempted cases, while the PPI monotherapy in five out of 10 (50%) attempted cases. CONCLUSIONS: In NHPH eradication, the triple-drug combination therapy was considered to be effective to some extent and to become the first-line therapy. While, although less successful, PPI monotherapy appeared to be a potentially promising option particularly for patients with allergy or resistance to antibiotics. Effectiveness of PPI monotherapy may be attributed to hyperacid environment preference of Helicobacter suis and PPI's acid-suppressive effect. Additionally, male predominance in NHPH-infected gastritis patients may be explained by gender difference in gastric acid secretory capacity. However, further evidence needs to be accumulated. STUDY REGISTRATION: This study was approved by the Research Ethics Committee of Kenwakai Hospital (No. 2,017,024).


Assuntos
Antibacterianos , Quimioterapia Combinada , Gastrite , Infecções por Helicobacter , Helicobacter heilmannii , Inibidores da Bomba de Prótons , Inibidores da Bomba de Prótons/administração & dosagem , Inibidores da Bomba de Prótons/uso terapêutico , Humanos , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/microbiologia , Masculino , Feminino , Pessoa de Meia-Idade , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Gastrite/tratamento farmacológico , Gastrite/microbiologia , Adulto , Idoso , Helicobacter heilmannii/isolamento & purificação , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/isolamento & purificação , Amoxicilina/administração & dosagem , Amoxicilina/uso terapêutico , Claritromicina/administração & dosagem , Claritromicina/uso terapêutico , Helicobacter/isolamento & purificação , Helicobacter/efeitos dos fármacos , Resultado do Tratamento , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia
2.
Helicobacter ; 29(2): e13083, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38671593

RESUMO

BACKGROUND: Non-Helicobacter pylori Helicobacter (NHPH) is rarely detected in duodenal mucosa due to its preference for slightly acidic environments. Here, we report four cases of NHPH-infected gastritis with duodenal spiral bacilli, potentially NHPH, indicating the possibility of duodenal mucosal infection. CASE PRESENTATION: In every case, gastric mucosa showed endoscopic findings characteristic of NHPH-infected gastritis, and a mucosal biopsy was taken from the duodenal bulb; spiral bacilli were identified under microscopy using Giemsa staining. Case 1, a 46-year-old man, had diffuse spotty redness, mucosal edema, and multiple tiny erosions in the duodenal bulb, along with larger erosions in the second portion of the duodenum upon endoscopic examination. Histopathologically, moderate infiltration of mononuclear cells and neutrophils in the lamina propria and gastric epithelial metaplasia were observed. Case 2, a 54-year-old man, showed an elevated lesion, 1 cm in diameter, with multiple red spots and a few tiny erosions in the duodenal bulb. Histopathologically, mild inflammatory cell infiltration and gastric epithelial metaplasia were observed. In Case 3, a 52-year-old man, endoscopy revealed a flat elevated lesion, 7 mm in diameter, with multiple red spots and a few tiny erosions in the anterior wall of the duodenal bulb. Histopathologically, we observed moderate inflammatory cell infiltration in the gastric antrum and gastric epithelial metaplasia in the duodenal bulb. Case 4, a 40-year-old man, showed mild spotty redness in the duodenal bulb. Histopathologically, mild mononucleocyte infiltration and gastric epithelial metaplasia were observed. A single spiral bacillus was observed in Case 4 by microscopy. In all but Case 2, Helicobacter suis was identified in the gastric juice by polymerase chain reaction analysis. CONCLUSIONS: Spiral bacilli resembling NHPH may infect the duodenal mucosa, particularly the bulb, causing inflammation. Gastric contents entering the duodenum may reduce the intraduodenal pH, promoting NHPH survival and proliferation.


Assuntos
Duodeno , Gastrite , Infecções por Helicobacter , Humanos , Masculino , Pessoa de Meia-Idade , Gastrite/microbiologia , Gastrite/patologia , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Infecções por Helicobacter/complicações , Duodeno/patologia , Duodeno/microbiologia , Biópsia , Helicobacter/isolamento & purificação , Helicobacter/fisiologia , Helicobacter/genética , Adulto , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia
3.
J Infect Chemother ; 2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38442770

RESUMO

INTRODUCTION: Carbon dioxide-dependent Proteus mirabilis has been isolated from clinical specimens. It is not clear whether mutations in carbonic anhydrase are responsible for the carbon dioxide dependence of P. mirabilis. The pathogenicity of carbon dioxide-dependent P. mirabilis also remains unclear. The purpose of this study was to determine the cause carbon dioxide dependence of P. mirabilis and its pathogenicity. METHODS: The DNA sequence of can encoding carbonic anhydrase of a carbon dioxide-dependent P. mirabilis small colony variant (SCV) isolate was analyzed. To confirm that impaired carbonic anhydrase activity is responsible for the formation of the carbon dioxide-dependent SCV phenotype of P. mirabilis, we performed complementation experiments using plasmids with intact can. Additionally, mouse infection experiments were performed to confirm the change in virulence due to the mutation of carbonic anhydrase. RESULTS: We found that the can gene of the carbon dioxide-dependent P. mirabilis SCV isolate showed had a frameshift mutation with a deletion of 1 bp (c. 173delC). The can of P. mirabilis encodes carbonic anhydrase was also found to function in Escherichia coli. The cause of the carbon dioxide-dependent SCV phenotype of P. mirabilis was an abnormality in carbonic anhydrase. Nevertheless, no changes were observed in virulence due to the mutation of carbonic anhydrase in mouse infection experiments. CONCLUSIONS: The can gene is essential for the growth of P. mirabilis in ambient air. The mechanisms underlying this fitness advantage in terms of infection warrant further investigation.

4.
Cancer Sci ; 115(1): 211-226, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37972575

RESUMO

The tumor microenvironment (TME) consists of cancer cells surrounded by stromal components including tumor vessels. Transforming growth factor-ß (TGF-ß) promotes tumor progression by inducing epithelial-mesenchymal transition (EMT) in cancer cells and stimulating tumor angiogenesis in the tumor stroma. We previously developed an Fc chimeric TGF-ß receptor containing both TGF-ß type I (TßRI) and type II (TßRII) receptors (TßRI-TßRII-Fc), which trapped all TGF-ß isoforms and suppressed tumor growth. However, the precise mechanisms underlying this action have not yet been elucidated. In the present study, we showed that the recombinant TßRI-TßRII-Fc protein effectively suppressed in vitro EMT of oral cancer cells and in vivo tumor growth in a human oral cancer cell xenograft mouse model. Tumor cell proliferation and angiogenesis were suppressed in tumors treated with TßRI-TßRII-Fc. Molecular profiling of human cancer cells and mouse stroma revealed that K-Ras signaling and angiogenesis were suppressed. Administration of TßRI-TßRII-Fc protein decreased the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF), interleukin-1ß (IL-1ß) and epiregulin (EREG) in the TME of oral cancer tumor xenografts. HB-EGF increased proliferation of human oral cancer cells and mouse endothelial cells by activating ERK1/2 phosphorylation. HB-EGF also promoted oral cancer cell-derived tumor formation by enhancing cancer cell proliferation and tumor angiogenesis. In addition, increased expressions of IL-1ß and EREG in oral cancer cells significantly enhanced tumor formation. These results suggest that TGF-ß signaling in the TME controls cancer cell proliferation and angiogenesis by activating HB-EGF/IL-1ß/EREG pathways and that TßRI-TßRII-Fc protein is a promising tool for targeting the TME networks.


Assuntos
Neoplasias Bucais , Proteínas Serina-Treonina Quinases , Humanos , Camundongos , Animais , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Células Endoteliais/metabolismo , Microambiente Tumoral , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fator de Crescimento Transformador beta1 , Neoplasias Bucais/genética , Fatores de Crescimento Transformadores
5.
Microbiol Spectr ; 11(6): e0216523, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37823633

RESUMO

IMPORTANCE: We characterized Streptococcus pneumoniae serotype 24F sequence type (ST) 162 isolated from Japanese children with invasive pneumococcal disease (IPD). Owing to its highly invasive nature, serotype 24F is expected to be isolated from clinically significant cases. Serotype 24F ST162 isolates tested in the present study did not grow at 35°C in ambient air. Therefore, antimicrobial susceptibility testing using the broth microdilution method, which is usually conducted in ambient air, cannot be performed, posing a clinical challenge. Clinical practitioners and laboratory personnel should be aware of the epidemiological, bacteriological, and molecular characteristics of serotype 24F ST162. We believe that our findings can help diagnose and treat IPD caused by serotype 24F ST162, a serotype expected to become problematic in the post-13 valent pneumococcal conjugate vaccine era.


Assuntos
Infecções Pneumocócicas , Streptococcus pneumoniae , Criança , Humanos , Lactente , Dióxido de Carbono , Sorogrupo , Temperatura , Japão/epidemiologia , Infecções Pneumocócicas/prevenção & controle , Sorotipagem
6.
iScience ; 26(6): 106955, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37288342

RESUMO

Several antibody therapeutics have been developed against SARS-CoV-2; however, they have attenuated neutralizing ability against variants. In this study, we generated multiple broadly neutralizing antibodies from B cells of convalescents, by using two types of receptor-binding domains, Wuhan strain and the Gamma variant as bait. From 172 antibodies generated, six antibodies neutralized all strains prior to the Omicron variant, and the five antibodies were able to neutralize some of the Omicron sub-strains. Structural analysis showed that these antibodies have a variety of characteristic binding modes, such as ACE2 mimicry. We subjected a representative antibody to the hamster infection model after introduction of the N297A modification, and observed a dose-dependent reduction of the lung viral titer, even at a dose of 2 mg/kg. These results demonstrated that our antibodies have certain antiviral activity as therapeutics, and highlighted the importance of initial cell-screening strategy for the efficient development of therapeutic antibodies.

7.
Viruses ; 15(5)2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37243257

RESUMO

Coronaviruses, including SARS-CoV-2, SARS-CoV, MERS-CoV and influenza A virus, require the host proteases to mediate viral entry into cells. Rather than targeting the continuously mutating viral proteins, targeting the conserved host-based entry mechanism could offer advantages. Nafamostat and camostat were discovered as covalent inhibitors of TMPRSS2 protease involved in viral entry. To circumvent their limitations, a reversible inhibitor might be required. Considering nafamostat structure and using pentamidine as a starting point, a small set of structurally diverse rigid analogues were designed and evaluated in silico to guide selection of compounds to be prepared for biological evaluation. Based on the results of in silico study, six compounds were prepared and evaluated in vitro. At the enzyme level, compounds 10-12 triggered potential TMPRSS2 inhibition with low micromolar IC50 concentrations, but they were less effective in cellular assays. Meanwhile, compound 14 did not trigger potential TMPRSS2 inhibition at the enzyme level, but it showed potential cellular activity regarding inhibition of membrane fusion with a low micromolar IC50 value of 10.87 µM, suggesting its action could be mediated by another molecular target. Furthermore, in vitro evaluation showed that compound 14 inhibited pseudovirus entry as well as thrombin and factor Xa. Together, this study presents compound 14 as a hit compound that might serve as a starting point for developing potential viral entry inhibitors with possible application against coronaviruses.


Assuntos
COVID-19 , Coronavírus da Síndrome Respiratória do Oriente Médio , Humanos , SARS-CoV-2 , Benzamidinas/farmacologia , Internalização do Vírus , Antivirais/farmacologia , Antivirais/química
8.
J Infect Chemother ; 29(8): 803-805, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37098379

RESUMO

A small-colony variant (SCV) of carbon dioxide-dependent Escherichia coli was isolated from a patient with acute bacterial cystitis. After the urine sample was inoculated on 5% sheep blood agar and incubated overnight at 35 °C in ambient air, no colony formation was observed. However, after overnight incubation at 35 °C in 5% CO2-enhanced ambient air, numerous colonies were obtained. We failed to characterize or identify the SCV isolate using the MicroScan WalkAway-40 System because the isolate did not grow in the system. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing were useful for identifying this SCV isolate. Genome sequencing analysis of the isolates revealed the presence of an 11-bp deletion mutation leading to premature translational truncation in the carbonic anhydrase gene, can, and the presence of 10 known antimicrobial resistance genes. The results of the antimicrobial susceptibility tests performed under CO2-enhanced ambient air were consistent with the presence of antimicrobial resistance genes. Our results also showed that Can is important to grow E. coli in ambient air, and that antimicrobial susceptibility testing of carbon dioxide-dependent SCVs should be performed in 5% CO2-enhanced ambient air. A revertant strain was obtained by passaging the SCV isolate, but the deletion mutation in can remained. To the best of our knowledge, this is the first case in Japan of acute bacterial cystitis caused by carbon dioxide-dependent E. coli with a deletion mutation in can.


Assuntos
Infecções Bacterianas , Cistite , Animais , Ovinos/genética , Escherichia coli/genética , Dióxido de Carbono , RNA Ribossômico 16S/genética , Deleção de Sequência , Mutação
9.
J Infect Chemother ; 29(6): 631-633, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36996937

RESUMO

A hemin-requiring Proteus vulgaris small-colony variant (SCV) was isolated from a urine culture. This isolate was grown on 5% sheep blood agar but not on modified Drigalski agar. The single nucleotide substitution was found in the SCV of the hemC gene (c.55C > T), and this substitution caused a nonsense mutation (p.Gln19Ter). Porphyrin test results showed that the biosynthesis of δ-aminolevulinic acid stopped up to porphobilinogen and not pre-uroporphyrinogen due to a mutation in the hemC gene. To our knowledge, this is the first report of hemin-requiring P. vulgaris.


Assuntos
Hemina , Porfirinas , Animais , Ovinos , Proteus vulgaris/genética , Ágar , Meios de Cultura
10.
Commun Biol ; 6(1): 284, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36932164

RESUMO

The control of cell movement through manipulation of cytoskeletal structure has therapeutic prospects notably in the development of novel anti-metastatic drugs. In this study, we determine the structure of Ras-binding domain (RBD) of ELMO1, a protein involved in cytoskeletal regulation, both alone and in complex with the activator RhoG and verify its targetability through computational nanobody design. Using our dock-and-design approach optimized with native-like initial pose selection, we obtain Nb01, a detectable binder from scratch in the first-round design. An affinity maturation step guided by structure-activity relationship at the interface generates 23 Nb01 sequence variants and 17 of them show enhanced binding to ELMO1-RBD and are modeled to form major spatial overlaps with RhoG. The best binder, Nb29, inhibited ELMO1-RBD/RhoG interaction. Molecular dynamics simulation of the flexibility of CDR2 and CDR3 of Nb29 reveal the design of stabilizing mutations at the CDR-framework junctions potentially confers the affinity enhancement.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Simulação de Dinâmica Molecular , Proteínas rho de Ligação ao GTP , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo
11.
J Biol Chem ; 299(2): 102877, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36621628

RESUMO

The red blood cells (RBCs) of vertebrates have evolved into two basic shapes, with nucleated nonmammalian RBCs having a biconvex ellipsoidal shape and anuclear mammalian RBCs having a biconcave disk shape. In contrast, camelid RBCs are flat ellipsoids with reduced membrane deformability, suggesting altered membrane skeletal organization. However, the mechanisms responsible for their elliptocytic shape and reduced deformability have not been determined. We here showed that in alpaca RBCs, protein 4.1R, a major component of the membrane skeleton, contains an alternatively spliced exon 14-derived cassette (e14) not observed in the highly conserved 80 kDa 4.1R of other highly deformable biconcave mammalian RBCs. The inclusion of this exon, along with the preceding unordered proline- and glutamic acid-rich peptide (PE), results in a larger and unique 90 kDa camelid 4.1R. Human 4.1R containing e14 and PE, but not PE alone, showed markedly increased ability to form a spectrin-actin-4.1R ternary complex in viscosity assays. A similar facilitated ternary complex was formed by human 4.1R possessing a duplication of the spectrin-actin-binding domain, one of the mutations known to cause human hereditary elliptocytosis. The e14- and PE-containing mutant also exhibited an increased binding affinity to ß-spectrin compared with WT 4.1R. Taken together, these findings indicate that 4.1R protein with the e14 cassette results in the formation and maintenance of a hyperstable membrane skeleton, resulting in rigid red ellipsoidal cells in camelid species, and suggest that membrane structure is evolutionarily regulated by alternative splicing of exons in the 4.1R gene.


Assuntos
Processamento Alternativo , Camelídeos Americanos , Forma Celular , Proteínas do Citoesqueleto , Eritrócitos , Animais , Humanos , Actinas/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Eritrócitos/citologia , Eritrócitos/metabolismo , Membranas/metabolismo , Peptídeos/metabolismo , Ligação Proteica , Espectrina/genética , Espectrina/metabolismo , Forma Celular/genética
12.
Jpn J Infect Dis ; 76(2): 159-161, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36575027

RESUMO

Klebsiella oxytoca is an opportunistic pathogen that causes nosocomial infections. Here, we describe an unusual clinical strain of indole-negative K. oxytoca, GU175, isolated from the urine of a patient with cystitis. The GU175 strain was identified as K. pneumoniae with a probability of 99.40%, negative for indole production, and resistant to third-generation cephalosporins by using the MicroScan Walkaway 40 SI system with the Negative combo EN1 J panel. Biochemical characterization of this strain using lysine-indole motility medium was negative for indole production. However, identification tests using the MALDI Biotyper system and 16S rRNA gene sequence analysis revealed that GU175 is K. oxytoca. DNA sequence analysis of the tryptophanase operon comparing the GU175 strain with the revertant GU176 strain, which tested positive for indole, revealed a point mutation in the Shine-Dalgarno sequence upstream of tnaC in the GU175 strain. This is the first report of indole-negative K. oxytoca, which was attributed to a mutation in the DNA sequence of the tryptophanase operon isolated from a patient with a urinary tract infection. As indole-negative K. oxytoca can be misidentified as K. pneumoniae by biochemical characterization, clinical microbiologists should be aware of such misidentifications.


Assuntos
Cistite , Infecções por Klebsiella , Humanos , Klebsiella oxytoca/genética , RNA Ribossômico 16S/genética , Triptofanase , Klebsiella pneumoniae/genética , Indóis , Cistite/diagnóstico , Infecções por Klebsiella/diagnóstico
13.
iScience ; 25(12): 105596, 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36406861

RESUMO

The use of therapeutic neutralizing antibodies against SARS-CoV-2 infection has been highly effective. However, there remain few practical antibodies against viruses that are acquiring mutations. In this study, we created 494 monoclonal antibodies from patients with COVID-19-convalescent, and identified antibodies that exhibited the comparable neutralizing ability to clinically used antibodies in the neutralization assay using pseudovirus and authentic virus including variants of concerns. These antibodies have different profiles against various mutations, which were confirmed by cell-based assay and cryo-electron microscopy. To prevent antibody-dependent enhancement, N297A modification was introduced. Our antibodies showed a reduction of lung viral RNAs by therapeutic administration in a hamster model. In addition, an antibody cocktail consisting of three antibodies was also administered therapeutically to a macaque model, which resulted in reduced viral titers of swabs and lungs and reduced lung tissue damage scores. These results showed that our antibodies have sufficient antiviral activity as therapeutic candidates.

14.
J Infect Chemother ; 28(11): 1513-1518, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35948249

RESUMO

INTRODUCTION: Small-colony variants (SCVs) of bacteria are subpopulations with a small colony size, low growth rate, and atypical colony morphology. The purpose of this study was to comprehensively elucidate the characteristics and underlying mechanism of the development of a glutamine-dependent SCV of E. coli, GU-92SCV, isolated from the blood of a patient with pyelonephritis. METHODS: The GU-92SCV strain was tested for auxotrophy testing for glutamine. DNA mutations in genes related to glutamine synthesis were analysed by sequencing. The isolate's proliferation and antimicrobial susceptibility in Mueller-Hinton II medium supplemented with glutamine were examined. RESULTS: The colony of the GU-92SCV strain did not grow on Mueller-Hinton II agar, but growth around the filter paper containing l-glutamine was enhanced on Mueller-Hinton II agar. The GU-92SCV strain had a single nucleotide substitution in glnA, c.193G>A, corresponding to p.Asp65Asn. Changing c.193G>A to the wild-type sequence in glnA restored these phenotypes. Because GU-92SCV did not grow in Mueller-Hinton II broth, antimicrobial susceptibility test results were not obtained; however, in the presence of 10 mg mL-1l-glutamine, the results were consistent with those of the revertant strain GU-92REV. CONCLUSION: To the best of our knowledge, this is the first clinical isolation of a glutamine-dependent E. coli SCV from a patient blood culture. Our data showed that glnA was important for the growth of E. coli in Mueller-Hinton II medium, which also required the presence of glutamine when performing antimicrobial susceptibility testing for glutamine-dependent SCV strains.


Assuntos
Anti-Infecciosos , Infecções por Escherichia coli , Escherichia coli , Glutamato-Amônia Ligase , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções por Escherichia coli/tratamento farmacológico , Glutamato-Amônia Ligase/genética , Glutamina/genética , Humanos , Mutação de Sentido Incorreto
15.
J Virol ; 96(5): e0168621, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-34985994

RESUMO

Hepatitis B virus (HBV) infects 240 million people worldwide. Current therapy profoundly suppresses HBV replication but requires long-term maintenance therapy. Therefore, there is still a medical need for an efficient HBV cure. HBV enters host cells by binding via the preS1 domain of the viral L protein to the Na+/taurocholate cotransporting polypeptide (NTCP). Thus, NTCP should be a key target for the development of anti-HBV therapeutics. Indeed, myrcludex B, a synthetic form of the myristoylated preS1 peptide, effectively reduces HBV/hepatitis D virus (HDV) infection and has been approved as Hepcludex in Europe for the treatment of patients with chronic HDV infection. We established a monoclonal antibody (MAb), N6HB426-20, that recognizes the extracellular domain of human NTCP and blocks HBV entry in vitro into human liver cells but has much less of an inhibitory effect on bile acid uptake. In vivo, administration of the N6HB426-20 MAb prevented HBV viremia for an extended period of time after HBV inoculation in a mouse model system without strongly inhibiting bile acid absorption. Among the extracellular loops (ECLs) of NTCP, regions of amino acids (aa) 84 to 87 in ECL1 and aa 157 to 165 near ECL2 of transmembrane domain 5 are critically important for HBV/HDV infection. Epitope mapping and the three-dimensional (3D) model of the NTCP structure suggested that the N6HB426-20 MAb may recognize aa 276/277 at the tip of ECL4 and interfere with binding of HBV to the region from aa 84 to 87. In summary, we identified an in vivo neutralizing NTCP-targeting antibody capable of preventing HBV infection. Further improvements in efficacy of this drug will pave the way for its clinical applications. IMPORTANCE A number of entry inhibitors are being developed to enhance the treatment of HBV patients with oral nucleoside/nucleotide analogues (NA). To amplify the effectiveness of NA therapy, several efforts have been made to develop therapeutic MAbs with neutralizing activity against HBs antigens. However, the neutralizing effect of these MAbs may be muted by a large excess of HBsAg-positive noninfectious particles in the blood of infected patients. The advantage of NTCP-targeted HBV entry inhibitors is that they remain effective regardless of viral genotype, viral mutations, and the presence of subviral particles. Although N6HB426-20 requires a higher dose than myrcludex to obtain equivalent suppression of HBV in a model mouse system, it maintained the inhibitory effect for a long time postadministration in proportion to the half-life of an IgG MAb. We believe that further improvements will make this antibody a promising treatment option for patients with chronic hepatitis B.


Assuntos
Vírus da Hepatite B , Hepatite B , Transportadores de Ânions Orgânicos Dependentes de Sódio , Simportadores , Internalização do Vírus , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Células Hep G2 , Hepatite B/tratamento farmacológico , Hepatite B/prevenção & controle , Hepatite B/virologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Hepatócitos , Humanos , Camundongos , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Simportadores/metabolismo , Proteínas Virais/metabolismo , Internalização do Vírus/efeitos dos fármacos
16.
J Infect Chemother ; 28(3): 455-458, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34973875

RESUMO

Here, we report a 60-year-old chronically bedridden man with cerebral palsy who had septic shock following a history of urinary tract infection with extended spectrum ß-lactamase-producing and auxotrophic Proteus mirabilis detected on blood and urine cultures. This auxotroph formed small colonies only on the blood agar at 24 h in 5% CO2, but not in the conditions without CO2, and lacked motility and some biochemical activities. The five-year history of stones in the right renal pelvis suggests chronic urinary tract infection with P. mirabilis requiring a 28-day antibiotic treatment. This paper highlights that the CO2-dependent P. mirabilis small colony variant may cause sepsis, probably due to chronic infection in uroliths, which should warrant immediate identification.


Assuntos
Infecções por Proteus , Choque Séptico , Antibacterianos/uso terapêutico , Pessoas Acamadas , Dióxido de Carbono , Humanos , Masculino , Pessoa de Meia-Idade , Infecção Persistente , Infecções por Proteus/tratamento farmacológico , Proteus mirabilis , Choque Séptico/tratamento farmacológico , beta-Lactamases/genética
17.
J Med Microbiol ; 70(10)2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34668852

RESUMO

Introduction . Capnocytophaga species are common inhabitants of the oral cavity and can be responsible for systemic diseases in immunocompromised patients with granulocytopenia. Furthermore, it has been reported that some clinical isolates of Capnocytophaga species produce extended-spectrum ß-lactamases (ESBLs).Gap statement. Information is lacking about the types of ß-lactamase genes possessed by Capnocytophaga spp. and the antimicrobial susceptibility of Capnocytophaga spp. possessing each ß-lactamase gene.Aim. The aim of this study was to investigate the presence of ß-lactamase genes in clinical strains of ß-lactamase-producing Capnocytophaga species isolated from clinical samples acquired at Shinshu University Hospital and examine the antimicrobial susceptibility of those strains.Methodology. The ß-lactamase-producing Capnocytophaga species (n=49) were obtained from clinical specimens. PCR assays were used to detect bla CfxA, bla CSP, bla TEM, bla CepA/CblA and transposon Tn4555 genes. Southern hybridization assays were used to detect bla CfxA and bla CSP. The minimum inhibitory concentration of some ß-lactams was determined using the E-test method.Results. PCR analysis indicated that the bla CfxA gene was present in 15 (30.6 %) and the bla CSP gene in 35 (69.3 %) of the 49 Capnocytophaga strains investigated, . Both bla CfxA and bla CSP genes were detected in a Capnocytophaga gingivalis strain. The PCR results were confirmed by Southern hybridization assays. Transposon Tn4555 was only detected in Capnocytophaga spp. harbouring the bla CfxA gene. All the ß-lactamase-producing Capnocytophaga isolates were susceptible to ceftazidime-clavulanic acid, cefoxitin and imipenem. In contrast, most of the isolates were resistant to amoxicillin.Conclusions. The clinical isolates of Capnocytophaga spp. showed a high prevalence of the bla CSP gene in Japan. The presence of the bla CSP gene was distributed in Capnocytophaga sputigena as well as other Capnocytophaga spp. These results seem to suggest the dissemination of bla CfxA and bla CSP ß-lactamase genes among Capnocytophaga species.


Assuntos
Capnocytophaga/genética , Resistência Microbiana a Medicamentos , Infecções por Bactérias Gram-Negativas/epidemiologia , Boca/microbiologia , beta-Lactamases/genética , Japão , Prevalência
18.
Helicobacter ; 26(4): e12814, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33977610

RESUMO

BACKGROUND: Non-Helicobacter pylori Helicobacter (NHPH) is not widely recognized as a cause of acute gastric mucosal lesions (AGML), as only a few cases of AGML caused by NHPH have been reported. We present here one case and examine the species and eradication of NHPH together with the three previously reported cases. CASE PRESENTATION: A 52-year-old woman presented with a two-day history of severe epigastric pain, nausea, and vomiting. An esophagogastroduodenoscopy showed mucosal edema, multiple erosions, and ulcerations in the antrum. Biopsy specimens taken from the antrum revealed long spiral-shaped organisms, suggesting NHPH. As both serum anti-Helicobacter pylori (H. pylori) antibody and H. pylori stool antigen test were negative, this case was diagnosed as AGML caused by NHPH. After the administration of esomeprazole 20 mg for 14 days and the interval of the following 12 days, AGML was deemed to have been cured endoscopically. In addition, microscopic examination and PCR analysis confirmed the success of NHPH eradication. CONCLUSIONS: NHPH should be considered a probable cause of AGML in cases that are not attributed to the other causes already recognized. Taking probability of spontaneous eradication into consideration, it is appropriate to start eradication therapy after confirming the chronicity of NHPH infection.


Assuntos
Gastrite , Infecções por Helicobacter , Helicobacter , Doença Aguda , Esomeprazol , Feminino , Mucosa Gástrica , Gastrite/diagnóstico , Gastrite/tratamento farmacológico , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori , Humanos , Pessoa de Meia-Idade
19.
Helicobacter ; 26(4): e12811, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33908121

RESUMO

BACKGROUND AND AIM: There are only a few reports of non-Helicobacter pylori Helicobacter (NHPH) gastritis in Japanese patients. We aimed to examine its prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings based on 50 patients encountered in one facility. MATERIALS AND METHODS: Subjects were all patients who had undergone gastric mucosal biopsy endoscopically at Kenwakai Hospital for approximately 10 years. NHPH infection was diagnosed by microscopic findings of Giemsa staining performed on all specimens. PCR analysis of urease genes was performed to detect and identify NHPH, when informed consent was obtained. Helicobacter pylori-diagnostic tests were also performed. NHPH-infected patients were questioned about symptoms and animal contact. RESULTS: NHPH gastritis was found in 50 of 3847 patients (1.30%). The percentage increased to 3.35% (30 of 896 patients) in the latter 2 years and 4 months with increasing recognition of its characteristic endoscopic findings by endoscopists. PCR analysis, performed in 30 patients, detected NHPH in 28 patients: 26 as Helicobacter suis and 2 as Helicobacter heilmanii/Helicobacter ailurogastricus. Helicobacter pylori-diagnostic tests were almost negative. However, anti-H. pylori antibody showed high-negative titer (3.0-9.9 U/ml) in 12. Of 50 patients (consisting of 49 men and 1 woman), almost all were asymptomatic, and 25 were keeping pets. Regarding EGD findings, in all 50 patients, "crack-like mucosa" and/or nodular gastritis was noted in gastric antrum, and regular arrangement of collecting venules (RAC) was noted in gastric corpus. None of the patients infected with NHPH were co-infected with H. pylori. CONCLUSIONS: The prevalence was finally estimated to be approximately 3.35%. Helicobacter suis was the most common NHPH species. "Crack-like mucosa" and/or nodular gastritis in gastric antrum, RAC in gastric corpus, and H. pylori-negativity by H. pylori-diagnostic tests especially containing a high-negative titer of anti-H. pylori antibody may indicate NHPH infection.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Animais , Feminino , Mucosa Gástrica , Gastroscopia , Helicobacter , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Humanos , Japão/epidemiologia , Masculino , Prevalência
20.
Bioorg Med Chem Lett ; 38: 127858, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33609658

RESUMO

Mutant activin receptor-like kinase-2 (ALK2) is associated with the pathogenesis of fibrodysplasia ossificans progressiva, making it an attractive target for therapeutic intervention. We synthesized a new series of bicyclic pyrazoles and evaluated their mutant ALK2 enzyme inhibitory activities, leading to the identification of 8 as the most potent inhibitor. This compound showed moderate microsomal metabolic stability and human ether-a-go-go related gene (hERG) safety. In C2C12 cells carrying mutant ALK2 (R206H), 8 efficiently inhibited the bone morphogenetic protein (BMP)-induced alkaline phosphatase activity.


Assuntos
Receptores de Ativinas Tipo I/antagonistas & inibidores , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Miosite Ossificante/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Linhagem Celular , Relação Dose-Resposta a Droga , Humanos , Camundongos , Estrutura Molecular , Mutação , Miosite Ossificante/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade
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