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1.
J Allergy Clin Immunol Pract ; 12(5): 1095-1106, 2024 May.
Article in English | MEDLINE | ID: mdl-38724164

ABSTRACT

Risk stratification in drug allergy implies that specific risk categories (eg, low, moderate, and high) classify historical drug hypersensitivity reactions. These risk categories can be based on reaction phenotypic characteristics, the timing of the reaction and evaluation, the required reaction management, and individual characteristics. Although a multitude of frameworks have been described in the literature, particularly for penicillin allergy labels, there has yet to be a global consensus, and approaches continue to vary between allergy centers. Immune-mediated drug allergies can sometimes be confirmed using skin testing, but a negative drug challenge is required to demonstrate tolerance and remove the allergy from the electronic health record ("delabel" the allergy). Even for quintessential IgE-mediated drug allergy, penicillin allergy, recent data reveal that a direct oral challenge, without prior skin testing, is an appropriate diagnostic strategy in those who are considered low-risk. Drug allergy pathogenesis and clinical manifestations may vary depending on the culprit drug, and as such, the optimal approach should be based on risk stratification that considers individual patient and reaction characteristics, the likely hypersensitivity reaction phenotype, the drug class, and the patient's clinical needs. This article will describe low-risk drug allergy labels, focusing on ß-lactam and sulfonamide antibiotics, nonsteroidal anti-inflammatory drugs, iodinated contrast media, and common chemotherapeutics. This review will also address practical management approaches using currently available risk stratification and clinical decision tools.


Subject(s)
Drug Hypersensitivity , Humans , Drug Hypersensitivity/diagnosis , Drug Hypersensitivity/therapy , Skin Tests , Risk Assessment , Penicillins/adverse effects , Penicillins/immunology , Immunoglobulin E , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/immunology
3.
J Insect Sci ; 23(6)2023 Nov 01.
Article in English | MEDLINE | ID: mdl-38055943

ABSTRACT

Managed populations of honey bees (Apis mellifera Linnaeus; Hymenoptera: Apidae) are regularly exposed to infectious diseases. Good hive management including the occasional application of antibiotics can help mitigate infectious outbreaks, but new beekeeping tools and techniques that bolster immunity and help control disease transmission are welcome. In this review, we focus on the applications of beneficial microbes for disease management as well as to support hive health and sustainability within the apicultural industry. We draw attention to the latest advances in probiotic approaches as well as the integration of fermented foods (such as water kefir) with disease-fighting properties that might ultimately be delivered to hives as an alternative or partial antidote to antibiotics. There is substantial evidence from in vitro laboratory studies that suggest beneficial microbes could be an effective method for improving disease resistance in honey bees. However, colony level evidence is lacking and there is urgent need for further validation via controlled field trials experimentally designed to test defined microbial compositions against specific diseases of interest.


Subject(s)
Beekeeping , Bees , Fermentation , Gastrointestinal Microbiome , Probiotics , Animals , Anti-Bacterial Agents/immunology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Beekeeping/methods , Bees/drug effects , Bees/immunology , Bees/microbiology , Fermentation/immunology , Gastrointestinal Microbiome/immunology , Probiotics/pharmacology , Probiotics/therapeutic use
4.
Pesqui. bras. odontopediatria clín. integr ; 23: e220048, 2023. tab, graf
Article in English | LILACS, BBO - Dentistry | ID: biblio-1448793

ABSTRACT

ABSTRACT Objective: To evaluate and compare antibiotic prescriptions for endodontic infections of last-year undergraduate Dentistry students and dental surgeons from Brazil. Material and Methods: A questionnaire comprised of 15 questions was applied, including a series of hypothetical clinical cases through multiple choice questions. The survey respondents had the option to respond in favor or against the prescription of antimicrobials in each case. Afterwards, the commented answer keys of all topics contained in the survey form were released for educational purpose. Results: A total of 42 undergraduates and 115 dental surgeons answered the survey. Regarding the questions about antimicrobial prescriptions, 91.3% of the professional dentists and 69.8% of the dentistry students indicated that they prescribe antibiotics for a limited number of patients. However, when they responded about drug recommendations, most professionals (76.5%) and students (76.7%) chose to recommend antimicrobials without any clinical recommendation. Conclusion: In the groups herein evaluated, many antibiotic prescriptions could have been avoided. The rational use of these drugs is still a conduct that needs further disclosure and commitment among prescribers.


Subject(s)
Humans , Male , Female , Drug Prescriptions , Students, Dental , Anti-Bacterial Agents/immunology , Brazil/epidemiology , Surveys and Questionnaires , Data Interpretation, Statistical , Observational Studies as Topic
5.
Pesqui. bras. odontopediatria clín. integr ; 23: e210078, 2023. tab, graf
Article in English | LILACS, BBO - Dentistry | ID: biblio-1529122

ABSTRACT

ABSTRACT Objective: To evaluate the antibacterial effect of electrolytically generated hypochlorous acid on Streptococcus gordonii, Fusobacterium nucleatum, and Porphyromonas gingivalis. Material and Methods: In this in vitro experiment, the effect of hypochlorous acid (HOCl) on the strains S. gordonii, F. nucleatum, and P. gingivalis was evaluated using 4% sodium hypochlorite, 0.12% chlorhexidine, and distilled water as controls. The four groups were placed on each plate, and each group was replicated five times. The agar diffusion method by zones measurement was used. The data were processed with SPSS using the Kruskal-Wallis test and multiple comparison tests. Results: Hypochlorous acid showed an average inhibition halo of 9.28 mm on S. gordonii. As expected with distilled water, no zone of inhibition was noted for any of the bacteria, nor were zones of inhibition observed with HOCl for F. nucleatum and P. gingivalis. Conclusion: Hypochlorous acid showed antimicrobial properties against only S. gordonii and was less effective than 4% sodium hypochlorite and 0.12% chlorhexidine, although no significant differences were found between the latter.


Subject(s)
Sodium Hypochlorite , Anti-Bacterial Agents/immunology , Periapical Diseases , Analysis of Variance , Statistics, Nonparametric
6.
Yale J Biol Med ; 95(4): 445-463, 2022 12.
Article in English | MEDLINE | ID: mdl-36568838

ABSTRACT

Microbial resistance to antibiotics is an ancient and dynamic issue that has brought a situation reminiscent of the pre-antibiotic era to the limelight. Currently, antibiotic resistance and the associated infections are widespread and pose significant global health and economic burden. Thus, the misuse of antibiotics, which has increased resistance, has necessitated the search for alternative therapeutic agents for combating resistant pathogens. Antimicrobial peptides (AMPs) hold promise as a viable therapeutic approach against drug-resistant pathogens. AMPs are oligopeptides with low molecular weight. They have broad-spectrum antimicrobial activities against pathogenic microorganisms. AMPs are nonspecific and target components of microbes that facilitate immune response by acting as the first-line defense mechanisms against invading pathogenic microbes. The diversity and potency of AMPs make them good candidates for alternative use. They could be used alone or in combination with several other biomaterials for improved therapeutic activity. They can also be employed in vaccine production targeting drug-resistant pathogens. This review covers the opportunities and advances in AMP discovery and development targeting antimicrobial resistance (AMR) bacteria. Briefly, it presents an overview of the global burden of the antimicrobial resistance crisis, portraying the global magnitude, challenges, and consequences. After that, it critically and comprehensively evaluates the potential roles of AMPs in addressing the AMR crisis, highlighting the major potentials and prospects.


Subject(s)
Anti-Bacterial Agents , Antimicrobial Peptides , Drug Resistance, Bacterial , Immunity, Innate , Humans , Anti-Bacterial Agents/immunology , Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Peptides/immunology , Antimicrobial Peptides/pharmacology , Bacteria/drug effects , Bacteria/immunology , Immunity, Innate/drug effects , Immunity, Innate/immunology , Drug Resistance, Bacterial/drug effects , Drug Resistance, Bacterial/immunology , Global Burden of Disease , Drug Discovery , Drug Development
7.
Front Cell Infect Microbiol ; 12: 898796, 2022.
Article in English | MEDLINE | ID: mdl-35909964

ABSTRACT

Calprotectin is a transition metal chelating protein of the innate immune response known to exert nutritional immunity upon microbial infection. It is abundantly released during inflammation and is therefore found at sites occupied by pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus. The metal limitation induced by this protein has previously been shown to mediate P. aeruginosa and S. aureus co-culture. In addition to the transition metal sequestration role of calprotectin, it has also been shown to have metal-independent antimicrobial activity via direct cell contact. Therefore, we sought to assess the impact of this protein on the biofilm architecture of P. aeruginosa and S. aureus in monomicrobial and polymicrobial culture. The experiments described in this report reveal novel aspects of calprotectin's interaction with biofilm communities of P. aeruginosa and S. aureus discovered using scanning electron microscopy and confocal laser scanning microscopy. Our results indicate that calprotectin can interact with microbial cells by stimulating encapsulation in mesh-like structures. This physical interaction leads to compositional changes in the biofilm extracellular polymeric substance (EPS) in both P. aeruginosa and S. aureus.


Subject(s)
Biofilms , Immunity, Innate , Leukocyte L1 Antigen Complex , Pseudomonas aeruginosa , Staphylococcus aureus , Anti-Bacterial Agents/immunology , Anti-Bacterial Agents/pharmacology , Extracellular Polymeric Substance Matrix/genetics , Extracellular Polymeric Substance Matrix/immunology , Humans , Immunity, Innate/genetics , Immunity, Innate/immunology , Leukocyte L1 Antigen Complex/genetics , Leukocyte L1 Antigen Complex/immunology , Phagocytosis , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/immunology , Staphylococcus aureus/genetics , Staphylococcus aureus/immunology
8.
Natal; s.n; 03 mar 2022. 23 p. tab, ilus.
Thesis in Portuguese | BBO - Dentistry | ID: biblio-1513018

ABSTRACT

Introdução: Os selantes resinosos apresentam uma alta taxa de sucesso na prevenção da cárie dentária, porém não possuem atividade antibacteriana, sendo a incidência de novas lesões um dos fatores que ainda causam impacto negativo na qualidade de vida das pessoas. A biomodificação com o extrato da Schinopsis brasiliensis (Braúna) pode ser uma alternativa no aperfeiçoamento das suas características clínicas. Objetivo: Avaliar se a biomodificação do selante Fluroshield® com diferentes concentrações do extrato do caule do Schinopsis brasiliensis afeta sua resistência máxima à tração (resistência coesiva). Metodologia: O extrato foi pesado em balança analítica e misturado ao selante nas concentrações de 0 mg/mL (controle), 20 mg/mL, 5 mg/mL e 1,25 mg/mL e espatulado por 1 min., utilizando uma placa de vidro. Amostras em formato de barra com dimensões de 8 mm (comprimento) x 2 mm (largura) e 1 mm (espessura) foram confeccionadas (n=3) e submetidas ao teste de resistência máxima à tração em máquina de ensaio semi universal (OM 100). Antes da fixação delas nas placas de ensaio, a medida da secção transversal (mm2) foi aferida com paquímetro. Os dados foram obtidos em Kgf e transformados em MPa. A análise estatística foi realizada pelo teste de Kruskal-Wallis (p<0,05). Resultados: A resistência máxima à tração dos grupos em mediana (mínimo-máximo) dos grupos 0 mg/mL (controle), 20 mg/mL, 5 mg/mL e 1,25 mg/mL foi, respectivamente, 56 (29-56), 53 (45-60), 48 (46-62) e 61 (38-64). Não houve diferenças estatisticamente significativas entre os grupos (p=0,8). Conclusão: A adição do extrato do caule de Schinopsis brasiliensis não reduziu a resistência máxima à tração do selante Fluroshield® (AU).


Introduction: Resin-based sealants have a high success rate in preventing dental caries, but they do not have antibacterial activity, so that a high incidence of caries lesions is observed, which negatively impacts on health quality. The biomodification with the Schinopsis brasiliensis (Braúna) stem extract may be an alternative to improve its clinical characteristics. Objective: To evaluate if the biomodification of the Fluroshield® sealant with different amounts of Schinopsis brasiliensis affects its ultimate tensile strength. Methods: The extract was weighed on an analytical balance and mixed with the sealant in different concentrations: 0 mg/mL (control), 20 mg/mL, 5 mg/mL and 1.25 mg/mL by mixing for 1 min. Bar-shaped specimens with dimensions of 8 mm x 2 mm x 1 mm were prepared (n=3). The ultimate tensile strength was measured using a microtensile machine (OM100). Before testing, the sectional area (mm2) was obtained with a caliper. Data were obtained in Kgf and transformed into MPa. Statistical analysis was performed using the Kruskal-Wallis test (p<0.05). Results: The maximum tensile strength in median (minimum-maximum) of the 0 mg/mL (control), 20 mg/mL, 5 mg/mL and 1.25 mg/mL groups was, respectively, 56 (29-56), 53 (45-60), 48 (46- 62) and 61 (38-64). There were no statistically significant differences among the groups (p=0.8). Conclusion: The addition of Schinopsis brasiliensis stem extract did not decrease the ultimate tensile strength of the Fluroshield® sealant (AU).


Subject(s)
Pit and Fissure Sealants , Plant Extracts/pharmacology , Anti-Bacterial Agents/immunology , Tensile Strength/drug effects , In Vitro Techniques/methods , Statistics, Nonparametric , Mouth Diseases/pathology
9.
Lung ; 200(1): 119-128, 2022 02.
Article in English | MEDLINE | ID: mdl-34825965

ABSTRACT

PURPOSE: Transport of secretory immunoglobulin A (SIgA) through the airway epithelial cell barrier into the mucosal lumen by the polymeric immunoglobulin receptor (pIgR) is an important mechanism of respiratory mucosal host defense. Identification of immunomodulating substances that regulate secretory immunity might have therapeutic implications with regard to an improved immune exclusion. Thus, we sought to analyze secretory immunity under homeostatic and immunomodulating conditions in different compartments of the murine upper and lower respiratory tract (URT&LRT). METHODS: Pigr gene expression in lung, trachea, and nasal-associated lymphoid tissue (NALT) of germ-free mice, specific pathogen-free mice, mice with an undefined microbiome, as well as LPS- and IFN-γ-treated mice was determined by quantitative real-time PCR. IgA levels in bronchoalveolar lavage (BAL), nasal lavage (NAL), and serum were determined by ELISA. LPS- and IFN-γ-treated mice were colonized with Streptococcus pneumoniae and bacterial CFUs were determined in URT and LRT. RESULTS: Respiratory Pigr expression and IgA levels were dependent on the degree of exposure to environmental microbial stimuli. While immunostimulation with LPS and IFN-γ differentially impacts respiratory Pigr expression and IgA in URT vs. LRT, only prophylactic IFN-γ treatment reduces nasal colonization with S. pneumoniae. CONCLUSION: Airway-associated secretory immunity can be partly modulated by exposure to microbial ligands and proinflammatory stimuli. Prophylactic IFN-γ-treatment modestly improves antibacterial immunity in the URT, but this does not appear to be mediated by SIgA or pIgR.


Subject(s)
Immunoglobulin A, Secretory , Receptors, Polymeric Immunoglobulin , Respiratory Mucosa , Animals , Anti-Bacterial Agents/immunology , Anti-Bacterial Agents/pharmacology , Immunoglobulin A, Secretory/immunology , Immunoglobulin A, Secretory/metabolism , Lung/drug effects , Lung/immunology , Lung/metabolism , Mice , Receptors, Cell Surface/immunology , Receptors, Cell Surface/metabolism , Receptors, Polymeric Immunoglobulin/immunology , Receptors, Polymeric Immunoglobulin/metabolism , Respiratory Mucosa/drug effects , Respiratory Mucosa/immunology , Respiratory Mucosa/metabolism
10.
Proc Natl Acad Sci U S A ; 118(51)2021 12 21.
Article in English | MEDLINE | ID: mdl-34903650

ABSTRACT

In mammals, cyclic dinucleotides (CDNs) bind and activate STING to initiate an antiviral type I interferon response. CDNs and STING originated in bacteria and are present in most animals. By contrast, interferons are believed to have emerged in vertebrates; thus, the function of CDN signaling in invertebrates is unclear. Here, we use a CDN, 2'3' cyclic guanosine monophosphate-adenosine monophosphate (2'3'-cGAMP), to activate immune responses in a model cnidarian invertebrate, the starlet sea anemone Nematostella vectensis Using RNA sequencing, we found that 2'3'-cGAMP induces robust transcription of both antiviral and antibacterial genes in N. vectensis Many of the antiviral genes induced by 2'3'-cGAMP are homologs of vertebrate interferon-stimulated genes, implying that the interferon response predates the evolution of interferons. Knockdown experiments identified a role for NF-κB in specifically inducing antibacterial genes downstream of 2'3'-cGAMP. Some of these putative antibacterial genes were also found to be induced during Pseudomonas aeruginosa infection. We characterized the protein product of one of the putative antibacterial genes, the N. vectensis homolog of Dae4, and found that it has conserved antibacterial activity. This work suggests that a broad antibacterial and antiviral transcriptional response is an evolutionarily ancestral output of 2'3'-cGAMP signaling in animals.


Subject(s)
Anti-Bacterial Agents/immunology , Antiviral Agents/immunology , Nucleotides, Cyclic/immunology , Sea Anemones/immunology , Animals , Immunity, Innate/genetics , NF-kappa B/genetics , NF-kappa B/immunology , Pseudomonas Infections/genetics , Pseudomonas Infections/immunology , Pseudomonas aeruginosa/physiology , Sea Anemones/genetics , Signal Transduction , Transcriptional Activation
11.
Int J Biol Macromol ; 193(Pt B): 2173-2182, 2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34780895

ABSTRACT

Although class B scavenger receptors (SR-Bs) in mammals are multifunctional molecules, the functions of SR-Bs in invertebrates remain largely unknown. In this study, we characterized an SR-B homolog, namely SpSR-B2, from Scylla paramamosain. SpSR-B2 shared high similarity with mammalian SR-Bs, and exhibited specific binding activity to ac-LDL, indicating that it may be a new member of SR-B class in invertebrates. SpSR-B2 was upregulated after challenge with white spot syndrome virus (WSSV) or bacteria. Binding assays showed that SpSR-B2 specifically interacted with WSSV envelope protein VP24. Besides, SpSR-B2 could bind to all tested bacterial cells and agglutinate these bacteria. SpSR-B2 also exhibited a strong binding activity to LPS but weak binding activities to other tested polysaccharides. These findings indicated that SpSR-B2 was a potential recognition molecule for viral protein VP24 and bacterial LPS. Knockdown of SpSR-B2 resulted in dramatically decreased expressions of certain antimicrobial peptides (AMPs), and overexpression of SpSR-B2 led to the increased expression of the AMP of SpALF2, suggesting that SpSR-B2 could regulate the expression of AMPs. Taken together, this study revealed that SpSR-B2 functioned as a potential pattern recognition receptor participating in antiviral and antibacterial immunity, and provided new insights into the immune functions of invertebrate SR-Bs.


Subject(s)
Anti-Bacterial Agents/immunology , Antiviral Agents/immunology , Arthropod Proteins/immunology , Brachyura/immunology , Receptors, Pattern Recognition/immunology , Animals , Antimicrobial Peptides/immunology , Bacteria/immunology , Immunity/immunology , Lipopolysaccharides/immunology , Phylogeny , White spot syndrome virus 1/immunology
12.
Fish Shellfish Immunol ; 118: 283-293, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34537337

ABSTRACT

Interleukin-1ß is a key pro-inflammatory cytokine functioning in initiation of inflammatory responses against bacterial- and viral-infections. In the present study, a putative IL-1ß counterpart was identified from Siberian sturgeon (Acipenser baeri) and designated as AbIL-1ß. The Abil-1ß cDNA sequence consists of 1130 bp with an open reading frame (ORF) of 585 bp, which encodes a 194 amino acid (aa) protein. Multiple amino acid sequence alignment revealed that a possible mature peptide could start at Leu18, although no cut site for ICE (IL-1ß converting enzyme) enzyme was present in Siberian sturgeon IL-1ß. Even if AbIL-1ß shares a relative low identity (33.6%) with another sturgeon type II IL-1ß gene from Acipenser dabryanus, they still clustered together in phylogenetic tree. Endogenous Abil-1ß was highly expressed in brain, blood, head kidney and spleen of healthy Siberian sturgeon, and remarkably up regulated in head kidney, spleen, and liver upon Aeromonas hydrophila (A.h) challenge. Consistently, in vitro stimulation test using heat-killed A.h and LPS significantly increased Abil-1ß transcripts of primary spleen cells. To investigate the bactericidal capability of AbIL-1ß, recombinant AbIL-1ß (rAbIL-1ß) was generated by prokaryotes. Pre-injection of rAbIL-1ß reduced the bacterial load in sturgeon spleen after A.h infection. Further, rAbIL-1ß was served as feed additive and demonstrated to enhance hybrid sturgeon's defense against A.h infection by increased expressional levels of immune-related genes (IL-1ß, IL-6, IL-8, IgM and MHCIIß), elevated activities of serum lysosome, ACH50, and MPO, as well as higher percent survival. In summary, the current results suggested that AbIL-1ß functions in immune regulation and could improve sturgeon's resistance to bacterial infection.


Subject(s)
Aeromonas hydrophila , Anti-Bacterial Agents , Fish Proteins , Fishes , Inflammation , Interleukin-1beta , Aeromonas hydrophila/immunology , Amino Acid Sequence , Animals , Anti-Bacterial Agents/immunology , Evolution, Molecular , Fish Proteins/chemistry , Fish Proteins/genetics , Fish Proteins/immunology , Fishes/genetics , Fishes/immunology , Fishes/microbiology , Inflammation/immunology , Interleukin-1beta/chemistry , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Phylogeny
13.
Biochem Soc Trans ; 49(5): 2411-2429, 2021 11 01.
Article in English | MEDLINE | ID: mdl-34495299

ABSTRACT

The importance of vaccine-induced protection was repeatedly demonstrated over the last three decades and emphasized during the recent COVID-19 pandemic as the safest and most effective way of preventing infectious diseases. Vaccines have controlled, and in some cases, eradicated global viral and bacterial infections with high efficiency and at a relatively low cost. Carbohydrates form the capsular sugar coat that surrounds the outer surface of human pathogenic bacteria. Specific surface-exposed bacterial carbohydrates serve as potent vaccine targets that broadened our toolbox against bacterial infections. Since first approved for commercial use, antibacterial carbohydrate-based vaccines mostly rely on inherently complex and heterogenous naturally derived polysaccharides, challenging to obtain in a pure, safe, and cost-effective manner. The introduction of synthetic fragments identical with bacterial capsular polysaccharides provided well-defined and homogenous structures that resolved many challenges of purified polysaccharides. The success of semisynthetic glycoconjugate vaccines against bacterial infections, now in different phases of clinical trials, opened up new possibilities and encouraged further development towards fully synthetic antibacterial vaccine solutions. In this mini-review, we describe the recent achievements in semi- and fully synthetic carbohydrate vaccines against a range of human pathogenic bacteria, focusing on preclinical and clinical studies.


Subject(s)
Anti-Bacterial Agents/immunology , Bacteria/immunology , Bacterial Infections/immunology , Carbohydrates/immunology , Glycoconjugates/immunology , Vaccines, Synthetic/immunology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Bacteria/drug effects , Bacterial Infections/microbiology , Bacterial Infections/prevention & control , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/immunology , COVID-19 Vaccines/therapeutic use , Carbohydrate Sequence , Carbohydrates/chemistry , Glycoconjugates/chemistry , Glycoconjugates/therapeutic use , Humans , Vaccines, Synthetic/chemistry , Vaccines, Synthetic/therapeutic use
14.
Infect Immun ; 89(10): e0016221, 2021 09 16.
Article in English | MEDLINE | ID: mdl-34310884

ABSTRACT

Extremely drug-resistant (XDR) Acinetobacter baumannii is a notorious and frequently encountered pathogen demanding novel therapeutic interventions. An initial monoclonal antibody (MAb), C8, raised against A. baumannii capsule, proved a highly effective treatment against a minority of clinical isolates. To overcome this limitation, we broadened coverage by developing a second antibody for use in a combination regimen. We sought to develop an additional anti-A. baumannii MAb through hybridoma technology by immunizing mice with sublethal inocula of virulent, XDR clinical isolates not bound by MAb C8. We identified a new antibacterial MAb, 65, which bound to strains in a pattern distinct from and complementary to that of MAb C8. MAb 65 enhanced macrophage opsonophagocytosis of targeted strains and markedly improved survival in lethal bacteremic sepsis and aspiration pneumonia murine models of A. baumannii infection. MAb 65 was also synergistic with colistin, substantially enhancing protection compared to monotherapy. Treatment with MAb 65 significantly reduced blood bacterial density, ameliorated cytokine production (interleukin-1ß [IL-1ß], IL-6, IL-10, and tumor necrosis factor), and sepsis biomarkers. We describe a novel MAb targeting A. baumannii that broadens immunotherapeutic strain coverage, is highly potent and effective, and synergistically improves outcomes in combination with antibiotics.


Subject(s)
Acinetobacter Infections/immunology , Acinetobacter baumannii/immunology , Antibodies, Monoclonal/immunology , Acinetobacter Infections/blood , Acinetobacter Infections/microbiology , Animals , Anti-Bacterial Agents/immunology , Antibodies, Bacterial/immunology , Biomarkers/blood , Colistin/immunology , Cytokines/blood , Cytokines/immunology , Drug Resistance, Multiple, Bacterial/immunology , Mice , Microbial Sensitivity Tests/methods , Sepsis/blood , Sepsis/immunology , Sepsis/microbiology
15.
Sci Rep ; 11(1): 13213, 2021 06 24.
Article in English | MEDLINE | ID: mdl-34168196

ABSTRACT

Acinetobacter baumannii (A. baumannii), an opportunistic, gram-negative pathogen, has evoked the interest of the medical community throughout the world because of its ability to cause nosocomial infections, majorly infecting those in intensive care units. It has also drawn the attention of researchers due to its evolving immune evasion strategies and increased drug resistance. The emergence of multi-drug-resistant-strains has urged the need to explore novel therapeutic options as an alternative to antibiotics. Due to the upsurge in antibiotic resistance mechanisms exhibited by A. baumannii, the current therapeutic strategies are rendered less effective. The aim of this study is to explore novel therapeutic alternatives against A. baumannii to control the ailed infection. In this study, a computational framework is employed involving, pan genomics, subtractive proteomics and reverse vaccinology strategies to identify core promiscuous vaccine candidates. Two chimeric vaccine constructs having B-cell derived T-cell epitopes from prioritized vaccine candidates; APN, AdeK and AdeI have been designed and checked for their possible interactions with host BCR, TLRs and HLA Class I and II Superfamily alleles. These vaccine candidates can be experimentally validated and thus contribute to vaccine development against A. baumannii infections.


Subject(s)
Acinetobacter baumannii/immunology , Bacterial Vaccines/immunology , Acinetobacter Infections/immunology , Amino Acid Sequence , Anti-Bacterial Agents/immunology , Computational Biology/methods , Cross Infection/immunology , Epitopes/immunology , Genome, Bacterial/immunology , Genomics/methods , Proteomics/methods , Vaccinology/methods
16.
Bioelectrochemistry ; 141: 107877, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34171508

ABSTRACT

Tiamulin (TML) is a pleuromutilin antibiotic and mainly used to treat pulmonary and gastrointestinal infections. However, excessive use of TML can bring health threats to consumers. In this work, a label-free electrochemical immunosensor was proposed for sensitive detection of TML in pork and pork liver. Silver nanoparticles (AgNPs) were synthesized in situ on graphene oxide (GO), in which GO acted as a carrier for loading more AgNPs and AgNPs exhibited both strong conductivity and good redox property. In addition, staphylococcal protein A (SPA) was applied to oriented immobilization of fragment crystallizable (Fc) region of the TML monoclonal antibody. Under the optimal condition, the developed electrochemical immunosensor exhibited a good linear response with a concentration of TML ranging from 0.05 ng mL-1 to 100 ng mL-1 and the limit of detection (LOD) was 0.04 ng mL-1. Furthermore, the designed immunosensor was applied to detect TML in real samples with a good accuracy. Therefore, the label-free electrochemical immunosensor could be used as a potential method to detect TML and other antibiotic residues in animal derived foods.


Subject(s)
Anti-Bacterial Agents/analysis , Electrochemical Techniques/instrumentation , Graphite/chemistry , Metal Nanoparticles/chemistry , Nanocomposites/chemistry , Silver/chemistry , Staphylococcal Protein A/chemistry , Anti-Bacterial Agents/immunology , Antibodies, Monoclonal/immunology , Biosensing Techniques , Diterpenes/analysis , Diterpenes/immunology , Electric Conductivity , Limit of Detection , Oxidation-Reduction , Reproducibility of Results
17.
mBio ; 12(3): e0020221, 2021 06 29.
Article in English | MEDLINE | ID: mdl-34061593

ABSTRACT

Pseudomonas aeruginosa causes life-threatening infections that are associated with antibiotic failure. Previously, we identified the antibiotic G2637, an analog of arylomycin, targeting bacterial type I signal peptidase, which has moderate potency against P. aeruginosa. We hypothesized that an antibody-antibiotic conjugate (AAC) could increase its activity by colocalizing P. aeruginosa bacteria with high local concentrations of G2637 antibiotic in the intracellular environment of phagocytes. Using a novel technology of screening for hybridomas recognizing intact bacteria, we identified monoclonal antibody 26F8, which binds to lipopolysaccharide O antigen on the surface of P. aeruginosa bacteria. This antibody was engineered to contain 6 cysteines and was conjugated to the G2637 antibiotic via a lysosomal cathepsin-cleavable linker, yielding a drug-to-antibody ratio of approximately 6. The resulting AAC delivered a high intracellular concentration of free G2637 upon phagocytosis of AAC-bound P. aeruginosa by macrophages, and potently cleared viable P. aeruginosa bacteria intracellularly. The molar concentration of AAC-associated G2637 antibiotic that resulted in elimination of bacteria inside macrophages was approximately 2 orders of magnitude lower than the concentration of free G2637 required to eliminate extracellular bacteria. This study demonstrates that an anti-P. aeruginosa AAC can locally concentrate antibiotic and kill P. aeruginosa inside phagocytes, providing additional therapeutic options for antibiotics that are moderately active or have an unfavorable pharmacokinetics or toxicity profile. IMPORTANCE Antibiotic treatment of life-threatening P. aeruginosa infections is associated with low clinical success, despite the availability of antibiotics that are active in standard microbiological in vitro assays, affirming the need for new therapeutic approaches. Antibiotics often fail in the preclinical stage due to insufficient efficacy against P. aeruginosa. One potential strategy is to enhance the local concentration of antibiotics with limited inherent anti-P. aeruginosa activity. This study presents proof of concept for an antibody-antibiotic conjugate, which releases a high local antibiotic concentration inside macrophages upon phagocytosis, resulting in potent intracellular killing of phagocytosed P. aeruginosa bacteria. This approach may provide new therapeutic options for antibiotics that are dose limited.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antibodies, Monoclonal/pharmacology , Macrophages/drug effects , Macrophages/immunology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/immunology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/immunology , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/metabolism , Drug Delivery Systems/methods , Humans , Macrophages/microbiology , Mice , Microbial Viability/drug effects , Phagocytosis/drug effects , Proof of Concept Study , Pseudomonas Infections/drug therapy , Pseudomonas Infections/immunology , Pseudomonas aeruginosa/metabolism , RAW 264.7 Cells , Rats
18.
Ann Allergy Asthma Immunol ; 127(4): 456-461, 2021 10.
Article in English | MEDLINE | ID: mdl-34048884

ABSTRACT

BACKGROUND: Patients with cystic fibrosis (CF) often have a history of antibiotic adverse drug reactions (ADRs) that pose a barrier to receiving recommended first-line treatment. Targeted antibiotic allergy evaluations are increasingly recognized as an important strategy for optimization of antimicrobial stewardship. OBJECTIVE: To improve first-line antibiotic use in patients with CF with antibiotic ADRs by streamlining access to antibiotic allergy evaluations and standardizing documentation of plans for antibiotic reintroduction. METHODS: We incorporated allergy evaluations into a multidisciplinary CF clinic and used telemedicine when allergy evaluations could not be performed during CF clinic. Standard documentation of antibiotic allergy plans was used to enable safe reintroduction of first-line antibiotics by CF providers. RESULTS: Strategies used in this study allowed 81.3% (26 of 32) of patients with CF to receive allergy evaluations and antibiotic allergy plans for prioritized antibiotics (penicillin, cephalosporin, sulfonamide), with removal of 41.0% (16 of 39) of prioritized antibiotic ADRs. Only 5.1% (2 of 39) of prioritized antibiotic ADRs evaluated required strict avoidance after evaluation. There were 9 patients who received at least 1 prioritized antibiotic, with 66.6% (6 of 9) of these patients given the antibiotic after only 1 allergy evaluation visit. Furthermore, these strategies allowed allergy evaluations of 23 nonprioritized antibiotics to occur, with removal of the ADR in 39.1% (9 of 23) and use of 77.8% (7 of 9) of nonprioritized antibiotics after removal. CONCLUSION: Incorporating allergy evaluations into a multidisciplinary CF clinic can liberalize first-line antibiotic use in patients with CF. Standard documentation of antibiotic allergy plans allowed antibiotic reintroduction to occur even before complete removal of documented antibiotic ADRs.


Subject(s)
Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Antimicrobial Stewardship/methods , Cystic Fibrosis/drug therapy , Drug Hypersensitivity/prevention & control , Adult , Anti-Bacterial Agents/immunology , Cephalosporins/adverse effects , Cephalosporins/immunology , Cephalosporins/therapeutic use , Drug Hypersensitivity/therapy , Female , Humans , Male , Middle Aged , Penicillins/adverse effects , Penicillins/immunology , Penicillins/therapeutic use , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Sulfonamides/adverse effects , Sulfonamides/immunology , Sulfonamides/therapeutic use , Young Adult
19.
Article in English | MEDLINE | ID: mdl-33965586

ABSTRACT

Cathelicidins are an important antimicrobial peptide family and are expressed in many different vertebrates. They play an important role in the innate immune system of the host. However, amphibian cathelicidins are poorly understood. In this study, the cDNA of the cathelicidin gene was obtained from the skin transcriptome of tiger frog (Hoplobatrachus rugulosus). The predicted amino acid sequence of tiger frog cathelicidin (HR-CATH) comprises a signal peptide, a cathelin domain, and a mature peptide. The HR-CATH amino acid sequence alignment with other frog cathelicidins showed that the functional mature peptide is highly variable in amphibians, whereas the cathelin domain is conserved. A phylogenetic tree analysis showed that HR-CATH is most closely related to cathelicidin-NV from Nanorana ventripunctata. HR-CATH was chemically synthesized and its in vitro activity was determined. It had high antibacterial activity against Vibrio parahaemolyticus, Staphylococcus aureus, and the pathogenic bacterium Aeromonas hydrophila. HR-CATH damaged the cell membrane integrity of A. hydrophila according to a lactate dehydrogenase release assay and was able to hydrolyze the genomic DNA from A. hydrophila in a dose-dependent manner. Furthermore, in RAW264.7 cells (mouse leukemic monocyte/macrophage cell line), HR-CATH induced chemotaxis and enhanced respiratory burst. Our study shows that amphibian cathelicidin has antimicrobial activity and an immunomodulatory effect on immune cells.


Subject(s)
Amphibian Proteins , Anti-Bacterial Agents , Anura/immunology , Bacteria/drug effects , Cathelicidins , Amphibian Proteins/immunology , Amphibian Proteins/pharmacology , Animals , Anti-Bacterial Agents/immunology , Anti-Bacterial Agents/pharmacology , Cathelicidins/immunology , Cathelicidins/pharmacology , Mice , RAW 264.7 Cells
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