scholarly journals Neutrophil function in gram-negative rod bacteremia. The interaction between phagocytic cells, infecting organisms, and humoral factors.

1976 ◽  
Vol 58 (1) ◽  
pp. 190-199 ◽  
Author(s):  
R J Weinstein ◽  
L S Young
Keyword(s):  
Neutrophil Function ◽  
Phagocytic Cells ◽  
Humoral Factors ◽  
Gram Negative ◽  
Infecting Organisms

Factors Influencing the Entry of Dye into Neutrophil Leucocytes in the Nitroblue Tetrazolium Test

1975 ◽  
Vol 48 (3) ◽  
pp. 201-212
Author(s):  
A. W. Segal ◽  
A. J. Levi
Keyword(s):  
Acute Phase Protein ◽  
Normal Subjects ◽  
Neutrophil Function ◽  
Nitroblue Tetrazolium ◽  
Phagocytic Cells ◽  
Humoral Factors ◽  
Nbt Test ◽  
Nitroblue Tetrazolium Test

1. The Nitroblue Tetrazolium (NBT) test is a measure of the phagocytosis of particulate complexes of NBT and heparin and/or fibrinogen by neutrophil leucocytes. 2. Humoral factors in the plasma of ill patients stimulate neutrophil leucocytes of normal subjects to ingest these complexes. 3. The acute phase protein, orosomucoid and endotoxin stimulate reduction of NBT in vitro and could be responsible for some positive NBT tests in vivo. 4. The effect of factors promoting phagocytosis may be masked by an inability of neutrophil leucocytes to respond to stimulation. 5. This defective neutrophil function could result from the replacement of circulating neutrophil leucocytes by less mature, less actively phagocytic cells or by the presence of circulating immune complexes.

Infections in Patients with Acute Non-Lymphocytic Leukemia Nursed with Central or Peripheral Venous Access

1993 ◽  
Vol 79 (2) ◽  
pp. 112-115 ◽  
Author(s):  
Gianpiero Fasola ◽  
Chiara Savignano ◽  
Maria Gloria Revignas ◽  
Luigi Virgolini ◽  
Michele Baccarani
Keyword(s):  
Risk Factor ◽  
Central Venous Access ◽  
Venous Access ◽  
Lymphocytic Leukemia ◽  
Nursing Facilities ◽  
Central Venous ◽  
Gram Negative ◽  
Peripheral Venous Access ◽  
Almost All ◽  
Infecting Organisms

Aims and Background Infections are a major problem in patients undergoing induction chemotherapy for acute leukemia. Granulocytopenia is the single most imporant risk factor, but the pattern of infecting organisms can change according to nursing facilities or bacterial and fungal prophylaxis. Methods We reviewed the patterns and types of infections in 30 patients with acute non-lymphocytic leukemia. Eighty-nine periods of neutropenia following chemotherapy were evaluated: in 60 courses patients had central and in 29 had peripheral venous access. Results Almost all patients (97 %) became febrile after the 1st course of therapy, but one-third remained apyretic after the fourth course (P = 0.002). In this series, the incidence of gram-positive, gram-negative and mycotic isolations were respectively 76 %, 18 % and 6 %. The need for antimicrobic treatment varied in relation to the course of chemotherapy. Conclusions We conclude that in acute non-lymphocytic leukemia the first neutropenic period following the onset of disease is the most critical regarding infectious problems. Both quinolonic prophylaxis and central venous access could be responsible for the microbiologic findings.

Serum amyloid A is an innate immune opsonin for Gram-negative bacteria

Blood ◽  
2006 ◽  
Vol 108 (5) ◽  
pp. 1751-1757 ◽  
Author(s):  
Chandrabala Shah ◽  
Ranjeeta Hari-Dass ◽  
John G. Raynes
Keyword(s):  
Serum Amyloid A ◽  
Serum Amyloid ◽  
Reactive Oxygen Intermediate ◽  
Gram Negative Bacteria ◽  
Phagocytic Cells ◽  
Peripheral Blood Mononuclear ◽  
Gram Negative ◽  
E Coli ◽  
Amyloid A ◽  
Innate Recognition

Serum amyloid A (SAA) is the major acute-phase protein in man and most mammals. Recently we demonstrated that SAA binds to many Gram-negative bacteria including Escherichia coli and Pseudomonas aeruginosa through outer membrane protein A (OmpA) family members. Therefore we investigated whether SAA altered the response of innate phagocytic cells to bacteria. Both the percentage of neutrophils containing E coli and the number of bacteria per neutrophil were greatly increased by SAA opsonization, equivalent to the increase seen for serum opsonization. In contrast, no change was seen for Streptococcus pneumoniae, a bacteria that did not bind SAA. Neutrophil reactive oxygen intermediate production in response to bacteria was also increased by opsonization with SAA. SAA opsonization also increased phagocytosis of E coli by peripheral blood mononuclear cell-derived macrophages. These macrophages showed strong enhancement of TNF-α and IL-10 production in response to SAA-opsonized E coli and P aeruginosa. SAA did not enhance responses in the presence of bacteria to which it did not bind. These effects of SAA occur at normal concentrations consistent with SAA binding properties and a role in innate recognition. SAA therefore represents a novel innate recognition protein for Gram-negative bacteria.

scholarly journals Variation, Modification and Engineering of Lipid A in Endotoxin of Gram-Negative Bacteria

2021 ◽  
Vol 22 (5) ◽  
pp. 2281
Author(s):  
Kazuyoshi Kawahara
Keyword(s):  
Fatty Acids ◽  
Lipid A ◽  
Hydroxy Fatty Acids ◽  
Hydroxyl Groups ◽  
Gram Negative Bacteria ◽  
Vaccine Adjuvants ◽  
Phagocytic Cells ◽  
Gram Negative ◽  
Electrostatic Charges ◽  
Lipid A Structure

Lipid A of Gram-negative bacteria is known to represent a central role for the immunological activity of endotoxin. Chemical structure and biosynthetic pathways as well as specific receptors on phagocytic cells had been clarified by the beginning of the 21st century. Although the lipid A of enterobacteria including Escherichia coli share a common structure, other Gram-negative bacteria belonging to various classes of the phylum Proteobacteria and other taxonomical groups show wide variety of lipid A structure with relatively decreased endotoxic activity compared to that of E. coli. The structural diversity is produced from the difference of chain length of 3-hydroxy fatty acids and non-hydroxy fatty acids linked to their hydroxyl groups. In some bacteria, glucosamine in the backbone is substituted by another amino sugar, or phosphate groups bound to the backbone are modified. The variation of structure is also introduced by the enzymes that can modify electrostatic charges or acylation profiles of lipid A during or after its synthesis. Furthermore, lipid A structure can be artificially modified or engineered by the disruption and introduction of biosynthetic genes especially those of acyltransferases. These technologies may produce novel vaccine adjuvants or antagonistic drugs derived from endotoxin in the future.

Host Defense in Infantile Osteopetrosis

PEDIATRICS ◽  
1979 ◽  
Vol 64 (2) ◽  
pp. 202-206
Author(s):  
Jerry D. Reeves ◽  
Charles S. August ◽  
James R. Humbert ◽  
William L. Weston
Keyword(s):  
Host Defense ◽  
Host Resistance ◽  
Neutrophil Function ◽  
Early Age ◽  
Phagocytic Cells ◽  
Bacterial Killing ◽  
Nitroblue Tetrazolium Reduction ◽  
Malignant Osteopetrosis ◽  
Resistance To Infection ◽  
Tetrazolium Reduction

Since infants with malignant osteopetrosis often die from infection at an early age, we studied several aspects of host defense in five such infants. No consistent abnormality was found in cellular or humoral immunity. Monocyte cellular chemotaxis and phagocytosis were normal in four tested infants. However, all four of these infants had decreased intracellular bacterial killing by monocytes. Neutrophil function tests in five infants showed that two had defective bacterial phagocytosis and four had reduced cellular chemotaxis, decreased nitroblue tetrazolium reduction, and decreased intracellular bacterial killing. The severity of the decreased bactericidal capacity of granulocytes did not correlate with the number of circulating immature granulocytes. Our data suggest that abnormal function of circulating monocytes and granulocytes may contribute to impaired host resistance to infection. We postulate that this defect may reflect a more generalized inherited abnormality of phagocytic cells and perhaps osteoclasts that plays a role in the pathogenesis of infantile osteopetrosis.

scholarly journals Virulence Factors of Salmonella Typhi

2021 ◽  
Author(s):  
Noor S.K. Al-Khafaji ◽  
Ali M.K. Al-Bayati ◽  
Hussein O.M. Al-Dahmoshi
Keyword(s):  
Small Intestine ◽  
Virulence Factors ◽  
Blood Stream ◽  
Salmonella Typhi ◽  
Phagocytic Cells ◽  
Gram Negative ◽  
The Family ◽  
Gram Negative Organisms ◽  
Salmonella Pathogenicity Islands ◽  
Vi Antigen

S. Typhi is an enteric bacillus which belongs,to the genus Salmonella in the family Enterobacteriacaea and it is a multi–organs pathogen which inhibits the lymphatic tissues of the small intestine, liver, spleen, and blood stream of infected humans.S.Typhi has a mixture of features that make it an efficient pathogen. This species contains an endotoxin that is characteristic of Gram-negative organisms, as well as the virulence-enhancing Vi antigen. Many of the S. Typhi virulence factors are clustered in some areas of the chromosome known as Salmonella pathogenicity islands (SPI), such as adhesion, invasion, and toxin genes. A protein known as invasin that permits non-phagocytic cells is also produced and excreted by the bacterium., Where it is capable of intracellular living. The oxidative burst of leukocytes may also be inhibited, making innate immune reaction ineffective.

scholarly journals Putting the Jigsaw Together - A Brief Insight Into the Tularemia

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
K. Kubelkova ◽  
A. Macela
Keyword(s):  
Francisella Tularensis ◽  
Severe Disease ◽  
Standard Of Care ◽  
Phagocytic Cells ◽  
Current Standard ◽  
Gram Negative ◽  
Infectious Dose ◽  
Multiple Routes ◽  
Bioterrorism Agent ◽  
Insight Into

AbstractTularemia is a debilitating febrile and potentially fatal zoonotic disease of humans and other vertebrates caused by the Gram-negative bacterium Francisella tularensis. The natural reservoirs are small rodents, hares, and possibly amoebas in water. The etiological agent, Francisella tularensis, is a non-spore forming, encapsulated, facultative intracellular bacterium, a member of the γ-Proteobacteria class of Gram-negative bacteria. Francisella tularensis is capable of invading and replicating within phagocytic as well as non-phagocytic cells and modulate inflammatory response. Infection by the pulmonary, dermal, or oral routes, respectively, results in pneumonic, ulceroglandular, or oropharyngeal tularemia. The highest mortality rates are associated with the pneumonic form of this disease. All members of Francisella tularensis species cause more or less severe disease Due to their abilities to be transmitted to humans via multiple routes and to be disseminated via biological aerosol that can cause the disease after inhalation of even an extremely low infectious dose, Francisella tularensis has been classified as a Category A bioterrorism agent. The current standard of care for tularemia is treatment with antibiotics, as this therapy is highly effective if used soon after infection, although it is not, however, absolutely effective in all cases.

Gram-negative Rod Bacteraemia: function of phagocytic cells and opsonic activity of serum

1979 ◽  
Vol 45 (3) ◽  
pp. 517-517
Author(s):  
Willemien C. van Dijk ◽  
H. A. Verbrugh ◽  
Marijke E. van der Tol ◽  
J. Verhoef
Keyword(s):  
Phagocytic Cells ◽  
Opsonic Activity ◽  
Gram Negative

CHRONIC GRANULOMATOUS DISEASE: CORRELATION BETWEEN PATHOGENESIS AND CLINICAL FINDINGS

PEDIATRICS ◽  
1971 ◽  
Vol 48 (5) ◽  
pp. 730-739 ◽  
Author(s):  
Richard B. Johnston ◽  
Robert L. Baehner
Keyword(s):  
Hydrogen Peroxide ◽  
Chronic Granulomatous Disease ◽  
Chronic Infection ◽  
Reticuloendothelial System ◽  
Clinical Findings ◽  
Granulomatous Disease ◽  
Phagocytic Cells ◽  
Gram Negative ◽  
Serious Infections ◽  
Suppurative Lymphadenitis

Chronic granulomatous disease (CGD) results from a failure of patients' phagocytic cells to kill ingested bacteria. The inability to kill intraphagocytic microorganisms leads to granuloma formation and abscesses throughout the reticuloendothelial system. Thus, the clinical picture of CGD is characterized by suppurative lymphadenitis, hepatosplenomegaly, pneumonia, and hematologic evidence of chronic infection. The bactericidal defect which characterizes CGD phagocytes appears to be due to their inability to generate hydrogen peroxide (H2O2). The organisms which infect patients are those which require phagocytic production of H2O2 for death–staphylococci and gram-negative enterics. There are simple means of confirming a clinical diagnosis of CGD, and prolonged therapy with specific antibiotics may therefore suppress the frequency of such serious infections.

scholarly journals Antimicrobial peptides of mammals: biological functions different from antibiotic (review)

2021 ◽  
pp. 4-11
Author(s):  
Г.М. Алешина
Keyword(s):  
Antimicrobial Peptides ◽  
Biological Fluids ◽  
Antimicrobial Properties ◽  
Main Function ◽  
Biological Functions ◽  
Phagocytic Cells ◽  
Humoral Factors ◽  
Invertebrate Species ◽  
Antibiotic Drugs ◽  
New Generation

Антимикробные пептиды животных являются одними из ключевых молекулярных факторов врожденного иммунитета, ответственными за умерщвление потенциально опасных микроорганизмов. В настоящее время охарактеризовано несколько сотен полипептидов и белков с антимикробными свойствами, выделенных из тканей различных видов позвоночных и беспозвоночных животных. Некоторые из этих пептидов локализованы в гранулах фагоцитарных клеток, другие являются гуморальными факторами, и выявляются в различных биологических жидкостях организма. Основной их функцией считается антибиотическое действие, на что указывает и их локализация в гранулах фагоцитов и в слизистых оболочках. Всё чаще они рассматриваются как потенциальные матрицы для создания на их основе антибиотических препаратов нового поколения для медицины и ветеринарии. В то же время появляется всё больше фактов, что их функции не ограничиваются только антимикробным действием. В настоящем обзоре изложены данные о дополнительных свойствах представителей самых распространенных семейств антимикробных пептидов млекопитающих - дефенсинов и кателицидинов. Показано, что они могут выступать как хемоаттрактанты и дегрануляторы тучных клеток, оказывают влияние на продукцию хемокинов и цитокинов, проявляют кортикостатическое действие. Antimicrobial peptides of animals are a key molecular factor of innate immunity responsible for elimination of potentially dangerous microorganisms. At present, several hundred polypeptides and proteins with antimicrobial properties have been isolated from tissues of various vertebrate and invertebrate species and characterized. Some of these peptides are localized in granules of phagocytic cells while others are humoral factors detected in various biological fluids. Their main function is considered to be the antibiotic activity as indicated by their localization in the granules of phagocytes and in epithelial cells. Often, they are considered as potential matrices for new generation antibiotic drugs for medicine and veterinary. At the same time, multiple facts have suggested that their functions are not limited to the antimicrobial activity. This review presents data on additional properties of representatives of the most common families of mammalian antimicrobial peptides, defensins and cathelicidins. It has been shown that they can act as chemoattractants and degranulators of mast cells, influence the production of chemokines and cytokines, and exert a corticostatic effect.

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