Bacteriolytic and bactericidal activity of maternal and cord sera. Relationship to complement, lysozyme, transferrin, and immunoglobulin levels

1972 ◽  
Vol 18 (10) ◽  
pp. 1551-1555 ◽  
Author(s):  
W. Pruzanski ◽  
W.-D. Leers ◽  
A. C. Wardlaw
Keyword(s):  
Escherichia Coli ◽  
Human Serum ◽  
Bactericidal Activity ◽  
Significant Relationship ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bacteriolytic Activity ◽  
Cord Serum ◽  
Normal Human ◽  
Immunoglobulin Levels

Bacteriolytic activity and its relationship to the level of immunoglobulins, complement, lysozyme, and transferrin was measured in 20 pairs and bactericidal activity in 6 pairs of maternal and cord serum. Escherichia coli Lilly, an organism easily lysed by normal human serum and four other Gram-negative bacteria were used.Cord sera invariably had lower bacteriolytic and bactericidal activity than their corresponding maternal sera. No statistically significant relationship between these activities and the level of immunoglobulins, complement, lysozyme, or transferrin was detected. A higher level of lysozyme was unable to compensate for the lower levels of other factors in the cord sera.

Susceptibility of Gram-negative bacteria to the synergistic bactericidal action of serum and polymyxin B nonapeptide

1986 ◽  
Vol 32 (1) ◽  
pp. 66-69 ◽  
Author(s):  
Petri Viljanen ◽  
Helena Käyhty ◽  
Martti Vaara ◽  
Timo Vaara
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Enterobacter Cloacae ◽  
Polymyxin B ◽  
Gram Negative Bacteria ◽  
Bactericidal Action ◽  
Gram Negative ◽  
Degree Of Sensitization ◽  
Normal Human ◽  
Klebsiella Spp

Polymyxin B nonapeptide was able to sensitize Escherichia coli strains and strains of Salmonella typhimurium, Klebsiella spp., Enterobacter cloacae, Pseudomonas aeruginosa, and Haemophilus influenzae to the bactericidal action of fresh normal human serum. The degree of sensitization varied significantly within the strains. Strains of Proteus mirabilis, Neisseria gonorrhoeae, and N. meningitidis remained resistant.

scholarly journals Group IIA secreted phospholipase A2in human serum kills commensal but not clinicalEnterococcus faeciumisolates

2018 ◽  
Author(s):  
Fernanda L. Paganelli ◽  
Helen L. Leavis ◽  
Samantha He ◽  
Nina M. van Sorge ◽  
Christine Payré ◽  
...  
Keyword(s):  
Human Serum ◽  
Enterococcus Faecium ◽  
Opportunistic Infections ◽  
Normal Serum ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Serum Killing ◽  
Normal Human

AbstractHuman innate immunity employs cellular and humoral mechanisms to facilitate rapid killing of invading bacteria. The direct killing of bacteria by human serum is mainly attributed to the activity of the complement system that forms pores in Gram-negative bacteria. Although Gram-positive bacteria are considered resistant to serum killing, we here uncover that normal human serum effectively killsEnterococcus faecium.Comparison of a well-characterized collection of commensal and clinicalE. faeciumisolates revealed that human serum specifically kills commensalE. faeciumstrains isolated from normal gut microbiota, but not clinical isolates. Inhibitor studies show that the human group IIA secreted phospholipase A2 (hGIIA), but not complement, is responsible for killing of commensalE. faeciumstrains in human normal serum. This is remarkable since hGIIA concentrations in ‘non-inflamed’ serum were considered too low to be bactericidal against Gram-positive bacteria. Mechanistic studies showed that serum hGIIA specifically causes permeabilization of commensalE. faeciummembranes. Altogether, we find that a normal serum concentration of hGIIA effectively kills commensalE. faeciumand that hGIIA resistance of clinicalE. faeciumcould have contributed to the ability of these strains to become opportunistic pathogens in hospitalized patients.ImportanceHuman normal serum contains antimicrobial components that effective kill invading Gram-negative bacteria. Although Gram-positive bacteria are generally considered resistant to serum killing, here we show that normal human effectively kills the Gram-positiveEnterococcus faeciumstrains that live as commensals in the gut of humans. In contrast, clinicalE. faeciumstrains that are responsible for opportunistic infections in debilitated patients are resistant against human serum. The key factor in serum responsible for killing is group IIA secreted phospholipase A2 (hGIIA) that effectively destabilizes commensalE. faeciummembranes. We believe that hGIIA resistance by clinicalE. faeciumcould have contributed to the ability of these strains to cause opportunistic infections in hospitalized patients. Altogether, understanding mechanisms of immune defense and bacterial resistance could aid in further development of novel anti-infective strategies against medically important multidrug resistant Gram-positive pathogens.

scholarly journals Sequential metabolic expressions of the lethal process in human serum-treated Escherichia coli: role of lysozyme

1980 ◽  
Vol 28 (3) ◽  
pp. 735-745
Author(s):  
R J Martinez ◽  
S F Carroll
Keyword(s):  
Escherichia Coli ◽  
Human Serum ◽  
Membrane Integrity ◽  
Response To Treatment ◽  
Gram Negative Bacteria ◽  
Human Lysozyme ◽  
E Coli ◽  
Normal Human ◽  
Hydrolysis Of

Several metabolic parameters indicative of Escherichia coli function and integrity were kinetically examined in response to treatment with normal human serum in the presence and absence of functional human lysozyme. Specific inhibition of this enzyme in bacteriolytic and bactericidal reactions was accomplished by using purified rabbit anti-human lysozyme immunoglobulin G. Initiation of the complement-mediated alterations of cytoplasmic membrane integrity, as judged by the leakage of 86Rb from prelabeled cells or the hydrolysis of o-nitrophenyl-beta-D-galactopyranoside by a cryptic strain, was found to be independent of lysozyme action. Furthermore, inhibition of macromolecular synthesis by E. coli in response to serum treatment occurred at the same time regardless of the functional state of lysozyme. Although the rate and extent of bacteriolysis were reduced in the absence of lysozyme, the bactericidal kinetics was unaffected. These results demonstrate that the lethal events associated with the action of antibody and complement on gram-negative bacteria are independent of lysozyme, suggesting an accessory role for this enzyme in immune reactions. A possible temporal sequence of complement-induced effects occurring at the cell surface is presented.

scholarly journals HUBUNGAN KEBIASAAN MANDI DI SUNGAI DENGAN INFEKSI SALURAN KEMIH PADA ANAK DI KELURAHAN SINDULANG 1

e-CliniC ◽  
2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Chensilya Kusumanarwasti ◽  
Adrian Umboh ◽  
Johnny Rompis
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Significant Relationship ◽  
Gram Negative Bacteria ◽  
Preliminary Survey ◽  
Cross Sectional ◽  
Gram Negative ◽  
Tract Infections ◽  
The City

Abstrak: Infeksi saluran kemih (ISK) pada anak merupakan salah satu masalah kesehatan yang paling sering terjadi, dengan angka kejadian yang hanya sedikit lebih rendah dibandingkan ISPA dan infeksi digestif. Salah satu keadaan penting yang perlu diperhatikan pada gejala ISK adalah bakteriuria. Bakteriuria adalah suatu keadaan dimana bakteri dapat ditemukan didalam urin, tetapi keadaan ini tidak selalu berarti ISK. Bakteri gram negatif, khususnya Eschericia coli merupakan penyebab utama ISK (85-90%). Survei awal yang dilakukan peneliti di kelurahan Sindulang 1, kecamatan Tuminting, kota Manado, menduga bahwa sungai Tondano di daerah tersebut tercemar E.coli. Penelitian ini merupakan penelitian analitik observasional dengan pendekatan potong lintang (cross sectional). Penelitian dilakukan di kelurahan Sindulang 1, kecamatan Tuminting, kota Manado, selama bulan November sampai Desember 2012, dengan sampel adalah 60 anak yang berusia antara 5-12 tahun. Hasil penelitian yang diperoleh, terdapat 39 orang anak yang memiliki kebiasaan mandi di sungai dan 21orang anak tidak memiliki kebiasaan mandi disungai.  39 orang yang mandi di sungai, didapatkan 2 orang anak yang positif menderita ISK. Hasil statistik menunjukan bahwa terdapat hubungan yang bermakna antara mandi di sungai dengan kejadian ISK. Kata kunci: kebiasaan mandi di sungai, ISK, urinalisis     Abstract: Urinary tract infections (UTI) in children is one of the most common health problems, the incidence is only slightly lower than the respiratory and digestive infections. One of the most important conditions that need attention from some symptoms of UTI is bacteriuria. Bacteriuria is a condition in which bacteria can be found in the urine, but this situation does not always mean UTI. Gram-negative bacteria, especially Escherichia coli is the leading cause of UTI (85-90%). Preliminary survey conducted by researchers at the Sindulang 1 village, of the Tuminting district, of the city of Manado, suspect that the Tondano river is polluted by E.coli. This was an observational analytic study with cross-sectional approach. The study was conducted in the Sindulang 1 village, of the Tuminting district, of the city of Manado, during November and December 2012, the sample was 60 children aged between 5-12 years. The results obtained, there are 39 childrens who have a river bathing habit and 21 child doesn’t. 39 people who bathe in the river, got 2 children who were positive for UTI. Subjects suffering from UTI confirmed by performing urinalysis, where meaningful results if leukocytes is  ≥ 5 WBC/hpf. From the statistical showed that there is a significant relationship between bathing in the river with the incidence of UTI. Keywords: river bathing habits, UTI, urinalysis

Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

2013 ◽  
pp. 125-133
Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Brine Shrimp ◽  
Inhibitory Concentration ◽  
Lethal Dose ◽  
Macrophomina Phaseolina ◽  
Chloroform Extract ◽  
Citrus Reticulata ◽  
Gram Negative Bacteria ◽  
Gram Negative

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

scholarly journals Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tessa B. Moyer ◽  
Ashleigh L. Purvis ◽  
Andrew J. Wommack ◽  
Leslie M. Hicks
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antimicrobial Peptides ◽  
Mechanism Of Action ◽  
Gram Negative Bacteria ◽  
Amaranthus Tricolor ◽  
Core Motif ◽  
Gram Negative ◽  
E Coli ◽  
Membrane Lysis

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.

scholarly journals MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

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