scholarly journals Interactions Between Acanthamoeba culbertsoni and Pathogenic Bacteria and their Inhibition by Lectin-Antibodies

2020 ◽  
Vol 14 (3) ◽  
pp. 1687-1693
Author(s):  
Suk-Yul Jung
Keyword(s):  
Monoclonal Antibody ◽  
Pathogenic Bacteria ◽  
Coli Strain ◽  
Reservoir Host ◽  
High Association ◽  
E Coli ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Acanthamoeba Culbertsoni ◽  
Polyclonal Serum

In this study, using pathogenic and non-pathogenic bacteria, it was analyzed whether a polyclonal serum and a monoclonal antibody to A. culbertsoni mannose-binding protein (MBP) could inhibit its interaction. The association of the amoeba with E. coli O157:H7 was very strong at a level of over 100%, but the non-pathogenic E. coli strain was about five times lower at 22%. Pathogenic K. pnueumoniae also showed high association with amoeba by about 92% as compared with pathogenic E. coli O157:H7 and S. agalactiae. The polyclonal serum to MBP inhibited E. coli O157:H7 association to amoeba 2.5 times more than untreated E. coli O157:H7. Monoclonal antibody to MBP also inhibited bacterial association with amoeba but was not stronger than the polyclonal serum. Pathogenic E. coli O157:H7 showed about 88% invasion into amoeba and decreased about 22% as compared with associated E. coli O157:H7. Polyclonal serum to MBP inhibited about 55%, 50%, and 44% in E. coli O157:H7, K. pneumoniae and S. agalactiae, respectively. The invasion of K. pneumoniae and S. agalactiae was not high as polyclonal serum but was about 8% to 10% weaker than polyclonal serum. The pathogenic strains of K. pneumoniae and S. agalactiae showed less decrease in survival as shown at invasion than E. coli O157:H7 without antibody. This study provided the information that the pathogenic bacteria could be more interactive with A. culbertsoni trophozoites as a reservoir host than non-pathogenic E. coli, and the amoeba should interact with bacteria by the MBP lectin.

scholarly journals Production of a monoclonal antibody against a mannose-binding protein of Acanthamoeba culbertsoni and its localization

2018 ◽  
Vol 192 ◽  
pp. 19-24 ◽  
Author(s):  
A-Young Kang ◽  
A-Young Park ◽  
Ho-Joon Shin ◽  
Naveed Ahmed Khan ◽  
Sutherland K. Maciver ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Binding Protein ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Acanthamoeba Culbertsoni

Mannose-Binding Activity of Escherichia coli: a Determinant of Attachment and Ingestion of the Bacteria by Macrophages

1980 ◽  
Vol 29 (2) ◽  
pp. 417-424
Author(s):  
Zvi Bar-Shavit ◽  
Rachel Goldman ◽  
Itzhak Ofek ◽  
Nathan Sharon ◽  
David Mirelman
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Pathogenic Bacteria ◽  
Binding Activity ◽  
Exponential Phase ◽  
Restrictive Temperature ◽  
Filamentous Bacteria ◽  
Phagocytic Cells ◽  
E Coli ◽  
Mannose Binding

Recently, it was suggested that a mannose-specific lectin on the bacterial cell surface is responsible for the recognition by phagocytic cells of certain nonopsonized Escherichia coli strains. In this study we assessed the interaction of two strains of E. coli at different phases of growth with a monolayer of mouse peritoneal macrophages and developed a direct method with [ 14 C]mannan to quantitate the bacterial mannose-binding activity. Normal-sized bacteria were obtained from logarithmic and stationary phases of growth. Nonseptated filamentous cells were formed by growing the organisms in the presence of cephalexin or at a restrictive temperature. Attachment to macrophages of all bacterial forms was inhibited by methyl α- d -mannoside and mannan but not by other sugars tested. The attachment of stationary phase and filamentous bacteria to macrophages, as well as their mannose-binding activity, was similar, whereas in the exponential-phase bacteria they were markedly reduced. The results show a linear relation between the two parameters ( R = 0.98, P < 0.001). The internalization of the filamentous cells attached to macrophages during 45 min of incubation was much less efficient (20%) compared to that of exponential-phase, stationary-phase, or antibody-coated filamentous bacteria (90%). The results indicate that the mannose-binding activity of E. coli determines the recognition of the organisms by phagocytes. They further suggest that administration of β-lactam antibiotics may impair elimination of certain pathogenic bacteria by inducing the formation of filaments which are inefficiently internalized by the host's phagocytic cells.

scholarly journals Rat Mannose-Binding Protein A Binds CD14

2001 ◽  
Vol 69 (3) ◽  
pp. 1587-1592 ◽  
Author(s):  
Hirofumi Chiba ◽  
Hitomi Sano ◽  
Daisuke Iwaki ◽  
Seiji Murakami ◽  
Hiroaki Mitsuzawa ◽  
...  
Keyword(s):  
Lipid A ◽  
Binding Protein ◽  
Protein A ◽  
Cellular Responses ◽  
Dependent Manner ◽  
Soluble Cd14 ◽  
Concentration Dependent Manner ◽  
E Coli ◽  
Mannose Binding Protein ◽  
Mannose Binding

ABSTRACT Lipopolysaccharide (LPS) has been known to induce inflammation by interacting with CD14, which serves as a receptor for LPS. Mannose-binding protein (MBP) belongs to the collectin subgroup of the C-type lectin superfamily, along with surfactant proteins SP-A and SP-D. We have recently demonstrated that SP-A modulates LPS-induced cellular responses by interaction with CD14 (H. Sano, H. Sohma, T. Muta, S. Nomura, D. R. Voelker, and Y. Kuroki, J. Immunol. 163:387–395, 2000) and that SP-D also interacts with CD14 (H. Sano, H. Chiba, D. Iwaki, H. Sohma, D. R. Voelker, and Y. Kuroki, J. Biol. Chem. 275:22442–22451, 2000). In this study, we examined whether MBP, a collectin highly homologous to SP-A and SP-D, could bind CD14. Recombinant rat MBP-A bound recombinant human soluble CD14 in a concentration-dependent manner. Its binding was not inhibited in the presence of excess mannose or EDTA. MBP-A bound deglycosylated CD14 treated with N-glycosidase F, neuraminidase, and O-glycosidase, indicating that MBP-A interacts with the peptide portion of CD14. Since LPS was also a ligand for the collectins, we compared the characteristics of binding of MBP-A to LPS with those of binding to CD14. MBP-A bound to lipid A fromSalmonella enterica serovar Minnesota and rough LPS (S. enterica serovar Minnesota Re595 and Escherichia coli J5, Rc), but not to smooth LPS (E. coli O26:B6 and O111:B4). Unlike CD14 binding, EDTA and excess mannose attenuated the binding of MBP-A to rough LPS. From these results, we conclude that CD14 is a novel ligand for MBP-A and that MBP-A utilizes a different mechanism for CD14 recognition from that for LPS.

Optimizing the expression of a monoclonal antibody fragment under the transcriptional control of the Escherichia coli lac promoter

2000 ◽  
Vol 46 (6) ◽  
pp. 532-541 ◽  
Author(s):  
Robert S Donovan ◽  
Campbell W Robinson ◽  
Bernard R Glick
Keyword(s):  
Escherichia Coli ◽  
Monoclonal Antibody ◽  
Antibody Fragment ◽  
Coli Strain ◽  
Fab Fragment ◽  
Iptg Induction ◽  
E Coli ◽  
Fab Fragments ◽  
The Cost ◽  
Lac Promoter

The expression of a monoclonal antibody Fab fragment in Escherichia coli strain RB791/pComb3, induced with either lactose or isopropyl-beta-D-thiogalactoside (IPTG), was compared to determine if lactose might provide an inexpensive alternative to induction with IPTG. Induction of Fab expression imposed a metabolic load on the recombinant cells, resulting in lower final cell yields compared to the non-induced controls. An IPTG concentration of 0.05 mM was sufficient to achieve maximal expression of soluble Fab protein when inducing in the early-, mid-, or late-log phases of batch cultures grown using either glucose or glycerol as a carbon source. The largest overall yield of Fab fragments when using 0.05 mM IPTG was achieved by increasing the final yield of cells through glycerol feeding following induction in late-log phase. Lactose was as effective as IPTG for inducing Fab expression in E. coli RB791/pComb3. The greatest overall level of Fab expression was found when cells grown on glycerol were induced with 2 g/L lactose in late-log phase. Since the cost of 0.05 mM of IPTG is significantly greater than the cost of 2 g/L lactose, lactose provides an inexpensive alternative to IPTG for inducing the expression of Fab fragments, and possibly other recombinant proteins, from the E. coli lac promoter.

scholarly journals Characterization of a Hemoglobin Protease Secreted by the Pathogenic Escherichia coli Strain EB1

1998 ◽  
Vol 188 (6) ◽  
pp. 1091-1103 ◽  
Author(s):  
Ben R. Otto ◽  
Silvy J.M. van Dooren ◽  
Jan H. Nuijens ◽  
Joen Luirink ◽  
Bauke Oudega
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Affinity Purification ◽  
Coli Strain ◽  
E Coli ◽  
Heme Acquisition ◽  
Pathogenic Escherichia Coli ◽  
Iga1 Protease ◽  
Animal Pathogens

Many pathogenic bacteria can use heme compounds as a source of iron. Pathogenic Escherichia coli strains are capable of using hemoglobin as an iron source. However, the mechanism of heme acquisition from hemoglobin is not understood for this microorganism. We present the first molecular characterization of a hemoglobin protease (Hbp) from a human pathogenic E. coli strain. The enzyme also appeared to be a heme-binding protein. Affinity purification of this bifunctional protein enabled us to identify the extracellular gene product, and to clone and analyze its gene. A purification procedure developed for Hbp allowed us to perform functional studies. The protein interacted with hemoglobin, degraded it and subsequently bound the released heme. These results suggest that the protein is involved in heme acquisition by this human pathogen. Hbp belongs to the so-called IgA1 protease-like proteins, as indicated by the kinetics of its membrane transfer and DNA sequence similarity. The gene of this protein appears to be located on the large pColV-K30 episome, that only has been isolated from human and animal pathogens. All these characteristics indicate that Hbp may be an important virulence factor that may play a significant role in the pathogenesis of E. coli infections.

scholarly journals Mechanism of action of oxazolidinones: effects of linezolid and eperezolid on translation reactions.

1997 ◽  
Vol 41 (10) ◽  
pp. 2132-2136 ◽  
Author(s):  
D L Shinabarger ◽  
K R Marotti ◽  
R W Murray ◽  
A H Lin ◽  
E P Melchior ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Pathogenic Bacteria ◽  
Coli Strain ◽  
In Vitro Translation ◽  
E Coli ◽  
Initiation Phase ◽  
New Class ◽  
Bacterial Translation

The oxazolidinones are a new class of synthetic antibiotics with good activity against gram-positive pathogenic bacteria. Experiments with a susceptible Escherichia coli strain, UC6782, demonstrated that in vivo protein synthesis was inhibited by both eperezolid (formerly U-100592) and linezolid (formerly U-100766). Both linezolid and eperezolid were potent inhibitors of cell-free transcription-translation in E. coli, exhibiting 50% inhibitory concentrations (IC50s) of 1.8 and 2.5 microM, respectively. The ability to demonstrate inhibition of in vitro translation directed by phage MS2 RNA was greatly dependent upon the amount of RNA added to the assay. For eperezolid, 128 microg of RNA per ml produced an IC50 of 50 microM whereas a concentration of 32 microg/ml yielded an IC50 of 20 microM. Investigating lower RNA template concentrations in linezolid inhibition experiments revealed that 32 and 8 microg of MS2 phage RNA per ml produced IC50s of 24 and 15 microM, respectively. This phenomenon was shared by the translation initiation inhibitor kasugamycin but not by streptomycin. Neither oxazolidinone inhibited the formation of N-formylmethionyl-tRNA, elongation, or termination reactions of bacterial translation. The oxazolidinones appear to inhibit bacterial translation at the initiation phase of protein synthesis.

Prevalence, drug resistance, and virulence genes of potential pathogenic bacteria in pasteurized milk of Chinese Fresh Milk Bar

2021 ◽  
Author(s):  
Shifeng Wang ◽  
Zhongna Yu ◽  
Jun Wang ◽  
Harvey Ho ◽  
Yongxin Yang ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistance Genes ◽  
Dairy Products ◽  
Pathogenic Bacteria ◽  
Virulence Genes ◽  
Coli Strain ◽  
Penicillin G ◽  
Pasteurized Milk ◽  
E Coli ◽  
Fresh Milk

Fresh Milk Bar (FMB), an emerging dairy retail franchise, is used to instantly produce and sell pasteurized milk and other dairy products in China. However, the quality and safety of pasteurized milk in FMB have received little attention. The objective of this study is to investigate the prevalence, antimicrobial resistance, and virulence genes of Escherichia coli (E. coli) , Staphylococcus aureus (S. aureus) , and Streptococcus in 205 pasteurized milk samples collected from FMBs in China. Four (2.0%) isolates of E. coli , seven (3.4%) isolates of S. aureus , and three (1.5%) isolates of S. agalactiae  were isolated and identified. The E. coli  isolates were resistant to amikacin (100%), streptomycin (50%), and tetracycline (50%). Their detected resistance genes include  aac(3)-III (75%), blaTEM  (25%), aadA  (25%), aac(3)-II  (25%), catI  (25%) and qnrB (25%). The S. aureus  isolates were mainly resistant to penicillin G (71.4%), trimethoprim-sulfamethoxazole (71.4%), kanamycin (57.1%), gentamicin (57.1%), amikacin (57.1%) and clindamycin (57.1%).  blaZ (42.9%),  mecA (28.6%), ermB (14.3%) and ermC  (14.3%) were detected as their resistance genes. The Streptococcus strains were mainly resistant to tetracycline (66.7%) and contained resistance genes:  pbp2b (33.3%) and tetM (33.3%). The virulence genes eae  and stx2  were only found in one E. coli  strain (25%), and sec  was detected in two S. aureus strains(28.6%), while bca  was detected in one  S. agalactiae  strain (33.3%) .  The results of this study indicate that bacteria with drug resistance and virulence genes isolated from the pasteurized milk of FMB are a potential risk to consumers' health.

scholarly journals Isolation of bacteriophages from untreated sewage water against multi-drug resistant E.coli - An initiative to fight against drug resistance

2019 ◽  
Author(s):  
Hina Qamar ◽  
Mohd Owais ◽  
Dushyant Kumar Chauhan ◽  
Sumbul Rehman
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Therapeutic Potential ◽  
Alternative Therapy ◽  
Sewage Water ◽  
Coli Strain ◽  
Drug Resistant ◽  
Range Analysis ◽  
E Coli ◽  
Untreated Sewage

Abstract Background: Pathogenic Escherichia coli, common drinking water contaminant, cause a large number of morbidity and mortality worldwide. According to the WHO estimates approximately 63,000 annual deaths are due to E. coli infections. Due to selective pressure on coliforms, resistant microbial strains are produced that threatens modern medicine where common infections could become more deadly. So, there is an urgent need to develop alternative anti-microbial to replace existing antibiotics for treating a broad spectrum of bacterial diseases. This revived the interest of scientists in phages as an alternative therapy. Phage therapy is defined as a therapeutic use of bacteriophages (natural predators of bacteria) for treating bacterial infections. In the present study pure phage strain was isolated from the untreated sewage water sample and subjected to 10 fold dilution following double agar layer assay to determine phage titer against multi-drug resistant E.coli following host range analysis and stability testing at varying temperature and pH. Results: Sewage water contains a vast variety of different sizes bacteriophages with clear to diffused boundaries. The pure plaque isolated after repeated plating showed that it was highly specific against tested E. coli strain and could not lyse strains from other species. The titer was calculated to be 109 PFU/ml that remained unchanged at 4°C, 37°C and 50°C temperature. However, at higher pH range phage viability decreases. Conclusions: In future, it would be expected that the isolated bacteriophages could be characterized and used as a therapeutic potential against multi-drug resistant E.coli that not only attenuate superbug spread but could also replace antibiotics. Beside, isolated phages would be utilized as a bio-component in biosensor development against food borne pathogenic bacteria.

scholarly journals The Role of Pea (Pisum sativum) Seeds in Transmission of Entero-Aggregative Escherichia coli to Growing Plants

2020 ◽  
Vol 8 (9) ◽  
pp. 1271
Author(s):  
Leonard S. van Overbeek ◽  
Carin Lombaers-van der Plas ◽  
Patricia van der Zouwen
Keyword(s):  
Escherichia Coli ◽  
Plant Growth ◽  
Pathogenic Bacteria ◽  
Vascular Tissue ◽  
Production Systems ◽  
Coli Strain ◽  
Crop Plants ◽  
Plant Colonization ◽  
Human Pathogens ◽  
E Coli

Crop plants can become contaminated with human pathogenic bacteria in agro-production systems. Some of the transmission routes of human pathogens to growing plants are well explored such as water, manure and soil, whereas others are less explored such as seeds. Fenugreek seeds contaminated with the entero-hemorrhagic Escherichia coli O104:H4 were suspected to be the principle vectors for transmission of the pathogen to sprouts at the food-borne disease outbreak in Hamburg and surrounding area in 2011. In this study we raised the questions of whether cells of the entero-aggregative E. coli O104:H4 strain 55989 is capable of colonizing developing plants from seeds and if it would be possible that, via plant internalization, these cells can reach the developing embryonic tissue of the next generation of seeds. To address these questions, we followed the fate of strain 55989 and of two other E. coli strains from artificially contaminated seeds to growing plants, and from developing flower tissue to mature seeds upon proximate introductions to the plant reproductive organs. Escherichia coli strains differing in origin, adherence properties to epithelial cells, and virulence profile were used in our experimentation to relate eventual differences in seed and plant colonization to typical E. coli properties. Experiments were conducted under realistic growth circumstances in greenhouse and open field settings. Entero-aggregative E. coli strain 55989 and the two other E. coli strains were able to colonize the root compartment of pea plants from inoculated seeds. In roots and rhizosphere soil, the strains could persist until the senescent stage of plant growth, when seeds had ripened. Colonization of the above-soil parts was only temporary at the start of plant growth for all three E. coli strains and, therefore, the conclusion was drawn that translocation of E. coli cells via the vascular tissue of the stems to developing pea seeds seems unlikely under circumstances realistic for agricultural practices. Proximate introductions of cells of E. coli strains to developing flowers also did not result in internal seed contamination, indicating that internal seed contamination with E. coli is an unlikely event. The fact that all three E. coli strains showed stronger preference for the root-soil zones of growing pea plants than for the above soil plant compartments, in spite of their differences in clinical behaviour and origin, indicate that E. coli in general will colonize root compartments of crop plants in production systems.

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