scholarly journals An Unusual Cause of Keratitis

1970 ◽  
Vol 12 (3) ◽  
pp. 177-178
Author(s):  
Saroj Gupta ◽  
Atul Aher
Keyword(s):  
Escherichia Coli ◽  
Normal Saline ◽  
Unusual Case ◽  
Polymyxin B ◽  
Nutrient Agar ◽  
Eye Drops ◽  
Minor Trauma ◽  
Parasite Culture ◽  
Wet Mount ◽  
Corneal Scraping

This report is of an unusual case of keratitis in a young healthy man who presented with minor trauma to his left eye. At examination, a characteristic ring infiltrate was seen in the centre of the cornea. Normal saline wet mount preparation of the corneal scraping showed unusual motile trophozoites of a parasite. Culture on non-nutrient agar with Escherichia coli overlay was negative. The patient was treated with topical neomycin, polymyxin B, and bacitracin eye drops and responded well to treatment.

scholarly journals A ten-year report of microbial keratitis in pediatric population under five years in a tertiary eye center

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mohammad Soleimani ◽  
Seyed Ali Tabatabaei ◽  
S. Saeed Mohammadi ◽  
Niloufar Valipour ◽  
Arash Mirzaei
Keyword(s):  
Pediatric Population ◽  
Cross Sectional Study ◽  
Eye Drops ◽  
Microbial Keratitis ◽  
Cyanoacrylate Glue ◽  
Cross Sectional ◽  
Under Five ◽  
Fluoroquinolone Antibiotics ◽  
Empiric Antibiotic ◽  
Corneal Scraping

Abstract Purpose To report characteristics of microbial keratitis in pediatric patients under five years. Methods Patients with infectious keratitis under the age of 5 years were included in this retrospective cross-sectional study for ten years. All patients were admitted and corneal scraping was performed in 81 children. Fortified empiric antibiotic eye drops including cefazolin (50 mg/cc) and amikacin (20 mg/cc) were started and the antibiotic regimen was continued or changed according to culture results. In the case of fungal keratitis, topical voriconazole (10 mg/cc) or natamycin (50 mg/cc) and topical chloramphenicol (5 mg/cc) were started. A tectonic procedure was done when corneal thinning or perforation was present. Results Ninety-Three Patients between 1 to 60 months with a mean age of 33 ± 18 months old with corneal ulcer were included in the study. The most common risk factor was trauma (40.9%) followed by contact lens use (8.6%). Cultures were negative for microbial growth in 28 (30.1%) patients. The most common pathogens were S. epidermidis (10.8%) and P. aeruginosa (10.8%). Fluoroquinolone antibiotics (ciprofloxacin; 93.8% sensitivity) were the most potent antibiotic against bacterial pathogens. Forty-one patients underwent tectonic procedures, which the most common ones were cyanoacrylate glue 18.3% followed by keratoplasty 16.1%. Conclusion This study emphasizes the role of trauma as the primary cause and S. epidermidis as the most frequent microorganism in pediatric keratitis; according to antibiogram results and poor cooperation of patients under five years, monotherapy with fluoroquinolones could be a good regimen in small non-central lesions without thinning.

Two Novel Mutations Associated with Polymyxin-B Resistance in a Pandemic Lineage of Uropathogenic Escherichia coli of the Sequence Type 69

Chemotherapy ◽  
2021 ◽  
pp. 1-7
Author(s):  
Carla Adriana dos Santos ◽  
Rodrigo Tavanelli Hernandes ◽  
Marcos Paulo Vieira Cunha ◽  
Filipe Onishi Nagamori ◽  
Claudia Regina Gonçalves ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Susceptibility Testing ◽  
Polymyxin B ◽  
Antimicrobial Treatment ◽  
Sequence Type ◽  
Broth Microdilution ◽  
Economic Costs ◽  
Novel Mutations ◽  
E Coli ◽  
Total Inhibition

<b><i>Background:</i></b> Uropathogenic <i>Escherichia coli</i> (UPEC) are frequent pathogens worldwide, impacting on the morbidity and economic costs associated with antimicrobial treatment. <b><i>Objectives:</i></b> We report two novel mutations associated with polymyxin-B resistance in an UPEC isolate collected in 2019. <b><i>Methods:</i></b> Isolate was submitted to antimicrobial susceptibility testing including broth microdilution for polymyxin B. Whole genome was sequenced and analyzed. <b><i>Results:</i></b> Polymyxin-B total inhibition occurred at 16 mg/L (resistant). UPEC isolate was assigned to the phylogroup D, serotype O117:H4, and Sequence Type 69. <i>mcr</i> genes were not detected, but two novel mutations in the <i>pmrA/basS</i> (A80S) and <i>pmrB/</i>basR (D149N) genes were identified. <b><i>Conclusions:</i></b> The occurrence of non-<i>mcr</i> polymyxin resistance in <i>E. coli</i> from extraintestinal infections underscores the need of a continuous surveillance of this evolving pathogen.

scholarly journals ISOLASI BAKTERI YANG BERSIMBION DENGAN ASCIDIAN Herdmania momus YANG MEMILIKI AKTIVITAS ANTIBAKTERI

2020 ◽  
Vol 8 (2) ◽  
pp. 20
Author(s):  
Silvia E Koyongian ◽  
Deiske A Sumilat ◽  
Rosita A J Lintang ◽  
Stenly Wullur ◽  
Sandra O Tilaar ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Marine Invertebrates ◽  
Nutrient Agar ◽  
Symbiotic Bacteria ◽  
Bacterial Isolates ◽  
Marine Broth ◽  
Antibacterial Screening ◽  
Coral Reef Ecosystems ◽  
And Staphylococcus Aureus

 Ascidian is marine invertebrates in coral reef ecosystems that produce many bioactive compounds for pharmacology. The presence of symbiotic bacteria with marine organisms is protected the host biota by producing secondary metabolites. The purpose of this study is to obtain symbiotic bacterial isolates with Herdmania momus ascidian, then to observe the antibacterial activity of these bacterial isolates against Escherichia coli, and Staphylococcus aureus. Isolation and culture of the symbiotic bacteria were made on Nutrient Agar and Zobell Marine Broth media. The antibacterial screening showed that the Herdmania momus symbiotic bacteria were able to inhibit the growth of Staphylococcus aureus and Escherichia coli.Keywords: ascidians, Herdmania momus, bacteria, isolation, antibacterialAbstak          Ascidian adalah avetebrata laut di ekosistem terumbu karang yang banyak menghasilkan senyawa bioaktif untuk bidang farmakologi. Keberadaan bakteri yang bersimbion dengan organisme laut pada umumnya untuk melindungi biota yang ditumpanginya dan dirinya dengan cara menghasilkan senyawa metabolit sekunder. Tujuan dari penelitian ini yaitu untuk mendapatkan isolat bakteri yang bersimbion dengan ascidian Herdmania momus, kemudian mengamati aktivitas antibakteri dari isolat bakteri tersebut terhadap Escherichia coli, dan Staphylococcus aureus. Isolasi dan kultur bakteri yang bersimbion dengan ascidian dibuat pada media Nutrient Agar dan Zobell Marine Broth. Skrining aktivitas antibakteri menunjukkan isolat bakteri yang bersimbion dengan ascidian Herdmania momus mampu menghambat pertumbuhan organisme uji Staphylococcus aureus dan Escherichia coli.Kata kunci: ascidian, Herdmania momus, bakteri, isolasi, antibakteri

scholarly journals Antibiotic-Mediated Modulations of Outer Membrane Vesicles in Enterohemorrhagic Escherichia coli O104:H4 and O157:H7

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Andreas Bauwens ◽  
Lisa Kunsmann ◽  
Helge Karch ◽  
Alexander Mellmann ◽  
Martina Bielaszewska
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Shiga Toxin ◽  
Membrane Vesicles ◽  
Polymyxin B ◽  
Outer Membrane Vesicles ◽  
Enterohemorrhagic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Major Virulence Factor

ABSTRACT Ciprofloxacin, meropenem, fosfomycin, and polymyxin B strongly increase production of outer membrane vesicles (OMVs) in Escherichia coli O104:H4 and O157:H7. Ciprofloxacin also upregulates OMV-associated Shiga toxin 2a, the major virulence factor of these pathogens, whereas the other antibiotics increase OMV production without the toxin. These two effects might worsen the clinical outcome of infections caused by Shiga toxin-producing E. coli. Our data support the existing recommendations to avoid antibiotics for treatment of these infections.

Comparison of the Elevated Temperature Plate Count (ETPC) and MPN Procedure to Estimate the Densities of Fecal Coliforms and Escherichia coli in Soft-Shell Clams

1977 ◽  
Vol 40 (11) ◽  
pp. 763-764 ◽  
Author(s):  
S. VARGA ◽  
R. E. DOBSON ◽  
R. EARLE
Keyword(s):  
Escherichia Coli ◽  
Elevated Temperature ◽  
Fecal Coliform ◽  
Enterobacter Aerogenes ◽  
Nutrient Agar ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Soft Shell ◽  
Cell Densities

The Elevated Temperature Plate Count procedure of Hefferman and Cabelli was assessed to measure the sanitary quality of soft shell clams. The method, compared to the standard MPN procedure, underestimated the densities of fecal coliforms by about 10%. The estimated cell densities of Escherichia coli and Enterobacter aerogenes in saline suspension were about 20% lower than the estimate obtained on nutrient agar plates. Thus, the fecal coliform standard used in the assessment of sanitary quality of clams would need to be modified when the analysis is conducted by the Elevated Temperature Plate Count procedure.

scholarly journals Structure and Association of Human Lactoferrin Peptides with Escherichia coli Lipopolysaccharide

2004 ◽  
Vol 48 (6) ◽  
pp. 2190-2198 ◽  
Author(s):  
Daniel S. Chapple ◽  
Rohanah Hussain ◽  
Christopher L. Joannou ◽  
Robert E. W. Hancock ◽  
Edward Odell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Bactericidal Activity ◽  
Membrane Surface ◽  
Polymyxin B ◽  
Cd Spectroscopy ◽  
Time Dependent ◽  
Human Lactoferrin ◽  
Lag Phase ◽  
Ligand Interaction

ABSTRACT An 11-amino-acid amphipathic synthetic peptide homologous to a helical region on helix 1 of human lactoferrin HLP-2 exhibited bactericidal activity against Escherichia coli serotype O111, whereas an analogue synthesized with Pro substituted for Met, HLP-6, had greatly reduced antimicrobial activity. The bactericidal activity of HLP-2 was 10-fold greater than that of HLP-6 in both buffer and growth medium by time-kill assays. These assays also showed a pronounced lag phase that was both concentration and time dependent and that was far greater for HLP-2 than for HLP-6. Both peptides, however, were shown to be equally efficient in destabilizing the outer membrane when the hydrophobic probe 1-N-phenylnaphthylamine was used and to have the same lipopolysaccharide (LPS) binding affinity, as shown by polymyxin B displacement. Circular dichroism (CD) spectroscopy was used to study the structure and the organization of the peptides in solution and upon interaction with E. coli LPS. In the presence of LPS, HLP-2 and HLP-6 were found to bind and adopt a β-strand conformation rather than an α-helix, as shown by nonimmobilized ligand interaction assay-CD spectroscopy. Furthermore, this assay was used to show that there is a time-dependent association of peptide that results in an ordered formation of peptide aggregates. The rate of interpeptide association was far greater in HLP-2 LPS than in HLP-6 LPS, which was consistent with the lag phase observed on the killing curves. These results allow us to propose a mechanism by which HLP-2 folds and self-assembles at the outer membrane surface before exerting its activity.

Quantitative proteomic analysis reveals the mechanisms of polymyxin B toxicity to Escherichia coli

Chemosphere ◽  
2020 ◽  
Vol 259 ◽  
pp. 127449 ◽  
Author(s):  
Juan Liu ◽  
Zhiyan Huang ◽  
Bo Ruan ◽  
Huimin Wang ◽  
Meiqing Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Proteomic Analysis ◽  
Polymyxin B ◽  
Quantitative Proteomic Analysis

scholarly journals Polymyxin B–modified upconversion nanoparticles for selective detection of Gram-negative bacteria such as Escherichia coli

2020 ◽  
Vol 44 (11-12) ◽  
pp. 756-761
Author(s):  
Yan Qiao ◽  
Hongchao Geng ◽  
Ning Jiang ◽  
Xingqi Zhu ◽  
Chenyi Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Limit Of Detection ◽  
Polymyxin B ◽  
Upconversion Nanoparticles ◽  
Selective Detection ◽  
Gram Negative Bacteria ◽  
Cationic Antimicrobial Peptide ◽  
Gram Negative ◽  
In Vivo Fluorescence Imaging

Upconversion nanoparticles, Yb,Tm,Fe-doped NaYF4 nanoparticles, are synthesized and modified with polymyxin B for the selective detection of Gram-negative bacteria. Polymyxin B, a cyclic cationic antimicrobial peptide which can specifically bind to the lipopolysaccharides of cell wall of Gram-negative bacteria, such as Escherichia coli, is used to target and bind Gram-negative bacteria. The bacteria are then quantified by measuring the fluorescence intensity of the upconversion nanoparticle–bacteria complexes at 801 nm under 980 nm excitation. A limit of detection of 36 CFU/mL is achieved in the detection of Escherichia coli, and Escherichia coli in soybean milk is successfully detected. The limited autofluorescence and photobleaching properties of the upconversion nanoparticles make the proposed method useful for in vivo fluorescence imaging of Gram-negative bacteria.

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