A comparison of the bactericidal efficacy of 18 disinfectants used in the food industry against Escherichia coli O157:H7 and Pseudomonas aeruginosa at 10 and 20 oC

Los péptidos antimicrobianos han atraído mucha atención como nuevos agentes terapéuticos contra enfermedades infecciosas. En este estudio se hizo el diseño racional in silico de 18 péptidos catiónicos con actividad antimicrobiana contra bacterias patógenas resistentes utilizando el programa DEPRAMP desarrollado en el Grupo de Investigación en Bioquímica y Microbiología de la Universidad Industrial de Santander. Posteriormente, los péptidos diseñados se sintetizaron en fase sólida con el método de 9-fluorenilmetoxicarbonilo en medio ácido. Se obtuvieron secuencias cortas de 17 aminoácidos con un grado de pureza entre 95 y 98 %, estructura secundaria de hélice alfa, carga neta catiónica (entre +3 y +6), punto isoeléctrico entre 10,04 y 12,03 e índice de hidropatía entre -0,62 y 1,14. Todos los péptidos antimicrobianos mostraron actividad antibacteriana y bactericida in vitro frente al menos una de las cepas patógenas estudiadas: Escherichia coli O157: H7, Pseudomonas aeruginosa y Staphylococcus aureus resistente a la meticilina. Los péptidos antimicrobianos GIBIM-P5S9K y GIBIM-P5F8W registraron la mejor actividad antibacteriana, alcanzando una concentración mínima inhibitoria (CMI 99) en rangos de 0,5 a 25 μM frente a las tres cepas evaluadas, de las cuales Escherichia coli O157: H7 fue la más sensible frente al péptido antimicrobiano GIBIMP5F8W, con una CMI 99 de 0,5 μM y una concentración mínima bactericida de 10 μM, en tanto que la cepa de Pseudomonas aeruginosa fue la más resistente, con una CMI de más de 100 μM frente a más de cinco péptidos antimicrobianos. La toxicidad de los péptidos sobre los eritrocitos produjo un porcentaje de hemólisis menor al 40 % en concentraciones de 50 μM. Por su parte, en las líneas celulares de carcinoma de pulmón A549 y HepG2, el único compuesto que presentó toxicidad fue GIBIM-P5F8W, presentando un 36% de células viables en concentraciones de 100 μM del péptido en la línea celular A549.

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Oligosaccharides Isolated from MGO™ Manuka Honey Inhibit the Adhesion of Pseudomonas aeruginosa, Escherichia Coli O157:H7 and Staphylococcus Aureus to Human HT-29 cells

Foods ◽

10.3390/foods8100446 ◽

2019 ◽

Vol 8 (10) ◽

pp. 446

Author(s):

Lane ◽

Calonne ◽

Slattery ◽

Hickey

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Pseudomonas Aeruginosa ◽

New Zealand ◽

Anion Exchange Chromatography ◽

Exchange Chromatography ◽

Escherichia Coli O157 ◽

Manuka Honey ◽

Bacterial Killing ◽

Ht 29

Historically, honey is known for its anti-bacterial and anti-fungal activities and its use for treatment of wound infections. Although this practice has been in place for millennia, little information exists regarding which manuka honey components contribute to the protective nature of this product. Given that sugar accounts for over 80% of honey and up to 25% of this sugar is composed of oligosaccharides, we have investigated the anti-infective activity of manuka honey oligosaccharides against a range of pathogens. Initially, oligosaccharides were extracted from a commercially-available New Zealand manuka honey—MGO™ Manuka Honey (Manuka Health New Zealand Ltd)—and characterized by High pH anion exchange chromatography coupled with pulsed amperiometric detection. The adhesion of specific pathogens to the human colonic adenocarcinoma cell line, HT-29, was then assessed in the presence and absence of these oligosaccharides. Manuka honey oligosaccharides significantly reduced the adhesion of Escherichia coli O157:H7 (by 40%), Staphylococcus aureus (by 30%), and Pseudomonas aeruginosa (by 52%) to HT-29 cells. This activity was then proven to be concentration dependent and independent of bacterial killing. This study identifies MGO™ Manuka Honey as a source of anti-infective oligosaccharides for applications in functional foods aimed at lowering the incidence of infectious diseases.

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Escherichia coli O157: H7: Overview of Clinical and Epidemiological Issues

Journal of Food Protection ◽

10.4315/0362-028x-57.7.632 ◽

1994 ◽

Vol 57 (7) ◽

pp. 632-637 ◽

Cited By ~ 15

Author(s):

PHILLIP I. TARR

Keyword(s):

Escherichia Coli ◽

Hemolytic Uremic Syndrome ◽

Food Industry ◽

The United States ◽

Human Infection ◽

Escherichia Coli O157 ◽

Human Pathogen ◽

E Coli ◽

Life Threatening ◽

Uremic Syndrome

Escherichia coli O157:H7 is an important and common human pathogen which causes diarrhea, bloody diarrhea (hemorrhagic colitis) and the life threatening post-diarrheal disorder, hemolytic uremic syndrome (HUS). Escherichia coli O157:H7 produces one or two potent cytotoxins, designated Shiga-like toxins (or verocytotoxins) I and II. While additional serotypes of cytotoxin-producing E. coli may cause human disease, E. coli O157:H7 is the most important such enteric pathogen in the United States. Epidemiologic data suggest that the incidence of hemolytic uremic syndrome is probably increasing. Until data emerge from controlled studies, conservative management of infected patients remains the mainstay of therapy, rather than specific antibacterial or antitoxin therapy. The serious nature of illness caused by E. coli O157:H7 should make prevention of human infection with this pathogen a high priority for the food industry.

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