scholarly journals Postantibiotic and Sub-MIC Effects of Azithromycin and Isepamicin against Staphylococcus aureus and Escherichia coli

1998 ◽  
Vol 42 (2) ◽  
pp. 414-418 ◽  
Author(s):  
F. Fuentes ◽  
J. Izquierdo ◽  
M. M. Martín ◽  
M. L. Gomez-Lus ◽  
J. Prieto
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Infection Model ◽  
Continuous Administration ◽  
E Coli ◽  
Previously Treated ◽  
In Vitro Data

ABSTRACT Investigations of pharmacodynamic parameters (postantibiotic effect [PAE], sub-MIC effects [SMEs], etc.) have been progressively employed for the design of dosing schedules of antimicrobial agents. However, there are fewer in vivo than in vitro data, probably because of the simplicity of the in vitro procedures. In this study, we have investigated the in vitro PAE, SME, and previously treated (postantibiotic [PA]) SME (1/2 MIC, 1/4 MIC and 1/8 MIC) of azithromycin and isepamicin against standard strains ofStaphylococcus aureus and Escherichia coliby using centrifugation to remove the antibiotics. In addition, the in vivo PAE and SME have been studied with the thigh infection model in neutropenic mice. Finally, in vivo killing curves with two dosing schedules were determined to examine whether the PAE can cover the time that antimicrobial agents are below the MIC. The two antimicrobial agents induced moderate-to-high in vitro PAEs, SMEs, and PA SMEs against S. aureus (>8 h) andE. coli (3.38 to >7.64 h). The in vivo PAEs were also high (from 3.0 to 3.6 h), despite the fact that isepamicin had lower times above the MIC in serum. Only azithromycin showed a high in vivo SME against the two strains (1.22 and 1.75 h), which indicated that the in vivo PAEs were possibly overestimated. In the killing kinetics, no great differences (<0.5 log10) were observed between the schedule that took the PAE into account and the continuous administration of doses. These results are comparable with those of other authors and suggest that these antimicrobial agents could be administered at longer intervals without losing effectiveness.

scholarly journals Biological Cost of Single and Multiple Norfloxacin Resistance Mutations in Escherichia coli Implicated in Urinary Tract Infections

2005 ◽  
Vol 49 (6) ◽  
pp. 2343-2351 ◽  
Author(s):  
Patricia Komp Lindgren ◽  
Linda L. Marcusson ◽  
Dorthe Sandvang ◽  
Niels Frimodt-Møller ◽  
Diarmaid Hughes
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Infection Model ◽  
Resistance Mutations ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Tract Infections ◽  
Subsequent Selection

ABSTRACT Resistance to fluoroquinolones in urinary tract infection (UTIs) caused by Escherichia coli is associated with multiple mutations, typically those that alter DNA gyrase and DNA topoisomerase IV and those that regulate AcrAB-TolC-mediated efflux. We asked whether a fitness cost is associated with the accumulation of these multiple mutations. Mutants of the susceptible E. coli UTI isolate Nu14 were selected through three to five successive steps with norfloxacin. Each selection was performed with the MIC of the selected strain. After each selection the MIC was measured; and the regions of gyrA, gyrB, parC, and parE, previously associated with resistance mutations, and all of marOR and acrR were sequenced. The first selection step yielded mutations in gyrA, gyrB, and marOR. Subsequent selection steps yielded mutations in gyrA, parE, and marOR but not in gyrB, parC, or acrR. Resistance-associated mutations were identified in almost all isolates after selection steps 1 and 2 but in less than 50% of isolates after subsequent selection steps. Selected strains were competed in vitro, in urine, and in a mouse UTI infection model against the starting strain, Nu14. First-step mutations were not associated with significant fitness costs. However, the accumulation of three or more resistance-associated mutations was usually associated with a large reduction in biological fitness, both in vitro and in vivo. Interestingly, in some lineages a partial restoration of fitness was associated with the accumulation of additional mutations in late selection steps. We suggest that the relative biological costs of multiple mutations may influence the evolution of E. coli strains that develop resistance to fluoroquinolones.

scholarly journals Evaluation du potentiel antimicrobien et de la toxicité des extraits de Jatropha multifida Linn, (Euphorbiaceae)

2020 ◽  
Vol 151 ◽  
pp. 15550-15558
Author(s):  
Amégninou Agban ◽  
Yao Hoekou ◽  
Passimna Pissang ◽  
Tchadjobo Tchacondo ◽  
Komlan Batawila
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Aqueous Extract ◽  
E Coli ◽  
Toxicological Studies ◽  
Jatropha Multifida

Objectif : L’objectif de ce travail était d’évaluer in vitro l’activité antimicrobienne des extraits de feuilles et tige de Jatropha multifida sur la croissance de Candida albicans, Escherichia coli et Staphylococcus aureus, puis d’évaluer in vivo la toxicité de cette plante. Méthodologie et résultats : Les méthodes de diffusion en milieu gélosé et de microdilution en milieu liquide ont été utilisées pour évaluer l’effet antimicrobien. Une étude en subaigüe était réalisée afin d’explorer les effets toxiques de l’extrait aqueux des feuilles. Les résultats des tests antimicrobiens montrent une activité des extraits de feuilles et tige de J. multifida sur la croissance des souches utilisées avec des diamètres de zones d’inhibition allant de 8 à 25 mm et des concentrations minimales inhibitrices (CMI) variant de 0,039 mg/mL à 1,25 mg/mL à l’exception des souches de E. coli qui sont résistantes aux extraits de la tige. L’administration en subaigüe de l’extrait aqueux des feuilles de J. multifida à la dose de 600 mg/kg entraîne une perte significative de poids chez les souris. Conclusion et applications des résultats : Les extraits aqueux, éthanolique et hydroéthanolique des feuilles et tige de J. multifida possèdent d’activité antimicrobienne et pourraient être utilisés dans le traitement des Candidoses à C. albicans et des infections à S. aureus. Mais l’essai de toxicité subaigüe montre que l’extrait aqueux de la plante serait toxique. Des études toxicologiques approfondies restent donc nécessaires sur ces extraits afin de mieux élucider leur inocuité. Mots-clés : Jatropha multifida, extraits de feuilles et de tige, activités antifongique et antibactérienne, toxicité. Agban et al., J. Appl. Biosci. 2020 Evaluation du potentiel antimicrobien et de la toxicité des extraits de Jatropha multifida Linn, (Euphorbiaceae) 15551 Evaluation of antimicrobial potential and toxicity of Jatropha multifida Linn, (Euphorbiaceae) extracts ABSTRACT Objective: The objective of this study was to evaluate in vitro the antimicrobial activity of leaves and stem of Jatropha multifida extracts against Candida albicans, Escherichia coli and Staphylococcus aureus, and then to evaluate in vivo the toxicity of this plant. Methodology and Results: The agar well-diffusion and the NCCLS broth microdilution methods were used to assess the antimicrobial effect. A subacute study was carried out to explore the toxic effects of the aqueous extract of the leaves. The results of the antimicrobial tests show an activity of the extracts of leaves and stems of J. multifida on the growth of the strains used with diameters of inhibitory zones ranging from 8 to 25 mm and minimum inhibitory concentrations (MIC) varying from 0.039 mg/mL to 1.25 mg/mL exception E. coli strains which are resistant to extracts from the stem. Subacute administration of the aqueous extract of the leaves of J. multifida at a dose of 600 mg/kg leads to a significant loss of weight in the mice. Conclusion and application of findings : The aqueous, ethanolic and hydroethanolic extracts of the leaves and stem of J. multifida have antimicrobial activity and could be used in the treatment of Candidiasis and bacterial infections due respectively to C. albicans and S. aureus. But the subacute toxicity test shows that the aqueous extract of the plant would be toxic. Extensive toxicological studies therefore remain necessary on these extracts in order to better elucidate their safety. Keywords: Jatropha multifida extracts of leaves and stem, antifungal and antibacterial activities, toxicity

scholarly journals Structure-activity relationships of 3-substituted-5,5- diphenylhydantoins as potential antiproliferative and antimicrobial agents

2011 ◽  
Vol 76 (12) ◽  
pp. 1597-1606 ◽  
Author(s):  
Nemanja Trisovic ◽  
Bojan Bozic ◽  
Ana Obradovic ◽  
Olgica Stefanovic ◽  
Snezana Markovic ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Human Colon ◽  
Antibacterial Activities ◽  
E Coli ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Almost All

A series of twelve 3-substituted-5,5-diphenylhydantoins was synthesized, including some whose anticonvulsant activities have already been reported in the literature. Their antiproliferative activities against HCT-116 human colon carcinoma cells were evaluated to determine structure-activity relationships. Almost all of the compounds exhibited statistically significant antiproliferative effects at a concentration of 100 ?M, while the derivative bearing a benzyl group was active even at lower concentrations. Moreover, their in vitro antibacterial activities against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and clinical isolates of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus were evaluated. Only the 3-iso-propyl and 3-benzyl derivatives showed weak antibacterial activities against the Gram-positive bacterium E. faecalis and the Gram-negative bacteria E. coli ATCC 25922 and E. coli.

scholarly journals Determinación de la cinética, pruebas de crecimiento y efecto de inhibición in vitro de Lactobacillus casei en Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae y Escherichia coli

2015 ◽  
Vol 62 (2) ◽  
Author(s):  
Henry Jurado-Gámez ◽  
Manuel Gúzman-Insuasty
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Streptococcus Agalactiae ◽  
Staphylococcus Epidermidis ◽  
Lactobacillus Casei ◽  
E Coli

<p>Se determinó la cinética, pruebas de crecimiento y el efecto de inhibición <em>in vitro</em> de <em>Lactobacillus casei</em> sobre <em>Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae </em>y<em> Escherichia coli</em>. Se usaron cepas de casa comercial y cepas aisladas en la Vereda La Victoria, Corregimiento de Catambuco al suroccidente del municipio de Pasto, Nariño, Colombia. Se evaluó el efecto de los antibióticos Dicloxacilina, Cefepima, Cefalotina, Ciprofloxacina, Gentamicina, Penicilina, Trimetropim Sulfa y Ampicilina. Se evaluó la inhibición producida por <em>L. casei</em> y su sobrenadante sobre las bacterias patógenas. El crecimiento de la bacteria láctica se evaluó con tres niveles de pH (2,5, 4,5 y 7),  tres concentraciones de sales biliares (0,5, 1 y 2%) y dos de bilis bovina (1 y 1,2%), y dos temperaturas (38 y 45°C). Igualmente se determinó la cinética de crecimiento y las variables pH, azúcar total, proteína y ácido láctico.  Mediante HPLC se determinaron los péptidos y los ácidos orgánicos presentes en el sobrenadante. <em>L. casei </em>mostró susceptibilidad a la Ciprofloxacina y Ampicilina, mientras que <em>S. aureus </em>mostró susceptibilidad y resistencia a todos los antibióticos para la cepa comercial y aislada respectivamente, el mismo comportamiento se presentó con <em>S. epidermidis</em>. Las cepas de <em>S. agalactiae</em> y <em>E. coli</em> aisladas y comerciales mostraron susceptibilidad a los antibióticos.  La cepa láctica mostró un efecto de inhibición de <em>S. aureus</em>, <em>S. epidermidis</em> y  <em>S. agalactiae</em>, pero no fue efectiva con <em>E. coli</em>, igual comportamiento se observó con el uso del sobrenadante de la bacteria láctica. Se encontró crecimiento de 1 x 10<sup>10</sup> y 5,1 x 10<sup>7</sup> UFC/ml para 1 y 1,2 % de bilis bovina; 2,3 x 10<sup>7</sup>, 1 x 10<sup>9</sup> y 3 x 10<sup>8</sup> UFC/ml para 0,5, 1 y 2 % de sales biliares respectivamente; 1,1 x 10<sup>11</sup>, 2,0 x 10<sup>10</sup> y 1,0 x 10<sup>10</sup> UFC/ml para  pH de 2,5, 4,5 y 7 respectivamente. La fase exponencial se encontró a 16:48 horas con un crecimiento de 3 x 10<sup>10</sup> UFC/ml. La variables pH, azúcar, acidez y proteína durante la fase exponencial fueron de 4,94, 0,88 mg/l, 2,89 mg/l y 1,9 mg/l, respectivamente. La prueba de HPLC para péptidos mostró la presencia de una cadena VAL-TIR-VAL y para ácidos orgánicos se encontró una producción de 83,46% de ácido láctico. <em>L. casei </em> mostró buenas características probiótica que permitirían su aplicación en ensayos in vivo para el control de microorganismos causantes de mastitis subclínica en vacas.</p>

scholarly journals In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella Typhimurium, Escherichia coli and Staphylococcus aureus

2019 ◽  
Author(s):  
Md Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Phenolic Compounds ◽  
Phenolic Compound ◽  
Virulence Factors ◽  
In Vitro Cytotoxicity ◽  
E Coli ◽  
And Staphylococcus Aureus

Abstract Background: Bacteria have remarkable abilities to acquire resistance against antibiotics by several mechanisms. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. This study aimed to increase the efficacy of existing antibiotics by combining them with the opportunistic phenolic compound gallic acid (GA) and its derivatives. Fractional inhibitory concentration (FIC) indexes of phenolic compound-antibiotic combinations against Salmonella enterica serovar Typhimurium, Escherichia coli and Staphylococcus aureus were determined. Based on the FIC indexes and clinical importance, 3 combinations were selected to evaluate their effects on the virulence factors of these bacteria. The in vitro cytotoxicity of GA and hamamelitannin in the Rattus norvegicus (IEC-6) cell line were evaluated. Results: Phenolic compounds demonstrated considerable antibacterial effects as the minimum inhibitory concentrations (MICs) of epigallocatechin, GA and hamamelitannin found against different strains were (32–1024), (128–1024) and (512–≥2048) μg/mL, respectively. The FIC indexes of the combined antibacterials against these strains were 0.281–1.016. The ultrastructural morphology and time-kill assays showed that the GA-ceftiofur combination, and hamamelitannin-erythromycin and GA-ampicillin combinations more efficiently inhibited the growth of S. Typhimurium and E. coli, respectively, compared to the individual antibiotics. Biofilm viability and the swimming and swarming motilities of S. Typhimurium in the presence of GA-ceftiofur and E. coli in the presence of the hamamelitannin-erythromycin and GA-ampicillin combinations were more competently inhibited than individual antimicrobials. The 50% inhibitory concentrations (IC50) of GA and hamamelitannin in IEC-6 cells were 564.55 μM and 988.54 μM, respectively. Conclusions: The phenolic compounds increase the efficacy of existing antibiotics might be by disrupting virulence factors. We can conclude that these antibacterial combinations are safe and can be potential medications to treat S. Typhimurium, E. coli and S. aureus infections in animals and humans. Further study to confirm this effect in in vivo system and to determine the precise mechanism of action should be undertaken to establish these combinations as medications.

scholarly journals Synergy between Florfenicol and Aminoglycosides against Multidrug-Resistant Escherichia coli Isolates from Livestock

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 185 ◽  
Author(s):  
Shukho Kim ◽  
Jung Hwa Woo ◽  
So Hyun Jun ◽  
Dong Chan Moon ◽  
Suk-Kyung Lim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effect ◽  
Antimicrobial Agents ◽  
Alternative Therapy ◽  
Multidrug Resistant ◽  
Combination Regimen ◽  
E Coli ◽  
Effective Combination

The increasing prevalence of antimicrobial resistance and the laborious development of novel antimicrobial agents have limited the options for effective antimicrobial therapy. The combination of previously used antimicrobial agents represents an alternative therapy for multidrug-resistant (MDR) pathogens. The objective of this study was to investigate the synergistic effect of a florfenicol (FFL)-based combination with other antimicrobial agents against MDR Escherichia coli isolates from livestock using checkerboard assays and murine infection models. The FFL/amikacin (AMK) and FFL/gentamicin (GEN) combinations showed synergy against 10/11 and 6/11 MDR E. coli isolates in vitro, respectively. The combination of FFL with aminoglycosides (AMK or GEN) exhibited a better synergistic effect against MDR E. coli isolates than the cephalothin (CEF)/GEN or FFL/CEF combinations. The combination of FFL with AMK or GEN could reduce the emergence of resistant mutants in vitro. The FFL/AMK combination showed a higher survival rate of mice infected with MDR E. coli isolates than FFL or AMK alone. In summary, the combination of FFL with aminoglycosides (AMK or GEN) is highly effective against MDR E. coli isolates both in vitro and in vivo. Our findings may contribute to the discovery of an effective combination regimen against MDR E. coli infections in veterinary medicine.

scholarly journals Συνδυασμός αντιβιοτικών με μεταλλικά ιόντα σε μια ενιαία οντότητα για στοχευμένη θεραπεία στον καρκίνο του μαστού

2021 ◽  
Author(s):  
Μαρία Χρυσούλη
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Artemia Salina ◽  
E Coli ◽  
Ft Ir ◽  
Cetrimonium Bromide ◽  
Mcf 7

Συντέθηκε και χαρακτηρίστηκε πλήρως το νέο μεταλλοθεραπευτικό Ph2Sn(CIP)2 (CIPTIN) (HCIP = σιπροφλοξασίνη) από την αντίδραση του εμπορικά διαθέσιμου αντιβιοτικού υδροχλωριωμένη σιπροφλοξασίνη (HCIP·HCl) με το άλας του διφαινυλοδιχωροκασσιτέρου (Ph2SnCl2 DPTD). Επίσης απομονώθηκε και λύθηκε η κρυσταλλική δομή του εσωτερικού άλατος της σιπροφλοξασίνης (HCIP). Στη συνέχεια, με σκοπό να ενισχυθεί η υδατοδιαλυτότητα και κατ’ επέκταση η βιολογική δράση και η βιοδιαθεσιμότητα του CIPTIN και του DPTD, παρασκευάστηκαν τα μικκύλια SLS@CIPTIN, CTAB@CIPTIN, SLS@DPTD και CTAB@DPTD (SLS = sodium lauryl sulphate and CTAB = cetrimonium bromide).Το νέο μεταλλοθεραπευτικό χαρακτηρίστηκε σε στερεά κατάσταση με μελέτη της περίθλασης ακτίνων Χ (XRD), ανάλυση της περίθλασης ακτίνων Χ κόνεως (XRPD), φασματοσκοπία φθορισμού ακτίνων Χ (XRF), φασματοσκοπία υπερύθρου (FT-IR), φασματοσκοπία 119Sn Mössbauer, θερμική ανάλυση (TG / DTA), διαφορική θερμιδομετρία σάρωσης (DSC), μελέτη του σημείου τήξεως και σε υγρή κατάσταση με φασματοσκοπία υπεριώδους-ορατού (UV-VIS), φασματοσκοπία πυρηνικού μαγνητικού συντονισμού πρωτονίου (1Η-NMR) και με φασματοσκοπία μάζας ιοντικού ηλεκτροψεκασμού (ESI-MS). Ο χαρακτηρισμός των μικκυλίων πραγματοποιήθηκε με μελέτη του σημείου τήξεως, με φασματοσκοπία φθορισμού ακτίνων Χ, υπερύθρου, 119Sn Mössbauer, πυρηνικού μαγνητικού συντονισμού πρωτονίου, με θερμική ανάλυση και με διαφορική θερμιδομετρία σάρωσης. Η αντιπολλαπλασιαστική δράση του CIPTIN και των μικκυλίων SLS@CIPTIN, CTAB@CIPTIN, SLS@DPTD και CTAB@DPTD, μελετήθηκε έναντι των ανθρώπινων καρκινικών κυτταρικών σειρών του μαστού: MCF-7 (εκφράζουν οιστρογονικούς υποδοχείς) και MDA-MB-231 (δεν εκφράζουν οιστρογονικούς υποδοχείς). Η τοξικότητα των ενώσεων ελέγχθηκε in vitro έναντι φυσιολογικών κυττάρων MRC-5 και in vivo με το ζωικό μοντέλο Artemia Salina, ενώ η πιθανή γονοτοξικότητα ελέγχθηκε in vitro με μελέτη των μικροπυρηνίσκων και in vivo με τη βοήθεια του μοντέλου Allium cepa. Οι μελέτες της μορφολογίας των κυττάρων, του κυτταρικού κύκλου και του κατακερματισμού του πυρηνικού DNA που πραγματοποιήθηκαν σε κύτταρα MCF-7 μετά την επώασή τους με τις ενώσεις που συντέθηκαν και αποδεικνύουν ότι οι νέες ενώσεις προκαλούν κυτταρικό θάνατο μέσω απόπτωσης. Ταυτόχρονα, οι μελέτες της διαπερατότητας της μιτοχονδριακής μεμβράνης αποκάλυψαν ότι οι νέες ενώσεις προκαλούν απόπτωση μέσω της επίδρασής τους στα μιτοχονδριακά μονοπάτια των κυττάρων. Επιπλέον, μελετήθηκε η αλληλεπίδραση των ενώσεων με το DNA, καθώς και η αντιμικροβιακή δράση των νέων ενώσεων έναντι των βακτηριακών στελεχών Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) και Staphylococcus epidermidis (S. epidermidis), με προσδιορισμό της ελάχιστης ανασταλτικής συγκέντρωσης (MIC), της ελάχιστης βακτηριοστατικής συγκέντρωσης (MBC), των ζωνών αναστολής (IZs) και της επίδρασης των ενώσεων στο σχηματισμό βακτηριακού βιοφίλμ. Τέλος, διερευνήθηκε η σχέση μεταξύ της αντικαρκινικής και της αντιμικροβιακής δράσης που επιδεικνύουν οι βιοδραστικές ενώσεις.

scholarly journals In Vitro and In Vivo Biological Activity of Berberine Chloride against Uropathogenic E. coli Strains Using Galleria mellonella as a Host Model

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5010
Author(s):  
Giulio Petronio Petronio ◽  
Marco Alfio Cutuli ◽  
Irene Magnifico ◽  
Noemi Venditti ◽  
Laura Pietrangelo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Galleria Mellonella ◽  
Biological Activities ◽  
Antibacterial Properties ◽  
In Vivo Model ◽  
Infection Model ◽  
E Coli ◽  
Urinary Infections

Berberine is an alkaloid of the protoberberine type used in traditional oriental medicine. Its biological activities include documented antibacterial properties against a wide variety of microorganisms; nonetheless, its use against Escherichia coli strains isolated from urinary infections has not yet been widely investigated in vivo. The emergence of antimicrobial resistance requires new therapeutic approaches to ensure the continued effectiveness of antibiotics for the treatment and prevention of urinary infections. Moreover, uropathogenic Escherichia coli (UPEC) has developed several virulence factors and resistance to routine antibiotic therapy. To this end, several in vitro and in vivo tests were conducted to assess the activity of berberine on uropathogenic E. coli strains. Galleria mellonella as an infection model was employed to confirm the in vivo translatability of in vitro data on berberine activity and its influence on adhesion and invasion proprieties of E. coli on human bladder cells. In vitro pre-treatment with berberine was able to decrease the adhesive and invasive UPEC ability. In vivo treatment increased the larvae survival infected with UPEC strains and reduced the number of circulating pathogens in larvae hemolymph. These preliminary findings demonstrated the efficacy and reliability of G. mellonella as in vivo model for pre-clinical studies of natural substances.

Experimental model of vaginal dysbiosis treatment with fraction of serum antimicrobial peptides

2019 ◽  
pp. 141-147
Author(s):  
В.Г. Арзуманян ◽  
А.М. Иксанова ◽  
Т.А. Артемьева ◽  
Л.М. Бутовченко ◽  
Е.Т. Мальбахова
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Antimicrobial Peptides ◽  
Drug Treatment ◽  
Bromocresol Purple ◽  
E Coli ◽  
In Vivo Experiments

Широкое использование антибиотиков и противогрибковых препаратов при лечении дисбиозов влагалища сопровождается появлением резистентных штаммов микроорганизмов. В этой связи актуальной является разработка новых препаратов, в частности, основанных на натуральных антимикробных пептидах (АМП), отличающихся более широким спектром действия и высокой активностью. Цель работы - изучение возможности использования сывороточных АМП в лечении вагинальных дисбиозов различной этиологии на мышиной модели. Методика. Активность АМП фракции сыворотки крови кролика оценивали в опытах in vitro и in vivo. В первом случае проверяли действие АМП на клетки Candida albicans, Escherichia coli и Staphylococcus aureus спектрофотометрическим методом. Данный метод основан на поглощении красителя бромкрезолового пурпурного клетками с нарушенной цитоплазматической мембраной и, как результат, снижении оптической плотности надосадочной жидкости в опытных вариантах по сравнению с контрольными. Во втором случае оценивали лечебный эффект концентрированного препарата сывороточных АМП на мышах, зараженных интравагинально теми же культурами. После заражения мышей пролечивали введением препарата тем же путем, а результат оценивали методом высевов из влагалища на селективные среды. Результаты. Установлено, что наиболее выраженное действие в опытах in vitro сывороточные АМП оказывали на клетки C. albicans (активность составила 32,9 % от контроля), тогда как менее выраженный эффект имел место в отношении E. coli (23,3 %) и S. aureus (14,4 %). Аналогичная закономерность имела место и в опытах in vivo: высев C. albicans после лечения препаратом АМП составил 44,6% от исходного в сравнении с 42,2% после лечения пимафуцином и 90,2% без лечения (плацебо); высев E. coli - 65,6% от исходного в сравнении с 26,3% после лечения метронидазолом и 94,8% в варианте плацебо; высев S. aureus - 76,9% от исходного в сравнении с 11,4% после лечения клиндамицином и 73,0% в варианте плацебо. Заключение. Наибольшей чувствительностью к сывороточным АМП среди изученных видов обладали клетки C. albicans, а наименьшей - S. aureus, причем как в опытах in vitro, так и in vivo. Препарат на основе АМП фракции сыворотки крови можно рассматривать как альтернативу традиционным препаратам при лечении вагинальных дисбиозов, особенно вульвовагинального кандидоза. Extensive use of antibiotics and antimycotics in the treatment of vaginal dysbiosis may result in emergence of resistant microbial strains. Therefore, development of new, broad-spectrum and highly active drugs, particularly based on antimicrobial peptides (AMP) is relevant. The aim of the present study was to evaluate a possibility of using serum AMP in the treatment of vaginal dysbiosis of different etiology on a murine model. Methods. Activity of the AMP fraction of rabbit serum was evaluated in in vitro and in vivo experiments. In the in vitro experiment, the effect of AMP on Candida albicans, Escherichia coli, and Staphylococcus aureus cells was measured spectrophotometrically. This method was based on uptake of the bromocresol purple stain by cytoplasmic membranes of destroyed cells, which resulted in decreased optical density of the supernatant in experimental variants compared to the control. In the in vivo experiments, the therapeutic effect of concentrated serum AMP was evaluated in mice intravaginally infected with the same microbial cultures. The infected mice were treated similarly with the AMP preparation, and the outcome was evaluated using the inoculation of plates with selective media by vaginal material. Results. The serum AMP fraction exerted the most noticeable effect in in vitro experiments on C. albicans cells (activity 32.9 % of control) vs. lower effects on E. coli (23.3 %) and S. aureus (14.4 %). Consistently in the in vivo experiments, the abundance of C. albicans colonies was 44.6% of the initial value after the AMP drug treatment compared to 42.2% after the pimafucin treatment and 90.2% in placebo. The abundance of E. coli colonies after the AMP drug treatment was 65.6% of the initial compared to 26.3% after the metronidazole treatment and 94.8% in placebo; for S. aureus, the abundance was 76.9% (AMP) compared to 11.4% (clindamycin) and 73.0% (placebo). Conclusion. Among the studied microorganisms, C. albicans had the highest susceptibility to serum AMP while S. aureus was the least susceptible both in in vitro and in vivo experiments. Drugs based on the serum AMP preparation may be considered as a possible alternative to traditional medications for the treatment of vaginal dysbiosis, especially for vulvovaginal candidiasis.

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