scholarly journals In Vitro Activity of 3 Commercial Bacteriophage Cocktails Against Salmonella and Shigella spp. Isolates of Human Origin

2018 ◽  
Vol 3 (1) ◽  
pp. 72 ◽  
Author(s):  
Odette J. Bernasconi ◽  
Valentina Donà ◽  
Regula Tinguely ◽  
Andrea Endimiani
Keyword(s):  
Multidrug Resistant ◽  
In Vivo Studies ◽  
Salmonella Spp ◽  
Salmonella Infections ◽  
Shigella Spp ◽  
Resistant Strains ◽  
Emergence Of Resistance ◽  
First Time

Background: Salmonella and Shigella spp. are 2 of the most frequent and deadly enteric bacterial pathogens recorded worldwide. In developing countries Salmonella infections are responsible for many deaths annually and these mortality rates are prone to increase due to the emergence of resistance to antibiotics. In this overall scenario new alternative therapeutic approaches are needed.Methods: For the first time, we investigated the activity of 3 commercial bacteriophage cocktails (INTESTI, Septaphage, PYO) against a collection of contemporary Salmonella spp. (n = 30) and Shigella spp. (n = 20) strains isolated in Switzerland. Phage susceptibility was determined by implementing the spot test.Results: The overall susceptibility of Salmonella spp. to INTESTI and Septaphage was 87% and 77%, respectively. With regard to Shigella spp., the overall susceptibility to INTESTI and Septaphage was 95% and 55%, respectively. PYOwas observed to be active against only 10% of Salmonella spp. but against 95% of Shigella spp.Conclusions: Our results seem promising, especially for the INTESTI biopreparation against Salmonella enterica infections. Nevertheless, such speculation should be supported by further in vivo studies to confirm efficacy and safety of the cocktails. We also emphasize the importance of large in vitro screening analyses aimed to assess the activity of such biopreparations against contemporary multidrug-resistant strains that are emerging worldwide.Keywords: commercial; bacteriophages; Salmonella; Shigella cocktails

Effects of Probiotics in the Management of Infected Chronic Wounds: From Cell Culture to Human Studies

2020 ◽  
Vol 15 (3) ◽  
pp. 193-206
Author(s):  
Brognara Lorenzo ◽  
Salmaso Luca ◽  
Mazzotti Antonio ◽  
Di M. Alberto ◽  
Faldini Cesare ◽  
...  
Keyword(s):  
Chronic Wounds ◽  
Animal Experiments ◽  
Multidrug Resistant ◽  
Preliminary Evidence ◽  
Human Studies ◽  
In Vivo Studies ◽  
Resistant Bacteria ◽  
Keywords Probiotics

Background: Chronic wounds are commonly associated with polymicrobial biofilm infections. In the last years, the extensive use of antibiotics has generated several antibiotic-resistant variants. To overcome this issue, alternative natural treatments have been proposed, including the use of microorganisms like probiotics. The aim of this manuscript was to review current literature concerning the application of probiotics for the treatment of infected chronic wounds. Methods: Relevant articles were searched in the Medline database using PubMed and Scholar, using the keywords “probiotics” and “wound” and “injuries”, “probiotics” and “wound” and “ulcer”, “biofilm” and “probiotics” and “wound”, “biofilm” and “ulcer” and “probiotics”, “biofilm” and “ulcer” and “probiotics”, “probiotics” and “wound”. Results: The research initially included 253 articles. After removal of duplicate studies, and selection according to specific inclusion and exclusion criteria, 19 research articles were included and reviewed, accounting for 12 in vitro, 8 in vivo studies and 2 human studies (three articles dealing with animal experiments included also in vitro testing). Most of the published studies about the effects of probiotics for the treatment of infected chronic wounds reported a partial inhibition of microbial growth, biofilm formation and quorum sensing. Discussion: The application of probiotics represents an intriguing option in the treatment of infected chronic wounds with multidrug-resistant bacteria; however, current results are difficult to compare due to the heterogeneity in methodology, laboratory techniques, and applied clinical protocols. Lactobacillus plantarum currently represents the most studied strain, showing a positive application in burns compared to guideline treatments, and an additional mean in chronic wound infections. Conclusions: Although preliminary evidence supports the use of specific strains of probiotics in certain clinical settings such as infected chronic wounds, large, long-term clinical trials are still lacking, and further research is needed.

scholarly journals Silver Nanoparticles and Their Antibacterial Applications

2021 ◽  
Vol 22 (13) ◽  
pp. 7202
Author(s):  
Tamara Bruna ◽  
Francisca Maldonado-Bravo ◽  
Paul Jara ◽  
Nelson Caro
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Secondary Effects ◽  
Cytotoxic Effects ◽  
Factors Affecting ◽  
Gram Positive Bacteria ◽  
Resistant Strains

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.

scholarly journals Designing P. aeruginosa synthetic phages with reduced genomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diana P. Pires ◽  
Rodrigo Monteiro ◽  
Dalila Mil-Homens ◽  
Arsénio Fialho ◽  
Timothy K. Lu ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Antibacterial Properties ◽  
Genetically Engineered ◽  
In Vivo Studies ◽  
Infection Model ◽  
Promising Therapeutic Approach ◽  
Genes Encoding ◽  
First Time

AbstractIn the era where antibiotic resistance is considered one of the major worldwide concerns, bacteriophages have emerged as a promising therapeutic approach to deal with this problem. Genetically engineered bacteriophages can enable enhanced anti-bacterial functionalities, but require cloning additional genes into the phage genomes, which might be challenging due to the DNA encapsulation capacity of a phage. To tackle this issue, we designed and assembled for the first time synthetic phages with smaller genomes by knocking out up to 48% of the genes encoding hypothetical proteins from the genome of the newly isolated Pseudomonas aeruginosa phage vB_PaeP_PE3. The antibacterial efficacy of the wild-type and the synthetic phages was assessed in vitro as well as in vivo using a Galleria mellonella infection model. Overall, both in vitro and in vivo studies revealed that the knock-outs made in phage genome do not impair the antibacterial properties of the synthetic phages, indicating that this could be a good strategy to clear space from phage genomes in order to enable the introduction of other genes of interest that can potentiate the future treatment of P. aeruginosa infections.

scholarly journals In Vitro and In Vivo Anti-Salmonella Evaluation of Pectin Extracts and Hydrolysates from “Cas Mango” (Spondias dulcis)

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Denis Zofou ◽  
Golda Lum Shu ◽  
Josepha Foba-Tendo ◽  
Merveille Octavie Tabouguia ◽  
Jules-Clement N. Assob
Keyword(s):  
Multidrug Resistant ◽  
Positive Control ◽  
Resistant Bacteria ◽  
Therapeutic Effects ◽  
Diffusion Technique ◽  
Resistant Strains ◽  
Almost All ◽  
Broth Dilution

Background. The threat to human health posed by multidrug-resistant strains of Salmonella typhi (S. typhi) and Salmonella paratyphi (S. paratyphi) is of growing concern. Generally, there has been increasing resistance and even multidrug resistance to almost all classes of antibiotics. This has rendered treatment with antibiotics difficult and costly. The present study investigated the bioactivity of pectin and pectin hydrolysates derived from a local fruit, Spondias dulcis, against four strains of Salmonellae. Methods. Pectin was extracted from alcohol extractives-free peel by acidic hydrolysis at a temperature of 80°C for one hour at pH 2 and 4. The pectin was precipitated with 95% alcohol at an extract to alcohol ratio of 1:10 v/v. Antimicrobial activity was determined using agar well diffusion technique. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined using the broth dilution technique. An in vivo study was then carried out with the bioactive extracts against the most resistant bacteria strain, to fully establish the therapeutic effect of these extracts. Balb/C mice were used, and ciprofloxacin was the positive control antibiotic. The extracts were administered to mice at two doses, 5mg/Kg and 10mg/Kg. The efficacy of extracts in the treatment of typhoid was evaluated based on survival rate, change in body weight, and change in bacteria load. Results. Only one of the extracts (crude pectin pH 2.5) was active against all the Salmonellae by well diffusion, and the growth inhibition varied from 12mm to 15mm at100 μg/ml. Three of the extracts (crude pectin pH 2.5, pH 4, 12h hydrolysate, and pH 4, 1h hydrolysate) had MIC and MBC against all four Salmonellae strains with MIC ranging from 5.68 to 44.45 μg/ml and MBC from 11.36 to 44.45 μg/mL. Three treatments, namely, the pH4-12 hr, hydrolysate at 10mg/Kg and 5mg/Kg, and the pH4-1hr, hydrolysate at 10mg/Kg, had therapeutic effects against Salmonella infection in mice. Conclusion. The present study highlights the potential of pectin oligosaccharides as new source of anti-Salmonella drugs. Further investigations including exploration of mechanism of action of the most active pectin extracts/hydrolysates are envisaged.

scholarly journals Sontochin as a Guide to the Development of Drugs against Chloroquine-Resistant Malaria

2012 ◽  
Vol 56 (7) ◽  
pp. 3475-3480 ◽  
Author(s):  
Sovitj Pou ◽  
Rolf W. Winter ◽  
Aaron Nilsen ◽  
Jane Xu Kelly ◽  
Yuexin Li ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Plasmodium Yoelii ◽  
Significant Activity ◽  
Drug Resistant ◽  
Content Type ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Derivatives Of

ABSTRACTSontochin was the original chloroquine replacement drug, arising from research by Hans Andersag 2 years after chloroquine (known as “resochin” at the time) had been shelved due to the mistaken perception that it was too toxic for human use. We were surprised to find that sontochin, i.e., 3-methyl-chloroquine, retains significant activity against chloroquine-resistant strains ofPlasmodium falciparum in vitro. We prepared derivatives of sontochin, “pharmachins,” with alkyl or aryl substituents at the 3 position and with alterations to the 4-position side chain to enhance activity against drug-resistant strains. Modified with an aryl substituent in the 3 position of the 7-chloro-quinoline ring, Pharmachin 203 (PH-203) exhibits low-nanomolar 50% inhibitory concentrations (IC50s) against drug-sensitive and multidrug-resistant strains andin vivoefficacy against patent infections ofPlasmodium yoeliiin mice that is superior to chloroquine. Our findings suggest that novel 3-position aryl pharmachin derivatives have the potential for use in treating drug resistant malaria.

scholarly journals Is there any association between antibiotic resistance and virulence genes in Enterococcus isolates?

2019 ◽  
Vol 6 (12) ◽  
pp. 310-315
Author(s):  
Nergis Aşgın ◽  
Emre Taşkın
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Automated System ◽  
High Frequencies ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
High Level

Objective: In this study, we aim to determine the frequency of antibiotic resistance and five virulence genes in Enterococcus species and the relationship between antibiotic resistance and virulence genes. Material and Methods: A total of 86 Enterococcus strains isolated from inpatients between 2015 and 2016 were included. Identification and antibiotic susceptibilities of strains were determined using a BD Phoenix fully automated system. The presence of virulence-associated genes (esp, gel E, asa1, hyl, and cyl) were investigated by using PCR method. Results: Of the 86 Enterococcus strains, 53 (61.6%) and 33 (38.4%) were Enterococcus faecium and Enterococcus faecalis, respectively. Vancomycin and high-level gentamicin resistance (HLGR) in E. faecalis strains were 0.6% and 60.6%, respectively. Furthermore, 52 of the 53 E. faecium strains were both vancomycin-resistant and HLGR. The frequency of esp, gel E, asa1, cyl, and hyl was 91.9%, 60.5%, 54.7%, 43%, and 26.7%, respectively.  The asa 1, cyl, and gel E genes were detected at high frequencies in vancomycin-susceptible and non-HLGR strains, whereas hyl gene was detected at high frequencies in vancomycin-resistant and HLGR strains. Conclusion: Virulence genes were more frequent in vancomycin-susceptible and non-HLGR Enterococcus strains than in the resistant strains. Although infections caused by multidrug-resistant strains are difficult to treat, it should be considered that susceptible strains have more virulence genes. This may reduce the in vivo efficacy of drugs and lead to treatment failures. Therefore, in addition to the in vitro susceptibilities of drugs, clinical efficacy should be monitored.

scholarly journals In Vitro Interactions of Echinocandins with Triazoles Against Multidrug-Resistant Candida auris

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S82-S82
Author(s):  
Hamid Badalii
Keyword(s):  
Amphotericin B ◽  
Antifungal Susceptibility ◽  
Multidrug Resistant ◽  
In Vivo Studies ◽  
Synergistic Activity ◽  
Candida Auris ◽  
Unsuccessful Treatment ◽  
In Vitro Interactions

Abstract Background Blood stream infections due to Candida auris are related to a high mortality rate and treatment failure attributed to resistance to fluconazole, voriconazole, amphotericin B, and caspofungin. Thus, the precise identification of agents and in vitro antifungal susceptibility testing is highly recommended. Novel therapeutic strategies, such as combination therapy, are essential for increasing the efficacy and reducing the toxicity of antifungal agents. Therefore, we investigated the in vitro combination of micafungin plus voriconazole against multidrug-resistant C. auris isolated from cases of candidemia. Methods The in vitro interactions between echinocandins and azoles were determined against ten multidrug-resistant Candida auris strains by using a microdilution checkerboard technique. Results Results revealed that MICs range for voriconazole and micafungin were 0.5–8 and 0.25–8 mg/l, respectively. The checkerboard analysis revealed that the combination of micafungin with voriconazole exhibited synergistic activity against all 10 multidrug-resistant C. auris isolates (FICI range: 0.15–0.5). Overall, no antagonistic effects were observed in this experiments. Conclusion In vitro studies have previously suggested that among azoles isavuconazole and posaconazole are more active drugs against C. auris. In addition, the majority of isolates reported are resistant to fluconazole. Remarkably, unsuccessful treatment of C. auris infections with fluconazole, voriconazole, amphotericin B, caspofungin, and anidulafungin has been already on record. Here in we demonstrates that interaction between micafungin with voriconazole exhibited synergistic activity against multidrug-resistant C. auris isolates. It seems that lower concentrations of drugs cause fewer side-effects and improve the treatment outcomes. However, in vivo studies with suitable animal models of C. auris infection is highly recommended. Disclosures All authors: No reported disclosures.

Effect of bovine lactoferrin on the minimum inhibitory concentrations of ampicillin and trimethoprim–sulfamethoxazole for clinical Shigella spp. strains1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal’s usual peer review process.

2012 ◽  
Vol 90 (3) ◽  
pp. 412-416 ◽  
Author(s):  
Susan Mosquito ◽  
Gianina Zegarra ◽  
Claudia Villanueva ◽  
Joaquin Ruiz ◽  
Theresa J. Ochoa
Keyword(s):  
Peer Review Process ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
In Vivo Studies ◽  
Bovine Lactoferrin ◽  
Shigella Boydii ◽  
Microdilution Method ◽  
Shigella Spp ◽  
Resistant Strains

Here, we determined the effect of bovine lactoferrin (bLF) on the minimum inhibitory concentration (MIC) of ampicillin and trimethoprim–sulfamethoxazole in Shigella . Using a microdilution method, the MIC was determined in the presence or absence of bovine lactoferrin (10 mg/mL) on 88 Shigella strains (56 Shigella flexneri , 15 Shigella boydii , 13 Shigella sonnei , and 4 Shigella dysenteriae ) previously isolated from peruvian children <2 years old. A fold change of 2 or more in MIC values was considered significant. For ampicillin, 67 (76%) strains were highly resistant; one-third of the strains (32%) showed a decrease in ampicillin MIC in the presence of LF. This was more typical of MIC values in less resistant strains. For 7 (8%) ampicillin-resistant strains, the decrease in the MIC resulted in the strains reaching the cutoff for susceptible in the presence of bLF. For trimethoprim–sulfamethoxazole, 93% of the isolates (n = 82) were highly resistant and only 4 isolates (5%) decreased their MIC in the presence of bLF. None of the trimethoprim–sulfamethoxazole resistant strains became susceptible in the presence of LF. The decrease in the MIC in the presence of bLF seems to depend on the mechanisms of action of each antibiotic. In vivo studies are needed to further evaluate bLF as a coadjuvant to antibiotic treatment of resistant Shigella.

scholarly journals N-Butyldeoxygalactonojirimycin Induces Reversible Infertility in Male CD Rats

2019 ◽  
Vol 21 (1) ◽  
pp. 301
Author(s):  
Vijayalaxmi Gupta ◽  
Sheri A. Hild ◽  
Sudhakar R. Jakkaraj ◽  
Erick J. Carlson ◽  
Henry L. Wong ◽  
...  
Keyword(s):  
Major Effect ◽  
In Vivo Studies ◽  
Pharmacokinetic Studies ◽  
Male Mice ◽  
Lead Compounds ◽  
Contraceptive Effect ◽  
First Time ◽  
Major Target

This study shows for the first time that an iminosugar exerts anti-spermiogenic effect, inducing reversible infertility in a species that is not related to C57BL/6 male mice. In CD rats, N-butyldeoxygalactonojirimycin (NB-DGJ) caused reversible infertility at 150 mg/kg/day when administered daily as single oral dose. NB-DGJ inhibited CD rat-derived testicular β-glucosidase 2 (GBA2) activity at 10 µM but did not inhibit CD rat-derived testicular ceramide-specific glucosyltransferase (CGT) at doses up to 1000 µM. Pharmacokinetic studies revealed that sufficient plasma levels of NB-DGJ (50 µM) were achieved to inhibit the enzyme. Fertility was blocked after 35 days of treatment and reversed one week after termination of treatment. The rapid return of fertility indicates that the major effect of NB-DGJ may be epididymal rather than testicular. Collectively, our in vitro and in vivo studies in rats suggest that iminosugars should continue to be pursued as potential lead compounds for development of oral, non-hormonal male contraceptives. The study also adds evidence that GBA2, and not CGT, is the major target for the contraceptive effect of iminosugars.

Sign in / Sign up

Export Citation Format

Share Document