scholarly journals The Membranotropic Peptide gH625 to Combat Mixed Candida albicans/Klebsiella pneumoniae Biofilm: Correlation between In Vitro Anti-Biofilm Activity and In Vivo Antimicrobial Protection

2021 ◽  
Vol 7 (1) ◽  
pp. 26
Author(s):  
Angela Maione ◽  
Elisabetta de Alteriis ◽  
Federica Carraturo ◽  
Stefania Galdiero ◽  
Annarita Falanga ◽  
...  

The antibiofilm activity of a gH625 analogue was investigated to determine the in vitro inhibition and eradication of a dual-species biofilm of Candida albicans and Klebsiella pneumoniae, two leading opportunistic pathogens responsible for several resistant infections. The possibility of effectively exploiting this peptide as an alternative anti-biofilm strategy in vivo was assessed by the investigation of its efficacy on the Galleria mellonella larvae model. Results on larvae survival demonstrate a prophylactic efficacy of the peptide towards the infection of each single microorganism but mainly towards the co-infection. The expression of biofilm-related genes in vivo showed a possible synergy in virulence when these two species co-exist in the host, which was effectively prevented by the peptide. These findings provide novel insights into the treatment of medically relevant bacterial–fungal interaction.

2020 ◽  
Vol 8 (3) ◽  
pp. 336 ◽  
Author(s):  
Emilia Galdiero ◽  
Valeria Di Onofrio ◽  
Angela Maione ◽  
Edvige Gambino ◽  
Renato Gesuele ◽  
...  

The present study assesses the in vitro antibiofilm potential activity of extracts of wild Allium ursinum and Allium oschaninii. The active ingredients of the extracts were obtained with a technique named Naviglio (rapid solid–liquid dynamic extraction, RSLDE) which is based on an innovative and green solid–liquid extraction methodology. The extracts were tested against models of mono- and polymicrobial biofilm structures of clinically antibiotic-resistant pathogens, Klebsiella pneumoniae ATCC 10031 and Candida albicans ATCC 90028. Biofilms were studied using a static and a dynamic model (microtiter plates and a CDC reactor) on three different surfaces reproducing what happens on implantable medical devices. Antimicrobic activities were determined through minimum inhibitory concentration (MIC), while antibiofilm activity was assessed by minimum biofilm eradication concentration (MBEC) using a crystal violet (CV) biofilm assay and colony forming unit (CFU) counts. Results showed that both Allium extracts eradicated biofilms of the tested microorganisms well; biofilms on Teflon were more susceptible to extracts than those on polypropylene and polycarbonate, suggesting that when grown on a complex substrate, biofilms may be more tolerant to antibiotics. Our data provide significant advances on antibiotic susceptibility testing of biofilms grown on biologically relevant materials for future in vitro and in vivo applications.


2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.


Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 56
Author(s):  
Dalila Mil-Homens ◽  
Maria Martins ◽  
José Barbosa ◽  
Gabriel Serafim ◽  
Maria J. Sarmento ◽  
...  

Klebsiella pneumoniae, one of the most common pathogens found in hospital-acquired infections, is often resistant to multiple antibiotics. In fact, multidrug-resistant (MDR) K. pneumoniae producing KPC or OXA-48-like carbapenemases are recognized as a serious global health threat. In this sense, we evaluated the virulence of K. pneumoniae KPC(+) or OXA-48(+) aiming at potential antimicrobial therapeutics. K. pneumoniae carbapenemase (KPC) and the expanded-spectrum oxacillinase OXA-48 isolates were obtained from patients treated in medical care units in Lisbon, Portugal. The virulence potential of the K. pneumonia clinical isolates was tested using the Galleria mellonella model. For that, G. mellonella larvae were inoculated using patients KPC(+) and OXA-48(+) isolates. Using this in vivo model, the KPC(+) K. pneumoniae isolates showed to be, on average, more virulent than OXA-48(+). Virulence was found attenuated when a low bacterial inoculum (one magnitude lower) was tested. In addition, we also report the use of a synthetic polycationic oligomer (L-OEI-h) as a potential antimicrobial agent to fight infectious diseases caused by MDR bacteria. L-OEI-h has a broad-spectrum antibacterial activity and exerts a significantly bactericidal activity within the first 5-30 min treatment, causing lysis of the cytoplasmic membrane. Importantly, the polycationic oligomer showed low toxicity against in vitro models and no visible cytotoxicity (measured by survival and health index) was noted on the in vivo model (G. mellonella), thus L-OEI-h is foreseen as a promising polymer therapeutic for the treatment of MDR K. pneumoniae infections.


2021 ◽  
Vol 12 ◽  
Author(s):  
Arumugam Priya ◽  
Anthonymuthu Selvaraj ◽  
Dass Divya ◽  
Ramalingam Karthik Raja ◽  
Shunmugiah Karutha Pandian

Early childhood caries (ECC), a severe form of caries due to cross-kingdom interaction of Candida albicans and Streptococcus mutans, is a serious childhood dental disease that affects majority of the children with poor background. The present study investigated the anti-infective potential of thymol against C. albicans and S. mutans dual species for the management of ECC. Thymol, a plant derivative of the monoterpene group, has been well known for its numerous biological activities. Thymol at 300 μg/ml concentration completely arrested growth and proliferation of dual species of C. albicans and S. mutans. Rapid killing efficacy of pathogens, within a span of 2 min, was observed in the time kill assay. In addition, at sub-inhibitory concentrations, thymol effectively diminished the biofilm formation and virulence of both C. albicans and S. mutans such as yeast-to-hyphal transition, hyphal-to-yeast transition, filamentation, and acidogenicity and acidurity, respectively, in single and dual species state. qPCR analysis was consistent with virulence assays. Also, through the invertebrate model system Galleria mellonella, in vivo toxicity and efficacy of the phytocompound was assessed, and it was found that no significant toxic effect was observed. Moreover, thymol was found to be proficient in diminishing the infection under single and dual state in in vivo condition. Overall, the results from the present study illustrate the anti-infective potential of thymol against the ECC-causing dual species, C. albicans and S. mutans, and the applicability of thymol in medicated dentifrice formulation.


2019 ◽  
Vol 14 (18) ◽  
pp. 1545-1557 ◽  
Author(s):  
Ying Gong ◽  
Siwen Li ◽  
Weixin Wang ◽  
Yiman Li ◽  
Wenli Ma ◽  
...  

Aim: To evaluate whether chelerythrine (CHT) exhibited antifungal activity against Candida albicans in vitro and in vivo and to explore the underlying mechanisms. Materials & methods: Broth microdilution assay and Galleria mellonella model were used to evaluate the antifungal effect in vitro and in vivo, respectively. Mechanism studies were investigated by morphogenesis observation, Fluo-3/AM, DCFH-DA and rhodamine6G assay, respectively. Results: CHT exhibited antifungal activity against C. albicans and preformed biofilms with minimum inhibitory concentrations ranged from 2 to 16 μg/ml. Besides, CHT protected G. mellonella larvae infected by C. albicans. Mechanisms studies revealed that CHT inhibited hyphal growth, increased intracellular calcium concentration, induced accumulation of reactive oxygen species and inhibited drug transporter activity. Conclusion: CHT exhibited antifungal activity against C. albicans.


Author(s):  
Gabriela Fernanda Bombarda ◽  
Janaina de Cássia Orlandi Sardi ◽  
Pedro L. Rosalen ◽  
Josy G. Lazarini ◽  
Eder R. Paganini ◽  
...  

Biofilms are organized microbial communities formed from an ecological succession. Biofilm formation functions as a mechanism of virulence and favors the development of diseases, including oral diseases such as dental caries and periodontal disease, in which the microorganisms Streptococcus mutans and Candida albicans are closely related. Previous studies have shown that interactions between S. mutans and C. albicans are associated with the pathogenesis of early childhood caries (ECC). Therefore, there is a great interest in finding new prototypes for antimicrobial drugs, mainly for the development of structural analogues of chalcones, which constitute one of the largest classes of natural products belonging to the flavonoid family and are considered strategic molecules for this purpose.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mei-nian Xu ◽  
Li Li ◽  
Wen Pan ◽  
Huan-xin Zheng ◽  
Meng-lei Wang ◽  
...  

Purpose: Zinc oxide nanoparticles (ZnO-NPs) have exerted antimicrobial properties. However, there is insufficient evaluation regarding the in vivo antifungal activity of ZnO-NPs. This study aimed to investigate the efficacy and mechanism of ZnO-NPs in controlling Candida albicans in the invertebrate Galleria mellonella.Methods:Galleria mellonella larvae were injected with different doses of ZnO-NPs to determine their in vivo toxicity. Non-toxic doses of ZnO-NPs were chosen for prophylactic injection in G. mellonella followed by C. albicans infection. Then the direct in vitro antifungal effect of ZnO-NPs against C. albicans was evaluated. In addition, the mode of action of ZnO-NPs was assessed in larvae through different assays: quantification of hemocyte density, morphology observation of hemocytes, characterization of hemocyte aggregation and phagocytosis, and measurement of hemolymph phenoloxidase (PO) activity.Results: Zinc oxide nanoparticles were non-toxic to the larvae at relatively low concentrations (≤20 mg/kg). ZnO-NP pretreatment significantly prolonged the survival of C. albicans-infected larvae and decreased the fungal dissemination and burden in the C. albicans-infected larvae. This observation was more related to the activation of host defense rather than their fungicidal capacities. Specifically, ZnO-NP treatment increased hemocyte density, promoted hemocyte aggregation, enhanced hemocyte phagocytosis, and activated PO activity in larvae.Conclusion: Prophylactic treatment with lower concentrations of ZnO-NPs protects G. mellonella from C. albicans infection. The innate immune response primed by ZnO-NPs may be part of the reason for the protective effects. This study provides new evidence of the capacity of ZnO-NPs in enhancing host immunity and predicts that ZnO-NPs will be attractive for further anti-infection applications.


2019 ◽  
Author(s):  
L. Blasco ◽  
A. Ambroa ◽  
R. Trastoy ◽  
E. Perez-Nadales ◽  
F. Fernández-Cuenca ◽  
...  

ABSTRACTThe multidrug resistance (MDR) among pathogenic bacteria is jeopardizing the worth of antimicrobials, which had previously changed medical sciences. In this study, we used bioinformatic tools to identify the endolysins ElyA1 and ElyA2 (GH108-PG3 family) present in the genome of bacteriophages Ab1051Φ and Ab1052Φ, respectively. The muralytic activity of these endolysins over MDR clinical isolates (Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae) was tested using the turbidity reduction assay. The minimal inhibitory concentrations (MICs) of endolysin, colistin and their combination were determined using the microdilution checkerboard method. The antimicrobial activity of the combinations was confirmed by time kill curves and in vivo assays in larvae of Galleria mellonella. Our results showed that ElyA1 displayed activity against all 25 strains of A. baumannii and P. aeruginosa tested and against 13 out of 17 strains of K. pneumoniae. No activity was detected when assays were done with endolysin ElyA2. The combined antimicrobial activity of colistin and endolysin ElyA1 yielded a reduction in the colistin MIC for all strains studied, except K. pneumoniae. These results were confirmed in vivo in G. mellonella survival assays. In conclusion, the combination of colistin with new endolysins such as ElyA1 could increase the bactericidal activity and reduce the MIC of the antibiotic, thus also reducing the associated toxicity.IMPORTANCEThe development of multiresistance by pathogen bacteria increases the necessity of the development of new antimicrobial strategies. In this work, we combined the effect of the colistin with a new endolysin, ElyA1, from a bacteriophage present in the clinical strain of Acinetobacter baumannii Ab105. ElyA1 is a lysozyme-like family (GH108-GP3), whose antimicrobial activity was described for first time in this work. Also, another endolysin, ElyA2, with the same origin and family, was characterized but in this case no activity was detected. ElyA1 presented lytic activity over a broad spectrum of strains from A. baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. When colistin was combined with ElyA1 an increase of the antimicrobial activity was observed with a reduced concentration of colistin, and this observation was also confirmed in vivo in Galleria mellonella larvae. The combination of colistin with new endolysins as ElyA1 could increase the bactericidal activity and lowering the MIC of the antibiotic, thus also reducing the associated toxicity.


2021 ◽  
Author(s):  
Willames Martins ◽  
Juliana Cino ◽  
Mei Li ◽  
Michael Lenzi ◽  
Kirsty Sands ◽  
...  

Abstract This study aimed to develop a phage-based approach against Klebsiella pneumoniae sequence type (ST16). Phages were investigated using sewage samples from Brazil, Bangladesh, Saudi Arabia, Thailand and the United Kingdom. After isolation, the bacteriophages were submitted to microbiological, structural and genomic characterisation. The best phages were selected to integrate a phage-cocktail for potential use in humans. In vitro and in vivo experiments were performed to demonstrate the efficiency of this approach using a collection of 56 clinical strains of K. pneumoniae ST16 with distinct genetic backgrounds. Anti-biofilm activity, synergism with meropenem and activity in human body fluids were also evaluated. Fourteen lytic phages were isolated, belonging to Autographiviridae, Ackermannviridae, Demerecviridae, Drexlerviridae, and Myoviridae families. The viruses demonstrated good activity against our collection of K. pneumoniae ST16 at a different range of temperatures but also against other important Klebsiella clones such as ST11, ST15, and ST258. The cocktail Katrice-16 was highly active in vitro against K. pneumoniae ST16 collection consisting of isolates from several disparate countries. It demonstrated good in vivo activity in the Galleria mellonella model, anti-biofilm and synergic activity with meropenem. In addition, we also showed the Katrice-16 activity in human body fluids. Our results reinforce how effective bacteriophages can be, supporting their capacity for human clinical use to combat prevalent antimicrobial resistance bacterial clones.


Sign in / Sign up

Export Citation Format

Share Document