Emergence Of Multidrug-resistant Microorganisms Research Articles

Green synthesis of silver nanoparticles through oil: Promoting full-thickness cutaneous wound healing in methicillin-resistant Staphylococcus aureus infections.

Due to the emergence of multi-drug resistant microorganisms, the development and discovery of alternative eco-friendly antimicrobial agents have become a top priority. In this study, a simple, novel, and valid green method was developed to synthesize Litsea cubeba essential oil-silver nanoparticles (Lceo-AgNPs) using Lceo as a reducing and capping agent. The maximum UV absorbance of Lceo-AgNPs appeared at 423 nm and the size was 5–15 nm through transmission electron microscopy result. The results of Fourier transform infrared and DLS showed that Lceo provided sufficient chemical bonds for Lceo-AgNPs to reinforce its stability and dispersion. The in vitro antibacterial effects of Lceo-AgNPs against microbial susceptible multidrug-resistant Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) were determined. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Lceo-AgNPs against E. coli were 25 and 50 μg/ml. The MIC and MBC of Lceo-AgNPs against MRSA were 50 and 100 μg/ml, respectively. The results of scanning electron microscopy showed that the amount of bacteria obviously decreased and the bacteria cells were destroyed by Lceo-AgNPs. In vivo research disclosed significant wound healing and re-epithelialization effects in the Lceo-AgNPs group compared with the self-healing group and the healing activity was better than in the sulfadiazine silver group. In this experiment, Lceo-AgNPs has been shown to have effects on killing multidrug-resistant bacteria and promoting wound healing. This study suggested Lceo-AgNPs as an excellent new-type drug for wound treatment infected with multidrug-resistant bacteria, and now expects to proceed with clinical research.

Recent Advances in the Development and Antimicrobial Applications of Metal-Phenolic Networks.

Due to the abuse of antibiotics and the emergence of multidrug resistant microorganisms, medical devices, and related biomaterials are at high risk of microbial infection during use, placing a heavy burden on patients and healthcare systems. Metal–phenolic networks (MPNs), an emerging organic–inorganic hybrid network system developed gradually in recent years, have exhibited excellent multifunctional properties such as anti‐inflammatory, antioxidant, and antibacterial properties by making use of the coordination between phenolic ligands and metal ions. Further, MPNs have received widespread attention in antimicrobial infections due to their facile synthesis process, excellent biocompatibility, and excellent antimicrobial properties brought about by polyphenols and metal ions. In this review, different categories of biomaterials based on MPNs (nanoparticles, coatings, capsules, hydrogels) and their fabrication strategies are summarized, and recent research advances in their antimicrobial applications in biomedical fields (e.g., skin repair, bone regeneration, medical devices, etc.) are highlighted.

Infecciones en el paciente inmunocomprometido (I). Paciente con tratamiento esteroideo y otros inmunosupresores. Paciente neutropénico

Infections represent one of the main causes of morbidity and mortality in immunosuppressed patients. Prolonged, profound neutropenia is one of the most important risk factors of sepsis and associated mortality. Fever may be the only clinical symptom these patients manifest; it is considered a medical emergency. Glucocorticoids act on various levels of inflammatory and immunological processes, facilitating opportunistic infections. Biological therapies are becoming more and more varied, with effects that remain to be studied. Therefore, the indications must be updated and reviewed periodically. A rapid diagnosis that guides effective treatment is crucial for avoiding infectious complications in these patients. The emergence of multidrug-resistant microorganisms is a challenge to the treatment approach to patients with febrile neutropenia.

<i>In vitro</i> Analysis of the Antimicrobial Properties of Propolis Collected from Jimma, Ethiopia

The effectiveness of antimicrobial drugs becomes uncertain due to the emergence of multidrug resistant microorganisms, which highlights the need for alternative antibacterial agents. Natural products are of great importance in the search for biologically active compounds. The present study aimed at investigating the antibacterial properties of propolis, one of the natural bee products, against <em>S. aureus</em>, <em>P. aeruginosa</em> and <em>E. coli.</em> Propolis was extracted using 30 %, 50 %, 70 %, and 99.9 % ethanol. The <em>in vitro</em> antibacterial activities of propolis extracts were evaluated by the disc diffusion method with concentrations between 500 and 4000 ?g/ml. Among the extracts, the 50 % and 70 % propolis extracts showed strong antibacterial activity against all tested strains with inhibition zones ranging from 6.64 ± 0.15 to 11.99 ± 0.04 mm.<em> P. aeruginosa</em> was sensitive strain to the ethanolic extracts of propolis with the highest inhibition zone diameter of 11.99 ± 0.04 mm. Statistically significant differences in growth inhibition were observed among the types of extracts (30 %, 50 %, 70 % and 99.9 %) against <em>P. aeruginosa</em> (p < 0.05) and <em>E. coli</em> (p < 0.05), but the effect was not significant on <em>S. aureus</em> (p > 0.05). All propolis extracts showed no effect on <em>S. aureus</em> at concentrations below 2000 ?g/ml. Propolis extracts showed a lower zone of inhibition compared to the effect demonstrated by the positive control. Overall, the results indicate that ethanolic extracts of Ethiopian propolis has a promising antibacterial activity which could be of an antibiotic development benefit.

Seaweed-associated heterotrophic bacteria: are they future novel sources of antimicrobial agents against drug-resistant pathogens?

Emergence of multidrug-resistant microorganisms and requirements for novel antimicrobial compounds necessitate exploring newer habitats to develop potential bioactive leads. Culture-contingent analysis of heterotrophic bacterial flora from the seaweeds led to the isolation of bioactive strains possessing potential antibacterial properties against wide-ranging clinical pathogens viz., methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VREfs). Seven of the most active strains belonging to the phylum Firmicutes isolated from a brown seaweed (Phaeophyceae) Sargassum wightii exhibited spot-over-lawn assay guided inhibition zone of larger than 30mm. Integrated phenotypic and genotypic studies have led to the characterization of the seaweed-associated bacteria particularly belonging to the phylum Firmicutes. The organic extracts of the studied bacteria exhibited promising antibacterial properties againstMRSA and VREfs with minimum inhibitory concentration ranging between 6.25 and 12.50μg/mL. Time-kill kinetic profiles of those bacteria displayed rapid bactericidal activity against both E. coli and MRSA, showing a ≥ 3log10 reduction in viable cell count than the initial. Among the studied bioactive Bacillus spp, B. tequilensis MTCC13043 and B. altiitudinis MTCC13046 were found to possess functional polyketide synthase (pks) gene (MW027664 and MW027660) that could be amplified. The outcome of amplified genes encrypting for polyketide synthase in conjunction with antibacterial activities unveiled the broad-spectrum antimicrobial activities of the marine heterotrophic Firmicutes, which could be further used against the emergent problem of antibiotic-resistant bacterial pathogens.

Molecular detection of β-lactamase genes in Klebsiella pneumoniae and Escherichia coli isolated from different clinical sources.

The rising occurrence of infections generated by Escherichia coli and Klebsiella pneumoniae that produce extended-spectrum β-lactamase (ESBL) is reason for concern. Due to the recent emergence of multidrug-resistant microorganisms that develop ESBL. The purpose of this work was to detect the ESBLs in clinical isolates of E. coli and K. pneumoniae. 118 samples of E. coli and 63 isolates of K. pneumoniae were collected from clinical samples. Polymerase chain reaction was used to detect β-lactamase genes (i.e., blaTEM, blaSHV, and blaCTX-M). Phenotypic detection revealed that 48.31% and 85.19% of E. coli and K. pneumoniae produced ESBLs, respectively. Whereas screening of ESBL genes in both bacteria employing a multiplex PCR test revealed that 24.58% of the ESBL-producing E. coli strains contained blaTEM, 50.85% contained blaSHV, and 32.2% contained blaCTX-M. Nevertheless, in K. pneumoniae, 40.74% blaTEM, 35.19% blaSHV, and 64.81% blaCTX-M genes were present. Antimicrobial resistance profiles of E. coli and K. pneumoniae isolates to twenty antibiotics were observed to vary significantly. Additionally, it was determined that the majority of E. coli and K. pneumoniae isolates were multidrug resistant (MDR). Additionally, 80.51% of E. coli isolates were resistant to the AMC antibiotic, while 0.00% were resistant to IPM and MEM. From the other hand, the resistant proportion of K. pneumoniae isolates was heterogeneous, ranging from 69.84% against CAZ to 0.00% against CIP and G antibiotics. The blaSHV gene was the most widespread among different forms of ESBLs in E. coli, but the most common gene in K. pneumoniae isolates was blaCTX-M (64.81%).

Novel Arginine End-Tagging Antimicrobial Peptides to Combat Multidrug-Resistant Bacteria.

The emergence of multidrug-resistant microorganisms has been termed one of the most common global health threats, emphasizing the discovery of new antibacterial agents. To address this issue, we engineered peptides harboring "RWWWR" as a central motif plus arginine (R) end-tagging and then tested them in vitro and in vivo. Our results demonstrate that Pep 6, one of the engineered peptides, shows great potential in combating Escherichia coli bacteremia and the Staphylococcus aureus skin burn infection model, which induces a 62-90% reduction in bacterial burden. Remarkably, after long serial passages of S. aureus and E. coli for 30 days, Pep 6 is still highly efficient in killing pathogens, compared with 64- and 128-fold increase in minimal inhibitory concentrations (MICs) for vancomycin and polymyxin B, respectively. We also found that Pep 6 exhibited robust biofilm-inhibiting activity and eliminated 61.33% of the mature methicillin-resistant Staphylococcus aureus (MRSA) biofilm with concentration in the MIC level. These results suggest that the RWWWR motif and binding of arginine end-tagging could be harnessed as a new agent for combating multidrug-resistant bacteria.

Antimicrobial Peptides: Novel Source and Biological Function With a Special Focus on Entomopathogenic Nematode/Bacterium Symbiotic Complex.

The rapid emergence of multidrug resistant microorganisms has become one of the most critical threats to public health. A decrease in the effectiveness of available antibiotics has led to the failure of infection control, resulting in a high risk of death. Among several alternatives, antimicrobial peptides (AMPs) serve as potential alternatives to antibiotics to resolve the emergence and spread of multidrug-resistant pathogens. These small proteins exhibit potent antimicrobial activity and are also an essential component of the immune system. Although several AMPs have been reported and characterized, studies associated with their potential medical applications are limited. This review highlights the novel sources of AMPs with high antimicrobial activities, including the entomopathogenic nematode/bacterium (EPN/EPB) symbiotic complex. Additionally, the AMPs derived from insects, nematodes, and marine organisms and the design of peptidomimetic antimicrobial agents that can complement the defects of therapeutic peptides have been used as a template.

Biosynthesis of silver nanoparticles for the fabrication of non cytotoxic and antibacterial metallic polymer based nanocomposite system

Nanomaterials have significantly contributed in the field of nanomedicine as this subject matter has combined the usefulness of natural macromolecules with organic and inorganic nanomaterials. In this respect, various types of nanocomposites are increasingly being explored in order to discover an effective approach in controlling high morbidity and mortality rate that had triggered by the evolution and emergence of multidrug resistant microorganisms. Current research is focused towards the production of biogenic silver nanoparticles for the fabrication of antimicrobial metallic-polymer-based non-cytotoxic nanocomposite system. An ecofriendly approach was adapted for the production of silver nanoparticles using fungal biomass (Aspergillus fumigatus KIBGE-IB33). The biologically synthesized nanoparticles were further layered with a biodegradable macromolecule (chitosan) to improve and augment the properties of the developed nanocomposite system. Both nanostructures were characterized using different spectrographic analyses including UV–visible and scanning electron microscopy, energy dispersive X-ray analysis, dynamic light scattering, and Fourier transform infrared spectroscopic technique. The biologically mediated approach adapted in this study resulted in the formation of highly dispersed silver nanoparticles that exhibited an average nano size and zeta potential value of 05 nm (77.0%) and − 22.1 mV, respectively with a polydispersity index of 0.4. Correspondingly, fabricated silver–chitosan nanocomposites revealed a size of 941 nm with a zeta potential and polydispersity index of + 63.2 mV and 0.57, respectively. The successful capping of chitosan on silver nanoparticles prevented the agglomeration of nanomaterial and also facilitated the stabilization of the nano system. Both nanoscopic entities exhibited antimicrobial potential against some pathogenic bacterial species but did not displayed any antifungal activity. The lowest minimal inhibitory concentration of nanocomposite system (1.56 µg ml−1) was noticed against Enterococcus faecalis ATCC 29212. Fractional inhibitory concentration index of the developed nanocomposite system confirmed its improved synergistic behavior against various bacterial species with no cytotoxic effect on NIH/3T3 cell lines. Both nanostructures, developed in the present study, could be utilized in the form of nanomedicines or nanocarrier system after some quantifiable trials as both of them are nonhazardous and have substantial antibacterial properties.

Antimicrobial and Antibiofilm Activities of Essential Oils against Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus (MRSA).

The emergence of multidrug resistant microorganisms represents a global challenge due to the lack of new effective antimicrobial agents. In this sense, essential oils (EOs) are an alternative to be considered because of their anti-inflammatory, antiviral, antibacterial, and antibiofilm biological activities. Therefore, multiple efforts have been made to consider the potential use of EOs in the treatment of infections which are caused by resistant microorganisms. In this study, 15 EOs of both Colombian and introduced aromatic plants were evaluated against pathogenic strains of E. coli O157:H7 and methicillin resistant Staphylococcus aureus (MRSA) in planktonic and sessile states in order to identify relevant and promising alternatives for the treatment of microbial infections. Forty different compounds were identified in the 15 EO with nine of them constituted mainly by oxygenated monoterpenes (OM). EOs from Lippia origanoides, chemotypes thymol, and carvacrol, displayed the highest antibacterial activity against E. coli O157:H7 (MIC50 = 0.9 and 0.3 mg/mL, respectively) and MRSA (MIC50 = 1.2 and 0.6 mg/mL, respectively). These compounds from EOs had also the highest antibiofilm activity (inhibition percentage > 70.3%). Using scanning electron microscopy (SEM), changes in the size and morphology of both bacteria were observed when they were exposed to sub-inhibitory concentrations of L. origanoides EO carvacrol chemotype. EOs from L. origanoides, thymol, and carvacrol chemotypes represented a viable alternative for the treatment of microbial infections; however, the Selectivity Index (SI ≤ 3) indicated that it was necessary to study alternatives to reduce its in vitro cytotoxicity.

An Overview of the Activities of Cefiderocol Against Sensitive and Multidrug- Resistant (MDR) Bacteria.

The need for new therapeutics and drug delivery systems has become necessary owing to the public health concern associated with the emergence of multidrug-resistant microorganisms. Among the newly discovered therapeutic agents is cefiderocol, which was discovered by Shionogi Company, Japan as an injectable siderophore cephalosporin. Just like the other β-lactam antibiotics, cefiderocol exhibits antibacterial activity via cell wall synthesis inhibition, especially in Gram negative bacteria (GNB); it binds to the penicillin-binding proteins, but its unique attribute is that it crosses the periplasmic space of bacteria owing to its siderophore-like attribute; it also resists the activity of β-lactamases. Among all the synthesized compounds with the modified C-7 side chain, cefiderocol (3) presented the best and well-balanced activity against multi-drug resistant (MDR) Gram negative bacteria, including those that are resistant to carbapenem. İn this article, an overview of the recent studies on cefiderocol was presented.

Synthesis and antibiofilm evaluation of 3-hydroxy-2,3-dihydroquinazolin-4(1H)-one derivatives against opportunistic pathogen Acinetobacter baumannii

The emergence of multidrug resistant microorganisms has triggered the impending need for new aitimicrobial strategies. The antivirulence strategy with the benefite of alleviating the drug resistance becomes the focus of research. In this study, 22 quorum sensing inhibitors were synthesized by mimicking the structure of autoinducer and acinetobactin and up to 34% biofilm inhibition was observed with 5u. The biofilm inhibition effect was further demonstrated with extracellular polysaccharides inhibition and synergism with Gentamycin sulphate.

Efficacy and safety of fecal microbiota transplantation for decolonization of intestinal multidrug-resistant microorganism carriage: beyond Clostridioides difficile infection

Persistent reservoirs of multidrug-resistant microorganisms (MDRO) that are prevalent in hospital settings and communities can lead to the spread of MDRO. Currently, there are no effective decolonization strategies, especially non-pharmacological strategies without antibiotic regimens. Our aim was to evaluate the efficacy and safety of fecal microbiota transplantation (FMT) for the eradication of MDRO. A systematic literature search was performed to identify studies on the use of FMT for the decolonization of MDRO. PubMed, EMBASE, Web of Science, and Cochrane Library were searched from inception through January 2019. Of the 1395 articles identified, 20 studies met the inclusion and exclusion criteria. Overall, the efficacy of FMT for the eradication of each MDRO was 70.3% (102/146) in 121 patients from the 20 articles. The efficacy rates were 68.2% (30/44) for gram-positive bacteria and 70.6% (72/102) for gram-negative bacteria. Minor adverse events, including vomiting, diarrhea, abdominal pain, and ileus, were reported in patients who received FMT. FMT could be a promising strategy to eradicate MDRO in patients. Further studies are needed to confirm these findings and establish a comprehensive FMT protocol for standardized treatment.Key messagesThe development of new antibiotics lags behind the emergence of multidrug-resistant microorganisms (MDRO). New strategies are needed.Theoretically, fecal microbiota transplantation (FMT) might recover the diversity and function of commensal microbiota from dysbiosis in MDRO carriers and help restore colonization resistance to pathogens.A literature review indicated that FMT could be a promising strategy to eradicate MDRO in patients.

The Cytotoxic Properties of Some Tricyclic 1,3-Dithiolium Flavonoids.

Background: Due to the emergence of multidrug resistant microorganisms, new classes of antibiotics are needed. In this paper, we present the cytotoxic effects of five tricyclic flavonoids, one of which was previously identified as a potent antimicrobial agent. Methods: All five derivatives were tested against human HOS and MCF7 cancer cell lines using a wound scratch assay. The cytotoxic properties of previously reported flavonoid 4a were also evaluated using the standard MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) and live/dead assays, using NHDF, HOS and MCF7 cell lines. Results: All five derivatives were found to inhibit to some degree the proliferation of cancer cells. 4a was also found to be less toxic towards regular versus cancerous human cells. Moreover, the minimum bactericidal concentration of 4a against Staphylococcus aureus was found to be non-toxic for any of the tested human cell lines. Conclusions: Derivative 4a has the potential of being used as a therapeutic agent against certain microorganisms. Further structure optimization is required for use against tumors.

Novel Approaches for Efficient Antifungal Drug Action.

The emergence of multidrug-resistant microorganisms, as well as fungal infectious diseases that further threaten health, especially in immunodeficient populations, is a major global problem. The development of new antifungal agents in clinical trials is inferior to the incidence of drug resistance, and the available antifungal agents are restricted. Their mechanisms aim at certain characteristics of the fungus in order to avoid biological similarities with the host. Synthesis of the cell wall and ergosterol are mainly targeted in clinical use. The need for new approaches to antifungal therapeutic agents or development alternatives has increased. This review explores new perspectives on mechanisms to effectively combat fungal infections and effective antifungal activity. The clinical drug have a common feature that ultimately causes caspase-dependent cell death. The drugs-induced cell death pathway is associated with mitochondrial dysfunction, including mitochondrial membrane depolarization and cytochrome c release. This mechanism of action also reveals antimicrobial peptides, the primary effector molecules of innate systems, to highlight new alternatives. Furthermore, drug combination therapy is suggested as another strategy to combat fungal infection. The proposal for a new approach to antifungal agents is not only important from a basic scientific point of view, but will also assist in the selection of molecules for combination therapy.

Antimicrobial use in European acute care hospitals: results from the second point prevalence survey (PPS) of healthcare-associated infections and antimicrobial use, 2016 to 2017.

Antimicrobial agents used to treat infections are life-saving. Overuse may result in more frequent adverse effects and emergence of multidrug-resistant microorganisms. In 2016–17, we performed the second point-prevalence survey (PPS) of healthcare-associated infections (HAIs) and antimicrobial use in European acute care hospitals. We included 1,209 hospitals and 310,755 patients in 28 of 31 European Union/European Economic Area (EU/EEA) countries. The weighted prevalence of antimicrobial use in the EU/EEA was 30.5% (95% CI: 29.2–31.9%). The most common indication for prescribing antimicrobials was treatment of a community-acquired infection, followed by treatment of HAI and surgical prophylaxis. Over half (54.2%) of antimicrobials for surgical prophylaxis were prescribed for more than 1 day. The most common infections treated by antimicrobials were respiratory tract infections and the most commonly prescribed antimicrobial agents were penicillins with beta-lactamase inhibitors. There was wide variation of patients on antimicrobials, in the selection of antimicrobial agents and in antimicrobial stewardship resources and activities across the participating countries. The results of the PPS provide detailed information on antimicrobial use in European acute care hospitals, enable comparisons between countries and hospitals, and highlight key areas for national and European action that will support efforts towards prudent use of antimicrobials.

Antimicrobial Efficacy and Chemical Properties of Caryophyllus aromaticus and Origanum majorana Essential Oils Against Foodborne Bacteria Alone and in Combination

Background: Food products need to be protected against pathogenic and non-pathogenic microorganisms. One method is adding antimicrobial agents. Consumers’ tendency to use synthetic additives is drastically decreasing due to their side effects and also the emergence of multidrug resistant microorganisms. Plant essential oils (EOs) are natural antimicrobial compounds which are widely used in food industry. Objective: The objectives were to determine the chemical compositions of Caryophyllus aromaticus and Origanum majorana EOs and also to assess their antimicrobial activities against foodborne bacteria alone and in combination. Materials and Methods: The EOs were analyzed by gas chromatography-mass spectrometry. Antibacterial activities of the EOs against foodborne bacteria were assessed using disc diffusion method. The minimum inhibitory concentration (MIC) values of the EOs were determined by microdilution broth method and then minimum bactericidal concentration (MBC) values were determined. Checkerboard synergy testing was performed to determine the fractional inhibitory concentration index. Then time-kill curves were drawn based on the bacterial population (CFU/mL) against time (h). Results: The major constituents of C. aromaticus were eugenol and carvacrol, while O. majorana had carvacrol, thymol, trans-caryophyllene, and cymene as the main constituents. Zone of inhibition for O. majorana EO was greater than that for C. aromaticus EO. The inhibition zone of O. majorana EO against all the tested bacteria except for Bacillus subtilis was significantly greater than that of streptomycin (P ˂ 0.05). MIC value of the EOs against bacteria was 0.1% except for O. majorana EO against B. subtilis (0.3%). MBC values of C. aromaticus and O. majorana EOs ranged from 0.5% to 1.0% and 0.3% to 0.5% (v/v), respectively. The EOs were more effective on gram-positive bacteria than gram-negative ones. The combination of EOs revealed synergistic activity against Listeria monocytogenes, partial synergistic activity against B. subtilis, and additive effect against Salmonella typhimurium, Escherichia coli O157:H7 and Staphylococcus aureus were indifferent against the combination of EOs. Time–kill curves of the EOs demonstrated strong bactericidal effect against all foodborne bacteria at 6 and 24 hours either alone or in combination. Conclusion: The synergistic, partial synergistic, and additive effects of the combination of C. aromaticus and O. majorana EOs strengthen the antimicrobial activity, expand the spectrum of activity, reduce the concentrations required, decrease the side effects, and prevent the alteration of organoleptic properties of food.

Investigation on the effect of known potent S. aureus NorA efflux pump inhibitors on the staphylococcal biofilm formation

The emergence of multidrug resistant microorganisms has triggered the impending need of developing effective antibacterial strategies.

Rapid Detection of Bacterial Susceptibility or Resistance to Quinolones.

The emergence of multidrug resistant microorganisms together with the decline in discovery and development of new antibiotics is of great concern in health-care policy. In this alarming context, an early and well-tailored antibiotic therapy is a relevant strategy not only to improve clinical outcome but also to avoid appearance and spreading of perilous resistant strains. One of the most common antibiotic classes is fluoroquinolones. They trap the DNA girase and/or topoisomerase IV on the DNA, resulting in DNA fragmentation. We have developed the Micromax® assay to determine, in situ, the integrity of the chromosomal DNA-nucleoid from microorganisms. This was validated as a simple procedure for the rapid assessment of the susceptibility or resistance to quinolones in gram-negative bacteria. After incubating with the quinolone, cells are trapped in an agarose microgel on a slide and incubated with a specific lysing solution to remove the cell wall and visualize the nucleoids under fluorescence microscopy. If the strain is susceptible to the quinolone, the bacterial nucleoids show a halo of diffusing DNA spots of fragmented DNA, whereas they appear intact in the resistant strain. The technical processing is performed in 40 min with practically total sensitivity and specificity.

A Portable 3D Printer System for the Diagnosis and Treatment of Multidrug-Resistant Bacteria

Summary Multidrug-resistant bacteria are a major threat to human health, but broad-spectrum antibiotics are losing efficacy. There is a need to screen a given drug against a bacterial infection outside of the laboratory. To address this need, we have designed and built an inexpensive and easy-to-use 3D-printer-based system that allows easily readable quantitative tests for the performance of antibacterial drugs. The platform creates a sterile diagnostic device by using 3D printing, and the device is filled automatically with growth medium, and then antibiotics are sprayed onto the medium by ink-jet technology. The sample for testing can be introduced via a fluid port, and the printer hot bed is used to incubate the device, allowing operation in the field. Combining advantages from various established tests of antibacterial performance, this allows the comparison of a specific antibiotics and bacteria. Also, this system can create and test several antibiotic formulations for therapeutic use, and we demonstrate this potential by investigating a mixture of pathogens that are only killed by a mixture of drugs.