Resistant Microorganisms Research Articles

Interactive effects of drought and deforestation on multitrophic communities and aquatic ecosystem functions in the Neotropics-a test using tank bromeliads.

Together with the intensification of dry seasons in Neotropical regions, increasing deforestation is expected to exacerbate species extinctions, something that could lead to dramatic shifts in multitrophic communities and ecosystem functions. Recent studies suggest that the effects of habitat loss are greater where precipitation has decreased. Yet, experimental studies of the pure and interactive effects of drought and deforestation at ecosystem level remain scarce. Here, we used rainshelters and transplantation from rainforest to open areas of natural microcosms (the aquatic ecosystem and microbial-faunal food web found within the rainwater-filled leaves of tank bromeliads) to emulate drought and deforestation in a full factorial experimental design. We analysed the pure and interactive effects of our treatments on functional community structure (including microorganisms, detritivore and predatory invertebrates), and on leaf litter decomposition in tank bromeliad ecosystems. Drought or deforestation alone had a moderate impact on biomass at the various trophic level, but did not eliminate species. However, their interaction synergistically reduced the biomass of all invertebrate functional groups and bacteria. Predators were the most impacted trophic group as they were totally eliminated, while detritivore biomass was reduced by about 95%. Fungal biomass was either unaffected or boosted by our treatments. Decomposition was essentially driven by microbial activity, and did not change across treatments involving deforestation and/or drought. Our results suggest that highly resistant microorganisms such as fungi (plus a few detritivores) maintain key ecosystem functions in the face of drought and habitat change. We conclude that habitat destruction compounds the problems of climate change, that the impacts of the two phenomena on food webs are mutually reinforcing, and that the stability of ecosystem functions depends on the resistance of a core group of organisms. Assuming that taking global action is more challenging than taking local-regional actions, policy-makers should be encouraged to implement environmental action plans that will halt habitat destruction, to dampen any detrimental interactive effect with the impacts of global climate change.

Synthesis and characterization of porphyrin-MWCNT nanohybrid and its utilization as an antimicrobial agent against S. aureus and E. coli

In the past two decades, the overuse of antibiotic drugs has increased resistance against various available medications in the market. Therefore, the rise in multi-drug resistant microorganisms poses a formidable global health challenge. So, to cope with these situations, we have synthesized a nanohybrid composed of MWCNT and porphyrin, which could be a suitable alternative. Herein, porphyrin is utilized as a visible light photosensitizer to produce reactive oxygen species, which can cause toxicity for bacteria and, ultimately cell death. We have evaluated the effectiveness of MWCNT-porphyrin nanohybrid against the biofilm of Escherichia coli and Staphylococcus aureus pathogens. The Microdilution method shows a concentration of 62.5 [Formula: see text]g/mL as a MIC50 value, which reduces the population of both organisms by around 50%. This nanohybrid can be used as an efficient substitute for conventional antibiotics to treat local infections.

Enhancing the Antibacterial Impact of Lipopeptide Extracted from Bacillus licheniformis as a Probiotic against MDR Acinetobacter baumannii.

The antibiotic resistance of microorganisms is escalating rapidly. Infections caused by opportunistic pathogens in immunocompromised individuals have prompted researchers to seek for potent and safe antibacterial agents. The purpose of this investigation was to explore the suppression of virulence gene expression, specifically the pga operon genes responsible in biofilm formation in Acinetobacter baumannii, through the utilization of metabolites obtained from probiotic bacteria. To assess the antimicrobial properties, standard strains of five probiotic bacteria were tested against a standard strain of multidrug-resistant (MDR) A. baumannii employing the agar gel diffusion technique. Following the identification of the most potent probiotic strain (Bacillus licheniformis), the existence of its LanA and LanM genes was confirmed using the polymerase chain reaction (PCR) test. High-performance liquid chromatography (HPLC) and fourier-transform infrared spectroscopy (FTIR) techniques were employed to identify the intended metabolite, which was found to be a lipopeptide nature. The minimum inhibitory concentration (MIC) values and anti-biofilm activity of the targeted metabolite were determined using a dilution method in 96-well microplates and field emission scanning electron microscopy (FE-SEM). Real-time PCR (qPCR) was utilized for comparing the expression of pga operon genes, including pgaABCD, in A. baumannii pre- and post-exposure to the derived lipopeptide. The MIC results indicated that the probiotic product inhibited the growth of A. baumannii at concentrations lower than those needed for conventional antibiotics. Furthermore, it was observed that the desired genes' expression decreased due to the effect of this substance. This research concludes that the B. licheniformis probiotic product could be a viable alternative for combating drug resistance in A. baumannii.

Antibacterial, Phytochemical and Toxicological Activities of Garcinia kola Extracts against Multidrug Resistant Clinical Bacteria

Objective: The rise in multiple antibiotic resistant microorganisms has led to a decline in the efficacy of many antibiotics, prompting the investigation of alternative solutions such as medicinal plants. To tackle this concerning issue, this study was undertaken to evaluate the phytochemical composition, antibacterial activity, and toxicological characteristics of Garcinia kola extracts against multidrug-resistant bacteria commonly found in clinical settings. Material-Method: The cold maceration technique was employed to extract the root and leaf of Garcinia kola using water and methanol. The extracts were then subjected to phytochemical screening. To evaluate the extracts' potential to inhibit bacterial growth, five multidrug-resistant isolates were utilized in this study. Agar well assay was used to determine the zones of inhibition. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined using the broth macro dilution technique. Additionally, Brine shrimp lethality assay was conducted to determine the lethal concentration (LC50) of the extracts. The extracts were also combined for synergism. Results: The investigation found that the root extract in methanol had the highest yield at 25.58%. All four extracts contained ten out of the fourteen tested phytochemicals. The methanol leaf and root extracts exhibited the highest and lowest inhibition zones of 20mm and 9mm against Staphylococcus aureus, respectively. The MIC values ranged from 250 to 600 mg/ml, indicating broad-spectrum antibacterial activity. The cytotoxicity test showed a range of 33.03 to 126.3µg/mL for the aqueous and methanol extracts. Conclusion: Although Garcinia kola shows potential as a source of antibacterial compounds, caution should be exercised due to its toxic effects.

Antibiotic resistance of microorganisms isolated from the urine of patients before surgical treatment for benign prostatic hyperplasia: results from a 7-year single-center study

Introduction. The tendency of microorganisms to develop resistance mechanisms is a widely discussed and significant problem worldwide. Studying regional differences in the qualitative characteristics of microorganisms provides valuable information for empirically preventing and treating infectious complications, as well as providing an enhanced understanding of the variability in microbial community properties within the clinical context of diseases and patients' comorbidity status.Objective. To assess the antibiotic resistance of microorganisms isolated in high titers from the urine samples of patients with benign prostate hyperplasia (BPH) prior to surgery.Materials & Methods. This single-center, retrospective study conducted from March 2016 to February 2023 included 59 suprapubic-draining BPH-patients (Group I), 46 drainage-free BPH-patients with leukocyturia (Group II), and 44 drainage-free BPH-patients and no leukocyturia (Group III). Inclusion criteria: indications for BPH surgery, no history of sexually transmitted diseases, no symptoms of urinary tract infection, and no prostate cancer. The patient's voluntary informed consents to participate were also obtained.Results. The rates of resistance to ciprofloxacin in patients of Group I were statistically significantly higher compared to Group II (85.7% vs 55.6%, p = 0.002). Resistance of gram-negative microorganisms to meropenem and imipenem was higher in Group III compared to Group I (31.1% vs 13.7%, p = 0.006 for meropenem and 44.5% vs 9.8%, p = 0.001 for imipenem, respectively). Resistance of Gram-positive microorganisms to ampicillin in Groups I to III was 13.6%,6.3% and 20.0%, respectively with no significant difference between groups (p > 0.05). However, there was extremely high resistance among verified Gram-positive organisms to all the drugs in the fluoroquinolone class (ciprofloxacin, norfloxacin, levofloxacin) ranged from 63.6% to 80.0%.Conclusion. The present study demonstrates that the isolation frequency of antibiotic-resistant microorganisms from the urine sample of drainage-free BPH-patients or no clinical and laboratory signs of inflammation in the urinary tract is high. The presence of antibiotic resistance provides risks for developing difficult-to-control infectious complications. Currently, assessment of urine-derived microbial antibiotic resistance should be considered in every BPH-patient with indications for surgical management of bladder outlet obstruction, regardless of the presence of risk factors.

Detecting Class 1 Integrons and Their Variable Regions in Escherichia coli Whole-Genome Sequences Reported from Andean Community Countries.

Various genetic elements, including integrons, are known to contribute to the development of antimicrobial resistance. Class 1 integrons have been identified in E. coli isolates and are associated with multidrug resistance in countries of the Andean Community. However, detailed information on the gene cassettes located on the variable regions of integrons is lacking. Here, we investigated the presence and diversity of class 1 integrons, using an in silico approach, in 2533 whole-genome sequences obtained from EnteroBase. IntFinder v1.0 revealed that almost one-third of isolates contained these platforms. Integron-bearing isolates were associated with environmental, food, human, and animal origins reported from all countries under scrutiny. Moreover, they were identified in clones known for their pathogenicity or multidrug resistance. Integrons carried cassettes associated with aminoglycoside (aadA), trimethoprim (dfrA), cephalosporin (blaOXA; blaDHA), and fluoroquinolone (aac(6')-Ib-cr; qnrB) resistance. These platforms showed higher diversity and larger numbers than previously reported. Moreover, integrons carrying more than three cassettes in their variable regions were determined. Monitoring the prevalence and diversity of genetic elements is necessary for recognizing emergent patterns of resistance in pathogenic bacteria, especially in countries where various factors are recognized to favor the selection of resistant microorganisms.

Response of nitrification system to co-exposure of sucralose and single or combined disinfectants: Reducing damage to nitrification performance and aggravating the spread of intracellular resistance genes

Sucralose (SUC) is an artificial sweetener for everyday consumption and often co-exists with disinfectants such as triclosan (TCS) and dialkyldimethyl ammonium compound (DAC) in sewage. Considering their continuous accumulation in sewage, it is essential to understand the impacts of their single and combined stress on the evolution of resistance genes (RGs) and microorganisms. In this study, three sequencing batch reactors (SBRs) were established, which were added with SUC, disinfectant, SUC and disinfectant, respectively, and named SSBR, DSBR and SDSBR in turn. There were four stages in total, the first two stages and the latter two stages were set to explore the effects of co-exposure of SUC and single disinfectant (TCS), SUC and combined disinfectants (TCS and DAC) on nitrification system, respectively. SSBR showed excellent ammonia oxidation performance in the whole operation stages. Compared with DSBR, the microorganisms in SDSBR under the combined stress of SUC and TCS were less inhibited. TCS and DAC destroyed the ammonia oxidation performance of DSBR and SDSBR. Within 120 days, the removal efficiency of TCS reached 90 %. In SSBR, 1 mg/L SUC promoted the proliferation of RGs, especially induced free RGs in water (w-RGs) to maintain high abundance and persistence. Compared with single stress, the abundances of intracellular RGs in sludge were higher under the combined stress of SUC and TCS, and the risk of RGs transmission was greater. The combined stress of SUC and disinfectants (TCS and DAC) led to a higher enrichment of w-RGs, exacerbating the risk of w-RGs transmission.

Poly(acid lactic)-montmorillonite clay bionanocomposites loaded with tea tree oil for application in antibacterial wound healing

This study evaluated the ability of tea tree essential oil (TT) incorporated into polymer-clay bionanocomposites to in vitro eliminate resistant microorganisms towards applications in antibacterial wound healing. Antimicrobial bionanocomposites were prepared in two steps, namely sonication and melt intercalation, and montmorillonite clay and poly(acid lactic) (PLA) were chosen because they constitute a polymer-clay bionanocomposite to be applied in wound dressing. X-ray diffraction (XRD) results indicated good incorporation of the organic compounds, TT oil, and glycerol (G) (the latter used as a plasticizer) into the clay galleries. Dynamic-mechanical analysis (DMA) results showed a 2–30 % increase in storage modulus and up to 10 °C decrease in glass transition temperature, proving the influence of both TT oil and G on the stress transfer of the reinforcement clay phase. Thermogravitmetric analyses (TGA) revealed TT oil and G addition worsened the thermal stability of the bionanocomposites, which show a mass loss onset decrease up to 90 °C and a clay content between 1.5 and 3 wt%. In vitro antimicrobial activity tests revealed only the combinations of TT oil and G reduced Escherichia coli and Staphylococcus aureus satisfactorily and showed the antimicrobial activity of the bionanocomposites.

Heat resistance of five spoilage microorganisms in a carbonated broth

Despite their acidic pH, carbonated beverages can be contaminated by spoilage microorganisms. Thermal treatments, before and/or after carbonation, are usually applied to prevent the growth of these microorganisms. However, the impact of CO2 on the heat resistance of spoilage microorganisms has never been studied. A better understanding of the combined impact of CO2 and pH on the heat resistance of spoilage microorganisms commonly found in carbonated beverages might allow to optimize thermal treatment.Five microorganisms were selected for this study: Alicyclobacillus acidoterrestris (spores), Aspergillus niger (spores), Byssochlamys fulva (spores), Saccharomyces cerevisiae (vegetative cells), and Zygosaccharomyces parabailii (vegetative cells). A method was developed to assess the impact of heat treatments in carbonated media on microbial resistance.The heat resistances of the five studied species are coherent with the literature, when data were available. However, neither the dissolved CO2 concentration (from 0 to 7 g/L), nor the pH (from 2.8 to 4.1) have an impact on the heat resistance of the selected microorganisms, except for As. niger, for which the presence of dissolved CO2 reduced the heat resistance. This study improved our knowledge about the heat resistance of some spoilage microorganisms in presence of CO2.

A cellulosomal yeast reaction system of lignin-degrading enzymes for cellulosic ethanol fermentation.

Biofuel production from lignocellulose feedstocks is sustainable and environmentally friendly. However, the lignocellulosic pretreatment could produce fermentation inhibitors causing multiple stresses and low yield. Therefore, the engineering construction of highly resistant microorganisms is greatly significant. In this study, a composite functional chimeric cellulosome equipped with laccase, versatile peroxidase, and lytic polysaccharide monooxygenase was riveted on the surface of Saccharomyces cerevisiae to construct a novel yeast strain YI/LVP for synergistic lignin degradation and cellulosic ethanol production. The assembly of cellulosome was assayed by immunofluorescence microscopy and flow cytometry. During the whole process of fermentation, the maximum ethanol concentration and cellulose conversion of engineering strain YI/LVP reached 8.68g/L and 83.41%, respectively. The results proved the availability of artificial chimeric cellulosome containing lignin-degradation enzymes for cellulosic ethanol production. The purpose of the study was to improve the inhibitor tolerance and fermentation performance of S. cerevisiae through the construction and optimization of a synergistic lignin-degrading enzyme system based on cellulosome.

Identification and biological characteristics of Enterococcus casseliflavus TN-47 isolated from Monochamus alternatus.

With the widespread use of antibiotics, the incidence of antibiotic resistance in microorganisms has increased. Monochamus alternatus is a trunk borer of pine trees. This study aimed to investigate the in vitro antimicrobial and biological characteristics of Enterococcus casseliflavus TN-47 (PP411196), isolated from the gastrointestinal tract of M. alternatus in Jilin Province, PR China. Among 13 isolates obtained from the insects, five were preliminarily screened for antimicrobial activity. E. casseliflavus TN-47, which exhibited the strongest antimicrobial activity, was identified. E. casseliflavus TN-47 possessed antimicrobial activity against Staphylococcus aureus USA300 and Salmonella enterica serovar Pullorum ATCC 19945. Furthermore, E. casseliflavus TN-47 was sensitive to tetracyclines, penicillins (ampicillin, carbenicillin, and piperacillin), quinolones and nitrofuran antibiotics, and resistant to certain beta-lactam antibiotics (oxacillin, cefradine and cephalexin), macrolide antibiotics, sulfonamides and aminoglycosides. E. casseliflavus TN-47 could tolerate low pH and pepsin-rich conditions in the stomach and grow in the presence of bile acids. E. casseliflavus TN-47 retained its strong auto-aggregating ability and hydrophobicity. This strain did not exhibit any haemolytic activity. These results indicate that E. casseliflavus TN-47 has potential as a probiotic. This study provides a theoretical foundation for the future applications of E. casseliflavus TN-47 and its secondary metabolites in animal nutrition and feed.

NEW ANTIMICROBIAL AGENTS IN THE DIHYDROXANTHONE SERIES: ESTABLISHMENT OF STRUCTURE-ACTIVITY RELATIONSHIPS AND STANDARDIZATION

Introduction. Irrational use of antimicrobial drugs, chemical and biological agents leads to the emergence and spread of resistance in microorgan-isms. Therefore, there is an increasing need for the search and development of new antimicrobial compounds. Dihydroxanthone derivatives, which have a wide spectrum of action, are one of the promising groups of antimicrobial substances. New derivatives of 4,4a-dihydroxanthone were obtained at the St. Petersburg State Chemical and Pharmaceutical University (SPCFU) at the Department of Organic Chemistry. Synthetic 4,4a-dihydroxanthones are structurally similar to antimicrobial xanthones of natural origin – fomalevones A and C. Therefore, 4,4a-dihydroxanthones are promising compounds for the creation of new antimicrobial substances. Purpose of the study. To establish the relationship between the chemical structure of the synthesized dihydroxanthones and their antimicrobial ac-tivity and to standardize the active compound. Materials and methods. 20 new derivatives of 4,4a-dihydroxanthone were synthesized. The structure and identity of the compounds was estab-lished using physical and chemical methods of analysis. The antimicrobial activity of these derivatives was studied by double serial dilution method. Quality standards for the most promising compound 5-bromo-7-chloro-4,4-dimethyl-9-oxo-4,4a-dihydroxanthone (a17) were developed. Results. In preliminary studies, we found that 4,4a-dihydroxanthones synthesized in SPCFU have a pronounced effect against gram-positive bacteria. It was found, that the antibacterial activity of 4,4a-dihydroxanthone derivatives depended on their structure. The presence of substituents with acceptor properties led to an increase in activity, while donor substituents reduced the antimicrobial effect of the compounds. 5-Bromo-7-chloro-4,4-dimethyl-9-oxo-4,4a-dihydroxanthone (a17) turned out to be the most active compound, and we carried out its standardization for some indicators. Conclusions. During the study of the antimicrobial activity of the synthesized dihydroxanthones, it was found that they are active against gram-positive bacteria. The antibacterial activity of 4,4a-dihydroxanthone derivatives depends on their structure. Among them, the most active compound was identified – leader a17, which has a pronounced antistaphylococcal effect. Its standardization has been carried out for some indicators.

A Comprehensive Review of Recent Research into the Effects of Antimicrobial Peptides on Biofilms-January 2020 to September 2023.

Microbial biofilm formation creates a persistent and resistant environment in which microorganisms can survive, contributing to antibiotic resistance and chronic inflammatory diseases. Increasingly, biofilms are caused by multi-drug resistant microorganisms, which, coupled with a diminishing supply of effective antibiotics, is driving the search for new antibiotic therapies. In this respect, antimicrobial peptides (AMPs) are short, hydrophobic, and amphipathic peptides that show activity against multidrug-resistant bacteria and biofilm formation. They also possess broad-spectrum activity and diverse mechanisms of action. In this comprehensive review, 150 publications (from January 2020 to September 2023) were collected and categorized using the search terms 'polypeptide antibiotic agent', 'antimicrobial peptide', and 'biofilm'. During this period, a wide range of natural and synthetic AMPs were studied, of which LL-37, polymyxin B, GH12, and Nisin were the most frequently cited. Furthermore, although many microbes were studied, Staphylococcus aureus and Pseudomonas aeruginosa were the most popular. Publications also considered AMP combinations and the potential role of AMP delivery systems in increasing the efficacy of AMPs, including nanoparticle delivery. Relatively few publications focused on AMP resistance. This comprehensive review informs and guides researchers about the latest developments in AMP research, presenting promising evidence of the role of AMPs as effective antimicrobial agents.

Antibiotic Resistance of Foodborne Microorganisms Isolated in the Republic of Tajikistan

Introduction: The sanitary and epidemiological well-being of the population is mainly determined by food quality. The World Health Organization is alarmed by the increasing widespread use of antibiotics in animal, poultry, and fish production. The number of drugs used in agriculture is almost twice as high as the number of those used to treat humans. Objective: To establish antibiotic resistance of microorganisms isolated from food products. Materials and methods: Bacteria isolated from 261 samples of food products (eggs, meat and dairy products) on the territory of the Republic of Tajikistan in 2022 were used as materials for the study. Microorganisms (n = 138) were isolated and identified by the bacteriological method using differential diagnostic media. The phenotypic sensitivity of bacteria to nine antimicrobials was determined by the disc diffusion method (DDM). The statistical significance of the results was assessed by calculating the arithmetic mean (M) and standard error of the mean (m) in Microsoft Excel (2010). Results: A total of 138 Enterobacterales (52.2 %) and Staphylococcus (47.8 %) bacteria were tested. Analysis of the phenotypic profile of antibiotic sensitivity of cultures in the genus Staphylococcus showed that most of them were resistant to kanamycin and rifampicin (66.7 %); 54.6 % and 45.5 % were resistant to ceftriaxone and lincomycin, respectively. About 30 % of the staphylococci were resistant to erythromycin, tobramycin, levofloxacin, and gentamicin, while the share of staphylococci resistant to ciprofloxacin was the smallest (15.2 %). Enterobacteria showed high resistance to kanamycin (94.5 %), more than 61.2 % of cultures were resistant to tobramycin; 41.7 % and 33.4 % of cultures were resistant to ceftriaxone and gentamicin. Conclusion: Our findings demonstrate the importance of continuous surveillance over the spread of antibiotic-resistant bacteria in food products.

Metal-based Nanoparticles in the Treatment of Infectious Diseases

Abstract: Infectious diseases caused by different pathogens are responsible for high mortality across the globe. Multi-drug resistance (MDR) of microorganisms towards different antibiotics has posed a great challenge in treating infectious diseases efficiently. The metal-based nanoparticles (MNPs) have demonstrated great promise in treating infectious diseases because of their inherent antimicrobial potential. Besides, these NPs show site-specific delivery of antibiotic therapeutics, thereby minimizing dose, dose frequency, and side effects. Further, the synergistic effect of MNPs with an antibiotic can reduce the MDR. However, the fabrication of MNPs using an apt fabrication technique with proper control of charge, size, and morphology is highly required to achieve better therapeutic performance. This review focuses on MNPs as a potential avenue to treat infectious diseases. The role of MNPs in combating MDR, different sorts of MNPs, and their fabrication techniques are discussed. Furthermore, assorted types of MNPs employed in antibiotic delivery to treat infectious diseases are discussed with manifold case studies. In short, MNPs alone or as a carrier of antibiotics seems to be an effective strategy in wiping out infectious diseases.

Combination of photodynamic therapy with antibiotic therapy - future or misalliance?

SignificanceThe growing antibiotic resistance of microorganisms is an increasingly important challenge for modern medicine. In the next few decades, the so-called post antibiotic era is likely to begin. For this reason, the search for new solutions using PACT seems particularly promising. ApproachFour new chlorin compounds were tested and photochemically characterized for singlet oxygen generation efficiency and photostability. They have been evaluated for bactericidal properties against MRSA, E. coli (ESBL+) and C. albicans. Their synergism with antibiotics from the group of cephalosporins and carbapenems was evaluated. ResultsA reduction of approximately 3 logs or more was achieved for each of the bacterial strains. A decrease in MIC values was observed for all bacteria, the greatest for ceftriaxone. ConclusionsCombining traditional antibiotic therapy with PACT may be a promising route in the case of antibiotic-resistant infections, but requires further in-depth research.

Antimicrobial resistance and associated risk factors in Escherichia coli isolated from Peruvian dogs: A focus on extended-spectrum β-lactamases and colistin.

Established antimicrobial resistance (AMR) surveillance in companion animals is lacking, particularly in low-middle-income countries. The aim of this study was to analyze AMR and its risk factors in Escherichia coli isolated from dogs at two veterinary centers in Lima (Peru). Ninety dogs were included in the study. Antimicrobial susceptibility was established by disk diffusion, whereas microdilution was used to determine colistin susceptibility. Mechanisms related to extended-spectrum β-lactamases (ESBL) and colistin resistance were determined by polymerase chain reaction. Clonal relationships of colistin-resistant isolates were assessed by XbaI-pulsed-field gel electrophoresis. Thirty-five E. coli strains were isolated. High levels of resistance to ampicillin (57.1%), nalidixic acid (54.3%), tetracycline (48.6%), and azithromycin (25.7%) were detected. Cephalosporin resistance levels were ≥20% and those for colistin were 14.3%. Twelve (34.2%) isolates were ESBL producers; of these, six blaCTX-M-55 (50.0%), 2 (16.6%) blaCTX-M-15, and 2 (16.6%) blaCTX-M-8-like genes were found. The five colistin-resistant isolates were clonally unrelated, with four of them presenting amino acid codon substitutions in the mgrB gene (V8A) or mutations in the mgrB promoter (a12g, g98t, and c89t). Furthermore, dog age, <6 years (p = 0.027) and raw diet (p = 0.054) were associated with resistance to a greater number of antibiotic families. Despite small number of samples included, the study found that dogs studied were carriers of multidrug-resistant E. coli, including last-resort antimicrobials, representing a public health problem due to close contact between dogs and humans. This issue suggests the need for larger studies addressed to design strategies to prevent the spread of resistant micro-organisms in small animal clinics and domestic settings.

The effect of Thymus Vulgaris extracted silver nanoparticles on multi-drug resistant Microorganisms. (Student project)

The effect of Thymus Vulgaris extracted silver nanoparticles on multi-drug resistant Microorganisms. (Student project)

Efektivitas Kunyit (Curcuma longa L.) sebagai Suplemen Pakan Ikan

Feed supplements for aquaculture activities are materials that currently widely used. There are many feed supplements using herbal ingredients, because it is considered more safety for fish. It is based on prohibition of antibiotics usage, because it can create resistance in microorganisms and has a negative impact on environment. Turmeric is a spice that widely used as a feed supplement. Most turmeric is used for cooking ingredient, but it is also widely used in traditional medicine. Several active compounds in turmeric such as curcumin and turmerone have been studied. These active compound have been proven could increase antioxidant and prevent lipid peroxidation, so it can increase the fish growth. Apart from that, this active compound is also useful in inhibiting bacterial growth by damaging membrane and preventing the formation of biofilms.

Nanoencapsulation of natural products and their role in the preservation and control of contaminations in the food industry

Microbial resistance is a problem of high notoriety and importance, being investigated in several scientific areas. Directly correlated to the abuse of macrolides in the pandemic context, the difficulty in eliminating resistant microorganisms and the control of bacterial contamination in an industrial food environment have been increasingly worrying nowadays. The present study demonstrates hypotheses of microbial control using the encapsulation of essential oils and products of natural origin through the technology used in nanocomposites. The aid in the prevention and control of microorganisms with high antimicrobial resistance factors in food industry environments can be seen. Furthermore, new approaches and themes applied in the denaturation of pathogenic biofilms and nanoencapsulation and the use of common metals and transition metals are highlighted.