Resistant Pathogenic Bacteria Research Articles

Antibacterial potential of Euphorbia canariensis against Pseudomonas aeruginosa bacteria causing respiratory tract infections

The widespread dissemination of bacterial resistance has led to great attention being paid to finding substitutes for traditionally used antibiotics. Plants are rich in various phytochemicals that could be used as antibacterial therapies. Here, we elucidate the phytochemical profile of Euphorbia canariensis ethanol extract (EMEE) and then elucidate the antibacterial potential of ECEE against Pseudomonas aeruginosa clinical isolates. ECEE showed minimum inhibitory concentrations ranging from 128 to 512 µg/mL. The impact of ECEE on the biofilm-forming ability of the tested isolates was elucidated using crystal violet assay and qRT-PCR to study its effect on the gene expression level. ECEE exhibited antibiofilm potential, which resulted in a downregulation of the expression of the biofilm genes (algD, pelF, and pslD) in 39.13% of the tested isolates. The antibacterial potential of ECEE was studied in vivo using a lung infection model in mice. A remarkable improvement was observed in the ECEE-treated group, as revealed by the histological and immunohistochemical studies. Also, ELISA showed a noticeable decrease in the oxidative stress markers (nitric oxide and malondialdehyde). The gene expression of the proinflammatory marker (interleukin-6) was downregulated, while the anti-inflammatory biomarker was upregulated (interleukin-10). Thus, clinical trials should be performed soon to explore the potential antibacterial activity of ECEE, which could help in our battle against resistant pathogenic bacteria.

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.

An effective antibiofilm strategy based on bacteriophages armed with silver nanoparticles

The emerging antibiotic resistance in pathogenic bacteria is a key problem in modern medicine that has led to a search for novel therapeutic strategies. A potential approach for managing such bacteria involves the use of their natural killers, namely lytic bacteriophages. Another effective method involves the use of metal nanoparticles with antimicrobial properties. However, the use of lytic phages armed with nanoparticles as an effective antimicrobial strategy, particularly with respect to biofilms, remains unexplored. Here, we show that T7 phages armed with silver nanoparticles exhibit greater efficacy in terms of controlling bacterial biofilm, compared with phages or nanoparticles alone. We initially identified a novel silver nanoparticle-binding peptide, then constructed T7 phages that successfully displayed the peptide on the outer surface of the viral head. These recombinant, AgNP-binding phages could effectively eradicate bacterial biofilm, even when used at low concentrations. Additionally, when used at concentrations that could eradicate bacterial biofilm, T7 phages armed with silver nanoparticles were not toxic to eukaryotic cells. Our results show that the novel combination of lytic phages with phage-bound silver nanoparticles is an effective, synergistic and safe strategy for the treatment of bacterial biofilms.

Antibacterial Activity of Ethanol Extract of Larch Sponge Fruiting Body

Antibiotic resistance in pathogenic bacteria is a worldwide problem. In recent years, there has been increasing interest in the evaluation of plants and fungi with antibacterial activity against various infectious agents. The antibacterial activity of ethanol extract of Laricifomes officinalis (Vill.) Kotl. et Pouzar (Polyporaceae) fruiting body was studied. Activity was assessed using the disk diffusion method. L.officinalis ethanol extract showed high activity against Yersinia pseudotuberculosis, as well as moderate activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, and Staphylococcus aureus. Listeria monocytogenes were not sensitive to ethanol extract of the fruiting body of L.officinalis.

Nanoparticle-Mediated Plasmid Curing in Combating Antibiotic Resistance in Pathogenic Bacteria

Background: Nanotechnology has emerged as a pivotal domain in material science research with extensive applications across various sectors including biotechnology and medicine. Nanoparticles offer unique properties facilitating advancements in nanobiotechnology, particularly in nanomedicine, to combat bacterial infections and antibiotic resistance. This study aimed to determine the application of nanoparticles, specifically nano-TiO2, in treating plasmid-mediated antibiotic resistance in both Gram-negative and Gram-positive bacteria. Method: We evaluated antibiotic and nanomaterial sensitivity through disc diffusion and broth microdilution assays. Plasmid curing experiments were conducted using varying concentrations of nano-TiO2 and SDS as curing agents, followed by plasmid isolation and DNA extraction. The efficacy of nano-TiO2 in plasmid curing and DNA extraction was assessed, alongside the impact on bacterial growth and antibiotic resistance. Results: Results showed successful plasmid elimination with nano-TiO2 treatment, evidenced by the loss of plasmid DNA bands. Additionally, nano-TiO2 substantially enhanced DNA extraction efficiency and quality. The study indicated nano-TiO2's potential in combating antibiotic resistance by targeting plasmids, thereby presenting a novel approach in molecular biology techniques. Conclusion: In conclusion, this study underscores the promising role of nanoparticles in addressing bacterial infections and combating antibiotic resistance. Nano-TiO2 emerges as a valuable tool in DNA purification and plasmid curing, offering new avenues in molecular biology and antibiotic resistance research. However, further investigations are warranted to elucidate the broader implications of nanoparticles across diverse bacterial species and strains. These findings represent a significant step towards harnessing the potential of nanotechnology in combating antimicrobial resistance and advancing healthcare paradigms.

LL-37: Structures, Antimicrobial Activity, and Influence on Amyloid-Related Diseases.

Antimicrobial peptides (AMPs), as well as host defense peptides (HDPs), constitute the first line of defense as part of the innate immune system. Humans are known to express antimicrobial precursor proteins, which are further processed to generate AMPs, including several types of α/β defensins, histatins, and cathelicidin-derived AMPs like LL37. The broad-spectrum activity of AMPs is crucial to defend against infections caused by pathogenic bacteria, viruses, fungi, and parasites. The emergence of multi-drug resistant pathogenic bacteria is of global concern for public health. The prospects of targeting antibiotic-resistant strains of bacteria with AMPs are of high significance for developing new generations of antimicrobial agents. The 37-residue long LL37, the only cathelicidin family of AMP in humans, has been the major focus for the past few decades of research. The host defense activity of LL37 is likely underscored by its expression throughout the body, spanning from the epithelial cells of various organs-testis, skin, respiratory tract, and gastrointestinal tract-to immune cells. Remarkably, apart from canonical direct killing of pathogenic organisms, LL37 exerts several other host defense activities, including inflammatory response modulation, chemo-attraction, and wound healing and closure at the infected sites. In addition, LL37 and its derived peptides are bestowed with anti-cancer and anti-amyloidogenic properties. In this review article, we aim to develop integrative, mechanistic insight into LL37 and its derived peptides, based on the known biophysical, structural, and functional studies in recent years. We believe that this review will pave the way for future research on the structures, biochemical and biophysical properties, and design of novel LL37-based molecules.

Synthesis, Structure-Activity Relationship Study, Bioactivity, and Nephrotoxicity Evaluation of the Proposed Structure of the Cyclic Lipodepsipeptide Brevicidine B.

The brevicidines represent a novel class of nonribosomal antimicrobial peptides that possess remarkable potency and selectivity toward highly problematic and resistant Gram-negative pathogenic bacteria. A recently discovered member of the brevicidine family, coined brevicidine B (2), comprises a single amino acid substitution (from d-Tyr2 to d-Phe2) in the amino acid sequence of the linear moiety of brevicidine (1) and was reported to exhibit broader antimicrobial activity against both Gram-negative (MIC = 2-4 μgmL-1) and Gram-positive (MIC = 2-8 μgmL-1) pathogens. Encouraged by this, we herein report the first total synthesis of the proposed structure of brevicidine B (2), building on our previously reported synthetic strategy to access brevicidine (1). In agreement with the original isolation paper, pleasingly, synthetic 2 demonstrated antimicrobial activity toward Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae (MIC = 4-8 μgmL-1). Interestingly, however, synthetic 2 was inactive toward all of the tested Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus strains. Substitution of d-Phe2 with its enantiomer, and other hydrophobic residues, yields analogues that were either inactive or only exhibited activity toward Gram-negative strains. The striking difference in the biological activity of our synthetic 2 compared to the reported natural compound warrants the re-evaluation of the original natural product for purity or possible differences in relative configuration. Finally, the evaluation of synthetic 1 and 2 in a human kidney organoid model of nephrotoxicity revealed substantial toxicity of both compounds, although 1 was less toxic than 2 and polymyxin B. These results indicate that modification to position 2 may afford a strategy to mitigate the nephrotoxicity of brevicidine.

Chemical Characterization and Biological Properties Assessment of Euphorbia resinifera and Euphorbia officinarum Moroccan Propolis.

Although the plants of the genus Euphorbia are largely exploited by therapists in Morocco, the composition and antibacterial activities of propolis from these plants are still unknown. To address this gap, this study aimed to characterize the pollen type, the volatile compounds, and the phenolic and mineral profiles of three Euphorbia propolis samples collected in Morocco and evaluate their antimicrobial activities. The minimum inhibitory concentration of the propolis samples was determined by the microdilution method, and the anti-adherence activity was evaluated by the crystal violet assay. The examination of anti-quorum-sensing proprieties was performed using the biosensor Chromobacterium violaceum CV026. Pollen analysis revealed that Euphorbia resinifera pollen dominated in the P1 sample (58%), while E. officinarum pollen dominated in the P2 and P3 samples (44%). The volatile compounds were primarily composed of monoterpene hydrocarbons, constituting 35% in P1 and 31% in P2, with α-pinene being the major component in both cases, at 16% in P1 and 15% in P2. Calcium (Ca) was the predominant mineral element in both E. resinifera (P1) and E. officinarum (P2 and P3) propolis samples. Higher levels of phenols, flavonoids and dihydroflavonoids were detected in the E. officinarum P2 sample. The minimum inhibitory concentration (MIC) value ranged from 50 to 450 µL/mL against Gram-positive and Gram-negative bacteria. Euphorbia propolis displayed the ability to inhibit quorum sensing in the biosensor C. violaceum CV026 and disrupted bacterial biofilm formation, including that of resistant bacterial pathogens. In summary, the current study evidences the potential use of E. officinarum propolis (P2 and P3) to combat important features of resistant pathogenic bacteria, such as quorum sensing and biofilm formation.

Nanoencapsulation of Zataria multiflora Essential Oil Containing Linalool Reduced Antibiofilm Resistance against Multidrug-resistant Clinical Strains

Background: The rise in antimicrobial resistance, caused by the production of biofilms by bacteria, is a significant concern in the field of healthcare. Nanoemulsion technology presents itself as a viable alternative in the quest to circumvent antibiotic resistance in pathogenic bacteria. Objective: The aim of this research was to form a sustainable nanoemulsion from Z. multiflora, and evaluate its antibacterial and anti-biofilm activities against the clinical isolates of Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus. Materials and Methods: Bioactive compounds of the oil were identified using GC-MS. Zataria multiflora essential oil (ZMEO) nanoemulsion was formulated as a water-dispersible nanoemulsion with a diameter of 184.88 ± 1.18 nm. The antibacterial and antibiofilm activities of the essential oil in both pure and nanoemulsion forms were assessed against pathogenic bacteria causing hospital-acquired infections using minimal inhibitory concentrations (MICs) and the microtiter method, respectively. Results: The main constituents were found to be linalool (78.66 %), carvacrol (14.25 %), and α- pinene (4.53%). Neither ZMEO nor the emulsified ZMEO showed any antimicrobial activity. However, ZMEO exhibited a low inhibition of biofilm formation by P. mirabilis, S. aureus, and P. aeruginosa. The most promising finding was that when the emulsified ZMEO was present at a concentration of 750 μg/mL, it significantly reduced biofilm formation by the aforementioned bacteria to 39.68% ± 2.62, 56.54% ± 3.35, and 59.60% ± 2.88, respectively. This result suggests that ZMEO nanoemulsion has the potential to effectively disrupt persistent biofilms and enhance the penetration of antimicrobial agents into the biofilm matrix. Conclusion: In conclusion, the study provides evidence supporting the use of ZMEO nanoemulsion as a potential treatment option for combating biofilm-related infections caused by Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus. Further research is warranted to explore the practical application of the proposed essential oil in clinical settings.

Green synthesized silver nanoparticles (AgNPs) using aqueous extract of <i>Calotropis procera</i> and its antimicrobial activity on clinical bacteria isolates

The green synthesis of nanoparticles, utilizing aqueous plant extract as a capping and stabilizing agent, has attracted significant attention in various domains, particularly in pharmaceuticals and drug delivery. In this investigation, silver nitrate (AgNO3) salts were employed as precursors to fabricate silver nanoparticles using Calotropis procera (leaves/flower) extract, and the resulting nanoparticles were characterized. Fourier Transform Infrared (FTIR) spectroscopy revealed three primary functional groups at peaks of 2851.4 cm-1, 1543.1 cm-1, and 1323.2 cm-1, responsible for capping and stabilizing the synthesized C.p-AgNPs. Scanning Electron Microscopy (SEM) demonstrated that the synthesized C.p-AgNPs exhibited spherical shapes with an average particle size ranging from 20 nm to 30 nm. Energy-dispersive X-ray (EDX) analysis of the synthesized C.p-AgNPs indicated the presence of pure silver (Ag) at 54.32% in the region of 2.7 to 3.1 keV. Furthermore, the antimicrobial activity of C.p-AgNPs was examined, with the best inhibition observed at 0.5 mg/mL on Gram-negative bacteria S. aureus (12.0 mm) and Streptococcus spp (13.0 mm), and on Gram-positive bacteria E. coli (16.0 mm) and Salmonella spp (14.0 mm). The antimicrobial efficacy was dose-dependent, suggesting the potential for eradicating resistant human pathogenic bacteria. The antibacterial potential of C.p-AgNPs could be enhanced by increasing their concentration, depending on the specific application. Based on the study's findings, C.p-AgNPs derived from Calotropis procera can be employed for various biomedical purposes, such as textile coating by incorporating C.p-AgNPs in fibers and food storage by nanocapsulation of food items to extend their shelf life.

Identification and characterization of integrated prophages and CRISPR-Cas system in Bacillus subtilis RS10 genome.

Bacteriophages have been extensively investigated due to their prominent role in the virulence and resistance of pathogenic bacteria. However, little attention has been given to the non-pathogenic Bacillus phages, and their role in the ecological bacteria genome is overlooked. In the present study, we characterized two Bacillus phages with a linear DNA genome of 33.6kb with 44.83% GC contents and 129.3kb with 34.70% GC contents. A total of 46 and 175 putative coding DNA sequences (CDS) were identified in prophage 1 (P1) and prophage 2 (P2), respectively, with no tRNA genes. Comparative genome sequence analysis revealed that P1 shares eight CDS with phage Jimmer 2 (NC-041976), and phage Osiris (NC-028969), and six with phage phi CT9441A (NC-029022). On the other hand, P2 showed high similarity with Bacill_SPbeta_NC_001884 and Bacillus phage phi 105. Further, genome analysis indicates several horizontal gene transfer events in both phages during the evolution process. In addition, we detected two CRISPR-Cas systems for the first time in B. subtilis. The identified CRISPR system consists of 24 and 25 direct repeats and integrase coding genes, while the cas gene which encodes Cas protein involved in the cleavage of a target sequence is missing. These findings will expand the current knowledge of soil phages as well as help to develop a new perspective for investigating more ecological phages to understand their role in bacterial communities and diversity.

Inhibitory effect of 14 essential oils against resistant pathogenic bacteria and fungi and chemical compositions of selected essential oils

Inhibitory effect of 14 essential oils against resistant pathogenic bacteria and fungi and chemical compositions of selected essential oils

Bioactivity and enzymatic properties of culturable endophytic fungi associated with black seeds (Nigella sativa L.)

Extracellular enzymes of the endophytes are degraders of the polysaccharides available in the host plants. The study evaluated the activity of amylase, protease, lipase, and laccase enzymes produced by one hundred endophytes previously isolated from the seed. In addition, their antimicrobial activity against Listeria monocytogenes, Staphylococcus aureus (ATTC 25923), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853) was determined using the disc diffusion assay. The data show that 93% of the isolates were capable of producing amylase, followed by protease, lipase, and laccase with 72%, 81%, and 10%, respectively. Out of 100 endophytic fungi, only nineteen (n = 19) displayed activity against the target bacteria. Of the 19 endophytic fungi showing antibacterial activity, 9 (47%) belonged to the Penicillium genus, 5 (26%) to Alternaria spp, 3 (16%) to Cladosporium, and only 1 (5%) to the Fusarium genus. The highest antibacterial activities against all pathogenic bacteria tested were recorded for Alternaria alternata (MH879772.1) and Penicillium goetzii (MF151170.1). In conclusion, the study not only demonstrates the array of extracellular enzymes produced by the endophytes isolated from black seeds but also reports on their antibacterial properties, thus highlighting the importance of these endophytes in the development of endophyte-based technologies and drug development against resistance pathogenic bacteria.

Traditional Knowledge Driven Screening of 30 Medicinal Plants from Gandhmardhan, Odisha, That are Effective Against Human Multidrug Resistant Pathogenic Bacteria

The medico folklore use of medicinal plants is the mainstay healthcare system of the tribals in and around the Gandhamardan, Western Odisha. These people depend on the forest and traditional Vaidyas to treat various health ailments, including bacterial infections. While documenting folklore claims, we found the acute dependency of traditional diarrhoea on 30 medicinal plants from the Gandhamardan for treating respiratory tract infections, skin diseases, wound infections, diarrhoea, and dysentery. The plant parts of these plants were collected from the wild, and their phytochemical composition was determined using aqueous and ethanol extracts. The crude extracts at different concentrations were used to elucidate their antibacterial activity based on the zone of inhibition using the agar well diffusion method using eight pathogenic bacteria. The plant extracts revealed the presence of eight secondary metabolites, viz. alkaloids, glycosides, terpenoids, reducing sugar, saponins, tannins, flavonoids, and steroids. All 30 plants were very effective against all the MDR bacteria. The study would provide a scientific basis for clandestine ethnobotanical knowledge that would benefit the antimicrobial stewardship program.

Prevalence and molecular characterization of Multidrug-Resistant ESBL-Producing E. coli in commercial poultry

Background: Rural poultry farmers are gradually changing from the backyard poultry production to intensive production, which made poultry more vulnerable to diseases and lead to indiscriminate use of antimicrobials in poultry production. As per OIE, FAO and WHO, multiple spread antimicrobial resistant pathogenic bacteria are a serious global human and animal health problem. Hence the study has been carried out to know the antimicrobial resistance status of poultry in Tirunelveli, Tamil Nadu, India. Methods: The study was aimed to find the occurrence of extended spectrum beta lactamases (ESBLs) producing E. coli from poultry origin. Caecum samples from the broiler (n=180), desi chicken (n=180) and Japanese quail (n=180) were processed for the isolation and phenotypic identification of ESBL E. coli. The isolates were tested for antimicrobial susceptibility test and characterization of ESBL and virulence genes done by PCR. Result: On phenotypic confirmation of ESBL producing E. coli by combined disk diffusion test (CDDT), a total of 9.63% samples were positive for extended spectrum beta lactamase producer (ESBL). Multi drug resistance (MDR) was observed in 38.23% of the broiler isolates, 27.27% and 57.14% in desi chicken and Japanese quail isolates, respectively. All the phenotypically confirmed ESBL producing E. coli isolates (n=52) were positive for uspA gene by PCR confirming the isolates as E. coli. The overall presence of the blaTEM gene was 57.69%, with broiler isolates having the highest prevalence of 67.47%, followed by desi chicken 36.36% and Japanese quail 42.85%. In contrast, the blaSHV gene was found in only 17.64% of the broiler isolates, but none were positive for the blaCTXM and blaOXA-1 gene.

In-vitro Antimicrobial Effects and Phytochemical Contents of Stingless Bee Meliponula beccarii Honey and Pollen from Baringo County, Kenya

Background: Afro-tropical stingless bees produce several products including honey, propolis, cerumen and pollen, which are widely used as traditional medicine and food. In Baringo County, Kenya stingless bee honey in particular is widely used as a traditional remedy for respiratory disorders, stomach disorders and oral thrush, commonly associated with bacterial and fungal infections. However, scientific data on the antimicrobial activities and phytochemical content of stingless bee products from Baringo is scarce. Objectives: The objective of this study was to investigate the in vitro antimicrobial activities and phytochemical content of Meliponula beccarii stingless bee honey and pollen from Baringo County. Materials and methods: Eleven honey and pollen samples were conveniently sampled from eleven wild occurring stingless bee nests in three ecologically distinct areas. Increasing concentrations of honey and pollen samples were then prepared and tested against H. influenzae, E. coli, MRSA and C. albicans using agar well diffusion assay. The broth microdilution test was further performed to determine the Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs). Standard qualitative methods were used to analyse the phytochemical contents of the honey and pollen samples. Data was analysed by two-way ANOVA and Tukey’s post-hoc tests. Results: in comparison to distilled water (negative control), the honey samples had a significantly higher mean zones of inhibition at concentration of 100% v/v against E. coli (9.0±4.7 mm vs 0 mm, p<0.0001, N=11), H. influenzae (11.1±5.0 mm vs 0 mm, p<0.0001, N=11), and MRSA (10.8±5.9 mm vs 0 mm, p>0.0001, N=11). However, compared to ciprofloxacin standard (30ug/ml), all the concentrations of honey samples had significantly lower mean zones of inhibition against H. influenzae (8.8±2.4 mm vs 25±0.58 mm, p<0.0001, N=11), E. coli (5.7±3.4 mm vs 31.7±1.5 mm, p<0.0001, N=11) and MRSA (8.1±2.8 mm vs 27±0 mm). All the honey samples did not exhibit activity against C. albicans even at 100% (v/v). The mean MICs against E. coli, H. influenzae and MRSA were 9.38% (v/v), 18.75% (v/v) and 18.75% (v/v), respectively. Notably, the honey samples exhibited bactericidal activity, only against MRSA with a mean MBC of 60.94% (v/v). All the pollen samples showed no antibacterial and antifungal activities against the tested micro-organisms. Qualitative analyses revealed that the honey and pollen samples of Meliponula beccarii contain alkaloids, phenolics, triterpenoids, flavonoids, saponins, tannins, glycosides and steroids, but not terpenoids. Conclusion: Some but not all Meliponula beccarii honey samples from Baringo County has antibacterial activities. The honey and pollen are rich in various phytochemical compounds. Our findings validate the use of Meliponula beccarii honey in traditional treatment of bacterial infections and its further investigation as a potential source of novel agents against drug resistant pathogenic bacteria.

IDENTIFIKASI DAN PROFIL RESISTENSI BAKTERI PADA MINUMAN AIR TAHU DAN AIR TEBU DI WILAYAH KOTA PONTIANAK

Tofu and sugarcane juice drinks are in great demand because they taste delicious and affordable. These drinks can be contaminated with pathogenic bacteria due to hygiene and poor environment. Contamination of pathogenic bacteria that are resistant to antibiotics is a serious health threat. The objective of this study is to identify and provide antibiotic resistance bacteria from tofu and sugarcane juice drinks overview. This Study is a descriptive-observation with a cross-sectional design. Bacterial identification is carried out by culture, while resistance testing is carried out by Kirby-Bauer. Penicillin, amoxicillin, ampicillin, ciprofloxacin, chloramphenicol, gentamicin, tetracycline, and vancomycin were used. 43 samples of tofu water drink and 70 samples of sugarcane juice drink were selected by purposive sampling. Staphylococcus aureus, Salmonella typhi, Enterobacter aerogenes, and Klebsiella pneumoniae founds in tofu drinks, while Enterobacter aerogenes, Salmonella typhi, Shigella dysenteriae, and Escherichia coli founds in sugarcane juice. Staphylococcus aureus resistant to penicillin (100%), Salmonella typhi resistant to penicillin (66.6%), Enterobacter aerogenes resistant to tetracycline (70%), Klebsiella pneumoniae resistant to penicillin (100%), Shigella dysenteriae resistant to ampicillin and gentamicin (100%), and Escherichia coli resistant to vancomycin (100%). Pathogenic-resistant bacteria in tofu and sugarcane juice drinks show the risk of spreading resistant bacteria which can trigger bacterial resistance with a wider spectrum.

Metallic Gallium Droplets Exhibit Poor Antibacterial Properties.

The rise of antibiotic resistance in pathogenic bacteria requires new therapeutics to be developed. Several metallic nanoparticles such as those made from silver, copper, and zinc have shown significant antibacterial activity, in part due to metal ion leaching. Ga3+ containing compounds have also been shown to have antibacterial properties. Accordingly, it is estimated that metallic Ga droplets may be antibacterial, and some studies to date have confirmed this. Here, multiple concentrations of Ga droplets were tested against the antibiotic resistant Gram-positive bacteria methicillin-resistantStaphylococcus aureus (MRSA) and the Gram-negative bacteria Pseudomonas aeruginosa (P. aeruginosa) Despite a high concentration (2 mg/mL), Ga droplets had only modest antibacterial activity against both bacteria after 24 h of interaction. Finally, we demonstrated that Ga droplets were easily functionalized through a galvanic replacement reaction to develop antibacterial particles with copper and silver demonstrating a total detectable reduction of MRSA and >96% reduction ofP. aeruginosa. Altogether, these results contradict previous literature and show that Ga droplets demonstrate no antibacterial activity at concentrations comparable to those of conventional antibiotics and well-established antibacterial nanomaterials and only modest antibacterial activity at very high concentrations. However, we demonstrate that their antibacterial activity can be easily enhanced by functionalization.

Silver nanoparticles synthesized by probiotic bacteria and antibacterial role in resistant bacteria

Many dangerous bacteria have become highly resistant to traditional antibiotics, which is a huge public health concern. This study investigated the use of silver nanoparticles biosynthesized in a culture filtrate of Lactobacillus acidophilus as antimicrobials. UV–visual spectrophotometry, Fourier-transform-infrared spectroscopy, X-ray power diffraction, and scanning electron microscopy have all validated the findings. The biosynthesized nanoparticles ranged in size from 33 to 90 nm. The cytotoxicity of the nanosilver generated was then investigated using nine 200 g BW rats separated into three groups. When compared to the control group, the treated rats showed little signs of toxicity; parameters of physiological function, including alanine transaminase, aspartate aminotransferase, albumin, creatinine, and urea were significantly different in treated and non-treated animals. Moreover, the antibacterial role of the generated silver nanoparticles was examined in multi-drug resistant (MDR) pathogenic bacteria, Proteus vulgaris, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, revealing high antibacterial activity against the examined bacteria. For more demonstration of the effect of the nanosilver on transcription and gene regulation of treated and non-treated bacteria differential display droplet digital-PCR was used, and the results revealed that several genes were up- and down-regulated. Some genes were selected for DNA sequencing and according to the sequence analysis, these genes were mecA, beta-lactam, and unidentified protein genes, and these have been deposited in the GenBank Database with the following accession numbers: Staphylococcus MZ748472 and Klebsiella MZ748473. We conclude that silver nanoparticles biosynthesized by L. acidophilus are environmentally friendly and have antibacterial activities against MDR pathogenic bacteria.

Novel Approaches for Combating Antibiotic Resistance in Pathogenic Bacteria

Antibiotic resistance has historically been mostly linked to the established mechanisms such target alteration, efflux pumps, and enzymatic inactivation. Also, the ability of bacteria to form biofilm is a formidable challenge to antibiotic efficacy. The extracellular matrix forms a protective barrier that renders most antibiotics ineffective, by limiting the interaction of the drug to its target. The emergence of novel antibiotic resistance mechanisms in pathogenic bacteria and its rapid propagation, by means of horizontal gene transfer or mobile genetic elements, is a constant challenge to the medical community. Bacteria are able to exchange genetic material, conferring to antibiotic resistance, at a startling rate that helps them adapt quickly. This is especially dangerous when antibiotics use is abused. The field of antibiotic resistance has experienced a notable shift in the past few years, owing to the identification of new resistance mechanisms utilized by pathogenic bacteria to impede the effectiveness of antibiotics. Over the past decade researchers have been rigorously studying these resistance mechanisms and working on strategies to overcome the ordeal. Notably, nanoparticles research targeting antibiofilm therapy to combat the antibiotic-resistance mechanisms has been truly innovative. There have also been positive reports on utilizing the CRISPR-Cas as a promising next-generation antibiotic that can be used to eliminate antibiotic resistant genes (ARGs) and resensitize bacterial populations to antibiotics. This review aims for a comprehensive understanding of the ongoing research on antibiotic resistance mechanisms and strategies to counter them, the remaining challenges for widespread clinical implementation and the importance of continued research.