Emergence Of Multidrug-resistant Bacteria Research Articles

Synthesis and biological evaluation of 3,5-substituted pyrazoles as possible antibacterial agents

The emergence of multi-drug resistant bacteria has increased the need for novel antibiotics to help overcome what may be considered the greatest threat to modern medicine. Here we report the synthesis of fifteen novel 3,5-diaryl-1H- pyrazoles obtained via one-pot cyclic oxidation of a chalcone and hydrazine-monohydrate. The synthesised pyrazoles were then screened against Staphylococcus aureus and Escherichia coli to determine their antibacterial potential. The results show that compound 7p is bacteriostatic at MIC 8 µg/mL. The compound is non-toxic against healthy mammalian cells, 3T3-L1 at the highest test concentration 50 µg/mL. Furthermore, compound 7p significantly affected bacterial morphogenesis before cell lysis in Bacillus subtilis when treated above the MIC concentration. From the results, a promising lead compound was identified for future development.

Plant Phyto-constituents as Antibiotic Adjuvants: A Systematic Review and Bibliometric Analysis

The advent of antibiotics in the 19th century has significantly reduced the morbidity and mortality of infectious diseases. However, irrational use of antibiotics in humans as well as in animals has driven the 21st century to the rapid emergence of MultiDrug Resistance Bacteria (MRB). Moreover, the dissemination of COVID-19 pandemic has paved the way for MRB, typically due to increased use of antibiotics to avoid secondary infections.
 The fast pace progression of bacterial resistance for the antibiotics and their combinations is making the management of MRB infections tough and increasing the cost of the treatment as well. However, use of Efflux Pump Inhibitors (EPI) as adjuvant for antibiotics has shown a ray of hope by retaining the susceptibility of the antibiotics and thereby reducing the burden of immediate requirement of new antibiotics for MRB. Accordingly, the present paper is aimed to scrutinize the predominant literature depicting the plant Phyto-constituents as an EPI and adjuvant for antibiotics in the management of MRB infections.
 The systematic review of the present paper indicates that the plant phyto-constituents belonging to the class of alkaloids, terpenoids, flavonoids can effectively be used as EPIs for antibiotics such as Ciprofloxacin, Norfloxacin, Tetracyclines and Chloramphenicol. Bibliometric analysis indicates that the Journal of Antimicrobial Chemotherapy, Antimicrobial Agents and Chemotherapy and BMC Complementary & Alternative Medicine have published impactful articles on EPI potential of plant phyto-constituents. Further, authors Kuete V, Dzotam JK, Falcao-silva VD, Gibbons S, Kuiate JR, Mbaveng AT, Tankeo SB and Voukeng IK are the major contributors and productive authors.

Impact of a 5-year antimicrobial stewardship program focusing on fluoroquinolone prescriptions.

Within the context of the wide use of fluoroquinolones (FQs) and the emergence of multidrug-resistant bacteria, French recommendations concerning the appropriate use of systemic FQs in adults were published in 2015. This study assessed the impact of antibiotic stewardship intervention on the use of FQs over a 5-year period. Five annual audits were performed to evaluate FQ prescriptions. Following the baseline audit, a campaign of appropriate antibiotic use was initiated with courses on antibiotics including FQs. All audits included quantitative and qualitative evaluations to calculate an index of therapeutic adequacy (ITA) with six criteria: indication, molecule type, dosage, duration, route of administration and association. These audits were performed annually from 2015 to 2019. The number of prescriptions decreased substantially from 90 in 2015 to 17 in 2019. This reduction was consistent with consumption data, such that the defined daily dose for 1000 bed days diminished from 67 in 2015 to 42 in 2019. Between 2015 and 2016, the ITA decreased significantly from 3.27 to 1.79 (P = 0.001), corresponding to an improvement in prescription quality. The ITA stabilised between 2016 and 2019. Moreover, improvements were observed in the proportion of entirely conforming prescriptions, conformity of indications, choice of molecule type among FQs and proportion of prescriptions with non-conforming treatment durations. Between 2015 and 2019, we observed quantitative and qualitative improvements in FQ prescriptions within the hospital. Prescription follow-up through annual audits, combined with training courses, contributed to consistent results.

Efficacy of Tigecycline and Linezolid Against Pan-Drug-Resistant Bacteria Isolated From Companion Dogs in South Korea.

The emergence of multidrug-resistant bacteria in companion animals is an increasing concern in view of the concept of One Health. The antimicrobials linezolid (LZD) and tigecycline (TGC) are effective against multidrug-resistant bacteria isolated from humans; however, thus far, no previous study has evaluated the efficacy of these drugs against bacteria isolated from companion animals. This study aimed to evaluate the efficacy of LZD and TGC against bacteria that were isolated from companion dogs and showed resistance to all classes of antimicrobial agents. Clinical samples (auditory channel, eye, skin, and urine) were collected from dogs that visited the Veterinary Medical Teaching Hospital of Konkuk University (Seoul, South Korea) from October 2017 to September 2020. In total, 392 bacterial isolates were obtained, of which 85 were resistant to all classes of antimicrobial agents tested and were, therefore, considered potentially pan-drug resistant (PDR). The susceptibility of isolates to LZD and TGC was determined by the disk diffusion method and interpreted using the Clinical Laboratory Standards Institute guidelines. In total, 95.6% (43/45) and 97.8% (44/45) of gram-positive isolates were susceptible to LZD and TGC, respectively, whereas 82.5% (33/40) of gram-negative isolates were sensitive to TGC. In conclusion, both agents showed favorable efficacy, with the susceptibility rates for all potential PDR bacteria, except Pseudomonas spp., ranging from 72.7 to 100%. Thus, these drugs may serve as excellent antimicrobial options for veterinary medicine in the future.

Neonatal calf diarrhea: A potent reservoir of multi-drug resistant bacteria, environmental contamination and public health hazard in Pakistan

Though emergence of multi-drug resistant bacteria in the environment is a demonstrated worldwide phenomenon, limited research is reported about the prevalence of resistant bacteria in fecal ecology of neonatal calf diarrhea (NCD) animals in Pakistan. The present study aimed to identify and assess the prevalence of bacterial pathogens and their resistance potential in the fecal ecology of NCD diseased animals of Pakistan. The presence of antibiotic resistance genes (blaTEM, blaNDM-1, blaCTX-M, qnrS) was also investigated. A total of 51 bacterial isolates were recovered from feces of young diarrheic animals (n = 11), collected from 7 cities of Pakistan and identified on the basis of 16S rRNA gene sequence and phylogenetic analysis. Selected isolates were subjected to antimicrobial susceptibility by disc diffusion method while polymerase chain reaction (PCR) was used to characterize the blaTEM, blaNDM-1, blaCTX-M, qnrS and mcr-1 antibiotic resistance genes. Based on the 16S rRNA gene sequences (Accession numbers: LC488898 to LC488948), all isolates were identified that belonged to seventeen genera with the highest prevalence rate for phylum Proteobacteria and genus Bacillus (23%). Antibiotic susceptibility explained the prevalence of resistance in isolates ciprofloxacin (100%), ampicillin (100%), sulfamethoxazole-trimethoprim (85%), tetracycline (75%), amoxicillin (55%), ofloxacin (50%), ceftazidime (45%), amoxicillin/clavulanic acid (45%), levofloxacin (30%), cefpodoxime (25%), cefotaxime (25%), cefotaxime/clavulanic acid (20%), and imipenem (10%). MICs demonstrated that almost 90% isolates were multi-drug resistant (against at least three antibiotics), specially against ciprofloxacin, and tetracycline with the highest resistance levels for Shigella sp. (NCCP-421) (MIC-CIP up to 75 μg mL−1) and Escherichia sp. (NCCP-432) (MIC-TET up to 250 μg mL−1). PCR-assisted detection of antibiotic resistance genes showed that 54% isolates were positive for blaTEM gene, 7% isolates were positive for blaCTX-M gene, 23% isolates were positive for each of qnrS and mcr-1 genes, 23% isolates were co-positive in combinations of qnrS and mcr-1 genes and blaTEM and mcr-1 genes, whereas none of the isolate showed presence of blaNDM-1 gene.

Effects of Lipidation on a Proline-Rich Antibacterial Peptide.

The emergence of multidrug-resistant bacteria is a worldwide health problem. Antimicrobial peptides have been recognized as potential alternatives to conventional antibiotics, but still require optimization. The proline-rich antimicrobial peptide Bac7(1-16) is active against only a limited number of Gram-negative bacteria. It kills bacteria by inhibiting protein synthesis after its internalization, which is mainly supported by the bacterial transporter SbmA. In this study, we tested two different lipidated forms of Bac7(1-16) with the aim of extending its activity against those bacterial species that lack SbmA. We linked a C12-alkyl chain or an ultrashort cationic lipopeptide Lp-I to the C-terminus of Bac7(1-16). Both the lipidated Bac-C12 and Bac-Lp-I forms acquired activity at low micromolar MIC values against several Gram-positive and Gram-negative bacteria. Moreover, unlike Bac7(1-16), Bac-C12, and Bac-Lp-I did not select resistant mutants in E. coli after 14 times of exposure to sub-MIC concentrations of the respective peptide. We demonstrated that the extended spectrum of activity and absence of de novo resistance are likely related to the acquired capability of the peptides to permeabilize cell membranes. These results indicate that C-terminal lipidation of a short proline-rich peptide profoundly alters its function and mode of action and provides useful insights into the design of novel broad-spectrum antibacterial agents.

Pyridinium Modified Anthracenes and Their Endoperoxides Provide a Tunable Scaffold with Activity against Gram-Positive and Gram-Negative Bacteria.

Due to the emergence of multidrug resistant bacteria, the development of new antibiotics is required. We introduce here asymmetrically modified positively charged bis(methylpyridinium) anthracenes as a novel tunable scaffold, in which the two positive charges can be placed at a defined distance and angle. Our structure-activity relationship reveals that coupling the methylpyridiniums with alkynyl linkers to the central anthracene unit yields antibacterial compounds against a wide range of bacteria, including Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis. Also, different mycobacteria, such as Mycobacterium smegmatis and Mycobacterium tuberculosis, are efficiently targeted by these compounds. The antibacterial activity depends on the number of alkynyl linkers and consequently also on the distance of the positive charges in the rigid anthracene scaffold. Additionally, the formation of an anthracene endoperoxide further increases the antibacterial activity, likely due to the release of toxic singlet oxygen that converts the endoperoxide back to the antibacterial anthracene scaffold with half-lives of several hours.

Antibacterial Potential of Biosynthesized Zinc Oxide Nanoparticles against Poultry-Associated Foodborne Pathogens: An In Vitro Study.

Simple SummaryThe overuse of antibiotics in the poultry industry has led to the emergence of multidrug-resistant microorganisms. Thus, there is a need to find an alternative to conventional antibiotics. Recently, zinc oxide nanoparticles (ZnO NPs) have gained much attention due to their excellent antibacterial activity. In addition, ZnO NPs is an essential trace mineral in poultry diets. In this sense, incorporating ZnO NPs into poultry can promote growth and performance while serving as an alternative antibacterial agent to control diseases. Therefore, this study aimed to assess the in vitro antibacterial activity and antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus). The obtained findings demonstrated effective antibacterial actions against the tested microorganisms. The nanotechnology approach could represent a new tool for combating pathogens in the poultry industry.Since the emergence of multidrug-resistant bacteria in the poultry industry is currently a serious threat, there is an urgent need to develop a more efficient and alternative antibacterial substance. Zinc oxide nanoparticles (ZnO NPs) have exhibited antibacterial efficacy against a wide range of microorganisms. Although the in vitro antibacterial activity of ZnO NPs has been studied, little is known about the antibacterial mechanisms of ZnO NPs against poultry-associated foodborne pathogens. In the present study, ZnO NPs were successfully synthesized using Lactobacillus plantarum TA4, characterized, and their antibacterial potential against common avian pathogens (Salmonella spp., Escherichia coli, and Staphylococcus aureus) was investigated. Confirmation of ZnO NPs by UV-Visual spectroscopy showed an absorption band center at 360 nm. Morphologically, the synthesized ZnO NPs were oval with an average particle size of 29.7 nm. Based on the dissolution study of Zn2+, ZnO NPs released more ions than their bulk counterparts. Results from the agar well diffusion assay indicated that ZnO NPs effectively inhibited the growth of the three poultry-associated foodborne pathogens. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed using various concentrations of ZnO NPs, which resulted in excellent antibacterial activity as compared to their bulkier counterparts. S. aureus was more susceptible to ZnO NPs compared to the other tested bacteria. Furthermore, the ZnO NPs demonstrated substantial biofilm inhibition and eradication. The formation of reactive oxygen species (ROS) and cellular material leakage was quantified to determine the underlying antibacterial mechanisms, whereas a scanning electron microscope (SEM) was used to examine the morphological changes of tested bacteria treated with ZnO NPs. The findings suggested that ROS-induced oxidative stress caused membrane damage and bacterial cell death. Overall, the results demonstrated that ZnO NPs could be developed as an alternative antibiotic in poultry production and revealed new possibilities in combating pathogenic microorganisms.

Oxygen Self-Supplying Nanotherapeutic for Mitigation of Tissue Hypoxia and Enhanced Photodynamic Therapy of Bacterial Keratitis.

Hypoxia, a common characteristic of bacterial infections, is known to be closely associated with the emergence of multidrug-resistant bacteria, which hastens the need to develop advanced microbicides and antibacterial techniques. Photodynamic therapy is a promising strategy to reduce bacterial antibiotic resistance and employs photosensitizers, excitation light sources, and sufficient oxygen to generate toxic reactive oxygen species (ROS). The inherent limitation of PDT is that the generation of ROS is restricted by the hypoxic microenvironment in infection sites. Here, an oxygen self-supplying nanotherapeutic is developed to enhance antibacterial activity against multidrug-resistant bacteria on the basis of fluorinated boron dipyrromethene (BODIPY)-based glycomimetics. The nanotherapeutic not only could capture the bacteria efficiently but also was able to act as an oxygen carrier to relieve the hypoxic microenvironment of bacterial infections, thus achieving enhanced PDT efficacy. In a Pseudomonas aeruginosa infection of a rat cornea, typical administration of the nanotherapeutic decreased the infiltrate and showed a faster healing capacity in comparison with BODIPY-based glycomimetics. Self-supplying oxygen nanotherapeutics that relieve the hypoxic microenvironment and interfere with bacterial colonization have been shown to be a promising candidate for the management of drug-resistant microbial keratitis.

Novel Broad-Spectrum Antimicrobial Peptide Derived from Anoplin and Its Activity on Bacterial Pneumonia in Mice.

The emergence of multidrug-resistant bacteria has major issues for treating bacterial pneumonia. Currently, anoplin (GLLKRIKTLL-NH2) is a natural antimicrobial candidate derived from wasp venom. In this study, a series of new antimicrobial peptide (AMP) anoplin analogues were designed and synthesized. The relationship between their biological activities and their positive charge, hydrophobicity, amphipathicity, and secondary structure are described. The characteristic shared by these peptides is that positively charged amino acids and hydrophobic amino acids are severally arranged on the hydrophilic and hydrophobic surface of the α-helix to form a completely amphiphilic structure. To achieve ideal AMPs, below the range of the threshold of the cytotoxicity and hemolytic activity, their charges and hydrophobicity were increased as much. Among the new analogues, A-21 (KWWKKWKKWW-NH2) exhibited the greatest antimicrobial activity (geometric mean of minimum inhibitory concentrations = 4.76 μM) against all the tested bacterial strains, high bacterial cell selectivity in vitro, high effectiveness against bacterial pneumonia in mice infected with Klebsiella pneumoniae, and low toxicity in mice (LD50 = 82.01 mg/kg). A-21 exhibited a potent bacterial membrane-damaging mechanism and lipopolysaccharide-binding ability. These data provide evidence that A-21 is a promising antimicrobial candidate for the treatment of bacterial pneumonia.

Antibacterial Activity of Moroccan Zantaz Honey and the Influence of Its Physicochemical Parameters Using Chemometric Tools

The emergence of multidrug-resistant bacteria has prompted the development of alternative therapies, including the use of natural products with antibacterial properties. The antibacterial properties of Zantaz honey produced in the Moroccan Atlas Mountains against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was evaluated and analyzed using chemometric tools. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) against S. aureus were the lowest (112.5 ± 54.5 mg/mL), revealing that this species was most sensitive to Zantaz honey. P. aeruginosa showed an intermediate sensitivity (MIC= 118.75 ± 51.9 mg/mL), while E. coli was the most resistant to treatment (MIC = 175 ± 61.2 mg/mL). Content of monosaccharides, certain minerals, and phenolic compounds correlated with antibacterial activity (p < 0.05). Principal component analysis of physicochemical characteristics and antibacterial activity indicated that the parameters most associated with antibacterial activity were color, acidity, and content of melanoidins, fructose, epicatechin, methyl syringate, 4-coumaric acid, and 3-coumaric acid.

Glycoconjugates, hypothetical proteins, and post-translational modification: Importance in host-pathogen interaction and antitubercular intervention development.

With the emergence of multidrug-resistant bacteria, insufficiency of the established chemotherapy, and the existing vaccine BCG, tuberculosis (TB) subsists as the chief cause of death in different parts of the world. Thus, identification of novel target proteins is urgently required to develop more effective TB interventions. However, the novel vaccine and drug target knowledge based on the essentiality of the pathogen cell envelope components such as glycoconjugates, glycans, and the peptidoglycan layer of the lipid-rich capsule are limited. Furthermore, most of the genes encoding proteins are characterized as hypothetical and functionally unknown. Correspondingly, some researchers have shown that the lipid and sugar components of the envelope glycoconjugates are largely in charge of TB pathogenesis and encounter many drugs and vaccines. Therefore, in this review we provide an insight into a comprehensive study concerning the importance of cell envelope glycoconjugates and hypothetical proteins, the impact of post-translational modification, and the bioinformatics-based implications for better antitubercular intervention development.

Marine Microbial Metabolites: A new wave of drugs for Combating Antimicrobial Resistance

The steady increase in the emergence of multidrug-resistant bacteria amongst medical centers, environment, animals, and food is of major concern for health care professionals. Most of the currently used mainline antibacterial drugs were discovered during the golden era of antibiotic discovery (1950-60). During this period, many natural, semi-synthetic, and synthetic molecules were screened for their antimicrobial potential against a spectrum of clinical pathogens. Nevertheless, there was a gap of forty long years until the release of a newer class of antibiotics in the market. It is very vital to develop an integrated approach to combat antimicrobial resistance. There has been a paradigm shift in the field of marine drug discovery in the last two decades. Bioactive metabolites derived from the marine ecosystem are known to exhibit a wide array of pharmacological activity than the terrestrial source. Among all marine organisms, secondary metabolites derived from microbes are the most underexplored natural source. Screening of marine microbes for various antimicrobial molecules has become a noteworthy trend in marine drug discovery and provides a ray of hope for combating antimicrobial resistance.

Engineered endolysin-based \u201cartilysins\u201d for controlling the gram-negative pathogen Helicobacter pylori

Helicobacter pylori infection can cause a variety of gastrointestinal diseases. In severe cases, there is a risk of gastric cancer. Antibiotics are often used for clinical treatment of H. pylori infections. However, because of antibiotic overuse in recent years and the emergence of multidrug-resistant bacteria, there is an urgent need to develop new treatment methods and drugs to achieve complete eradication of H. pylori. Endolysins and holins encoded by bacterial viruses (i.e., phages) represent a promising avenue of investigation. These lyase-based antibacterial drugs act on the bacterial cell wall to destroy the bacteria. Currently, a type of endolysin that has been studied more frequently acts on the amide bond between peptidoglycans, and holin is a transmembrane protein that can punch holes in the cell membrane. However, as a Gram-negative bacterium, H. pylori possesses a layer of impermeable lipopolysaccharides on the cell wall, which prevents endolysin interaction with the cell wall. Therefore, we designed a genetic linkage between an endolysin enzyme and a holin enzyme with a section of polypeptides (e.g., polycations and hydrophobic peptides) that enable penetration of the outer membrane. These complexes were designated “artilysins” and were efficiently expressed in Escherichia coli. In vitro bacteriostasis experiments showed that the purified artilysins had strong bacteriostatic effects on H. pylori. In addition, the surface of H. pylori was perforated and destroyed, as confirmed by electron microscopy, which was proved that artilysins had bacteriolytic effect on H. pylori.

Trends in bacterial bloodstream infections and resistance in immuno-compromised patients with febrile neutropenia: a retrospective analysis.

Bacterial infections remain a major cause of morbidity and mortality in immunocompromised children. From the onset of fever, an early administration of broad-spectrum antibiotics is begun; this strategy could induce emergence of multi-drug resistant bacteria (MDR). We describe the incidence and microbiological spectrum, including MDR bacteria of bacterial documented blood-stream infections (BSI) in immunocompromised children. A retrospective, descriptive study was conducted in a tertiary referral centre in France from January 2014 to December 2017. Our cohort included a large scale of patients with febrile neutropenia: haematological and oncological malignancies, haematopoietic stem cell transplantations, severe combined immunodeficiency syndromes. BSI were defined by positive blood culture samples associated with fever. Among 760 febrile neutropenia episodes in 7301 admitted patients, we identified 310 documented BSI with a mean of 7.4 BSI/1000 patient bed days. Only 2.9% BSIs were caused by MDR bacteria, none vancomycin resistant. Coagulase-negative staphylococci were identified in 49.7% BSI and Staphylococcus aureus caused 6.5% infections. Gram-negative bacilli accounted for 21.6% of isolated bacteria, Pseudomonas for 4.8%. The incidence of BSI annually decreased by 0.75% (p = 0.002).Conclusion: With a step-down strategy at 48h of initial broad-spectrum antibiotic therapy, we reported a low number of MDR bacteria, no deaths related to BSI. What is Known: • Bacterial bloodstream infections are a leading cause of morbidity and mortality in immunocompromised children • Multi-drug resistant bacteria are emerging worldwide. What is New: • Initial broad-spectrum antibiotic therapy with a step-down strategy at 48h: no deaths related to bloodstream infections with a low number of resistant bacteria. • Parental and nurse stewardship to decrease bloodstream infections incidence with a drop of staphylococcal infections.

POS-769 DOES EARLY ASYMPTOMATIC BACTERIURIA AFFECT GRAFT OUTCOMES IN KIDNEY TRANSPLANT RECIPIENTS FROM SOUTH ASIA?

Infections remain a major cause of mortality and morbidity among kidney transplant (KT) recipients. The benefits of treating asymptomatic bacteriuria (ASB) in the early post-transplant period is uncertain. Treatment of ASB lead to emergence of multidrug resistant bacteria which can be circumvented if there is no added benefit. There is paucity of literature on the outcomes of ASB in kidney transplant recipients with a normal urinary tract.

Enhanced antibacterial activity of a novel biocompatible triarylmethane based ionic liquid-graphene oxide nanocomposite

Biofilm formation on medical implants and devices has been a severe concern that results in their impaired performance and life-threatening complications. Thus, development of novel functional coatings for infection prone surfaces with biofilm inhibiting characteristics is of prime significance considering the rapid emergence of multidrug resistant bacteria. Herein we present a novel nanocomposite derived from Graphene Oxide (GO) and a newly developed functional Ionic liquid (IL) obtained through a metathesis reaction between a triarylmethane dye hexamethyl pararosaniline chloride or crystal violet (CV) and sodium dodeceyl sulfate (SDS) to yield [CV][DS] (hexamethyl pararosaniline dodecyl sulfate). This highly biocompatible [CV][DS]-GO nanocomposite exhibit more than four times improved antibacterial activity in comparison to bare GO against both gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus). As suggested by XRD, FTIR and UV absorption and SEM results improved activity of [CV][DS]-GO nanocomposite is ascribed to the synergistic effect of reduced nanocomposite sheet thickness, enhanced amphiphilicity imparted by dodecylsulfate (DS), exposed active ArN+ groups of CV and some inherent functionalities of GO. This is also complemented by the ruptured and diffused S. aureus cell walls as observed in bacterial SEM result. In contrast, the nanocomposites of the precursors with GO do not demonstrate any significant antibacterial effect. Coatings developed using GO upon infestation with E. coli revealed significant biofilm formation after 48 and 72 h of incubation while [CV][DS]-GO coated surface demonstrated no colony growth under similar circumstances. Thus, [CV][DS]-GO nanocomposite coatings exhibit excellent resistance to bacterial growth even up to 72 h incubation signifying its bactericidal effect. Therefore, the developed nanocomposite may be considered as one of the improved antibacterial wash resistant coating material for biomedical devices and surfaces susceptible to to biofilm formation.

Bacteria-specific pro-photosensitizer kills multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa

The emergence of multidrug-resistant bacteria has become a real threat and we are fast running out of treatment options. A combinatory strategy is explored here to eradicate multidrug-resistant Staphlococcus aureus and Pseudomonas aeruginosa including planktonic cells, established biofilms, and persisters as high as 7.5 log bacteria in less than 30 min. Blue-laser and thymol together rapidly sterilized acute infected or biofilm-associated wounds and successfully prevented systematic dissemination in mice. Mechanistically, blue-laser and thymol instigated oxidative bursts exclusively in bacteria owing to abundant proporphyrin-like compounds produced in bacteria over mammalian cells, which transformed harmless thymol into blue-laser sensitizers, thymoquinone and thymohydroquinone. Photo-excitations of thymoquinone and thymohydroquinone augmented reactive oxygen species production and initiated a torrent of cytotoxic events in bacteria while completely sparing the host tissue. The investigation unravels a previously unappreciated property of thymol as a pro-photosensitizer analogous to a prodrug that is activated only in bacteria.

Learning From Mistakes: The Role of Phages in Pandemics.

The misuse of antibiotics is leading to the emergence of multidrug-resistant (MDR) bacteria, and in the absence of available treatments, this has become a major global threat. In the middle of the recent severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic, which has challenged the whole world, the emergence of MDR bacteria is increasing due to prophylactic administration of antibiotics to intensive care unit patients to prevent secondary bacterial infections. This is just an example underscoring the need to seek alternative treatments against MDR bacteria. To this end, phage therapy has been proposed as a promising tool. However, further research in the field is mandatory to assure safety protocols and to develop appropriate regulations for its use in clinics. This requires investing more in such non-conventional or alternative therapeutic approaches, to develop new treatment regimens capable of reducing the emergence of MDR and preventing future global public health concerns that could lead to incalculable human and economic losses.

Influence of multidrug resistance bacteria in river Ganges in the stretch of Rishikesh to Haridwar

Waterborne pathogens result in around 4% of all deaths and emergence of antimicrobial resistance in the pathogens is a global concern. This paper assesses the bacterial population in river Ganga, and discusses the impact of antibiotics and the emergence of multidrug resistant bacteria (MDR) through horizontal gene transfer (HGT) and anthropogenic activities. Forty-nine bacterial isolates were identified through different biochemical tests in the water samples, and were subjected to eighteen antibiotics of different classes to check the susceptibility. 20 out of 49 bacterial isolates were found to have resistance against the broad-spectrum antibiotic, Imipenem. It was observed that the bacterial species reduces with the movement of water in the river course indicating the self-cleansing nature of river Ganga. It was also observed that the river water in the downstream of STP at Jagjitpur contains Bacillus subtilis, Clostridium difficile and Neisseria spp., absent in upstream samples, indicating requirement of improvement in the disinfection of STP treated water.