scholarly journals Antimicrobials Functioning through ROS-Mediated Mechanisms: Current Insights

2021 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Ankita Vaishampayan ◽  
Elisabeth Grohmann
Keyword(s):  
Oxidative Stress ◽  
Antibiotic Resistance ◽  
Defense Mechanisms ◽  
Normal Growth ◽  
Multidrug Resistant ◽  
Oxidation Potential ◽  
Resistant Bacteria ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Alternative Antimicrobials

Antibiotic resistance and infections caused by multidrug-resistant bacteria are global health concerns. Reducing the overuse and misuse of antibiotics is the primary step toward minimizing the antibiotic resistance crisis. Thus, it is imperative to introduce and implement novel antimicrobial strategies. Recently, several alternative antimicrobials targeting oxidative stress in bacteria have been studied and shown to be promising. Oxidative stress occurs when bacterial cells fail to detoxify the excessive reactive oxygen species (ROS) accumulated in the cells. Bacteria deploy numerous defense mechanisms against oxidative stress. The oxidative stress response is not essential for the normal growth of bacteria, but it is crucial for their survival. This toxic oxidative stress is created by the host immune response or antimicrobials generating ROS. ROS possess strong oxidation potential and cause serious damage to nucleic acids, lipids, and proteins. Since ROS-based antimicrobials target multiple sites in bacteria, these antimicrobials have attracted the attention of several researchers. In this review, we present recent ROS-based alternative antimicrobials and strategies targeting oxidative stress which might help in mitigating the problem of antibiotic resistance and dissemination.

scholarly journals Testudines as Sentinels for Monitoring the Dissemination of Antibiotic Resistance in Marine Environments: An Integrative Review

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 775
Author(s):  
Kezia Drane ◽  
Roger Huerlimann ◽  
Michelle Power ◽  
Anna Whelan ◽  
Ellen Ariel ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Anthropogenic Activities ◽  
Sea Turtles ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Marine Environments ◽  
Beta Lactam ◽  
Antibiotic Resistant ◽  
Sensitivity Tests ◽  
Standard Culture

Dissemination of antibiotic resistance (AR) in marine environments is a global concern with a propensity to affect public health and many ecosystems worldwide. We evaluated the use of sea turtles as sentinel species for monitoring AR in marine environments. In this field, antibiotic-resistant bacteria have been commonly identified by using standard culture and sensitivity tests, leading to an overrepresentation of specific, culturable bacterial classes in the available literature. AR was detected against all major antibiotic classes, but the highest cumulative global frequency of resistance in all represented geographical sites was against the beta-lactam class by a two-fold difference compared to all other antibiotics. Wastewater facilities and turtle rehabilitation centres were associated with higher incidences of multidrug-resistant bacteria (MDRB) accounting for an average of 58% and 49% of resistant isolates, respectively. Furthermore, a relatively similar prevalence of MDRB was seen in all studied locations. These data suggest that anthropogenically driven selection pressures for the development of AR in sea turtles and marine environments are relatively similar worldwide. There is a need, however, to establish direct demonstrable associations between AR in sea turtles in their respective marine environments with wastewater facilities and other anthropogenic activities worldwide.

scholarly journals Liposomes as Antibiotic Delivery Systems: A Promising Nanotechnological Strategy against Antimicrobial Resistance

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2047
Author(s):  
Magda Ferreira ◽  
Maria Ogren ◽  
Joana N. R. Dias ◽  
Marta Silva ◽  
Solange Gil ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Private Investment ◽  
Therapeutic Index ◽  
Multidrug Resistant ◽  
Current Treatment ◽  
Delivery Systems ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Antimicrobial Drugs

Antimicrobial drugs are key tools to prevent and treat bacterial infections. Despite the early success of antibiotics, the current treatment of bacterial infections faces serious challenges due to the emergence and spread of resistant bacteria. Moreover, the decline of research and private investment in new antibiotics further aggravates this antibiotic crisis era. Overcoming the complexity of antimicrobial resistance must go beyond the search of new classes of antibiotics and include the development of alternative solutions. The evolution of nanomedicine has allowed the design of new drug delivery systems with improved therapeutic index for the incorporated compounds. One of the most promising strategies is their association to lipid-based delivery (nano)systems. A drug’s encapsulation in liposomes has been demonstrated to increase its accumulation at the infection site, minimizing drug toxicity and protecting the antibiotic from peripheral degradation. In addition, liposomes may be designed to fuse with bacterial cells, holding the potential to overcome antimicrobial resistance and biofilm formation and constituting a promising solution for the treatment of potential fatal multidrug-resistant bacterial infections, such as methicillin resistant Staphylococcus aureus. In this review, we aim to address the applicability of antibiotic encapsulated liposomes as an effective therapeutic strategy for bacterial infections.

scholarly journals Antibiotic Resistance in Pediatric Infections: Global Emerging Threats, Predicting the Near Future

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 393
Author(s):  
Alessandra Romandini ◽  
Arianna Pani ◽  
Paolo Andrea Schenardi ◽  
Giulia Angela Carla Pattarino ◽  
Costantino De Giacomo ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Pediatric Population ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Pediatric Age ◽  
Carbapenem Resistant ◽  
Pediatric Infections ◽  
Surgical Treatments ◽  
Developing System ◽  
Near Future

Antibiotic resistance is a public health threat of the utmost importance, especially when it comes to children: according to WHO data, infections caused by multidrug resistant bacteria produce 700,000 deaths across all ages, of which around 200,000 are newborns. This surging issue has multipronged roots that are specific to the pediatric age. For instance, the problematic overuse and misuse of antibiotics (for wrong diagnoses and indications, or at wrong dosage) is also fueled by the lack of pediatric-specific data and trials. The ever-evolving nature of this age group also poses another issue: the partly age-dependent changes of a developing system of cytochromes determine a rather diverse population in terms of biochemical characteristics and pharmacokinetics profiles, hard to easily codify in an age- or weight-dependent dosage. The pediatric population is also penalized by the contraindications of tetracyclines and fluoroquinolones, and by congenital malformations which often require repeated hospitalizations and pharmacological and surgical treatments from a very young age. Emerging threats for the pediatric age are MRSA, VRSA, ESBL-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae and the alarming colistin resistance. Urgent actions need to be taken in order to step back from a now likely post-antibiotic era, where simple infections might cause infant death once again.

scholarly journals Prevalence of Antibiotic-Resistant Bacteria ESKAPE among Healthy People Estimated by Monitoring of Municipal Wastewater

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 495
Author(s):  
Masateru Nishiyama ◽  
Susan Praise ◽  
Keiichi Tsurumaki ◽  
Hiroaki Baba ◽  
Hajime Kanamori ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
General Population ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Municipal Wastewater Treatment ◽  
Antibiotic Resistant ◽  
Carbapenem Resistant ◽  
Wastewater Samples

There is increasing attention toward factors that potentially contribute to antibiotic resistance (AR), as well as an interest in exploring the emergence and occurrence of antibiotic resistance bacteria (ARB). We monitored six ARBs that cause hospital outbreaks in wastewater influent to highlight the presence of these ARBs in the general population. We analyzed wastewater samples from a municipal wastewater treatment plant (MWWTP) and hospital wastewater (HW) for six species of ARB: Carbapenem-resistant Enterobacteria (CARBA), extended-spectrum β-lactamase producing Enterobacteria (ESBL), multidrug-resistant Acinetobacter (MDRA), multidrug-resistant Pseudomonas aeruginosa (MDRP), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE). We registered a high percentage of ARBs in MWWTP samples (>66%) for all ARBs except for MDRP, indicating a high prevalence in the population. Percentages in HW samples were low (<78%), and no VRE was detected throughout the study. CARBA and ESBL were detected in all wastewater samples, whereas MDRA and MRSA had a high abundance. This result demonstrated the functionality of using raw wastewater at MWWTP to monitor the presence and extent of ARB in healthy populations. This kind of surveillance will contribute to strengthening the efforts toward reducing ARBs through the detection of ARBs to which the general population is exposed.

scholarly journals Prevalence of Mastitis and Antibiotic Resistance of Bacterial Isolates from CMT Positive Milk Samples Obtained from Dairy Cows, Camels, and Goats in Two Pastoral Districts in Southern Ethiopia

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1530
Author(s):  
Amanuel Balemi ◽  
Balako Gumi ◽  
Kebede Amenu ◽  
Sisay Girma ◽  
Muuz Gebru ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Dairy Cows ◽  
Raw Milk ◽  
Multidrug Resistant ◽  
Southern Ethiopia ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococcus ◽  
Bacterial Isolates ◽  
E Coli ◽  
Milk Samples

A study was carried out from August 2017 to February 2018 on lactating dairy cows, one-humped dromedary camels, and goats to determine mastitis in the Bule Hora and Dugda Dawa districts of in Southern Ethiopia. Milk samples from 564 udder quarters and udder halves from 171 animals consisting of 60 dairy cows, 51 camels, and 60 goats were tested for mastitis. Sixty-four positive udder milk samples were cultured, and bacterial mastitis pathogens were isolated and identified. The antibiotic resistance of bacterial isolates from milk with mastitis was tested against nine antimicrobials commonly used in the study area. Cow- and quarter-level prevalence of mastitis in dairy cows, camels, and goats was 33.3%, 26.3%, and 25% and 17.6%, 14.5%, and 20%, respectively. In cattle, the prevalence was significantly higher in Dugda Dawa than in Bule Hora. Major bacterial isolates were coagulase-negative Staphylococcus species (39.1%), S. aureus (17.2%), S. hyicus (14.1%), and S. intermedius and Escherichia coli (9.4% each). In camels, udder abnormality and mastitis were significantly higher in late lactation than in early lactation. Mastitis tends to increase with parity in camels. E. coli isolates were highly resistant to spectinomycin, vancomycin, and doxycycline, whereas most S. aureus isolates were multidrug-resistant. Most of the rural and periurban communities in this area consume raw milk, which indicates a high risk of infection with multidrug-resistant bacteria. We recommend a community-focused training program to improve community awareness of the need to boil milk and the risk of raw milk consumption.

scholarly journals Environmental Spread of New Delhi Metallo-β-Lactamase-1-Producing Multidrug-Resistant Bacteria in Dhaka, Bangladesh

2017 ◽  
Vol 83 (15) ◽  
Author(s):  
Mohammad Aminul Islam ◽  
Moydul Islam ◽  
Rashedul Hasan ◽  
M. Iqbal Hossain ◽  
Ashikun Nabi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Tap Water ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
New Delhi ◽  
Multidrug Resistant Bacteria ◽  
Content Type ◽  
Wastewater Samples

ABSTRACT Resistance to carbapenem antibiotics through the production of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes an emerging challenge in the treatment of bacterial infections. To monitor the possible source of the spread of these organisms in Dhaka, Bangladesh, we conducted a comparative analysis of wastewater samples from hospital-adjacent areas (HAR) and from community areas (COM), as well as public tap water samples, for the occurrence and characteristics of NDM-1-producing bacteria. Of 72 HAR samples tested, 51 (71%) samples were positive for NDM-1-producing bacteria, as evidenced by phenotypic tests and the presence of the bla NDM-1 gene, compared to 5 of 41 (12.1%) samples from COM samples (P < 0.001). All tap water samples were negative for NDM-1-producing bacteria. Klebsiella pneumoniae (44%) was the predominant bacterial species among bla NDM-1-positive isolates, followed by Escherichia coli (29%), Acinetobacter spp. (15%), and Enterobacter spp. (9%). These bacteria were also positive for one or more other antibiotic resistance genes, including bla CTX-M-1 (80%), bla CTX-M-15 (63%), bla TEM (76%), bla SHV (33%), bla CMY-2 (16%), bla OXA-48-like (2%), bla OXA-1 (53%), and bla OXA-47-like (60%) genes. Around 40% of the isolates contained a qnr gene, while 50% had 16S rRNA methylase genes. The majority of isolates hosted multiple plasmids, and plasmids of 30 to 50 MDa carrying bla NDM-1 were self-transmissible. Our results highlight a number of issues related to the characteristics and source of spread of multidrug-resistant bacteria as a potential public health threat. In view of the existing practice of discharging untreated liquid waste into the environment, hospitals in Dhaka city contribute to the potential dissemination of NDM-1-producing bacteria into the community. IMPORTANCE Infections caused by carbapenemase-producing Enterobacteriaceae are extremely difficult to manage due to their marked resistance to a wide range of antibiotics. NDM-1 is the most recently described carbapenemase, and the bla NDM-1 gene, which encodes NDM-1, is located on self-transmissible plasmids that also carry a considerable number of other antibiotic resistance genes. The present study shows a high prevalence of NDM-1-producing organisms in the wastewater samples from hospital-adjacent areas as a potential source for the spread of these organisms to community areas in Dhaka, Bangladesh. The study also examines the characteristics of the isolates and their potential to horizontally transmit the resistance determinants. The significance of our research is in identifying the mode of spread of multiple-antibiotic-resistant organisms, which will allow the development of containment measures, leading to broader impacts in reducing their spread to the community.

scholarly journals Studies on genes expression pattern of antioxidant enzymes and enzymes involved into the genetic information implementation in E.coli cells due to the antibiotic resistance against apramycin and cefatoxime

2020 ◽  
Vol 17 ◽  
pp. 00103
Author(s):  
Oleg Fomenko ◽  
Evgeny Mikhailov ◽  
Nadezhda Pasko ◽  
Svetlana Grin ◽  
Andrey Koshchaev ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antioxidant Enzymes ◽  
Genetic Information ◽  
Bacterial Resistance ◽  
Resistant Bacteria ◽  
Control Group ◽  
Bacterial Cells ◽  
E Coli ◽  
Antimicrobial Substances ◽  
Dna And Rna

The emergence of antibiotic-resistant bacteria is considered a serious problem. The resistance of bacteria against antimicrobial substances becomes important in the repair systems for damage to DNA and RNA molecules. The role of the antioxidant system in the development of bacterial resistance against antibiotics is not yet practically studied. The article studied the expression regulation of the genes of antioxidant enzymes and enzymes involved in the genetic information in E. coli cells with the antibiotic resistance against apramycin and cefatoxime. The study was conducted on bacterial cells resistant against these two antibiotics. The genes blaOXA-1, blaSHV, blaTEM, mdtK, aadA1, aadA2, sat, strA, blaCTX, blaPER-2, tnpA, tnpR, intC1 and intC1c were identified in bacterial cell case. This indicates the presence of plasmids in bacteria with these genes, which provide bacterial resistance to apramycin and cefatoxime. It was established that during the formation of cefotaxime resistance, there was a sharp increase in the expression of the Cu, Zn superoxide dismutase gene: in comparison with the control group, the representation of its transcripts increased 141.04 times for cefotoxime and 155.42 times for apramycin. It has been established that during the formation of resistance to the studied antibiotics in E. coli, an increase in the expression of the end4 and end3 genes is observed. There is tendency toward an increase in the number of transcripts of the pol3E gene observed in the formation of resistance against cefotaxime and apromycin.

scholarly journals Report of Antibiotic Resistance in Urban and Rural Wastewaters from West Bengal, India

2021 ◽  
pp. 274-285
Author(s):  
Meesha Singh ◽  
Rupsha Karmakar ◽  
Sayak Ganguli ◽  
Mahashweta Mitra Ghosh
Keyword(s):  
Antibiotic Resistance ◽  
Biochemical Characterization ◽  
Chemical Properties ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Medical Facility ◽  
Antibiotic Resistant ◽  
Two Samples ◽  
Resistance Patterns ◽  
Antibiotic Resistance Patterns

Aims: This study aims at comparative identification of antibiotic resistance patterns in bacteria isolated from samples collected from rural environment (LS) and urban environments (SS). Metagenomic profiling gave us insights into the microbial abundance of the two samples. This study focused on culture-based methods for complete identification of antibiotic resistant isolates and estimation of comparative antibiotic resistance among the two samples. Study Design: Untreated medical waste and anthropogenic waste disposal can lead to the propagation of different antibiotic resistant strains in wastewater environments both in urban and rural set ups which provide an insight towards this study approach mentioned in the methodology segment. Place and Duration of Study: Sewer system of a medical facility located in Purulia, India was the collection site for liquid sludge. Solid sludge and associated wastewater were collected in vicinity of a large urban medical facility from central Kolkata, India. Methodology: Physico-chemical properties were analyzed followed by microbiological and biochemical characterization. The antibiotic resistance patterns were determined by Kirby-Bauer disc diffusion assay. Potent multidrug resistant isolates were identified using 16srRNA gene amplification followed by Phylogenetic profiling, using CLC Genomics workbench. Results: We observed maximum resistance in an E. coli isolate which was resistant up to 22 antibiotics. Combined data for resistance from urban and rural samples were found to exhibit 83.9% resistance to beta lactams, 85.7% to macrolides, 44.2% to fluoroquinolones, 50% to glycopeptides and cephalosporins, 35.7 % to carbapenems and sulfonamides, 28.5 % to tetracycline, and 23.8 % to aminoglycosides. Conclusion: The high prevalence of antibiotic-resistant bacteria harbouring diverse resistance traits across samples indicated towards probable horizontal gene transfer across environmental niches. This study can prove to be useful to understand and map the patterns of resistance and stringently apply the counter measures related to public health practices.

scholarly journals Accumulation and expression of multiple antibiotic resistance genes in Arcobacter cryaerophilus that thrives in sewage

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3269 ◽  
Author(s):  
Jess A. Millar ◽  
Rahul Raghavan
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Resistance Genes ◽  
Treatment Plant ◽  
Antibiotic Resistance Genes ◽  
Environmental Water ◽  
Multidrug Resistant ◽  
Municipal Sewage ◽  
Animal Origin ◽  
Resistant Bacteria

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also determined that a majority of ARGs was being expressed in sewage, suggestive of trace levels of antibiotics or other stresses that could act as a selective force that amplifies multidrug resistant bacteria in municipal sewage. Because all bacteria are not eliminated even after several rounds of wastewater treatment, ARGs in sewage could affect public health due to their potential to contaminate environmental water.

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