Use Of Antibiotics In Medicine Research Articles

Antibiotic resistance in lactococci and enterococci: phenotypic and molecular-genetic aspects

Abstract Extensive use of antibiotics in medicine, veterinary practice and animal husbandry has promoted the development and dissemination of bacterial drug resistance. The number of resistant pathogens causing common infectious diseases increases rapidly and creates worldwide public health problem. Commensal bacteria, including lactic acid bacteria of genera Enterococcus and Lactococcus colonizing gastrointestinal and urogenital tracts of humans and animals may act as vehicles of antibiotic resistance genes similar to those found in pathogens. Lactococci and enterococci are widely used in manufacturing of fermented products and as probiotics, therefore monitoring and control of transmissible antibiotic resistance determinants in industrial strains of these microorganisms is necessary to approve their Qualified Presumption of Safety status. Understanding the nature and molecular mechanisms of antibiotic resistance in enterococci and lactococci is essential, as intrinsic resistant bacteria pose no threat to environment and human health in contrast to bacteria with resistance acquired through horizontal transfer of resistance genes. The review summarizes current knowledge concerning intrinsic and acquired antibiotic resistance in Lactococcus and Enterococcus genera, and discusses role of enterococci and lactococci in distribution of this feature.

Antibiotic Resistance and Ways to Overcome It. Commentary on the Article of Svetlana V. Ilyina «Irrational Use of Antibiotics in Medicine: Crisis of Antibiotic Resistance and what We Can Do»

Antibiotic Resistance and Ways to Overcome It. Commentary on the Article of Svetlana V. Ilyina «Irrational Use of Antibiotics in Medicine: Crisis of Antibiotic Resistance and what We Can Do»

Irrational Use of Antibiotics in Medicine: Crisis of Antibiotic Resistance and what We Can Do

научный биометрический журнал, который знакомит читателя с клиническими рекомендациями и особенностями применения лекарственных и вакцинных средств у детей, предоставляет исчерпывающую информацию о воздействии лекарственных средств на плод, о проводимых в

Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

ABSTRACT Monitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs). CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC) which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP) effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM) in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene) in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant)/Low (Antibiotic Sensitive) MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No Observable Effect Concentration (NOEC) for each antibiotic which were compared to maximum Measured Exposure Concentrations (MEC) in the environment to predict individual environmental risks. Four antibiotics had high MEC/NOEC and high MIC ratios and were identified as higher risks for concern based upon this approach, but only Triclosan had MEC/NOEC ratios >1 and was recommended for monitoring in future studies.

Analysis of antibiotics by CE and their use as chiral selectors: An update.

The widespread use of antibiotics in medicine and as growth-promoting agents has increased the demand for suitable analytical techniques for their analysis. Analytical methods based on CE or miniaturized CE systems have proved over the years their ability for the analysis of antibiotics. Since our last review (Electrophoresis 2014, 35, 28-49) several new CE methodologies have been reported for antibiotic analysis. This review presents an update of the literature published from June 2013 to June 2015 for the analysis of antibiotics by CE. UV continues being the most used detection system for antibiotics analysis by CE. Strategies to improve sensitivity as the use of sensitive detection systems and the application of preconcentration techniques appear to be the major developments. Furthermore, the use of portable and miniaturized devices for antibiotic analysis is presented in detail. Applications of the developed methodologies to the determination of residues of antibiotics in biological, food, and environmental samples are carefully described. Finally, new developments and applications of antibiotics as chiral selectors in CE are also included.

Nonmedical Uses of Antibiotics: Time to Restrict Their Use?

The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted.

Multidrug-resistant pathogens in the food supply.

Antimicrobial resistance, including multidrug resistance (MDR), is an increasing problem globally. MDR bacteria are frequently detected in humans and animals from both more- and less-developed countries and pose a serious concern for human health. Infections caused by MDR microbes may increase morbidity and mortality and require use of expensive drugs and prolonged hospitalization. Humans may be exposed to MDR pathogens through exposure to environments at health-care facilities and farms, livestock and companion animals, human food, and exposure to other individuals carrying MDR microbes. The Centers for Disease Control and Prevention classifies drug-resistant foodborne bacteria, including Campylobacter, Salmonella Typhi, nontyphoidal salmonellae, and Shigella, as serious threats. MDR bacteria have been detected in both meat and fresh produce. Salmonellae carrying genes coding for resistance to multiple antibiotics have caused numerous foodborne MDR outbreaks. While there is some level of resistance to antimicrobials in environmental bacteria, the widespread use of antibiotics in medicine and agriculture has driven the selection of a great variety of microbes with resistance to multiple antimicrobials. MDR bacteria on meat may have originated in veterinary health-care settings or on farms where animals are given antibiotics in feed or to treat infections. Fresh produce may be contaminated by irrigation or wash water containing MDR bacteria. Livestock, fruits, and vegetables may also be contaminated by food handlers, farmers, and animal caretakers who carry MDR bacteria. All potential sources of MDR bacteria should be considered and strategies devised to reduce their presence in foods. Surveillance studies have documented increasing trends in MDR in many pathogens, although there are a few reports of the decline of certain multidrug pathogens. Better coordination of surveillance programs and strategies for controlling use of antimicrobials need to be implemented in both human and animal medicine and agriculture and in countries around the world.

Purification and Characterization of Venom Components as Source for Antibiotics

The extensive use of antibiotics in medicine, food industry, and agriculture has led to a frequent emergence of multidrug-resistant bacteria, which creates an urgent need for new antibiotics. It is now widely recognized that venom proteins could play a promising role against multidrug-resistant bacteria. Different proteins with antibacterial activity have been characterized from the venoms of snakes, spiders and scorpions in the last decade. This review summarizes the proteins and peptides that have been purified and characterized from different venoms with antibacterial activity. Keywords: Antimicrobial activity, snake, spider, scorpion, venom, peptides.

Country-specific antibiotic use practices impact the human gut resistome

Despite increasing concerns over inappropriate use of antibiotics in medicine and food production, population-level resistance transfer into the human gut microbiota has not been demonstrated beyond individual case studies. To determine the “antibiotic resistance potential” for entire microbial communities, we employ metagenomic data and quantify the totality of known resistance genes in each community (its resistome) for 68 classes and subclasses of antibiotics. In 252 fecal metagenomes from three countries, we show that the most abundant resistance determinants are those for antibiotics also used in animals and for antibiotics that have been available longer. Resistance genes are also more abundant in samples from Spain, Italy, and France than from Denmark, the United States, or Japan. Where comparable country-level data on antibiotic use in both humans and animals are available, differences in these statistics match the observed resistance potential differences. The results are robust over time as the antibiotic resistance determinants of individuals persist in the human gut flora for at least a year.

In-vitro antioxidant and antibacterial activities of Xanthium strumarium L. extracts on methicillin-susceptible and methicillin-resistant Staphylococcus aureus.

Background and Aims:The excessive and repeated use of antibiotics in medicine has led to the development of antibiotic-resistant microbial strains, including Staphylococcus aureus whose emergence of antibiotic-resistant strains has reduced the number of antibiotics available to treat clinical infections caused by this bacterium. In this study, antioxidant and antimicrobial activities of methanolic extract of Xanthium strumarium L. leaves were evaluated on methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA) spp.Materials and Methods:Antiradical and antioxidant activities X. strumarium L. leaf extract were evaluated based on its ability to scavenge the synthetic 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and by the paired diene method, respectively, whereas the antimicrobial activity was assayed by the disc diffusion method.Statistical Analysis:Data were subjected to analysis of variance following an entirely random design to determine the least significant difference at P < 0.05 using SPSS v. 11.5.Results and Conclusions:The IC50 values of the extract were 0.02 mg/mL and 0.09 mg/mL for the antioxidant and DPPH-scavenging capacity, respectively. X. strumarium extract affected both methicillin-sensitive Staphylococcus aureus and MRSA, though antibacterial activity was more effective on methicillin-susceptible S. aureus spp. The antibacterial and antioxidant activities exhibited by the methanol extract may justify the traditional use of this plant as a folk remedy worldwide.

Co-occurrence of resistance to different antibiotics among aquatic bacteria.

BackgroundAntibiotic resistance is not confined to pathogens, but is also widespread in various natural environments. In nature the microbes producing antibiotic compounds have been around for millions of years. Heavy use of antibiotics in medicine and veterinary practice may lead to the accumulation of resistance genes in microbial populations, followed by a rise in multiresistant bacteria.ResultsTo test the extent of resistance among aquatic bacteria, we have collected 760 isolates resistant to at least one antibiotic. The phylogeny of the isolates covers a wide range of Proteobacteria, Actinobacteria and Bacteroidetes. In order to determine the extent of multiresistance, the isolates were tested on six antibiotics. As the growth rate of the different bacteria was highly variable, the classical medical resistance tests could not be used, and an alternative method considering the full growth curve was developed. In general, the overall resistances to different antibiotics could be explained by random, independent distribution. An exception to this was the resistances against tetracycline and chloramphenicol, which tended to occur in pairs.ConclusionsWe conclude that there is no massive spread of multiresistance determinants in the studied environment, although some specific cases can be found, awaiting for molecular characterization of the resistance mechanisms.

Membrane-Active Action Mode of Polybia-CP, a Novel Antimicrobial Peptide Isolated from the Venom of Polybia paulista

The extensive use of antibiotics in medicine, the food industry, and agriculture has resulted in the frequent emergence of multidrug-resistant bacteria, which creates an urgent need for new antibiotics. It is now widely recognized that antimicrobial peptides (AMPs) could play a promising role in fighting multidrug-resistant bacteria. Antimicrobial peptide polybia-CP was purified from the venom of the social wasp Polybia paulista. In this study, we synthesized polybia-CP and studied its action mode of antibacterial activity. Our results revealed that polybia-CP has potent antibacterial activity against both Gram-positive and Gram-negative bacteria. The results from both the real bacterial membrane and the in vitro model membrane showed that polybia-CP is membrane active and that its action target is the membrane of bacteria. It is difficult for bacteria to develop resistance to polybia-CP, which may thus offer a new strategy for defending against resistant bacteria in medicine and the food and farming industries.

Mechanisms of Penicillin Antibiotic Interactions with Human Erythrocytes

Significant effects of penicillin antibiotics, used in pediatrics, on the erythrocyte structural characteristics were detected by recording kinetic curves of osmotic and acid hemolysis. Possible relationships between erythrocyte properties and concentrations, duration of exposure to, and structure of antibiotics were revealed. Recommendations for dose correction for effective use of antibiotics in medicine with consideration for individual features of the patient are proposed.

The development of a rapid screening technique to measure antibiotic activity in effluents and surface water samples

Use of antibiotics in medicine, farming and aquaculture results in a continual supply of these pharmaceuticals and their breakdown products reaching the environment. A method has been developed to use for screening environmental samples to establish whether they contain antibiotics. The assay is based on a commercially available test kit and uses some modifications of the test procedure and SPE techniques to deliver a fast, semi-quantifiable result. Development of the assay and results from spiked and environmental samples are discussed.

Direct detection of antibiotic resistance genes in specimens of chicken and pork meat

Antibiotic resistance (AR) in bacteria, a major threat to human health, has emerged in the last few decades as a consequence of the selective pressure exerted by the widespread use of antibiotics in medicine, agriculture and veterinary practice and as growth promoters in animal husbandry. The frequency of 11 genes [ tet(M), tet(O), tet(K), erm(A), erm(B), erm(C), vanA, vanB, aac (6′)-Ie aph (2″)-Ia, mecA, blaZ] encoding resistance to some antibiotics widely used in clinical practice was analysed in raw pork and chicken meat and in fermented sausages as well as in faecal samples from the relevant farm animals using a molecular approach based on PCR amplification of bacterial DNA directly extracted from specimens. Some of the 11 AR genes were highly prevalent, the largest number being detected in chicken meat and pig faeces. The genes found most frequently in meat were tet(K) and erm(B); vanB and mecA were the least represented. All 11 determinants were detected in faecal samples except mecA, which was found only in chicken faeces. erm(B) and erm(C) were detected in all faecal samples. The frequency of AR genes was not appreciably different in meat compared to faecal specimens of the relevant animal except for vanB, which was more prevalent in faeces. Our findings suggest that AR genes are highly prevalent in food-associated bacteria and that AR contamination is likely related to breeding rather than processing techniques. Finally, the cultivation-independent molecular method used in this work to determine the prevalence of AR genes in foods proved to be a rapid and reliable alternative to traditional tools.

Impact des recommandations sur l’usage des antibiotiques en médecine de ville

Series of Recommendations regarding a proper use of antibiotics in medicine have been established during the last ten years. The epidemiology of bacterial resistance, a large number of viral infections treated empirically by antibiotics, the varying therapeutic strategies and the resulting high costs are factors leading to improvement and diffusion of recommendations. However their application in medical practice is somewhat disappointing. The application of “Opposable Medical References” (OMR) established in the 1980s in France has often resulted in irrational therapeutic strategies. The more recent offical Recommendations (AFSSAPS) have shown an even less reliable impact on antibiotic use but only few studies have evaluated their real effect. The development of rapid diagnostic tests will permit a much more proper and rational prescription, like in tonsillitis. Behaviour of practitioners in terms of Recommendations is extremely variable, depending on several social, psychological, economical factors ; the level of knowledge plays also a role: these factors are variably associated and they differ from one to another practice area. All “local actors” playing a role in antibiotic use must be implicated. This review analyses these factors and presents few solutions for control of antibiotic prescription.

Phagotherapy in terms of bacteriophage genetics: hopes, perspectives, safety, limitations

The appearance and spreading of multidrug-resistant bacterial pathogens is a consequence of the large-scale use of antibiotics in medicine. In view of this, claims for the phage therapy were renewed: in recent studies, the natural phages and their products neutralizing various proteins, as well as the bacterial products often controlled by defective prophages (bacteriocins) were applied for treatment of bacterial infections. Constructs obtained by gene engineering are increasingly used to change some bacteriophage: properties to expand the spectrum of their lytic activity and to eliminate therapeutic drawbacks of some natural phages. In this review, the problem of phage therapy is discussed in general with respect to bacteriophage properties, their genetics, structure, evolution, taking into account long-term experience of the author in the field of bacteriophage genetics. Note that the general concept of phage therapy should be developed to ensure long-term, efficient and harmless phage therapy.

Evolution of resistance in microorganisms of human origin

Resistance to antimicrobials in bacteria results from either evolution of “new” DNA or from variation in existing DNA. Evidence suggests that new DNA did not originate since the use of antibiotics in medicine, but evolved long ago in soil bacteria. This evidence is based on functional and structural homologies of resistance proteins in human pathogens, and resistance proteins or physiological proteins of soil bacteria. Variation in existing DNA has been shown to comprise variations in structural or regulatory genes of the normal chromosome or mutations in already existing plasmid-mediated resistance genes modifying the resistance phenotype. The success of R-determinants in human pathogens was due to their horizontal spread by transformation, transduction and conjugation. Futhermore, transposition has enabled bacteria to efficiently distribute R-determinants between independent DNA-molecules. Since the genetic processes involved in the development of resistance are rare events, the selective pressure exerted by antibiotics has significantly contributed to the overall evolutionary picture. With few exceptions, experimental data about the role of antibiotic usage outside human medicine with respect to the resistance problem in human pathogens are missing. Epidemiological data about the occurrence of resistance in human pathogens seem to indicate that the major contributing factor to the problem we face today was the extensive use of antibiotics in medicine itself.

Conjugative plasmids in bacteria of the ‘pre-antibiotic’ era

Antibiotic resistance is common in bacteria that cause disease in man and animals and is usually determined by plasmids. The prevalence of such plasmids, and the range of drugs to which they confer resistance, have increased greatly in the past 25 yr. It has become clear from work in many laboratories that plasmids have acquired resistance genes, of ultimately unknown origin, as insertions into their circular DNA. The intensive use of antibiotics since their introduction in the 1940s can explain the spread of plasmids that have acquired such genes but little is known of the incidence of plasmids in pathogenic bacteria before the widespread use of antibiotics in medicine. E.D.G. Murray collected strains of Enterobacteriaceae from 1917 to 1954; we now report that 24% of these encode information for the transfer of DNA from one bacterium to another. From at least 19% of the strains, conjugative plasmids carrying no antibiotic resistance were transferred to Escherichia coli K-12.