Franco, Beatriz Espinosa; Altagracia Martínez, Marina; Sánchez Rodríguez, Martha A; Wertheimer, Albert I
The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community. To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem. We conducted a MedLine search using the key words "determinants", "antibiotic", and "antibiotic resistance" to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded. The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance. Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.
Beatriz Espinosa Franco
Full Text Available Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM, Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community.Objectives: To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem.Methods: We conducted a MedLine search using the key words “determinants”, “antibiotic”, and “antibiotic resistance” to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded.Results: The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance.Conclusions: Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.Keywords: antibiotic drug resistance
Convergent acquisition of antibiotic resistance determinants amongst the Enterobacteriaceae isolates of the Mhlathuze River, KwaZulu-Natal (RSA) ... The possibility of transmission of resistant genes between bacteria (especially pathogenic) which invade human and animal populations within this river poses a health risk ...
Beatriz Espinosa Franco; Marina Altagracia Martínez; Martha A Sánchez Rodríguez; Albert I Wertheimer
Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM), Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a se...
Martinez, Jose Luis
Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.
Martinez, Jose Luis, E-mail: firstname.lastname@example.org [Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Darwin 3, Cantoblanco, 28049 Madrid, and CIBERESP (Spain)
Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.
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Full Text Available In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance.
Godziszewska, Jolanta; Guzek, Dominika; Głąbski, Krzysztof; Wierzbicka, Agnieszka
In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance.
Blanco, Paula; Hernando-Amado, Sara; Reales-Calderon, Jose Antonio; Corona, Fernando; Lira, Felipe; Alcalde-Rico, Manuel; Bernardini, Alejandra; Sanchez, Maria Blanca; Martinez, Jose Luis
Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics. PMID:27681908
Blanco, Paula; Hernando-Amado, Sara; Reales-Calderon, Jose Antonio; Corona, Fernando; Lira, Felipe; Alcalde-Rico, Manuel; Bernardini, Alejandra; Sanchez, Maria Blanca; Martinez, Jose Luis
Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics.
otic susceptibility study using disc-diffusion method. Transferable resistance genes and MGEs were amplified using Polymerase chain reaction (PCR) analysis and amplicons sequenced. Results: Varied resistance was observed against all the antibiotics tested. About 56% of the isolates were MDR including those from ...
Hansen, Malene Plejdrup; Hoffmann, Tammy C; McCullough, Amanda R
Numerous opportunities are available in primary care for alleviating the crisis of increasing antibiotic resistance. Preventing patients from developing an acute respiratory infection (ARI) will obviate any need for antibiotic use downstream. Hygiene measures such as physical barriers and hand...... will greatly improve the use of antibiotics for ARIs. However, used in concert, combinations are likely to enable clinicians and health care systems to implement the strategies that will reduce antimicrobial resistance in the future....... antibiotic prescribing are a major factor in the prescribing for ARIs. Professional interventions with educational components are effective, although they have modest effects, and are expensive. GPs' perceptions - that mistakenly assume as a default that patients want antibiotics for their ARIs - are often...
Hoettges, Kai F; Dale, Jeremy W; Hughes, Michael P
In recent years, infections due to antibiotic-resistant strains of bacteria such as methillicin-resistant Staphylococcus aureus and ciprofloxacin-resistant Escherichia coli are on the rise, and with them the demand for rapid antibiotic testing is also rising. Conventional tests, such as disc diffusion testing, require a primary sample to be tested in the presence of a number of antibiotics to verify which antibiotics suppress growth, which take approximately 24 h to complete and potentially place the patient at severe risk. In this paper we describe the use of dielectrophoresis as a rapid marker of cell death, by detecting changes in the electrophysiology of the cell caused by the administration of an antibiotic. In contrast to other markers, the electrophysiology of the cell changes rapidly during cell death allowing live cells to be distinguished from dead (or dying) cells without the need for culturing. Using polymyxin B as an example antibiotic, our studies indicate that significant changes in cell characteristics can be observed as soon as 1 h passes after isolating a culture from nutrient broth
of antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I......Bacteria can avoid extinction during antimicrobial exposure by becoming resistant. They achieve this either via adaptive mutations or horizontally acquired resistance genes. If resistance emerges in clinical relevant species, it can lead to treatment failure and ultimately result in increasing...... morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources...
Lisa Ann Blankinship
Full Text Available Sampling of common use items (e.g., student cell phones for bacterial presence, identification, and antibiotic resistance profiling helps students to recognize the need for routine cleaning of personal items and encourages thoughtful use of currently available medications. This multilab period project can be used to teach or reinforce several methods from general microbiology including aseptic technique, isolation streak, serial dilution, spread plating, Kirby Bauer testing, unknown identification, and media production. The data generated can be saved and added to each semester, thus providing a data set that reflects a local trend of antibiotic resistance.
Rothrock, Michael J; Keen, Patricia L; Cook, Kimberly L; Durso, Lisa M; Franklin, Alison M; Dungan, Robert S
Although historically, antibiotic resistance has occurred naturally in environmental bacteria, many questions remain regarding the specifics of how humans and animals contribute to the development and spread of antibiotic resistance in agroecosystems. Additional research is necessary to completely understand the potential risks to human, animal, and ecological health in systems altered by antibiotic-resistance-related contamination. At present, analyzing and interpreting the effects of human and animal inputs on antibiotic resistance in agroecosystems is difficult, since standard research terminology and protocols do not exist for studying background and baseline levels of resistance in the environment. To improve the state of science in antibiotic-resistance-related research in agroecosystems, researchers are encouraged to incorporate baseline data within the study system and background data from outside the study system to normalize the study data and determine the potential impact of antibiotic-resistance-related determinants on a specific agroecosystem. Therefore, the aims of this review were to (i) present standard definitions for commonly used terms in environmental antibiotic resistance research and (ii) illustrate the need for research standards (normalization) within and between studies of antibiotic resistance in agroecosystems. To foster synergy among antibiotic resistance researchers, a new surveillance and decision-making tool is proposed to assist researchers in determining the most relevant and important antibiotic-resistance-related targets to focus on in their given agroecosystems. Incorporation of these components within antibiotic-resistance-related studies should allow for a more comprehensive and accurate picture of the current and future states of antibiotic resistance in the environment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.
... in Farm Animals FDA: Cutting-Edge Technology Sheds Light on Antibiotic Resistance For More Information Antibiotics and Antibiotic Resistance Antimicrobial Resistance Information for Consumers and Health Professionals CDC: Get Smart: Know When Antibiotics Work More in Consumer Updates ...
Walsh, Ciara; Duffy, Geraldine
Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 anti...
Duque, Estrella; Fernández, Matilde; Molina-Santiago, Carlos; Roca, Amalia; Porcel, Mario; de la Torre, Jesús; Segura, Ana; Plesiat, Patrick; Jeannot, Katy; Ramos, Juan-Luis
Environmental microbes harbor an enormous pool of antibiotic and biocide resistance genes that can impact the resistance profiles of animal and human pathogens via horizontal gene transfer. Pseudomonas putida strains are ubiquitous in soil and water but have been seldom isolated from humans. We have established a collection of P. putida strains isolated from in-patients in different hospitals in France. One of the isolated strains (HB3267) kills insects and is resistant to the majority of the antibiotics used in laboratories and hospitals, including aminoglycosides, ß-lactams, cationic peptides, chromoprotein enediyne antibiotics, dihydrofolate reductase inhibitors, fluoroquinolones and quinolones, glycopeptide antibiotics, macrolides, polyketides and sulfonamides. Similar to other P. putida clinical isolates the strain was sensitive to amikacin. To shed light on the broad pattern of antibiotic resistance, which is rarely found in clinical isolates of this species, the genome of this strain was sequenced and analysed. The study revealed that the determinants of multiple resistance are both chromosomally-borne as well as located on the pPC9 plasmid. Further analysis indicated that pPC9 has recruited antibiotic and biocide resistance genes from environmental microorganisms as well as from opportunistic and true human pathogens. The pPC9 plasmid is not self-transmissible, but can be mobilized by other bacterial plasmids making it capable of spreading antibiotic resistant determinants to new hosts. PMID:24465371
Oldfield, Eric; Feng, Xinxin
New antibiotics are needed because drug resistance is increasing while the introduction of new antibiotics is decreasing. We discuss here six possible approaches to develop 'resistance-resistant' antibiotics. First, multitarget inhibitors in which a single compound inhibits more than one target may be easier to develop than conventional combination therapies with two new drugs. Second, inhibiting multiple targets in the same metabolic pathway is expected to be an effective strategy owing to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, repurposing existing drugs can lead to combinations of multitarget therapeutics. Fifth, targets need not be proteins. Sixth, inhibiting virulence factor formation and boosting innate immunity may also lead to decreased susceptibility to resistance. Although it is not possible to eliminate resistance, the approaches reviewed here offer several possibilities for reducing the effects of mutations and, in some cases, suggest that sensitivity to existing antibiotics may be restored in otherwise drug-resistant organisms. Copyright © 2014 Elsevier Ltd. All rights reserved.
... Work Contact Us ABOUT THE ISSUE What is Antibiotic Resistance? General Background Science of Resistance Glossary References ... for Adaptation Genetics and Drug Resistance Reservoirs of Antibiotic Resistance Project (ROAR) INTERNATIONAL CHAPTERS APUA Chapter Network ...
Full Text Available As one of the most influential and troublesome human pathogens, Acinetobacter baumannii (A. baumannii has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices. These 35 antigens include 11 TonB dependent receptors, 8 porins, 7 efflux pump proteins, and 2 fimbrial proteins (FilF and CAM87009.1. CAM86003.1 was predicted to be an adhesin outer membrane protein absent from 3 antibiotic-sensitive strains and conserved in 21 antibiotic-resistant strains. Feasible anti-resistance vaccine candidates also include one extracellular protein (QnrA, 3 RND type outer membrane efflux pump proteins, and 3 CTX-M type β-lactamases. Among 39 β-lactamases, A. baumannii CTX-M-2, -5, and -43 enzymes are predicted as adhesins and better vaccine candidates than other β-lactamases to induce preventive immunity and enhance antibiotic treatments. This report represents the first reverse vaccinology study to systematically predict vaccine antigen candidates against antibiotic resistance for a microbial pathogen.
Ni, Zhaohui; Chen, Yan; Ong, Edison; He, Yongqun
As one of the most influential and troublesome human pathogens, Acinetobacter baumannii ( A. baumannii ) has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices. These 35 antigens include 11 TonB dependent receptors, 8 porins, 7 efflux pump proteins, and 2 fimbrial proteins (FilF and CAM87009.1). CAM86003.1 was predicted to be an adhesin outer membrane protein absent from 3 antibiotic-sensitive strains and conserved in 21 antibiotic-resistant strains. Feasible anti-resistance vaccine candidates also include one extracellular protein (QnrA), 3 RND type outer membrane efflux pump proteins, and 3 CTX-M type β-lactamases. Among 39 β-lactamases, A. baumannii CTX-M-2, -5, and -43 enzymes are predicted as adhesins and better vaccine candidates than other β-lactamases to induce preventive immunity and enhance antibiotic treatments. This report represents the first reverse vaccinology study to systematically predict vaccine antigen candidates against antibiotic resistance for a microbial pathogen.
Background: Globally, and particularly in developing countries, the menace of anti-microbial resistance is an accelerating problem. In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies have been reported. Objectives: This study screened for presence of ...
Abstract. Background: Globally, and particularly in developing countries, the menace of anti-microbial resistance is an accelerating prob- lem. In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies have been reported. Objectives: This study screened for ...
María B Sánchez
Full Text Available Environmental bacteria harbor a plethora of genes that, upon their horizontal transfer to new hosts, may confer resistance to antibiotics, although the number of such determinants actually acquired by pathogenic bacteria is very low. The founder effect, fitness costs and ecological connectivity all influence the chances of resistance transfer being successful. We examined the importance of these bottlenecks using the family of quinolone resistance determinants Qnr. The results indicate the epigenetic compatibility of a determinant with the host genome to be of great importance in the acquisition and spread of resistance. A plasmid carrying the widely distributed QnrA determinant was stable in Escherichia coli, whereas the SmQnr determinant was unstable despite both proteins having very similar tertiary structures. This indicates that the fitness costs associated with the acquisition of antibiotic resistance may not derive from a non-specific metabolic burden, but from the acquired gene causing specific changes in bacterial metabolic and regulatory networks. The observed stabilization of the plasmid encoding SmQnr by chromosomal mutations, including a mutant lacking the global regulator H-NS, reinforces this idea. Since quinolones are synthetic antibiotics, and since the origin of QnrA is the environmental bacterium Shewanella algae, the role of QnrA in this organism is unlikely to be that of conferring resistance. Its evolution toward this may have occurred through mutations or because of an environmental change (exaptation. The present results indicate that the chromosomally encoded Qnr determinants of S. algae can confer quinolone resistance upon their transfer to E. coli without the need of any further mutation. These results suggest that exaptation is important in the evolution of antibiotic resistance.
... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Antibiotic-Resistant Gonorrhea Recommend on Facebook Tweet Share Compartir ... Threat Gonorrhea has progressively developed resistance to the antibiotic drugs prescribed to treat it. Following the spread ...
Seyyedeh Hoorieh Fallah
Full Text Available Background: Salmonellosis is one of the most common food borne diseases in industrial and developing countries. In recent years, an increase in antimicrobial drug resistance, among non-typhoid Salmonella spp has been observed. Objectives: The aim of this study was to isolate and determine antibiotic resistance pattern in non-typhoid Salmonella spp. Materials and Methods: This descriptive study was done on 100 samples of chickens collected from 196 retail markets and was examined for the presence of Salmonella using standard bacteriological procedures and stereotyping kit. Antimicrobial susceptibility testing was performed by disk diffusion methods according to the National Committee for Clinical Laboratory Standards (CLSI. The data were analyzed by using the SPSS software version 18. Result: Forty- four percent of samples were contaminated with Salmonella infection and 56% didn’t have any contamination. The stereotyping results showed that 34 of 44 isolates of Salmonella belonged to Salmonella infantis (79.5 %, one strain (2.3% of group C and 8 strain (18.2% of group D. However, all these strains were sensitive to Cefotaxime and Ciprofloxacin, and 100% were resistant to Nalidixic acid, Tetracyclin and Sterptomycin. The most common resistance pattern (34.1% was towards six antibiotics, and 6.8% of strains were resistant to at least three antibiotics. Conclusion: High levels of resistance to antibiotics that are used commonly for human and poultry can be a warning for our community health and this information must be used to form important strategies for improvement of infection control.
The use of antibiotics in animal production has been highlighted as a key contributor to the increasing prevalence of antibiotic resistance in agroecosystems. Gram negative bacteria, such as the Enterobacteriaceae, are important facilitators for resistance gene dissemination in the environment and i...
... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Antibiotic-Resistant Gonorrhea Basic Information Recommend on Facebook Tweet Share Compartir Antibiotic-Resistant Gonorrhea: An Overview Antibiotic resistance is the ...
Johari, Juliana; Huebner, Yvonne; Hull, Judith C; Dale, Jeremy W; Hughes, Michael P
The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics. (note)
Longenecker, Nevin E.; Oppenheimer, Dan
A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)
One of the major threats to human health in the 21st century is the emergence of pathogenic bacteria that are resistant to multiple antibiotics, thereby limiting treatment options. An important route through which pathogens become resistant is via acquisition of resistance genes from environmental
One of the major threats to human health in the 21st century is the emergence of pathogenic bacteria that are resistant to multiple antibiotics, thereby limiting treatment options. An important route through which pathogens become resistant is via acquisition of resistance genes from
Elal Mus, Tulay; Cetinkaya, Figen; Cibik, Recep; Soyutemiz, Gul Ece; Simsek, Husniye; Coplu, Nilay
In this study, the presence of genes responsible for the pathogenicity and antibiotic resistance profile of enterococci isolated from various foodstuffs of animal origin was investigated. The percentage prevalence of enterococci was 54.1% (203/375) and the average count was found to be 3.81 log cfu/ml-g. Species-specific primers revealed Enterococcus faecalis as the predominant species carrying one or more virulence-associated traits of efa, gelE, ace, esp and agg genetic markers. Only one E. faecium isolate (from milk) was positive for the esp gene. Regarding antibiotic resistance, the highest frequency of resistance was observed for tetracycline (21.7%), followed by quinupristin/dalfopristin (13.3%), ciprofloxacin (2.0%), penicillin (2.0%), linezolid (1.0%), ampicillin (1.0%), streptomycin (1.0%), and gentamicin (0.5%). Enterococcus faecalis showed a higher prevalence of antibiotic resistance than other enterococci. The percentage of multidrug resistance among the isolates was 3.4%. Twenty-nine E. faecalis isolates (26.6%) carrying one of the virulence-associated traits were at the same time resistant to at least one antibiotic. Our results show that foods of animal origin, including ready-to-eat products, may be reservoirs of antibiotic-resistant and potentially virulent enterococci.
Wright, Gerard D
Rooted in the mechanism of action of antibiotics and subject to bacterial evolution, antibiotic resistance is difficult and perhaps impossible to overcome. Nevertheless, strategies can be used to minimize the emergence and impact of resistance. Antibiotic adjuvants offer one such approach. These are compounds that have little or no antibiotic activity themselves but act to block resistance or otherwise enhance antibiotic action. Antibiotic adjuvants are therefore delivered in combination with antibiotics and can be divided into two groups: Class I agents that act on the pathogen, and Class II agents that act on the host. Adjuvants offer a means to both suppress the emergence of resistance and rescue the activity of existing drugs, offering an orthogonal strategy complimentary to new antibiotic discovery VIDEO ABSTRACT. Copyright © 2016 Elsevier Ltd. All rights reserved.
Farid Khalili Borujeni
Full Text Available Background and objectives: Listeria monocytogenes and Listeria ivanovii are two pathogenic species of Listeria. The role of Listeria ivanovii is important in abortion, stillbirth, septicemia in animals and this bacterium sometimes is pathogenic in humans. Contamination of ovine carcasses during the slaughter and processing can cause foodborne infections in humans. In this study we examined the contamination of sheep meat in slaughter house of Shahrekord city to Listeria ivanovii and determined its antibiotic resistance pattern.Material and Methods: A total 200 samples of sheep meat were collected from abattoir and processed by use of two enrichment method. After doing specific biochemical tests and PCR, Listeria spp was identified and antibiotic resistance of isolated Listeria were tested by the agar disc diffusion method. Results: The contamination of sheep carcasses with listeria was 2.5% (5 out of 200 samples. All five isolates (2.5% were recognized as Listeria ivanovii and were resistant to four antibiotics, sensitive to six antibiotics and intermediate to other antibiotics. Conclusion: According to the contamination rate in sheep carcasses with Listeria ivanovii and the relatively high antibiotic resistance specified in this bacteria, the role of red meat in transmission of Listeria spp. and appropriate use of antibiotics against this bacteria should be considered.
Full Text Available Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic-resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic-resistance in pathogens. In the natural milieu, antibiotics are often found to be present in subinhibitory concentrations acting as signalling molecules supporting quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host-parasite interactions (e.g., phagocytosis, adherence to the target cell and so on. The evolutionary and ecological aspects of antibiotics and antibiotic-resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behaviour of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and genes that confer resistance to antibiotics in
Le, Thai-Hoang; Ng, Charmaine; Chen, Hongjie; Yi, Xin Zhu; Koh, Tse Hsien; Barkham, Timothy Mark Sebastian; Zhou, Zhi; Gin, Karina Yew-Hoong
Wastewater discharged from clinical isolation and general wards at two hospitals in Singapore was examined to determine the emerging trends of antibiotic resistance (AR). We quantified the concentrations of 12 antibiotic compounds by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS), antibiotic-resistant bacteria (ARB), the class 1 integrase gene (intI1), and 16 antibiotic resistance genes (ARGs) that confer resistance to 10 different clinically relevant antibiotics. A subset of 119 antibiotic-resistant isolates were phylogenetically classified and tested for the presence of ARGs encoding resistance to β-lactam antibiotics (bla NDM , bla KPC , bla SHV , bla CTX-M ), amikacin [aac(6')-Ib], co-trimoxazole (sul1, sul2, dfrA), ciprofloxacin (qnrA, qnrB), and the intI1 gene. Among these resistant isolates, 80.7% were detected with intI1 and 66.4% were found to carry at least 1 of the tested ARGs. Among 3 sampled locations, the clinical isolation ward had the highest concentrations of ARB and the highest levels of ARGs linked to resistance to β-lactam (bla KPC ), co-trimoxazole (sul1, sul2, dfrA), amikacin [aac(6')-Ib], ciprofloxacin (qnrA), and intI1 We found strong positive correlations (P bacteria resistant to meropenem, ceftazidime, amikacin, co-trimoxazole, and ciprofloxacin and abundances of bla KPC , aac(6')-Ib, sul1, sul2, dfrA, qnrA, and intI1 genes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Full Text Available Introduction & Objective: Methicillin–Resistant Staphylococcus aureus (MRSA is one of the most important causes of hospital infections worldwide. Treatment of these infections has become more difficult because of resistance to methicillin/oxacillin and other antibiotics. The aim of this study was to determine the incidence of MRSA infections in hospitals affiliated to Hamadan University of Medical Sciences.Materials & Methods: Seventy S. aureus clinical strains were isolated from patients from June, 2005 to June, 2006 and examined by conventional microbiological tests and PCR, respectively. Then, the antibiotic susceptibility to methicillin/oxacillin and other antibiotic were performed by Disk Diffusion Agar (DDA.Results: The results of this study showed that Methicillin resistance gene was detected in 35 (50% and 22 (31.4% cases by PCR and DDA, respectively. The results of antibiotic sensitivity assays also showed there was high resistance in MRSA strains to Penicillin (100%, Cloxacillin (91.4%, Tetracycline (74.2%, Cotrimoxazole (68.6% Erythromycin (68.5% and Ceftazidim (51.4%. The strains of Methicillin-Sensitive Staphylococcus aureus (MSSA showed high sensitivity results to antibiotic used, except penicillin, which all of the isolates were penicillin resistance.Conclusion: As a conclusion, the resistant to methicillin/oxacillin in Hamadan hospitals has reached to 50% and they show multi-drug resistant.
Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed.
Murgia, Manuela; Bouchrif, Brahim; Timinouni, Mohammed; Al-Qahtani, Ahmed; Al-Ahdal, Mohammed N; Cappuccinelli, Pietro; Rubino, Salvatore; Paglietti, Bianca
Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies. Copyright © 2015 Elsevier B.V. All rights reserved.
Bulajić Snežana; Mijačević Zora; Savić-Radovanović Radoslava
Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolat...
Munita, Jose M.; Arias, Cesar A.
Emergence of resistance among the most important bacterial pathogens is recognized as a major public health threat affecting humans worldwide. Multidrug-resistant organisms have emerged not only in the hospital environment but are now often identified in community settings, suggesting that reservoirs of antibiotic-resistant bacteria are present outside the hospital. The bacterial response to the antibiotic “attack” is the prime example of bacterial adaptation and the pinnacle of evolution. “Survival of the fittest” is a consequence of an immense genetic plasticity of bacterial pathogens that trigger specific responses that result in mutational adaptations, acquisition of genetic material or alteration of gene expression producing resistance to virtually all antibiotics currently available in clinical practice. Therefore, understanding the biochemical and genetic basis of resistance is of paramount importance to design strategies to curtail the emergence and spread of resistance and devise innovative therapeutic approaches against multidrug-resistant organisms. In this chapter, we will describe in detail the major mechanisms of antibiotic resistance encountered in clinical practice providing specific examples in relevant bacterial pathogens. PMID:27227291
Grossman, Trudy H
Tetracyclines possess many properties considered ideal for antibiotic drugs, including activity against Gram-positive and -negative pathogens, proven clinical safety, acceptable tolerability, and the availability of intravenous (IV) and oral formulations for most members of the class. As with all antibiotic classes, the antimicrobial activities of tetracyclines are subject to both class-specific and intrinsic antibiotic-resistance mechanisms. Since the discovery of the first tetracyclines more than 60 years ago, ongoing optimization of the core scaffold has produced tetracyclines in clinical use and development that are capable of thwarting many of these resistance mechanisms. New chemistry approaches have enabled the creation of synthetic derivatives with improved in vitro potency and in vivo efficacy, ensuring that the full potential of the class can be explored for use against current and emerging multidrug-resistant (MDR) pathogens, including carbapenem-resistant Enterobacteriaceae, MDR Acinetobacter species, and Pseudomonas aeruginosa. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.
Rams, Thomas E.; Degener, John E.; van Winkelhoff, Arie J.
Background: Patients with chronic periodontitis (CP) may yield multiple species of putative periodontal bacterial pathogens that vary in their antibiotic drug susceptibility. This study determines the occurrence of in vitro antibiotic resistance among selected subgingival periodontal pathogens in
Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue.
Barton, Mary D; Pratt, Rachael; Hart, Wendy S
There is currently no systematic surveillance or monitoring of antibiotic resistance in Australian animals. Registration of antibiotics for use in animals is tightly controlled and has been very conservative. Fluoroquinolones have not been registered for use in food producing animals and other products have been removed from the market because of human health concerns. In the late 1970s, the Animal Health Committee coordinated a survey of resistance in Salmonella and Escherichia coli isolates from cattle, pigs and poultry and in bovine Staphylococcus aureus. Some additional information is available from published case reports. In samples collected prior to the withdrawal of avoparcin from the market, no vancomycin resistant Enterococcus faecium or Enterococcus faecalis were detected in samples collected from pigs, whereas some vanA enterococci, including E. faecium and E. faecalis, were found in chickens. No vanB enterococci were detected in either species. Virginiamycin resistance was common in both pig and poultry isolates. Multiple resistance was common in E. coli and salmonellae isolates. No fluoroquinolone resistance was found in salmonellae, E. coli or Campylobacter. Beta-lactamase production is common in isolates from bovine mastitis, but no methicillin resistance has been detected. However, methicillin resistance has been reported in canine isolates of Staphylococcus intermedius and extended spectrum beta-lactamase producing E. coli has been found in dogs.
Kabir Md. Shahidul; Akter Asma; Feroz Farahnaaz; Ahsan Sunjukta
The present study was aimed to ascertain the antimicrobial resistance of pathogenic bacteria associated with urinary tract infections (UTIs). Escherichia coli was found to be the most prevalent uropathogen (75.0%), followed by Klebsiella pneumoniae (12.5%), Pseudomonas spp. (8.33%) and Staphylococcus aureus (4.16%). Isolated bacteria (n=24) were characterized for their sensitivity to commonly prescribed antibiotics. Although Congo red binding assay indicated that all of the isolates (100%) we...
Sang Hee Lee
Full Text Available Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs and various data such as pharmacokinetic (PK and pharmacodynamic (PD properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST, clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic resistance. All major resistance-control strategies recommend education for patients, children (e.g., through schools and day care, the public, and relevant healthcare professionals (e.g., primary-care physicians, pharmacists, and medical students regarding unique features of bacterial infections and antibiotics, prudent antibiotic prescribing as a positive construct, and personal hygiene (e.g., handwashing. The problem of antibiotic resistance can be minimized only by concerted efforts of all members of society for ensuring the continued efficiency of antibiotics.
Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.
Johnson, Alan P.
Surveillance involves the collection and analysis of data for the detection and monitoring of threats to public health. Surveillance should also inform as to the epidemiology of the threat and its burden in the population. A further key component of surveillance is the timely feedback of data to stakeholders with a view to generating action aimed at reducing or preventing the public health threat being monitored. Surveillance of antibiotic resistance involves the collection of antibiotic susceptibility test results undertaken by microbiology laboratories on bacteria isolated from clinical samples sent for investigation. Correlation of these data with demographic and clinical data for the patient populations from whom the pathogens were isolated gives insight into the underlying epidemiology and facilitates the formulation of rational interventions aimed at reducing the burden of resistance. This article describes a range of surveillance activities that have been undertaken in the UK over a number of years, together with current interventions being implemented. These activities are not only of national importance but form part of the international response to the global threat posed by antibiotic resistance. PMID:25918439
Full Text Available Background: Urinary tract infection (UTI is the second prevalent infection in human mostly caused by Escherichia coli and Klebsiella pneumonia. The aim of this study was to determine the antibiotic resistance profile and detect the prevalence of antibiotic resistance encoding genes in K .pneumoniae isolated from UTI. Materials and Methods: Fifty K. pneumonia strains isolated from 122 UTI samples of hospitalized patients in Payambaran Hospital (Tehran, Iran which were subjected to this study (2014 were confirmed by standard biochemical tests. Isolates were tested for susceptibility to 10 antimicrobial drugs by using disk diffusion method. Antibiotic resistance encoding genes frequently include the aadA1, aac(3-IV, sul1, blaSHV, Cat1, cmlA, tetA, tetB, dfrA1, CITM, qnr in isolates were determined by PCR. Results: The highest antibiotic resistance in K. pneumoniae isolates were for Tetracycline and the lowest resistance (2% for Gentamicin and Imipenem. To determine the frequency of antibiotic resistant genes, 64% and 4% of isolates had tetA and Gentamicin-(aac(3-IV resistant genes, respectively. Conclusion: Frequency of antibiotic resistance encoding genes may have important and basic role in the occurrence and transfer of antibiotic resistance which can be due to the indiscriminate use of antibiotics.
Full Text Available The aim of the present study was to develop a PCR assay for identification of antibiotic resistance genes at Staphylococcus aureus clinical isolates. Thirty five isolates from the Emergency County Hospital and Clinical Hospital for Infectious Diseases in Cluj-Napoca, Romania, were analyzed. The bacteria were isolated over two years period, in 2007 and 2009 and serotyped at the Clinical Hospital of Infectious Disease, Cluj-Napoca. In order to develop a PCR assay for identification of antibiotic resistance genes at S. aureus clinical isolates, the bacterial strains were tested for the presence of the tst, sea, mecA, femA, ermC and ermA genes using the polymerase chain reaction and gene-specific primers. We succeeded in amplifying mecA gene to all isolates that exhibit methicillin resistance. Our result concord 100% with standard culture method but they were obtained in 5 hours instead of four days. In order to increase the efficiency of PCR typing and reduce reagent costs, multiple sets of primers were included in a single reaction tube in a multiplex PCR. We succeeded in elaborating a multiplex PCR for mecA and femA genes.
Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger
isolates). In addition, 23 isolates had "empty" integrons without inserted gene cassettes. As far as OTC resistance was concerned, only 66 (30%) out of 216 resistant aeromonads could be assigned to resistance determinant class A (19 isolates), D (n = 6), or E (n = 39); three isolates contained two...... tetracycline resistance determinants (AD, AE, and DE). Forty OTC-resistant isolates containing large plasmids were selected as donors in a conjugation assay, 27 of which also contained a class I integron. Out of 17 successful R- plasmid transfers to Escherichia coli recipients, the respective integrons were...... cotransferred along with the tetracycline resistance determinants in 15 matings. Transconjugants were predominantly tetA positive (10 of 17) and contained class I integrons with two or more inserted antibiotic resistance genes. While there appeared to be a positive correlation between conjugative R...
Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff
The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.
McArthur, Andrew G.; Waglechner, Nicholas; Nizam, Fazmin; Yan, Austin; Azad, Marisa A.; Baylay, Alison J.; Bhullar, Kirandeep; Canova, Marc J.; De Pascale, Gianfranco; Ejim, Linda; Kalan, Lindsay; King, Andrew M.; Koteva, Kalinka; Morar, Mariya; Mulvey, Michael R.; O'Brien, Jonathan S.; Pawlowski, Andrew C.; Piddock, Laura J. V.; Spanogiannopoulos, Peter; Sutherland, Arlene D.; Tang, Irene; Taylor, Patricia L.; Thaker, Maulik; Wang, Wenliang; Yan, Marie; Yu, Tennison
The field of antibiotic drug discovery and the monitoring of new antibiotic resistance elements have yet to fully exploit the power of the genome revolution. Despite the fact that the first genomes sequenced of free living organisms were those of bacteria, there have been few specialized bioinformatic tools developed to mine the growing amount of genomic data associated with pathogens. In particular, there are few tools to study the genetics and genomics of antibiotic resistance and how it impacts bacterial populations, ecology, and the clinic. We have initiated development of such tools in the form of the Comprehensive Antibiotic Research Database (CARD; http://arpcard.mcmaster.ca). The CARD integrates disparate molecular and sequence data, provides a unique organizing principle in the form of the Antibiotic Resistance Ontology (ARO), and can quickly identify putative antibiotic resistance genes in new unannotated genome sequences. This unique platform provides an informatic tool that bridges antibiotic resistance concerns in health care, agriculture, and the environment. PMID:23650175
Full Text Available Abstract Background Antibiotics which inhibit bacterial peptidoglycan biosynthesis are the most widely used in current clinical practice. Nevertheless, resistant strains increase dramatically, with serious economic impact and effects on public health, and are responsible for thousands of deaths each year. Critical clinical situations should benefit from a rapid procedure to evaluate the sensitivity or resistance to antibiotics that act at the cell wall. We have adapted a kit for rapid determination of bacterial DNA fragmentation, to assess cell wall integrity. Results Cells incubated with the antibiotic were embedded in an agarose microgel on a slide, incubated in an adapted lysis buffer, stained with a DNA fluorochrome, SYBR Gold and observed under fluorescence microscopy. The lysis affects the cells differentially, depending on the integrity of the wall. If the bacterium is susceptible to the antibiotic, the weakened cell wall is affected by the lysing solution so the nucleoid of DNA contained inside the bacterium is released and spread. Alternatively, if the bacterium is resistant to the antibiotic, it is practically unaffected by the lysis solution and does not liberate the nucleoid, retaining its normal morphological appearance. In an initial approach, the procedure accurately discriminates susceptible, intermediate and resistant strains of Escherichia coli to amoxicillin/clavulanic acid. When the bacteria came from an exponentially growing liquid culture, the effect on the cell wall of the β-lactam was evident much earlier that when they came from an agar plate. A dose-response experiment with an E. coli strain susceptible to ampicillin demonstrated a weak effect before the MIC dose. The cell wall damage was not homogenous among the different cells, but the level of damage increased as dose increased with a predominant degree of effect for each dose. A microgranular-fibrilar extracellular background was evident in gram
Hamed, Engy A; AbdelRahman, Mona A A; Shalaby, Azhar G; Morsy, Mai M; Nasef, Soad A
Thirty-three isolates of Campylobacter coli and three isolates of Campylobacter jejuni were recovered from 150 1-day-old ducklings. All isolates were sensitive to chloramphenicol and amikacin, but resistant to sulfamethoxazole-trimethoprim (SXT) by the disc diffusion method. Most isolates were susceptible to tetracycline and erythromycin, but resistant to ofloxacin and ciprofloxacin. Of the 33 C. coli isolates, nine were positive for the tetracycline resistance gene tet(O), although only two of these were resistant to tetracycline in the disc diffusion test. None of the isolates possessed mutations in the quinolone resistance-determining region (QRDR) of the gyrA gene infrequently linked to FQ-resistance. The finding indicated that ducklings may be a source of antibiotic resistant Campylobacter spp. with potential poultry and public health hazard. Copyright © 2016 Elsevier Ltd. All rights reserved.
Tabasi, Mohsen; Asadi Karam, Mohammad Reza; Habibi, Mehri; Yekaninejad, Mir Saeed; Bouzari, Saeid
Urinary tract infection caused by uropathogenic Escherichia coli (UPEC) strains is one of the most important infections in the world. UPEC encode widespread virulence factors closely related with pathogenesis of the bacteria. The purpose of this study was to evaluate the presence of different phenotypic virulence markers in UPEC isolates and determine their correlation with antibiotic resistance pattern. UPEC isolates from patients with different clinical symptoms of UTI were collected and screened for biofilm and hemolysin production, mannose resistant, and mannose sensitive hemagglutination (MRHA and MSHA, respectively). In addition, antimicrobial resistance pattern and ESBL-producing isolates were recorded. Of the 156 UPEC isolates, biofilm and hemolysin formation was seen in 133 (85.3%) and 53 (34%) isolates, respectively. Moreover, 98 (62.8%) and 58 (37.2%) isolates showed the presence of Types 1 fimbriae (MSHA) and P fimbriae (MRHA), respectively. Our results also showed a relationship between biofilm formation in UPEC isolated from acute cystitis patients and recurrent UTI cases. Occurrence of UTI was dramatically correlated with the patients' profiles. We observed that the difference in antimicrobial susceptibilities of the biofilm and nonbiofilm former isolates was statistically significant. The UPEC isolates showed the highest resistance to ampicillin, tetracycline, amoxicillin, and cotrimoxazole. Moreover, 26.9% of isolates were ESBL producers. This study indicated that there is a relationship between the phenotypic virulence traits of the UPEC isolates, patients' profiles, and antibiotic resistance. Detection of the phenotypic virulence factors could help to improve understanding of pathogenesis of UPEC isolates and better medical intervention.
Perry, Julie; Waglechner, Nicholas; Wright, Gerard
Antibiotic resistance is a global problem that is reaching crisis levels. The global collection of resistance genes in clinical and environmental samples is the antibiotic "resistome," and is subject to the selective pressure of human activity. The origin of many modern resistance genes in pathogens is likely environmental bacteria, including antibiotic producing organisms that have existed for millennia. Recent work has uncovered resistance in ancient permafrost, isolated caves, and in human specimens preserved for hundreds of years. Together with bioinformatic analyses on modern-day sequences, these studies predict an ancient origin of resistance that long precedes the use of antibiotics in the clinic. Understanding the history of antibiotic resistance is important in predicting its future evolution. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.
Full Text Available The problem of antibiotic resistance is a serious threat to the global public health and requires action by both the state and the public. The World Health Organization identified 15 most dangerous and prevalent superbugs, which it ranked based on three levels of threat they present to the public health. At the heart of the fight against antibiotic resistance lies the increased awareness of the health professionals and general public that incorrect and excessive use of antibiotics amid poor practices in infection prevention and control contributes to the acceleration of antibiotic resistance.
Carnelli, Alessandro; Mauri, Federica; Demarta, Antonella
Aeromonas spp. and fecal coliforms, two abundant and cultivable bacterial populations that can be found in water ecosystems, might substantially contribute to the spread of antibiotic resistance. We investigated the presence and spread of transposons (elements that can move from one location to another in the genome), integrons (structures able to capture and incorporate gene cassettes) and resistance plasmids in strains isolated from polluted and unpolluted water. We recovered 231 Aeromonas and 250 fecal coliforms from water samplings with different degrees of pollution (hospital sewage, activated sludge of a wastewater treatment plant, river water before and after treatment and water from an alpine lake). Sixteen Aeromonas spp. and 22 fecal coliforms carried intI, coding for the site-specific integrase of class 1 integrons, while 22 Aeromonas spp. and 14 fecal coliforms carried tnpA, the transposase gene of the Tn3-family of replicative transposons. The majority of intI and tnpA-positive strains were phenotypically resistant to at least four antibiotics. Integrons and transposons were mainly located on mobilizable plasmids. Our results did not detect common mobile structures in the two populations and therefore relativize the role played by Aeromonas spp. as vectors of antimicrobial resistance determinants between water and commensal gut bacteria. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
Full Text Available Background: Shigellosis is endemic throughout the world and it is among the most common causes of bacterial diarrheal diseases. Antibiotic resistance of Shigella is becoming a progressive problem in world. The aim of this study was the survey of shigellosis frequency and determination of antibiotic resistance profile of isolated strains from infected children in Tehran. Material and Methods: This study conducted on 9131 patients with acute diarrheal disease. For isolation of Shigella spp. from stool samples, culture performed on different selective and differential media. After confirmation of bacteria by biochemical tests, susceptibility testing was done by disc diffusion method according to clinical and laboratory standards (CLSI recomendations. Results: Among 9131 stool samples, Shigella spp. was isolated from 90 cases. Shigella sonnei was the most common isolated species. 92/2 % of isolates were resistant to cotrimoxazole. In contrast, most of the Shigella spp. was founded to be sensitive to ciprofloxacin, imipenem and third-generation cephalosporins. Conclusion: Surveillance programs on antimicrobial resistance not only identify pathogenic bacterial species, by reporting data like serotyping, microorganisms incidence rates, and susceptibility to the antimicrobial agents currently used for treatment, but also contribute to monitoring the intervention strategies including removing organism from reservoirs.
Plantinga, Nienke L; Wittekamp, Bastiaan H J; van Duijn, Pleun J; Bonten, Marc J M
Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to classical infection prevention protocols and surveillance programs, counterintuitive interventions, such as selective decontamination with antibiotics and antibiotic rotation have been applied and investigated to control the emergence of antibiotic resistance. This review provides an overview of selective oropharyngeal and digestive tract decontamination, decolonization of methicillin-resistant Staphylococcus aureus and antibiotic rotation as strategies to modulate antibiotic resistance in the intensive care unit.
Miller, William R; Munita, Jose M; Arias, Cesar A
Multidrug-resistant (MDR) enterococci are important nosocomial pathogens and a growing clinical challenge. These organisms have developed resistance to virtually all antimicrobials currently used in clinical practice using a diverse number of genetic strategies. Due to this ability to recruit antibiotic resistance determinants, MDR enterococci display a wide repertoire of antibiotic resistance mechanisms including modification of drug targets, inactivation of therapeutic agents, overexpression of efflux pumps and a sophisticated cell envelope adaptive response that promotes survival in the human host and the nosocomial environment. MDR enterococci are well adapted to survive in the gastrointestinal tract and can become the dominant flora under antibiotic pressure, predisposing the severely ill and immunocompromised patient to invasive infections. A thorough understanding of the mechanisms underlying antibiotic resistance in enterococci is the first step for devising strategies to control the spread of these organisms and potentially establish novel therapeutic approaches. PMID:25199988
Full Text Available Water supply systems are the main source of potable water for many inhabitants. The European Union and Polish laws demand high quality of tap water, but the aspect of antibiotic resistant bacteria (ARB is not mentioned. The special emphasis is placed on the presence of pathogenic microorganisms in water, determining by the presence of chosen indicators. Although these regulations provide quite good quality of drinking water, the neglect of resistance vectors could lead to a serious threat to human health. In this study the randomly chosen sample of water from the Wroclaw water supply system was tested in order to evaluate the usefulness of Kirby-Bauer antibiogram method for the assessment of the presence of ARB. The susceptibility testing with 6 chosen antibiotics was performed on bacterial strains isolated from the sample. The diameters of growth inhibition zones were measured and the preliminary identification of strains was carried out, including Gram staining and bacterial cellular morphologies assessments. Although full recognition of the drug resistance phenomenon demands the identification of bacterial species for the comparison with susceptibility testing guidelines, this preliminary research could answer the question, whether the Kirby-Bauer method is sufficient for investigations of ARB dwelling in Wroclaw tap water or the other solution should be applied.
Mayrhofer, S.; Hoek, van A.H.A.M.; Mair, C.; Huys, G.; Aarts, H.J.M.; Kneifel, W.; Domig, K.J.
The range of antibiotic susceptibility to 13 antibiotics in 101 strains of the Lactobacillus acidophilus group was examined using the lactic acid bacteria susceptibility test medium (LSM) and broth microdilution. Additionally, microarray analysis and PCR were applied to identify resistance genes
Sommer, Morten; Dantas, Gautam
Since the discovery and clinical application of antibiotics, pathogens and the human microbiota have faced a near continuous exposure to these selective agents. A well-established consequence of this exposure is the evolution of multidrug-resistant pathogens, which can become virtually untreatable....... Less appreciated are the concomitant changes in the human microbiome in response to these assaults and their contribution to clinical resistance problems. Studies have shown that pervasive changes to the human microbiota result from antibiotic treatment and that resistant strains can persist for years...... expand our understanding of the interplay between antibiotics and the microbiome....
Akhtardanesh, Baharak; Ghanbarpour, Reza; Ganjalikhani, Sadaf; Gazanfari, Parisa
The aim of this study was to determine antibiotic resistance genes, phylogenetic groups and anti-microbial resistance patterns of Escherichia coli isolates from fecal samples of healthy pet cats in Kerman city. Ninety E. coli isolates were recovered from obtained rectal swabs. Antibiotic resistance pattern of the isolates against seven selected antibiotic was determined using disc diffusion method. Phylogenetic background of the isolates was determined according to the presence of the chuA , yjaA and TspE4C2 markers. Theisolates were examined to determine a selection of antibiotic resistance genes including tetA, tetB, aadA, sulI and dhfrV by polymerase chain reaction. Forty two isolates (46.6%) were positive at least for one of the examined genes. Phylotyping revealed that the isolates are segregated in phylogenetic groups A (66.7%), B1 (1.2%), B2 (13.4%) and D (18.9%). Among 90 isolates, 26.6% were positive for tetB gene, 10.0% for c qnrS gene, 12.3% for sulI and aadA genes, 8.9% for tetA and 2.2% for dhfrV gene. None of the E. coli isolates were positive for qnrA and qnrB genes. Sixteen combination patterns of antibiotic resistance genes were identified which belonged to four phylogroups. Maximum and minimum resistant isolates were recorded against to tetracycline (82.3%) and gentamycin (1.2%), respectively. Fifteen antibiotic resistance patterns were determined in different phylo-genetic groups. In conclusion, feces of healthy pet cat in Kerman could be a source of antibiotic resistant E. coli isolates, whereas these isolates were distributed all over the main phylogroups.
Bacterial resistance to antibiotics constitutes a major cause of failure in the treatment of bacterial infections. The genetic exchange of plasmids containing antibiotic resistant determinants between bacteria is believed to play a critical role in the evolution of antibiotics resistant bacteria and this has been shown in S. aureus.
Munoz-Price, L. Silvia; Frencken, Jos F.; Tarima, Sergey; Bonten, Marc
Elucidating quantitative associations between antibiotic exposure and antibiotic resistance development is important. In the absence of randomized trials, observational studies are the next best alternative to derive such estimates. Yet, as antibiotics are prescribed for varying time periods,
Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David
Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This
... resistance in the environment. The strong correlation (r=0.97) between the ARPs of the clinical and the environmental isolates may suggest a link between diarrhoeal incidence and the water quality in the region. It is thus imperative that the determination of antibiotic susceptibility/resistance patterns of isolated microbes is ...
9 mars 2015 ... strategy to prevent the spread of this resistance. Keywords: Staphylococci; Staphylococcus aureus; Oxacillin; Antibiotic resistance; Disc diffusion. Author Correspondence, e-mail: email@example.com. ICID: 1142924. Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at.
Viera Ducková; Margita Čanigová; Miroslav Kročko
Enterococci are important part of microflora of food animal origin. They have positive (probiotic effect, production flavor compounds during food ripening) and also negative (production biogenic amine, antibiotic resistance, biofilm production) properties. The aim of this work was to determine resistance to different concentrations of thyme essential oil and antibiotic resistance of enterococci isolated from pork (n=3) and poultry (n=17). The antibiotic resistance of isolates was determined b...
Hoiby, N.; Bjarnsholt, T.; Givskov, M.
A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...... to the survival of biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy and they can be treated by chronic suppressive therapy. A promising strategy may be the use of enzymes that can dissolve the biofilm matrix (e.g. DNase and alginate lyase) as well as quorum...
In the past 10 years, the number of strains of Streptococcus pneumoniae and other common respiratory pathogens that are resistant to penicillin has increased. The Iowa Department of Public Health convened a multidisciplinary task force in January 1998 to develop strategies to combat antibiotic resistance in the state because they were alarmed by these reports. Within 18 months, the task force implemented statewide surveillance of resistant organisms and posted information about the surveillance on the Internet, distributed a public health guide on judicious antibiotic use and infection control measures to 7500 healthcare providers, and held a press conference to inform the public about antibiotic resistance. The task force collaborated with several major insurers in the state to profile the top prescribers of antibiotic agents in their plan. The profiling and educational interventions led to a substantial decrease in both overall antibiotic prescribing and drug costs. Other states may want to undertake similar programs to help protect their citizens from infections caused by resistant pathogens.
Immediately after their introduction in the beginning of the fourties of the previous century, the agents used to combat infectious diseases caused by bacteria were regarded with suspicion, but not long thereafter antibiotics had the status of miracle drugs. For decades mankind has lived under the
Ghassan Khudhair Ismaeel
Full Text Available None response to the treatment by an antibiotic called antibiotics resistance result from some genes called resistance genes .This mechanism is widespread in most of the bacteria, like E.coli . All of the extended resistance genes called (ESBIS is a typical example for study of some genes that resistance beta-lactam antibiotic is subject of this research. Fifty feces sample were collected from cattle suffering from diarrhea in alqaissiyah city were cultured on selective media for E.coli , then DNA was extracted from all E.coli isolates for antibiotic resistance gene detection by PCR ; The results of this study revealed the prevalence of B-lactamase gene four B-lactamases genes in E.coli blaAmpc gene were (91.4%, the blactx-m gene were (80%, blaTem were (62.8% and finally and blaSHV gene were (22% among isolates E.coli ; blaAMPC gene has high prevalence than others genes while blaSHV was a lower percentage than other genes
Tian, Baoyu; Fadhil, Nibal H.; Powell, J. Elijah; Kwong, Waldan K.; Moran, Nancy A.
ABSTRACT Antibiotic treatment can impact nontarget microbes, enriching the pool of resistance genes available to pathogens and altering community profiles of microbes beneficial to hosts. The gut microbiota of adult honeybees, a distinctive community dominated by eight bacterial species, provides an opportunity to examine evolutionary responses to long-term treatment with a single antibiotic. For decades, American beekeepers have routinely treated colonies with oxytetracycline for control of larval pathogens. Using a functional metagenomic screen of bacteria from Maryland bees, we detected a high incidence of tetracycline/oxytetracycline resistance. This resistance is attributable to known resistance loci for which nucleotide sequences and flanking mobility genes were nearly identical to those from human pathogens and from bacteria associated with farm animals. Surveys using diagnostic PCR and sequencing revealed that gut bacteria of honeybees from diverse localities in the United States harbor eight tetracycline resistance loci, including efflux pump genes (tetB, tetC, tetD, tetH, tetL, and tetY) and ribosome protection genes (tetM and tetW), often at high frequencies. Isolates of gut bacteria from Connecticut bees display high levels of tetracycline resistance. Resistance genes were ubiquitous in American samples, though rare in colonies unexposed for 25 years. In contrast, only three resistance loci, at low frequencies, occurred in samples from countries not using antibiotics in beekeeping and samples from wild bumblebees. Thus, long-term antibiotic treatment has caused the bee gut microbiota to accumulate resistance genes, drawn from a widespread pool of highly mobile loci characterized from pathogens and agricultural sites. PMID:23111871
Sertaç Argun Kıvanç
Conclusion: Diabetic patients seem to be more prone to B. cereus infections than healthy individuals. It would be greatly beneficial to understand and recognize the prevalence of microorganisms and their resistance patterns for better outcome in ocular surgeries.
Ságová-Marečková, M.; Ulanová, Dana; Šanderová, P.; Omelka, M.; Kameník, Zdeněk; Olšovská, J.; Kopecký, J.
Roč. 15, APR 2015 (2015) ISSN 1471-2180 Institutional support: RVO:61388971 Keywords : Actinobacteria * 16S rRNA diversity * Resistance genes Subject RIV: EH - Ecology, Behaviour Impact factor: 2.581, year: 2015
Dubodelov, D V; Lubasovskaya, L A; Shubina, E S; Mukosey, I S; Korostin, D O; Kochetkova, T O; Bogacheva, N A; Bistritskiy, A A; Gordeev, A B; Trofimov, D Y; Priputnevich, T V; Zubkov, V V
According to the results of analysis of whole genome sequencing, the presence of genes having resistance to β-lactam antibiotics in hospital-associated strains of Klebsiella pneumoniae was studied. The strains were isolated from neonatal intensive care units. The data obtained were compared with the results of antimicrobial susceptibility testing of isolated microorganisms. Among other strains resistant to cephalosporins, the dominance of genes of CTX-M-type extended-spectrum β-lactamases was shown. It was revealed that one of eight strains phenotypically resistant and moderately resistant to carbapenems have the blaOXA-48 carbapenemase gene.
Delport, Tiffany C; Harcourt, Robert G; Beaumont, Linda J; Webster, Koa N; Power, Michelle L
Greater interaction between humans and wildlife populations poses significant risks of anthropogenic impact to natural ecosystems, especially in the marine environment. Understanding the spread of microorganisms at the marine interface is therefore important if we are to mitigate adverse effects on marine wildlife. We investigated the establishment of Escherichia coli in the endangered Australian sea lion (Neophoca cinerea) by comparing fecal isolation from wild and captive sea lion populations. Fecal samples were collected from wild colonies March 2009-September 2010 and from captive individuals March 2011-May 2013. Using molecular screening, we assigned a phylotype to E. coli isolates and determined the presence of integrons, mobile genetic elements that capture gene cassettes conferring resistance to antimicrobial agents common in fecal coliforms. Group B2 was the most abundant phylotype in all E. coli isolates (n = 37), with groups A, B1, and D also identified. Integrons were not observed in E. coli (n = 21) isolated from wild sea lions, but were identified in E. coli from captive animals (n = 16), from which class I integrases were detected in eight isolates. Sequencing of gene cassette arrays identified genes conferring resistance to streptomycin-spectinomycin (aadA1) and trimethoprim (dfrA17, dfrB4). Class II integrases were not detected in the E. coli isolates. The frequent detection in captive sea lions of E. coli with resistance genes commonly identified in human clinical cases suggests that conditions experienced in captivity may contribute to establishment. Identification of antibiotic resistance in the microbiota of Australian sea lions provides crucial information for disease management. Our data will inform conservation management strategies and provide a mechanism to monitor microorganism dissemination to sensitive pinniped populations.
Demir, Cengiz; Keşli, Recep
The aim of this study was to identify gram-negative anaerobic bacilli isolated from various clinical specimens that were obtained from patients with suspected anaerobic infections and to determine the antibiotic resistance profiles by using the antibiotic concentration gradient method. The study was performed in Afyon Kocatepe University Ahmet Necdet Sezer Research and Practice Hospital, Medical Microbiology Laboratory between 1 November 2014 and 30 October 2015. Two hundred and seventyeight clinical specimens accepted for anaerobic culture were enrolled in the study. All the samples were cultivated anaerobically by using Schaedler agar with 5% defibrinated sheep blood and Schaedler broth. The isolated anaerobic gram-negative bacilli were identified by using both the conventional methods and automated identification system (VITEK 2, bioMerieux, France). Antibiotic susceptibility tests were performed with antibiotic concentration gradient method (E-test, bioMerieux, France); against penicillin G, clindamycin, cefoxitin, metronidazole, moxifloxacin, imipenem, meropenem, ertapenem and doripenem for each isolate. Of the 28 isolated anaerobic gram-negative bacilli; 14 were identified as Bacteroides fragilis group, 9 were Prevotella spp., and 5 were Fusobacterium spp. The highest resistance rate was found against penicillin (78.5%) and resistance rates against clindamycin and cefoxitin were found as 17.8% and 21.4%, respectively. No resistance was found against metronidazole, moxifloxacin, imipenem, meropenem, ertapenem and doripenem. As a result, isolation and identification of anaerobic bacteria are difficult, time-consuming and more expensive when compared with the cost of aerobic culture. The rate of anaerobic bacteria isolation may be increased by obtaining the appropriate clinical specimen and appropriate transportation of these specimens. We believe that the data obtained from the study in our center may offer benefits for the follow up and treatment of infections
Suzuki, Shingo; Horinouchi, Takaaki; Furusawa, Chikara
We analyzed the effect of combinatorial use of antibiotics with a trade-off relationship of resistance, i.e., resistance acquisition to one drug causes susceptibility to the other drug, and vice versa, on the evolution of antibiotic resistance. We demonstrated that this combinatorial use of antibiotics significantly suppressed the acquisition of resistance. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
The introduction of antibiotics into clinical practice represented one of the most important interventions for the control of infectious diseases. Antibiotics have saved millions of lives and have also brought a revolution in medicine. However, an increasing threat has deteriorated the effectiveness of these drugs, that of bacterial resistance to antibiotics, which is defined here as the ability of bacteria to survive in antibiotic concentrations that inhibit/kill others of the same species. In this review some recent and important examples of resistance in pathogens of concern for mankind are mentioned. It is explained, according to present knowledge, the process that led to the current situation in a short time, evolutionarily speaking. It begins with the resistance genes, continues with clones and genetic elements involved in the maintenance and dissemination, and ends with other factors that contribute to its spread. Possible responses to the problem are also reviewed, with special reference to the development of new antibiotics. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Kim, Jeongjin; Jo, Ara; Chukeatirote, Ekachai; Ahn, Juhee
Background Bacteria treated with different classes of antibiotics exhibit changes in susceptibility to successive antibiotic treatments. This study was designed to evaluate the influence of sequential antibiotic treatments on the development of antibiotic resistance in Klebsiella pneumoniae associated with ?-lactamase and efflux pump activities. Methods The antibiotic susceptibility, ?-lactamase activity, and efflux activity were determined in K. pneumoniae grown at 37??C by adding initial (0...
Full Text Available Infections account for a major cause of death throughout the developing world. This is mainly due to the emergence of newer infectious agents and more specifically due to the appearance of antimicrobial resistance. With time, the bacteria have become smarter and along with it, massive imprudent usage of antibiotics in clinical practice has resulted in resistance of bacteria to antimicrobial agents. The antimicrobial resistance is recognized as a major problem in the treatment of microbial infections. The biochemical resistance mechanisms used by bacteria include the following: antibiotic inactivation, target modification, altered permeability, and “bypass” of metabolic pathway. Determination of bacterial resistance to antibiotics of all classes (phenotypes and mutations that are responsible for bacterial resistance to antibiotics (genetic analysis are helpful. Better understanding of the mechanisms of antibiotic resistance will help clinicians regarding usage of antibiotics in different situations. This review discusses the mechanism of action and resistance development in commonly used antimicrobials.
Cattle feedlot soils receive manure containing both antibiotic residues and antibiotic resistant bacteria. The fates of these constituents are largely unknown with potentially serious consequences for increased antibiotic resistance in the environment. Determine if common antimicrobials (tetracycl...
... Role What CDC is Doing: AR Solutions Initiative Investing in States: Map Antibiotic Resistance Lab Network Antibiotic ... CDC and Partners Tackle Drug-Resistant TB in India Newly Reported Gene, mcr -1, Threatens Last-Resort ...
Background: The resistance of bacteria causing urinary tract infection (UTI) to commonly prescribed antibiotics is increasing both in developing and developed countries. Resistance has emerged even to more potent antimicrobial agents. This study was undertaken to determine the current antibiotic resistance pattern ...
Leyla S. Namazova-Baranova
Full Text Available The article brings up the topic not only vital and urgent for further development of modern medical science, but also affecting the interests of mankind as a whole and of every inhabitant of the Earth in particular: that is the irrational use of antibiotics and antibiotic resistance which rate is growing rapidly. We investigate the reasons for the epidemic of antibiotic resistance and discuss in detail all the necessary measures in order to cope with this problem. The shocking data on the almost universal irrational use of antibiotics by both medical workers and parents is provided. We demonstrate the microbiome changes that follow antibacterial drugs application resulting in the development of severe chronic pediatric diseases which cause severe disability or life-threatening conditions in children with long-term results in adult age. In conclusion, we summarize the evidence-based research in phytomedicine that present the phytopreparations as a serious alternative to antibiotics in a number of clinical settings.
Nowadays, vaginal candidiasis and bacterial vaginosis are frequently encountered in medical practice and antibiotic resistance in implicated pathogens has not been reported in Dschang. This study sought to determine the antimicrobial susceptibility patterns of 198 isolates of Candida albicans and 300 strains of ...
Dr. David Denning, President of the Global Action Fund for Fungal Infections and an infectious diseases clinician, discusses antimicrobial resistance and fungus. Created: 2/28/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID). Date Released: 2/28/2017.
Zhang, Chong-Miao; Xu, Li-Mei; Wang, Xiaochang C; Zhuang, Kai; Liu, Qiang-Qiang
To evaluate the effect of ultraviolet (UV) disinfection on antibiotic-resistant Escherichia coli (E. coli). Antibiotic-resistant E. coli strains were isolated from a wastewater treatment plant and subjected to UV disinfection. The effect of UV disinfection on the antibiotic resistance profiles and the antibiotic resistance genes (ARGs) of antibiotic-resistant E. coli was evaluated by a combination of antibiotic susceptibility analysis and molecular methods. Results indicated that multiple-antibiotic-resistant (MAR) E. coli were more resistant at low UV doses and required a higher UV dose (20 mJ cm -2 ) to enter the tailing phase compared with those of antibiotic-sensitive E. coli (8 mJ cm -2 ). UV disinfection caused a selective change in the inhibition zone diameters of surviving antibiotic-resistant E. coli and a slight damage to ARGs. The inhibition zone diameters of the strains resistant to antibiotics were more difficult to alter than those susceptible to antibiotics because of the existence and persistence of corresponding ARGs. The resistance of MAR bacteria to UV disinfection at low UV doses and the changes in inhibition zone diameters could potentially contribute to the selection of ARB in wastewater treatment after UV disinfection. The risk of spread of antibiotic resistance still exists owing to the persistence of ARGs. Our study highlights the acquisition of other methods to control the spread of ARGs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Leibovici, Leonard; Paul, Mical; Garner, Paul
Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies....... This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should...... be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized...
Plantinga, Nienke L.; Wittekamp, Bastiaan H J; Van Duijn, Pleun J.; Bonten, Marc J M
Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to
Full Text Available Introduction. The problem of formation of bacterial resistance to glycopeptides and beta-lactam antibiotics (cephalosporins and carbapenems are used worldwide for the treatment of severe community acquired and nosocomial infections, especially caused by polymicrobial flora has become global and is a major factor limiting the effectiveness of antibiotic therapy. In this regard, the study of genetic microbial resistance determinants allows not only to carry out an effective antibiotic therapy, but also to identify two main processes leading to the development of epidemiologically significant events: the introduction of the agent in the risk population from the outside and in situ pathogen (spontaneous genetic drift targeted restructuring of the population. Therefore, the aim of our study was to investigate the resistance genes to carbapenems, cephalosporins, glycopeptides have clinically important phenotype of resistant strains of microorganisms families Enterobacteriaceae, Pseudomonadaceae, Bacteroidaceae, Enterococcaceae, Peptostreptococcaceae. Materials and methods. As a material for PCR studies 712 phenotypically resistant strains of microorganisms isolated from 80 rats "Wistar" line in microbiological study microflora of the wall were used. During the investigation 474 isolates of bacteria of the family Enterobacteriaceae, 39 - Pseudomonadaceae, 71 - Bacteroidaceae, 96 - Enterococcaceae, 32 - Peptostreptococcaceae were studied. Isolation of DNA from bacteria in the study was performed using reagents "DNA-Express" ("Litekh", Russia. For the detection of resistance genes by PCR in real time (RT-PCR reagent kits "FLUOROPOL-RV" ("Litekh", Russia were used. During the experiment, the VIM genes, OXA-48, NDM, KPC, responsible for the resistance of microorganisms to carbapenems, CTX-M - resistance to cephalosporins, as well as genes Van A and van B, the development of resistance to glycopeptides (vancomycin and teicoplanin were determined. Analysis
Antibiotic resistance is a growing problem which threatens modern healthcare globally. Resistance has traditionally been viewed as a clinical problem, but recently non-clinical environments have been highlighted as an important factor in the dissemination of antibiotic resistance genes (ARGs). Horizontal gene transfer (HGT) events are likely to be common in aquatic environments; integrons in particular are well suited for mediating environmental dissemination of ARGs. A growing body of evidence suggests that ARGs are ubiquitous in natural environments. Particularly, elevated levels of ARGs and integrons in aquatic environments are correlated to proximity to anthropogenic activities. The source of this increase is likely to be routine discharge of antibiotics and resistance genes, for example, via wastewater or run-off from livestock facilities and agriculture. While very high levels of antibiotic contamination are likely to select for resistant bacteria directly, the role of sub-inhibitory concentrations of antibiotics in environmental antibiotic resistance dissemination remains unclear. In vitro studies have shown that low levels of antibiotics can select for resistant mutants and also facilitate HGT, indicating the need for caution. Overall, it is becoming increasingly clear that the environment plays an important role in dissemination of antibiotic resistance; further studies are needed to elucidate key aspects of this process. Importantly, the levels of environmental antibiotic contamination at which resistant bacteria are selected for and HGT is facilitated at should be determined. This would enable better risk analyses and facilitate measures for preventing dissemination and development of antibiotic resistance in the environment. PMID:26356096
Zhao, Bin; Zhang, Xiaoying
Multi-antibiotic resistance in bacterial infections is a growing threat to public health. Some experiments were carried out to study the multi-antibiotic resistance. The changes of the multi-antibiotic resistance with time were achieved by numerical simulations and the mathematical models, with the calculated temperature field, velocity field, and the antibiotic concentration field. The computed results and experimental results are compared. Both numerical simulations and the analytic models suggest that minor low concentrations of antibiotics could induce antibiotic resistance in bacteria. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Flórez, Ana Belén; Mayo, Baltasar
This work reports the composition and succession of tetracycline- and erythromycin-resistant bacterial communities in a model cheese, monitored by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Bacterial 16S rRNA genes were examined using this technique to detect structural changes in the cheese microbiota over manufacturing and ripening. Total bacterial genomic DNA, used as a template, was extracted from cultivable bacteria grown without and with tetracycline or erythromycin (both at 25 μg ml(-1)) on a non-selective medium used for enumeration of total and viable cells (Plate Count agar with Milk; PCA-M), and from those grown on selective and/or differential agar media used for counting various bacterial groups; i.e., lactic acid bacteria (de Man, Rogosa and Sharpe agar; MRSA), micrococci and staphylococci (Baird-Parker agar; BPA), and enterobacteria (Violet Red Bile Glucose agar; VRBGA). Large numbers of tetracycline- and erythromycin-resistant bacteria were detected in cheese samples at all stages of ripening. Counts of antibiotic-resistant bacteria varied widely depending on the microbial group and the point of sampling. In general, resistant bacteria were 0.5-1.0 Log10 units fewer in number than the corresponding susceptible bacteria. The PCR-DGGE profiles obtained with DNA isolated from the plates for total bacteria and the different bacterial groups suggested Escherichia coli, Lactococcus lactis, Enterococcus faecalis and Staphylococcus spp. as the microbial types resistant to both antibiotics tested. This study shows the suitability of the PCR-DGGE technique for rapidly identifying and tracking antibiotic resistant populations in cheese and, by extension, in other foods. Copyright © 2015 Elsevier B.V. All rights reserved.
Full Text Available Biofilms give to bacteria micro-environmental benefits; confers protection against antimicrobials. Bacteria have antibiotic resistance by conventional and unusual mechanisms leading to delayed wound healing, to increase recurrent chronic infections and nosocomial contamination of medical devices. Objective: This narrative review aims to introduce the characteristics of Bacteria-biofilms, antimicrobial resistance mechanisms and potential alternatives for prevention and control of its formation. Methods: Search strategy was performed on records: PubMed / Medline, Lilacs, Redalyc; with suppliers such as EBSCO and thesaurus MeSH and DeCS. Conclusions: Knowledge and research performance of biofilm bacteria are relevant in the search of technology for detection and measuring sensitivity to antibiotics. The identification of Bacterial-biofilms needs no-traditional microbiological diagnosis.
N. Shabani Lokarani
Full Text Available Escherichia coli as a fecal contamination and is considered as an index in water. The aim of this study was to determine the phenotypic and genotypic characteristics of E. coli and antibiotic resistance of the isolates collected from qanats and springs in East-Azerbaijan province. For this purpose, 118 samples were selected from above mentioned area and examined by MPN method. The positive coliform samples were identified by phenotypic and genotypic methods. Afterwards, to determine the genetic diversity of E. coli isolates, phylogenetic typing we conducted by means of multiplex PCR. To determine the antibiotic resistance profile, antibiotic discs of Nalidixic Acid, Co-trimoxazol, Amoxicillin, Gentamaicin Ciprofloxacin, Chloramphenicol, Imipenem, Cefotaxime and Ceftazidime antibiogram were used. Based on results, 48% of the samples were evaluated as positive for coliform including 40% for E. coli and 19% for Klebsiella. Amongst 23 isolates confirmed as E. coli by PCR. Phylogenetic typing revealed that 44% of E. coli strains belonged to type D and B2 and 56% belonged to A and B1 phylotypes. Antimicrobial susceptibility pattern showed that 92% of E. coli isolates were resistant to Amoxicillin. All E. coli isolates were sensitive to Imipenem. It was concluded that presence of pathogenic E. coli with high rate of antibacterial resistance in waters source could be considered as a human health hazard.
Ouwehand, Arthur C; Forssten, Sofia; Hibberd, Ashley A; Lyra, Anna; Stahl, Buffy
Probiotics are live microorganisms, mainly belonging to the genera Lactobacillus and Bifidobacterium, although also strain of other species are commercialized, that have a beneficial effect on the host. From the perspective of antibiotic use, probiotics have been observed to reduce the risk of certain infectious disease such as certain types of diarrhea and respiratory tract infection. This may be accompanied with a reduced need of antibiotics for secondary infections. Antibiotics tend to be effective against most common diseases, but increasingly resistance is being observed among pathogens. Probiotics are specifically selected to not contribute to the spread of antibiotic resistance and not carry transferable antibiotic resistance. Concomitant use of probiotics with antibiotics has been observed to reduce the incidence, duration and/or severity of antibiotic-associated diarrhea. This contributes to better adherence to the antibiotic prescription and thereby reduces the evolution of resistance. To what extent probiotics directly reduce the spread of antibiotic resistance is still much under investigation; but maintaining a balanced microbiota during antibiotic use may certainly provide opportunities for reducing the spread of resistances. Key messages Probiotics may reduce the risk for certain infectious diseases and thereby reduce the need for antibiotics. Probiotics may reduce the risk for antibiotic-associated diarrhea Probiotics do not contribute to the spread of antibiotic resistance and may even reduce it.
Wolska, Katarzyna; Kot, Barbara; Piechota, Małgorzata; Frankowska, Aneta
The main problem in the treatment of nosocomial infections is the increasing drug resistance of microorganisms that cause them, limiting the number of effective antibiotics. Pseudomonas aeruginosa bacilli are the cause of many serious hospital-acquired infections occurring primarily in patients within high-risk groups. The most vulnerable are those with weakened immune systems, as well as those with extensive surgical wounds and burn wounds. Infections are usually of the nature of secondary infections, caused by multidrug strains. Due to the high antimicrobial activity, beta-lactams, aminoglycosides and quinolones are drugs commonly used in hospitals, both in prevention and treatment of infections with P. aeruginosa. However, their irrational use is associated with selection and spread of strains resistant to these antibiotics. Resistance of P. aeruginosa to antibiotics is the result of a number of independent co-occurring mechanisms. These are: reducing the membrane permeability, the efflux system, and production of enzymes inactivating and degrading antibiotics. The paper devotes special attention to the determination of resistance mechanisms responsible for this phenomenon.
Full Text Available Background & aim: Because of its ubiquitous nature, ability to survive in moist environments, and innate resistance to many antibiotics and antiseptics, P. aeruginosa is a common pathogen in hospitals. The goals of this study were detection of Psudomonas aeruginosa harboring blaCTX gene causing infections in hospitals and determination of their susceptibility to antibiotics and ESBL production. Methods: In the present cross-sectional study, clinical samples from hospitalized patients were collected and culture was done on apropriate media. Final identification was performed using biochemical tests and API 20NE system. According to the protocol CLSI 2014 disc diffusion, combination disk, modified hodge test (MHT and E-test were used for antibiotic susceptibility, ESBL production, carbapenemas production, and MIC values of imipenem respectively. The blaCTX gene was detected in the isolates by PCR molecular method. Results: In the current study, 45 isolates of Pseudomonas aeroginosa were obtained from hospitalized patients, consisting of 19 males (42.2% and 26 females (57.8%. As observed, 57.8% (26 strains of isolates were recovered from sputum. The most effective antibiotics against isolates were amikacin and colistin with 97.8% suseptibility whereas the highest resistance was to cefotaxime (97.8%. As revealed 77.8% of isolates showed response to group 2 carbapenems (imipenem, meropenem. All imipenem resistant strains had the MIC more than 32. Seventeen strains (37.7% were showed resistant to quinolones (ciprofloxacin, norfloxacin. The results of PCR on blaCTX gene indicated that 15.5% of the isolates possess the gene. Conclusion: Carbapenem group of antibiotic in 22% of infections caused by Pseudomonas aeruginosa were ineffective and indiscriminate prescribing of these drugs will increase the ratet of resistance.
Worthington, Roberta J; Melander, Christian
β-Lactam antibiotics are one of the most important antibiotic classes but are plagued by problems of resistance, and the development of new β-lactam antibiotics through side-chain modification of existing β-lactam classes is not keeping pace with resistance development. In this JOCSynopsis, we summarize small molecule strategies to overcome resistance to β-lactam antibiotics. These approaches include the development of β-lactamase inhibitors and compounds that interfere with the ability of the bacteria to sense an antibiotic threat and activate their resistance mechanisms.
Antibiotic resistance, a global concern, is particularly pressing in developing nations, including India, where the burden of infectious disease is high and healthcare spending is low. The Global Antibiotic Resistance Partnership (GARP) was established to develop actionable policy recommendations specifically relevant to low- and middle-income countries where suboptimal access to antibiotics - not a major concern in high-income countries - is possibly as severe a problem as is the spread of resistant organisms. This report summarizes the situation as it is known regarding antibiotic use and growing resistance in India and recommends short and long term actions. Recommendations aim at (i) reducing the need for antibiotics; (ii) lowering resistance-enhancing drug pressure through improved antibiotic targeting, and (iii) eliminating antibiotic use for growth promotion in agriculture. The highest priority needs to be given to (i) national surveillance of antibiotic resistance and antibiotic use - better information to underpin decisions on standard treatment guidelines, education and other actions, as well as to monitor changes over time; (ii) increasing the use of diagnostic tests, which necessitates behavioural changes and improvements in microbiology laboratory capacity; (iii) setting up and/or strengthening infection control committees in hospitals; and (iv) restricting the use of antibiotics for non-therapeutic uses in agriculture. These interventions should help to reduce the spread of antibiotic resistance, improve public health directly, benefit the populace and reduce pressure on the healthcare system. Finally, increasing the types and coverage of childhood vaccines offered by the government would reduce the disease burden enormously and spare antibiotics. PMID:21985810
Full Text Available Peptidoglycan (PG is an essential cross-linked polymer that surrounds most bacterial cells to prevent osmotic rupture of the cytoplasmic membrane. Its synthesis relies on penicillin-binding proteins, the targets of beta-lactam antibiotics. Many Gram-negative bacteria, including the opportunistic pathogen Pseudomonas aeruginosa, are resistant to beta-lactams because of a chromosomally encoded beta-lactamase called AmpC. In P. aeruginosa, expression of the ampC gene is tightly regulated and its induction is linked to cell wall stress. We reasoned that a reporter gene fusion to the ampC promoter would allow us to identify mutants defective in maintaining cell wall homeostasis and thereby uncover new factors involved in the process. A library of transposon-mutagenized P. aeruginosa was therefore screened for mutants with elevated ampC promoter activity. As an indication that the screen was working as expected, mutants with transposons disrupting the dacB gene were isolated. Defects in DacB have previously been implicated in ampC induction and clinical resistance to beta-lactam antibiotics. The screen also uncovered murU and PA3172 mutants that, upon further characterization, displayed nearly identical drug resistance and sensitivity profiles. We present genetic evidence that PA3172, renamed mupP, encodes the missing phosphatase predicted to function in the MurU PG recycling pathway that is widely distributed among Gram-negative bacteria.
Full Text Available Abstract Background Bacterial genomes are mosaic structures composed of genes present in every strain of the same species (core genome, and genes present in some but not all strains of a species (accessory genome. The aim of this study was to compare the genetic diversity of core and accessory genes of a Salmonella enterica subspecies enterica serovar Typhimurium (Typhimurium population isolated from food-animal and human sources in four regions of Mexico. Multilocus sequence typing (MLST and macrorestriction fingerprints by pulsed-field gel electrophoresis (PFGE were used to address the core genetic variation, and genes involved in pathogenesis and antibiotic resistance were selected to evaluate the accessory genome. Results We found a low genetic diversity for both housekeeping and accessory genes. Sequence type 19 (ST19 was supported as the founder genotype of STs 213, 302 and 429. We found a temporal pattern in which the derived ST213 is replacing the founder ST19 in the four geographic regions analyzed and a geographic trend in the number of resistance determinants. The distribution of the accessory genes was not random among chromosomal genotypes. We detected strong associations among the different accessory genes and the multilocus chromosomal genotypes (STs. First, the Salmonella virulence plasmid (pSTV was found mostly in ST19 isolates. Second, the plasmid-borne betalactamase cmy-2 was found only in ST213 isolates. Third, the most abundant integron, IP-1 (dfrA12, orfF and aadA2, was found only in ST213 isolates. Fourth, the Salmonella genomic island (SGI1 was found mainly in a subgroup of ST19 isolates carrying pSTV. The mapping of accessory genes and multilocus genotypes on the dendrogram derived from macrorestiction fingerprints allowed the establishment of genetic subgroups within the population. Conclusion Despite the low levels of genetic diversity of core and accessory genes, the non-random distribution of the accessory genes
High diversity of bacterial pathogens and antibiotic resistance in salmonid fish farm pond water as determined by molecular identification employing 16S rDNA PCR, gene sequencing and total antibiotic susceptibility techniques.
Moore, John E; Huang, Junhua; Yu, Pengbo; Ma, Chaofeng; Moore, Peter Ja; Millar, Beverley C; Goldsmith, Colin E; Xu, Jiru
The aim of this study was to examine the microbiological and related parameters (antibiotic resistance and pathogen identification) of water at two salmonid fish farms in Northern Ireland. Total Bacterial Counts at the Movanagher Fish Farm was 1730 colony forming units (cfu)/ml water (log10 3.24cfu/ml) and 3260cfu/ml (log10 3.51cfu/ml) at the Bushmills Salmon Station. Examination of resulting organisms revealed 10 morphological phenotypes, which were subsequently sequenced to determine their identification. All these organisms were Gram-negative and no Gram-positive organisms were isolated from any water sample. From these phenotypes, eight different genera were identified including Acinetobacter, Aeromonas, Chryseobacterium, Erwinia, Flavobacterium, Pseudomonas and Rheinheimera. One unnamed novel taxon was identified from water at the Movanagher Fish Farm, belonging to the genus Acinetobacter and has been tentatively named Acinetobacter movanagherensis. No other novel taxa were observed. All but one of these environmental organisms (Erwinia) are potential pathogens of fish disease. Total antibiotic resistance was observed to varying degrees in water specimens. The most resistant populations were observed in water taken from the Bushmills Salmon Station inlet, followed by water from the Movanagher Fish Farm. No resistance was observed against tetracycline and there was only one occurrence of resistance against ciprofloxacin. Overall, this study indicates that potential fish pathogens made up the majority of environmental organisms identified, even in the absence of recorded fish disease. There was also relatively high levels of total antibiotic resistance in the bacterial water populations examined, where tetracycline was the only antibiotic with zero resistance. These data indicate that the threat of bacterial disease is relatively close due to the indigenous colonization of farm water and that husbandry standards should be maintained at a high standard to avert
Alant, O.; Jaszsagi-Nagy, E.; Lendvay, J.; Schmidt, M.
For the objective choice of an antibiotic a method is needed which is capable of giving informations with an essentially shorter time delay than that of the conventional bacteriological tests i.e. practically in a few hours concerning the sensitivity to the tested antibiotic of the pathogen germ cultured from the sample withdrawn from the patient under surgical treatment. The new measurement method is based on the incubation of the test material in an adequate medium containing glucose labelled with C-14 as only sugar source. The amount of the formed 14 CO 2 is proportional to the multiplication rate of the bacterium. Experience observed with 312 surgical patients indicated that the sensitivity to an antibiotic agent can be determined in 4-6 hours from the septic intergrowth or from the discharge obtained during the surgical action and in the case of chronical diseases the successfulness of the treatment with the antibiotic can be established precisely. The equipment needed for the tests is simple and the measurements can be carried out readily in hospital laboratories. (P.J.)
Jiang, Xinglin; Ellabaan, Mostafa M Hashim; Charusanti, Pep
It has been hypothesized that some antibiotic resistance genes (ARGs) found in pathogenic bacteria derive from antibiotic-producing actinobacteria. Here we provide bioinformatic and experimental evidence supporting this hypothesis. We identify genes in proteobacteria, including some pathogens......, that appear to be closely related to actinobacterial ARGs known to confer resistance against clinically important antibiotics. Furthermore, we identify two potential examples of recent horizontal transfer of actinobacterial ARGs to proteobacterial pathogens. Based on this bioinformatic evidence, we propose...... results support the existence of ancient and, possibly, recent transfers of ARGs from antibiotic-producing actinobacteria to proteobacteria, and provide evidence for a defined mechanism....
Critchley, I A; Karlowsky, J A
Increasing concern about the emergence of resistance in clinically important pathogens has led to the establishment of a number of surveillance programmes to monitor the true extent of resistance at the local, regional and national levels. Although some programmes have been operating for several years, their true usefulness is only now being realised. This review describes some of the major surveillance initiatives and the way in which the data have been used in a number of different settings. In the hospital, surveillance data have been used to monitor local antibiograms and determine infection control strategies and antibiotic usage policies. In the community, surveillance data have been used to monitor public health threats, such as infectious disease outbreaks involving resistant pathogens and the effects of bioterrorism countermeasures, by following the effects of prophylactic use of different antibiotics on resistance. Initially, the pharmaceutical industry sponsored surveillance programmes to monitor the susceptibility of clinical isolates to marketed products. However, in the era of burgeoning resistance, many developers of antimicrobial agents find surveillance data useful for defining new drug discovery and development strategies, in that they assist with the identification of new medical needs, allow modelling of future resistance trends, and identify high-profile isolates for screening the activity of new agents. Many companies now conduct pre-launch surveillance of new products to benchmark activity so that changes in resistance can be monitored following clinical use. Surveillance data also represent an integral component of regulatory submissions for new agents and, together with clinical trial data, are used to determine breakpoints. It is clear that antibiotic resistance surveillance systems will continue to provide valuable data to health care providers, university researchers, pharmaceutical companies, and government and regulatory agencies.
Widespread adoption of point-of-care resistance diagnostics (POCRD) reduces ineffective antibiotic use but could increase overall antibiotic use. Indeed, in the context of a standard susceptible-infected epidemiological model with a single antibiotic, POCRD accelerates the rise of resistance in the disease-causing bacterial population. When multiple antibiotics are available, however, POCRD may slow the rise of resistance even as more patients receive antibiotic treatment, belying the conventional wisdom that antibiotics are "exhaustible resources" whose increased use necessarily promotes the rise of resistance. © 2017 New York Academy of Sciences.
Artemova, Tatiana; Gerardin, Ylaine; Hsin-Jung Li, Sophia; Gore, Jeff
Since the discovery of penicillin, antibiotics have been our primary weapon against bacterial infections. Unfortunately, bacteria can gain resistance to penicillin by acquiring the gene that encodes beta-lactamase, which inactivates the antibiotic. However, mutations in this gene are necessary to degrade the modern antibiotic cefotaxime. Understanding the conditions that favor the spread of these mutations is a challenge. Here we show that bacterial growth in beta-lactam antibiotics is cooperative and that the nature of this growth determines the conditions in which resistance evolves. Quantitative analysis of the growth dynamics predicts a peak in selection at very low antibiotic concentrations; competition between strains confirms this prediction. We also find significant selection at higher antibiotic concentrations, close to the minimum inhibitory concentrations of the strains. Our results argue that an understanding of the evolutionary forces that lead to antibiotic resistance requires a quantitative understanding of the evolution of cooperation in bacteria.
Wang, H Y; Uh, Y; Kim, S; Lee, H
Rapid and accurate identification of the causative pathogens of bloodstream infections (BSIs) is crucial for initiating appropriate antimicrobial therapy, which decreases the related morbidity and mortality rates. The aim of this study was to evaluate the usefulness of a newly developed multiplexed, bead-based bioassay system, the Quantamatrix Multiplexed Assay Platform (QMAP) system, obtained directly from blood culture bottles, to simultaneously detect the presence of bacteria and identify the genes for antibiotic resistance. The QMAP system was used to evaluate 619 blood culture bottles from patients with BSIs and to compare the results of conventional culture methods. Using conventional bacterial cultures as the reference standard, the sensitivity, specificity, positive predictive value, and negative predictive value of the QMAP system for detection of bacterial pathogens in positive blood culture (PBC) samples were 99.8% (n=592, 95% CI 0.9852-1.000, p antibiotic resistance were 99.4% (n=158, 95% CI 0.9617-0.9999, p <0.009) and 99.6% (95% CI 0.9763-0.9999, p <0.0001), respectively. Obtaining results using the QMAP system takes about 3 hr, while culture methods can take 48-72 hr. Therefore, analysis using the QMAP system is rapid and reliable for characterizing causative pathogens in BSIs. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Pawlowski, Andrew C; Stogios, Peter J; Koteva, Kalinka; Skarina, Tatiana; Evdokimova, Elena; Savchenko, Alexei; Wright, Gerard D
The production of antibiotics by microbes in the environment and their use in medicine and agriculture select for existing and emerging resistance. To address this inevitability, prudent development of antibiotic drugs requires careful consideration of resistance evolution. Here, we identify the molecular basis for expanded substrate specificity in MphI, a macrolide kinase (Mph) that does not confer resistance to erythromycin, in contrast to other known Mphs. Using a combination of phylogenetics, drug-resistance phenotypes, and in vitro enzyme assays, we find that MphI and MphK phosphorylate erythromycin poorly resulting in an antibiotic-sensitive phenotype. Using likelihood reconstruction of ancestral sequences and site-saturation combinatorial mutagenesis, supported by Mph crystal structures, we determine that two non-obvious mutations in combination expand the substrate range. This approach should be applicable for studying the functional evolution of any antibiotic resistance enzyme and for evaluating the evolvability of resistance enzymes to new generations of antibiotic scaffolds.
The Salmonella isolates tested displayed multiple antibiotic resistance to a number of antibiotics used to treat both humans and animals. No resistance was seen to disinfectants used at the manufacturer\\'s recommended rate of dilution. The bacteria were resistant, though, at lower dilutions, highlighting the necessity of ...
John B. Horowitz; H. Brian Moehring
Initially, economic development increases resistance because migration of people to urban areas in developing countries increases incomes, crowding and the use of antibiotics. Also, developing countries often don't require prescriptions or distribute high quality antibiotics. In developed countries, antibiotic resistance often falls or there is a decline in the rate of growth of resistance because infections decline with improvements in water quality, sanitation, housing and nutrition. Howeve...
Full Text Available Uropathogenic strains from inpatient and outpatient departments were studied from April 1997 to March 1999 for their susceptibility profiles. The various isolates were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii and Enterococcus faecalis. Antibiotic susceptibility pattern of these isolates revealed that for outpatients, first generation cephalosporins, nitrofurantoin, norfloxacin/ciprofloxacin were effective for treatment of urinary tract infection but for inpatients, parenteral therapy with newer aminoglycosides and third generation cephalosporins need to be advocated as the organisms for nosocomial UTI exhibit a high degree of drug resistance. Trimethoprim and sulphamethoxazole combination was not found to be effective for the treatment of urinary tract infections as all the uropathogens from inpatients and outpatients showed high degree of resistance to co-trimoxazole. Culture and sensitivity of the isolates from urine samples should be done as a routine before advocating the therapy.
Rowe, Will P M; Baker-Austin, Craig; Verner-Jeffreys, David W; Ryan, Jim J; Micallef, Christianne; Maskell, Duncan J; Pearce, Gareth P
Effluents contain a diverse abundance of antibiotic resistance genes that augment the resistome of receiving aquatic environments. However, uncertainty remains regarding their temporal persistence, transcription and response to anthropogenic factors, such as antibiotic usage. We present a spatiotemporal study within a river catchment (River Cam, UK) that aims to determine the contribution of antibiotic resistance gene-containing effluents originating from sites of varying antibiotic usage to the receiving environment. Gene abundance in effluents (municipal hospital and dairy farm) was compared against background samples of the receiving aquatic environment (i.e. the catchment source) to determine the resistome contribution of effluents. We used metagenomics and metatranscriptomics to correlate DNA and RNA abundance and identified differentially regulated gene transcripts. We found that mean antibiotic resistance gene and transcript abundances were correlated for both hospital ( ρ = 0.9, two-tailed P resistance genes ( bla GES and bla OXA ) were overexpressed in all hospital effluent samples. High β-lactam resistance gene transcript abundance was related to hospital antibiotic usage over time and hospital effluents contained antibiotic residues. We conclude that effluents contribute high levels of antibiotic resistance genes to the aquatic environment; these genes are expressed at significant levels and are possibly related to the level of antibiotic usage at the effluent source. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.
Heß, Stefanie; Gallert, Claudia
Tolerance of antibiotic susceptible and antibiotic resistant Escherichia coli, Enterococcus and Staphylococcus strains from clinical and wastewater samples against ozone was tested to investigate if ozone, a strong oxidant applied for advanced wastewater treatment, will affect the release of antibiotic resistant bacteria into the aquatic environment. For this purpose, the resistance pattern against antibiotics of the mentioned isolates and their survival after exposure to 4 mg/L ozone was determined. Antibiotic resistance (AR) of the isolates was not correlating with higher tolerance against ozone. Except for ampicillin resistant E. coli strains, which showed a trend towards increased resistance, E. coli strains that were also resistant against cotrimoxazol, ciprofloxacin or a combination of the three antibiotics were similarly or less resistant against ozone than antibiotic sensitive strains. Pigment-producing Enterococcus casseliflavus and Staphylococcus aureus seemed to be more resistant against ozone than non-pigmented species of these genera. Furthermore, aggregation or biofilm formation apparently protected bacteria in subsurface layers from inactivation by ozone. The relatively large variance of tolerance against ozone may indicate that resistance to ozone inactivation most probably depends on several factors, where AR, if at all, does not play a major role.
Yılmaz, Çiğdem; Özcengiz, Gülay
The discovery of penicillin followed by streptomycin, tetracycline, cephalosporins and other natural, semi-synthetic and synthetic antimicrobials completely revolutionized medicine by reducing human morbidity and mortality from most of the common infections. However, shortly after they were introduced to clinical practice, the development of resistance was emerged. The decreasing interest from antibiotic industry in spite of rapid global emergence of antibiotic resistance is a tough dilemma from the pointview of public health. The efficiency of antimicrobial treatment is determined by both pharmacokinetics and pharmacodynamics. In spite of their selective toxicity, antibiotics still cause severe, life-threatening adverse reactions in host body mostly due to defective drug metabolism or excessive dosing regimen. The present article aims at updating current knowledge on pharmacokinetics/pharmacodynamics concepts and models, toxicity of antibiotics as well as antibiotic resistance mechanisms, resistome analyses and search for novel antibiotic resistance determinants with special emphasis given to the-state-of-the-art regarding multidrug efflux pumps and their additional physiological functions in stress adaptation and virulence of bacteria. All these issues are highly linked to each other and not only important for most efficient and prolonged use of current antibiotics, but also for discovery and development of new antibiotics and novel inhibitors of antibiotic resistance determinants of pathogens. Copyright © 2016 Elsevier Inc. All rights reserved.
Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David
Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized controlled trials or systematic reviews. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: firstname.lastname@example.org.
Ma, Hongyan; Bryers, James D.
Biofilms cause much of all human microbial infections. Attempts to eradicate biofilm-based infections rely on disinfectants and antibiotics. Unfortunately, biofilm bacteria are significantly less responsive to antibiotic stressors than their planktonic counterparts. Sublethal doses of antibiotics can actually enhance biofilm formation. Here, we have developed a non-invasive microscopic image analyses to quantify plasmid conjugation within a developing biofilm. Corroborating destructive sample...
Determining the prevalence of SCCmec polymorphism, virulence and antibiotic resistance genes among methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from selected hospitals in west of Iran.
Taherikalani, Morovat; Mohammadzad, Mohammad Reza; Soroush, Setareh; Maleki, Mohammad Hossein; Azizi-Jalilian, Farid; Pakzad, Iraj; Sadeghifard, Nourkhoda; Asadollahi, Parisa; Emaneini, Mohammad; Monjezi, Aazam; Alikhani, Mohammad Yousef
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens worldwide and compared to other staphylococcal species that are associated with higher mortality rate. A total of 500 Staphylococcus spp. was collected from selected hospitals in Ilam, Kermanshah, Khorram Abad and Hamadan cities and, via phenotypic and genotypic methods, was assessed to find MRSA. The presence or absence of prevalent antibiotic resistance genes and virulence genes was evaluated among MRSA isolates, using polymerase chain reaction (PCR) method, and then the SCCmec typing of these isolates was assayed by multiplex PCR. A total of 372 (74.4%) Stapylococcus spp. isolates were identified as S. aureus, among which 200 (53.8%) possessed the mecA gene and were distinguished as MRSA. All of MRSA isolates contained blaZ gene. The frequency of ermA and ermC genes among erythromycin-resistant MRSA isolates was 21.6% and 66.7%, respectively. The frequency of the virulence genes eta, hla and sea among MRSA isolates was 10%, 80.5% and 100%, respectively. SCCmec type IV accounted for 30.6% of the MRSA isolates and SCCmec type III, SCCmec type II and SCCmec type I accounted for 30%, 22% and 17.5% of the isolates, respectively. The antibiotic resistance genes and the virulence genes of blaZ, hla, sea, eta and ermC had high frequencies among the MRSA isolates. This study showed that the antibiotic resistance genes had higher frequencies among SCCmec types I and IV, which confirms the previous reports in this field.
Resistance to available antibiotics in pathogenic bacteria is currently a global challenge since the number of strains that are resistant to multiple types of antibiotics has increased dramatically each year and has spread worldwide. To unlock this problem, the use of an 'antibiotic adjuvant' in combination with an antibiotic is now being exploited. This approach enables us to prolong the lifespan of these life-saving drugs. This digests review provides an overview of the main types of antibiotic adjuvants, the basis of their operation and the remaining issues to be tackled in this field. Particular emphasis is placed on those compounds that are already in clinical development, namely β-lactamase inhibitors. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Nicoloff, Hervé; Andersson, Dan I
Indirect resistance (IR), the ability of an antibiotic-resistant population of bacteria to protect a susceptible population, has been previously observed for β-lactamase-producing bacteria and associated with antimicrobial treatment failures. Here, we determined whether other resistance determinants could cause IR in the presence of five other classes of antibiotics. A test was designed to detect IR and 14 antibiotic resistance genes were tested in the presence of 13 antibiotics from six classes. A bioassay was used to measure the ability of resistance-causing enzymes to decrease the concentration of active antibiotics in the medium. We confirmed IR in the presence of β-lactam antibiotics (ampicillin and mecillinam) when TEM-1A was expressed. We found that bacteria expressing antibiotic-modifying or -degrading enzymes Ere(A), Tet(X2) or CatA1 caused IR in the presence of macrolides (erythromycin and clarithromycin), tetracyclines (tetracycline and tigecycline) and chloramphenicol, respectively. IR was not observed with resistance determinants that did not modify or destroy antibiotics or with enzymes modifying aminoglycosides or degrading fosfomycin. IR was dependent on the resistance enzymes decreasing the concentration of active antibiotics in the medium, hence allowing nearby susceptible bacteria to resume growth once the antibiotic concentration fell below their MIC. IR was not limited to β-lactamase-producing bacteria, but was also caused by resistant bacteria carrying cytoplasmic antibiotic-modifying or -degrading enzymes that catalyse energy-consuming reactions requiring complex cellular cofactors. Our results suggest that IR is common and further emphasizes that coinfecting agents and the human microflora can have a negative impact during antimicrobial therapy. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: email@example.com.
Kitaoka, Maya; Miyata, Sarah T; Unterweger, Daniel; Pukatzki, Stefan
As the causative agent of cholera, the bacterium Vibrio cholerae represents an enormous public health burden, especially in developing countries around the world. Cholera is a self-limiting illness; however, antibiotics are commonly administered as part of the treatment regimen. Here we review the initial identification and subsequent evolution of antibiotic-resistant strains of V. cholerae. Antibiotic resistance mechanisms, including efflux pumps, spontaneous chromosomal mutation, conjugative plasmids, SXT elements and integrons, are also discussed. Numerous multidrug-resistant strains of V. cholerae have been isolated from both clinical and environmental settings, indicating that antibiotic use has to be restricted and alternative methods for treating cholera have to be implemented.
Megraud, Francis; Coenen, Samuel; Versporten, Ann
OBJECTIVE: Resistance to antibiotics is the major cause of treatment failure of Helicobacter pylori infection. A study was conducted to assess prospectively the antibacterial resistance rates of H pylori in Europe and to study the link between outpatient antibiotic use and resistance levels...... in different countries. DESIGN: Primary antibiotic resistance rates of H pylori were determined from April 2008 to June 2009 in 18 European countries. Data on yearly and cumulative use over several years of systemic antibacterial agents in ambulatory care for the period 2001-8 were expressed in Defined Daily...... Doses (DDD) per 1000 inhabitants per day. The fit of models and the degree of ecological association between antibiotic use and resistance data were assessed using generalised linear mixed models. RESULTS: Of 2204 patients included, H pylori resistance rates for adults were 17.5% for clarithromycin, 14...
Chen, Qing-Lin; Li, Hu; Zhou, Xin-Yuan
Landfills are so far the most common practice for the disposals of municipal solid waste (MSW) worldwide. Since MSW landfill receives miscellaneous wastes, including unused/expired antibiotics and bioactive wastes, it gradually becomes a huge potential bioreactor for breeding antibiotic resistance...... be the potential hosts of ARGs. These findings provide evidence that groundwater near MSW landfill is an underappreciated hotspot of antibiotic resistance and contribute to the spread of ARGs via the flowing contaminated groundwater....
Allen, Rosalind; Waclaw, Bartłomiej
The problem of antibiotic resistance poses challenges across many disciplines. One such challenge is to understand the fundamental science of how antibiotics work, and how resistance to them can emerge. This is an area where physicists can make important contributions. Here, we highlight cases where this is already happening, and suggest directions for further physics involvement in antimicrobial research.
Oct 3, 2017 ... In the last decade the detection of the resistance of bacteria to antibiotics treatment, developed by different kind of bacteria, is becoming a huge problem. We hereby present a different approach to the current problem of detection of bacteria resistance to antibiotics. Our aims were to use the atomic force ...
Raymond G Lahaie
Full Text Available Resistance to antibiotics can be a major problem in the treatment of bacterial infections. As the use of antibiotics increases, bacterial resistance to these agents is rising and in many cases is responsible for the failure of treatment regimens. Although the treatment of Helicobacter pylori infection requires the use of more than one antibiotic to obtain adequate eradication rates, the efficacy of the currently used antibiotic combinations has been shown to be decreased by resistance to one of the antibiotics. The use of antibiotics in regimens for the treatment of H pylori is increasing in many countries, including Canada. This increase is both in the use of these antibiotics alone for the treatment of nongastrointestinal infections and in their use in association with proton pump inhibitors for the treatment of H pylori infection. In several European and Asian countries, where resistance to antibiotics is being monitored, it has been demonstrated that H pylori resistance to metronidazole and to clarithromycin increased throughout the 1990s. Thus far, the data available in Canada do not show increased resistance to either of these antibiotics. As for other antibiotics used in the treatment of H pylori infection, such as tetracycline and amoxicillin, the rate of resistance to these agents is still very low and does not constitute a significant problem. Because the efficacy of the regimens used in the treatment of H pylori infection is compromised by resistance to the antibiotics used, it is important that H pylori resistance rates in Canada and throughout the world continue to be monitored. Only with such reliable data can the most optimal regimens be recommended.
Antibiotic resistance (AR) is a significant public health issue, and agroecosystems are often viewed as major environmental sources of antibiotic resistant foodborne pathogens. While the use of antibiotics in agroecosystems can potentially increase AR, appropriate background resistance levels in th...
Bukharin, O V; Perunova, N B; Fadeev, S B; Timokhina, T Kh; Iavnova, S V
To study of circadian dynamics of antibiotic susceptibility and resistance of Gram-positive and Gram-negative microorganisms. Circadian dynamics of antibiotic susceptibility was studied on clinical strains of enterobacteria, non-fermenting Gram-negative bacteria, and staphylococci which were isolated and identified by common methods. During a day, with 3-hours intervals, studied strains were tested on susceptibility to ampicillin, oxacillin, ceftriaxone, meropenem, gentamycin, and ciprofloxacin using method of serial dilutions in agar. Circadian biorhythms of resistance to antibiotics in studied microorganisms were revealed. Along with common patterns, differences in temporal changes of microrganisms' susceptibility to antibacterial drugs were noted. Chronobiologic approach allowed to reveal significant amplitude of changes of minimal inhibitoryconcentration (MIC) of antibiotics versus resistant Gram-positive cocci reflecting presence of susceptibility periods, whereas in susceptible Gram-negative bacteria peaks of resistance were observed. Circadian dynamics of MIC of majority of antibiotics versus resistant Gram-negative bacteria and susceptible Gram-positive cocci was characterized by lower amplitude of changes without shifts from antibiotic resistance to susceptibility and vice versa. Obtained data open perspective of using biorhythmological approach in study of susceptibility of microorganisms to antibiotics during the elucidation of mechanisms of pathogens adaptation to environmental conditions and creation of new strategies of control for antibiotic resistance strains.
Wong, Aloysius Tze
Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.
This study determined E. coli resistance to commonly used antibiotics together with their virulence properties in Ile-Ife, Nigeria. A total of 137 E. coli isolates from cases of urinary tract infection were tested for their sensitivity to commonly used antibiotics and possession of virulence factors using standard methods.
Bacterial resistance to antibiotic in food animals is an emerging public health concern as a result of increasing multi-resistant bacteria found in Abeokuta. Therefore, occurrence rate and resistant profile of the emerging enteric pathogens were determined in food animals in Abeokuta, Nigeria. Fecal and rectal samples of 82 ...
Full Text Available Current in vitro combination testing methods involve enumeration by bacterial plating, which is labor-intensive and time-consuming. Measurement of bioluminescence, released when bacterial adenosine triphosphate binds to firefly luciferin-luciferase, has been proposed as a surrogate for bacterial counts. We developed an ATP bioluminescent combination testing assay with a rapid turnaround time of 24h to determine effective antibiotic combinations.100 strains of carbapenem-resistant (CR GNB [30 Acinetobacter baumannii (AB, 30 Pseudomonas aeruginosa (PA and 40 Klebsiella pneumoniae (KP] were used. Bacterial suspensions (105 CFU/ml were added to 96-well plates containing clinically achievable concentrations of multiple single and two-antibiotic combinations. At 24h, the luminescence intensity of each well was measured. Receiver operator characteristic curves were plotted to determine optimal luminescence threshold (TRLU to discriminate between inhibitory/non-inhibitory combinations when compared to viable plating. The unweighted accuracy (UA [(sensitivity + specificity/2] of TRLU values was determined. External validation was further done using 50 additional CR-GNB.Predictive accuracies of TRLU were high for when all antibiotic combinations and species were collectively analyzed (TRLU = 0.81, UA = 89%. When individual thresholds for each species were determined, UA remained high. Predictive accuracy was highest for KP (TRLU = 0.81, UA = 91%, and lowest for AB (TRLU = 0.83, UA = 87%. Upon external validation, high overall accuracy (91% was observed. The assay distinguished inhibitory/non-inhibitory combinations with UA of 80%, 94% and 93% for AB, PA and KP respectively.We developed an assay that is robust at identifying useful combinations with a rapid turn-around time of 24h, and may be employed to guide the timely selection of effective antibiotic combinations.
Xie, Yongchao; Wu, Bing; Zhang, Xu-Xiang; Yin, Jinbao; Mao, Liang; Hu, Maojie
Graphene is a promising candidate as an antibacterial material owning to its bacterial toxicity. However, little information on influence of graphene on gut microbiota is available. In this study, mice were exposed to graphene for 4 weeks, and high-throughput sequencing was applied to characterize the changes in microbial community and antibiotic resistance genes (ARGs) in mouse gut. The results showed that graphene exposure increased biodiversity of gut microbiota, and changed their community. The 1 μg/d graphene exposure had higher influences on the gut microbiota than 10 μg/d and 100 μg/d graphene exposures, which might be due to higher aggregation of high-level graphene. The influence of graphene on gut microbiota might attribute to that graphene could induce oxidative stress and damage of cell membrane integrity. The results were verified by the increase of ratio of Gram-negative bacteria. Outer membrane of Gram-negative bacteria could reduce the membrane damage induced by graphene and make them more tolerance to graphene. Further, we found that graphene exposure significantly increased the abundance and types of ARGs, indicating a potential health risk of graphene. This study firstly provides new insight to the health effects of graphene on gut microbiota. Copyright © 2015 Elsevier Ltd. All rights reserved.
Kim, Min Kyoung; Chuang, Sung-Kiang; August, Meredith
This study assessed the antibiotic resistance profile in patients with severe orofacial infections treated at a single institution from 2009 through 2014. Factors contributing to resistance were studied. The resistance profile was compared with that of a cohort of similar patients treated a decade previously to identify changes in antibiotic resistance. In addition, the effect of antibiotic resistance on in-hospital course was studied. This was a 5-year retrospective cohort study. Patients were identified through the oral and maxillofacial surgery data registry. Inclusion criteria were patients treated for orofacial infection requiring hospital admission, surgical drainage, and availability of complete medical, surgical, and microbiological data. Patients with incomplete data or treated as outpatients or nonsurgically were excluded. Sixty patient charts were identified for review. Demographic data; medical, dental, and surgical histories; and hospital course and treatment specifics were obtained for each patient. Linear regression and logistic analyses were used to analyze the data. Men composed 60% of the cohort (mean age, 45 yr). Average hospital stay was 5.5 days. Penicillin resistance was found in 32.5% of aerobic isolates and clindamycin resistance was found in 29.3%. Streptococcus viridans and Staphylococcus species showed increased resistance to clindamycin and erythromycin compared with historic controls. Younger patient age, surgical history, and number of cultured aerobes showed a relevant correlation to antibiotic resistance. The need for changes in antibiotics, repeat surgical drainage, and increased serum urea nitrogen levels correlated with longer hospital stay. A serious increase in clindamycin and erythromycin resistance was found for S viridans and Staphylococcus species. Age, surgical history, and number of cultured aerobes showed a statistically meaningful correlation to antibiotic resistance. Presence of antibiotic resistance failed to show
There is widespread interest in monitoring the development of antibiotic resistant bacteria and antibiotic resistance genes in agriculturally impacted environments, however little is known about the relationships between bacterial community structure, and antibiotic resistance gene profiles. Cattl...
Pal, Chandan; Asiani, Karishma; Arya, Sankalp; Rensing, Christopher; Stekel, Dov J; Larsson, D G Joakim; Hobman, Jon L
Antibiotic resistance is recognised as a major global threat to public health by the World Health Organization. Currently, several hundred thousand deaths yearly can be attributed to infections with antibiotic-resistant bacteria. The major driver for the development of antibiotic resistance is considered to be the use, misuse and overuse of antibiotics in humans and animals. Nonantibiotic compounds, such as antibacterial biocides and metals, may also contribute to the promotion of antibiotic resistance through co-selection. This may occur when resistance genes to both antibiotics and metals/biocides are co-located together in the same cell (co-resistance), or a single resistance mechanism (e.g. an efflux pump) confers resistance to both antibiotics and biocides/metals (cross-resistance), leading to co-selection of bacterial strains, or mobile genetic elements that they carry. Here, we review antimicrobial metal resistance in the context of the antibiotic resistance problem, discuss co-selection, and highlight critical knowledge gaps in our understanding. © 2017 Elsevier Ltd. All rights reserved.
Smith, Daniel J; Ramsay, Kay A; Yerkovich, Stephanie T; Reid, David W; Wainwright, Claire E; Grimwood, Keith; Bell, Scott C; Kidd, Timothy J
In cystic fibrosis (CF), chronic Pseudomonas aeruginosa infection is associated with increased morbidity, antibiotic treatments and mortality. By linking Australian CF registry data with a national microbiological data set, we examined the association between where treatment was delivered, its intensity and P. aeruginosa antibiotic resistance. Sputa were collected from paediatric and adult CF patients attending 18 Australian CF centres. P. aeruginosa antibiotic susceptibilities determined by local laboratories were correlated with clinical characteristics, treatment intensity and infection with strains commonly shared among Australian CF patients. Between-centre differences in treatment and antibiotic resistance were also compared. Large variations in antibiotic usage, maintenance treatment practices and multi-antibiotic resistant P. aeruginosa (MARPA) prevalence exist between Australian CF centres, although the overall proportions of MARPA isolates were similar in paediatric and adult centres (31% vs 35%, P = 0.29). Among paediatric centres, MARPA correlated with intravenous antibiotic usage and the Australian state where treatment was delivered, while azithromycin, reduced lung function and treating state predicted intravenous antibiotic usage. In adult centres, body mass index (BMI) and treating state were associated with MARPA, while intravenous antibiotic use was predicted by gender, BMI, dornase-alpha, azithromycin, lung function and treating state. In adults, P. aeruginosa strains AUST-01 and AUST-02 independently predicted intravenous antibiotic usage. Increased treatment intensity in paediatric centres and the Australian state where treatment was received are both associated with greater risk of MARPA, but not worse clinical outcomes. © 2015 Asian Pacific Society of Respirology.
Leisner, Jørgen; Jørgensen, Niels O. G.; Middelboe, Mathias
Genes encoding resistance to antibiotics appear, like the antibiotics themselves, to be ancient, originating long before the rise of the era of anthropogenic antibiotics. However, detailed understanding of the specific biological advantages of antibiotic resistance in natural environments is still......, predation is potentially an important mechanism for driving antibiotic resistance during slow or stationary phase of growth when nutrients are deprived. This adds to explain the ancient nature and widespread occurrence of antibiotic resistance in natural environments unaffected by anthropogenic antibiotics...
Masiero, Giuliano; Filippini, Massimo; Ferech, Matus; Goossens, Herman
Outpatient antibiotic consumption widely varies across Europe. The investigation of the causes of such variation may help to identify interventions that would improve the efficient use of antibiotics. The aim of this study was to assess the impact of socioeconomic determinants and the role played by information about bacterial resistance. Comparable data on systemically administered antibiotics and socioeconomic determinants in 17 European countries were available between 2000 and 2005. We estimated an ad hoc econometric model by means of a hybrid log-log functional form and random effects generalised least squares regressions. Lagged values and the instrumental variable method were applied to address endogeneity of bacterial resistance and infections. Bacterial resistance was measured by the rate of penicillin non-susceptible Streptococcus pneumoniae isolates (PNSP) and methicillin-resistant Staphylococcus aureus (MRSA). The population income, demographic structure, density of general practitioners and their remuneration method appeared to be significant determinants of antibiotic consumption. Although countries with higher levels of bacterial resistance exhibited significantly higher levels of per capita antibiotic use, ceteris paribus, the responsiveness of antibiotic use to changes in bacterial resistance was relatively low (0.09-0.18). The study confirms that socioeconomic factors should be taken into account while explaining differences in outpatient antibiotic use across countries. The impact of supply-side factors and incentives attached to payment schemes for physicians need to be considered in government interventions to reduce inequalities and improve effectiveness in antibiotic utilisation.
Antibiotic resistance is a growing and worrying problem associated with increased deaths and suffering for people. Overall, there are only two factors that drive antimicrobial resistance, and both can be controlled. These factors are the volumes of antimicrobials used and the spread of resistant micro-organisms and/or the genes encoding for resistance. The One Health concept is important if we want to understand better and control antimicrobial resistance. There are many things we can do to better control antimicrobial resistance. We need to prevent infections. We need to have better surveillance with good data on usage patterns and resistance patterns available across all sectors, both human and agriculture, locally and internationally. We need to act on these results when we see either inappropriate usage or resistance levels rising in bacteria that are of concern for people. We need to ensure that food and water sources do not spread multi-resistant micro-organisms or resistance genes. We need better approaches to restrict successfully what and how antibiotics are used in people. We need to restrict the use of 'critically important' antibiotics in food animals and the entry of these drugs into the environment. We need to ensure that 'One Health' concept is not just a buzz word but implemented. We need to look at all sectors and control not only antibiotic use but also the spread and development of antibiotic resistant bacteria - both locally and internationally. © 2015 Royal Australasian College of Physicians.
Conclusion: Due to high presence of Pseudomonas aeruginosa in raw milk and existence of antibiotic resistance genes in this bacterium, applying appropriate strategies for hygiene control in animal husbandries, is necessary to prevent the spread of bacteria.
Watkins, Richard R; Bonomo, Robert A
The rapid and ongoing spread of antibiotic resistance poses a serious threat to global public health. The indiscriminant use of antibiotics in agriculture and human medicine along with increasingly connected societies has fueled the distribution of antibiotic-resistant bacteria. These factors together have led to rising numbers of infections caused by multidrug-resistant and pan-resistant bacteria, with increases in morbidity and mortality. This article summarizes the trends in antibiotic resistance, discusses the impact of antibiotic resistance on society, and reviews the use of antibiotics in agriculture. Feasible ways to tackle antibiotic resistance to avert a post-antibiotic era are suggested. Copyright © 2016 Elsevier Inc. All rights reserved.
Mathew, A. G.; Saxton, A. M.; Upchurch, W. G.; Chattin, S. E.
Antibiotic resistance of Escherichia coli from sows and pigs was determined to compare patterns between pigs of various ages and degrees of antibiotic use. Resistance patterns differed between farm types and pigs of differing ages, indicating that pig age and degree of antibiotic use affect resistance of fecal E. coli.
Osman, Kamelia M; Samir, Ahmed; Abo-Shama, Usama H; Mohamed, Essam H; Orabi, Ahmed; Zolnikov, Tara
One of the foodborne pathogens is Listeria monocytogenes, which causes serious invasive illness in elderly and immunocompromised patients, pregnant women, newborns and infants ranking second after salmonellosis because of its high case fatality rate. Listerial cow mastitis marked by abnormal milk, increased cell counts and reduced production has not been reported. Therefore, apparently healthy cows can be reservoirs of L. monocytogenes. A number of 203 udder milk samples from apparently healthy animals (buffalo, n = 100; cow, n = 103) were collected and tested for Listeria. Isolated colonies on the PALCAM agar were Listeria species confirmed according to their biochemical and the Christie-Atkins-Munch-Petersen (CAMP) reactions. The Listeria species pathogenicity of was tested by phosphatidylinositol-specific phospholipase C, DL-alanine-β-naphthylamide HCl, Dalanine-p-nitroanilide tests, chick embryo, mice inoculation tests, Vero cell cytotoxicity and biofilm formation. The virulence-associated genes, hlyA, plcB, actA and iap associated with Listeria were molecularly assayed. The 17 isolated Listeria spp. represented a prevalence rate of 8.4 %. Of these 3 (1.4 %), 2 (1 %), 5 (2.5 %), 4 (2 %) and 3 (1.5 %) were confirmed as L. monocytogenes, L. innocua, L. welshimeri, L. seelegeri, respectively. While the L. monocytogenes isolate displayed all the four virulence-associated genes, L. seelegeri carried the hlyA gene only. The L. monocytogenes had a strong in vitro affinity to form a biofilm, in particular serotype 4 which is associated with human infections. L. monocytogenes showed resistance for 9/27 antibiotics. The biofilm forming capability of the Listeria spps. makes them particularly successful in colonizing surfaces within the host thus being responsible for persistence infections and due to their antimicrobial resistant phenotype that this structure confers. In addition, strains belonging to serotypes associated with human infections and
Pikkemaat, M.G.; Yassin, H.; Fels-Klerkx, H.J.; Berendsen, B.J.A.
Antibiotic usage has benefited the animal industry and helped providing affordable animal proteins to the growing human population. However, since extensive use of antibiotics results in the inhibition of susceptible organisms while selecting for the resistant ones, agricultural use is contributing
In particular, we studied Klebsiella pneumoniae bacteria provided by the Lavagna Hospital ASL4Liguria (Italy), where there are cases linked with antibiotics resistance of the Klebsiella pneumoniae. By comparing AFMimages of bacteria strains treated with different antibiotics is possible to identify unambiguously the ...
In the last decade the detection of the resistance of bacteria to antibiotics treatment, developed by different kind of bacteria,is becoming a huge problem. We hereby present a different approach to the current problem of detection of bacteriaresistance to antibiotics. Our aims were to use the atomic force microscopy (AFM) to ...
McMurray, Claire L; Hardy, Katherine J; Verlander, Neville Q; Hawkey, Peter M
Staphylococci are a significant cause of hospital-acquired infection. Nasal carriage of Staphylococcus aureus is an important risk factor for infection in surgical patients and coagulase-negative staphylococci (CNS) are a major cause of prosthetic joint infections. The impact that antibiotic surgical prophylaxis has on the nasal carriage of staphylococci has not been studied. Daily nasal swabs were taken from 63 patients who received antibiotic surgical prophylaxis and 16 patients who received no antibiotics. Total aerobic bacterial count, S. aureus and CNS were enumerated by culture from nasal swabs. Representative isolates were typed by staphylococcal interspersed repeat units (SIRU) typing and PFGE, and MICs to nine antibiotics were determined. After antibiotic administration, there was a reduction in S. aureus counts (median - 2.3 log(10)c.f.u. ml(- 1)) in 64.0 % of S. aureus carriers, compared with only a 0.89 log(10)c.f.u. ml(- 1) reduction in 75.0 % of S. aureus carriers who did not receive antibiotics. A greater increase in the nasal carriage rate of meticillin-resistant CNS was observed after antibiotic surgical prophylaxis compared with hospitalization alone, with increases of 16.4 and 4.6 %, respectively. Antibiotic-resistant S. epidermidis carriage rate increased by 16.6 % after antibiotic administration compared with 7.5 % with hospitalization alone. Antibiotic surgical prophylaxis impacts the nasal carriage of both S. aureus and CNS.
Background: There is growing concern worldwide about the role of polluted soil and water - 77 environments in the development and dissemination of antibiotic resistance. 78 Objective: To identify management options for reducing the spread of antibiotics and 79 antibiotic resist...
... GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Health Topics → Antibiotic Resistance URL of this page: https://medlineplus.gov/antibioticresistance. ...
Molecular analysis and antibiotic resistance investigation of Staphylococcus aureus isolates associated with staphylococcal food poisoning and nosocomial infections. Y Zhang, S Cheng, G Ding, M Zhu, X Pan, L Zhang ...
(26). Prevention of emergence of antibiotic resistance during treatment is therefore an important goal when prescribing antimicrobials. Problems affecting the operation of laboratories at the peripheral level are widespread.
Haaber, Jakob; Penadés, José R; Ingmer, Hanne
Staphylococcus aureus is a serious human pathogen with remarkable adaptive powers. Antibiotic-resistant clones rapidly emerge mainly by acquisition of antibiotic-resistance genes from other S. aureus strains or even from other genera. Transfer is mediated by a diverse complement of mobile genetic...... of plasmids that can be transferred by conjugation and the efficiency with which transduction occurs. Here, we review the main routes of antibiotic resistance gene transfer in S. aureus in the context of its biology as a human commensal and a life-threatening pathogen. Staphylococcus aureus cells...... are effective in exchanging mobile genetic elements, including antibiotic-resistance genes.During colonization or infection of host organisms, the exchange appears to be particularly effective.Bacteriophage-mediated transfer involves both transduction and autotransduction, which may enable lysogenic S. aureus...
Plantinga, Nienke L.; Bonten, Marc J. M.
Selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) have been associated with reduced mortality and lower ICU-acquired bacteremia and ventilator-associated pneumonia rates in areas with low levels of antibiotic resistance. However, the effect of selective
Lawson, Michael A.
The term "antibiotic" was first proposed by Vuillemin in 1889 but was first used in the current sense by Walksman in 1941. An antibiotic is defined as a "derivative produced by the metabolism of microorganisms that possess antibacterial activity at low concentrations and is not toxic to the host." In this article, the author describes how…
Ignasiak, Katarzyna; Maxwell, Anthony
Background Although plants produce many secondary metabolites, currently none of these are commercial antibiotics. Insects feeding on specific plants can harbour bacterial strains resistant to known antibiotics suggesting that compounds in the plant have stimulated resistance development. We sought to determine whether the occurrence of antibiotic-resistant bacteria in insect guts was a widespread phenomenon, and whether this could be used as a part of a strategy to identify antibacterial com...
Antibiotic resistance currently represents one of the biggest challenges for human health and in recent years the environmental dimension of antibiotic resistance has been increasingly recognized. The soil environment serves as an important reservoir of antibiotic resistance determinants....... In addition to direct selection of antibiotic resistance by antibiotics, metals may co-select for antibiotic resistance via different mechanisms causing environmental selection of antibiotic resistance in metal contaminated soils. Horizontal gene transfer of mobile genetic elements (MGEs) like plasmids...... is generally considered one of the most important co-selection mechanisms as multiple resistance genes can be located on the same MGE. This PhD thesis focused on the impact of metals (Cu and Zn) on the development of antibiotic resistance in bacterial communities in soils exposed to different degrees...
Wegener, Henrik Caspar
Animals and humans constitute overlapping reservoirs of resistance, and consequently use of antimicrobials in animals can impact on public health. For example, the occurrence of vancomycin-resistant enterococci in food-animals is associated with the use of avoparcin, a glycopeptide antibiotic used...... as a feed additive for the growth promotion of animals. Vancomycin-resistant enterococci and vancomycin resistance determinants can therefore spread from animals to humans. The bans on avoparcin and other antibiotics as growth promoters in the EU have provided scientists with a unique opportunity...
Lü, Lu; Zhang, Meng-lu; Wang, Chun-ming; Lin, Hui-rong; Yu, Xin
The effect of typical disinfection byproducts (DBPs) on bacterial antibiotic resistance was investigated in this study. chlorodibromomethane (CDBM), iodoacetic acid (IAA) and chloral hydrate (CH) were selected, which belong to trihalomethanes (THMs), haloacetic acids (HAAs) and aldehydes, respectively. After exposure to the selected DBPs, the resistance change of the tested strains to antibiotics was determined. As a result, all of the three DBPs induced Pseudomonas aeruginosa PAO1 to gain increased resistance to the five antibiotics tested, and the DBPs ranked as IAA > CH > CDBM according to their enhancement effects. Multidrug resistance could also be enhanced by treatment with IAA. The same result was observed in Escherichia coli K12, suggesting that the effect of DBPs on antibiotic resistance was a common phenomenon. The mechanism was probably that DBPs stimulated oxidative stress, which induced mutagenesis. And the antibiotic resistance mutation frequency could be increased along with mutagenesis. This study revealed that the acquisition of bacterial antibiotic resistance might be related to DBPs in drinking water systems. Besides the genotoxicological risks, the epidemiological risks of DBPs should not be overlooked.
Dantas, Gautam; Sommer, Morten
Mapping the exchange of genes between pathogens and nonpathogens offers new ways to understand and manage the spread of drug-resistant strains. In reality, the development of new antibiotics is only part of the solution, as pathogens will inevitably develop resistance to even the most promising new...... compounds. To save the era of antibiotics, scientists must figure out what it is about bacterial pathogens that makes resistance inevitable. Although most studies on drug resistance have focused on disease causing pathogens, recent efforts have shifted attention to the resistomes of nonpathogenic bacteria...
Full Text Available Antibiotic-resistant bacteria and genes enter the environment in different ways. The release of these factors into the environment has increased concerns related to public health. The aim of the study was to evaluate the antibiotic resistance genes (ARGs in the environmental resources. In this systematic review, the data were extracted from valid sources of information including ScienceDirect, PubMed, Google Scholar and SID. Evaluation and selection of articles were conducted on the basis of the PRISMA checklist. A total of 39 articles were included in the study, which were chosen from a total of 1249 papers. The inclusion criterion was the identification of genes encoding antibiotic resistance against the eight important groups of antibiotics determined by using the PCR technique in the environmental sources including municipal and hospital wastewater treatment plants, animal and agricultural wastes, effluents from treatment plants, natural waters, sediments, and drinking waters. In this study, 113 genes encoding antibiotic resistance to eight groups of antibiotics (beta-lactams, aminoglycosides, tetracyclines, macrolides, sulfonamides, chloramphenicol, glycopeptides and quinolones were identified in various environments. Antibiotic resistance genes were found in all the investigated environments. The investigation of microorganisms carrying these genes shows that most of the bacteria especially gram-negative bacteria are effective in the acquisition and the dissemination of these pollutants in the environment. Discharging the raw wastewaters and effluents from wastewater treatments acts as major routes in the dissemination of ARGs into environment sources and can pose hazards to public health.
Hiramatsu, Keiichi; Igarashi, Masayuki; Morimoto, Yuh; Baba, Tadashi; Umekita, Maya; Akamatsu, Yuzuru
By screening cultures of soil bacteria, we re-discovered an old antibiotic (nybomycin) as an antibiotic with a novel feature. Nybomycin is active against quinolone-resistant Staphylococcus aureus strains with mutated gyrA genes but not against those with intact gyrA genes against which quinolone antibiotics are effective. Nybomycin-resistant mutant strains were generated from a quinolone-resistant, nybomycin-susceptible, vancomycin-intermediate S. aureus (VISA) strain Mu 50. The mutants, occurring at an extremely low rate (generation), were found to have their gyrA genes back-mutated and to have lost quinolone resistance. Here we describe nybomycin as the first member of a novel class of antibiotics designated 'reverse antibiotics'. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Aim: This study was aimed at determining the prevalence, antibiotic resistance and heat resistance profile of bacterial isolates obtained from ready to eat roasted beef (suya) sold in Abuja, Nigeria. Methods and Results: Fifty samples of suya were purchased from different vendors within the Federal Capital Territory and ...
Staphylococcus aureus is a bacterial specie that opposed more resistance again many antibiotics. This study aimed to determine the resistance profile of Staphylococcus aureus isolated from biological patient's liquids. A total of 303 samples including urine and vaginal pus samples from human were collected.
Infants, children and the aged are among the groups most vulnerable to microbial infections more so when these microbial agents become resistant to antimicrobials. The antibiotic resistant profile of Staphylococcus aureus and selected coagulase negative staphylococci were determined by standard methods. Of the 178 ...
The objective of this study was to determine antibiotic resistance patterns and specific resistance genes in Gram-negative enteric bacteria recovered from 42 different drinking water sources servicing 2 rural villages in south-western Uganda. These water sites were prone to contamination by both human and cattle activity.
mega Dalton (MDa) conjugative plasmid. Evidence supported the theory that this resistance gene was introduced into the plasmid 48 through a one...six percent of clinical Gc isolates carry a 2.6 mega Dalton (MDa) cryptic plasmid, but this plasmid is not associated with any known virulence...so many strains. This theory is supported by the fact that portions of the plasmid, both large and small, are incorporated into the chromosome
Karkman, Antti; Do, Thi Thuy; Walsh, Fiona; Virta, Marko P J
Waste water and waste water treatment plants can act as reservoirs and environmental suppliers of antibiotic resistance. They have also been proposed to be hotspots for horizontal gene transfer, enabling the spread of antibiotic resistance genes between different bacterial species. Waste water contains antibiotics, disinfectants, and metals which can form a selection pressure for antibiotic resistance, even in low concentrations. Our knowledge of antibiotic resistance in waste water has increased tremendously in the past few years with advances in the molecular methods available. However, there are still some gaps in our knowledge on the subject, such as how active is horizontal gene transfer in waste water and what is the role of the waste water treatment plant in the environmental resistome? The purpose of this review is to briefly describe some of the main methods for studying antibiotic resistance in waste waters and the latest research and main knowledge gaps on the issue. In addition, some future research directions are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Boehnke, Kevin F; Valdivieso, Manuel; Bussalleu, Alejandro; Sexton, Rachael; Thompson, Kathryn C; Osorio, Soledad; Novoa Reyes, Italo; Crowley, John J; Baker, Laurence H; Xi, Chuanwu
Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori , a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA , vacA m1, or vacA m2 and antibiotic resistance. The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively.
Boehnke, Kevin F; Valdivieso, Manuel; Bussalleu, Alejandro; Sexton, Rachael; Thompson, Kathryn C; Osorio, Soledad; Reyes, Italo Novoa; Crowley, John J; Baker, Laurence H; Xi, Chuanwu
Objectives Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. Materials and methods H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. Results Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance. Conclusion The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively. PMID:28331349
Singh, Nina; Yeh, Pamela J
Antibiotic effectiveness often changes when two or more such drugs are administered simultaneously and unearthing antibiotic combinations with enhanced efficacy (synergy) has been a longstanding clinical goal. However, antibiotic resistance, which undermines individual drugs, threatens such combined treatments. Remarkably, it has emerged that antibiotic combinations whose combined effect is lower than that of at least one of the individual drugs can slow or even reverse the evolution of resistance. We synthesize and review studies of such so-called 'suppressive interactions' in the literature. We examine why these interactions have been largely disregarded in the past, the strategies used to identify them, their mechanistic basis, demonstrations of their potential to reverse the evolution of resistance and arguments for and against using them in clinical treatment. We suggest future directions for research on these interactions, aiming to expand the basic body of knowledge on suppression and to determine the applicability of suppressive interactions in the clinic.
vealed several aminoglycoside resistances in nonculturable bac- teria. Notwithstanding the availability of so many antimicrobial agents, infectious diseases still remain the second leading cause of death worldwide. Eventually, the widespread occurrence of antibiotic-resistant bacteria has added a new dimension to the.
provided a distinct advantage to the physicians in controlling bacterial infections. Discovery of streptomycin, the ... resistance to virtually all the therapeutically useful antibiotics had been evidenced. Emergence of ..... Genomic tools are helping us to select for antibacterial targets and understand bacterial resistance. On the ...
Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of. S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic ...
Conclusion: Pneumococcal resistance was significant in this group of children with easy access to paediatric services and antibiotic use. The implication of such high resistance for the treatment of pneumococcal diseases is that high-dose amoxicillin is the preferred empirical oral therapy for treatment of otitis media.
Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic ...
Beginning in the 1940s, mass production of antibiotics involved the industrial-scale growth of microorganisms to harvest their metabolic products. Unfortunately, the use of antibiotics selects for resistance at answering scale. The turn to the study of antibiotic resistance in microbiology and medicine is examined, focusing on the realization that individual therapies targeted at single pathogens in individual bodies are environmental events affecting bacterial evolution far beyond bodies. In turning to biological manifestations of antibiotic use, sciences fathom material outcomes of their own previous concepts. Archival work with stored soil and clinical samples produces a record described here as 'the biology of history': the physical registration of human history in bacterial life. This account thus foregrounds the importance of understanding both the materiality of history and the historicity of matter in theories and concepts of life today.
Microbial resistance to antibiotics. ... African Journal of Biotechnology ... Microorganisms develop resistance to antibiotics by any of the following mechanisms: selection, mutation, phage transduction, and transference while microbial resistance can either be inherent in the organism or acquired through the environment.
S. Nijssen (Saskia); A.C. Fluit (Ad); D.A.M.C. van de Vijver (David); J. Top (Janetta); R.J.L. Willems (Rob); M.J.M. Bonten (Marc)
textabstractBackground: We determined the effects of two antibiotic policies (predominance of either β-lactam antibiotics or fluroquinolones) on acquisition with third-generation cephalosporin-resistant Enterobacteriaceae (CRE) and fluoroquinolone-resistant CRE (FCRE) in two ICUs, with monitoring of
Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J.; Stålsby Lundborg, Cecilia
The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the blaTEM gene being more common than blaCTX-M. Co-harbouring of the blaCTX-M, blaTEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs. PMID:28661465
Lien, La Thi Quynh; Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J; Stålsby Lundborg, Cecilia
The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla TEM gene being more common than bla CTX-M . Co-harbouring of the bla CTX-M , bla TEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.
Antibiotic resistance in food animals has received increased scrutiny in recent years due to the increased prevalence of antibiotic resistant infections in the human clinical setting. The extent to which antibiotic usage in food animals is responsible for the burden of antibiotic resistance in human...
Fredericks, Ian; Hollingworth, Samantha; Pudmenzky, Alex; Rossato, Laurence; Kairuz, Therése
Australians are among the highest users of antibiotics in the developed world. The primary aim was to determine the 'age' of antibiotic prescriptions at the time of dispensing as a possible contributor to antibiotic misuse and ultimately, resistance. The secondary aim was to test customised software to permit extraction and de-identification of dispensing records for analysis. Data were extracted and de-identified from computerised dispensing systems in three community pharmacies in Brisbane, Australia, according to a strict ethical protocol. All prescription records dispensed between 1 January 2010 and 31 December 2012 were merged to form a complete dataset of 1 158 871 de-identified dispensing records which were analysed using Microsoft Excel ® . A retrospective drug utilisation study was conducted on a subset of 100 573 antibiotic records. In a substudy conducted at a single pharmacy site, all antibiotic records dispensed over a 4-month (winter) period were examined to determine the age of prescriptions. Nearly one in ten antibiotics (9.0%) was dispensed from prescriptions that were more than a month old, and over one in five (22.1%) were dispensed from a repeat prescription. Health system factors may contribute to inappropriate antibiotic use in Australia, including availability and validity of repeat antibiotic prescriptions. Government health departments, prescribers, pharmacists, other health professionals and consumers have to share the responsibility of ensuring that antibiotics are used appropriately. © 2016 Royal Pharmaceutical Society.
Li, X; Zhong, Y L; Feng, Y J
A growing body of diversified antibiotic resistances raises a significant challenge to anti-infection clinical therapeutics. The emergence of superbugs carrying MCR-1/2 or NDM-1 determinants underlines the importance and urgency in elucidation of molecular mechanisms shared by antibiotic resistances. It is aware that different classes of bactericidal antibiotics consistently stimulate the production of deleterious reactive oxygen species (ROS), which are accompanied with metabolic disturbance. The different destinations of ROS determine its consequence on bacterial fate. Here, we review antibiotic-induced production, progression and transformation of ROS, as well as its role in the development of antibiotic resistance. Additionally, we anticipate that mesosome-like structures-aided exclusion of hydrogen peroxide might represent a previously-unknown mechanism for antibiotic resistance. This mini-review is aiming to present an update overview on antibiotic resistance and provide clues to the development of novel antibiotics.
Sharkey, Liam K R; Edwards, Thomas A; O'Neill, Alex J
Members of the ABC-F subfamily of ATP-binding cassette proteins mediate resistance to a broad array of clinically important antibiotic classes that target the ribosome of Gram-positive pathogens. The mechanism by which these proteins act has been a subject of long-standing controversy, with two competing hypotheses each having gained considerable support: antibiotic efflux versus ribosomal protection. Here, we report on studies employing a combination of bacteriological and biochemical techniques to unravel the mechanism of resistance of these proteins, and provide several lines of evidence that together offer clear support to the ribosomal protection hypothesis. Of particular note, we show that addition of purified ABC-F proteins to anin vitrotranslation assay prompts dose-dependent rescue of translation, and demonstrate that such proteins are capable of displacing antibiotic from the ribosomein vitro To our knowledge, these experiments constitute the first direct evidence that ABC-F proteins mediate antibiotic resistance through ribosomal protection.IMPORTANCEAntimicrobial resistance ranks among the greatest threats currently facing human health. Elucidation of the mechanisms by which microorganisms resist the effect of antibiotics is central to understanding the biology of this phenomenon and has the potential to inform the development of new drugs capable of blocking or circumventing resistance. Members of the ABC-F family, which includelsa(A),msr(A),optr(A), andvga(A), collectively yield resistance to a broader range of clinically significant antibiotic classes than any other family of resistance determinants, although their mechanism of action has been controversial since their discovery 25 years ago. Here we present the first direct evidence that proteins of the ABC-F family act to protect the bacterial ribosome from antibiotic-mediated inhibition. Copyright © 2016 Sharkey et al.
McEachran, Andrew D; Blackwell, Brett R; Hanson, J Delton; Wooten, Kimberly J; Mayer, Gregory D; Cox, Stephen B; Smith, Philip N
Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized. The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards. PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing. Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind. Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs.
Choudhury, R; Panda, S; Singh, D V
Antibiotic resistance is a major problem in clinical health settings. Interestingly the origin of many of antibiotic resistance mechanisms can be traced back to non-pathogenic environmental organisms. Important factors leading to the emergence and spread of antibiotic resistance include absence of regulation in the use of antibiotics, improper waste disposal and associated transmission of antibiotic resistance genes in the community through commensals. In this review, we discussed the impact of globalisation on the transmission of antibiotic resistance genes in bacteria through immigration and export/import of foodstuff. The significance of surveillance to define appropriate use of antibiotics in the clinic has been included as an important preventive measure.
Flach, Carl-Fredrik; Pal, Chandan; Svensson, Carl Johan; Kristiansson, Erik; Östman, Marcus; Bengtsson-Palme, Johan; Tysklind, Mats; Larsson, D G Joakim
There is concern that heavy metals and biocides contribute to the development of antibiotic resistance via co-selection. Most antifouling paints contain high amounts of such substances, which risks turning painted ship hulls into highly mobile refuges and breeding grounds for antibiotic-resistant bacteria. The objectives of this study were to start investigate if heavy-metal based antifouling paints can pose a risk for co-selection of antibiotic-resistant bacteria and, if so, identify the underlying genetic basis. Plastic panels with one side painted with copper and zinc-containing antifouling paint were submerged in a Swedish marina and biofilms from both sides of the panels were harvested after 2.5-4weeks. DNA was isolated from the biofilms and subjected to metagenomic sequencing. Biofilm bacteria were cultured on marine agar supplemented with tetracycline, gentamicin, copper sulfate or zinc sulfate. Biofilm communities from painted surfaces displayed lower taxonomic diversity and enrichment of Gammaproteobacteria. Bacteria from these communities showed increased resistance to both heavy metals and tetracycline but not to gentamicin. Significantly higher abundance of metal and biocide resistance genes was observed, whereas mobile antibiotic resistance genes were not enriched in these communities. In contrast, we found an enrichment of chromosomal RND efflux system genes, including such with documented ability to confer decreased susceptibility to both antibiotics and biocides/heavy metals. This was paralleled by increased abundances of integron-associated integrase and ISCR transposase genes. The results show that the heavy metal-based antifouling paint exerts a strong selection pressure on marine bacterial communities and can co-select for certain antibiotic-resistant bacteria, likely by favoring species and strains carrying genes that provide cross-resistance. Although this does not indicate an immediate risk for promotion of mobile antibiotic resistance, the
Ham, Young-Sik; Kobori, Hiromi; Kang, Joo-Hyon; Matsuzaki, Takayuki; Iino, Michiyo; Nomura, Hayashi
Antibiotic-resistant E. coli concentrations showed large spatial and temporal variations, with greater concentrations observed in tributaries and downstream than in the upstream and midstream. Twenty percent of the geometric mean concentrations of antibiotic-resistant E. coli in the Tama River basin (Japan) exceeded the maximum acceptable concentration of indicator E. coli established by the USEPA. The indicator E. coli concentrations were positively correlated with those of antibiotic-resistant E. coli and multiple-antibiotic-resistant E. coli (resistance to more than two kinds of antibiotics), respectively, but not the detection rate of antibiotic-resistant E. coli, implying that use of antibiotic-resistant E. coli concentration rather than the detection rate can be a better approach for water quality assessment. Multiple-antibiotic-resistant E. coli is a useful indicator for estimating the resistance diffusion, water quality degradation and public health risk potential. This assessment provides beneficial information for setting national regulatory or environmental standards and managing integrated watershed areas. - Highlights: ► We extensively observed antibiotic-resistant E. coli (AREc) in Tama River (Japan). ► AREc count rather than the detection rate is better approach for water quality test. ► Multiple-AREc is resistant to the antibiotic to which single-AREc has no resistance. ► Multiple-AREc increase will accelerate the diffusion of antibiotic resistance. - Multiple-antibiotic-resistant E. coli in the watershed can cause the diffusion of conventionally rare antibiotic resistance.
Vilaichone, Ratha-Korn; Gumnarai, Pornpen; Ratanachu-Ek, Thawee; Mahachai, Varocha
The objectives of this study are to survey the antibiotic-resistant pattern of Helicobacter pylori infection in different geographical locations in Thailand and to determine factors associated with antibiotic resistance. Dyspeptic patients undergoing upper gastrointestinal endoscopy from the Northern, Northeastern, Central, and Southern regions of Thailand between January 2004 and December 2012 were enrolled in this study. Two antral gastric biopsies were obtained for culture; susceptibility tests were performed using E-test. A total of 3964 were enrolled, and 1350 patients (34.1%) were infected with H. pylori as identified by rapid urease test. Cultures were positive in 619 isolates. E-test for amoxicillin, clarithromycin, metronidazole, and tetracycline were successful in 400 isolates and for levofloxacin and ciprofloxacin in 208 isolates. Antibiotic resistance was present in 50.3% including amoxicillin 5.2%, tetracycline 1.7%, clarithromycin 3.7%, metronidazole 36%, ciprofloxacin 7.7%, levofloxacin 7.2%, and multi-drugs in 4.2%. Clarithromycin resistance was significantly more common in those older than 40 years (i.e., 100% versus 0%; P = 0.04). The prevalence of metronidazole resistant in Southern Thailand was significantly higher than in the Northeastern region (66.7% versus 33.3% P = 0.04). Metronidazole resistance remains the most common antibiotic resistant type of H. pylori in Thailand. The pattern of H. pylori antibiotic resistance over 9 years demonstrated a fall in clarithromycin resistance such that currently age >40 years is a predictor for clarithromycin resistance in Thailand. Quinolone resistance is a growing problem. © 2013.
Gould, Ian M
The current worldwide pandemic of antibiotic resistance shows no signs of abating. It is clear that it is driven mainly by heavy and often inappropriate antibiotic use. Although control measures are widely practised, it is important that we assess their efficacy critically in order to concentrate expensive control efforts where they will be most effective. The past year has seen much activity in this area, with evidence-based assessments of the literature according to strict guidelines, as well as progress in basic science studies of mechanisms of resistance, and their causes and relations to pathogenicity and adaptability. The present review summarizes current developments in the causes of antibiotic resistance, the classification of antibiotic stewardship and control measures, the evidence base for their efficacy, current problems in hospital practice, the adaptability of bacteria, the content of antibiotic policies and anticipated activities. The conclusions from the published literature are that much of it that pertains to changing prescribing practices does not stand up to modern evidence-based analysis concepts. Nevertheless, we can learn from experience in changing other areas of medical practice. We must be pragmatic and must not expect to change the world, but rather take it step by step, recognizing barriers and measuring outcomes and quality indicators. Studies into the molecular basis of resistance confirm the superb genetic adaptability of micro-organisms. They will always be several steps ahead of us. Nevertheless, we are learning how to modify our prescribing habits to minimize resistance, not only by using antibiotics less frequently but also by altering dosing schedules in various ways.
Multi-drug resistant bacterial strains evolving worldwide has created a great public health problem that needs urgent attention; as such bacteria show resistance to the drug of choice for treatment as well as being resistant to newer and last line antibiotics. In this study, the antibiotic susceptibility, multi antibiotic resistance ...
Background. Antibiotic resistance is a growing problem worldwide. Mechanisms of resistance vary, and some can confer resistance to multiple classes of antibiotics. Objective. To characterise the antibiotic resistance profiles of Escherichia coli isolates obtained from stool samples of young rural children exposed or ...
After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed.
Next, we added the phage displaying #39 or a randomized version of #39 to growing staphylococci and showed that #39, but not the randomized...synergy with oxacillin against methicillin-resistant staphylococci as well as synergy with vancomycin against vancomycin-resistant staphylococci . We...below in Task 3). 2 Task 3. Test top binding display phage against whole staphylococci . (months 7-9) Despite being covalently attached to a
Peña-Miller, Rafael; Gori, Fabio; Iredell, Jonathan
Abstract Can we exploit our burgeoning understanding of molecular evolution to slow the progress of drug resistance? One role of an infection clinician is exactly that: to foresee trajectories to resistance during antibiotic treatment and to hinder that evolutionary course. But can this be done at a hospital-wide scale? Clinicians and theoreticians tried to when they proposed two conflicting behavioral strategies that are expected to curb resistance evolution in the clinic, these are known as “antibiotic cycling” and “antibiotic mixing.” However, the accumulated data from clinical trials, now approaching 4 million patient days of treatment, is too variable for cycling or mixing to be deemed successful. The former implements the restriction and prioritization of different antibiotics at different times in hospitals in a manner said to “cycle” between them. In antibiotic mixing, appropriate antibiotics are allocated to patients but randomly. Mixing results in no correlation, in time or across patients, in the drugs used for treatment which is why theorists saw this as an optimal behavioral strategy. So while cycling and mixing were proposed as ways of controlling evolution, we show there is good reason why clinical datasets cannot choose between them: by re-examining the theoretical literature we show prior support for the theoretical optimality of mixing was misplaced. Our analysis is consistent with a pattern emerging in data: neither cycling or mixing is a priori better than the other at mitigating selection for antibiotic resistance in the clinic. Key words: antibiotic cycling, antibiotic mixing, optimal control, stochastic models. PMID:28096304
Beardmore, Robert Eric; Peña-Miller, Rafael; Gori, Fabio; Iredell, Jonathan
Can we exploit our burgeoning understanding of molecular evolution to slow the progress of drug resistance? One role of an infection clinician is exactly that: to foresee trajectories to resistance during antibiotic treatment and to hinder that evolutionary course. But can this be done at a hospital-wide scale? Clinicians and theoreticians tried to when they proposed two conflicting behavioral strategies that are expected to curb resistance evolution in the clinic, these are known as "antibiotic cycling" and "antibiotic mixing." However, the accumulated data from clinical trials, now approaching 4 million patient days of treatment, is too variable for cycling or mixing to be deemed successful. The former implements the restriction and prioritization of different antibiotics at different times in hospitals in a manner said to "cycle" between them. In antibiotic mixing, appropriate antibiotics are allocated to patients but randomly. Mixing results in no correlation, in time or across patients, in the drugs used for treatment which is why theorists saw this as an optimal behavioral strategy. So while cycling and mixing were proposed as ways of controlling evolution, we show there is good reason why clinical datasets cannot choose between them: by re-examining the theoretical literature we show prior support for the theoretical optimality of mixing was misplaced. Our analysis is consistent with a pattern emerging in data: neither cycling or mixing is a priori better than the other at mitigating selection for antibiotic resistance in the clinic. : antibiotic cycling, antibiotic mixing, optimal control, stochastic models. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Nowadays methicillin-resistant strain Staphylococcus aureus (MRSA) is one of the most widespread multiresistant bacteria. Photodynamic inactivation (PDI) of microorganisms by photosensitizers (PS) may be an effective and alternative therapeutic option against antibiotic resistant bacteria. The effectiveness of new PS cationic porphyrin Zn-TBut4PyP was tested on two strains of S. aureus (MRSA and methicillin-sensitive S. aureus). It is shown that Zn-TBut4PyP has high photodynamic activity against both strains
Garcia, Alexander; Delorme, Thierry; Nasr, Payman
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of nosocomial infections. A thorough understanding of the epidemiology and distribution of MRSA allows the development of better preventive measures and helps to control or reduce the rate of infection among the general population. A retrospective survey was performed on 511 cases of MRSA infections from inpatient, outpatient and nursing home populations over a 12-month period. To study the relationships between two continuous quantitative variables (patient age vs resistance percentage), a simple linear regression was calculated for each antibiotic to predict the antibiotic resistance percentage with respect to patient age.Results/Key findings. The pattern of antibiotic resistance with respect to the age of patients depended on the antibiotic mode of action. Antibiotics that target DNA synthesis (i.e. fluoroquinolones) display a direct correlation with the age of patients, with higher rates of resistance among the older population, while antibiotics that target ribosomal functions (i.e. aminoglycosides) or cell wall synthesis (i.e. cephalosporin) do not display an age-dependent pattern and have a consistent degree of resistance across all age classes. Antibiotics that target DNA synthesis result in a progressively higher number of resistant isolates among the older population. The results emphasize the importance of patient age on antibiotic selection as a preventive measure to reduce the rate of resistant infections in each susceptible population. This pattern suggests that physicians should take into consideration patient age as another factor in determining the best antibiotic regiment with the aim of curtailing the emergence of newer resistant phenotypes in the future.
Purpose: To investigate the antibiotic resistance pattern of uropathogenic Escherichia coli (UPEC) strains isolated from pregnant women with history of recurrent urinary tract infections (RUTIs) and healthy pregnant women. Methods: A total of 485 high vaginal swab specimens were collected from pregnant women with ...
Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus, ..... and Argentina . CONCLUSION. As far as we know, the present study is the first prevalence report on antibiotic resistance pattern of UPEC strains in ... serogroups profiles of uropathogenic Escherichia coli isolated ...
Introduction. Stenotrophomonas maltophilia is a resistant pathogen that can cause bacteremia, endocarditis, respiratory system, central nervous system and urinary tract infections in patients with risk factors like malignancy or neutrope- nia, use of broad-spectrum antibiotics like carbapenem or long-term hospitalization1,2.
The carriage of Streptococcus pneumoniae, serotypes, antimicrobial susceptibility patterns and disease development are poorly understood in Yei. Availability of affordable antibiotics over the counter, lack of laboratory infrastructure and high rates of penicillin resistance have the potential to aggravate rates of childhood ...
Full Text Available PSM-mec is a secreted virulence factor that belongs to the phenol-soluble modulin (PSM family of amphipathic, alpha-helical peptide toxins produced by Staphylococcus species. All known PSMs are core genome-encoded with the exception of PSM-mec, whose gene is found in specific sub-types of SCCmec methicillin resistance mobile genetic elements present in methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci. In addition to the cytolytic translational product, PSM-mec, the psm-mec locus encodes a regulatory RNA. In S. aureus, the psm-mec locus influences cytolytic capacity, methicillin resistance, biofilm formation, cell spreading and the expression of other virulence factors, such as other PSMs, which results in a significant impact on immune evasion and disease. However, these effects are highly strain-dependent, which is possibly due to differences in PSM-mec peptide versus psm-mec RNA-controlled effects. Here, we summarize the functional properties of PSM-mec and the psm-mec RNA molecule and their roles in staphylococcal pathogenesis and physiology.
Geoffrey Ivan Scott
Full Text Available ABSTRACTMonitoring 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
Prevalence and antibiotic resistance patterns of methicillin-resistant Staphylococcus aureus in raw milk and soft cheese (wara) sold in Abeokuta, Nigeria. ... (100%), ampicillin 16 (94.1%), doxycycline 11 (64.7%), tetracycline 17 (100%), oxacillin 15 (88.2%), augmentin 17 (100%), gentamycin 15 (88.2%), colistin 15 (88.2%), ...
Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates was examined by paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which ...
Samples of fresh faeces were obtained from a free-range chicken source, three commercial chicken farms and a commercial ostrich farm, all located around Bulawayo City, Zimbabwe, in order to determine the antibiotic resistance profile of selected bacterial isolates of interest in food-related human infections. Samples were ...
ABSTRACT. This a prospective study to determine the prevalence of antibiotic resistance among organisms causing urinary tract infections in a Teaching Hospitai between August 2003 and July 2004 and to compare them with an earlier study in 1993. A total of HM urine samples were collected in sterile universal ...
Olson, Ronald P.; Haith, Karen
Objective: To determine resistance to antibiotics of "Escherichia coli" in uncomplicated urinary tract infections (uUTIs) in female college students. Participants: Symptomatic patients presenting to a student health service from September 2008 to December 2009. Methods: Clean catch midstream urine samples were tested for urinalysis (UA) and…
Brock, David; Boeke, Caroline; Josowitz, Rebecca; Loya, Katherine
The study developed a simple experimental protocol for studying antibiotic resistant bacteria that will allow students to determine the proportion of such bacteria found on common fruit and vegetable crops. This protocol can open up the world of environmental science and show how human behavior can dramatically alter ecosystems.
Rams, Thomas E.; Degener, John E.; van Winkelhoff, Arie J.
ObjectivesBecause antimicrobial therapy is often employed in the treatment of infectious dental implant complications, this study determined the occurrence of in vitro antibiotic resistance among putative peri-implantitis bacterial pathogens. MethodsSubmucosal biofilm specimens were cultured from
Jan 19, 2009 ... Prevalence of multiple antibiotic resistant bacteria and chromosomal determinants in surface water of. Bangladesh. Hasan M. Zahid1*, Zinat Mahal2, and Mamun R. Chowdhury2. 1Tissue Banking and Biomaterial Research Unit, Atomic Energy Research Establishment, Bangladesh Atomic Energy.
Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.
Boel, Jonas; Andreasen, Viggo; Jarløv, Jens Otto
OBJECTIVES: We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital. METHODS: The study was conducted as a retrosp......OBJECTIVES: We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital. METHODS: The study was conducted...... as a retrospective controlled interrupted time series (ITS) at two university teaching hospitals, intervention and control, with 736 and 552 beds, respectively. The study period was between January 2008 and September 2014. We used ITS analysis to determine significant changes in antibiotic use and resistance levels......% CI -177, -126)] and fluoroquinolones [-44.5 DDDs/1000 bed-days (95% CI -58.9, -30.1)]. Resistance of E. coli showed a significant change in slope for cefuroxime [-0.13 percentage points/month (95% CI -0.21, -0.057)] and ciprofloxacin [-0.15 percentage points/month (95% CI -0.26, -0.038)]. CONCLUSIONS...
Full Text Available Shigellosis is an important public health problem, especially in developing countries. Antibiotic treatment of bacterial dysentery, aimed at resolving diarrhea or reducing its duration is especially indicated whenever malnutrition is present. First-line drugs include ampicillin and trimethoprim sulfamethoxazole(TMP-SMX; however multidrug-resistance has occurred and careful antibiotic selection must be considered in prescribing .When epidemiologic data indicate a rise in resistancy, fluoroquinolones may be used in adults and oral third-generation cephalosporins and nalidixic acid in children. All children (n=2400 with acute diarrhea who were admitted to the Pediatric department of Dr.sheykh Hospital Mashhad, Iran from March 2004 to March 2005 were selected and their stool culture were obtained, then positive cultures (312 cases,13% were evaluated by antibiogram. This study showed that in heavily populated areas of IRAN like Mashhad, 97% shigella strain isolated from children with bloody diarrhea were sensitive to nalidixic acid, ciprofloxacin and cefixime and rarely susceptible to ampicillin and cotrimoxazole. There is increasing resistance of Shigella to most of the antibiotics in use, and for this reason, careful selection of antibiotics must use considered in each area. Development and use of new drugs are expensive and have severe limitations in the third world. Simple prophylactic alternatives are therefore, required, such as awareness of hygienic child care practices and early promotion of breast feeding. For treatment of shigellosis in infants Ceftriaxon, and in children Nalidixic Acid is recommended.
Pruden, Amy; Larsson, D.G. Joakim; Amézquita, Alejandro
Background: There is growing concern worldwide about the role of polluted soil and water environments in the development and dissemination of antibiotic resistance. Objective: Our aim in this study was to identify management options for reducing the spread of antibiotics and antibiotic resistance...... of management strategies is also highlighted. Finally, we describe a case study in Sweden that illustrates the critical role of communication to engage stakeholders and promote action. Conclusions: Environmental releases of antibiotics and antibiotic-resistant bacteria can in many cases be reduced at little...... associated with antibiotic resistance strongly indicate the need for action....
Full Text Available This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L. The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L. By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L. However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.
Yuan, Qing-Bin; Guo, Mei-Ting; Yang, Jian
This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L). The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L). By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L). However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.
Zaman, Sojib Bin; Hussain, Muhammed Awlad; Nye, Rachel; Mehta, Varshil; Mamun, Kazi Taib; Hossain, Naznin
Antibiotics are the 'wonder drugs' to combat microbes. For decades, multiple varieties of antibiotics have not only been used for therapeutic purposes but practiced prophylactically across other industries such as agriculture and animal husbandry. Uncertainty has arisen, as microbes have become resistant to common antibiotics while the host remains unaware that antibiotic resistance has emerged. The aim of this review is to explore the origin, development, and the current state of antibiotic resistance, regulation, and challenges by examining available literature. We found that antibiotic resistance is increasing at an alarming rate. A growing list of infections i.e., pneumonia, tuberculosis, and gonorrhea are becoming harder and at times impossible to treat while antibiotics are becoming less effective. Antibiotic-resistant infections correlate with the level of antibiotic consumption. Non-judicial use of antibiotics is mostly responsible for making the microbes resistant. The antibiotic treatment repertoire for existing or emerging hard-to-treat multidrug-resistant bacterial infections is limited, resulting in high morbidity and mortality report. This review article reiterates the optimal use of antimicrobial medicines in human and animal health to reduce antibiotic resistance. Evidence from the literature suggests that the knowledge regarding antibiotic resistance in the population is still scarce. Therefore, the need of educating patients and the public is essential to fight against the antimicrobial resistance battle.
.... Although antibiotic resistance (AR) in foodborne pathogens has been studied extensively, the contribution of foodborne commensals in disseminating the resistance genes has been neglected in the past...
Pooja D. Gupta
Full Text Available The discovery of antibiotics in the previous century lead to reduction in mortality and morbidity due to infectious diseases but their inappropriate and irrational use has resulted in emergence of resistant microbial populations. Alteration of target sites, active efflux of drugs and enzymatic degradations are the strategies employed by the pathogenic bacteria to develop intrinsic resistance to antibiotics. This has led to an increased interest in medicinal plants since 25–50% of current pharmaceuticals are plant derived. Crude extracts of medicinal plants could serve as an alternate source of resistance modifying agents owing to the wide variety of secondary metabolites. These metabolites (alkaloids, tannins, polyphenols etc. could act as potentials for antimicrobials and resistance modifiers. Plant extracts have the ability to bind to protein domains leading to modification or inhibition protein–protein interactions. This enables the herbals to also present themselves as effective modulators of host related cellular processes viz immune response, mitosis, apoptosis and signal transduction. Thus they may exert their activity not only by killing the microorganism but by affecting key events in the pathogenic process, thereby, the bacteria, fungi and viruses may have a reduced ability to develop resistance to botanicals. The article is meant to stimulate research wherein the cidal activity of the extract is not the only parameter considered but other mechanism of action by which plants can combat drug resistant microbes are investigated. The present article emphasizes on mechanisms involved in countering multi drug resistance.
Mansfield, Jillian M; Herrmann, Paul; Jesionowski, Amy M; Vickerman, M Margaret
Streptococcus gordonii produces a pheromone heptapeptide, s.g.cAM373, which induces a conjugative mating response in Enterococcus faecalis cells carrying the responsive plasmid, pAM373. We investigated the extent of this intergeneric signaling on DNA acquisition by streptococcal species likely to cohabit oral biofilms. E. faecalis/pAM373/pAMS470 cells were incubated with synthetic s.g.cAM373, reverse peptide s.g.cAM373-R, or peptide-free medium and examined for their abilities to transfer plasmid DNA to streptococcal species in the presence of DNase. Preinduction of E. faecalis donors with s.g.cAM373 resulted in transconjugation frequencies in non-pheromone producing strains of Streptococcus mutans, Streptococcus sanguinis, Streptococcus anginosus, and Streptococcus suis that were significantly higher than frequencies when donors were preincubated with s.g.cAM373-R or medium alone. Peptide-mediated communication between commensal streptococci and E. faecalis carrying pheromone-responsive plasmids may facilitate conjugative DNA transfer to bystander species, and influence the reservoir of antibiotic resistance determinants of enterococcal origin in the oral metagenome.
Li, J; Yao, M S
The world is facing more deaths due to increasing antibiotic-resistant bacterial infections and the shortage of new highly effective antibiotics, however the air media as its important transmission route has not been adequately studied. Based on the latest literature acquired in this work, we have discussed the state-of-the-art research progress of the concentration, distribution and spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in different environmental air media, and also analyzed some future prevention and control measures. The large use of antibiotics in the medical settings and animal husbandry places has resulted in higher abundances of ARB and ARGs in the relevant and surrounding atmosphere than in urban and general indoor air environments. ARGs can be spread by adhering to airborne particles, and researchers have also found that air media contain more abundant ARGs than other environmental media such as soil, water and sediment. It was suggested in this review that strengthening the monitoring, study on spreading factors and biological toxicity, and also research and development on pathogen accurate diagnosis and new green antibiotic are expected to help effectively monitor, prevent and control of the impacts of airborne resistant bacteria and resistance genes on both human and ecologies.
Full Text Available Enterococci are important part of microflora of food animal origin. They have positive (probiotic effect, production flavor compounds during food ripening and also negative (production biogenic amine, antibiotic resistance, biofilm production properties. The aim of this work was to determine resistance to different concentrations of thyme essential oil and antibiotic resistance of enterococci isolated from pork (n=3 and poultry (n=17. The antibiotic resistance of isolates was determined by disc diffusion method and the antibacterial effect of thyme essential oil was assayed by a microdilution method in 96-well microtitration plates after determination of absorbance at 630 nm (A630. Of 20 tested enterococci, 85 % were resistant to tetracycline, 35 % to erythromycin, 15 % to ampicillin and 5 % to gentamicin. No resistance to vancomycin was detected. All tested strains of enterococci were able to grow and reproduce at concentrations of thyme essential oil 0.033 % and 0.066 %. Inhibitory effect of thyme essential oil began at a concentration of 0.099 %, but only for 10 % of the tested strains. Even the highest concentration tested thyme essential oil 0.166 % did not inhibit all the tested strains, because 25 % of enterococcal strains continued to grow. No correlation between antibiotic resistance and resistance to the thyme essential oil was detected for tested enterococci. The thyme essential oil has potential for using in food industry to inhibit spoilage or pathogenic microorganisms, but it is necessary to test antimicrobial activity in other in vitro and in vivo experiments and also in experiments with impact on the sensory properties of food.
Zaman, Sojib Bin; Hussain, Muhammed Awlad; Nye, Rachel; Mehta, Varshil; Mamun, Kazi Taib; Hossain, Naznin
Antibiotics are the ?wonder drugs? to combat microbes. For decades, multiple varieties of antibiotics have not only been used for therapeutic purposes but practiced prophylactically across other industries such as agriculture and animal husbandry. Uncertainty has arisen, as microbes have become resistant to common antibiotics while the host remains unaware that antibiotic resistance has emerged. The aim of this review is to explore the origin, development, and the current state of antibiotic ...
Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.
Full Text Available Enterococci represent an important part of contaminate microflora in raw milk and dairy products. They constitute significant part of nosocomial pathogens with a remarkable capacity of expressing resistance to several antimicrobial agents. We aimed to assess occurrence and antibiotic resistance of enterococci in the raw milk samples and pasteurized milk samples. In this study total bacterial count, psychrotrophic count and count of enterococci were determine in raw milk cistern samples, storage tank milk samples and milk samples after pasteurization. A collection of 46 enterococcal isolates were identified and screened for their antibiotic resistance. Isolates of E. faecalis were dominant in raw milk samples (56.5 %. Sensitive to teicoplanine (30 mcg/disk were 97.9 % of enterococcal isolates and 15.2 % isolates were resistant to vankomycin (30 mcg/disk.
Bruinsma, N; Filius, PMG; De Smet, PAGM; Degener, J; Endtz, P; Van den Bogaard, AE; Stobberingh, EE
Regional differences of antibiotic use and antibiotic resistance in the fecal indicator bacteria Escherichia coli and enterococci were determined in different cities in the south, west, and north of The Netherlands. In 1999, differences in antibiotic consumption were observed between the different
Bruinsma, N.; Filius, P.M.; Smet, P.A.G.M. de; Degener, J.E.; Endtz, P.; Bogaard, A.E. van den; Stobberingh, E.E.
Regional differences of antibiotic use and antibiotic resistance in the fecal indicator bacteria Escherichia coli and enterococci were determined in different cities in the south, west, and north of The Netherlands. In 1999, differences in antibiotic consumption were observed between the different
Full Text Available Context: Staphylococcus aureus is one of the most devastating human pathogen. The organism has a differential ability to spread and cause outbreak of infections. Characterization of these strains is important to control the spread of infection in the hospitals as well as in the community. Aim: To identify the currently existing phage groups of Staphylococcus aureus, their prevalence and resistance to antibiotics. Materials and Methods: Study was undertaken on 252 Staphylococcus aureus strains isolated from clinical samples. Strains were phage typed and their resistance to antibiotics was determined following standard microbiological procedures. Statistical Analysis: Chi square test was used to compare the antibiotic susceptibility between methicillin resistant Staph. aureus (MRSA and methicillin sensitive S. aureus (MSSA strains. Results: Prevalence of MRSA and MSSA strains was found to be 29.36% and 70.65% respectively. Of these 17.56% of MRSA and 40.44% of MSSA strains were community acquired. All the MSSA strains belonging to phage type 81 from the community were sensitive to all the antibiotics tested including clindamycin and were resistant to penicillin. Forty five percent strains of phage group III and 39% of non-typable MRSA strains from the hospital were resistant to multiple antibiotics. Conclusion: The study revealed that predominant phage group amongst MRSA strains was phage group III and amongst MSSA from the community was phage group NA (phage type 81. MSSA strains isolated from the community differed significantly from hospital strains in their phage type and antibiotic susceptibility. A good correlation was observed between community acquired strains of phage type 81 and sensitivity to gentamycin and clindamycin.
Full Text Available The main goal of this manuscript is to review different treatment strategies and mechanisms for combating the antibiotic resistant bacteria (ARB and antibiotic resistant genes (ARGs in the wastewater environment. The high amount of antibiotics is released into the wastewater that may promote selection of ARB and ARGs which find their way into natural environments. Emerging microbial pathogens and increasing antibiotic resistance among them is a global public health issue. The propagation and spread of ARB and ARGs in the environment may result in an increase of antibiotic resistant microbial pathogens which is a worldwide environmental and public health concern. A proper treatment of wastewater is essential before its discharge into rivers, lake, or sewage system to prevent the spread of ARB and ARGs into the environment. This review discusses various treatment options applied for combating the spread of ARB and ARGs in wastewater treatment plants (WWTPs. It was reported that low-energy anaerobic–aerobic treatment reactors, constructed wetlands, and disinfection processes have shown good removal efficiencies. Nanomaterials and biochar combined with other treatment methods and coagulation process are very recent strategies regarding ARB and ARGs removal and need more investigation and research. Based on current studies a wide-ranging removal efficiency of ARGs can be achieved depending on the type of genes present and treatment processes used, still, there are gaps that need to be further investigated. In order to find solutions to control dissemination of antibiotic resistance in the environment, it is important to (1 study innovative strategies in large scale and over a long time to reach an actual evaluation, (2 develop risk assessment studies to precisely understand occurrence and abundance of ARB/ARGs so that their potential risks to human health can be determined, and (3 consider operating and environmental factors that affect the
Kimman, T.G.; Smits, M.A.; Kemp, B.; Wever, P.; Verheijden, J.
Resistance of bacteria to antibiotics in animal husbandry is increasing and a point of growing concern. The large use of antibiotics in agriculture undoubtedly leads to the development of antibiotic resistance. This has resulted in a growing public concern on the rise of antibiotic resistance, and in particular on the transmission of resistant bacteria and resistance markers from animals to humans. Large antibiotic use in animal husbandry and antibiotic resistance threatens the health and wel...
Background: The differences in swine manure lagoon effluent based on differing management styles or approaches such as different stages of swine rearing determines the presence of variable antibiotic resistance determinants and functional microbial populations. These concerns determine the suitabil...
Kim, Jeongjin; Jo, Ara; Chukeatirote, Ekachai; Ahn, Juhee
Bacteria treated with different classes of antibiotics exhibit changes in susceptibility to successive antibiotic treatments. This study was designed to evaluate the influence of sequential antibiotic treatments on the development of antibiotic resistance in Klebsiella pneumoniae associated with β-lactamase and efflux pump activities. The antibiotic susceptibility, β-lactamase activity, and efflux activity were determined in K. pneumoniae grown at 37 °C by adding initial (0 h) and second antibiotics (8 or 12 h). Treatments include control (CON; no first and second antibiotic addition), no initial antibiotic addition followed by 1 MIC ciprofloxacin addition (CON-CIP), no initial antibiotic addition followed by 1 MIC meropenem addition (CON-MER), initial 1/4 MIC ciprofloxacin addition followed by no antibiotic addition (1/4CIP-CON), initial 1/4 MIC ciprofloxacin addition followed by 1 MIC ciprofloxacin addition (1/4CIP-CIP), and initial 1/4 MIC ciprofloxacin addition followed by 1 MIC meropenem addition (1/4CIP-MER). Compared to the CON, the initial addition of 1/4 MIC ciprofloxacin inhibited the growth of K. pneumoniae throughout the incubation period. The ciprofloxacin treatments (CON-CIP and 1/4CIP-CIP) showed significant reduction in the number of K. pneumoniae cells compared to meropenem (CON-MER and 1/4CIP-MER). The 1/4CIP-CIP achieved a further 1 log reduction of K. pneumoniae, when compared to the 1/4CIP-CON and 1/CIP-MER. The increase in sensitivity of K. pneumoniae to cefotaxime, kanamycin, levofloxacin, nalidixic acid was observed for CON-CIP. Noticeable cross-resistance pattern was observed at the 1/4CIP-CIP, showing the increased resistance of K. pneumoniae to chloramphenicol, ciprofloxacin, kanamycin, levofloxacin, nalidixic acid norfloxacin, sulphamethoxazole/trimethoprim, and tetracycline. The levels of β-lactamase activities were estimated to be 8.4 μmol/min/ml for CON, 7.7 μmol/min/ml for 1/4CIP-CON and as low as 2.9 μmol/min/ml for CON
Ali, Syed Abid; Bin-Asif, Hassan; Hasan, Khwaja Ali; Rehman, Marium; Abbasi, Atiya
Enterococci, no more regarded as GRAS (Generally Recognized As Safe) organism, are emerging as an important source of nosocomial infections worldwide. The main contributors in pathogenesis of enterococci are the presence of various virulent factors and antibiotic resistance genes. We aimed to examine the prevalence, dissemination, antibiotic resistance and virulent factors associated with enterococci from bulk soil (BS). A total of 372 enterococci were isolated from 500 soil samples. PCR was used to identify the isolates up to species level and for carriage of 16 virulence genes including hospital associated marker (i.e. IS16). E. faecium (77%), E. faecalis (10%), E. hirae (4%) and E. casseliflavus (1%) were the major species isolated. The efaAfs was the most dominant gene (100%), followed by gelE (78.9%), sprE (76.3%) and esp (13%) in E. faecalis isolates. The E. faecium carried largely efaAfm (86.8%) and acm (50.3%) genes. Presence of entP (10%), entA (8.3%) and entB (6.9%) genes was detected mostly in E. faecium, while enlA (18%) and ef1097 (2.6%) was only detected in E. faecalis isolates. 50% E. faecalis and 2% E. faecium isolates harbored IS16, while five E. faecalis harbored both IS16 and espTIM genes providing strong evidence about the presence of espTIM gene on 64 Kb pathogenicity island. BOX and RAPD PCR analysis revealed high degree of genetic variation within the species. Degree of resistance against 12 major antibiotics showed chloramphenicol as the most effective and meropenom as the least effective antibiotic. Presence of multiple antibiotic resistant, virulent and hospital associated enterococci in bulk soil represents a potential source for further dissemination to humans and animals and poses potential impact on public health. Copyright © 2017 Elsevier Ltd. All rights reserved.
Priscilla A. Johanesen
Full Text Available Clostridium difficile is well recognized as the leading cause of antibiotic-associated diarrhea, having a significant impact in both health-care and community settings. Central to predisposition to C. difficile infection is disruption of the gut microbiome by antibiotics. Being a Gram-positive anaerobe, C. difficile is intrinsically resistant to a number of antibiotics. Mobile elements encoding antibiotic resistance determinants have also been characterized in this pathogen. While resistance to antibiotics currently used to treat C. difficile infection has not yet been detected, it may be only a matter of time before this occurs, as has been seen with other bacterial pathogens. This review will discuss C. difficile disease pathogenesis, the impact of antibiotic use on inducing disease susceptibility, and the role of antibiotic resistance and mobile elements in C. difficile epidemiology.
Yurtsev, Eugene; Dai, Lei; Gore, Jeff
The emergence of antibiotic resistance in bacteria is a significant health concern. A frequent mechanism of antibiotic resistance involves the production of an enzyme which inactivates the antibiotic. By inactivating the antibiotic, resistant cells can ``share'' their resistance with other cells in the bacterial population, suggesting that it may be possible to observe cooperation between strains that inactivate different antibiotics. Here, we experimentally track the population dynamics of two E. coli strains in the presence of two different antibiotics. We find that together the strains are able to grow in antibiotic concentrations that inhibit growth of either of the strains individually. We observe that even when there is stable coexistence between the two strains, the population size of each strain can undergo large oscillations. We expect that our results will provide insight into the evolution of antibiotic resistance and the evolutionary origin of phenotypic diversity and cooperative behaviors.
Safari Sinegani, Ali Akbar; Younessi, Nayereh
The main objective of this study was to determine the relationship between the antibiotic and heavy metal tolerance of culturable bacteria isolated from mining waste, pasture, and agricultural soils containing different levels of heavy metals. The populations of total culturable bacteria, and heavy metal- and antibiotic-tolerant bacteria in the soils were enumerated on nutrient agar, nutrient agar amended with metals, and Mueller-Hinton agar amended with antibiotics, respectively. The multiple antibiotic resistance index, and patterns of antibiotic resistance and heavy metal-antibiotic co-resistance were determined for 237 isolates. Among all the samples, those of the tailings of mines with higher levels of heavy metals had the lowest number of bacteria, but a relatively higher abundance of heavy metal- and antibiotic-resistant bacteria. A high degree of resistance was observed for ampicillin and amoxicillin in the isolates from all soils. The agricultural soil isolates had a high prevalence of resistance towards vancomycin, tetracycline, and streptomycin. Among all the tested antibiotics, gentamicin was the most potent. The most frequent pattern of multiple antibiotic resistance in the isolates from agricultural soils was amoxicillin, ampicillin, streptomycin, vancomycin, tetracycline, and doxycycline. The percentage of isolates with multiple antibiotic resistance was considerably higher in the agricultural soils than in the mining waste soils. A high rate of co-resistance towards Hg and antibiotics was observed among the gram-negative isolates, and towards Zn, Ni, Hg, and the beta-lactam antibiotics among the gram-positive isolates. The higher percentage of isolates with multiple antibiotic resistance in the agricultural soils that in the mining waste soils may be related to (1) the level of soil heavy metals, (2) the population and diversity of soil bacteria, (3) the application of manures, and (4) other factors affecting gene transfer between bacteria
Yildiz, B.; Kural, N.; Yarar, C.; Ak, I.; Akcar, N.
Objective was to determine the resistance of antibiotics for complicated urinary tract infection (UTI), including urinary tract anomaly (UTA), for empirical antibiotic therapy of complicated UTI. Four hundred and twenty two urine isolates were obtained from 113 patients with recurrent UTI, who used prophylactic antibiotics between February 1999 and November 2004 in the Eskisehir Osmangazi University, Eskisehir, Turkey. Reflux was found to be most important predisposing factor for recurrent UTI (31.9%). Renal scar was detected more in patients with UTA than without UTA (59.2% versus 12.4%, p<0.05). Gram-negative organisms were dominant in patients with and without UTA (91.5% and 79.2%). Enterococci and Candida spp. were more prevalent in children with UTA than without UTA (p<0.001). Isolates were significantly more resistant to ampicillin, trimethoprim-sulfamethoxazole, amikacin, co-amoxiclav, ticarcillin-clvalanate and piperacillin-tazobactam in patients with UTA than without UTA. We found low resistance to ciprofloxacin and nitrofurantoin in UTI with and without UTA. Enterococci spp. was highly resistance to ampicillin and amikacin in patients with UTA. Aztreonam, meropenem and ciprofloxacin seemed to be the best choice for treatment of UTI with UTA due to Escherichia coli and Klebsiella spp. Nitrofurantoin and nalidixic acid may be first choice antibiotics for prophylaxis in UTI with and without UTA. The UTI with UTA caused by Enterococci spp. might not benefit from a combination of amikacin and ampicillin, it could be treated with glycopeptides. (author)
Schmidt, Gunilla Veslemøy; Mellerup, Anders; Christiansen, Lasse Engbo
The aim of this article was to define the sampling level and method combination that captures antibiotic resistance at pig herd level utilizing qPCR antibiotic resistance gene quantification and culture-based quantification of antibiotic resistant coliform indicator bacteria. Fourteen qPCR assays...... for commonly detected antibiotic resistance genes were developed, and used to quantify antibiotic resistance genes in total DNA from swine fecal samples that were obtained using different sampling and pooling methods. In parallel, the number of antibiotic resistant coliform indicator bacteria was determined...... in the same swine fecal samples. The results showed that the qPCR assays were capable of detecting differences in antibiotic resistance levels in individual animals that the coliform bacteria colony forming units (CFU) could not. Also, the qPCR assays more accurately quantified antibiotic resistance genes...
Seveno, N.; Kallifidas, D.; Smalla, K.; Elsas, van J.D.; Collard, J.M.; Karagouni, A.; Wellington, E.M.H.
Antibiotic resistance genes have become highly mobile since the development of antibiotic chemotherapy. A considerable body of evidence exists proving the link between antibiotic use and the significant increase in drug-resistant human bacterial pathogens. The application of molecular detection and
The research revealed a high level of antibiotic resistance among E. coli. The percentage of resistance observed for the antibiotics included in this study reflected the degree of their respective uses in pig production in the study area. This work further supports the need for prudent use of each of the antibiotics in animal ...
Yurtsev, Eugene; Xiao Chao, Hui; Datta, Manoshi; Artemova, Tatiana; Gore, Jeff
The emergence of antibiotic resistance in bacteria is a significant health concern. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removal of the antibiotic. The presence of a cooperative mechanism of resistance suggests that a cheater strain - which does not contribute to breaking down the antibiotic - may be able to take advantage of resistant cells. We find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We use a simple model in conjunction with difference equations to explain the observed population dynamics as a function of cell density and antibiotic concentration. Our experimental difference equations resemble the logistic map, raising the possibility of oscillations or even chaotic dynamics.
Li, Jianan; Cheng, Weixiao; Xu, Like; Strong, P J; Chen, Hong
In this study, we determined the abundance of 8 antibiotics (3 tetracyclines, 4 sulfonamides, and 1 trimethoprim), 12 antibiotic-resistant genes (10 tet, 2 sul), 4 antibiotic-resistant bacteria (tetracycline, sulfamethoxazole, and combined resistance), and class 1 integron integrase gene (intI1) in the effluent of residential areas, hospitals, and municipal wastewater treatment plant (WWTP) systems. The concentrations of total/individual targets (antibiotics, genes, and bacteria) varied remarkably among different samples, but the hospital samples generally had a lower abundance than the residential area samples. The WWTP demonstrated removal efficiencies of 50.8% tetracyclines, 66.8% sulfonamides, 0.5 logs to 2.5 logs tet genes, and less than 1 log of sul and intI1 genes, as well as 0.5 log to 1 log removal for target bacteria. Except for the total tetracycline concentration and the proportion of tetracycline-resistant bacteria (R (2) = 0.330, P antibiotics and the corresponding resistant bacteria (P > 0.05). In contrast, various relationships were identified between antibiotics and antibiotic resistance genes (P antibiotic-resistant bacteria (P < 0.01).
Chen, Songcan; Li, Xiaomin; Sun, Guoxin; Zhang, Yingjiao; Su, Jianqiang; Ye, Jun
Co-contamination of antibiotics and heavy metals prevails in the environment, and may play an important role in disseminating bacterial antibiotic resistance, but the selective effects of heavy metals on bacterial antibiotic resistance is largely unclear. To investigate this, the effects of heavy metals on antibiotic resistance were studied in a genome-sequenced bacterium, LSJC7. The results showed that the presence of arsenate, copper, and zinc were implicated in fortifying the resistance of LSJC7 towards tetracycline. The concentrations of heavy metals required to induce antibiotic resistance, i.e., the minimum heavy metal concentrations (MHCs), were far below (up to 64-fold) the minimum inhibition concentrations (MIC) of LSJC7. This finding indicates that the relatively low heavy metal levels in polluted environments and in treated humans and animals might be sufficient to induce bacterial antibiotic resistance. In addition, heavy metal induced antibiotic resistance was also observed for a combination of arsenate and chloramphenicol in LSJC7, and copper/zinc and tetracycline in antibiotic susceptible strain Escherichia coli DH5α. Overall, this study implies that heavy metal induced antibiotic resistance might be ubiquitous among various microbial species and suggests that it might play a role in the emergence and spread of antibiotic resistance in metal and antibiotic co-contaminated environments.
Somaye Nikoogoftar Ranjbar
Full Text Available Background and Objectives: Antibiotics are among the most effective drugs used to treat humans. These materials enter in different ways into sewage and known as important biological contaminants in aquatic and agricultural environment. The availability of conditions for antibiotic resistance gene transfer to sewage bacteria, converted human environmental wastes to an important source of antibiotic resistant bacteria. Considering the spread of antibiotic resistant strains in treatment centers of Qom province, the aim of this study is to investigate the frequency and antibiotic resistance pattern in coliform bacteria isolated from wastewater treatment system of Qom city in different seasons. Methods: This study was carried out on 120 samples of municipal wastewater treatment plant (incoming and outgoing in Qom. After sampling, transport of samples to the laboratory, isolation and phenotypic identification of bacteria, and Determination of antibiotic resistance pattern, were performed according to CLSI standards. The frequency of bacteria was determined using most probable number (MPN method. Results: In this study, of 384 strains of bacteria (isolated in spring, summer, and winter, Escherichia coli (50%, Citrobacter (30%, Enterobacter (11%, Klebsiella (1% and non-coliform bacteria (Proteus sp. 8%, were identified. The most antibiotic resistance was observed in Citrobacter and Enterobacter bacteria (isolated in summer to penicillin G with a frequency of 94%. Conclusion: Due to the high frequency of antibiotic resistance in Citrobacter and Enterobacter strains in the sewage treatment plant in Qom province, especially in the summer, this ecosystem can be reported as an important source of spread of antibiotic-resistant strains.
Besant, Justin D; Sargent, Edward H; Kelley, Shana O
Rapid phenotyping of bacteria to identify drug-resistant strains is an important capability for the treatment and management of infectious disease. At present, the rapid determination of antibiotic susceptibility is hindered by the requirement that, in existing devices, bacteria must be pre-cultured for 2-3 days to reach detectable levels. Here we report a novel electrochemical approach that achieves rapid readout of the antibiotic susceptibility profile of a bacterial infection within one hour. The electrochemical reduction of a redox-active molecule is monitored that reports on levels of metabolically-active bacteria. Bacteria are captured in miniaturized wells, incubated with antimicrobials and monitored for resistance. This electrochemical phenotyping approach is effective with clinically-relevant levels of bacteria, and provides results comparable to culture-based analysis. Results, however, are delivered on a much faster timescale, with resistance profiles available after a one hour incubation period.
Singer, R.S.; Finch, R.; Wegener, Henrik Caspar
Antibiotic-resistant bacteria were first identified in the 1940s, but while new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. Today, the excessive use of antibiotics compounded by the paucity of new agents on the market has...... meant the problem of antibiotic resistance is fast escalating into a global health crisis. There is no doubt that misuse of these drugs in human beings has contributed to the increasing rates of resistance, but recently the use of antibiotics in food animals and its consequent effect on resistance....... There is a growing concern over the transmission of resistant bacteria via the food chain. Many questions will be difficult to resolve, such as how do you distinguish the fraction of resistance in human beings that originated from animals? If we wait to see evidence that a significant amount of antibiotic resistance...
Tuite, Ashleigh R; Gift, Thomas L; Chesson, Harrell W; Hsu, Katherine; Salomon, Joshua A; Grad, Yonatan H
Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.
Bogaard, A.E. van den; London, N.; Driessen, C.A.G.G.; Stobberingh, E.E.
The percentage of faecal samples containing resistant Echerichia coli and the proportion of resistant faecal E. coli were determined in three poultry populations: broilers and turkeys commonly given antibiotics, and laying hens treated with antibiotics relatively infrequently. Faecal samples of five
Recently public concern has increased regarding industrial and environmental substances that may have adverse hormonal effects in human and wildlife populations. This concern has also been expanded to include antibiotic-resistant bacteria and the presence of various antibiotics a...
Buul, L.W. van; Steen, J.T. van der; Veenhuizen, R.B.; Achterberg, W.P.; Schellevis, F.G.; Essink, R.T.G.M.; Benthem, B.H.B. van; Natsch, S.; Hertogh, C.M.P.M.
Introduction: The common occurrence of infectious diseases in nursing homes and residential care facilities may result in substantial antibiotic use, and consequently antibiotic resistance. Focusing on these settings, this article aims to provide a comprehensive overview of the literature available
Cohen, Margot E; Salmasian, Hojjat; Li, Jianhua; Liu, Jianfang; Zachariah, Philip; Wright, Jason D; Freedberg, Daniel E
Antibiotic-resistant infections have high rates of morbidity and mortality, and exposure to antibiotics is the crucial risk factor for development of antibiotic resistance. If surgical antibiotic prophylaxis (SAP) increases risk for antibiotic-resistant infections, prophylaxis may cause net harm, even if it decreases overall infection rates. This retrospective cohort study included adults who underwent elective surgical procedures and developed infections within 30 postoperative days. Procedures from multiple disciplines were included if SAP was considered discretionary by current guidelines. Postoperative antibiotic-resistant infections were defined as positive culture results from any site within 30 postoperative days, showing intermediate or nonsusceptibility across 1 or more antibiotic classes. Surgical antibiotic prophylaxis included use of antibiotics within any class and at any dose from 1 hour before first incision until the end of the operation. Among 689 adults with postoperative infections, 338 (49%) had postoperative resistant infections. Use of SAP was not associated with postoperative antibiotic-resistant infections (odds ratio [OR] 0.99; 95% CI 0.67 to 1.46). This result remained robust when the SAP definition was extended to antibiotics given within 4 hours before first incision (OR 0.94; 95% CI 0.63 to 1.40) and when the follow-up window was narrowed to 14 days (OR 0.82; 95% CI 0.50 to 1.34). Previous antibiotic-resistant infections were associated with risk for postoperative antibiotic-resistant infections (OR 1.81; 95% CI 1.16 to 2.83). Use of SAP was not associated with risk for postoperative antibiotic-resistant infections in a large cohort of patients with postoperative infections. This provides important reassurance regarding use of surgical antibiotic prophylaxis. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.
Full Text Available Aim: The aim of this study was to determine the antibiotic susceptibilities of S.aureus strains isolated from various clinical specimens between the years 2011-2014 and to investigate the changes of these susceptibilities over the years. Material and Method: Identification and antibiotic susceptibility testing of the strains were performed by Vitek 2 compact automated system (bioMérieux, France. The strains found to be intermediate susceptible to vancomycin and teicoplanin were also tested by E-test method. Results: S.aureus strains (n=1442 were most commonly isolated from wound, urine and blood samples. The isolation rates of methicillin-resistant S.aureus (MRSA in hospitalized patients were significantly higher than the isolation rates of MRSA in outpatients. All strains were susceptible to vancomycin, teicoplanin, linezolid and tigecycline. The total of four years resistance rates of MRSA strains to erythromycin, clindamycin, ciprofloxacin, moxifloxacin, gentamicin, co-trimoxazole, fusidic acid were significantly higher than the resistance rates of methicillin-sensitive S.aureus (MSSA. The changes in the rates of antibiotic resistance were not statistically significant in MSSA strains over the years, and statistically significant decrease was found in erythromycin, clindamycin, ciprofloxacin, moxifloxacin and gentamicin resistance in MRSA strains. Discussion: Glycopeptides, linezolid and tigecycline were the most effective antibiotics against S.aureus strains. It was considered as necessary to detect antimicrobial resistance profiles by effective surveillance studies and monitor the changes occurred over the years in order to prevent the development of resistance and control of infections.
Johnson, Timothy A; Stedtfeld, Robert D; Wang, Qiong; Cole, James R; Hashsham, Syed A; Looft, Torey; Zhu, Yong-Guan; Tiedje, James M
they are genetically linked. No links to bacterial membership were observed for these clusters of resistance genes. These findings urge deeper understanding of colocalization of resistance genes and mobile genetic elements in resistance islands and their distribution throughout antibiotic-exposed microbiomes. As governments seek to combat the rise in antibiotic resistance, a balance is sought between ensuring proper animal health and welfare and preserving medically important antibiotics for therapeutic use. Metagenomic and genomic monitoring will be critical to determine if resistance genes can be reduced in animal microbiomes, or if these gene clusters will continue to be coselected by antibiotics not deemed medically important for human health but used for growth promotion or by medically important antibiotics used therapeutically. Copyright © 2016 Johnson et al.
Wegener, Henrik Caspar; Aarestrup, Frank Møller; Gerner-Smidt, P.
Antibiotic resistance develops in zoonotic bacteria in response to antibiotics used in food animals. A close association exists between the amounts of antibiotics used and the levels of resistance observed. The classes of antibiotics routinely used for treatment of human infections are also used...... for animals either for therapy or for growth promotion. Antibiotic resistance in zoonotic bacteria constitute a public health hazard, primarily through the increased risk of treatment failures. This paper describes the zoonotic bacteria, salmonella, campylobacter, yersinia and enterohaemorrhagic E. coli (EHEC......). Infections with these agents do not generally require antibiotic therapy, but in some cases antibiotics are essential to obtain a successful cure. The levels and types of resistance observed in zoonotic bacteria in some countries, especially the increasing levels of fluoroquinolone resistance in salmonella...
Full Text Available Antibiotic resistance is a major problem in clinical health settings. Interestingly the origin of many of antibiotic resistance mechanisms can be traced back to non-pathogenic environmental organisms. Important factors leading to the emergence and spread of antibiotic resistance include absence of regulation in the use of antibiotics, improper waste disposal and associated transmission of antibiotic resistance genes in the community through commensals. In this review, we discussed the impact of globalisation on the transmission of antibiotic resistance genes in bacteria through immigration and export/import of foodstuff. The significance of surveillance to define appropriate use of antibiotics in the clinic has been included as an important preventive measure.
Miller, Jennifer H.; Novak, John T.; Knocke, William R.; Pruden, Amy
Understanding fate of antibiotic resistant bacteria (ARB) versus their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1- a Pseudomonas sp.) and thermophilic (Iso T10- a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts ...
Makoka, Mwai H; Miller, William C; Hoffman, Irving F; Cholera, Rushina; Gilligan, Peter H; Kamwendo, Debbie; Malunga, Gabriel; Joaki, George; Martinson, Francis; Hosseinipour, Mina C
Life-threatening infections present major challenges for health systems in Malawi and the developing world because routine microbiologic culture and sensitivity testing are not performed due to lack of capacity. Use of empirical antimicrobial therapy without regular microbiologic surveillance is unable to provide adequate treatment in the face of emerging antimicrobial resistance. This study was conducted to determine antimicrobial susceptibility patterns in order to inform treatment choices and generate hospital-wide baseline data. Culture and susceptibility testing was performed on various specimens from patients presenting with possible infectious diseases at Kamuzu Central Hospital, Lilongwe, Malawi. Between July 2006 and December 2007 3104 specimens from 2458 patients were evaluated, with 60.1% from the adult medical service. Common presentations were sepsis, meningitis, pneumonia and abscess. An etiologic agent was detected in 13% of patients. The most common organisms detected from blood cultures were Staphylococcus aureus, Escherichia coli, Salmonella species and Streptococcus pneumoniae, whereas Streptococcus pneumoniae and Cryptococcus neoformans were most frequently detected from cerebrospinal fluid. Haemophilus influenzae was rarely isolated. Resistance to commonly used antibiotics was observed in up to 80% of the isolates while antibiotics that were not commonly in use maintained susceptibility. There is widespread resistance to almost all of the antibiotics that are empirically used in Malawi. Antibiotics that have not been widely introduced in Malawi show better laboratory performance. Choices for empirical therapy in Malawi should be revised accordingly. A microbiologic surveillance system should be established and prudent use of antimicrobials promoted to improve patient care.
Tazzyman, Samuel J; Hall, Alex R
The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under phage parasitism, the likelihood that antibiotic-resistant genetic backgrounds spread depends on their initial frequency, mutation rate and intrinsic growth rate relative to drug-susceptible genotypes, because these parameters determine relative rates of phage-resistance evolution on different genetic backgrounds. Moreover, the average cost of antibiotic resistance in terms of intrinsic growth in the antibiotic-free experimental environment was small relative to the benefits of an increased mutation rate in the presence of phages. This is consistent with our theoretical work indicating that, under phage selection, typical costs of antibiotic resistance can be outweighed by realistic increases in mutability if drug resistance and hypermutability are genetically linked, as is frequently observed in clinical isolates. This suggests the long-term distribution of antibiotic resistance depends on the relative rates at which different lineages adapt to other types of selection, which in the case of phage parasitism is probably extremely common, as well as costs of resistance inferred by classical in vitro methods. PMID:25268496
Pontes, Daniela Santos; de Araujo, Rodrigo Santos Aquino; Dantas, Natalina; Scotti, Luciana; Scotti, Marcus Tullius; de Moura, Ricardo Olimpio; Mendonca-Junior, Francisco Jaime Bezerra
The ever increasing number of multidrug-resistant microorganism pathogens has become a great and global public health threat. Antibiotic mechanisms of action and the opposing mechanisms of resistance are intimately associated, but comprehension of the biochemical and molecular functions of such drugs is not a simple exercise. Both the environment, and genetic settings contribute to alterations in phenotypic resistance (natural bacterial evolution), and make it difficult to control the emergence and impacts of antibiotic resistance. Under such circumstances, comprehension of how bacteria develop and/or acquire antibiotic resistance genes (ARG) has a critical role in developing propositions to fight against these superbugs, and to search for new drugs. In this review, we present and discuss both general information and examples of common genetic and molecular mechanisms related to antibiotic resistance, as well as how the expression and interactions of ARGs are important to drug resistance. At the same time, we focus on the recent achievements in the search for antibiotic adjuvants, which help combat antibiotic resistance through deactivation of bacterial mechanisms of action such as β-lactamases. Recent advances involving the use of anti-resistance drugs such as: efflux pump inhibitors; anti-virulence drugs; drugs against quorum sensing; and against type II/III secretion systems are revealed. Such antibiotic adjuvants (as explored herein) collaborate against the problems of antibiotic resistance, and may restore or prolong the therapeutic activity of known antibiotics. Copyright© Bentham Science Publishers; For any queries, please email at firstname.lastname@example.org.
Lisa M. Casanova
Full Text Available Sources of antibiotic resistant organisms, including concentrated animal feeding operations (CAFOs, may lead to environmental surface and groundwater contamination with resistant enteric bacteria of public health concern. The objective of this research is to determine whether Salmonella, Escherichia coli, Yersinia enterocolitica, and enterococci resistant to clinically relevant antibiotics are present in surface and groundwater sources in two eastern North Carolina counties, Craven and Wayne. 100 surface and groundwater sites were sampled for Salmonella, E. coli, and enterococci, and the bacteria isolated from these samples were tested for susceptibility to clinically relevant antibiotics. Salmonella were detected at low levels in some surface but not groundwater. E. coli were in surface waters but not ground in both counties. Enterococci were present in surface water and a small number of groundwater sites. Yersinia was not found. Bacterial densities were similar in both counties. For Salmonella in surface water, the most frequent type of resistance was to sulfamethoxazole. There was no ciprofloxacin resistance. There were a few surface water E. coli isolates resistant to chloramphenicol, gentamicin, and ampicillin. Enterococci in surface water had very low levels of resistance to vancomycin, chloramphenicol, ampicillin, and streptomycin. E. coli and enterococci are present more frequently and at higher levels in surface water than Salmonella, but groundwater contamination with any of these organisms was rare, and low levels of resistance can be found sporadically. Resistant bacteria are relatively uncommon in these eastern N.C. surface and groundwaters, but they could pose a risk of human exposure via ingestion or primary contact recreation.
Delost, Gregory R; Delost, Maria E; Armile, James; Lloyd, Jenifer
Overuse of antibiotics has led to the development of antibiotic-resistant strains of Staphylococcus aureus, which are occurring more frequently within the community. We sought to determine whether long-term antibiotic therapy for acne alter the carriage rate and antibiotic resistance profiles of S aureus. This was a prospective, cross-sectional, quasiexperimental study. Samples of anterior nares were obtained from dermatology patients given a diagnosis of acne vulgaris (n = 263) who were treated with antibiotics (n = 142) or who were not treated with antibiotics (n = 121). Specimens were tested for the presence of S aureus by growth on mannitol salt agar and then isolated on 5% sheep blood agar. Identification was confirmed based on colonial morphology, Gram stain, catalase, and coagulase testing. Antibiotic susceptibility testing was performed using the VITEK 2 system (bioMerieux, Marcy-l'Étoile, France). The S aureus carriage rate was significantly lower in patients with acne treated with antibiotics (6.3%) compared with those not treated with antibiotics (15.7%; P = .016). The percentage of S aureus isolates resistant to 1 or more antibiotics did not significantly differ between the 2 groups (P = .434). Cross-sectional study, patient compliance, and effects of prior acne treatments are limitations. Treatment of patients with acne using antibiotics decreases the S aureus carriage rate but does not significantly alter the antibiotic resistance rates. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.
Chen, Chaoqi; Li, Jing; Chen, Peipei; Ding, Rui; Zhang, Pengfei; Li, Xiqing
Non-irrigated and wastewater-irrigated soils were collected from five wastewater irrigation areas in Beijing and Tianjin, China. The concentrations of sulfadiazine, sulfamethoxazole, oxytetracycline and chlortetracycline in the soils were determined. Abundances of antibiotic resistant bacteria and corresponding resistance genes were also measured to examine the impact of wastewater irrigation. No significant difference in antibiotic resistance bacteria was observed between irrigated and non-irrigated soils. However, the concentrations of antibiotics and abundances of resistance genes were significantly greater in irrigated soils, indicating that agricultural activities enhanced the occurrence of antibiotics and resistance genes in the soils. In addition, no significant difference was observed between previously and currently wastewater-irrigated soils. Therefore, cessation of wastewater irrigation did not significantly reduce the levels of antibiotic concentrations and resistance gene abundances. Other factors, e.g., manure application, may explain the lack of significant difference in the occurrence of antibiotics and resistance genes between previously and currently wastewater-irrigated soils. Copyright © 2014. Published by Elsevier Ltd.
Lucas, D; Badia-Fabregat, M; Vicent, T; Caminal, G; Rodríguez-Mozaz, S; Balcázar, J L; Barceló, D
The emergence and spread of antibiotic resistance represents one of the most important public health concerns and has been linked to the widespread use of antibiotics in veterinary and human medicine. The overall elimination of antibiotics in conventional wastewater treatment plants is quite low; therefore, residual amounts of these compounds are continuously discharged to receiving surface waters, which may promote the emergence of antibiotic resistance. In this study, the ability of a fungal treatment as an alternative wastewater treatment for the elimination of forty-seven antibiotics belonging to seven different groups (β-lactams, fluoroquinolones, macrolides, metronidazoles, sulfonamides, tetracyclines, and trimethoprim) was evaluated. 77% of antibiotics were removed after the fungal treatment, which is higher than removal obtained in conventional treatment plants. Moreover, the effect of fungal treatment on the removal of some antibiotic resistance genes (ARGs) was evaluated. The fungal treatment was also efficient in removing ARGs, such as ermB (resistance to macrolides), tetW (resistance to tetracyclines), blaTEM (resistance to β-lactams), sulI (resistance to sulfonamides) and qnrS (reduced susceptibility to fluoroquinolones). However, it was not possible to establish a clear link between concentrations of antibiotics and corresponding ARGs in wastewater, which leads to the conclusion that there are other factors that should be taken into consideration besides the antibiotic concentrations that reach aquatic ecosystems in order to explain the emergence and spread of antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.
Juliana Pena Porto
Full Text Available Introduction Methicillin-resistant Staphylococcus aureus (MRSA is among the most important pathogens of nosocomial infections, mainly in intensive care units (ICUs, and accounts for 40-60% of all healthcare-associated S. aureus infections. We evaluated the incidence of nosocomial infection by S. aureus, identified the risk factors for MRSA infection, and evaluated the effect of resistance to methicillin on mortality in patients. Methods We conducted MRSA surveillance at a university hospital in Brazil from January 1, 2010, to December 31, 2010, and performed a retrospective case-control matched study to evaluate the frequency of subsequent MRSA bacteremia and death among patients. We evaluated and compared the risk factors between patients with MRSA and methicillin-sensitive Staphylococcus aureus (MSSA infection. Results Sepsis was the most common cause of infection (17.7/1,000 patient-days, followed by surgical site (11.4/1,000 patient-days, pneumonia (4.1/1,000 patient-days, and urinary tract infection (2.4/1,000 patient-days. The significant risk factors were time of hospitalization, use of central vascular catheter (CVC, urinary catheter, nasogastric tube, parenteral nutrition, tracheostomy, mechanical ventilation, and previous antibiotic administration, the latter of which was the only independent risk factor for MRSA infection. Mortality was significantly higher in patients with MRSA. The number of antibiotics tested was not related to increases in the frequency of MRSA/1,000 patient-days. The incidence of mortality attributable to MRSA (bloodstream infection BSI was 50%. Conclusions Surveillance results showed that the use of high levels of antibiotics was directly related to the development of MRSA infection, and the mortality attributable to MRSA in patients with bacteremia was significant.
Baquero, Fernando; Tedim, Ana P.; Coque, Teresa M.
Antibiotics have natural functions, mostly involving cell-to-cell signaling networks. The anthropogenic production of antibiotics, and its release in the microbiosphere results in a disturbance of these networks, antibiotic resistance tending to preserve its integrity. The cost of such adaptation is the emergence and dissemination of antibiotic resistance genes, and of all genetic and cellular vehicles in which these genes are located. Selection of the combinations of the different evolutionary units (genes, integrons, transposons, plasmids, cells, communities and microbiomes, hosts) is highly asymmetrical. Each unit of selection is a self-interested entity, exploiting the higher hierarchical unit for its own benefit, but in doing so the higher hierarchical unit might acquire critical traits for its spread because of the exploitation of the lower hierarchical unit. This interactive trade-off shapes the population biology of antibiotic resistance, a composed-complex array of the independent “population biologies.” Antibiotics modify the abundance and the interactive field of each of these units. Antibiotics increase the number and evolvability of “clinical” antibiotic resistance genes, but probably also many other genes with different primary functions but with a resistance phenotype present in the environmental resistome. Antibiotics influence the abundance, modularity, and spread of integrons, transposons, and plasmids, mostly acting on structures present before the antibiotic era. Antibiotics enrich particular bacterial lineages and clones and contribute to local clonalization processes. Antibiotics amplify particular genetic exchange communities sharing antibiotic resistance genes and platforms within microbiomes. In particular human or animal hosts, the microbiomic composition might facilitate the interactions between evolutionary units involved in antibiotic resistance. The understanding of antibiotic resistance implies expanding our knowledge on multi
Zhang, Songhe; Han, Bing; Gu, Ju; Wang, Chao; Wang, Peifang; Ma, Yanyan; Cao, Jiashun; He, Zhenli
Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants of environmental concern. Heterotrophic bacteria in activated sludge have an important role in wastewater treatment plants (WWTPs). However, the fate of cultivable heterotrophic ARB and ARGs in WWPTs process remains unclear. In the present study, we investigated the antibiotic-resistant phenotypes of cultivable heterotrophic bacteria from influent and effluent water of three WWTPs and analysed thirteen ARGs in ARB and in activated sludge from anoxic, anaerobic and aerobic compartments. From each influent or effluent sample of the three plants, 200 isolates were randomly tested for susceptibility to 12 antibiotics. In these samples, between 5% and 64% isolates showed resistance to >9 antibiotics and the proportion of >9-drug-resistant bacteria was lower in isolates from effluent than from influent. Eighteen genera were identified in 188 isolates from influent (n=94) and effluent (n=94) of one WWTP. Six genera (Aeromonas, Bacillus, Lysinibacillus, Microbacterium, Providencia, and Staphylococcus) were detected in both influent and effluent samples. Gram-negative and -positive isolates dominated in influent and effluent, respectively. The 13 tetracycline-, sulphonamide-, streptomycin- and β-lactam-resistance genes were detected at a higher frequency in ARB from influent than from effluent, except for sulA and CTX-M, while in general, the abundances of ARGs in activated sludge from two of the three plants were higher in aerobic compartments than in anoxic ones, indicating abundant ARGs exit in the excess sledges and/or in uncultivable bacteria. These findings may be useful for elucidating the effect of WWTP on ARB and ARGs. Copyright © 2015 Elsevier Ltd. All rights reserved.
the treatment of other infections would inevitably lead to the development of resistance. S Afr Med J 1994; 84: 600-602. Antibiotic resistance is a major problem in developing countries.' There are many reasons for this, including antibiotic use in animal feeds, inappropriate prescribing and poor sanitation. Resistance rates in ...
The extent to which carriage of antibiotic resistant bacteria in food animals is responsible for the burden of antibiotic resistance in human infections is currently not well known. Thus, there is a need to further evaluate the genomic diversity of multidrug resistant (MDR) bacteria and the microbi...
Tang, Yizhi; Fang, Liangxing; Xu, Changyun; Zhang, Qijing
Campylobacter is a major foodborne pathogen and is commonly present in food producing animals. This pathogenic organism is highly adaptable and has become increasingly resistant to various antibiotics. Recently, both the Centers for Disease Control and Prevention and the World Health Organization have designated antibiotic-resistant Campylobacter as a serious threat to public health. For the past decade, multiple mechanisms conferring resistance to clinically important antibiotics have been described in Campylobacter, and new resistance mechanisms constantly emerge in the pathogen. Some of the recent examples include the erm(B) gene conferring macrolide resistance, the cfr(C) genes mediating resistance to florfenicol and other antimicrobials, and a functionally enhanced variant of the multidrug resistance efflux pump, CmeABC. The continued emergence of new resistance mechanisms illustrates the extraordinary adaptability of Campylobacter to antibiotic selection pressure and demonstrate the need for innovative strategies to control antibiotic-resistant Campylobacter. In this review, we will briefly summarize the trends of antibiotic resistance in Campylobacter and discuss the mechanisms of resistance to antibiotics used for animal production and important for clinical therapy in humans. A special emphasis will be given to the newly discovered antibiotic resistance.
Deris, Barrett; Kim, Minsu; Zhang, Zhongge; Okano, Hiroyuki; Hermsen, Rutger; Gore, Jeff; Hwa, Terence
To predict the emergence of antibiotic resistance, quantitative relations must be established between the fitness of drug-resistant organisms and the molecular mechanisms conferring resistance. We have investigated E. coli strains expressing resistance to translation-inhibiting antibiotics. We show that resistance expression and drug inhibition are linked in a positive feedback loop arising from an innate, global effect of drug-inhibited growth on gene expression. This feedback leads generically to plateau-shaped fitness landscapes and concomitantly, for strains expressing at least moderate degrees of drug resistance, gives rise to an abrupt drop in growth rates of cultures at threshold drug concentrations. A simple quantitative model of bacterial growth based on this innate feedback accurately predicts experimental observations without ad hoc parameter fitting. We describe how drug-inhibited growth rate and the threshold drug concentration (the minimum inhibitory concentration, or MIC) depend on the few biochemical parameters that characterize the molecular details of growth inhibition and drug resistance (e.g., the drug-target dissociation constant). And finally, we discuss how these parameters can shape fitness landscapes to determine evolutionary dynamics and evolvability.
Yao, Hong; Shen, Zhangqi; Wang, Yang; Deng, Fengru; Liu, Dejun; Naren, Gaowa; Dai, Lei; Su, Chih-Chia; Wang, Bing; Wang, Shaolin; Wu, Congming; Yu, Edward W; Zhang, Qijing; Shen, Jianzhong
prevalence of a unique efflux pump variant that is much more powerful in the efflux of antibiotics and confers multidrug resistance in Campylobacter, which is a major foodborne pathogen transmitted to humans via the food chain. Unlike other specific resistance determinants that only allow bacteria to resist a particular antimicrobial, the acquisition of a functionally enhanced efflux pump will empower bacteria with simultaneous resistance to multiple classes of antibiotics. These findings reveal a previously undescribed mechanism for enhanced multidrug resistance and open a new direction for us to understand how bacteria adapt to antibiotic treatment. Copyright © 2016 Yao et al.
Harbarth, Stephan; Albrich, Werner; Brun-Buisson, Christian
The prevalence of penicillin-nonsusceptible pneumococci is sharply divided between France (43%) and Germany (7%). These differences may be explained on different levels: antibiotic-prescribing practices for respiratory tract infections; patient-demand factors and health-belief differences; social determinants, including differing child-care practices; and differences in regulatory practices. Understanding these determinants is crucial for the success of possible interventions. Finally, we emphasize the overarching importance of a sociocultural approach to preventing antibiotic resistance in the community.
Lin, Y. F.; Yannarell, A. C.; Mackie, R. I.; Krapac, I. G.; Chee-Sanford, J. S.; Koike, S.
The use of antibiotics at concentrated animal feeding operations (CAFOs) for disease prevention, disease treatment, and growth promotion can contribute to the spread of antibiotic compounds, their breakdown products, and antibiotic resistant bacteria and/or the genes that confer resistance. In addition, constitutive use of antibiotics at sub-therapeutic levels can select for antibiotic resistance among the bacteria that inhabit animal intestinal tracts, onsite manure treatment facilities, and any environments receiving significant inputs of manure (e.g. through waste lagoon leakage or fertilizer amendments to farm soils). If the antibiotic resistant organisms persist in these new environments, or if they participate in genetic exchanges with the native microflora, then CAFOs may constitute a significant reservoir for the spread of antibiotic resistance to the environment at large. Our results have demonstrated that leakage from waste treatment lagoons can influence the presence and persistence of tetracycline resistance genes in the shallow aquifer adjacent to swine CAFOs, and molecular phylogeny allowed us to distinguish "native" tetracycline resistance genes in control groundwater wells from manure-associated genes introduced from the lagoon. We have also been able to detect the presence of erythromycin resistance genes in CAFO surface and groundwater even though erythromycin is strictly reserved for use in humans and thus is not utilized at any of these sites. Ongoing research, including modeling of particle transport in groundwater, will help to determine the potential spatial and temporal extent of CAFO-derived antibiotic resistance.
A variety of plasmids were isolated physically, and most antibiotic resistance is thought to be plasmid mediated. A number of characters (e.g., resistance to erythromycin or methicillin, and production of pigment) are determined by genes that do not give clear indications of either plasmid or chromosomal location. Although the formation of a particular plasmid is probably, even in bacterial terms, a very rare event, once formed such an element can spread rapidly among the bacterial population. The spectacular increase in the incidence of penicillinase-producing hospital strains in the late 1940's could have been due in part to this process. Evidence is stronger, however, for the intercell transfer of recently isolated plasmids coding for resistance to fusidic acid (and penicillinase production), or for neomycin, or for tetracycline resistance. Study of bacterial plasmids can resolve fundamental biochemical problems, and give some insight into the life of the cell at the molecular level. But the immediate application of the study of staphylococcal plasmids may be directed towards improving the effectiveness of antibiotic therapy. The most important aspect of future anti-staphylococcal chemotherapy should thus be the limitation of the use of antibiotics, particularly for application to the skin and nose. (U.S.)
Full Text Available Aim: Although prophylactic antibiotic treatment is still debatable, it is currently in use in recurrent urinary tract infections (UTIs. In the present study, we aimed to observe if prophylactic antibiotic use had any effect on the development of antibiotic resistance in patients with recurrent UTIs who we followed up in our clinic. Methods: The present study was performed on patients aged between one month and 16 years, who had recurrent UTIs, and were followed up by the Department of Pediatrics at Bülent Ecevit University Medical School. Patient files were retrospectively reviewed, and 50 patients who received antibiotic prophylaxis and 100 patients without prophylaxis were enrolled in the study. Urinary tests, subsequent urinary culture results, and antibiotic resistances were compared between the groups. Results: The mean age was 42.7±44.2 months. The most frequently cultured isolated bacterium was Escherichia coli (E. coli (58.4%. No difference was determined in bacteria in cultures between prophylaxis receivers and non-receivers. Isolation rate of E. coli was higher in urinary cultures in females than in males (p<0.001. When antibiotic resistance of all urinary culture-isolated bacteria was compared between the two groups, there was no statistically significant difference. However, an increased resistance against amoxicillin/clavulanic acid, ceftriaxone, and piperacillin was determined in prophylaxis group in whom E. coli was grown. In this study, general antibiotic resistance was most frequently observed against ampicillin (71.9%. Conclusion: In the present study, we observed that prophylaxis did not contribute so much to resistance other than E. coli. We recommend not preferring antibiotics which have increased resistance in our institution especially in children receiving prophylaxis for empirical treatment.
Gbaguidi-Haore, Houssein; Dumartin, Catherine; L'Hériteau, François; Péfau, Muriel; Hocquet, Didier; Rogues, Anne-Marie; Bertrand, Xavier
To identify the antibiotics potentially the most involved in the occurrence of antibiotic-resistant bacteria from an ecological perspective in French healthcare facilities (HCFs). This study was based on data from the French antimicrobial surveillance network (ATB-RAISIN, 2007-09). Antibiotics were expressed in defined daily doses per 1000 patient-days. Antibiotic-resistant bacteria were considered as count data adjusted for patient-days. These were third-generation cephalosporin (3GC)- and ciprofloxacin-resistant Escherichia coli, cefotaxime-resistant Enterobacter cloacae, methicillin-resistant Staphylococcus aureus and ceftazidime-, imipenem- and ciprofloxacin-resistant Pseudomonas aeruginosa. Three-level negative binomial regression models were built to take into account the hierarchical structure of data: level 1, repeated measures each year (count outcome, time, antibiotics); level 2, HCFs (type and size); and level 3, regions (geographical area). A total of 701 HCFs from 20 French regions and up to 1339 HCF-years were analysed. The use of ceftriaxone, but not of cefotaxime, was positively correlated with incidence rates of 3GC- and ciprofloxacin-resistant E. coli. In contrast, both 3GCs were positively correlated with the incidence rate of cefotaxime-resistant E. cloacae. Higher levels of use of ciprofloxacin and/or ofloxacin, but not of levofloxacin, were associated with higher incidence rates of 3GC- and ciprofloxacin-resistant E. coli, cefotaxime-resistant E. cloacae, methicillin-resistant S. aureus and ceftazidime- and ciprofloxacin-resistant P. aeruginosa. Our study suggests differences within antibiotic classes in promoting antibiotic resistance. We identified ceftriaxone, ciprofloxacin and ofloxacin as priority targets in public health strategies designed to reduce antibiotic use and antibiotic-resistant bacteria in French HCFs.
Full Text Available Antibiotic resistance is a global challenge that impacts all pharmaceutically used antibiotics. The origin of the genes associated with this resistance is of significant importance to our understanding of the evolution and dissemination of antibiotic resistance in pathogens. A growing body of evidence implicates environmental organisms as reservoirs of these resistance genes; however, the role of anthropogenic use of antibiotics in the emergence of these genes is controversial. We report a screen of a sample of the culturable microbiome of Lechuguilla Cave, New Mexico, in a region of the cave that has been isolated for over 4 million years. We report that, like surface microbes, these bacteria were highly resistant to antibiotics; some strains were resistant to 14 different commercially available antibiotics. Resistance was detected to a wide range of structurally different antibiotics including daptomycin, an antibiotic of last resort in the treatment of drug resistant Gram-positive pathogens. Enzyme-mediated mechanisms of resistance were also discovered for natural and semi-synthetic macrolide antibiotics via glycosylation and through a kinase-mediated phosphorylation mechanism. Sequencing of the genome of one of the resistant bacteria identified a macrolide kinase encoding gene and characterization of its product revealed it to be related to a known family of kinases circulating in modern drug resistant pathogens. The implications of this study are significant to our understanding of the prevalence of resistance, even in microbiomes isolated from human use of antibiotics. This supports a growing understanding that antibiotic resistance is natural, ancient, and hard wired in the microbial pangenome.
Bhullar, Kirandeep; Waglechner, Nicholas; Pawlowski, Andrew; Koteva, Kalinka; Banks, Eric D; Johnston, Michael D; Barton, Hazel A; Wright, Gerard D
Antibiotic resistance is a global challenge that impacts all pharmaceutically used antibiotics. The origin of the genes associated with this resistance is of significant importance to our understanding of the evolution and dissemination of antibiotic resistance in pathogens. A growing body of evidence implicates environmental organisms as reservoirs of these resistance genes; however, the role of anthropogenic use of antibiotics in the emergence of these genes is controversial. We report a screen of a sample of the culturable microbiome of Lechuguilla Cave, New Mexico, in a region of the cave that has been isolated for over 4 million years. We report that, like surface microbes, these bacteria were highly resistant to antibiotics; some strains were resistant to 14 different commercially available antibiotics. Resistance was detected to a wide range of structurally different antibiotics including daptomycin, an antibiotic of last resort in the treatment of drug resistant Gram-positive pathogens. Enzyme-mediated mechanisms of resistance were also discovered for natural and semi-synthetic macrolide antibiotics via glycosylation and through a kinase-mediated phosphorylation mechanism. Sequencing of the genome of one of the resistant bacteria identified a macrolide kinase encoding gene and characterization of its product revealed it to be related to a known family of kinases circulating in modern drug resistant pathogens. The implications of this study are significant to our understanding of the prevalence of resistance, even in microbiomes isolated from human use of antibiotics. This supports a growing understanding that antibiotic resistance is natural, ancient, and hard wired in the microbial pangenome.
Olesen, Scott; Barnett, Michael; MacFadden, Derek; Lipsitch, Marc; Grad, Yonatan H
Abstract Background Antibiotic consumption is considered a major driver of antibiotic resistance, but it remains unclear whether the consumption–resistance relationship is apparent for many organisms and drugs, and whether aggregate consumption is the best predictor of resistance. Methods We conducted a landscape assessment of the consumption-resistance relationship by comparing a 20% sample of Medicare Part D outpatient antibiotic pharmacy claims with a nationwide survey of hospital antibiotic susceptibility reports. Antibiotic consumption was summarized in individual states and hospital-referral regions (HRRs) using traditional, aggregate consumption or by metrics that account for the concentration of consumption in a few individuals (Gini coefficient). The consumption–resistance relationships for 17 organism–drug combinations were simultaneously evaluated (Spearman’s rho; linear models predicting resistance from aggregate consumption and Gini coefficient) and corrected for multiple-hypothesis testing (Benjamini–Hochberg). Results We identified a significant correlation between aggregate consumption of an antibiotic and an organism’s reported resistance to that antibiotic in only a few cases: quinolones and E. coli (Spearman’s rho = 0.65, adjusted P < 10−4) and E. cloacae (rho = 0.50, adjusted P = 0.006). In other cases, notably E. coli with trimethoprim–sulfamethoxazole, the distribution of antibiotic consumption among consumers has a marginal relationship with antibiotic resistance (−1.0 p.p. resistance per p.p. Gini coefficient of consumption among consumers, unadjusted P < 0.001). Conclusion There is a clear correlation between aggregate consumption of an antibiotic and resistance of an organism to that antibiotic in only a few cases, suggesting that antibiotic steward efforts might maximize their effectiveness by focusing on particular organisms, drugs, and consumer groups rather than overall, aggregate consumption
El-Halfawy, Omar M; Klett, Javier; Ingram, Rebecca J; Loutet, Slade A; Murphy, Michael E P; Martín-Santamaría, Sonsoles; Valvano, Miguel A
The potential for microbes to overcome antibiotics of different classes before they reach bacterial cells is largely unexplored. Here we show that a soluble bacterial lipocalin produced by Burkholderia cenocepacia upon exposure to sublethal antibiotic concentrations increases resistance to diverse antibiotics in vitro and in vivo These phenotypes were recapitulated by heterologous expression in B. cenocepacia of lipocalin genes from Pseudomonas aeruginosa , Mycobacterium tuberculosis , and methicillin-resistant Staphylococcus aureus Purified lipocalin bound different classes of bactericidal antibiotics and contributed to bacterial survival in vivo Experimental and X-ray crystal structure-guided computational studies revealed that lipocalins counteract antibiotic action by capturing antibiotics in the extracellular space. We also demonstrated that fat-soluble vitamins prevent antibiotic capture by binding bacterial lipocalin with higher affinity than antibiotics. Therefore, bacterial lipocalins contribute to antimicrobial resistance by capturing diverse antibiotics in the extracellular space at the site of infection, which can be counteracted by known vitamins. IMPORTANCE Current research on antibiotic action and resistance focuses on targeting essential functions within bacterial cells. We discovered a previously unrecognized mode of general bacterial antibiotic resistance operating in the extracellular space, which depends on bacterial protein molecules called lipocalins. These molecules are highly conserved in most bacteria and have the ability to capture different classes of antibiotics outside bacterial cells. We also discovered that liposoluble vitamins, such as vitamin E, overcome in vitro and in vivo antibiotic resistance mediated by bacterial lipocalins, providing an unexpected new alternative to combat resistance by using this vitamin or its derivatives as antibiotic adjuvants. Copyright © 2017 El-Halfawy et al.
Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.
El-Halfawy, Omar M; Valvano, Miguel A
Communication of antibiotic resistance among bacteria via small molecules is implicated in transient reduction of bacterial susceptibility to antibiotics, which could lead to therapeutic failures aggravating the problem of antibiotic resistance. Released putrescine from the extremely antibiotic-resistant bacterium Burkholderia cenocepacia protects less-resistant cells from different species against the antimicrobial peptide polymyxin B (PmB). Exposure of B. cenocepacia to sublethal concentrations of PmB and other bactericidal antibiotics induces reactive oxygen species (ROS) production and expression of the oxidative stress response regulator OxyR. We evaluated whether putrescine alleviates antibiotic-induced oxidative stress. The accumulation of intracellular ROS, such as superoxide ion and hydrogen peroxide, was assessed fluorometrically with dichlorofluorescein diacetate, while the expression of OxyR and putrescine synthesis enzymes was determined in luciferase assays using chromosomal promoter-lux reporter system fusions. We evaluated wild-type and isogenic deletion mutant strains with defects in putrescine biosynthesis after exposure to sublethal concentrations of PmB and other bactericidal antibiotics. Exogenous putrescine protected against oxidative stress induced by PmB and other antibiotics, whereas reduced putrescine synthesis resulted in increased ROS generation and a parallel increased sensitivity to PmB. Of the 3 B. cenocepacia putrescine-synthesizing enzymes, PmB induced only BCAL2641, an ornithine decarboxylase. This study reveals BCAL2641 as a critical component of the putrescine-mediated communication of antibiotic resistance and as a plausible target for designing inhibitors that would block the communication of such resistance among different bacteria, ultimately reducing the window of therapeutic failure in treating bacterial infections. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
Abstract. Background: Urinary tract infections (UTI) are one of the major causes of prescribing and antibiotic con- sumption. In order to use the best antibiotic treatment for their patients, reliable and recent data about epidemiology and antibiotic resistance profile of uropathogenic bacteria must be available for clinicians.
Background: Urinary tract infections (UTI) are one of the major causes of prescribing and antibiotic consumption. In order to use the best antibiotic treatment for their patients, reliable and recent data about epidemiology and antibiotic resistance profile of uropathogenic bacteria must be available for clinicians. Therefore ...
Price, Lance B.; Newland, Jason; Bole, Aparna
edical and public health organizations around the world agree that more prudent use of antibiotics in human medicine and in livestock production is paramount to slow the spread of antibiotic resistance. Of particular concern is the widespread use of antibiotics important to human medicine in food...... animals. In the U.S., such use accounts for 70% of all sales of medically important antibiotics. It is against this backdrop that 12 antibiotic resistance experts from the fields of infectious disease medicine, veterinary medicine, microbiology, epidemiology and public health joined to craft a policy...... roadmap to help move the U.S. forward in addressing the contribution of livestock antibiotic use to the growing global threat of antibiotic resistance. The policy roadmap consists of 11 core policy recommendations that are aimed at a broad set of stakeholders: federal, state and local policymakers, food...
Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)
By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.
Full Text Available Introduction: Drug resistant Staphylococci are the most important agents of nosocomial infections. In this survey, effect of different antibiotics on these bacteria and their drug resistance was investigated. Methods: The study included 500 strains of Staphylococci. Minimum Inhibitory Concentrations of all antibiotics was determined by the broth macro dilution technique and standard methods from the National Committee for Clinical Laboratory Standards. Result : Oxacillin resistance of S. aureus was 14.2% and that of coagulase-negative staphylococci was 53.4%. The activity of different antibiotics is presented in detail. Conclusion: Surveillance of strains resistant to methicillin is necessary.
Full Text Available From samples of raw sheep's milk were determined results of bacteriological examination from two herds in region of Eastern Slovakia in three years lasting study. The occurrence of Staphylococcus spp. 41.6% (124 was determined from 298 samples. The seven species of staphylococci were on a regular basis isolated: S. epidermidis (34, S. chromogenes (26, S. aureus (16. Alternately have been recorded S. warneri (16, S. schleiferi (15, S. haemolyticus (9 and S. xylosus (8. All isolated pathogens were tested by in vitro test on Mueller-Hinton agar by disc methods on resistance to 10 types of antibiotics. Highest value of resistance was determined to Penicilin 21.0%, Neomycin 10.5% and Novobiocin 9.7%. Lower resistance was in to Oxacilin 7.2% and Amoxicilin 6.5%. Minimal resistance was founded to Cefoxitin 0.8%, Linkomycin 2.4%, Erytromycin, and Streptomycin 3.2%. Was founded total resistance (21.0% to all antibiotics in S. epidermidis (34 during the three years, S. chromogenes (26 showed resistance to 8 types of antibiotics (12.9%, S. aureus (16 to 6 antibiotics (10.5% and S. warneri (16 to 4 antibiotics (5.6%. It was confirmed that sheep's milk remains a major source of staphylococci. Bacteria in comparison with isolates from cows' raw milk, showed lower values of resistance, but were resistant to more than two antibiotics. Recorded occurrence of resistance in staphylococci may be connected with a minimum use of antibiotics in the treatment of mastitis and other diseases in sheep herds. Reported resistance to the tested antibiotics became the basis for the recommendation to use preparations to treat mastitis in sheep principally by the detection of resistance to antibiotics contained.
The problem of antibiotic resistance is associated with the indiscriminate usage of antibiotics. Efforts have been directed at encouraging the rational use of these drugs to reduce the volume of antibiotic consumption and decrease resistance rates. There is evidence to suggest that the misuse of antibiotics by patients may also contribute to the problem. We describe a survey of a random selection of patients attending a General Practitioners\\' surgery over a six week period in an effort to estimate the level of non-compliance to antibiotic therapy in the community. The results suggest that there may be a significant level of antibiotic misuse prevalent in the local community. We discuss these results and present evidence in the literature suggesting how antibiotic misuse may affect resistance in the community. The factors affecting patient compliance to therapy are outlined along with suggested measures to improve compliance among patients.
Eom, Sung-Hwan; Kim, Young-Mog; Kim, Se-Kwon
Methicillin-resistant Staphylococcus aureus (MRSA) is the most problematic Gram-positive bacterium in the context of public health due to its resistance against almost all available antibiotics except vancomycin and teicoplanin. Moreover, glycopeptide-resistant S. aureus have been emerging with the increasing use of glycopeptides. Recently, resistant strains against linezolid and daptomycin, which are alternative drugs to treat MRSA infection, have also been reported. Thus, the development of new drugs or alternative therapies is clearly a matter of urgency. In response to the antibiotic resistance, many researchers have studied for alternative antibiotics and therapies. In this review, anti-MRSA substances isolated from marine bacteria, with their potential antibacterial effect against MRSA as potential anti-MRSA agents, are discussed and several strategies for overcoming the antibiotic resistance are also introduced. Our objective was to highlight marine bacteria that have potential to lead in developing novel antibiotics or clinically useful alternative therapeutic treatments.
Mazer-Amirshahi, Maryann; Pourmand, Ali; May, Larissa
Millions of patients are evaluated every year in the emergency department (ED) for bacterial infections. Emergency physicians often diagnose and prescribe initial antibiotic therapy for a variety of bacterial infections, ranging from simple urinary tract infections to severe sepsis. In life-threatening infections, inappropriate choice of initial antibiotic has been shown to increase morbidity and mortality. As such, initiation of appropriate antibiotic therapy on the part of the emergency physician is critical. Increasing rates of antibiotic resistance, drug allergies, and antibiotic shortages further complicates the choice of antibiotics. Patients may have a history of prior resistant infections or culture data indicating that common first-line antibiotics used in the ED may be ineffective. In recent years, there have been several new antibiotic approvals as well as renewed interest in second and third line antibiotics because of the aforementioned concerns. In addition, several newly approved antibiotics have the advantage of being administered once weekly or even as a single infusion, which has the potential to decrease hospitalizations and healthcare costs. This article reviews newly approved antibiotics and antibiotics used to treat resistant infections with a focus on implications for emergency medicine. Copyright © 2016 Elsevier Inc. All rights reserved.
Martínez, José Luis; Baquero, Fernando
The emergence and spread of antibiotic resistance among human pathogens is a relevant problem for human health and one of the few evolution processes amenable to experimental studies. In the present review, we discuss some basic aspects of antibiotic resistance, including mechanisms of resistance, origin of resistance genes, and bottlenecks that modulate the acquisition and spread of antibiotic resistance among human pathogens. In addition, we analyse several parameters that modulate the evolution landscape of antibiotic resistance. Learning why some resistance mechanisms emerge but do not evolve after a first burst, whereas others can spread over the entire world very rapidly, mimicking a chain reaction, is important for predicting the evolution, and relevance for human health, of a given mechanism of resistance. Because of this, we propose that the emergence and spread of antibiotic resistance can only be understood in a multi-parameter space. Measuring the effect on antibiotic resistance of parameters such as contact rates, transfer rates, integration rates, replication rates, diversification rates, and selection rates, for different genes and organisms, growing under different conditions in distinct ecosystems, will allow for a better prediction of antibiotic resistance and possibilities of focused interventions.
Baquero, Fernando; Coque, Teresa M; Cantón, Rafael
To fight against antibiotic resistance, prevention-only is no longer an acceptable strategy. The old concept 'one-infection, one-bug, one-drug', genocentrism in antibiotic discovery, and lack of integration between different antimicrobial strategies have probably contributed to current weaknesses in confronting antibiotic resistance. Resistance should be combatted in all fronts simultaneously, in the patient (complex therapy), the group (where resistance is maintained), and the significant environment (polluted by resistance). This paper is reviewing why specific 'therapeutic' approaches are needed in each of these fronts, using different types of 'drugs' directed to a variety of targets, in the goal of inhibiting antibiotic resistant bacteria. Multi-target integrated combination strategies and therapies should be more extensively evaluated, not only in the infected patient (using novel formats for clinical trials), but as associations of 'therapeutic strategies' in the different compartments where antibiotic resistance emerges and flows (measuring global effects in resistance). Multi-targeted therapeutic approaches require a relaxation of barriers among the various compounds, including systemic and topic antibiotics, antiseptics, biocides, anti-resistant clones vaccination, phages, decontamination products, and in general eco-evo drugs acting on factors influencing ecology and evolution of resistant bacteria. The application of methods of systems biology will facilitate such a multi-lateral attack to antibiotic resistance. Such advances should be paralleled by a simultaneous progress in regulatory sciences and close coordination among all stakeholders.
The resistance pattern of the 55 S. aureus isolates showed that all the isolates were resistant to two or more antibiotics. Multidrug resistance was detected in 96.4% of the isolates. All the S. aureus were resistant to penicillin 55 (100.0%) rates of resistance to ampicillin (90.9%; n=50), tetracycline (81.8%; n=45) and ...
Susanne Schjørring; Karen A. Krogfelt
We assessed horizontal gene transfer between bacteria in the gastrointestinal (GI) tract. During the last decades, the emergence of antibiotic resistant strains and treatment failures of bacterial infections have increased the public awareness of antibiotic usage. The use of broad spectrum antibiotics creates a selective pressure on the bacterial flora, thus increasing the emergence of multiresistant bacteria, which results in a vicious circle of treatments and emergence of new antibiotic res...
Bell, B.G.; Schellevis, F.; Stobberingh, E.; Goossens, H.; Pringle, M.
Background: Greater use of antibiotics during the past 50 years has exerted selective pressure on susceptible bacteria and may have favoured the survival of resistant strains. Existing information on antibiotic resistance patterns from pathogens circulating among community-based patients is
Bell, B.G.; Schellevis, F.; Stobberingh, E.; Goossen, H.; Pringle, M.
Background: Greater use of antibiotics during the past 50 years has exerted selective pressure on susceptible bacteria and may have favoured the survival of resistant strains. Existing information on antibiotic resistance patterns from pathogens circulating among community-based patients is
Full Text Available A preliminary study of antibiotic production and antibiotic resistance was conducted in Great Onyx Cave in Mammoth Cave National Park, KY, to determine if gypsum (CaSO4∙2H2O affects these bacterial activities. The cave crosses through the width of Flint Ridge, and passages under the sandstone caprock are dry with different amounts of gypsum. The Great Kentucky Desert hypothesis posits that gypsum limits the distribution of invertebrates in the central areas of Great Onyx Cave. Twenty-four bacterial isolates were cultivated from swabs and soils. Using three methods (soil crumb, soil crumb with indicator bacteria, and the cross-streak method using isolated bacteria we did not detect any production of antibiotics. Antibiotic resistance was widespread, with all 24 isolates resistant to a minimum of two antibiotics of seven tested, with three isolates resistant to all. Antibiotic resistance was high and not correlated with depth into the cave or the amount of gypsum. The Great Kentucky Desert hypothesis of the negative effects of gypsum seems to have no impact on bacterial activity.
Billington, John K
Antibiotics have prevented countless deaths from common infections and have made possible many modern medical procedures. Over the past few decades, antibiotic-resistant bacteria have become a global threat, spreading between healthcare facilities and throughout communities worldwide at an alarming pace. Antibiotic overuse and misuse in humans, animals, and the environment accelerate resistance by selecting for bacteria with antibiotic-resistant traits, which then become predominant and infect others. Meanwhile, few antibiotics remain active against the most resistant bacteria. There is an urgent need for new antibiotics and other antibacterial products to replace second-line and last resort therapies when they no longer work. This Article proposes a new U.S.-based, non-governmental, not-for-profit product development partnership (PDP) model specifically designed for antibacterial development. This new model should both supplement and complement existing government-led efforts and should be built with mechanisms in place to balance the values of innovation, access, and conservation.
Mezzatesta, Maria Lina; Gona, Floriana; Stefani, Stefania
Species of the Enterobacter cloacae complex are widely encountered in nature, but they can act as pathogens. The biochemical and molecular studies on E. cloacae have shown genomic heterogeneity, comprising six species: Enterobacter cloacae, Enterobacter asburiae, Enterobacter hormaechei, Enterobacter kobei, Enterobacter ludwigii and Enterobacter nimipressuralis, E. cloacae and E. hormaechei are the most frequently isolated in human clinical specimens. Phenotypic identification of all species belonging to this taxon is usually difficult and not always reliable; therefore, molecular methods are often used. Although the E. cloacae complex strains are among the most common Enterobacter spp. causing nosocomial bloodstream infections in the last decade, little is known about their virulence-associated properties. By contrast, much has been published on the antibiotic-resistance features of these microorganisms. In fact, they are capable of overproducing AmpC β-lactamases by derepression of a chromosomal gene or by the acquisition of a transferable ampC gene on plasmids conferring the antibiotic resistance. Many other resistance determinants that are able to render ineffective almost all antibiotic families have been recently acquired. Most studies on antimicrobial susceptibility are focused on E. cloacae, E. hormaechei and E. asburiae; these studies reported small variations between the species, and the only significant differences had no discriminating features.
Edern, Anita; Fines-Guyon, Marguerite; Castrale, Cindy; Ficheux, Maxence; Ryckelynck, Jean-Philippe; Lobbedez, Thierry
Peritonitis remains a common complication of peritoneal dialysis. The aim of our study is to describe the mechanisms of antibiotic resistance in bacteria isolated during peritonitis in peritoneal dialysis, to determine whether antibiotic therapy proposed by the International Society for Peritoneal Dialysis (ISPD) is adapted to the mechanisms of resistance. All causative microorganisms of peritonitis, isolated in 106 dialysis patients and reported 170 episodes of peritonitis, during the study period (01/01/2005 to 31/12/2010) were reviewed. According to the usual classification, twelve groups of microorganism were created. An interpretive reading of antibiograms was performed in each group to identify resistance phenotypes. The species most frequently isolated are coagulase-negative staphylococci (n=73) of which 46 had PBP2a (penicillin-binding protein). Many Enterobacteriaceae were also isolated (n=45), they are susceptible to third generation cephalosporins with the exception of Enterobacteriaceae producing an extended spectrum β-lactamase (ESBL) or a cephalosporinase. Except for staphylococci, probabilistic antibiotic therapy recommended by the ISPD to treat peritonitis is effective. Indeed, many staphylococci producing a PBP2a, a first-generation cephalosporin cannot be administered in all cases. It is therefore necessary to identify patients with a strain of staphylococcus producing a PBP2a, it must be treated by vancomycin. Copyright © 2012 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.
Sandra G. Zárate
Full Text Available Resistance to aminoglycoside antibiotics has had a profound impact on clinical practice. Despite their powerful bactericidal activity, aminoglycosides were one of the first groups of antibiotics to meet the challenge of resistance. The most prevalent source of clinically relevant resistance against these therapeutics is conferred by the enzymatic modification of the antibiotic. Therefore, a deeper knowledge of the aminoglycoside-modifying enzymes and their interactions with the antibiotics and solvent is of paramount importance in order to facilitate the design of more effective and potent inhibitors and/or novel semisynthetic aminoglycosides that are not susceptible to modifying enzymes.
Kimman, T.G.; Smits, M.A.; Kemp, B.; Wever, P.; Verheijden, J.
Resistance of bacteria to antibiotics in animal husbandry is increasing and a point of growing concern. The large use of antibiotics in agriculture undoubtedly leads to the development of antibiotic resistance. This has resulted in a growing public concern on the rise of antibiotic resistance, and
Robert, A; Nguyen, Y; Bajolet, O; Vuillemin, B; Defoin, B; Vernet-Garnier, V; Drame, M; Bani-Sadr, F
We aimed to evaluate factors associated with knowledge of antibiotics and drug resistance. A questionnaire was handed out by 14 family physicians to their patients between December 20, 2014 and April 20, 2015 in Rethel (North-East of France). We conducted a cross-sectional study using a logistical regression model to assess factors associated with antibiotic knowledge. Three criteria were used to assess that knowledge. Overall, 293 questionnaires were analysed; 48% of patients had received antibiotics in the previous 12 months. Only 44% and 26% gave a correct answer for the statements "Antibiotics are effective against bacteria and ineffective against viruses" and "Antibiotic resistance decreases if the antibiotic use decreases", respectively. Characteristics such as female sex, age>30 years, high level of education, high professional categories, and having received antibiotic information by the media were associated with high level of knowledge about antibiotics and/or antibiotic resistance. In contrast, having received antibiotic information from family physicians was not associated with good knowledge. Although media awareness campaigns had an independent impact on a higher public knowledge of antibiotics, the overall public knowledge remains low. It would be necessary to strengthen antibiotic campaigns with clearer information on the relation between the excessive use of antibiotics and the increased risk of antibiotic resistance. Family physicians should be more involved to improve antibiotic knowledge among target groups such as men, young patients, and people from a poor social and cultural background. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Allahverdiyev, Adil M; Kon, Kateryna Volodymyrivna; Abamor, Emrah Sefik; Bagirova, Malahat; Rafailovich, Miriam
The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria.
Band, Victor I.; Crispell, Emily K.; Napier, Brooke A.; Herrera, Carmen M.; Tharp, Greg K.; Vavikolanu, Kranthi; Pohl, Jan; Read, Timothy D.; Bosinger, Steven E.; Trent, M. Stephen; Burd, Eileen M.; Weiss, David S.
Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infect...
Li, Xinhui; Li, Yingli; Alvarez, Valente; Harper, Willis James; Wang, Hua H.
Controlling antibiotic-resistant (ART) bacteria in cheese fermentation is important for food safety and public health. A plant-maintained culture was found to be a potential source for ART bacterial contamination in cheese fermentation. Antibiotics had a detectable effect on the ART population from contamination in the finished product. The decrease in the prevalence of antibiotic resistance (AR) in retail cheese samples from 2010 compared to data from 2006 suggested the effectiveness of targ...
Vogwill, T; Comfort, A C; Furió, V; MacLean, R C
Bacterial persistence represents a simple of phenotypic heterogeneity, whereby a proportion of cells in an isogenic bacterial population can survive exposure to lethal stresses such as antibiotics. In contrast, genetically based antibiotic resistance allows for continued growth in the presence of antibiotics. It is unclear, however, whether resistance and persistence are complementary or alternative evolutionary adaptations to antibiotics. Here, we investigate the co-evolution of resistance and persistence across the genus Pseudomonas using comparative methods that correct for phylogenetic nonindependence. We find that strains of Pseudomonas vary extensively in both their intrinsic resistance to antibiotics (ciprofloxacin and rifampicin) and persistence following exposure to these antibiotics. Crucially, we find that persistence correlates positively to antibiotic resistance across strains. However, we find that different genes control resistance and persistence implying that they are independent traits. Specifically, we find that the number of type II toxin-antitoxin systems (TAs) in the genome of a strain is correlated to persistence, but not resistance. Our study shows that persistence and antibiotic resistance are complementary, but independent, evolutionary adaptations to stress and it highlights the key role played by TAs in the evolution of persistence. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.
Apr 16, 2007 ... Antibiotic resistance profiles and the correlation of enteric bacterial pathogens from HIV positive indivi- duals with and ... from the various study cohorts showed multiple antibiotic resistance to penicillin, amoxicillin, ampicillin, erythromycin .... chose to work closely with support groups, NGOs and HIV care-.
Antibiotic resistance is increasing rapidly and developing countries are the worse affected since they provide conditions and practices that support the development and spread of resistant microbes. For better health policy on antibiotic use a national surveillance program is needed to provide baseline data from different ...
Huijbers, P.M.C. (2016). Transmission of antibiotic resistance from animals to humans: Broilers as a reservoir of ESBL-producing bacteria. PhD thesis, Wageningen University, Wageningen, the Netherlands.
Antibiotic resistance in animals becomes a public health issue when there is
The problem of antibiotic resistance, which has limited the use of cheap and old antibiotics, has necessitated the need for a continued search for new antimicrobial compounds. Understanding the mechanisms of resistance is important in the development of strategies to solving the problem. Active efflux of drugs, alteration of ...
Antibiotic resistance plasmids found in wastewater treatment plants (WWTPs) may represent a threat to public health if they are readily disseminated into the environment and ultimately into pathogenic bacteria. The wastewater environments provide an ideal ecosystem for development and evolution of antibiotic resistance ...
ter Kuile, B.; Brul, S.; Sofos, J.
Antibiotic resistance in human pathogens is becoming a major threat to human health. This is partly due to agriculture, because large amounts of antibiotics are used to treat animals, which encourages resistant genes to appear and transfer to humans through foodstuffs. This is a food safety issue.
Hoek, van A.H.A.M.; Aarts, H.J.M.
In the presented study, 143 Salmonella isolates belonging to 26 different serovars were screened for the presence of antibiotic resistance genes by microarray analysis. The microarray contained a total of 223 oligonucleotides representing genes encoding for resistance to the following antibiotic
Antibiotic-resistant bacteria in the aquatic environment are considered reservoirs for drug-resistant genes. Therefore, culturable heterotrophic bacteria isolated from Lagos Lagoon surface waters between 2011 and 2012 were screened for their susceptibility to 14 commonly used antibiotics belonging to six major classes.
Jun 25, 2010 ... Bacterial resistance to antibiotics has been attributed to many different factors with emphasis on the widespread use, misuse or overuse of antibiotics. Current thinking has referenced these as providing the selective pressure favouring propagation of resistant organisms (Livermore, 2003). This, however ...
Xavier, Basil Britto; Das, Anupam J.; Cochrane, Guy
The unrestricted use of antibiotics has resulted in rapid acquisition of antibiotic resistance (AR) and spread of multidrug-resistant (MDR) bacterial pathogens. With the advent of next-generation sequencing technologies and their application in understanding MDR pathogen dynamics, it has become...
The S. aureus. isolates varied in their antibiotic susceptibility pattern when tested for their sensitivity to 16 antibiotics. Eighty percent of the isolates were resistant to more than one antimicrobial agent. All the isolates showed resistance to nalidixic acid and 100% sensitivity to rifampicin. Key words: Staphylococcus aureus, ...
Background Greater use of antibiotics during the past 50 years has exerted selective pressure on susceptible bacteria and may have favoured the survival of resistant strains. Existing information on antibiotic resistance patterns from pathogens circulating among community-based patients is substantially less than from hospitalized patients on whom guidelines are often based. We therefore chose to assess the relationship between the antibiotic resistance pattern of bacteria circulating in the community and the consumption of antibiotics in the community. Methods Both gray literature and published scientific literature in English and other European languages was examined. Multiple regression analysis was used to analyse whether studies found a positive relationship between antibiotic consumption and resistance. A subsequent meta-analysis and meta-regression was conducted for studies for which a common effect size measure (odds ratio) could be calculated. Results Electronic searches identified 974 studies but only 243 studies were considered eligible for inclusion by the two independent reviewers who extracted the data. A binomial test revealed a positive relationship between antibiotic consumption and resistance (p resistance than other regions. Conclusions Using a large set of studies we found that antibiotic consumption is associated with the development of antibiotic resistance. A subsequent meta-analysis, with a subsample of the studies, generated several significant predictors. Countries in southern Europe produced a stronger link between consumption and resistance than other regions so efforts at reducing antibiotic consumption may need to be strengthened in this area. Increased consumption of antibiotics may not only produce greater resistance at the individual patient level but may also produce greater resistance at the community, country, and regional levels, which can harm individual patients. PMID:24405683
Hiltunen, Teppo; Virta, Marko; Laine, Anna-Liisa
The legacy of the use and misuse of antibiotics in recent decades has left us with a global public health crisis: antibiotic-resistant bacteria are on the rise, making it harder to treat infections. At the same time, evolution of antibiotic resistance is probably the best-documented case of contemporary evolution. To date, research on antibiotic resistance has largely ignored the complexity of interactions that bacteria engage in. However, in natural populations, bacteria interact with other species; for example, competition and grazing are import interactions influencing bacterial population dynamics. Furthermore, antibiotic leakage to natural environments can radically alter bacterial communities. Overall, we argue that eco-evolutionary feedback loops in microbial communities can be modified by residual antibiotics and evolution of antibiotic resistance. The aim of this review is to connect some of the well-established key concepts in evolutionary biology and recent advances in the study of eco-evolutionary dynamics to research on antibiotic resistance. We also identify some key knowledge gaps related to eco-evolutionary dynamics of antibiotic resistance, and review some of the recent technical advantages in molecular microbiology that offer new opportunities for tackling these questions. Finally, we argue that using the full potential of evolutionary theory and active communication across the different fields is needed for solving this global crisis more efficiently.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'. © 2016 The Authors.
The legacy of the use and misuse of antibiotics in recent decades has left us with a global public health crisis: antibiotic-resistant bacteria are on the rise, making it harder to treat infections. At the same time, evolution of antibiotic resistance is probably the best-documented case of contemporary evolution. To date, research on antibiotic resistance has largely ignored the complexity of interactions that bacteria engage in. However, in natural populations, bacteria interact with other species; for example, competition and grazing are import interactions influencing bacterial population dynamics. Furthermore, antibiotic leakage to natural environments can radically alter bacterial communities. Overall, we argue that eco-evolutionary feedback loops in microbial communities can be modified by residual antibiotics and evolution of antibiotic resistance. The aim of this review is to connect some of the well-established key concepts in evolutionary biology and recent advances in the study of eco-evolutionary dynamics to research on antibiotic resistance. We also identify some key knowledge gaps related to eco-evolutionary dynamics of antibiotic resistance, and review some of the recent technical advantages in molecular microbiology that offer new opportunities for tackling these questions. Finally, we argue that using the full potential of evolutionary theory and active communication across the different fields is needed for solving this global crisis more efficiently. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences'. PMID:27920384
Berg, J.; Tom-Petersen, A.; Nybroe, O.
Aims: The objective of this study was to determine whether Cu-amendment of field plots affects the frequency of Cu resistance, and antibiotic resistance patterns in indigenous soil bacteria. Methods and Results: Soil bacteria were isolated from untreated and Cu-amended field plots. Cu...... to chloramphenicol and multiple (greater than or equal to2) antibiotics than corresponding isolates from control plots. Significance and Impact of the Study: The results of this field experiment show that introduction of Cu to agricultural soil selects for Cu resistance, but also indirectly selects for antibiotic...... resistance in the Cu-resistant bacteria. Hence, the widespread accumulation of Cu in agricultural soils worldwide could have a significant effect on the environmental selection of antibiotic resistance....
Band, Victor I; Crispell, Emily K; Napier, Brooke A; Herrera, Carmen M; Tharp, Greg K; Vavikolanu, Kranthi; Pohl, Jan; Read, Timothy D; Bosinger, Steven E; Trent, M Stephen; Burd, Eileen M; Weiss, David S
Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infection, but in the absence of colistin, innate immune defences led to an increased frequency of the resistant subpopulation, leading to inefficacy of subsequent colistin therapy. An isolate with a lower-frequency colistin-resistant subpopulation similarly caused treatment failure but was misclassified as susceptible by current diagnostics once cultured outside the host. These data demonstrate the ability of low-frequency bacterial subpopulations to contribute to clinically relevant antibiotic resistance, elucidating an enigmatic cause of antibiotic treatment failure and highlighting the critical need for more sensitive diagnostics.
Band, Victor I.; Crispell, Emily K.; Napier, Brooke A.; Herrera, Carmen M.; Tharp, Greg K.; Vavikolanu, Kranthi; Pohl, Jan; Read, Timothy D.; Bosinger, Steven E.; Trent, M. Stephen; Burd, Eileen M.; Weiss, David S.
Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infection, but in the absence of colistin, innate immune defences led to an increased frequency of the resistant subpopulation, leading to inefficacy of subsequent colistin therapy. An isolate with a lower-frequency colistin-resistant subpopulation similarly caused treatment failure but was misclassified as susceptible by current diagnostics once cultured outside the host. These data demonstrate the ability of low-frequency bacterial subpopulations to contribute to clinically relevant antibiotic resistance, elucidating an enigmatic cause of antibiotic treatment failure and highlighting the critical need for more sensitive diagnostics. PMID:27572838
Velez, Roseann; Sloand, Elizabeth
To emphasise the impact of antibiotic resistance as a persistent, global health threat and highlight efforts to improve this complex problem. Political agendas, legislation, development of therapies and educational initiatives are essential to mitigate the increasing rate of antibiotic resistance. Original manuscript. Prescribers, policymakers and researchers are charged with the complex task of mitigating antibiotic resistance in an era when new treatments for bacterial infections are limited. Monitoring, surveillance and incentivising of practice, policy and new treatments provide solutions to antibiotic resistance in both the human and agricultural sectors. This article emphasises the complexity of antibiotic resistance and highlights the need for a multifaceted approach to improve health care outcomes. © 2016 John Wiley & Sons Ltd.
The global impact of antibiotic resistance is potentially devastating, threatening to set back progress against certain infectious diseases to the pre-antibiotic era. Although most antibiotic-resistant bacteria originally emerged in hospitals, drug-resistant strains are becoming more common in the community. Factors that facilitate the development of resistance within the community can be categorized as behavioral or environmental/policy. Behavioral factors include inappropriate use of antibiotics and ineffective infection control and hygiene practices. Environmental/policy factors include the continued use of antibiotics in agriculture and the lack of new drug development. A multifaceted approach that includes behavioral strategies in the community and the political will to make difficult regulatory decisions will help to minimize the problem of antimicrobial resistance globally.
Ignasiak, Katarzyna; Maxwell, Anthony
Although plants produce many secondary metabolites, currently none of these are commercial antibiotics. Insects feeding on specific plants can harbour bacterial strains resistant to known antibiotics suggesting that compounds in the plant have stimulated resistance development. We sought to determine whether the occurrence of antibiotic-resistant bacteria in insect guts was a widespread phenomenon, and whether this could be used as a part of a strategy to identify antibacterial compounds from plants. Six insect/plant pairs were selected and the insect gut bacteria were identified and assessed for antibiotic susceptibilities compared with type strains from culture collections. We found that the gut strains could be more or less susceptible to antibiotics than the type strains, or show no differences. Evidence of antibacterial activity was found in the plant extracts from five of the six plants, and, in one case Catharanthus roseus (Madagascar Periwinkle), compounds with antibacterial activity were identified. Bacterial strains isolated from insect guts show a range of susceptibilities to antibiotics suggesting a complex interplay between species in the insect gut microbiome. Extracts from selected plants can show antibacterial activity but it is not easy to isolate and identify the active components. We found that vindoline, present in Madagascar Periwinkle extracts, possessed moderate antibacterial activity. We suggest that plant-derived antibiotics are a realistic possibility given the advances in genomic and metabolomic methodologies.
Jang, Hyun Min; Lee, Jangwoo; Kim, Young Beom; Jeon, Jong Hun; Shin, Jingyeong; Park, Mee-Rye; Kim, Young Mo
This study examines the fate of twenty-three representative antibiotic resistance genes (ARGs) encoding tetracyclines, sulfonamides, quinolones, β-lactam antibiotics, macrolides, florfenicol and multidrug resistance during thermophilic aerobic digestion (TAD) of sewage sludge. The bacterial community, class 1 integrons (intI1) and four metal resistance genes (MRGs) were also quantified to determine the key drivers of changes in ARGs during TAD. At the end of digestion, significant decreases in the quantities of ARGs, MRGs and intI1 as well as 16S rRNA genes were observed. Partial redundancy analysis (RDA) showed that shifts in temperature were the key factors affecting a decrease in ARGs. Shifts in temperature led to decreased amounts of ARGs by reducing resistome and bacterial diversity, rather than by lowering horizontal transfer potential via intI1 or co-resistance via MRGs. Copyright © 2017 Elsevier Ltd. All rights reserved.
Kubicek-Sutherland, Jessica Z; Heithoff, Douglas M; Ersoy, Selvi C; Shimp, William R; House, John K; Marth, Jamey D; Smith, Jeffrey W; Mahan, Michael J
Current antibiotic testing does not include the potential influence of host cell environment on microbial susceptibility and antibiotic resistance, hindering appropriate therapeutic intervention. We devised a strategy to identify the presence of host-pathogen interactions that alter antibiotic efficacy in vivo. Our findings revealed a bacterial mechanism that promotes antibiotic resistance in vivo at concentrations of drug that far exceed dosages determined by standardized antimicrobial testing. This mechanism has escaped prior detection because it is reversible and operates within a subset of host tissues and cells. Bacterial pathogens are thereby protected while their survival promotes the emergence of permanent drug resistance. This host-dependent mechanism of transient antibiotic resistance is applicable to multiple pathogens and has implications for the development of more effective antimicrobial therapies.
Jessica Z. Kubicek-Sutherland
Full Text Available Current antibiotic testing does not include the potential influence of host cell environment on microbial susceptibility and antibiotic resistance, hindering appropriate therapeutic intervention. We devised a strategy to identify the presence of host–pathogen interactions that alter antibiotic efficacy in vivo. Our findings revealed a bacterial mechanism that promotes antibiotic resistance in vivo at concentrations of drug that far exceed dosages determined by standardized antimicrobial testing. This mechanism has escaped prior detection because it is reversible and operates within a subset of host tissues and cells. Bacterial pathogens are thereby protected while their survival promotes the emergence of permanent drug resistance. This host-dependent mechanism of transient antibiotic resistance is applicable to multiple pathogens and has implications for the development of more effective antimicrobial therapies.
Nova Nayarit-Ballesteros; María Salud Rubio-Lozano; Enrique Delgado-Suárez; Danilo Méndez-Medina; Diego Braña-Varela; Oscar Rodas-Suárez
Objective. To determine the serotype and antibiotic resistance profile of Salmonella spp. isolated from retail ground beef in Mexico City. Materials and methods. A total of 100 samples of ground beef were analyzed. The pathogen was isolated by conventional methods and confirmed by PCR (invA gene, 284 bp). The antibiotic resistance profile was determined by the Kirby-Bauer method while serotyping was performed according to the Kauffman-White scheme. Results. We isolated a total of 19 strains o...
Huang, Tianxun; Zheng, Yan; Yan, Ya; Yang, Lingling; Yao, Yihui; Zheng, Jiaxin; Wu, Lina; Wang, Xu; Chen, Yuqing; Xing, Jinchun; Yan, Xiaomei
The evolution and spread of antibiotic-resistant pathogens has become a major threat to public health. Advanced tools are urgently needed to quickly diagnose antibiotic-resistant infections to initiate appropriate treatment. Here we report the development of a highly sensitive flow cytometric method to probe minority population of antibiotic-resistant bacteria via single cell detection. Monoclonal antibody against TEM-1 β-lactamase and Alexa Fluor 488-conjugated secondary antibody were used to selectively label resistant bacteria green, and nucleic acid dye SYTO 62 was used to stain all the bacteria red. A laboratory-built high sensitivity flow cytometer (HSFCM) was applied to simultaneously detect the side scatter and dual-color fluorescence signals of single bacteria. By using E. coli JM109/pUC19 and E. coli JM109 as the model systems for antibiotic-resistant and antibiotic-susceptible bacteria, respectively, as low as 0.1% of antibiotic-resistant bacteria were accurately quantified. By monitoring the dynamic population change of a bacterial culture with the administration of antibiotics, we confirmed that under the antimicrobial pressure, the original low population of antibiotic-resistant bacteria outcompeted susceptible strains and became the dominant population after 5hours of growth. Detection of antibiotic-resistant infection in clinical urine samples was achieved without cultivation, and the bacterial load of susceptible and resistant strains can be faithfully quantified. Overall, the HSFCM-based quantitative method provides a powerful tool for the fundamental studies of antibiotic resistance and holds the potential to provide rapid and precise guidance in clinical therapies. Copyright © 2016 Elsevier B.V. All rights reserved.
Bottery, Michael; Wood, A. Jamie; Brockhurst, Michael
Multidrug resistance (MDR) plasmids frequently carry antibiotic resistance genes conferring qualitatively different mechanisms of resistance. We show here that the antibiotic concentrations selecting for the RK2 plasmid in Escherichia coli depend upon the sociality of the drug resistance: the selection for selfish drug resistance (efflux pump) occurred at very low drug concentrations, just 1.3% of the MIC of the plasmid-free antibiotic-sensitive strain, whereas selection for cooperative drug ...
Wong, Aloysius Tze
Abstract Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.
Full Text Available Abstract Background Studies indicate that antibiotics are sold against regulation and without prescription in private drugstores in rural Tanzania. The objective of the study was to explore and describe antibiotics sale and dispensing practices and link it to drugseller knowledge and perceptions of antibiotics and antibiotic resistance. Methods Exit customers of private drugstores in eight districts were interviewed about the drugstore encounter and drugs bought. Drugsellers filled in a questionnaire with closed- and open-ended questions about antibiotics and resistance. Data were analyzed using mixed quantitative and qualitative methods. Results Of 350 interviewed exit customers, 24% had bought antibiotics. Thirty percent had seen a health worker before coming and almost all of these had a prescription. Antibiotics were dispensed mainly for cough, stomachache, genital complaints and diarrhea but not for malaria or headache. Dispensed drugs were assessed as relevant for the symptoms or disease presented in 83% of all cases and 51% for antibiotics specifically. Non-prescribed drugs were assessed as more relevant than the prescribed. The knowledge level of the drugseller was ranked as high or very high by 75% of the respondents. Seventy-five drugsellers from three districts participated. Seventy-nine percent stated that diseases caused by bacteria can be treated with antibiotics but 24% of these also said that antibiotics can be used for treating viral disease. Most (85% said that STI can be treated with antibiotics while 1% said the same about headache, 4% general weakness and 3% 'all diseases'. Seventy-two percent had heard of antibiotic resistance. When describing what an antibiotic is, the respondents used six different kinds of keywords. Descriptions of what antibiotic resistance is and how it occurs were quite rational from a biomedical point of view with some exceptions. They gave rise to five categories and one theme: Perceiving antibiotic
Full Text Available Abstract Background Concerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies on antibiotic prescription quantity in a hospital and antibiotic residue levels and resistant bacteria in the effluent of the same hospital are few. Therefore, we quantified antibiotic residues in waters associated with a hospital in India and assessed their association, if any, with quantities of antibiotic prescribed in the hospital and the susceptibility of Escherichia coli found in the hospital effluent. Methods This cross-sectional study was conducted in a teaching hospital outside the city of Ujjain in India. Seven antibiotics - amoxicillin, ceftriaxone, amikacin, ofloxacin, ciprofloxacin, norfloxacin and levofloxacin - were selected. Prescribed quantities were obtained from hospital records. The samples of the hospital associated water were analysed for the above mentioned antibiotics using well developed and validated liquid chromatography/tandem mass spectrometry technique after selectively isolating the analytes from the matrix using solid phase extraction. Escherichia coli isolates from these waters were tested for antibiotic susceptibility, by standard Kirby Bauer disc diffusion method using Clinical and Laboratory Standard Institute breakpoints. Results Ciprofloxacin was the highest prescribed antibiotic in the hospital and its residue levels in the hospital wastewater were also the highest. In samples of the municipal water supply and the groundwater, no antibiotics were detected. There was a positive correlation between the quantity of antibiotics prescribed in the hospital and antibiotic residue levels in
Saramago, Margarida; Domingues, Susana; Viegas, Sandra Cristina; Arraiano, Cecília Maria
Biofilm formation and antibiotic resistance are important determinants for bacterial pathogenicity. Ribonucleases control RNA degradation and there is increasing evidence that they have an important role in virulence mechanisms. In this report, we show that ribonucleases affect susceptibility against ribosome-targeting antibiotics and biofilm formation in Salmonella.
Alam, Md Kausar; Alhhazmi, Areej; DeCoteau, John F; Luo, Yu; Geyer, C Ronald
Antibiotic resistance arises from the maintenance of resistance mutations or genes acquired from the acquisition of adaptive de novo mutations or the transfer of resistance genes. Antibiotic resistance is acquired in response to antibiotic therapy by activating SOS-mediated DNA repair and mutagenesis and horizontal gene transfer pathways. Initiation of the SOS pathway promotes activation of RecA, inactivation of LexA repressor, and induction of SOS genes. Here, we have identified and characterized phthalocyanine tetrasulfonic acid RecA inhibitors that block antibiotic-induced activation of the SOS response. These inhibitors potentiate the activity of bactericidal antibiotics, including members of the quinolone, β-lactam, and aminoglycoside families in both Gram-negative and Gram-positive bacteria. They reduce the ability of bacteria to acquire antibiotic resistance mutations and to transfer mobile genetic elements conferring resistance. This study highlights the advantage of including RecA inhibitors in bactericidal antibiotic therapies and provides a new strategy for prolonging antibiotic shelf life. Copyright © 2016 Elsevier Ltd. All rights reserved.
Makoka Mwai H
Full Text Available Abstract Background Life-threatening infections present major challenges for health systems in Malawi and the developing world because routine microbiologic culture and sensitivity testing are not performed due to lack of capacity. Use of empirical antimicrobial therapy without regular microbiologic surveillance is unable to provide adequate treatment in the face of emerging antimicrobial resistance. This study was conducted to determine antimicrobial susceptibility patterns in order to inform treatment choices and generate hospital-wide baseline data. Methods Culture and susceptibility testing was performed on various specimens from patients presenting with possible infectious diseases at Kamuzu Central Hospital, Lilongwe, Malawi. Results Between July 2006 and December 2007 3104 specimens from 2458 patients were evaluated, with 60.1% from the adult medical service. Common presentations were sepsis, meningitis, pneumonia and abscess. An etiologic agent was detected in 13% of patients. The most common organisms detected from blood cultures were Staphylococcus aureus, Escherichia coli, Salmonella species and Streptococcus pneumoniae, whereas Streptococcus pneumoniae and Cryptococcus neoformans were most frequently detected from cerebrospinal fluid. Haemophilus influenzae was rarely isolated. Resistance to commonly used antibiotics was observed in up to 80% of the isolates while antibiotics that were not commonly in use maintained susceptibility. Conclusions There is widespread resistance to almost all of the antibiotics that are empirically used in Malawi. Antibiotics that have not been widely introduced in Malawi show better laboratory performance. Choices for empirical therapy in Malawi should be revised accordingly. A microbiologic surveillance system should be established and prudent use of antimicrobials promoted to improve patient care.
Capita, Rosa; Alonso-Calleja, Carlos
Antibiotic-resistant bacteria were first described in the 1940s, but whereas new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. At present, the paucity of new antimicrobials coming into the market has led to the problem of antibiotic resistance fast escalating into a global health crisis. Although the selective pressure exerted by the use of antibiotics (particularly overuse or misuse) has been deemed the major factor in the emergence of bacterial resistance to these antimicrobials, concerns about the role of the food industry have been growing in recent years and have been raised at both national and international levels. The selective pressure exerted by the use of antibiotics (primary production) and biocides (e.g., disinfectants, food and feed preservatives, or decontaminants) is the main driving force behind the selection and spread of antimicrobial resistance throughout the food chain. Genetically modified (GM) crops with antibiotic resistance marker genes, microorganisms added intentionally to the food chain (probiotic or technological) with potentially transferable antimicrobial resistance genes, and food processing technologies used at sub-lethal doses (e.g., alternative non-thermal treatments) are also issues for concern. This paper presents the main trends in antibiotic resistance and antibiotic development in recent decades, as well as their economic and health consequences, current knowledge concerning the generation, dissemination, and mechanisms of antibacterial resistance, progress to date on the possible routes for emergence of resistance throughout the food chain and the role of foods as a vehicle for antibiotic-resistant bacteria. The main approaches to prevention and control of the development, selection, and spread of antibacterial resistance in the food industry are also addressed.
Schmidt, Gunilla Veslemøy; Mellerup, Anders; Christiansen, Lasse Engbo; Ståhl, Marie; Olsen, John Elmerdahl; Angen, Øystein
The aim of this article was to define the sampling level and method combination that captures antibiotic resistance at pig herd level utilizing qPCR antibiotic resistance gene quantification and culture-based quantification of antibiotic resistant coliform indicator bacteria. Fourteen qPCR assays for commonly detected antibiotic resistance genes were developed, and used to quantify antibiotic resistance genes in total DNA from swine fecal samples that were obtained using different sampling and pooling methods. In parallel, the number of antibiotic resistant coliform indicator bacteria was determined in the same swine fecal samples. The results showed that the qPCR assays were capable of detecting differences in antibiotic resistance levels in individual animals that the coliform bacteria colony forming units (CFU) could not. Also, the qPCR assays more accurately quantified antibiotic resistance genes when comparing individual sampling and pooling methods. qPCR on pooled samples was found to be a good representative for the general resistance level in a pig herd compared to the coliform CFU counts. It had significantly reduced relative standard deviations compared to coliform CFU counts in the same samples, and therefore differences in antibiotic resistance levels between samples were more readily detected. To our knowledge, this is the first study to describe sampling and pooling methods for qPCR quantification of antibiotic resistance genes in total DNA extracted from swine feces.
Malo, Sara; Rabanaque, María José; Feja, Christina
As mentioned, antibiotic consumption in heavy users, especially in children, is really striking. Certainly, our results revealed an antibiotic use in this age group higher than published in previous studies, and in line with different reports repeatedly presenting the high antibiotic consumption...... of antibiotics, as observed in heavy users, could also be due to factors related to the GP, patient and parents' expectations or the influence exerted by the pharmaceutical industry (2). This article is protected by copyright. All rights reserved....
Daeseleire, Els; De Graef, Evelyne; Rasschaert, Geertrui; De Mulder, Thijs; Van den Meersche, Tina; Van Coillie, Els; Dewulf, Jeroen; Heyndrickx, Marc
The widespread use of antibiotics in animals is causing concerns about the growing risk for development and the spread of antibiotic-resistant bacteria. Antibiotic consumption is higher in animals than in humans as reported in a joint publication of EFSA (European Food Safety Agency), ECDC (European Centre for Disease Prevention and Control), and EMA (European Medicines Agency) using data from 2011 and 2012. Both in humans and animals, positive associations between the consumption of antibiotics and resistant bacteria are observed. Responsible use of antibiotics in humans and animals should therefore be promoted. In this paper some general aspects of antibiotic resistance such as microbiological versus clinical resistance, intrinsic versus acquired resistance, resistance mechanisms, and transfer of resistance are briefly introduced. In 2012, the Belgian Center of Expertise on Antimicrobial Consumption and Resistance in Animals (AMCRA) was founded. Its mission is to collect and analyze all data related to antibiotic use and resistance in animals in Belgium and to communicate these findings in a neutral and objective manner. One of AMCRA's 10 objectives is a 50% reduction in antibiotic consumption in veterinary medicine in Belgium by 2020. The aim of this paper is to report on the achievements of this national project. The Institute for Agricultural and Fisheries Research (ILVO, Merelbeke-Melle), in collaboration with Ghent University, is currently working on three nationally funded projects on antibiotic resistance in animal husbandry. In the first project, an in vitro model is used to study the influence of low antibiotic concentrations due to carry-over after production and usage of medicated feed on the development of resistance in the pig gut. Part of that project is to develop a quantitative risk assessment model. A second project focuses on tracking excreted antibiotics used in pig rearing and their influence on the development of antibiotic resistance in pig
Pamer, Eric G
The intestinal microbiota, which is composed of diverse populations of commensal bacterial species, provides resistance against colonization and invasion by pathogens. Antibiotic treatment can damage the intestinal microbiota and, paradoxically, increase susceptibility to infections. Reestablishing microbiota-mediated colonization resistance after antibiotic treatment could markedly reduce infections, particularly those caused by antibiotic-resistant bacteria. Ongoing studies are identifying commensal bacterial species that can be developed into next-generation probiotics to reestablish or enhance colonization resistance. These live medicines are at various stages of discovery, testing, and production and are being subjected to existing regulatory gauntlets for eventual introduction into clinical practice. The development of next-generation probiotics to reestablish colonization resistance and eliminate potential pathogens from the gut is warranted and will reduce health care-associated infections caused by highly antibiotic-resistant bacteria. Copyright © 2016, American Association for the Advancement of Science.
Pradipta, Ivan Surya; Sodik, Dian Chairunnisa; Lestari, Keri; Parwati, Ida; Halimah, Eli; Diantini, Ajeng; Abdulah, Rizky
Background: The appropriate selection of empirical antibiotics based on the pattern of local antibiotic resistance can reduce the mortality rate and increase the rational use of antibiotics. Aims: We analyze the pattern of antibiotic use and the sensitivity patterns of antibiotics to support the rational use of antibiotics in patients with sepsis. Materials and Methods: A retrospective observational study was conducted in adult sepsis patient at one of Indonesian hospital during January-December 2011. Data were collected from the hospital medical record department. Descriptive analysis was used in the processing and interpretation of data. Results: A total of 76 patients were included as research subjects. Lung infection was the highest source of infection. In the 66.3% of clinical specimens that were culture positive for microbes, Klebsiella pneumoniae, Escherichia coli, Staphylococcus hominis were detected with the highest frequency. The six most frequently used antibiotics, levofloxacin, ceftazidime, ciprofloxacin, cefotaxime, ceftriaxone, and erythromycin, showed an average resistance above 50%. Conclusions: The high use of antibiotic with a high level resistance requires a policy to support its rational use. Local microbial pattern based on site infection and pattern of antibiotics sensitivity test can be used as supporting data to optimize appropriateness of empirical antibiotics therapy in sepsis patients. PMID:23923107
Lehtinen, Sonja; Blanquart, François; Croucher, Nicholas J; Turner, Paul; Lipsitch, Marc; Fraser, Christophe
Understanding how changes in antibiotic consumption affect the prevalence of antibiotic resistance in bacterial pathogens is important for public health. In a number of bacterial species, including Streptococcus pneumoniae, the prevalence of resistance has remained relatively stable despite prolonged selection pressure from antibiotics. The evolutionary processes allowing the robust coexistence of antibiotic sensitive and resistant strains are not fully understood. While allelic diversity can be maintained at a locus by direct balancing selection, there is no evidence for such selection acting in the case of resistance. In this work, we propose a mechanism for maintaining coexistence at the resistance locus: linkage to a second locus that is under balancing selection and that modulates the fitness effect of resistance. We show that duration of carriage plays such a role, with long duration of carriage increasing the fitness advantage gained from resistance. We therefore predict that resistance will be more common in strains with a long duration of carriage and that mechanisms maintaining diversity in duration of carriage will also maintain diversity in antibiotic resistance. We test these predictions in S. pneumoniae and find that the duration of carriage of a serotype is indeed positively correlated with the prevalence of resistance in that serotype. These findings suggest heterogeneity in duration of carriage is a partial explanation for the coexistence of sensitive and resistant strains and that factors determining bacterial duration of carriage will also affect the prevalence of resistance.
Full Text Available Antibiotic resistance in Helicobacter pylori (H. pylori is the main factor affecting the efficacy of current treatment methods against infection caused by this organism. The traditional culture methods for testing bacterial susceptibility to antibiotics are expensive and require 10 to 14 days. Since resistance to clarithromycin, fluoroquinolone, and tetracycline seems to be exclusively caused by specific mutations in a small region of the responsible gene, molecular methods offer an attractive alternative to the above-mentioned techniques. The technique of polymerase chain reaction (PCR is an accurate and rapid method for the detection of mutations that confer antibiotic resistance. This review highlights the mechanisms of antibiotic resistance in H. pylori and the molecular methods for antibiotic susceptibility testing.
Full Text Available On 27 Feb., 2017, the World Health Organization (WHO announced the first list of important antibiotic-resistant bacteria (http://www.who.int/mediacentre/news/releases/2017/bacteria-antibiotics-needed/en/, which tremendously threat human-being’s health. This list included 12 kinds of bacteria that were categorized into three priority tiers: Critical, High and Medium. In the first tier, Critical, three Gram negative bacteria were included: Acinetobacter baumannii with carbapenem-resistant, Pseudomonas aeruginosa with carbapenem-resistant; and Enterobacteriaceae with carbapenem-resistant, the third generation cephalosporin-resistant. In the second tier, High, six bacteria were suggested: Enterococcus faecium with vancomycin-resistant, Staphylococcus aureus with methicillin-resistant, vancomycin intermediate and resistant, Helicobacter pylori with clarithromycin-resistant, Campylobacter with fluoroquinolone-resistant, Salmonella spp. with fluoroquinolone-resistant, Neisseria gonorrhoeae with the third generation cephalosporin-resistant, fluoroquinolone-resistant. In the third tier, Medium, three bacteria were listed: Streptococcus pneumonia with penicillin-non-susceptible, Haemophilus influenza with ampicillin-resistant, and Shigella spp. with fluoroquinolone-resistant. This list was proposed by an expert panel, chaired by Dr. E. Tacconelli from Infectious Diseases, DZIF Center, Tübingen University, Germany and Dr. N. Magrini from EMP Department of WHO. This proposal recommended some key steps to countermeasure the challenges posed by multi-drug- and extensively drug-resistant bacteria, including research and development of new classes of antibiotics for the paediatric population, for preventing cross- and co-resistance to existing classes of antibiotics, and for oral formulations for community-acquired diseases with a high morbidity burden. This list will guide our future research and development of new antibiotics in future.
Rezzonico, Fabio; Stockwell, Virginia O.; Duffy, Brion
Streptomycin is used in plant agriculture for bacterial disease control, particularly against fire blight in pome fruit orchards. Concerns that this may increase environmental antibiotic resistance have led to bans or restrictions on use. Experience with antibiotic use in animal feeds raises the possible influence of formulation-delivered resistance genes. We demonstrate that agricultural streptomycin formulations do not carry producer organism resistance genes. By using an optimized extracti...
Thaller, Maria Cristina; Migliore, Luciana; Marquez, Cruz; Tapia, Washington; Cedeño, Virna; Rossolini, Gian Maria; Gentile, Gabriele
Antibiotic resistance, evolving and spreading among bacterial pathogens, poses a serious threat to human health. Antibiotic use for clinical, veterinary and agricultural practices provides the major selective pressure for emergence and persistence of acquired resistance determinants. However, resistance has also been found in the absence of antibiotic exposure, such as in bacteria from wildlife, raising a question about the mechanisms of emergence and persistence of resistant strains under similar conditions, and the implications for resistance control strategies. Since previous studies yielded some contrasting results, possibly due to differences in the ecological landscapes of the studied wildlife, we further investigated this issue in wildlife from a remote setting of the Galapagos archipelago. Screening for acquired antibiotic resistance was carried out in commensal enterobacteria from Conolophus pallidus, the terrestrial iguana of Isla Santa Fe, where: i) the abiotic conditions ensure to microbes good survival possibilities in the environment; ii) the animal density and their habits favour microbial circulation between individuals; and iii) there is no history of antibiotic exposure and the impact of humans and introduced animal species is minimal except for restricted areas. Results revealed that acquired antibiotic resistance traits were exceedingly rare among bacteria, occurring only as non-dominant strains from an area of minor human impact. Where both the exposure to antibiotics and the anthropic pressure are minimal, acquired antibiotic resistance traits are not normally found in bacteria from wildlife, even if the ecological landscape is highly favourable to bacterial circulation among animals. Monitoring antibiotic resistance in wildlife from remote areas could also be a useful tool to evaluate the impact of anthropic pressure.
Maria Cristina Thaller
Full Text Available BACKGROUND: Antibiotic resistance, evolving and spreading among bacterial pathogens, poses a serious threat to human health. Antibiotic use for clinical, veterinary and agricultural practices provides the major selective pressure for emergence and persistence of acquired resistance determinants. However, resistance has also been found in the absence of antibiotic exposure, such as in bacteria from wildlife, raising a question about the mechanisms of emergence and persistence of resistant strains under similar conditions, and the implications for resistance control strategies. Since previous studies yielded some contrasting results, possibly due to differences in the ecological landscapes of the studied wildlife, we further investigated this issue in wildlife from a remote setting of the Galapagos archipelago. METHODOLOGY/PRINCIPAL FINDINGS: Screening for acquired antibiotic resistance was carried out in commensal enterobacteria from Conolophus pallidus, the terrestrial iguana of Isla Santa Fe, where: i the abiotic conditions ensure to microbes good survival possibilities in the environment; ii the animal density and their habits favour microbial circulation between individuals; and iii there is no history of antibiotic exposure and the impact of humans and introduced animal species is minimal except for restricted areas. Results revealed that acquired antibiotic resistance traits were exceedingly rare among bacteria, occurring only as non-dominant strains from an area of minor human impact. CONCLUSIONS/SIGNIFICANCE: Where both the exposure to antibiotics and the anthropic pressure are minimal, acquired antibiotic resistance traits are not normally found in bacteria from wildlife, even if the ecological landscape is highly favourable to bacterial circulation among animals. Monitoring antibiotic resistance in wildlife from remote areas could also be a useful tool to evaluate the impact of anthropic pressure.
Sharma, Virender K; Johnson, Natalie; Cizmas, Leslie; McDonald, Thomas J; Kim, Hyunook
Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARG) in the aquatic environment have become an emerging contaminant issue, which has implications for human and ecological health. This review begins with an introduction to the occurrence of ARB and ARG in different environmental systems such as natural environments and drinking water resources. For example, ARG or ARB with resistance to ciprofloxacin, sulfamethoxazole, trimethoprim, quinolone, vancomycin, or tetracycline (e.g., tet(A), tet(B), tet(C), tet(G), tet(O), tet(M), tet(W), sul I, and sul II) have been detected in the environment. The development of resistance may be intrinsic, may be acquired through spontaneous mutations (de novo), or may occur due to horizontal gene transfer from donor bacteria, phages, or free DNA to recipient bacteria. An overview is also provided of the current knowledge regarding inactivation of ARB and ARG, and the mechanism of the effects of different disinfection processes in water and wastewater (chlorination, UV irradiation, Fenton reaction, ozonation, and photocatalytic oxidation). The effects of constructed wetlands and nanotechnology on ARB and ARG are also summarized. Copyright © 2015 Elsevier Ltd. All rights reserved.
Perfetto, Eleanor M; Gondek, Kathleen
Escherichia coli is typically the causative organism in uncomplicated urinary tract infection (UTI). Resistance rates of E. coli to trimethoprim/sulfamethoxazole (TMP/SMX) are increasing, exceeding 10% in many communities. Guidelines recommend using alternative treatments in these areas. Providers must reevaluate policies to include considerations for E. coli resistance. A model was developed, with cases for illustration, to help organizations determine the resistance rate threshold, where TMP/SMX is no longer first-line therapy. Using published data, a 19% to 21% threshold was derived, supporting a previous report of 22%. The model can aid decision makers updating internal policies to conform with guidelines for the treatment of uncomplicated UTI and to improve care.
Full Text Available High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio spp; however, tox-R assay showed that only 44.4% (200/450 of these were Vibrio parahaemolyticus. Out of these 200 samples, 6.5% (13/200 were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all Vibrio parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin ,70.5% to kanamycin, 73% to cefotaxime and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to 5 antibiotics. Among the 13 trh-positive strains, almost 70% (9/13 demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all Vibrio parahaemolyticus isolates revealed that 86.5% (173/200 contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2kb to greater than 10kb. 6/13 of the pathogenic V. pathogenic strains contained
Letchumanan, Vengadesh; Pusparajah, Priyia; Tan, Loh Teng-Hern; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan
High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid
Espigares, E; Moreno Roldan, E; Espigares, M; Abreu, R; Castro, B; Dib, A L; Arias, Á
The aim of this research was to study the phenotypic resistances to disinfectants and antibiotics in strains of methicillin-resistant Staphylococcus aureus (MRSA) obtained from Canary black pigs. Analyses were performed on 54 strains of MRSA, isolated in Canary black pigs from the province of Tenerife (Spain); all of them carried the mecA gene. The strains were isolated by means of nasal swab samples of healthy pigs, collected under veterinarian supervision. Bactericidal activity of antiseptics and disinfectants was tested by means of the dilution-neutralization method. Susceptibility to the disinfectants glutaraldehyde, peracetic acid and silver nitrate was assessed, as well as to the antiseptics chlorhexidine, benzalkonium chloride and povidone iodine. Susceptibility to a wide array of antibiotics representing the main groups was determined by means of the disc diffusion method. All the strains demonstrated susceptibility to the disinfectants tested at the recommended concentration, and even to dilutions equal to or lesser than 1/16. The most effective antiseptic and disinfectant were, respectively, chlorhexidine and silver nitrate. With regard to the antibiotics, the strains proved to be multiresistant. All presented phenotypic resistance to the β-lactam antibiotics ampicillin, penicillin and cefoxitin, as well as to numerous aminoglycosides, tetracycline and trimethoprim-sulfamethoxazole. It was also observed that 61.1% of the strains were carriers of plasmids. Our results underline that in the strains such as MRSA, which show multiple resistances to antibiotics, the antiseptics and disinfectants show great efficacy. Moreover, as other authors also suggest, for the treatment and prevention of infections caused by MRSA, the use of β-lactam and aminoglycoside antibiotics may be less effective. © 2016 Blackwell Verlag GmbH.
Wong, Carmen Ka Man; Kung, Kenny; Au-Doung, Philip Lung Wai; Ip, Margaret; Lee, Nelson; Fung, Alice; Wong, Samuel Yeung Shan
Uncomplicated urinary tract infections (UTI) are common in primary care. Whilst primary care physicians are called to be antimicrobial stewards, there is limited primary care antibiotic resistance surveillance and physician antibiotic prescription data available in southern Chinese primary care. The study aimed to investigate the antibiotic resistance rate and antibiotic prescription patterns in female patients with uncomplicated UTI. Factors associated with antibiotic resistance and prescrip...
O'Malley, S M; Emele, F E; Nwaokorie, F O; Idika, N; Umeizudike, A K; Emeka-Nwabunnia, I; Hanson, B M; Nair, R; Wardyn, S E; Smith, T C
Antibiotic-resistant Staphylococcus aureus including methicillin-resistant strains (MRSA) are a major concern in densely populated urban areas. Initial studies of S. aureus in Nigeria indicated existence of antibiotic-resistant S. aureus strains in clinical and community settings. 73 biological samples (40 throat, 23 nasal, 10 wound) were collected from patients and healthcare workers in three populations in Nigeria: Lagos University Teaching Hospital, Nigerian Institute of Medical Research, and Owerri General Hospital. S. aureus was isolated from 38 of 73 samples (52%). Of the 38 S. aureus samples, 9 (24%) carried the Panton-Valentine leukocidin gene (PVL) while 16 (42%) possessed methicillin resistance genes (mecA). Antibiotic susceptibility profiles indicated resistance to several broad-spectrum antibiotics. Antibiotic-resistant S. aureus isolates were recovered from clinical and community settings in Nigeria. Insight about S. aureus in Nigeria may be used to improve antibiotic prescription methods and minimize the spread of antibiotic-resistant organisms in highly populated urban communities similar to Lagos, Nigeria. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.
Full Text Available Abstract Background Staphylococcus aureus is an important pathogen causing a wide range of infections in the hospital and community setting. In order to have adequate information for treatment of S. aureus infections, it is crucial to understand the trends in the antibiotic-resistance patterns. In addition, the occurrence and changes in types of S. aureus, clonal identities, and their geographic spread is essential for the establishment of adequate infection control programmes. In this study, 68 S. aureus isolates obtained from clinical and non-clinical sources in Nigeria between January and April 2009 were characterized using phenotypic and molecular methods. Results All the S. aureus isolates were susceptible to teicoplanin, vancomycin, phosphomycin, fusidic acid, rifampicin, daptomycin, mupirocin, linezolid and tigecycline. Sixteen percent of the isolates were resistant to oxacillin, while 55% and 72% of isolates were resistant to tetracycline and trimethoprim/sulphamethoxazole (cotrimoxazole, respectively (Table 1. There was excellent correlation between the broth microdilution assay and detection of antibiotic resistance genes by the multiplex PCR, in the determination of S. aureus resistance to erythromycin, gentamicin, methicillin and tetracycline. A total of 28 spa types were identified in the study, and the predominant spa type among the methicillin-susceptible S. aureus (MSSA isolates was t084 (13 isolates. The t037-ST241-SCCmecIII type was the only clone identified in Maiduguri (North-East Nigeria while in South-West Nigeria, diversity among the MRSA isolates (t451-ST8-SCCmecV; t008-ST94-SCCmecIV; t002-ST5-SCCmecV; t064-ST8-SCCmecV was observed. The toxin genes seh and etd were detected in isolates affiliated with clonal complexes CC1, CC80 and sequence type ST25, respectively. The proportion of PVL-positive isolates among MSSA was high (40%. Most of the PVL-positive MSSA isolates were obtained from wound infections and associated
Isolation, identification and susceptibility pattern of the isolates was determined. The methicillin resistant strains were confirmed by the polymerase chain reaction (PCR) detection of the mecA gene. The entire tests were done according to standard protocols. Forty S. aureus strains were identified and were observed to be ...
Purpose: The antimicrobial susceptibility of 149 coagulase-negative staphylococci (CoNS) isolates from faecal samples of children in Ile-Ife, Nigeria, was evaluated in order to determine their contribution to antimicrobial resistance in the community. Methods: The isolates were identified to the species level by conventional ...
Singer, R.S.; Finch, R.; Wegener, Henrik Caspar
meant the problem of antibiotic resistance is fast escalating into a global health crisis. There is no doubt that misuse of these drugs in human beings has contributed to the increasing rates of resistance, but recently the use of antibiotics in food animals and its consequent effect on resistance...... levels in people has also come under scrutiny. Antimicrobials are used therapeutically and prophylactically in animals. More controversially, antimicrobials are also used as growth promoters to improve the ability of the animal to convert feed into body mass. Some argue that the impact of use...... of antibiotics in animals-whether therapeutic or as growth promoters-pales by comparison with human use, and that efforts should be concentrated on the misuse of antibiotics in people. Others warn of the dangers of unregulated and unnecessary use of antibiotics, especially growth promoters in animal husbandry...
Youenou, Benjamin; Favre-Bonté, Sabine; Bodilis, Josselin; Brothier, Elisabeth; Dubost, Audrey; Muller, Daniel; Nazaret, Sylvie
Stenotrophomonas maltophilia, a ubiquitous Gram-negative γ-proteobacterium, has emerged as an important opportunistic pathogen responsible for nosocomial infections. A major characteristic of clinical isolates is their high intrinsic or acquired antibiotic resistance level. The aim of this study was to decipher the genetic determinism of antibiotic resistance among strains from different origins (i.e., natural environment and clinical origin) showing various antibiotic resistance profiles. To this purpose, we selected three strains isolated from soil collected in France or Burkina Faso that showed contrasting antibiotic resistance profiles. After whole-genome sequencing, the phylogenetic relationships of these 3 strains and 11 strains with available genome sequences were determined. Results showed that a strain's phylogeny did not match their origin or antibiotic resistance profiles. Numerous antibiotic resistance coding genes and efflux pump operons were revealed by the genome analysis, with 57% of the identified genes not previously described. No major variation in the antibiotic resistance gene content was observed between strains irrespective of their origin and antibiotic resistance profiles. Although environmental strains generally carry as many multidrug resistant (MDR) efflux pumps as clinical strains, the absence of resistance-nodulation-division (RND) pumps (i.e., SmeABC) previously described to be specific to S. maltophilia was revealed in two environmental strains (BurA1 and PierC1). Furthermore the genome analysis of the environmental MDR strain BurA1 showed the absence of SmeABC but the presence of another putative MDR RND efflux pump, named EbyCAB on a genomic island probably acquired through horizontal gene transfer. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Full Text Available The spread of antibiotic-resistant bacteria is a growing problem and a public health issue. In recent decades, various genetic mechanisms involved in the spread of resistance genes among bacteria have been identified. Integrons -- genetic elements that acquire, exchange and express genes embedded within gene cassettes (GC -- are one of these mechanisms. Integrons are widely distributed, especially in Gram-negative bacteria; they are carried by mobile genetic elements, plasmids and transposons, which promote their spread within bacterial communities. Initially studied mainly in the clinical setting for their involvement in antibiotic resistance, their role in the environment is now an increasing focus of attention. The aim of this review is to provide an in-depth analysis of recent studies of antibiotic-resistance integrons in the environment, highlighting their potential involvement in antibiotic resistance outside the clinical context. We will focus particularly on the impact of human activities (agriculture, industries, wastewater treatment, etc..
Haag, Anthony M; Medina, Audrie M; Royall, Ariel E; Herzog, Norbert K; Niesel, David W
Antibiotic resistance is a growing problem worldwide. For this reason, clinical laboratories often determine the susceptibility of the bacterial isolate to a number of different antibiotics in order to establish the most effective antibiotic for treatment. Unfortunately, current susceptibility assays are time consuming. Antibiotic resistance often involves the chemical modification of an antibiotic to an inactive form by an enzyme expressed by the bacterium. Selected reaction monitoring (SRM) has the ability to quickly monitor and identify these chemical changes in an unprecedented time scale. In this work, we used SRM as a technique to determine the susceptibility of several different antibiotics to the chemically modifying enzymes β-lactamase and chloramphenicol acetyltransferase, enzymes used by bacteria to confer resistance to major classes of commonly used antibiotics. We also used this technique to directly monitor the effects of resistant bacteria grown in a broth containing a specific antibiotic. Because SRM is highly selective and can also identify chemical changes in a multitude of antibiotics in a single assay, SRM has the ability to detect organisms that are resistant to multiple antibiotics in a single assay. For these reasons, the use of SRM greatly reduces the time it takes to determine the susceptibility or resistance of an organism to a multitude of antibiotics by eliminating the time-consuming process found in other currently used methods. Copyright © 2013 John Wiley & Sons, Ltd.
I.C. Mgbemena; J.C. Nnokwe; L.A. Adjeroh; N.N. Onyemekara
This study is aimed at determining the resistance of bacteria to heavy metals and some antibiotics. The ability of aquatic bacteria isolates from Otamiri River at Ihiagwa in Owerri North, Imo State to tolerate or resist the presence of certain selected heavy metals: Pb+, Zn2+ and Fe2+ and some antibiotics was investigated. Identification tests for the bacteria isolates from Otamiri River revealed them to belong to the genera Pseudomonas, Aeromonas, Bacillus, Escherichia, Micrococcus and Prote...
Environmental influences on antibiotic activity and resistance can wreak havoc with in vivo antibiotic efficacy and, ultimately, antimicrobial chemotherapy. In nature, bacteria encounter a variety of metal ions, particularly copper (Cu) and zinc (Zn), as contaminants in soil and water, as feed additives in agriculture, as clinically-used antimicrobials, and as components of human antibacterial responses. Importantly, there is a growing body of evidence for Cu/Zn driving antibiotic resistance development in metal-exposed bacteria, owing to metal selection of genetic elements harbouring both metal and antibiotic resistance genes, and metal recruitment of antibiotic resistance mechanisms. Many classes of antibiotics also form complexes with metal cations, including Cu and Zn, and this can hinder (or enhance) antibiotic activity. This review highlights the ways in which Cu/Zn influence antibiotic resistance development and antibiotic activity, and in so doing impact in vivo antibiotic efficacy. Copyright © 2017 Elsevier Ltd. All rights reserved.
Coussens, Nathan P; Molinaro, Ashley L; Culbertson, Kayla J; Peryea, Tyler; Zahoránszky-Köhalmi, Gergely; Hall, Matthew D; Daines, Dayle A
The increasing emergence of multidrug-resistant bacteria is recognized as a major threat to human health worldwide. While the use of small molecule antibiotics has enabled many modern medical advances, it has also facilitated the development of resistant organisms. This minireview provides an overview of current small molecule drugs approved by the US Food and Drug Administration (FDA) for use in humans, the unintended consequences of antibiotic use, and the mechanisms that underlie the development of drug resistance. Promising new approaches and strategies to counter antibiotic-resistant bacteria with small molecules are highlighted. However, continued public investment in this area is critical to maintain an edge in our evolutionary "arms race" against antibiotic-resistant microorganisms. Impact statement The alarming increase in antibiotic-resistant microorganisms is a rapidly emerging threat to human health throughout the world. Historically, small molecule drugs have played a major role in controlling bacterial infections and they continue to offer tremendous potential in countering resistant organisms. This minireview provides a broad overview of the relevant issues, including the diversity of FDA-approved small molecule drugs and mechanisms of drug resistance, unintended consequences of antibiotic use, the current state of development for small molecule antibacterials and financial challenges that impact progress towards novel therapies. The content will be informative to diverse stakeholders, including clinicians, basic scientists, translational scientists and policy makers, and may be used as a bridge between these key players to advance the development of much-needed therapeutics.
Hernando-Amado, Sara; Sanz-García, Fernando; Blanco, Paula; Martínez, José L
Acquisition of antibiotic resistance is a relevant problem for human health. The selection and spread of antibiotic-resistant organisms not only compromise the treatment of infectious diseases, but also the implementation of different therapeutic procedures as organ transplantation, advanced surgery or chemotherapy, all of which require proficient methods for avoiding infections. It has been generally accepted that the acquisition of antibiotic resistance will produce a general metabolic burden: in the absence of selection, the resistant organisms would be outcompeted by the susceptible ones. If that was always true, discontinuation of antibiotic use would render the disappearance of resistant microorganisms. However, several studies have shown that, once resistance emerges, the recovery of a fully susceptible population even in the absence of antibiotics is not easy. In the present study, we review updated information on the effect of the acquisition of antibiotic resistance in bacterial physiology as well as on the mechanisms that allow the compensation of the fitness costs associated with the acquisition of resistance. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.
McCusker, Kevin P; Fujimori, Danica Galonić
The continued ability to treat bacterial infections requires effective antibiotics. The development of new therapeutics is guided by knowledge of the mechanisms of action of and resistance to these antibiotics. Continued efforts to understand and counteract antibiotic resistance mechanisms at a molecular level have the potential to direct development of new therapeutic strategies in addition to providing insight into the underlying biochemical functions impacted by antibiotics. The interaction of antibiotics with the peptidyltransferase center and adjacent exit tunnel within the bacterial ribosome is the predominant mechanism by which antibiotics impede translation, thus stalling growth. Resistance enzymes catalyze the chemical modification of the RNA that composes these functional regions, leading to diminished binding of antibiotics. This review discusses recent advances in the elucidation of chemical mechanisms underlying resistance and driving the development of new antibiotics.
Full Text Available INTRODUCTION: Bacterial infections account for a huge proportion of neonatal deaths worldwide. The problem of antibiotic resistance among common bacterial pathogens mainly the gram negative bacteria is emerging globally which is of more serious concern in developing countries like Nepal. METHODS: A one year retrospective hospital based study was carried out to analyze the results of neonatal blood, cerebrospinal fluid, urine, stool and surface cultures and to look into the sensitivity pattern of the commonly used antibiotics. RESULTS: The positive yield of blood, urine, eye swab and CSF cultures were 19.56%, 38.5%, 60% and 0.36% respectively. The most common isolates in the blood culture were coagulase negative Staphylococcus, Acinetobacter, Enterobacter and non-haemolytic Streptococcus. A significant percent of the isolates were resistant to the first line antibiotics. Among the gram negative isolates more than 30% are resistant to cefotaxime and more than 50% are resistant to gentamicin. During the one year period we had Nursery outbreaks of methicillin resistant Staphylococcus aureus and Salmonella infections. With the help of environmental cultures we were able to trace the source and intervene appropriately. CONCLUSIONS: Continuous surveillance for antibiotic susceptibility, rational use of antibiotics and the strategy of antibiotic cycling can provide some answers to the emerging problem of antibiotic resistance.
Shrestha, S; Adhikari, N; Rai, B K; Shreepaili, A
Bacterial infections account for a huge proportion of neonatal deaths worldwide. The problem of antibiotic resistance among common bacterial pathogens mainly the gram negative bacteria is emerging globally which is of more serious concern in developing countries like Nepal. A one year retrospective hospital based study was carried out to analyze the results of neonatal blood, cerebrospinal fluid, urine, stool and surface cultures and to look into the sensitivity pattern of the commonly used antibiotics. The positive yield of blood, urine, eye swab and CSF cultures were 19.56%, 38.5%, 60% and 0.36% respectively. The most common isolates in the blood culture were coagulase negative Staphylococcus, Acinetobacter, Enterobacter and non-haemolytic Streptococcus. A significant percent of the isolates were resistant to the first line antibiotics. Among the gram negative isolates more than 30% are resistant to cefotaxime and more than 50% are resistant to gentamicin. During the one year period we had Nursery outbreaks of methicillin resistant Staphylococcus aureus and Salmonella infections. With the help of environmental cultures we were able to trace the source and intervene appropriately. Continuous surveillance for antibiotic susceptibility, rational use of antibiotics and the strategy of antibiotic cycling can provide some answers to the emerging problem of antibiotic resistance.
Versluis, Dennis; de Evgrafov, Mari Cristina Rodriguez; Sommer, Morten Otto Alexander
Wide application of antibiotics has contributed to the evolution of multi-drug resistant human pathogens, resulting in poorer treatment outcomes for infections. In the marine environment, seawater samples have been investigated as a resistance reservoir; however, no studies have methodically...... examined sponges as a reservoir of antibiotic resistance. Sponges could be important in this respect because they often contain diverse microbial communities that have the capacity to produce bioactive metabolites. Here, we applied functional metagenomics to study the presence and diversity of functional......). Fifteen of 37 inserts harbored resistance genes that shared resistance gene could be identified with high confidence, in which case we predicted resistance to be mainly mediated by antibiotic efflux. One marine-specific ampicillin-resistance...
Heister, Thomas; Hagist, Christian; Kaier, Klaus
The emergence and spread of antimicrobial resistance (AMR) is still an unresolved problem worldwide. In intensive care units (ICUs), first-line antibiotic therapy is highly standardized and widely empiric while treatment failure because of AMR often has severe consequences. Simultaneously, there is a limited number of reserve antibiotics, whose prices and/or side effects are substantially higher than first-line therapy. This paper explores the implications of resistance-induced substitution effects in ICUs. The extent of such substitution effects is shown in a dynamic fixed effect regression analysis using a panel of 66 German ICUs with monthly antibiotic use and resistance data between 2001 and 2012. Our findings support the hypothesis that demand for reserve antibiotics substantially increases when resistance towards first-line agents rises. For some analyses the lagged effect of resistance is also significant, supporting the conjecture that part of the substitution effect is caused by physicians changing antibiotic choices in empiric treatment by adapting their resistance expectation to new information on resistance prevalence. The available information about resistance rates allows physicians to efficiently balance the trade-off between exacerbating resistance and ensuring treatment success. However, resistance-induced substitution effects are not free of charge. These effects should be considered an indirect burden of AMR. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Rezzonico, Fabio; Stockwell, Virginia O; Duffy, Brion
Streptomycin is used in plant agriculture for bacterial disease control, particularly against fire blight in pome fruit orchards. Concerns that this may increase environmental antibiotic resistance have led to bans or restrictions on use. Experience with antibiotic use in animal feeds raises the possible influence of formulation-delivered resistance genes. We demonstrate that agricultural streptomycin formulations do not carry producer organism resistance genes. By using an optimized extraction procedure, Streptomyces 16S rRNA genes and the streptomycin resistance gene strA were not detected in agricultural streptomycin formulations. This diminishes the likelihood for one potential factor in resistance development due to streptomycin use.
Parada, J L; De Nardo, J; Rebollo, M; Marcenac, F; Fernández, A
The present study was carried out with 111 multiresistant pathogenic strains of enterobacterias isolated from different sources with increased resistance to three or more antibiotics. Among the identified species are included E. coli, Shigella sp., Salmonella oranienburg, Klebsiella pneumoniae and Citrobacter freundii. In general, the minimal inhibitory concentration of antibiotics was above 100 microgram/ml and in some cases it was superior to 1000 microgram/ml. Resistance transfer factors were detected in 72% of the strains; 33% movilized the complete pattern of resistance and 67% did it partially because some of the determinants were not transfered. The Citrobacter strains show a high frequency of transference (10(-1)), while for the others species it was in the order of 10(-2)--10(-3). The use of a multi-inoculator allows to perform in a simple way the preliminar evaluation about the presence or absence of R transfer factors in multiresistant strains. This technique has shown good correlation with the data obtained by the usual dilution and plating method.
Full Text Available Aim: The aim was to determine the prevalence and evaluation of antibiotic resistance pattern and minimum inhibitory concentration (MIC of Campylobacter species isolated from foods of animal origin. Materials and Methods: A total of 280 samples (comprising 150 chicken meat, 50 chevon and 80 milk were collected from retail meat markets, slaughter houses and dairy farms and analyzed for isolation of Campylobacter species. A total of 29 isolates comprising 23 Campylobacter jejuni and 6 Campylobacter coli were recovered, characterized biochemically and confirmed by polymerase chain reaction. These isolates were then tested for antibiotic resistance pattern through disc diffusion method, and MIC was assessed by MIC strips. The antibiotic resistance assessment was performed against 8 antibiotics viz. ampicillin, co-trimoxazole, erythromycin, levofloxacin, gentamicin, ciprofloxacin, ceftriaxone, and norfloxacin. Results: The prevalence of Campylobacter spp. in chicken meat, chevon and milk samples were observed 17.33%, 6% and 0%, respectively. All the isolates were resistant to co-trimoxazole but sensitive to erythromycin. All the isolates showed different resistance pattern for the rest of the antibiotics. MIC results revealed that all the isolates were within prescribed concentrations for sensitivity for the antibiotics tested. Conclusions: The foods of animal origin are source of Campylobacter infections to human beings. Thus, the development of antibiotic-resistant strains emphasizes the requirement of better surveillance and monitoring of the foods of animal origin and the use of antimicrobials in veterinary and human medicine require careful regulation.
Dubreuil, L; Odou, M F
The purpose of this article is to set out some important considerations on the main emerging antibiotic resistance patterns among anaerobic bacteria. The first point concerns the Bacteroides fragilis group and its resistance to the combination of β-lactam+β-lactamase inhibitor. When there is overproduction of cephalosporinase, it results in increased resistance to the β-lactams while maintaining susceptibility to β-lactams/β-lactamase inhibitor combinations. However, if another resistance mechanism is added, such as a loss of porin, resistances to β-lactam+β-lactamase inhibitor combinations may occur. The second point is resistance to metronidazole occurring due to nim genes. PCR detection of nim genes alone is not sufficient for predicting resistance to metronidazole; actual MIC determinations are required. Therefore, it can be assumed that other resistance mechanisms can also be involved. Although metronidazole resistance remains rare for the B. fragilis group, it has nevertheless been detected worldwide and also been observed spreading to other species. In some cases where there is only a decreased susceptibility, clinical failures may occur. The last point concerns resistance of Clostridium species to glycopeptides and lipopeptides. Low levels of resistance have been detected with these antibiotics. Van genes have been detected not only in clostridia but also in other species. In conclusion, antibiotic resistance involves different mechanisms and affects many anaerobic species and is spreading worldwide. This demonstrates the need to continue with antibiotic resistance testing and surveys in anaerobic bacteria. Copyright Â© 2010 Elsevier Ltd. All rights reserved.
A novel antibiotic resistant mechanism among biofilms is glucan-mediated sequestration in which ndvB gene encodes a glucosyltransferase involved in the formation of this glucans. We studied the biofilm formation and antibiotic susceptibility pattern of P. aeruginosa isolated from clinical samples, and measured the ...
Antibiotic resistance may emerge by antibiotic selection pressure but is perpetuated by diverse risk factors and maintained within environments as a result of poor infection control. Population-specific drug pharmacokinetics and pharmacodynamics also play a role. The WHO, US, UK and EU have initiated strategies for the ...
Antibiotics are commonly used in livestock production to promote growth and combat disease. Recent studies have shown the potential for spread of antibiotic resistance genes (ARG) to the environment following application of livestock manures. In this study, concentrations of bacteria with ARG in soi...
Grundmann, Hajo; Klugman, Keith P.; Walsh, Timothy; Ramon-Pardo, Pilar; Sigauque, Betuel; Khan, Wasif; Laxminarayan, Ramanan; Heddini, Andreas; Stelling, John
The foreseen decline in antibiotic effectiveness explains the needs for data to inform the global public health agenda about the magnitude and evolution of antibiotic resistance as a serious threat to human health and development. Opportunistic bacterial pathogens are the cause of the majority of
management. Clones of E. coli (each bacterial colony emanating from a single genome) were obtained from normal (non-diarrhoeal) stools of young children enrolled in MAL-ED SA, followed by antibiotic susceptibility and minimum inhibitory testing, and detection of genes coding for antibiotic resistance. Worthy of note is ...
The Advisory Council for Health Research (RGO) advised the Dutch Minister of Health on research into the epidemiology, prevention and research of antibiotic resistance in the Netherlands. Good antimicrobial practice, insight into antibiotic use, implementation of measures to prevent development of
Aarts, H.J.M.; Boumedine, K.S.; Nesme, X.; Cloeckaert, A.
This review will discuss a number of molecular tools which are currently used as well as some innovative approaches for the characterisation of antibiotic-resistant bacterial strains. Various methods involved in the detection and characterisation of genes and mutations associated with antibiotic
1. Introduction 1.1. How bacteria exhibit resistance 1.1.1. Resistance to -lactams 1.1.2. Resistance to sulphonamides and trimethoprim 1.1.3. Resistance to macrolides 1.1.4. Resistance to fluoroquinolones 1.1.5. Resistance to tetracyclines 1.1.6. Resistance to nitroimidaz...
Bezerra, Camila Fonseca; Camilo, Cicera Janaine; do Nascimento Silva, Maria Karollyna; de Freitas, Thiago Sampaio; Ribeiro-Filho, Jaime; Coutinho, Henrique Douglas Melo
The treatment of infections caused by microorganisms that are resistant to antibiotics represent one of the main challenges of medicine today, especially due to the inefficacy of long-term drug therapy. In the search for new alternatives to treat these infections, many researchers have been looking for new substances derived from natural products to replace, or be used in combination with conventional antibiotics. Vanillin is a phenolic compound whose antimicrobial activity has been used in the elimination of pathogens present in fruits and vegetables. However, its antibacterial and modulating properties remain to be characterized. Therefore, this work aimed to evaluate the antibacterial activity and analyze the modulator activity of vanillin in association with conventional antibiotics. The antimicrobial activity of vanillin was evaluated using the microdilution method to determine the Minimum Inhibitory Concentration (MIC) Standard strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and multi-resistant strains of Escherichia coli 06, Staphylococcus aureus 10, Pseudomonas aeruginosa 24 were used in this study. The antibiotic modulating effect was analyzed by combining vanillin with Norfloxacin, Imipenem, Gentamicin, Erythromycin and Tetracycline against the following multiresistant bacteria strains: Escherichia coli 06, Staphylococcus aureus 10 and Pseudomonas aeruginosa 24. Data were analyzed using the ANOVA test of two tracks followed by the post hoc Bonferroni test. Vanillin presented CIMs ≥1024μg/mL against all tested strains demonstrating that it did not present significant antibacterial activity. However, modulated the activity of gentamicin and imipenem against S. aureus and E. coli, causing a synergistic effect, but did not affect the activity of norfloxacin, tetracycline and erythromycin against these same microorganisms. A synergistic effect was also obtained from the association of vanillin with norfloxacin against P
Full Text Available Integrating conjugative elements (ICEs are a class of bacterial mobile genetic elements that disseminate via conjugation and then integrate into the host cell genome. The SXT/R391 family of ICEs consists of more than 30 different elements that all share the same integration site in the host chromosome but often encode distinct properties. These elements contribute to the spread of antibiotic resistance genes in several gram-negative bacteria including Vibrio cholerae, the agent of cholera. Here, using comparative analyses of the genomes of several SXT/R391 ICEs, we found evidence that the genomes of these elements have been shaped by inter-ICE recombination. We developed a high throughput semi-quantitative method to explore the genetic determinants involved in hybrid ICE formation. Recombinant ICE formation proved to be relatively frequent, and to depend on host (recA and ICE (s065 and s066 loci, which can independently and potentially cooperatively mediate hybrid ICE formation. s065 and s066, which are found in all SXT/R391 ICEs, are orthologues of the bacteriophage lambda Red recombination genes bet and exo, and the s065/s066 recombination system is the first Red-like recombination pathway to be described in a conjugative element. Neither ICE excision nor conjugative transfer proved to be essential for generation of hybrid ICEs. Instead conjugation facilitates the segregation of hybrids and could provide a means to select for functional recombinant ICEs containing novel combinations of genes conferring resistance to antibiotics. Thus, ICEs promote their own diversity and can yield novel mobile elements capable of disseminating new combinations of antibiotic resistance genes.
Muhammad, Zardad; Ahmed, Ashfaq; Hayat, Umar; Wazir, Muhammad Salim; Rafiyatullah; Waqas, Huma
Neonatal sepsis is one of the major causes of neonatal morbidity and mortality, particularly in developing countries. The objective of this study was to determine the causative bacteria and level of their resistance to commonly used antibiotics. This descriptive study was carried out at Ayub Teaching Hospital, Abbottabad from April 2009 to January 2010. All neonates of either gender admitted in neonatology unit with clinical sepsis and positive blood culture were included in the study. Neonatal period was defined as 28 days of life at term and up to 44 weeks of gestational age in preterm babies. One hundred and thirty neonates of either gender were studied during the period. Blood sample for culture was taken from a peripheral vein or an artery ensuring standard anti-septic measures. BACTEC technique was used for obtaining bacterial growth and drug sensitivity after incubation of 24-48 hours. Second blood culture was also performed in few cases which were not showing improvement after initial treatment. Male to female ratio was 1.3:1. Early and late onset sepsis was found in 29.2% and 70.8% respectively. Gram-negative bacteria were more frequent than gram-positive bacteria with a frequency of 54.6% and 45.4% respectively. Gram-positive and gram-negative bacteria showed high resistance against commonly used antibiotics such as ampicillin, amoxicillin, cefotaxime, ceftriazone and gentamicin. Staph. aureus is the most common gram-positive bacterium and E. coli is the most common gram-negative bacterium causing neonatal sepsis. Gram-positive and gram-negative bacteria are highly resistant against commonly used antibiotics such as ampicillin, amoxicillin, cefotaxime, ceftriazone and gentamicin, and are relatively more sensitive to less commonly used drugs like amikacin and ceftazidime.
Antibiotic resistance in bacterial pathogens causing meningitis in children at Harare Central Hospital, Zimbabwe. M Gudza-Mugabe, R.T. Mavenyengwa, M.P. Mapingure, S Mtapuri-Zinyowera, A Tarupiwa, V.J. Robertson ...
Preliminary studies on antibiotic-resistant Escherichia coli isolated from cattle and children in the pastoral community of Nyabushozi, Uganda. J Okwee-Acai, S Majalija, SG Okech, MBS Kisaka, J Acon ...
Elder, David P; Kuentz, Martin; Holm, René
The development of antibiotic resistance is a major problem for mankind and results in fatal consequences on a daily basis across the globe. There are a number of reasons for this situation including increasing globalization with worldwide travel, health tourism, over use and ineffective use (both in man and animals), and counterfeiting of the antimicrobial drug products we have available currently. Although there are huge economical, demographic, legal and logistic differences among the global communities, there are also differences regarding the best approach to dealing with antibiotic resistance. However, as resistant bacteria do not respect international borders, there is clearly a need for a global strategy to minimize the spread of antibiotic resistance, to optimize the use of antibiotics, and to facilitate the development of new and effective medications. This commentary provides an insight into the issues and some of the ongoing programs to ensure an effective treatment for the future. Copyright © 2016. Published by Elsevier Inc.
Infections with antibiotic-resistant bacteria are a worldwide problem in hospitals and their rates remain high in many countries despite efforts to reduce the rates. Infection prevention is complicated by asymptomatic carriers. Using mathematical modelling, different intervention strategies were
Antibiotic resistance profiles and relatedness of enteric bacterial pathogens isolated from HIV/AIDS patients with and without diarrhoea and their household drinking water in rural communities in Limpopo Province South Africa.
Argues that reduction in the use of antibiotics would enable antibiotic-sensitive bacteria to flourish. Presents an activity designed to show students how a small, seemingly unimportant difference in doubling time can, over a period of time, make an enormous difference in population size. (DDR)
Ciofu, Oana; Tolker-Nielsen, Tim
One of the most important features of microbial biofilms is their tolerance to antimicrobial agents and components of the host immune system. The difficulty of treating biofilm infections with antibiotics is a major clinical problem. Although antibiotics may decrease the number of bacteria...
Miller, Jennifer H; Novak, John T; Knocke, William R; Young, Katherine; Hong, Yanjuan; Vikesland, Peter J; Hull, Matthew S; Pruden, Amy
Water resource recovery facilities have been described as creating breeding ground conditions for the selection, transfer, and dissemination of antibiotic resistance genes (ARGs) among various bacteria. The objective of this study was to determine the effect of direct addition of antibiotic and silver nanoparticles (Ag NPs, or nanosilver) on the occurrence of ARGs in thermophilic anaerobic digesters. Test thermophilic digesters were amended with environmentally-relevant concentrations of Ag NP (0.01, 0.1, and 1.0 mg-Ag/L; corresponding to approximately 0.7, 7.0, and 70 mg-Ag/kg total solids) and sulfamethoxazole (SMX) that span susceptible to resistant classifications (1, 5, and 50 mg/L) as potential selection pressures for ARGs. Tetracycline (tet(O), tet(W)) and sulfonamide (sulI, sulII) ARGs and the integrase enzyme gene (intI1) associated with Class 1 integrons were measured in raw sludge, test thermophilic digesters, a control thermophilic digester, and a control mesophilic digester. There was no apparent effect of Ag NPs on thermophilic anaerobic digester performance. The maximum SMX addition (50 mg/L) resulted in accumulation of volatile fatty acids and low pH, alkalinity, and volatile solids reduction. There was no significant difference between ARG gene copy numbers (absolute or normalized to 16S rRNA genes) in amended thermophilic digesters and the control thermophilic digester. Antibiotic resistance gene copy numbers in digested sludge ranged from 10(3) to 10(6) copies per microL (approximately 8 x10(1) to 8 x 10(4) copies per microg) of sludge as result of a 1-log reduction of ARGs (2-log reduction for intI1). Quantities of the five ARGs in raw sludge ranged from 10(4) to 10(8) copies per microL (approximately 4 x 10(2) to 4 x 10(6) per microg) of sludge. Test and control thermophilic digesters (53 degrees C, 12-day solids retention time [SRT]) consistently reduced but did not eliminate levels of all analyzed genes. The mesophilic digester (37 degrees C
Chuah, Li-Oon; Effarizah, M E; Goni, Abatcha Mustapha; Rusul, Gulam
Catfish is one of the most cultivated species worldwide. Antibiotics are usually used in catfish farming as therapeutic and prophylactic agents. In the USA, only oxytetracycline, a combination of sulfadimethoxine and ormetoprim, and florfenicol are approved by the Food Drug Administration for specific fish species (e.g., catfish and salmonids) and their specific diseases. Misuse of antibiotics as prophylactic agents in disease prevention, however, is common and contributes in the development of antibiotic resistance. Various studies had reported on antibiotic residues and/or resistance in farmed species, feral fish, water column, sediments, and, in a lesser content, among farm workers. Ninety percent of the world aquaculture production is carried out in developing countries, which lack regulations and enforcement on the use of antibiotics. Hence, efforts are needed to promote the development and enforcement of such a regulatory structure. Alternatives to antibiotics such as antibacterial vaccines, bacteriophages and their lysins, and probiotics have been applied to curtail the increasing emergence of antibiotic-resistant bacteria due to the imprudent application of antibiotics in aquaculture.
Danilova, Natasha; Galitskaya, Polina; Selivanovskaya, Svetlana
Antibiotics are medicines widely used to treat and prevent bacterial infections not only in human medicine but also in veterinary. Besides, in animal husbandry antibiotics are often used in for stimulation of animal's growth. Many antibiotics used for veterinary purposes are weakly absorbed in the animal's gut. So up to 90% of the administered antibiotics are excreted with manure and urine. Therefore use of manure as an organic fertilizer leads to formation and spreading of antibiotic resistance among soil microbes. Another reason of such spreading is the horizontal transfer of genes encoding antibiotic resistance from manure to soil microflora. The level of antibiotic resistance genes pollution of soils has not been properly studied yet. The aim of this study was to estimate the contamination of agricultural soils by antibiotic resistant genes. 30 samples of agricultural soils were selected around of Kazan city (Tatarstan Republic) with 1.3 Mio citizens. Since tetracycline is reported to be the most wide spread veterinary antibiotic in Russia, we estimated the level of soil contamination by tet(X) gene encoding tetracycline decomposition in microbial cell. Real time PCR method with specific primers was used as a method of investigation. Particle size type distribution of 31% of soil samples was estimated to be sandy clay, and 69% of soil samples - to silty clay. Content of dissoluble organic carbon ranged from 0,02 mg g -1 (sample 20) to 0,46 mg g -1 (sample 16). Respiration activity and microbial biomass of soils were estimated to be 0,80-5,28 CO2 C mg g -1 h-1 and 263,51-935,77 µg kg - 1 respectively. The values presented are typical for soils of Tatarstan Republic. In terms of the antibiotic resistant gene content, 27 of 30 samples investigated contained tet(X) gene, while 52% of the samples were highly contaminated, 34% of samples were middle contaminated and 14% of samples - weakly contaminated.
Stange, C; Sidhu, J P S; Tiehm, A; Toze, S
Widespread fecal pollution of surface water may present a major health risk and a significant pathway for dissemination of antibiotic resistance bacteria. The River Rhine is one of the longest and most important rivers in Europe and an important raw water source for drinking water production. A total of 100 coliform isolates obtained from River Rhine (Germany) were examined for their susceptibility to seven antimicrobial agents. Resistances against amoxicillin, trimethoprim/sulfamethoxazole and tetracycline were detected in 48%, 11% and 9% of isolates respectively. The antibiotic resistance could be traced back to the resistance genes bla TEM , bla SHV , ampC, sul1, sul2, dfrA1, tet(A) and tet(B). Whereby, the ampC gene represents a special case, because its presence is not inevitably linked to a phenotypic antibiotic resistance. Multiple antibiotics resistance was often accompanied by the occurrence of class 1 or 2 integrons. E. coli isolates belonging to phylogenetic groups A and B1 (commensal) were more predominant (57%) compared to B2 and D groups (43%) which are known to carry virulent genes. Additionally, six E. coli virulence genes were also detected. However, the prevalence of virulence genes in the E. coli isolates was low (not exceeding 4.3% per gene) and no diarrheagenic E. coli pathotypes were detected. This study demonstrates that surface water is an important reservoir of ARGs for a number of antibiotic classes such as sulfonamide, trimethoprim, beta-lactam-antibiotics and tetracycline. The occurrence of antibiotic resistance in coliform bacteria isolated from River Rhine provides evidence for the need to develop management strategies to limit the spread of antibiotic resistant bacteria in aquatic environment. Copyright © 2016 Elsevier GmbH. All rights reserved.
Ivanova, Kristina Dimitrova
The accelerated emergence of drug resistant bacteria is one of the most serious problems in healthcare and the difficulties in finding new antibiotics make it even more challenging. To overcome the action of antibiotics bacteria develop effective resistance mechanisms including the formation of biofilms. Biofilms are bacterial communities of cells embedded in a self-produced polymeric matrix commonly found on medical devices such as indwelling catheters. When pathogens adopt this mode of grow...
Sommer, Morten; Church, George M; Dantas, Gautam
The increasing levels of multi-drug resistance in human pathogenic bacteria are compromising our ability to treat infectious disease. Since antibiotic resistance determinants are readily exchanged between bacteria through lateral gene transfer, there is an increasing interest in investigating...... reservoirs of antibiotic resistance accessible to pathogens. Due to the high likelihood of contact and genetic exchange with pathogens during disease progression, the human microflora warrants special attention as perhaps the most accessible reservoir of resistance genes. Indeed, numerous previous studies...... have demonstrated substantial antibiotic resistance in cultured isolates from the human microflora. By applying metagenomic functional selections, we recently demonstrated that the functional repertoire of resistance genes in the human microbiome is much more diverse than suggested using previous...
Soriano, Allan N.; Adamos, Kristoni G.; Bonifacio, Pauline B.; Adornado, Adonis P.; Bungay, Vergel C.; Vairavan, Rajendaran
The fate of antibiotics entering the environment raised concerns on the possible effect of antimicrobial resistance bacteria. Prediction of the fate and transport of these particles are needed to be determined, significantly the diffusion coefficient of antibiotic in water at infinite dilution. A systematic determination of diffusion coefficient of antibiotic in water at infinite dilution of five different kinds of livestock antibiotics namely: Amtyl, Ciprotyl, Doxylak Forte, Trisullak, and Vetracin Gold in the 293.15 to 313.15 K temperature range are reported through the use of the method involving the electrolytic conductivity measurements. A continuous stirred tank reactor is utilized to measure the electrolytic conductivities of the considered systems. These conductivities are correlated by using the Nernst-Haskell equation to determine the infinite dilution diffusion coefficient. Determined diffusion coefficients are based on the assumption that in dilute solution, these antibiotics behave as strong electrolyte from which H+ cation dissociate from the antibiotic's anion.
Antibiotic resistance is a worldwide problem and changes are needed in the way antibiotics are used. The value of engaging children as key contributors in health care campaigns to increase the appropriate use of antibiotics has not been fully recognized. Little is known about how to design educational materials for children in order to enable them to be agents of change in their communities. Science education needs to improve the way it engages children so as to give them the tools needed to make responsible decisions on antibiotic use.
Osman, K M; Elhariri, M
The use of antibiotic feed additives in broiler chickens results in a high prevalence of resistance among their enteric bacteria, with a consequent emergence of antibiotic resistance in zoonotic enteropathogens. Despite growing concerns about the emergence of antibiotic-resistant strains, which show varying prevalences in different geographic regions, little work has been done to investigate this issue in the Middle East. This study provides insight into one of the world's most common and financially crippling poultry diseases, necrotic enteritis caused by Clostridium perfringens. The study was designed to determine the prevalence of antibiotic resistance in C. perfringens isolates from clinical cases of necrotic enteritis in broiler chickens in Egypt. A total of 125 isolates were obtained from broiler flocks in 35 chicken coops on 17 farms and were tested using the disc diffusion method. All 125 isolates were resistant to gentamicin, streptomycin, oxolinic acid, lincomycin, erythromycin and spiramycin. The prevalence of resistance to other antibiotics was also high: rifampicin (34%), chloramphenicol (46%), spectinomycin (50%), tylosin-fosfomycin (52%), ciprofloxacin (58%), norfloxacin (67%), oxytetracycline (71%), flumequine (78%), enrofloxacin (82%), neomycin (93%), colistin (94%), pefloxacin (94%), doxycycline (98%) and trimethoprim-sulfamethoxazole (98%). It is recommended that C. perfringens infections in Egypt should be treated with antibiotics for which resistant isolates are rare at present; namely, amoxicillin, ampicillin, cephradine, fosfomycin and florfenicol.
Full Text Available Background: The emergence of antimicrobial-resistant bacteria with biofilm formation ability may be a major threat to public health and food safety and sanitation. Objectives: The aim of this study was to determine antibiotic resistance patterns and biofilm production characteristics of Salmonella typhimurium isolated from different species of birds. Materials and Methods: The antibiotic resistance patterns of 38 pre-identified isolates were screened by standard Kirby-Bauer disc-diffusion method performed on Mueller–Hinton agar to a panel of 17 antibiotics. The extent of biofilm formation was measured by Microtiter plate (MTP-based systems. Results: The highest antimicrobial resistance was detected against nalidixic acid (97%, followed by doxycycline (86%, colistin (84%, streptomycin (84% and tetracycline (84%. All isolates were sensitive to amikacin (100% and 97% and 95% of the isolates were sensitive to ceftazidime and ceftriaxone, respectively. Twenty one different antibiotic resistance patterns were observed among S. typhimurium isolates. According to the results of the microtitre plate biofilm assay, there was a wide variation in biofilm forming ability among S. typhimurium isolates. Most of the isolates (60.52% were not capable of producing biofilm, while 26.31%, 7.89%, and 5.26% isolates were weak, strong and moderate biofilm producers, respectively. Conclusions: It was concluded that nearly all S. typhimurium isolates revealed a high multiple antibiotic resistant with low biofilm forming capabilities which proposed low association between biofilm formation and antibiotic resistance of a major food important pathogen.
Korshunov, V.M.; Pinegin, B.V.; Ivanova, N.P.; Maltsev, V.N.
Elimination of intestinal dysbacteriosis in irradiated animals by combining antibiotics and peparations of bifidobacteria resistant to these antibiotics prolonging the life of these animals was investigated. Broad spectrum antibiotics are used to treat intestinal dysbacteriosis. Bifidobacterial preparations are used to restore the microbial cenosis and their administration is started after antibiotics are discontinued. There are some flaws to deferred administration of bifidobacteria, since the process of colonization of the intestine with commercial bifidobacterial preparations is rather lengthy, and there is slow elevation of bifidobacterium level in the intestinal tract, whereas exogenous recontamination of the intestine by conditionally pathogenic bacteria is possible after antibiotic therapy is discontinued. Use of antibiotics alone could be the cause of intestinal dysbacteriosis
de Vries, Lisbeth Elvira; Valles, Yvonne; Agersø, Yvonne
The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case...... study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc-r) in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc-r genes. Fecal fosmid...... library, Tc-r was present exclusively in streptococci carrying tet(M), tet(L) and erm(T) within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within...
Undo edits Methods: In this cross - sectional study, 397 of the anterior nasal samples of medical personnel and hospital services were collected by swab. The identification of S.aureus was determined by biochemical tests and microbiology, and the antibiotic resistances of isolates were determined by disk diffusion method for 13 antibiotics. In this method, the inhibition zone for methicillin-resistant strains was ≤ 10 mm the minimum inhibitory concentrations (MIC against antibiotic vancomycin, ticoplanin, linezolid and synercid were determined by E-test method. Results: In the present study, 11.3% of personals carried S. aureus in the nose. Among them, 90% were health care workers and 10% were health service workers. The most sensitivity was observed resistance to Ciprofloxacin, rifampin, linezolid and synercid (91.1%, but the lowest sensitivity was to penicillin (4.7%. of 9 MRSA strains, 1 strain was resistance to vancomycin and 2 strains were resistant to teicoplanin and linezolid. Conclusion: Because of S. aureus strains isolated from hospital staffs were resistant to most common antibiotics, identification and treatment of health care and health service workers can prevent nosocomial infections. Key words: Staphylococcu aureus carriers, hospital personnel, antibiotic resistance.
Farzana, K.; Hameed, A.
Among the samples received in pathology laboratory, Pakistan institute of Medical Science, Islamabad, 5069 samples had bacterial growth, among these 2580 (51%) samples were Gram-positive cocci and 1688 were Staphylococcus aureus during a period of two years. Out of these Gram-positive cocci 56% were resistant to penicillin group, 27% were resistant to cephalosporin group, 22% were resistant to aminoglycoside group 15% were resistant to quinolone group and 31% were resistant to other antibiotics (cotrimaxazole, erythromycin, aztreonam, vancomycin, nitrofurantion and meropenam). Antibio-grams of Gram-positive cocci were determined against various antibiotics by disc diffusion method. The rate of resistance to most of the antibiotics such as ampicillin, piperacillin, carbenicillin, penicillin, cephradine, cefotaxime, erythromycin, ceclor, ofloxacin, pefloxacin, ciprofloxacin, cotrimexazole (septran), gentamicin, meropenem, ceftazidime, erythromycin, tobramycin, enoxacin was higher when tested against the isolates collected from pus as compared to those from blood and urine. Antibiotic resistant strains were more prevalent in pus samples than other clinical isolates (blood and urine). The randomly selected 155 strains of Staphylococcus aureus when tested against five groups of antibiotics showed resistance rate against ampicillin (92%), cephradine (92%), cephradine (60%), and gentamicin (58%). However intermediate resistance was found in case of vancomicin (38%), in hospitalized and non-hospitalized patients. (author)
Alessandro Delli Paoli Carini
Full Text Available This study aimed to test multidrug resistant isolates from hospitalised green turtles (Chelonia mydas and their environment in North Queensland, Australia, for in vitro susceptibility to bacteriophages. Seventy-one Gram-negative bacteria were isolated from green turtle eye swabs and water samples. Broth microdilution tests were used to determine antibiotic susceptibility. All isolates were resistant to at least two antibiotics, with 24% being resistant to seven of the eight antibiotics. Highest resistance rates were detected to enrofloxacin (77% and ampicillin (69.2%. More than 50% resistance was also found to amoxicillin/clavulanic acid (62.5%, ceftiofur (53.8%, and erythromycin (53.3%. All the enriched phage filtrate mixtures resulted in the lysis of one or more of the multidrug resistant bacteria, including Vibrio harveyi and V. parahaemolyticus. These results indicate that antibiotic resistance is common in Gram-negative bacteria isolated from hospitalised sea turtles and their marine environment in North Queensland, supporting global concern over the rapid evolution of multidrug resistant genes in the environment. Using virulent bacteriophages as antibiotic alternatives would not only be beneficial to turtle health but also prevent further addition of multidrug resistant genes to coastal waters.
Giubilini, Alberto; Birkl, Patrick; Douglas, Thomas; Savulescu, Julian; Maslen, Hannah
Antibiotic use in animal farming is one of the main drivers of antibiotic resistance both in animals and in humans. In this paper we propose that one feasible and fair way to address this problem is to tax animal products obtained with the use of antibiotics. We argue that such tax is supported both by (a) deontological arguments, which are based on the duty individuals have to compensate society for the antibiotic resistance to which they are contributing through consumption of animal products obtained with the use of antibiotics; and (b) a cost-benefit analysis of taxing such animal products and of using revenue from the tax to fund alternatives to use of antibiotics in animal farming. Finally, we argue that such a tax would be fair because individuals who consume animal products obtained with the use of antibiotics can be held morally responsible, i.e. blameworthy, for their contribution to antibiotic resistance, in spite of the fact that each individual contribution is imperceptible.
Li, Chao; Lu, Jianjiang; Liu, Jiang; Zhang, Genlin; Tong, Yanbing; Ma, Na
Various antibiotics have been extensively used to treating infectious diseases in hospitals. In this study, the abundance and diversity of antibiotics and antibiotic resistance genes (ARGs) were observed in the wastewater samples from five hospitals in Xinjiang, China. The total concentrations of tetracyclines, sulphonamides, and quinolones in hospital influents ranged from 363.4 to 753.3 ng/L, 285.5 to 634.9 ng/L, and 1355.8 to 1922.4 ng/L, respectively. However, the removal efficiency of tetracyclines, sulphonamides, and quinolones in wastewater treatment processes ranged from 72.4 to 79.3 %, 36.0 to 52.2 %, and 45.1 to 55.4 %, respectively. The contamination levels of the selected ARGs varied in all wastewater samples. The highest relative concentrations of sul1, sul2, tetQ, and qnrS were significantly higher than those of other ARGs in this study. Significant positive correlations between the relative abundance of partial ARGs and concentrations of certain antibiotics were observed in hospital wastewaters. Results show that integrons played an important role in disseminating and distributing ARGs in microorganism systems. Furthermore, strong correlations were observed between tetQ, sulphonamide resistance genes (except sulA) and intI1. This study aimed to determine the contamination levels of antibiotics and ARGs and analyze the relationships among ARGs, and antibiotics and integron genes in hospital wastewaters.
Asbell, Penny A; Sanfilippo, Christine M; Pillar, Christopher M; DeCory, Heleen H; Sahm, Daniel F; Morris, Timothy W
The Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) study is the only ongoing nationwide antibiotic resistance surveillance program specific to ocular pathogens. To report resistance rates and trends among common ocular isolates collected during the first 5 years of the ARMOR study. This antibiotic resistance surveillance study was performed at an independent central laboratory. Clinical centers across the United States were invited to submit ocular isolates of Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa. Isolates were collected from January 1, 2009, through December 31, 2013, and analyzed from January 16 to May 15, 2015. Minimum inhibitory concentrations for various antibiotic classes were determined by broth microdilution according to the guidelines of the Clinical and Laboratory Standards Institute. Minimum inhibitory concentrations were interpreted as susceptible, intermediate, or resistant based on established break points. A total of 3237 ocular isolates (1169 S aureus, 992 CoNS, 330 S pneumoniae, 357 H influenzae, and 389 P aeruginosa) were collected from 72 centers. Methicillin resistance was found among 493 S aureus isolates (42.2%; 95% CI, 39.3%-45.1%) and 493 CoNS isolates (49.7%; 95% CI, 46.5%-52.9%), and methicillin-resistant (MR) isolates had a high probability of concurrent resistance to fluoroquinolones, aminoglycosides, or macrolides (P < .001). Multidrug resistance to at least 3 additional antibiotic classes was found in 428 MR S aureus isolates (86.8%) and 381 MRCoNS isolates (77.3%). All staphylococcal isolates were susceptible to vancomycin. Resistance among S pneumoniae isolates was highest for azithromycin (113 isolates [34.2%]) whereas resistance among P aeruginosa and H influenzae was low against the antibiotics tested. Staphylococcal isolates from elderly patients were more likely to be MR, as were S aureus isolates
Proia, Lorenzo; Anzil, Adriana; Subirats, Jessica; Borrego, Carles; Farrè, Marinella; Llorca, Marta; Balcázar, Jose Luis; Servais, Pierre
Urban rivers are impacted ecosystems which may play an important role as reservoirs for antibiotic-resistant (AR) bacteria. The main objective of this study was to describe the prevalence of antibiotic resistance along a sewage-polluted urban river. Seven sites along the Zenne River (Belgium) were selected to study the prevalence of AR Escherichia coli and freshwater bacteria over a 1-year period. Culture-dependent methods were used to estimate E. coli and heterotrophic bacteria resistant to amoxicillin, sulfamethoxazole, nalidixic acid and tetracycline. The concentrations of these four antibiotics have been quantified in the studied river. The antibiotic resistance genes (ARGs), sul1, sul2, tetW, tetO, blaTEM and qnrS were also quantified in both particle-attached (PAB) and free-living (FLB) bacteria. Our results showed an effect of treated wastewaters release on the spread of antibiotic resistance along the river. Although an increase in the abundance of both AR E. coli and resistant heterotrophic bacteria was observed from upstream to downstream sites, the differences were only significant for AR E. coli. A significant positive regression was also found between AR E. coli and resistant heterotrophic bacteria. The concentration of ARGs increased from upstream to downstream sites for both particle-attached (PAB) and free-living bacteria (FLB). Particularly, a significant increase in the abundance of four among six ARGs analyzed was observed after crossing urban area. Although concentrations of tetracycline significantly correlated with tetracycline resistance genes, the antibiotic levels were likely too low to explain this correlation. The analysis of ARGs in different fractions revealed a significantly higher abundance in PAB compared to FLB for tetO and sul2 genes. This study demonstrated that urban activities may increase the spread of antibiotic resistance even in an already impacted river. Copyright © 2018 Elsevier B.V. All rights reserved.
McKinney, Chad W; Loftin, Keith A; Meyer, Michael T; Davis, Jessica G; Pruden, Amy
Although livestock operations are known to harbor elevated levels of antibiotic resistant bacteria, few studies have examined the potential of livestock waste lagoons to reduce antibiotic resistance genes (ARGs). The purpose of this study was to determine the prevalence and examine the behavior of tetracycline [tet(O) and tet(W)] and sulfonamide [sul(I) and sul(II)] ARGs in a broad cross-section of livestock lagoons within the same semiarid western watershed. ARGs were monitored for one year in the water and the settled solids of eight lagoon systems by quantitative polymerase chain reaction. In addition, antibiotic residues and various bulk water quality constituents were analyzed. It was found that the lagoons of the chicken layer operation had the lowest concentrations of both tet and sul ARGs and low total antibiotic concentrations, whereas sul ARGs were highest in the swine lagoons, which generally corresponded to the highest total antibiotic concentrations. A marginal benefit of organic and small dairy operations also was observed compared to conventional and large dairies, respectively. In all lagoons, sul ARGs were observed to be generally more recalcitrant than tet ARGs. Also, positive correlations of various bulk water quality constituents were identified with tet ARGs but not sul ARGs. Significant positive correlations were identified between several metals and tet ARGs, but Pearson's correlation coefficients were mostly lower than those determined between antibiotic residues and ARGs. This study represents a quantitative characterization of ARGs in lagoons across a variety of livestock operations and provides insight into potential options for managing antibiotic resistance emanating from agricultural activities.
McKinney, C.W.; Loftin, K.A.; Meyer, M.T.; Davis, J.G.; Pruden, A.
Although livestock operations are known to harbor elevated levels of antibiotic resistant bacteria, few studies have examined the potential of livestock waste lagoons to reduce antibiotic resistance genes (ARGs). The purpose of this study was to determine the prevalence and examine the behavior of tetracycline [tet(O) and tet(W)] and sulfonamide [sul(I) and su/(II)] ARGsin a broad cross-section of livestock lagoons within the same semiarid western watershed. ARGs were monitored for one year in the water and the settled solids of eight lagoon systems by quantitative polymerase chain reaction. In addition, antibiotic residues and various bulk water quality constituents were analyzed. It was found that the lagoons of the chicken layer operation had the lowest concentrations of both tet and sul ARGs and low total antibiotic concentrations, whereas su ARGs were highest in the swine lagoons, which generally corresponded to the highest total antibiotic concentrations. A marginal benefit of organic and small dairy operations also was observed compared to conventional and large dairies, respectively. In all lagoons, su ARGs were observed to be generally more recalcitrant than tet ARGs. Also, positive correlations of various bulk water quality constituents were identified with tet ARGs but not sul ARGs. Significant positive correlations were identified between several metals and tet ARGs, but Pearson's correlation coefficients were mostly lower than those determined between antibiotic residues and ARGs. This study represents a quantitative characterization of ARGs in lagoons across a variety of livestock operations and provides insight into potential options for managing antibiotic resistance emanating from agricultural activities. ?? 2010 American Chemical Society.
Full Text Available Fifteen Bacillus strains which were isolated from soil samples were examined for resistance to 17 different antibiotics (ampicillin, methicillin, erythromycin, norfloxacin, cephalotine, gentamycin, ciprofloxacin, streptomycin, tobramycin, chloramphenicol, trimethoprim-sulfamethoxazole, tetracycline, vancomycin, oxacilin, neomycin, kanamycin and, novabiocin and to 10 different heavy metals (copper, lead, cobalt, chrome, iron, mercury, zinc, nickel, manganese and, cadmium and for the presence of plasmid DNA. A total of eleven strains (67% were resistant to at least one antibiotic. The most common resistance was observed against methicillin and oxacillin. The most resistance strains were found as Bacillus sp. B3 and Bacillus sp. B11. High heavy metal resistance against copper, chromium, zinc, iron and nickel was detected, but mercury and cobalt resistance was not detected, except for 3 strains (B3, B11, and B12 which showed mercury resistance. It has been determined that seven Bacillus strains have plasmids. The isolated plasmids were transformed into the Bacillus subtilis W168 and it was shown that heavy metal and antibiotic resistance determinants were carried on these plasmids. These results showed that there was a correlation between plasmid content and resistance for both antibiotic and heavy metal resistance
Full Text Available There have been many calls for more information about the natural resistome and these have also highlighted the importance of understanding the soil resistome in the preservation of antibiotics for the treatment of infections. However, to date there have been few studies which have investigated the culturable soil resistome, which highlights the difficulties faced by microbiologists in designing these experiments to produce meaningful data. The World Health Organization definition of resistance is the most fitting to non-clinical environmental studies: Antimicrobial resistance is resistance of a microorganism to an antimicrobial medicine to which it was previously sensitive. The ideal investigation of non-clinical environments for antibiotic resistance of clinical relevance would be using standardized guidelines and breakpoints. This review outlines different definitions and methodologies used to understand antibiotic resistance and suggests how this can be performed outside of the clinical environment.
... 300 million to bring a new antibiotic to market. Many efforts to find novel drugs in fungi ... sulbactam are already in use for blocking the beta-lactamase enzymes that destroy the penicillin family of ...
Jeljaszewicz, J.; Hawiger, J.
The increasing number of antibiotic-resistant strains of micro-organisms is posing serious problems. A nation-wide survey has therefore been carried out in Poland to determine the resistance of strains of Staphylococcus aureus from different sources to eight antibiotics; in all, some 31 000 strains were examined. In general, the most resistant strains from humans were derived from faeces, urine and blood, and the least resistant from bile and pus. Food yielded strains of even lower resistance. Strains from hospital material were, in general, considerably more resistant than those from non-hospital material. The only exception was in resistance to neomycin; the strains most resistant to this antibiotic were obtained from bile and throat, and the least resistant from urine and cerebrospinal fluid; moreover, non-hospital strains were more resistant than hospital ones. On the average, the proportions of strains resistant to the eight antibiotics were: penicillin, 84.0%; streptomycin, 69.5%; tetracycline, 60.1%; chlortetracycline, 56.9%; oxytetracycline, 56.7%; neomycin, 56.2%; chloramphenicol, 48.6%; erythromycin, 47.4%. PMID:5297006
Heloisa Helena Karnas Hoefel
Full Text Available The success of antibiotics treatment and development of bacterial resistance depend on many factors. The preparation and management of these factors are associated with nursing care. The aim of this paper is review literature about preparation, management and knowledge of intravenous antibiotics errors analyzing possibilities of influence of bacterial resistance prevention by nurses. Methods: a systematic review was done from LiILACS and Medline searching for the word nursing and bacterial resistance, antibiotics control, hospital infections, administration drugs, errors and adverse events. There were chose 58 papers about nursing and/or were basics for international and Brazilian studies. Results: It was described international classifications errors and consequences analyzing their possible influences on antibiotics effects. Based on these knowledge, interventions are recommended to implement safety practice and care.
Fluit, A. C.; van der Bruggen, J. T.; Aarestrup, Frank Møller
, be longitudinal, and cover a sufficiently large and representative population. However, many fall short of these requirements that define good surveillance studies. Moreover, current efforts are dispersed among many, mostly small, initiatives with different objectives. These studies must be tailored...... the diagnosis of hospitalised patients, and the DANMAP programme, which collects data in the veterinary sector. As already noted by the WHO, genetic studies that include both the typing of isolates and the characterisation of resistance determinants are necessary to understand fully the spread and development...
Ciofu, Oana; Tolker-Nielsen, Tim
One of the most important features of microbial biofilms is their tolerance to antimicrobial agents and components of the host immune system. The difficulty of treating biofilm infections with antibiotics is a major clinical problem. Although antibiotics may decrease the number of bacteria...... in biofilms, they will not completely eradicate the bacteria in vivo which may have important clinical consequences in form of relapses of the infection....
Nguyen, Kinh Van; Thi Do, Nga Thuy; Chandna, Arjun; Nguyen, Trung Vu; Pham, Ca Van; Doan, Phuong Mai; Nguyen, An Quoc; Thi Nguyen, Chuc Kim; Larsson, Mattias; Escalante, Socorro; Olowokure, Babatunde; Laxminarayan, Ramanan; Gelband, Hellen; Horby, Peter; Thi Ngo, Ha Bich; Hoang, Mai Thanh; Farrar, Jeremy; Hien, Tran Tinh; Wertheim, Heiman F L
Antimicrobial resistance is a major contemporary public health threat. Strategies to contain antimicrobial resistance have been comprehensively set forth, however in developing countries where the need for effective antimicrobials is greatest implementation has proved problematic. A better understanding of patterns and determinants of antibiotic use and resistance in emerging economies may permit more appropriately targeted interventions.Viet Nam, with a large population, high burden of infectious disease and relatively unrestricted access to medication, is an excellent case study of the difficulties faced by emerging economies in controlling antimicrobial resistance. Our working group conducted a situation analysis of the current patterns and determinants of antibiotic use and resistance in Viet Nam. International publications and local reports published between 1-1-1990 and 31-8-2012 were reviewed. All stakeholders analyzed the findings at a policy workshop and feasible recommendations were suggested to improve antibiotic use in Viet Nam.Here we report the results of our situation analysis focusing on: the healthcare system, drug regulation and supply; antibiotic resistance and infection control; and agricultural antibiotic use. Market reforms have improved healthcare access in Viet Nam and contributed to better health outcomes. However, increased accessibility has been accompanied by injudicious antibiotic use in hospitals and the community, with predictable escalation in bacterial resistance. Prescribing practices are poor and self-medication is common - often being the most affordable way to access healthcare. Many policies exist to regulate antibiotic use but enforcement is insufficient or lacking.Pneumococcal penicillin-resistance rates are the highest in Asia and carbapenem-resistant bacteria (notably NDM-1) have recently emerged. Hospital acquired infections, predominantly with multi-drug resistant Gram-negative organisms, place additional strain on
Tammer, I; Geginat, G; Lange, S; Kropf, S; Lodes, U; Schlüter, D; Lippert, H; Meyer, F
Antibiotic resistence is increasing worldwide. A longitudinal analysis of the influence of the density of antibiotic use on the development of resistance in surgical units was undertaken. Over five years the incidence of pathogens and the resistance rates of isolates from patients of normal surgical units and those of a surgical ICU at a university hospital were examined. The resistence rates were correlated with the density of antibiotic use - calculated from the antibiotic consumption (in DDD) and the number of patient-days. At both units, Enterobacteriaceae and Enterococci were mostly cultured. Among the Enterobacteriaceae, E. coli, Klebsiella spp., Proteus mirabilis and Enterobacter predominated. In the group of Enterococci, E. faecalis predominated at wards whereas at ICU E. faecium was the most frequent. Anaerobes ranked third at normal wards and Candida spp. at ICU. From 2007 to 2011, there was an increasing resistance against ciprofloxacin in P. mirabilis (r = 0.87; p = 0.054) and against imipenem (r = 0.86; p = 0.06) and piperacillin (r = 0.81; p = 0.09) in P. aeruginosa at normal wards. At ICU, the resistance rates of imipenem in P. aeruginosa rose (r = 0.88; p = 0.049). Resistance against ciprofloxacin in E. coli increased (r = 0.65; p = 0.23). Due to the increasing use of ciprofloxacin and meropenem at normal wards, the density of antibiotic usage rose 1.4 %/year (r = 0.94; p = 0.02). Despite the increase of meropenem use at ICU (r = 0.9; p = 0.035), the total antibiotic uptake rate remained almost constant. The antibiotic usage density was 3-fold higher at ICU than at normal wards. At normal wards, the ciprofloxacin usage correlated with the rate of resistance against ciprofloxacin in P. mirabilis P. m. At ICU, an association was detected between the uptake rate of ceftazidime and the rate of resistance against cefotaxime in the CES group. In P. aeruginosa, the use of piperacillin and the rate
María Blanca Sánchez
Full Text Available Stenotrophomonas maltophilia is an environmental bacterium found in the soil, associated with plants and animals, and in aquatic environments. It is also an opportunistic pathogen now causing an increasing number of nosocomial infections. The treatment of S. maltophilia is quite difficult given its intrinsic resistance to a number of antibiotics, and because it is able to acquire new resistances via horizontal gene transfer and mutations. Certainly, strains resistant to quinolones, cotrimoxale and/or cephalosporins - antibiotics commonly used to treat S. maltophilia infections - have emerged. The increasing number of available S. maltophilia genomes has allowed the identification and annotation of a large number of antimicrobial and heavy metal resistance genes. Most encode inactivating enzymes and efflux pumps, but information on their role in intrinsic and acquired resistance is limited. Non-typical antibiotic resistance mechanisms that also form part of the intrinsic resistome have been identified via mutant library screening. These include non-typical antibiotic resistance genes, such as bacterial metabolism genes, and non-inheritable resistant phenotypes, such as biofilm formation and persistence. Their relationships with resistance are complex and require further study.
Full Text Available Antibiotic resistance patterns of bacterial isolates from both quarter teat-tip swabs and their quarter milk samples were evaluated in smallholder dairy farms in northern Thailand with excessive use of antibiotics (HIGH compared with normal use (NORM. Results from teat-tip swab samples showed that the percentage of Bacillus spp. resistance to overall antibiotics was significantly lower in the NORM group than that of the HIGH group, whereas, the resistance percentage of coagulase-negative staphylococci in the NORM group was higher than that of the HIGH one. The overall mastitis-causing bacteria isolated from milk samples were environmental streptococci (13.8%, coagulase-negative staphylococci (9.9%, Staphylococcus aureus (5.4%, and Corynebacterium bovis (4.5%. Both staphylococci and streptococci had significantly higher percentages of resistance to cloxacillin and oxacillin in the HIGH group when compared to the NORM one. An occurrence of vancomycin-resistant bacteria was also observed in the HIGH group. In conclusion, the smallholder dairy farms with excessive use of antibiotics had a higher probability of antibiotic-resistant pattern than the farms with normal use.
On 27 Feb., 2017, the World Health Organization (WHO) announced the first list of important antibiotic-resistant bacteria (http://www.who.int/mediacentre/news/releases/2017/bacteria-antibiotics-needed/en/), which tremendously threat human-being’s health. This list included 12 kinds of bacteria that were categorized into three priority tiers: Critical, High and Medium. In the first tier, Critical, three Gram negative bacteria were included: Acinetobacter baumannii with carbapenem-resis...
Torres-Cortés, Gloria; Millán, Vicenta; Ramírez-Saad, Hugo C; Nisa-Martínez, Rafael; Toro, Nicolás; Martínez-Abarca, Francisco
The soil microbial community is highly complex and contains a high density of antibiotic-producing bacteria, making it a likely source of diverse antibiotic resistance determinants. We used functional metagenomics to search for antibiotic resistance genes in libraries generated from three different soil samples, containing 3.6 Gb of DNA in total. We identified 11 new antibiotic resistance genes: 3 conferring resistance to ampicillin, 2 to gentamicin, 2 to chloramphenicol and 4 to trimethoprim. One of the clones identified was a new trimethoprim resistance gene encoding a 26.8 kDa protein closely resembling unassigned reductases of the dihydrofolate reductase group. This protein, Tm8-3, conferred trimethoprim resistance in Escherichia coli and Sinorhizobium meliloti (γ- and α-proteobacteria respectively). We demonstrated that this gene encoded an enzyme with dihydrofolate reductase activity, with kinetic constants similar to other type I and II dihydrofolate reductases (K(m) of 8.9 µM for NADPH and 3.7 µM for dihydrofolate and IC(50) of 20 µM for trimethoprim). This is the first description of a new type of reductase conferring resistance to trimethoprim. Our results indicate that soil bacteria display a high level of genetic diversity and are a reservoir of antibiotic resistance genes, supporting the use of this approach for the discovery of novel enzymes with unexpected activities unpredictable from their amino acid sequences. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
Zhang, Song He; Lv, Xiaoyang; Han, Bing; Gu, Xiucong; Wang, Pei Fang; Wang, Chao; He, Zhenli
The rapid development of antibiotic-resistant bacteria (ARB) has been of concern worldwide. In this study, antibiotic resistance genes (ARGs) were investigated in antibiotic-resistant Escherichia coli isolated from surface water samples (rivers, n = 17; Taihu Lake, n = 16) and from human, chicken, swine, and Egretta garzetta sources in the Taihu Basin. E. coli showing resistance to at least five drugs occurred in 31, 67, 58, 27, and 18% of the isolates from surface water (n = 665), chicken (n = 27), swine (n = 29), human (n = 45), and E. garzetta (n = 15) sources, respectively. The mean multi-antibiotic resistance (MAR) index of surface water samples (0.44) was lower than that of chicken (0.64) and swine (0.57) sources but higher than that of human (0.30) and E. garzetta sources (0.15). Ten tetracycline, four sulfonamide, four quinolone, five β-lactamase, and two streptomycin resistance genes were detected in the corresponding antibiotic-resistant isolates. Most antibiotic-resistant E. coli harbored at least two similar functional ARGs. Int-I was detected in at least 57% of MAR E. coli isolates. The results of multiple correspondence analysis and Spearman correlation analysis suggest that antibiotic-resistant E. coli in water samples were mainly originated from swine, chicken, and/or human sources. Most of the ARGs detected in E. garzetta sources were prevalent in other sources. These data indicated that human activities may have contributed to the spread of ARB in the aquatic environment.
Full Text Available Antibiotic resistance is one of the most relevant problems in the healthcare: the growth of resistant micro-organisms in healthcare settings is a worrisome threat, raising length to stay (LOS, morbidity and mortality in those patients. The importance of the antibiotic resistance and its spread around the world, gave rise to the activation of several surveillance systems, based especially on the collection of laboratory data to local or national level. The objective of this work is to carry out a review of the scientific literature existing on the topic and scientific activities related to surveillance on antibiotic resistance in countries bordering the Mediterranean Sea. Recent Data from European Centre for Disease Prevention and Control (November 2015 show, for different combinations bacterium-drug, an increase of resistance from North to South and from West to East of Europe; it is particularly worrying the phenomenon of resistance carried out by some gram negative, specifically Klebsiella pneumoniae and Escherichia coli to third-generation cephalosporin, often combined in opposition to fluoroquinolones and amino glycosides. Is particularly relevant the incidence of resistance to carbapenems by strains of Enterobacteriaceae (Klebsiella included. The resistance exerted by MRSA (Methicillin-resistant Staphylococcus aureus continues to be relevant, albeit showing some decline in recent years. The incidence of resistance carried on by Streptococcus pneumoniae is stable and is mainly relevant to macrolides. Finally, a significant increase in recording relatively exercised by Enterococcus faecium to Vancomycin. Detecting, preventing, and controlling antibiotic resistance requires strategic, coordinated, and sustained efforts. It also depends on the engagement of governments, academia, industry, healthcare providers, the general public, and the agricultural community, as well as international partners. Committing to combating antibiotic-resistant
Herrick, J B; Haynes, R; Heringa, S; Brooks, J M; Sobota, L T
Transmissible plasmids captured from stream and soil bacteria conferring resistance to tetracycline in Pseudomonas were evaluated for linked resistance to antibiotics used in the treatment of human infections. Cells released from stream sediments and soils were conjugated with a rifampicin-resistant, plasmid-free Pseudomonas putida recipient and selected on tetracycline and rifampicin. Each transconjugant contained a single 50-80 kb plasmid. Resistance to 11 antibiotics, in addition to tetracycline, was determined for the stream transconjugants using a modification of the Stokes disc diffusion antibiotic susceptibility assay. Nearly half of plasmids conferred resistance to six or more antibiotics. Resistance to streptomycin, gentamicin, and/or ticarcillin was conferred by a majority of the plasmids, and resistance to additional human clinical use antibiotics such as piperacillin/tazobactam, ciprofloxacin and aztreonam was observed. MICs of 16 antibiotics for representative sediment and soil transconjugants revealed large increases, relative to the Ps. putida recipient, for 11 of 16 antibiotics tested, including the expanded spectrum antibiotics cefotaxime and ceftazidime, as well as piperacillin/tazobactam, lomefloxacin and levofloxacin. Resistance to multiple antibiotics-including those typically used in clinical Pseudomonas and enterobacterial infections-can be conferred by transmissible plasmids in streams and soils. Selective pressure exerted by the use of one antibiotic, such as the common agricultural antibiotic tetracycline, may result in the persistence of linked genes conferring resistance to important human clinical antibiotics. This may impact the spread of resistance to human use antibiotics even in the absence of direct selection. © 2014 The Society for Applied Microbiology.
Wu, Xiaozhe; Li, Zhan; Li, Xiaolu; Tian, Yaomei; Fan, Yingzi; Yu, Chaoheng; Zhou, Bailing; Liu, Yi; Xiang, Rong; Yang, Li
Antibiotic-resistant bacteria present a great threat to public health. In this study, the synergistic effects of antimicrobial peptides (AMPs) and antibiotics on several multidrug-resistant bacterial strains were studied, and their synergistic effects on azithromycin (AZT)-resistance genes were analyzed to determine the relationships between antimicrobial resistance and these synergistic effects. A checkerboard method was used to evaluate the synergistic effects of AMPs (DP7 and CLS001) and several antibiotics (gentamicin, vancomycin [VAN], AZT, and amoxicillin) on clinical bacterial strains ( Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii , and Escherichia coli ). The AZT-resistance genes ( ermA, ermB, ermC, mefA , and msrA ) were identified in the resistant strains using quantitative polymerase chain reaction. For all the clinical isolates tested that were resistant to different antibiotics, DP7 had high antimicrobial activity (≤32 mg/L). When DP7 was combined with VAN or AZT, the effect was most frequently synergistic. When we studied the resistance genes of the AZT-resistant isolates, the synergistic effect of DP7-AZT occurred most frequently in highly resistant strains or strains carrying more than two AZT-resistance genes. A transmission electron microscopic analysis of the S. aureus strain synergistically affected by DP7-AZT showed no noteworthy morphological changes, suggesting that a molecular-level mechanism plays an important role in the synergistic action of DP7-AZT. AMP DP7 plus the antibiotic AZT or VAN is more effective, especially against highly antibiotic-resistant strains.
Nzalie, Rolf Nyah-tuku; Gonsu, Hortense Kamga; Koulla-Shiro, Sinata
Introduction. Community-acquired urinary tract infections (CAUTIs) are usually treated empirically. Geographical variations in etiologic agents and their antibiotic sensitivity patterns are common. Knowledge of antibiotic resistance trends is important for improving evidence-based recommendations for empirical treatment of UTIs. Our aim was to determine the major bacterial etiologies of CAUTIs and their antibiotic resistance patterns in a cosmopolitan area of Cameroon for comparison with pres...
Ayhan, Dilay Hazal; Tamer, Yusuf Talha; Akbar, Mohammed; Bailey, Stacey M; Wong, Michael; Daly, Seth M; Greenberg, David E; Toprak, Erdal
The lack of effective and well-tolerated therapies against antibiotic-resistant bacteria is a global public health problem leading to prolonged treatment and increased mortality. To improve the efficacy of existing antibiotic compounds, we introduce a new method for strategically inducing antibiotic hypersensitivity in pathogenic bacteria. Following the systematic verification that the AcrAB-TolC efflux system is one of the major determinants of the intrinsic antibiotic resistance levels in Escherichia coli, we have developed a short antisense oligomer designed to inhibit the expression of acrA and increase antibiotic susceptibility in E. coli. By employing this strategy, we can inhibit E. coli growth using 2- to 40-fold lower antibiotic doses, depending on the antibiotic compound utilized. The sensitizing effect of the antisense oligomer is highly specific to the targeted gene's sequence, which is conserved in several bacterial genera, and the oligomer does not have any detectable toxicity against human cells. Finally, we demonstrate that antisense oligomers improve the efficacy of antibiotic combinations, allowing the combined use of even antagonistic antibiotic pairs that are typically not favored due to their reduced activities.
Wong, Michael; Daly, Seth M.; Greenberg, David E.; Toprak, Erdal
The lack of effective and well-tolerated therapies against antibiotic-resistant bacteria is a global public health problem leading to prolonged treatment and increased mortality. To improve the efficacy of existing antibiotic compounds, we introduce a new method for strategically inducing antibiotic hypersensitivity in pathogenic bacteria. Following the systematic verification that the AcrAB-TolC efflux system is one of the major determinants of the intrinsic antibiotic resistance levels in Escherichia coli, we have developed a short antisense oligomer designed to inhibit the expression of acrA and increase antibiotic susceptibility in E. coli. By employing this strategy, we can inhibit E. coli growth using 2- to 40-fold lower antibiotic doses, depending on the antibiotic compound utilized. The sensitizing effect of the antisense oligomer is highly specific to the targeted gene’s sequence, which is conserved in several bacterial genera, and the oligomer does not have any detectable toxicity against human cells. Finally, we demonstrate that antisense oligomers improve the efficacy of antibiotic combinations, allowing the combined use of even antagonistic antibiotic pairs that are typically not favored due to their reduced activities. PMID:27631336
Laport, Marinella Silva; Pontes, Paula Veronesi Marinho; Dos Santos, Daniela Silva; Santos-Gandelman, Juliana de Fátima; Muricy, Guilherme; Bauwens, Mathieu; Giambiagi-deMarval, Marcia; George, Isabelle
Although antibiotic-resistant pathogens pose a significant threat to human health, the environmental reservoirs of the resistance determinants are still poorly understood. This study reports the detection of resistance genes (ermB, mecA, mupA, qnrA, qnrB and tetL) to antibiotics among certain culturable and unculturable bacteria associated with the marine sponge Petromica citrina. The antimicrobial activities elicited by P. citrina and its associated bacteria are also described. The results indicate that the marine environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.
Full Text Available In this paper the antibiotic resistance of microbial contaminations isolated from husbandry animals and foodstuffs were investigated. Microorganisms isolated from animals and foodstuffs were contaminations of selective media as MacConkey agar for Enterobacteriaceae genera and MRS agar for lactobacilli strains. Microorganisms were isolated and puryfied by agar four ways streak plate method. Identification of isolated microorganisms was done by mass-spectrometry method in MALDI-TOF MS Biotyper. For investigation of antibiotic resistance disc diffusion method by EUCAST was used. In this study Gram-negative and Gram-positive bacteria were identified. The most resistant or multi-resistant bacteria as Pseudomonas aeruginosa, Acinetobacter lwoffi, Lysinibacillus sphaericus, Staphylococcus aureus and Staphylococcus epidermis were determined. Other identified microorganisms were resistant to one antibiotic or not at all.
Abdul-Aziz, Mohd H; Lipman, Jeffrey; Roberts, Jason A
Nosocomial pneumonia caused by multidrug-resistant pathogens is increasing in the ICU, and these infections are negatively associated with patient outcomes. Optimization of antibiotic dosing has been suggested as a key intervention to improve clinical outcomes in patients with nosocomial pneumonia. This review describes the recent pharmacokinetic/pharmacodynamic data relevant to antibiotic dosing for nosocomial pneumonia caused by multidrug-resistant pathogens. Optimal antibiotic treatment is challenging in critically ill patients with nosocomial pneumonia; most dosing guidelines do not consider the altered physiology and illness severity associated with severe lung infections. Antibiotic dosing can be guided by plasma drug concentrations, which do not reflect the concentrations at the site of infection. The application of aggressive dosing regimens, in accordance to the antibiotic's pharmacokinetic/pharmacodynamic characteristics, may be required to ensure rapid and effective drug exposure in infected lung tissues. Conventional antibiotic dosing increases the likelihood of therapeutic failure in critically ill patients with nosocomial pneumonia. Alternative dosing strategies, which exploit the pharmacokinetic/pharmacodynamic properties of an antibiotic, should be strongly considered to ensure optimal antibiotic exposure and better therapeutic outcomes in these patients.
Marosevic, Durdica; Kaevska, Marija; Jaglic, Zoran
An excessive use of antimicrobial agents poses a risk for the selection of resistant bacteria. Of particular interest are antibiotics that have large consumption rates in both veterinary and human medicine, such as the tetracyclines and macrolide-lincosamide-streptogramin (MLS) group of antibiotics. A high load of these agents increases the risk of transmission of resistant bacteria and/or resistance determinants to humans, leading to a subsequent therapeutic failure. An increasing incidence of bacteria resistant to both tetracyclines and MLS antibiotics has been recently observed. This review summarizes the current knowledge on different tetracycline and MLS resistance genes that can be linked together on transposable elements.
Andersson, Dan I; Hughes, Diarmaid
Ever since antibiotics were introduced into human and veterinary medicine to treat and prevent bacterial infections there has been a steady selection and increase in the frequency of antibiotic resistant bacteria. To be able to reduce the rate of resistance evolution, we need to understand how various biotic and abiotic factors interact to drive the complex processes of resistance emergence and transmission. We describe several of the fundamental factors that underlay resistance evolution, including rates and niches of emergence and persistence of resistant bacteria, time- and space-gradients of various selective agents, and rates and routes of transmission of resistant bacteria between humans, animals and other environments. Furthermore, we discuss the options available to reduce the rate of resistance evolution and/ or transmission and their advantages and disadvantages.
Leibovici, Leonard; Soares-Weiser, Karla; Paul, Mical; Goldberg, Elad; Herxheimer, Andrew; Garner, Paul
Microorganisms resistant to antibiotic drugs are a threat to the health and chances of survival of patients. Systematic reviews on antibiotic drugs that ignore the topic of resistance present readers with a skewed view, emphasizing short-term efficacy or effectiveness while ignoring long-term consequences. To examine whether systematic reviews of antibiotic treatment consider resistance; if not, to find out whether data on resistance were reported in the original trials; and based on that, to offer a framework for taking resistance into account in systematic reviews. The Cochrane Database of Systematic Reviews (the Cochrane Library, 2001, issue 2); and MEDLINE, 1996-2000. (i) Systematic reviews or meta-analyses of antimicrobial therapy, published during 1996-2000. (ii) Randomized, controlled trials abstracted in systematic reviews that addressed a topic highly relevant to antibiotic resistance. We examined each systematic review, and each article, to see whether the implications of resistance were discussed; and whether data on resistance were collected. Out of 111 systematic reviews, only 44 (40%) discussed resistance. Ten reviews (9%) planned or performed collection of data on the response of patients with susceptible or resistant isolates. In 22 systematic reviews (20%), collection of data on induction of resistance was planned or performed. The topic of 41 reviews was judged highly relevant to resistance, and these reviews extracted data from 337 articles, out of which we retrieved 279 articles (83%). In 201 (72%) articles, resistance was discussed or data pertaining to it were collected. Ninety-seven articles (35%) gave actual data on resistance of pathogens to the study drugs, 71 articles (25%) data on efficacy of antibiotic drugs in patients with susceptible and resistant pathogens, and 55 articles (20%) provided data on infection or colonization with resistant strains during treatment. Most systematic reviews on antibiotic treatment ignored the issue of
Chitanand, M P; Kadam, T A; Gyananath, G; Totewad, N D; Balhal, D K
Bacteriological analysis of the water samples collected from upstream, midstream and downstream points along the bank of the river revealed high populations of Escherichia coli, Citrobacter freundii, Citrobacter diversus, Enterobacter aerogens and Klebsiella species. All these isolates were screened against eight antibiotics to determine the prevalence of multiple antibiotic resistance among isolates at different sites of the river. The study revealed that multiple antibiotic resistance was prominently seen in coliforms at downstream sites (Average multiple antibiotic resistance index, MAR Index = 0.43) while it was low in coliforms at upstream sites (MAR Index = 0.15). These differences in MAR indices provide a method for distinguishing high risk contamination sites in aquatic environment.
Mira, Portia M; Meza, Juan C; Nandipati, Anna; Barlow, Miriam
Most studies on the evolution of antibiotic resistance are focused on selection for resistance at lethal antibiotic concentrations, which has allowed the detection of mutant strains that show strong phenotypic traits. However, solely focusing on lethal concentrations of antibiotics narrowly limits our perspective of antibiotic resistance evolution. New high-resolution competition assays have shown that resistant bacteria are selected at relatively low concentrations of antibiotics. This finding is important because sublethal concentrations of antibiotics are found widely in patients undergoing antibiotic therapies, and in nonmedical conditions such as wastewater treatment plants, and food and water used in agriculture and farming. To understand the impacts of sublethal concentrations on selection, we measured 30 adaptive landscapes for a set of TEM β-lactamases containing all combinations of the four amino acid substitutions that exist in TEM-50 for 15 β-lactam antibiotics at multiple concentrations. We found that there are many evolutionary pathways within this collection of landscapes that lead to nearly every TEM-genotype that we studied. While it is known that the pathways change depending on the type of β-lactam, this study demonstrates that the landscapes including fitness optima also change dramatically as the concentrations of antibiotics change. Based on these results we conclude that the presence of multiple concentrations of β-lactams in an environment result in many different adaptive landscapes through which pathways to nearly every genotype are available. Ultimately this may increase the diversity of genotypes in microbial populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: email@example.com.
Younis, N; Quol, K; Al-Momani, T; Al-Awaisheh, F; Al-Kayed, D
Urinary tract infection is certainly one of the most common childhood infections. Emerging resistance to the antibiotics is not unusual. Current hospitalization for children with urinary tract infection is reserved for severe or complicated cases. The aim of the present study was to determine the antibiotic resistance pattern among children with recurrent or complicated urinary tract infection. A retrospective study carried out at Prince Hashem hospital, Zarqa city, eastern Jordan and involved 336 episodes of culture proved urinary tract infection obtained from 121 patients with recurrent UTI, who used prophylactic antibiotics during the period from April 1, 2004 to December 31, 2006. The isolated microorganisms and there antibiotics susceptibility were studied. Seventy three patients (60.3%) were found to have some forms of urinary tract anomaly, significantly more prevalent among male children PUTA were significantly more resistant to most antibiotics tested. Pediatric urine culture isolates are becoming increasingly resistant to commonly used antibiotics. Empirical treatment with Trimethoprim-Sulfamethoxazole (TMP-SMX) or Cephalexin as the initial drug is ineffective. Nitrofurantoin and Nalidixic acid can be considered as the first line antibiotics for prophylaxis and or treatment of patients with recurrent UTI, while Meropenam and Ciprofloxacin can be used empirically in treating patients with complicated UTI.
Full Text Available The increasing levels of antimicrobial resistance among foodborne bacteria are recognised as an important emerging public health problem. Reduced susceptibility to biocides also appears to be increasing. A potential concern is the possibility that the widespread use of biocides is responsible for the selection and maintenance of antibiotic-resistant bacteria. Here, we examine the prevalence of erythromycin, ciprofloxacin, triclosan, benzalkonium chloride, chlorhexidine diacetate, cetylpyridinium chloride, trisodium phosphate and sodium dodecyl sulphate resistance among 27 isolates of Campylobacter coli and 15 isolates of Campylobacter jejuni from food, animal, human and environmental water sources. These antimicrobial susceptibilities were determined by the broth microdilution method. In the 42 Campylobacter strains studied, different antibiotic resistance levels were seen. The resistance to erythromycin and ciprofloxacin was observed in 14.3 % of Campylobacter strains. A higher rate of erythromycin resistance and multi-resistance was observed among isolated C. coli than among C. jejuni strains. Similar situations were seen for triclosan. Conversely, the level of benzalkonium chloride resistance was higher in C. jejuni than in C. coli. No correlation between biocide and antibiotic resistance was observed. This study does not provide evidence to confirm that tolerance to biocides is connected to antibiotic resistance in Campylobacter.
Zhang, Xuelian; Li, Yanxia; Liu, Bei; Wang, Jing; Feng, Chenghong; Gao, Min; Wang, Lina
This study investigated the occurrence of 12 veterinary antibiotics (VAs) and the susceptibility of Escherichia coli (E. coli) in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L−1. The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment. PMID:25372873
Zhang, Xuelian; Li, Yanxia; Liu, Bei; Wang, Jing; Feng, Chenghong; Gao, Min; Wang, Lina
This study investigated the occurrence of 12 veterinary antibiotics (VAs) and the susceptibility of Escherichia coli (E. coli) in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L(-1). The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment.
Full Text Available This study investigated the occurrence of 12 veterinary antibiotics (VAs and the susceptibility of Escherichia coli (E. coli in a rural water system that was affected by livestock production in northern China. Each of the surveyed sites was determined with at least eight antibiotics with maximum concentration of up to 450 ng L(-1. The use of VAs in livestock farming probably was a primary source of antibiotics in the rivers. Increasing total antibiotics were measured from up- to mid- and downstream in the two tributaries. Eighty-eight percent of the 218 E. coli isolates that were derived from the study area exhibited, in total, 48 resistance profiles against the eight examined drugs. Significant correlations were found among the resistance rates of sulfamethoxazole-trimethoprim, chloromycetin and ampicillin as well as between tetracycline and chlortetracycline, suggesting a possible cross-selection for resistance among these drugs. The E. coli resistance frequency also increased from up- to midstream in the three rivers. E. coli isolates from different water systems showed varying drug numbers of resistance. No clear relationship was observed in the antibiotic resistance frequency with corresponding antibiotic concentration, indicating that the antibiotic resistance for E. coli in the aquatic environment might be affected by factors besides antibiotics. High numbers of resistant E. coli were also isolated from the conserved reservoir. These results suggest that rural surface water may become a large pool of VAs and resistant bacteria. This study contributes to current information on VAs and resistant bacteria contamination in aquatic environments particularly in areas under intensive agriculture. Moreover, this study indicates an urgent need to monitor the use of VAs in animal production, and to control the release of animal-originated antibiotics into the environment.
Prevalence, antibiotic-resistance properties and enterotoxin gene profile of Bacillus cereus strains isolated from milk-based baby foods. ... Conclusion: Considerable prevalence of resistant and toxigenic B. cereus and high consumption of milk-based infant foods in Iran, represent an important public health issue which ...
Results: A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern ...
Sorg, Robin A; Lin, Leo; van Doorn, G Sander; Sorg, Moritz; Olson, Joshua; Nizet, Victor; Veening, Jan-Willem
The structure and composition of bacterial communities can compromise antibiotic efficacy. For example, the secretion of β-lactamase by individual bacteria provides passive resistance for all residents within a polymicrobial environment. Here, we uncover that collective resistance can also develop
A survey of antibiotic resistant Staphylococcus aureus strains from clinical specimens was carried out. A total of 100 different clinical specimens were investigated with a yield of 48 Staphylococcus aureus isolates. A high resistance of 95.8% to penicillin, 89.6% to ampicillin, 87.5% to tetracycline, and 75.0% to ...
Success rate of transient transformation and cell growth in selective culture were significantly increased by use of fgmR instead of a native gentamicin resistance gene, suggesting that codon optimization improved translation efficiency of the marker gene and increased antibiotic resistance. Our result shows that similarity in ...
Results: 14.0% of the faecal samples yielded S. aureus with the carriage rate among the subjects being found to be highest at about 1 month approximately in subjected ages. Sixty-five percent of the isolates were found to be resistant to more than three different antibiotics with more than 50% being resistant to penicillin, ...
The dynamics of colonization of antibiotic-resistant bacteria in hospital settings are complex and depend on bacteria and healthcare worker related characteristics. Many factors influence colonization and in addition these factors interact with each other as well. Knowledge of local resistance
Dr J. T. Ekanem
from ≤0.55kbp to ≥1.14kbp. This indicates that plasmids allow the movement of genetic materials, including antimicrobial resistance genes between bacterial species and strains. Keywords: Diarrheagenic pathogens, antibiotics resistance plasmids profile. E-mail: firstname.lastname@example.org; Tel: 08053336108, 08063418265.
The present study aimed at assessing the resistance pattern to multiple heavy metals by wastewater bacteria and associated antibiotic resistance. Methodology and results: Standard microbiological methods were used to isolate fecal streptococci, fecal coliforms, Vibrio and Salmonella species from raw animal wastewaters ...
The healthy swine intestine is populated by upwards of 500 bacterial species, mainly obligate anaerobes. Our research focuses on the roles of these commensal bacteria in antimicrobial resistance and on interventions to reduce the prevalence of antibiotic resistant bacteria. In comparisons of intes...
In spite of the many advances in microbiology, biochemistry and drug discovery and development in recent years, the world is not keeping pace with the ability of bacteria to adapt to and resist antibacterials. It is believed that the rise in bacterial resistance is partly because there have been no new classes of antibiotics.
Full Text Available Abstract Resistance to antibiotics has increased dramatically over the past few years and has now reached a level that places future patients in real danger. Microorganisms such as Escherichia coli and Klebsiella pneumoniae, which are commensals and pathogens for humans and animals, have become increasingly resistant to third-generation cephalosporins. Moreover, in certain countries, they are also resistant to carbapenems and therefore susceptible only to tigecycline and colistin. Resistance is primarily attributed to the production of beta-lactamase genes located on mobile genetic elements, which facilitate their transfer between different species. In some rare cases, Gram-negative rods are resistant to virtually all known antibiotics. The causes are numerous, but the role of the overuse of antibiotics in both humans and animals is essential, as well as the transmission of these bacteria in both the hospital and the community, notably via the food chain, contaminated hands, and between animals and humans. In addition, there are very few new antibiotics in the pipeline, particularly for Gram-negative bacilli. The situation is slightly better for Gram-positive cocci as some potent and novel antibiotics have been made available in recent years. A strong and coordinated international programme is urgently needed. To meet this challenge, 70 internationally recognized experts met for a two-day meeting in June 2011 in Annecy (France and endorsed a global call to action ("The Pensières Antibiotic Resistance Call to Action". Bundles of measures that must be implemented simultaneously and worldwide are presented in this document. In particular, antibiotics, which represent a treasure for humanity, must be protected and considered as a special class of drugs.
Toska, Aikaterini; Geitona, Mary
Greece is among the countries with the highest rates of antimicrobial resistance (AMR) and simultaneous antibiotic consumption. The aim of this study was to assess the perceptions and knowledge of AMR and irrational antibiotic prescribing of nurses working in paediatric hospitals in Greece. A self-administered questionnaire was distributed to nurses in paediatric hospitals and paediatric clinics in Greece. Descriptive and multivariate statistical analyses were performed. Levels of significance were two-tailed and statistical significance was p=0.05. A total of 87% of participants reported irrational prescribing to be an important cause of AMR. Diagnostic uncertainty was stated by 55.5% as the main cause of irrational antibiotic prescribing and 94% suggested the use of protocols and guidelines as the main measure to control overprescribing. Parental demand for antibiotics in hospitals has increased according to 51.8% of respondents. Strong correlation was observed between social-demographic characteristics and antibiotic resistance, as well as irrational prescribing. Assessing nurses' knowledge and perceptions of antimicrobial resistance and irrational prescribing is vital as nurses actively participate in the antibiotics administration process and antimicrobial management in Greece. Their involvement could contribute to educate patients and parents on the public-health implications of overprescribing and antimicrobial resistance.
Partridge, Sally R; Tsafnat, Guy
Multiresistance in Gram-negative bacteria is often due to acquisition of several different antibiotic resistance genes, each associated with a different mobile genetic element, that tend to cluster together in complex conglomerations. Accurate, consistent annotation of resistance genes, the boundaries and fragments of mobile elements, and signatures of insertion, such as DR, facilitates comparative analysis of complex multiresistance regions and plasmids to better understand their evolution and how resistance genes spread. To extend the Repository of Antibiotic resistance Cassettes (RAC) web site, which includes a database of 'features', and the Attacca automatic DNA annotation system, to encompass additional resistance genes and all types of associated mobile elements. Antibiotic resistance genes and mobile elements were added to RAC, from existing registries where possible. Attacca grammars were extended to accommodate the expanded database, to allow overlapping features to be annotated and to identify and annotate features such as composite transposons and DR. The Multiple Antibiotic Resistance Annotator (MARA) database includes antibiotic resistance genes and selected mobile elements from Gram-negative bacteria, distinguishing important variants. Sequences can be submitted to the MARA web site for annotation. A list of positions and orientations of annotated features, indicating those that are truncated, DR and potential composite transposons is provided for each sequence, as well as a diagram showing annotated features approximately to scale. The MARA web site (http://mara.spokade.com) provides a comprehensive database for mobile antibiotic resistance in Gram-negative bacteria and accurately annotates resistance genes and associated mobile elements in submitted sequences to facilitate comparative analysis.
Fair, Richard J; Tor, Yitzhak
Dangerous, antibiotic resistant bacteria have been observed with increasing frequency over the past several decades. In this review the factors that have been linked to this phenomenon are addressed. Profiles of bacterial species that are deemed to be particularly concerning at the present time are illustrated. Factors including economic impact, intrinsic and acquired drug resistance, morbidity and mortality rates, and means of infection are taken into account. Synchronously with the waxing of bacterial resistance there has been waning antibiotic development. The approaches that scientists are employing in the pursuit of new antibacterial agents are briefly described. The standings of established antibiotic classes as well as potentially emerging classes are assessed with an emphasis on molecules that have been clinically approved or are in advanced stages of development. Historical perspectives, mechanisms of action and resistance, spectrum of activity, and preeminent members of each class are discussed. PMID:25232278
This article takes its cue from the original work of sir Alexander Fleming on penicillin, published in the first issue of Recenti Progressi in Medicina in 1946 and reproduced here on the occasion of the approaching 70-year anniversary of the journal. In 1928, at the time when penicillin was discovered, it could not be imagined that bacterial resistance to antibiotics would develop so rapidly: the introduction of every new class of antibiotics has been shortly followed by the emergence of new strains of bacteria resistant to that class. Bacterial resistance to antibiotic treatment is a huge concern. In this respect, an action plan against antimicrobial resistance has been devised in the United States that is targeted for a 50% reduction over the next five years.
Turnbull, Isaiah R; Buckman, Sara A; Horn, Christopher B; Bochicchio, Grant V; Mazuski, John E
Antibiotic-impregnated central venous catheters (CVCs) decrease the incidence of infection in high-risk patients. However, use of these catheters carries the hypothetical risk of inducing antibiotic resistance. We hypothesized that routine use of minocycline and rifampin-impregnated catheters (MR-CVC) in a single intensive care unit (ICU) would change the resistance profile for Staphylococcus aureus. We reviewed antibiotic susceptibilities of S. aureus isolates obtained from blood cultures in a large urban teaching hospital from 2002-2015. Resistance patterns were compared before and after implementation of MR-CVC use in the surgical ICU (SICU) in August 2006. We also compared resistance patterns of S. aureus obtained in other ICUs and in non-ICU patients, in whom MR-CVCs were not used. Data for rifampin, oxacillin, and clindamycin were available for 9,703 cultures; tetracycline resistance data were available for 4,627 cultures. After implementation of MR-CVC use in the SICU, rifampin resistance remained unchanged, with rates the same as in other ICU and non-ICU populations (3%). After six years of use of MR-CVCs in the SICU, the rate of tetracycline resistance was unchanged in all facilities (1%-3%). The use of MR-CVCs was not associated with any change in S. aureus oxacillin-resistance rates in the SICU (66% vs. 60%). However, there was a significant decrease in S. aureus clindamycin resistance (59% vs. 34%; p resistance of S. aureus isolates to rifampin or tetracyclines.
On the contribution of reclaimed wastewater irrigation to the potential exposure of humans to antibiotics, antibiotic resistant bacteria and antibiotic resistance genes - NEREUS COST Action ES1403 position paper
Piña, Benjamin; Bayona, Josep M.; Christou, Anastasis
Antibiotic resistance (AR) is becoming a worldwide threat due to the increasing occurrence of antibiotic-resistant pathogenic bacterial strains. There is a general consensus about the potential implications of the use of antibiotics in livestock on the onset of antibiotic resistant bacteria (ARB)...
Fan, Y.; Ping, C.; Mei, L.S.
The aim of the present study was to determine the level of heavy metal resistance and antibiotic resistance patterns of bacterial isolates from environment of swine farms in China. A total of 284 bacteria were isolated, 158 from manure, 62 from soil and 64 from wastewater in different swine farm samples. All the isolates were tested for resistant against eight heavy metals. From the total of 284 isolates, maximum bacterial isolates were found to be resistant to Zn/sup 2+/ (98.6%) followed by Cu/sup 2+/ (97.5%), Cd/sup 2+/ (68.3%), Mn/sup 2+/ (60.2%), Pb/sup 2+/(51.4%), Ni/sup 2+/(41.5%) and Cr/sup 2+/(45.1%). However, most of the isolates were sensitive to Co/sup 2+/. Meanwhile,all the isolates were tested for sensitively to nine antibiotics. The results shows that most isolates were sensitive to cefoxitin and oxacillin, but resistance to tetracycline, ampicillin, gentamicin, amikacin, erythromycin, clindamycin were widespread. Multiple resistant to metals and antibiotics were also observed in this study. Most isolates were tolerant to different concentrations of various heavy metals and antibiotics. Our results confirmed that environment of swine farms in China has a significant proportion of heavy metal and antibiotic resistant bacteria, and these bacteria constitute a potential risk for swine health and public health. (author)
Full Text Available In this study, the resistance of 83 strains of lactic acid bacteria isolated from Turkish cheese, yogurt, kefir and boza samples to 6 antibiotics (gentamicin, tetracycline, chloramphenicol, erythromycin, vancomycin and ciprofloxacin was evaluated. The 83 isolates were identified by 16S rRNA gene sequencing and according to BLAST comparisons with sequences in the data banks, those strains showing the highest similarities with the isolates were Enterococcus faecium (10, Lactococcus lactis subsp. Lactis (10, Lactobacillus fermentum (6, Lactobacillus plantarum (6, Lactobacillus coryniformis (7, Lactobacillus casei (13, Leuconostoc mesenteroides (14, Pediococcus pentosaceus (10, Weisella confusa (7. Antimicrobial resistance of strains to 6 antibiotics was determined using the agar dilution method. The antibiotic resistance among all the isolates was detected against chloramphenicol (31,3 % of the isolates, tetracycline (30,1 %, erythromycin (2,4 %, ciprofloxacin (2,41%, vancomycin (73,5 %, intrinsic resistance. Overall 19,3 % of the isolates showed resistance against multiple antibiotics. Antibiotic resistance genes were studied by PCR and the following genes were detected; tet(M gene in Lactobacillus fermentum (1, Lactobacillus plantarum (1, Pediococcus pentosaceus (5, Enterococcus faecium (2, Weisella confusa (4 and the vancomycin resistance gene van(A in one Weisella confusa strain.
Michaelidis, Constantinos I; Fine, Michael J; Lin, Chyongchiou Jeng; Linder, Jeffrey A; Nowalk, Mary Patricia; Shields, Ryan K; Zimmerman, Richard K; Smith, Kenneth J
Ambulatory antibiotic prescribing contributes to the development of antibiotic resistance and increases societal costs. Here, we estimate the hidden societal cost of antibiotic resistance per antibiotic prescribed in the United States. In an exploratory analysis, we used published data to develop point and range estimates for the hidden societal cost of antibiotic resistance (SCAR) attributable to each ambulatory antibiotic prescription in the United States. We developed four estimation methods that focused on the antibiotic-resistance attributable costs of hospitalization, second-line inpatient antibiotic use, second-line outpatient antibiotic use, and antibiotic stewardship, then summed the estimates across all methods. The total SCAR attributable to each ambulatory antibiotic prescription was estimated to be $13 (range: $3-$95). The greatest contributor to the total SCAR was the cost of hospitalization ($9; 69 % of the total SCAR). The costs of second-line inpatient antibiotic use ($1; 8 % of the total SCAR), second-line outpatient antibiotic use ($2; 15 % of the total SCAR) and antibiotic stewardship ($1; 8 %). This apperars to be an error.; of the total SCAR) were modest contributors to the total SCAR. Assuming an average antibiotic cost of $20, the total SCAR attributable to each ambulatory antibiotic prescription would increase antibiotic costs by 65 % (range: 15-475 %) if incorporated into antibiotic costs paid by patients or payers. Each ambulatory antibiotic prescription is associated with a hidden SCAR that substantially increases the cost of an antibiotic prescription in the United States. This finding raises concerns regarding the magnitude of misalignment between individual and societal antibiotic costs.
Khennavong, Manisone; Davone, Viengmon; Vongsouvath, Manivanh; Phetsouvanh, Rattanaphone; Silisouk, Joy; Rattana, Olay; Mayxay, Mayfong; Castonguay-Vanier, Josée; Moore, Catrin E.; Strobel, Michel; Newton, Paul N.
Widespread use of antibiotics may be important in the spread of antimicrobial resistance. We estimated the proportion of Lao in- and outpatients who had taken antibiotics before medical consultation by detecting antibiotic activity in their urine added to lawns of Bacillus stearothermophilus, Escherichia coli, and Streptococcus pyogenes. In the retrospective (N = 2,058) and prospective studies (N = 1,153), 49.7% (95% confidence interval [CI] = 47.4–52.0) and 36.2% (95% CI = 33.4–38.9), respec...
Thames, Callie H.; Pruden, Amy; James, Robert E.; Ray, Partha P.; Knowlton, Katharine F.
Elevated levels of antibiotic resistance genes (ARGs) in soil and water have been linked to livestock farms and in some cases feed antibiotics may select for antibiotic resistant gut microbiota. The purpose of this study was to examine the establishment of ARGs in the feces of calves receiving milk replacer containing no antibiotics versus subtherapeutic or therapeutic doses of tetracycline and neomycin. The effect of antibiotics on calf health was also of interest. Twenty-eight male and female dairy calves were assigned to one of the three antibiotic treatment groups at birth and fecal samples were collected at weeks 6, 7 (prior to weaning), and 12 (5 weeks after weaning). ARGs corresponding to the tetracycline (tetC, tetG, tetO, tetW, and tetX), macrolide (ermB, ermF), and sulfonamide (sul1, sul2) classes of antibiotics along with the class I integron gene, intI1, were monitored by quantitative polymerase chain reaction as potential indicators of direct selection, co-selection, or horizontal gene transfer of ARGs. Surprisingly, there was no significant effect of antibiotic treatment on the absolute abundance (gene copies per gram wet manure) of any of the ARGs except ermF, which was lower in the antibiotic-treated calf manure, presumably because a significant portion of host bacterial cells carrying ermF were not resistant to tetracycline or neomycin. However, relative abundance (gene copies normalized to 16S rRNA genes) of tetO was higher in calves fed the highest dose of antibiotic than in the other treatments. All genes, except tetC and intI1, were detectable in feces from 6 weeks onward, and tetW and tetG significantly increased (P calves. Overall, the results provide new insight into the colonization of calf gut flora with ARGs in the early weeks. Although feed antibiotics exerted little effect on the ARGs monitored in this study, the fact that they also provided no health benefit suggests that the greater than conventional nutritional intake applied
Lima, Thais Bergamin; Silva, Osmar Nascimento; de Almeida, Keyla Caroline; Ribeiro, Suzana Meira; Motta, Dielle de Oliveira; Maria-Neto, Simone; Lara, Michelle Brizolla; Filho, Carlos Roberto Souza; Ombredane, Alicia Simalie; de Faria Junior, Celio; Parachin, Nadia Skorupa; Magalhães, Beatriz Simas; Franco, Octávio Luiz
Enterobacter cloacae is a Gram-negative bacterium associated with high morbidity and mortality in intensive care patients due to its resistance to multiple antibiotics. Currently, therapy against multi-resistant bacteria consists of using colistin, in spite of its toxic effects at higher concentrations. In this context, colistin-resistant E. cloacae strains were challenged with lower levels of colistin combined with other antibiotics to reduce colistin-associated side effects. Colistin-resistant E. cloacae (ATCC 49141) strains were generated by serial propagation in subinhibitory colistin concentrations. After this, three colistin-resistant and three nonresistant replicates were isolated. The identity of all the strains was confirmed by MALDI-TOF MS, VITEK 2 and MicroScan analysis. Furthermore, cross-resistance to other antibiotics was checked by disk diffusion and automated systems. The synergistic effects of the combined use of colistin and chloramphenicol were observed via the broth microdilution checkerboard method. First, data here reported showed that all strains presented intrinsic resistance to penicillin, cephalosporin (except fourth generation), monobactam, and some associations of penicillin and β-lactamase inhibitors. Moreover, a chloramphenicol and colistin combination was capable of inhibiting the induced colistin-resistant strains as well as two colistin-resistant clinical strains. Furthermore, no cytotoxic effect was observed by using such concentrations. In summary, the data reported here showed for the first time the possible therapeutic use of colistin-chloramphenicol for infections caused by colistin-resistant E. cloacae.
Sabiha Y. Essack
Full Text Available The mechanisms that bacteria use to acquire additional genetic material, including genes coding for antibiotic resistance, are principally the secondary pathways that have been described as transformation and conjugation pathways. The farming industry often is reported as a hotspot for antibiotic-resistance reservoirs. In this review, we consider the exposure of food animals during the course of their lifespans to preventative, therapeutic or prophylactic treatment with antibiotic agents. In this context, zoonotic bacteria are commonly recognised as a potential threat to human health, with therapeutic treatment of pathogenic organisms on farms increasing the likelihood of selective antibiotic pressure influencing the commensal flora of the intestines. Existing literature indicates, however, that the effective impact on human health of such interventions in the food production process is still subject to debate.
Antibiotic residues and resistant bacteria in cattle feedlot manure may impact antibiotic resistance in the environment. This study investigated common antimicrobials (tetracyclines and monensin) and associated resistance genes in cattle feedlot soils over time. Animal diets and other feedlot soil...
DeSouza, M.J.B.D.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.
in 68% of the isolates. Depending on the antibiotics the isolates showed different percentage of resistance. Multiple drug and metal-resistance were observed. High incidence of resistance to both antibiotics and metals were common among the pigmented...
Full Text Available Background Few studies have investigated the gut microbiome of infants, fewer still preterm infants. In this study we sought to quantify and interrogate the resistome within a cohort of premature infants using shotgun metagenomic sequencing. We describe the gut microbiomes from preterm but healthy infants, characterising the taxonomic diversity identified and frequency of antibiotic resistance genes detected. Results Dominant clinically important species identified within the microbiomes included C. perfringens, K. pneumoniae and members of the Staphylococci and Enterobacter genera. Screening at the gene level we identified an average of 13 antimicrobial resistance genes per preterm infant, ranging across eight different antibiotic classes, including aminoglycosides and fluoroquinolones. Some antibiotic resistance genes were associated with clinically relevant bacteria, including the identification of mecA and high levels of Staphylococci within some infants. We were able to demonstrate that in a third of the infants the S. aureus identified was unrelated using MLST or metagenome assembly, but low abundance prevented such analysis within the remaining samples. Conclusions We found that the healthy preterm infant gut microbiomes in this study harboured a significant diversity of antibiotic resistance genes. This broad picture of resistances and the wider taxonomic diversity identified raises further caution to the use of antibiotics without consideration of the resident microbial communities.
Zhang, Songhe; Pang, Si; Wang, PeiFang; Wang, Chao; Han, Nini; Liu, Bin; Han, Bing; Li, Yi; Anim-Larbi, Kwaku
Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event. Several antibiotics, lactose-fermenting bacteria and cultivable heterotrophic bacteria concentrations increased in surface water and/or surface sediment of two small urban lakes (Lake Xuanwu and Wulongtan) after strong storm event. In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes, Aeromonas and Bacillus were dominant genera in samples from two lakes, while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively. Presences of nine antibiotic resistance genes (ARGs) in the 100 isolates were detected and most of these isolates harbored at least two ARGs with different functions. The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. The most prevalent integron in 100 isolates was int(II) (n = 28), followed by int(I) (n = 17) and int(III) (n = 17). Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes.
van Dijk, Thomas; Hwang, Sungmin; Krug, Joachim; de Visser, J. Arjan G. M.; Zwart, Mark P.
Whether evolution can be predicted is a key question in evolutionary biology. Here we set out to better understand the repeatability of evolution, which is a necessary condition for predictability. We explored experimentally the effect of mutation supply and the strength of selective pressure on the repeatability of selection from standing genetic variation. Different sizes of mutant libraries of antibiotic resistance gene TEM-1 β-lactamase in Escherichia coli, generated by error-prone PCR, were subjected to different antibiotic concentrations. We determined whether populations went extinct or survived, and sequenced the TEM gene of the surviving populations. The distribution of mutations per allele in our mutant libraries followed a Poisson distribution. Extinction patterns could be explained by a simple stochastic model that assumed the sampling of beneficial mutations was key for survival. In most surviving populations, alleles containing at least one known large-effect beneficial mutation were present. These genotype data also support a model which only invokes sampling effects to describe the occurrence of alleles containing large-effect driver mutations. Hence, evolution is largely predictable given cursory knowledge of mutational fitness effects, the mutation rate and population size. There were no clear trends in the repeatability of selected mutants when we considered all mutations present. However, when only known large-effect mutations were considered, the outcome of selection is less repeatable for large libraries, in contrast to expectations. We show experimentally that alleles carrying multiple mutations selected from large libraries confer higher resistance levels relative to alleles with only a known large-effect mutation, suggesting that the scarcity of high-resistance alleles carrying multiple mutations may contribute to the decrease in repeatability at large library sizes.
Barriere, Steven L
The concern over antibiotic resistance has been voiced since the discovery of modern antibiotics > 75 years ago. The concerns have only increased with time, with efforts to control resistance caused by widespread overuse of antibiotics in human medicine and far more than appreciated use in the feeding of animals for human consumption to promote growth. The problem is worldwide, but certain regions and selected health care institutions report far more resistance, including strains of Gram-negative bacteria that are susceptible only to the once discarded drugs polymyxin B or colistin, and pan-resistant strains are on the rise. One of the central efforts to control resistance, apart from antimicrobial stewardship, is the development of new antimicrobial agents. This has lagged significantly over the past 10 - 15 years, for a variety of reasons; but promising new agents are being developed, unfortunately none thus far addressing all potentially resistant strains. There is the unlikely, but not unreal, possibility that we could return to a pre-antibiotic era, where morbidity and mortality rates have risen dramatically and routine surgical procedures are not performed for fear of post-operative infections. The onus of control of resistance is a moral imperative that falls on the shoulders of all.
González-Plaza, Juan J.; Šimatović, Ana; Milaković, Milena; Bielen, Ana; Wichmann, Fabienne; Udiković-Kolić, Nikolina
Environments polluted by direct discharges of effluents from antibiotic manufacturing are important reservoirs for antibiotic resistance genes (ARGs), which could potentially be transferred to human pathogens. However, our knowledge about the identity and diversity of ARGs in such polluted environments remains limited. We applied functional metagenomics to explore the resistome of two Croatian antibiotic manufacturing effluents and sediments collected upstream of and at the effluent discharge sites. Metagenomic libraries built from an azithromycin-production site were screened for resistance to macrolide antibiotics, whereas the libraries from a site producing veterinary antibiotics were screened for resistance to sulfonamides, tetracyclines, trimethoprim, and beta-lactams. Functional analysis of eight libraries identified a total of 82 unique, often clinically relevant ARGs, which were frequently found in clusters and flanked by mobile genetic elements. The majority of macrolide resistance genes identified from matrices exposed to high levels of macrolides were similar to known genes encoding ribosomal protection proteins, macrolide phosphotransferases, and transporters. Potentially novel macrolide resistance genes included one most similar to a 23S rRNA methyltransferase from Clostridium and another, derived from upstream unpolluted sediment, to a GTPase HflX from Emergencia. In libraries deriving from sediments exposed to lower levels of veterinary antibiotics, we found 8 potentially novel ARGs, including dihydrofolate reductases and beta-lactamases from classes A, B, and D. In addition, we detected 7 potentially novel ARGs in upstream sediment, including thymidylate synthases, dihydrofolate reductases, and class D beta-lactamase. Taken together, in addition to finding known gene types, we report the discovery of novel and diverse ARGs in antibiotic-polluted industrial effluents and sediments, providing a qualitative basis for monitoring the dispersal of ARGs
In order to make informed decisions on how best to manage agricultural antibiotics, we need to be able to track and quantify the antibiotic resistant bacteria, and antibiotic resistance genes. PCR-based methods are widely used to both detect and quantify antibiotic resistance genes, however there ar...
BD Phoenixautomated microbiology system (Becton Dickinson, USA) was utilized for species level identification and antibiotic susceptibility testing. Results: Sixty seven of S. maltophilia strains were isolated from tracheal aspirate isolates, 17 from blood, 10 from sputum, 10 from wound and 14 from other clinical specimens.