scholarly journals Mechanisms of antimicrobial resistance development in bacteria

2020 ◽  
Vol 8 (3) ◽  
pp. 226-236
Author(s):  
T. I. Stetsko ◽  
V. P. Muzyka ◽  
M. R. Kozak
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agent ◽  
Resistance Genes ◽  
Target Genes ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Animal Health ◽  
Significant Risk ◽  
Animal Origin

Antimicrobial resistance poses a significant risk to animal health by reducing the effectiveness of the treatment and prevention of many infections caused by bacteria. Antibiotic resistance threatens human health by transmitting resistant strains of microorganisms or resistance genes from animals to humans through the food chain. Life-threatening infections that were previously manageable can become incurable through antimicrobial resistance. Antimicrobial resistance can be divided into two main types: natural and acquired. Natural bacterial resistance is associated with the absence or inaccessibility of target cites for the action of certain antimicrobial agents. The acquired resistance is specific and associated with the acquisition of extraneous resistance genes or mutational modification of chromosomal target genes. The resistance of bacteria to antimicrobial drugs varies depending on the antimicrobial agent, species or genus of bacteria, and the mechanism of resistance. Resistance to the same antimicrobial agent can be mediated by different resistance mechanisms. In some cases, the same resistance gene or mechanism are related to a wide variety of bacteria, whereas in other cases, resistance genes or mechanisms are restricted to certain bacterial species or genera. Bacterial resistance to different classes of antibiotics with common mechanisms often leads to the multidrug resistance. The data presented in this review focuses exclusively on the resistance genes and mechanisms found in bacteria of animal origin and on antimicrobials used in the veterinary medicine. For better coverage of the topic, information on the mechanisms of resistance is presented separately for each class of antimicrobial agents.

Antimicrobials: Modes of Action and Mechanisms of Resistance

2003 ◽  
Vol 22 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Patrick F. Mc Dermott ◽  
Robert D. Walker ◽  
David G. White
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Bacterial Pathogens ◽  
Animal Health ◽  
Animal Origin ◽  
Mobile Dna ◽  
Genetic Event ◽  
Active Efflux ◽  
Dna Elements

After six decades of widespread antibiotic use, bacterial pathogens of human and animal origin are becoming increasingly resistant to many antimicrobial agents. Antimicrobial resistance develops through a limited number of mechanisms: (a) permeability changes in the bacterial cell wall/membrane, which restrict antimicrobial access to target sites; (b) active efflux of the antimicrobial from the cell; (c) mutation in the target site; (d) enzymatic modification or degradation of the antimicrobial; and (e) acquisition of alternative metabolic pathways to those inhibited by the drug. Numerous bacterial antimicrobial resistance phenotypes result from the acquisition of external genes that may provide resistance to an entire class of antimicrobials. These genes are frequently associated with large transferable extrachromosomal DNA elements called plasmids, on which may be other mobile DNA elements such as transposons and integrons. An array of different resistance genes may accumulate on a single mobile element, presenting a situation in which multiple antibiotic resistance can be acquired via a single genetic event. The versatility of bacterial populations in adapting to toxic environments, along with their facility in exchanging DNA, signifies that antibiotic resistance is an inevitable biological phenomenon that will likely continue to be a chronic medical problem. Successful management of current antimicrobials, and the continued development of new ones, is vital to protecting human and animal health against bacterial pathogens.

scholarly journals Critically important antimicrobial preparations for veterinary medicine

2018 ◽  
Vol 20 (87) ◽  
pp. 19-26 ◽  
Author(s):  
T.I. Stetsko ◽  
V.P. Muzyka ◽  
V.M. Hunchak
Keyword(s):  
Veterinary Medicine ◽  
Antimicrobial Resistance ◽  
Antimicrobial Therapy ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Animal Health ◽  
Point Of View ◽  
Animal Origin ◽  
European Medicines Agency ◽  
Antimicrobial Substances

The resistance of microorganisms, bacterial pathogens, to antimicrobials is a global problem in both healthcare and veterinary medicine. It is believed that the main reason for the emergence and spread of antimicrobial resistance in humans is the transfer of antibiotic resistant strains of microorganisms or genes, determinants of resistance, through products of animal origin from productive animals to humans. Thus, the main way of antimicrobial resistance containment is to restrain and minimize it through the prudent use of antibiotics in veterinary medicine, especially those that are critically important for productive animals. In addition, some classes of antibacterial substances and antibiotics, that are widely used in humane medicine, are used in veterinary medicine. The need to use and preserve these important therapeutic agents is relevant from the point of view of the concept «One Health». The article provides a list of all antibacterial substances used by productive animals for their importance in veterinary medicine, developed by a special group of experts of the World Organisation for Animal Health (OIE). Any antimicrobial agent authorized for use in veterinary medicine for productive animals, in accordance with the criteria for quality, safety and efficacy as defined in Section 6.9 of the Terrestrial Animal Health Code, is considered to be important for veterinary medicine. All the antimicrobial substances used for productive animals are divided in this list on critical, very important and important for veterinary medicine. Attention was also drawn to the peculiarities of the use of critical antimicrobial agents in veterinary medicine, especially those recognized as critical in humane medicine. These include aminoglycosides, cephalosporins of the 3rd and 4th generation, fluoroquinolones, glycopeptides, macrolides, some penicillins and polymyxins. The article also describes the classification of critical antimicrobials by the European Medicines Agency (EMA) and the Panel of Experts on Antimicrobials (AMEG) of the WHO based on the risk profile for humans through the development of antimicrobial resistance after application to productive animals. Such an assessment will give veterinary practitioners an important justification when they make decisions about the clinical treatment of bacterial infections and the responsible appointment of antimicrobial therapy. This will help to reach the balance among the achievement of the effectiveness of antimicrobial therapy of productive animals, reducing of the selective pressure on the development of antibiotic resistance and ensuring of a high level of human health.

scholarly journals Phenotypic and genotypic characterization of mcr-1-positive multidrug-resistant Escherichia coli ST93, ST117, ST156, ST10, and ST744 isolated from poultry in Poland

2021 ◽  
Author(s):  
Katarzyna Ćwiek ◽  
Anna Woźniak-Biel ◽  
Magdalena Karwańska ◽  
Magdalena Siedlecka ◽  
Christine Lammens ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Genetic Relatedness ◽  
Multidrug Resistant ◽  
E Coli ◽  
Antimicrobial Resistance Genes

Abstract Background A plasmid-mediated mechanism of bacterial resistance to polymyxin is a serious threat to public health worldwide. The present study aimed to determine the occurrence of plasmid-mediated colistin resistance genes and to conduct the molecular characterization of mcr-positive Escherichia coli strains isolated from Polish poultry. Methods In this study, 318 E. coli strains were characterized by the prevalence of mcr1–mcr5 genes, antimicrobial susceptibility testing by minimal inhibitory concentration method, the presence of antimicrobial resistance genes was screened by PCR, and the biofilm formation ability was tested using the crystal violet staining method. Genetic relatedness of mcr-1-positive E. coli strains was evaluated by multilocus sequence typing method. Results Among the 318 E. coli isolates, 17 (5.35%) harbored the mcr-1 gene. High antimicrobial resistance rates were observed for ampicillin (100%), tetracycline (88.24%), and chloramphenicol (82.35%). All mcr-1-positive E. coli strains were multidrug-resistant, and as many as 88.24% of the isolates contained the blaTEM gene, tetracycline (tetA and tetB), and sulfonamide (sul1, sul2, and sul3) resistance genes. Additionally, 41.18% of multidrug-resistant, mcr-1-positive E. coli isolates were moderate biofilm producers, while the rest of the strains showed weak biofilm production. Nine different sequence types were identified, and the dominant ST was ST93 (29.41%), followed by ST117 (17.65%), ST156 (11.76%), ST 8979 (11.76%), ST744 (5.88%), and ST10 (5.88%). Moreover, the new ST was identified in this study. Conclusions Our results showed a low occurrence of mcr-1-positive E. coli strains isolated from Polish poultry; however, all the isolated strains were resistant to multiple antimicrobial agents and were able to form biofilms at low or medium level.

scholarly journals Antimicrobial Susceptibility Testing and Tentative Epidemiological Cutoff Values for FiveBacillusSpecies Relevant for Use as Animal Feed Additives or for Plant Protection

2018 ◽  
Vol 84 (19) ◽  
Author(s):  
Yvonne Agersø ◽  
Birgitte Stuer-Lauridsen ◽  
Karin Bjerre ◽  
Michelle Geervliet Jensen ◽  
Eric Johansen ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Animal Feed ◽  
Bacterial Species ◽  
Feed Additives ◽  
Content Type ◽  
Cutoff Values ◽  
Antimicrobial Resistance Genes ◽  
Species Specific

ABSTRACTBacillus megaterium(n= 29),Bacillus velezensis(n= 26),Bacillus amyloliquefaciens(n= 6),Bacillus paralicheniformis(n= 28), andBacillus licheniformis(n= 35) strains from different sources, origins, and time periods were tested for the MICs for nine antimicrobial agents by the CLSI-recommended method (Mueller-Hinton broth, 35°C, for 18 to 20 h), as well as with a modified CLSI method (Iso-Sensitest [IST] broth, 37°C [35°C forB. megaterium], 24 h). This allows a proposal of species-specific epidemiological cutoff values (ECOFFs) for the interpretation of antimicrobial resistance in these species. MICs determined by the modified CLSI method were 2- to 16-fold higher than with the CLSI-recommended method for several antimicrobials. The MIC distributions differed between species for five of the nine antimicrobials. Consequently, use of the modified CLSI method and interpretation of resistance by use of species-specific ECOFFs is recommended. The genome sequences of all strains were determined and used for screening for resistance genes against the ResFinder database and for multilocus sequence typing. A putative chloramphenicol acetyltransferase (cat) gene was found in oneB. megateriumstrain with an elevated chloramphenicol MIC compared to the otherB. megateriumstrains. InB. velezensisandB. amyloliquefaciens, a putative tetracycline efflux gene,tet(L), was found in all strains (n= 27) with reduced tetracycline susceptibility but was absent in susceptible strains. AllB. paralicheniformisand 23% ofB. licheniformisstrains had elevated MICs for erythromycin and harboredermD. The presence of these resistance genes follows taxonomy suggesting they may be intrinsic rather than horizontally acquired. Reduced susceptibility to chloramphenicol, streptomycin, and clindamycin could not be explained in all species.IMPORTANCEWhen commercializing bacterial strains, likeBacillusspp., for feed applications or plant bioprotection, it is required that the strains are free of acquired antimicrobial resistance genes that could potentially spread to pathogenic bacteria, thereby adding to the pool of resistance genes that may cause treatment failures in humans or animals. Conversely, if antimicrobial resistance is intrinsic to a bacterial species, the risk of spreading horizontally to other bacteria is considered very low. Reliable susceptibility test methods and interpretation criteria at the species level are needed to accurately assess antimicrobial resistance levels. In the present study, tentative ECOFFs for fiveBacillusspecies were determined, and the results showed that the variation in MICs followed the respective species. Moreover, putative resistance genes, which were detected by whole-genome sequencing and suggested to be intrinsic rather that acquired, could explain the resistance phenotypes in most cases.

Related Antimicrobial Resistance Genes Detected in Different Bacterial Species Co-isolated from Swine Fecal Samples

2011 ◽  
Vol 8 (6) ◽  
pp. 663-679 ◽  
Author(s):  
Jonathan G. Frye ◽  
Rebecca L. Lindsey ◽  
Richard J. Meinersmann ◽  
Mark E. Berrang ◽  
Charlene R. Jackson ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Bacterial Species ◽  
Fecal Samples ◽  
Antimicrobial Resistance Genes

scholarly journals Antimicrobial susceptibility profiles of Staphylococcus intermedius isolates from clinical cases of canine pyoderma in South Africa

2013 ◽  
Vol 84 (1) ◽  
Author(s):  
Catherine A. Blunt ◽  
Moritz Van Vuuren ◽  
Jacqueline Picard
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Temporal Trends ◽  
Companion Animals ◽  
Diagnostic Laboratory ◽  
Staphylococcus Intermedius ◽  
Susceptibility Profiles ◽  
Broth Dilution

Successful treatment of canine pyoderma has become compromised owing to the development of antimicrobial resistance with accompanying recurrence of infection. Canine skin samples submitted to a veterinary diagnostic laboratory for microbiological culture and sensitivity between January 2007 and June 2010, from which Staphylococcus intermedius was isolated, were selected for this investigation. Antimicrobial resistance of S. intermedius was most prevalent with reference to ampicillin followed by resistance to tetracycline and then potentiated sulphonamides. In general, antimicrobial resistance was low and very few methicillin-resistant isolates were detected. Temporal trends were not noted, except for ampicillin, with isolates becoming more susceptible, and potentiated sulphonamides (co-trimoxazole), with isolates becoming more resistant. In general, both the Kirby–Bauer disc diffusion and broth dilution minimum inhibitory concentration tests yielded similar results for the antimicrobial agents tested. The main difference was evident in the over-estimation of resistance by the Kirby–Bauer test for ampicillin, co-trimoxazole, penicillin and doxycycline. Knowledge of trends in bacterial resistance is important for veterinarians when presented with canine pyoderma. Analysis of antimicrobial susceptibility profiles of S. intermedius isolated from canine pyodermas will guide veterinarians’ use of the most appropriate agent and encourage prudent use of antimicrobials in companion animals.

Prevalence, Concentration, and Antimicrobial Resistance Profiles of Salmonella Isolated from Florida Poultry Litter

2020 ◽  
Vol 83 (12) ◽  
pp. 2179-2186
Author(s):  
ALAN GUTIERREZ ◽  
JAYSANKAR DE ◽  
KEITH R. SCHNEIDER
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Agricultural Soils ◽  
Geometric Mean ◽  
Poultry Litter ◽  
Ammonia Nitrogen ◽  
Animal Origin ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number

ABSTRACT For over a decade, Salmonella contamination has increasingly led to outbreaks of foodborne illness associated with fresh produce. The use of untreated animal manures, or biological soil amendments of animal origin, to amend agricultural soils holds a risk of contamination from foodborne pathogens, such as Salmonella. This study was conducted to determine the prevalence, concentration, serotypes, and antimicrobial resistance profiles of Salmonella in poultry litter from Florida farms. Litter pH, total Kjeldahl nitrogen, total ammonia nitrogen, total phosphorus (P2O5), total potassium (K2O), moisture content, total solids, total ash, organic matter, and aerobic plate count (APC) were also measured. Litter samples (n = 54) were collected from 18 broiler farms across three seasons (spring, summer, and winter). Salmonella concentrations were enumerated using a most-probable-number (MPN) method, and antimicrobial susceptibility testing was performed. The prevalence of Salmonella in litter samples was 61.1%, with a geometric mean of 0.21 ± 20.7 MPN/g. Across all seasons, Salmonella concentrations were not influenced by the chemical, physical, or microbial properties measured. Recovered Salmonella isolates (n = 290) were grouped into serogroups O:4 (43.1%), O:7 (26.9%), O:8 (11.0%), O:1,3,10,19 (7.9%), and O:9,46 (7.2%). Serotyping Salmonella isolates (n = 47) resulted in 12 serotypes, with the most common being Typhimurium (27.7%), Kentucky (17.0%), Enteritidis (14.9%), and Mbandaka (14.9%). Antimicrobial resistance to tetracycline (29.8%), sulfisoxazole (23.4%), and streptomycin (14.9%) was observed. No isolates were resistant to more than two antimicrobial agents. This study provides valuable information for future risk assessments for the use of poultry litter as an untreated biological soil amendment of animal origin. HIGHLIGHTS

Detection of Multiple-Antimicrobial Resistance and Characterization of the Implicated Genes in Escherichia coli Isolates from Foods of Animal Origin in Tunis

2009 ◽  
Vol 72 (5) ◽  
pp. 1082-1088 ◽  
Author(s):  
AHLEM JOUINI ◽  
KARIM BEN SLAMA ◽  
YOLANDA SÁENZ ◽  
NAOUEL KLIBI ◽  
DANIELA COSTA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Food Samples ◽  
Animal Origin ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Class 1 ◽  
Agar Dilution

Phenotypic and genotypic characterization of antimicrobial resistance was conducted for 98 Escherichia coli isolates recovered from 40 food samples of animal origin (poultry, sheep, beef, fish, and others) obtained in supermarkets and local butcheries in Tunis during 2004 and 2005. Susceptibility to 15 antimicrobial agents was tested by disk diffusion and agar dilution methods, the mechanisms of resistance were evaluated using PCR and sequencing methods, and the clonal relationship among isolates was evaluated using pulsed-field gel electrophoresis. High resistance was detected to tetracycline, sulphonamides, nalidixic acid, ampicillin, streptomycin, and trimethoprim-sulfamethoxazole (29 to 43% of isolates), but all isolates were susceptible to cefotaxime, ceftazidime, cefoxitin, azthreonam, and amikacin. One-third of the isolates had multiresistant phenotypes (resistance to at least five different families of antimicrobial agents). Different variants of blaTEM, tet, sul, dfrA, aadA, and aac(3) genes were detected in most of the strains resistant to ampicillin, tetracycline, sulphonamide, trimethoprim, streptomycin, and gentamicin, respectively. The presence of class 1 and class 2 integrons was studied in 15 sulphonamide-resistant unrelated E. coli strains, and 14 of these strains harbored class 1 integrons with five different arrangements of gene cassettes, and a class 2 integron with the dfrA1 + sat + aadA1 arrangement was found in one strain. This study revealed the high diversity of antimicrobial resistance genes, some of them included in integrons, in E. coli isolates of food origin.

scholarly journals Diversity of Antimicrobial-Resistant Aeromonas Species Isolated from Aquatic Environments in Brazil

2020 ◽  
Author(s):  
Danieli Conte ◽  
Jussara Kasuko Palmeiro ◽  
Adriane de Almeida Bavaroski ◽  
Luiza Souza Rodrigues ◽  
Daiane Cardozo ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Aquatic Ecosystems ◽  
Bacterial Resistance ◽  
Genetic Relatedness ◽  
Anthropogenic Activities ◽  
Treatment Plant ◽  
Aeromonas Species ◽  
Aquatic Environments ◽  
Antimicrobial Resistance Genes

ABSTRACTIn the present study, we characterized antimicrobial resistance profile and genetic relatedness of Aeromonas spp. isolated from healthcare and urban effluents, wastewater treatment plant (WWTP), and river water. We detected the presence of genes responsible for the resistance to β-lactam, quinolone, and aminoglycoside. Enterobacterial Repetitive Intergenic Consensus PCR and multilocus sequence typing (MLST) were carried out to differentiate the strains and multilocus phylogenetic analysis (MLPA) was used to identify species. A total of 28 Aeromonas spp. cefotaxime-resistant strains were identified that carried a variety of resistance determinants, including uncommon GES-type β-lactamases. Multidrug-resistant Aeromonas spp. were found in hospital wastewater, WWTP, and sanitary effluent. Among these isolates, we detected A. caviae producing GES-1 or GES-5, as well as A. veronii harboring GES-7 or GES-16. We successfully identified Aeromonas spp. by using MLPA and found that A. caviae was the most prevalent species (85.7%). In contrast, it was not possible to determine sequence type of all isolates, suggesting incompleteness of the Aeromonas spp. MLST database. Our findings reinforce the notion about the ability of Aeromonas spp. to acquire determinants of antimicrobial resistance from the environment. Such ability can be enhanced by the release of untreated healthcare effluents, in addition to the presence of antimicrobials, recognized as potential factors for the spread of resistance. Thus, Aeromonas spp. could be included as priority pathogens under the One Health concept.IMPORTANCEAeromonas species are native bacteria in aquatic ecosystems worldwide. However, they have also been isolated from humans and animals. Globally, aquatic environments have been affected by anthropogenic activities. For example, the excessive use of antimicrobials in medical and veterinary practice causes the development of bacterial resistance. In addition, eliminated hospital and sanitary effluents can also serve as potential sources of bacteria carrying antimicrobial resistance genes. Thereby, impacted environments play an important role in the transmission of these pathogens, their evolution, and dissemination of genes conferring resistance to antimicrobials. Aeromonas spp. have been reported as a reservoir of antimicrobial resistance genes in the environment. In this study, we identified a great repertoire of antimicrobial resistance genes in Aeromonas spp. from diverse aquatic ecosystems, including those that encode enzymes degrading broad-spectrum antimicrobials widely used to treat healthcare-associated infections. These are a public health threat as they may spread in the population.

scholarly journals Surveillance of antimicrobial resistance in humans, food stuffs and livestock in Denmark

1997 ◽  
Vol 2 (3) ◽  
pp. 17-19 ◽  
Author(s):  
H C Wegener ◽  
F Bager ◽  
F M Aarestrup
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Animal Production ◽  
Resistant Bacteria ◽  
General Increase

A general increase in antimicrobial resistance among pathogenic bacteria is causing concern worldwide that the widespread use of antimicrobial agents in animal production may promote the development of resistant bacteria or resistance genes that can be tr

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