scholarly journals ANTIBIOTIC RESISTANCE OF BACTERIA OF THE FAMILY PASTEURELLACEAE, PATHOGENS OF RESPIRATORY INFECTIONS OF CATTLE AND PIGS

2021 ◽  
Vol 22 (1) ◽  
pp. 197-208
Author(s):  
T. I. Stetsko
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Bacterial Cell ◽  
Respiratory Diseases ◽  
Natural Resistance ◽  
23S Rrna ◽  
Active Efflux ◽  
The Family ◽  
Chromosomal Genes ◽  
Enzymatic Inactivation

In the article a literature review of scientific papers on the topic of antimicrobial resistance of bacteria of the family Pasteurellaceae, pathogens of respiratory diseases in pigs and cattle, is presented. The main mechanisms of the development of Pasteurellaceae resistance to β-lactam antibiotics are the synthesis of β-lactamases by bacteria, what are able to break the beta-lactam ring, thereby inactivating β-lactams, or alteration of the penicillin-binding proteins structure. Other mechanisms, such as reduced permeability of the outer membrane or the process of active removal of antibiotics from the bacterial cell (efflux), are very rare. Resistance among Pasteurellaceae to β-lactams is often associated with plasmids. Eflux and ribosomal protection are the main mechanisms for the development of resistance of Pasteurellaceae to tetracyclines. At least nine tetracycline resistance genes (tet genes) have been identified in bacteria of the genus Pasteurella, Mannheimia, Actinobacillus and Haemophilus, what encode these processes. Resistance to aminoglycosides and aminocyclitols is mainly caused by enzymatic inactivation of antibiotics, as well as through mutations in chromosomal genes. Many plasmids carry genes of resistance to aminoglycosides, causing resistance to antibiotics of other groups. Chemical modification of a ribosomal target by rRNA methylases and mutations in ribosomal proteins are the main resistance mechanisms of bacteria of the family Pasteurellaceae to macrolides. Many gram-negative bacteria have a natural resistance to macrolide antibiotics. The development of lincosamide resistance is influenced by methyltransferase 23S rRNA, active efflux proteins, enzymatic inactivation and chromosomal mutations. Resistance of bacteria of the family Pasteurellaceae to chloramphenicol is caused mainly by enzymatic inactivation, while the emergence of resistance to fluorophenicol is associated with the efflux of an antibiotic from a bacterial cell. Plasmids carrying phenicol resistance genes were detected in isolates of P. multocida, M. haemolytica, A. pleuropneumoniae and H. parasuis. Usually the level of bacteria sensitivity of the genus Pasteurella, Mannheimia, Actinobacillus and Haemophilus to quinolones is quite high. Resistance to quinolones mainly occurs due to mutational alterations in chromosomal genes, and may also be in consequence of the export antibiotics from the cell by membrane proteins or thanks to qnr genes of plasmids. The main mechanism of resistance to sulfonamides and trimethoprim is both plasmid-mediated and mutation-induced production of altered dihydropteroate synthetase and dihydrofolate reductase with reduced affinity with these antimicrobials. Monitoring of antibiotic resistance with the determination of its mechanism phenomenon will facilitate the choice of an effective agent of etiotropic therapy of respiratory diseases of cattle and pigs caused by bacteria of the family Pasteurellaceae.

scholarly journals pCTX-M3—Structure, Function, and Evolution of a Multi-Resistance Conjugative Plasmid of a Broad Recipient Range

2021 ◽  
Vol 22 (9) ◽  
pp. 4606
Author(s):  
Izabela Kern-Zdanowicz
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Mobile Genetic Elements ◽  
Conjugative Plasmid ◽  
Conjugation System ◽  
Incompatibility Group ◽  
Genetic Elements ◽  
The Family ◽  
Stable Maintenance

pCTX-M3 is the archetypic member of the IncM incompatibility group of conjugative plasmids (recently referred to as IncM2). It is responsible for the worldwide dissemination of numerous antibiotic resistance genes, including those coding for extended-spectrum β-lactamases and conferring resistance to aminoglycosides. The IncM plasmids acquired during evolution diverse mobile genetic elements found in one or two multiple resistance regions, MRR(s), grouping antibiotic resistance genes as well as mobile genetic elements or their remnants. The IncM plasmids can be found in bacteria inhabiting various environments. The information on the structure and biology of pCTX-M3 is integrated in this review. It focuses on the functional modules of pCTX-M3 responsible for its replication, stable maintenance, and conjugative transfer, indicating that the host range of the pCTX-M3 replicon is limited to representatives of the family Enterobacteriaceae (Enterobacterales ord. nov.), while the range of recipients of its conjugation system is wide, comprising Alpha-, Beta-, and Gammaproteobacteria, and also Firmicutes.

scholarly journals High prevalence of antibiotic resistance inHelicobacter pyloriisolates from Iran: importance of functional and mutational analysis of resistance genes and virulence genotyping

2019 ◽  
Author(s):  
Nastaran Farzi ◽  
Abbas Yadegar ◽  
Hamid Asadzadeh Aghdaei ◽  
Amir Sadeghi ◽  
Mohammad Reza Zali
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Mutational Analysis ◽  
Rrna Genes ◽  
23S Rrna ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Virulence Markers ◽  
High Prevalence ◽  
H Pylori

AbstractThe high prevalence of antibiotic resistance inHelicobacter pylorihas become a great challenge in Iran. The genetic mutations that contribute to the resistance have yet to be precisely identified. This study aimed to investigate the prevalence of antibiotic resistance and virulence markers in IranianH. pyloriisolates and to analyze if there is any association between resistance and genotype. Antibiotic susceptibility patterns of 33H. pyloriisolates were investigated against metronidazole, clarithromycin, amoxicillin, rifampicin, ciprofloxacin, levofloxacin and tetracycline by the agar dilution method. ThefrxA, rdxA, gyrA, gyrBand 23S rRNA genes of the isolates were sequenced. The virulence genotypes were also determined using PCR. Metronidazole resistance was present in 81.8% of the isolates, followed by clarithromycin (36.4%), ciprofloxacin (36.4%), amoxicillin (30.3%), rifampicin (30.3%), levofloxacin (27.3%) and tetracycline (6.1%). Most of the metronidazole-resistant isolates carried frameshift mutations in bothfrxAandrdxAgenes, and premature termination was occurred in positions Q5Stop and Q50Stop, respectively. Amino acid substitutions M191I, G208E, and V199A were predominantly found ingyrAgene of fluoroquinolone-resistant isolates. A2143G and C2195T mutations of 23S rRNA were found in four isolates. Interestingly, significant associations were demonstrated between intactcagPAI and resistance to rifampicin (P= 0.027), and between susceptibility to amoxicillin andcagPAI intactness (P= 0.016). The prevalence ofH. pyloriantibiotic resistance is high in our region, particularly that of metronidazole, clarithromycin, ciprofloxacin and multidrug resistance. Occurrence of mutations in resistance genes were involved in the development of resistance, especially in less virulent isolates.

scholarly journals Phenotypic and genotypic characterization of linezolid-resistant Enterococcus faecium from the USA and Pakistan

2019 ◽  
Vol 74 (12) ◽  
pp. 3445-3452 ◽  
Author(s):  
Kate E Wardenburg ◽  
Robert F Potter ◽  
Alaric W D’Souza ◽  
Tahir Hussain ◽  
Meghan A Wallace ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Enterococcus Faecium ◽  
Antibiotic Resistance Genes ◽  
23S Rrna ◽  
Linezolid Resistance ◽  
Geographical Regions ◽  
The Us ◽  
The Usa ◽  
Acquired Antibiotic Resistance

Abstract Objectives Linezolid is an important therapeutic option for the treatment of infections caused by VRE. Linezolid is a synthetic antimicrobial and resistance to this antimicrobial agent remains relatively rare. As a result, data on the comparative genomics of linezolid resistance determinants in Enterococcus faecium are relatively sparse. Methods To address this knowledge gap in E. faecium, we deployed phenotypic antibiotic susceptibility testing and Illumina WGS on hospital surface (environmental) and clinical isolates from the USA and Pakistan. Results We found complete concordance between isolate source country and mechanism of linezolid resistance, with all the US isolates possessing a 23S rRNA gene mutation and the Pakistan isolates harbouring two to three acquired antibiotic resistance genes. These resistance genes include the recently elucidated efflux-pump genes optrA and poxtA and a novel cfr-like variant. Although there was no difference in the linezolid MIC between the US and Pakistan isolates, there was a significant difference in the geometric mean of the MIC between the Pakistan isolates that had two versus three of the acquired antibiotic resistance genes. In five of the Pakistan E. faecium that possessed all three of the resistance genes, we found no difference in the local genetic context of poxtA and the cfr-like gene, but we identified different genetic contexts surrounding optrA. Conclusions These results demonstrate that E. faecium from different geographical regions employ alternative strategies to counter selective pressure of increasing clinical linezolid use.

scholarly journals Tetracyclines in veterinary medicine and bacterial resistance to them

2012 ◽  
Vol 49 (No. 3) ◽  
pp. 79-100 ◽  
Author(s):  
E. Michalova ◽  
PNovotna ◽  
J. Schlegelova
Keyword(s):  
Resistance Genes ◽  
Bacterial Resistance ◽  
Tetracycline Resistance ◽  
Growth Promoters ◽  
Active Efflux ◽  
Tetracycline Resistance Genes ◽  
Enzymatic Inactivation ◽  
Resistant Strains ◽  
Horizontal Spread ◽  
Transporter Systems

Since their discovery in 1945, tetracyclines have been used extensively in the therapy and prophylaxis of infectious diseases and as growth promoters. These wide applications have led to the equally fast spread of tetracycline resistant strains of gram-positive and gram-negative bacterial genera, including strains belonging to pathogenic as well as nonpathogenic species. Nonpathogenic bacteria could act as a reservoir of resistance determinants, which can be disseminated by horizontal transfer into pathogens. More than thirty different tetracycline resistance genes have been characterized. They encode two major mechanisms of resistance: 1 – active efflux of the antibiotic, and 2 – protection of ribosomes. Further mechanisms of tetracycline resistance include enzymatic inactivation of antibiotic, permeability barriers, mutations or multidrug transporter systems. Effective horizontal spread is favoured by the location of tetracycline resistance genes on mobile genetic elements such as plasmids and transposons. Their exchange, enhanced by the use of tetracyclines, is observed between bacteria of the same or different species and genera as well. Thus, questions of reevaluating and global reducing of tetracyclines in human and animal healthcare and food production are extensively discussed.

Evaluation of clinical efficacy of Derinat® in form of spray in practice of district therapist

2019 ◽  
Vol 1 (9) ◽  
pp. 38-46
Author(s):  
A. P. Babkin ◽  
A. A. Zuikova ◽  
O. N. Krasnorutskaya ◽  
Yu. A. Kotova ◽  
D. Yu. Bugrimov ◽  
...  
Keyword(s):  
Clinical Efficacy ◽  
Respiratory Diseases ◽  
Viral Infections ◽  
Pharmacological Action ◽  
The Body ◽  
Natural Resistance ◽  
Acute Respiratory Diseases ◽  
T Helpers ◽  
T Killers ◽  
Stimulation Of

The widespread worldwide spread of acute respiratory diseases is an urgent problem in health care. Expressed polyetiology of respiratory diseases does not allow to limit the use of specific vaccine preparations and dictates the need to use to combat them a variety of non-specific means that stimulate the natural resistance of the human body. The main pharmacological action of sodium deoxyribonucleate is the stimulation of phagocytic activity of T-helpers and T-killers, increasing the functional activity of neutrophils and monocytes/ macrophages, providing regeneration and repair processes in the epithelial component of antiviral protection of the body. Based on the above, the study of the clinical efficacy of Derinat® in the form of spray in the treatment of acute respiratory viral infections is relevant.

Quintuplex PCR to Detect Antibiotic Resistance Genes in Streptococcus pneumoniae

2016 ◽  
Vol 1 (2) ◽  
pp. 22 ◽  
Author(s):  
Navindra Kumari Palanisamy ◽  
Parasakthi Navaratnam ◽  
Shamala Devi Sekaran
Keyword(s):  
Antibiotic Resistance ◽  
Streptococcus Pneumoniae ◽  
Resistance Genes ◽  
Bacterial Pathogen ◽  
Antibiotic Resistance Genes ◽  
Pcr Amplification ◽  
Penicillin Resistance ◽  
Penicillin Binding Proteins ◽  
Efflux Mechanism ◽  
Mic Value

Introduction: Streptococcus pneumoniae is an important bacterial pathogen, causing respiratory infection. Penicillin resistance in S. pneumoniae is associated with alterations in the penicillin binding proteins, while resistance to macrolides is conferred either by the modification of the ribosomal target site or efflux mechanism. This study aimed to characterize S. pneumoniae and its antibiotic resistance genes using 2 sets of multiplex PCRs. Methods: A quintuplex and triplex PCR was used to characterize the pbp1A, ermB, gyrA, ply, and the mefE genes. Fifty-eight penicillin sensitive strains (PSSP), 36 penicillin intermediate strains (PISP) and 26 penicillin resistance strains (PRSP) were used. Results: Alteration in pbp1A was only observed in PISP and PRSP strains, while PCR amplification of the ermB or mefE was observed only in strains with reduced susceptibility to erythromycin. The assay was found to be sensitive as simulated blood cultures showed the lowest level of detection to be 10cfu. Conclusions: As predicted, the assay was able to differentiate penicillin susceptible from the non-susceptible strains based on the detection of the pbp1A gene, which correlated with the MIC value of the strains.

The gut microbiota resistome provides development of drug resistance in causative agents of human infectious diseases

2017 ◽  
pp. 20-32 ◽  
Author(s):  
Е.Н. Ильина ◽  
Е.И. Олехнович ◽  
А.В. Павленко
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Integrated Approach ◽  
Modern Medicine ◽  
Pathogenic Microorganisms ◽  
Human Pathogens ◽  
Potential Source ◽  
Causative Agents ◽  
Bacterial Genes

С течением времени подходы к изучению резистентности к антибиотикам трансформировались от сосредоточения на выделенных в виде чистой культуры патогенных микроорганизмах к исследованию резистентности на уровне микробных сообществ, составляющих биотопы человека и окружающей среды. По мере того, как продвигается изучение устойчивости к антибиотикам, возникает необходимость использования комплексного подхода для улучшения информирования мирового сообщества о наблюдаемых тенденциях в этой области. Все более очевидным становится то, что, хотя не все гены резистентности могут географически и филогенетически распространяться, угроза, которую они представляют, действительно серьезная и требует комплексных междисциплинарных исследований. В настоящее время резистентность к антибиотикам среди патогенов человека стала основной угрозой в современной медицине, и существует значительный интерес к определению ниши, в которых бактерии могут получить гены антибиотикорезистентности, и механизмов их передачи. В данном обзоре мы рассматриваем проблемы, возникшие на фоне широкого использования человечеством антибактериальных препаратов, в свете формирования микрофлорой кишечника резервуара генов резистентности. Over the time, studies of antibiotic resistance have transformed from focusing on pathogenic microorganisms isolated as a pure culture to analysis of resistance at the level of microbial communities that constitute human and environmental biotopes. Advancing studies of antibiotic resistance require an integrated approach to enhance availability of information about observed tendencies in this field to the global community. It becomes increasingly obvious that, even though not all resistance genes can geographically and phylogenetically spread, the threat they pose is indeed serious and requires complex interdisciplinary research. Currently, the antibiotic resistance of human pathogens has become a challenge to modern medicine, which is now focusing on determining a potential source for bacterial genes of drug resistance and mechanisms for the gene transmission. In this review, we discussed problems generated by the widespread use of antibacterial drugs in the light of forming a reservoir of resistance genes by gut microflora.

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