scholarly journals Mechanisms of antibiotic resistance in Haemophilus parainfluenzae

2017 ◽  
Vol 32 (3) ◽  
pp. 111-114
Author(s):  
Regina E. Abotsi ◽  
Usha Govinden ◽  
Sabiha Y. Essack
Keyword(s):  
Antibiotic Resistance ◽  
Literature Review ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Antibiotic Resistance Genes ◽  
Healthy Individuals ◽  
Mechanisms Of Resistance ◽  
Haemophilus Parainfluenzae ◽  
Life Threatening

Haemophilus parainfluenzae is part of the HACEK group of fastidious bacteria commonly implicated in endocarditis and bacteremia. Previously considered as a normal respiratory, oral and sometimes genitourinary commensal, it has been recognised as a pathogen that can cause life-threatening infections in both immunocompromised and healthy individuals. It has also been reported as a bacterium that can harbor transferable antibiotic resistance genes. This paper presents a literature review on the molecular mechanisms of resistance of H. parainfluenzae to commonly prescribed antibiotics and discusses areas for further research.

scholarly journals Mechanisms of Resistance in Multiple-Antibiotic-Resistant Escherichia coli Strains of Human, Animal, and Food Origins

2004 ◽  
Vol 48 (10) ◽  
pp. 3996-4001 ◽  
Author(s):  
Yolanda Sáenz ◽  
Laura Briñas ◽  
Elena Domínguez ◽  
Joaquim Ruiz ◽  
Myriam Zarazaga ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Amino Acid ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Mechanisms Of Resistance ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Class 1 ◽  
Human Animal

ABSTRACT Seventeen multiple-antibiotic-resistant nonpathogenic Escherichia coli strains of human, animal, and food origins showed a wide variety of antibiotic resistance genes, many of them carried by class 1 and class 2 integrons. Amino acid changes in MarR and mutations in marO were identified for 15 and 14 E. coli strains, respectively.

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

2017 ◽  
Vol 1 (1) ◽  
pp. 10-17
Author(s):  
Danuta Plotnikava ◽  
Anastasiya Sidarenka ◽  
Galina Novik
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Antibiotic Resistance Genes ◽  
Public Health Problem ◽  
Animal Husbandry ◽  
Resistant Bacteria ◽  
Monitoring And Control ◽  
Bacterial Drug Resistance

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

Antibiotic susceptibility profiles and frequency of resistance genes in clinical Shiga toxin-producing Escherichia coli isolates from Michigan over a 14-year period

2021 ◽  
Author(s):  
Sanjana Mukherjee ◽  
Heather M. Blankenship ◽  
Jose A. Rodrigues ◽  
Rebekah E. Mosci ◽  
James T. Rudrik ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Antibiotic Susceptibility ◽  
Genetic Relatedness ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Mechanisms Of Resistance ◽  
Susceptibility Profiles

Background: Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that contributes to over 250,000 infections in the US each year. Because antibiotics are not recommended for STEC infections, resistance in STEC has not been widely researched despite an increased likelihood for the transfer of resistance gene from STEC to opportunistic pathogens residing within the same microbial community. Methods: Between 2001 and 2014, 969 STEC isolates were collected from Michigan patients. Serotyping and antibiotic susceptibility profiles to clinically relevant antibiotics were determined using disc diffusion, while epidemiological data was used to identify factors associated with resistance. Whole genome sequencing was used to examine genetic relatedness and identify genetic determinants and mechanisms of resistance in the non-O157 isolates. Results: Increasing frequencies of resistance to at least one antibiotic was observed over the 14 years (p=0.01). While the non-O157 serogroups were more commonly resistant than O157 (Odds Ratio: 2.4; 95% Confidence Interval:1.43-4.05), the frequency of ampicillin resistance among O157 isolates was significantly higher in Michigan compared to the national average (p=0.03). Genomic analysis of 321 non-O157 isolates uncovered 32 distinct antibiotic resistance genes (ARGs). Although mutations in genes encoding resistance to ciprofloxacin and ampicillin were detected in four isolates, most of the horizontally acquired ARGs conferred resistance to aminoglycosides, β-lactams, sulfonamides and/or tetracycline. Conclusions: This study provides insight into the mechanisms of resistance in a large collection of clinical non-O157 STEC isolates and demonstrates that antibiotic resistance among all STEC serogroups has increased over time, prompting the need for enhanced surveillance.

scholarly journals Interplay between bacterial clone and plasmid in the spread of antibiotic resistance genes in the gut: lessons from a temporal study in veal calves

2021 ◽  
Author(s):  
Méril Massot ◽  
Pierre Châtre ◽  
Bénédicte Condamine ◽  
Véronique Métayer ◽  
Olivier Clermont ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Antibiotic Resistance Genes ◽  
Field Work ◽  
E Coli ◽  
Veal Calves ◽  
Evolutionary Forces ◽  
Extended Spectrum

Intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli is a frequent, increasing and worrying phenomenon, but little is known about the molecular scenario and the evolutionary forces at play. We screened 45 veal calves, known to have high prevalence of carriage, for ESBL-producing E. coli on 514 rectal swabs (one randomly selected colony per sample) collected over six months. We characterized the bacterial clones and plasmids carrying bla ESBL genes with a combination of genotyping methods, whole genome sequencing and conjugation assays. One hundred and seventy-three ESBL-producing E. coli isolates [ bla CTX-M-1 (64.7%), bla CTX-M -14 (33.5%) or bla CTX-M-15 (1.8%)] were detected, belonging to 32 bacterial clones, mostly of phylogroup A. Calves were colonized successively by different clones with a trend in decreasing carriage. The persistence of a clone in a farm was significantly associated with the number of calves colonized. Despite a high diversity of E. coli clones and bla CTX-M -carrying plasmids, few bla CTX-M gene/plasmid/chromosomal background combinations dominated, due to (i) efficient colonization of bacterial clones and/or (ii) successful plasmid spread in various bacterial clones. The scenario ‘clone vs. plasmid spread’ depended on the farm. Thus, epistatic interactions between resistance genes, plasmids and bacterial clones contribute to optimize fitness in specific environments. Importance The gut microbiota is the epicenter of the emergence of resistance. Considerable amount of knowledge on the molecular mechanisms of resistance has been accumulated but the ecological and evolutionary forces at play in nature are less studied. In this context, we performed a field work on temporal intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in veal farms. Veal calves are animals with one of the highest levels of ESBL producing E. coli fecal carriage, due to early high antibiotic exposure. We were able to show that calves were colonized successively by different ESBL-producing E. coli clones, and that two main scenarios were at play in the spread of bla CTX-M genes among calves: efficient colonization of several calves by a few bacterial clones and successful plasmid spread in various bacterial clones. Such knowledge should help develop new strategies to fight the emergence of antibiotic-resistance.

scholarly journals PixR, a Novel Activator of Conjugative Transfer of IncX4 Resistance Plasmids, Mitigates the Fitness Cost of mcr-1 Carriage in Escherichia coli

mBio ◽  
2022 ◽  
Author(s):  
Lingxian Yi ◽  
Romain Durand ◽  
Frédéric Grenier ◽  
Jun Yang ◽  
Kaiyang Yu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Antibiotic Resistance Genes ◽  
Fitness Cost ◽  
Conjugative Transfer ◽  
Resistance Plasmids

The spread of clinically relevant antibiotic resistance genes is often linked to the dissemination of epidemic plasmids. However, the underlying molecular mechanisms contributing to the successful spread of epidemic plasmids remain unclear.

scholarly journals Whole-Genome Sequence of ablaOXA-48-Harboring Raoultella ornithinolytica Clinical Isolate from Lebanon

2016 ◽  
Vol 60 (4) ◽  
pp. 2548-2550 ◽  
Author(s):  
Charbel Al-Bayssari ◽  
Abiola Olumuyiwa Olaitan ◽  
Thongpan Leangapichart ◽  
Liliane Okdah ◽  
Fouad Dabboussi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Clinical Isolate ◽  
Genome Sequence ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Antibiotic Resistance Genes ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Content Type ◽  
Genetic Organization

ABSTRACTWe analyzed the whole-genome sequence of ablaOXA-48-harboringRaoultella ornithinolyticaclinical isolate from a patient in Lebanon. The size of theRaoultella ornithinolyticaCMUL058 genome was 5,622,862 bp, with a G+C content of 55.7%. We deciphered all the molecular mechanisms of antibiotic resistance, and we compared our genome to other availableR. ornithinolyticagenomes in GenBank. The resistome consisted of 9 antibiotic resistance genes, including a plasmidicblaOXA-48gene whose genetic organization is also described.

Inhibition effect of kaolinite on the development of antibiotic resistance genes in Escherichia coli induced by sublethal ampicillin and its molecular mechanism

2019 ◽  
Vol 16 (5) ◽  
pp. 347 ◽  
Author(s):  
Xiaolin Lai ◽  
Pingxiao Wu ◽  
Bo Ruan ◽  
Juan Liu ◽  
Zehua Liu ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Natural Environment ◽  
Cellular Response ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Antibiotic Resistance Genes ◽  
E Coli

Environmental contextAntibiotic resistance by microorganisms in the natural environment poses a threat to ecosystems and public health. We report findings suggesting kaolinite can effectively inhibit the development of antibiotic resistance genes in microorganisms, and present a new understanding of the molecular mechanisms that promote the development of antibiotic resistance. These results are critical to mitigating environmental and public health risks resulting from the abuse of antibiotics. AbstractAntibiotic resistance and antibiotic resistance genes (ARGs) in the natural environment pose a threat to ecosystems and public health; therefore, better strategies are needed to mitigate the emergence of resistance. This study examined the expression of ARGs in Escherichia coli (E. coli) after exposure to sub-MIC (minimum inhibitory concentration) antibiotics for 15 days in the presence and absence of kaolinite. The results of the real-time polymerase chain reaction (PCR) showed that the expression levels of the eight target genes of E. coli adhering to kaolinite were relatively decreased, and the MIC results also indicated that the final resistance was lower than that of the strains without kaolinite. A close relationship between E. coli and kaolinite was also revealed, as well as a unique interfacial interaction. In addition, the differential protein expression was further analysed to detect proteins and genes associated with ARGs mutations, and then the underlying mechanisms of cell growth and metabolism were identified under low dose ampicillin stress to elucidate the role of kaolinite in the process. Molecular mechanisms analysis determined that when cells adhering to kaolinite were stressed, transport of ampicillin to the periplasmic space was reduced, and the redox metabolism of bacteria was promoted to combat the harsh environment. Moreover, cells synthesised related peptides or proteins under the action of ribosomal proteins to prevent toxic damage. Therefore, this work not only provides new insights into the cellular response to antibiotic stress, but also provides a topic for more research on methods to delay the emergence of ARGs.

Faecal phageome of healthy individuals: presence of antibiotic resistance genes and variations caused by ciprofloxacin treatment

2019 ◽  
Vol 74 (4) ◽  
pp. 854-864 ◽  
Author(s):  
Dietmar Fernández-Orth ◽  
Elisenda Miró ◽  
Maryury Brown-Jaque ◽  
Lorena Rodríguez-Rubio ◽  
Paula Espinal ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Healthy Individuals

scholarly journals Mathematical Models of Plasmid Population Dynamics

2021 ◽  
Vol 12 ◽  
Author(s):  
José Carlos Ramón Hernández-Beltrán ◽  
Alvaro San Millán ◽  
Ayari Fuentes-Hernández ◽  
Rafael Peña-Miller
Keyword(s):  
Population Dynamics ◽  
Antibiotic Resistance ◽  
Mathematical Models ◽  
Resistance Genes ◽  
Molecular Mechanisms ◽  
Evolutionary Dynamics ◽  
Antibiotic Resistance Genes ◽  
Public Health Problem ◽  
Theoretical Models ◽  
Cellular Level

With plasmid-mediated antibiotic resistance thriving and threatening to become a serious public health problem, it is paramount to increase our understanding of the forces that enable the spread and maintenance of drug resistance genes encoded in mobile genetic elements. The relevance of plasmids as vehicles for the dissemination of antibiotic resistance genes, in addition to the extensive use of plasmid-derived vectors for biotechnological and industrial purposes, has promoted the in-depth study of the molecular mechanisms controlling multiple aspects of a plasmids’ life cycle. This body of experimental work has been paralleled by the development of a wealth of mathematical models aimed at understanding the interplay between transmission, replication, and segregation, as well as their consequences in the ecological and evolutionary dynamics of plasmid-bearing bacterial populations. In this review, we discuss theoretical models of plasmid dynamics that span from the molecular mechanisms of plasmid partition and copy-number control occurring at a cellular level, to their consequences in the population dynamics of complex microbial communities. We conclude by discussing future directions for this exciting research topic.

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