Mutation frequency of Escherichia coli isolated from river water: potential role in the development of antimicrobial resistance

2021 ◽  
Author(s):  
Tomohiro Yamazaki ◽  
Junji Matsuo
Keyword(s):  
Antimicrobial Resistance ◽  
River Water ◽  
Mutation Frequency ◽  
Potential Role ◽  
Relative Increase ◽  
Natural Environments ◽  
E Coli ◽  
Stressful Environment ◽  
Antimicrobial Sensitivity

Bacteria acquire genetic variations to adapt to stressful environmental conditions, which may be associated with the development of antimicrobial resistance. Here we investigated the mutation frequencies of 270 E. coli isolates from river water, representing a relatively less stressful environment. As we predicted, mutation frequencies of such E. coli isolates ranged from < 1 ×10<sup>-11 </sup>to 6.3 ×10<sup>-8</sup> (median, 1.7 × 10<sup>-9</sup>), and a strong mutator (4×10<sup>-7</sup> ≤) was not detected. To better understand the role of mutation frequency in the development of antimicrobial resistance, we assessed antimicrobial sensitivity after exposure of the E. coli isolates to subinhibitory concentrations of ciprofloxacin as a surrogate for stress. We found that antimicrobial resistance increased in bacteria with a low mutation frequency after exposure, and the relative increase in antimicrobial resistance generally increased depending on the mutation frequency. Thus, mutation frequency may contribute to the development of antimicrobial resistance of bacteria in natural environments.

scholarly journals High Prevalence and Diversity of Cephalosporin-Resistant Enterobacteriaceae Including Extraintestinal Pathogenic E. coli CC648 Lineage in Rural and Urban Dogs in Northwest Spain

Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 468 ◽  
Author(s):  
Fátima Abreu-Salinas ◽  
Dafne Díaz-Jiménez ◽  
Isidro García-Meniño ◽  
Pilar Lumbreras ◽  
Ana María López-Beceiro ◽  
...  
Keyword(s):  
High Risk ◽  
Antimicrobial Resistance ◽  
One Health ◽  
Potential Role ◽  
Multidrug Resistant ◽  
E Coli ◽  
Rural And Urban ◽  
High Prevalence ◽  
Healthy Dogs

The aim of this work was to assess the prevalence of extended spectrum-β-lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae in fecal samples recovered from rural and urban healthy dogs in Northwest Spain (Galicia) to identify potential high-risk clones and to molecularly characterize positive isolates regarding the genes coding for ESBL/pAmpC resistance and virulence. Thirty-five (19.6%) out of 179 dogs were positive for cephalosporin-resistant Enterobacteriaceae, including Escherichiacoli and Klebsiella pneumoniae (39 and three isolates, respectively). All the isolates were multidrug resistant, with high rates of resistance to different drugs, including ciprofloxacin (71.4%). A wide diversity of ESBL/pAmpC enzymes, as well as E. coli phylogroups (A, B1, C, D, E, F and clade I) were found. The eight isolates (20.5%) found to conform to the ExPEC status, belonged to clones O1:H45-clade I-ST770 (CH11-552), O18:H11-A-ST93-CC168 (CH11-neg), O23:H16-B1-ST453-CC86 (CH6-31), and O83:H42-F-ST1485-CC648 (CH231-58), with the latter also complying the uropathogenic (UPEC) status. The three K. pneumoniae recovered produced CTX-M-15 and belonged to the ST307, a clone previously reported in human clinical isolates. Our study highlights the potential role of both rural and urban dogs as a reservoir of high-risk Enterobacteriaceae clones, such as the CC648 of E. coli and antimicrobial resistance traits. Within a One-Health approach, their surveillance should be a priority in the fight against antimicrobial resistance.

scholarly journals Population Structure and Antimicrobial Resistance of Canine UropathogenicEscherichia coli

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Tessa E. LeCuyer ◽  
Barbara A. Byrne ◽  
Joshua B. Daniels ◽  
Dubraska V. Diaz-Campos ◽  
G. Kenitra Hammac ◽  
...  
Keyword(s):  
Population Structure ◽  
Antimicrobial Resistance ◽  
Companion Animals ◽  
Sequence Type ◽  
Content Type ◽  
E Coli ◽  
Extraintestinal Disease ◽  
Human Infections ◽  
Sequence Types

ABSTRACTEscherichia coliis the most common cause of human and canine urinary tract infection (UTI). Clonal groups, often with high levels of antimicrobial resistance, are a major component of theE. colipopulation that causes human UTI. While little is known about the population structure ofE. colithat causes UTI in dogs, there is evidence that dogs and humans can share fecal strains ofE. coliand that human-associated strains can cause disease in dogs. In order to better characterize theE. colistrains that cause canine UTI, we analyzed 295E. coliisolates obtained from canine urine samples from five veterinary diagnostic laboratories and analyzed their multilocus sequence types, phenotypic and genotypic antimicrobial resistance profiles, and virulence-associated gene repertoires. Sequence type 372 (ST372), an infrequent human pathogen, was the predominant sequence type in dogs at all locations. Extended-spectrum β-lactamase-producing isolates withblaCTX-Mgenes were uncommon in canine isolates but when present were often associated with sequence types that have been described in human infections. This provides support for occasional cross-host-species sharing of strains that cause extraintestinal disease and highlights the importance of understanding the role of companion animals in the overall transmission patterns of extraintestinal pathogenicE. coli.

scholarly journals Superoxide is a mediator of an altruistic aging program in Saccharomyces cerevisiae

2004 ◽  
Vol 166 (7) ◽  
pp. 1055-1067 ◽  
Author(s):  
Paola Fabrizio ◽  
Luisa Battistella ◽  
Raffaello Vardavas ◽  
Cristina Gattazzo ◽  
Lee-Loung Liou ◽  
...  
Keyword(s):  
Mutation Frequency ◽  
Premature Aging ◽  
Natural Environments ◽  
Computational Simulations ◽  
Changing Environments ◽  
High Mutation Frequency ◽  
Aging Program ◽  
Programmed Aging ◽  
Age Dependent

Aging is believed to be a nonadaptive process that escapes the force of natural selection. Here, we challenge this dogma by showing that yeast laboratory strains and strains isolated from grapes undergo an age- and pH-dependent death with features of mammalian programmed cell death (apoptosis). After 90–99% of the population dies, a small mutant subpopulation uses the nutrients released by dead cells to grow. This adaptive regrowth is inversely correlated with protection against superoxide toxicity and life span and is associated with elevated age-dependent release of nutrients and increased mutation frequency. Computational simulations confirm that premature aging together with a relatively high mutation frequency can result in a major advantage in adaptation to changing environments. These results suggest that under conditions that model natural environments, yeast organisms undergo an altruistic and premature aging and death program, mediated in part by superoxide. The role of similar pathways in the regulation of longevity in organisms ranging from yeast to mice raises the possibility that mammals may also undergo programmed aging.

scholarly journals Milk Hygiene in Rural Southwestern Uganda: Prevalence of Mastitis and Antimicrobial Resistance Profiles of Bacterial Contaminants of Milk and Milk Products

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Paul Ssajjakambwe ◽  
Gloria Bahizi ◽  
Christopher Setumba ◽  
Stevens M. B. Kisaka ◽  
Patrick Vudriko ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Production Efficiency ◽  
Sub Saharan Africa ◽  
Milk Products ◽  
E Coli ◽  
Antimicrobial Sensitivity ◽  
Causative Agents ◽  
Sub Saharan ◽  
The Government ◽  
Milk Hygiene

Mastitis and antimicrobial resistance are a big challenge to the dairy industry in sub-Saharan Africa. A study was conducted in Kashongi and Keshunga subcounties of Kiruhura District (in Uganda) where the government and private sector have deliberate programs to improve production efficiency, quality, and safety of milk and its products. The study aimed to determine the prevalence of mastitis, its common causative agents, antimicrobial sensitivity of mastitis causing organisms, and contaminants of processed milk products: yoghurt and ghee. Seventy-one milk, fourteen yoghurt, and three ghee samples were collected from nine farms. Of the 71 cows tested, 54 (76.1%) had mastitis. The mastitis cases from Keshunga were 32 (59.3%) and Kashongi contributed 22 (40.7%) of the cases. The common mastitis causative agents wereStaphylococcusspp. (30.8%),Streptococcusspp. (12.3%),Corynebacteriumspp.(15.4%), andE. coli(7.7%). Some of the isolates were resistant to tetracycline and penicillin. Prevalent contaminants of yoghurt wereStaphylococcusspp. (8.3%),Streptococcusspp. (8.3%),Corynebacteriumspp. (8.3%), andE. coli(8.3%), whereas all ghee containedStreptococcusspp. (100%). Prevalence of mastitis, antimicrobial resistance, and contamination of milk products are high in the study area. Targeted programs to prevent and control mastitis as well as antibiotic resistance are recommended.

scholarly journals Antimicrobial resistance among GLASS priority pathogens from Pakistan: 2006–2018

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dania Khalid Saeed ◽  
Joveria Farooqi ◽  
Sadia Shakoor ◽  
Rumina Hasan
Keyword(s):  
Antimicrobial Resistance ◽  
Potential Role ◽  
Carbapenem Resistance ◽  
Steady Increase ◽  
Published Data ◽  
Situational Analysis ◽  
Antimicrobial Surveillance ◽  
Evolution Of Resistance ◽  
Resistance Rates

Abstract Background In 2018 Pakistan initiated its national antimicrobial resistance (AMR) surveillance aligned with Global Antimicrobial Surveillance System (GLASS). To complement this surveillance, we conducted a situational analysis of AMR rates among GLASS organisms in the country. Data from published studies and from antibiograms was compared and role of antibiograms as potential contributors to national AMR surveillance explored. Methods AMR rates for GLASS specified pathogen/antimicrobials combination from Pakistan were reviewed. Data sources included published studies (2006–2018) providing AMR rates from Pakistan (n = 54) as well as antibiograms (2011–2018) available on the Pakistan Antimicrobial Resistance Network (PARN) website. Resistance rates were categorized as follows: Very low: 0–10%, Low: 11–30%, Moderate: 30–50% and High: > 50%. Results Published data from hospital and community/laboratory-based studies report resistance rates of > 50% and 30–50% respectively to 3rd generation cephalosporins, fluoroquinolones and cotrimoxazole amongst Klebsiella pneumoniae and Escherichia coli. Carbapenem resistance rates amongst these organisms remained below 30%. High (> 50%) resistance was reported in Acinetobacter species to aminoglycosides and carbapenems among hospitalized patients. The evolution of ceftriaxone resistant Salmonella Typhi and Shigella species is reported. The data showed > 50% to fluoroquinolones amongst Neisseria gonorrhoeae and the spread of methicillin resistant Staphylococcus aureus (< 30%; 2008) to (> 50%; 2010) in hospital settings. Resistance reported in published studies aligned well with antibiogram data. The latter also captured a clear picture of evolution of resistance over the study period. Conclusion Both published studies as well antibiograms suggest high rates of AMR in Pakistan. Antibiogram data demonstrating steady increase in AMR highlight its potential role towards supplementing national AMR surveillance efforts particularly in settings where reach of national surveillance may be limited.

scholarly journals Carriage of ESBL and Amp-C -b -lactamase among Escherichia coli strains isolated from dogs in kennels Dak Lak province

2021 ◽  
Vol 5 (2) ◽  
pp. 1198-1207
Author(s):  
Kien Chi Le ◽  
Cuong Quoc Vo ◽  
Xuan Thanh Tran ◽  
Hung Manh Dang ◽  
Huyen Ngoc My Nguyen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Viet Nam ◽  
Beta Lactamase ◽  
Sensitivity Testing ◽  
Beta Lactamases ◽  
E Coli ◽  
Antimicrobial Sensitivity ◽  
Extended Spectrum ◽  
Genes Encoding

The global prevalence of antimicrobial resistance and Extended-Spectrum and AmpC Beta- Lactamases is continuously widespread among Escherichia coli during recent years, especially in Viet Nam. In Viet Nam, there have been researches on ESBL and AmpC-carrying E. coli inhabiting animal and human. However, studies of antimicrobial resistance in E. coli residing in pets, especially dogs are unavailable. The aim of the study was to investigate the antimicrobial sensitivity testing (AST), the resistance to 3rd cephalosporin and penicillin, also to assess the molecular detection of ESBL and Amp-C-beta -lactamase in E. coli isolates inhabiting the digestive tract of dogs at kennels Dak Lak. By using double disk synergy test (DDST), and ceftazidime-imipenem antagonism test (CIAT) to detect phenotypic characteristic of E. coli strains producing extended-spectrum beta- lactamases (ESBLs) and plasmid-mediated Amp-C-beta -lactamase, and by using multiplex polymerase chain reaction (multiplex PCR) to confirm the presence of ESBL genes (class A): blaCTX-M(1;2;8;9;25), bla TEM, bla SHV , bla OXA and genes encoding AmpC-type beta lactamase (class C): bla MOX-1;2 , bla CMY- (1;2-7;8-11) , blaLAT-(1;4) ,bla DHA-(1;2), bla ACC, bla FOX-(1-5B) ,bla MIR-1 ,bla ACT-1. From of three hundred twelve bacteial strains isolated from sixty-four rectal swabs two hundred sixty-nine E. Coli, isolates accounting for 86%, were identified and isolated, forty-four (16%) and twelve (4%) E. coli isolates encoding with ESBL and Amp-C-beta -lactamases. From molecular diagnosis with regard to phenotype, production of ESBL was shown in thirty-nine (15%) E. coli isolates and Amp-C enzymes in eight (3%) E. coli isolates. The high percentage of E. coli exhibiting antibiotic resistance revealed the accelerated overuse of antibiotics. Result of this study will contribute to the monitoring of epidemiologic resistance.

scholarly journals Prevalence and Antibiotic Resistance Pattern of Escherichia coli Isolated from Raw Dairy Milk

2018 ◽  
Vol 6 (9) ◽  
pp. 1108
Author(s):  
Abul Hasan ◽  
Ahsanur Reza ◽  
Farzana Islam Rume ◽  
Mirza Mienur Meher ◽  
Md. Shafiullah Parvej ◽  
...  
Keyword(s):  
Raw Milk ◽  
Resistance Pattern ◽  
Drug Resistant ◽  
E Coli ◽  
Milk Samples ◽  
Antimicrobial Sensitivity ◽  
Food Borne ◽  
Sensitivity Tests ◽  
Dairy Milk

E. coli is one of the most important food borne pathogen, which could be transmitted by milk and milk products. To assess the role of dairy milk as the source of drug resistant E. coli, we examined 50 raw dairy milk samples (25-farm milk + 25-market milk) from some selected areas of Bangladesh by cultural, morphological, biochemical and antimicrobial sensitivity tests. In the preliminary observation, the mean total aerobic mesophilic count of market and farm raw milk samples were 8.98 and 8.68 log CFU/ml, while mean coliform count were 4.20 and 3.03 log CFU/ml respectively. Thirty-three E. coli isolates were recovered from collected samples (66% 33 of 50) and this pathogen was more prevalent in market milk (76%, 19 of 25) than farm milk (56%, 14 of 25). In addition, most of the isolated E. coli exhibited resistance against ampicillin and cefotaxime. This result shows that, the raw dairy milk and its products could be a source of human drug resistant E. coli.

scholarly journals Exoribonuclease and Endoribonuclease Activities of RNase BN/RNase Z both Function in Vivo

2012 ◽  
Vol 287 (42) ◽  
pp. 35747-35755 ◽  
Author(s):  
Tanmay Dutta ◽  
Arun Malhotra ◽  
Murray P. Deutscher
Keyword(s):  
Potential Role ◽  
Wild Type ◽  
X Ray ◽  
E Coli ◽  
Phage T4 ◽  
A Cell ◽  
Rnase Z

Escherichia coli RNase BN, a member of the RNase Z family of endoribonucleases, differs from other family members in that it also can act as an exoribonuclease in vitro. Here, we examine whether this activity of RNase BN also functions in vivo. Comparison of the x-ray structure of RNase BN with that of Bacillus subtilis RNase Z, which lacks exoribonuclease activity, revealed that RNase BN has a narrower and more rigid channel downstream of the catalytic site. We hypothesized that this difference in the putative RNA exit channel might be responsible for the acquisition of exoribonuclease activity by RNase BN. Accordingly, we generated several mutant RNase BN proteins in which residues within a loop in this channel were converted to the corresponding residues present in B. subtilis RNase Z, thus widening the channel and increasing its flexibility. The resulting mutant RNase BN proteins had reduced or were essentially devoid of exoribonuclease activity in vitro. Substitution of one mutant rbn gene (P142G) for wild type rbn in the E. coli chromosome revealed that the exoribonuclease activity of RNase BN is not required for maturation of phage T4 tRNA precursors, a known specific function of this RNase. On the other hand, removal of the exoribonuclease activity of RNase BN in a cell lacking other processing RNases leads to slower growth and affects maturation of multiple tRNA precursors. These findings help explain how RNase BN can act as both an exo- and an endoribonuclease and also demonstrate that its exoribonuclease activity is capable of functioning in vivo, thus widening the potential role of this enzyme in E. coli.

Pharmacokinetic and pharmacodynamic principles of antimicrobials

2016 ◽  
Author(s):  
Menino Osbert Cotta ◽  
Jason Roberts
Keyword(s):  
Antimicrobial Resistance ◽  
Protein Binding ◽  
Clinical Outcomes ◽  
Antimicrobial Therapy ◽  
Potential Role ◽  
Volume Of Distribution ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Dosing Regimens ◽  
Dosing Strategies

The continual threat of antimicrobial resistance means that optimizing current antimicrobial therapy is of paramount importance. Antimicrobial pharmacokinetics and pharmacodynamics (PK/PD) play a central role in developing dosing regimens that target maximal clinical outcomes and microbiological eradication. This chapter describes the three main PK/PD indices into which current antimicrobials are categorized. Elements of PK that require due consideration when optimizing antimicrobial therapy, including volume of distribution, antimicrobial clearance, and protein binding, are also discussed. Finally, specific attention is paid to antimicrobial dosing among challenging populations, namely the critically ill and obese, and the potential role of alternative dosing strategies, such as use of loading doses and extended/continuous infusions, is also outlined.

scholarly journals Antimicrobial use in food-producing animals: a rapid evidence assessment of stakeholder practices and beliefs

2017 ◽  
Vol 181 (19) ◽  
pp. 510-510 ◽  
Author(s):  
Jo Hockenhull ◽  
Andrea E Turner ◽  
Kristen K Reyher ◽  
David C Barrett ◽  
Laura Jones ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Antimicrobial Resistance ◽  
Potential Role ◽  
Current Knowledge ◽  
Antimicrobial Use ◽  
Livestock Industry ◽  
Animal Agriculture ◽  
The World ◽  
Public Pressure

Food-producing animals throughout the world are likely to be exposed to antimicrobial (AM) treatment. The crossover in AM use between human and veterinary medicine raises concerns that antimicrobial resistance (AMR) may spread from food-producing animals to humans, driving the need for further understanding of how AMs are used in livestock practice as well as stakeholder beliefs relating to their use. A rapid evidence assessment (REA) was used to collate research on AM use published in peer-reviewed journals between 2000 and 2016. Forty-eight papers were identified and reviewed. The summary of findings highlights a number of issues regarding current knowledge of the use of AMs in food-producing animals and explores the attitudes of interested parties regarding the reduction of AM use in livestock. Variation between and within countries, production types and individual farms demonstrates the complexity of the challenge involved in monitoring and regulating AM use in animal agriculture. Many factors that could influence the prevalence of AMR in livestock are of concern across all sections of the livestock industry. This REA highlights the potential role of farmers and veterinarians and of other advisors, public pressure and legislation to influence change in the use of AMs in livestock.

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