7 results on '"Muna F. Anjum"'
Search Results
2. Molecular epidemiology of isolates with multiple mcr plasmids from a pig farm in Great Britain: the effects of colistin withdrawal in the short and long term
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Nicholas A. Duggett, Muna F. Anjum, Christopher Teale, Fabrizio Lemma, Miranda Kirchner, Luke P. Randall, Javier Nunez-Garcia, Susanna Williamson, R.A. Horton, and Camilla Brena
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DNA, Bacterial ,0301 basic medicine ,Microbiology (medical) ,Salmonella ,Farms ,Livestock ,Time Factors ,Swine ,medicine.drug_class ,030106 microbiology ,Antibiotics ,Transferases (Other Substituted Phosphate Groups) ,Microbial Sensitivity Tests ,Biology ,medicine.disease_cause ,Microbiology ,Feces ,03 medical and health sciences ,Plasmid ,Enterobacteriaceae ,Drug Resistance, Multiple, Bacterial ,medicine ,Animals ,Pharmacology (medical) ,Escherichia coli ,Pharmacology ,Whole Genome Sequencing ,Molecular epidemiology ,Colistin ,Escherichia coli Proteins ,Enterobacteriaceae Infections ,biology.organism_classification ,United Kingdom ,Anti-Bacterial Agents ,Infectious Diseases ,hormones, hormone substitutes, and hormone antagonists ,Plasmids ,medicine.drug - Abstract
Background The environment, including farms, might act as a reservoir for mobile colistin resistance (mcr) genes, which has led to calls for reduction of usage in livestock of colistin, an antibiotic of last resort for humans. Objectives To establish the molecular epidemiology of mcr Enterobacteriaceae from faeces of two cohorts of pigs, where one group had initially been treated with colistin and the other not, over a 5 month period following stoppage of colistin usage on a farm in Great Britain; faecal samples were also taken at ∼20 months. Methods mcr-1 Enterobacteriaceae were isolated from positive faeces and was WGS performed; conjugation was performed on selected Escherichia coli and colistin MICs were determined. Results E. coli of diverse ST harbouring mcr-1 and multiple resistance genes were isolated over 5 months from both cohorts. Two STs, from treated cohorts, contained both mcr-1 and mcr-3 plasmids, with some isolates also harbouring multiple copies of mcr-1 on different plasmids. The mcr-1 plasmids grouped into four Inc types (X4, pO111, I2 and HI2), with mcr-3 found in IncP. Multiple copies of mcr plasmids did not have a noticeable effect on colistin MIC, but they could be transferred simultaneously to a Salmonella host in vitro. Neither mcr-1 nor mcr-3 was detected in samples collected ∼20 months after colistin cessation. Conclusions We report for the first known time on the presence in Great Britain of mcr-3 from MDR Enterobacteriaceae, which might concurrently harbour multiple copies of mcr-1 on different plasmids. However, control measures, including stoppage of colistin, can successfully mitigate long-term on-farm persistence.
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- 2018
3. Longitudinal study on the occurrence in pigs of colistin‐resistant Escherichia coli carrying mcr‐1 following the cessation of use of colistin
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Muna F. Anjum, Robin R. L. Simons, Fabrizio Lemma, Richard J. Ellis, Nicholas A. Duggett, R.A. Horton, Susanna Williamson, Richard P. Smith, S.J. Evans, Francesca Martelli, Luke P. Randall, Christopher Teale, Jon Rogers, Miranda Kirchner, and Camilla Brena
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0301 basic medicine ,Salmonella ,Veterinary medicine ,Swine ,medicine.drug_class ,030106 microbiology ,Antibiotics ,Biology ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Colistin resistance ,Feces ,03 medical and health sciences ,Drug Resistance, Bacterial ,Escherichia coli ,medicine ,Animals ,Longitudinal Studies ,Pig farms ,Escherichia coli Infections ,Colistin ,Escherichia coli Proteins ,General Medicine ,Anti-Bacterial Agents ,030104 developmental biology ,MCR-1 ,hormones, hormone substitutes, and hormone antagonists ,Biotechnology ,medicine.drug - Abstract
Aims In 2015, colistin-resistant Escherichia coli and Salmonella with the mcr-1 gene were isolated from a pig farm in Great Britain. Pigs were subsequently monitored over a ~20-month period for the occurrence of mcr-1-mediated colistin resistance and the risk of mcr-1 E. coli entering the food chain was assessed. Methods and results Pig faeces and slurry were cultured for colistin-resistant E. coli and Salmonella, tested for the mcr-1 gene by PCR and selected isolates were further analysed. Seventy-eight per cent of faecal samples (n = 275) from pigs yielded mcr-1 E. coli after selective culture, but in positive samples only 0·2-1·3% of the total E. coli carried mcr-1. Twenty months after the initial sampling, faecal samples (n = 59) were negative for E. coli carrying mcr-1. Conclusions The risk to public health from porcine E. coli carrying mcr-1 was assessed as very low. Twenty months after cessation of colistin use, E. coli carrying mcr-1 was not detected in pig faeces on a farm where it was previously present. Significance and impact of the study The results suggest that cessation of colistin use may help over time to reduce or possibly eliminate mcr-1 E. coli on pig farms where it occurs.
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- 2018
4. mcr-1 and mcr-2 (mcr-6.1) variant genes identified in Moraxella species isolated from pigs in Great Britain from 2014 to 2015
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Manal AbuOun, Emma Stubberfield, Richard P. Smith, Javier Nunez-Garcia, Derrick W. Crook, Muna F. Anjum, Luke P. Randall, Christopher Teale, Luisa Dormer, Fabrizio Lemma, Nicholas A. Duggett, and Miranda Kirchner
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0301 basic medicine ,Pharmacology ,Microbiology (medical) ,Tetracycline ,030106 microbiology ,Biology ,medicine.disease_cause ,biology.organism_classification ,Microbiology ,03 medical and health sciences ,Infectious Diseases ,Plasmid ,Composite transposon ,medicine ,Colistin ,Pharmacology (medical) ,MCR-1 ,Moraxella osloensis ,Escherichia coli ,Moraxella ,hormones, hormone substitutes, and hormone antagonists ,Original Research ,medicine.drug - Abstract
Objectives To determine the occurrence of mcr-1 and mcr-2 genes in Gram-negative bacteria isolated from healthy pigs in Great Britain. Methods Gram-negative bacteria (n = 657) isolated from pigs between 2014 and 2015 were examined by WGS. Results Variants of mcr-1 and mcr-2 were identified in Moraxella spp. isolated from pooled caecal contents of healthy pigs at slaughter collected from six farms in Great Britain. Other bacteria, including Escherichia coli from the same farms, were not detected harbouring mcr-1 or mcr-2. A Moraxella porci-like isolate, MSG13-C03, harboured MCR-1.10 with 98.7% identity to MCR-1, and a Moraxella pluranimalium-like isolate, MSG47-C17, harboured an MCR-2.2 variant with 87.9% identity to MCR-2, from E. coli; the isolates had colistin MICs of 1-2 mg/L. No intact insertion elements were identified in either MSG13-C03 or MSG47-C17, although MSG13-C03 harboured the conserved nucleotides abutting the ISApl1 composite transposon found in E. coli plasmids and the intervening ∼2.6 kb fragment showed 97% identity. Six Moraxella osloensis isolates were positive for phosphoethanolamine transferase (EptA). They shared 62%-64.5% identity to MCR-1 and MCR-2, with colistin MICs from 2 to 4 mg/L. Phylogenetic analysis indicated that MCR and EptA have evolved from a common ancestor. In addition to mcr, the β-lactamase gene, blaBRO-1, was found in both isolates, whilst the tetracycline resistance gene, tetL, was found in MSG47-C17. Conclusions Our results add further evidence for the mobilization of the mcr-pap2 unit from Moraxella via composite transposons leading to its global dissemination. The presence of mcr-pap2 from recent Moraxella isolates indicates they may comprise a reservoir for mcr.
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- 2017
5. Detection of anmcr-1-encoding plasmid mediating colistin resistance inSalmonella entericafrom retail meat in Portugal: Table 1
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Muna F. Anjum, Constança Pomba, Gabriela Jorge Da Silva, Roderick M. Card, Javier Nunez, Rui Figueiredo, and Nuno Mendonça
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0301 basic medicine ,Pharmacology ,Microbiology (medical) ,biology ,030106 microbiology ,biology.organism_classification ,Microbiology ,Colistin resistance ,03 medical and health sciences ,030104 developmental biology ,Infectious Diseases ,Plasmid ,Salmonella enterica ,Pharmacology (medical) ,MCR-1 - Published
- 2016
6. Identifying antimicrobial resistance genes of human clinical relevance within Salmonella isolated from food animals in Great Britain
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Martin J. Woodward, Muna F. Anjum, Muriel Mafura, Peter Slickers, L. C. Snow, Victoria Morrison, Ralf Ehricht, and Suman Choudhary
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DNA, Bacterial ,Microbiology (medical) ,Serotype ,Salmonella ,Livestock ,Genomic Islands ,Tetracycline ,Microbial Sensitivity Tests ,medicine.disease_cause ,Integron ,Microbiology ,Antibiotic resistance ,Ampicillin ,Drug Resistance, Bacterial ,medicine ,Animals ,Pharmacology (medical) ,Oligonucleotide Array Sequence Analysis ,Pharmacology ,Salmonella Infections, Animal ,biology ,Salmonella enterica ,Microarray Analysis ,biology.organism_classification ,Antimicrobial ,United Kingdom ,Anti-Bacterial Agents ,Infectious Diseases ,Genes, Bacterial ,Conjugation, Genetic ,biology.protein ,Plasmids ,medicine.drug - Abstract
To investigate the occurrence of antimicrobial resistance genes of human clinical relevance in Salmonella isolated from livestock in Great Britain. Two hundred and twenty-five Salmonella enterica isolates were characterized using an antimicrobial resistance gene chip and disc diffusion assays. Plasmid profiling, conjugation experiments and identification of Salmonella genomic island 1 (SGI1) were performed for selected isolates. Approximately 43% of Salmonella harboured single or multiple antimicrobial resistance genes with pig isolates showing the highest numbers where 96% of Salmonella Typhimurium harboured one or more resistance genes. Isolates harbouring multiple resistances divided into three groups. Group 1 isolates harboured ampicillin/streptomycin/sulphonamide/tetracycline resistance and similar phenotypes. This group contained isolates from pigs, cattle and poultry that were from several serovars including Typhimurium, 4,[5],12:i:-, Derby, Ohio and Indiana. All Group 2 isolates were from pigs and were Salmonella Typhimurium. They contained a non-sul-type class 1 integron and up to 13 transferrable resistances. All Group 3 isolates harboured a class 1 integron and were isolated from all animal species included in the study. Most isolates were Salmonella Typhimurium and harboured SGI1. Salmonella isolated from livestock was shown to harbour antimicrobial resistance genes although no or little resistance to third-generation cephalosporins or ciprofloxacin, respectively, was detected. The preponderance in pigs of multidrug-resistant Salmonella Typhimurium makes it important to introduce control measures such as improved biosecurity to ensure that they do not pass through the food chain and limit human therapeutic options.
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- 2011
7. Response of the NAD(P)H-oxidising flavohaemoglobin (Hmp) to prolonged oxidative stress and implications for its physiological role inEscherichia coli
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Muna F. Anjum, Robert K. Poole, and Nicolaos Ioannidis
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Hemeproteins ,Paraquat ,animal structures ,Recombinant Fusion Proteins ,Biology ,medicine.disease_cause ,Microbiology ,chemistry.chemical_compound ,Bacterial Proteins ,Dihydropteridine Reductase ,Diaphorase ,Escherichia coli ,Genetics ,medicine ,NADH, NADPH Oxidoreductases ,Promoter Regions, Genetic ,Molecular Biology ,Strain (chemistry) ,Escherichia coli Proteins ,Gene Expression Regulation, Bacterial ,NAD ,In vitro ,Oxidative Stress ,Lac Operon ,chemistry ,Biochemistry ,Genes, Bacterial ,NAD+ kinase ,Oxidation-Reduction ,NADP ,Oxidative stress ,Intracellular - Abstract
The Escherichia coli flavohaemoglobin (Hmp) has a globin-like N-terminal domain and a ferredoxin-NADP-reductase-like C-terminal domain. We show here that purified Hmp oxidises both NADH and NADPH with K m values of 1.8 and 19.6 μM, respectively. Prolonged incubation of a hmp-lacZ fusion strain with the redox cycling agent paraquat resulted in a 28-fold induction of hmp gene expression, nearly 3-fold higher than after short periods of exposure. A strain overproducing Hmp was significantly more sensitive to paraquat than was the wild-type strain but, in vitro, purified Hmp was not an effective NADPH-paraquat diaphorase. Prolonged incubation of a wild-type strain with paraquat increased intracellular Hmp to spectrally detectable levels.
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- 1998
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