Functional and Structural Characterization of Acquired Pan-Aminoglycoside Resistance 16S rRNA Methyltransferase NpmB1

2021 ◽  
Author(s):  
Akito Kawai ◽  
Masahiro Suzuki ◽  
Kentaro Tsukamoto ◽  
Yusuke Minato ◽  
Yohei Doi
Keyword(s):  
Amino Acid ◽  
16S Rrna ◽  
Amino Acid Identity ◽  
Single Amino Acid ◽  
Aminoglycoside Resistance ◽  
E Coli ◽  
The United Kingdom ◽  
Amino Acid Variant ◽  
A Site

Post-translational methylation of the A site of 16S rRNA at position A1408 leads to pan-aminoglycoside resistance encompassing both 4,5- and 4,6-disubstituted 2-deoxystreptamine (DOS) aminoglycosides. To date, NpmA is the only acquired enzyme with such function. Here, we present function and structure of NpmB1 whose sequence was identified in Escherichia coli genomes registered from the United Kingdom. NpmB1 possesses 40% amino acid identity with NpmA1 and confers resistance to all clinically relevant aminoglycosides including 4,5-DOS agents. Phylogenetic analysis of NpmB1 and NpmB2, its single amino acid variant, revealed that the encoding gene was likely acquired by E. coli from a soil bacterium. The structure of NpmB1 suggests that it requires a structural change of the β6/7 linker in order to bind to 16S rRNA. These findings establish NpmB1 and NpmB2 as the second group of acquired pan-aminoglycoside resistance 16S rRNA methyltransferases.

Screening of OXA-244 producers, a difficult-to-detect and emerging OXA-48 variant?

2020 ◽  
Author(s):  
Cecile Emeraud ◽  
Laura Biez ◽  
Delphine Girlich ◽  
Agnès B Jousset ◽  
Thierry Naas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Hydrolytic Activity ◽  
Single Amino Acid ◽  
Broth Microdilution ◽  
Mlst Analysis ◽  
E Coli ◽  
Amino Acid Variant ◽  
High Prevalence ◽  
High Concentrations

Abstract Background OXA-244, a single amino acid variant of OXA-48, demonstrates weaker hydrolytic activity towards carbapenems and temocillin compared with OXA-48. Of note, these antimicrobials are present in high concentrations in several carbapenemase-producing Enterobacterales (CPE) screening media. As a result, some screening media fail to grow OXA-244-producing isolates, while the prevalence of OXA-244 producers is constantly increasing in France. Methods Here, we evaluate the performance of three commercially available CPE screening media [ChromID® CARBA SMART (bioMérieux), Brilliance™ CRE (Thermo Fisher) and mSuperCARBA™ (MAST Diagnostic)] for their ability to detect OXA-244 producers (n = 101). As OXA-244 producers may also express an ESBL, two additional ESBL screening media were tested (Brilliance™ ESBL and ChromID® BLSE). MICs of temocillin and imipenem were determined by broth microdilution. The clonality of OXA-244-producing Escherichia coli isolates (n = 97) was assessed by MLST. Results Overall, the sensitivity of the ChromID® CARBA SMART, Brilliance™ CRE and mSuperCARBA™ media were 14% (95% CI = 8.1%–22.5%), 54% (95% CI = 43.3%–63.4%) and 99% (95% CI = 93.8%–100%), respectively, for the detection of OXA-244 producers. Among the 101 OXA-244-producing isolates, 96% were E. coli and 77%–78% grew on ESBL screening media. MLST analysis identified five main STs among OXA-244-producing E. coli isolates: ST38 (n = 37), ST361 (n = 17), ST69 (n = 12), ST167 (n = 11) and ST10 (n = 8). Conclusions Our results demonstrated that the mSuperCARBA™ medium is very efficient in the detection of OXA-244 producers, unlike the ChromID® CARBA SMART medium. The high prevalence of ESBLs among OXA-244 producers allowed detection of 77%–78% of them using ESBL-specific screening media.

scholarly journals Coproduction of 16S rRNA Methyltransferase RmtD or RmtG with KPC-2 and CTX-M Group Extended-Spectrum β-Lactamases in Klebsiella pneumoniae

2013 ◽  
Vol 57 (5) ◽  
pp. 2397-2400 ◽  
Author(s):  
Maria Fernanda C. Bueno ◽  
Gabriela R. Francisco ◽  
Jessica A. O'Hara ◽  
Doroti de Oliveira Garcia ◽  
Yohei Doi
Keyword(s):  
Amino Acid ◽  
16S Rrna ◽  
Klebsiella Pneumoniae ◽  
Amino Acid Identity ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
Acid Identity ◽  
Paulo State ◽  
Extended Spectrum ◽  
High Level

ABSTRACTEightKlebsiella pneumoniaeclinical strains with high-level aminoglycoside resistance were collected from eight hospitals in São Paulo State, Brazil, in 2010 and 2011. Three of them produced an RmtD group 16S rRNA methyltransferase, RmtD1 or RmtD2. Five strains were found to produce a novel 16S rRNA methyltransferase, designated RmtG, which shared 57 to 58% amino acid identity with RmtD1 and RmtD2. Seven strains coproduced KPC-2 with or without various CTX-M group extended-spectrum β-lactamases, while the remaining strain coproduced CTX-M-2.

Mutations in aarE, the ubiA Homolog of Providencia stuartii, Result in High-Level Aminoglycoside Resistance and Reduced Expression of the Chromosomal Aminoglycoside 2′-N-Acetyltransferase

1998 ◽  
Vol 42 (4) ◽  
pp. 959-962 ◽  
Author(s):  
Michael R. Paradise ◽  
Gregory Cook ◽  
Robert K. Poole ◽  
Philip N. Rather
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Identity ◽  
Second Step ◽  
Aminoglycoside Resistance ◽  
Acid Identity ◽  
E Coli ◽  
Small Colony ◽  
Providencia Stuartii ◽  
High Level

ABSTRACT The aarE1 allele was identified on the basis of the resulting phenotype of increased aminoglycoside resistance. TheaarE1 mutation also resulted in a small-colony phenotype and decreased levels of aac(2′)-Ia mRNA. The deduced AarE gene product displayed 61% amino acid identity to theEscherichia coli UbiA protein, an octaprenyltransferase required for the second step of ubiquinone biosynthesis. Complementation experiments in both Providencia stuartiiand E. coli demonstrated that aarE andubiA are functionally equivalent.

scholarly journals Characterization of Aminoglycoside Modifying Enzymes Producing E. coli and Klebsiella pneumoniae Clinical Isolates

2021 ◽  
Author(s):  
Eman El-Gebaly ◽  
Mohammed Farrag ◽  
Tarek Dishisha ◽  
Walid Bakeer
Keyword(s):  
16S Rrna ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Aminoglycoside Resistance ◽  
Efficient Treatment ◽  
E Coli ◽  
Isolation And Characterization ◽  
Antimicrobial Resistance Gene

Antimicrobial resistance gene profile characterization and dissemination offer useful detail on the possible challenge in treating bacteria. The development of aminoglycoside modifying enzymes (AMEs) is considered as the primary mechanism of resistance to aminoglycosides, in addition to the 16S rRNA methylases. This study aimed at isolation and characterization of aminoglycosides resistant clinical isolates of enterobacteriaceae family from different clinical samples. Over a period of 24 months, thirty samples were collected and 49 clinical isolates of E. coli [n=25], Klebsiella [n=13], Enterobacter species (n=7) and Proteus species (n=4) were isolated from Egyptian clinical laboratories. The identities of the cultures were confirmed following standard microbiological procedures. Resistance of the isolates to aminoglycosides was determined by the disc diffusion method and isolates with highest resistance (n=9) were selected and investigated for 16S rRNA methylase and AMES encoding genes by polymerase chain reaction (PCR) and sequencing. In general, aminoglycoside resistance was found in 95% of the isolates; the isolates displayed the highest rate of resistance to netilmicin (75%) and kanamycin (55%), while resistance to gentamycin (18%) and tobramycin (16%) was low. A total of 9 isolates have the highest aminoglycoside resistant rate, showed the highest appearance for aac(6′)-Ib as well as ant (3″)-Ia resistant genes, with aac (3)-II (44%) and ant (4′)-IIb (34%) following closely. The high prevalence of AMEs observed among resistant isolates in this study suggests the urgent need for more efficient treatment designs to mitigate the selection burden as well as improved care of patients who have been infected with these drug-resistant organisms.

Cloning and Characterization of a Carotenoid Cleavage Dioxygenase from Artemisia Annua L

2011 ◽  
Vol 108 ◽  
pp. 274-281
Author(s):  
Shuo Qian Liu ◽  
Na Tian ◽  
Zhong Hua Liu ◽  
Jia Nan Huang ◽  
Juan Li
Keyword(s):  
Amino Acid ◽  
Artemisia Annua ◽  
Amino Acid Identity ◽  
Carotenoid Cleavage Dioxygenase ◽  
E Coli ◽  
Acid Protein ◽  
Rapid Amplification ◽  
First Time

In order to discover the formation mechanism of carotenoid derived aroma, which has been wildly used on protection of crop against insect attacks, the full-length cDNA of an Artemisia annua carotenoid cleavage dioxygenase (AaCCD1) was cloned by rapid amplification of cDNA ends. The function of AaCCD1 was characterized by expression of AaCCD1 in a strain of E. coli accumulating carotenoids and enzyme assay in vitro. The completed open read frame of AaCCD1 was 1629 bp and it encoded a 542-amino acid protein with a 77% amino acid identity to Arabidopsis thaliana CCD1, a predicted molecular mass of 61.04 kDa and a pI of 5.8. AaCCD1 efficiently cleaves carotenoids and regulate the formation of terpenoid compounds. This is the first time to report the cloning and identification of carotenoid cleavage dioxygenase from Atemisia annua, which will play a great role on understanding the regulation of volatile compounds.

scholarly journals Personalized Proteome: Comparing Proteogenomics and Open Variant Search Approaches for Single Amino Acid Variant Detection

2021 ◽  
Author(s):  
Renee Salz ◽  
Robbin Bouwmeester ◽  
Ralf Gabriels ◽  
Sven Degroeve ◽  
Lennart Martens ◽  
...  
Keyword(s):  
Amino Acid ◽  
Single Amino Acid ◽  
Amino Acid Variant ◽  
Variant Detection

scholarly journals A single amino acid substitution in the Ω-like loop of E. coli PBP5 disrupts its ability to maintain cell shape and intrinsic beta-lactam resistance

Microbiology ◽  
2015 ◽  
Vol 161 (4) ◽  
pp. 895-902 ◽  
Author(s):  
Mouparna Dutta ◽  
Debasish Kar ◽  
Ankita Bansal ◽  
Sandeep Chakraborty ◽  
Anindya S. Ghosh
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Cell Shape ◽  
Single Amino Acid Substitution ◽  
Single Amino Acid ◽  
Beta Lactam ◽  
E Coli

Mutant Fetal Hemoglobin Causing Cyanosis in a Newborn

PEDIATRICS ◽  
1989 ◽  
Vol 83 (5) ◽  
pp. 734-736
Author(s):  
John R. Priest ◽  
Jan Watterson ◽  
Richard T. Jones ◽  
Anne E. Faassen ◽  
Bo E. Hedlund
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Clinical Evidence ◽  
Fetal Hemoglobin ◽  
Single Amino Acid Substitution ◽  
Single Amino Acid ◽  
Globin Chain ◽  
Chain Synthesis ◽  
A Site ◽  
Β Chain

A well but cyanotic newborn was found to have a mutant γ-globin chain, leading to a functionally abnormal fetal hemoglobin. A single amino acid substitution was found in a site consistent with known adult M hemoglobins. This patient showed no clinical evidence of cyanosis at 5 weeks of age as γ-chain synthesis was replaced by β-chain synthesis. A sibling born 20 months later was also cyanotic and the same mutant hemoglobin was found.

Biochemical and genetic characterization of a yeast TFIID mutant that alters transcription in vivo and DNA binding in vitro

1992 ◽  
Vol 12 (5) ◽  
pp. 2372-2382
Author(s):  
K M Arndt ◽  
S L Ricupero ◽  
D M Eisenmann ◽  
F Winston
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Direct Repeat ◽  
Single Amino Acid ◽  
Wild Type ◽  
Dna Binding Specificity ◽  
Selection For

A mutation in the gene that encodes Saccharomyces cerevisiae TFIID (SPT15), which was isolated in a selection for mutations that alter transcription in vivo, changes a single amino acid in a highly conserved region of the second direct repeat in TFIID. Among eight independent spt15 mutations, seven cause this same amino acid change, Leu-205 to Phe. The mutant TFIID protein (L205F) binds with greater affinity than that of wild-type TFIID to at least two nonconsensus TATA sites in vitro, showing that the mutant protein has altered DNA binding specificity. Site-directed mutations that change Leu-205 to five different amino acids cause five different phenotypes, demonstrating the importance of this amino acid in vivo. Virtually identical phenotypes were observed when the same amino acid changes were made at the analogous position, Leu-114, in the first repeat of TFIID. Analysis of these mutations and additional mutations in the most conserved regions of the repeats, in conjunction with our DNA binding results, suggests that these regions of the repeats play equivalent roles in TFIID function, possibly in TATA box recognition.

scholarly journals Single Amino Acid Variant Discovery in Small Numbers of Cells

2018 ◽  
Author(s):  
Zhijing Tan ◽  
Xinpei Yi ◽  
Nicholas J. Carruthers ◽  
Paul M. Stemmer ◽  
David M. Lubman
Keyword(s):  
Amino Acid ◽  
Single Amino Acid ◽  
Variant Discovery ◽  
Amino Acid Variant
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