scholarly journals Investigating the OXA Variants of ESKAPE Pathogens

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1539
Author(s):  
Deeksha Pandey ◽  
Neelja Singhal ◽  
Manish Kumar
Keyword(s):  
Amino Acid ◽  
Antimicrobial Resistance ◽  
Phylogenetic Tree ◽  
Nosocomial Infections ◽  
Phylogenetic Relationships ◽  
Copy Number ◽  
Detailed Report ◽  
Priority List ◽  
Global Priority ◽  
Eskape Pathogens

ESKAPE pathogens are the leading cause of nosocomial infections. The Global Priority List of WHO has categorized ESKAPE as priority 1 and 2 pathogens. Even though several mechanisms contribute to antimicrobial resistance, OXA β-lactamase has emerged as a new threat in combating nosocomial infections. In the present study we have investigated the presence of OXA and their variants, copy number, distribution on chromosomes/plasmids, subfamilies, phylogenetic relationships, amino acid identities and variabilities in ESKAPE pathogens. Our results revealed that a total of 929 OXA were present in 2258 completely assembled genomes, which could be further subdivided into 16 sub-families. Among all the ESKAPE pathogens, OXA were highly prevalent in A. baumannii, followed by P. aeruginosa and K. pneumoniae but completely absent in E. faecium and S. aureus while, only a few copies were found in Enterobacter spp. Most of the OXA variants belonged to the OXA-51-like subfamily (200 proteins), followed by OXA-50-like subfamily (189 proteins), OXA-23-like subfamily (156 proteins) and OXA-1-like subfamily (154 proteins). OXA-51-like, OXA-213-like, OXA-134-like, OXA-58-like, OXA-24-like and OXA-20-like subfamilies were present exclusively in A. baumannii. Phylogenetic tree of the subfamilies revealed that OXA-1-like and OXA-33-like, OXA-51-like and OXA-213-like and, OXA-5-like and OXA-10-like belonged to the same branches with amino acid identities as 100%, 97.10% and 80.90% respectively. This indicates that the members of these subfamily-pairs might have evolved from the same ancestor or have recently diverged. Thus, a judicious use of carbapenems is warranted to curtail the rise of new OXA enzymes and preserve them. This is the first detailed report about the OXA of ESKAPE pathogens.

scholarly journals Antibiotic Pipeline Coordinators

2018 ◽  
Vol 46 (S1) ◽  
pp. 25-31 ◽  
Author(s):  
Enrico Baraldi ◽  
Olof Lindahl ◽  
Miloje Savic ◽  
David Findlay ◽  
Christine Årdal
Keyword(s):  
Research And Development ◽  
World Health ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Priority List ◽  
Non Profit ◽  
Global Priority ◽  
The World ◽  
New Antibiotics ◽  
Health Organization

The World Health Organization (WHO) has published a global priority list of antibiotic-resistant bacteria to guide research and development (R&D) of new antibiotics. Every pathogen on this list requires R&D activity, but some are more attractive for private sector investments, as evidenced by the current antibacterial pipeline. A “pipeline coordinator” is a governmental/non-profit organization that closely tracks the antibacterial pipeline and actively supports R&D across all priority pathogens employing new financing tools.

scholarly journals Techniques for the verification of minimal phylogenetic trees illustrated with ten mammalian haemoglobin sequences

1980 ◽  
Vol 187 (1) ◽  
pp. 65-74 ◽  
Author(s):  
D Penny ◽  
M D Hendy ◽  
L R Foulds
Keyword(s):  
Amino Acid ◽  
Phylogenetic Tree ◽  
Protein Sequence ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Protein Sequences ◽  
Nucleotide Sequences ◽  
Amino Acid Sequences ◽  
Minimal Tree ◽  
Protein Sequence Data

We have recently reported a method to identify the shortest possible phylogenetic tree for a set of protein sequences [Foulds Hendy & Penny (1979) J. Mol. Evol. 13. 127–150; Foulds, Penny & Hendy (1979) J. Mol. Evol. 13, 151–166]. The present paper discusses issues that arise during the construction of minimal phylogenetic trees from protein-sequence data. The conversion of the data from amino acid sequences into nucleotide sequences is shown to be advantageous. A new variation of a method for constructing a minimal tree is presented. Our previous methods have involved first constructing a tree and then either proving that it is minimal or transforming it into a minimal tree. The approach presented in the present paper progressively builds up a tree, taxon by taxon. We illustrate this approach by using it to construct a minimal tree for ten mammalian haemoglobin alpha-chain sequences. Finally we define a measure of the complexity of the data and illustrate a method to derive a directed phylogenetic tree from the minimal tree.

scholarly journals Mechanisms of Antimicrobial Resistance in ESKAPE Pathogens

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sirijan Santajit ◽  
Nitaya Indrawattana
Keyword(s):  
Public Health ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Global Public Health ◽  
Drug Usage ◽  
Inappropriate Use ◽  
Public Health Challenges ◽  
Eskape Pathogens

The ESKAPE pathogens (Enterococcus faecium,Staphylococcus aureus,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa, andEnterobacterspecies) are the leading cause of nosocomial infections throughout the world. Most of them are multidrug resistant isolates, which is one of the greatest challenges in clinical practice. Multidrug resistance is amongst the top three threats to global public health and is usually caused by excessive drug usage or prescription, inappropriate use of antimicrobials, and substandard pharmaceuticals. Understanding the resistance mechanisms of these bacteria is crucial for the development of novel antimicrobial agents or other alternative tools to combat these public health challenges. Greater mechanistic understanding would also aid in the prediction of underlying or even unknown mechanisms of resistance, which could be applied to other emerging multidrug resistant pathogens. In this review, we summarize the known antimicrobial resistance mechanisms of ESKAPE pathogens.

scholarly journals Non-Penicillin-Susceptible Streptococcus suis Isolated from Humans

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1178
Author(s):  
Nichari Bamphensin ◽  
Peechanika Chopjitt ◽  
Rujirat Hatrongjit ◽  
Parichart Boueroy ◽  
Nahuel Fittipaldi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Streptococcus Suis ◽  
Amino Acid Substitutions ◽  
Continuous Control ◽  
Antimicrobial Resistance Genes ◽  
Genes Encoding ◽  
Invasive Infections ◽  
Almost All

Streptococcus suis is a pathogen that causes invasive infections in humans and pigs. In this study, 448 S. suis isolates recovered from human infections in Thailand were characterized with regard to their antimicrobial susceptibility and antimicrobial resistance genes, including, for non-penicillin-susceptible isolates, sequence analyses of five genes encoding penicillin-binding proteins (pbp1a, pbp1b, pbp2a, pbp2b, and pbp2x). All 448 isolates were susceptible to cefepime and ceftriaxone, whereas 99.6%, 91.7%, and 72.9% of the isolates were susceptible to levofloxacin, penicillin, and chloramphenicol, respectively. Almost all isolates were resistant to tetracycline (98.2%), clindamycin (94%), erythromycin (92.4%), and azithromycin (82.6%). Genes tet(O) and ermB were the predominant resistance genes detected among macrolide- and tetracycline-resistant isolates. A total of 37 out of 448 isolates (8.2%) showed intermediately resistance to penicillin. Most of these isolates (59.5%) belonged to serotype 2-ST233. Comparison of the predicted translated sequences of five PBP proteins of a penicillin-susceptible isolate (strain P1/7) to the respective PBP sequences of ten non-penicillin-susceptible isolates revealed multiple amino acid substitutions. Isolates of CC221/234 showed highly variable amino acid substitutions in all PBP proteins. An ST104 isolate had a higher number of amino acid substitutions in PBP2X. Isolates belonging to CC233/379 had numerous substitutions in PBP2B and PBP2X. ST25 isolates exhibited fewer amino acid substitutions than isolates of other STs in all five PBPs. The antimicrobial resistance of S. suis is increasing worldwide; therefore, restrictions on antimicrobial use, continuous control, and the surveillance of this bacterium throughout the pork supply chain are crucial for ensuring public health and must be a priority concern.

scholarly journals The characterization of ESBL genes in Escherichia coli and Klebsiella pneumoniae causing nosocomial infections in Vietnam

2013 ◽  
Vol 7 (12) ◽  
pp. 922-928 ◽  
Author(s):  
Nguyen Hoang Thu Trang ◽  
Tran Vu Thieu Nga ◽  
James I Campbell ◽  
Nguyen Trong Hiep ◽  
Jeremy Farrar ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Nosocomial Infections ◽  
Enteric Bacteria ◽  
E Coli ◽  
Plasmid Analysis ◽  
Resistance Plasmids ◽  
Genes Encoding ◽  
Third Generation Cephalosporins

Background: Extended-spectrum β-lactamases (ESBLs) are enzymes capable of hydrolyzing oxyimino-β-lactams and inducing resistance to third generation cephalosporins. The genes encoding ESBLs are widespread and generally located on highly transmissible resistance plasmids. We aimed to investigate the complement of ESBL genes in E. coli and Klebsiella pneumoniae causing nosocomial infections in hospitals in Ho Chi Minh City, Vietnam. Methodology: Thirty-two non-duplicate isolates of E. coli and Klebsiella pneumoniae causing nosocomial infections, isolated between March and June 2010, were subjected to antimicrobial susceptibility testing. All isolates were PCR-amplified to detect the blaSHV, blaTEM and blaCTX-M ESBL genes and subjected to plasmid analysis. Results: We found that co-resistance to multiple antimicrobials was highly prevalent, and we report the predominance of the blaCTX-M-15 and blaCTX-M-27 genes, located on highly transmissible plasmids ranging from 50 to 170 kb in size. Conclusions: Our study represents a snap shot of ESBL-producing enteric bacteria causing nosocomial infections in this setting. We suggest that antimicrobial resistance in nosocomial E. coli and Klebsiella pneumoniae is rampant in Vietnam and ESBL organisms are widespread. In view of these data and the dramatic levels of antimicrobial resistance reported in Vietnam we advocate an urgent review of antimicrobial use in the Vietnamese healthcare system.

Identification of mariner-like elements in Sitodiplosis mosellana (Diptera: Cecidomyiidae)

2006 ◽  
Vol 138 (2) ◽  
pp. 138-146 ◽  
Author(s):  
O. Mittapalli ◽  
R.H. Shukle ◽  
I.L. Wise
Keyword(s):  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Blot Analysis ◽  
Copy Number ◽  
Southern Blot Analysis ◽  
Pcr Primers ◽  
Amino Acid Sequences ◽  
Degenerate Pcr ◽  
Sitodiplosis Mosellana ◽  
Wheat Midge

AbstractMariner-like element sequences were recovered from the genome of the orange wheat midge, Sitodiplosis mosellana (Géhin), with degenerate PCR primers designed to conserved regions of mariner transposases. The deduced amino acid sequences of the mariner-like transposases from S. mosellana showed 67% to 78% identity with the peptide sequences of other mariner transposases. A phylogenetic analysis revealed that the mariner-like elements from S. mosellana grouped in the mauritiana subfamily of mariner transposons. Results from Southern blot analysis suggest mariner-like elements are at a moderate copy number in the genome of S. mosellana.

Effects of Antibiotic, Nicotine and Aminoacid starvation stresses on biofilm production in respiratory Klebsiella pneumoniae

2021 ◽  
Vol 30 (1) ◽  
pp. 61-69
Author(s):  
Rochell Davis and Paul D. Brown
Keyword(s):  
Amino Acid ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Genetic Relatedness ◽  
Amino Acid Starvation ◽  
Biofilm Production ◽  
Mar Index ◽  
Type 3 ◽  
Hospital Acquired

Background: Klebsiella pneumoniae is a major cause of hospital-acquired infections in Jamaica. Objective: We aimed to determine their antimicrobial resistance profiles and to assess biofilm formation in the presence of antibiotic, nicotine and amino acid starvation stresses. Methodology: Antimicrobial susceptibility and multiple antimicrobial resistance (MAR) index were determined for 23 K. pneumoniae strains. Biofilm production was evaluated in the presence of 50 μg/ml ceftazidime or gentamicin, 0–4 mg/ml nicotine, or 0.5 mg/ml serine hydroxamate (to induce amino acid starvation). Genetic relatedness, and the presence of type 3 fimbriae (mrkA) and determinants for extended spectrum β-lactamase and carbapenamases (bla-IMP, bla-VIM, bla-GIM and bla-SIM) were assessed by PCR-based amplification. Results: All strains were susceptible to imipenem (p<0.05); frequencies of resistance varied from 4% (for amikacin) and 8.7% (for meropenem) to over 30% for the other antimicrobials. About half of strains were resistant to ceftazidime, gentamicin and piperacillin. Mean MAR index was 0.31. The presence of antibiotics and nicotine at 2 and 4 mg/ml negatively affected biofilm formation for most strains. However, with amino acid starvation, almost 60% of strains retained medium or high biofilm production. Most strains harboured determinants for carbapenemase or metallo--lactamase, and one-third were PCRpositive for the OXA-1 gene. Strains were clustered into three groups based on ERICPCR analysis. Conclusion: These data suggest that certain antibiotics could inhibit biofilm production in K. pneumoniae even as multidrug resistance in this organism is evident. Further, this species has the propensity to harbour several genetic determinants for antimicrobial resistance.

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