scholarly journals Analysis of Antibiotic Resistance Genes and its Associated SCC mec Types among Nasal Carriage of Methicillin Resistant Coagulase Negative Staphylococci from Community Settings, Chennai, Southern India

2015 ◽  
Author(s):  
Saravanan Murugesan
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Nasal Carriage ◽  
Southern India ◽  
Community Settings ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant

scholarly journals Virulence Factors in Coagulase-Negative Staphylococci

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 170
Author(s):  
Angela França ◽  
Vânia Gaio ◽  
Nathalie Lopes ◽  
Luís D. R. Melo
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Coagulase Negative Staphylococci ◽  
Healthcare Associated ◽  
Major Pathogens

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.

The Staphylococcal Cassette Chromosome mec (SCCmec) Analysis and Biofilm Formation of Methicillin-Resistant Staphylococcus cohnii Isolated from Clinical Samples in Tehran, Iran

2021 ◽  
Vol 16 ◽  
Author(s):  
Somaye Delfani ◽  
Faranak Rezaei ◽  
Setareh Soroush ◽  
Pegah Shakib
Keyword(s):  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Mobile Element ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
Sccmec Types

Background: Methicillin-resistant coagulase-negative staphylococci is responsible for hospital and community-acquired infections. Objective: This study aimed to investigate the antibiotic-resistance patterns, antibiotic-resistance genes, namely, ermA, ermB, ermC, blaZ, msrA, tetK, tetM, mup, and vanA, biofilm formation, and prevalence of different SCCmec types among the Staphylococcus cohniistrains isolated from clinical samples in Tehran, Iran. Methods: In this study,S. cohniiisolates were screened from the clinical samples from March 2012 to February 2013 in Tehran, Iran.Antimicrobial susceptibility test and inducible clindamycin resistance were evaluated by disc diffusion method, andresistance genes were examined using Polymerase Chain Reaction (PCR) assays. Then, biofilm formation assay was analyzed by Microtiter-plate test to detect the icaA and icaDgenes. The SCCmec and the Arginine Catabolite Mobile Element (ACME) typing were performed using the PCRmethod. Results: FromtwentyS. cohnii, all isolates were resistant to cefoxitin. 95% of the S. cohnii was defined as multidrug resistance (MDR)strains. The ermB, ermC, and vanA genes were not detected in any isolates; however, the blaZ gene had the highest frequency.95% of the S. cohnii isolates produced biofilm. Also, 4 SCCmec types, including V, IV, III+ (C2), VIII+ (AB1), were identified. Therefore, the majority of SCCmec were untypable. Based on the ACME typing, arcA and opp3 genes were positive in 13 (65%) and 1 (5%) isolates, respectively. Conclusion: Due to the high antimicrobial resistance and the spread of untypableSCCmecamong the isolates studied, the control and treatment of methicillin-resistantS. cohnii in hospitals and public health centers is a significant concern.

scholarly journals Structural analysis of avibactam-mediated activation of the bla and mec divergons in methicillin-resistant Staphylococcus aureus

2020 ◽  
Vol 295 (32) ◽  
pp. 10870-10884 ◽  
Author(s):  
J. Andrew N. Alexander ◽  
Mariia Radaeva ◽  
Dustin T. King ◽  
Henry F. Chambers ◽  
Artem Cherkasov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Physiological Role ◽  
Antibiotic Resistance Genes ◽  
Binding Pocket ◽  
Methicillin Resistant ◽  
Mortality And Morbidity ◽  
Expression Of Genes ◽  
Genes Encoding

Methicillin-resistant Staphylococcus aureus (MRSA) infections cause significant mortality and morbidity globally. MRSA resistance to β-lactam antibiotics is mediated by two divergons that control levels of a β-lactamase, PC1, and a penicillin-binding protein poorly acylated by β-lactam antibiotics, PBP2a. Expression of genes encoding these proteins is controlled by two integral membrane proteins, BlaR1 and MecR1, which both have an extracellular β-lactam–binding sensor domain. Here, we solved the X-ray crystallographic structures of the BlaR1 and MecR1 sensor domains in complex with avibactam, a diazabicyclooctane β-lactamase inhibitor at 1.6–2.0 Å resolution. Additionally, we show that S. aureus SF8300, a clinically relevant strain from the USA300 clone of MRSA, responds to avibactam by up-regulating the expression of the blaZ and pbp2a antibiotic-resistance genes, encoding PC1 and PBP2a, respectively. The BlaR1–avibactam structure of the carbamoyl-enzyme intermediate revealed that avibactam is bound to the active-site serine in two orientations ∼180° to each other. Although a physiological role of the observed alternative pose remains to be validated, our structural results hint at the presence of a secondary sulfate-binding pocket that could be exploited in the design of future inhibitors of BlaR1/MecR1 sensor domains or the structurally similar class D β-lactamases. The MecR1–avibactam structure adopted a singular avibactam orientation similar to one of the two states observed in the BlaR1–avibactam structure. Given avibactam up-regulates expression of blaZ and pbp2a antibiotic resistance genes, we suggest further consideration and research is needed to explore what effects administering β-lactam–avibactam combinations have on treating MRSA infections.

Antibiotic Resistance Genes in Coagulase-negative Staphylococci Isolated from Food

1998 ◽  
Vol 21 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Vincent Perreten ◽  
Natalina Giampà ◽  
Ursula Schuler-Schmid ◽  
Michael Teuber
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Coagulase Negative Staphylococci

scholarly journals Antibiogram and Antibiotic Resistance Genes among Coagulase-Negative Staphylococci recovered from Bovine Mastitis

2021 ◽  
Vol 9 (8) ◽  
Author(s):  
Mousa S. Walid ◽  
Akram A. Salama ◽  
Shimaa S. Elnahriry ◽  
Eman E. Abdeen ◽  
Ghada Abd Elmonsef Hadad ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Bovine Mastitis ◽  
Antibiotic Resistance Genes ◽  
Coagulase Negative Staphylococci

scholarly journals Deciphering pathogenicity and antibiotic resistance islands in methicillin-resistant Staphylococcus aureus genomes

Open Biology ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 170094 ◽  
Author(s):  
Mehul Jani ◽  
Soham Sengupta ◽  
Kelsey Hu ◽  
Rajeev K. Azad
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Genomic Islands ◽  
Hospital Environment ◽  
Gene Clustering ◽  
Methicillin Resistant ◽  
Modern Hospital

Staphylococcus aureus is a versatile pathogen that is capable of causing infections in both humans and animals. It can cause furuncles, septicaemia, pneumonia and endocarditis. Adaptation of S. aureus to the modern hospital environment has been facilitated, in part, by the horizontal acquisition of drug resistance genes, such as mecA gene that imparts resistance to methicillin. Horizontal acquisitions of islands of genes harbouring virulence and antibiotic resistance genes have made S. aureus resistant to commonly used antibiotics. To decipher genomic islands (GIs) in 22 hospital- and 9 community-associated methicillin-resistant S. aureus strains and classify a subset of GIs carrying virulence and resistance genes as pathogenicity and resistance islands respectively, we applied a host of methods for localizing genomic islands in prokaryotic genomes. Surprisingly, none of the frequently used GI prediction methods could perform well in delineating the resistance islands in the S. aureus genomes. Rather, a gene clustering procedure exploiting biases in codon usage for identifying horizontally transferred genes outperformed the current methods for GI detection, in particular in identifying the known islands in S. aureus including the SCC mec island that harbours the mecA resistance gene. The gene clustering approach also identified novel, as yet unreported islands, with many of these found to harbour virulence and/or resistance genes. These as yet unexplored islands may provide valuable information on the evolution of drug resistance in S. aureus .

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