Genetic Diversity in Staphylococcus aureus and Its Relation to Biofilm Production

2021 ◽  
Author(s):  
Furqan Awan ◽  
Muhammad Muddassir Ali ◽  
Muhammad Hassan Mushtaq ◽  
Muhammad Ijaz

Staphylococcus aureus (S. aureus) has been a substantial economic problem due to its antibiotic resistance, persistence inside host and recurrence of disease. It escapes from immunity because of its intra-cellular growth. Moreover, it forms biofilm on both living and in-animate surfaces that leads to recurrent infections and growth in food industry, respectively. Further, S. aureus undergoes the vertical and horizontal evolution that has genetically diversified the bacterial population. All the factors such as point mutations, plasmids, phages etc. have played their roles in diversifying this bacterium. Many bacterial physiological characteristics have been affected by genetic diversity. Biofilm forming ability is also considered as a variable characteristic of S. aureus that can help the bacteria to survive in different environments with different levels of biofilm production. In adapting the environment, S. aureus also forms different types of biofilm for its better survival. How genetic diversity is playing its role in this division of S. aureus is yet to be revealed. This chapter focuses on the factors related to genetic diversity and biofilm formation of S. aureus.








2019 ◽  
Author(s):  
Rosy Pandey ◽  
Angela Shrestha ◽  
Shyam Kumar Mishra

Abstract Background: “ESKAPE” is an acronym for group of organisms as Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter calcoaceticus baumannii complex, Pseudomonas aeruginosa and Enterobacter spp. They are associated in causing life threatening infections. Global efforts on controlling multidrug resistant (MDR) organisms have been hampered by their rapid emergence, inadequate tests for rapid detection and their ability to escape the antibacterial drugs. The objective of this study was to determine the prevalence of ESKAPE pathogens with prime focus on biofilm production and antibiotic resistance. Methods: A total of 8756 clinical specimens were processed for the isolation and identification of ESKAPE pathogens following standard microbiological protocol. These isolates were subjected to antibiotic sensitivity test as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Detection of resistance phenotypes, viz., extended-spectrum-beta-lactamase (ESBL), metallo-beta-lactamase (MBL), Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant enterococci (VRE) was done by disk diffusion method and E- test method as applicable. The VRE isolates were subjected for detection of Van A and Van B genes. All the isolates were processed for biofilm detection by tube adherence method. Results: The percentage distribution of Staphylococcus aureus was 33.5%, followed by Klebsiella pneumoniae 33.0%, Pseudomonas aeruginosa 18.3%, Acinetobacter calcoaceticus baumannii complex 8.7%, Enterococcus faecium 5.6% and Enterobacter aerogenes 0.9%. MRSA was 57.6% and Vancomycin resistance among Enterococcus faecium was 20%. ESBL and MBL producing Klebsiella pneumoniae were 16.1%, and 8.1%, Acb complex 10.3% each and Pseudomonas aeruginosa 10.7% and 8.3% respectively. A total of 42.3% of isolates were biofilm producers. Linezolid was drug of choice for VRE isolates. Piperacillin- tazobactam was found to be effective against Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterobacter aerogenes; Ampicillin-sulbactam was the most effective drug against Acb complex excluding polymyxins. Van A gene was detected in all the VRE isolates. Conclusion: This study estimates the burden of the ESKAPE organisms and their antibiotic resistance pattern in a Nepalese hospital. The increasing percentages of drug resistance among these biofilm-producing pathogens pose great threat in medical setting. Surveillance targeting ESKAPE pathogens should be incorporated in infection control policy in Nepal.



2017 ◽  
Vol 65 ◽  
pp. 20-27 ◽  
Author(s):  
Lisbeth Mehli ◽  
Sunniva Hoel ◽  
Gunn Merethe Bjørge Thomassen ◽  
Anita Nordeng Jakobsen ◽  
Hanne Karlsen


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 97 ◽  
Author(s):  
Maria Vitale ◽  
Paola Galluzzo ◽  
Patrizia Giuseppina Buffa ◽  
Eleonora Carlino ◽  
Orazio Spezia ◽  
...  

Background: The diffusion of antimicrobial resistance is a significant concern for public health worldwide. Staphylococcus aureus represents a paradigm microorganism for antibiotic resistance in that resistant strains appear within a decade after the introduction of new antibiotics. Methods: Fourteen S. aureus isolates from human specimens and twenty-one from samples of animal origin, were compared for their antimicrobial resistance and biofilm capability. In addition, they were characterized at the molecular level to detect the antimicrobial resistance mecA gene and genes related with enterotoxin, toxin, and biofilm production. Results: Both phenotypic and molecular analysis showed main differences among human- and animal-derived isolates. Among the human-derived isolates, more multidrug-resistant isolates were detected and mecA gene, enterotoxin, and toxin genes were more prevalent. Different genes involved in biofilm production were detected with bap present only in animal-derived isolates and sasC present in both isolates, however, with a higher prevalence in the human-derived isolates. Biofilm capability was higher in human-derived isolates mainly associated to the sasC gene. Conclusions: The overall results indicate that human S. aureus isolates are more virulent and resistant than the isolates of animal origin randomly selected with no infection anamnesis. This study confirms that selection for more virulent and resistant S. aureus strains is related to the clinical practice.







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