Diversity and Clinical Significance of Coagulase-negative Staphylococci: A Review of Identification, Virulence Factors & Drug Resistance | Chapter 11 | Pharmaceutical Science: New Insights and Developments Vol. 4

Coagulase-negative Staphylococci (CoNS) are normal flora of human skin and mucous membranes, they have previously been considered nonpathogenic or contaminant having little clinical significance. CoNS are gram-positive, nonmotile, non-sporeforming cocci. CoNS have gained more importance as a pathogenic organism in recent years as a causative organism for infections in both humans and animals. CONS are mostly prevalent in immunocompromised patients, critically ill patients and patients having invasive medical devices. This study provides a comprehensive review of the understanding of microbiological profile, identification method and virulence factors associated with different Coagulase-Negative Staphylococci (CoNS) species.

 

The incidence of CoNS varied across different geographic locations in humans and animals. Also, there are varying antibiotic resistance patterns observed in CoNS species, with high methicillin resistance and cross-resistance against many antibiotics. Staphylococcus epidermidis, Staphylococcus hemolyticus, Staphylococcus xylosus are the most commonly reported species in various studies. Various virulence factors in CONS are responsible for enhanced pathogenicity. In addition to virulence factors, the presence of many antibiotic-resistant genes found in CoNS is concerning and complicates treatment. Because of advancements in diagnostic techniques understanding of molecular mechanisms of CONS pathogenicity is possible.  Recent advances in identification and typing methods and virulence screening methods will help to assess the true pathogenic potential of CoNS species. Future research should explore novel disinfection techniques, improved hand hygiene compliance strategies, and alternative antimicrobial agents to combat CoNS infection.

 

Author (s) Details

 

Suvarna Sande
Department of Microbiology, Datta Meghe Medical College, Wanadongri, Nagpur, DMIHER (DU), India.

 

 

Please see the book here:- https://doi.org/10.9734/bpi/psnid/v4/4760

Study on Bacteremia in Hemodialytic Patients and Antibiotics Susceptibility Pattern | Chapter 11 | Innovations in Microbiology and Biotechnology Vol. 1

 Bacteremia is a condition in which bacteria are found in the bloodstream. Because hemodialysis patients are immunocompromised, the most common cause of death is bacterial bloodstream infection. Gram-positive cocci are the most common cause of bloodstream infections in hemodialysis users. Patients on hemodialysis are particularly vulnerable if the infection is caused by Staphylococcus aureus, which has a death rate of greater than 8%.

Methods: For six months, a cross-sectional study was conducted at Nepal's National Kidney Center. Individuals having hemodialysis treatment had their blood samples taken. The collected blood samples were inoculated in a blood culture bottle with BHI biphasic medium and incubated aerobically at 37°C for 18-24 hours (up to 1 week if necessary). The colony shape and hemolytic reactions were detected after it was sub-cultured on blood agar plate. A variety of biochemical experiments were carried out in attempt to identify the isolate species. The antimicrobial susceptibility test was performed using a modified Kirby Bauer technique. All of the data was recorded and analysed using the SPSS software.

The study enlisted the participation of a hundred patients. Gram-positive bacteria were discovered to be the most common (61.5 percent ). Gram-positive bacteria like Staphylococcus aureus (26.9%) and CoNS (88.4%) were often isolated, as were Gram-negative bacteria including Escherichia coli (3.8%), Klebsiella pneumoniae (3.8%), and Pseudomonas aeruginosa (3.8%). The most common Gram-positive isolate among hemodialysis patients was found to be Staphylococcus aureus. Methicillin resistance was found in 37.5 percent of the 16 S. aureus isolates, despite the fact that the majority of these bacteria were amoxicillin resistant. Amoxicillin was found to be the least effective antibiotic against most Gram-positive bacteria, whereas ciprofloxacin was found to be the most effective.

Conclusion: The goal of this study is to learn more about the prevalence of bacteria in hemodialysis patients, as well as the antibiogram of the isolates, because it is Nepal's first investigation into bloodstream infections in hemodialysis patients. These findings could serve as a springboard for further research into bacteriological infection in hemodialysis patients and antibiogram.

Author (S) Details

Shrestha Prasansah
Department of Microbiology, National College, Kathmandu, Nepal.

Pokharel Nabaraj
Department of Microbiology, National College, Kathmandu, Nepal.

Pant Anil Dev
National Kidney Center, Kathmandu, Nepal.

View Book :- https://stm.bookpi.org/IMB-V1/article/view/3769