Publication: Biofilm-Associated Multidrug-Resistant and Methicillin-Resistant Staphylococcus aureus Infections
Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Nepal Health Research Council
Abstract
Background: The ability of Staphylococcus aureus to form biofilms—architectural complexes that cause chronic and recalcitrant infections—along with its notorious variant, methicillin-resistant Staphylococcus aureus (MRSA), leads to multidrug-resistant (MDR) infections that are challenging to treat with antibiotics. This cross-sectional study investigated the prevalence of S. aureus infections in Kanti Children’s Hospital and characterized the antibiograms of MDR, MRSA, and biofilm-forming strains, along with their coexistence.
Methods: S. aureus strains were isolated and identified from clinical samples and tested for antibiograms following standard microbiology guidelines. MDR strains were non-susceptible to at least one agent in three antimicrobial categories, whereas MRSA strains were cefoxitin-resistant. The microtiter plate method was used to detect biofilms. Statistical analyses were performed using SPSS version 17.0.
Results: S. aureus was detected in 9.0% (11.4-6.6%, 95% Confidence Interval) of 543 samples, primarily from pus (79.6%, 39/49). Children aged 1 to <3 years most commonly contracted infections (30.6%, 15/49), and males (67.4%, 33/49) had twice as many infections as females (32.7%, 16/49). As high as 84.7% (83/98) of strains were penicillin-resistant, while 18.4% (27/147) were aminoglycoside-resistant. MDR accounted for 79.6% (39/49) of all S. aureus infections, while MRSA and biofilm-formers accounted for 67.6% (33/49) and 24.5% (12/49), respectively. Fluoroquinolone resistance in non-MDR-MRSA-biofilm-formers, MDR-MRSA, MDR-biofilm-formers, and MRSA-biofilm-formers was 31.3%, 46.8%, 58.3%, and 60.0%, respectively, while aminoglycoside resistance was 0%, 32.3%, 50.0%, and 45.0%, and penicillin resistance was 87.5%, 85.5%, 100.0%, and 100.0%.
Conclusions: MDR-isolates and MRSA caused nearly four-fifths of S. aureus infections. Compared to MDR and MRSA strains, biofilm-formers triggered higher levels of antimicrobial resistance.
Keywords: Antibiotics; biofilms; children; resistance; staphylococcus aureus.
Description
Shila Shrestha
Department of Medical Microbiology, Shi-Gan International College of Science and Technology, Tribhuvan University, Shankhamarg, Kathmandu, Nepal
Ajaya Basnet
Department of Medical Microbiology, Shi-Gan International College of Science and Technology, Tribhuvan University, Shankhamarg, Kathmandu, Nepal
Rajendra Maharjan
Department of Pathology, Nepal Armed Police Force Hospital, Balambu, Kathmandu, Nepal
Bijaya Basnet
Department of Clinical Laboratory, Houston Methodist Hospital, Texas, United States of America
Pramod Joshi
Nepal Health Research Council, Ramshah path, Kathmandu, Nepal