Prevalence of Biofilm Formation Among Methicillin Resistance Staphylococcus aureus Isolated From Nasal Carriers

Abstract

Background: Methicillin -resistant staphylococcus aureus (MRSA) is associated with serious infections. Having the ability of biofilmformation decrease their susceptibility to antibiotics. Objectives: The aim of this study was to determine the prevalence of biofilm formation among MRSA isolated from nasal carriers in the Beheshti Teaching Hospital in Kashan, Iran. Materials and Methods: A cross-sectional study was conducted in 810 patients referred to emergency department in Beheshti Hospital in Kashan. Sterilized nasal swabs were used for collecting nasal bacteria. Nasal specimens were further recognized as S. aureus strains by standard biochemical tests, and MRSA isolates were detected by disk diffusion method. PCR assay was used for detecting mecA gene in MRSA isolates. The susceptibility of MRSA isolates to amikacin, clindamycin, gentamicin, ciprofloxacin, SXT, erythromycin, tetracycline were determined by using disk diffusion method according to recommendation of CLSI. Biofilm formation ability of MRSA isolates were examined by crystal violet microtitre plate assay and Congo red agar (CRA). Results: Two hundred and ninety six (36.5%) out of 810 isolates were S. aureus. Twenty six (8.8%) of all S. aureus isolates were recognized as MRSA. All the MRSA isolates have the ability of biofilm formation which 15.4%, 19.2% and 65.4% of them were strong, medium and weak biofilm producer respectively. The resistance rate of strong biofilm producer were; erythromycin (100%), clindamycin (75%), ciprofloxacin (75%), SXT (75%), gentamycin (50%), tetracycline (0%), amikacin (0%). Conclusions: High rate of MRSA nasal carrier and having the ability of biofilm formation which decrease their susceptibility to antibiotics, is an alarming for public health. Statistically significant correlation between susceptibility to tetracycline and MRSA carrier was observed.

Detection of Biofilm Production Capability and icaA/D Genes Among Staphylococci Isolates from Shiraz, Iran

“…Ohadian Moghadam et al showed high rates of biofilm production (more than 80%) among S. aureus isolates obtained from bourn wound samples in Tehran, North of Iran (23). In another study from Kashan, all MRSA isolates from nasal carries were able to form biofilms (24). These variations in frequency of biofilm producing staphylococci are documented in other parts of the world, as well.…”

“…On the other hand, S. epidermidis biofilm producers revealed higher resistance to ampicillin and tetracycline compared to non-biofilm producing isolates (P < 0.05). In two Iranian studies, similar to our findings, most of the biofilm forming staphylococci isolates had higher antibiotic resistance and multiple drug resistance (MDR) rates (23,24). The same findings have been reported by Sahal et al in Turkey, indicating that majority of strong biofilm forming S. epidermidis strains were β-lactams resistant, and notably 100% of them were MDR (33).…”

Survey on Biofilm Production and Presence of Attachment Factors in Human Uropathogenic Strains of Escherichia coli

“…Biofilm development could be stopped by removing any of the followings: microbes, slime-exopolysaccharides, and surface (7). Different superficial appendices of organisms are related to the first stage of biofilm formation and attachment to eukaryotic host cells such as flagella, fimbriae, autotransporter proteins, curli, F conjugative pilus, and exopolysaccharide production (8).…”

Genotype Diversity and Evaluation of Biofilm Formation in sasX Positive Methicillin-Resistant Staphylococcus aureus

“…2017; 4(2):e46049. 100% of MRSA isolates could form a biofilm (14,15). The findings showed that the number of biofilm isolates from the normal flora were more than other clinical samples, which agrees with some previous studies (16,17).…”