Volume 29, Issue 1 (3-2026)
J Arak Uni Med Sci 2026, 29(1): 13-18 |
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Ataei Alamdari S, Arjomandzadegan M, Nassaj Manizani M, Ahmadi A. Phenotypic and Genotypic Evaluation of Biofilm Formation in Vancomycin-Resistant Enterococcus Isolates from Cancer Patients. J Arak Uni Med Sci 2026; 29 (1) :13-18
URL: http://jams.arakmu.ac.ir/article-1-8026-en.html
URL: http://jams.arakmu.ac.ir/article-1-8026-en.html
1- , mmatinam81@yahoo.com
Abstract: (889 Views)
Introduction: Vancomycin-resistant enterococci (VRE) are among common causes of nosocomial infections, and their ability to form biofilms may contribute to increased antibiotic resistance. This study aimed to evaluate the biofilm-forming ability of VRE isolates and their antibiotic resistance patterns.
Methods: A total of 70 stool samples were collected from cancer patients. Suspected Enterococcus isolates were identified through biochemical tests including catalase test (negative), growth in 6.5% NaCl, positive PYR test, and bile esculin hydrolysis. In total, 22 Enterococcus isolates were confirmed and preserved for further analysis. Resistance to vancomycin was determined using the disk diffusion method according to CLSI guidelines. Biofilm formation was evaluated using the microtiter plate assay. The presence of biofilm-associated genes gelE and cylA was detected by polymerase chain reaction (PCR).
Results: The results showed that 68.2% of the isolates were capable of forming biofilm. Based on optical density in the microtiter plate assay, 27.2% were strong, 13.6% moderate, and 27.2% weak biofilm producers. Additionally, 31.8% of isolates were non-biofilm producers. PCR results revealed that among the 22 isolates, gelE and cylA genes were present in 77.3% and 63.6% of cases, respectively.
Conclusions: Biofilm formation played a significant role in enhancing antibiotic resistance in VRE isolates. Identification of biofilm-associated factors seems to be beneficial in designing effective therapeutic strategies against these bacteria.
Methods: A total of 70 stool samples were collected from cancer patients. Suspected Enterococcus isolates were identified through biochemical tests including catalase test (negative), growth in 6.5% NaCl, positive PYR test, and bile esculin hydrolysis. In total, 22 Enterococcus isolates were confirmed and preserved for further analysis. Resistance to vancomycin was determined using the disk diffusion method according to CLSI guidelines. Biofilm formation was evaluated using the microtiter plate assay. The presence of biofilm-associated genes gelE and cylA was detected by polymerase chain reaction (PCR).
Results: The results showed that 68.2% of the isolates were capable of forming biofilm. Based on optical density in the microtiter plate assay, 27.2% were strong, 13.6% moderate, and 27.2% weak biofilm producers. Additionally, 31.8% of isolates were non-biofilm producers. PCR results revealed that among the 22 isolates, gelE and cylA genes were present in 77.3% and 63.6% of cases, respectively.
Conclusions: Biofilm formation played a significant role in enhancing antibiotic resistance in VRE isolates. Identification of biofilm-associated factors seems to be beneficial in designing effective therapeutic strategies against these bacteria.
Keywords: Cancer patients, Biofilm formation, Vancomycin-resistant Enterococcus (VRE), Antibiotic resistance, gelE gene, cylA gene
Type of Study: Original Atricle |
Subject:
Basic Sciences
Received: 2025/05/27 | Accepted: 2025/09/9
Received: 2025/05/27 | Accepted: 2025/09/9
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