DESIGN: A case-control study.
METHODS: This study received ethical approval (NMRR Research ID 23957) and informed consent was obtained from all participants. It involved 20 participants with 20 samples of pterygium and 20 samples of normal conjunctiva that were obtained from the same eye of each participant. All the participants underwent history taking, slit lamp examination, and pterygium excision surgery. Both samples underwent immunohistochemistry procedure. Pretreatment procedure was conducted using heat-induced epitope retrieval with PT link, subsequently followed by EnVision FLEX staining procedure and incubation with anti‒IL-17 antibody and anti‒IL-23 antibody. Slides were examined in high-power fields (400x) for both samples in 3 different fields. Total positive stained cell counts in all 3 fields with IL-17 and IL-23 between pterygium and normal conjunctiva were analyzed by using Wilcoxon signed rank test.
RESULTS: IL-17 positive cell counts for normal conjunctiva showed mean 196.10 ± 80.487 but for pterygium was 331.10 ± 108.416. As for IL-23, the mean for positive cell counts for normal conjunctiva was 62.10 ± 33.462 and IL-23 positive cell counts for pterygium showed mean 102.95 ± 41.378. Both IL-17 and IL-23 were significantly increased in pterygium compared with normal conjunctiva (P < 0.001).
CONCLUSIONS: Both IL-17 and IL-23 were found to be significantly higher in the pterygium group than in the normal conjunctiva group with P < 0.001 by Wilcoxon signed rank test.
METHODS AND RESULTS: The leaves of D. linearis were subjected to sonication-assisted extraction using hexane (HEX), dichloromethane, ethyl acetate and methanol (MeOH). It was found that only the MeOH fraction exhibited antimicrobial activity using broth microdilution assay; while all four fractions do not exhibit biofilm inhibition activity against S. aureusATCC 6538P, S. aureusATCC 43300, S. aureusATCC 33591 and S. aureusATCC 29213 using crystal violet assay. Among the four fractions tested, only the HEX fraction showed biofilm disrupting ability, with 60-90% disruption activity at 5 mg ml-1against all four S. aureus strains tested. Bioassay-guided purification of the active fraction has led to the isolation of α-tocopherol. α-Tocopherol does not affect the cells within the biofilms but instead affects the biofilm matrix in order to disrupt S. aureus biofilms.
CONCLUSIONS: α-Tocopherol was identified to be the bioactive component of D. linearis with disruption activity against S. aureus biofilm matrix.
SIGNIFICANCE AND IMPACT OF THE STUDY: The use of α-tocopherol as a biofilm disruptive agent might potentially be useful to treat biofilm-associated infections in the future.
METHODS: Swabs from four body sites of 129 HIV-infected patients were cultured for S. aureus and identified by standard microbiological procedures. The isolates were subjected to antimicrobial susceptibility testing by disk diffusion against penicillin, erythromycin, clindamycin, and cotrimoxazole. PCR was used to detect the PVL gene and genetic relationship between the isolates was determined by using pulse field gel electrophoresis.
RESULTS: A total of 51 isolates of S. aureus were obtained from 40 (31%) of the patients. The majority (43.1%) of the isolates were obtained from the anterior nares. Thirteen (25.5%) of all the isolates were resistant to more than one category of antibiotics, with one isolate identified as MRSA. Thirty-eight (74.5%) isolates (including the MRSA isolate) carried PVL gene where the majority (44.7%) of these isolates were from the anterior nares. A dendogram revealed that the isolates were genetically diverse with 37 distinct pulsotypes clustered in 11 groups.
CONCLUSION: S. aureus obtained from multiple sites of the HIV patients were genetically diverse without any clonality observed.