METHODS: The antibacterial activity of four NSAIDs (aspirin, ibuprofen, diclofenac and mefenamic acid) were tested against ten pathogenic bacterial strains using the microdilution broth method. The interaction between NSAIDs and antibiotics (cefuroxime/chloramphenicol) was estimated by calculating the fractional inhibitory concentration (FICI) of the combination.
RESULTS: Aspirin, ibuprofen and diclofenac exhibited antibacterial activity against the selected pathogenic bacteria. The interaction between ibuprofen/aspirin with cefuroxime was demonstrated to be synergistic against methicillin-sensitive S. aureus (MSSA) and the MRSA reference strain, whereas for MRSA clinical strains additive effects were observed for both NSAIDs and cefuroxime combinations. The combination of chloramphenicol with ibuprofen/aspirin was synergistic against all of the tested MRSA strains and displayed an additive effect against MSSA. A 4-8192-fold reduction in the cefuroxime minimum inhibitory concentration (MIC) and a 4-64-fold reduction of the chloramphenicol MIC were documented.
CONCLUSIONS: Overall, the NSAIDs ibuprofen and aspirin showed antibacterial activity against strains of S. aureus. Although individually less potent than common antibiotics, these NSAIDs are synergistic in action with cefuroxime and chloramphenicol and could potentially be used as adjuvants in combating multidrug-resistant MRSA.
AIM: This review highlights the anti-staphylococcal activities of pentacyclic triterpenoids, particularly α-amyrin (AM), betulinic acid (BA) and betulinaldehyde (BE). These compounds are based on a 30-carbon skeleton comprising five six-membered rings (ursanes and lanostanes) or four six-membered rings and one five-membered ring (lupanes and hopanes).
METHODS: Electronic databases such as ScienceDirect, PubMed and Scopus were used to search scientific contributions until March 2018, using relevant keywords. Literature focusing on the antimicrobial and antibiofilms of effects of pentacyclic triterpenoids on S. aureus were identified and summarized.
RESULTS: Pentacyclic triterpenoids can be divided into three representative classes, namely ursane, lupane and oleananes. This class of compounds have been shown to exhibit analgesic, immunomodulatory, anti-inflammatory, anticancer, antioxidant, antifungal and antibacterial activities. In studies of the antimicrobial activities and targets of AM, BA and BE in sensitive and multidrug-resistant S. aureus, these compounds acted synergistically and have different targets from the conventional antibiotics.
CONCLUSION: The inhibitory mechanisms of S. aureus in novel targets and pathways should stimulate further researches to develop AM, BA and BE as therapeutic agents for infections caused by S. aureus. Continued efforts to identify and exploit synergistic combinations by the three compounds and peptidoglycan inhibitors, are also necessary as alternative treatment options for S. aureus infections.
METHODS: Polymerase chain reaction (PCR) was used to detect the presence of sasX, qacA/B and mupA genes from 47 paired MRSA isolates. A paired isolate was defined as one nasal swab (colonising) isolate and clinical isolate that caused infection in the same patient. 22 selected paired isolates were subjected to multilocus sequence typing (MLST). The genetic relatedness among the isolates and association between the putative genes with epidemic sequence types (STs) were investigated.
RESULTS: 7 (14.9%, n = 14) paired isolates were positive for the sasX gene. qacA/B genes were positive in 7.4% (n = 7) of the isolates, from three paired isolates and one clinical isolate whose paired colonising isolate was negative. The paired sample of three patients were positive for both genes. The mupA gene was not detected in all the isolates. MLST revealed two epidemic STs, ST22 and ST239, and a novel ST4649. sasX and qacA/B genes were found in ST239 in 29.5% (n = 13) and 13.6% (n = 6) of cases, respectively. Gene co-existence occurred in 13.6% (n = 6) of MRSA ST239 and 2.3% (n = 1) of MRSA ST4649.
CONCLUSION: sasX and qacA/B genes were present in the MRSA isolates, while the mupA gene was undetected. ST22 and ST239 were the major MRSA clones. The circulating MRSA genotypes conferred different virulence and resistance determinants in our healthcare settings.
METHODS: In this study, we synthesized ZnO-CR NPs and characterized them using SEM, FTIR, and XRD techniques to authenticate their composition and structural attributes. Moreover, our investigation revealed that ZnO-CR NPs possess better free radical scavenging capabilities, as evidenced by their effective activity in the DPPH and ABTS assay.
RESULTS: The antimicrobial properties of ZnO-CR NPs were systematically assessed using a zone of inhibition assay against dental pathogens of S. aureus, S. mutans, E. faecalis, and C. albicans, demonstrating their substantial inhibitory effects at a minimal concentration of 50 μg/mL. We elucidated the interaction between CR and the receptors of dental pathogens to further understand their mechanism of action. The ZnO-CR NPs demonstrated a dose-dependent anticancer effect at concentrations of 5 μg/mL, 25 μg/mL, 50 μg/mL, and 100 μg/mL on KB cells, a type of Human Oral Epidermal Carcinoma. The mechanism by which ZnO-CA NPs induced apoptosis in KB cells was determined by observing an increase in the expression of the BCL-2, BAX, and P53 genes.
CONCLUSION: Our findings unveil the promising potential of ZnO-CR NPs as a candidate with significant utility in dental applications. The demonstrated biocompatibility, potent antioxidant and antiapoptotic activity, along with impressive antimicrobial efficacy position these NPs as a valuable resource in the ongoing fight against dental pathogens and oral cancer.