Search

Studies on environmental-friendly surfactants are essential to potentially replace those highly toxic and non-biodegradable commercially available surfactants. Two biocompatible polymeric anionic (AS1) and nonionic (NS1) surfactants were successfully synthesised from palm oil derivatives via polyesterification. The cytotoxicity of surfactants was measured by in vitro succinate dehydrogenase activity (MTT assay). Results revealed that both surfactants achieved cell viability above 80% against human keratinocytes (HaCaT), mouse fibroblasts (3T3), mouse hepatocytes (H2.35) and canine kidney cells (MDCK) in both dose- and time-dependent manners. Antimicrobial potential of both surfactants was evaluated using minimum bactericidal concentration (MBC) assay. Results indicated that AS1 had a significant antimicrobial activity against most of the tested Gram-positive bacteria. Meanwhile, only one of the Gram-negative bacteria (Acinetobacter baumannii) was successfully reduced by NS1. Both surfactants were subsequently compounded into natural rubber latex (NRL). From rheological study, AS1 exhibited better viscosity behaviour with longer linear viscoelastic region (LVR) towards high ammonia (HA) NRL, signifying its potential in providing stability in the latex environment.

Geraniol, an active constituent of rose and palmarosa essential oils, possesses several pharmacological properties, including antioxidant, antibacterial and antiulcer activity. Geraniol was therefore investigated for its antiulcer and anti-Helicobacter pyloriactivity in rats. Ulcers were induced by injecting acetic acid into the sub-serosal layer of the stomach followed by orogastric inoculation of H. pylorifor 7 days. Geraniol (15 and 30 mg/kg), vehicle and a standard drug combination (amoxicillin, 50 mg/kg; clarithromycin, 25 mg/kg and omeprazole, 20 mg/kg) were administered twice daily for 14 days. All the parameters were measured at the end of treatment. The ulcer index was significantly (P < 0.05) lowered in geraniol and standard drug-treated rats as compared to the H. pyloricontrol group (4.13 ± 0.43). Treatment with geraniol (30 mg/kg) significantly (P < 0.01) increased the gastric pH along with a reduction in total acidity and gastric juice volume. Geraniol significantly (P < 0.05) attenuated the myeloperoxidase activity and augmented the total glutathione level in gastric mucosa. The extent of damage in the stomach was measured using a histopathological score. The score in H. pyloricontrol, geraniol (30 mg/kg) and standard drugs was 9, 3.5 and 2.0 respectively. In the rapid urease test, treatment with geraniol (30 mg/kg) and the standard drugs produced a 33% and 67% cure respectively from H. pyloriinfection. Further, the reduction in bacterial load in the gastric mucosa was confirmed using modified Giemsa staining. Geraniol was observed to exhibit significant antiulcer and anti-H. pyloriactivity in a rodent model.

ABSTRACTThe exoproteome of Staphylococcus aureuscontains enzymes and virulence factors that are important for host adaptation. We investigated the exoprotein profiles and cytokine/chemokine responses obtained in three different S. aureus-host interaction scenarios by using two-dimensional gel electrophoresis (2-DGE) and two-dimensional immunoblotting (2D-IB) combined with tandem mass spectrometry (MS/MS) and cytometric bead array techniques. The scenarios included S. aureusbacteremia, skin and soft tissue infections (SSTIs), and healthy carriage. By the 2-DGE approach, 12 exoproteins (the chaperone protein DnaK, a phosphoglycerate kinase [Pgk], the chaperone GroEL, a multisensor hybrid histidine kinase, a 3-methyl-2-oxobutanoate hydroxymethyltransferase [PanB], cysteine synthase A, an N-acetyltransferase, four isoforms of elongation factor Tu [EF-Tu], and one signature protein spot that could not be reliably identified by MS/MS) were found to be consistently present in more than 50% of the bacteremia isolates, while none of the SSTI or healthy-carrier isolates showed any of these proteins. By the 2D-IB approach, we also identified five antigens (methionine aminopeptidase [MetAPs], exotoxin 15 [Set15], a peptidoglycan hydrolase [LytM], an alkyl hydroperoxide reductase [AhpC], and a haptoglobin-binding heme uptake protein [HarA]) specific for SSTI cases. Cytokine and chemokine production varied during the course of different infection types and carriage. Monokine induced by gamma interferon (MIG) was more highly stimulated in bacteremia patients than in SSTI patients and healthy carriers, especially during the acute phase of infection. MIG could therefore be further explored as a potential biomarker of bacteremia. In conclusion, 12 exoproteins from bacteremia isolates, MIG production, and five antigenic proteins identified during SSTIs should be further investigated for potential use as diagnostic markers.

ABSTRACTMethicillin-resistant Staphylococcus aureus(MRSA) of sequence type 398 (ST398) has frequently been detected in pigs and pig handlers. However, in Malaysia, sampling 360 pigs and 90 pig handlers from 30 farms identified novel ST9-spatype t4358-staphylococcal cassette chromosome mectype V MRSA strains that were found to transiently colonize more than 1% of pigs and 5.5% of pig handlers.

The antibacterial activity of geraniol and its effect in combination with ampicillin, amoxicillin and clarithromycin against Staphylococcus aureus, Escherichia coliand Helicobacter pyloriwas tested. The minimum inhibitory concentrations (MICs) and combinatory effects of geraniol against the bacteria were assessed by using the modified broth microdilution and checkerboard assay, respectively. The combinatory effect is expressed as fractional inhibitory concentration index (FICI). The MIC of geraniol against S. aureus, E. coliand H. pyloriwas found to be 11200, 5600, and 7325 μg/mL, respectively. A significant synergistic effect was observed with geraniol and ampicillin against S. aureuswith FICI in the range 0.19 to 0.32. Geraniol and ampicillin exhibited a partial synergistic effect against E. coli. A similar effect was observed with geraniol and clarithromycin against S. aureus. A partial synergistic effect was observed with clarithromycin and geraniol against H. pyloriwith the FICI value in the range 0.86 to 0.89. An additive effect was observed with geraniol and amoxicillin combination against H. pylori. However, the amoxicillin and clarithromycin dose was reduced by thirty-two fold when combined with geraniol against H. pylori. The anti-H. pylorieffect of geraniol with clarithromycin and amoxicillin could be of potential interest in the treatment of H. pyloriinfection and associated ulcers in humans. Further, geraniol, in combination with other antibiotics, has substantial therapeutic potential against S. aureusand E.coliinfection.