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Biomedical subjects

T V Riley

Publications and source records attributed to T V Riley.

At least 37 records · Page 2Linked to original sources
PubMed2001

A comparison of two methods for identifying surgical site infections following orthopaedic surgery.

Many infection control practitioners (ICPs) dedicate a significant amount of time and resources to surveillance of surgical site infections (SSIs). Alternative surveillance methods need to be explored to reflect the changes to the healthcare system and the increasing economic constraints placed on infection control units. This study was undertaken to compare two methods of identifying SSIs in orthopaedic surgery. Surveillance data collected routinely by ICPs was compared with data obtained from the International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) coding in the medical record. Concordant results between the two methods were obtained. The use of ICD-9-CM coding, as stored in hospital patient administration system databases, has the ability to enhance routine surgical site surveillance programmes. These systems can be used as the basis for screening large data sets for SSIs and identifying where SSIs resulted in patient re-admission. A reduction in the duplication of data and time spent by the ICP on the collection of information for surveillance purposes can be achieved.

Forms and Records Control↗
PubMed2000

Terpinen-4-ol, the main component of the essential oil of Melaleuca alternifolia (tea tree oil), suppresses inflammatory mediator production by activated human monocytes.

OBJECTIVE AND DESIGN: To evaluate potential antiinflammatory properties of tea tree oil, the essential oil steam distilled from the Australian native plant, Melaleuca alternifolia. MATERIAL AND METHODS: The ability of tea tree oil to reduce the production in vitro of tumour necrosis factor-alpha (TNFalpha), interleukin (IL)-1beta, IL-8, IL-10 and prostaglandin E2 (PGE2) by lipopolysaccharide (LPS)-activated human peripheral blood monocytes was examined. RESULTS: Tea tree oil emulsified by sonication in a glass tube into culture medium containing 10% fetal calf serum (FCS) was toxic for monocytes at a concentration of 0.016% v/v. However, the water soluble components of tea tree oil at concentrations equivalent to 0.125% significantly suppressed LPS-induced production of TNFalpha, IL-1beta and IL-10 (by approximately 50%) and PGE2 (by approximately 30%) after 40 h. Gas chromatography/mass spectrometry identified terpinen-4-ol (42 %), a-terpineol (3 %) and 1,8-cineole (2%, respectively, of tea tree oil) as the water soluble components of tea tree oil. When these components were examined individually, only terpinen-4-ol suppressed the production after 40 h of TNFalpha, IL-1beta, IL-8, IL-10 and PGE2 by LPS-activated monocytes. CONCLUSION: The water-soluble components of tea tree oil can suppress pro-inflammatory mediator production by activated human monocytes.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Prevalence of delayed hypersensitivity to the European standard series in a self-selected population.

There are limited reports of the prevalence of positive reactions in healthy adults to patch tests with standard allergens; there are no recent comprehensive studies from Australia. Healthy adult volunteers (n = 219) from the Western Australian community were patch tested using the European standard series of allergens. Seventy-seven (35%) reacted to at least one allergen, positive patch tests being most prevalent to nickel sulfate (20%), potassium dichromate (9%), cobalt chloride (6%) and fragrance mix (4%). Prevalence of positive patch tests to nickel and chromate was higher than that reported for another healthy population, which may stem from self-selection of volunteers or geographical differences, including extent of exposure to allergens.

Adolescent↗
PubMed2000

Tea tree oil as an alternative topical decolonization agent for methicillin-resistant Staphylococcus aureus.

The combination of a 4% tea tree oil nasal ointment and 5% tea tree oil body wash was compared with a standard 2% mupirocin nasal ointment and triclosan body wash for the eradication of methicillin-resistant Staphylococcus aureus carriage. The tea tree oil combination appeared to perform better than the standard combination, although the difference was not statistically significant due to the small number of patients.

Administration, Cutaneous↗
PubMed2000

Precipitate production by some Malassezia species on Dixon's agar.

The production of a precipitate by Malassezia species on Dixon's agar was observed. Malassezia furfur (n = 12), M. obtusa (n = 2) and M. slooffiae (n = 3) were precipitate negative, while M. sympodialis (n = 32) and M. globosa (n = 6) were precipitate positive. This test may be useful in differentiating Malassezia species.

Agar↗
PubMed2000

In vitro activities of ketoconazole, econazole, miconazole, and Melaleuca alternifolia (tea tree) oil against Malassezia species.

The in vitro activities of ketoconazole, econazole, miconazole, and tea tree oil against 54 Malassezia isolates were determined by agar and broth dilution methods. Ketoconazole was more active than both econazole and miconazole, which showed very similar activities. M. furfur was the least susceptible species. M. sympodialis, M. slooffiae, M. globosa, and M. obtusa showed similar susceptibilities to the four agents.

Antifungal Agents↗
PubMed2000

Comparison of methods for detection of Erysipelothrix spp. and their distribution in some Australasian seafoods.

For many years, Erysipelothrix rhusiopathiae has been known to be the causative agent of the occupationally related infection erysipeloid. A survey of the distribution of Erysipelothrix spp. in 19 Australasian seafoods was conducted, and methodologies for the detection of Erysipelothrix spp. were evaluated. Twenty-one Erysipelothrix spp. were isolated from 52 seafood parts. Primary isolation of Erysipelothrix spp. was most efficiently achieved with brain heart infusion broth enrichment followed by subculture onto a selective brain heart infusion agar containing kanamycin, neomycin, and vancomycin after 48 h of incubation. Selective tryptic soy broth, with 48 h of incubation, was the best culture method for the detection of Erysipelothrix spp. with PCR. PCR detection was 50% more sensitive than culture. E. rhusiopathiae was isolated from a variety of different fish, cephalopods, and crustaceans, including a Western rock lobster (Panulirus cygnus). There was no significant correlation between the origin of the seafoods tested and the distribution of E. rhusiopathiae. An organism indistinguishable from Erysipelothrix tonsillarum was isolated for the first time from an Australian oyster and a silver bream. Overall, Erysipelothrix spp. were widely distributed in Australasian seafoods, illustrating the potential for erysipeloid-like infections in fishermen.

Animals↗
PubMed2000

Melaleuca alternifolia (tea tree) oil inhibits germ tube formation by Candida albicans.

The effect of tea tree oil (TTO) on the formation of germ tubes by Candida albicans was examined. Two isolates were tested for germ tube formation (GTF) in the presence of TTO concentrations (% v/v) ranging from 0.25% (1/2 minimum inhibitory concentration [MIC]) to 0.004% (1/128 MIC). GTF at 4 h in the presence of 0.004 and 0.008% (both isolates) and 0.016% (one isolate) TTO did not differ significantly (P > 0.05) from controls. At all other concentrations at 4 h, GTF differed significantly from controls (P < 0.01). A further eight isolates were tested for GTF in the presence of 0.031% TTO, and at 4h the mean GTF for all 10 isolates ranged 10.0-68.5%. Two isolates were examined for their ability to form germ tubes after 1 h of pre-exposure to several concentrations of TTO, prior to induction of germ tubes in horse serum. Cells pre-exposed to 0.125 and 0.25% TTO formed significantly fewer germ tubes than control cells at 1 h (P < 0.05), but only those cells pre-exposed to 0.25% differed significantly from control cells at later time points (P < 0.01). GTF by C. albicans is affected by the presence of, or pre-exposure to, sub-inhibitory concentrations of TTO. This may have therapeutic implications.

Anti-Infective Agents, Local↗
PubMed1999

Lack of association between seropositivity to Chlamydia pneumoniae and carotid atherosclerosis.

Since the Chlamydia pneumoniae (C. pneumoniae)-specific antibody was shown to be associated with acute myocardial infarction and chronic coronary heart disease, the role of C. pneumoniae in the etiology of cardiovascular disease has been studied by a number of groups. We investigated the association between the C. pneumoniae-specific antibody, measured by microimmunofluorescence, risk factors for cardiovascular disease, and atherosclerosis in a randomly selected urban population. Overall, immunoglobulin-G (IgG) seroprevalence to C. pneumoniae in this sample of 1,034 subjects was 58%, whereas IgA seroprevalence was 32%. There was a decline in seropositivity with age for IgG but not IgA. Men were more likely than women to be IgG (66% vs 51%, chi-square p = 0.001) and IgA seropositive (36% vs 28%, chi-square p = 0.005). Current smokers had higher IgA seropositivity than nonsmokers (43% vs 30%). Those patients with a family history of cerebrovascular disease were more likely to have IgG antibody than those without (75% vs 57%, chi-square p= 0.007). Neither IgG nor IgA seropositivity was associated with the standard risk factors of hypertension, hyperlipidemia, or family history of ischemic heart disease, nor was seropositivity associated with carotid intima medial thickening (IMT) or atherosclerotic plaque as measured by carotid B-mode ultrasound. There was no difference between those participants who were IgG or IgA seropositive and seronegative in measurements of mean IMT, prevalence of abnormal IMT, and percentage with atherosclerotic plaque. In conclusion, although C. pneumoniae was associated with several risk factors for cardiovascular disease in a large cross-sectional population, we found no independent association between seroprevalence to C. pneumoniae and carotid atherosclerosis as measured by carotid IMT.

Adult↗
PubMed1999

Influence of organic matter, cations and surfactants on the antimicrobial activity of Melaleuca alternifolia (tea tree) oil in vitro.

The effect of some potentially interfering substances and conditions on the antimicrobial activity of Melaleuca alternifolia (tea tree) oil was investigated. Agar and broth dilution methods were used to determine minimum inhibitory and cidal concentrations of tea tree oil in the presence and absence of each potentially interfering substance. Activity was determined against Gram-positive and -negative bacteria, and Candida albicans. Minimum inhibitory or cidal concentrations differed from controls by two or more dilutions, for one or more organisms, where Tween-20, Tween-80, skim-milk powder and bovine serum albumin were assessed. These differences were not seen when assays were performed in anaerobic conditions, or in the presence of calcium and magnesium ions. The effect of organic matter on the antimicrobial activity of tea tree oil was also investigated by an organic soil neutralization test. Organisms were exposed to lethal concentrations of tea tree oil ranging from 1-10% (v/v), in the presence of 1-30% (w/v) dry bakers' yeast. After 10 min contact time, viability was determined. At > or = 1%, organic matter compromised the activity of each concentration of tea tree oil against Staphylococcus aureus and C. albicans. At 10% or more, organic matter compromised the activity of each tea tree oil concentration against Pseudomonas aeruginosa. Organic matter affected 1 and 2% tea tree oil, but not 4 and 8%, against Escherichia coli. In conclusion, organic matter and surfactants compromise the antimicrobial activity of tea tree oil, although these effects vary between organisms.

Agar↗
PubMed1999

Antimicrobial activity of essential oils and other plant extracts.

The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia col, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of < or = 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives.

Anti-Bacterial Agents↗
PubMed1999

Community strain of methicillin-resistant Staphylococcus aureus involved in a hospital outbreak.

Western Australia (WA) has been able to prevent methicillin-resistant Staphylococcus aureus (MRSA) strains from outside of the state from becoming established in its hospitals. Recently, a single-strain outbreak of MRSA occurred in a WA metropolitan teaching hospital following admission of an infected patient from a remote community. The strain responsible for the outbreak was unrelated to any imported strains and spread rapidly in the hospital. Screening of two remote communities in the region from which the index case came revealed that 42% of the people in one community and 24% in the other carried MRSA. Isolates were typed by resistance pattern, plasmid analysis, contour-clamped homogeneous electric field electrophoresis, bacteriophage pattern, and coagulase gene restriction fragment length polymorphism. It was found that of the people carrying MRSA, 39% in the former community and 17% in the latter community were carrying an MRSA strain which was indistinguishable from the strain that caused the hospital outbreak.

Cross Infection↗