Antimicrobial activity of lavender,tea tree and lemon oils in cosmetic preservative systems

Aims: The aim of the study was to verify the antimicrobial activity of commercial essential oils: lavender, tea tree and lemon as the components of a preservative system in oil in water body milks. Methods and Results: The inhibition efficacy of essential oils alone (0·5%), in mixtures (1%) as well as combined with the synthetic preservative 1,3‐dimethylol‐5,5‐dimethylhydantoin and a 3‐iodo‐2‐propynyl butyl carbamate mixture (0·1% and 0·2%) was tested against Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027, Candida sp. ?OCK 0008 and Aspergillus niger ATCC 16404 in compliance with the standards of the European Pharmacopoeia Commission. The in vitro activity of oils determined by an impedimetric method was also compared with their activity in cosmetic preparations. Criterion A for bacteria (reduction in the inoculum by 3 logarithmic units within 7 days with no increase up to the 28th day) and fungi (reduction in the inoculum by 2 logarithmic units within 14 days with no increase up to the 28th day) was fulfilled for cosmetic formulations containing the tested essential oils with 0·2% of the synthetic preservative. The preservative concentration could be decreased to 0·1% (with preserving the same efficacy) in combination with lavender and tea tree oils at a concentration of 0·5% each. Conclusions: In all combinations of essential oils with the synthetic preservative, a synergistic effect of the preservative system components was observed, which made it possible to reduce the usable level of the synthetic preservative up to 8·5 times. Significance and Impact of the Study: To develop an effective preservative system in cosmetics in which a synthetic chemical preservative is replaced by natural essential oils.     

Essential oil analysis and antimicrobial activity of eight Stachys species from Greece

The volatile composition of eight Stachys species has been studied. The investigated taxa were St. alopecuros (L.) Bentham., St. scardica (Griseb.) Hayek, St. cretica L. ssp. cretica, St. germanica L. ssp. heldreichii (Boiss.) Hayek, St. recta L., St. spinulosa L., St. euboica Rech. and St. menthifolia Vis., growing wild in Greece. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the substances was made by comparison of mass spectra and retention indices with literature records. Sesquiterpene hydrocarbons were shown to be the main group of constituents of all taxa. Furthermore, the obtained essential oils were tested against the following six bacteria: Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 35210), Bacillus subtilis (ATCC 10907), Bacillus cereus (clinical isolates), Micrococcus flavus (ATCC 10240), Staphylococcus epidermidis (ATCC 2228), as well as against the following five fungi: Aspergillus niger (ATCC 6275), Penicillium ochrochloron (ATCC 9112), Epidermophyton floccosum (clinical isolates), Candida albicans (clinical isolates) and Trichophyton mentagrophytes (clinical isolates). The tested essential oils showed better activity against bacterial species than against fungi. Pseudomonas aeruginosa was the most resistant strain, as none of the essential oils was active against this strain. The essential oil of St. scardica has been proven most active against both bacteria and fungi.     

The use of impedance for preservative efficacy testing of pharmaceuticals and cosmetic products

Impedance was investigated for its applicability to preservative efficacy testing of pharmaceuticals and cosmetics. A good correlation between impedance detection time ( Td ) and total colony counts (colony-forming units (cfu) was obtained for untreated suspensions of Staphylococcus aureus, Candida albicans, Aspergillus niger and Pseudomonas aeruginosa in phosphate-buffered saline (PBS). A good correlation between Td and the number of cfu was also obtained for suspensions of test organisms treated for varying contact periods with selected concentrations of chlorhexidine, methyl paraben and phenoxyethanol in PBS, and methyl paraben in cetomacrogol cream, but these correlations were significantly different from those for untreated suspensions. It was found that for any given number of cfu the Td for preservative treated cells was extended. It is concluded that impedance represents a valid method for preservative efficacy testing of pharmaceuticals and cosmetics which could be used to achieve more comprehensive but economic screening of formulations against a wider range of preservative systems and concentrations than is the current approach where only a limited range of systems are tested because of the workload involved.     

Essential Oils and Herbal Extracts as Antimicrobial Agents in Cosmetic Emulsion

The cosmetic industry adapts to the needs of consumers seeking to limit the use of preservatives and develop of preservative-free or self-preserving cosmetics, where preservatives are replaced by raw materials of plant origin. The aim of study was a comparison of the antimicrobial activity of extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinallis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben. Extracts (2.5 %), essential oils (2.5 %) and methylparaben (0.4 %) were tested against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Candida albicans ATCC 14053. Essentials oils showed higher inhibitory activity against tested microorganism strain than extracts and methylparaben. Depending on tested microorganism strain, all tested extracts and essential oils show antimicrobial activity 0.8–1.7 and 1–3.5 times stronger than methylparaben, respectively. This shows that tested extracts and essential oils could replace use of methylparaben, at the same time giving a guarantee of microbiological purity of the cosmetic under its use and storage.     

Preservative properties of Calamintha officinalis essential oil with and without EDTA

AIMS: This study was focused on the preserving properties of Calamintha officinalis essential oil, a plant known for its diaphoretic, expectorant and aromatic properties. METHODS AND RESULTS: The commercial aerial parts of C. officinalis Moench were hydrodistilled and the essential oil analysed by Gas chromatography/Electron impact mass spectrometry (GC/EIMS). The inhibition efficacy of this essence, alone (0.5 and 1.0% v/v) and in combination with 2.0 mM EDTA, was assayed, in culture medium and in cetomacrogol cream, using preservative efficacy testing against standard microrganisms (E. coli ATCC 25922, Ps. aeruginosa ATCC 9027, Staph. aureus ATCC 6538P, C. albicans ATCC 10231 and A. niger ATCC 16404). C. officinalis essential oil in cetomacrogol cream with EDTA showed long-lasting antimicrobial activity, satisfying the European Pharmacopoeia Commission (E. P.) criteria. CONCLUSION: C. officinalis essential oil could have a potential for a future use as a cosmetic preservative. IMPACT OF THE STUDY: To find natural compounds with antimicrobial activity which could be alternatives to the synthetic chemical preservatives.     

Genome-based analysis of virulence genes in a non-biofilm-forming Staphylococcus epidermidis strain (ATCC 12228)

Staphylococcus epidermidis strains are diverse in their pathogenicity; some are invasive and cause serious nosocomial infections, whereas others are non-pathogenic commensal organisms. To analyse the implications of different virulence factors in Staphylococcus epidermidis infections, the complete genome of Staphylococcus epidermidis strain ATCC 12228, a non-biofilm forming, non-infection associated strain used for detection of residual antibiotics in food products, was sequenced. This strain showed low virulence by mouse and rat experimental infections. The genome consists of a single 2499 279 bp chromosome and six plasmids. The chromosomal G + C content is 32.1% and 2419 protein coding sequences (CDS) are predicted, among which 230 are putative novel genes. Compared to the virulence factors in Staphylococcus aureus, aside from delta-haemolysin and beta-haemolysin, other toxin genes were not found. In contrast, the majority of adhesin genes are intact in ATCC 12228. Most strikingly, the ica operon coding for the enzymes synthesizing interbacterial cellular polysaccharide is missing in ATCC 12228 and rearrangements of adjacent genes are shown. No mec genes, IS256, IS257, were found in ATCC 12228. It is suggested that the absence of the ica operon is a genetic marker in commensal Staphylococcus epidermidis strains which are less likely to become invasive.     

Interference in adhesion of bacteria and yeasts isolated from explanted voice prostheses to silicone rubber by rhamnolipid biosurfactants

AIMS: The effects and extent of adhesion of four different bacterial and two yeast strains isolated from explanted voice prostheses to silicone rubber with and without an adsorbed rhamnolipid biosurfactant layer obtained from Pseudomonasaeruginosa DS10-129 was studied. METHODS AND RESULTS: The ability of rhamnolipid biosurfactant to inhibit adhesion of micro-organisms to silicone rubber was investigated in a parallel-plate flow chamber. The anti-adhesive activity of the biosurfactant at different concentrations was significant against all the strains and depended on the micro-organism tested. The results showed an effective reduction in the initial deposition rates, and the number of bacterial cells adhering after 4 h, for all micro-organisms tested at the 4 g l(-1) undiluted rhamnolipid solution. Maximum initial reduction of adhesion rate (an average of 66%) occurred for Streptococcus salivarius GB 24/9 and Candida tropicalis GB 9/9. The number of cells adhering after 4 h on silicone rubber conditioned with biosurfactant was reduced to 48% for Staphylococcus epidermidis GB 9/6, Strep. salivarius GB 24/9, Staphylococcus aureus GB 2/1 and C. tropicalis GB 9/9 in comparison to controls. Perfusing the flow chamber with biosurfactant containing solution followed by the passage of a liquid-air interface, to investigate detachment of micro-organisms adhering to silicone rubber, produced high detachment (96%) of adhered cells for all micro-organisms studied, except for Staph. aureus GB 2/1 (67%). SIGNIFICANCE AND IMPACT OF THE STUDY: It is concluded that biosurfactant represent suitable compounds that should be considered in developing future strategies to prevent the microbial colonization of silicone rubber voice prostheses.     

Modification of phospholipid composition in Pseudomonas putida A ATCC 12633 induced by contact with tetradecyltrimethylammonium

AIMS: The aim of this work was to establish if the response to tetradecyltrimethylammonium (TDTMA), a representative quaternary ammonium compound (QAC), involves changes in the phospholipid (PL) composition of Pseudomonas putida A ATCC 12633. METHODS AND RESULTS: Pseudomonas putida was exposed to 50 mg l(-1) of TDTMA for 15 min, and PL composition was analysed. With respect to control values, phosphatidic acid and phosphatidylglycerol increased by 140% and 120%, respectively; cardiolipin decreased about 60%. In TDTMA-adapted bacteria, the most significant change was a 380% increase in phosphatidic acid. Accompanying this change was a 130% increase in phosphatidylglycerol and a 70% decrease in cardiolipin. The changes in adapted cells were reverted after two subcultures without biocide. CONCLUSIONS: Pseudomonas putida responded to TDTMA through quantitative changes in PLs with specific variations in the content of phosphatidic acid, phosphatidylglycerol and cardiolipin. These modifications indicated that these PLs are involved in cellular responses to QACs, utilizing phosphatidic acid principally to neutralize the high positive charge density given for the ammonium quaternary moiety from TDTMA. SIGNIFICANCE AND IMPACT OF THE STUDY: The changes in PL composition give a new insight about the response inflicted by Ps. putida when these bacteria are exposed to QACs.     

Staphylococci in orthopaedic surgical wounds.

From 50 infected surgical wounds of orthopaedic patients, 43 (86%) staphylococcal strains were isolated. 34 of all these staphylococci belonged to Staphylococcus aureus species (i.e. 68 % of all isolates from surgical wounds; 79% of staphylococcal isolates); 9 were coagulase-negative staphylococci (i.e. 21% of all isolates from surgical wounds; 18% of staphylococcal isolates). Among microorganisms isolated from the wounds we also found 2 (4%) of the Enterobacteriaceae family; 2 (4%) of the Pseudomonas genus; 3 (6%) of the Streptococcus genus. Thus, orthopaedic surgical wounds were infected by staphylococci (mainly S. aureus) more frequently than by other micro-organisms. All the staphylococcal strains were screened for methicillin resistance by agar disk diffusion testing and for the presence of mecA gene responsible for methicillin resistance by PCR. 32% of the S. aureus and 33% of the S. epidermidis strains resulted methicillin resistant and mecA-positive. The data confirm the diffusion of methicillin resistant S. aureus in surgical site infections and shows that the so-called "new pathogens", i.e. S. epidermidis and other coagulase-negative staphylococci, also exhibit a frequent and hazardous methicillin-resisting ability.     

Interactions of Candida albicans with other Candida spp. and bacteria in the biofilms

AIMS: To study the interactions between Candida albicans and 12 other species of Candida and bacteria in biofilms. METHODS AND RESULTS: The number of cells within growing biofilms in a polystyrene tube model was measured after adding C. albicans to preformed biofilms of other micro-organisms and vice versa. It was also measured after simultaneous biofilm formation of C. albicans and other micro-organisms. The number of cells of C. albicans within the growing biofilms decreased significantly (P < 0.05) when the fungus was added to preformed biofilms of Candida spp. and bacteria except, with C. parapsilosis, Torulopsis glabrata and the glycocalyx producer Pseudomonas aeruginosa. When C. parapsilosis, Staphylococcus epidermidis (nonglycocalyx producer) or Serratia marcescens was added to preformed biofilms of C. albicans, the number of cells of these micro-organisms increased in the growing biofilms. CONCLUSIONS: Biofilms of C. albicans are capable of holding other micro-organisms and more likely to be heterogeneous with other bacteria and fungi in the environment and on medical devices. SIGNIFICANCE AND IMPACT OF THE STUDY: Recognition of the heterogeneity of biofilm-associated organisms can influence treatment decisions, particularly in patients who do not respond to initial appropriate therapy.     

Antibacterial activity of plasma from crocodile (Crocodylus siamensis) against pathogenic bacteria

ABSTRACT: BACKGROUND: The Siamese crocodile (Crocodylus siamensis) is a critically endangered species of freshwater crocodiles. Crocodilians live with opportunistic bacterial infection but normally suffer no adverse effects. They are not totally immune to microbial infection, but their resistance thereto is remarkably effective. In this study, crude and purified plasma extracted from the Siamese crocodile were examined for antibacterial activity against clinically isolated, human pathogenic bacterial strains and the related reference strains. METHODS: Crude plasma was prepared from whole blood of the Siamese crocodile by differential sedimentation. The crude plasma was examined for antibacterial activity by the liquid growth inhibition assay. The scanning electron microscopy was performed to confirm the effect of crude crocodile plasma on the cells of Salmonella typhi ATCC 11778. Effect of crude crocodile plasma on cell viability was tested by MTT assay. In addition, the plasma was purified by anion exchange column chromatography with DEAE-Toyopearl 650M and the purified plasma was tested for antibacterial activity. RESULTS: Crude plasma was prepared from whole blood of the Siamese crocodile and exhibited substantial antibacterial activities of more than 40% growth inhibition against the six reference strains of Staphylococcus aureus, Salmonella typhi, Escherichia coli, Vibrio cholerae, Pseudomonas aeruginosa, and Staphylococcus epidermidis, and the four clinical isolates of Staphylococcus epidermidis, Pseudomonas aeruginosa, Salmonella typhi, and Vibrio cholerae. Especially, more than 80% growth inhibition was found in the reference strains of Salmonella typhi, Vibrio cholerae, and Staphylococcus epidermidis and in the clinical isolates of Salmonella typhi and Vibrio cholerae. The effect of the crude plasma on bacterial cells of Salmonella typhi, a certain antibacterial material probably penetrates progressively into the cytoplasmic space, perturbing and damaging bacterial membranes. The effect of the crude plasma was not toxic by the yellow tetrazolium bromide (MTT) assay using a macrophage-like cell, RAW 264.7. The pooled four fractions, designated as fractions D1-D4, were obtained by column chromatography, and only fraction D1 showed growth inhibition in the reference strains and the clinical, human pathogenic isolates. CONCLUSIONS: The crude and purified plasma from the Siamese crocodile significantly showed antibacterial activity against pathogenic bacteria and reference strains by damage cell membrane of target bacterial cells. From the MTT assay, the Siamese crocodile plasma was not cytotoxic to the cells.     

Selective growth of Staphylococcus aureus from flushed dairy manure wastewater using acriflavine-supplemented mannitol salt agar

AIMS: To investigate the use of mannitol salt agar (MSA) supplemented with acriflavine for selective growth and quantification of Staphylococcus aureus from flushed dairy manure wastewater (FDMW). METHODS AND RESULTS: Minimal inhibitory concentrations of acriflavine in MSA were determined by comparing the growth of S. aureus subsp. aureus (ATCC 33591) and Staphylococcus epidermidis (ATCC 155) in pure culture. Acriflavine concentrations of 1.3, 1.4 and 1.5 mg l(-1) reduced CFU of S. epidermidis by 43%, 55% and 87%, respectively, while CFU of S. aureus subsp. aureus were only reduced by 15%, 20% and 26% at the respective concentrations of acriflavine. MSA supplemented with 1.5 mg l(-1) acriflavine was tested for selective growth of indigenous S. aureus from three grab samples of FDMW. Acriflavine concentrations of 1.5 mg l(-1) reduced background flora without significantly reducing (P < 0.05) indigenous S. aureus counts. CONCLUSIONS: Acriflavine-supplemented MSA provides an effective media for selective growth and quantification of indigenous S. aureus from FDMW in the presence of high levels of background microflora. SIGNIFICANCE AND IMPACT OF THE STUDY: S. aureus is implicated for mastitis infections in dairy cows. Therefore, a reliable means for monitoring and detecting the organism in FDMW provides a tool for measuring the effectiveness of treatment for reducing S. aureus levels and implementing flushwater recycling without affecting herd health.     

Antimicrobial activities of eucalyptus leaf extracts and flavonoids from Eucalyptus maculata

AIMS: We investigated the antimicrobial activities of eucalyptus leaf extracts to find effective antibacterial agents. METHODS AND RESULTS: The antimicrobial activities of leaf extracts from 26 species of eucalyptus were measured. Extracts of Eucalyptus globulus, E. maculata and E. viminalis significantly inhibited the growth of six Gram-positive bacteria (Staphylococcus aureus, MRSA, Bacillus cereus, Enterococcus faecalis, Alicyclobacillus acidoterrestris, Propionibacterium acnes), and of a fungus (Trichophyton mentagrophytes), but they did not show strong antibacterial activity against Gram-negative bacteria (Escherichia coli, Pseudomonas putida). 2',6'-dihydroxy-3'-methyl-4'-methoxy-dihydrochalcone, eucalyptin and 8-desmethyl-eucalyptin, isolated from E. maculata extracts, exhibited potent antimicrobial activities against seven micro-organisms with minimum inhibitory concentrations (MIC) ranging from 1.0 to 31 mg l(-1). CONCLUSIONS: The eucalyptus extracts and three compounds from E. maculata were found to be effective against micro-organisms that cause food poisoning, acne and athlete's foot. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows potential uses of extracts from E. globulus, E. maculata and E. viminalis, and antimicrobial compounds isolated from E. maculata.     

Microbial survey of shared-use cosmetic test kits available to the public

Summary Some people like to try cosmetics before purchasing them. With repeated use by different customers, however, the tester kits provided by many retail outlets can become potential vectors of microbial pathogens. A survey was conducted to assess the health risk from bacteria found on shared-use cosmetics. A total of 3027 shared-use cosmetic product samples were collected from 171 retail establishments throughout the contiguous United States. Eye, face and lip cosmetics were tested within situ nondestructive swabbing and the use of the Transette 3R Modified Amies Charcoal Culture and Transport System. Bacteria were isolated from about 50% of the items for all three categories. Semiquantitatively-estimated mean densities were 2288, 1685 and 1088 CFU g^–1 for eye, face and lip products, respectively. Ranges for all categories were 0–15⁵ CFU g^–1. About 5% of the items had bacterial counts above 5000 CFU g^–1 (eye products) or 10 000 CFU g^–1 (other products). More than 60% of isolates were typical of microflora from human skin; the remainder were environmental microbes. About 60% of the isolates were Gram-positive cocci:Staphylococcus spp. (especiallyS. epidermidis) andMicrococcus spp. The Gram-negative pathogenPseudomonas aeruginosa constituted 0.07% of the isolates. The survey results suggest that the preservation systems of some of the cosmetics failed under excessive use (abuse), and indicated a potential for microbiological safety problems with shared-use consmetics.     

In Vitro Synergistic Activities of Essential Oils and Surfactants in Combination with Cosmetic Preservatives Against Pseudomonas aeruginosa and Staphylococcus aureus

The aim of this study is to evaluate possible synergistic antimicrobial interactions between common cosmetic preservatives and selected essential oils or surfactants. The antimicrobial efficacy of six essential oils, three surfactants and five preservatives against Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 43387 was assessed by a broth micro-dilution assay. MICs for individual and combined antimicrobials were determined and then transformed to fractional inhibitory concentration (FIC) indexes. All essential oils exhibited antibacterial activity; among surfactants, bacteria resulted most susceptible to the cationic agent. Synergy was observed when essential oils of eucalyptus and mint were combined with methylparaben against P. aeruginosa, while essential oils of mint, oregano and sage combined with propylparaben and imidazolidinyl urea acted against S. aureus. Many binary mixtures of preservatives and surfactants produced synergistic activity with the most effective interactions involving the cationic and amphoteric compounds under study. FIC indexes demonstrated synergistic effects when preservatives were combined with either essential oils or surfactants against both bacterial strains. These results highlight the potential usefulness of essential oils and surfactants to enhance the activities of conventional biocides. This kind of study should contribute to the selection and optimization of preservative systems for cosmetic preparations.     

几种常用防腐剂对日化产品中腐败微生物抑制效果研究

了解几种常用防腐剂在日化产品基质中的防腐效果。采用最低抑菌浓度方法测试卡松、对羟基苯甲酸甲酯、苯氧乙醇、咪唑烷基脲、苯甲醇对腐败微生物的抑菌活性;采用微生物挑战性实验验证卡松、对羟基苯甲酸甲酯、咪唑烷基脲、苯氧乙醇和苯甲醇的抑菌效果。日化产品中分离的腐败微生物对卡松耐受性接近0.0015%,接近《化妆品卫生规范》2007版的限定,其它4种防腐剂在规定的使用范围内对分离的微生物都具有较好的抑制效果;卡松剂量在0.0015%、对羟基苯甲酸甲酯剂量在0.2%、咪唑烷基脲剂量在0.075%、苯甲醇剂量在0.2%时日化产品能通过微生物挑战。日化企业应根据实际情况筛选、复配防腐剂,建立更加高效、经济的防腐体系。     

Loss of effectiveness of preservative systems of mascaras with age.

The preservative systems of unused, anhydrous mascaras were challenged periodically with microorganisms, using a modified membrane procedure. Shelf life of preservative activity against Pseudomonas aeruginosa varied for different brands from as little as 1 month to over 36 months. Generally, P. aeruginosa grew in mascaras after the mascaras were challenged first with Staphylococcus epidermidis or Candida albicans.     

Use of the 'ex vivo' test to study long-term bacterial survival on human skin and their sensitivity to antisepsis

AIMS: To determine bacterial survival on human skin and their sensitivity to antisepsis. METHODS AND RESULTS: An 'ex vivo' protocol which uses human skin samples placed into diffusion cells, and electron microscopy (EM), were used to study the growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa inoculated onto skin samples over a 46-h incubation period at 32 degrees C. Concurrently variation in skin pH was evaluated at different time intervals during this period. In addition the antimicrobial activity of three antiseptics against the incubated micro-organisms was assessed quantitatively with the 'ex vivo' test, while their detrimental effects against bacteria were observed by EM. All three bacteria were still present in high number after 46 h inoculation on skin, although the concentration of E. coli and S. aureus were reduced by 2.74 and 1.58 log(10) reduction, respectively, over this period of time. Electron micrographs showed clear evidence of cell division and some bacteria appeared to be embedded into the skin layers. The antiseptics tested had some antibacterial activity against bacteria incubated on skin for 3 and 10 h, and EM evidence showed some morphological damages including cellular blebbing and the presence of fibrillar material around the cells. All micro-organisms had an acidifying effect on skin samples. CONCLUSIONS: Here, it was shown that bacterial pathogens can survive and grow when incubated on human skin. In addition, it is possible that they can penetrate the stratum corneum, which can provide some protection against antisepsis. SIGNIFICANCE AND IMPACT OF THE STUDY: The apparent low bactericidal activity of biocides attributed in part to bacterial protection from skin layers is particularly important to assess in order to ensure antisepsis efficacy.     

Evaluation of six commercial identification kits for the identification of Staphylococcus aureus isolated from bovine mastitis

AIMS: Comparison of six commercially available in human medicine well-established slide agglutination systems for the identification of Staphylococcus aureus. METHODS AND RESULTS: Slide agglutination tests were compared with the conventional tube coagulase test, biochemical identification and with the molecular identification by polymerase chain reaction (PCR) amplification of species-specific parts of the gene encoding the 23S RNA. Systems evaluated included Masta-Staph (Mast Diagnostics), Staphylase-Test (Oxoid), Staphytect-Plus (Oxoid), Staphyloslide Latex (Becton Dickinson), Slidex Staph Plus (bioMerieux) and Dry Spot Staphytect Plus (Oxoid). A total of 141 staphylococcal strains isolated from cases of bovine mastitis including 90 S. aureus, 14 Staphylococcus epidermidis, 10 Staphylococcus warneri, 13 Staphylococcus xylosus, 11 Staphylococcus haemolyticus and three other coagulase-negative staphylococci were tested with each method. Staphylococcus aureus strains were selected by macrorestriction analysis with pulsed field gel electrophoresis (PFGE). Only genetically unrelated strains were included in the study. The sensitivities and specificities of the test were as follows: Masta-Staph 86.7 and 90.1%, Staphylase-Test 78.4 and 85.1%, Staphytect-Plus 81.1 and 86.5%, Staphyloslide Latex 77.8 and 84.4%, Slidex Staph Plus 77.8 and 84.4%, Dry Spot Staphytect Plus 75.6 and 83.0%. CONCLUSIONS: The results of this evaluation suggest that the six slide agglutination methods tested can provide rapid identification of S. aureus also from bovine mastitis. The sensitivity and specificity seems to be less than those reported from human S. aureus isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: This is one of the first comparative reported investigations about the applicability of different commercially available slide agglutination tests for the detection of S. aureus from bovine mastitis using PFGE selected clinical isolates.