Melaleuca alternifolia essential oil possesses potent anti-staphylococcal activity extended to strains resistant to antibiotics.

Melaleuca alternifolia Cheel essential oil (TTO) and its major component terpinen-4-ol were examined against a large number of clinical isolates of Staphylococcus aureus to establish their anti-staphylococcal activities. Classic and established procedures were used to study M.I.C., time-kill curves, synergism and mutational frequency. The anti-staphylococcal activity of terpinen-4-ol and TTO were superior to those of antibiotics belonging to the major families (all the tested drugs are for topical use or included in ointments, eye drops or used during surgery); terpinen 4-ol and TTO were active against strains resistant to mupirocin, fusidic acid, vancomycin, methicillin and linezolid. TTO and terpinen-4-ol were bactericidal as revealed by time-kill curves; the frequency of mutational frequency to TTO was < 2.9 x 10 9. The study demonstrates good anti-staphylococcal activity of TTO and terpinen-4-ol against a large number of S.aureus isolates and suggests the possible application of these agents for topical treatment of staphylococcal infections. This is the first extensive study on the anti-staphylococcal activity of TTO. The results suggest that this compound may have application as a topical agent for the control of superficial staphylococcal infections, including activity against organisms resistant to antibiotics which can be used, or are specific, for topical use.

Genetic variability among Blastoschizomyces capitatus isolates from different clinical sources.

Sixteen clinical isolates and nine ATCC reference strains of Blastoschizomyces capitatus were analysed genetically, examined for the cellobiose, arbutin and salicin assimilation and tested for the aspartyl-proteinase secretion. The restriction endonuclease analysis (REA) with HpaII and HinfI enzymes and the electrophoretic karyotype (EK) were investigated. Both the restriction enzymes revealed two groups (I, II) constituted by the same isolates: 17 isolates (68%) in group I and 8 (32%) in group II. The EK analysis revealed sixteen groups. These data prompts for a genetic variability of the isolates of Blastoschizomyces capitatus and their account in two distinct genetic groups as suggested by REA. This grouping was confirmed by examining the utilisation of cellobiose, arbutin and salicin. The tests for secretory aspartyl proteinase (Sap) were positive only for three isolates, suggesting a marginal role of this specific enzyme in pathogenesis for these isolates.

Antimycotic activity of Melaleuca alternifolia essential oil and its major components.

AIMS: The aim of this study was to analyse the antimycotic properties of Melaleuca alternifolia essential oil (tea tree oil, TTO) and its principal components and to compare them with the activity of 5-fluorocytosine and amphotericin B. METHODS AND RESULTS: The screening for the antimycotic activity was performed by serial twofold dilutions in Roswell Park Memorial Institute medium with the inclusion of Tween-80 (0.5%). TTO and terpinen-4-olo were the most active compounds. CONCLUSIONS: The majority of the organisms were sensitive to the essential oil, with TTO and terpinen-4-olo being the most active oils showing antifungal activity at minimum inhibitory concentration values lower than other drugs. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides a sample large enough to determine the antifungal properties of TTO and terpinen-4-olo and suggests further studies for a possible therapeutic use.

Correlation of SfiI macrorestriction endonuclease fingerprint analysis of Candida parapsilosis isolates with source of isolation.

SfiI macrorestriction digests from whole chromosome DNA preparations of 46 isolates of Candida parapsilosis from vaginal (20 isolates), blood (23 isolates) and soil (three isolates) sources were examined by CHEF-MAPPER pulsed-field electrophoresis. The isolates were grouped into nine macrorestriction endonuclease fingerprint (MEF) classes according to the number or size of the macrorestriction fragments, or both. The electrophoretic karyotype (EK) was also examined and found to contain 18 karyotypic classes (named A-R). A comparison between SfiI MEF and EK demonstrated that the former correlated much better than the latter with the source of C. parapsilosis isolates. Five SfiI classes (I-V) contained only vaginal isolates (or vaginal and three soil isolates, class I), and the blood isolates were distributed between four classes (VI-IX). This relationship was less evident with the EK classes as several of these were composed of both vaginal and blood isolates (B, G, L and M). The three soil isolates were in class A which also included one vaginal isolate. We conclude that SfiI macrorestriction endonuclease patterns seem to be useful in discriminating among C. parapsilosis isolates, with apparent association with source of isolation.

Elevated aspartic proteinase secretion and experimental pathogenicity of Candida albicans isolates from oral cavities of subjects infected with human immunodeficiency virus.

Isolates of Candida albicans from the oral cavities of subjects at different stages of human immunodeficiency virus (HIV) infection or uninfected controls were examined for (i) production of aspartic proteinase(s), a putative virulence-associated factor(s); (ii) the presence in the fungal genome of two major genes (SAP1 and SAP2) of the aspartic proteinase family; and (iii) experimental pathogenicity in a murine model of systemic infection. It was found that the fungal isolates from symptomatic patients secreted, on average, up to eightfold more proteinase than the isolates from uninfected or HIV-infected but asymptomatic subjects. This differential property was stably expressed by the strains even after years of maintenance in stock cultures. Moreover, representative high-proteinase isolates were significantly more pathogenic for mice than low-proteinase isolates of C. albicans. The characters high proteinase and increased virulence were not associated with a single molecular type or category identifiable through DNA fingerprinting or pulsed-field electrophoretic karyotype, and both SAP1 and SAP2 genes were present in both categories of isolates, on the same respective chromosomes. In conclusion, our data suggest that during HIV infection more-virulent strains or biotypes of C. albicans which are identifiable by direct analysis of virulence determinants are selected. It also appears that the biotype switch to increased aspartic proteinase and virulence properties occurs before the HIV-infected subject enters the symptomatic stage and overt AIDS.

Vaginopathic and proteolytic Candida species in outpatients attending a gynaecology clinic.

Non-pregnant, non-diabetic outpatients were examined for the presence of pathogenic vaginal yeasts to determine if a correlation existed between a specific yeast and clinical disease. Yeasts were isolated as single vaginal species from 186 of 228 subjects with clinically diagnosed candidal vaginitis, as well as from 122 out of 380 asymptomatic, age-matched controls. Apart from Candida albicans and C glabrata, other prevalent species were C krusei, C parapsilosis and Saccharomyces cerevisiae which accounted for 9.2%, 6.0% and 5.4%, and 9.0%, 2.4% and 19.7%, of yeasts from patients and carriers, respectively. Only C albicans and C parapsilosis were significantly more common in those with vaginitis. Only the isolates of these two species secreted aspartyl proteinase in vitro, and the amount of the enzymes secreted by the isolates from patients was significantly higher than that secreted by the isolates from carriers. These two species consistently produced vaginal infection in pseudoestrus rats, whereas none of the non-proteolytic species tested (C glabrata, C krusei, and S cerevisiae) colonised the vagina in these rats. Proteinase secretion correlated with experimental vaginal infection; it could also be a reliable factor for distinguishing clinically active infection from asymptomatic fungal carriage.

The effect of antimycotics on secretory acid proteinase of Candida albicans.

The effect of antimycotics on secretory aspartate (acid) proteinase, a virulence enzyme of Candida albicans, was investigated. The conditions of the study were such as to induce proteinase production in the stationary phase of growth (25-40 hours), when no antifungal tested, except the polyene derivative methyl partricin, significantly reduced the viability of the culture. Among azole derivatives, fenticonazole (FZ) but not miconazole, fluconazole or ketoconazole, exerted strong inhibition on proteinase, in typical dose-diphasic pattern, (0.01 microgram/ml; 1-10 micrograms/ml). 5-fluorocytosine (5-FC) was also inhibitory at a dose interval 1-10 micrograms/ml. In all cases, the inhibition concerned the synthesis of the enzyme rather that its activity as suggested by the results of comparative ELISA, SDS-PAGE and spectrophotometric methods of proteinase detection. Finally, the inhibition of proteinase production by FZ and 5-FC mainly reflected the effect of these antimycotics on general protein synthesis.

Experimental pathogenicity and acid proteinase secretion of vaginal isolates of Candida parapsilosis.

Isolates of Candida parapsilosis from women with or without candidal vaginitis were compared for their ability to produce secretory aspartate (acid) proteinase and their virulence for normal or cyclophosphamide-immunodepressed mice. Although all isolates were strongly proteolytic in vitro, only those from candidosis-affected subjects were appreciably pathogenic for neutropenic mice. In these animals, organ invasion was monitored after challenge with representative isolates of each category. The number of yeast cells in the kidneys of animals infected with an isolate from a subject without candidal vaginitis was approximately one order of magnitude less than that in mice infected with either one of two isolates from patients with candidal vaginitis. Mice infected with either category of C. parapsilosis isolates developed antibodies against a mannoprotein-rich extract of the cell wall, and these antibodies did not cross-react with a chemically similar preparation from Candida albicans. However, only those animals which had been challenged with one of the isolates from a candidosis subject produced a low level of antibodies, detectable by ELISA, against an acid proteinase of C. parapsilosis. These antibodies cross-reacted with a highly purified enzyme preparation of C. albicans. The data demonstrate differences in the potential virulence of different isolates of C. parapsilosis and suggest that the ability to express the acid proteinase in vivo may be related to differences in pathogenicity.

Prevalence of non-specific vaginitis and correlation with isolation of Gardnerella vaginalis in Italian outpatients.

Among all subjects attending a Center for prevention of female genital tract cancer Gardnerella vaginalis was isolated from 57 out of 171 women affected by non-specific vaginitis (NSV), from 15 of 703 non-NSV vaginitis patients and from 10 of 338 healthy adults. Postmenopausal women showed an increased rate of asymptomatic carriage of G. vaginalis. The data suggest a relatively weak association between clinical diagnosis of NSV and isolation of G. vaginalis.

[Contraception and Gardnerella vaginalis. First study of the Italian population]. / Contraccezione e Gardnerella vaginalis. Prima indagine sulla popolazione Italiana.

The association between contraception and Gardnerella vaginalis was studied in the population of L'Aquila. This research was conducted in the cytocolposcopic Center of the Obstetrics and Gynaecology Clinic, and the Department of Biotechnology and Biometry at L'Aquila University on 1212 females. Of the examined patients, 178 (14.7%) employed a prophylactic method and of these 104 (58.4%) used barrier-systems, while 74 (41.6%) used estroprogestins. Gardnerella vaginalis was isolated in 63 females (6.1%) that used no contraceptive and 19 (10.7%) that employed one.

[Gardnerella vaginalis: role of a microorganism emerging as a vaginopathic agent and its placement in the vaginal microbial ecosystem]. / Gardnerella vaginalis: ruolo di un microorganismo emergente quale agente vaginopatico e suo inquadramento nell'ecosistema microbico vaginale.

In this review the role of an emergent pathogen, Gardnerella vaginalis (G. vaginalis), as aetiologic agent of the so called "non specific vaginitis" is systematically evaluated. The microorganism is described in its morphological, biochemical and virulence aspects in the framework of the complex vaginal ecosystem. The diagnostic criteria of the disease as well as a possible association of G. vaginalis with other vaginal bacteria, especially anaerobes, in the aetiology of the disease, are discussed. Literature data on prevalence and incidence of G. vaginalis in different population groups are integrated by more recent investigations of the Authors on prevalence and carriage of microorganism in a group of outpatients in Italy.

Evidence for a correlation between proteinase secretion and vulvovaginal candidosis.

Candida albicans isolates from nondiabetic, nonpregnant outpatients with vaginitis were compared for in vitro proteinase secretion with isolates from women without specific candidal vaginitis symptomatology (carriers). Proteinase production was assayed in medium containing bovine hemoglobin (BH-P; 39 isolates in 69 independent determinations) or bovine serum albumin (BSA-P; 39 isolates in a single determination each). All isolates had measurable, consistent BH-P secretion, and most also showed detectable BSA-P activity. However, isolates from patients were more proteolytic than those from carriers, with the difference being statistically highly significant. When the patients with vaginitis were categorized according to signs and symptoms, the highest BH-P values were recorded for those with full symptomatology, whereas the only BSA-P-negative isolates were from the group without vaginitis. Isolates from the patient and carrier groups did not differ as a whole in their growth potential in vitro, and all were germ tube responders in serum, independent of their source.

Simplified identification of bacteria belonging to the genus Salmonella.

A new, simplified procedure for identification of bacteria belonging to the genus Salmonella is reported. By this procedure which is a new combination of well know tests, Salmonella spp. are easily and reproducibly differentiated from non Salmonella spp. after 6 h of incubation at 37 degrees C.

[Serological typing of Salmonella in the Aquilano area]. / Tipizzazione sierologica di Salmonellae nel territorio Aquilano.

During the years '80 and '81 16 stocks of Salmonellae are been isolated from 1200 coprocoltures coming from no hospital subjects in the Sanitary and Prophylaxis Laboratory. The percentage of positivity(1, 33%) is par from the last research carried out in 1977 and it is par from other researches in other countries. We confirm that women, more than men, are bearer(1, 65% against 1, 10%) the isolated species are 7, with a slight prevalence of the Salmonella anatum.

[Comparison of different methods for the identification of groups of streptococci]. / Confronto di più metodi per l'identificazione di gruppo degli streptococchi.

The Streptococci, isolated from 500 mucus-pharyngeal tampons, have been tested, for a group identification, by means of four different techniques in order to value the specificity and reliability in comparison with more traditional and, sometimes, more complex tests; such as Maxted and Lancefield. The most suitable method for routine researchers of microbiology laboratories is the one based on the extraction, by means of enzyme obtained from Streptomyces Griseus, of streptococci antigens before starting their serum identification, possible for A-B-C-D-F-G groups (Streptex). On the contrary, the method based on the links of group-specific antibodies with the A protein of the surface of Staphylococci Cowan I, has resulted more defective because Streptococci D and F cannot be grouped, and less specific because of frequent co-agglutinations.

[Anti-tetanus immunity in Aquila residents]. / Studio dell'immunità antitetanica nella popolazione Aquilana.

The AA have studied immunologic conditions against tetanus in the people of L'Aquila, through the dosage of the antibodies against the tetanic toxin. Some aged classes are resulted to be less protected, specially grown-up people, because they aren't vaccinated. The female grown-up people and the old women are less protected than the male people.

[Identification by phage, biochemistry and serology of Salmonellae isolated in the province of Aquila and their resistance to antibiotics]. / Identificazione fagica, biochimica e sierologica di ceppi di Salmonellae isolate nella Provincia de L'Aquila e loro resistenza agli antibiotici.

From 1036 coprocolture, coming from hospital subjects and non hospital subjects in the municipality of L'Aquila, are been isolated 18 stocks of Salmonellae through research with phage 0-1, biochemist and serologique. The phage 0-1, confirming the present data in literature, hasn't shown activity towards 2 stocks. The active antibiotics, according to Kirby-Bauer, have resulted to be the Cloramfenicola and the Gentamicina; the Tetracicline haven't resulted active.

[Antitoxic antibodies and antitetanus protection in the Aquila area]. / Anticorpi antitossici e protezione antitetanica nel territorio Aquilano.

A serological survey was carried out on the population in the l'Aquila district to assess the protection level against tetanus. The antitosin titre was evaluated by indirect haemagglutination in 534 sera from healthy subjects of both sexes and all age-groups. The protection level against tetanus was found usually good for subjects till age fifteen, partial and insufficient for older subjects, women especially.