A bioavailable strontium (87Sr/86Sr) isoscape for Aotearoa New Zealand: Implications for food forensics and biosecurity.

As people, animals and materials are transported across increasingly large distances in a globalized world, threats to our biosecurity and food security are rising. Aotearoa New Zealand is an island nation with many endemic species, a strong local agricultural industry, and a need to protect these from pest threats, as well as the economy from fraudulent commodities. Mitigation of such threats is much more effective if their origins and pathways for entry are understood. We propose that this may be addressed in Aotearoa using strontium isotope analysis of both pests and products. Bioavailable radiogenic isotopes of strontium are ubiquitous markers of provenance that are increasingly used to trace the origin of animals and plants as well as products, but currently a baseline map across Aotearoa is lacking, preventing use of this technique. Here, we have improved an existing methodology to develop a regional bioavailable strontium isoscape using the best available geospatial datasets for Aotearoa. The isoscape explains 53% of the variation (R2 = 0.53 and RMSE = 0.00098) across the region, for which the primary drivers are the underlying geology, soil pH, and aerosol deposition (dust and sea salt). We tested the potential of this model to determine the origin of cow milk produced across Aotearoa. Predictions for cow milk (n = 33) highlighted all potential origin locations that share similar 87Sr/86Sr values, with the closest predictions averaging 7.05 km away from their true place of origin. These results demonstrate that this bioavailable strontium isoscape is effective for tracing locally produced agricultural products in Aotearoa. Accordingly, it could be used to certify the origin of Aotearoa's products, while also helping to determine if new pest detections were of locally breeding populations or not, or to raise awareness of imported illegal agricultural products.

'TB or not TB': the conundrum of pre-European contact tuberculosis in the Pacific.

Tuberculosis (TB) is a major global health threat, infecting one-third of the world's population. Despite this prominence, the age, origin and spread of the disease have been topics of contentious debate. Molecular studies suggest that Mycobacterium tuberculosis 'sensu stricto', the most common strain of TB infecting humans today, originated in Africa and from there spread into Europe and Asia. The M. tuberculosis strains most commonly found across the Pacific and the Americas today are most closely related to European strains, supporting a hypothesis that the disease only reached these regions relatively recently via European sailors or settlers. However, this hypothesis is inconsistent with palaeopathological evidence of TB-like lesions in human remains from across the Pacific that predate European contact. Similarly, genetic evidence from pre-European South American mummies challenges the notion of a European introduction of the disease into the Pacific. Here, we review the complex evidence for the age and origin of TB in the Pacific, and discuss key gaps in our knowledge and how these may be addressed. This article is part of the theme issue 'Insights into health and disease from ancient biomolecules'.

First bioarchaeological evidence of probable scurvy in Southeast Asia: Multifactorial etiologies of vitamin C deficiency in a tropical environment.

This paper presents the first bioarchaeological evidence of probable scurvy in Southeast Asia from a six-year-old child at the historic-era site of Phnom Khnang Peung (15-17th centuries A.D.) in the Cardamom Mountains, Cambodia. Examination of skeletal material shows evidence consistent with scurvy - specifically, abnormal porosity on the greater wings of the sphenoid bone and hard palate, and vascular impressions on the ectocranial surface of the frontal bone and maxillary alveolar bone. In addition, this individual has evidence of cribra orbitalia indicative of anemia. Although a nutritionally linked etiology is the most common cause of scurvy, a number of other factors influencing ascorbic acid levels need to be considered in an environment with sufficient vitamin C potentially available in the diet. Assessing the environmental evidence, the possibility of a number of interrelated factors contributing to the development of scurvy in this individual seems the most plausible explanation. Factors affecting vitamin C levels may have included social aspects of food allocation or choice of food, genetic predisposition, anemia, pathogens, and nutrient malabsorption.

Leprosy and tuberculosis in Iron Age Southeast Asia?

The recent excavation of a sample of 120 human skeletons from an Iron Age site in the valley of the Mun River, a tributary of the Mekong River on the Khorat Plateau in northeast Thailand, has provided the largest sample from this period in the region to date. This paper reviews three individuals from the sample with pathological changes for which the differential diagnosis includes systemic infectious disease. In two of these, both males with lesions of the hands and feet, leprosy and psoriatic arthritis are discussed as differential diagnoses, with leprosy the most probable. In the third, a female with lesions of the spine, the differential diagnosis includes tuberculosis and nonspecific osteomyelitis. Tuberculosis is the most probable diagnosis. Although the focus of this paper is a presentation of the evidence for infectious disease at Noen U-Loke, the significance of probable diagnoses of mycobacterial diseases for the history of the diseases and for prehistory in mainland Southeast Asia is also briefly discussed.

Skeletal pathology in a prehistoric Pacific Island sample: issues in lesion recording, quantification, and interpretation.

This paper presents a profile of evidence of disease in a skeletal sample from Taumako Island, Southeast Solomon Islands, Melanesia, and aims to increase awareness of the prehistoric Pacific Island disease environment. It also addresses issues of lesion recording, quantification, and interpretation. Two methodologies for the determination of lesion prevalence were applied, one based on prevalence in observable individuals and one in skeletal elements. The aim of these methodologies was to provide objective data on skeletal lesions in this sample, with transparency in methods for application in comparative studies. The types of lesions observed were predominantly osteoblastic and affecting multiple bones, particularly in the lower limbs. The individual analysis yielded a prevalence of lesions affecting 56.4% of the postcranial sample from birth to old age. As expected, the skeletal element analysis yielded a lower prevalence, with 15.0% of skeletal elements affected. The skeletal element analysis also revealed a pattern of greater lower limb involvement, with a predilection for the tibia. The pattern of skeletal involvement was similar in both analyses, suggesting the validity of employing either method in paleopathological studies. A differential diagnosis of the lesions included osteomyelitis, treponemal disease, and leprosy. Metabolic disease was also considered for subadult lesions. Based on lesion type, skeletal distribution, and epidemiology of lesions in the sample, an etiology of yaws (Treponema pertenue) was suggested as responsible for nearly half the adult lesions, while multiple causes, including yaws, were suggested for the lesions in subadults.

Skeletal pathology in prehistoric Pacific Island sample: issues in lesion recording, quantification, and interpretation

This paper presents a profile of evidence of disease in a skeletal sample from Taumako Island, Southeast Solomon Islands, Melanesia, and aims to increase awareness of the prehistoric Pacific Island disease environment. It also addresses issues of lesion recording, quantification, and interpretation. Two methodologies for the determination of lesion prevalence were applied, one based on prevalence in observable individuals and one in skeletal elements. The aim of these methodologies was to provide objective data on skeletal lesions in this sample, with transparency in methods for application in comparative studies. The types of lesions observed were predominantly osteoblastic and affecting multiple bones, particularly in the lower limbs. The individual analysis yielded a prevalence of lesions affecting 56.4% of the postcranial sample from birth to old age. As expected, the skeletal element analysis yielded a lower prevalence, with 15.0% of skeletal elements affected. The skeletal element analysis also revealed a pattern of greater lower limb involvement, with a predilection for the tibia. The pattern of skeletal involvement was similar in both analyses, suggesting the validity of employing either method in paleopathological studies. A differential diagnosis of the lesions included osteomyelitis, treponemal disease, and leprosy. Metabolic disease was also considered for subadult lesions. Based on lesion type, skeletal distribution, and epidemiology of lesions in the sample, an etiology of yaws (Treponema pertenue) was suggested as responsible for nearly half the adult lesions, while multiple causes, including yaws, were suggested for the lesions in subadults.

Isolation of a gene encoding a putative polyamine transporter from Candida albicans, GPT1.

A gene encoding a transport protein from the pathogenic yeast, Candida albicans, has been isolated during a complementation experiment utilizing an ornithine decarboxylase-negative (spe1 Delta) strain of Saccharomyces cerevisiae. This gene restores gamma-aminobutyric acid (GABA) transport to a GABA transport-negative mutant of S. cerevisiae and encodes a protein which putatively allows transport of one or more of the polyamines. We have assigned the name GPT1 (GABA/polyamine transporter) to this gene.

Subadult health and disease in prehistoric Tonga, Polynesia.

This article focuses on the differential diagnosis of pathologic lesions recorded on the limbs and crania of 17 subadults from two pre-European burial mounds in Tonga, western Polynesia. All affected subadults were between the ages of 6 months and 3 years at death. The lesions described consist primarily of subperiosteal new bone deposition on the limbs and endocranial surface. However, the presence of cribra orbitalia in a number of individuals indicates concurrent iron-deficiency anaemia. A differential diagnosis of haematogenous osteomyelitis, congenital syphilis, yaws, scurvy, hypervitaminosis A, trauma, Caffey's disease, and iron-deficiency anaemia is discussed. It was concluded that the most likely cause for the lesions observed is a synergistic relation between infection (weanling diarrhoea, yaws) and metabolic disease (scurvy and possibly hypervitaminosis A). Trauma is not ruled out as contributing to the development of some pathologic lesions. It is concluded that, in the Pacific Islands at least, multiple causes for skeletal pathology in subadults should be considered rather than a single aetiology.

Evaluation of the RapID Yeast Plus System for the identification of yeast.

We evaluated the RapID Yeast Plus System using 117 fresh and frozen clinical yeast isolates. The Uni-Yeast-Tek System was used to establish the correct identification. The Vitek System was used as the arbiter for any discrepant results, along with morphology. Of 117 isolates tested, the RapID Yeast Plus System identified 96.6% correctly. The RapID Yeast Plus System is an accurate and reliable alternative to other commonly used yeast identification systems.

Isolation and sequence of the gene encoding ornithine decarboxylase, SPE1, from Candida albicans by complementation of a spe1 delta strain of Saccharomyces cerevisiae.

The gene encoding ornithine decarboxylase, SPE1, from the pathogenic yeast Candida albicans has been isolated by complementation of an ornithine decarboxylase-negative (spe1 delta) strain of Saccharomyces cerevisiae. Four transformants, three of which contain plasmids with the SPE1 gene, were isolated by selection on polyamine-free medium. The C. albicans ornithine decarboxylase (ODC) showed high homology with other eukaryotic ODCs at both the amino acid and nucleic acid levels.

Production of IL-6 and TNF-alpha by the macrophage-like cell line RAW 264.7 after treatment with a cell wall extract of Candida albicans.

Treatment of the cell wall of Candida albicans with ethylenediamine yields an extract that is antigenic for both the humoral and cell-mediated arms of the immune system. This extract has been shown in previous studies by this laboratory and others to possess potent immunomodulatory activity. We report results here that show that treatment of the macrophage-like cell line RAW 264.7 with the ethylenediamine cell wall (EDA-CW) extract results in an increase in the production of both interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). Our results also show that the EDA-CW extract possess potent costimulatory activity when combined with interferon-gamma (IFN-gamma). We have found, on the other hand, that EDA-CW extract-treated cells fail to produce elevated levels of IL-1 either alone or in combination with IFN-gamma as a costimulus. Our analysis also shows that the activation of TNF-alpha production by the EDA-CW extract appears to be at the level of transcription, since Northern blot analysis shows that the increase in the level of TNF-alpha mRNA is essentially identical to the rise in TNF-alpha activity released. We suggest that a component of the immunomodulatory activity of the EDA-CW extract is via the activation of macrophage function.

Fluorescence studies on the molecular action of amphotericin B on susceptible and resistant fungal cells.

The molecular action of amphotericin B (AmB) on the cell membranes of both AmB-susceptible and AmB-resistant fungal cells was investigated through the use of the fluorescent membrane probe trimethylammonium diphenylhexatriene (TMA-DPH). AmB, the most effective drug for the treatment of systemic fungal infections, is known to interact specifically with membrane sterols, especially ergosterol (the major sterol in fungal cells). Treatment of AmB-susceptible Candida albicans and Cryptococcus neoformans cells with AmB induced a novel biphasic change in TMA-DPH fluorescence intensity over time. The initial decrease in fluorescence intensity results from energy transfer between AmB and TMA-DPH when AmB binds to the fungal cell membrane. The second phase of increasing fluorescence intensity is interpreted in terms of a combination of probe repartitioning and probe segregation as a result of the formation of membrane pores via the aggregation of AmB-ergosterol complexes. An AmB-resistant strain of C. neoformans, containing 94% of aberrant delta-8 double-bonded ergosterol precursors and only 4% of ergosterol (74% ergosterol in wild-type cells), exhibited the first phase of AmB binding but not the second phase of increasing fluorescence intensity. This result suggests that AmB's antifungal activity lies in its ability to form membrane pores due to aggregation of AmB-ergosterol complexes. The AmB-Induced biphasic fluorescence intensity profile may lead to further elucidation of the molecular action of AmB on fungal cells and may provide a sensitive method for screening the development of drug resistance in fungal cells.

Activation of murine resident peritoneal macrophages by a cell wall extract of Candida albicans.

Ethylenediamine extraction of the cell walls of Candida albicans yields an extract which possesses antigenic activity, and like other whole cell and cell wall preparations of Candida, has been shown previously to possess immunomodulatory activity. We report here results which show that non-elicited, resident peritoneal macrophages treated with the ethylenediamine cell wall extract exhibit morphological characteristics of activated macrophages. Treated cells also manifest an increased respiratory burst response and secrete elevated levels of IL-6. The treatment with the extract appears to provide a co-priming signal to the resting macrophages, since co-stimulation with interferon-gamma results in an increased level of IL-6 and IL-1. Our results also show that extract-treated cells manifest increased responsiveness to a lipopolysaccharide as measured by the production of tumour necrosis factor-alpha. These results provide an additional basis for our understanding of the immunomodulatory activity of components of the Candida cell wall.

Chronic fungal vaginitis: the value of cultures.

OBJECTIVE: Our purpose was to examine the importance of fungal cultures in evaluating patients with symptoms of chronic vaginitis by assessing the relative contribution of various yeast species and by comparing infections caused by Candida albicans with those caused by other species. STUDY DESIGN: A prospective observational study of patients referred with chronic vaginal symptoms was undertaken. In addition to a standard evaluation of symptoms, cultures for yeast were performed on modified Sabouraud agar plates. RESULTS: Seventy-seven isolates were obtained from 74 patients. A total of 68% were Candida albicans; 32% were other species. The clinical syndromes caused by non-Candida albicans isolates were indistinguishable from Candida albicans infections. Fluconazole gave a short-term mycologic cure in all Candida albicans but only 25% of non-Candida albicans cases (p < 0.001). In non-Candida albicans infections, boric acid suppositories achieved the best mycologic cure rate (85%). CONCLUSION: Because non-Candida albicans species are responsible for a significant number of chronic fungal vaginal infections and are more resistant to therapy with fluconazole, fungal cultures are a valuable aid in confirming the diagnosis and selecting appropriate therapy.

Saccharomyces cerevisiae vaginitis: transmission from yeast used in baking.

OBJECTIVE: To determine whether vaginitis due to Saccharomyces cerevisiae can be caused by exposure to exogenous sources of baker's yeast. METHODS: Eight women with S cerevisiae vaginitis were identified from a cohort of women referred for the evaluation of chronic vaginal symptoms. In those with high-level exposure to exogenous sources of S cerevisiae, isolates from the vagina and those sources were sent in a blinded fashion for contour-clamped homogeneous electric-field electrophoresis. RESULTS: Four women from a cohort of approximately 750 referred patients had high-level exposures to S cerevisiae. In one of these patients, electrophoresis analysis revealed similarities between the strains isolated from her vagina, her husband's fingers, and the yeast he used in his pizza shop. CONCLUSION: Saccharomyces cerevisiae vaginitis can be the result of the inoculation of this yeast from exogenous sources.

Production of a hemolytic factor by Candida albicans.

Candida albicans exhibits hemolytic activity when grown on glucose-enriched blood agar. This activity is present on intact organisms, and it is secreted into the culture medium. Hemoglobin released from lysed erythrocytes can restore the transferrin-inhibited growth of C. albicans. We conclude that C. albicans expresses a hemolytic factor which allows it to acquire iron from host erythrocytes.

Malassezia furfur folliculitis of the vulva: olive oil solves the mystery.

BACKGROUND: In treating women with chronic fungal infections, it is important to know which organism is responsible for the infection. In the past, organisms thought to cause vaginitis and vulvitis could all be cultured on modified Sabouraud agar. CASE: We describe a case of a woman whose chronic fungal vulvar folliculitis masqueraded as squamous epithelial hyperplasia. The 46-year-old woman, taking immunosuppressive therapy for rheumatoid arthritis, was referred with an 8-month history of vulvar vesicles, itching, and burning. Her examination revealed a vulvar folliculitis. When fungal cultures were initially negative, a vulvar biopsy revealed a squamous epithelial hyperplasia. However, a fungal culture covered with sterile olive oil eventually grew Malassezia furfur, a yeast with peculiar growth requirements. She was cured with a 2-week course of fluconazole. CONCLUSION: Malassezia furfur, an organism rarely described in the vaginitis literature, can cause vulvar folliculitis in a patient on immunosuppressive therapy.

Synergism between the antifungal agents amphotericin B and alkyl glycerol ethers.

The alkyl glycerol ether rac-1-O-dodecylglycerol inhibited the growth of members of two genera of yeasts, Candida and Cryptococcus, and was strongly synergistic with amphotericin B. At one-half its MIC, dodecylglycerol decreased the MIC of amphotericin B by as much as 80-fold. This high degree of synergism between dodecylglycerol and amphotericin B was demonstrated against a number of species of yeasts including Candida albicans, Candida tropicalis, Candida parapsilosis, Cryptococcus neoformans, Cryptococcus albidus, and Cryptococcus laurentii. All fractional inhibitory concentrations (for all strains and species) were calculated to be less than 1, and most were less than 0.6, again demonstrating strong synergism. Other alkyl glycerol ethers with alkyl chain lengths ranging from 8 to 18 carbon atoms were also found to be synergistic with amphotericin B against C. neoformans and C. albicans. Electron microscopy experiments showed that C. neoformans grown in the presence of dodecylglycerol had severely abnormal, deformed capsules. Although the mechanism of action of dodecylglycerol is not known, dodecylglycerol was not simply acting as a detergent. The natural detergent sodium deoxycholate could not substitute for dodecylglycerol. At comparable and higher concentrations, sodium deoxycholate had no fungicidal effect on its own, nor did it potentiate the activity of amphotericin B. Dodecylglycerol did not interact synergistically with the water-soluble antifungal agent fluconazole. The lipid-soluble hydrophobic properties of amphotericin B appear to be important for this synergistic effect, in that alkyl glycerol ethers could promote synergism with amphotericin B by potentially increasing the interaction between membrane-bound ergosterol and amphotericin B.

Protection against murine disseminated candidiasis mediated by a Candida albicans-specific T-cell line.

The role of T lymphocytes in disseminated candidiasis in a mouse model of irradiation-induced immunosuppression was investigated. A continuously cultured Candida albicans-specific T-cell line mediated protection of sublethally irradiated mice from disseminated candidiasis as measured by both the fungal load in the kidneys and mortality. These results are the first to demonstrate directly a role for antigen-specific T cells in the protective immune response against murine disseminated candidiasis.