High-latitude warming initiated the onset of the last deglaciation in the tropics.

Atmospheric greenhouse gas concentrations are thought to have synchronized global temperatures during Pleistocene glacial-interglacial cycles, yet their impact relative to changes in high-latitude insolation and ice-sheet extent remains poorly constrained. Here, we use tropical glacial fluctuations to assess the timing of low-latitude temperature changes relative to global climate forcings. We report 10Be ages of moraines in tropical East Africa and South America and show that glaciers reached their maxima at ~29 to 20 ka, during the global Last Glacial Maximum. Tropical glacial recession was underway by 20 ka, before the rapid CO2 rise at ~18.2 ka. This "early" tropical warming was influenced by rising high-latitude insolation and coincident ice-sheet recession in both polar regions, which lowered the meridional thermal gradient and reduced tropical heat export to the high latitudes.

Susceptibility to Melaleuca alternifolia (tea tree) oil of yeasts isolated from the mouths of patients with advanced cancer.

Yeasts that are resistant to azole antifungal drugs are increasingly isolated from the mouths of cancer patients suffering from oral fungal infections. Tea tree oil is an agent possessing antimicrobial properties that may prove useful in the prevention and management of infections caused by these organisms. In this study, 301 yeasts isolated from the mouths of 199 patients suffering from advanced cancer were examined by an in vitro agar dilution assay for susceptibility to tea tree oil. All of the isolates tested were susceptible, including 41 that were known to be resistant to both fluconazole and itraconazole. Clinical studies of tea tree oil as an agent for the prevention and treatment of oral fungal infections in immunocompromised patients merit consideration.

Voriconazole susceptibility of yeasts isolated from the mouths of patients with advanced cancer.

The in vitro activity of voriconazole was compared with those of fluconazole and itraconazole against 270 clinical isolates of yeasts from the mouths of patients receiving palliative care for advanced cancer. A broth micro-dilution assay as described by the National Committee for Clinical Laboratory Standards was employed for determination of MICs. Of the 270 isolates, 206 (76 %) were fluconazole sensitive and 64 were fluconazole resistant. Voriconazole showed more potent activity than either fluconazole or itraconazole, including against some isolates resistant to both fluconazole and itraconazole. However, for fluconazole-resistant isolates, the MICs of itraconazole and voriconazole were proportionally higher than for the fluconazole-susceptible isolates, suggesting cross-resistance. Voriconazole may be a useful additional agent for the management of oral fungal infections caused by strains resistant to fluconazole and itraconazole, but susceptibility cannot be assumed and in vitro MIC determination is recommended prior to its use.

Evaluation of the recurrence of denture stomatitis and Candida colonization in a small group of patients who received itraconazole.

OBJECTIVES: The aim of the study was to determine the recurrence rate of denture stomatitis and persistence of Candida in 22 patients (5 male and 17 female, mean age 71 years) over a 3-year period. STUDY DESIGN: Denture hygiene practice, denture cleanliness, and the presence of palatal erythema were assessed for each patient at the start of the study (baseline). The oral cavity was sampled for yeasts by imprint culture and denture discs. Ten patients received a capsular form of itraconazole (100 mg twice daily for 15 days) and 12 patients were provided with 100 mg of itraconazole in the form of a mouthwash (10 mL twice daily), which was then swallowed. No further antifungal treatment was administered to any of the patients. Clinical and microbiological assessments were repeated for each patient at 6 months and 3 years after the original appointment. Yeasts were identified by colony color on CHROMagar Candida, germ-tube formation, and API-32C profiling. Selected isolates were then typed by inter-repeat polymerase chain reaction (IR PCR). RESULTS: Candida albicans was isolated at baseline from all patients either alone (12 patients) or in combination with another species (10 patients). Other yeast species recovered were C glabrata (5 patients), C tropicalis (1 patient), C guilliermondii (1 patient), C krusei (1 patient), C parapsilosis (1 patient), C kefyr (1 patient), and Saccharomyces cerevisiae (2 patients). Candida albicans and/or C glabrata were recovered from 11 of the 22 patients after 6 months or 3 years. A complete and consistent change of yeast species from baseline was observed in 6 patients after 6 months and at 3 years. The remaining 5 patients were yeast-free at the follow-up assessments. PCR fingerprinting of C albicans and C glabrata indicated strain persistence over 6 months in 10 patients and in 4 patients after 3 years. A switch in strain type occurred for 1 patient after 6 months and for 3 patients after 3 years. CONCLUSIONS: The recurrence of denture stomatitis in patients who maintained a high standard of denture cleanliness was low. Although itraconazole was beneficial in reducing the fungal load, there may be strain persistence or subsequent recolonization of the oral cavity by a broader range of potentially less sensitive yeast species.

Identification of bacteria associated with spreading odontogenic infections by 16S rRNA gene sequencing.

OBJECTIVE: To determine the bacterial species associated with spreading odontogenic infections (SOIs). STUDY DESIGN: Pus samples from 4 cases of SOI were analyzed by microbiological culture methods for the presence of bacteria, and by polymerase chain reaction (PCR) amplification, cloning, and sequencing of bacterial 16S rRNA genes. RESULTS: Culture methods identified species from the genera Prevotella, Streptococcus, and Fusobacterium, as well as anaerobic streptococci. Molecular detection methods identified a far more diverse microflora. The predominant genus detected was Prevotella, representing 102 (50.2%) of 203 clones analyzed. Prevotella oris was the most abundant species identified, representing 45 (22.2%) of 203 clones analyzed. Twelve clones (5.9%) represented uncultivable species, namely Prevotella PUS9.180, an uncultured Peptostreptococcus species, and an uncultured bacterium belonging to the Bacteroidetes phylum. CONCLUSIONS: Prevotella species may play an important role in SOIs, and further work to examine in more detail the pathogenicity determinants of these organisms and associated host responses is warranted.

Bordetella petrii clinical isolate.

We describe the first clinical isolate of Bordetella petrii from a patient with mandibular osteomyelitis. The only previously documented isolation of B. petrii occurred after the initial culture of a single strain from an environmental source.

Antimicrobial susceptibility of viridans group streptococcal blood isolates to eight antimicrobial agents.

A total of 155 viridans group streptococci blood culture isolates identified by the Rapid ID32 Strep system were tested for their minimum inhibitory concentrations (MICs) to penicillin, amoxicillin, ceftriaxone, erythromycin, clindamycin, rifampicin, vancomycin and teicoplanin using the E-test. The following species were identified: S. oralis (n = 67), S. mitis (n = 66), S. sanguis (n = 7), S. salivarius (n = 5), S. parasanguis (n = 4), S. gordonii (n = 3) and S. mutans (n = 3). S. oralis and S. mitis demonstrated the highest levels of resistance to the agents tested. There were 27% of S. oralis isolates resistant to pencillin, 51% resistant to erythromycin and 6% resistant to clindamycin. For S. mitis 11% were resistant to penicillin, 40% resistant to erythromycin and 3% resistant to clindamycin. Penicillin resistant isolates (MIC > or = 2 mg/l) also demonstrated decreased susceptibility to other antimicrobial agents tested in this study. High level resistance (MIC > or = 2 mg/l) to ceftriaxone was found in 12 isolates. The isolates identified as ceftriaxone resistant comprised S. oralis (n = 7), S. mitis (n = 4) and S. parasanguis (n = 1). This study has highlighted the difference in susceptibility between different species of viridans group streptococci. These findings are of concern in the light of spread of antibiotic resistance genes from S. oralis and S. mitis to the more invasive pneumococcus.