Candida auris: A pathogen difficult to identify, treat, and eradicate and its characteristics in Japanese strains.

Candida auris is a multidrug-resistant and emergent pathogen that has caused healthcare-associated infection outbreaks. Recently, C. auris has spread worldwide; nevertheless, it was unexpectedly rare before 2009. Based on the molecular epidemiological analysis, C. auris may independently emerge at specific areas at first and recently may be transmitted to other continents. As C. auris cannot be detected using conventional methods, internally transcribed spacers, D1/D2 regions of the 26S rDNA sequencing, and/or matrix-assisted laser desorption ionization time-of-flight mass spectrometry method can be selected as comparatively accessible choices. Thus, detection of C. auris using the conventional method might be underestimated. In Japan, all C. auris strains were isolated from ear specimen and not from invasive mycoses. Japan strains were classified as an East Asian clade under a single clone. Although colonization, virulence, and infection pattern are almost the same as with other Candida species, its antifungal resistance is different. Fluconazole resistance is notably common, but resistance to all three classes of antifungals (azole, polyene, and echinocandin) rarely exists. Once C. auris is detected, screening, emphasis on hand hygiene adherence, use of single-patient room isolation, contact precaution, surveillance, and eradication from the environment and patients are appropriately required for infection control.

Recognition of B-cell epitopes of the 65 kDa HSP in Behçet's disease.

B-cell epitopes of the mycobacterial 65 kDa heat shock protein (HSP) were mapped in sera from patients with Behçet's Disease (BD). A series of 47 overlapping synthetic peptides (15ers) derived from the sequence of the Mycobacterium tuberculosis 65 kDa HSP was used in ELISA. Significant increases in IgA and IgG antibody levels were observed with peptides 111-125, 154-172 and 311-326 in sera from BD, compared with those from controls. Homologous peptides derived from the sequence of the human mitochondrial 60 kDa HSP were then examined. Peptides 136-150 and 336-351 showed comparable results to the homologous mycobacterial peptides 111-125 and 311-326, respectively. The B-cell epitopes defined in this investigation overlap with the T-cell epitopes the authors have previously reported in BD. Inhibition studies are consistent with the view that antibodies to each of the three B-cell epitope peptides represent a small proportion of the total B-cell epitope repertoire elicited by the 65 or 60 kD HSP. Sequential antibody studies suggest that IgA and IgG antibody titres to one or all three peptides tested may increase during exacerbation of ocular disease. The functional role of these antibodies needs to be determined, but the peptides may be involved in the immunopathogenesis of BD as they can induce experimental uveitis in Lewis rats, which is a principal manifestation of BD.

Microwave digestion using dual PTFE containers for analysis of trace elements in small amounts of biological samples.

The analysis of trace elements in biological samples is essential to extend our knowledge on human health and disease. Inductively coupled plasma mass spectrometry (ICP-MS) makes it possible to simultaneously determine these elements in trace amounts. Before analysis, however, biological samples such as organs and tissues must be liquefied and extra organic materials must be decomposed by acid digestion. We established a method of microwave digestion using dual PTFE containers to minimize the amount of samples. Samples (35-45 mg) of standard reference materials, bovine liver (1577a, NIST) and fish flesh (MA-A-2, IAEA), were weighed in PTFE-PFA vials and a small amount of nitric acid (0.5 ml) was added. The vials were sealed and two PTFE-PFA vials were placed in a PTFE-TFM vessel containing 6 ml of pure water. Then the vessels were placed in a rotor and the samples were digested for 38 min in a microwave oven according to a pre-set program. After the program was completed, the samples were analyzed by ICP-MS. The determined values of elements of the microwave-digested samples matched the certified values of the standard reference materials. Therefore, the digestion using dual containers was successfully applied to small samples.