Immediate hypersensitivity to iodinated contrast media: diagnostic accuracy of skin tests and intravenous provocation test with low dose.

BACKGROUND: The diagnosis of HSR to iodinated contrast media (ICM) is challenging based on clinical history and skin tests. OBJECTIVE: This study evaluates the negative predictive value (NPV) of skin tests and intravenous provocation test (IPT) with low-dose ICM in patients with suspected immediate hypersensitivity reaction (HSR) to ICM. METHODS: Thirty-seven patients with suspected immediate hypersensitivity reaction to ICM were included retrospectively. Skin tests and a single-blind placebo-controlled intravenous provocation test (IPT) with low-dose iodinated contrast media (ICM) were performed. RESULTS: Skin tests with ICM were positive in five cases (one skin prick test and five intradermal test). Thirty-six patients were challenged successfully by IPT, and only one patient had a positive challenge result, with a grade I reaction by the Ring and Messmer classification. Ten of 23 patients followed up by telephone were re-exposed to a negative tested ICM during radiologic examination; two experienced a grade I immediate reaction. CONCLUSIONS & CLINICAL RELEVANCE: For immediate hypersensitivity reaction to ICM, the NPV for skin tests and IPT with low dose was 80% (95% CI 44-97%).

Saccharomyces cerevisiae fungemia, a possible consequence of the treatment of Clostridium difficile colitis with a probioticum.

The yeast Saccharomyces boulardii is a biotherapeutic agent used for the prevention and treatment of several gastrointestinal diseases, such as diarrhoea caused by Clostridium difficile, in addition to the antibiotic therapy. In this study we report a case of Saccharomyces cerevisiae fungemia in a patient with Clostridium difficile-associated diarrhoea (CDAD) treated orally with S. boulardii in association with vancomycin. The identification of the S. cerevisiae was confirmed by molecular technique. Fungemia is a rare, but a serious complication to treatment with probiotics. We believe it is important to remind the clinicians of this risk when prescribing probiotics, especially to immunocompromised patients.

Microbiological and molecular characterization of extreme drug-resistant carbapenemase-producing Klebsiella pneumoniae isolates.

Fifteen Klebsiella pneumoniae clinical isolates showing non-susceptibility to carbapenems and resistant to colistin were collected in an Italian hospital. All isolates resulted negative to AmpC, MBL and ESBL production but positive to modified Hodge test, therefore were evaluated as KPC producers. The presence of blaKPC genes was verified by polymerase chain reaction (PCR) and sequencing. Furthermore, molecular typing was performed by multilocus sequence typing (MLST). PCR analysis and nucleotide sequencing revealed that all 15 isolates carried the blaKPC-3 gene. MLST analysis attributed the isolates from all patients to belong to the sequence type ST512. All isolates showed extensively drug-resistant (XDR) phenotype. The emergence of colistin-resistant K. pneumoniae underscores the implementation of strict control measures to prevent the dissemination of these organisms in hospitals.

Kodamaea ohmeri isolate from two immunocompromised patients: first report in Italy.

Kodamaea ohmeri is an unusual yeast-form fungus that has recently been identified as an important aetiological agent of fungaemia, endocarditis, cellulitis, funguria and peritonitis in immunocompromised patients. We present two new isolated of K. ohmeri. The microorganisms were identified by CHROMagar Candida medium, VitekII system and API ID32C. Biochemical identification of the two yeast isolates was confirmed by sequence analysis of the 26S ribosomal DNA. Antifungal susceptibility testing done by Sensititre YeastOne showed that the isolates were susceptible to amphotericin B, voriconazole and itraconazole. This work is the first report of isolation of K. ohmeri in immunocompromised patients in Italy.