Comparison of 16S ribosomal RNA gene sequence analysis and conventional culture in the environmental survey of a hospital.

BACKGROUND: Nosocomial infection is one of the most common complications within health care facilities. Certain studies have reported outbreaks resulting from contaminated hospital environments. Although the identification of bacteria in the environment can readily be achieved using culturing methods, these methods detect live bacteria. Sequencing of the 16S ribosomal RNA (16S rRNA) gene is recognized to be effective for bacterial identification. In this study, we surveyed wards where drug-resistant bacteria had been isolated and compared conventional culture methods with 16S rRNA gene sequencing methods. METHODS: Samples were collected using sterile swabs from two wards (northern and southern) at Gunma University Hospital contaminated by Acinetobacter sp.. We extracted DNA directly from the swabs. Following extraction, the DNA was amplified using polymerase chain reaction (PCR). The PCR products were cloned using the plasmid vector. The plasmid DNA were sequenced, and identification were performed using database. 16S rRNA gene sequence analyses were compared conventional culture methods. RESULTS: In the northern ward, Acinetobacter sp. was detected from only two of 14 samples using the culture method. In contrast, 16S rRNA gene sequencing analysis detected Acinetobacter sp. from seven of 14 samples. Drug-resistant Acinetobacter sp. was isolated from bathrooms of the southern ward and was detected from four of seven samples using the culture method in comparison with six of seven samples by 16S rRNA gene sequencing analysis. CONCLUSIONS: Molecular biological analysis showed a higher sensitivity to detect specific bacteria and detected a greater number of species than the culture method. Our results suggest that 16S rRNA gene sequencing analysis is useful to identify range of contamination which were not found in conventional culture method. When a nosocomial outbreak cannot be adequately controlled, molecular biological analysis may serve as a useful tool for environmental surveys in hospitals.

Palonosetron, aprepitant, and dexamethasone for prevention of nausea and vomiting after high-dose melphalan in autologous transplantation for multiple myeloma: A phase II study.

Chemotherapy-induced nausea and vomiting (CINV) is a significant side effect in multiple myeloma (MM) patients receiving high-dose melphalan treatment followed by autologous stem cell transplantation (ASCT). We evaluated the efficacy and safety of a triple antiemetic combination of palonosetron, aprepitant, and low-dose dexamethasone in 24 MM patients who received melphalan conditioning (100 mg/m2 on days 1-2) before ASCT (on day 4). Intravenous palonosetron (0.75 mg on day 1), oral aprepitant (125 mg on day 1; 80 mg on days 2-4), and intravenous dexamethasone (6.6 mg on days 1-4) were administered for prevention of CINV. Complete response (no emesis and no rescue antiemetic) and complete control (no emesis, no rescue antiemetic, and no more than mild nausea) rates were 75 and 68% during the overall phase (0-120 h), while they were 88 and 86% in the acute phase (0-48 h), 75 and 68% in the delayed phase (48-120 h), and 67 and 59% in the extended phase (120-168 h), respectively. There were no serious adverse events related to the antiemetic therapy. In conclusion, the three-antiemetic regimen consisting of palonosetron, aprepitant, and dexamethasone was safe and effective for controlling CINV due to high-dose melphalan treatment, especially during the delayed phase.

Reduced risk of bacterial infection in multiple myeloma patients with VAD regimen without intermittent high-dose dexamethasone.

Vincristine-adriamycin-dexamethasone (VAD) regimen with intermittent high-dose dexamethasone (HD) has been used as primary chemotherapy for multiple myeloma (MM) patients who are candidates for high-dose therapy or present with renal failure. However, dexamethasone increases the risk of infection in MM patients. We retrospectively evaluated treatment efficacy and infectious events in MM patients undergoing VAD with or without HD. Seventy-seven consecutive patients who received VAD without HD (n = 37) or VAD-HD (n = 40) at our institution were assessed. Characteristics of patients and VAD regimens were retrospectively analyzed to detect correlations with the incidence of infections. During 218 VAD cycles, 48 infectious episodes were documented in 39 patients. Of these, 32 episodes in 26 patients were severe (grade ≥ 3). By analyzing each patient, VAD-HD was associated with risk of all-grade and severe bacterial infection, while International Staging System stage ≥ 2 was independently correlated with severe bacterial infection. Response rates after two cycles were comparable between the 2 VAD regimens. In conclusion, risk of infection is lower in VAD without HD than in VAD-HD, and the clinical response is equivalent. VAD-HD should thus be avoided for MM patients with high risk of infection.