Evaluation of bacterial presence on lead X-ray aprons utilised in the operating room via IBIS and standard culture methods.

BACKGROUND: Despite precautions, surgical procedures carry risk of infection. Radiation-protective lead aprons worn by operating personnel are a potential source of bacterial contamination and have not been fully evaluated. AIM/OBJECTIVE: To evaluate lead aprons as a source of bacterial contamination, identify organisms most commonly found on this source, and devise a method with which to lower the risk of contamination. METHODS: In this basic science study, 20 randomly selected lead X-ray aprons were swabbed at three time points. The experimental treatment was with a hospital-grade disinfectant wipe. The samples were assessed for bacterial growth via traditional plating methods and mass spectrometry. Plates were graded on a scale of 0 to 4+ based on the number of quadrants with growth. Growth on one quadrant or more was considered contaminated. FINDINGS/RESULTS: Bacteria were initially detected via IBIS on a majority of the aprons (32/40), most commonly Staphylococcus epidermidis and Propionibacterium acnes. Virulent organisms cultured were Methicillin-resistant Staphylococcus epidermidis (MRSE), Neisseria, Streptococcus viridans and pseudomonas. MRSE were detected on 5/20 of the samples. Immediately after treatment, the majority of aprons showed less bacterial contamination (0/20 standard culture positive; 13/20 IBIS positive) with some recurrence at the 6-h time point (2/20 standard culture positive, 16/20 IBIS positive). All MRSE detected initially was eradicated. DISCUSSION: Lead X-ray aprons worn in the operating room harbour bacteria. Disinfecting before use may prevent the introduction of virulent organisms to patients. Our proposed method of sanitising with a disinfectant wipe is quick and effective.

The use of PCR/Electrospray Ionization-Time-of-Flight-Mass Spectrometry (PCR/ESI-TOF-MS) to detect bacterial and fungal colonization in healthy military service members.

BACKGROUND: The role of microbial colonization in disease is complex. Novel molecular tools to detect colonization offer theoretical improvements over traditional methods. We evaluated PCR/Electrospray Ionization-Time-of-Flight-Mass Spectrometry (PCR/ESI-TOF-MS) as a screening tool to study colonization of healthy military service members. METHODS: We assessed 101 healthy Soldiers using PCR/ESI-TOF-MS on nares, oropharynx, and groin specimens for the presence of gram-positive and gram-negative bacteria (GNB), fungi, and antibiotic resistance genes. A second set of swabs was processed by traditional culture, followed by identification using the BD Phoenix automated system; comparison between PCR/ESI-TOF-MS and culture was carried out only for GNB. RESULTS: Using PCR/ESI-TOF-MS, at least one colonizing organism was found on each individual: mean (SD) number of organisms per subject of 11.8(2.8). The mean number of organisms in the nares, groin and oropharynx was 3.8(1.3), 3.8(1.4) and 4.2(2), respectively. The most commonly detected organisms were aerobic gram-positive bacteria: primarily coagulase-negative Staphylococcus (101 subjects: 341 organisms), Streptococcus pneumoniae (54 subjects: 57 organisms), Staphylococcus aureus (58 subjects: 80 organisms) and Nocardia asteroides (45 subjects: 50 organisms). The mecA gene was found in 96 subjects. The most commonly found GNB was Haemophilus influenzae (20 subjects: 21 organisms) and the most common anaerobe was Propionibacterium acnes (59 subjects). Saccharomyces species (30 subjects) were the most common fungi detected. Only one GNB (nares E. coli) was identified in the same subject by both diagnostic systems. CONCLUSION: PCR/ESI-TOF-MS detected common colonizing organisms and identified more typically-virulent bacteria in asymptomatic, healthy adults. PCR/ESI-TOF-MS appears to be a useful method for detecting bacterial and fungal organisms, but further clinical correlation and validation studies are needed.

Can we trust intraoperative culture results in nonunions?

OBJECTIVES: To identify the presence of bacterial biofilms in nonunions comparing molecular techniques (multiplex polymerase chain reaction and mass spectrometry, fluorescent in situ hybridization) with routine intraoperative cultures. METHODS: Thirty-four patients with nonunions were scheduled for surgery and enrolled in this ongoing prospective study. Intraoperative specimens were collected from removed implants, surrounding tissue membrane, and local soft tissue followed by standard culture analysis, Ibis's second generation molecular diagnostics (Ibis Biosystems), and bacterial 16S rRNA-based fluorescence in situ hybridization (FISH). Confocal microscopy was used to visualize the tissue specimens reacted with the FISH probes, which were chosen based on the Ibis analysis. RESULTS: Thirty-four patient encounters were analyzed. Eight were diagnosed as infected nonunions by positive intraoperative culture results. Ibis confirmed the presence of bacteria in all 8 samples. Ibis identified bacteria in a total of 30 of 34 encounters, and these data were confirmed by FISH. Twenty-two of 30 Ibis-positive samples were culture-negative. Four samples were negative by all methods of analysis. No samples were positive by culture, but negative by molecular techniques. CONCLUSIONS: Our preliminary data indicate that molecular diagnostics are more sensitive for identifying bacteria than cultures in cases of bony nonunion. This is likely because of the inability of cultures to detect biofilms and bacteria previously exposed to antibiotic therapy. LEVEL OF EVIDENCE: Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

The microbiome of chronic rhinosinusitis: culture, molecular diagnostics and biofilm detection.

BACKGROUND: Bacteria and fungi are believed to influence mucosal inflammation in chronic rhinosinusitis (CRS). However their presence and relationship to disease is debated. This study used multiple detection methods to compare microbial diversity and microbial abundance in healthy and diseased sinonasal mucosa. The utility of contemporary detection methods is also examined. METHODS: Sinonasal mucosa was analyzed from 38 CRS and 6 controls. Bacterial and fungal analysis was performed using conventional culture, molecular diagnostics (polymerase chain reaction coupled with electrospray ionization time-of-flight mass spectrometry) and fluorescence in situ hybridization. RESULTS: Microbes were detected in all samples, including controls, and were often polymicrobial. 33 different bacterial species were detected in CRS, 5 in control patients, with frequent recovery of anaerobes. Staphylococcus aureus and Propionibacterium acnes were the most common organisms in CRS and controls, respectively. Using a model organism, FISH had a sensitivity of 78%, and a specificity of 93%. Many species were detected in both CRS and controls however, microbial abundance was associated with disease manifestation. CONCLUSIONS: This study highlights some cornerstones of microbial variations in healthy and diseased paranasal sinuses. Whilst the healthy sinus is clearly not sterile, it appears prevalence and abundance of organisms is critical in determining disease. Evidence from high-sensitivity techniques, limits the role of fungi in CRS to a small group of patients. Comparison with molecular analysis suggests that the detection threshold of FISH and culture is related to organism abundance and, furthermore, culture tends to select for rapidly growing organisms.