A Multipathogen Bile Sample-based PCR Assay Can Guide Empirical Antimicrobial Strategies in Cholestatic Liver Diseases.

Background and objectives: Polymerase chain reaction (PCR) techniques provide rapid detection of pathogens. This pilot study evaluated the diagnostic utility and clinical impact of multiplex real-time PCR (mRT-PCR, SeptiFast) vs. conventional microbial culture (CMC) in bile samples of patients with chronic cholestatic liver diseases (cCLDs), endoscopic retrograde cholangio-pancreatography (ERCP), and peri-interventional-antimicrobial-prophylaxis (pAP). Methods: We prospectively collected bile samples from 26 patients for microbiological analysis by CMC and mRT-PCR. Concordance of the results of both methods was determined by Krippendorff's alpha (α) for inter-rater reliability and the Jaccard index of similarity. Results: mRT-PCRbile and CMCbile results were concordant for only Candida albicans (α=0.8406; Jaccard index=0.8181). mRT-PCRbile detected pathogens in 8/8 cases (100%), CMCbile in 7/8 (87.5%), and CMCblood in 5/8 (62.5%) with clinical signs of infection. mRT-PCRbile, CMCbile, and CMCblood had identical detection results in 3/8 (37.5%) with clinical signs of infection (two Klebsiella spp. and one Enterococcus faecium). The total pathogen count was significantly higher with mRT-PCRbile than with CMCbile (62 vs. 31; χ2=30.031, p<0.001). However, pathogens detected by mRT-PCRbile were more often susceptible to pAP according to the patient infection/colonization history (PI/CH) and surveillance data for antibiotic resistance in our clinic (DARC). Pathogens identified by mRT-PCRbile and resistant to pAP by PI/CH and DARC were likely to be clinically relevant. Conclusions: mRT-PCR in conjunction with CMCs for bile analysis increased diagnostic sensitivity and may benefit infection management in patients with cholestatic diseases. Implementation of mRT-PCR in a bile sample-based diagnostic routine can support more rapid and targeted use of antimicrobial agents in cCLD-patients undergoing ERCP and reduce the rate/length of unnecessary administration of broad-spectrum antibiotics.

Candida Contamination in Kidney and Liver Organ Preservation Solution: Does It Matter?

INTRODUCTION: Fungal infections remain a major challenge affecting outcomes after kidney (KT) and liver transplantation (LT). METHODS: In this retrospective single center study, the incidence of Candida contamination in renal and hepatic graft preservation solution (PS) was evaluated. In addition, Candida associated infections in recipients and related complications were analyzed. RESULTS: Overall, the PS of 1248 hepatic and 1273 renal grafts were evaluated. The incidence of fungal contamination in the PS of hepatic and renal grafts was 1.2% and 0.86%, respectively. Additionally, the hepatic PS of one patient who underwent a combined liver-kidney transplant had Candida contamination. Candida albicans was the most common organism (70.4%) and 65.4% of the patients received antifungal treatment. Candida-associated complications in the recipients was 19%. Complications in LT patients included Candida peritonitis and Candida sepsis. Two KT recipients with contaminated PS developed a mycotic aneurysm at the anastomotic site resulting in severe bleeding. The 1-year mortality in patients with PS contamination for LT and KT recipients was 33% and 18%, respectively. Although the incidence of fungal contamination of PS was low, contaminated PS was associated with a high mortality. CONCLUSION: The results of the study suggest that PS should be evaluated for fungal growth.

Donor Leucocytosis Predicts Bacterial and Fungal Contamination of the Preservation Solution in Visceral Organ Transplantation.

INTRODUCTION: Contamination of the preservation solution may contribute to septic complications that can occur after transplantation and cause higher morbidity and mortality among recipients. The aim of this study was to determine potential donor-related predictors of positive microbiological findings in the preservation solution. DESIGN: We retrospectively studied 16 donor parameters on data from our center for microbiological findings in the preservation solution used in solid-organ recovery. From January 2008 through December 2011, 976 solid organs were transplanted, and in 167, the solution was positive for contaminants. RESULTS: The most frequently detected contaminant was coagulase-negative staphylococci. Only the donor leucocyte count (cutoff at 9.1 × 109/L) predicted positive microbiological findings in the preservation solution ( P = .0024). Multivariable regression analysis found that donor age, donor sex, intensive care unit stay, total number of organs recovered, and leucocyte count differentiated various categories of potentially pathogenic bacteria. CONCLUSION: Donor leucocyte count higher than 9.1 × 109/L predicts contamination of preservation solution.

Influence of culture conditions on the fatty acid profiles of laboratory-adapted and freshly isolated strains of Helicobacter pylori.

Cellular fatty acids of Helicobacter pylori have taxonomic, physiological, and pathogenic implications. However, little is known about the fatty acid composition under various culture conditions. H. pylori is usually grown on blood-supplemented complex media, and the fatty acids in the blood may affect the fatty acids in the cells. In addition, frequently subcultivated laboratory-adapted strains may have properties different from those of fresh clinical isolates, which are culturable only for a limited number of passages. Therefore, the cellular fatty acid profiles of laboratory-adapted strains (LAS) and freshly isolated strains (FIS) were compared after growth on agar that was fatty acid free and growth on blood agar that contained fatty acids. LAS ATCC 43504, 51932, and 700392 and the FIS IMMi 88, 89, and 92, each with <10 subcultures, were cultured in parallel on a fatty acid-free agar (ISAF) and on 5% sheep blood agar (SBA), which contained oleic acid (18:1 9c), hexadecanoic acid (16:0), and octadecanoic acid (18:0). ISAF-grown cultures showed no 18:1 9c and no appreciable differences between the profiles of FIS and LAS. After culture on SBA, the strains showed 18:1 9c and increased 16:0 and 18:0 content combined with decreased tetradecanoic acid (14:0) content compared to ISAF-grown cells. The changes in the fatty acid profiles were much more pronounced in FIS than in LAS. LAS are obviously characterized by a lower uptake of the fatty acids from the growth medium than FIS. Furthermore, it could be shown that this LAS behavior is most likely a primary strain attribute that is favored under laboratory conditions. The pronounced uptake of fatty acids by strains with FIS behavior may be associated with the expression of virulence properties.

Influence of mucin on the activity of the antiseptic Lavasept against Staphylococcus aureus.

BACKGROUND: Lavasept, containing the polymeric biguanide polyhexanide, may be effective against Staphylococcus aureus colonizing the nasal mucosa. To obtain basic data on its suitability for that purpose, its antimicrobial activity was examined in the presence of mucin. METHODS: A disk diffusion test was applied using Mueller-Hinton agar, and disks soaked with a therapeutic and a 10-fold higher concentration of Lavasept. Commercially available mucin preparations from porcine stomach were added to the test system. Reference strains and 20 clinically isolates of S. aureus, and reference strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, and Candida albicans were tested. RESULTS: Supplementation of the test medium with 1% mucin completely abolished the activity of disks loaded with the therapeutically used concentration of the antiseptic. The neutralizing effect of mucin occurred with all test strains. CONCLUSIONS: The inactivation of Lavasept by mucin may hamper a reliable clearance of nasal S. aureus carriage.