[Bacterial load of the surroundings during rigid diagnostic bronchoscopy under high frequency jet-ventilation]. / Mikrobielle Belastung der Umgebung während der Anwendung der Hochfrequenz-Jetventilation in der Bronchoskopie.

BACKGROUND: High-frequency jet ventilation (HFJV) is used in pneumological endoscopy for rigid, diagnostic, and therapeutic bronchoscopies. It is unclear to what extent the unobstructed flow of respiratory gas from the patient's lungs causes microbial contamination of the surrounding air. MATERIAL AND METHODS: After the start of the HFJV (15 min) in 16 rigid bronchoscopies, airborne pathogen measurements were taken directly at the distal endoscope outlet, at examiner height (40 cm above the endoscope outlet), at a 2 m distance from the endoscope in the room and at the supply air outlet of the examination room using an RCS air sampler. The number and type of pathogens isolated in the air samples were then determined, as well as germs in the bronchoalveolar lavage fluid (BALF) from the patient's lungs. RESULTS: An increased bacterial density (136 and 114 CFU/m3) was detected directly at the distal end of the endoscope and at examiner height at a distance of 40 cm, which decreased significantly with increasing distance from the bronchoscope (98 CFU/m3 at a distance of 2 m and 82 CFU/m3 at the supply air outlet). The most frequently detected bacteria were Staphylococcus spp., Micrococcus spp. and Bacillus spp. In the BALF, pathogens could only be cultivated in four of 16 samples, but the same pathogens were detected in the BALF and the ambient air. CONCLUSION: When performing a rigid bronchoscopy, in which patients are mechanically ventilated in a controlled manner using an open HFJV system, there is an increased pathogen load in the ambient air and therefore a potential risk for the examiner.

Previous antibiotic therapy as independent risk factor for the presence of vancomycin-resistant enterococci in surgical inpatients. Results from a matched case-control study.

BACKGROUND: Investigation of risk factors for the presence of vancomycin-resistant enterococci (VRE) in inpatients on surgical wards and associated intensive care units of a German tertiary care hospital. METHODS: A single-centre retrospective matched case-control study was performed with surgical inpatients admitted between July 2013 and December 2016. Patients with in-hospital detection of VRE later than 48 h after admission were included and comprised 116 VRE-positive cases and 116 VRE-negative matched controls. VRE isolates of cases were typed by multi-locus sequence typing. RESULTS: ST117 was identified as the dominant VRE sequence type. Next to length of stay in hospital or on an intensive care unit and previous dialysis the case-control study revealed previous antibiotic therapy as a risk factor for the in-hospital detection of VRE. The antibiotics piperacillin/tazobactam, meropenem, and vancomycin were associated with the highest risks. After taking into account length of stay in hospital as possible confounder other potential contact-related risk factors such as previous sonography, radiology, central venous catheter, and endoscopy were not significant. CONCLUSIONS: Previous dialysis and previous antibiotic therapy were identified as independent risk factors for the presence of VRE in surgical inpatients.

Semi-automated contact tracing and management of contact precautions during the COVID-19 pandemic within a tertiary hospital.

Background: Evaluation of a spreadsheet-based COVID-19 contact-tracing tool (CTT) and determination of risk factors for SARS-CoV-2 transmission among hospital staff members. Design: Observational descriptive study on the application and acceptance of the CTT. Retrospective case-control study for SARS-CoV-2 transmission risk factor determination and for evaluation of the CTT's risk stratification algorithm. Setting: Tertiary hospital in Germany. Participants: 3514 contacts of hospital staff members to 322 SARS-CoV-2-positive cases. Methods: A case-control study was performed to identify risk factors for SARS-CoV-2 transmission and for unprotected contacts among staff members. To evaluate strengths and weaknesses of the CTT performance statistics were analyzed and users completed a questionnaire measuring satisfaction and acceptance of the tool. Results: In 2021, the CTT was used for the algorithm-based semi-automated management of 3514 in-hospital contacts. The tool determined the risk category of individual contacts and generated messages for the information of the local public health department, the in-hospital SARS-CoV-2 test center and all staff members who had contact to the index case. Staff members without regular contacts to patients had significantly (P<0.005) more unprotected contacts to other staff members (25.5% vs. 9.6%) and more SARS-CoV-2 transmissions per contact (4.9% vs. 0.6%) than staff members with frequent contacts to patients. The profession "nurse or medical technical service" was associated with significantly (P<0.005) more unprotected contacts between staff members (11.0% vs. 2.6%) compared to the profession "physician". Conclusions: Digital tools can increase the efficiency of in-hospital contact tracing. The CTT enable a timely systematic analysis of risk factors among staff members.

Serratia marcescens outbreak in a neonatal intensive care unit associated with contaminated donor milk.

OBJECTIVE: Investigation of the origin of a Serratia marcescens outbreak in a neonatal intensive care unit. DESIGN: Retrospective case-control study. SETTING: Regional level 3 perinatal center in Germany. PATIENTS: This study included 4 S. marcescens-positive and 19 S. marcescens-negative neonates treated between February 1 and February 26, 2019, in the neonatal intensive care unit. METHODS: A case-control study was performed to identify the source of the outbreak. The molecular investigation of S. marcescens isolates collected during the outbreak was performed using pulsed-field gel electrophoresis and next-generation sequencing. RESULTS: The retrospective case-control study showed a significant correlation (P < .0001) between S. marcensens infection or colonization and consumption of donor milk that had tested negative for pathogenic bacteria from a single breast milk donor. Pulsed-field gel electrophoresis and next-generation sequencing retrospectively confirmed an S. marcescens strain isolated from the breast milk of this donor as the possible origin of the initial outbreak. The outbreak was controlled by the implementation of an infection control bundle including a multidisciplinary infection control team, temporary nutrition of infants with formula only and/or their mother's own milk, repeated screening of all inpatients, strict coat and glove care, process observation, retraining of hand hygiene and continuous monitoring of environmental cleaning procedures. CONCLUSIONS: Low-level contaminated raw donor milk can be a source of infection and colonization of preterm infants with S. marcescens even if it tests negative for bacteria.

[Influence of the COVID-19 pandemic on robotic visceral surgery in Germany]. / Auswirkungen der COVID-19-Pandemie auf die robotische Viszeralchirurgie in Deutschland.

BACKGROUND: Robotic procedures are gaining more and more importance in visceral surgery and seem to develop into an indispensable tool in minimally invasive visceral surgery. In 2020 the COVID-19 pandemic caused unexpected changes in daily surgical routines with still ongoing challenges. We evaluated the impact of the COVID-19 pandemic on robotic visceral procedures and the associated training provided in Germany. MATERIAL AND METHODS: We performed a thorough evaluation of German hospitals and identified 89 surgical departments performing robotic visceral procedures. After extensive topic-related literature search an online questionnaire was developed. It included 35 questions referring to all relevant topics on robotic surgery, such as training programs and influence of the COVID-19 pandemic. The survey was sent via email three times to each department. Descriptive and subgroup analysis were performed. RESULTS: We reported a response to our questionnaire from 22 (24.7%) surgical departments and17 questionnaires were analyzable. The vast majority of them weresurgical departments of university hospitals (58.8%), 17.6% maximum care clinics and 23.5% main care clinics. Robotic procedures were performed for the upper gastrointestinal tract (UGI 88.2%), the hepatopancreaticobiliary system (HPB 82.4%), in the colorectal region (94.1%) and for hernias (35.3%). The relative proportion of robotic operations in comparison to all visceral procedures was between 0.3% and 15.4%. The average conversion rate was 4.6 ± 3.2% referring to 2020. All participating clinics used the robotic DaVinci® system (Intuitive Surgical Inc., CA, USA). In summary 22 robotic systems were used mainly in an interdisciplinary setting (82.4%). For teaching purposes, 7 departments (41.2%) provided a second robotic console. On average 13.2 ± 6.5% of surgeons per clinic were involved in robotic procedures. Defined operating room (OR) teams (82.4%) consisted of consultants, specialists and residents. Team training for surgeons and OR nurses was mainly (52.9%) based on clinic-specific programs. Due to the COVID-19 pandemic the number of robotic procedures decreased in 70.0% of the participating departments compared to 2019 with the highest decline reported during the second quarter of 2020 (64.7%). Referring to this, staff shortage of non-surgical disciplines (anesthesiologists 35.3%, OR nurses 35.3%, intensive care medics 17.6%), COVID-19-specific regulations (58.8%) and limited capacities of intensive and intermediate care (47.1%) were specified as underlying causes. Due to the COVID-19 pandemic, caused by a decline in numbers of robotic procedures, robotic training was paused completely in assistance at the operating table in 23.5% and at the second console in 42.9%. CONCLUSION: Robotic visceral surgery is already implemented with a broad spectrum of operations in many German clinics of different care levels; however, the relative proportion of robotic procedures is low, when compared to the overall caseload of each clinic. Training concepts are heterogeneous and focused on experts. In surgeons with growing experience in robotic surgery, conversion rates are recorded to be very low. There was a negative impact on robotic case numbers and training provided in 2020 caused by the COVID-19 pandemic. Therefore, a further endorsement of robotic training programs and an improvement of training designs seem to be essential tools in order to enforce robotic procedures in visceral surgery.

The Need of Antimicrobial Stewardship in Post-Operative Infectious Complications of Abdominal Surgery.

Background: Post-operative infection is a common complication following abdominal surgery. The two most common infections are secondary peritonitis and surgical site infections, which lead to increased perioperative morbidity, prolonged hospitalization, higher mortality rates, and increased treatment costs. In addition to surgical procedures, treatment is based on effective antibiotic therapy. Due to increasing antimicrobial resistance, the correct use of antimicrobials is becoming more complex. Many initiatives call for the implementation of an antimicrobial stewardship (AMS) programme to optimize anti-infective therapy. The review article summarizes current recommendations in anti-infective therapy of post-operative peritonitis and surgical site infections and highlights the importance of an AMS programme in abdominal surgery. Summary: Larger studies evaluating the benefit of AMS in abdominal surgery are lacking. However, national and international guidelines have formulated appropriate recommendations for the rational use of antibiotics in post-operative peritonitis and surgical site infections. The rate of post-operative infections can be significantly reduced by perioperative antibiotic prophylaxis. The increase in multidrug-resistant bacteria complicates anti-infective therapy for post-operative infections. Analysis of local susceptibility patterns helps choose an adequate empiric therapy. A high rate of extended-spectrum beta-lactamase-producing bacteria may necessitate the use of other reserve antibiotics in addition to carbapenems, which are approved for the treatment of complicated intra-abdominal infections. A key role for the AMS team is the subsequent de-escalation of antibiotic therapy which limits the use of unnecessary broad-spectrum antibiotics. Key Messages: The increase in multidrug-resistant bacteria poses challenges for abdominal surgery. Post-operative infections should be treated by an interdisciplinary team of surgeons and specialists for AMS.

[New Antibiotics for Treatment of Highly Resistant Gram-negative Bacteria]. / Neue Antibiotika für die Therapie von multiresistenten gramnegativen Bakterien.

New ß-lactam/ß-lactamase inhibitor (BLI) combinations (ceftolozan/tazobactam, ceftazidim/avibactam, meropenem/vaborbactam, imipenem/relebactam, aztreonam/avibactam) are the focus of newly approved antibiotics or those currently in advanced clinical testing. In contrast to the BLI currently available, the new inhibitors avibactam, vaborbactam and relebactam are not structurally ß-lactams.The combination with a BLI protects ß-lactam from degradation by broad-spectrum ß-lactamases from gram-negative pathogens. The main indications for the new substances are therefore infections with multi-resistant gram-negative bacteria.In clinical use, it should be noted that the BLI does not close efficacy gaps in the ß-lactam/BLI combination (e.g. no effect of cephalosporin/BLI combinations on anaerobes or enterococci).Cefiderocol is the first representative of the siderophore cephalosporin antibiotic group to enter phase II clinical testing.Eravacyclin (tetracycline derivative) and plazomicin (aminoglycoside) are new non-ß-lactam antibiotics in advanced clinical testing (phase III).In order to maintain the efficacy of new reserve antibiotics for as long as possible, a prescription should only be made if an additional benefit in comparison to established substances has been proven, e.g. by a resistance test.

[Rhinocerebral Mucormycosis]. / Rhinocerebrale Mucormykose.

Mucormycosis is a rare but serious type of fungal infection, which can progress rapidly especially in immunsupressed patients.We report about a 47 year old female patient with ptosis on the left eye. The ophthalmological report offered no further pathologic findings. Diabetes mellitus was known and the blood sugar value was very high.A computed tomography of the paranasal sinuses showed a shadow in the ethmoid bone and in an additonally performed MRI-scan, an increase of orbital fat and an extension of the ocular muscle were visible.As the patient lost her ability o look above, an operation of the paranasal sinus was done.The microbial results revealed a Mucormycosis (Lichtheimia). As the patient went blind in the further course, indication for orbital exenteration on the left side and revision of the paranasal sinus was given. High doses of Liposomal Ampthotericin B and Posaconazol were given and blood sugar was monitored very strictly. MRI-scans revealed a further progression of the infection and required additional surgeries and a dura resection accompanied by complications like recurrent septical episodes, renal insufficiency, a bifrontal epidural hematoma and multiple cerebral microinfarcts that impeded the recovery of our patient in the further course. After 8 months she was able to leave the hospital, an epithesis was adjusted and she is without a relapse for 24 month since the diagnosis.

Management of a cluster of Clostridium difficile infections among patients with osteoarticular infections.

BACKGROUND: Here we describe a cluster of hospital-acquired Clostridium difficile infections (CDI) among 26 patients with osteoarticular infections. The aim of the study was to define the source of C. difficile and to evaluate the impact of general infection control measures and antibiotic stewardship on the incidence of CDI. METHODS: Epidemiological analysis included typing of C. difficile strains and analysis of possible patient to patient transmission. Infection control measures comprised strict isolation of CDI patients, additional hand washings, and intensified environmental cleaning with sporicidal disinfection. In addition an antibiotic stewardship program was implemented in order to prevent the use of CDI high risk antimicrobials such as fluoroquinolones, clindamycin, and cephalosporins. RESULTS: The majority of CDI (n = 15) were caused by C. difficile ribotype 027 (RT027). Most RT027 isolates (n = 9) showed high minimal inhibitory concentrations (MIC) for levofloxacin, clindamycin, and remarkably to rifampicin, which were all used for the treatment of osteoarticular infections. Epidemiological analysis, however, revealed no closer genetic relationship among the majority of RT027 isolates. The incidence of CDI was reduced only when a significant reduction in the use of fluoroquinolones (p = 0.006), third generation cephalosporins (p = 0.015), and clindamycin (p = 0.001) was achieved after implementation of an intensified antibiotic stewardship program which included a systematic review of all antibiotic prescriptions. CONCLUSION: The successful reduction of the CDI incidence demonstrates the importance of antibiotic stewardship programs focused on patients treated for osteoarticular infections.

Prostaglandin E2 from Candida albicans Stimulates the Growth of Staphylococcus aureus in Mixed Biofilms.

BACKGROUND: Previous studies showed that Staphylococcus aureus and Candida albicans interact synergistically in dual species biofilms resulting in enhanced mortality in animal models. METHODOLOGY/PRINCIPAL FINDINGS: The aim of the current study was to test possible candidate molecules which might mediate this synergistic interaction in an in vitro model of mixed biofilms, such as farnesol, tyrosol and prostaglandin (PG) E2. In mono-microbial and dual biofilms of C.albicans wild type strains PGE2 levels between 25 and 250 pg/mL were measured. Similar concentrations of purified PGE2 significantly enhanced S.aureus biofilm formation in a mode comparable to that observed in dual species biofilms. Supernatants of the null mutant deficient in PGE2 production did not stimulate the proliferation of S.aureus and the addition of the cyclooxygenase inhibitor indomethacin blocked the S.aureus biofilm formation in a dose-dependent manner. Additionally, S. aureus biofilm formation was boosted by low and inhibited by high farnesol concentrations. Supernatants of the farnesol-deficient C. albicans ATCC10231 strain significantly enhanced the biofilm formation of S. aureus but at a lower level than the farnesol producer SC5314. However, C. albicans ATCC10231 also produced PGE2 but amounts were significantly lower compared to SC5314. CONCLUSION/SIGNIFICANCE: In conclision, we identified C. albicans PGE2 as a key molecule stimulating the growth and biofilm formation of S. aureus in dual S. aureus/C. albicans biofilms, although C. albicans derived farnesol, but not tyrosol, may also contribute to this effect but to a lesser extent.

Direct disk diffusion test using European Clinical Antimicrobial Susceptibility Testing breakpoints provides reliable results compared with the standard method.

Sepsis represents a life-threatening infection requiring the immediate start of antibacterial treatment to reduce morbidity. Thus, laboratories use direct antimicrobial susceptibility testing (AST) to rapidly generate preliminary results from positive blood cultures. As the direct AST has not yet been published to be evaluated with EUCAST breakpoints, the purpose of the study was to investigate the reliability of the direct agar diffusion test to correctly produce AST results from positive monobacterial blood cultures compared with the VITEK2-based definitive AST, when current EUCAST breakpoints were used. A total of 428 isolates from unselected monobacterial routine blood cultures and 110 challenge strains were included. Direct agar diffusion-based and standard VITEK2-based AST of 2803 bacterium-drug combinations yielded a total clinical category agreement of 95.47% with 1.28% very major errors and 3.42% combined major and minor errors. On the species level, very major errors were observed in the species-drug combinations Enterococcus spp.-high-level gentamicin (10.87%) and Staphylococcus spp.-rifampicin (5%), only. No very major errors occurred with Enterobacteriaceae and Pseudomonas aeruginosa. In most species-drug combinations, the direct agar diffusion test using EUCAST breakpoints precisely predicted the result of the definitive antibiotic susceptibility test and, thus, it can be used to optimize empiric antibiotic therapy until definitive results are available.

Impact of minimal inhibitory concentration breakpoints on local cumulative bacterial susceptibility data and antibiotic consumption.

BACKGROUND: The phenotypic antimicrobial susceptibility testing (AST) of bacteria depends on minimal inhibitory concentration breakpoints issued by national and international breakpoint committees. The current study was performed in order to test the influence of different AST standards on local cumulative AST data and on antibiotic consumption. METHODS: Automated AST was performed with clinical isolates of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus faecalis, and E. faecium. From each species 100 prospectively collected non-duplicate clinical isolates were tested and MIC data were interpreted according to the interpretation standards issued by DIN and EUCAST, respectively. In addition cumulative AST data from clinical isolates and antibiotic consumption were monitored before and after implementation of new EUCAST MIC breakpoints. RESULTS: The susceptibility rate of P. aeruginosa against piperacillin and gentamicin, and of C. freundii against piperacillin/tazobactam increased significantly, whereas the susceptibility rates of E. cloacae, S. marcescens, and M. morganii against ciprofloxacin decreased significantly after switching from DIN to EUCAST MIC breakpoints. These changes in the cumulative antibiotic resistance pattern were reflected by enhanced consumption of piperacillin/tazobactam after implementation of EUCAST MIC breakpoints. CONCLUSIONS: These data show that changes of AST breakpoints have a significant influence on local cumulative AST data and on antibiotic consumption.

Induction of Candida albicans biofilm formation on silver-coated vascular grafts.

OBJECTIVES: Silver exhibits excellent antimicrobial properties and is used to protect medical devices from microbial colonization. Because few data are available on the influence of silver coating of vascular prostheses on Candida biofilm formation, this study aimed to investigate the effect of silver on yeast biofilm formation in an in vitro model. METHODS: Prosthesis material was co-cultivated with two different strains of Candida albicans and the effect of silver on attachment and the growth of biofilms was monitored by microscopy and by quantification of cfu and mitochondrial dehydrogenase activity. RESULTS: Silver collagen-coated vascular prostheses significantly reduced C. albicans biofilm formation in serum-free medium. Paradoxically, in the presence of 50% serum, silver increased the growth of biofilms on silver-containing prostheses 2- to 10-fold compared with silver-free prostheses. Silver ion concentrations between 1.7 and 0.17 mg/L, corresponding roughly to 1/20 to 1/200 of the MIC of silver nitrate, stimulated biofilm formation by C. albicans. CONCLUSIONS: Serum proteins reduced the concentration of silver ions delivered from the surface of vascular prostheses to a subinhibitory level, which stimulated the attachment and biofilm formation of C. albicans on grafts. Silver collagen coating therefore seems to be unsuitable for the prevention of growth of C. albicans on vascular prostheses under physiological conditions.

Taxonomic revision of the African genus Trechosiella Jeannel (Coleoptera: Carabidae: Trechinae).

The genus Trechosiella Jeannel, 1960 (Carabidae: Trechinae) is revised. In addition to the known species T. laetula (Péringuey, 1898), T. scotti (Jeannel, 1937), T. basilewskyi Jeannel, 1960 and T. katicola Jeannel, 1964, T. endroedyyoungai spec. nov., T. oligophthalma spec. nov. and T. scotti swartbergensis subspec. nov. are newly described. Trechosiella laetulaperingueyi (Jeannel, 1926) is recognized as a new synonym of T. laetula sensu stricto. Trechosiella macroptera Casale, 1986 is demoted to become a subspecies of T. scotti, as T scotti macroptera status demotus. An identification key to the known species and subspecies of Trechosiella and a distribution map of the southern African taxa are provided.

Candidiasis caused by Candida kefyr in a neonate: case report.

BACKGROUND: Systemic Candidia infections are of major concern in neonates, especially in those with risk factors such as longer use of broad spectrum antibiotics. Recent studies showed that also term babies with underlying gastrointestinal or urinary tract abnormalities are much more prone to systemic Candida infection. We report a very rare case of candidiasis caused by Candida kefyr in a term neonate. CASE PRESENTATION: Renal agenesis on the left side was diagnosed antenatally and anal atresia postnatally. Moreover, a vesico-ureteral-reflux (VUR) grade V was detected by cystography. The first surgical procedure, creating a protective colostoma, was uneventful. Afterwards our patient developed urosepsis caused by Enterococcus faecalis and was treated with piperacillin. The child improved initially, but deteriorated again. A further urine analysis revealed Candida kefyr in a significant number. As antibiotic resistance data about this non-albicans Candida species are limited, we started liposomal amphotericin B (AMB), but later changed to fluconazole after receiving the antibiogram. Candiduria persisted and abdominal imaging showed a Candida pyelonephritis. Since high grade reflux was prevalent we instilled AMB into the child's bladder as a therapeutic approach. While undergoing surgery (creating a neo-rectum) a recto-vesical fistula could be shown and subsequently was resected. The child recovered completely under systemic fluconazole therapy over 3 months. CONCLUSIONS: Candidiasis is still of major concern in neonates with accompanying risk factors. As clinicians are confronted with an increasing number of non-albicans Candida species, knowledge about these pathogens and their sensitivities is of major importance.

Linkage of bacterial protein synthesis and presentation of MHC class I-restricted Listeria monocytogenes-derived antigenic peptides.

The processing and MHC class I-restricted presentation of antigenic peptides derived from the p60 protein of the facultative intracellular bacterium Listeria monocytogenes is tightly linked to bacterial protein synthesis. We used non-linear regression analysis to fit a mathematical model of bacterial antigen processing to a published experimental data set showing the accumulation and decay of p60-derived antigenic peptides in L. monocytogenes-infected cells. Two alternative models equally describe the experimental data. The simulation accounting for a stable and a hypothetical rapidly degraded form of antigen predicts that the antigenic peptides p60 217-225 and p60 449-457 are derived from a putative instable form of p60 with an average intracellular half-life of approximately 3 minutes accounting for approximately 31% of all p60 molecules synthesized. The alternative model predicts that both antigenic peptides are processed from p60 degraded intracellularly with a half-life of 109 min and that antigen processing only occurs as long as bacterial protein synthesis is not inhibited. In order to decide between both models the intracellular accumulation of p60 in infected cells was studied experimentally and compared with model predictions. Inhibition of p60 degradation by the proteasome inhibitor epoxomicin revealed that during the first 3 h post infection approximately 30% of synthesized p60 molecules were degraded. This value is significantly lower than the approximately 50% degradation of p60 that would be expected in the presence of the predicted putative short-lived state of p60 and also fits precisely with the predictions of the alternative model, indicating that the tight connection of bacterial protein biosynthesis and antigen processing and presentation of L. monocyctogenes-derived antigenic peptides is not caused by the presence of a highly instable antigenic substrate.

Pseudomonas aeruginosa outbreak in a pediatric oncology care unit caused by an errant water jet into contaminated siphons.

We analyzed an outbreak of invasive infections with an exotoxin U positive Pseudomonas aeruginosa strain within a pediatric oncology care unit. Environmental sampling and molecular characterization of the Pseudomonas aeruginosa strains led to identification of the outbreak source. An errant water jet into the sink within patient rooms was observed. Optimized outbreak management resulted in an abundance of further Pseudomonas aeruginosa infections within the pediatric oncology care unit.

Production of prostaglandins, isoprostanes and thromboxane by Aspergillus fumigatus: identification by gas chromatography-tandem mass spectrometry and quantification by enzyme immunoassay.

Aspergillus fumigatus has been reported to produce prostaglandin (PG)-like substances. The molecular structure of these fungal eicosanoids is however still unknown. By using the gas chromatography-tandem mass spectrometry (GC-MS/MS) methodology we identified a number of eicosanoids that were formed upon incubation of the precursor arachidonic acid ethyl ester (AAE, 10 µM) with three strains of A. fumigatus. The eicosanoids identified include the prostaglandins (PG) PGE(2), 6-keto-PGF(1α) (the stable hydrolysis product of prostacyclin PGI(2)) and PGF(2α), the isoprostanes 15(S)-8-iso-PGF(2α) and 15(S)-8-iso-PGE(2), and thromboxane B(2) (TxB(2), the stable hydrolysis product of TxA(2)). These eicosanoids are identical with those produced by cyclooxygenases (COX) in humans. The biosynthesis of all of these eicosanoids could not be inhibited by the human COX inhibitors indomethacin (100 µM), acetylsalicylic acid (100 µM) or the non-selective human lipoxygenase (LOX) inhibitor nordihydroguaiaretic acid (100 µM). By contrast, the selen-containing antioxidant ebselen (100 µM) was found to inhibit their synthesis. Our results suggest that mammals and fungi employ different eicosanoid biosynthesis pathways. As some of the detected eicosanoids are potent immunomodulators and bronchoconstrictors, they could play a possible role in pulmonary diseases associated with A. fumigatus infection.