Bacterial contamination of automated MRI contrast injectors in clinical routine.

Aim: To quantify the frequency of bacterial contamination of the injected contrast agent/saline solution by an automated contrast injection system, and to evaluate whether usage of a novel tube system can reduce it. Methods: For bacterial contamination quantification two identical automated piston pump MRI contrast injectors were used in combination with a standard tube system. 3-5 ml of the contrast agent/saline solution was collected from the system prior to its connection to the patients' venous cannula in 104 consecutive patients. To test, whether a novel tube system reduces contamination, a tube system with shielded screw connections was used with the same contrast injectors and contrast agent/saline samples were collected in further 101 patients. Specimens were microbiologically analyzed. Frequencies of contamination were compared using Fisher exact test. Results: With the standard tube system, bacterial contamination was observed in 5.8% (6 out of 104 specimens). With the novel tube system, contamination was observed in 2.0% (2 out of 101 specimens, p=0.280). Staphylococcus epidermidis was the most common germ (5 cases) followed by Micrococcus luteus (2 cases) and Oligella ureolytica (1 case). Conclusion: Bacterial contaminations of MRI contrast injectors occurred in a non-negligible frequency especially with S. epidermidis. A trend towards reduced bacterial contamination was seen when a novel tube system with shielded screw connections was used.

Microbiological contamination of ear, nose and throat (ENT) units.

Aim: In ENT (Ear, Nose and Throat) treatment units, medical devices for examination are commonly stored on open trays. The aim of this study is to investigate whether open storage is a relevant cause for microbiological contamination of ENT instruments during a working day. Methods: Qualitative and quantitative tests, such as imprints and swabs, were performed on the instruments and the surfaces of the treatment units in an ENT outpatient clinic at the beginning and at the end of consultation hours. The microbiological analysis of the samples focused on potential pathogens, e.g., Staphylococcus aureus or Pseudomonas aeruginosa, bacteria of skin and oral microbiota, as well as the number of colony forming units (CFU). The samples were collected at three distinct ENT treatment units over five working days. Results: The samples taken at the beginning of consultation hours showed a low number of CFU and no pathogens. Overall, 5% of the instruments were contaminated with bacteria of skin microbiota. At the end of a working day, this rate increased significantly to 17.5% (p<0.01). At the beginning of the working day, the mean number on the instrument trays was 4 CFU/25 cm², which increased to 34 CFU/25 cm² at the end of the working day. In some cases of the imprints taken at the end of the working day showed that a bacterial lawn had formed. In two cases, the pathogens Ralstonia picketii and Enterobacter cloacae were detected; in another case Bacillus spp. was identified. The contamination of ENT instruments and the ENT treatment unit increased significantly (p<0.01) over the duration of consultation hours. Conclusion: The results show that the current hygiene requirements for storage und reprocessing are not sufficient to conform to the mandatory guidelines of the German Commission on Hospital Hygiene and Infection Prevention. Although we could not find a pressing risk for the patients, we also cannot exclude it in the long term. Thus, new concepts are needed.

Antiretroviral therapy suppresses rectal HIV-RNA shedding despite inflammation in MSM with rectal C. trachomatis and N. gonorrhoeae infections-a cross-sectional, single-center study.

OBJECTIVES: Rectal infections with Chlamydia trachomatis and/or Neisseria gonorrhoeae (CT/NG) are common in men who have sex with men (MSM) and are linked to HIV transmission. However, rectal CT/NG infections are often asymptomatic and it is not known how they contribute to HIV transmission. We assessed clinical and cytological signs of inflammation as well as rectal HIV-RNA in HIV-infected MSM with and without CT/NG infection. METHODS: 112 HIV-positive MSM with or without rectal symptoms and with or without antiretroviral therapy who underwent high-resolution anoscopy (HRA) at the proctological outpatient centre of the University Hospital Essen, Germany, between November 2013 and February 2014 were included in this cross-sectional study. During the examination, rectal swabs for the assessment of CT/NG, HIV-RNA and inflammatory cells (granulocytes, lymphocytes, histiocytes) were collected. 110 patients were assessed according to the study protocol, and no imputation of missing data was performed. RESULTS: Rectal infections with CT or NG were detected in 17 participants, and 4 participants were coinfected. Only symptomatic CT/NG infections (8/17) showed signs of inflammation in HRA. Symptomatic CT/NG infections were also associated with the detection of lymphocytes and histiocytes in rectal cytology (both P<0.001). In contrast, asymptomatic CT/NG infections neither resulted in clinical nor cytological signs of inflammation. Rectal HIV-RNA was undetectable in all participants with rectal CT/NG infections who received combined antiretroviral therapy (ART) when plasma HIV-RNA was below the limit of detection (n=13). Besides rectal CT/NG infections, syphilis (n=4) and HPV-associated lesions (n=37) were frequently detected, and proctological symptoms were associated with simultaneous infection with ≥2 STDs. CONCLUSIONS: Only symptomatic but not asymptomatic rectal infections with CT and/or NG were associated with clinical and cytological signs of inflammation. Rectal HIV shedding was not promoted by CT/NG infections in patients receiving ART with suppressed plasma HIV-RNA. TRIAL REGISTRATION NUMBER: UTN: U1111-1150-4804. German Clinical Trials Register (DRKS): DRKS00005468.

Monitoring of endoscope reprocessing with an adenosine triphosphate (ATP) bioluminescence method.

Background: The arising challenges over endoscope reprocessing quality proposes to look for possibilities to measure and control the process of endoscope reprocessing. Aim: The goal of this study was to evaluate the feasibility of monitoring endoscope reprocessing with an adenosine triphosphate (ATP) based bioluminescence system. Methods: 60 samples of eight gastroscopes have been assessed from routine clinical use in a major university hospital in Germany. Endoscopes have been assessed with an ATP system and microbial cultures at different timepoints during the reprocessing. Findings: After the bedside flush the mean ATP level in relative light units (RLU) was 19,437 RLU, after the manual cleaning 667 RLU and after the automated endoscope reprocessor (AER) 227 RLU. After the manual cleaning the mean total viable count (TVC) per endoscope was 15.3 CFU/10 ml, and after the AER 5.7 CFU/10 ml. Our results show that there are reprocessing cycles which are not able to clean a patient used endoscope. Conclusion: Our data suggest that monitoring of flexible endoscope with ATP can identify a number of different influence factors, like the endoscope condition and the endoscopic procedure, or especially the quality of the bedside flush and manual cleaning before the AER. More process control is one option to identify and improve influence factors to finally increase the overall reprocessing quality, best of all by different methods. ATP measurement seems to be a valid technique that allows an immediate repeat of the manual cleaning if the ATP results after manual cleaning exceed the established cutoff of 200 RLU.

Spectrum of pathogens in native liver, bile, and blood during pediatric liver transplantation.

During LTX, there may be a risk that pathogens of the native liver are released into the systemic circulation. No investigations on incidence/spectrum of pathogens in native livers have been published. We hypothesized that pathogens are found in the native liver of a large proportion of pediatric patients during LTX and investigated the microbiology of native livers. These data may help optimize antibiotic therapy. Twenty-two consecutive pediatric patients (median age 14 months, range, 5 months-15 yr) receiving LTX in our department from October 2010 to October 2011 were included in this prospective study. Tissue and bile were collected from the explanted liver and were cultivated on different media. All liver tissues were investigated using a broad-range PCR (SepsiTest(®)). In 16 patients, blood cultures were collected post-transplantation. Eleven patients (50%) had at least one pathogen detected; nine of these patients had an underlying diagnosis of biliary atresia. SepsiTest(®) was positive in seven patients. In four patients it was the only test detecting any pathogen. In detail, the positivity rate for liver tissue in all patients was 41% (n = 9); for bile 25% (n = 3); and for blood 25% (n = 4). Thirteen different pathogens (69% bacterial, 31% fungal) were isolated. A highly-sensitive broad-range PCR appears to be an effective method to detect pathogens in native livers of patients undergoing LTX. A high number and variety of microbes, including a high proportion of fungal pathogens, were detected.

Latent Toxoplasma gondii infection leads to improved action control.

The parasite Toxoplasma gondii has been found to manipulate the behavior of its secondary hosts to increase its own dissemination which is commonly believed to be to the detriment of the host (manipulation hypothesis). The manipulation correlates with an up-regulation of dopaminergic neurotransmission. In humans, different pathologies have been associated with T. gondii infections but most latently infected humans do not seem to display overt impairments. Since a dopamine plus does not necessarily bear exclusively negative consequences in humans, we investigated potential positive consequences of latent toxoplasmosis (and the presumed boosting of dopaminergic neurotransmission) on human cognition and behavior. For this purpose, we focused on action cascading which has been shown to be modulated by dopamine. Based on behavioral and neurophysiological (EEG) data obtained by means of a stop-change paradigm, we were able to demonstrate that healthy young humans can actually benefit from latent T. gondii infection as regards their performance in this task (as indicated by faster response times and a smaller P3 component). The data shows that a latent infection which is assumed to affect the dopaminergic system can lead to paradoxical improvements of cognitive control processes in humans.