N-chlorotaurine, a potent weapon against multiresistant bacteria.

AIMS: N-chlorotaurine (NCT) is a body-own mild oxidizing antiseptic that can be applied topically as a well-tolerated anti-infective at many body sites. The objective of this study was to demonstrate its activity against representative nosocomial multidrug-resistant bacteria. METHODS AND RESULTS: The bactericidal activity of NCT was tested in quantitative killing assays against a panel of multiresistant Gram-positive and Gram-negative clinical isolates. N-chlorotaurine (1%, 55 mmol l-1 ) reduced the number of CFU of strains of methicillin-resistant Staphylococcus aureus, linezolid-resistant Staphylococcus epidermidis, vancomycin-resistant, and linezolid- and vancomycin-resistant Enterococcus faecium, 3MRGN and 4MRGN Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae by at least 2 log10 steps after 15 min and completely or nearly to the detection limit after 30 min at pH 7·1 and 37°C. CONCLUSION: The activity of NCT against these clinical isolates is similar to that against non-resistant ATCC strains and therefore not influenced by antibiotic resistance. This can be explained by the oxidizing and chlorinating mechanism of action of NCT, which leads to an attack of multiple targets in the microorganisms. SIGNIFICANCE AND IMPACT OF THE STUDY: The bactericidal spectrum of NCT is not restricted by resistance against antibiotics. Therefore, it can be used against resistant strains, too.

The correct blood volume for paediatric blood cultures: a conundrum?

BACKGROUND: Bloodstream infections (BSIs) are a major cause of morbidity and mortality in paediatric patients. For fast and accurate diagnosis, blood culture (BC) is the reference standard. However, the procedure for blood sampling in paediatric patients, particularly the optimal blood volume, is the subject of controversy stemming from a lack of knowledge of the bacterial load and because of several obstacles such as low intravascular volume and the risk of causing anaemia. AIMS: The aim of this narrative review is to summarize current knowledge on blood sampling in paediatric patients for BC purposes, in particular blood volume and number and type of BC bottles needed for reasonable future guidelines/recommendations. SOURCES: A comprehensive literature search of PubMed, including all publications in English, was performed in June 2019 using the search terms 'blood culture', 'blood volume', 'bloodstream infection', 'diagnostic', 'paediatric' and/or 'sepsis'. CONTENT: The amount of inoculated blood determines the sensitivity, specificity and time to positivity of a BC, and low-level bacteraemia (≤10 cfu/mL) in paediatric patients is presumed to be more common than reported. Current approaches for 'adequate' blood volume for paediatric BC are mainly weight- or age-dependent. Of these recommendations, the scheme devised by Gaur and colleagues seems most appropriate and calls for a sample of 1-1.5 mL for children weighing <11 kg and 7.5 mL for a patient weight of 11-17 kg to be drawn into one BC bottle. Inclusion of a more detailed grading in the weight range 4-14 kg, as published by Gonsalves and colleagues, might be useful. IMPLICATIONS: This review could be important for future guidelines on paediatric BC collection and thus could contribute to improving patient management and lowering the economic and global health burden associated with BSI. Furthermore, upcoming molecular-based approaches with low sample volumes might be an interesting alternative.

High-quality endoscope reprocessing decreases endoscope contamination.

OBJECTIVES: Several outbreaks of severe infections due to contamination of gastrointestinal (GI) endoscopes, mainly duodenoscopes, have been described. The rate of microbial endoscope contamination varies dramatically in literature. The aim of this multicentre prospective study was to evaluate the hygiene quality of endoscopes and automated endoscope reprocessors (AERs) in Tyrol/Austria. METHODS: In 2015 and 2016, a total of 463 GI endoscopes and 105 AERs from 29 endoscopy centres were analysed by a routine (R) and a combined routine and advanced (CRA) sampling procedure and investigated for microbial contamination by culture-based and molecular-based analyses. RESULTS: The contamination rate of GI endoscopes was 1.3%-4.6% according to the national guideline, suggesting that 1.3-4.6 patients out of 100 could have had contacts with hygiene-relevant microorganisms through an endoscopic intervention. Comparison of R and CRA sampling showed 1.8% of R versus 4.6% of CRA failing the acceptance criteria in phase I and 1.3% of R versus 3.0% of CRA samples failing in phase II. The most commonly identified indicator organism was Pseudomonas spp., mainly Pseudomonas oleovorans. None of the tested viruses were detected in 40 samples. While AERs in phase I failed (n = 9, 17.6%) mainly due to technical faults, phase II revealed lapses (n = 6, 11.5%) only on account of microbial contamination of the last rinsing water, mainly with Pseudomonas spp. CONCLUSIONS: In the present study the contamination rate of endoscopes was low compared with results from other European countries, possibly due to the high quality of endoscope reprocessing, drying and storage.

How to: identify non-tuberculous Mycobacterium species using MALDI-TOF mass spectrometry.

BACKGROUND: The implementation of MALDI-TOF MS for microorganism identification has changed the routine of the microbiology laboratories as we knew it. Most microorganisms can now be reliably identified within minutes using this inexpensive, user-friendly methodology. However, its application in the identification of mycobacteria isolates has been hampered by the structure of their cell wall. Improvements in the sample processing method and in the available database have proved key factors for the rapid and reliable identification of non-tuberculous mycobacteria isolates using MALDI-TOF MS. AIMS: The main objective is to provide information about the proceedings for the identification of non-tuberculous isolates using MALDI-TOF MS and to review different sample processing methods, available databases, and the interpretation of the results. SOURCES: Results from relevant studies on the use of the available MALDI-TOF MS instruments, the implementation of innovative sample processing methods, or the implementation of improved databases are discussed. CONTENT: Insight about the methodology required for reliable identification of non-tuberculous mycobacteria and its implementation in the microbiology laboratory routine is provided. IMPLICATIONS: Microbiology laboratories where MALDI-TOF MS is available can benefit from its capacity to identify most clinically interesting non-tuberculous mycobacteria in a rapid, reliable, and inexpensive manner.

Cross-sectional point prevalence survey to study the environmental contamination of nosocomial pathogens in intensive care units under real-life conditions.

BACKGROUND: In intensive care units (ICUs), inanimate surfaces and equipment may be contaminated by nosocomial pathogens, including multi-drug-resistant micro-organisms. AIMS: To assess the degree of environmental contamination close to and distant from patients, and contamination of healthcare workers' (HCWs) hands with nosocomial pathogens under real-life conditions and to investigate potential transmission events. METHODS: Over the course of three weeks, agar contact samples were taken close to and distant from patient areas and from HCWs' hands in eight ICUs of a tertiary care hospital in Innsbruck, Austria. Each ICU was visited once without announcement. Species identification and antimicrobial susceptibility testing were performed according to standard methods, and corresponding strains from patient, environment and hand samples were genotyped using pulsed-field gel electrophoresis. FINDINGS: Among 523 samples, HCWs' hands were most frequently contaminated with potentially pathogenic bacteria (15.2%), followed by areas close to patients (10.9%) and areas distant from patients (9.1%). Gram-positive bacteria were identified most often (67.8%), with Enterococcus spp. being the most prevalent species (70% vancomycin sensitive and 30% vancomycin resistant) followed by Staphylococcus aureus, of which 64% were classified as meticillin-resistant Staphylococcus aureus. Molecular typing documented identical strains among patient, environment and hand isolates. CONCLUSION: This study found widespread contamination of the ICU environment with clinically relevant pathogens, including multi-drug-resistant micro-organisms, despite cleaning and disinfection. The bioburden might not be restricted to areas close to patients. The role of extended environmental disinfection of areas distant from patients in order to improve infection prevention needs further discussion.

Mammary candidiasis: molecular-based detection of Candida species in human milk samples.

In this prospective and monocentric study, we investigated the performance of a commercialized real-time polymerase chain reaction (RT-PCR) test system for the specific detection of DNA from Candida albicans, C. dubliniensis, C. glabrata, C. krusei, C. lusitaniae, C. parapsilosis, and C. tropicalis in human milk samples of patients suspicious of mammary candidiasis. For this purpose, 43 breast-feeding women with characteristic symptoms of mammary candidiasis and 40 asymptomatic controls were enrolled. By culture, Candida spp. were detected in 8.8 % (4/46) and 9.3 % (4/43) of patient and control samples, respectively. Candida albicans (2/46), C. parapsilosis (1/46), and C. guilliermondii (1/46) were present in patient samples, and C. lusitaniae (3/43) and C. guilliermondii (1/43) were present in the controls. After RT-PCR was applied, Candida spp. were found to be present in 67.4 % (31/46) and 79.1 % (34/43) of patient and control samples investigated, respectively. PCR detection of C. albicans and C. parapsilosis revealed only a low sensitivity and specificity of 67.4 % and 41.9 %, respectively. Our data do not support the use of Candida RT-PCR for sensitive and specific diagnosis of mammary candidiasis.

Comparison of the BD MAX® Enteric Bacterial Panel assay with conventional diagnostic procedures in diarrheal stool samples.

Although infectious diarrhea is one of the most predominant diseases around the world, the identification of the causative microorganism is still challenging. The aim of this study was the evaluation of the BD MAX® Enteric Bacterial Panel assay in comparison to conventional diagnostic procedures concerning the detection of the enteric pathogens Salmonella spp., Campylobacter spp., Shigella spp., and Shiga toxin-producing Escherichia coli. For this purpose, 971 prospectively collected stool samples were evaluated. Utilization of the BD MAX Enteric Bacterial Panel elevated the overall detection rate from 5.26 % to 8.06 %. The positive percent agreement of the BD MAX Enteric Bacterial Panel assay and stool culture or enzyme immunoassay was 0.97 for Campylobacter spp., 0.75 for Salmonella spp., 1.00 for Shigella spp., and 0.88 for Shiga toxins. Furthermore, a negative percent agreement of 0.98 for Campylobacter spp., 0.99 for Salmonella spp., 0.99 for Shigella spp., and 0.99 for Shiga toxins has been demonstrated. This study highlighted the superior detection rate of molecular assays compared to conventional diagnostic procedures.

Genetic Geostatistical Framework for Spatial Analysis of Fine-Scale Genetic Heterogeneity in Modern Populations: Results from the KORA Study.

Aiming to investigate fine-scale patterns of genetic heterogeneity in modern humans from a geographic perspective, a genetic geostatistical approach framed within a geographic information system is presented. A sample collected for prospective studies in a small area of southern Germany was analyzed. None indication of genetic heterogeneity was detected in previous analysis. Socio-demographic and genotypic data of German citizens were analyzed (212 SNPs; n = 728). Genetic heterogeneity was evaluated with observed heterozygosity (H O ). Best-fitting spatial autoregressive models were identified, using socio-demographic variables as covariates. Spatial analysis included surface interpolation and geostatistics of observed and predicted patterns. Prediction accuracy was quantified. Spatial autocorrelation was detected for both socio-demographic and genetic variables. Augsburg City and eastern suburban areas showed higher H O values. The selected model gave best predictions in suburban areas. Fine-scale patterns of genetic heterogeneity were observed. In accordance to literature, more urbanized areas showed higher levels of admixture. This approach showed efficacy for detecting and analyzing subtle patterns of genetic heterogeneity within small areas. It is scalable in number of loci, even up to whole-genome analysis. It may be suggested that this approach may be applicable to investigate the underlying genetic history that is, at least partially, embedded in geographic data.

Treatment costs and quality of life of patients with peripheral arterial occlusive disease--the German perspective.

BACKGROUND: To objectify the debate about the restricted resources of the health system, examinations about the treatment costs and quality of life implications of different illnesses are necessary. The aims of the examination were the quantification of costs that are caused by a patient with PAD per year and the determination of the quality of life. PATIENTS AND METHODS: 280 patients (mean 66.6 years) in Fontaine stages II to IV were included in the study to determine their treatment costs for the year 2001 retrospectively from patient records. Health-related quality of life was recorded through the standardized questionnaires PAVK-86, SF-36 and EQ-5D. RESULTS: A patient with PAD in stage Ila costs on average 1792.45 Euros, in stage IIb 2551.28 Euros, in stage III 4356.48 Euros and in stage IV 6225.89 Euros. The costs of the in-hospital treatment dominated the total result on average with 44.4% of the direct costs. Further cost factors were the drugs with 33.4%, the out-patient medical treatment with 9.9%, the expenditures for care with 6.7%, rehabilitation with 3.6% and adjuvants with a share of 1.9%. The indirect costs played a subordinate role with 9.67% of the total costs. The quality of life was clearly restricted in all stages of the PAD. The quality of life especially was strongly decreased from the Fontaine stage IIb on. The problems were mainly in the areas of the physicalfunctions and pain. CONCLUSION: The study showed that the treatment of patients with PAD is very cost-intensive and that patients have to suffer from a considerable loss of quality of life.

Expression of multiple cytochrome p450 enzymes and multidrug resistance-associated transport proteins in human skin keratinocytes.

Cytochrome P450 enzymes metabolize various endogenous and exogenous small molecular weight compounds. Transport-associated proteins, such as P-glycoprotein, multidrug resistance-associated protein and lung resistance protein are overexpressed in drug-resistant cell lines, as well as in human tumors from various histologic origins, including malignant melanoma. Little is known about the expression and function of cytochrome enzymes and multidrug resistance-associated transport proteins in human skin; therefore, the aim of this study was to analyze the expression pattern of cytochrome enzymes and multidrug resistance-associated transport proteins in proliferating human epidermal keratinocytes under constitutive conditions and after induction with various inducers. Reverse transcription-polymerase chain reaction revealed constitutive expression of cytochromes 1A1, 1B1, 2B6, 2E1, and 3A5 in keratinocytes and showed expression of cytochrome 3A4 after incubation with dexamethasone. The expression of cytochrome 1A1 was enhanced on the mRNA level after induction with benzanthracene. Reverse transcription-polymerase chain reaction analysis of the multidrug resistance-associated transport proteins revealed constitutive expression of multidrug resistance-associated proteins 1 and 3-6, and lung resistance protein in human epithelial keratinocytes and was negative for multidrug resistance 1 and 2. Expression of 1 was seen after induction with dexamethasone. Reverse transcription-polymerase chain reaction results were confirmed by immunoblots which showed expression of cytochromes 1A1, 2B6, 2E1, and 3A, multidrug resistance-associated proteins 1, 3, and 5 as well as multidrug resistance 1 after induction with dexamethasone. Immunohistology showed positive immunofluorescence in skin specimens for cytochromes 1A1, 2B6, 2E1, and 3A and multidrug resistance-associated protein 1 and multidrug resistance 1. Constitutive activity of cytochrome 1A1, 2B, 2E1, and 3A enzymes was measured by catalytic assays. These results show that keratinocytes of the human skin express various transport-associated enzymes and detoxifying metabolic enzymes. Previous studies have revealed that cytochrome enzymes and transport-associated proteins play complementary parts in drug disposition by biotransformation (phase I) and anti-transport (phase III) and act synergistically as a drug bioavailability barrier.

The influence of systemic growth hormone administration on the healing time of skin graft donor sites in a pig model.

A more rapid healing of skin graft donor sites has often been observed during ultimoratio therapies with growth hormone in adults who have suffered extremely severe burns. The purpose of this animal experimental study was to examine the influence of systemic growth hormone administration on the healing time of skin graft donor sites under standardized conditions in pigs. The animals were 14 (7 experimental and 7 control) male, sexually mature, German domestic pigs, in which 30 skin graft donor sites 8 cm x 4 cm and 0.6 mm deep were created. Fifteen each of the skin graft donor sites were bandaged with the same material [hydrocolloid bandage (Varihaesive E) and PVP-iodine gauze (Braunovidon Gaze)]. The test period was 15 days for each pig, whereby recombinant growth hormone (0.5 IU/kg body weight per day) was applied subcutaneously in the experimental group. The bandages were changed under brief narcosis every 2 days, during which one skin-punch biopsy was taken per skin graft donor site, and blood samples were drawn for determination of the serum IGF-1 values. Photographic documentation was also recorded. The biopsies were examined histologically (hematoxylin and eosin stain) and immunohistochemically (collagen IV and VII, and laminin), whereby histologically the start of keratinization was assessed as a healing criterion. The serum IGF-1 values in the growth hormone group were statistically significantly higher than in the control group. Immunohistochemically, a complete basal membrane was observed in both the experimental and the control group after the 7th or 8th day. A clearly elevated serum IGF-1 level correlated in the growth hormone group with the skin graft donor sites healing. It could thus be demonstrated both clinically and histologically that systemic application of growth hormone results in a statistically significantly more rapid healing of the skin graft donor sites by 2 days earlier than in the control group.

[Preliminary studies of the immunization of shrimp (Penaeus monodon) against vibrio infections]. / Vorversuche zur Immunisierung von Garnelen (Penaeus monodon) gegen Vibrioneninfektionen.

There is a great demand for an applicable vaccine against bacterial infections of prawns, especially Vibriosis. The results of the tests that had been carried out can be evaluated as promising and indicate that the vaccination of prawns against bacterial diseases is possible. Nevertheless it is still necessary to increase the scale of research on this subject, above all, the basics of the immuno-system of prawns. Adult prawns should be vaccinated to check if they are able to pass their immuno-protection to their progeny. If that is the case only a few breeding animals have to be vaccinated, instead of all the larvae. Actually the prophylactic application of antibiotics is the only method to prevent infections with Vibriosis. 100-150 mg of Oxytetracycline per kg of prawns are fed during one production period and these antibiotics are also used in humans. Assuming that the average amount of harvested prawns per production unit is 8-10 metric tons/pond (1 ha). 800-1500 g of antibiotics are used. Since different pathogenic strains have developed resistance to Oxytetracycline, also other kinds of antibiotics (for example oxolinic acid) are given today. Antibiotics are often fed until harvesting, however, there are laws which prohibit use to antibiotics during the last thirty days before harvesting, to prevent residues in the prawn body. A vaccine against bacterial diseases could decrease the production costs and reduce the amount of the applied antibiotics.