Spectrum of enteropathogens detected by the FilmArray GI Panel in a multicentre study of community-acquired gastroenteritis.

The European, multicentre, quarterly point-prevalence study of community-acquired diarrhoea (EUCODI) analysed stool samples received at ten participating clinical microbiology laboratories (Austria, Finland, France, Germany, Greece, Ireland, Italy, Portugal, Romania, and the UK) in 2014. On four specified days, each local laboratory submitted samples from ≤20 consecutive patients to the Austrian Study Centre for further testing with the FilmArray GI Panel (BioFire Diagnostics, Salt Lake City, UT, USA). Of the 709 samples from as many patients received, 325 (45.8%) tested negative, 268 (37.8%) yielded only one organism, and 116 (16.4%) yielded multiple organisms. Positivity rates ranged from 41% (30 of 73 samples) in France to 74% (59 of 80 samples) in Romania. With the exception of Entamoeba histolytica and Vibrio cholerae, all of the 22 targeted pathogens were detected at least once. Enteropathogenic Escherichia coli, Campylobacter species, toxigenic Clostridium difficile, enteroaggregative E. coli, norovirus and enterotoxigenic E. coli were the six most commonly detected pathogens. When tested according to local protocols, seven of 128 positive samples (5.5%) yielded multiple organisms. Overall, the FilmArray GI Panel detected at least one organism in 54.2% (384/709) of the samples, as compared with 18.1% (128/709) when testing was performed with conventional techniques locally. This underlines the considerable potential of multiplex PCR to improve routine stool diagnostics in community-acquired diarrhoea. Classic culture methods directed at the isolation of specific pathogens are increasingly becoming second-line tools, being deployed when rapid molecular tests give positive results. This optimizes the yield from stool examinations and dramatically improves the timeliness of diagnosis.

Pseudomonas aeruginosa: a formidable and ever-present adversary.

Pseudomonas aeruginosa is a versatile pathogen associated with a broad spectrum of infections in humans. In healthcare settings the bacterium is an important cause of infection in vulnerable individuals including those with burns or neutropenia or receiving intensive care. In these groups morbidity and mortality attributable to P. aeruginosa infection can be high. Management of infections is difficult as P. aeruginosa is inherently resistant to many antimicrobials. Furthermore, treatment is being rendered increasingly problematic due to the emergence and spread of resistance to the few agents that remain as therapeutic options. A notable recent development is the acquisition of carbapenemases by some strains of P. aeruginosa. Given these challenges, it would seem reasonable to identify strategies that would prevent acquisition of the bacterium by hospitalised patients. Environmental reservoirs of P. aeruginosa are readily identifiable, and there are numerous reports of outbreaks that have been attributed to an environmental source; however, the role of such sources in sporadic pseudomonal infection is less well understood. Nevertheless there is emerging evidence from prospective studies to suggest that environmental sources, especially water, may have significance in the epidemiology of sporadic P. aeruginosa infections in hospital settings, including intensive care units. A better understanding of the role of environmental reservoirs in pseudomonal infection will permit the development of new strategies and refinement of existing approaches to interrupt transmission from these sources to patients.

Case report: Rhodococcus erythropolis osteomyelitis in the toe.

The Rhodococcus species rarely cause musculoskeletal infections, with only two cases reported in the literature. We report the case of a 53-year-old woman who had an infection develop after first metatarsophalangeal joint fusion. A year after surgery, she continued to have pain and swelling with nonunion. She underwent revision of the arthrodesis and tissue samples from surgery revealed Rhodococcus erythropolis. The patient's symptoms improved with oral antibiotics. One year after the revision surgery, the fusion had united. We believe this is the first report of a case of a musculoskeletal infection caused by Rhodococcus erythropolis.

A new tool for the management of infection in patients with febrile neutropenia.

BACKGROUND: We describe a novel analytical technique for determining instantaneous trends in body temperature data, which may assist clinicians in optimizing antimicrobial therapy in patients with febrile neutropenia. The paper presents a new algorithm, based on a modified second backward difference (M2BD) matrix filter for monitoring temperature response to anti-microbial chemotherapies in neutropenic patients and develops techniques for extracting accurate, instantaneous trend data from clinical time series data. Such an algorithm is needed because it is difficult to assess patient wellbeing in those who are neutropenic. Temperature data, a key indicator of response to antimicrobial therapy, are typically very noisy, with many fluctuations, making it very difficult to identify underlying trends in real time. Clinicians are therefore forced to make important decisions concerning drug therapy on imperfect data. METHODS: In order to determine the underlying temperature trend, analysis of synthetic time series data (with a known underlying trend) was undertaken using both the CUSUM technique and the M2BD matrix filter. The CUSUM analysis was undertaken using four reference temperatures, 37.5 degrees C, 38.0 degrees C, 38.5 degrees C and 39.0 degrees C. A validation study was also undertaken using four sets of noisy synthetic temperature data to evaluate the performance of the M2BD filter. The M2BD filter was then used to analyse anonymized serial temperature data from a neutropenic patient undergoing chemotherapy. RESULTS: For all four reference temperatures the CUSUM analysis failed to predict the underlying temperature trend. By comparison, the M2BD filter extracted, in real time, the underlying temperature trend with great accuracy and no time lag. In the validation study, the M2BD filter accurately extracted the underlying temperature trend for all four of the synthetic datasets. With regard to the anonymized patient data, the M2BD filter again performed well, accurately determining the underlying trend. CONCLUSION: The study demonstrated that the M2BD filter is capable of instantaneously extracting underlying trends from clinical time series data. This finding suggests that this algorithm has great potential as a tool for assisting clinicians in the management of patients with febrile neutropenia.

Best practice in primary care pathology: review 6.

This sixth best practice review examines four series of common primary care questions in laboratory medicine: (1) laboratory monitoring in hypertension and heart failure abnormalities; (2) markers of inflammatory joint disease; (3) laboratory investigation of chronic diarrhoea; and (4) mumps and chickenpox. The review is presented in question-answer format, referenced for each question series. The recommendations represent a precis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus based rather than evidence based. They will be updated periodically to take account of new information.

Best practice in primary care pathology: review 7.

This seventh best-practice review examines four series of common primary care questions in laboratory medicine: (1) blood count abnormalities 2; (2) cardiac troponins; (3) high-density lipoprotein cholesterol; and (4) viral diseases 2. The review is presented in a question-answer format, with authorship attributed for each question series. The recommendations are a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. The recommendations are not standards, but form a guide to be set in the clinical context. Most are consensus based rather than evidence based. They will be updated periodically to take account of new information.

Modelling the transmission of airborne infections in enclosed spaces.

The Wells-Riley equation for modelling airborne infection in indoor environments is incorporated into an SEIR epidemic model with a short incubation period to simulate the transmission dynamics of airborne infectious diseases in ventilated rooms. The model enables the effect of environmental factors such as the ventilation rate and the room occupancy to be examined, and allows the long-term impact of infection control measures to be assessed. A theoretical parametric study is carried out to demonstrate how changes to both the physical environment and infection control procedures may potentially limit the spread of short-incubation-period airborne infections in indoor environments such as hospitals.

Best practice in primary care pathology: review 2.

This second best practice review examines five series of common primary care questions in laboratory medicine: (1) laboratory testing for allergy, (2) diagnosis and monitoring of menopause, (3) the use of urine cytology, (4) the usefulness of the erythrocyte sedimentation rate, and (5) the investigation of possible urinary tract infection. The review is presented in a question-answer format. The recommendations represent a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents, and evidence based medicine reviews, supplemented by MEDLINE EMBASE searches to identify relevant primary research documents. They are standards but form a guide to be set in the clinical context. Most are consensus rather than evidence based. They will be updated periodically to take account of new information.

Effects of zinc oxide and Enterococcus faecium SF68 dietary supplementation on the performance, intestinal microbiota and immune status of weaned piglets.

The objective of this study was to determine the effects of zinc oxide (ZnO) and the probiotic Enterococcus faecium SF68 (Cylactin) dietary supplementation on the performance, intestinal microbiota and immune parameters of the weaned piglet reared under commercial conditions. The diets were devoid of antibiotic growth promoters (AGP). Two hundred and eight crossbred piglets were allocated to a 2 x 2 factorial experiment involving two levels of zinc oxide supplementation (0 or 3100 mg ZnO/kg feed), and two levels of E. faecium SF68 supplementation (0 or 1.4 x 10(9)CFU/kg feed (Cylactin ME10)). The diets were offered ad libitum for 20 days post-weaning. Piglet performance was assessed by calculating average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) on a pen basis. In addition, components of the distal ileal digesta, tissue-associated and mesenteric lymph node (MLN) bacterial populations were enumerated and serum immunoglobulin G (IgG) and intestinal immunoglobulin A (IgA) concentrations were determined on days 6 and 20 post-weaning. Regression analysis was used to determine the relationship between the bacterial populations at the different sites. Supplementation of the post-weaning diet with either ZnO or E. faecium SF68 did not affect piglet performance. E. faecium SF68 did not affect gastrointestinal bacterial populations but did tend to reduce serum IgG (P<0.1) on day 20. Zinc oxide reduced anaerobic (P<0.05) and tended to decrease lactic acid (P<0.1) bacterial translocation to the MLN, and tended to increase intestinal IgA concentration (P<0.1) on day 20. Generally, luminal bacterial populations were found to be poor predictors of tissue-associated or MLN populations. ZnO and E. faecium SF68 dietary supplementation were ineffective under these trial conditions. Further investigations into the possible immunomodulator role of dietary ZnO are warranted.

Could hospital patients' hands constitute a missing link?

The relationship between contamination of patients' hands and transmission of healthcare-associated infection has received only limited attention, but may represent a previously overlooked but potentially significant link in the chain of infection. This paper aims critically to review the literature to determine whether this possible epidemiological relationship is worthy of further consideration. Studies that have investigated the microbiology or hand hygiene behaviours of patients and other groups are examined to establish their limitations and implications for future practice and research. Examples of healthcare-associated infections where improving patient hand hygiene may have a favourable impact on transmission, and how this might be achieved within the context of current UK health service initiatives, are discussed. It is recommended that systematic studies of the role of patients' hands in the chain of hospital infection should be undertaken.

Provision of safe potable water for immunocompromised patients in hospital.

We conducted a survey of hospital drinking water provision for patients with immunocompromising conditions in 15 Trusts in the north of England. Ten trusts replied, reporting on provision of drinking water in 14 separate units. Of these, nine provided only tap water to all patients, irrespective of underlying condition. In two units, iced water, with ice from commercially available makers, was used. Five units distinguished between neutropenic and non-neutropenic patients, with the former group receiving cooled, boiled water (three units), sterile water and sterile water or carbonated water (one unit each). No unit provided filtered water. Water in jugs was changed daily, twice daily or only when empty in seven, three and four units, respectively. On 10 units, patients were allowed to provide their own drinking water, but no unit provided written advice to patients on potable water. A survey within our own Trust revealed similar inter-unit disparity. The options for potable water provision were reviewed, taking into account: microbiological quality, organoleptic (perceived taste/smell) acceptability, cost and factors relating to staff safety and patient confidentiality [as it was possible for human immunodeficiency virus (HIV) seropositive patients on some wards to be identified because they were provided with cooled, boiled water]. It concluded that end-line commercially available water filters were the optimal way to provide drinking water to immunocompromised patients in hospital.

Stenotrophomonas maltophilia contamination of nebulizers used to deliver aerosolized therapy to inpatients with cystic fibrosis.

There is circumstantial evidence that nebulizer equipment may be a source of Stenotrophomonas maltophilia for patients with cystic fibrosis. Eighty-nine inpatient nebulizers were examined for evidence of S. maltophilia contamination of which nine (10%) yielded 14 strains of the bacterium. Environmental samples were obtained from 73 different sites on the ward, of which 17 (23%) yielded a further 21 strains. Positive sites included taps, sink drains, and potable water. Genotyping using ERIC-PCR and pulsed-field gel electrophoresis revealed that two pairs of patients' nebulizers were contaminated with closely related strains. None of the S. maltophilia isolates obtained from the ward environment shared genotypes with those obtained from the nebulizers. The frequency of isolation of S. maltophilia from potable water sources on the ward suggests that contamination may result from using it to clean reusable nebulizer equipment, particularly if this is followed by inadequate drying. Although the actual source of S. maltophilia contamination of hospital-use nebulizer equipment in this study remained elusive, these results have important infection control implications.

Bacterial colonisation of Doppler probes on vascular surgical wards.

AIM: hospital acquired infections cost the NHS 1 pound sterling billion each year and medical equipment may act both as source and vector of nosocomial infection. This study examined bacterial contamination of Doppler ultrasound probes (USP) in routine use on vascular surgical wards in six hospitals and the knowledge of staff about the potential for cross infection from contaminated probes. METHODS: probe head impressions and swab cultures of probe holders were plated on mannitol salt agar before and after cleaning with a paper towel. Putative S. aureus isolates were identified to species level and susceptibility to selected antimicrobials tested. Concurrently, junior medical staff were surveyed about probe cleaning protocols. RESULTS: methicillin susceptible S. aureus was isolated from 2/21 (10%) with near confluent bacterial growth from six others (28%). The latter may have obscured low numbers of S. aureus. Further since swabs were plated without prior enrichment culture, it is likely that contamination with S. aureus might have been underestimated. No positive cultures were obtained after wiping the USP with a paper towel. 22/23 (95%) junior doctors failed to clean the USP prior to use. CONCLUSION: USP contamination with pathogenic bacteria occurs under "in-use" conditions and junior medical staff are unaware of simple measures to prevent this. Strict guidelines for USP cleaning between patient use should, therefore, be adopted particularly when monitoring postoperative graft patency.

Differential invasion of respiratory epithelial cells by members of the Burkholderia cepacia complex.

To investigate whether there are differences between members of the Burkholderia cepacia complex in their ability to invade human respiratory epithelial cells, 11 strains belonging to genomovars I-V were studied in an antibiotic protection assay using the A549 cell line. Strains belonging to genomovars II and III were more invasive than those of genomovars I, IV and V. There was also intra-genomovar variation in invasiveness. No correlation between invasiveness and other putative virulence factors of importance in B. cepacia infection in individuals with cystic fibrosis, cable pilus and B. cepacia epidemic strain marker was identified.