Evaluation of the Genmark ePlex® and QIAstat-Dx® respiratory pathogen panels in detecting bacterial targets in lower respiratory tract specimens.

BACKGROUND: The ePlex® and QIAstat-Dx® respiratory pathogen panels detect multiple respiratory pathogens, mainly viruses but also Legionella pneumophila, Mycoplasma pneumoniae and Bordetella pertussis. The assays have been marketed for use in nasopharyngeal swab specimens. For diagnosing bacterial pneumonia, lower respiratory tract (LRT) specimens are indicated. Aim of this study was to evaluate the performance of these syndromic panels for these three bacterial targets in samples from the LRT. Fifty-six specimens were collected from our repositories, five negative samples and fifty-one samples which had been previously tested positive with the routine diagnostic real-time PCR assays for Legionella spp. (N = 20), Bordetella spp. (N = 16) or M. pneumoniae (N = 15). RESULTS: The QIAstat-Dx Respiratory Panel V2 (RP) assay detected all of the L. pneumophila and B. pertussis positive samples but only 11/15 (73.3 %) of the M. pneumoniae targets. The ePlex Respiratory Pathogen Panel (RPP) assay detected 10/14 (71.4 %) of the L. pneumophila targets, 8/12 (66.7 %) of the B. pertussis positive samples and 13/15 (86.7 %) of the M. pneumoniae targets. CONCLUSIONS: No false-positive results were reported for all three bacterial pathogens by both assays. The clinical performance of both assays depended highly on the bacterial load in the sample and the type of specimen under investigation.

Clinical implications of bile cultures obtained during pancreatoduodenectomy: a cohort study and meta-analysis.

BACKGROUND: The association between intraoperative bile cultures and infectious complications after pancreatoduodenectomy remains unclear. This cohort study and meta-analysis aimed to determine the predictive role of intraoperative bile cultures in abdominal infectious complications after pancreatoduodenectomy. METHODS: The cohort study included 114 patients undergoing pancreatoduodenectomy. Regression analyses were used to estimate the odds to develop an organ space infection (OSI) or isolated OSI (OSIs without a simultaneous complication potentially contaminating the intraabdominal space) after a positive bile culture. A systematic review and meta-analysis was performed on abdominal infectious complications (Mantel-Haenszel fixed-effect model). RESULTS: The positive bile culture rate was 61%, predominantly in patients after preoperative biliary drainage (98% vs 26%, p < 0.001). OSIs occurred in 35 patients (31%) and isolated OSIs in nine patients (8%) and were not associated with positive bile cultures (OSIs: odds ratio = 0.6, 95% CI = 0.25-1.23, isolated OSIs: odds ratio = 0.77, 95% CI = 0.20-3.04). In the meta-analysis, 15 studies reporting on 2047 patients showed no association between positive bile cultures and abdominal infectious complications (pooled odds ratio = 1.3, 95% CI = 0.98-1.65). CONCLUSION: Given the rare occurrence of isolated OSIs and similar odds for patients with positive and negative bile cultures to develop abdominal infectious complications, routine performance of bile cultures should be reconsidered.

Diagnosing diabetic foot osteomyelitis.

Bone involvement during an infection of the diabetic foot represents a serious complication associated with a high risk of amputation, prolonged antibiotic treatment and hospitalization. Diabetic foot osteomyelitis (DFOs) require a multidisciplinary approach given the usual complexity of these situations. DFO should be suspected in most cases especially in the most severe forms of soft tissue diabetic foot infections (DFIs) where the prevalence of bone infection may be up to 60%. Suspicion is based on clinical signs in particular a positive probe-to-bone (PTB) test, elevated inflammatory biomarkers especially erythrocyte sedimentation rate and abnormal imaging assessment using plain X-ray as a first-line choice. The combination of PTB test with plain X-ray has proven effective in the diagnosis of DFO. The confirmation (definite) diagnosis of DFO is based on the results of a bone sample examination obtained by either surgical or percutaneous biopsy. Sophisticated imaging examinations such as Magnetic Resonance Imaging (MRI) and nuclear imaging techniques are useful where doubt persists after first-line imaging assessment. These techniques may also help localize the bone infection site and increase the diagnostic performance of percutaneous bone biopsy. The quality of the microbiological documentation of DFO is likely to improve the adequacy of the antimicrobial therapy especially when medical (ie, no surgical resection of the infected bone tissues) is considered. The use of new (molecular) techniques for the identification of the bone pathogens have not yet proven superiority on classic cultural techniques for the management of such patients.

Diagnostic Accuracy of Probe to Bone to Detect Osteomyelitis in the Diabetic Foot: A Systematic Review.

The probe-to-bone (PTB) test is a commonly used clinical test for osteomyelitis (OM), but its utility has been questioned in clinical settings where the prevalence of OM is low. This article aims to systematically review the accuracy of the PTB test to diagnose diabetic foot OM. We searched Ovid Medline and Scopus databases for studies using the keywords "probe to bone," "osteomyelitis," and "diabetic foot" from 1946 to May 2015. We summarized characteristics of the included studies and pooled the accuracy numbers using a bivariate random-effects model. Seven studies met our inclusion criteria. Pooled sensitivity and specificity for the PTB test was 0.87 (95% confidence interval [CI], .75-.93) and 0.83 (95% CI, .65-.93), respectively. We conclude that the PTB test can accurately rule in diabetic foot OM in the high-risk patients and rule out OM in low-risk patients.

[Emergence of amatoxin poisoning in the Netherlands]. / De giftige groene knolamaniet.

CASE DESCRIPTION: A 34-year-old woman from Thai origin developed acute liver failure after ingestion of a soup which contained the death cap (Amanita phalloides). BACKGROUND: In patients with poisoning due to amatoxin-containing mushrooms, gastro-intestinal complaints usually develop several hours after ingestion, followed by acute hepatic failure which occasionally leads to death. The incidence of reported mushroom poisonings in the Netherlands has increased in 2019, which is possibly associated with migration of asylum seekers who regularly pick and eat mushrooms. CONCLUSION: In the Netherlands mushroom intoxication is rare. Therefore, there is a lack of knowledge among health care personnel and foragers. The present case report highlights the importance of awareness of the poisonous death cap to prevent intoxications and optimize treatment decisions.

Complications during the treatment of diabetic foot osteomyelitis.

AIM: To identify complications of medical treatment in patients with diabetic foot osteomyelitis (DFO). METHODS: We reviewed 143 records of consecutive patients admitted with DFO, confirmed by bone histopathology or culture. Complications monitored included acute kidney injuries (AKI), development of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), gastrointestinal complications, and venous catheter related complications during a 12months follow-up period. RESULTS: Forty-seven AKI episodes were reported during follow-up; half occurred during the first hospitalization with involvement of antimicrobial therapy in 14 events (29.8%). Patients with AKI were more likely to have recurrent ulcerations (69.2% vs. 45.2%, p=0.02), recurrent infections (38.5% vs. 17.3%, p=0.01), and recurrent hospitalizations (43.6% vs. 28.8%, p=0.02) during follow-up. Only 14 MRSA isolates were found in bone samples at baseline (9.8%). Resistant strains of MRSA and VRE were identified in twenty-one patients (14.7%) during follow-up. Patients re-hospitalized for infection were more likely to have resistant bacterial strains (52.6% vs. 25.8%, p=0.02). CONCLUSIONS: In this study, the rates of VRE and MRSA in bone biopsies of patients with DFO were lower than in previous reports. Acute kidney injury occurred frequently in our patient population but might not be associated with antibiotic exposure.

Update on the Role of Infection and Biofilms in Wound Healing: Pathophysiology and Treatment.

BACKGROUND: Chronic wounds, and among these infected diabetic foot ulcers, are a worldwide problem. The poor treatment outcomes result in high healthcare costs, amputations, a decreased quality of life, and an increased mortality. These outcomes are influenced by several factors, including biofilm formation. A biofilm consists of pathogenic bacteria that are encased in an exopolysaccharide layer and communicate through secretion of signaling molecules. Bacteria that live in a biofilm are refractory to host responses and treatment. METHODS: We performed a nonsystematic review of the currently published to-date medical biofilm literature. The review summarizes the evidence of biofilm in chronic wounds, the role of biofilm in wound healing, detection of biofilm, and available antibiofilm treatments. Articles containing basic science and clinical research, as well as systematic reviews, are described and evaluated. The articles have variable levels of evidence. All articles have been peer reviewed and meet the standards of evidence-based medicine. RESULTS: Both animal and human studies have identified biofilm in chronic wounds and have suggested that healing might be influenced by its presence. A promising development in biofilm detection is rapid molecular diagnostics combined with direct microscopy. This technique, rather than classic culture, might support individualized treatment in the near future. A wide range of treatments for chronic wounds also influence biofilm formation. Several agents that specifically target biofilm are currently being researched. CONCLUSIONS: Biofilm formation has a substantial role in chronic wounds. Several diagnostic and therapeutic methods against biofilm are currently being developed.