WGS for infection prevention and control in Africa

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Antifungal-Loaded Acrylic Bone Cement in the Treatment of Periprosthetic Hip and Knee Joint Infections : A Review

Little is known about the clinical use of antifungal-loaded acrylic bone cement in the treatment of periprosthetic hip and knee joint infections (PJIs). Hence, we performed a literature search using PubMed/MEDLINE from inception until December 2021. Search terms were “cement” in combination with 13 antifungal agents. A total of 10 published reports were identified, which described 11 patients and 12 joints in which antifungal-loaded cement was employed. All studies were case reports or case series, and no randomized controlled trials were identified. In 6 of 11 patients, predisposing comorbidities regarding the emergence of a fungal PJI were present. The majority of the studies reported on infections caused by Candida species. In six cases (seven joints), the cement was solely impregnated with an antifungal, but no antibiotic agent (amphotericin B, voriconazole, and fluconazole). In the other five joints, the cement was impregnated with both antibiotic(s) and antifungals. Great discrepancies were seen regarding the exact loading dose. Four studies investigated the local elution of antifungal agents in the early postoperative period and observed a local release of antifungals in vivo. We conclude that there is a paucity of data pertaining to the clinical use of antifungal-loaded bone cement, and no studies have assessed the clinical efficacy of such procedures. Future studies are urgently required to evaluate this use of antifungals in PJI

Recent Advances and Potential Future Applications of MALDI-TOF Mass Spectrometry for Identification of Helminths

Helminth infections caused by nematodes, trematodes, and cestodes are major neglected tropical diseases and of great medical and veterinary relevance. At present, diagnosis of helminthic diseases is mainly based on microscopic observation of different parasite stages, but microscopy is associated with limited diagnostic accuracy. Against this background, recent studies described matrixassisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry as a potential, innovative tool for helminth identification and differentiation. MALDI-TOF mass spectrometry is based on the analysis of spectra profiles generated from protein extracts of a given pathogen. It requires an available spectra database containing reference spectra, also called main spectra profiles (MSPs), which are generated from well characterized specimens. At present, however, there are no commercially available databases for helminth identification using this approach. In this narrative review, we summarize recent developments and published studies between January 2019 and September 2022 that report on the use of MALDI-TOF mass spectrometry for helminths. Current challenges and future research needs are identified and briefly discussed

Teaching Medical Microbiology With a Web-Based Course During the COVID-19 Pandemic: Retrospective Before-and-After Study

Background: The COVID-19 pandemic has imposed unprecedented hurdles on health care systems and medical faculties alike. Lecturers of practical courses at medical schools have been confronted with the challenge of transferring knowledge remotely. Objective: We sought to evaluate the effects of a web-based medical microbiology course on learning outcomes and student perceptions. Methods: During the summer term of 2020, medical students at Saarland University, Germany, participated in a web-based medical microbiology course. Teaching content comprised clinical scenarios, theoretical knowledge, and instructive videos on microbiological techniques. Test performance, failure rate, and student evaluations, which included open-response items, for the web-based course were compared to those of the on-site course from the summer term of 2019. Results: Student performance was comparable between both the online-only group and the on-site comparator for both the written exam (n=100 and n=131, respectively; average grade: mean 7.6, SD 1.7 vs mean 7.3, SD 1.8; P=.20) and the oral exam (n=86 and n=139, respectively; average grade: mean 33.6, SD 4.9 vs mean 33.4, SD 4.8; P=.78). Failure rate did not significantly differ between the online-only group and the comparator group (2/84, 2.4% vs 4/120, 3.3%). While lecturer expertise was rated similarly as high by students in both groups (mean 1.47, SD 0.62 vs mean 1.27, SD 0.55; P=.08), students who took the web-based course provided lower scores for interdisciplinarity (mean 1.7, SD 0.73 vs mean 2.53, SD 1.19; P<.001), opportunities for interaction (mean 1.46, SD 0.67 vs mean 2.91, SD 1.03; P<.001), and the extent to which the educational objectives were defined (mean 1.61, SD 0.76 vs mean 3.41, SD 0.95; P<.001). Main critiques formulated within the open-response items concerned organizational deficits. Conclusions: Web-based courses in medical microbiology are a feasible teaching option, especially in the setting of a pandemic, leading to similar test performances in comparison to on-site courses. The lack of interaction and the sustainability of acquired manual skills warrant further research

Update on Coagulase-Negative Staphylococci—What the Clinician Should Know

Coagulase-negative staphylococci (CoNS) are among the most frequently recovered bacteria in routine clinical care. Their incidence has steadily increased over the past decades in parallel to the advancement in medicine, especially in regard to the utilization of foreign body devices. Many new species have been described within the past years, while clinical information to most of those species is still sparse. In addition, interspecies differences that render some species more virulent than others have to be taken into account. The distinct populations in which CoNS infections play a prominent role are preterm neonates, patients with implanted medical devices, immunodeficient patients, and those with other relevant comorbidities. Due to the property of CoNS to colonize the human skin, contamination of blood cultures or other samples occurs frequently. Hence, the main diagnostic hurdle is to correctly identify the cases in which CoNS are causative agents rather than contaminants. However, neither phenotypic nor genetic tools have been able to provide a satisfying solution to this problem. Another dilemma of CoNS in clinical practice pertains to their extensive antimicrobial resistance profile, especially in healthcare settings. Therefore, true infections caused by CoNS most often necessitate the use of second-line antimicrobial drugs

MALDI-TOF mass spectrometry as a diagnostic tool in human and veterinary helminthology: a systematic review

Background Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) has become a widely used technique for the rapid and accurate identification of bacteria, mycobacteria and certain fungal pathogens in the clinical microbiology laboratory. Thus far, only few attempts have been made to apply the technique in clinical parasitology, particularly regarding helminth identification. Methods We systematically reviewed the scientific literature on studies pertaining to MALDI-TOF MS as a diagnostic technique for helminths (cestodes, nematodes and trematodes) of medical and veterinary importance. Readily available electronic databases (i.e. PubMed/MEDLINE, ScienceDirect, Cochrane Library, Web of Science and Google Scholar) were searched from inception to 10 October 2018, without restriction on year of publication or language. The titles and abstracts of studies were screened for eligibility by two independent reviewers. Relevant articles were read in full and included in the systematic review. Results A total of 84 peer-reviewed articles were considered for the final analysis. Most papers reported on the application of MALDI-TOF for the study of Caenorhabditis elegans, and the technique was primarily used for identification of specific proteins rather than entire pathogens. Since 2015, a small number of studies documented the successful use of MALDI-TOF MS for species-specific identification of nematodes of human and veterinary importance, such as Trichinella spp. and Dirofilaria spp. However, the quality of available data and the number of examined helminth samples was low. Conclusions Data on the use of MALDI-TOF MS for the diagnosis of helminths are scarce, but recent evidence suggests a potential role for a reliable identification of nematodes. Future research should explore the diagnostic accuracy of MALDI-TOF MS for identification of (i) adult helminths, larvae and eggs shed in faecal samples; and (ii) helminth-related proteins that are detectable in serum or body fluids of infected individuals

Evaluation of the Qvella FAST System and the FAST-PBC cartridge for rapid species identification and antimicrobial resistance testing directly from positive blood cultures

Blood culture diagnostics require rapid and accurate identification (ID) of pathogens and antimicrobial susceptibility testing (AST). Standard procedures, involving conventional cultivation on agar plates, may take up to 48 hours or more until AST completion. Recent approaches aim to shorten the processing time of positive blood cultures (PBC). The FAST System is a new technology, capable of purifying and con centrating bacterial/fungal pathogens from positive blood culture media and produc ing a bacterial suspension called “liquid colony” (LC), which can be further used in downstream analyses (e.g., ID and AST). Here, we evaluated the performance of the FAST System LC generated from PBC in comparison to our routine workflow includ ing ID by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using Sepsityper, AST by automatized MicroScan WalkAway plus and directly inocula ted disk diffusion (DD), and MICRONAUT-AM for yeast/fungi. A total of 261 samples were analyzed, of which 86.6% (226/261) were eligible for the comparative ID and AST analyses. In comparison to the reference technique (culture-grown colonies), ID concordance of the FAST System LC and Sepsityper was 150/154 (97.4%) and 123/154 (79.9%), respectively, for Gram positive; 67/70 (95.7%) and 64/70 (91.4%), respectively, for Gram negative. For AST, categorical agreement (CA) of the FAST System LC in comparison to the routine workflow for Gram-positive bacteria was 96.1% and 98.7% for MicroScan and DD, respectively. Similar results were obtained for Gram-negative bacteria with 96.6% and 97.5% of CA for MicroScan and DD, respectively. Taken together, the FAST System LC allowed the laboratory to significantly reduce the time to obtain correct ID and AST (automated MicroScan) results 1 day earlier and represents a promising tool to expedite the processing of PBC

Detection of Bordetella trematum in a diabetic patient with a skin and soft tissue infection

A 38-year-old obese male with spastic diplegia and diabetes was hospitalized due to progressive ulcers of both lower extremities (Figure 1A). Computed tomography showed subcutaneous inflammation with suspected fascial involvement. The patient underwent surgical debridement, after which clindamycin was started empirically. Cultures from tissue samples grew gram-negative rods, identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as Bordetella trematum (Figure 1B) and, in minor quantity, Myroides odoratimimus. Antimicrobial susceptibility testing of B. trematum was performed to obtain minimal inhibitory concentrations (in μg/mL; ampicillin ≤2; piperacillin ≤4; cefuroxime ≥64; ceftazidime 4; meropenem ≤0.25; moxifloxacin 2). Following the debridement, the patient’s condition improved substantially (Figure 1C), and he was discharged soon thereafter

Assessing numbers and faces: a prerequisite for improving access to lymphatic filariasis morbidity care

Concerted efforts to eliminate lymphatic filariasis worldwide have registered success; multiple rounds of mass drug administration have led to the interruption of transmission in many previously endemic areas. However, the management of patients with established clinical disease (e.g., lymphoedema, hydrocoele and acute dermatolymphangioadenitis) has not been addressed sufficiently. Two recent studies from Malawi underscore the need for accurate epidemiological and clinical data, and comprehensive morbidity assessments across various domains of daily life. Addressing these issues will guide the implementation of programmes to improve access to treatment and disability prevention for affected individuals in Malawi and beyon

Late-onset native valve endocarditis caused by Corynebacterium kroppenstedtii

Corynebacterium kroppenstedtii is an emerging cause of granulomatous mastitis and recurrent breast abscesses in women, but data on its clinical relevance in nongynecological disease conditions are limited. Here, we report the first case of a late-onset endocarditis of a native aortic valve in a 73-year-old male patient who presented with symptomatic aortic insufficiency. Echocardiography and cardiac computed tomography revealed the perforation of the noncoronary cusp and a large perivalvular abscess cavity. Hence, the surgical replacement of the aortic valve and aortic root were performed. Intraoperatively obtained tissue specimens grew C. kroppenstedtii and the patient made a full recovery after a 6-week course of antibiotic treatment. We briefly review the literature pertaining to antimicrobial susceptibility patterns of C. kroppenstedtii and available treatment recommendations. Our report calls for further studies to assess the role of this bacterium as a causative agent of infections other than granulomatous mastitis