Up to 20% of all infective endocarditis are blood culture-negative and therefore a diagnostic challenge. Here we present the case of an infective endocarditis due to Helicobacter cinaedi finally diagnosed using different molecular methods. This highly fastidious gram-negative spiral rod is increasingly recognized as a human pathogen, above all in immunocompromised patients. So far H. cinaedi has been associated with bacteremia, cellulitis, arthritis and meningitis. A 71-year-old man presented with fever and progressive dyspnea for weeks. He was immunocompromised by long-term steroid therapy. As one major and two minor Duke’s criteria (vegetation, fever and aortic valve stenosis as predisposition) were present, an infective endocarditis was suspected and an empiric therapy with amoxicillin/clavulanic acid and gentamicin was established. The persistent severe aortic regurgitation resulted in a valve replacement. Histological evaluation of the aortic valve showed a polypous-ulcerative endocarditis. Gram stain and culture remained negative. Broad-range bacterial PCR targeting the 16S rRNA gene on the biopsy of the aortic valve identified H. cinaedi as the causative agent. The antibiotic therapy was simplified accordingly to ceftriaxone and gentamicin with a recommended duration of 6 weeks. Ten days after valve replacement the patient was discharged. To complete our molecular finding, we sequenced nearly the complete 16S rRNA gene (accession number KF914917) resulting in 99.9% identity with H. cinaedi reference sequences. Based on this result, 2 species-specific PCR tests amplifying part of the ctd gene were established and applied to the valve specimen. The 2 PCRs confirmed H. cinaedi. In addition, we analyzed stool, urine and saliva from the patient using H. cinaedi PCR. The fecal and urine specimen showed a positive signal, saliva was PCR-negative. We identified H. cinaedi as causative agent of a culture-negative endocarditis in an immunocompromised patient using broad-range and specific PCR. In addition to 2 cases from Japan presented on international meetings in 2010 and 2013, our case report shows that H. cinaedi should be recognized as additional causative organism of infective endocarditis. The use of molecular diagnostic techniques proved to be a powerful complement for the detection of blood culture-negative infective endocarditis.

In patients, rapid identification of bacterial species may help to guide treatment at early stages. New protocols for the identification directly from positive blood culture flasks significantly helped in the presented case report. Two patients (a father and son) presented with diarrhea, malaise, and fever of 3 to 4 days duration. Blood cultures from both patients cultured short Gram-positive rods. MALDI-TOF based rapid identification protocol direct from positive blood culture identified Listeria monocytogenes as the cause of sepsis and could be confirmed with conventional methods. Listeria monocytogenes was identified 24 h later by conventional biochemical identification methods (VITEK 2). Antibiotic treatment was adjusted early in response to the MALDI-TOF based identification of bacteremia. Pulsed field gel electrophoresis confirmed the suspected relatedness of the father’s and son’s isolates. MALDI-TOF based may provide a rapid identification of bacterial species directly from positive blood culture.

Zusammenfassung. Wir beschreiben einen Patienten mit einem diabetischen Fuss und herausfordernden Infektionskomplikationen. Nach einer Hospitalisation in Sri Lanka aufgrund einer Weichteilinfektion folgte die Rückverlegung in die Schweiz. Bei Nachweis von mehreren multiresistenten Keimen wurde eine Vorfussamputation mit Spalthautdeckung durchgeführt, gefolgt von einer kurzen, resistenzgerechten antibiotischen Therapie mit gutem klinischem Ergebnis. Dieser Fall veranschaulicht die Zunahme multiresistenter Keime, mit denen wir konfrontiert werden. Insbesondere zeigt er die Wichtigkeit krankenhaushygienischer Massnahmen bei Rückkehrern aus Ländern mit einer hohen Prävalenz an multiresistenten Keimen (v.a. nach einer Hospitalisation), und die Notwendigkeit einer engen interdisziplinären Zusammenarbeit, um eine bestmögliche Therapie zu gewährleisten und die Ausbreitung dieser Erreger einzudämmen.

Background: The epidemiology, characteristics and outcomes of coinfections in COVID-19 are still poorly understood. Methods: We investigated the prevalence of coinfections in COVID-19 patients hospitalized in Switzerland over the first three epidemic waves between 1 March 2020 and 1 June 2021, as well as risk factors and outcomes. Patients were identified from six hospitals of the Swiss prospective surveillance system database (CH-SUR). Details of the type and treatment of coinfections were retrieved retrospectively from medical charts. We assessed the proportion of patients with suspected coinfections and analyzed risk factors and 90-day in-hospital survival using logistic and Cox regression. Results: Of 13,265 identified patients, 36.6% (4859/13,625) had suspected coinfections, and 44.8% (5941/13,625) received antibiotics. Respiratory coinfections (25.6%) were the most common, followed by bloodstream (19.8%) and urinary tract infections (14.6%). Escherichia coli (14.8%), Staphylococcus aureus (10.7%) and Klebsiella pneumoniae (6.1%) were the most frequently isolated pathogens. The risk factors for coinfections included increasing age, male gender, certain underlying medical conditions and immunosuppression. Suspected coinfections were associated with a longer hospital stay (13 vs. 7 days, p < 0.001), more frequent ICU admission (26% vs. 6.7%, p < 0.001) and higher rates of in-hospital death (24% vs. 9.5%, p < 0.001). Hospitalization in the ICU at the time of COVID-19 diagnosis had the strongest association with coinfections. Conclusions: A high proportion of COVID-19 patients had coinfections, particularly respiratory infections, and received antibiotics. Coinfections were associated with severe illness and worse outcomes.

# Introduction In Europe, mucormycosis is predominantly observed in patients with underlying hematological disorders and physicians are accustomed to considering invasive fungal diseases as a potential complication in these patients. However, on a global scale, the most common predisposing condition for mucormycosis is diabetes mellitus, particularly in India. # Case and management A 57-year-old diabetic patient with a history of tobacco use presented with coughing, hemoptysis and weight loss. A computed tomography (CT) scan of the chest showed a cavitating lesion in the right lower lobe with concomitant lymphadenopathy. Pulmonary malignancy was suspected and a bronchoscopy with transbronchial biopsy was performed. Histology revealed invasive fungal disease confirmed as pulmonary mucormycosis by a positive Mucorales-specific and panfungal polymerase chain reaction (PCR). Species identification via sequence analysis demonstrated Rhizopus arrhizus as the causative organism. Treatment with liposomal amphotericin B was initiated and surgical resection was performed. This comprehensive approach resulted in a complete and sustained recovery. # Discussion Mucormycosis is an aggressive and often fatal disease that necessitates fast diagnosis and treatment. We aim to increase awareness among European physicians to consider pulmonary mucormycosis as a possible differential diagnosis in patients with lung lesions and diabetes mellitus. A rapid and interdisciplinary approach may affect the outcome positively. PEER REVIEWED ARTICLE Peer reviewers: Two anonymous peer reviewers. Received: December 16, 2024; Accepted after peer review: January 8, 2024