Actinotignum schaalii infection - a case series from a tertiary hospital in Greece.

Introduction: Actinotignum schaalii is a small Gram-positive facultative anaerobic coccoid rod that was reclassified in 1997 from the genus Actinomyces and is difficult to culture with usual microbiological techniques, as it is slowly growing. A. schaalii is an emerging human pathogen that is most commonly implicated in urinary tract infections (UTIs), but has also been isolated less frequently from abscesses of various sites (such as the skin, the genitourinary tract, surgical sites or intraabdominal). Methods: All cases where A. schaalii was identified during a 6-year period (January 2016 - January 2022) in the University Hospital of Heraklion were reviewed. Results: A. schaalii was isolated in 11 cultures from 10 patients. The site of infection was skin and soft tissue in nine out of eleven cultures (81.8%) and the bone was the site of infection in two patients (18.2%). Most cultures were polymicrobial. The median age of patients was 55.5 years (interquartile range 34-63 years), and 80% (n=8) were male. A. schaalii was susceptible to beta-lactams, quinolones and vancomycin, but resistant to clindamycin, erythromycin and metronidazole. Moreover, two cases of diabetic patients diagnosed with polymicrobial diabetic foot osteomyelitis from this organism are presented in detail. Both patients were successfully managed with targeted antimicrobial treatment and prompt surgical management. Conclusions: A. schaalii is an emerging pathogen that is likely under-reported due to difficulties in isolation and identification. Herein two cases of diabetic foot osteomyelitis are also presented in detail, successfully managed with targeted antimicrobial therapy and surgical debridement.

Risk factors for early mortality in haematological malignancy patients with pulmonary mucormycosis.

Pulmonary mucormycosis (PM) is a life-threatening opportunistic mycosis with a variable clinical evolution and few prognostic markers for outcome assessment. Several clinical risk factors for poor outcome present at the diagnosis of PM were analyzed in 75 consecutive hematology patients from 2000-2012. Significant variables (P < 0.1) were entered into a multivariate Cox-proportional hazard regression model adjusting for baseline APACHE II to identify independent risk factors for mortality within 28 days. Twenty-eight of 75 patients died within 4-week follow up. A lymphocyte count < 100/mm³ at the time of diagnosis (adjusted hazard ratio 4.0, 1.7-9.4, P = 0.01) and high level of lactate dehydrogenase (AHR 3.7, 1.3-10.2, P = 0.015) were independent predictors along with APACHE II score for 28-day mortality. A weighted risk score based on these 3 baseline variables accurately identified non-surviving patients at 28 days (area under the receiver-operator curve of 0.87, 0.77-0.93, P < 0.001). A risk score > 22 was associated with 8-fold high rates of mortality (P < 0.0001) within 28 days of diagnosis and median survival of 7 days versus ≥28 days in patients with risk scores ≤22. We found that APACHE II score, severe lymphocytopenia and high LDH levels at the time of PM diagnosis were independent markers for rapid disease progression and death.