Characterization of Listeria monocytogenes Strains Isolated in Palermo (Sicily and Italy) during the Years 2018-2020 from Severe Cases of Listeriosis.

Listeria monocytogenes (LM), the etiological agent of listeriosis, can cause foodborne zoonosis. In this study, we characterized 23 strains that caused human severe listeriosis in Palermo (Sicily, Italy) during the period of 2018-2020. In addition, we assessed the phenotypic susceptibility of clinical isolates to antibiotics in accordance with EUCAST guidelines. The serogroup was determined through the use of PCR, while MLST and MVLST were identified through the sequencing of housekeeping genes. Finally, susceptibility to antibiotics was assessed by means of the Phoenix automatic system. Patients hospitalized with listeriosis were predominantly males (56% vs. 44% of females). The cases not associated with pregnancy included patients >65 years of age (60%), two of whom were affected by cancer, while cases associated with pregnancy included two pregnant women and three preterm infants. The data collected showed that the main pathologies shown by patients were meningitis (60.9%) and bacteremia (39.1%). The LM strains were isolated from the blood (52%), cerebrospinal fluid (26%), cerebrospinal fluid + blood (13%), blood + a nasal swab (4%), and ascitic fluid (4%). The predominant serogroup was IVb (96%), whereas only one strain belonged to serogroup IIa (4%). Among the strains with serotypes 4b, 4d, and 4e, ST2/VT21 (92%) and ST6/VT19 (4%) were determined, while only isolates with serotypes 1/2a and3a show ST155/VT45 (CC155). This study reveals the widespread circulation of a clinical strain (ST2/VT21) associated with suspected food contamination, demonstrating the importance of carrying out molecular epidemiological surveillance. Our clinical isolates were susceptible to the beta-lactams assayed, in agreement with the literature data.

Editorial: Special Issue: "Legionella pneumophila: A Microorganism with a Thousand Faces".

Legionella pneumophila is a microorganism that is able to contaminate the freshwater environment and, consequently, human-made water systems [...].

Aggregatibacter aphrophilus and Eikenella corrodens: a case of brain abscess.

We report a case of a 26-year-old female who developed a brain abscess that was strongly suspected to be caused by Staphylococcus epidermidis, A. aphrophilus, and E. corrodens species. In general, A. aphrophilus and E. corrodens, members of the HACEK group (Haemophilus spp., Aggregatibacter spp., C. hominis, E. corrodens, and K. kingae), have been associated with the development of endocarditis, meningitis, sinusitis, otitis media, pneumonia, osteomyelitis, peritonitis, and wound infections. Cerebral abscesses are a rare manifestation of these bacteria; only a few cases are described in the literature, generally related to the diffusion of these organisms through the bloodstream after a dental procedure or a heart disease. Our case is unique because the rarity of the infection site appeared apparently in absence of risk factors. The patient underwent surgery to drain the abscess and was subsequently put on intravenous antibiotic treatment with ceftriaxone, vancomycin, and metronidazole. After 6 months, brain imaging revealed that the lesion had disappeared. The patient achieved excellent results with this approach.

Four-Year Environmental Surveillance Program of Legionella spp. in One of Palermo's Largest Hospitals.

Legionella is a ubiquitous bacterium that lives in freshwater environments and colonizes human-made water systems. Legionella pneumophila is the most virulent species, and risk factors for Legionnaires' disease include increasing age, smoking, chronic diseases, and immunodeficiency. For this reason, it is very important to assess and monitor hospital water systems in order to prevent legionellosis. We have monitored a large hospital in Palermo for four years. To determine the presence of microorganisms, according to national guidelines, we used the culture method, which is considered the gold standard for Legionella detection. Sampling was divided into five macro-areas, and a total of 251 samples were collected during the period of investigation, 49% of which were Legionella spp.-positive and 51% were Legionella spp.-negative. Positive samples with L. pneumophila. sgr 2-15 were most frequent in the Underground (55.6%, p = 0.0184), Medicine (42.9%, p = 0.0184) and Other (63.2%, p = 0.002) areas; while positive samples for L. pneumophila sgr 1 were less frequent in the Underground (0.0%, p = 0.0184) and Surgery areas (4.5%, p = 0.033), and for Legionella anisa, were less frequent in the Medicine (4.1%, p = 0.021), Oncohematology (0.0%, p = 0.0282), and Other (0.0%, p = 0.016) areas. Finally, no significant differences were observed among the areas for each isolate considered. The surveillance carried out in these years demonstrates the importance of monitoring, which allows us to analyze the conditions of hospital facilities and, therefore, prevent Legionella spp. infections.

Transfusion-Transmitted Malaria of Plasmodium malariae in Palermo, Sicily.

Transfusion-transmitted malaria (TTM) is a rare occurrence with serious consequences for the recipient. In non-endemic areas, the incidence of transmission of malaria by transfusion is very low. We report a clinical case of transfusion-transmitted malaria due to Plasmodium malariae, which happened in a patient with acute hemorrhagic gastropathy.Case presentation: In April 2019, a 70-year-old Italian man with recurrent spiking fever for four days was diagnosed with a P. malariae infection, as confirmed using microscopy and real-time PCR. The patient had never been abroad, but about two months before, he had received a red blood cell transfusion for anemia. Regarding the donor, we revealed that they were a missionary priest who often went to tropical regions. Plasmodium spp. PCR was also used on donor blood to confirm the causal link. Discussion and Conclusions: The donations of asymptomatic blood donors who are predominantly "semi-immune" with very low parasitic loads are an issue. The main problem is related to transfusion-transmitted malaria. Our case suggests that P. malariae infections in semi-immune asymptomatic donors are a threat to transfusion safety. Currently, microscopy is considered the gold standard for the diagnosis of malaria but has limited sensitivity to detect low levels of parasitemia. Screening using serological tests and molecular tests, combined with the donor's questionnaire, should be used to reduce the cases of TTM.

Potential Activity of Albino Grifola frondosa Mushroom Extract against Biofilm of Meticillin-Resistant Staphylococcus aureus.

Mushroom extracts are a rich source of natural compounds with antimicrobial properties, which are able to prevent, to some extent, the growth of foodborne pathogens. The aim of this study was to investigate the potential of extracts from albino Grifola frondosa (GF), commonly known as maitake, to inhibit the growth of some bacteria and the biofilm production by Staphylococcus aureus. We obtained not only a significant reduction of OD score between biofilm and biofilm plus albino G. frondosa extract group, but also a reduction of category of biofilm. In addition, we observed a significant presence of isolates with strong category for the biofilm group and a significant presence of isolates with absent category for the biofilm plus albino G. frondosa extract group. These results confirm that the use of albino G. frondosa extract reduces in significant way the presence of biofilm. Our results suggest and confirm that albino G. frondosa extracts could be employed as functional food and could be used as a natural additive for food process control and food safety.

Prone positioning and convalescent plasma therapy in a critically ill pregnant woman with COVID-19.

Prone positioning is feasible in pregnancy and may have contributed to the positive outcome in this case. Doctors should not be reluctant to move a patient to a prone position just because they are pregnant.