Elisa Simona Marra

Polymorphonuclear Cell Functional Impairment in Relapsing Remitting Multiple Sclerosis Patients: Preliminary Data

Multiple Sclerosis patients run an increased risk of microbial infections, which leads to high rates of hospitalization and infection-related mortality. Although immunotherapy may increase infection risk in some cases, data as to the relationship among microbial factors, immunotherapy and alterations in the innate immunity of these patients are still scanty. On these grounds, this interdisciplinary study aims at investigating the role the functional activity of polymorphonuclear cells (PMNs) play in relapsing remitting multiple sclerosis at different stages. The in vitro ability of PMNs from patients, either untreated or treated with immunosuppressant or immunomodulatory drugs to kill Klebsiella pneumonia or Candida albicans, were investigated and compared to PMNs from healthy subjects. The release of various cytokines was also assessed, as was the production of reactive oxygen species and their ability to regulate apoptosis after microbial stimulation. Our results indicate that although patients have a normal number of PMNs, they have a statistically significant (p<0.05) reduction in intracellular killing activity. Although variations are strongly related to the therapeutic management of patients, they are independent from their disease stage. As no statistically significant differences were observed between patients and controls in cytokine release values, reactive oxygen species production or apoptosis, we came to the conclusion that other factors may be involved. Supportive validation of these results from further studies might well help in identifying a subset of patients at high risk of infection who could benefit from a closer follow-up and/or antibiotic prophylaxis.

Unexpected Listeria monocytogenes detection with a dithiothreitol-based device during an aseptic hip revision

Prosthetic joint infection diagnosis is often difficult since biofilm-embedded microorganisms attach well to the prosthetic surfaces and resist their detection by conventional methods. DL-dithiothreitol has been described as a valid method for biofilm detachment on orthopedic devices. We report the case of an occasional detection of Listeria monocytogenes in a non immuno-compromised patient with a preoperative diagnosis of aseptic loosening. The infection diagnosis due to such rare bacteria was made postoperatively, thanks to a DL-dithiothreitol-based device. This may be considered a feasible approach for the microbiological analysis of prosthetic joint infection, considering that a prompt diagnosis of such biofilm-associated infections could bring some advantages, such as an early and appropriate antibiotic therapy administration and a reduction of undiagnosed infections.

Advances in Microbiology, Infectious Diseases and Public Health: Fungal Occurrence in the Hair and Skin of Symptomatic Pets in Turin, Italy

Companion animals, often asymptomatic reservoir of fungi, can be important sources of infection in humans, due to the close contact with their owners. The present study was aimed to assess the occurrence of dermatophytes and other fungi isolated from pet dermatological lesions in Turin, Italy. Dermatological specimens were examined for fungal elements by direct microscopy and cultured to detect dermatophytes, other filamentous fungi and yeasts: 247 pets (118 cats, 111 dogs and 18 dwarf rabbits) were positive for fungal detection in culture. Microsporum canis was the most frequent dermatophyte in cats and dogs, whereas Trichophyton mentagrophytes was the most common in rabbits. Among the other fungi, for all examined pets, dematiaceous fungi were the most isolated, followed by Mucorales, penicilli, yeasts and yeast-like fungi, and aspergilli. No gender predisposition was detected for dermatophyte growth; on the contrary, for the other fungi male cats were more susceptible than female. The highest fungal occurrence was recorded in <1-year-old cats for dermatophytes, and in <5-year-old cats and dogs for the other fungi. Autumn was the period associated with a relevant incidence of fungal infection. Finally, fungi were more frequent in non pure-breed cats and in pure-breed dogs. These data underline the importance to timely inform pet owners about the potential health risk of infection caused not only by dermatophytes but also by non-dermatophyte fungi, routinely considered to be contaminants or harmless colonizers, since their role as source of zoonotic infections is not to be excluded.