ALP and TNS performed experiments and analyzed data. ALP and LGG wrote the manuscript and were responsible for concepts, vision and direction for the AZD6738 cost study. ACMMG and ACGA carried out the electron microscopy and image acquisition. All authors read and approved the final manuscript.”
“Background Nocardia represent a genus of aerobic actinomycetes and belong specifically to the family Mycobacteriaceae [1]. Nocardia are aerobic, gram-positive, filamentous, branching rods and can be found as ubiquitous environmental saprophytes in soil, dust, organic matter and water. Due to
recent advances in phenotypic and molecular characterization (especially 16S rRNA gene sequencing) the spectrum of Nocardia has expanded, with more than 30 species described [2]. At least 13 Nocardia species have been implicated in human infection with varying geographic prevalence throughout the world [3]. Human infections usually arise from inhalation or direct inoculation into skin or soft tissue structures. Major forms of Nocardia infection are pulmonary nocardiosis, disseminated and CNS nocardiosis, cutaneous/lymphocutaneous nocardiosis and mycetoma. Nocardiosis may be considered as opportunistic infection with chronic lung disease (often in association with long-term corticosteroid treatment), selleck transplantation, malignancies, diabetes mellitus and alcohol abuse
as most prevalent underlying conditions [4]. Nevertheless, a Selleck 10058-F4 Urease review of more than 1000 cases of Nocardia infection revealed no identifiable predisposing immunocompromising factors in approximately 30% of patients [5]. Additionally, Nocardia are well-recognized pathogens in animals with bovine masititis representing the most important infection. The characteristic histopathological feature of nocardiosis
consisting of an acute pyogenic inflammatory reaction i.e. a predominant neutrophil-rich infiltrate as well as results of prior studies point towards an important role of innate defense mechanism against Nocardia species. Antimicrobial peptides (AMPs) represent evolutionarily conserved multifunctional molecules of innate immunity. In mammals, AMPs like human β-defensins (hBD) 1-3 and bovine lingual or tracheal antimicrobial peptide (LAP, TAP) are expressed by cells within the epithelial lining or are delivered to sites of infection by circulating leukocytes [6–8]. Examples of the latter group of AMPs include human neutrophil peptides (HNPs) 1-3, bovine indolicidin or human cathelicidin LL-37 [9–11]. AMPs are produced constitutively or are induced upon infection or inflammation and exert activity against a broad spectrum of microorganisms including gram-positive and gram-negative bacteria, enveloped viruses, protozoa and fungi [12]. Apart from a direct microbicidal effect, AMPs exhibit a variety of additional functions by promoting chemotaxis and phagocytosis, stimulating angiogenesis and wound healing or neutralizing LPS effects [13].