Patients who are particularly susceptible include those who are neutropenic following chemotherapy, selleck products transplant, surgical and ICU patients (Ben-Ami et al., 2009; Zilberberg & Shorr, 2009). Moreover, patients with genetic or functional abnormalities, particularly in the lungs such as those with cystic fibrosis (CF) or chronic obstructive pulmonary disease provide a natural environment that has a predilection for Aspergillus colonization and biofilm formation (Bakare et al., 2003; Ader et al.,
2009; Horre et al., 2010; Moss, 2010). Aspergillus produce small spores called conidia that have an average size of 2–3.5 μm. These are dispersed in the air and remain in the atmosphere for prolonged periods, and are inhaled into the respiratory tract in their hundreds
each day by humans and other mammals (Rivera et al., 2006). Aspergillus fumigatus can cause a spectrum of clinical disease, including allergic bronchopulmonary aspergillosis, an aspergilloma or invasive aspergillosis (IA) (Denning, 1998). Of these the aspergilloma, a localized infection consisting of a spherical mass of hyphae has clear biofilm characteristics. Aspergillomas can develop in immune competent hosts, but usually require a pre-existing cavity such as those resulting from prior tuberculosis. Some are asymptomatic; however, where symptoms exist, they commonly include a chronic cough and haemoptysis. Another form this website of aspergillosis infection, aspergillary bronchitis, is characterized by bronchial casts containing mucus and mycelia, which are associated with pathological damage (Young et al., 1970). Compact masses are formed, which may be expectorated. Moreover, bronchoalveolar lavage (BAL) in some patients with aspergillosis reveals the presence of numerous hyphae in the form of a complex multicellular mycetoma
structure samples when examined histologically (Jayshree et al., 2006). In contrast, IA disease is more diffuse with multiple points of angioinvasion within the pulmonary tissue. Nevertheless, filamentous intertwined hyphae Exoribonuclease are important to this process, as in other forms of aspergillosis (Mowat et al., 2007). Notably, antifungal treatment is often ineffectual, which may relate to the biofilm phenotype (Beauvais et al., 2007; Mowat et al., 2007, 2008b; Seidler et al., 2008; Fiori et al., 2011; Rajendran et al., 2011). Clearer evidence of Aspergillus biofilms is demonstrated in infections affecting other sites. Aspergilli can enter the host through alternative routes causing other serious biomaterial-related biofilm infections, including catheters, joint replacements, cardiac pace makers, heart valves and breast augmentation implants (Rosenblatt & Pollock, 1997; Langer et al., 2003; Escande et al., 2011; Jeloka et al., 2011). Aspergillus is also frequently associated with complex sinus infections, which in canines have been described as superficial mucosal fungal plaque (Grosjean & Weber, 2007; Day, 2009; Laury & Delgaudio, 2010; Sato et al., 2010).