Discovery of Aspergillus frankstonensis sp. nov. during environmental sampling for animal and human fungal pathogens

Invasive fungal infections, IFI, due to species in Aspergillus section Fumigati, ASF, including the Aspergillus viridinutans species complex, AVSC, are increasingly reported in humans and cats. The risk of exposure to these medically important fungi in Australia is unknown. Air and soil was sampled from the domiciles of pet cats diagnosed with these IFI and from a nature reserve in Frankston, Victoria, where Aspergillus viridinutans sensu stricto was discovered in, . Of, ASF species isolated, were A. fumigatus sensu stricto, were AVSC, A. felis-clade and A. frankstonensis sp. nov., and, were other species, . Seven pathogenic ASF species known to cause disease in humans and animals, A. felis-clade, A. fischeri, A. thermomutatus, A. lentulus, A. laciniosus A. fumisynnematus, A. hiratsukae, comprised, of isolates overall. AVSC species were only isolated from Frankston soil where they were abundant, suggesting a particular ecological niche. Phylogenetic, morphological and metabolomic analyses of these isolates identified a new species, A. frankstonensis that is phylogenetically distinct from other AVSC species, heterothallic and produces a unique array of extrolites, including the UV spectrum characterized compounds DOLD, RAIMO and CALBO. Shared morphological and physiological characteristics with other AVSC species include slow sporulation, optimal growth at, ÊC, no growth at, ÊC, and viriditoxin production. Overall, the risk of environmental exposure to pathogenic species in ASF in Australia appears to be high, but there was no evidence of direct environmental exposure to AVSC species in areas where humans and cats cohabitate.Jessica J. Talbot, Jos Houbraken, Jens C. Frisvad, Robert A. Samson, Sarah E. Kidd, John Pitt, Sue Lindsay, Julia A. Beatty, Vanessa R. Barr

Computed tomographic features of feline sino-nasal and sino-orbital aspergillosis

Feline upper respiratory tract aspergillosis (URTA) occurs as two distinct anatomic forms, sinonasal aspergillosis (SNA) and sino-orbital aspergillosis (SOA). An emerging pathogen, Aspergillus felis is frequently involved. The pathogenesis of URTA, in particular, the relationship between the infecting isolate and outcome, is poorly understood. Computed tomography was used to investigate the route of fungal infection and extension in 16 cases (SNA n=7, SOA n=9) where the infecting isolate had been identified by molecular testing. All cases had nasal cavity involvement except one cat with SNA that had unilateral frontal sinus changes. A strong association between the infecting species and anatomic form was identified. A. fumigatus infections remained within the sino-nasal cavity. Cryptic species infections were associated with orbital and paranasal soft-tissue involvement and with orbital lysis. These species were further associated with a mass in the nasal cavity, paranasal sinuses or nasopharynx. Orbital masses showed heterogeneous contrast enhancement, with central coalescing hypoattenuating foci and peripheral rim enhancement. Severe, cavitated turbinate lysis, typical of canine SNA, was present only in cats with SNA. These findings support that the nasal cavity is the portal of entry for fungal spores in feline URTA and that the route of extension to involve the orbit is via direct naso-orbital communication from bone lysis. Additionally, a pathogenic role for A. wyomingensis and a sinolith in a cat with A. udagawae infection are reported for the first time. Keywords: Aspergillus felis; Aspergillosis; Cats; Sino-nasal; Sino-orbita

Computed tomographic features of feline sino-nasal and sino-orbital aspergillosis

Feline upper respiratory tract aspergillosis (URTA) occurs as two distinct anatomic forms, sinonasal aspergillosis (SNA) and sino-orbital aspergillosis (SOA). An emerging pathogen, Aspergillus felis is frequently involved. The pathogenesis of URTA, in particular, the relationship between the infecting isolate and outcome, is poorly understood. Computed tomography was used to investigate the route of fungal infection and extension in 16 cases (SNA n=7, SOA n=9) where the infecting isolate had been identified by molecular testing. All cases had nasal cavity involvement except one cat with SNA that had unilateral frontal sinus changes. A strong association between the infecting species and anatomic form was identified. A. fumigatus infections remained within the sino-nasal cavity. Cryptic species infections were associated with orbital and paranasal soft-tissue involvement and with orbital lysis. These species were further associated with a mass in the nasal cavity, paranasal sinuses or nasopharynx. Orbital masses showed heterogeneous contrast enhancement, with central coalescing hypoattenuating foci and peripheral rim enhancement. Severe, cavitated turbinate lysis, typical of canine SNA, was present only in cats with SNA. These findings support that the nasal cavity is the portal of entry for fungal spores in feline URTA and that the route of extension to involve the orbit is via direct naso-orbital communication from bone lysis. Additionally, a pathogenic role for A. wyomingensis and a sinolith in a cat with A. udagawae infection are reported for the first time. Keywords: Aspergillus felis; Aspergillosis; Cats; Sino-nasal; Sino-orbita

Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis.

Highlights: Feline antibodies against cryptic Aspergillus spp. cross react with an aspergillin containing A. fumigatus antigens. • Brachycephalic cats are prone to upper respiratory tract aspergillosis (URTA). • The agar gel immunodiffusion (AGID) assay has low sensitivity for diagnosis of URTA. • IgG ELISA has high sensitivity and specificity for diagnosis of URTA. • This study provides evidence that cats with URTA are systemically immunocompetent. Abstract Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1). Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA. Keywords: Aspergillosis; Aspergillus spp; Sino-nasal; Sino-orbital; Felinefunded by an Australian Companion Animal Health Foundation grant (015/201

Feline parvovirus seroprevalence is high in domestic cats from disease outbreak and non-outbreak regions in Australia

Multiple, epizootic outbreaks of feline panleukopenia (FPL) caused by feline parvovirus (FPV) occurred in eastern Australia between 2014 and 2018. Most affected cats were unvaccinated. We hypothesised that low population immunity was a major driver of re-emergent FPL. The aim of this study was to (i) determine the prevalence and predictors of seroprotective titres to FPV among shelter-housed and owned cats, and (ii) compare the prevalence of seroprotection between a region affected and unaffected by FPL outbreaks. FPV antibodies were detected by haemagglutination inhibition assay on sera from 523 cats and titres ≥1:40 were considered protective. Socioeconomic indices based on postcode and census data were included in the risk factor analysis. The prevalence of protective FPV antibody titres was high overall (94.3%), even though only 42% of cats were known to be vaccinated, and was not significantly different between outbreak and non-outbreak regions. On multivariable logistic regression analysis vaccinated cats were 29.94 times more likely to have protective FPV titres than cats not known to be vaccinated. Cats from postcodes of relatively less socioeconomic disadvantage were 5.93 times more likely to have protective FPV titres. The predictors identified for FPV seroprotective titres indicate targeted vaccination strategies in regions of socioeconomic disadvantage would be beneficial to increase population immunity. The critical level of vaccine coverage required to halt FPV transmission and prevent FPL outbreaks should be determined