Mortierella wolfii isolated from the liver of a cow in Australia

Abstract

THE fungus Mortierella wolfii is known to be a cause of mycotic abortion and pneumonia in cattle in New Zealand (di others 1972, Carter and others 1973), the UK (MacDonald and Corbel 1981), the USA- (Knudtson and Kirkbride 1992) and Australia (Neilan and others 1982), but there are few reports of M wolfii lesions in, and of its isolation from, sources other than bovine female reproductive tracts and fetuses (MacDonald and Corbel 1981, Knudston and Kirkbride 1992). This short communication reports on the isolation of M wolfii from the liver of a cow.The liver of a four-year-old cow was examined within one hour of slaughter, during a survey of hepatic lesions at an abattoir in Queensland, Australia. The cow, which originated from a feedlot in Gympie, south-east Queensland, had passed a routine antemortem inspection, but the liver was condemned at postmortem inspection due to the presence of a visible surface abscess. The abscess was approximately 4 to 5 cm in diameter, protruded from the visceral surface of the left hepatic lobe and had a fibrous wall about 2 cm thick. It contained semi-fluid, creamy yellowish material centrally. The rest of the liver had a normal appearance, and liver sections approximately 1 cm thick revealed no other lesions. Information about lesions elsewhere in the carcase was not available.A sample of the lesion was collected aseptically and kept on ice before being examined microbiologically within two hours of collection. The external surface of the liver abscess was seared with a hot spatula and a sample of abscess material was obtained with a sterile pipette. This was then inoculated onto two plates of 10 per cent sheep blood agar (SBA; Oxoid) and a MacConkey agar plate (Oxoid). A smear was prepared from the abscess material and was Gram stained. One SBA plate was inoculated aerobically and the other anaerobically. All the plates were incubated at 37°C and examined at 24,48 and 72 hours.An additional sample which included the wall of the abscess and adjacent livet tissue was collected and fixed by immersion in 10 per cent buffered formalin for 24 hours. Three blocks were obtained from this sample and embedded in paraffin wax, sectioned at 6 pim and stained with haematoxylin and eosin, periodic acid-Schiff plus haematoxylin (PASH), Gram and Grocott methanamine stains. After this, the blocks were serially sectioned and every 10th section was stained with PASH.No bacteria or fungi were seen in the Gram-stained smear of the liver abscess aspirate, and no aerobic or anaerobic bacterial growth was observed on any of the plates after 72 hours. Ten identical fungal colonies were observed on the aerobically incubated SBA plates. These colonies were fast growing, white to greyish-white and downy, with a zonated or lobed surface appearance. The fungus was provisionally identified as a member of the genus Mortierella. As it is usually difficult to induce sporulation in such species, subcultures were made on a variety of culture media including: Sabouraud dextrose (SDA; Oxoid), potato dextrose (P...

CotH3 mediates fungal invasion of host cells during mucormycosis

“…In the present study, the CotH family of proteins was found to be highly conserved among Mucorales organisms that are known to cause invasive disease (Table 1). CotH proteins were present in Mucor spp., Lichtheimia, Rhizomucor, Mortierella, and Lentamyces, which are known to cause invasive infections to mammals and to other Mucorales (29)(30)(31)(32)(33)(34)(35). Notably, the CotH family was not present in any other organisms, including Conidiobolus coronatus, which was previously classified as a Zygomycete and causes superficial infections (2).…”

Actinomortierella wolfii: Identity and pathology

“…Three species have been identified in Actinomortierella [ 6 ], as shown in Fig. 3 , of which only A. wolfii is reported as an animal opportunist [ 22 , 23 ].…”

“…Although the transmission route in the present case is unknown [ 12 ], transmission to humans and other animals may be via inhalation from environmental sources or ingestion of contaminated food [ 25 ]. This species is of veterinary import, particularly in cattle abortion due to placentitis and endometritis [ 13 , 25 ], bovine nephritis, pyogranulomatous pneumonia and meningoencephalitis [ 12 , 22 , 23 ]. Davies et al [ 10 ] reported a bovine case of systemic infection following abortion, while Munday et al [ 11 ] described a disseminated case of a neonatal calf, and Wada et al [ 26 ], an equine eye infection.…”