Identification of Fungal Species Associated with Gall Oak (Quercus infectoria) Decline in Iran

The gall oak (Quercus infectoria Oliv.) tree is one of the most important and valuable forestry species in the Northern Zagros forests in the west of Iran. Gall oak decline is considered to be one of the most important diseases currently affecting the Zagros oak forests in Iran. The main objective of the present study, conducted in the years 2021 to 2023, was to investigate the possible role of fungi as causative agents of gall oak dieback in the Zagros forests of Iran. Wood samples were taken from gall oak trees showing canker, dieback, and internal wood discoloration symptoms. Fungal isolates recovered from gall oak trees were identified based on cultural and morphological characteristics, as well as phylogenetic analyses using DNA sequencing of the internal transcribed spacer region of rDNA and partial beta-tubulin. Achaetomium aegilopis, Alternaria tenuissima, Apiospora intestini, Botrytis cinerea, Coniochaeta sp., Coniothyrium palmarum, Coniothyrium sp., Cytospora rhodophila, Dialonectria episphaeria, Diatrype sp., Diatrypella macrospora, Endoconidioma populi, Fonsecazyma sp., Fusarium ipomoeae, Jattaea discreta, Kalmusia variispora, Microsphaeropsis olivacea, Neoscytalidium dimidiatum, Paecilomyces lecythidis, Paramicrosphaeropsis eriobotryae, Paramicrosphaeropsis ellipsoidea, and Seimatosporium pezizoides were identified from diseased trees. Pathogenicity tests were performed by artificial inoculation of excised branches of healthy gall oak trees under controlled conditions and evaluated after 35 days by measuring the discolored lesion length at the inoculation site. N. dimidiatum was the most virulent species and caused the longest wood necrosis within 35 days of inoculation. In the greenhouse test, only some species induced typical symptoms of canker. All isolated fungi are reported for the first time on gall oak trees in the world.

Isolation and genome characterization of Paenibacillus polymyxa 188, a potential biocontrol agent against fungi

AIMS

In this work, we aimed to isolate marine bacteria that produce metabolites with antifungal properties.

METHODS AND RESULTS

Paenibacillus polymyxa 188 was isolated from a marine sediment sample, and it showed excellent antifungal activity against many fungi pathogenic to plants (Fusarium tricinctum, Pestalotiopsis clavispora, Fusarium oxysporum, F. oxysporum f. sp. Cubense (Foc), Curvularia plantarum, and Talaromyces pinophilus) and to humans (Aspergillus terreus, Penicillium oxalicum, and Microsphaeropsis arundinis). The antifungal compounds produced by P. polymyxa 188 were extracted and analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The complete genome sequence and biosynthetic gene clusters of P. polymyxa 188 were characterized and compared with those of other strains. A total of 238 carbohydrate-active enzymes (CAZymes) were identified in P. polymyxa 188. Two antibiotic gene clusters, fusaricidin and tridecaptin, exist in P. polymyxa 188, which is different from other strains that typically have multiple antibiotic gene clusters.

CONCLUSIONS

Paenibacilluspolymyxa 188 was identified with numerous biosynthetic gene clusters, and its antifungal ability against pathogenic fungi was verified.

Riverine mycobiome dynamics: From South African tributaries to laboratory bioreactors

Riverine fungi have the capacity for both pathogenicity, pertinent for countries with elevated immunosuppressed individuals, and bioremediation potential. The purpose was (i) to screen for the presence of clinically relevant riverine fungi and associations with anthropogenic influence, and (ii) the acclimatisation of environmental communities toward potential bioremediation application. Communities were harvested from polluted rivers in Stellenbosch, South Africa, and mycobiomes characterised by high-throughput amplicon sequencing. The remainder of the biomass was inoculated into continuous bioreactors with filtered river water or sterile minimal medium. Seven weeks later, the mycobiomes were re-sequenced. At least nine clinically relevant species were detected, including agents of mycoses belonging to the genus Candida. The occurrence of genera that harbour opportunisticstrains was significantly higher (P = 0.04) at more polluted sites. Moreover, positive correlations occured between some genera and pollution indices, demonstrating the potential of fungi for addition to water quality indicators. Despite biomass increase, almost all pathogens were undetectable after seven weeks, demonstrating less resilience in conditions mimicking rivers. Thus, when screening riverine biomes for bioremediation potential, ambient reactors select against human pathogens. This indicates a transient introduction of allochthonous opportunistic species into rivers due to insufficient sanitation, and the potential of bioremediation strategies that selects for environmental rather than pathogenic traits.

Invasive Fungal Infections and Oomycoses in Cats: 1. Diagnostic approach

CLINICAL RELEVANCE

In contrast to superficial fungal infections, such as dermatophytosis, invasive fungal infections (IFIs) are characterised by penetration of tissues by fungal elements. Disease can spread locally within a region or can disseminate haematogenously or via the lymphatics. The environment is the most common reservoir of infection. Since fungal spores are airborne, indoor cats are also susceptible to IFIs. Some environmental fungi are ubiquitous and present globally, while others are endemic or hyperendemic within specific geographic regions. Zoonotic pathogens include Microsporum canis, Sporothrix schenckii and Sporothrix brasiliensis.

AIM

In the first of a two-part article series, the approach to the investigation of feline IFIs and oomycoses is reviewed. As well as tips for diagnosis, and information on the ecological niche and distribution of fungal pathogens, the review covers clinical presentation of the most common IFIs, including cryptococcosis, histoplasmosis, blastomycosis, coccidioidomycosis, sporotrichosis, phaeohyphomycosis, aspergillosis and dermatophytic pseudomycetoma, as well as the oomycoses pythiosis, lagenidiosis and paralagenidiosis. In Part 2, the spectrum of activity, mechanisms of action, pharmacokinetic and pharmacodynamic properties and adverse effects of antifungal drugs are reviewed, and the treatment and prognosis for specific IFIs and oomycoses are discussed.

EVIDENCE BASE

The review draws on published evidence and the authors' combined expertise in feline medicine, mycology, dermatology, clinical pathology and anatomical pathology.

Squamous Cell Carcinoma with Co-infection of Microsphaeropsis arundinis and Geotrichum candidum: A Rare Case Report

BACKGROUND: Squamous cell carcinoma (SCC) is a non-melanoma skin cancer is a malignant carcinoma with an increasing incidence. The diagnosis of SCC is mainly based on clinical features and an excisional biopsy with histologic confirmation should be performed on all clinically suspected lesions to determine the prognostic and management of SCC. The first-line treatment of SCC of the skin is complete surgical excision. Microsphaeropsis arundinis and Geotrichum candidum are types of fungi that can infect the skin. CASE REPORT: We report a case of a 46-year-old female patient that was diagnosed with SCC based on clinical, dermoscopy, and histopathological features. In addition, M. arundinis and G. candidum were also found on culture examination, where these fungi are rarely found, especially in cases of SCC. CONCLUSION: The patient underwent tumor excision and amputation.

Feline disseminated cutaneous phaeohyphomycosis due to Exophiala spinifera

A six-year-old domestic shorthair cat was presented for a subcutaneous digital nodular lesion on the right forelimb. On physical examination a similar lesion was identified on the right hindlimb. Disseminated cutaneous phaeohyphomycosis was diagnosed from histopathological changes in representative tissue biopsies and fungal culture. The isolate was identified by sequencing of ITS rDNA as Exophiala spinifera. This is the first report of disseminated cutaneous disease caused by E. spinifera in the cat.

Metastatic pulmonary carcinomas in cats ('feline lung-digit syndrome'): further variations on a theme

CASE SERIES SUMMARY

The aim of this retrospective case series was to describe seven cases where cats with primary lung tumours were presented because of metastases to extra-pulmonary sites ('feline lung-digit syndrome'). Specifically, we wanted to emphasise less typical case descriptions where tumour emboli resulted in lesions developing in the musculature (including the muscles of the head), skin or distal aorta.

RELEVANCE AND NOVEL INFORMATION

The cases are presented to increase clinical awareness of this entity in feline practice, especially when characteristic combinations of clinical signs are present. When clinicians have a high index of suspicion for these presentations, radiology (thorax and digits) or ultrasound (distal aorta), combined with collection of fine needle aspirate specimens for cytology, are usually sufficient to secure a definitive diagnosis. Novel information in this series includes CT and MRI findings from some cases. Typically, needle aspiration or biopsy targeting the skin, digits and lesions in musculature is far easier compared with sampling the primary tumour site in the lungs. The differential diagnosis and investigation of multiple digital lesions is also considered.

Practical urinalysis in the cat: 2: Urine microscopic examination 'tips and traps'

SERIES OUTLINE

This is the second article in a two-part series on urinalysis in the cat. The specific focus is urine microscopic examination. Part 1, which appeared in the March 2016 issue, discussed urine macroscopic examination.

PRACTICAL RELEVANCE

Urinalysis is an essential procedure in feline medicine but often little attention is paid to optimising the data yielded or minimising factors that can affect the results.

CLINICAL CHALLENGES

For the best results, appropriately collected urine should be prepared promptly by specialist laboratory personnel for the relevant tests and assessed by a clinical pathologist. This is invariably impractical in clinical settings but careful attention can minimise artefacts and allow maximum useful information to be obtained from this seemingly simple process.

AUDIENCE

Clinical pathologists would be familiar with the information provided in this article, but it is rarely available to general or specialist practitioners, and both groups can potentially benefit.

EQUIPMENT

Most of the required equipment is routinely available to veterinarians. However, instructions have been provided to give practical alternatives for specialist procedures in some instances.

EVIDENCE BASE

The evidence base for feline microscopic urinalysis is quite poor and information has largely been extrapolated from the human literature. Information from feline studies has been included where available. In addition, practical clinicopathological and clinical observations are provided.