Isolation and characterization of a strain of Lichtheimia corymbifera (ex Absidia corymbifera) from a case of bovine abortion

Simultaneous detection of Aspergillus nidulans, Aspergillus luchuensis and Lichtheimia sp. in a bovine abortion

Abortion in dairy cattle may be caused by infectious (viruses, fungi and protozoa) and non-infectious causes mostly related to bad management practices and genetic factors. Recently, the significant contribution of mycotic infection to bovine abortion has been recognized. This report describes an abortion case in a Chianina cow due to Aspergillus nidulans, Aspergillus luchuensis and Lichtheimia sp. diagnosed by histology, cytology, culture and molecular assays. A mixed infection due to more than one fungus in abortion is rarely demonstrated. To our knowledge, this is the first case of bovine abortion caused by co-infection with three different moulds.

Isolation of Mucorales from biological environment and identification of Rhizopus among the isolates using PCRRFLP

Background and aims: Mucorales are fungi belonging to the category of Zygomycetes, found much in nature. Culture-based methods for clinical samples are often negative, difficult and time-consuming and mainly identify isolates to the genus level, and sometimes only as Mucorales. Therefore, applying fast and accurate diagnosis methods such as molecular approaches seems necessary. This study aims at isolating Mucorales for determination of Rhizopus genus between the isolates using molecular methods. Methods: In this descriptive observational study, a total of 500 samples were collected from air and different surfaces and inoculated on Sabouraud Dextrose Agar supplemented with chloramphenicol. Then, the fungi belonging to Mucorales were identified and their pure culture was provided. DNA extraction was done using extraction kit and the chloroform method. After amplification, the samples belonging to Mucorales were identified by observing 830 bp bands. For enzymatic digestion, enzyme BmgB1 was applied for identification of Rhizopus species by formation of 593 and 235 bp segments. Results: One hundred pure colonies belonging to Mucorales were identified using molecular methods and after enzymatic digestion, 21 isolates were determined as Rhizopus species. The sequencing of PCR products and macroscopic and microscopic studies confirmed the existence of R. stolonifera, R. oryzae and R. caespitosus in the samples. Conclusion: Generally, developing a reliable method for determining Zygomycete species can be a useful tool for better understanding of the epidemiology of mucoromycosis.

Local extensive granulomatous inflammation of the neck region and lymphangitis caused by Lichtheimia corymbifera infection in a Japanese Black calf

A 7-month-old female Japanese Black calf developed elongated, nodular mass measuring 30 × 16 cm extended from the retropharyngeal region to mid lateral neck region. Histological examination revealed granulomatous lymphangitis with non-septate fungal hyphae recognized throughout the lesions. Fungal culture, DNA sequencing and molecular phylogenetic tree analysis confirmed the sequence of Lichtheimia corymbifera. The lymphogenous route was speculated to be the main route of fungal spread leading to the characteristic nodular appearance of this case.

Rhinocerebral Zygomycosis Due to a Lichtheimia ramosa Infection in a Calf: Neural Spread Through the Olfactory Nerves

Here, we report a case of rhinocerebral zygomycosis due to a Lichtheimia ramosa infection in a calf. A histopathological examination revealed that a fungus had invaded the brain through the olfactory nerves. Lichtheimia ramosa was detected by polymerase chain reaction analysis of DNA extracted from formalin-fixed paraffin-embedded samples of the affected tissue. This is the first case of rhinocerebral zygomycosis to involve cattle. Also, this is the first such case to involve fungal invasion into the central nervous system through the cranial nerve itself, rather than through perineural tissue.

Molecular Identification of Mucor and Lichtheimia Species in Pure Cultures of Zygomycetes

Background

The Mucorales are an important opportunistic fungi that can cause mucormycosis in immunocompromised patients. The fast and precise diagnosis of mucormycosis is very important because, if the diagnosis is not made early enough, dissemination often occurs. It is now well established that molecular methods such as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) are feasible and reliable tools for the early and accurate diagnosis of mucormycosis agents.

Objectives

The present study was conducted to evaluate the validity of PCR-RFLP for the identification of Mucorales and some important Mucor and Lichtheimia species in pure cultures of Zygomycetes.

Materials and Methods

Specific sense and anti-sense primers were used to amplify the Mucorales, Mucor, and Lichtheimia DNA. The PCR products were digested by AfIII, XmnI, and AcII restriction enzymes, and the resultant restriction pattern was analyzed.

Results

On the basis of the molecular and morphological data, we identified Mucor plumbeus (10.83%), M. circinelloides (9.17%), Lichtheimia corymbifera (9.17%), M. racemosus (5.83%), M. ramosissimus (3.33%), and L. blakesleeana (0.83%).

Conclusions

It seems that PCR-RFLP is a suitable technique for the identification of Mucorales at the species level.

Possible effects of glyphosate on Mucorales abundance in the rumen of dairy cows in Germany

Glyphosate (N-phosphonomethyl glycine) is registered as a herbicide for many food and non-food crops, as well as non-crop areas where total vegetation control is desired. Glyphosate influences the soil mycobiota; however, the possible effect of glyphosate residues in animal feed (soybean, corn, etc.) on animal mycobiota is almost unknown. Accordingly, the present study was initiated to investigate the mycological characteristics of dairy cows in relationship to glyphosate concentrations in urine. A total of 258 dairy cows on 14 dairy farms in Germany were examined. Glyphosate was detected in urine using ELISA. The fungal profile was analyzed in rumen fluid samples using conventional microbiological culture techniques and differentiated by MALDI-TOF mass spectrometry. LPS-binding protein (LBP) and antibodies (IgG1, IgG2, IgA, and IgM) against fungi were determined in blood using ELISA. Different populations of Lichtheimia corymbifera, Lichtheimia ramosa, Mucor, and Rhizopus were detected. L. corymbifera and L. ramosa were significantly more abundant in animals containing high glyphosate (>40 ng/ml) concentrations in urine. There were no significant changes in IgG1 and IgG2 antibodies toward isolated fungi that were related to glyphosate concentration in urine; however, IgA antibodies against L. corymbifera and L. ramosa were significantly lower in the higher glyphosate groups. Moreover, a negative correlation between IgM antibodies against L. corymbifera, L. ramosa, and Rhizopus relative to glyphosate concentration in urine was observed. LBP also was significantly decreased in animals with higher concentrations of glyphosate in their urine. In conclusion, glyphosate appears to modulate the fungal community. The reduction of IgM antibodies and LBP indicates an influence on the innate immune system of animals.

Mucormycoses caused by Lichtheimia species

Mucormycoses are life-threatening infections with fungi from the order Mucorales (Mucoromycotina). Although mucormycoses are uncommon compared to other fungal infections, e.g. aspergillosis and candidiasis, the number of cases is increasing especially in immunocompromised patients. Lichtheimia (formerly Absidia) species represent the second to third most common cause of mucormycoses in Europe. This mini review presents current knowledge about taxonomy and clinical relevance of Lichtheimia species. In addition, clinical presentation and risk factors will be discussed. Proper animal infection models are essential for the understanding of the pathogenesis and the identification of virulence factors of fungal pathogens. To date, several animal models have been used to study Lichtheimia infection. A brief overview of the different models and the main conclusions from the infection experiments is summarised in this review.

Liposomal amphotericin B and surgery as successful therapy for pulmonary Lichtheimia corymbifera zygomycosis in a pediatric patient with acute promyelocytic leukemia on antifungal prophylaxis with posaconazole

Pulmonary zygomycosis, also referred to as mucormycosis, is a fungal infection of lungs caused by fungi of the order Mucorales in the class of Zygomycetes. It is usually associated with high morbidity and mortality. Here, we report the case of a 14-year-old girl with pediatric acute promyelocytic leukemia (APL) on antifungal prophylaxis with posaconazole, who developed pulmonary Lichtheimia corymbifera (formerly Absidia corymbifera) zygomycosis. She was successfully treated by means of liposomal amphotericin B (L-AmB) and surgery. To our knowledge, this is the first published report on pediatric APL and pulmonary zygomycosis in the English language literature. At present, the patient is in complete remission of her APL and without any signs of recurrence of zygomycosis. This report suggests that efficient diagnostics, increased physician awareness, and reliance on adjunctive surgical therapy can result in a favorable outcome of pulmonary zygomycosis in immunocompromised children with hematological malignancies.