Scedosporium apiospermum isolated from a skin wound in a dog and in vitro activity of eleven antifungal drugs

Scedosporium apiospermum, an emerging opportunistic fungus, is increasingly implicated with serious invasive mycoses in immunocompromised patients. Rare occurrence and difficulty in identification of this species complicate the management of infection in dogs. In the present report, the characterization of a Scedosporium apiospermum isolate obtained from a dog’s skin wound is described. Identification was obtained through macroscopic and microscopic examination of the cultured isolate and by sequencing the internal transcribed spacer (ITS) gene of the rRNA region. Numerous hyaline septate hyphae along with conidia were observed histologically. The isolate exhibited low MIC values for voriconazole, itraconazole and isavuconazole while high MIC/MEC values were recorded for the remaining antifungals. To the best of the authors’ knowledge, this is the first reported case of isolation of S. apiospermum from a skin wound in a dog.

Detection of dermatophytes in healthy companion dogs and cats in eastern India

In recent times increasing occurrence of dermatophytosis, especially among the school children in eastern India was evidenced along with increased tendency of keeping companion animals such as dogs and cats. This study was undertaken to detect the occurrence of dermatophytes with antifungal susceptibility among the companion animals. A total of 1501 healthy companion animals comprising 1209 dogs and 292 cats belonged to individual owners in and around Kolkata (West Bengal, India) were examined for the evidence of dermatophytosis during 2011-2013. The collected samples were subjected to direct examination by standard KOH mount technique. The samples were inoculated into both Sabouraud dextrose agar (SDA) with 0.05% chloramphenicol and 0.5% cycloheximide and dermatophyte test medium (DTM). Each of the fungal isolate was identified based upon its colony characteristics and hyphal and conidial cells it produced. Antifungal susceptibility of the isolates was tested by broth micro dilution assay using fluconazole, ketoconazole, itraconazole, miconazole, griseofulvin and amphotericin-B antifungals. Among the 1209 samples from dogs and 292 samples from cats, 253 (20.93%) and 109 (37.33%) samples were positive for dermatophytes by direct examination. Three identified species of dermatophytes with predominant occurrence were Microsporum canis, Microsporum gypseum and Trichophyton mentagrophytes. Ketoconazole (0.06-0.5 µgm/ml), itraconazole (0.03-0.5 µgm/ml) and amphotericin-B (0.03-0.5 µgm/ml) showed lowest MIC values against M. canis, T. mentagrophytes and M. gypseum, respectively. This is the first systemic report of dermatophytes in healthy companion animals with large numbers of samples in India.

Detection and characterization of zoonotic dermatophytes from dogs and cats in and around Kolkata

Aim:

The ringworms of pet dogs, cats, and stray animals (dogs, cats, and other animals) could be a potential source of zoonotic infections causing a serious public health problem in the busy city Kolkata. The pet owners are more susceptible to get this infection from their pets, because of the close contact with them as dermatophytosis is very much prevalent in those pets. So, this study was aimed to check the prevalence of dermatophytosis in dogs, cats, and in pet owners.

Materials and Methods:

A total of 362 clinically suspected cases of dermatophytosis from dogs (123 in number), cats (202 in number), and human beings (37 in number) were collected and studied from in and around Kolkata to detect the presence of significant dermatophytes. Direct microscopy and cultural examination of the isolates were performed following standard methodology. Identification and characterization of the isolates were done by different biochemical tests.

Results:

Samples (n=285) having significant dermatophytic fungal infections were found to be of highest number in cats (158, 55.5%) than in dogs (108, 37.8%) and humans (19, 6.7%), respectively. The incidence of Microsporum canis (60.0%) was the highest from affecting dogs, cats, and human beings in comparison to Microsporum gypseum (22.5%), Trichophyton mentagrophytes (15.8%) and Trichophyton rubrum (1.7%). Detection of T. rubrum was only from human cases in this study, whereas the presence of rest three were slightly higher in cats than that of the dogs and humans in this present study. The incidences were higher in young animals and in humans of the age group of 21-30 years, during the rainy season (from April to August) and also in in-contact human beings.

Conclusion:

M. canis was the most commonly pathogen among all causing dermatophytosis in animals and also in the pet owners. M. gypseum and T. mentagrophytes were other pathogens associated with these infections. These infections were more prevalent in the rainy seasons and in in-contact human patients or pet owners.

Synthesis of LiNbO3 Nanoparticles by Citrate Gel Method

We present investigations on the preparation of nearly stoichiometric lithium niobate (LiNbO3) nanoparticles using citrate gel method. Citric acid is used as a chelating agent and ethylene glycol is added for polyestarification between the chelates. In addition to the main lithium niobate phase, the secondary phase of lithium niobate, LiNb3O8, and an unreacted phase of Nb2O5 were also observed in the resultant product. The appearance of unwanted phases is a serious problem in citrate gel method. We have observed that the synthesis parameters such as molar ratio of citric acid to metal ions (R1), pH, molar ratio of ethylene glycol to citric acid (R2) and calcination temperature strongly influence the presence of the unwanted phases and these parameters are optimized to remove these phases. Evolution of the phase was investigated by powder XRD whereas TG/DTA was done to find out the crystallization temperature. It was observed that nearly stoichiometric and pure LiNbO3 nanoparticles can be obtained with the optimized parameters, R1 = 3, pH = 8, R2 ≥ 2 and calcination temperature = 700 degrees C. The stoichiometry of the synthesized LiNbO3 nanoparticles was investigated using Raman spectroscopy.

Determination of the antimalaria drug artemether in pharmaceutical preparations by differential pulse polarography

A differential pulse polarographic method has been developed for the determination of artemether in its pharmaceutical formulations. The polarographic behaviour of artemether was examined in various buffer systems over the pH range 3.0-10.0. In phosphate buffer pH 5.5/methanol solution (7:3, v/v) the differential pulse polarograms displayed reproducible peaks at Ep-0.01 V versus Ag/AgCl. Under these conditions strict linearity between artemether concentration and peak height was observed in 3.4x10(-7)-3.0x10(-5)mol/L concentration range (R=0.9998). The detection limit was calculated to be 32 ng/mL. The polarographic method was applied to the determination of the content of artemether in tablets and capsules by using the standard addition method. The analysis of tablets containing 20mg artemether showed a mean value of 19.73 mg with a relative standard deviation (R.S.D.) of +/-1.01%. A content of 39.74 mg artemether was found in 40 mg capsules with a relative standard deviation of +/-0.53%. The polarographic method is characterised to be cheap, precise and not time-consuming and can therefore be used for routine analysis of artemether in its pharmaceutical preparations.