Evaluation of Dermatophyte Test Medium and Sabouraud Dextrose Agar for Isolation of Dermatophyte Species

Background and Objective: Dermatophyte infections require laboratory diagnosis before treatment is started. Although direct microscopy is routinely performed but culture of dermatophytes is the gold standard. However, it takes about 4 weeks for species identification on primary media. Our aim was to compare dermatophyte test medium (DTM) as a screening medium for the isolation of dermatophytes in comparison with sabouraud dextrose agar (SDA). Methods: It was a comparative study carried out at the Department of Microbiology of Post Graduate Medical Institute, Lahore over a period of nine months. Samples were collected from one hundred patients with clinically suspected dermatophytoses after taking informed written consent. The samples were examined microscopically and then inoculated on two types of culture media, one Sabouraud dextrose agar (SDA) with added chloramphenicol, gentacin and cycloheximide and other dermatophyte test medium (DTM) with added chlortetracycline, gentacin and cyclohexamide. Results: Fungal growth was observed in fifty-six samples on culture. Out of the fifty-six positive on cultures, nineteen were that of dermatophytes. Out of n = 100 patients, ten were positive on SDA while n = 14 dermatophyte species were able to grow on DTM. A significantly higher positivity (P ³ 0.05) for isolating dermatophytes was observed by DTM as compared to SDA. DTM was able to isolate (71%) of the dermatophytes in first 10 days. Isolation rate of dermatophyte species was higher (73.68%) on DTM as compared to SDA which was 52.6%. Conclusion: Authors recommend the use of dermatophyte test medium for the primary isolation and identification of dermatophyte species to be more effective and time saving.

Experimental design of a culture approach for corneal endothelial cells

Background The harvesting of corneal endothelial cells (CECs) has received special attention given its potential as therapy for corneal blindness. The main challenges to overcome for this purpose are related to the culture media formulation, cellular density at the primary isolation, and the number of passages in which CECs can retain their functional characteristics. The alternance of different media formulations to harvest CECs has an impact on the cellular yield and morphology. We herein analyzed eight different sequences of growth factor-supplemented proliferative (P) and non-supplemented resting (R) media upon passages to find the optimal P/R culture media sequence in regards of cell yield, morphology, procollagen I production, ATPase function, and the expression of ZO-1 and ATPase. Results PRPR and PRRR sequences showed the higher cell yield and hexagonal morphology rate. CECs cultured in the PRRR sequence produced procollagen I, showed Na/K-ATPase function, and expression of ZO-1 and Na/K-ATPase by immunocytochemistry. Our study sets a culture approach to guarantee CECs expansion, as well as functionality for their potential use in tissue engineering and in vivo analyses. Conclusions Alternation of P and R culture media improves CECs culture. PRRR sequence demonstrated to be effective and for CECs proliferation lowering the cost implied in PRPR sequences. We discarded the use of pituitary extract and ROCK inhibitors as essential for CECs proliferation.

RARE SPECIES IN THE STRUCTURE OF ACID-RESISTANT MEMBERS OF THE ORDER ACTINOMYCETALES ISOLATED FROM CLINICAL MATERIAL

The article presents data on the structure of acid-resistant members of the order Actinomycetales and rare species that have been isolated and identified using various methods. The study included strains of non-tuberculous mycobacteria (NTM) isolated from clinical material during examination for tuberculosis in the period from 2016 to 2019. The total number of samples with signs of NTMs growth that were included in the study was 316 samples. Primary isolation on Levenshtein-Jensen, Finn II, and MGIT media and NTMs identification by DNA-hybridization. All strains that were not identified prior to the species and culture, identified as microorganisms with a high G+C content (High GC GR +) were re-identified using a MALDI-ToF Microflex LT mass spectrometer (Bruker®). By the method of DNA-hybridization, 188 strains isolated by NTM were successfully identified to form 58.5% of all selected cultures. Among the selected species, representatives of slowly growing NTMs (M. avium complex, M. gordonae, M. kansasii) predominated, which amounted to 67.0% of all NTM strains identified to the species. Among the cultures for which DNA hybridization failed to carry out acceptable identification, predominantly NTMs were found, among which M. gordonae, M. avium, M. kansasii dominated. A number of NTMs were represented by rare species: M. iranicum and M. pseudoshottsii. Among this group of microorganisms, other acid-resistant aerobic actinomycetes were isolated, including those of potential clinical significance: Gordonia spp., Tsukamurella spp., Rhodococcus spp., Nocardia spp. When identifying cultures containing high concentrations of G+C, the maximum number of microbial associations was revealed, including those consisting of two types of NTMs (M. monacense + M. flavescens, M. avium + M. kansasii), as well as associations of M. gordonae with staphylococci. The same group included rare NTM species: M. fredericbergense, M. szulgai, M. malmoense, M. bohemicum, M. septicum, as well as representatives of the genera Nocardia, Gordonia, Tsukamurella.

Comparative analysis of nutrient media for determination of the biochemical properties of Enterobacteria

The stage of identification of microorganisms is one of the most important and time-consuming stages of conducting bacteriological studies. On nutrient media with primary isolation by a combination of biochemical characteristics, several genera of enterobacteria can be detected simultaneously. Therefore, an important condition for the effectiveness of bacteriological studies to isolate representatives of the Enterobacteriaceae family is an adequate selection and quality of culture media. This allows you to determine the phenotypic properties of the grown cultures of microorganisms and correctly identify them. A comparative assessment of the biological properties of a number of modern nutrient media was carried out to determine the cultural-morphological and biochemical properties of enterobacteria. Key words: nutrient media, enterobacteria, phenotypic features, biochemical properties, differentiating properties, selectivity

Scanning of Processed Food Contaminating Fungi and Determine the Potential Aflatoxigenic type

This study was conducted in the plant protection dept., College of Agriculture, University of Basrah to investigate the food contaminated fungi in several food products involved potato chips, pasta, and popcorn to specify the potential aflatoxigenic species. Eight samples of food products were randomly collected from local market included two samples of pasta, 5 samples potato chips, and one sample of popcorn. The primary isolation was performed on potato dextrose agar (PDA) in 9 cm Petri dishes; the isolated fungi were purified then diagnosed morphologically. The isolation results revealed a presence of several species within three main fungal genera, which included, Penecillium sp., Alternaria alternata , Aspergillus flavus, A. niger, A. alliaceus, A. candidus, A. fumigatus and A. sclerotiorum in prevalence percentages 43.75 ,35.00 , 18.75, 27.50, 5.64, 3.75, 3.75, 3.75, 3.75 % respectively and frequency percentage 7.15, 2.60, 9.07, 10.69, 0.46, 1.28, 0.46, 1.00% respectively. A. flavus was obtained to examine its ability to produce Aflatoxin using ammonia vapor test. The results revealed that nine isolates of A. flavus showed a possible ability to produce Aflatoxin B1.

Microbiological and Clinical Aspects of Cervicofacial Actinomyces Infections: An Overview

Similarly to other non-spore-forming Gram-positive anaerobes, members of the Actinomyces genus are important saprophytic constituents of the normal microbiota of humans. Actinomyces infections are considered to be rare, with cervicofacial infections (also known as ‘lumpy jaw syndrome’) being the most prevalent type in the clinical practice. Actinomycoses are characterized by a slowly progressing (indolent) infection, with non-specific symptoms, and additionally, the clinical presentation of the signs/symptoms can mimic other pathologies, such as solid tumors, active Mycobacterium tuberculosis infections, nocardiosis, fungal infections, infarctions, and so on. The clinical diagnosis of actinomycosis may be difficult due to its non-specific symptoms and the fastidious, slow-growing nature of the pathogens, requiring an anaerobic atmosphere for primary isolation. Based on 111 references, the aim of this review is to summarize current advances regarding the clinical features, diagnostics, and therapy of cervicofacial Actinomyces infections and act as a paper for dentistry specialists, other physicians, and clinical microbiologists.

Detection Of Candida Albicans Responsible For Vulvovaginitis In Women

Background: The vaginal microbial ecosystem stability preclude many other organisms but sometimes the vaginal micro biota is disturbed and this cause change in the normal balance causing symptoms of vulvuvaginitis like abnormal or increased vaginal discharge, redness and itching. Objective: To prove C. albicans presence in their vagina clinically and laboratory by culture of vaginal swab on two media. Type of the study: This study is a case control study Methods: This study is a case control study in which 100 clinically patient women admitted to maternity hospital in kalar city and khanaqin hospital during the period from 1st August– 30th of October 2016 who were examined to prove C. albicans presence in their vagina clinically and laboratory by culture of vaginal swab on two media, the first media was used for primary isolation which was Sabouraud´s dextrose agar media and the second was to differentiate Candida spp. according to their color . Results: Results of this study presented that the highest invasion of the vagina of Candida spp was accounted for C. albicans (39.6%)from the (53) positive cultures , while other species were as follows: C. glabrata (26.4%), C. tropicalis (20.8%) ,C. krusi(13.2 %). Conclusions: this study presented that the highest invasion of the vagina of Candida spp was accounted for C. albicans