scholarly journals Phenotypic and Genotypic Identification and Antifungal Susceptibility of Some Fungi Isolated from Tympanotonus fuscatus var. radula

Author(s):  
Asemota Uwem Kelly ◽  
Obiekezie Smart Obuneme ◽  
Makut Makwin Danladi ◽  
Jubril Egwu Owuna

Aim: This study aimed to identify fungi isolated from Tympanotonus fuscatus var. radula and evaluate its level of susceptibility to known antifungal compounds. Place and Duration of Study: Biotechnology Advanced Research Centre, Sheda Science and Technology Complex, Abuja between September and December 2019. Methods: Tympanotonus fuscatus var. radula samples were purchased from the Keffi, Masaka, and Orange markets in Nasarawa State, Nigeria. Fungal isolation was achieved using Sabouraud dextrose agar supplemented with chloramphenicol and incubated at 28ᵒC for 5 days. ITS-1 and ITS-4 primers were used at 94°C for 2 min, 52°C for 1 min, and 72°C for 2 min for the polymerase chain reaction before sequencing at Inqaba Biotech South Africa. Disk diffusion technique was employed for antifungal susceptibility testing. Results: Data obtained revealed that the suspected fungal species exhibited a generally higher level of resistance (19-40 mm) to 1 µg voriconazole in addition to a 20-35.5 mm zone of inhibition against 10 µg ketoconazole. Blast sequence analysis of the isolated samples revealed a 99.65% sequence homology to Meyerozyma guilliermondii, 99.38% to Fusarium oxysporium isolate E-225 1 and 96.23% to Aspergillus terreus isolate A2S4.   Conclusion: Food safety involves isolating and accurately identifying disease causing pathogens such as fungi in food. Based on the fungal load obtained from this study, proper cooking and handling of sea-food which would otherwise cause disease, is highly recommended.

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Chibuzor M. Nsofor ◽  
Mirabeau Y. Tattfeng ◽  
Chijioke A. Nsofor

Abstract Background This study was aimed to determine the prevalence of qnr genes among fluoroquinolone-resistant Escherichia coli (FREC) isolates from Nigeria. Antimicrobial susceptibility testing was performed by disc diffusion technique. Polymerase chain reaction was used to identify Escherichia coli (E. coli) and for the detection of qnr genes. Results A total of 206 non-duplicate E. coli were isolated from 300 clinical specimens analyzed. In all, 30 (14.6%) of these isolates were FREC; the resistance to fluoroquinolones among these 30 FREC showed 80% (24), 86.7% (26), 86.7% (26), 100% (30), 86.7% (26), 93.3% (28) and 86.7% (26) were resistant to pefloxacin, ciprofloxacin, sparfloxacin, levofloxacin, nalidixic acid, ofloxacin and moxifloxacin, respectively. The distribution of FREC among the various sample sources analyzed showed that 14%, 10%, 13.3%, 16.7% and 20% of the isolates came from urine, stool, high vaginal swab, endo cervical swab and wound swab specimens, respectively. More FREC were isolated from female samples 73.3% (22) compared to male samples 26.7% (8) and were more prevalent among the age group 26–35 years (40%). Twenty eight out of the 30 (93.3%) FREC isolates possessed at least one fluoroquinolone resistance gene in the form of qnrA 10 (33.3%) and qnrB 18 (60%), respectively; qnrS was not detected among the FREC isolates analyzed and 13.5% of the isolates possessed both the qnrA and qnrB genes. Phylogenetic analysis showed that these isolates were genetically diverse. Conclusions These findings suggest a possible resistance to fluoroquinolone is of high interest for better management of patients and control of antimicrobial resistance in Nigeria.


2004 ◽  
Vol 34 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Vaidotas Lygis ◽  
Rimvydas Vasiliauskas ◽  
Jan Stenlid

Persistence of the root rot pathogen Heterobasidion annosum (Fr.) Bref. s.s. on infested areas and its transfer to a forest regeneration was studied in three forest sites in eastern Lithuania. The sites represented H. annosum disease centres in Pinus sylvestris L. stands, which were clear-felled and replanted with Betula pendula Roth 25 years prior to our study. Fungal isolation from trees and stumps on each site was performed on both replanted B. pendula and surrounding P. sylvestris from the previous generation. Low productivity of B. pendula stands (45.0–76.1 m3·ha–1), high mortality rates, and comparatively low vigor of trees (measured as crown densities) indicated a strong impact of root rot. Based on somatic incompatibility tests, we detected large spreading areas of clones of H. annosum (up to 48 m across) and old (35- to 40-year-old) clonal individuals. Territorial clones covered areas that encompassed both previous stands of P. sylvestris and current stands of B. pendula. Our results showed that H. annosum is able to persist in root systems of diseased trees for decades and readily attack birch replanted on infested sites. In addition, a total of 83 fungal species (out of 398 isolates) was found as a result of sampling 508 B. pendula, 49 P. sylvestris, 21 Juniperus communis L., and 1 Salix cinerea L. trees.


2021 ◽  
Vol 11 (3) ◽  
pp. 373-379
Author(s):  
Huitao Li ◽  
Xueyu Chen ◽  
Xiaomei Qiu ◽  
Weimin Huang ◽  
Chuanzhong Yang

Invasive fungal infection (IFI) is the leading cause of death in neonatal patients, yet the diagnosis of IFI remains a major challenge. At present, most IFI laboratory diagnostic methods are based on classical, but limited, methods such as fungal isolation and culture and histopathological examination. Recently, quantitative polymerase chain reaction (qPCR) and droplet digital polymerase chain reaction (ddPCR) technology have been adopted to quantify nucleic-acid identification. In this study, we established qPCR and ddPCR assays for IFI diagnosis and quantification. qPCR and ddPCR were carried out using identical primers and probe for the amplification of 18S rRNA. Assay results for three fungal strains were positive, whereas ten non-fungal strains had negative results, indicating 100% specificity for both ddPCR and qPCR methods. Genomic DNA of Candida albicans was tested after a serial dilution to compare the sensitivity of the two PCR methods. The limit of detection of ddPCR was 3.2 copies/L, which was a ten-fold increase compared with that of the qPCR method (32 copies/L). Blood samples from 127 patients with high-risk factors and clinical symptoms for IFI were collected from a NICU in Shenzhen, China, and analyzed using qPCR and ddPCR. Thirty-four blood samples from neonates had a proven or probable diagnosis of IFI, and 25 of these were positive by qPCR, whereas 30 were positive by ddPCR. Among the 93 blood samples from neonates who had a possible IFI or no IFI, 24 were positive using qPCR, and 7 were positive using ddPCR. In conclusion, ddPCR is a rapid and accurate pan-fungal detection method and provides a promising prospect for IFI clinical screening.


Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 122 ◽  
Author(s):  
Maryam Tavakol Noorabadi ◽  
Valiollah Babaeizad ◽  
Rasoul Zare ◽  
Bita Asgari ◽  
Miriam Haidukowski ◽  
...  

Knowledge of the genetic diversity detected among fungal species belonging to the genus Aspergillus is of key importance for explaining their important ecological role in the environment and agriculture. The current study aimed to identify Aspergillus species occurring in the rhizosphere of sugarcane in the South of Iran, and to investigate their mycotoxin profiles. One-hundred and twenty-five Aspergillus strains were isolated from the soil of eight major sugarcane-producing sites, and were molecularly identified using sequences of partial -tubulin (benA) and partial calmodulin (CaM) genes. Our molecular and phylogenetic results showed that around 70% of strains belonged to the Aspergillus section Nigri, and around 25% of species belonged to the Aspergillus section Terrei. Species belonging to both sections are able to produce different mycotoxins. The production of mycotoxins was measured for each species, according to their known mycotoxin profile: patulin (PAT) and sterigmatocystin (STG) for Aspergillus terreus; ochratoxin A (OTA) and fumonisins for Aspergillus welwitschiae; and OTA alone for Aspergillus tubingensis. The data showed that the production of OTA was detected in only 4 out of 10 strains of A. welwitschiae, while none of the A. tubingensis strains analyzed produced the mycotoxin. Fumonisins were produced by 8 out of 10 strains of A. welwitschiae. Finally, none of the 23 strains of A. terreus produced STG, while 13 of them produced PAT. The occurrence of such mycotoxigenic plant pathogens among the fungal community occurring in soil of sugarcane fields may represent a significant source of inoculum for the possible colonization of sugarcane plants, since the early stages of plant growth, due to the mycotoxin production capability, could have worrisome implications in terms of both the safety and loss of products at harvest.


2019 ◽  
Vol 10 (2) ◽  
pp. 1228-1232
Author(s):  
Shebi S ◽  
Geetha RV ◽  
Lakshmi Thangavelu Lakshmi Thangavelu

An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycoses such as athlete's foot, ringworm, candidiasis, serious systemic infections such as Cryptococcal meningitis, and others. In traditional medicine, extracts and essential oil from flowers and leaves are used in the belief they may be useful to treat a variety of fungal disorders. The aim of this study was to analyse the antimycotic properties of rosemary oil and its principal components. The Rosemary oil was screened for antifungal activity by the disc diffusion method. Activated cultures of Candida albicans in Sabouraud’s broth was adjusted to 0.5 McFarland standards [108cfu/ml]. 100 µl of the inoculum was introduced to molten Sabourauds dextrose agar and poured in the sterile Petri plates and allowed to set. Sterile filter paper discs (6.0 mm diameter) impregnated with 25µl, 50µl and 100µl /disc were placed on fungal seeded plates and incubated at 28oC for 48 hrs. Clear zones within which fungal growth was absent were measured and recorded as the diameter (mm) of complete growth inhibition. All the concentrations of the test solution inhibited the fungal species with varying degree of sensitivity. The extract showed good antifungal activity at different concentrations with a maximum zone of inhibition of 38 mm at concentration 100µl. This study provides a sample large enough to determine the antifungal properties of Rosemary oil and suggests further studies for possible therapeutic use.


Cocoons of earthworm Eudrilus eugeniae were collected from vermiculture bed and found that it had antibacterial activity. The size of zone of inhibition was directly proportional to the size of cocoons examined. Along with nutritious fluid and embryos, culturable bacterial community was found inside the cocoons. Bacterial colonies were isolated from the trails of newly hatched, juvenile worms in the nutrient agar medium and examined. Gram negative, rod shaped bacterium was found to be abundant in the trails of juvenile earthworms. Polymerase chain reaction was performed from this bacterium to amplify the gene of 16S rRNA and analyzed. Subsequent bi-directional DNA sequencing revealed that this abundant bacterium is highly related to 16S rRNA gene sequence of a strain, Alcaligenes faecalis. Based on available literature, we hypothesize that this bacterium could be symbiotically associated with cocoons of earthworms.


Author(s):  
A. Espinel-Ingroff ◽  
M. Sasso ◽  
J. Turnidge ◽  
M. Arendrup ◽  
F. Botterel ◽  
...  

Susceptibility testing is an important tool in the clinical setting; its utility is based on the availability of categorical endpoints, breakpoints (BPs) or epidemiological cutoff values (ECVs/ECOFFs). CLSI and EUCAST have developed antifungal susceptibility testing, BPs and ECVs for some fungal species. Although the Concentration Gradient Strip BioMerieux Etest is useful for routine testing in the clinical laboratory, ECVs are not available for all agent/species; the lack of clinical data precludes development of BPs. We re-evaluated and consolidated Etest data points from three previous studies, and included new data. We defined ECOFFinder Etest ECVs for three sets of species/agent combinations: fluconazole, posaconazole and voriconazole and 8 Candida spp.; amphotericin B and 3 non-prevalent Candida spp.; and caspofungin and 5 Aspergillus spp. The total of Etest MICs from 23 laboratories (Europe, the Americas, South Africa) included (antifungal agent/dependent): 17,242 Candida albicans , 244 C. dubliniensis , 5,129 C. glabrata species complex (SC), 275 C. guilliermondii ( Meyerozyma guilliermondii ), 1,133 C. krusei ( Pichia kudriavzevii ), 933 C. kefyr ( Kluyveromyces marxianus ), 519 C. lusitaniae ( Clavispora lusitaniae ), 2,947 C. parapsilosis SC, 2,214 C. tropicalis , 3,212 Aspergillus fumigatus , 232 A. flavus , 181 A. niger , and 267 A. terreus SC isolates. Triazole MICs for 66 confirmed non-wild-type (non-WT) Candida isolates were available ( ERG11 point mutations). Distributions fulfilling CLSI ECV criteria were pooled and ECOFFinder Etest ECVs were established for triazoles (9 Candida spp.); amphotericin B (3 less-prevalent Candida spp.) and caspofungin (4 Aspergillus spp.). Etest fluconazole ECVs could be good detectors of Candida non-WT isolates (59/61 Non-WT: 4 of 6 species).


2020 ◽  
Vol 6 (3) ◽  
pp. 103 ◽  
Author(s):  
Patrick Schwarz ◽  
Eric Dannaoui

The interaction of isavuconazole with immunosuppressors (tacrolimus, cyclosporin A, or sirolimus) against 30 Aspergillus isolates belonging to the most common species responsible for invasive aspergillosis in humans (Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) was evaluated in vitro by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing. The interpretation of the results was performed based on the fractional inhibitory concentration index. The combination of isavuconazole with tacrolimus, cyclosporin A, or sirolimus, was synergistic for 56, 20, or 10% of the isolates, respectively. Interestingly synergy of the combination of isavuconazole with tacrolimus was also achieved for the majority of azole-resistant isolates of A. fumigatus, and for all A. niger isolates with isavuconazole minimal inhibitory concentrations ≥ 8 µg/mL. Antagonistic interactions were never observed for any combination tested.


2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Olga Rivero-Menendez ◽  
Juan Carlos Soto-Debran ◽  
Narda Medina ◽  
Jose Lucio ◽  
Emilia Mellado ◽  
...  

ABSTRACT Antifungal resistance is one of the major causes of the increasing mortality rates for fungal infections, especially for those caused by Aspergillus spp. A surveillance program was established in 2014 in the Spanish National Center for Microbiology for tracking resistance in the most prevalent Aspergillus species. A total of 273 samples were included in the study and were initially classified as susceptible or resistant according to EUCAST breakpoints. Several Aspergillus cryptic species were found within the molecularly identified isolates. Cyp51 mutations were characterized for Aspergillus fumigatus, Aspergillus terreus, and Aspergillus flavus sensu stricto strains that were classified as resistant. Three A. fumigatus sensu stricto strains carried the TR34/L98H resistance mechanism, while two harbored G54R substitution and one harbored the TR46/Y121F/T289A mechanism. Seventeen strains had no mutations in cyp51A, with ten of them resistant only to isavuconazole. Three A. terreus sensu stricto strains harbored D344N substitution in cyp51A, one of them combined with M217I, and another carried an A249G novel mutation. Itraconazole-resistant A. flavus sensu stricto strains harbored P220L and H349R alterations in cyp51A and cyp51C, respectively, that need further investigation on their implication in azole resistance.


2020 ◽  
Vol 7 (3) ◽  
pp. 130
Author(s):  
Amin Tahoun ◽  
Helmy K. Elnafarawy ◽  
Ehab Kotb Elmahallawy ◽  
Abdelhamed Abdelhady ◽  
Amira M. Rizk ◽  
...  

Diagnosis and treatment of ocular fungal infection in equine seems very challenging for owners and clinicians. The present study aimed to identify and characterize fungal species isolated from the eyes of clinically healthy and diseased equines (N = 100) from Dakahlia Governorate, Egypt. The work also involved morphological and molecular characterization of the major fungal species. In addition, correlations between the occurrence of isolated fungi and some of the potential risk factors were also investigated. Interestingly, the prevalence rate of ocular mycosis in all examined equines in the study was 28% and there were major clinical signs associated with ocular fungal infection. Moreover, the identified fungal species included Aspergillus flavus, A. fumigatus, A. niger, Penicillium spp., Mucor spp., and Alternari spp. with a corresponding prevalence rate of 63.9%, 27.8%, 15.3%, 18.1%, 13.9%, and 4.2%, respectively, in healthy equine eyes, while their prevalence in diseased equine eyes was 57.1%, 32.1%, 21.4%, 7.1%, 3.6%, and 0%. Furthermore, a statistical significant association (p < 0.05) was found between the frequency of isolation of A. fumigatus and Penicillium and several risk factors (breed, sex, and ground type), while the remaining risk factors and occurrence of fungi were not statistically correlated. A subset of the Aspergillus species samples positive by polymerase chain reaction (PCR) were sequenced and their phylogenetic analysis identified three species of Aspergillus. Taken together, our study provides novel data related to the occurrence of ocular mycosis in equine in Egypt. Given the zoonotic potential of some identified fungi, our data may be helpful for implementation of novel diagnostic and therapeutic strategies for combating this sight-threatening infection in equine.


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