Journal of Advances in Microbiology

Clinicomycological Evaluation and Therapeutic Management of Secondary Malassezia pachydermatis Dermatitis Associated with Generalized Demodicosis in Dog

2026-08-20T07:27:28+00:00

Aim: To describe the clinicomycological, cytological, antifungal susceptibility and therapeutic findings of secondary Malassezia pachydermatis dermatitis associated with generalised demodicosis in a Pug and to emphasise the importance of an integrated diagnostic and therapeutic approach.

Presentation of case: An 8-year-old female Pug weighing 8.5 kg was presented with a 6-month history of generalised pruritus, alopecia, greasy seborrhoea, hyperpigmentation, lichenification and characteristic foul odour. Generalised demodicosis was diagnosed based on deep skin scrapings. Cutaneous cytology using Diff-Quik and New Methylene Blue staining revealed numerous budding yeast cells suggestive of Malassezia spp. Fungal culture followed by phenotypic characterisation confirmed the isolate as Malassezia pachydermatis, while antifungal susceptibility testing by the disc diffusion method supported the selection of itraconazole for systemic therapy. The dog was treated with an isoxazoline-based acaricide for generalised demodicosis, along with oral itraconazole and topical chlorhexidine–miconazole shampoo. Supportive treatment was also provided. The treatment resulted in the resolution of the cutaneous lesions and progressive hair regrowth, with complete clinical recovery. The dog was followed for one month after completion of treatment, during which no recurrence of dermatological lesions was observed.

Discussion: Generalised demodicosis may predispose dogs to secondary Malassezia overgrowth through disruption of the skin barrier and alteration of local immune responses. A combination of parasitological, cytological and mycological investigations facilitates a definitive diagnosis, while antifungal susceptibility testing may assist in selecting appropriate therapy. Concurrent treatment of the underlying demodicosis and secondary Malassezia dermatitis is important for achieving clinical resolution and reducing the risk of recurrence.

Conclusion: This case highlights the usefulness of integrated clinicomycological, parasitological and cytological investigations in the diagnosis and management of canine Malassezia dermatitis associated with generalised demodicosis. Early recognition and concurrent treatment of both conditions resulted in complete clinical resolution, with no recurrence observed during the one-month follow-up period.

Genotype-dependent Germination and Rhizophagus irregularis-associated Biomass Responses to NaCl in B73 and West African EV8728SR Maize Lines

2026-08-10T08:10:45+00:00

Aims: To determine how maize genotype, Rhizophagus irregularis inoculum, and NaCl affect germination and seedling performance, while distinguishing inoculum effects before root colonisation from responses after mycorrhizal establishment.
Study Design: A 2 × 2 × 3 factorial experiment compared B73 and EV8728SR, R. irregularis inoculum or a non-mycorrhizal control, and 0, 68, or 102 mM NaCl.

Place and Duration of Study: The five-day germination assay and subsequent greenhouse experiment were conducted at the Institut National Polytechnique Félix Houphouët-Boigny, Yamoussoukro, Côte d’Ivoire.

Methodology: The germination assay used three independent dishes per combination; most greenhouse endpoints used 11 independent pots per combination. Responses included final germination, mean germination time (MGT), germination speed index (GSI), biomass, morphology, chlorophyll, electrolyte leakage, tissue water content, and root colonisation. Endpoint-appropriate factorial models and Tukey-adjusted comparisons were applied.

Results: Final germination was statistically uninformative. EV8728SR germinated faster than B73 (MGT and GSI, P < 0.001), and GSI declined with NaCl (P = 0.019). Total dry biomass showed effects of genotype (P < 0.001), inoculum (P = 0.007), and NaCl (P < 0.001), with no significant interactions. At 102 mM, the descriptive Ri-associated biomass differences were 40.7% in B73 and 38.2% in EV8728SR. Mycorrhization intensity declined with NaCl (P = 0.011).

Conclusion: EV8728SR was the stronger-performing genotype, and Ri inoculation produced a modest average biomass benefit. Because interactions were not significant, the larger percentage differences at severe salinity are descriptive. Germination responses represent the inoculum treatment, not established symbiosis.

Phytochemical Constituents of Euphorbia hirta Extracts and Their Antifungal Activity against Dermatophytic and Non-dermatophytic Fungi from Human Skin Scrapings

2026-08-12T11:22:10+00:00

Euphorbia hirta is widely used in traditional medicine for the treatment of superficial fungal infections. This study evaluated the phytochemical composition, antifungal activity, and synergistic effects of extracts obtained from the leaves, flowers, stem bark, and roots of E. hirta against dermatophytic and non-dermatophytic fungi isolated from human skin scrapings. Plant extracts were prepared using water, hexane, and chloroform as extraction solvents. Qualitative and quantitative phytochemical analyses were performed, while antifungal activity was assessed using the agar well diffusion method, minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and extract-combination assays to evaluate synergistic activity. The highest extraction yield (47.43%) was obtained from the chloroform flower extract. Phytochemical analysis revealed a high phenolic content, with the leaf extract containing 417.46 ± 0.02 mg/g. Several extracts demonstrated notable antifungal activity. None of the chloroform extracts inhibited all the test isolates across the concentrations evaluated. Hexane extracts showed no activity against Aspergillus fumigatus, whereas only the hexane stem bark extract inhibited Aspergillus niger at 1000 mg/mL, producing an inhibition zone of 18.12 ± 0.14 mm. Trichophyton interdigitale was inhibited by the hexane leaf extract at 500 mg/mL, with an inhibition zone of 14.08 ± 0.17 mm. Aqueous extracts showed no activity against the Aspergillus isolates but inhibited T. interdigitale at concentrations ranging from 250 to 1000 mg/mL. Combinations of the extracts exhibited antifungal activity against A. niger and T. interdigitale. MIC values ranged from 120 mg/mL to >1000 mg/mL, while MFC values ranged from 125 mg/mL to >1000 mg/mL. These findings demonstrate that E. hirta possesses antifungal activity, particularly against T. interdigitale, and exhibits measurable synergistic effects when extract combinations are used. The presence of bioactive phytochemicals further supports the potential of E. hirta extracts as natural antifungal agents or adjunct therapies for the management of dermatophytic and non-dermatophytic fungal infections.

Pathogenicity and Antibiotic Resistance of Bacteria Isolated from Reused Dish-rinsing Water in Informal Restaurants in Daloa (Côte d’Ivoire)

2026-08-12T12:20:28+00:00

Background: In Daloa (Côte d’Ivoire), the reuse of dish-rinsing water in informal (street food) restaurants is a common practice that may constitute a major source of microbial contamination and the dissemination of antibiotic-resistant bacteria.

Aims: This study assessed the physicochemical and microbiological quality of such water, identified the bacterial species present, and analysed their resistance profiles.

Place and Duration of Study: The research was conducted at the Laboratory of Agrovalorisation, Department of Biochemistry-Microbiology, Jean LOROUGNON GUEDE University of Daloa, from February 2025 to March 2025.

Methodology: Thirty samples collected from ten restaurants in the Tazibouo district were analysed for pH, mesophilic aerobic germs (MAG), total coliforms, Escherichia coli, Salmonella spp., and Staphylococcus aureus. Isolates were identified using biochemical methods and tested for antibiotic susceptibility according to EUCAST (2025) guidelines. Resistance genes for β-lactams (bla_TEM, bla_SHV, bla_CTX-M), quinolones (qnrA, qnrB, qnrS), colistin (mcr-1) were detected by PCR.

Results: The results showed that 40% of the samples had a pH outside the recommended range and that most exceeded microbiological standards; Salmonella spp. was present in 10%, E. coli in 70%, and S. aureus in 80% of the samples. Klebsiella oxytoca was the predominant species (66.66%) and displayed complete resistance to amoxicillin-clavulanic acid and, in 29% of cases, resistance to fluoroquinolones and chloramphenicol. The most frequently detected resistance genes were bla_TEM and qnrA, whereas mcr-1 was not found.

Conclusion: These findings indicate that reused dish-rinsing water in these establishments is a potential reservoir of multidrug-resistant bacteria and poses a significant public health risk, underscoring the urgent need to improve hygiene practices, increase the frequency of water replacement, and implement regular monitoring.

Isolation, Molecular Characterization, and Screening for Hydrocarbon-degrading Potential of an Indigenous Enterobacter sp. from Petroleum-contaminated Soil for Bioremediation Applications

2026-08-19T11:39:10+00:00

Petroleum hydrocarbon contamination creates ecological risks and motivates sustainable remediation strategies. This study isolated indigenous oil-degrading bacteria from petroleum-contaminated soils and screened their relative hydrocarbon-degrading potential. Four soil samples were collected from automobile-workshop sites in and around Bengaluru and Chikkaballapur, Karnataka, India. Samples were enriched in Bushnell–Haas minimal salt medium supplemented with 3% (v/v) used engine oil as the sole carbon source. Eight isolates were obtained and screened using an agar well diffusion clearance-zone assay. Morphological and biochemical characterisation was followed by 16S rRNA gene sequencing of the most active isolate. Isolate K2 produced the largest clearance zone (30 mm), followed by C2 (25 mm) and K3 (20 mm), whereas W1 and S1 produced 5 mm zones. BLASTn and phylogenetic analysis placed K2 within the Enterobacter cloacae complex, with 99.93% sequence identity to reference sequences in GenBank. The results indicate that indigenous bacteria from chronically hydrocarbon-contaminated soils can show differing relative activities under the screening conditions, with K2 displaying the strongest response among the isolates tested. Because the agar well diffusion assay does not directly quantify hydrocarbon removal, the observed clearance zones should be interpreted as a relative screening measure. Quantitative gravimetric or chromatographic analyses, together with soil-based validation, are required before the degradation efficiency and bioremediation applicability of K2 can be established.