Bayesian analysis of two methods MALDI-TOF-MS system and culture test in otomycosis infection

Pseudomonas aeruginosa: Infections and novel approaches to treatment "Knowing the enemy" the threat of Pseudomonas aeruginosa and exploring novel approaches to treatment

Pseudomonas aeruginosa is an aerobic Gram-negative rod-shaped bacterium with a comparatively large genome and an impressive genetic capability allowing it to grow in a variety of environments and tolerate a wide range of physical conditions. This biological flexibility enables the P. aeruginosa to cause a broad range of infections in patients with serious underlying medical conditions, and to be a principal cause of health care associated infection worldwide. The clinical manifestations of P. aeruginosa include mostly health care associated infections and community-acquired infections. P. aeruginosa possesses an array of virulence factors that counteract host defence mechanisms. It can directly damage host tissue while utilizing high levels of intrinsic and acquired antimicrobial resistance mechanisms to counter most classes of antibiotics. P. aeruginosa co-regulates multiple resistance mechanisms by perpetually moving targets poses a significant therapeutic challenge. Thus, there is an urgent need for novel approaches in the development of anti-Pseudomonas agents. Here we review the principal infections caused by P. aeruginosa and we discuss novel therapeutic options to tackle antibiotic resistance and treatment of P. aeruginosa infections that may be further developed for clinical practice.

Single Topical Application of 1% Clotrimazole Cream in Otomycosis

Aim: To assess the clinical improvement after single dose topical application of 1% clotrimazole cream in otomycosis and follow up for recurrence at the end of first and the third month. Materials and Methods: A prospective observational study was carried out at Government Medical college hospital. Patients with KOH diagnosed fungal infection of external auditory canal were included in the study. After obtaining informed written consent from the participating patients, a detail clinical history was taken. Single topical application of 1% clotrimazole cream in otomycosis. The fungal debris was removed with the help of suction aspiration and dry mopping. A single topical application of 1% clotrimazole cream was applied under all aseptic precautions. On the 3rd day the applied cream was cleaned with help of suction under ear microscope. Patients were advised to follow up after one month and three months. During each follow up patients were assessed clinically and examined for residual fungal debris. Result: Otomycosis was seen predominantly in middle aged females, housewives and laborers by occupation. Earache was most common symptom seen in 65.2%. Unilateral involvement was seen in 89.3% cases. The most common organism isolated in otomycosis was Aspergillus niger. At the end of one month of treatment with a single dose of 1% clotrimazole cream, 102 (91.0%) patients were recovered and 10 (9.0%) patients were with persistence or recurrence of the symptoms. At the end of third month, the recovery rate was 84.8% and recurrence rate was 6.3%. Conclusion: Single topical application of 1% clotrimazole cream is effective in treating otomycosis.

Identification of Fungi Isolated from Oral Cavity of Patients with HIV Using MALDI-TOF MS

BACKGROUND

A growing incidence of invasive fungal infections, especially among immunocompromised patients, has given increased significance to microbiological diagnostics of yeast-like fungi. More accurate and faster fungi identification methods that can compete with classical methods are being searched for. In this paper, classical microbiological methods are compared to MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry).

METHODS

The diagnostic material was collected from buccal mucosa from 98 adults, including 69 with HIV. Only positive cultures were included in the study.

RESULTS

Matching results were obtained in 45 samples, and there were nonmatching results in 35 samples, with the majority of these in the study group, constituting 50% of identifications within this group. A particularly common mistake resulting from the use of classical methods is the false identification of C. dubliniensis as C. albicans. Additionally, C. tropicalis proves to be difficult to identify.

CONCLUSIONS

Our results and literature data suggest that MALDI-TOF MS should be considered an effective alternative to classical methods in terms of fungi identification, especially among HIV-positive patients, due to the different morphology of fungal colonies.

Molecular Identification and Antifungal Susceptibility of Yeasts and Molds Isolated from Patients with Otomycosis

Fungal otitis externa, an infection of the external auditory canal caused by molds and yeasts, accounts for approximately 10-20% of ear canal infections accompanying high recurrence. The purpose of the current study was to assess the pattern of etiological agents of otomycosis and resistance profile as well as the rate of tympanic membrane perforation. A total of 1040 patients with symptoms of fungal otitis externa, in a period of two years, were investigated. The mycological tests revealed the presence of different fungi in 237 ears (22.8%). Fungal otitis was more related to filamentous fungi of the species Aspergillus flavus (54.43%), A. tubingensis (10.97%), and A. niger (8.86%), followed by yeasts, Candida orthopsilosis (7.59%), C. albicans (6.75%), and C. parapsilosis (5.06%). Tympanic membrane perforation rate was found to be 6.75% and was more common with otomycosis caused by A. flavus, A. tubingensis and C. albicans. In antifungal susceptibility tests, all tested drugs showed generally good activity against most isolates of molds and yeasts, while tolnaftate, clotrimazole, nystatin, and terbinafine had lowest effects. We found that among Aspergillus isolates, one A. niger isolate was resistant to voriconazole, and one A. flavus isolate was resistant to amphotericin B. Furthermore, among Candida species, three isolates of C. orthopsilosis showed high MIC values to fluconazole, two C. albicans isolates were considered fluconazole resistant and one isolate of C. parapsilosis was resistant to caspofungin and 3 isolates were resistant to fluconazole. Regarding the existence of the cases with perforated tympanic membrane and emerging species causing fungal otitis in the current report, the importance of the early physical examination, precise molecular identification, and the antifungal susceptibility evaluation is highlighted.

Ultrasonic-assisted extraction and high-speed counter-current chromatography purification of zeaxanthin dipalmitate from the fruits of Lycium barbarum L

Zeaxanthin dipalmitate (ZDP) is a major non-saponified carotenoid in fully ripe fruits of Lycium barbarum L. In the present study, response surface methodology was used to optimize the ultrasonic-assisted extraction (UAE) conditions of carotenoids from the fruits of L. barbarum, and the optimal extraction conditions were determined as follows: ultrasonic power of 360 W, ultrasonic time of 40 min and the ratio of extraction solvent to sample of 30 mL/g. An actual value of ZDP content of 5.40 mg/g and short extraction time indicated the efficiency of UAE. Furthermore, a promising high-speed counter-current chromatography (HSCCC) method was established for the purification of ZDP from the fruits of L. barbarum. With a developed two-phase solvent system composed of n-hexane/dichloromethane/acetonitrile (10/3/7, v/v/v), ZDP with a purity of higher than 95% was successfully isolated from the crude extract. This is the first report on the purification of ZDP by using HSCCC.