Biofilm Formation, Pyocyanin Production, and Antibiotic Resistance Profile of Pseudomonas aeruginosa Isolates from Wounds

Pseudomonas aeruginosa is one of the most frequently resistant and dangerous bacteria isolated from infected wounds of patients. This study aimed to determine the prevalence of P. aeruginosa from infected wounds of patients in the Dschang District Hospital to evaluate their antibiotic susceptibility profiles and their ability to swarm and swim and correlate pyocyanin production with biofilm formation. Wound swab samples were collected and the identification of P. aeruginosa was performed using microbiological and biochemical tests. Their antimicrobial susceptibility was determined by the broth microdilution method. Swarming and swimming were determined by measuring the diameters of motility in semisolid/low-viscosity media. Furthermore, pyocyanin production and biofilm formation were evaluated spectrophotometrically using a microtiter plate. The prevalence of P. aeruginosa from infected wounds in our study population was 26%. All P. aeruginosa isolates were resistant to streptomycin and paromomycin, and the frequency of multidrug resistance (MDR) was 65.8%. All P. aeruginosa isolates showed the ability to produce biofilm and pyocyanin. Out of the 37 isolates screened, 19 including the reference strains (51.4%) were strong biofilm producers. A significant positive correlation was observed among biofilm formation, pyocyanin production, and the antibiotic resistance profile of the isolates. Findings from this study suggest that infected wounds could act as a reservoir for MDR and virulent P. aeruginosa. The presence of strong biofilm producers of P. aeruginosa in infected wounds is a serious public health concern. Therefore, surveillance programs to monitor and control MDR P. aeruginosa in these patients are required to prevent their dissemination in hospital settings

A New Unsaturated Aliphatic Anhydride from Aspergillus candidus T(12)19W1, an Endophytic Fungus, from Pittosporum mannii Hook f.

Juidzou GT, Anoumedem EGM, Sema DK, et al. A New Unsaturated Aliphatic Anhydride from Aspergillus candidus T(12)19W1, an Endophytic Fungus, from Pittosporum mannii Hook f. Journal of Chemistry. 2023;2023: 5938723.A new unsaturated aliphatic anhydride derivative (Z)-(12Z)-heptadec-12-enoic-2 '-hydroxypropanoic anhydride (1) and ten known compounds, three flavonoids (2-4), two terphenyllins (5-6), four triterpenoids (7-8, 10-11), and one n-fatty acid (9), were isolated from the EtOAc extract of Aspergillus candidus T(12)19W1, an endophytic fungus, inhabiting Pittosporum mannii. All the isolated compounds were characterized using 1D- and 2D-NMR and HR-EI experiments together with the reported literature. p-terphenyls are suggested to be the chemophenetic marker of the genus Aspergillus. The ethyl acetate crude extract as well as some isolated compounds of A. candidus was assayed for antibiofilm activity, anti-inflammatory (ROS) activity, and cytotoxicity on brine shrimps and the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxicity assay on 3T3 cell lines. The tested sample showed good antibiofilm activity with the lowest MBEC50 obtained at 64 mu g/mL. Compounds showed low anti-inflammatory activity even at high concentration (250 mu g center dot mL(-1) with an IC50 of 59.6 +/- 0.1 mu g center dot mL(-1)) with moderate cytotoxicity on brine shrimps at high concentration (1000 mu g center dot mL(-1), with 46.67% mortality). However, no cytotoxic activity was observed against 3T3 cell lines