ABSTRACT
Infectious keratitis is a significant global problem that can lead to corneal blindness and visual impairments. This study aimed to investigate the etiology of infectious bacterial and fungal keratitis, identify the causative pathogens and their antimicrobial resistance patterns, and analyze the risk factors associated with the development of infectious keratitis. The study was observational and retrospective, involving 226 eyes from 223 patients presented at the Ophthalmology Clinic of the County Clinical Emergency Hospital of Craiova, Romania. The inclusion criteria included corneal ulceration/abscess/infiltrate present on slit-lamp examination and positive microbiological sampling for bacteria or fungi. The study found that the most common causes of infectious keratitis were coagulase-negative staphylococci (35.40%), Staphylococcus aureus (11.06%), and Pseudomonas aeruginosa (14.16%). The Gram-positive bacteria showed high resistance rates to penicillin, moderate rates to gentamycin and clindamycin, and low resistance to chinolones. The Gram-negative bacteria were highly resistant to ampicillin and amoxicillin-clavulanic acid, while third-generation cephalosporins, quinolones, and carbapenems were effective. Systemic antibiotics, such as vancomycine, piperacillin-tazobactam, amikacin, and ceftazidime, show promise against keratitis with low resistance rates, whereas carbapenems and topical aminoglycosides had higher resistance, leaving moxifloxacin as a potential topical option for Gram-positive bacteria and Pseudomonas aeruginosa, albeit with resistance concerns for Klebsiella spp. Although fungal keratitis was rare, Fusarium spp. and Candida albicans were the leading fungal pathogens, with incidences of 2.65% and 2.21%, respectively. Candida albicans was broadly susceptible to most antifungals, while Fusarium solani, Curvularia lunata, and Alternaria alternata exhibited resistance to many antifungals. Amphotericin B and caspofungin can be used as systemic antifungals in fungal keratitis. The study also identified risk factors for keratitis such as ocular trauma (65.92%, OR: 2.5), contact lens wear (11.94%, OR: 1.8), and corneal scarring/leukoma (10.17%, OR: 1.6). Keratitis was more frequent in individuals over 60 years old. The findings of this study have implications for the development of effective diagnostic, therapeutic, and preventive strategies for infectious keratitis.
ABSTRACT
In this study, the antimicrobial activity of three Salvia spp. (S. glutinosa, S. splendens, S. verticillata) extracts prepared with different solvents was assessed using the diffusion method and the quantification of the minimum inhibitory concentration for each extract on S. aureus, E. coli and C. albicans standard strains. The results showed that the extracts of the three Salvia spp. are suppressing the growth of the bacteria tested with variable potency. Among the different solvent extracts, n-butanolic extracts of all the three species of Salvia spp. revealed the most important antibacterial activity against S. aureus and E. coli. S. splendens extracts proved to be the most efficient on C. albicans regardless of the solvent used.
ABSTRACT
The synthesis of nanoparticles inside microorganisms is an economical alternative to chemical and physical methods of nanoparticle synthesis. In this study, ferrihydrite nanoparticles synthesized by Klebsiella oxytoca bacterium in special conditions were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), small-angle X-ray (SAXS), UV-Vis spectroscopy, fluorescence, fluorescence resonance energy transfer (FRET), and molecular docking. The morphology and the structure of the particles were characterized by means of SEM and SAXS. The elemental content was determined by means of the EDS method. The absorption properties of the ferrihydrite nanoparticles were investigated by UV-Vis spectroscopy. The binding mechanism of the biogenic ferrihydrite nanoparticles to Bovine Serum Albumin (BSA) protein, studied by fluorescence, showed a static and weak process, combined with FRET. Protein denaturation by temperature and urea in the presence of the ferrihydrite nanoparticles demonstrated their influence on the unfolding process. The AutoDock Vina and UCSF Chimera programs were used to predict the optimal binding site of the ferrihydrite to BSA and to find the location of the hydrophobic cavities in the sub-domain IIA of the BSA structure.
ABSTRACT
Study Motivation: After assessing electronic databases of medical scientific literature, we have observed that the interrelation between urinary tract infections (UTIs) and chronic kidney disease (CKD) is poorly studied, especially when UTIs are caused by Klebsiella pneumoniae (K. pneumoniae). MATERIALS AND METHODS: K. pneumoniae was isolated in 14 urine samples from patients with CKD addmited in the Nephrology Department of the County Emergency Clinical Hospital Craiova. The isolated strains were statistically analyzed in the correlation with the different clinical and functional parameters (age, gender, CKD stage, comorbidities, biochemical parameters-serum urea, creatinine, uric acid and blood electrolytes). The degree of K. pneumoniae susceptibility to antibiotics from different pharmacodynamic classes was assessed. RESULTS: UTIs with K. pneumoniae in patients with CKD in the investigated period represented 0.51% from the total admissions in the clinic and 32.60% from cases of UTI. Eleven patients with this type of infection (78.56%) were in stage 4 and 5 CKD, and from them 4 also had diabetes mellitus type 2 (28.57%). We observed an increased level for serum creatinine (100%), blood urea (85.71%), and serum uric acid (45.45%). Two patients died after installation of cardiovascular changes in CKD, at advanced ages and in the presence of urinary infection. Multiple drug resistance occurred in 6 strains of K. pneumoniae correlated with the degree of kidney failure, advanced age, male gender, and diabetes mellitus. CONCLUSIONS: UTI with K. pneumoniae in patients with CKD is the second cause of urinary infection which raises problems of unfavorable evolution of CKD and also the recurrence of UTI with multiple drug resistance in CKD, which may lead to pharmacotherapeutical problems.
