effects of berberine and palmatine on efflux pumps inhibition with different gene patterns in Pseudomonas aeruginosa isolated from burn infections

Background: Related Multidrug Resistance [MDR] to efflux pumps is a significant problem in treating infections caused by Pseudomonas aeruginosa [P. aeruginosa]. Plant compounds have been identified as Pump Inhibitors [EPIs]. In the current study, the potential effect of Berberine and Palmatine as EPIs were investigated on efflux pump inhibition through focusing on different gene patterns in P. aeruginosa isolated from burn infections

Methods: All isolates were collected and identified using the standard biochemical tests. Antimicrobial sensitivity was performed based on disk agar diffusion method for 12 antibiotics. MIC-MBC tests were also performed based on the broth microdilution method to detect synergistic relationship between ciprofloxacin, Berberine and Palmatine. Detection of mexA, mexB, mexC, mexD, mexE, mexF and mexX was conducted by PCR assay. Fisher's Exact test and Logistic Regression were used as statistical tools

Results: A total of 60 P. aeruginosa isolates were collected. The highest and lowest levels of resistance were found to be respectively against clindamycin and tigecycline. Comparing the MIC with MBC distribution, it was found that Berberine and Palmatine lower the MIC-MBC level of ciprofloxacin. The PCR results indicated that the highest frequency is about MexAB-OprM operon. The statistical analysis among different gene patterns of efflux pumps showed that there were no significant relationships between the effectiveness of Berberine and Palmatine [p>0.05]

Conclusion: It can be speculated that Berberine and Palmatine both act as EPIs and can be used as auxiliary treatments with the purpose of increasing the effect of available antibiotics as well as decreasing the emergence of MDR bacteria. The efficiency of these combinations should be studied further under in vivo conditions to have a more comprehensive conclusion regarding this issue

Molecular investigation of Staphylococcus aureus isolated from the patients, personnel, air and environment of an ICU in a hospital in Tehran

The aim of this study was to determine the prevalence and characteristics of Staphylococcus aureus isolates from the patients, staff, air and environments of an ICU in a hospital in Tehran. During this study, 37 S. aureus isolates were collected and analyzed via the spa typing method. Of the 37 S. aureus isolates, 35 [94%] were methicillin resistant [MRSA], 28 [76%] were identified as SCCmec types III or IIIA, four [10%] were identified as SCCmec types I or IA and three [8%] were identified a SCCmec type IV. All of the MRSA isolates were resistant to oxacillin and contained mecA. The isolates were all spa typed and found to comprise 11 spa types, including t7688, t7689, and t7789, which have not previously been reported. The spa type t7688 was isolated from the hands of two ICU personnel. The spa type t7689 was observed among five isolates from the air and the environment. The spa type t7789 was observed among three isolates from the patients, ventilators and the air. The majority of the isolates [43%] belonged to spa types t030 and t037. Our results revealed that MRSA strains that were isolated from the air, the environment of the ICU and the patients who were colonized or infected with MRSA often exhibited the same spa and SCCmec types. These results also reveal that the isolates from the patients and environment were usually indistinguishable

Isolation of Herpetosiphon giganteus and ultrastructure analysis by electron microscopy

Herpetosiphon giganteus is a filamentous gliding bacterium. Gliding motility is the movement of the cells over surfaces without the aid of flagella. The mechanism responsible for bacterial gliding motility has not been known and there are only a few data on Herpetosiphon giganteus. The aim of this study was to observe the ultrastructure and negative staining of isolated strains of Herpetosiphon giganteus to find any organelles of locomotion. First, 35 strains of gliding bacteria were isolated from soil, freshwater, mud and activated sewage sludge. Then, 8 strains very closely related to Herpetosiphon giganteus were used for further examination. For extracellular slime and fibril observation, photoelectron micrographs were taken from different patterns on the cell surface of strains that were negatively stained. Thin sections with and without lysozyme treatment were prepared and examined by transmission electron microscopy. When the filaments were negatively stained, fibrils were detected in young cultures. There were two different kinds of fibrils in this study. The extracellular slime of these organisms was clearly visible. Examination with the electron microscopy revealed neither flagella nor an axial filament of any kind. There was no evidence for external organelles of locomotion. The results indicated that ring like structure localized at the cell surface connected with fibrils is responsible for gliding movement. The secretion of slime is necessary for adhesion of the cell to a solid surface and for ease of movement