Combination of essential oil and ciprofloxacin to inhibit/eradicate biofilms in multidrug-resistant Klebsiella pneumoniae

AIM

This study aimed to test biofilm inhibition activities of each of essential oils (EOs), main compounds of EOs and enzymes against pathogenic Klebsiella pneumoniae.

METHODS AND RESULTS

The effect of seven EOs and three enzymes was tested on formation and eradication of K. pneumoniae biofilm. Peppermint oil showed a robust biofilm inhibitory effect, causing inhibition that ranged from 69·2 to 98·2% at 5 μl ml^-1 . Thyme oil was found to have the best biofilm eradication ability, causing eradication that ranged from 80·1 to 98·0% at 10 μl ml^-1 . The most effective EOs were analysed by GC/MS, to determine the major chemical constitutes of each oil. Pure menthol was found to cause 75·3-97·5% biofilm inhibition at 2·5 μg ml^-1 , whereas thymol caused 85·1-97·8% biofilm eradication at 5 μg ml^-1 . However, moderate inhibition activity was detected for α-amylase and bromelain, while poor activity was detected for β-amylase. Ciprofloxacin combination with thyme oil and thymol was found to enhance antibiotic activity, and affect biofilm cell viability. The observed inhibitory/eradication activity on K. pneumoniae biofilms was confirmed by scanning electron microscopy.

CONCLUSIONS

Thyme and peppermint EOs, and their active components are promising antibiofilm agents alone and/or in combination with ciprofloxacin to inhibit/eradicate biofilms of K. pneumoniae.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presented results suggest the potential application of EOs against infections, caused by biofilm-producing K. pneumoniae, to prevent biofilm formation or decrease their resistance threshold. Moreover, the combination of EOs with ciprofloxacin minimizes the antibiotic concentration used and accordingly the potential accompanying toxic side effects.

Adrenal medulla of AS/AGU rats: a histological and immunohistochemical study

BACKGROUND

The outcome of the autograft therapy for Parkinson's disease including autologous cells from adrenal medulla was disappointing. This could be attributed to the pathological process in Parkinson's disease affecting cells of the adrenal medulla. This study was performed to investigate the histopathological changes in the adrenal medulla of AS/AGU rat, a model of Parkinson's disease, in comparison with Albino Swiss (AS) rats.

MATERIALS AND METHODS

A total of 24 male AS rats were divided into four groups, each of 6 animals: AS W1 - AS rats aged 1 week; AS adult - AS adult rats; AS/ /AGU W1 - AS/AGU rats aged 1 week; and AS/AGU adult - AS/AGU adult rats. The rats were sacrificed and the adrenal glands were dissected and processed for histological staining with haematoxylin and eosin and periodic acid Schiff and for immunohistochemical staining for S100 protein, ubiquitin and tyrosine hydroxylase.

RESULTS

The histological investigation of the adrenal medulla of AS/AGU rats showed vascular congestion, inflammatory cellular infiltration, pyknotic nuclei, necrotic chromaffin cells and medullary inclusion bodies. The immunohistochemical investigation of AS/AGU rats showed a statistically significant decrease in the expression of S100 protein, ubiquitin and tyrosine hydroxylase compared to AS rats.

CONCLUSIONS

The histological and immunohistological changes in the adrenal medulla could explain the failure of outcome of adrenal autograft therapy in Parkinson's disease.

Removal of chromium(III) from tannery wastewater using activated carbon from sugar industrial waste

Chromium is commonly found in huge quantities in tannery wastewaters. For this reason, the removal and recovery of the chromium content of tannery wastewaters is crucial for environmental protection and economic reasons. Removal and recovery of chromium were carried out by using low-cost potential adsorbents. For this purpose three types of activated carbon; C1, the waste generated from sugar industry as waste products and the others (C2, C3) are commercial granular activated carbon, were used. The adsorption process and extent of adsorption are dependent on the physical and chemical characteristics of the adsorbent, adsorbate and experimental condition. The effect of pH, particle size and different adsorbent on the adsorption isotherm of Cr(III) was studied in batch system. The sorption data fitted well with Langmuir adsorption model. The efficiencies of activated carbon for the removal of Cr(III) were found to be 98.86, 98.6 and 93 % for C1, C2 and C3, respectively. The order of selectivity is C1>C2>C3 for removal of Cr(III) from tannery wastewater. Carbon "C1" of the highest surface area (520.66 m(2)/g) and calcium content (333.3 mg/l) has the highest adsorptive capacity for removal of Cr(III). The results revealed that the trivalent chromium is significantly adsorbed on activated carbon collected from sugar industry as waste products and the method could be used economically as an efficient technique for removal of Cr(III) and purification of tannery wastewaters.

Transforming growth factor-beta1 SNPs: genetic and phenotypic correlations in progressive kidney insufficiency

Associations have been described between polymorphisms of cytokine and growth factor genes and susceptibility to, or progression of, an increasing number of diseases. TGF-beta1 plays an important role in the pathogenesis of experimental and clinical glomerulosclerosis and tubulointerstitial fibrosis. In this study, single nucleotide polymorphisms (SNPs) in the TGFbeta1 gene were investigated as possible markers for the progression of chronic kidney failure (CKF). 145 Caucasian patients with CKF were screened for four TGFbeta1 SNPs: T-509C in the promoter region; Arg25Pro and Leu10Pro in exon 1 and Thr263Ile in exon 5. There were significant differences between CKF patients and controls in allele frequencies of two of the SNPs, Leu10Pro (p = 0.038) and C-509T (p = 0.02) and in haplotype distributions (p = 0.0175), indicating an association with susceptibility to CKF. We also observed a significant association between progression of CKF and homozygosity for Arg25 (odds ratio 3.77, 95% confidence interval 1.57-9.04, p = 0.002). Homozygosity for Arg25 was also associated with severity of proteinuria at diagnosis (p = 0.038), plasma TGF-beta1 protein levels (p = 0.01), and severity of glomerulosclerosis (p = 0.04). Homozygosity for -509T was associated with severity of proteinuria at diagnosis (p = 0.0017), level of renal tubular TGF-beta1 immunostaining (p = 0.0006) and with severity of renal interstitial inflammatory cellular infiltration (p = 0.01). Tubular TGF-beta1 immunostaining was significantly higher in biopsies with inflammatory cellular infiltration compared those without inflammation (p = 0.0048). There was a significant difference in haplotype distributions between CKF patients with progressive, as opposed to non-progressive disease (p = 0.0484). TGFbeta1 SNPs may be useful prognostic indicators for the progression of CKF.

Anaerobic fermentation of gelatinized sago starch-derived sugars to acetone-1-butanol-ethanol solvent by Clostridium acetobutylicum

A study of the kinetics and performance of solvent-yielding batch fermentation of individual sugars and their mixture derived from enzymic hydrolysis of sago starch by Clostridium acetobutylicum showed that the use of 30 g/L gelatinized sago starch as the sole carbon source produced 11.2 g/L total solvent, i.e. 1.5-2 times more than with pure maltose or glucose used as carbon sources. Enzymic pretreatment of gelatinized sago starch yielding maltose and glucose hydrolyzates prior to the fermentation did not improve solvent production as compared to direct fermentation of gelatinized sago starch. The solvent yield of direct gelatinized sago starch fermentation depended on the activity and stability of amylolytic enzymes produced during the fermentation. The pH optima for alpha-amylase and glucoamylase were found to be at 5.3 and 4.0-4.4, respectively. alpha-Amylase showed a broad pH stability profile, retaining more than 80% of its maximum activity at pH 3.0-8.0 after a 1-d incubation at 37 degrees C. Since C. acetobutylicum alpha-amylase has a high activity and stability at low pH, this strain can potentially be employed in a one-step direct solvent-yielding fermentation of sago starch. However, the C. acetobutylicum glucoamylase was only stable at pH 4-5, maintaining more than 90% of its maximum activity after a 1-d incubation at 37 degrees C.

Toxoplasma infection of stray cats in Egypt

A seroepidemiological survey of cats for Toxoplasma antibody revealed a high infection rate. No significant difference was detected between males and females or between rural and urban areas, although acute infection seems to be more prevalent in males and in rural areas as revealed by the high titres of the dye test. Toxoplasmosis in cats, as revealed by serologic surveys, seems to prevail more during the warm rather than the hot season of the year being favoured by milder temperature and higher relative humidity and rainfall in the former season. Futhermore, it was concluded that infection rate with Toxoplasma increases with the age of the host. Toxoplasma antibody in the young age groups is to a great extent of maternal origin. Study of the relationship of Toxoplasma to Isospora showed no cross immunity. They follow a reversed pattern with increasing age of the host. Data also shows the high specificity of dye testing for detection of Toxoplasma antibody. Feeding experiments show that a relatively high percentage of cats shed oocysts in their faeces. Not only seropositive but also seronegative cats excrete oocysts, though at a lower rate in the latter case. The majority of cats shedding oocysts are those with either low positive titres or seronegative cats.