Liposome-mediated Functional Expression of Multiple Drug Resistance Gene in Human Bone Marrow CD34^+ Cells

Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34+ cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.0l). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34+ cells.

Effects of multidrug resistance, antisense RNA on the chemosensitivity of hepatocellular carcinoma cells

BACKGROUND: Multidrug resistance is a major obstacle in cancer chemotherapy. We examined whether the antisense RNA of multidrug resistance gene 1 (mdr1) could reverse multidrug resistance in the human hepatocellular carcinoma (HCC) cell line SMMC7721/ADM. METHODS: The recombinant adenoviruses pAdEasy- GFP-ASmdr1 product was produced by the adenoviral vector AdEasy system, which can express antisense RNA against the mdr1 gene. Following that, the recombinant adenovirus was transfected into the P-glycoprotein- producing multidrug resistance cell line, SMMC7721/ADM human HCC cells resistant to adriamycin (ADM) and daunorubicin (DNR). In order to investigate the reversal of multidrug resistance phenotype, we measured the expression of mdr1 mRNA by RT-PCR and the production of P-glycoprotein by flow cytometry. The sensitivities for ADM and DNR SMMC7721/ADM cells were examined by [3-(4, 5-dimethylthi-azol-2-yl)-2,5 diphenyl-terazolium bromide] (MTT) analysis. RESULTS: The low-level expression of mdr1 mRNA and P-glycoprotein production were observed in parental sensitive cells SMMC/7721 in addition to the overexpressionof mdr1 mRNA and P-glycoprotein in SMMC7721/ADM cells. The transfection of antisense-RNA into SMMC7721/ ADM cells resulted in decreases of mdr1 mRNA and P-glycoprotein, but increase of drug sensitivities. The sensitivities of transfected SMMC7721/ADM cells to ADM and DNR in IC50 reduced by 31.25% and 62.96% respectively. CONCLUSIONS: Mdr1 antisense RNA can increase the sensitivities of SMMC7721/ADM cells to anticancer drug by decreasing the expression of the mdr1 gene and inhibiting P-glycoprotein expression. This strategy may be applicable to cancer patients with P-glycoportein mediated multidrug resistance.

Enhanced anticancer effect of doxorubicin by TPGS-coated liposomes with Bcl-2 siRNA-corona for dual suppression of drug resistance

Multiple drug resistance(MDR)is a tough problem in developing hepatocellular carcinoma(HCC)therapy.Here,we developed TPGS-coated cationic liposomes with Bcl-2 siRNA corona to load doxorubicin(Dox)i.e.,Bcl-2 siRNA/Dox-TPGS-LPs,to enhance anticancer effect of Dox in HCC-MDR.TPGS i.e.,d-α-tocopheryl polyethylene glycol 1000 succinate,inhibited Pglycoprotein(P-gp)efflux pump and Bcl-2 siRNA suppressed anti-apoptotic Bcl-2 protein.The Bcl-2 siRNA loaded in the liposomal corona was observed under transmission electron microscopy.The stability and hemolysis evaluation demonstrated Bcl-2 siRNA/Dox-TPGSLPs had good biocompatibility and siRNA-corona could protect the liposomal core to avoid the attachment of fetal bovine serum.In drug-resistant cells,TPGS effectively prolonged intracellular Dox retention time and siRNA-corona did improve the internalization of Dox from liposomes.In vitro and in vivo anticancer effect of this dual-functional nanostructure was examined in HCC-MDR Bel7402/5-FU tumor model.MTT assay confirmed the IC50 value of Dox was 20–50 fold higher in Bel7402/5-FU MDR cells than that in sensitive Bel7402 cells.Bcl-2 siRNA corona successfully entered the cytosol of Bel7402/5-FU MDR cells to downregulate Bcl-2 protein levels in vitro and in vivo.Bcl-2 siRNA/Dox-TPGS-LPs showed superior to TPGS-(or siRNA-)linked Dox liposomes in cell apoptosis and cytotoxicity assay in Bel7402/5-FU MDR cells,and 7-fold greater effect than free Dox in tumor growth inhibition of Bel7402/5-FU xenograft nude mice.In conclusion,TPGS-coated cationic liposomes with Bcl-2 siRNA corona had the capacity to inhibit MDR dual-pathways and subsequently improved the anti-tumor activity of the chemotherapeutic agent co-delivered to a level that cannot be achieved by inhibiting a MDR single way.

Correlation between Cyclin A Gene Expression in Adult Patients with Acute Leukemia and Drug Resistance

In order to investigate the relationship between the expression of cyclin A and drug resistance in adult patients with acute leukemia (AL), the mRNA expression of cyclin A, mdr1, TopⅡ α , bcl-2 was detected in 64 adult patients with AL and 20 normal controls by semi-reverse transcription polymerse chain reaction (semi-RT-PCR). It was found that the cyclin A and TopⅡ α mRNA expression levels in drug resistant group were significantly lower than in sensitive group ( P <0.01). Under the same experimental condition no cyclin A mRNA expression was detectable in all normal controls. The mdr1 and bcl-2 mRNA expression levels in resistant group were significantly higher than in sensitive group ( P <0.01). cyclin A and TopⅡ α gene expression levels were closely correlated ( r s =+0.794, P=0.000, n =64) in all AL patients, but cyclin A was not correlated with mdr1 and bcl-2 gene expression levels. In drug resistant group there was a negative correlation between the gene expression levels of cyclin A and mdr1 ( r s =-0.337, P=0.029 ). The 10 AL patients with positive lower expression of both cyclin A and TopⅡ α were all resistant to drugs. Logistic regression of Binary analysis showed the correlation between the lower expression of cyclin A and drug resistance. It was concluded that lower expression of cyclin A gene might be an unfavorable prognostic factor for patients with AL, and detection of both cyclin A and TopⅡ α gene expression would predict drug resistance in AL patients.

Expression of Multidrug-associated Protein, P-glycoprotein, P53 and Bcl-2 Proteins in Bladder Cancer and Clinical Implication

The expression of multidrug resistant proteins in bladder cancer and clinical implication was studied. Expression of multidrug associated protein (MRP), P glycoprotein (P gp), P53 and Bcl 2 proteins were detected by using immunohistochemical method in 40 specimens of bladder transitional cell carcinoma. The results showed that the positive rate of MRP, P gp, P53 and Bcl 2 was 52.5 %, 57.5 %, 47.5 % and 62.5 % respectively. The positive rate of MRP, P gp, P53 and Bcl 2 in the grade Ⅰ, Ⅱ and Ⅲ of tumors was 46.3 %, 38.5 %, 38.5 %, 23.1 %; 52.9 %, 39.8 %, 47.1 %, 76.4 %; 60.0 %, 80.0 %, 60.0 %, 90.0 % respectively. The positive rate of MRP, P gp, P53 and Bcl 2 in 24 primary tumor specimens was 37.5 %, 41.7 %, 33.3 %, 45.8 % and that in 16 cases in recurrent specimens receiving chemotherapy 75.0 %, 81.3 %, 68.8 %, 87.5 % respectively. It was suggested the positive rate of MRP, P gp, P53 and Bcl 2 was increased with the advance of tumor grade. The positive rate of four proteins in all recurrent cases was significantly increased ( P <0.05). The expression of MRP, P gp, P53 and Bcl 2 proteins might be the important factors for chemotherapy failure.

Antiboitic Resistance of Uropathogenic Eshcherichia coli in Pateints of Hargeisa Group Hospital, Hargeisa, Somaliand

Background: Urinary tract infection is a common disease in Somaliland society. The predominant causative organism of Urinary tract infection is Escherichia coli. This research studies antibiotic resistance of uropathogenic E. coli in patients of Hargeisa Group Hospital. The study selected commonly prescribed antibiotics for urinary tract infection treatment. Methodology: Urine samples of patients were cultured to isolate causative organisms of the urinary tract infection. Chromo-agar media, CLED, and biochemical tests are applied to identify the type of bacteria. Antibiotic reactions to E. coli bacteria are measured to differentiate between sensitive and resistant drugs with the guidance of the Clinical and Laboratories Standard Institute (CLSI). Kirby Bauer disc diffusion method is applied to assess antimicrobial activity against E. coli. Data of patients such as age, sex, symptoms of UTI, previous UTI infection, and history of antibiotic use were recorded. SPSS and Microsoft Excel are applied to analyze and interpret data. Results: The predominant organism that caused urinary tract infection was Escherichia coli (55%), Klebsiella spp (15%), Candida spp (15%), Enterococcus spp (10%), Staph spp 2.5%, and Pseudomonas spp 2.5% while other 55% were negative. The study assessed antibiotic resistance of E. coli, which reported resistance to Tetracycline at (70%), Ampicillin (64%), and Cotrimoxazole (61%). The bacteria showed moderate resistance to Ceftriaxone (43.5%), Nalidixic acid (43%), and Ciprofloxacin (36%). The bacteria are sensitive to Amikacin (100%), Nitrofurantoin (96%), Levofloxacin (73%) and gentamicin (74%). Conclusion: The overall incidence of antibiotic resistance to E. coli is high because the bacteria show a percentage of resistance to each antibiotic except Amikacin which gives (100%) sensitivity. The research recommends public awareness of the risks associated with antibiotic use and periodic evaluation of antibiotic resistance to accomplish better managing urinary tract infections.

Hepatobiliary membrane transporters involving in the formation of cholesterol calculus

BACKGROUND: Cholecyst cholesterol lithiasis is a common disease of the digestive system; however, the cause of lithogenesis is still unclear. Although bile salt export pump (BSEP), multidrug resistance protein 2 (MRP2), and multiple drug resistance 3 (MDR3 ) are 3 well-known transporting proteins, their effect on lithogenesis has not been elucidated. This study was undertaken to examine the relationship between BSEP, MRP2, MDR3, and cholesterol calculus formation. METHODS: Liver tissue specimens were taken from 20 patients with cholesterol calculus and from 10 patients with normal liver. mRNA and protein expressions of BSEP, MRP2, and MDR3 were determined by reverse tran-scriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively. This study was approved by the ethics committee of China Medical University and informed consent was obtained from all patients. RESULTS: mRNA and protein expressions of BSEP, MRP2, and MDR3 were significantly down-regulated in the liver tissue of the patients with cholesterol calculus compared with normal liver tissue of the controls. CONCLUSION: The down-regulation of BSEP, MRP2, and MDR3 may be correlated with the formation of cholesterol calculus.

Imaging probes for non-invasive tumoral detection and functional monitoring of cancer multidrug resistance

Aim:Several cationic radiotracers originally developed as myocardial perfusion agents have shown potential for both early detection of cancer and non-invasive monitoring of multiple drug resistance(MDR)by single photon emission computed tomography.We have introduced two cationic complexes,^(99m)Tc-DMEOP[di-methoxy-tris-pyrazolyl-^(99m)Tc-(CO)_(3)]and ^(99m)Tc-TMEOP[tri-methoxy-tris-pyrazolyl-^(99m)Tc-(CO)_(3)],which showed excellent preclinical results as cardiac imaging probes,namely a persistent heart uptake with rapid blood and liver clearance.This study aimed at the evaluation of their usefulness for tumoral detection and functional assessment of MDR.Methods:The uptake and efflux kinetics of ^(99m)Tc-DMEOP and ^(99m)Tc-TMEOP were evaluated in human prostate,lung,and breast cancer cell lines,including drug-resistant cell lines that are known to overexpress the MDR P-glycoprotein(Pgp).The effects of MDR modulators were also studied.In vivo studies were performed in xenografted tumor models,and the MDR phenotype of the tumors was confirmed by Western blot.Results:The uptake kinetics of both complexes in human cancer cell lines is comparable with the one found for ^(99m)Tc-Sestamibi,increasing over time.The uptake of ^(99m)Tc-TMEOP is greatly reduced in cells overexpressing Pgp and increased in the presence of a Pgp modulator.In nude mice,the tumor uptake of ^(99m)Tc-TMEOP was higher in the MCF-7 xenografts compared with the MCF7 Pgp tumors.Conclusion:The uptake kinetics of both complexes in human cancer cell lines is comparable with the one found for ^(99m)Tc-Sestamibi,increasing over time.The uptake of ^(99m)Tc-TMEOP is greatly reduced in cells overexpressing Pgp,and increased in the presence of a Pgp modulator.In nude mice,the tumor uptake of ^(99m)Tc-TMEOP was higher in the MCF-7 xenografts compared with the MCF7 Pgp tumors.

Clinical relationship between MDR1 gene and gallbladder cancer

BACKGROUND: The most common mechanisms of mul- tidrug resistance (MDR) in cancer cells is the expression of an energy-dependent exfflux pump. P-glycoprotein (P-gp) encoded by MDR1 gene and multidrug associated protein (MRP) are well known proteins associated with MDR. In human cancers, the MDR1 gene expression is common in patients with intrinsic and acquired MDR. It is a major therapeutic problem in cancer chemotherapy. Previously we found that the MDR of HCC is related to MRP gene ex- pression and initiates the intrinsic MDR. The aim of this study is to study the expression of MDR1 gene encoding P-gp and MDR1 mRNA in primary gallbladder carcinoma, and analyze its clinical significance. METHODS: Immunohistochemistry (IHC) S-P method and in situ polymerase chain reaction (ISPCR) were used to detect the expression of P-gp and MDR1 mRNA in 53 cases of untreated primary gallbladder carcinoma and 12 ca- ses of cholecystitis (archival paraffin-embedded tissues). RESULTS: The positive expression rates of P-gp and MDR1 mRNA in the 53 cases and 12 cases were 60.38%, 71.69% and 25.00%, 33.33%, respectively. There was a significant difference between the two groups (P<0.05). The positive expression rate of P-gp and MDRlmRNA were 69.44%, 83.33% and 41.18%, 47.06% respectively in tissues in stage of Nevin against Nevin , (P<0.05). In well, moderately differentiated gallbladder carcinoma tissues, their expressions were 79.49%, 69.23% against 50.00%, 35.71% in low, undifferentiated tissues (P<0.05). CONCLUSIONS: MDR to gallbladder carcinoma is closely related to the intrinsic MDR and it provides an important evidence to reverse the MDR by detection of the MDR1gene. Meanwhile, MDR1 gene expression in gallbladder carcinoma is correlated with some biological characteris- tics , takes part in the carcinogenesis of gallbladder tissues, and acts as a valuable biomarker of prognosis.

MULTICELLULAR-MEDIATED EXPRESSION OF P-GP AND MRP AND RELATIONSHIP WITH CELL CYCLE PROFILES IN HUMAN OVARIAN CANCER SK-OV-3ip1 MULTICELLULAR AGGREGATES

Objective: To investigate the expression of P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP) and the relationship with cell cycle profiles in ovarian cancer SK-OV-3ip1 multicellular aggregates. Methods: Liquid overlay system was employed to obtain multicellular aggregates. Expression of P-gp and MRP was detected with flow cytometry (FCM). Outer, intermediate and inner cells from multicellular aggregates were collected by layer-trypsinized method. Cell cycle profiles were also analyzed by FCM. Results: Compared with control cells, no expression of P-gp and MRP was detected in monolyer cells (P=0.128 and P=0.604), but expression of P-gp and MRP in aggregate cells was significantly elevated (P<0.01). P-gp expression in every layer cells was also obviously increased (P<0.01). Furthermore, P-gp expression in every layer cells was also obviously increased (P=0.071). Tendency to increased G0–G1 phase and reduced S phase cells existed from outer through intermediate to inner layers in multicellular aggregates but with no statistical difference. Cell percentages in G2-M phase also had no difference. However, compared with monolayer cells, cells in G0–G1 phase increased and cells in S and G2-M phases lowered significantly in every layer and in the whole multicellular aggregates. Expression elevation of P-gp and MRP was consistent with increased G0–G1 percentage in aggregate cells. Conclusion: Expression of P-gp and MRP increases in cells of SK-OV-3ip1 multicellular aggregates and is consistent with increased G0–G1 percentage, which implies the possible relationship between them and the possible role in multicellular-mediated drug resistance.

Establishment of hepatocellular carcinoma multidrug resistant monoclone cell line HepG2/mdr1

Background The multidrug resistance （MDR） associated with the expression of the mdr1 gene and its product P-glycoprotein is a major factor in the prognosis of hepatocellular carcinoma cell （HCC） patients treated with chemotherapy. Our study was to establish a stable HCC MDR cell line where a de novo acquisition of multidrug resistance specifically related to overexpression of a transgenic mdr1. Methods The 4.5-kb mdrl cDNA obtained from the plasmid pHaMDR1-1 was cloned into the PCl-neo mammalian expression vector, later was transferred by liposome to human hepatocarcinoma cell line HepG2. Then the transfected HepG2 cells resisting G418 were clustered and cultured and the specific fragment of mdr1 cDNA, mRNA and the P-glycoprotein （Pgp） in these HepG2 cells were detected by PCR, RT-PCR and flow cytometry, respectively. The accumulation of the daunorubicin was determinated by flow cytometry simultaneously. The nude mice model of grafting tumour was established by injecting subcutaneously HepG2/mdr1 cells in the right axilla. When the tumour diameter reached 5 mm, adriamycin was injected into peritoneal cavity. The size and growth inhibition of tumour were evaluated. Results The mdr1 expression vector was constructed successfully and the MDR HCC line HepG2/mdr1 developed. The PCR analysis showed that the specific fragment of mdrl cDNA in HepG2/mdr1 cells, but not in the control group HepG2 cells. Furthermore, the content of the specific fragment of mdr1 mRNA and Pgp expression in HepG2/mdr1 cells were （59.7±7.9）% and （12.28±2.09）%, respectively, compared with （16.9±3.2）% and （3.07±1.06）% in HepG2 cells. In the nude mice HCC model, the tumour genes of both groups were identified. After ADM therapy, the mean size of HepG2 cell tumours was significantly smaller than HepG2/mdr1 cell tumours. Conclusion The approach using the transfer of mdr1 cDNA may be applicable to the development of MDR hepatocarcinoma cell line, whose MDR mechanism is known. This would provide the experimental basis of MDR research.

Coagulase-negative staphylococcus and enterococcus as predominant pathogens in liver transplant recipients with Gram-positive coccal bacteremia

Background Gram-positive bacteria such as Staphylococcus aureus have been a common cause of infection among liver transplant （LT） recipients in recent decades. The understanding of local epidemiology and its evolving trends with regard to pathogenic spectra and antibiotic susceptibility is beneficial to prophylactic and empiric treatment for LT recipients. This study aimed to investigate etiology, timing, antibiotic susceptibility and risk factors for multidrug resistant （MDR） Gram-positive coccal bacteremia after LT.Methods A cohort analysis of prospectively recorded data was performed to investigate etiologies, timing, antibiotic susceptibility and risk factors for MDR Gram-positive coccal bacteremia in 475 LT recipients.Results In 475 LT recipients in the first six months after LT, there were a total of 98 episodes of bacteremia caused by Gram-positive cocci in 82 （17%） patients. Seventy-five （77%） bacteremic episodes occurred in the first post-LT month.The most frequent Gram-positive cocci were methicillin-resistant coagulase-negative staphylococcus （CoNS, 46 isolates）,methicillin-resistant Staphylococcus aureus （MRSA, 13） and enterococcus （34, E. faecium 30, E. faecalis 4）. In all Gram-positive bacteremic isolates, 59 of 98 （60%） were MDR. Gram-positive coccal bacteremia and MDR Gram-positive coccal bacteremia predominantly occurred in patients with acute severe exacerbation of chronic hepatitis B and with fulminant/subfulminant hepatitis. Four independent risk factors for development of bacteremia caused by MDR Gram-positive coccus were： LT candidates with encephalopathy grades Ⅱ-Ⅳ （P=0.013, OR： 16.253, 95% CI：1.822-144.995）, pre-LT use of empirical antibiotics （P=0.018, OR： 1.029, 95% CI： 1.002-1.057）, post-LT urinary tract infections （P 〈0.001, OR： 20.340, 95% CI： 4.135-100.048） and abdominal infection （P=0.004, OR： 2.820, 95% CI：1.122-10.114）. The main infectious manifestations were coinfections due to gram-positive cocci and gram-negative bacilli.Conclusions Methicillin-resistant CoNS and enterococci are predominant pathogens among LT recipients with Gram-positive coccal bacteremia. Occurrences of Gram-positive coccal bacteremia may be associated with the severity of illness in the perioperative stage.

Ligustrazine as a salvage agent for patients with relapsed or refractory non-Hodgkin＇s lymphoma

Background The prognosis is poor for patients with relapsed or refractory non-Hodgkin＇s lymphoma （NHL）. The main reason for poor prognosis is multidrug resistance （MDR）, for which the main phenotype is overexpression of P-glycoprotein （P-gp）. This study explored the efficacy of ligustrazine as a salvage agent in patients with relapsed or refractory NHL, and the relationship to P-gp expression. Methods Sixty patients were randomized to a reversal agent group, receiving ligustrazine plus chemotherapy, and a control group, receiving chemotherapy alone. Flow cytometry was performed to evaluate P-gp expression. Results In the 56 patients we were able to evaluate, there was no statistically significant difference in progression-free survival （PFS） in the two groups （P=0.0651）, but the reversal agent group had a higher overall response rate （ORR） than did the control group （P=0.048）. Forty-one of 56 patients had P-gp（＋） tumor cells. Among these patients, six of eighteen patients in the reversal agent group and in the control group had complete remission or complete remission/unconfirmed （CR＋CRu） reflecting a significant advantage in the reversal agent group （P=0.048）. Patients with P-gp（＋） tumor cells in the reversal agent group had a higher overall response rate （ORR） than did the control group （11/18 vs. 6/23, P=0.024）. Kaplan-Meier Survival curve and log-rank test demonstrated that patients with P-gp（＋） tumor cells in the reversal agent group had longer progression-free survival than did the control group （P=0.0464）. A small number of patients who received ligustrazine had a decrease in blood pressure. Conclusion Ligustrazine as a salvage agent in combination with chemotherapy can elevate response rate, prolong PFS with manageable toxicity, and correlate with P-gp expression in relapsed or refractory NHL.

Rumex dentatus could be a potent alternative to treatment of microbial infections and of breast cancer

OBJECTIVE:To investigate the phytochemicals and in vitro antioxidant,antimicrobial and cytotoxic potential of Rumex dentatus(R.dentatus)leaf extracts.METHODS:The total phenolics and flavonoids content of R.dentatus extracts were evaluated by the Folin-Ciocalteu and aluminum chloride colorimetric methods respectively.Antioxidant potential of studied plant extracts was assessed through 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity,total reducing power and total antioxidant methods.Moreover,antibacterial and antifungal capacity was also evaluated by disc diffusion method against six clinically isolated multi-drug resistant bacterial strains as well as six fungal isolates.Further,cell cytotoxicity was also evaluated through3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay.RESULTS:Ethanol extract showed highest total phenolic[(38.9±1.5)μg gallic acid equivalent/mg]and total flavonoids[(17.2±1.9)μg quercetin equivalent/mg]contents.Antioxidant assays indicated that ethanol and methanol extracts possess potent antioxidant potential.Moreover,it was observed that ethanol and hexane extracts have the potential to inhibit most of the tested multi-drug resistant bacterial strains while methanol,chloroform and hexane extracts could inhibit the growth of pathogenic fungal strains successfully.Among all the studied extracts,ethanolic extract showed highest cytotoxicity against MCF-7 cell line then Hep-2 and DU-145 cell lines by MTT assay with lowest IC50 of 47.3μg/m L.CONCLUSION:These results suggest that R.dentatus could be a potent alternative candidate for treatment of microbial infections and for breast cancer treatment.

Enterococcal urinary tract infections: eight years experience at a regional hospital in Trinidad, West Indies

OBJECTIVE: To investigate the prevalence of significant enterococcal isolates from urine and determine what factors are associated with the increased prevalence, with particular reference to antibiotic susceptibilities. METHODS: Retrospective analysis over an 8-year period of hospital laboratory records of urinary isolates of enterococci was done. Species were identified via colony morphology, growth in 6.5% sodium chloride and their ability to hydrolyze esculin in the presence of 40% bile salts. Susceptibility testing via the disc diffusion technique with 9 commonly used antibiotics was also done as defined by the National Committee for Clinical Laboratory Standards. RESULTS: From 39,881 urine specimens, 9116 (22.9%) were culture positive. Of this 9116, 1001 (11.0%) were enterococci, the 4th most common urinary isolate. E. coli was the most common (36.2%). Most enterococci were from pediatric patients (28.4%) and the urology unit (24.5%). All enterococci were fully sensitive to ampicillin and augmentin (amoxicillin-clavulanic acid). Sensitivity to gentamicin decreased significantly from 79% in 1990 to 58% in 1997 (P