Suppression of P-gp induced multiple drug resistance in a drug resistant gastric cancer cell line by overexpression of Fas

AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved by FACS.The sensitivity of gastriccancer cells to apoptosis was determined by invitro apoptosis assay.The drug sensitization ofcells to several anti-tumor drugs was observedby MTT assay.Immunochemical method wasused to show expression of P-gp and Topo Ⅱ ingastric cancer cells.RESULTS Comparing to SGC7901 and pBK-SGC7901/VCR,fas-SGC7901/VCR showeddecreasing G2 cells and increasing S cells,theG2 phase fraction of pBK-SGC7901/VCR wasabout 3.0 times that of fas-SGC7901/VCR,but Sphase fraction of fas-SGC7901/VCR was about1.9 times that of pBK-SGC7901/VCR,indicatingS phase arrest of fas-SGC7901/VCR.FACS alsosuggested apoptosis of fas-SGC7901/VCR,fas-SGC7901/VCR was more sensitive to apoptosisinducing agent VM-26 than pBK-SGC7901/VCR.MTT assay showed increased sensitization offas-SGC7901/VCR to DDP,MMC and 5-FU,butsame sensitization to VCR according to pBK-SGC7901/VCR.SGC7901,pBK-SGC7901/ VCRand fas-SGC7901/VCR had positively stainedTopo Ⅱ equally.P-gp staining in pBK- SGC7901/VCR was stronger than in SG07901,but there was little staining of P-gp in fas.SGC7901/VCR.CONCLUSION fas gene transduction couldreverse the MDR of human drug-resistant gastriccancer cell SGC7901/VCR to a degree,possiblybecause of higher sensitization to apoptosis anddecreased expression of P-gp.

Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens

Objective:To evaluate the antibacterial properties ot Allium sativum(garlic) cloves and Zingiber officinale(ginger) rhizomes against multi-drug resistant clinical pathogens causing nosocomial infection.Methods:The cloves of garlic and rhizomes of ginger were extracted with 95%(v/v) ethanol.The ethanolic extracts were subjected to antibacterial sensitivity test against clinical pathogens.Results:Anti-bacterial potentials of the extracts of two crude garlic cloves and ginger rhizomes were tested against five gram negative and two gram positive multi-drug resistant bacteria isolates.All the bacterial isolates were susceptible to crude extracts of both plants extracts.Except Enterobacter sp.and Klebsiella sp.,all other isolates were susceptible when subjected to ethanolic extracts of garlic and ginger.The highest inhibition zone was observed with garlic(19.4S mm) against Pseudomonas aeruginosa(P.aeruginosa).The minimal inhibitory concentration was as low as 67.00 μg/mL against P.aeruginosa.Conclusions:Natural spices of garlic and ginger possess effective anti-bacterial activity against multi-drug clinical pathogens and can be used for prevention of drug resistant microbial diseases and further evaluation is necessary.

Assessment of the Indirect Cost of Drug Resistant Tuberculosis Treatment to Patients in a High Burden, Low Income Setting in Mozambique

Introduction: Tuberculosis is closely linked to poverty, with patients facing significant indirect treatment costs. Treating drug-resistant tuberculosis further increases these expenses. Notably, there is a lack of published data on the indirect costs incurred by patients with drug-resistant tuberculosis in Mozambique. Objective: To assess the indirect costs, income reduction, and work productivity incurred by patients undergoing diagnosis and treatment for Drug-Resistant Tuberculosis (DRTB) in Mozambique during their TB treatment. Methods: As part of a comprehensive mixed-methods study conducted from January 2021 to April 2023, this research utilized a descriptive cross-sectional approach, incorporating both quantitative and qualitative methods. The primary goal was to evaluate the costs incurred by the national health system due to drug-resistant TB. Additionally, to explore the indirect costs experienced by patients and their families during treatment, semi-structured interviews were conducted with 27 individuals who had been undergoing treatment for over six months. Results: All survey participants unanimously reported a significant decline in labour productivity, with 70.3% experiencing a reduction in their monthly income. Before falling ill, the majority of respondents (33.3%) earned up to $76.92 monthly, representing the minimum earnings range, while 29.2% had a monthly income above $230.77, the maximum earnings range. Among those who experienced income loss, the majority (22.2%) reported a decrease of up to $76.92 per month, and 18.5% cited a loss exceeding $230.77 per month. Notably, patients with Drug-Resistant Tuberculosis (DRTB) have not incurred the direct costs of the disease, as these are covered by the government. Conclusion: The financial burden of treating Drug-Resistant Tuberculosis (DRTB), along with the income reduction it causes, is substantial. Implementing a patient-centred, multidisciplinary, and multisector approach, coupled with strong psychosocial support, can significantly reduce the catastrophic costs DRTB patients incur.

Early efficacy of individual regimens containing bedaquiline in patients with drug resistant tuberculosis

Objective:To evaluate early efficacy of sputum conversion within 6 months of individual regimens containing bedaquiline in patients with drug resistant tuberculosis.Methods:We conducted a retrospective study among patients with drug resistant tuberculosis who were receiving individual regimens containing bedaquiline.The primary outcome was sputum conversion of both smear and culture within 6 months of treatment.We used medical records of drug resistant tuberculosis patients from January 2020 to December 2021.The study was conducted at Dr.Soetomo Hospital,Indonesia from August to October 2022.Results:In this study,44 eligible drug resistant tuberculosis patients were initiated on regimens containing bedaquiline.There were 52.3%males and the median age was 45.5 years.The rates of previous treatment(70.5%)and lung cavity(36.4%)were high.The most common companion drugs included clofazimine,cycloserine,levofloxacin,and linezolid.Sputum smear and culture conversion was seen in 79.4%and 82.1%at the 2nd month,respectively.More than 97%patients had smear and culture conversion at the end of 6 months.Conclusions:Among drug resistant tuberculosis patients,individual regimens containing bedaquiline were associated with high rates of smear and culture conversion at the end of 6 months.Early efficacy of regimens containing bedaquiline can be used to predict cure rate at the end of treatment.

A novel myeloma cell line identified for multidrug resistant study

Objective:To find out how to overcome resistance during multiple myeloma(MM) treatment through establishing a multidrug resistant human multiple myeloma cell line and investigating its biological features.Methods:The parent cell line MOLP-2 was exposed to different concentrations of melphalan and a melphalan-resistant cell line MOLP-2/R was identified by continuous stepwise selection.The cell morphology and growth curves were examined.Protein levels of P-gp, MRP and FANCD2 monoubiquitination were checked by Western blotting.The IC50 of melphalan and resistance index(RI) were detected by MTT assay.Results:A melphalan-resistant cell line MOLP-2/R was finally identified.The RI of MOLP-2/R cells to melphalan was 6.03.Besides melphalan it was cross resistant to other chemotherapeutic agents, including ADM, CTX, DDP and VP-16.The multiplication time was postponed(P < 0.05).Studies showed that FANCD2 protein monoubiquitination was enhanced, but the levels of P-gp and MRP expressions in the MOLP-2/R cells were similar with the parent cells.Conclusion:MOLP-2/R cell line may serve as an ideal model for exploring the mechanism of MDR.Over-expression of FANCD2 protein monoubiquitination might contribute to acquired drug resistance in MOLP-2/R cell line.

Type 2 reaction associated sensorineural hearing loss in a drug resistant lepromatous leprosy patient: A case report

Rationale:Leprosy,a chronic granulomatous disease often present clinically as erythema nodosum leprosum,a type 2 reaction.The involvement of cochlear part of audiovestibular system is a rarity.Patient concerns:A 26-year-old male patient with lepromatous leprosy developed bilateral sensorineural hearing loss(SNHL)during type 2 reactional episode.Diagnosis:Recurrent erythema nodosum leprosum in rifampicin-resistant lepromatous leprosy.Interventions:Corticosteroids and second-line multidrug therapy.Outcomes:The patient improved significantly and was further referred for management of psychosocial impact due to sensorineural hearing loss.Lessons:The hearing impairment is a rare complication of type 2 reaction.Any patient with suspected cranial nerve involvement should essentially be screened by tuning fork tests for early detection of hearing impairment and offer timely intervention as required.All high bacteriological index cases should be investigated for antimicrobial resistance in high endemic areas.

The emergence of drug resistant HIV variants and novel anti-retroviral therapy

After its identification in 1980s,HIV has infected more than 30 million people worldwide.Inthe era of highly active anti-retroviral therapy,anti-retroviral drug resistance results frominsufficient anti-retroviral pressure,which may lead to treatment failure.Preliminary studiessupport the idea that anti-retroviral drug resistance has evolved largely as a result of low-adherence of patients to therapy and extensive use of anti-retroviral drugs in the developedworld;however,a highly heterogeneous horde of viral quasi-species are currently circulating indeveloping nations.Thus,the prioritizing of strategies adopted in such two worlds should be quitedifferent considering the varying anti-retroviral drug resistance prevalence.In this article,weexplore differences in anti-retroviral drug resistance patterns between developed and developingcountries,as they represent two distinct ecological niches of HIV from an evolutionary standpoint.

Direct and Residual Microbicidal Efficacy of Various Antiseptics against Multi-Drug Resistant Bacteria

Background: Infections in ICU’s patients are known to often originate from the colonization of wounds by the patient’s endogenous microbiota, and to eventually lead to secondary sepsis. Aim: to compare in vitro the direct and residual effects after different exposure times of 4% chlorhexidine, and of 0.1% and 0.04% polyhexanide (in gel and solution forms), on ATCC-microorganisms, and too, on bacterial strains obtained from ICU patients. Methods: We used wild multi-drug resistant strains recently obtained from the wounds of patients hospitalized at ICU and reference strains from the American Type Culture Collection (ATCC). Chlorhexidine 4% was studied as a reference solution. The direct and residual effects of the 0.1% and 0.04% polyhexanide, in gel and solution forms, were analyzed using cotton germ carriers. To evaluate the direct effect, we exposed the strains to the antiseptic. To assess the residual effect, the germ-carriers were impregnated with antiseptic and were allowed to dry before we contaminated them. We inoculated the germ carriers in a culture medium with an inhibitor of antiseptic effect to count the number of surviving microorganisms. Findings: 0.1% Polyhexanide solution proved a direct and residual efficacy after 24 hours equivalent to 4% chlorhexidine. Is very important to highlight that this great efficacy did not change according to whether they were ATCC or multidrug-resistant strains. Conclusions: 0.1% polyhexanide demonstrated a great direct and residual efficacy (like 4% chlorhexidine), against multi-drug resistant strains isolated from ICU’s patients. Moreover, due to its few cytotoxicity against keratinocytes and fibroblasts can be an optimal antiseptic for burns, wounds or ulcers.

Novel mechanism of drug resistance to proteasome inhibitors in multiple myeloma

Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous disease and can be classified into a spectrum of subgroups based on their molecular and cytogenetic abnormalities. In the past decade, novel therapies, especially, the first-in-class proteasome inhibitor bortezomib, have been revolutionary for the treatment of MM patients. Despite these remarkable achievements, myeloma remains incurable with a high frequency of patients suffering from a relapse, due to drug resistance. Mutation in the proteasome β5-subunit(PSMB5) was found in a bortezomib-resistant cell line generated via long-term coculture with increasing concentrations of bortezomib in 2008, but their actual implication in drug resistance in the clinic has not been reported until recently. A recent study discovered four resistance-inducing PSMB5 mutations from a relapsed MM patient receiving prolonged bortezomib treatment. Analysis of the dynamic clonal evolution revealed that two subclones existed at the onset of disease, while the other two subclones were induced. Protein structural modeling and functional assays demonstrated that all four mutations impaired the binding of bortezomib to the 20 S proteasome, conferring different degrees of resistance. The authors further demonstrated two potential approaches to overcome drug resistance by using combination therapy for targeting proteolysis machinery independent of the 20 S proteasome.

Drug Resistance Pattern in Pulmonary Tuberculosis Patients and Risk Factors Associated with Multi-Drug Resistant Tuberculosis

Introduction: Anti-tuberculosis drug resistance is a major problem in tuberculosis (TB) control programme, particularly multi-drug resistance TB (MDR-TB) in Nepal. Drug resistance is difficult to treat due to its associated cost and side effects. The objective of this study was to assess the drug resistance pattern and assess risk factor associated with MDR-TB among pulmonary tuberculosis patients attending National Tuberculosis Center. Methodology: The comparative cross sectional study was conducted at National Tuberculosis Center during August 2015 to February 2015. Early morning sputum samples were collected from pulmonary tuberculosis suspected patients and subjected to Ziehl-Neelsen staining and fluorochrome staining and culture on Lowenstein-Jensen (LJ) medium. Drug Susceptibility test was performed on culture positive isolates by using proportion method. Univariate and multivariate analysis was computed to assess the risk factors of MDR-TB. Results: Out of 223 sputum samples, 105 were fluorochrome staining positive, 85 were ZN staining positive and 102 were culture positive. Out of 102 culture positive isolates, 37.2% were resistance to any four anti-TB drugs. 11 (28.9%) were initial drug resistance and 28 (43.7%) were acquired drug resistance. The overall prevalence of MDR-TB was 11.7%, of which 2 (5.3%) were initial MDR-TB and 10 (15.6%) were acquired MDR-TB. Univariate and multivariate analysis showed female were significantly associated (P = 0.05) with MDR-TB. Conclusion: Drug resistance TB particularly MDR-TB is high. The most common resistance pattern observed in this study was resistance to both isoniazid and rifampicin. Female were found to be associated with MDR-TB. Thus, early diagnosis of TB and provision of culture and DST are crucial in order to combat the threat of DR-TB.

Predominance of Multi-Drug Resistant <i>Klebsiella pneumonia</i>and Other Gram Negative Bacteria in Neonatal Sepsis in Equatorial Guinea

The study was conducted on new-born babies in whom septicemia was suspected, to determine the prevalence of bacterial strains isolated and their sensitivity to antimicrobial drugs. The study was carried out at La Paz Medical Center, Microbiology section, Malabo, Equatorial Guinea from August 2013 to October 2015. Out of 293 septicemia suspected cases, 29 (10%) blood cultures were positive, 28 with bacterial growth and 1 with growth of Candida sp. The mortality rate of neonates caused by Gram negative bacterial sepsis was 34.7%. Among the Gram negative bacteria (24 isolates), the most common types were Klebsiella pneumoniae (16 = 69.6%), followed by Escherichia coli (4 = 17.4%) and Acinetobacter species (4 = 17.4%). Four Gram positive bacteria were also isolated and identified all ascoagulase-negative staphylococci. All the Klebsiella pneumoniae isolates and Acinetobacter species demonstrated Multi Drug Resistance against different antibiotics with Extended-spectrum β-lactamase (ESBL) activity. The most frequent causative agent of bacterial sepsis in new-born children was Klebsiella pneumoniae. An alarming level of Multi Drug Resistance (MDR) Klebsiella pneumoniae strains to the first choice antibiotic treatment was observed.

Formation and Growth of Granular Carbides in Multiple Alloying Wear Resistant Cast Iron Containing RE Through Hot Deformation

The granular carbides formed from hot deformation in multiple alloying wear resistant cast iron were studied through the observation by means of optical microscope, SEM and TEM. The experimental results show that carbides with large size are formed from original short rhabdoid carbides existing in cast, those with small size directly nucleate in the matrix. Carbides with the size between the above are formed from precipitation induced by hot deformation. The bigger the deformation is, the larger the number of microsized granular carbides is. The mechanisms of nucleation and growth of granular carbides and the function of RE were discussed.

Bi-Directional Regulation by Chinese Herbal Formulae to Host and Parasite for Multi-Drug Resistant <i>Staphylococcus aureus</i>in Humans and Rodents

A decline in the immunopotential of the host plays acritical factor(s) in the occurrence of infections with methicillin-resistant Staphylococcus aureus (MRSA) or microorganisms by opportunistic infection. In such an infection, no way out for therapeutic concept, therefore bi-directional trial was the final choice. So we selected aformula, Dang Gui Liu Huang Tang (dLHT), which could both augmentimmune factorsin host and exert bacteriostatic effect. We sought to break through the epidemic by MRSA especially in elderly patient, by the fundamental and clinical trial by employing minor TCM, characterizing bidirectional ability of the decoction by western methods. Animal Experiment: Mitomycin-C (MMC)-treated mice with or without the infection of MRSA were made. The experimental design was made up to examine the bacteriostatic action as well as the immunopo-tentiating bias of the promising Chinese herbal medicine, dLHT, which was first proved for its immune potentiating activities as well as their sensitivity to antibiotics, but not direct aseptic effect was clear for MRSA. Both basic and clinical data showed that this formula was effective on repelling from the infectious focus after the treatment of MRSA infection. After the administration of dLHT, the number of white blood cells in MMC-treated mice recovered to 80% of the normal level. In addition, the phagocytic activity of macrophages increased to 70% in the dLHT-treated group, while that of the non-treated group was only 20%. The bactericidal activity also recovered to the level close to the normal value by dLHT. The ratio of neutrophils in the dLHT-administered group increased to 2.2% (normal mice, 2.6%), whereas that in the non-terated group was only 0.5%. The bacterial count in the liver of MRSA-challenged mice reached the peak at six hours after the challenge in both dLHT-treated and non-treated mice. However, the number of bacteria in dLHT group was much greater than that in the non-treated group. The bacterial count in the blood showed an increase 12 and 24 hours after the challenge. Even 24 hours after the challenge, a significant number of bacteria existed in the blood of dLHT-administered group, whereas only a small number of bacteria detectable 6 hours after the challenge and the number gradually decreased thereafter in the dLHT-administered group. MRSA-challenged MMC-treated mice were treated by dLHT, vancomycin, or dLHT and vancomycin. All of non-treated mice died 8 days after the MRSA challenge, whereas the survival rates were 60% after dLHT treatment, 40% after vancomycin treatment, and 80% after dLHT and vancomycin treatment. All of MMC-treated mice, to which the phagocytic cells prepared from MMC-treated mice with dLHT administration had adoptively been transferred, survived from MRSA challenge. On the other hand, the survival rate of MMC-treated mice, to which the lymphocytes prepared from the same mice had adoptively been transferred, was 40%. Clinical Trial: All cases with dLHT treatment showed negative culture results for MRSA after the dLHT administration. The culture generally became negative less than 50 days after the initial administration, whereas one control case needed more than 100 days and the other was dead of the infection. One representative case, who was a 78-year-old woman suffering from hypertension, atrial fibrillation, and cerebral bleeding in the right occipital lobe, infected with MRSA during the antibiotic therapy for Streptococcus pneumoniae. The antibiotic therapy was halted and the dLHT administration started. Three weeks later, the culture result became negative. In addition, serum protein and albumin values also returned to the level that they had had before the infection of MRSA.

Natural Remedies against Multi-Drug Resistant <i>Mycobacterium tuberculosis</i>

Tuberculosis (TB), caused by Mycobacterium tuberculosis is an infectious deadly disease and the treatment of which is one of the most severe challenges at the global level. Currently more than 20 chemical medications are described for the treatment of TB. Regardless of availability of several drugs to treat TB, the causative agent, M. tuberculosis is nowadays getting resistant toward the conventional drugs and leading to conditions known as Multidrug-resistant tuberculosis (MDR-TB) and extensively drug resistant tuberculosis (XDR-TB). This situation has terrified the global health community and raised a demand for new anti-tuberculosis drugs. Medicinal plants have been used to cure different common as well as lethal diseases by ancient civilizations due to its virtue of variety of chemical compounds which may have some important remedial properties. The aim of the present review is to focus the anti-tubercular medicinal plants native to India as well as the plants effective against MDR or XDR-TB across the globe. In the present review, we have addressed 25 medicinal plants for TB and 16 plants effective against MDR-TB testified from India and 23 herbal plants described for MDR-TB across the world during 2011-2015. These herbal plants can serve as promising candidates for developing novel medications to combat multidrug resistant M. tuberculosis.

Antiretroviral-Drug Resistant Mutations and Genetic Diversity in HIV-1 Infected Individuals in Nigeria

Introduction: Despite the success derived from antiretroviral therapy, drug resistance (DR) mutations are known to develop and are major impediments to treatment of HIV patients. Therefore, periodic assessment of HIVDR is needed to ensure continuous HAART efficacy. This study assessed the magnitude of drug resistance as well as HIV genetic variability in drug-naive and treated patients in Nigeria. Methodology: Genotypic analysis was performed by sequencing plasma specimens from 40 individuals in a cross sectional study involving 202 HIV infected patients from all the six geopolitical zones of Nigeria. Sequences were analyzed for presence of HIVDR mutation using the algorithm in Stanford HIVDR database and confirmed by IAS-USA 2009 mutation list. Phylogenetic and recombination analyses were done using PAUP V4.0 and REGA V2.0 respectively. Results: Major DR mutations were detected in the reverse transcriptase (RT) gene of 5 (33%) drug experienced and 2 (8%) na?ve patients. Most common mutations were M184V and K103N with no protease (PR) mutations detected. Thymidine analogue mutations (TAMs) and a complex multi resistance mutation Q151M were detected in 3 samples. Polymorphic substitutions were observed in both PR and RT gene. Phylogenetic analysis revealed Group M isolates of G (20), J (1), circulating recombinant forms: CRF02_AG (14), CRF-18-cpx (1), CRF06_cpx (3) and a unique AD recombinant (1). Conclusion: Our findings corroborate previous studies on circulating DR viruses in Nigeria while genetic diversity is on the increase. In view of ART scale-up, monitoring the resistance pattern and genetic diversity will aid in appropriate prevention strategies.

Antimicrobial activity of green tea extract against isolates of methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa

Objective:To evaluate antibacterial activity of the Indonesian water soluble green tea extract,Camellia sinensis,against clinical isolates of methicillin-resistantStaphylococcus aureus (S.aureus)(MRSA)and multi-drug resistant Pseudomonas aeruginosa(MDR-P.aeruginosa).Methods:Antimicrobial activity of green tea extract was determined by the disc diffusion method and the minimum inhibitory concentration(MIC)was determined by the twofold serial broth dilutions method.The tested bacteria using in this study were the standard strains and multi-drug resistant clinical isolates of S.aureus and P.aeruginosa,obtained from Laboratory of Clinical Microbiology,Faculty of Medicine,University of Indonesia.Results:The results showed that the inhibition zone diameter of green tea extracts forS.aureus ATCC 25923 and MRSA were(18.970依0.287)mm,and(19.130依0.250)mm respectively.While the inhibition zone diameter forP.aeruginosa ATCC 27853 and MDR-P.aeruginosawere(17.550依0.393)mm and(17.670依0.398)mm respectively.The MIC of green tea extracts againstS.aureus ATCC 25923 and MRSA were 400μg/mL and 400μg/mL,respectively,whereas the MIC for P.aeruginosa ATCC 27853 and MDR-P.aeruginosawere 800μg/mL,and 800μg/mL,respectively.Conclusions:Camellia sinensisleaves extract could be useful in combating emerging drug-resistance caused by MRSA andP.aeruginosa.

Cytotoxic and antibacterial substances against multi-drug resistant pathogens from marine sponge symbiont:Citrinin,a secondary metabolite of Penicillium sp.

Objective:To Isolate,purify,characterize,and evaluate the bioaclive compounds from the sponge-derived fungus Penicillium sp.FF001 and to elucidate its structure.Methods:The fungal strain FF001 with an interesting bioactivity profile was isolated from a marine Fijian sponge Melophlus sp.Based on conidiophores aggregation,conidia development and mycelia morphological characteristics,the isolate FF001 was classically identified as a Penicillium sp.The bioactive compound was identified using various spectral analysis of UV,high resolution electrospray ionization mass spectra,1H and 13C NMR spectral data.Further minimum inhibitory concentrations(MICs)assay and brine shrimp cytotoxicity assay were also carried out to evaluate the biological properties of the purified compound.Results:Bioassay guided fractionation of the EtOAc extract of a static culture of this Penicillium sp.by different chromatographic methods led the isolation of an antibacterial,anticryptococcal and cytotoxic active compound,which was identified as citrinin(1).Further,citrinin(1)is reported for its potent antibacterial activity against methicillin-resistant Staphylococcus aureus(S.aureus),rifampicin-resistant 5.aureus,wild type S.aureus and vancomycin-resistant Enterococcus faecium showed MICs of 3.90,0.97,1.95 and7.81μg/mL,respectively.Further citrinin(1)displayed significant activity against the pathogenic yeast Cryptococcus neoformans(MIC 3.90μg/mL),and exhibited cytotoxicity against brine shrimp larvae LD_(50)of 96μg/mL.Conclusions:Citrinin(1)is reported from sponge associated Penicillium sp.from this study and for its strong antibacterial activity against multi-drug resistant human pathogens including cytotoxicity against brine shrimp larvae,which indicated that sponge associated Penicillium spp.are promising sources of natural bioactive metabolites.

<i>In Vitro</i>Antibacterial Activity of Flavonoid Extracts of Two Selected Libyan Algae against Multi-Drug Resistant Bacteria Isolated from Food Products

This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemor-rhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.

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.

Antibacterial and antioxidant activities of Musa sp.leaf extracts against multidrug resistant clinical pathogens causing nosocomial infection

Objective:To investigate different Musa sp.leave extracts of hexane,ethyl acetate and methanol were evaluated for antibacterial activity against multi-drug resistant pathogens causing nosocomial infection by agar well diffusion method and also antioxidant activities.Methods:The four different Musa species leaves were extracted with hexane,ethyl acetate and methanol.Antibacterial susceptibility test,minimum inhibitory concentration and minimum inhibitory bacterial concentration were determined by agar well diffusion method.Total phenolic content and in vitro antioxidant activity was determined.Results:All the Musa sp.extracts showed moderate antibacterial activities expect Musa paradisiaca with the inhibition zone ranging from 8.0 to 18.6 mm.Among four species ethyl acetate extracts of Musa paradisiaca showed highest activity against tested pathogens particularly E.coli,P.aeruginosa and Citrobacter sp.The minimum inhibitory concentrations were within the value of 15.63-250μg/ml.and minimum bactericidal concentrations were ranging from 31.25-250μg/mL.Antioxidant activity of Musa acuminate exhibited maximum activity among other three Musa species.Conclusions:The present study concluded that among the different Musa species,Musa paradisiaca displayed efficient antibacterial activity followed by Musa acuminata against multidrug resistant nosocomial infection causing pathogens.Further,an extensive study is needed to identify the bioactive compounds,mode of action and toxic effect in.vivo of Musa sp.