Treatment Of Microbial Infections Research Articles

Evaluation of anti–resistant activity of Auklandia(Saussurea lappa) root against some human pathogens

ObjectiveThe antimicrobial activity of the ethanol extract of the Auklandia (Saussurea lappa)root plant was investigated to verify its medicinal use in the treatment of microbial infections. MethodsThe antimicrobial activity of the ethanol extract was tested against clinical isolates of some multidrug-resistant bacteria using the agar well diffusion method. Commercial antibiotics were used as positive reference standards to determine the sensitivity of the clinical isolates. ResultsThe extracts showed significant inhibitory activity against clinical isolates of methicillin resistant Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Extended Spectrum Beta-Lactemase, Acinetobacter baumannii. The minimum inhibitory concentration values obtained using the agar dilution test ranged from 2.0 μg/μL-12.0 μg/μL. In the contrary the water extract showed no activity at all against the tested isolates. Furthermore, the results obtained by examining anti-resistant activity of the plant ethanolic extract showed that at higher concentration of the plant extract (12 μg) all tested bacteria isolates were inhibited with variable inhibition zones similar to those obtained when we applied lower extract concentration using the well diffusion assay. ConclusionThe results demonstrated that the crude ethanolic extract of the Auklandia (Saussurea lappa) root plant has a wide spectrum of activity suggesting that it may be useful in the treatment of infections caused by the above clinical isolates (human pathogens).

English

This study assessed the influence of combining kanamycin and metronidazole against Gram positive and Gram negative bacteria by agar diffusion, checkerboard and time-kill assays. The test isolates were highly resistant with minimum inhibitory concentrations (MICs) ranging between 15.63 and >250 µg/ml for kanamycin and between 15.63 and 125 µg/ml for metronidazole. The antibacterial combinations resulted in drastic decreases in the MICs with an increased antibacterial activity that indicated synergistic interaction against all the bacteria except Acinetobacter calcaoceuticus UP, Enterobacter cloacae ATCC 13047 and Shigella flexneri KZN. The fractional inhibitory concentration indices (FICIs) showed synergy ranging from 0.31 to 0.50, additive interaction with FICI ranging from 0.53 to 1.25 and no antagonistic interaction. Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 10702, E. cloacae ATCC 13047, Klebsiella pneumoniae ATCC 10031, A. calcaoceuticus UP and Micrococcus luteus were totally eliminated by the antibacterial combinations within 24 h of incubation. The lack of antagonism between these antibacterial agents in checkerboard and time-kill assays suggests that kanamycin may prove to be effective in monotherapy and combination therapy. The study indicates the potential beneficial value of combining kanamycin and metronidazole in the treatment of microbial infections in clinical settings.   Key words: Drug-drug interactions, synergy, time-kill, FICI, microbial infections.

THERAPEUTIC SIGNIFICANCE OF QUINOLINE DERIVATIVES AS ANTIMICROBIAL AGENTS

Microbial infections are one of the leading diseases which are responsible for millions of deaths every year because of lack of effective antimicrobial therapy and this situation becomes more complicated because of microbial resistance towards conventional antibiotics. Qu inoline derivatives have proved their medicinal importance by having broad spectrum of pharmacological activities like an timicrobial, anticancer, antiviral and anti - inflammatory activities etc. This review article deals with the antimicrobial potential of novel quinoline derivatives as an effort to provide better treatment for microbial infections.

Screening and characterization of antimicrobial secondary metabolites from Halomonas salifodinae MPM-TC and its in vivo antiviral influence on Indian white shrimp Fenneropenaeus indicus against WSSV challenge

Antimicrobial secondary metabolites from extremophiles play a significant role in the pharmacological industry due to their stable and strong activity and it is used in the treatment of microbial infections. In the present work, Halomonas salifodinae MPM-TC (M. Peter Marian-T. Citarasu) was isolated from the solar salt works in India and identified by 16S rRNA sequencing. The secondary metabolites were extracted from H. salifodinae MPM-TC and tested for antibacterial activity against aquatic bacterial pathogens such as Vibrio harveyi, Vibrio parahaemolyticus, Pseudomonas aeruginosa and Aeromonas hydrophila isolated from infected fish/shrimp, and it effectively controlled them with more than 10mm of zone of inhibition. The metabolites were purified through silica column chromatography and in vitro antiviral activity was performed against White Spot Syndrome Virus (WSSV) using different fractions. Among the different tested fractions, fraction-III (F-III) was able to suppress WSSV replication. Shrimps challenged with a WSSV inoculum incubated with F-III and treated Fenneropenaeus indicus survived around twice as many as the controls. Gas chromatography–mass spectroscopic (GC–MS) analysis revealed that the antiviral active fraction contains around eight compounds including Perfluorotributylamine, Cyclopentane, 1-butyl-2-ethyl and 1,1′-Biphenyl]-3-amine. Further the active fraction F-III was incorporated in the artificial diets at the concentration of 200 (HS1), 400 (HS2) and 800 (HS3) μgkg−1 and fed to F. indicus for 30days. After 30days of culture, shrimps were challenged with virulent WSSV and studied for WSSV VP 28 gene expression, biochemical, haematological and immunological changes. Surprisingly, groups treated with lower concentrations of fraction F-III (HS1 or HS2) significantly (P<0.05) suppressed the viral replication. Different levels of protein and glucose, improved total haemocyte count (THC), coagulase activity and oxyhaemocyanin level all were comparable to controls. Also, immunological parameters such as prophenol oxidase and intracellular superoxide anion production were significantly increased (F=97.18; P⩽0.001 and F=5.70; P⩽0.05) in the groups treated with the three test concentrations. The presence of antiviral and immunostimulant active principles in the F-III fraction effectively suppressed the WSSV load and boosted F. indicus’s immune system. This research will help to develop novel antiviral drugs from plants against aquatic important pathogens.

Phytochemical, antimicrobial and toxicity studies on Phyllanthus amarus whole plant extract

This study investigated the phytochemical composition, antimicrobial activities and toxicological properties of methanolic whole plant extract of Phyllanthus amarus . Phytochemical analysis revealed the presence of saponins, tannins, flavonoids, terpenoids and cardiac glycosides. Antimicrobial sensitivity test using fourteen human pathogenic microorganisms showed that Phyllanthus amarus has bactericidal effect on four pathogens namely Proteus vulgaris , Micrococcus luteus , Bacillus polymyxa and Escherichia coli . The extract also demonstrated significant inhibitory effect on Corynebacterium pyrogenes , Bacillus subtilis , Clostridium sporogenes , Klebsiella pneumonia and Staphylococcus aureus but the microbes were able to recover after a few hours. Administration of Phyllanthus amarus extract to rats for 14 days caused growth depression with no significant change (P< 0.05) in serum concentrations of urea, creatinine, bilirubin and aminotransferases (ALT and AST) compared to untreated group. Measurement of organ: body weight index did not show any indication of kidney or liver enlargement. These result shows that Phyllanthus amarus leaf contains active phytochemicals which are inhibitory to bacteria and might be useful in the treatment of microbial infections in man. It also indicates that the extract might not be toxic to the kidney and the liver.

In vitro ethnotherapeutic potential of the acetone extract of the bark of Ziziphus mucronata Willd. subsp. mucronata Willd.: Antimicrobial and toxicity evaluations

The antimicrobial and the cytotoxicity activities of the crude acetone bark extract ofZiziphus mucronata were determined by agar diffusion, macrobroth dilution assays and brine shrimp lethality assay, respectively, to ascertain its relevance in ethnomedicine. The results show that both Gram negative and Gram positive bacteria tested were equally inhibited. At the highest concentration (10000 µg/ml) of the extract,the bacterial inhibition zones ranged between 16 and 21 ± 1.0 mm, the fungal inhibition zones ranged between 13 and 19 ± 1.0 mm while Fusarium sporotrichioides, Candida glabrata and Trichophyton mucoides were not affected. The minimum inhibitory concentrations (MICs) values of the extract were between 78.1 and 312.5 µg/ml for the bacteria while the minimum bactericidal concentrations (MBCs) were between 156.3 and 2500 µg/ml. For the fungi, the MICs were between 1250 and 10000 µg/ml, the minimum fungicidal concentrations (MFCs) were between 5000 and 20000 µg/ml and the LC50 of the brine shrimp lethality assay was 90.27 µg/ml indicating a low level of toxicity. The degree of the pharmacological activity of Z. mucronata shows the significant medicinal potential of this plant in the treatment of microbial infections and justifies its use in complementary and alternative medicines in South Africa. Key words: Ziziphus mucronata, antibacterial, cytotoxicity, fungicidal, ethanol extract, medicinal potential.

The effects of several antibiotics on neutrophil phagocytosis in the peripheral blood of sheep (in vivo)

The object of this study was in vivo evaluation of the effects of some common antibiotics in treatment of microbial infections on neutrophil phagocytosis in sheep. A period of antibiotic therapy administered in six sheep female lambs (oxytetracycline 5 mg/kg body weight (BW), enrofloxacin 5 mg/kg BW, penicillin 20,000 IU/kg BW, and lincospectin 1 ml/10 kg BW). Blood sample was taken in first, third, sixth, and ninth day of antibiotic therapy (first sample in day 1 was prior to administration) and tested for yeast phagocytosis. Mixed model (REML) was used as a statistical procedure. The results of this study show that estimated mean percentages of yeast phagocytosis were statistically significant between all antibiotics (P < 0.0001). Generally, antibiotics enhanced yeast phagocytosis up to sixth day. Lincospectin and oxytetracycline values returned in ninth day to its previous state on the first day, but, enrofloxacin and penicillin values were high even in ninth day (i.e., they need more time to decrease to the levels before drug administration). In conclusion, in vivo antibiotic therapy enhanced neutrophil in vitro yeast phagocytosis test.

An ent-Kaurane-Type Diterpene in Croton antisyphiliticus Mart.

Croton antisyphiliticus is a medicinal plant widely used in the treatment of microbial infections, especially those affecting the genital tract. Crude extract, fractions and pure compound isolated from roots of this species were investigated to validate their antimicrobial activity against Escherichia coli and Staphylococcus aureus. The compound ent-kaur-16-en-18-oic acid was isolated as a major component (0.7% of crude extract), and its MIC value determined against S. aureus (ATCC 6538) was 250 μg/mL. This is the first phytochemical work on the species monitored with antimicrobial assay.

Antimicrobial activity of selected South African medicinal plants

BackgroundNearly 3,000 plant species are used as medicines in South Africa, with approximately 350 species forming the most commonly traded and used medicinal plants. In the present study, twelve South African medicinal plants were selected and tested for their antimicrobial activities against eight microbial species belonging to fungi, Mycobacteria, Gram-positive and Gram-negative bacteria.MethodsThe radiometric respiratory technique using the BACTEC 460 system was used for susceptibility testing against Mycobacterium tuberculosis, and the liquid micro-broth dilution was used for other antimicrobial assays.ResultsThe results of the minimal inhibitory concentration (MIC) determinations indicated that the methanol extracts from Acacia karoo, Erythrophleum lasianthum and Salvia africana were able to prevent the growth of all the tested microorganisms. All other samples showed selective activities. MIC values below 100 μg/ml were recorded with A. karoo, C. dentate, E. lasianthum, P. obligun and S. africana on at least one of the nine tested microorganisms. The best activity (MIC value of 39.06 μg/ml) was noted with S. africana against E. coli, S. aureus and M. audouinii, and Knowltonia vesitoria against M. tuberculosis.ConclusionThe overall results of the present work provide baseline information for the possible use of the studied South African plant extracts in the treatment of microbial infections.

A review of the pharmacobiotic regulation of gastrointestinal inflammation by probiotics, commensal bacteria and prebiotics

The idea that microbes induce disease has steered medical research toward the discovery of antibacterial products for the prevention and treatment of microbial infections. The twentieth century saw increasing dependency on antimicrobials as mainline therapy accentuating the notion that bacterial interactions with humans were to be avoided or desirably controlled. The last two decades, though, have seen a refocusing of thinking and research effort directed towards elucidating the critical inter-relationships between the gut microbiome and its host that control health/wellness or disease. This research has redefined the interactions between gut microbes and vertebrates, now recognizing that the microbial active cohort and its mammalian host have shared co-evolutionary metabolic interactions that span millennia. Microbial interactions in the gastrointestinal tract provide the necessary cues for the development of regulated pro- and anti-inflammatory signals that promotes immunological tolerance, metabolic regulation and other factors which may then control local and extra-intestinal inflammation. Pharmacobiotics, using nutritional and functional food additives to regulate the gut microbiome, will be an exciting growth area of therapeutics, developing alongside an increased scientific understanding of gut-microbiome symbiosis in health and disease.

Tobacco smoking vs. lipid profile and anthropometric measures: A cross- sectional study among students in the Riyadh College of Health Sciences

Ziziphus mucronata Willd. subsp. mucronata Willd. is a medicinal plant widely used in South Africa for the treatment of various diseases. Like many medicinal plants to which traditional claims including the treatment of ailments of infectious origin but without scientific reports have been associated, Z. mucronata is not an exemption. The ethanolic stems bark extract ofZ. mucronata against medically important pathogens was investigated for the antimicrobial activity by the agar dilution method while the degree of its antimicrobial activity was determined by the macrobroth dilution method. The extract showed good antibacterial and antifungal activities. Both Gram-negative and Gram-positive bacteria were highly inhibited by the extract at very low concentrations. All the bacteria had inhibition zones greater than 20 mm at a concentration of 5 mg/ml with the exception of Pseudomonas aeruginosa (ATCC 19582) and Bacillus pumilus (ATCC 14884). For the bacteria, the minimum inhibitory concentration (MIC) values ranged between 0.078 and 0.625 mg/ml. For the fungi, the MIC values were between 2.5 to 10 mg/ml. The bacteria were more susceptible to the extract than the fungi. The antimicrobial activity of the extract indicated a broad spectrum, great therapeutic potential and justified the use of this plant by the rural communities in the treatment of microbial infections. Key words: Agar dilution, antimicrobial, broad spectrum, ethanol extract, fungicidal concentration.

Antimicrobial potency of the ethanolic crude bark extract of Ziziphus mucronata Willd. subsp. mucronata Willd

Ziziphus mucronata Willd. subsp. mucronata Willd. is a medicinal plant widely used in South Africa for the treatment of various diseases. Like many medicinal plants to which traditional claims including the treatment of ailments of infectious origin but without scientific reports have been associated, Z. mucronata is not an exemption. The ethanolic stems bark extract of Z. mucronata against medically important pathogens was investigated for the antimicrobial activity by the agar dilution method while the degree of its antimicrobial activity was determined by the macrobroth dilution method. The extract showed good antibacterial and antifungal activities. Both Gram-negative and Gram-positive bacteria were highly inhibited by the extract at very low concentrations. All the bacteria had inhibition zones greater than 20 mm at a concentration of 5 mg/ml with the exception of Pseudomonas aeruginosa (ATCC 19582) and Bacillus pumilus (ATCC 14884). For the bacteria, the minimum inhibitory concentration (MIC) values ranged between 0.078 and 0.625 mg/ml. For the fungi, the MIC values were between 2.5 to 10 mg/ml. The bacteria were more susceptible to the extract than the fungi. The antimicrobial activity of the extract indicated a broad spectrum, great therapeutic potential and justified the use of this plant by the rural communities in the treatment of microbial infections.

Antibacterial and antioxidant investigations of Hallea ledermannii leaf extract

Hallea ledermannii (Krause) Verdc. (Rubiaceae) is used for treatment of various microbial diseases such as dysentery and skin infections. The leaf extract was screened for antibacterial activities using agar cup plate method against pathogenic organisms like Staphylococcus aureus , Bacillus subtilis , Escherichia coli , Pseudomonas aeruginosa and Klebseilla pneumonia . The extract was active against both Gram positive and Gram negative bacteria with MIC value of 50.0, 12.5, 50.0, 18.75 and 12.5 mg/ml respectively. The antioxidant activities of the extract were also determined using total phenolic content and DPPH radical scavenging effect. The content of phenolic compounds in terms of gallic acid was found to be 88.0 mg/g. and scavenging power was found to increase with concentration. These may be responsible for the observed antimicrobial properties of the extract thus justifying its use in traditional medicine for treatment of microbial infections.

Screening Togolese medicinal plants for few pharmacological properties

Background:Terminalia macroptera Guill. et Perr. (Combretaceae), Sida alba L. (Malvaceae), Prosopis africana Guill et Perr. Taub. (Mimosaceae), Bridelia ferruginea Benth. (Euphorbiaceae), and Vetiveria nigritana Stapf. (Asteraceae) are traditionally used in Togolese folk medicine to treat several diseases including microbial infections.Objective:This study aimed to investigate the antimicrobial, antioxidant, and hemolytic properties of the crude extracts of the above-mentioned plants.Materials and Methods:The antimicrobial and the antioxidant activities were assayed using the NCCLS microdilution method and the DPPH free radical scavenging, respectively. Human A+ red blood cells were used to perform the hemolytic assay. Phenolics were further quantified in the extracts using spectrophotometric methods.Results:Minimal inhibitory concentrations in the range of 230-1800 μg/ml were recorded in the NCCLS broth microdilution for both bacterial and fungal strains with methanol extracts. The DPPH radical scavenging assay yielded interesting antioxidant activities of the extracts of P. africana and T. macroptera (IC50 values of 0.003 ± 0.00 μg/ml and 0.05 ± 0.03 μg/ml, respectively). These activities were positively correlated with the total phenolic contents and negatively correlated with the proanthocyanidin content of the extracts. The hemolytic assay revealed that great hemolysis occurred with the methanol extracts of T. macroptera, S. longepedunculata, and B. ferruginea.Conclusion:These results support in part the use of the selected plants in the treatment of microbial infections. In addition, the plant showed an interesting antioxidant activity that could be useful in the management of oxidative stress.

Anthemis wiedemanniana essential oil prevents LPS-induced production of NO in RAW 264.7 macrophages and exerts antiproliferative and antibacterial activities in vitro

Anthemis wiedemanniana is known in folk medicine for the treatment of microbial infections, cancer and also urinary and pulmonary problems. In this study, the chemical composition of the essential oil from A. wiedemanniana was evaluated and its antibacterial activity was tested against 10 bacterial strains. The oil was also tested for its potentiality to inhibit nitric oxide production in RAW 264.7 macrophages and for its cytotoxicity against four human cancer cell lines. A. wiedemanniana oil, rich of oxygenated monoterpenes (25.4%), showed a good antibacterial activity against Gram-positive bacteria and a good activity against the two Gram-negative bacteria, Escherichia coli and Proteus vulgaris. Besides that, it exhibited a high inhibitory effect on the LPS-induced nitrite production and a strong cytotoxic activity, especially against amelanotic melanoma (C32) and large lung cell carcinoma (COR-L23) cell lines.

Antimicrobial, antiplasmodial, haemolytic and antioxidant activities of crude extracts from three selected Togolese medicinal plants

Objective To investigate the antioxidant, antimicrobial, antiplasmodial, acute toxicity and haemolytic activities of methanolic extracts of three plants. Phytochemical analysis to determine the phenolic contents was also carried out. Methods The 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging, NCCLS broth microdilution and Plasmodium Lactate Dehydrogenase (pLDH) assays were used to determine antioxidant, antimicrobial and antiplasmodial activities, respectively. Haemolysis assay was conducted on A + human red blood cells and acute toxicity on male Swiss albino mice. Phenolics were quantitatively determined using spectrophotometric methods. Results The DPPH assay yielded interesting antioxidant activities of methanolic extract of Parinari curatellifolia (P. curatellifolia) and Entada africana (E. africana) (IC 50 were 0.20±0.01 μg/mL and 0.47±0.01 μg/mL, respectively). This activity was highly correlated with phenolic contents of extracts. The antimicrobial tests displayed minimal inhibitory concentrations (MICs) values ranging from 0.90 to 1.80 mg/mL for Serratia marcescens (S. marcescens) the most susceptible bacterial strain. MIC value was 1.20 mg/mL for susceptible fungal strains including Mucor rouxi (M. rouxi), Fusarium oxyporum (F. oxyporum) and Rhizopus nigricans (R. nigricans). pLDH assay showed moderate antiplasmodial activity of Balanites aegyptiaca (B. aegyptiaca) (IC 50 = 24.56±3.45 μg/mL), however this extract was highly haemolytic and toxic in mice (LD 50 = 625±128 mg/kg). Conclusions Our results support in part the use of the selected plants in the treatment of microbial infections. In addition the plant showed interesting antioxidant activity that could be useful in the management of oxidative stress.

Pharmacognostic Studies on the Leaves of Dyschoriste Perottetii Nees

To ensure reproducible quality of herbal products, proper control of starting material is important. The first step towards ensuring quality of starting material is authentication. Thus, in recent years there has been a rapid increase in the standardization of selected medicinal plants of potential therapeutic significance. Despite the modern techniques, identification of plant drugs by pharmacognostic studies is more reliable. Dyschoriste perrottetii Nees (Family-Acanthaceae) is an important medicinal plant used in various ways in the treatment of microbial infections, fever, measles and pains. Macroscopic, microscopic and chemo-microscopic studies of powdered and anatomical sections of the leaf were carried out using standard methods. This is necessary, for the purpose of identification and monograph preparation. The result shows diacytic stomata on the lower and upper surface, surrounded by wavy walled epidermal cells, unicellular covering trichomes, calcium oxalate crystal, which are mostly single and prismatic, lignified fibres and a characteristic collenchyma cells below the epidermis. Chemo-microscopic examination revealed the presence of starch, tannin, mucilage and cellulose. Quantitative evaluation of the powdered leaves gave moisture content of 7.5 %, total ash 12.5 %, water soluble ash 5.3 %, acid insoluble ash of 4.0 %, and alcohol extractive and water soluble extractive of 31.2 and 21 .08 % respectively. These findings are of importance in the establishing diagnostic indices for the identification, Result could be used for identification and preparation of monograph on the plant.

Photodynamic therapy based on 5‐aminolevulinic acid and its use as an antimicrobial Agent

Exogenous 5-aminolevulinic acid (ALA) is taken up directly by bacteria, yeasts, fungi, and some parasites, which then induces the accumulation of protoporphyrin IX (PPIX). Subsequent light irradiation of PPIX leads to the inactivation of these organisms via photodamage to their cellular structures. ALA uptake and light irradiation of PPIX produced by host cells leads to the inactivation of other parasites, along with some viruses, via the induction of an immune response. ALA-mediated PPIX production by host cells and light irradiation result in the inactivation of other viruses via either the induction of a host cell response or direct photodynamic attack on viral particles. This ALA-mediated production of light-activated PPIX has been extensively used as a form of photodynamic therapy (PDT) and has shown varying levels of efficacy in treating conditions that are associated with microbial infection, ranging from acne and verrucae to leishmaniasis and onychomycosis. However, for the treatment of some of these conditions by ALA-based PDT, the role of an antimicrobial effect has been disputed and in general, the mechanisms by which the technique inactivates microbes are not well understood. In this study, we review current understanding of the antimicrobial mechanisms used by ALA-based PDT and its role in the treatment of microbial infections along with its potential medical and nonmedical applications.

Antibacterial Activity of &lt;i&gt;Garcinia kola&lt;/i&gt; and &lt;i&gt;Cola nitida&lt;/i&gt; Seed Extracts

Antibacterial activity of Garcinia kola (Bitter Kola) and Cola nitida (Kola nut) against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Klebsiella pneumoniae was studied. Results showed that alcohol extract of Garcinia kola was active against Staphylococcus aureus and Klebsiella pneumoniae at various concentrations, with the latter displaying the lowest sensitivity. Escherichia coli and Salmonella typhi were completely resistant. Hot water extract of the same plant was however, active against Salmonella typhi, Staphylococcus aureus and Klebsiella pneumoniae. The other organisms showed sensitivity to the alcohol extract of Cola nitida, but higher sensitivity was observed with the hot water extract of the plant. Some of the results provided scientific evidence for the use of the plants by traditional herbalists in the treatment of microbial infections. Key word: Garcinia kola, Bitter Kola, Cola nitida, Kola nut, Antibacterial, extracts.

Preparation and properties of silver nanoparticles loaded in activated carbon for biological and environmental applications

Abstract Silver nanoparticles colloid has been prepared by a modified sonoelectrodeposition technique in which a silver plate was used as the source of silver ions. This technique allows producing Ag nanoparticles with the size of 4–30 nm dispersed in a non-toxic solution. The Ag nanoparticles were loaded in a high surface activated carbon produced from coconut husk, a popular agricultural waste in Vietnam by thermal activation. The surface area of the best activated carbon is 890 m 2/g. The presence of Ag nanoparticles does not change significantly properties of the activated carbon in terms of morphology and methylene blue adsorption ability. The Ag nanoparticle-loaded activated carbon shows a good antibacterial activity against Escherichia coli with very low minimal inhibitory concentration of 16 μg/ml and strong As(V) adsorption. The materials are potential for prevention and treatment of microbial infection and contamination for environmental applications.