Evaluating the Potency of Selected Antibiotic Medications Dispensed in Community Pharmacies in Gwale, Kano, Nigeria.

The worsening of antibiotic resistance is a multifactorial process. One aspect of this is the counterfeiting of antibiotic medications. This is supposed to be particularly high in developing countries, including Nigeria. Therefore, the potency of some antibiotic drugs dispensed in community pharmacies in Gwale, Kano, Nigeria, was investigated in this case study. Three products, each from different manufacturers, with the active ingredients of ceftriaxone, gentamicin, ciprofloxacin, and metronidazole, respectively, were included in this study. By means of a disc-diffusion assay, the effect against the typed strains Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) as well as Clostridium tetani isolated from soil was tested. Clinical isolates of S. aureus and E. coli were also used. While antibiotics, with the exception of ciprofloxacin-containing preparations against C. tetani, showed acceptable efficacy against the typed strains by comparison with the clinical science laboratory references, a predominant failure was observed with the clinical isolates. Thus, the investigated drug preparations can be considered of acceptable quality for the treatment of susceptible bacterial infections. This excludes counterfeits in the sampled preparations. However, the insufficient efficacy against clinical isolates further documents the severity of nosocomial bacteria.

Potential antibacterial and antioxidant inhibitory activities of Silybum marianum mediated biosynthesised He-Ne laser.

A potentially beneficial method in laser irradiation is currently gaining popularity. The biosynthesis of low-power lasers has also been applied to the therapy of disease in biological tissues. This study used laser pre-treatments of Silybum marianum (S. marianum) fruit extract as a stabilising agent to bio-fabricate a low-power laser. The silybin A and silybin B of the S. marianum fruit, which are derived from seedlings before S. marianum undergoes therapy with an He-Ne laser at various intervals, were assessed for their expressive properties in this study. The findings revealed that 6-min laser pre-treatments increased silybin A + B and bacterial inhibition and improved the medicinal property of S. marianum. The analysis of the reaction records was performed using ultraviolet-visible spectroscopy. The minimum inhibitory concentration (MIC) limit for the sphere dispersion approach's antimicrobial effect on the microorganisms under investigation was 50 to 100 g/mL. With an IC50 of 0.69 mg/mL, the laser-treated S. marianum (6 min) demonstrated radical scavenging activity. At MIC concentration, the laser-treated S. marianum (6 min) did not exhibit cytotoxicity in the MCF-7 cell line. Additionally, Salmonella typhi, methicillin-resistant Staphylococcus aureus (MRSA), and E. coli were more susceptible to the antimicrobial effects of ethanolic fruit extract with a greater silybin level. It was observed that the laser-treated S. marianum (6 min) showed beneficial antioxidant and antibacterial properties and could be employed without risk in several medical applications.

Microbial approaches for the assessment of toothpaste efficacy against oral species: A method comparison.

Antibacterial properties of toothpastes enable chemical plaque control in limited-access tooth regions that are mechanically not sufficiently reached by toothbrushes. Therefore, this study aimed to compare different microbial methods to assess antimicrobial toothpaste properties and evaluate different toothpastes in terms of their antibacterial efficacy against different oral microorganisms in an in vitro setting. Six toothpaste suspensions with varying antibacterial supplements were applied to a multispecies biofilm model (Actinomyces oris, Candida albicans, Fusobacterium nucleatum, Streptococcus oralis, and Streptococcus mutans) as well as to each microorganism. A culture method was used to assess the anti-biofilm effects and two different agar diffusion assays were performed for testing the antimicrobial effect on each microorganism. The measurements of the culture and diffusion analyses were statistically normalized and compared and toothpastes were ranked according to their antimicrobial efficacy. The results of both agar diffusion assays showed a high correlation across all tested species (Spearman correlation coefficients ρs > 0.95). The results of the multispecies biofilm model, however, substantially differed in its assessment of antibacterial properties (ρs ranging from 0.22 to 0.87) compared to the results of both diffusion assays. Toothpastes with amine fluoride (with and without stannous fluoride), and toothpastes with triclosan resulted in the highest antimicrobial efficacy. Activated carbon supplements in toothpastes were comparable in their antimicrobial action to the negative control NaCl. The appropriate selection of a broad range of oral microorganisms seems crucial when testing the chemical impact of toothpaste and toothpaste supplements.

Analysis of antibiotic resistance and virulence patterns in Klebsiella pneumoniae isolated from human urinary tract infections in India.

In this study, 504 urine samples collected from patients suffering from urinary tract infection (UTIs) were screened for the presence of Klebsiella pneumoniae. The overall occurrence of Klebsiella spp. and K. pneumoniae was found to be 23·2% (117/504) and 16·8% (85/504) respectively. Antibiotic susceptibility testing of 85 K. pneumoniae isolates was carried out by disc diffusion which revealed alarming levels of antibiotic resistance (ABR). Antimicrobial resistance was prominently observed against cefpodoxime (76·47%) followed by ampicillin (70·59%), ceftriaxone (52·94%), cefoxitin (50·59%), amoxyclav (48·24%), ofloxacin (45·88%), cefotaxime (44·71%), cefepime (43·53%) and doxycycline hydrochloride (40%). A small percentage of strains also exhibited resistance to other antimicrobials in the range of 7-35%. Around 77·6% of the isolates were found to be resistant to three or more antibiotic classes and 66·7% of the isolates had multiple antibiotic resistance index values >0·2. Screening of virulence genes in 85 K. pneumoniae isolates revealed that uge gene was the most predominant (11/85, 12·9%), followed by rmpA (9/85, 10·5%), kfu (4/85, 4·7%) and aerobactin genes (2/85, 2·35%). Further, the overall percentage of biofilm producers were found to be 17·65% (15/85). This study warrants hospitals and health care centres to reduce misuse of antibiotics and manage UTI with appropriate treatment after performing antibiotic susceptibility testing.

Biophysical characterization of antibacterial compounds derived from pathogenic fungi Ganoderma boninense.

There have been relatively few studies which support a link between Ganoderma boninense, a phytopathogenic fungus that is particularly cytotoxic and pathogenic to plant tissues and roots, and antimicrobial compounds. We previously observed that liquid-liquid extraction (LLE) using chloroformmethanol-water at a ratio (1:1:1) was superior at detecting antibacterial activities and significant quantities of antibacterial compounds. Herein, we demonstrate that antibacterial secondary metabolites are produced from G. boninense mycelia. Antibacterial compounds were monitored in concurrent biochemical and biophysical experiments. The combined methods included high performance thin-layer chromatography (HPTLC), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. The antibacterial compounds derived from mycelia with chloroform-methanol extraction through LLE were isolated via a gradient solvent elution system using HPTLC. The antibacterial activity of the isolated compounds was observed to be the most potent against Staphylococcus aureus ATCC 25923 and multidrug-resistant S. aureus NCTC 11939. GC-MS, HPLC, and FTIR analysis confirmed two antibacterial compounds, which were identified as 4,4,14α-trimethylcholestane (m/z = 414.75; lanostane, C30H54) and ergosta-5,7,22-trien-3ß-ol (m/z = 396.65; ergosterol, C28H44O). With the aid of spectroscopic evaluations, ganoboninketal (m/z = 498.66, C30H42O6), which belongs to the 3,4-seco-27-norlanostane triterpene family, was additionally characterized by 2D-NMR analysis. Despite the lack of antibacterial potential exhibited by lanostane; both ergosterol and ganoboninketal displayed significant antibacterial activities against bacterial pathogens. Results provide evidence for the existence of bioactive compounds in the mycelia of the relatively unexplored phytopathogenic G. boninense, together with a robust method for estimating the corresponding potent antibacterial secondary metabolites.

Ganoderma boninense mycelia for phytochemicals and secondary metabolites with antibacterial activity.

Antiplasmodial nortriterpenes with 3,4-seco-27-norlanostane skeletons, almost entirely obtained from fruiting bodies, represent the main evidential source for bioactive secondary metabolites derived from a relatively unexplored phytopathogenic fungus, Ganoderma boninense. Currently lacking is convincing evidence for antimicrobial secondary metabolites in this pathogen, excluding that obtained from commonly observed phytochemicals in the plants. Herein, we aimed to demonstrate an efficient analytical approach for the production of antibacterial secondary metabolites using the mycelial extract of G. boninense. Three experimental cultures were prepared from fruiting bodies (GBFB), mycelium cultured on potato dextrose agar (PDA) media (GBMA), and liquid broth (GBMB). Through solvent extraction, culture type-dependent phytochemical distributions were diversely exhibited. Water-extracted GBMB produced the highest yield (31.21 ± 0.61%, p < 0.05), but both GBFB and GBMA elicited remarkably higher yields than GBMB when polar-organic solvent extraction was employed. Greater quantities of phytochemicals were also obtained from GBFB and GBMA, in sharp contrast to those gleaned from GBMB. However, the highest antibacterial activity was observed in chloroform-extracted GBMA against all tested bacteria. From liquid-liquid extractions (LLE), it was seen that mycelia extraction with combined chloroform-methanol-water at a ratio of 1:1:1 was superior at detecting antibacterial activities with the most significant quantities of antibacterial compounds. The data demonstrate a novel means of assessing antibacterial compounds with mycelia by LLE which avoids the shortcomings of standardized methodologies. Additionally, the antibacterial extract from the mycelia demonstrate that previously unknown bioactive secondary metabolites of the less studied subsets of Ganoderma may serve as active and potent antimicrobial compounds.

Anti-biofilm and Antibacterial Activity of Allium sativum Against Drug Resistant Shiga-Toxin Producing Escherichia coli (STEC) Isolates from Patient Samples and Food Sources.

Escherichia coli (E. coli) colonizes human intestinal tract and is usually harmless to the host. However, several strains of E. coli have acquired virulent genes and could cause enteric diseases, urinary tract and even brain infections. Shiga toxin producing Escherichia coli (STEC) is an enterohaemorrhagic E. coli (EHEC) which can result in bloody diarrhoea and could potentially lead to deadly heamolytic uremic syndrome (HUS). STEC is one of the important food borne pathogens that causes food poisoning leading to diarrhoea and number of STEC outbreaks have occurred across the world. The use of standard antibiotics to treat STEC infection is not recommended as it increases the production of shiga toxin which could lead to HUS. Therefore, use of alternative approaches which include use of plant products to treat STEC infections have been gaining attention. The objective of this study was to evaluate the antibacterial and anti-biofilm activity of garlic (Allium sativum) against STEC strains isolated from various patient and food samples using in vitro assays. The microbiological isolation of STEC from various patient and food samples resulted in eight STEC isolates of which seven strains were multidrug resistant. Antibacterial assay results indicated that all the strains exhibited dose dependent sensitivity towards garlic with zone of inhibition diameters ranging from 7 to 24 mm with 15 µl of fresh garlic extract (FGE). Minimum inhibitory  concentration (MIC) of FGE for isolates ranged from 30 to 140 µl/ml. Interestingly, the biofilm formation of all isolates in presence of 4% of FGE decreased by 35 to 59%. FTIR analysis indicated that treatment with 1% FGE results in compositional and content changes in the biofilm. In addition, the total carbohydrate content of biofilm was reduced by 40% upon 1% FGE treatment. The results of the present study report for the first time the antibacterial and anti-biofilm activity of garlic against STEC. The findings will enable development of novel garlic organosulfide based drugs for the prevention and treatment of STEC infections.

Investigation of biological activities of the flowers of Lagerstroemia speciosa, the Jarul flower of Bangladesh.

BACKGROUND: Lagerstroemia speciosa (L.) Pers. (Family: Lythraceae) is used in traditional medicine in the treatment of diarrhea, diabetes and other diseases. The study was performed to conduct antioxidant, cytotoxic, thrombolytic, membrane stabilizing, antimicrobial, peripheral and central analgesic and hypoglycemic activity assays and phenobarbitone sodium-induced sleeping time test using crude methanol extract of flowers of L. speciosa and its different partitionates. METHOD: The antioxidant potential was evaluated by determining the ability of the samples to scavenge 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical. The cytotoxic potential was examined following the procedures of brine shrimp lethality bioassay. Thrombolytic potential was assayed using streptokinase as standard. The samples were subjected to membrane stabilizing activity assay under heat induced condition. Antimicrobial potential was observed by disc diffusion method. The ability of the extract to inhibit writhing induced by acetic acid was determined in peripheral analgesic activity assay. The extract was also tested for central analgesic and hypoglycemic activities by tail flicking and tail tipping methods in Swiss albino mice model, respectively. CNS depressant activity was evaluated by an assay in which sleep was induced in mice using phenobarbitone sodium. RESULTS: The chloroform soluble fraction of L. speciosa extract demonstrated the highest antioxidant activity (IC50 = 4.20 ± 0.41 µg/ml) while the most prominent cytotoxic potency was showed by hexane soluble fraction (LC50 = 2.00 ± 0.31 µg/ml). Among the test samples, the carbon tetrachloride soluble fraction induced clot lysis (64.80 ± 0.27%) and prevented heat induced haemolysis (41.90 ± 0.10%) to the maximum extent. The largest zone of inhibition (19.0 mm) against Staphylococcus aureus, was also observed for the same fraction. In peripheral analgesic activity assay, 16.68% inhibition of writhing was documented for the L. speciosa extract (400 mg/kg body weight dose). The extract (400 mg/kg dose) also reduced blood sugar level by 56.12% after three hours of administration of glucose solution. In CNS depressant activity assay, mice of the sample group slept for shorter period of time compared to control group. CONCLUSIONS: From our investigation, it can be suggested that, the extract should be further studied for possible phytochemicals responsible for the observed biological activities.

Bioactive potential of Indian stinging plants leaf extract against pathogenic fungi.

Background & methods We investigated the in vitro antioxidant and antifungal activity by agar disc diffusion assay of leaf extract of some stinging plants namely, Urtica dioica L., Tragia involucrate L., Carduus nutans L. and Mucuna pruriens (L.) DC., against pathogenic fungi causing infections/diseases. Results M. pruriens (Disc 4), T. involucrate (Disc 2), U. dioica (Disc 1) showed significant antifungal activity against all tested pathogens, while C. nutans (Disc 3) showed intermediate activity against only Chaetomium globosum (Cg). The leaf extract of M. Pruriens showed maximum total phenol content (~1004 µg g-1 dry wt) followed by T. involucrate, C. nutans and U. dioica. However, the ascorbate was observed highest in T. involucrate (~10.3 µg g-1 dry wt) followed by M. pruriens (~9.2 µg g-1 dry wt) but the difference was not significant (p ≤ 0.05). Likewise, M. pruriens showed maximum anthocyanin content (~0.3 µg g-1 dry wt). The activity of antioxidant enzymes revealed that M. Pruriens showed maximum ascorbate peroxidase (APX) activity, while the highest guaiacol peroxidase (GPX) and catalase (CAT) activities were observed in C. nutans and U. dioica, respectively. Conclusions M. Pruriens showed potential in vitro antioxidant and antifungal activity against studied pathogens that may be used for ethno-pharmacological uses.

Dual function of active constituents from bark of Ficus racemosa L in wound healing.

BACKGROUND: Different parts including the latex of Ficus racemosa L. has been used as a medicine for wound healing in the Ayurveda and in the indigenous system of medicine in Sri Lanka. This plant has been evaluated for its wound healing potential using animal models. The aim of this study was to obtain an insight into the wound healing process and identify the potential wound healing active substance/s present in F. racemosa L. bark using scratch wound assay (SWA) as the in-vitro assay method. METHOD: Stem bark extracts of F. racemosa were evaluated using scratch wound assay (SWA) on Baby Hamster Kidney (BHK 21) and Madin-Darby Canine Kidney (MDCK) cell lines and Kirby Bauer disc diffusion assay on common bacteria and fungi for cell migration enhancing ability and antimicrobial activity respectively. Dichloromethane and hexanes extracts which showed cell migration enhancement activity on SWA were subjected to bioactivity directed fractionation using column chromatography followed by preparative thin layer chromatography to identify the compounds responsible for the cell migration enhancement activity. RESULTS: Dichloromethane and hexanes extracts showed cell migration enhancement activity on both cell lines, while EtOAc and MeOH extracts showed antibacterial activity against Staphylococcus and Bacillus species and antifungal activity against Saccharomyces spp. and Candida albicans. Lupeol (1) and ß-sitosterol (2) were isolated as the potential wound healing active compounds which exhibited significant cell migration enhancement activity on BHK 21 and MDCK cell lines (> 80%) in par with the positive control, asiaticoside at a concentration of 25 µM. The optimum concentration of each compound required for the maximum wound healing has been determined as 30 µM and 35 µM for 1 and 2 respectively on both cell lines. It is also established that lupeol acetate (3) isolated from the hexanes extract act as a pro-drug by undergoing hydrolysis into lupeol in the vicinity of cells. CONCLUSION: Different chemical constituents present in stem bark of Ficus racemosa L show enhancement of cell migration (which corresponds to the cell proliferation) as well as antimicrobial activity. This dual action of F. racemosa stem bark provides scientific support for its traditional use in wound healing.

Direct suppression of a rice bacterial blight (Xanthomonas oryzae pv. oryzae) by monoterpene (S)-limonene.

Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile terpenes, induced by the infection of Xoo, and investigated their biological roles in the rice plant. Monoterpenes α-thujene, α-pinene, sabinene, myrcene, α-terpene, and (S)-limonene and sesquiterpenes cyclosativene, α-copaene, and ß-elemene were detected from 1-week-old Xoo-infected rice seedlings, by solid-phase microextraction-gas chromatography-mass spectrometry. All monoterpenes were constitutively released from rice seedlings before Xoo infection. However, (S)-limonene emission was further elicited after exposure of the seedlings to Xoo in coincidence with upregulation of limonene synthase gene (OsTPS20) transcripts. Only the stereospecific (S)-limonene [and not (R)-limonene or other monoterpenes] severely inhibited Xoo growth, as confirmed by disc diffusion and liquid culture assays. Rice seedlings showed suppressed pathogenic symptoms suggestive of resistance to Xoo infection after foliar treatment with (S)-limonene. Collectively, our findings suggest that (S)-limonene is a volatile phytoanticipin, which plays a significant role in suppressing Xoo growth in rice seedlings.

Comparative efficacy of herbal essences with amphotricin B and ketoconazole on Candida albicans in the in vitro condition.

BACKGROUND: The Candida species are the most important factors of fungal infections in humans and animals. It is necessary to prepare antifungal or antimicrobial drugs because of increasing drug resistance. The natural treatment of diseases of bacterial origin using medicinal plants is important. In this study the effect of antimicrobial medicinal herbal essential oils and conventional antifungal drugs were evaluated on Candida albicans in vitro. METHODS: Disc diffusion assay and the microbroth dilution method were used to investigate the anticandidal effects of Foeniculum vulgare Mill, Satureja hortensis L, Cuminum cyminum, and Zataria multiflora Boiss essential oils. The anticandidal effect of these essential oils was compared with that of amphotricin B and ketoconazole in vitro. We then measured the chemical composition of the studied essential oils using gas chromatography-mass spectroscopy. RESULTS: Z. multiflora Boiss essential oil at the minimum inhibitory concentration (MIC) of 34 µg/mL and minimal lethal concentration [i.e., minimal fungicidal concentration (MFC)] of 64 µg/mL had more powerful anti-Candida activity than the other essential oils. C. cyminum essential oil showed the least effect on the tested fungus. A comparison of the effect of the studied essential oils and antifungal drugs showed that the antifungal effect on the C. albicans fungus was better with the fungicides than with the essential oils. CONCLUSION: In the present study, essential oils with different components showed antifungal activity (especially Z. multiflora Boiss essential oil). They can therefore be used as new antifungal substances.

A large scale virtual screen of DprE1.

Tuberculosis continues to plague the world with the World Health Organization estimating that about one third of the world's population is infected. Due to the emergence of MDR and XDR strains of TB, the need for novel therapeutics has become increasing urgent. Herein we report the results of a virtual screen of 4.1 million compounds against a promising drug target, DrpE1. The virtual compounds were obtained from the Zinc docking site and screened using the molecular docking program, AutoDock Vina. The computational hits have led to the identification of several promising lead compounds.

Extraction, gas chromatography-mass spectrometry analysis and screening of fruits of Terminalia chebula Retz. for its antimicrobial potential.

BACKGROUND: Terminalia chebula is called the "king of medicines" in Tibet and is always listed first in the Ayurvedic meteria medica because of its extraordinary powers of healing. OBJECTIVE: Identification, isolation and screening of pyrogallol which are responsible for antimicrobial property of fruits of Terminalia chebula. MATERIALS AND METHODS: Ethyl acetate fraction of fruits of Terminalia chebula was subjected to Gas chromatography-mass spectrometry (GC-MS) for the components present in the extract. RESULTS: Sixty four constituents were identified out of which kaempferol-3-O-rutinoside flavonoid and Vitamin E has been detected for the first time in fruits of this plant. Pyrogallol (46.26%) which was the major component of the extract in GC-MS analysis was isolated and screened for antimicrobial activity against selected test pathogens by Disc Diffusion Assay. Crude ethyl acetate fraction of the fruits was showing the same activity potential as was observed for pure pyrogallol which was the major component as per GC-MS analysis. The most sensitive species among the bacteria was Enterobacter aerogenes with highest inhibition zone (IZ = 31 mm; AI = 1.409 ± 0.046) even at minimum inhibitory concentration (0.039 mg/ml). CONCLUSION: Hence activity shown by crude ethyl acetate fraction might be due to pyrogallol present in the extract. On the basis of results it can be advocate that achieved crude ethyl acetate fraction can be explored for preparing antimicrobial drugs in future for the infectious caused by the pathogens tested in the study.

In Vitro Antibacterial and Antifungal Properties of Aqueous and Non-Aqueous Frond Extracts of Psilotum nudum, Nephrolepis biserrata and Nephrolepis cordifolia.

Plants are an important source of neutraceuticals that have proved to be effective against important microbial infections of humans. Lower plants are gaining importance in this regard. The present study is aimed at investigating the antimicrobial properties of three selected ferns, Psilotum nudum, Nephrolepis biserrata and Nephrolepis cordifolia. The aerial parts of the selected ferns, P. nudum, N. biserrata and N. cordifolia, were fractionated in different solvents. These fractions were concentrated to obtain a powder and were tested against nine bacterial and three fungal strains according to disc diffusion method. The water and ethanol fractions were active against most of the tested bacterial and fungal strains, some of these were more effective than the controls tested. Present study suggests that the pteridophytes, P. nudum, N. biserrata and N. cordifolia could be good source of antimicrobials. These natural compounds might be more effective as the microbes may have lesser chance of developing resistant mutants.