Streptococcus Pyrogenes Research Articles

English

The chromatographic investigation of the chloroform soluble fraction of methanolic root extract of Ochna schweinfurthiana using a combination of silica and sephadex LH-20 led to the isolation of tri-methoxy derivative of lophirone A. The structure of this new compound was determined using both 1 and 2D nuclear magnetic resonance (NMR). The antimicrobial activity of the isolated compound was also investigated using agar diffusion and broth dilution techniques. Clinical isolates obtained from the Department of Medical Microbiology, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria were used for the studies. The compound was found to show activity against Staphylococcus aureus, Streptococcus pyrogenes, Pseudomonas aeruginosa, Klebsiella pneumonia and Samonella typhi, but was not active at the tested dose on methicillin resistant S. aureus, Bacillus subtilis, Corynobacterium ulcerans, Escherichia coli and the only fungi tested Candida albicans. The low concentration for minimum inhibitory concentration (MIC, 5 μg/ml) and minimum bactericidal concentration (MBC, 20 μg/ml) suggests the compound has a good antimicrobial activity against the susceptible organisms and validates the ethno medicinal use of the plant in the treatment of various bacterial infections, including infected wounds and typhoid fever. Key words: Ochna schweinfurthiana extract, antimicrobial, tri-methoxy, lophirone A, nuclear magnetic resonance (NMR).

Unusually High Prevalence of Asymptomatic Bacteriuria among Male University Students on Redemption Camp, Ogun State, Nigeria

Differences are known to occur in prevalence rates in urinary tract infections (UTI) between men and women due to the difference between the urinary tracts of the sexes. Moreover, different organisms are known to infect and cause bacteriuria in men. When urine samples from 55 apparently healthy male students of Redeemer’s University were examined, nine bacteria species including Micrococcus luteus, Viellonella parvula, Micrococcus varians, Streptococcus downei, Streptococcus pneumonia, Bacillus subtilis, Streptococcus pyrogenes, Staphylococcus saprophyticus,and Enterococcus aquimarinus were isolated from the samples. The two most prevalent organisms reported in this study were Micrococcus luteus (40%) and Micrococcus varians (27.3%). The implication of the high prevalence rates (54.5%) of asymptomatic bacteriuria obtained in this population is discussed.Key words: Asymptomatic UTI, bacteriuria, Micrococcus luteus

Metal content determination and antimicrobial properties of ochre from North-central Nigeria

Metal content of the ochre was determined by Flame photometry and atomic adsorption spectroscopic technique while the antimicrobial activity of ochre from North-Central Nigeria against selected organisms were investigated using standard methods. The results revealed the presence of Fe, Mg, Na, K, Ca, Mn, Cu, and Zn in ochre. Fe had the highest concentration (1122.7 mg/kg) followed by Mg (193.0 mg/kg). The lowest concentration was that of Zn followed by Cu at 0.65 and 3.8 mg/kg respectively. Sensitivity tests of ochre against Staphylococcus aureus, Streptococcus pyrogenes, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli and Dermatophilus congolensis revealed that ochre had the highest zone of inhibition against Dermatophilus congolensis compared to other pathogens. The MIC and MBC at 50% of the compounding with culture of 1000 µgcm-3were found to be favourable. The study therefore showed that ochre could be a good agent in the fight against infections associated with D. congolensis. Key words: Ochre, metals, North-Central Nigeria, antimicrobial properties.

Comparative Studies of Anti-microbial Activity of Turmeric and Selected Medicinal Plant Leaf Extracts Used in Indian Traditional Medicine

The present study aimed at evaluating and comparing the in vitro antimicrobial activity of 10 medicinal plants used in traditional and homemade medicines: Curcuma longa, Azadiracta indica, Ocimum sanctum, Adathoda vasica, Polygala grineris, Cynodon dactylon, Solanum nigrum, Cardiospermum halicacabum, Phylanthus niruri, and Acalypa indica. Gram-positive and gram-negative bacteria Serratia marcesens, Escherichia coli, Bacillus subtilis, Klebshiella pneumoniae, Streptococcus pyrogens, and Staphylococcus aureus and two pathogenic fungi—Candida albicans and Aspergillus niger—were tested on the leaf extracts. The methanolic extracts were tested at two concentrations for microbial susceptibility. Assays were done using agar well diffusion method and minimal inhibitory concentration for samples showing growth inhibition. All extracts inhibited the growth of S. pyrogens. Among the plant extracts tested, P. niruri showed the greatest inhibitory action.

Essential Oil Composition, Cytotoxic and Antibacterial Activities of Five Etlingera Species from Borneo

Essential oils obtained by hydrodistillation from the rhizomes of Etlingera pyramidosphaera (K. Schum.) R. M. Sm, E. megalocheilos (Griff.) A.D. Poulsen, comb. nov., E. coccinea (Blume) S. Sakai & Nagam, E. elatior (Jack) R. M. Sm, and E. brevilabrum (Valeton) R. M. Sm were analyzed by GCMS. The highest oil yield was obtained from E. pyramidosphaera (0.45%), followed by E. elatior (0.38%), E. coccinea (0.30%), E. brevilabrum (0.28%) and E. megalocheilos (0.25%). The major constituents of the essential oils were oxygenated monoterpenes, followed by sesquiterpenes, oxygenated sesquiterpenes, oxygenated diterpenes and diterpenes. The essential oils from E. pyramidosphaera and E. brevilabrum exhibited the best cytotoxicity against MCF 7 (LC50: 7.5 +/- 0.5 mg mL(-1)) and HL 60 (LC50: 5.0 mg mL(-1)), respectively. Strong inhibition was also observed for the essential oils of E. coccinea and E. megalocheilos against Staphylococcus aureus (MIC: 8.0 +/- 0.5 mg mL(-1), and 5.0 +/- 0.5 mg mL(-1)) and Streptococcus pyrogenes (MIC: 6.0 +/- 0.5 mg mL(-1) and 8.0 +/- 0.5 mg mL(-1)).

Smoking Impact on the Microbial Load of <i>Clarias gariepinus</i>

Effects of different smoking methods on microbial load on freshly collected freshwater mud fish, Clarias gariepinus samples from Oyo State Fisheries Department, Ibadan in South-Western Nigeria was carried out. Seventy-two C. gariepinus (505 ± 0.45g and 25.5 ± 1.30cm) were collected and sorted into 4 groups. 10 fish samples from groups 1, 2 and 3 were subjected to cold smoking, hot smoking and oven drying methods respectively using group 4 as standard. Samples were tested for microbial loads in triplicate at the end of 24, 48 and 72 hrs. Some of the microbes identified were; Streptococcus faecium, Proteus vulgaricus, Pseudomonas aureginiosa, Bacillus cereus; Micrococcus acidiophilus, Aerobacter aerogenes, E. Coli, Streptococcus pyrogenes, Streptococcus lactis, Bacillus subtilis, Pedio cerevisiae, Sacchomyces Sp, Fusarium oxysporum, F. compacticum, Penicillium oxalicum, P. chrysogenum, Aspergillus tamari, A. niger, Cladosporum sphacrosporum, Aspergillus terreus and Rhizopus nigericans. Others are Pseadomonas, Alteromonas, Moraxella, Acinetobacter, Flavobacterium, Cytophaga, Vibrio, Aeromonoas, Staphylococcus aureus, Samonella faecuim, P. fragii. Microbial load for cold smoked products were 72%, 66% and 38%; hot smoked products had 61%, 32% and 08%; while oven-dried had 12%, 0% and 0% at 24, 48 and 12 hrs respectively. Positive correlation r = 0.94, 0.92 and 0.51 were observed between the microbial load processing methods – oven dried, hot-smoked and cold-smoked respectively. Cold smoked had 41.63% C.P and oven-dried had 25.73% C.P. Consumers had highest preference (40%) for hot smoked, 35% for oven dried and 25% for cold smoked products.Key Words: Processing, storage, smoking, bacteria, Clarias gariepinus.

Post Streptococcal Syndromes, A Rheumatologist Perspective

Post streptococcal syndromes may manifest in multiple organs including the musculoskeletal, central nervous, urinary, integumentary, and circulatory systems. The commonly described post streptococcal syndromes include acute rheumatic fever, post streptococcal glomerulonephritis, post streptococcal arthritis, and pediatric autoimmune neuropsychiatric disorders. Classically, these complications occur more often in children. While much is written in the pediatric literature regarding these syndromes, a compilation of information is difficult to find. This article summarizes some of the frequently described post streptococcal syndromes and associations. DESCRIPTION OF STREPTOCOCCUS Group A beta-hemolytic streptococci (GAS), Streptococcus pyrogenes, the most extensively studied member of the streptococcal family is a gram-positive cocci that appears in chains and pairs and demonstrates beta hemolysis (full lysis) on blood agar. Five to fifteen percent of the general population harbor this bacterium in the upper respiratory tract without disease. Nonetheless, GAS maybe responsible for numerous infections and infection related syndromes.(Table 1). Figure 1

Calciomics: prediction and analysis of EF-hand calcium binding proteins by protein engineering

Ca2+ plays a pivotal role in the physiology and biochemistry of prokaryotic and mammalian organisms. Viruses also utilize the universal Ca2+ signal to create a specific cellular environment to achieve coexistence with the host, and to propagate. In this paper we first describe our development of a grafting approach to understand site-specific Ca2+ binding properties of EF-hand proteins with a helix-loop-helix Ca2+ binding motif, then summarize our prediction and identification of EF-hand Ca2+ binding sites on a genome-wide scale in bacteria and virus, and next report the application of the grafting approach to probe the metal binding capability of predicted EF-hand motifs within the streptococcal hemoprotein receptor (Shr) of Streptococcus pyrogenes and the nonstructural protein 1 (nsP1) of Sindbis virus. When methods such as the grafting approach are developed in conjunction with prediction algorithms we are better able to probe continuous Ca2+-binding sites that have been previously underrepresented due to the limitation of conventional methodology.

Assessment of the medicinal potentials of the methanol extracts of the leaves and stems of Buddleja saligna

BackgroundBuddleja saligna Willd (Loganiaceae) is a small to medium-sized evergreen tree; trunk short, often gnarled and crooked; crown dense, rounded or domed-shaped; foliage greyish green. The wild olives are traditionally used to lower blood pressures in many parts of the world. In southern Africa, bark and leaf decoctions are used to treat colic, coughs, colds, sore eyes, urinary problems and as purgatives.MethodsThe antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of Buddleja saligna were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the leaves and stem extracts of Buddleja saligna were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant.ResultsThe antioxidant activities of the leaves as determined by the ABTS and DPPH were similar to that of the stem. The flavonoids and the flavonols contents of the leaves were higher than that of the stem but the total phenols, proanthocyanidins and FRAP activities were higher in the methanol extracts of the stem. The extracts did show activity against both Gram-positive and Gram-negative bacteria. For instance, while the methanol extract of the leaves showed good activities on all the organisms except Serratia marcescens and Pseudomonas aeruginosa at MICs of between 2.5 and 5.0 mg/ml, the extract of the stem only showed activities on Bacillus cereus, Streptococcus pyrogens and Pseudomonas aeruginosa at the same concentration.ConclusionThe results from this study indicate that the leaves and stem extracts of Buddleja saligna possess antioxidant properties and could serve as free radical inhibitors or scavenger or, acting possibly as primary antioxidants. Although, the antibacterial properties of Buddleja saligna are not as effective as the standard drugs-Chloramphenicol and Streptomycin, they still possess some activity against bacterial strains used in this study. Buddleja saligna may therefore be a good candidate for functional foods as well as pharmaceutical plant-based products.

Microwave-irradiated synthesis and antimicrobial activity of 2-phenyl-7-substitutedalkyl/arylaminoquinoline-4-carboxylic acid derivatives

This report focuses on the synthesis of 2-phenyl-7-substitutedquinoline-4-carboxylic acid derivatives through both conventional and microwave-irradiated methods. Intermediate 7-chloro-2-phenyl-quinoline-4-carboxylic acid was synthesized by condensation and cyclization of benzaldehyde, pyruvic acid, and m-chloroaniline in the presence of absolute ethanol and further substituted with aromatic, aliphatic, and alicyclic amines to obtain the desired 2-phenyl-7-substitutedaryl/alkylamino-quinoline-4-carboxylic acid derivatives under the influence of microwave irradiation, with output power ranging from 160 to 480 W, yield ranging from 90% to 95%, and a shorter reaction time than with the conventional method. All the synthesized compounds were screened for in vitro antimicrobial activity against six gram-positive and four gram-negative organisms. All synthesized compounds are active against a broad spectrum of microorganisms, with prominent results for Streptococcus pyrogenes and Pseudomonas aeruginosa. Compounds 7c and 7h showed a minimum inhibitory concentration of less than 10 μg.

Antibacterial activity of tannins from the leaves of Solanum trilobatum Linn

Compounds of pharmacological interest (tannins) were isolated from the plant species, Solanum trilobatum Linn and assayed against the bacteria, Staphylococcus aureus, Streptococcus pyrogens, Salmonella typhi, Pseudomonas aeruginosa, Proteus vulgaris and Escherichia coli using agar diffusion method. Tannins exhibited antibacterial activities against all the tested microorganisms. S.aureus was the most resistant to tannins isolated from the plant material followed by Streptococcus pyrogens, Salmonella typhi, Escherichia coli, Proteus vulgari and Pseudomonas aeruginosa. Minimum inhibitory concentration of the tannins ranged between 1.0 and 2.0 mg/ml while the minimum bactericidal concentration ranged between 1.5 and 2.0 mg/ml. Keywords: Solanum trilobatum, tannins, methanol, bacterial pathogens, minimum inhibitory concentration, minimum bactericidal concentratio

OK432-Activated Human Dendritic Cells Kill Tumor Cells via CD40/CD40 Ligand Interactions

In vivo, dendritic cells (DC) are programmed to orchestrate innate and adaptive immunity in response to pathogen-derived "danger" signals. Under particular circumstances, DC can also be directly cytotoxic against tumor cells, potentially allowing them to release tumor associated Ags from dying cells and then prime antitumor immunity against them. In this study, we describe the innate characteristics of DC (OK-DC) generated in vitro after exposure of immature human myeloid-derived DC to OK432, a penicillin-inactivated and lyophilized preparation of Streptococcus pyrogenes. OK-DC produced proinflammatory cytokines, stimulated autologous T cell proliferation and IFN-gamma secretion, expressed CCR7, and migrated in response to MIP-3beta. Moreover, OK-DC displayed strong, specific cytotoxicity toward tumor cell targets. This cytotoxicity was associated with novel, OK432-induced up-regulation of CD40L on the cell surface of OK-DC, and was absolutely dependent on expression of CD40 on the tumor targets. These data demonstrate that maturation of human DC with OK432, an adjuvant suitable for clinical use, induces direct tumor cell killing by DC, and describes a novel CD40/CD40L-mediated mechanism for specific DC antitumor cytotoxicity.

The chemical composition and antibacterial activity of the leaf extract of Salvia repens Burch. Ex Benth

The chemical composition of the essential oil of S. repens contain the following major constituents: 1 – camphor (0.4%) para–cymene (34.1%), sabinene (23.9%), 1–b–pinene (16.9%),, myrcene (3.9%), γ -terpinene (1.8%), trans- b–Ocimene (1.3%), terpinene-4-ol (0.7%), nopol (0.4%), a-terpinolene (15.89%), b - caryophllene (0.6%). The antibacterial activity of the aerial parts of Salvia repenshas shown that the acetone extract inhibited the growth of Bacillus cereus,Streptococcus pyrogens and Escherichia coli bacteria tested at minimum inhibitory concentration (MIC) of 0, 5 mg/ml. The methanol extracts effectively inhibited the growth of both Staphylococcus epidermidus and Micrococcus kristinae at minimum concentration of 0, 5 mg/ml. At 0. 1 mg/ml the methanol extract inhibited the following B. cereus, S. pyrogens and E. coli bacteria whose inhibition concentration was below 0. 5 mg/l. The activity of the water extracts of the plants against Gram-negative and Gram-positive bacteria has shown inhibition at 1.0 and 2.5 mg/l respectively. The extract from the methanol also suggest that, the plant extract has intensive activity at low concentration compare to acetone and water. The antibacterial activity suggests a possibility of S. repens plant for use on medicinal applications Key words: Salvia repens, essential oil composition, antibacterial medicinal plant, para–cymene, sabinene, 1–b–pinene, a-terpinolene.

Antimicrobial Activity of Nepeta Isolates

Iridodial β-monoenol acetate and actinidine, constituents of Nepeta leucophylla Benth and N. clarkei Benth respectively were investigated for their in vitro antimicrobial activity against 11 fungi and 8 bacteria. Both compounds demonstrated broad spectrum antifungal activity. Iridodial β-monoenol acetate showed remarkable activity against Penicillium citrinum and Aspergillus fumigates, while actinidine was most active against A. ochraceus. Both were moderately active against Bacillus anthracis and Streptococcus pyrogenes.

Antibacterial Diterpenes from the Roots of Ceriops tagal

Investigation of the roots of Ceriops tagal led to the isolation of a new isopimarane, together with the known diterpenes isopimar-8(14)-en-15,16-diol and erythroxyl-4(17),15(16)-dien-3-one. The structure of the new compound was identified as isopimar-8(14)-en-16-hydroxy-15-one. These structures were determined from extensive spectroscopic data analysis. The isolates were screened for antibacterial activity using the agar dilution method against ten test bacterial strains ( Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, Micrococcus kristinae, Pseudomonas aeruginosa, Salmonella pooni, Serratia marcescens, Staphylococcus aureus, S. epidermidis and Streptococcus pyrogens). Isopimar-8(14)-en-16-hydroxy-15-one exhibited activity, with MIC values of 0.5 mg/mL against Streptococcus pyrogens; 0.25 mg/mL against Salmonella pooni and 0.1 mg/mL against Bacillus cereus, Staphylococcus aureus and Micrococcus kristinae.

The multiple mechanisms of Ca2+signalling by listeriolysin O, the cholesterol-dependent cytolysin of Listeria monocytogenes

Cholesterol-dependent cytolysins (CDCs) represent a large family of conserved pore-forming toxins produced by several Gram-positive bacteria such as Listeria monocytogenes, Streptococcus pyrogenes and Bacillus anthracis. These toxins trigger a broad range of cellular responses that greatly influence pathogenesis. Using mast cells, we demonstrate that listeriolysin O (LLO), a prototype of CDCs produced by L. monocytogenes, triggers cellular responses such as degranulation and cytokine synthesis in a Ca(2+)-dependent manner. Ca(2+) signalling by LLO is due to Ca(2+) influx from extracellular milieu and release of from intracellular stores. We show that LLO-induced release of Ca(2+) from intracellular stores occurs via at least two mechanisms: (i) activation of intracellular Ca(2+) channels and (ii) a Ca(2+) channels independent mechanism. The former involves PLC-IP(3)R operated Ca(2+) channels activated via G-proteins and protein tyrosine kinases. For the latter, we propose a novel mechanism of intracellular Ca(2+) release involving injury of intracellular Ca(2+) stores such as the endoplasmic reticulum. In addition to Ca(2+) signalling, the discovery that LLO causes damage to an intracellular organelle provides a new perspective in our understanding of how CDCs affect target cells during infection by the respective bacterial pathogens.

Medicinal Potential of the Root of Arctotis arctotoides.

The antioxidant and antimicrobial activity of the acetone, methanol, and water extracts from the root of Arctotis arctotoides. (L.f.) O. Hoffm (Asteraceae) were assessed in an effort to validate the medicinal potential of the subterranean part of the herb. The antioxidant activities of acetone and methanol extracts as determined by the ABTS, DPPH, and FRAP methods were higher than that of water extracts. The extracts showed significant activity against both Gram-positive and Gram-negative bacteria. The strongest activity was found in the acetone extract on Bacillus cereus., Staphylococcus aureus., Micrococcus kristinae., and Streptococcus pyrogens. with an MIC of 0.1 mg/mL. Although not completely fungicidal, these extracts showed significant growth inhibition against all the fungi tested. Antioxidant and antimicrobial activities of the extracts were strongly correlated with total phenols and to a lesser extent with their flavonoids and proanthocyanidins contents. This study has validated the medicinal potential of the underground part of A. arctotoides..

Disseminated Mycobacterium avium Complex Infection in a Patient with Autoantibody to Interferon-.GAMMA.

A 54-year-old man was admitted to our hospital because of intermittent high fever, general malaise, cough and body weight loss after he had been examined and treated at the former hospital for 3 years without a definitive diagnosis and effective therapy. Bacterial examination on admission revealed Streptococcus pyogenes in peripheral blood, bone marrow aspirates and pleural effusion. Furthermore, Mycobacterium avium complex (MAC) was detected in sputum, gastric juice, bone marrow liquid, pleural effusion by acid-fast bacillus culture or polymerase chain reaction (PCR). Biopsy of the neck lymph node showed multiple granulomas and the presence of acid-fast bacilli. Administration of ABPC/SBT and later CLDM resulted in disappearance of Streptococcus pyrogenes after 2 weeks. We suspected of generalized immunodeficiency that might underlie the severe bacteremia/osteomyelitis and disseminated MAC infection. We tested interferon (IFN)-gamma production of peripheral blood mononuclear cells (PBMC) of the patient after phytohemagglutinin (PHA)-stimulation and found that these cells produced no or undetectable levels of IFN-gamma in the presence of autologous plasma while produced almost normal levels of IFN-gamma in the presence of healthy donor's plasma. Since this neutralizing activity was co-purified in the IgG fraction, the immunodeficient state of the patient seemed to be caused by autoantibody to IFN-gamma. As far as we know, this is the first report of a Japanese case of disseminated MAC infection presumably due to autoantibody to IFN-gamma.

Phytochemical and antimicrobial studies on the leaves and stem of Desmodium scorpiurus Der (sw)

Phytochemical studies on the aerial parts of Desmodium scorpiurus Der (sw) revealed the presence of alkaloids, saponins, glycosides, steroids and carbohydrates. The petroleum spirit, chloroform and methanol extracts were screened for antimicrobial activity using clinical isolates of Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus cereus, Streptococcus pyrogenes and Klebsiella pneumoniae. The results showed that the plant is very active against Pseudomonas aeruginosa, Escherichia coli and Streptococcus pyrogenes with minimum inhibitory concentration (MIC) of 2 x 102 mg/ml.

Studies on Piper Betle of Sri Lanka

More than twelve cultivars of Piper betle are reported in Sri Lanka but no chemical studies have been carried out on them. The present study describes the morphological, physic0 - chemical, chemical and antimicrobial activities of six main cultivars of P. betle Linn namely Galdalu, Malzamaneru, Kudamaneru, Ratadalu, Nagawalli and Malabulath. The chemical constituents identified in the essential oil of Malabulath by Gas Chromatography-Mass Spectrometry (GC-MS) were different to those from the other cultivars. The major compound in Malabulath was allylpyrocatechol diacetate while that in all other cultivars categorized as common betel was safrole. Chemical compositions of the essential oil of t he leaf, stalk, stem, fruit and root were different. The major compounds in the leaf, Gampaha, Kalutara, Kurunegala, Kegalle, Ratnapura, Matale and Galle are the main betel cultivating districts in the country. In Sri Lanka, more than twelve cultivars of betel have been recognized by the villagers but no systematic nomenclature and scientific classification of these cultivars are recorded. The objectives of the present study are to identify the different cultivars of betel found in Sri Lanka using morphological characters and chemical properties of the oil.(to assist a scientific classification of the different P. betle Linn. cultivars found in Sri Lanka). In most stem, stalk and root oil was safrole but in the fruit it was P- Of the the constituents depend on the phellandrene. The composition of the oil also varied with maturity and the part analysed. Hence in the maturity. The essential oil from common betel was active against Escherichia coli (NCTC 101481, Pseudomonas present study, the chemical constituents of the aeruginosa (NCTC 106621, Staphylococcus eprdermidis oils from different parts of the plant (NCTC 4276), Staphylococcus aureus ( NCTC 8532 ), and at different maturity levels were also Streptococcus pyrogens. The essential oil and the ethanol investigated. extract were also active against Cladosporium sp.