Department of Microbiology-Journal Articles

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Open Access
In vitro time-kill studies of antibacterial agents from putative marine Streptomyces species isolated from the Nahoon beach, South Africa
(African Journal of Pharmacy and Pharmacology Vol. 4(12), 2010-12) Ogunmwonyi, Isoken H.; Mazomba, Ntsikelelo; Mabinya, Leonard; Ngwenya, Elvis; Green, Ezekiel; Akinpelu, David A.; Olaniran, Ademola O.; Okoh, Anthony I.
We assessed the antibiotic production potentials of ten putative Streptomyces strains isolated from the Nahoon beach and their antibacterial activities against a wide range of bacteria including reference strains, environmental strains and clinical isolates. The minimum inhibitory concentrations (MICs) of the crude ethyl acetate extracts ranged from 0.039 to 10 mg/mL and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/mL against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteriostatic and bactericidal activities. Average log reductions in viable cell counts for all the extracts ranged from 0.86 log10 and 3.99 log10 cfu/mL after 3 h interaction and 0.01 log10 and 4.86 log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50% elimination of most of the test bacteria within 3 and 6 h interaction. Our findings suggest that the marine Streptomyces isolated from the Nahoon beach have tremendous potential as sources of new antibacterial compounds.
Open Access
COMPARATIVE TREATMENT OF WELL AND STREAM WAGTER FOR DRINKING USING MORINGA OLEIFERA SEEDS, ALUM, SAND FILTER BEDS AND SOLAR RADIATION
(Crosshouse books, 2011) Benjamin, MOSES Ikechukwu; Babatunde, Awopetu; Odeyemi, Olu
Objectives The objective of this research work was to compare the coagulating power of Moringa oleifera seeds with that of alum. Raw water samples were collected from various wells and streams in Modakeke area, Ile-Ife, Osun state, Nigeria. Results show that Moringa oleifera seed is a better coagulating agent than alum because it had an average coagulating power of 85.3% while that of alum was 78.3%. The filter bed had 85.7% reduction in microbial load for Moringa oleifera treated water while there was 79.1% reduction in microbial load for alum treated water. Also, the effectiveness of solar disinfection for the Moringa oleifera treated clear filtrate was 98.1% while that of alum treated water was 91.5%. Hence, Moringa oleifera, sand filtration and solar energy are good alternatives for water treatment especially in rural areas that can’t afford sophisticated water treatment plant or chemicals.
Open Access
Preponderance of bacterial isolates in urine of HIV-positive malaria-infected pregnant women with urinary tract infection
(2014) Osho, Patrick; Adejuyigbe, Ebunoluwa; Ebhodaghe, Blessing Itohan; Ajibade, Kwashie; Ako, Nai
This study examined HIV and malaria co-infection as a risk factor for urinary tract infections (UTIs) in pregnancy. The study group included 74 pregnant women, 20 to 42 years of age, who attended the antenatal clinic at the Specialist Hospital at Akure, Ondo State, Nigeria. Forty-four of the pregnant women were either HIV seropositive with malaria infection (HIV+Mal+) or HIV seropositive without malaria (HIV+Mal-). The remaining thirty pregnant women served as controls and included women HIV seronegative but with malaria (HIV-Mal+) and women HIV seronegative without malaria. UTI was indicated by a bacterial colony count of greater than 105/mL of urine, using cysteine lactose electrolyte deficient medium (CLED) as the primary isolation medium. Bacterial isolates were characterized using convectional bacteriological methods, and antibiotics sensitivity tests were carried out using the disk diffusion method. A total of 246 bacterial isolates were recovered from the cultures, with a mean of 3.53 isolates per subject. Women who were HIV+Mal+ had the most diverse group of bacterial isolates and the highest frequency of UTIs. The bacterial isolates from the HIV+Mal+ women also showed the highest degree of antibiotic resistance. While pregnancy and HIV infection may each represent a risk factor for UTI, HIV and malaria co-infection may increase its frequency in pregnancy. The higher frequency of multiple antibiotic resistance observed among the isolates, particularly isolates from HIV+Mal+ subjects, poses a serious public health concern as these strains may aggravate the prognosis of both UTI and HIV infection.
Open Access
Preponderance of bacterial isolates in urine of HIV-positive malaria-infected pregnant women with urinary tract infection
(2014) Ebunoluwa, Adejuyigbe; Kwashie, Ajibade; Nai, Ako
Original Article Preponderance of bacterial isolates in urine of HIV-positive malaria-infected pregnant women with urinary tract infection Kwashie Ajibade Ako-Nai1, Blessing Itohan Ebhodaghe1, Patrick Osho2, Ebun Adejuyigbe3, Folasade Mubiat Adeyemi4, Olakunle O Kassim5 1 Department of Microbiology, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria 2 HIV Programme, Department of Haematology, State Specialist Hospital Akure, Ondo State, Nigeria 3 Department of Paediatrics and Child Health, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria 4 Department of Biological Sciences, Faculty of Basic and Applied Sciences, College of Science, Engineering and Technology, Osun State University, Osogbo, Nigeria 5 Department of Microbiology, Howard University College of Medicine, Washington DC, United States Abstract Introduction: This study examined HIV and malaria co-infection as a risk factor for urinary tract infections (UTIs) in pregnancy. The study group included 74 pregnant women, 20 to 42 years of age, who attended the antenatal clinic at the Specialist Hospital at Akure, Ondo State, Nigeria. Methodology: Forty-four of the pregnant women were either HIV seropositive with malaria infection (HIV+Mal+) or HIV seropositive without malaria (HIV+Mal-). The remaining thirty pregnant women served as controls and included women HIV seronegative but with malaria (HIV-Mal+) and women HIV seronegative without malaria. UTI was indicated by a bacterial colony count of greater than 105/mL of urine, using cysteine lactose electrolyte deficient medium (CLED) as the primary isolation medium. Bacterial isolates were characterized using convectional bacteriological methods, and antibiotics sensitivity tests were carried out using the disk diffusion method. Results: A total of 246 bacterial isolates were recovered from the cultures, with a mean of 3.53 isolates per subject. Women who were HIV+Mal+ had the most diverse group of bacterial isolates and the highest frequency of UTIs. The bacterial isolates from the HIV+Mal+ women also showed the highest degree of antibiotic resistance. Conclusions: While pregnancy and HIV infection may each represent a risk factor for UTI, HIV and malaria co-infection may increase its frequency in pregnancy. The higher frequency of multiple antibiotic resistance observed among the isolates, particularly isolates from HIV+Mal+ subjects, poses a serious public health concern as these strains may aggravate the prognosis of both UTI and HIV infection
Open Access
Characterization of a Novel Thermostable Nuclease Homolog (Nuc(M)) in a Highly Divergent Staphylococcus aureus Clade
( Journal of Clinical Microbiology, 2014-08) Schaumburg, Frieder; Pauly, Maude; Schubert, Grit; Shittu, Adebayo
A thermostable nuclease homologue (NucM) in an animal associated divergent clade of Staphylococcus aureus in sub-Saharan Africa has a highly divergent nucleotide sequence compared to classical nuc1 and nuc2 of S. aureus. The deduced amino acid sequences, tertiary structures nuclease activities are, however, similar.
Open Access
Characterization of a Novel Thermostable Nuclease Homolog (Nuc(M)) in a Highly Divergent Staphylococcus aureus Clade
(African Research Review. 1. 10.4314/afrrev.v1i1.40988, 2014-08) Schaumburg, Frieder; Pauly, Maude; Schubert, Grit; Shittu, Adebayo O
A thermostable nuclease homologue (NucM) in an animal associated divergent clade of Staphylococcus aureus in sub-Saharan Africa has a highly divergent nucleotide sequence compared to classical nuc1 and nuc2 of S. aureus. The deduced amino acid sequences, tertiary structures nuclease activities are, however, similar.
Open Access
Molecular identification and amylolytic potential of a thermophilic bacteria species from refuse dump in Ile-Ife, Nigeria
(International Journal of Biological Research, 2014-10) Omoboye, Olumide; Kolawole, Bakare Mufutau; Olusanjo, Adewale Isaac; Oyedeji, Olaoluwa
Molecular identification and amylolytic potential of a thermophilic bacterium species isolated from refuse dump was investigated. Bacte-rial isolates were identified by morphological and biochemical characterization while amylolytic bacterium of interest was identified by molecular analysis using 16S rRNA gene sequencing. The bacterium with the highest α-amylase activity was selected for enzyme pro-duction. The optimal conditions for α-amylase secretion were determined by varying the pH, temperature, percentage soluble starch, nitrogen sources and carbon sources. The isolated and identified bacteria were Bacillus alvei (40%) Bacillus licheniformis (40%) and Bacillus brevis (20%) while Bacillus licheniformis RD24 was identified by 16S rRNA gene sequencing. The peak of amylase production was at 20 h of incubation (925 µg/ml/min). The optimum pH and temperature for the enzyme production were 7 and 45oC respectively. Enzyme production medium with 1% starch gave highest enzyme activity of 102 ± 5.3 µg/ml/min. Peptone gave an enzyme activity of 165 ± 8.97 µg/ml/min and yeast extract gave 52.26 ± 2.86 µg/ml/min. Of the raw starches, cassava flour gave the highest specific activity of 72 ± 0.07 Units/mg proteins, while sorghum starch gave the lowest specific activity of 5 ± 1.52 Units/mg proteins. The study conclud-ed that starch-rich household waste can be employed for amylase production using Bacillus licheniformis RD24.
Open Access
Effects of different substrates on the morphological characteristics and proximate content of Pleurotus pulminarius. Food Science and Quality Management
(international journal of proximate content of Pleurotus pulminarius, 2014-10) Bakare, Mufutau Kolawole; A. O., Oluduro; Omoboye, Olumide; Leramo, Adefemi Joseph
Morphological characteristics and proximate content of Pleurotus pulminarius cultivated on different substrates were investigated. The substrates used are cotton waste, sawdust, palm fruit waste, paper, mixture of sawdust and palm fruit waste and mixture of cotton waste and paper (1:1) were sterilized and inoculated with Pleurotus pulminarius spawn (sorghum-produced) aseptically, incubated under controlled temperature and humidity before exposure to sunlight. Length and, diameter of stalk and pileus were measured during stages of harvest.Protein, fat, carbohydrate, crude fibre, ash and moisture content were determined by standard methods. Pleurotus pulminarius appeared on saw dust and cotton waste; paper, combination of saw dust and palm fruit waste, mixture of paper and cotton waste; and palm fruit waste after 2 days, 3 days and 5 days respectively. For the first stage of harvest, Saw dust had the highest length of stalk (cm) of 5.40 ± 0.63 and the lowest value of2.70 ± 0.14 was obtained from palm fruit waste only. Mixture of paper waste and cotton waste has the highest diameter of stalk (3.25 ± 0.61 cm) (second harvest), the lowest diameter of stalk (0.4 ± 0.1 cm) was recorded for palm fruit (third harvest). Cotton waste had the highest diameter of pileus (7.88 ± 1.29 cm) (first harvest) while the lowest value (1.78 ± 0.63 cm) was obtained from mushroom harvested on the mixture of paper and cotton waste (second harvest). Pleurotus pulminarius harvested on mixture of paper and cotton waste has the highest percentage protein of 40.54% while the least value 28.79% protein was obtained from mushroom harvested on saw dust. Mushroom harvested on saw dust has the highest percentage fat content of 0.99% and palm fruit waste gave the lowest percentage fat of 0.74%. Palm fruit waste displayed the highest percentage ash and crude fibre contents of 4.38% and 4.81% respectively while cotton and paper wastes had the least ash and crude fibre content of 1.81% and 0.47% respectively. Saw dust gave the highest percentage carbohydrate of 62.54%. Moisture content of 0.51% was obtained for mushrooms harvested on Palm fruit waste, Sawdust and mixture of sawdust and palm fruit waste as the least value while the mixture of paper and cotton waste has the highest moisture content of 3.49%. The study concluded that mushroom can serve as cheap source of food supplements such as protein, crude fibre, ash (micro and macro nutrients), fat, carbohydrate and moisture with beneficial bioconversion of agricultural and other wastes materials in the environment
Open Access
Molecular identification and amylolytic potential of a thermophilic bacteria species from refuse dump in Ile-Ife, Nigeria
(journal of molecular, 2014-10) Omoboye, Olumide; Kolawole, Bakare Mufutau; Olusanjo, Adewale Isaac; Olaoluwa, Oyedeji
Molecular identification and amylolytic potential of a thermophilic bacterium species isolated from refuse dump was investigated. Bacte-rial isolates were identified by morphological and biochemical characterization while amylolytic bacterium of interest was identified by molecular analysis using 16S rRNA gene sequencing. The bacterium with the highest α-amylase activity was selected for enzyme pro-duction. The optimal conditions for α-amylase secretion were determined by varying the pH, temperature, percentage soluble starch, nitrogen sources and carbon sources. The isolated and identified bacteria were Bacillus alvei (40%) Bacillus licheniformis (40%) and Bacillus brevis (20%) while Bacillus licheniformis RD24 was identified by 16S rRNA gene sequencing. The peak of amylase production was at 20 h of incubation (925 μg/ml/min). The optimum pH and temperature for the enzyme production were 7 and 45oC respectively. Enzyme production medium with 1% starch gave highest enzyme activity of 102 ± 5.3 μg/ml/min. Peptone gave an enzyme activity of 165 ± 8.97 μg/ml/min and yeast extract gave 52.26 ± 2.86 μg/ml/min. Of the raw starches, cassava flour gave the highest specific activity of 72 ± 0.07 Units/mg proteins, while sorghum starch gave the lowest specific activity of 5 ± 1.52 Units/mg proteins. The study conclud-ed that starch-rich household waste can be employed for amylase production using Bacillus licheniformis RD24
Open Access
Molecular identification and amylolytic potential of a thermophilic bacteria species from refuse dump in Ile-Ife
(International Journal of Biological Research, 2014-10) Omoboye, Olumide; Kolawole, Bakare Mufutau; Olusanjo, Adewale Isaac; Oyedeji, Olaoluwa
Molecular identification and amylolytic potential of a thermophilic bacterium species isolated from refuse dump was investigated. Bacte-rial isolates were identified by morphological and biochemical characterization while amylolytic bacterium of interest was identified by molecular analysis using 16S rRNA gene sequencing. The bacterium with the highest α-amylase activity was selected for enzyme pro-duction. The optimal conditions for α-amylase secretion were determined by varying the pH, temperature, percentage soluble starch, nitrogen sources and carbon sources. The isolated and identified bacteria were Bacillus alvei (40%) Bacillus licheniformis (40%) and Bacillus brevis (20%) while Bacillus licheniformis RD24 was identified by 16S rRNA gene sequencing. The peak of amylase production was at 20 h of incubation (925 µg/ml/min). The optimum pH and temperature for the enzyme production were 7 and 45oC respectively. Enzyme production medium with 1% starch gave highest enzyme activity of 102 ± 5.3 µg/ml/min. Peptone gave an enzyme activity of 165 ± 8.97 µg/ml/min and yeast extract gave 52.26 ± 2.86 µg/ml/min. Of the raw starches, cassava flour gave the highest specific activity of 72 ± 0.07 Units/mg proteins, while sorghum starch gave the lowest specific activity of 5 ± 1.52 Units/mg proteins. The study conclud-ed that starch-rich household waste can be employed for amylase production using Bacillus licheniformis RD24.
Open Access
Occurrence of Cucumber mosaic virus Subgroups IA and IB Isolates in Tomatoes in Nigeria
(journal of Plant Disease, 2014-12) Kayode, Adedeji; Odu, B. O.; Ako-Nai, K. A.; Alabi, Olufemi J.
Tomato (Solanum lycopersicum L.) is a major economic crop consumed globally in fresh or processed forms. During a routine field survey of major tomato-producing areas of southwestern Nigeria in May/June 2013, tomato plants cv. Roma VF showing virus-like symptoms including stunting, chlorosis, and narrowing of leaf blades were observed in 10 farmers' fields with varying levels of incidence averaging ~27%. Moderate to high aphid infestations were also observed in affected fields, and fruit production was significantly impacted based on visual observations. Since symptoms observed on affected plants are similar to those described for Cucumber mosaic virus (CMV) infection in tomato (5), leaf tissue samples collected from a total of 92 tomato plants across 10 commercial farms were subjected to antigen coated plate (ACP)-ELISA essentially as described previously (2). In ACP-ELISA using a CMV polyclonal antibody, 24 of the 92 samples (26.1%) derived from 7 of the 10 survey locations spread across Oyo, Ogun, Ekiti, and Osun states of southwestern Nigeria tested positive for CMV. Based on the ACP-ELISA results, one randomly selected sample from each of the CMV-positive survey locations, seven samples in total, was subjected to total nucleic acid extraction (1) followed by one step-single tube RT-PCR using primers CMV1/CMV2 and conditions described previously (4) with appropriate virus-positive and -negative controls. A ~500 bp DNA band was amplified from these seven ACP-ELISA-positive samples, thus confirming the presence of CMV. To further confirm these results and to enable molecular typing of CMV isolates from southwest Nigeria, the amplified DNA fragments were precipitated with the addition of 70% ethanol and centrifugation and directly sequenced using the ABI 3130xL Genetic Analyzer (Applied Biosystems, California) at the Bioscience Center of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Following the removal of primer- and 3′UTR-specific sequences, the remaining 366-bp partial CP-specific sequences (GenBank Accession Nos. KM091952 to 58) and corresponding sequences of global CMV isolates obtained from GenBank were subjected to multiple alignments using the MEGA 6.0 software. This analysis showed that tomato-infecting CMV isolates from southwest Nigeria shared 91.6 to 99.4% and 94.9 to 99.1% nucleotide (nt) and amino acid (aa) identities among themselves and 91.6 to 98.0% and 94.1 to 98.3%, 89.4 to 94.1% and 93.2 to 98.3%, and 75.2 to 78.8% and 84.0 to 87.3% with corresponding nt and aa sequences of representatives of CMV isolates belonging to subgroups IA (D10538), IB (AB008777), and II (M21464), respectively. Maximum likelihood phylogenetic analysis revealed the clustering of four and three CMV isolates obtained in this study into subgroups IA and IB, respectively, with >70% bootstrap support. CMV has been detected in tomato seeds (3) and its very wide host range includes cultivated crops and weed species (5). It is therefore plausible that contaminated seed lots and alternative weed and crop host plants serve as sources of CMV inoculum to cultivated tomato in affected farms. Although CMV has been reported from tomato from several countries worldwide, to our knowledge, this is the first empirical evidence for the occurrence of CMV subgroups IA and IB in cultivated tomato in Nigeria.
Open Access
Probable mechanisms of biocidal action of Cocos nucifera Husk extract and fractions on bacteria isolates
(BMC Complementary and Alternative Medicine, 2015-05-02) Akinpelu, David A; Alayande, Kazeem A; Aiyegoro, Olayinka A.; Akinpelu, Oluseun F.; Okoh, Anthony I
Background: The incidence of resistance to the existing antibiotics by microorganisms demand increased effort in the development of new antibiotics for the treatment of microbial infections and diseases. Infections due to multidrug resistant pathogens are difficult to manage due to relatively limited choices of antimicrobial agents. This study investigated antimicrobial activities of the husk extract of Cocos nucifera on some bacteria that are associated with human diseases. Methods: Powdered husk of Cocos nucifera was cold extracted using mixture of methanol and distilled water in ration 3:2 (v/v). Extract was partitioned into n-hexane. Chloroform, ethylacetate and n-butanol fractions and thereafter, the minimum inhibitory concentrations (MICs) of the extract and those of the fractions were determined. The ethylacetate fraction was found to be more active and was partially purified by a combination of thin-layer and column chromatography. Finally, the rate of killing, leakages of proteins, potassium ions and nucleotides from the tests bacterial cells were determined. Results: The minimum Inhibitory concentrations (MICs) of the extract ranged between 0.39 and 12.50 mg/ml and those of the fractions ranged between 0.16 and 5.00 mg/ml. The time-kill assay revealed a minimum of 27.8% killed at 1×MIC after 15 min contact time with the fractions and a minimum of 95% killed after 120 min. Varying amount of proteins, potassium ions as well as nucleotides were leaked from selected bacterial isolates by the four active fractions. The amount of proteins leaked from the cells after 15 min contact time ranged between 3.56 and 19.08 μg/ml at 1 × MIC and between 10.97 and 19.54 μg/ml at 2 × MIC. The amount of potassium ions leaked from the cells after 15 min contact time ranged between 0.182 and 0.379 mg/ml at 1 × MIC and between 0.227 and 0.561 mg/ml at 2 × MIC. The nucleotides leaked from the cells after 15 min contact time ranged between 0.609 and 2.446 μg/ml at 1 × MIC and between 0.897 and 2.841 μg/ml at 2 × MIC. Conclusions: This study established the possibility of developing antimicrobial agents of natural origin to combat resistance to antimicrobial compounds by some pathogens currently being experienced in agricultural and health care environments.
Open Access
Antiproliferative Activities of Fagara xanthoxyloides and Pseudocedrela kotschyi Against Prostate Cancer Cell Lines
(HHS Public Access, 2015-06-30) KASSIM, OLAKUNLE O.; COPELAND, ROBERT L.; KENGUELE, HILAIRE M.; NEKHAI, SERGEI; AKO-NAI, KWASHIE A.; KANAAN, YASMINE M.
Background/Aim—Roots of Fagara zanthoxyloides and Pseudocedrela kotchyii are used as chewing sticks and as medicinal remedies for diarrhea, cough and fever in West Africa. Extracts of the two plants also possess anti-bacterial, anti-fungal and anti-malarial activities. The aim of the present study was to determine the effects of such extracts on the growth, proliferation and induction of apoptosis in four prostate cancer cell lines. Materials and Methods—Androgen-independent PC3 and DU-145 and androgen-dependent LNCaP and CWR-22 prostate cancer cell lines were cultured for five days with different concentrations of the extracts and examined for growth inhibition and evidence of apoptosis. Results—Irrespective of their androgen dependence, all four cancer cell lines exhibited a dosedependent decrease in cell proliferation and viability by the 3-[4,5-dimethylthiazol-2yl]-2,5diphenyltetrazolium bromide (MTT) assay and in induction of apoptosis. The results also show that LNCap cells were the most sensitive to the two extracts, with highest inhibition at day 3 and exhibiting the highest rate of apoptosis. Conclusion—These observations suggest that F. zanthoxyloides and P. kotchyii could serve as potential chemopreventive agents in the treatment of prostate cancer
Open Access
An assessment on DNA microarray and sequence-based methods for the characterization of methicillin-susceptible Staphylococcus aureus from Nigeria
( Frontiers in Microbiology, 2015-10-20) Shittu, Adebayo O; Oyedara, Omotayo; Onko, Kenneth; Raji, Adeola; Peters, Georg; Müller, Lutz von; Schaumburg, Frieder; Herrmann, Mathias; Rufﬁng, Ulla
Staphylococcus aureus is an important human pathogen causing nosocomial and community-acquired infections worldwide. In the characterization of this opportunistic pathogen, DNA microarray hybridization technique is used as an alternative to sequence based genotyping to obtain a comprehensive assessment on the virulence, resistance determinants, and population structure. The objective of this study was to characterize a deﬁned collection of S. aureus isolates from Nigeria using the microarray technique, and to assess the extent that it correlates with sequence-based genotyping methods. The clonal diversity and genomic content of 52 methicillin-susceptible Staphylococcus aureus (MSSA)wereinvestigatedby spa typing,MLSTandDNAmicroarrayhybridization. More than half (55.8%) of these isolates were associated with clonal complexes (CCs) typically associated with methicillin-resistant S. aureus (MRSA) clones i.e., CC1, CC5, CC8,CC30,andCC45.Certaingeneslinkedwithvirulence(hlgAandclfA)andadherence (ebpS, fnbA, sspA, sspB, and sspP) were detected in all isolates. A number of genes or gene clusters were associated with distinct clonal types. The enterotoxin gene cluster (egc) was linked with CC5, CC25, CC30, CC45, and CC121, enterotoxin H gene (seh) with CC1, exfoliative toxin D gene (etd) with CC25 and CC80, and the epidermal cell differentiation inhibitor B gene (edinB) with CC25, CC80, and CC152. The excellent agreement between data from DNA microarray and MLST in the delineation of Nigerian MSSA isolates indicates that the microarray technique is a useful tool to provide information on antibiotic resistance, clonal diversity and virulence factors associated with infection and disease.
Open Access
Stem Bark Extract and Fraction of Persea americana (Mill.) Exhibits Bactericidal Activities against Strains of Bacillus cereus Associated with Food Poisoning
(journal of molecules, 2015-12) Akinpelu, David; Aiyegoro, Olayinka Ayobami; Akinpelu, F. Oluseun; Okoh, I. Anthony
The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged between 0.78 and 5.00 mg/mL. The minimum bactericidal concentrations ranged between 3.12 mg/mL-12.5 mg/mL and 1.25-10 mg/mL for the extract and the fraction, respectively. The butanolic fraction killed 91.49% of the test isolates at a concentration of 2× MIC after 60 min of contact time, while a 100% killing was achieved after the test bacterial cells were exposed to the butanolic fraction at a concentration of 3× MIC after 90 min contact time. Intracellular protein and potassium ion leaked out of the test bacterial cells when exposed to certain concentrations of the fraction; this is an indication of bacterial cell wall disruptions by the extract's butanolic fraction and, thus, caused a biocidal effect on the cells, as evident in the killing rate test results.
Open Access
Abstracts from the 6th Infection Control Africa Network Congress
(Antimicrobial Resistance and Infection Control, 2016) Wangai, Helen Wambui; Sikhosana, Mpho; Jombwe, Josephat
Infection prevention and control is a set of practices, protocols, and procedures that are put in place to prevent infections that are associated with health care service provision settings. It is an element of quality of care and safety in health care service delivery; health worker occupational health and safety practices; medical waste management; and is also concerned with clinical and public health surveillance and action. Healthcare facilities are ideal settings for the transmission of infections to patients (who are more susceptible), healthcare workers, their families and communities. Healthcare associated infections lead to prolonged hospital stay, increased cost of care and death. Therefore, the objective of this study was to assess infection prevention and control practices in various types and levels of health facilities in Nyandarua County, Kenya. Methodology A cross-sectional descriptive study was conducted in 47 health facilities that were sampled from a total of 153, using cluster sampling technique. The facilities were drawn from public, private and faith based organizations distributed across 5 sub-counties of Nyandarua County, Kenya. Data collection method was purely quantitative using a structured questionnaire. Descriptive analysis was done using SPSS version 17.
Open Access
Biocidal effects of stem bark extract of Chrysophyllum albidium G. Don on vancomycin-resistant Staphylococcus aureus
(BMC Complementary and Alternative Medicine, 2016-04-14) Akinpelu, David A; Odewade, Joseph O.; Aiyegoro, Olayinka A.; Ashafa, Anofi O. T.; Akinpelu, Oluseun F.; Agunbiade, Mayowa O.
Background: Staphylococcus aureus causes variety of infections in humans and animals worldwide and predominates in surgical wound infections. This study assessed the antimicrobial potential of the stem bark extract of Chrysophyllum albidum against an array of vancomycin resistant Staphylococcus aureus (VRSA) isolated from clinical samples. Methods: The methanolic crude extract of the plant was preliminary screened for the presence of phytochemicals; after then, the extract was partitioned into n-hexane, chloroform, ethyl acetate and butanol fractions. A range of concentrations of the plant extract fractions was prepared to assess its antimicrobial potency; the minimum inhibitory concentrations (MICs); the minimum bactericidal concentrations (MBCs); the rate of killing; the potassium ion leakage potential and nucleotides leakage ability against the VRSAs. Results: The phytochemical screening revealed the presence of tannins, alkaloids, flavonoids, saponins, steroids, reducing sugars and terpenoids as major phytoconstituents resident in the crude plant extract. The two active fractions (n-hexane and butanol) at a concentration of 10 mg/ml exhibited antibacterial activities with the MIC and MBC values for the fractions ranged between 0.63–10 mg/ml and 1.25–10 mg/ml respectively. The time kill assay revealed that the antibacterial action of the two fractions are time and concentration dependent; the n-hexane and butanol fractions achieved 100 % kill on the test isolates at a concentration of 3×MIC and 2×MIC respectively after 120 min of reaction time. Varying amount of potassium ions as well as nucleotides were leaked from the test cells by n-hexane and butanol fractions. Conclusions: This study has established the possibility of developing antimicrobial agents of natural origin to manage possible infection from vancomycin resistant Staphylococcus aureus that are now developing multi-resistance against many antibiotics.
Open Access
Fecal Carriage of Staphylococcus aureus in the Hospital and Community Setting: A Systematic Review
( Frontiers in Microbiology, 2016-05-16) Claassen-Weitz, Shantelle; Shittu2, Adebayo O; Ngwarai, Michelle R; Thabane, Lehana; Nicol, Mark P.; kaba, Mamadou
Africa Background and rationale: Staphylococcus aureus fecal carriage has been identiﬁed as a potential source for nosocomial transmission and a risk factor for disease development. This systematic review determined the overall S. aureus [including methicillin susceptible and resistant S. aureus (MSSA and MRSA)] fecal carriage rates within the community and healthcare settings. Methodology: Peer-reviewed articles indexed in Medline, Scopus, Academic Search Premier, Africa-Wide Information, CINAHL, and Web of Science were identiﬁed using applicable and controlled vocabulary through to 11 November 2015. Eligible studies were ascertained by three independent reviewers. Random-effects meta-analyses of proportions were performed to determine S. aureus, MSSA and MRSA fecal carriage rates reported by eligible studies. Results: Twenty six studies were included in this review. The pooled estimates for S. aureus, MSSA and MRSA fecal carriage were 26% (95% conﬁdence interval (CI): 16.8–36.3%), 86% (95% conﬁdence interval (CI): 65.9–97.9%) and 10% (95% CI: 0.7–27.0%), respectively. Fecal S. aureus carriage rates increased on average from 10 to 65% during the ﬁrst 8 weeks of life, followed by an average carriage rate of 64% at 6 monthsand46%at1yearoflife.Genotypingtechniqueswereemployedmainlyinstudies conducted in developed countries and comprised largely of gel-based techniques. Six studies reported on the role of S. aureus fecal strains in diarrhea (n = 2) and the risk for acquiring infections (n = 4). Eight of the 26 studies included in this review performed antibiotic susceptibility testing of S. aureus fecal isolates. Conclusion: This study provides evidence that screening for S. aureus fecal carriage, at least in populations at high risk, could be an effective measure for the prevention of S. aureus transmission and infection in the healthcare and community setting. More well-structured studies need to be conducted and sequence-based genotyping techniques should be employed for the comparison of isolates on a global scale in both developing and developed countries.
Open Access
Molecular epidemiology of hepatitis D virus circulating in Southwestern Nigeria
(Virology Journal, 2016-12) Opaleye, Oluyinka Oladele; Japhet, Margaret Oluwatoyin; Adewumi, Moses Olubusuyi; Omoruyi, Ewean Chukwuma
Background Hepatitis B virus (HBV) and hepatitis D virus (HDV) infections are major public health problems in sub-Saharan Africa. Whereas it is known that HBV infection is endemic in Nigeria, there is only little data about HDV prevalence available. Here, we assessed the HDV seroprevalence and determined the HDV and HBV genotypes distribution among HBsAg positive individuals in Southwestern Nigeria. Methods This cross-sectional study involved 188 serum samples from HBsAg positive outpatients recruited at four tertiary hospitals in Southwestern Nigeria. Anti-HDV antibodies were detected by ELISA while HDV-RNA was detected by RT-PCR. Sequencing followed by phylogenetic analyses and HBV genotype-specific PCR were used to characterize HDV and HBV genotypes, respectively. Results Out of 188 HBsAg positive serum samples, 17 (9 %) showed detectable HDV-RNA. Anti-HDV antibodies test was possible from 103 samples and were observed in 4.9 % (5/103) patients. There was no significant difference in HDV prevalence between four main cities across the country. 64.7 % of HDV-RNA positive samples were from males and 35.3 % from females (P < 0.05). No significant associations were observed with regard to HDV seroprevalence and available demographic factors. Phylogenetic analyses demonstrated a predominance of HDV genotype 1 and HBV genotype E among the HDV-RNA/HBsAg positive patients. Conclusions In conclusion, our study showed a high prevalence of HDV infection in HBsAg carriers and the predominance of HDV genotype 1 infection in Nigerian HBV endemic region. The findings contribute to a better understanding of the relevance of HDV/HBV co-infection and circulating genotypes
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EFFICACY OF SAND FILTRATION, Moringa oleifera SEED AND ALUM TREATMENT IN REDUCTION OF COLIFORMS AND TOTAL BACTERIA IN STABILIZATION POND EFFLUENT
(Department of Microbiology, Obafemi Awolowo University, Ile- Ife, Osun State, Nigeria, 2016-12-29) Babatunde A, Awopetu; Ikechuwkw, Moses; Odeyemi, Olu
Objectives A slow sand filter was designed and constructed with decreasing sizes of sand layers. Granulations were made out of the seeds of Moringa oleifera. Their turbidity clarification, coliform and total bacteria reduction were tested. Their abilities to reduce the densities of Salmonella typhi, Bacillus cereus, Shigella dysenteriae, Escherichia coli in waste water were also tested. Coliform number reduction was 78% by sand filtration, 78% alum treatment and 98% by M. oleifera ground seed treatment. The sand filter reduced total bacteria population by 4%, alum and M. oleifera treatments by 33% and 84% respectively. There was a 12% reduction in Shigella dysenteriae numbers by the slow sand filter, 57% reduction by alum and 76% reduction Moringa oleifera treatment. Sand filtration reduced Salmonella typhi population by 29%, alum and Moringa oleifera treatments did so by 43% and 71% respectively. Escherichia coli numbers were reduced by 10% by sand filtration, 27% by alum treatment and 56% by M. oleifera treatment. Bacillus cereus population was reduced by 9% by both sand filtration and alum treatment while Moringa oleifera application gave a 32% reduction. M. oleifera ground seed treatment was the best at coliform population reduction (98% reduction) of the three treatments. Sand filtration and alum treatment were found to be equal in coliform reduction rate since they both reduced coliform numbers by 78%. M. oleifera treatment was the most efficient in total bacteria population reduction, with an 84% reduction rate. Slow sand filtration was most effective on S. typhi (29% reduction) of the four organisms tested

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