Investigating physiological and genetic characteristics of community acquired infections and potential antimicrobial interventions

Staphylococcus aureus and Enterococcus sp. infections occur in hospital and, increasingly, in community settings, with the potential of having different susceptibility to antimicrobial agents. The purpose of this study was to investigate the effect of antimicrobial agents against community acquired S.aureus and investigate antibiotic characteristics, biofilm formation and gene expression following exposure to an antimicrobial agent. The susceptibility of S. aureus isolates and a vancomycin resistant Enterococcus faecium isolate to antibiotics, essential oils and disinfectants were investigated under planktonic conditions using standardised antimicrobial susceptibility tests and the Quantitative suspension and surface tests (EN 1276 and EN 13697) for the disinfectants. Biofilm formation, inhibition and eradication was investigated using the crystal violet (CV) assay while the viability of treated biofilms were investigated using the 2, 3-bis [2-methyloxy-4-nitro-5- sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay and CFU/ml assay. Multiplex PCR was used to determine the presence of PVL, icaA and IcaD genes as well as SCCmec typing while RT-PCR used to investigate changes in gene expression in five target genes following treatment of PVL CA MSSA and CA MRSA MW2 biofilms with grapefruit EO. The S. aureus isolates all formed biofilms and had similar molecular characteristics however one isolate (CA MRSA SR) was multidrug resistant and PVL negative. The VRE isolate was negative for biofilm formation. In suspension, household bleach and NaDCC caused >5 log reduction in viable counts and on stainless steel surfaces, there was <3.5 log reduction. Against biofilms, Household bleach at 5000ppm caused 100% biofilm eradication within 10 minutes while NaDCC eradicated <50% of the biofilm within one hour at 10,000ppm.The eco-friendly product did not demonstrate any antimicrobial activity against planktonic cells or biofilms. Antimicrobial activity of six essential oils (EO) (lime, lemon, lemongrass, geranium, grapefruit, bergamot), and two components (limonene and citral) was investigated for the S. aureus isolates. Following exposure to lemongrass EO extensive disruption to S. aureus biofilms was shown under scanning electron microscopy. The most notable changes in gene expression following exposure to grapefruit EO were the /caD, luxS and sodA genes when the PVL CA MSSA biofilms was compared to the prototype community acquired strain, CA MRSA MW2. The S. aureus isolates were susceptible to the essential oils with the exception of limonene and lemon EO. Lemongrass EO inhibited biofilm formation, metabolic activity and viability. No anti-biofilm activity was observed for Grapefruit EO against S. aureus except for one isolate (PVL positive CA MSSA), where an increase in metabolic activity was observed following treatment. Lemongrass EO was effective as an antibacterial and antibiofilm agent and could be a potential alternative to chemical based antimicrobial agents in both healthcare and non-healthcare environments

Laboratory evaluation of the Sigma Transwab® transport system for the recovery of Candida species using the Clinical and Laboratory Standards Institute (CLSI) document M40-A2

Rising healthcare complications due to fungal infections increase the importance of efficient specimen collection and maintenance systems for correct identification and diagnosis. The CLSI M40-A2 protocol provides guidelines for laboratories assessing quality of medical transport devices, including swab transport systems (STS). This study assessed the efficiency of the Sigma Transwab® foam and flock swab in recovering and maintaining viability of different Candida spp. including C. auris, in different test conditions. Both swab types recovered and maintained viability of all Candida spp. with greater CFU at room temperature after incubation (24 and 48h) in comparison with swabs maintained at 4°C

Utilization of Computer Software in Posting Transactions to Ledger Accounts in the Teaching of Financial Accounting in Tertiary Institutions in the North-East Nigeria

The study determined the extent of utilization of computer software in posting transactions to ledger accounts in teaching financial accounting in tertiary institutions in the North-East, Nigeria. The survey method was used for the study and the instrument for data collection was Computer Software Utilization Questionnaire (CSUQ). The Cronbach Alpha Coefficient was used to determine the level of reliability of the instrument, with the test yielding reliability coefficient of 0.99. The tools for analysis of data were the mean and standard deviation (S.D.) for the research question and ANOVA for testing the hypothesis. It was found that the accounting lecturers utilized computer software in posting transactions to ledger accounts, to a moderate extent. It was recommended that the proprietors of the institutions should provide appropriate facilities in the institutions and the lecturers should endeavour to improve their software utilization skills, among others. Keywords: utilization, computer software, posting transactions, ledger accounts, teaching, and financial accounting

Antimicrobial activity, cytotoxicity and chemical analysis of lemongrass essential oil (Cymbopogon flexuosus) and pure citral

© 2016, The Author(s). The aim of this study was to determine the antimicrobial effects of lemongrass essential oil (C. flexuosus) and to determine cytotoxic effects of both test compounds on human dermal fibroblasts. Antimicrobial susceptibility screening was carried out using the disk diffusion method. Antimicrobial resistance was observed in four of five Acinetobacter baumannii strains with two strains confirmed as multi-drug-resistant (MDR). All the strains tested were susceptible to both lemongrass and citral with zones of inhibition varying between 17 to 80mm. The mean minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of citral (mic—0.14% and mbc—0.3%v/v) was lower than that of Lemongrass (mic—0.65% and mbc—1.1%v/v) determined using the microtitre plate method. Cell viability using human dermal fibroblasts (HDF; 106-05a) was determined following exposure to both compounds and a control (Grapeseed oil) using the XTT assay and the IC50 determined at 0.095% (v/v) for citral and 0.126% (v/v) for lemongrass. Grapeseed oil had no effect on cell viability. Live cell imaging was performed using the LumaScope 500 imaging equipment and changes in HDF cell morphology such as necrotic features and shrinkage were observed. The ability of lemongrass essential oil (EO) and citral to inhibit and kill MDR A. baumannii highlights its potential for use in the management of drug-resistant infections; however, in vitro cytotoxicity does suggest further tests are needed before in vivo or ex vivo human exposure

Influence of Guidance and Counseling on Choice of Business Subjects Among Secondary School Students in Gombe State

This study investigated the influence of guidance and counseling  on choice of business subjects among secondary school students in Gombe state. Two specific objectives, two research questions and two null hypotheses were raised. Survey research design was adopted for the study. The population of the study was 21,465 secondary school students and 377 of them were randomly used for the study. Four rating scale structured questionnaire titled Choice of Business Subjects among Students (CVSS) constructed by the researcher were used for data collection. Data collected were analyzed using benchmark score of 2.5 and above for agree while simple logistic regression was employed in the test of the two null hypotheses at  0.05 alpha level of significance. The study revealed among others that guidance and counseling  has influence on choice of business subjects among secondary school students in Gombe state. In addition in contributed on gender disparity of students choice in business subjects. The resultant effect is that most secondary school students perceived that business subjects are either meant for academic misfits or female students. Based on the outcome of the study, the researcher recommended among others that teachers, especially those counseling  students should help to instill in students the positive attitude towards business subjects, this will develop in them interest and choice of business subjects at secondary school level. Keywords: - Guidance, Counseling , Choice, Business, Subjects, Students. DOI: 10.7176/RHSS/9-12-20 Publication date:June 30th 201

Evaluation of microbial viability and nucleic acid integrity after exposure to new molecular transport medium (Σ-MM™)

A range of organisms (bacteria and yeasts) were inoculated into Sigma MMTM. The inoculum was then aliquoted into TSB broth at 1 minute and 2 minutes to assess for turbidity indicating growth over a 10 day period. A separate aliquot was also removed for molecular assessment. No turbidity was noted at 10 days for any of the organisms tested. This study demonstrated that the Sigma MMTM molecular medium is able to rapidly inactivate bacteria and yeast whilst preserving bacterial DNA

In vitro antifungal activity of Cinnamomum zeylanicum bark and leaf essential oils against Candida albicans and Candida auris

Candida infections are a significant source of patient morbidity and mortality. Candida albicans is the most common pathogen causing Candida infections. Candida auris is a newly described pathogen that is associated with multi-drug-resistant candidiasis and candidaemia in humans. The antifungal effects of various essential oils and plant compounds have been demonstrated against human pathogenic fungi. In this study, the effect of cinnamon leaf and bark essential oils (CEOs) was determined against both C. albicans and C. auris. The disc diffusion (direct and vapour) and broth microdilution method was used to determine antifungal activity of the EOs against selected strains (C. albicans ATCC 10231, C. albicans ATCC 2091 and C. auris NCPF 8971) whilst the mode of action and haemolysin activity of the CEOs were determined using electron microscopy and light microscopy. Direct and vapour diffusion assays showed greater inhibitory activity of bark CEO in comparison with leaf CEO. The minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of bark CEO for all tested strains was below 0.03% (v/v), which was lower than the MICs of the leaf CEO (0.06–0.13%, v/v) dependent on the strain and the MFCs at 0.25% (v/v). In the morphological interference assays, damage to the cell membrane was observed and both CEOs inhibited hyphae formation. The haemolysin production assay showed that CEOs can reduce the haemolytic activity in the tested C. albicans and C. auris strains. At low concentrations, CEOs have potent antifungal and antihaemolytic activities in vitro against C. albicans and C. auris. Key points • Essential oils from Cinnamomum zeylanicum Blume bark and leaf (CBEO and CLEO) demonstrated fungicidal properties at very low concentrations. • The antifungal activity of CBEO was greater than that of CLEO consistent with other recent published literature. • The mode of action of CBEO and CLEO was damage to the membrane of C. albicans and C. auris. • Both CBEO and CLEO inhibited the formation of hyphae and reduced haemolysin production in C. albicans and C. auris. [Figure not available: see fulltext.]

Amylase production from marine sponge Hymeniacidon perlevis; potentials sustainability benefits

The marine sponge Hymeniacidon perlevis is a globally distributed and invasive species with extensive filter-feeding characteristics. The symbiotic relationship fostered between the sea sponge and the inhabiting microorganism is key in the production of metabolic enzymes which is the focus of this study. Sponge bacterial symbionts were grown on starch agar for 48hrs. Colourimetric analyses of amylase were conducted at 540nm using a spectrophotometric plate reader. Using an X-Bridge column (3.5μM, 4.6x150mm), 80/20 acetonitrile/water in 0.1% ammonium were the conditions used for the liquid chromatography-mass spectrometry (LC-MS) analyses. Seven reducing sugars were used to optimise LC-MS to determine the presence of the crude enzyme formed. Not all the bacterial symbionts isolated from H perlevis produced alpha and beta amylases to break down starch. From the statistical mean of crude enzyme concentrations from the hydrolysis of starch by amylase, isolate seven had the highest optical density (OD) at 0.43475 while isolate twelve had the lowest OD at 0.141417. From the LC-MS analysis, out of the seven sugars, Glucose and maltose constituted > 65% of the reducing sugars formed from the hydrolysis of starch by the amylases. Isolates 3,6 and 7 produced 6.906 mg/l, 12.309 mg/l, and 5.909 mg/l of glucose, while isolates 3,4,5,6 and 7 produced 203.391 mg/l, 176.238 mg/l, 139.938 mg/l, 39.030 mg/l, and 18.809 mg/l of maltose, respectively. Isolate two had the highest amount of maltose at a concentration of 267.237 mg/l while isolate four had the highest amount of glucose concentration of 53.084 mg/l. Enzymes from marine sponge bacteria offer greater potential for a green and sustainable production process. Amylase extraction from bacterial symbionts in H perlevis is sustainable and should be supported. They can serve as reliable sources of revenue for enzyme industries, and applications in food industries and biotechnological processes

Variations in bacteriological and physicochemical water quality characteristics of Asata River, Enugu, Nigeria

Background and Objective: Globally, river water remains an important source of water for drinking, domestic and other uses. This study aimed to assess the bacteriological and physicochemical properties of Asata River water. Materials and Methods: A total of 72 water samples were collected, over 12 months (September, 2017 to August, 2018), from six different sites along the river course, following standard methods. The physicochemical properties were determined in situ using appropriate measuring instruments. Total coliform counts (TCC) and Escherichia coli counts (EC) were determined using Chromocult Coliform Agar following the membrane filtration technique. Student’s t-test statistic was used to compare the variations in mean values obtained during the rainy and dry seasons. Results: Temperature, total dissolved solids, pH and electrical conductivity had mean values ranging from 24.8-26.8°C, 10.8-20.1 mg L–1, 4.0-7.1 and 15.8-29.5 μS cm–1, respectively. Mean values of bacteriological parameters ranged from 5.0×101-5.9×106 (TCC) and 1.0×101-4.6×106 (E. coli counts). Bacterial counts in the rainy season were significantly higher (p< 0.05) than counts during the dry season. A significant correlation existed between EC and other water quality parameters, temperature, pH, TDS, E. coli and TCC. Bacteriological properties were high and beyond the acceptable standard limits. Conclusion: Asata River water quality is poor and may constitute a serious public health risk if used without treatment. Adequate provision and use of suitable sanitary infrastructure will help protect this water source from further faecal contamination

Introducing the JMBE themed issue on science communication

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