Tube Test Research Articles

Evaluation of germ tube in Candida albicans identification by different media

Background: Candida albicans is a common pathogenic, and the germ tube test is one of the identification techniques for this fungal species. Objectives: 1. To experiment with the germ tube test of C. albicans in various media according to the different testing time. 2. To evaluate capacity ofthe germ tube test in C. albicans identification in various media. Methods: This study was carried out with 36 C. albicans isolates and 10 C. tropicalis isolates stored at the Department of Parasitology. Germ tube test was performed using various media, including human sera, 1% peptone medium, BHI broth, egg white, egg yolk, and fetal bovine serum. These experiments were checked after two hours, three hours, and four hours of incubation. Results: The highest rate of germ tube formation of C.albicans was recognized after 3 hours of incubation. The germ tube rates on human serum, 1% peptone medium, egg white, egg yolk, and fetal bovine serum were 91.67%; 58.33%; 25%; 33.33%; 91.67%; and 100%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of the germ tube test on serum and egg yolk medium were 91.67%, 100%, 100%, and 76.92%. Conclusions. The capacity to identify C. albicans of the germ tube test performed on fetal bovine serum, human serum and yolk egg could identify 100%, 91.67%, and 91.67%, respectively. It suggested that egg yolk could be used in diagnostic labs as well as mycology researches and training labs to perform germ tube test production to replace human serum since it is a simple and low cost procedure. Key words: Candida albicans, germ tube, fetal bovine serum, yolk egg

Aerospace grade acoustic metamaterial design, modeling, and experimental validation

Vertical Take-Off and Landing Urban Aerial Mobility vehicle propulsion systems use rotors and blades to achieve lift, which results in heightened noise at the blade passing frequency. These frequencies must be attenuated to reduce cabin discomfort and comply with noise exposure limits. The design must absorb 350 Hz noise, be fire retardant to comply with aviation standards, and be maximally one inch thick. This paper outlines the design, computational simulation, and experimental validation of a novel aerospace-grade acoustic metamaterial. It contributes to the field of computational analysis of new metamaterial structures and experimental validation using prototype Helmholtz unit cells. Achieving maximum sound absorption with the aerospace requirements of minimal mass and fire safety led to the consideration of Nomex honeycomb Helmholtz resonator acoustic panels. Their sub-wavelength attenuation, tunability, lightweight and fire resistance make them an optimal fit for this application. A novel phenomenon was observed in experimental impedance tube testing where multiple Nomex honeycomb cells acted as one resonator cavity. This discovery allowed for samples of only one inch in thickness (cell depth) to achieve 83% sound absorption at 348 Hz. Experimental values match well with the calculated analytical solution using the Helmholtz equation and simulated sound absorption in COMSOL MultiPhysics. The acoustic metamaterial achieves tunable noise attenuation with minimal thickness, weight, and fire suppression using a novel design.

A study on candiduria in neonates and infants from a tertiary care center, North India.

Candida albicans is the major cause of fungal UTI in neonates and infants but nowadays non albicans Candida is also increasing and these are mostly multidrug resistant. So it's important to know the species of candidal UTI for the proper management. This study was undertaken to determine the Candida species distribution in UTI along with their susceptibility pattern and outcome in infants and neonates admitted in different wards and ICU of our hospital. We also assess the incidence rate of candiduria in ICUs. Urine samples were collected from infants and neonates presented in pediatrics and neonatal ICU (intensive care units) and clinical wards with a clinical suspicion of candiduria and infants at risk of invasive candidiasis were also included in the study. Identification of Candida sp. was done by Gram's staining, germ tube test, chlamydospore formation on corn meal agar, color appearance on CHROM agar and also confirmed by MALDI-TOF Assay. Antifungal susceptibility was performed by using broth microdilution method as per the CLSI M27-A3/M27-S4. Urine samples were received from 219 infants, and Candida was isolated from samples from 52 infants (isolation rate 23.75%), of which 30 were admitted in pediatric or neonatal ICU and 22 in the wards. The incidence rate of candiduria in ICU was 3.25%. Candida albicans was the most frequently isolated species from the samples of infants in the wards (13/22 i.e. 59%), while Candida tropicalis was most frequently isolated from samples of infants in the ICUs (13/30 i.e. 43.34%). Candida glabrata was the least commonly isolated species and was only encopuntered in the ICU. There was no discrepancy between the results of conventional methods of identification and MALDI-TOF. Antifungal susceptibility was performed for 18 randomly selected isolates. All were found to be susceptible to caspofungin, micafungin, itraconazole, voriconazole, fluconazole, amphotericin B. High suspicion of candiduria is needed especially in ICU admitted infants and identification of candida at species level along with the susceptibility pattern is important for the better management of patients.

Numerically modeling the sound absorption behavior of 3D printed fibrous absorbers

Recently, we have demonstrated the feasibility of using extrusion-based additive manufacturing methods to fabricate fibrous sound absorbers [1]. Here, we investigate the feasibility of predicting the sound absorption behavior of such structures by extracting their geometry-based transport properties using the hybrid, multiphysics modeling approach. The acoustical transport properties are calculated by modeling the fibrous unit cell and solving three boundary value problems over the representative elementary volume of the periodic fluid domain. Our results show that the absorption predictions obtained using the as-designed unit cell significantly differ from the experimental measurements obtained using conventional two-microphone impedance tube tests. Further investigations conducted using an optical microscope reveal that while the printed fiber diameter remains uniform over its central portion, the fiber diameter decreases drastically near the fiber root. Finally, we show that incorporating these geometrical differences within the model improves computational predictions and accounts for the deviations between the numerical and experimental absorption coefficients. [1] Johnston W, Sharma B. Additive manufacturing of fibrous sound absorbers. Additive Manufacturing. 2021 May 1;41:101984.

Roles of recycled oils, polyphosphoric acid and sulfur on chemo-rheological and morphological properties of high-viscosity modified asphalt

Using recycled oils and chemical stabilizers as the additives in high-viscosity modified asphalt (HVMA) is being developed as a sustainable way to solve the severe segregation problems due to the large differences in nature between high-content styrene–butadienestyrene (SBS) and base asphalt. This paper attempts to use three recycled oils, namely castor oil (CO), waste cooking oil (WCO) and recycled engine oil (REO), as compatibilizers in combination with different chemical stabilizers (polyphosphoric acid, PPA; sulfur) to investigate their ameliorative roles on HVMA segregation problems. By means of the gel permeation chromatography, dynamic shear rheometer and fluorescence microscopy, the chemo-rheological properties and morphological structures of HVMA are investigated, as well as their storage stability. Results show that the recycled oils are more favorable to improve the high-temperature rheological performance of HVMA than aromatic oil (AO) by comprehensively considering the softening point, zero-shear viscosity, elastic recovery percent and large molecule percentage, and the role ranking is: REO > WCO > CO > AO. Compared with the addition of PPA or sulfur alone, when PPA and sulfur are added together, the rheological performance of HVMA is promoted most significantly, because of the synergistic cross-linking reaction of these chemical stabilizers with asphalt and polymers. Furthermore, the synergistic effect of PPA and sulfur markedly reduces the temperature sensitivity of HVMA. However, the cigar tube test reflects that adding recycled oils as compatibilizers alone can not improve the storage stability of HVMA, and CO and WCO even aggravate its segregation. Notably, adding REO and chemical stabilizers can markedly improve the storage stability of HVMA, and the effect is most obvious when REO, PPA and sulfur are added together.

Surface Activation of Wax-Based Additives to Enhance Asphalt Rheological Properties via Rotating Plasma Treatment

Wax-based additives have been widely used in asphalt pavement for their preferable environmental benefits. However, poor compatibility between wax-based warm mix additives and asphalt easily leads to precipitation of wax and cracking of asphalt pavement. Plasma treatment can effectively modify the surface of various materials. This study applies plasma treatment to improve the surface properties of wax-based additives for compatibility improvement in asphalt binder. Compatibility of two different wax-base additives in asphalt binder before and after surface treatment is investigated via cigar tube test and morphology test. In parallel, rheological properties of wax-modified asphalt are characterized from the perspectives of rotational viscosity, rutting resistance, and fatigue performance. Results show the enhanced surface roughness and chemical activity of wax-based additives after plasma treatment. The adhesion between waxes and the asphalt matrix is significantly improved. Waxes within binder are uniformly dispersed after plasma treatment. The incorporation of surface activated wax helps to promote the viscosity reduction of asphalt binder. Furthermore, the high-temperature performance of wax-based asphalt after surface activation treatment of wax is significantly improved, especially for fatty acid amide waxes. As for fatigue performance, plasma treatment improves the fatigue resistance from a compatibility perspective. Therefore, plasma has great promise for facilitating wax-modified asphalt properties from a compatibility perspective.

Hesperidin, Hesperetin, Rutinose, and Rhamnose Act as Skin Anti-Aging Agents.

Aging is a complex physiological process that can be accelerated by chemical (high blood glucose levels) or physical (solar exposure) factors. It is accompanied by the accumulation of altered molecules in the human body. The accumulation of oxidatively modified and glycated proteins is associated with inflammation and the progression of chronic diseases (aging). The use of antiglycating agents is one of the recent approaches in the preventive strategy of aging and natural compounds seem to be promising candidates. Our study focused on the anti-aging effect of the flavonoid hesperetin, its glycoside hesperidin and its carbohydrate moieties rutinose and rhamnose on young and physiologically aged normal human dermal fibroblasts (NHDFs). The anti-aging activity of the test compounds was evaluated by measuring matrix metalloproteinases (MMPs) and inflammatory interleukins by ELISA. The modulation of elastase, hyaluronidase, and collagenase activity by the tested substances was evaluated spectrophotometrically by tube tests. Rutinose and rhamnose inhibited the activity of pure elastase, hyaluronidase, and collagenase. Hesperidin and hesperetin inhibited elastase and hyaluronidase activity. In skin aging models, MMP-1 and MMP-2 levels were reduced after application of all tested substances. Collagen I production was increased after the application of rhamnose and rutinose.

Hybrid space filling curve metamaterials for transmissive flow in Jet Engine inlets

Acoustic metamaterials research has grown exponentially in the past 10 years driven by the advances in manufacturing and an increased understanding of damaging environment noise. 2050 was the first noise reduction target as set by Advisory Council for Aircraft Research and Innovation in Europe with a relative 65% decrease. This ambitions target will not be met by current engine noise control technology; however, metamaterials offer an encouraging alternative. Space Filling Curves (SFC) have the potential to provide a lightweight, thin, high performance acoustic liner. SFC have a history in mathematical geometry dating back to the 1890's but are a comparatively new addition to acoustics. They are designed with a sub-wavelength curled cross-section creating a maze-like pattern which slows acoustic wave propagation through the liner, enabling characteristics such as negative refraction and low frequency attenuation. This paper contains unique hybrid designs combining some of the most promising SFC metamaterial acoustic liner designs, in terms of the fundamental theory of the design category and a discussion of the reflection, absorption and transmission characteristics in terms of a grazing flow conditions. Experimental impedance tube testing compares 3D printed designs to the traditional Helmholtz resonator. The paper concludes with future application for aeroacoustics with particular focus on the engine inlet.

Multiscale characterisation of acoustic behaviour of a new bio-based porous material

This work aims at studying the mechanical and acoustic behaviours of a new bio-based porous epoxy resin obtained by a "green" adapted combination of the cationic photopolymerization and the porogen leaching technique. This new kind of material generally possesses interconnected complex morphology and it would be useful to consider this feature in a model. In this study, the effective properties of the material were estimated by using the asymptotic homogenization method. Four types of ordered pore arrangements together with systematic variations of the porosity and the pore size have been studied. Based on the results of these investigations, a subtle relation between the microstructure and mechanical/acoustic properties has been established. The estimated equivalent dynamic density and equivalent dynamic bulk modulus were compared with experimental results obtained by conducting the three-microphone impedance tube testing. The processing parameters of material elaboration could be adjusted so that the obtained porous material would possess the best sound absorption performance.

Reduced kinetic mechanism for methane/oxygen rocket engine applications: a reliable and numerically efficient methodology

CFD simulations of turbulent reacting flows based on finite rate chemistry often employ reduced kinetic mechanisms to decrease the computational cost, especially if the combustion of hydrocarbons is involved. This work presents a chemical-kinetic methodology, consisting of the formulation, development, testing and validation of a reduced, skeletal mechanism targeted to the Liquid Rocket Engines (LRE) combustion of CH4/O2. The reduced mechanism is generated for combustion processes involving medium-high pressures and ignition of undiluted methane-oxygen, using the 0D/1D open-source software Cantera. The presented mechanism, named Medium Pressure Rocket Burn (MPRB), is achieved from a semi-detailed kinetic scheme, i.e. Lu30, derived from the detailed mechanism GRI-Mech 3.0. Identification of the main chemical reaction paths and sensitivity analysis applied in a sequence leading to a final scheme consisting of 19 species and 51 reactions. Promising results are obtained in terms of ignition delay times and comparison with experimental measurements in high-pressure shock tube tests. The validation is extended to the turbulent case using a sub-scale single-injector combustion chamber with a gaseous injection of CH4/O2 as a benchmark. First, Improved Delayed Detached Eddy Simulations (IDDES) based on a non-adiabatic flamelet database are in good agreement with the available experimental data, although the average thermal load foreseen by MPRB is about 12.6% higher than the case with Lu30 used as reference. Secondly, RANS simulations based on the Eddy Dissipation Concept (EDC) show that accurate results can be obtained with an affordable computational cost, compared to the previously investigated detailed chemistry calculations. Overall the successful validation of the presented reduced mechanism encourages its use for CH4/O2 combustion regimes within this range of applicability.

Phenotypic and genotypic characteristics of Candida species isolated from some domestic insects in Diwaniya city / Al – Qadisiya governorate

This study was conducted to identify and characterize the Candida species isolates from external surfaces of American cockroaches and houseflies by using Hichrome Candida agar as differential culture medium, germ tube , chlamydospore production and carbohydrate assimilation test. Genotypic confirmation was performed by PCR. The results of this study showed that the predominant Candida species included C. albicans(44.6%), C. glabrata(23%), C.krusei(19.6%), C. tropicalis(7.4%), C. dubliniensis(3.6%) and C. parapsilisis (1.8%) . All 27 strains indicative of C. albicans and C. dubliniensis were confirmed by PCR as C.albicans (25 isolates) and C. dubliniensis (2isolates). The study should no difference between the species of Candida strains from American cockroaches and houseflies except that C. parapsilisis and C.dubliniensis which were isolated from American cockroaches. Antifungal susceptibility revealed that nystatin (98%) and fluconazole (89.3%) were highly effective against Candida species , on the hand , the highest resistance was observed in the case of ketoconazole (16%) and MICs method was excellent for determining the levels of dosage pattern for each species compare with disc diffusion method.

Innovative approach for the protection of recycled concrete by biogenic silica biodeposition

Over the past few years, the construction industry has sought to be more sustainable through use of more economically responsible materials and the use of environmentally friendly techniques such as bio-remediation. One promising area in this regard is that of surface treatments, particularly bio-repair techniques, to reduce the deterioration suffered by cement-based materials as a result of environmental conditions. This study presents original work on the use of silicaceous biodeposition by diatoms as a waterproofing surface treatment for recycled concrete. A recycled concrete mix containing a 50% substitution of recycled aggregates (RA) was used as a test substrate and the effectiveness of the bio-treatment was assessed using four different tests: capillary absorption, high-pressure water penetration, low-pressure water absorption and also characterised the biodeposited layer using SEM. Results demonstrate reductions of up to 33% in the capillary absorption test, while high-pressure water penetration decreased by 54.7%, compared to controls. In addition, Karsten tube tests showed low-pressure water absorption was delayed by up to 436 times relative to control samples. In combination these tests confirm the efficacy of diatom biodeposition as a protective surface treatment for cement-based construction materials.

A new WHO bottle bioassay method to assess the susceptibility of mosquito vectors to public health insecticides: results from a WHO-coordinated multi-centre study

BackgroundThe continued spread of insecticide resistance in mosquito vectors of malaria and arboviral diseases may lead to operational failure of insecticide-based interventions if resistance is not monitored and managed efficiently. This study aimed to develop and validate a new WHO glass bottle bioassay method as an alternative to the WHO standard insecticide tube test to monitor mosquito susceptibility to new public health insecticides with particular modes of action, physical properties or both.MethodsA multi-centre study involving 21 laboratories worldwide generated data on the susceptibility of seven mosquito species (Aedes aegypti, Aedes albopictus, Anopheles gambiae sensu stricto [An. gambiae s.s.], Anopheles funestus, Anopheles stephensi, Anopheles minimus and Anopheles albimanus) to seven public health insecticides in five classes, including pyrethroids (metofluthrin, prallethrin and transfluthrin), neonicotinoids (clothianidin), pyrroles (chlorfenapyr), juvenile hormone mimics (pyriproxyfen) and butenolides (flupyradifurone), in glass bottle assays. The data were analysed using a Bayesian binomial model to determine the concentration–response curves for each insecticide–species combination and to assess the within-bioassay variability in the susceptibility endpoints, namely the concentration that kills 50% and 99% of the test population (LC50 and LC99, respectively) and the concentration that inhibits oviposition of the test population by 50% and 99% (OI50 and OI99), to measure mortality and the sterilizing effect, respectively.ResultsOverall, about 200,000 mosquitoes were tested with the new bottle bioassay, and LC50/LC99 or OI50/OI99 values were determined for all insecticides. Variation was seen between laboratories in estimates for some mosquito species–insecticide combinations, while other test results were consistent. The variation was generally greater with transfluthrin and flupyradifurone than with the other compounds tested, especially against Anopheles species. Overall, the mean within-bioassay variability in mortality and oviposition inhibition were < 10% for most mosquito species-insecticide combinations.ConclusionOur findings, based on the largest susceptibility dataset ever produced on mosquitoes, showed that the new WHO bottle bioassay is adequate for evaluating mosquito susceptibility to new and promising public health insecticides currently deployed for vector control. The datasets presented in this study have been used recently by the WHO to establish 17 new insecticide discriminating concentrations (DCs) for either Aedes spp. or Anopheles spp. The bottle bioassay and DCs can now be widely used to monitor baseline insecticide susceptibility of wild populations of vectors of malaria and Aedes-borne diseases worldwide.Graphical abstract

Calcium alginate gels-functionalized polyurethane foam decorated with silver nanoparticles as an antibacterial agent for point-of-use water disinfection

This paper reports the preparation of calcium alginate gels-functionalized PUF decorated with AgNPs (CA/PUF@Ag) by in situ reduction of Ag+ ions to form AgNPs with weakly reducing glycerol in CA/PUF composite. The water-adsorbing capacity, chemical structure, crystalline nature, elemental composition and morphologies of the composite were characterized. The Ag release behavior of CA/PUF@Ag was investigated. The inhibition zone test, time-dependent co-culture assay, test tube test, and antibacterial filtration experiment with Escherichia coli as an indicator of bacterial contamination were conducted to explore the antimicrobial efficacy. Results indicated that the CA/PUF@Ag prepared at 0.25 % w/v of SA could absorb more water with a higher swelling ratio of 8.0 g/g than that of PUF@Ag (6.0 g/g), which was subsequently squeezed by minimal pressure stimuli. The CA/PUF@Ag had a larger initial AgNPs loading amount (8.48 mg/g), lower Ag release concentration (44.35 μg/L) and lower Ag release rate (0.27 %) after 14 days tests than those of PUF@Ag (7.93 mg/g, 80.87 μg/L and 0.60 % respectively). The CA/PUF@Ag was highly reusable because bacterial cells in the squeezed water recovered from the composite were completely inactivated over five cycles of operation, and exhibited good antibacterial efficacy as an antibacterial filter in a flow test.

Development of a detector tube for screening tadalafil and its analogues in adulterated sexual enhancement products.

Sexual enhancement products adulterated with phosphodiesterase 5 inhibitors (PDE-5i) pose a serious public health concern. Tadalafil and its analogues (Tds) are PDE-5i frequently detected as adulterants. In this study, a Td detector tube for the rapid detection of Tds was developed based on the color change reaction between sulfuric acid and Tds. The specificity of this test method was evaluated using 13 Tds, all of which elicited positive results. Additionally, 30 commonly found adulterants in dietary supplements, 11 active pharmaceutical ingredients of psychotropic drugs and 18 food ingredients were tested and obtained no false-positive results, except levomepromazine. The test tube accurately detected the presence or absence of Tds in 54 commercially available products. The visual detection limit was 2-50 and 5-20 μg/ml for Tds and tadalafil-spiked samples with matrix, respectively. The applicability of the developed detector tube to a semiquantitative test using digital image analyses were investigated using red, green, and blue color values. The results of the recovery test suggested that the tube test was affected by the dark-colored matrix. The results of semiquantitative analyses of tadalafil for five marketed products were consistent with the liquid chromatographic quantification results, except for the blue value. The detector tube developed in this study can facilitate with the rapid screening of Tds in adulterated sexual enhancement products.

Central Line-Associated Bloodstream Infections: Effect of Patient and Pathogen Factors on Outcome.

Patients on central lines are often having multiple morbidities, and invasive devices provide a niche for biofilm formation, which makes central line-associated bloodstream infections (CLABSIs), a serious concern in health-care settings, as the infections difficult to treat. In this study, we evaluated the common bacteria causing CLABSI, and various patient and pathogen factors affecting the clinical outcome. In the prospective observational study, patients diagnosed with CLABSI were recruited. Extensive clinical, microbiological, and other laboratory workup was done, and observations were recorded. Congo red agar method, tube test, and microtiter plate assay were used for eliciting the biofilm-forming attributes of the bacterial pathogens. Klebsiella pneumoniae was responsible for 48% of CLABSI, followed by Coagulase-negative Staphylococci (16%) and Staphylococcus aureus and Acinetobacter baumannii (12% each). Fifty-six percent of the isolates produced biofilms. The median (interquartile range) duration of hospital stay till death or discharge was 30 (20, 43) days. The all-cause mortality was 44%. Patients having a deranged liver function on the day of diagnosis (P value for total bilirubin 0.001 and for aspartate transaminase 0.02), and those infected with multidrug-resistant organisms (P value = 0.04) had significantly poor prognosis. The difference in the demographic, clinical, laboratory profile, and outcome of patients infected with biofilm producers and nonproducers was not found to be statistically significant. The study throws light on various host and pathogen factors determining the cause and outcome of CLABSI patients. To the best of our knowledge, this is the first study trying to decipher the role of biofilm formation in the virulence of pathogens and the prognosis of CLABSI.

Evaluation on current screening methods for insecticide resistance in mosquito vectors

Mosquito-borne illnesses are a major concern for worldwide public health and insecticides persist as the principal method for reducing potential vectors and disease control. As a result of widespread insecticide use emergence of resistance in mosquitoes is a global problem. In order to overcome this issue vector control programmers should routinely check localized mosquito vectors for insecticide resistance, which is essential for the efficient management of vector-borne diseases and schedule preventive actions in accordance. The major techniques for determining mosquito vectors insecticide resistance (such as dose-mortality bioassay, WHO tube testing, and CDC bottle bioassay) are highlighted in this review along with some insights into challenges that researchers are encountering when evaluating resistance.

Isolation and identification of candida species from oral of diabetic patients

Diabetes increases the risk of fungal infections in the mouth and in other parts of the body. Candidiasis may occur if there is a decrease in the flow of saliva, which allows the fungi to grow. The present study aimed to determine the prevalence of Candida spp and identify the potential risk factors among diabetic and non-diabetic groups. This cross-sectional study was conducted from November 2021 to May 2022. During this period, 130 oral swabs were collected, the following tests were done: direct microscopic examination, gram stain and cultured on sabaroud dextrose agar with chloramphenicol, complimentary tests such as germ tube test, sugar assimilation test, growing on chromogenic media, were carried out to differentiate between the Candida species. Out of 130 oral swab cultured, there were 102 (78.4%) yielded Candida species. 80 (89%) were diabetics, the results showed strong statistical relationship between diabetics and Candida infections p=0.001. The frequencies of isolated Candida species including C. albicans were 41(40.2%), while C. Glabrata 23 (22.5%) C. tropicalis 26 (25.5%), and C. krusei 12 (11.8 %) The results of this study revealed a higher prevalence of Candida infections in patients with diabetes, so the study recommends continuous follow-up and the necessary tests in response to any symptoms, and recommends health education and attention to clean food and drink. Furthermore, the study underscores the necessity for further research on the correlation between Candida infections and diabetic complications.

Vulvovaginal candidiasis in patients attending the Buea Regional Hospital-Cameroon: Prevalence and risk factors

Introduction: Infection of the female vulva and vagina due to Candida species results in Vulvovaginal candidiasis (VVC). Indiscriminate drug use causing drug resistance and varying lifestyle factors have led to increased spread of the infection. If early laboratory identification and confirmation is not done, this may evolve to serious genital abnormalities and the main reason for increase hospital consultations. Objective: To determine the prevalence of VVC in reproductive age women at Buea regional hospital and possible predisposing factors for its cause. Materials and Methods: We carried out a cross-sectional descriptive study from February to May 2023 in women between the ages 15-45 years attending the Buea Regional Hospital. Sterile vaginal swabs were employed to collect samples and then culture was done using Sabouraud Dextrose Agar. Gram staining and microscopy were conducted to isolate Candida. CHROMagar differential agar and germ tube tests, were used to differentiate the various species of Candida. Pre-tested questionnaires were used to collect socio-demographic and clinical data. Management and analyses of data were done using the SPSS version 22.0 and a significant relationship among variables was obtained when P&lt;0.05. Results: Out of a total of 190 samples analyzed from symptomatic cases of VVC, Candida species were present in 102 (54%) and all the positive cases of VVC were due to Candida albicans. The average age of study participants was 30 years and VVC was mostly frequent in patients &gt;35 years (77.8%). Participants who were single, married and students, had a prevalence of 63.2%, 39.5%, 67.5%, respectively (P&lt;0.05). Clinical presentation, such as, burning sensation while urinating and itches were significantly (P&lt;0.05) associated to high prevalence of VVC (46.1% and 53.9% respectively). Laboratory-confirmed VVC showed significant association to the practice of douching (OR: 3.71, 95%CI: 1.2-14.01, P&lt;0.05) and sexually active (OR: 2.87, 95%CI: 1.3-12.46, P &lt;0.05). Conclusion: Vulvovaginal candidiasis occurred more in women above 35 years, single and who presented with abnormal discharges. The use of antiseptic soap during douching and being sexually active were significantly associated to VVC. Women, especially those of child bearing age should be sensitized on the importance of practicing and maintaining good personal hygiene, safe sex, which will help to prevent and curb the prevalence of vulvovaginal candidiasis.

Effects of the housing system and environmental enrichment on social dominance in laboratory male rats

In laboratory rats, dominance manifests as agonistic behaviour that damages social bonds between individuals. In this study, the effect of the housing system and environmental enrichment on the social dominance in male Wistar rats was assessed in the social dominance tube test. Rats were housed in different housing systems (individual vs. social housing, with or without enrichment) from weaning and tested at the age of 7 weeks. In each test, two rats from different housing systems were released into opposite ends of a narrow tube and the rat that forced its opponent out of the tube was declared the winner (the more dominant animal). In this way, all possible combinations of housing systems were tested and number of wins were recorded and percentage of the total number of matches was calculated. The results show that environmental enrichment suppresses (P &lt; 0.001) dominant behaviour in individually housed rats while no such effect was seen in socially housed male rats (P = 0.532). However, social housing combined with enrichment was more effective in reduction of dominant behaviour compared to only providing enrichment for individually housed rats. Reduction of variability in the manifestations of dominant behaviour is important in animals used for experimental purposes from the perspective of greater homogeneity of animals, which ensures obtaining valid research results and at the same time better living conditions for laboratory animals.