Can metabolically generated CO 2 enhance Candida albicans biofilm formation within central venous catheters used in preterm infants?:An in vitro study

Candida albicans is responsible for the majority of invasive fungal infections in preterm infants. Biofilm formation within indwelling central venous catheter (CVC) used for these preterm babies leads to CVC related infections and may lead to antifungal resistance. Metabolically generated CO 2 can act as a communicating molecule triggering the yeast to filamentous transition that is essential for the pathological effects caused by C. albicans. The aim of this study was to demonstrate that CO 2 generated by C. albicans contributes to biofilm-formation in central venous catheters utilised in preterm infants. An in vitro model with neonatal CVCs, using established CO 2 bio indicator strain (CO 2 -BIS) to determine whether there is an accumulation of metabolic CO 2 within the catheters, which may be influencing C. albicans biofilm formation was developed. Biofilms formed within CVC lines showed an enhanced recovery of CO 2 -BIS (p=0.06) when co-incubated with another CO 2 donor C. albicans strain CAI4. This indicated that the metabolically generated CO 2 from neighbouring CAI4 cells within the biofilm had generated sufficient CO 2 to complement the growth demand of CO 2 -BIS. Therefore, these results highlight the importance of high concentrations of CO 2 in the circulatory system, which enhances fungal pathogenicity and may lead to invasive candidiasis. KEYWORDS: Candida albicans, biofilm, central venous catheters, metabolic CO

Laboratory diagnosis of Cryptosporidium parvum and Giardia intestinalis in children with diarrheoa; a hospital based study.

Objectives: This study was conducted to determine the proportion of Cryptosporidium parvum and Giardia intestinalis among children less than 12 years old with diarrhoea and to study the socio demographic aspects including the source of drinking water, level of hygiene in food preparation and hand washing practices of mothers/caretakers of children with diarrhoeaMethods: Children who attended the Lady Ridgeway Hospital for children with diarrheoa during August to October 2012 were enrolled into the study. We collected stool samples from 145 children with diarrhoea and tested them using Modified Ziehl Neelson stain for C.parvum and microscopy of saline and iodine wet mount and formal ether sedimentation technique for G. intestinalis infections in the laboratory. Interviewer administered questionnaire was administered to gather information on food preparation and hand washing practices of the mothers/caretakers of the children with diarrhoea.Results: C.parvum was detected in 48(33%) out of 145 stool samples. There were no positives for G.intestinalis. Children who were more than 12 months of age were more infected with C.parvum compared to children who were less than 12 months in age (p=<0.05).The level of hygiene in preparing food was excellent in 74% of the mothers/caretakers. Correct hand washing practices had been adopted by 91% of mothers/caretakers.Conclusions: C.parvum showed a higher proportion (33%) in stool samples collected from children with diarrhoeal illness compared to the other studies conducted locally decades ago. In the absence of an effective treatment to eradicate C.parvum from the patient, attention should be paid for preventive measures.

Multi centre study from Malaysia on student preparedness for clinical learning- Perspectives of lecturers and students from medicine, pharmacy and allied health sciences

Objectives: To determine the characteristics important in health profession students’ preparedness for clinical learning from the perspectives of lecturers and studentsMethods: A descriptive cross sectional study was conducted at International Medical University, Perdana University and Monash University in Malaysia. All lecturers involved in preparing students for clinical learning in medicine, dentistry, nursing, pharmacy, nutrition and dietetics, chiropractic and Chinese medicine and immediate preclinical students were invited. We explored views regarding student preparedness on knowledge and understanding, willingness to learn, professionalism, communication and interaction, personal attributes and interpersonal skills rated on a 7 point Likert scale in a questionnaire with 62 items.Results: A total of 187 lecturers and 317 students participated. Fifty percent of lecturers had 5-9year of experience. Neither the lecturers nor the students had differentiated or identified specific characteristics as more important over the others but rated all 62 items as important (score >5) for training. The mean score of the 6 themes for lecturers and students respectively were for knowledge and understanding (5.44,5.09), willingness (5.95,5.51), professionalism (5.89,5.49), communication and interaction (5.54,5.34), personal attributes (5.54,5.35) and interpersonal skills (5.54,5.38). Interesting suggestions such as promotion of inter-professional learning among student from different disciplines, case discussions as a team with other professional categories, self reflection for lecturers regarding their attitudes towards students and teaching methods had been stated by students.Conclusions: Both lecturers and students deem that the knowledge and understanding is not the most important characteristic that makes a student better prepared for clinical learning.

Perceived Risk of Dengue in Ones’ Living Environment as a Determinant of Behavior Change through Social Mobilization and Communication: Evidence from a High Risk area in Sri Lanka

Background: The aim of this study was to assess community knowledge and behavioral impact of the social mobili­zation and communication strategy applied in a dengue high-risk area in Sri Lanka. Methods: A group of adults visiting selected primary care facilities in Colombo district were interviewed to collect socio-demographicdata, attributes of knowledge regarding dengue and the responsive behaviors adopted by them following the dengue control program though the media and social marketing campaigns. These attributes were clas­sified as `good ', `fair,' or `poor' by developing a composite scale for analysis and interpretation of data. Results: The primary source of information was television in the majority. The overall knowledge of the disease, vector and control methods was poor. The overall level of contribution to dengue control activities was good. Conclusion: Awareness of the disease and its complications had not contributed to favorable behavior changes.  While the social mobilization and behavior change campaign in Sri Lanka had low impact on knowledge and be­haviors, a better understating of community perceptions of DF and how these perceptions are formulated within the social and cultural context; would be useful to improve uptake. This knowledge would be valuable for program plan­ners to strengthen dengue control activities in SL and other similar settings across the region

Tip-leakage losses in subsonic and transonic blade rows

In this paper the effect of blade-exit Mach number on unshrouded turbine tip-leakage flows is investigated. Previously published experimental data of a high-pressure turbine blade are used to validate a computational fluid dynamics (CFD) code, which is then used to study the tip-leakage flow at blade-exit Mach numbers from 0.6 to 1.4. Three-dimensional (3D) calculations are performed of a flat-tip and a cavity-tip blade. Two-dimensional calculations are also performed to show the effect of various squealer-tip geometries on an idealized tip flow. The results show that as the blade-exit Mach number is increased the tip-leakage flow becomes choked. Therefore the tip-leakage flow becomes independent of the pressure difference across the tip and hence the blade loading. Thus the effect of the tip-leakage flow on overall blade loss reduces at blade-exit Mach numbers greater than 1.0. The results suggest that for transonic blade rows it should be possible to raise blade loading within the tip region without increasing tip-leakage los

Clinical profile and sociodemographic aspects of trichomoniasis among females in the Western province of Sri Lanka

The objective of this study was to describe the sociodemographic aspects, presenting symptoms and findings of clinical examination of laboratory confirmed cases of trichomoniasis. Cases of trichomoniasis were studied, focusing on the sociodemographic aspects and presenting symptoms and signs at clinical examination. There were 29 laboratory confirmed cases of trichomoniasis. The infection was prevalent in equal proportions in all age groups (36-45, 15-25, 26-35 years- 38%, 31%, and 31%). The majority (76%) were married. There were 35% house wives and 28% sex workers. Contraceptives were not used by 48%. Only 41% were symptomatic at the time of detection. Out of those with a vaginal discharge, 50% complained of greenish yellow discharge and 34% a whitish thick discharge. In addition to the discharge, 7% had itching. None of the patients who were positive complained of dysuria. Findings at the clinical examination were mostly different to the symptoms described by the patients. On examination, the majority (81%) of T vaginalis infected women had a serous vaginal discharge and 14% a greenish yellow discharge. Twenty eight percent of infected females did not have any discharge. Presence of typical symptoms or type of vaginal discharge on examination cannot be used as the sole criterion for the diagnosis of trichomoniasis. These results indicate that treatment of patients based on symptoms per se can lead to over usage of metronidazole. This also shows the importance of laboratory support to diagnose T vaginalis infection. DOI: http://dx.doi.org/10.4038/sljid.v3i1.4690    </p

Validation of wet mount microscopy against Trichomonas culture among women of reproductive age group in Western province, Sri Lanka

Abstract. Wet mount microscopy is the most commonly used diagnostic method for trichomoniasis in clinical diagnostic services all over the world including Sri Lanka due to its availability, simplicity and is relatively inexpensive. However, Trichomonas culture and PCR are the gold standard tests. Unfortunately, neither the culture nor PCR is available for the diagnosis of trichomoniasis in Sri Lanka. Thus, it is important to validate the wet mount microscopy as it is the only available diagnostic test and has not been validated to date in Sri Lanka. The objective was to evaluate the validity and reliability of wet mount microscopy against gold standard Trichomonas culture among clinic based population of reproductive age group women in Western province, Sri Lanka. Women attending hospital and institutional based clinics were enrolled. They were interviewed and high vaginal swabs were taken for laboratory diagnosis by culture and wet mount microscopy. There were 601 participants in the age group of 15-45 years. Wet mount microscopy showed 68% sensitivity, 100% specificity, 100% positive (PPV) and 98% negative predictive values (NPV) (P=0.001, kappa=0.803) respectively against the gold standard culture. The area under the ROC curve was 0.840. Sensitivity of wet mount microscopy is low. However it has high validity and reliability as a specific diagnostic test for trichomoniasis. If it is to be used among women of reproductive age group in Western province, Sri Lanka, a culture method could be adopted as a second test to confirm the negative wet mount for symptomatic patients

Controlled delivery of the antiprotozoal agent (tinidazole) from intra-vaginal polymer matrices for treatment of the sexually transmitted infection, trichomoniasis

Microporous polymeric matrices prepared from poly(ɛ-caprolactone) [PCL] were evaluated for controlled vaginal delivery of the antiprotozoal agent (tinidazole) in the treatment of the sexually transmitted infection, trichomoniasis. The matrices were produced by rapidly cooling co-solutions of PCL and tinidazole in acetone to -80°C to induce crystallisation and hardening of the polymer. Tinidazole incorporation in the matrices increased from 1.4 to 3.9% (w/w), when the drug concentration in the starting PCL solution was raised from 10 to 20% (w/w), giving rise to drug loading efficiencies up to 20%. Rapid 'burst release' of 30% of the tinidazole content was recorded over 24h when the PCL matrices were immersed in simulated vaginal fluid. Gradual drug release occurred over the next six days resulting in delivery of around 50% of the tinidazole load by day 7 with the released drug retaining antiprotozoal activity at levels almost 50% that of the 'non-formulated' drug in solution form. Basic modelling predicted that the concentration of tinidazole released into vaginal fluid in vivo from a PCL matrix in the form of an intravaginal ring would exceed the minimum inhibitory concentration against Trichomonas vaginalis. These findings recommend further investigation of PCL matrices as intravaginal devices for controlled delivery of antiprotozoal agents in the treatment and prevention of sexually transmitted infections