Potential of cellulose paper coated with silver nanoparticles: a benign option for emergency drinking water filter

Point-of-use system is an appropriate choice in emergency situation because this system is efficient, easy to use, and highly portable. The present study aimed to determine the optimal parameter values associated with the preparation of cellulose paper coated with silver nanoparticles using response surface methodology via Box–Behnken Design (BBD) for the purpose of finding the appropriate filter material in point-of-use water purification system. In this case, the efficiency of cellulose paper coated with silver nanoparticles was investigated based on the optimal parameter values and tested using different types of water samples (tapwater, rainwater, and surface water) by taking into account the drinking water guidelines and health risks. Finally, the cellulose paper coated with silver nanoparticles was compared with other point-of-use technologies in determining its suitability during emergency situation. Box Behnken Design results showed that quadratic model was capable of describing the effects of parameters (silver nitrate solutions, sodium borohydride; silver nitrate ratio and immersion time) on the responses (E. coli removal efficiency). Moreover, second order polynomial equations, ANOVA, and three-dimensional surface plots were developed to evaluate the effects of each parameter on E. coli removal efficiency. The findings show that optimal parameters are found in silver nitrate concentration of 0.035 M and sodium borohydride: silver nitrate ratio of 5 with insignificant immersion time. The field testing results show that cellulose papers coated with silver nanoparticle is suitable for low-turbidity water as it meets the drinking water guidelines with low health risks. The comparison with other point-of-use technologies indicated that cellulose paper coated with silver nanoparticle is suitable to be used as a filter to supply clean drinking water in emergency situation

Candida albicans interdigital foot infection: a case report highlighting the importance of antifungal susceptibility testing

Candida species are opportunistic fungal pathogens which are often isolated from immunocompromised individuals. Candida albicans is the most frequently isolated species in both superficial and invasive candidiasis. Non-albicans species are equally striving in their pathogenic ability, but it is noticed that C. albicans continues to exert its relevance as the leading cause of candidiasis. This is confirmed by this case report finding, from the traditional laboratory culture-based phenotypic methods to molecular diagnostic methods and finally DNA sequencing. Antifungal susceptibility pattern was performed using E-test strip to determine the minimum inhibitory concentrations (MICs) of eight antifungal agents from the three main classes against C. albicans isolate. The MIC results were read at 24 and 48 h incubation according to Clinical and Laboratory Standards Institute (CLSI) guidelines. The results indicate susceptibility of C. albicans to amphotericin B with MIC value of 0.47 µg/mL, anidulafungin with MIC of 0.32 µg/mL; micafungin with MIC of 0.94 µg/mL and caspofungin with MIC of 0.125 µg/mL. The isolate was found to be resistant to all the four azole derivatives tested: fluconazole MIC ≥256 µg/mL; itraconazole, posaconazole and voriconazole with MIC values ≥32 µg/mL, indicating that the isolate may be azole resistant strain. Determination of the susceptibility pattern of this isolate is paramount for effective management of the case. Use of any echinocandins derivatives may be of help in the treatment of such fluconazole resistant strain. Here, we report a case of interdigital space infection (between 4th and 5th digits) due to C. albicans in a 41 year old African man

Detection of medically important Candida species by absolute quantitation real-time polymerase chain reaction

Background: Chronic obstructive pulmonary disease (COPD) is one of the most important causes of disability and mortality in the world. Although cigarette smoking and environmental pollutants have been recognized as the major causes of COPD, the role of infection in the pathogenesis and progression of COPD has also been reported. Objectives: The aim of the present study was to find the relationship between Helicobacter Pylori infection and COPD through anti H. pylori IgG serology, real time PCR of bronchoalveolar lavage and trans bronchial biopsy urease tests. Patients and Methods: This descriptive cross-sectional study was carried out on 60 adults with COPD. After obtaining the patient’s history, physical examination, spirometry and confirmation of COPD diagnosis by pulmonologist, subjects were selected through convenience sampling. In order to determine the severity and prognosis of disease, the global initiative for chronic obstructive lung disease (GOLD) criteria and BODE index were used. Subjects underwent bronchoscopy for obtaining bronchoalveolar lavage (BAL) samples and biopsy was performed. Biopsy and BAL samples were investigated respectively by urease test and real time PCR. Moreover, patients’ serum samples were serologically studied for detection of anti H. pylori IgG. Results: Mean age of the participants was 60.65 ± 9.15 years, and 25% were female and 75% were male. The prevalence rate of H. pylori in COPD patients was 10% according to real time PCR, 88.3% according to the serology test and 0% based on the urease test. According to the results of PCR and considering the severity of disease based on the GOLD criteria, from those with a positive PCR, one patient (16.6%) had very severe obstruction, three (50%) had severe obstruction and two patients (33.3%) had moderate obstruction. The relationship between H. pylori presence (based on PCR) and disease severity and prognosis was not statistically significant. Conclusions: These findings can justify the hypothesis of direct injury and chronic inflammation via inhalation and aspiration resulting in H. pylori colonization. In fact, it is thought that H. Pylori infection, beside the host genetic vulnerability and other environmental risk factors might make the patient susceptible to COPD or lead to COPD worsening. Although we found H. pylori infection in some patients with COPD, the results of this study, could not explain the pathogenic mechanisms of COPD

Yeast infection and diabetes mellitus among pregnant mother in Malaysia

Background: Vaginal yeast infection refers to irritation of the vagina due to the presence of opportunistic yeast of the genus Candida (mostly Candida albicans). About 75% of women will have at least one episode of vaginal yeast infection during their lifetime. Several studies have shown that pregnancy and uncontrolled diabetes increase the infection risk. Reproductive hormone fluctuations during pregnancy and elevated glucose levels characteristic of diabetes provide the carbon needed for Candida overgrowth and infection. The goal of this study was to determine the prevalence of vaginal yeast infection among pregnant women with and without diabetes. Methods: This was a case-control study using cases reports from Kepala Batas Health Clinic,Penang State,Malaysia from 2006 to 2012. In total,740 pregnant ladies were chosen as sample of which 370 were diabetic and 370 were non-diabetic cases. Results: No relationship between diabetes and the occurrence of vaginal yeast infection in pregnant women was detected, and there was no significant association between infection and age group, race or education level. Conclusion: In conclusion, within radius of this study, vaginal yeast infection can occur randomly in pregnant women

In vitro modulation of probiotic bacteria on the biofilm of Candida glabrata

A conspicuous new concept of pathogens living as the microbial societies in the human host rather than free planktonic cells has raised considerable concerns among scientists and clinicians. Fungal biofilms are communities of cells that possess distinct characteristic such as increased resistance to the immune defence and antimycotic agents in comparison to their planktonic cells counterpart. Therefore, inhibition of the biofilm may represent a new paradigm for antifungal development. In this study, we aim to evaluate the in vitro modulation of vulvovaginal candidiasis (VVC)-causing Candida glabrata biofilms using probiotic lactobacilli strains. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 were shown to have completely inhibited C. glabrata biofilms and the results were corroborated by scanning electron microscopy (SEM), which revealed scanty structures of the mixed biofilms of C. glabrata and probiotic lactobacilli strains. In addition, biofilm-related C. glabrata genes EPA6 and YAK1 were downregulated in response to the probiotic lactobacilli challenges. The present study suggested that probiotic L. rhamnosus GR-1 and L. reuteri RC-14 strains inhibited C. glabrata biofilm by partially impeding the adherence of yeast cells and the effect might be contributed by the secretory compounds produced by these probiotic lactobacilli strains. Further investigations are required to examine and identify the biofilm inhibitory compounds and the mechanism of probiotic actions of these lactobacilli strains

Anti-hyphal formation property of allicin in suppression of Aspergillus fumigatus growth

Aims: The aim of this study was to examine whether allicin, a compound derived from fresh garlic, leads to growth inhibition and changes in the ultrastructure of the cell surface on medically important filamentous fungi, particularly Aspergillus fumigatus. Methodology and results: The minimum inhibitory concentration (MIC) of allicin in A. fumigatus ATCC 36607 was determined by broth microdilution method according to the CLSI M38-A2 documents whereby the minimal fungicidal concentration (MFC) was determined by plating suspensions from visibly clear wells onto Sabouraud dextrose agar (SDA). Morphological changes on cell surface were observed through scanning electron microscopy (SEM) after 48 h incubation with allicin. In addition, time kill assay was conducted by incubating A. fumigatus at selected time points within 24 h period. Our finding indicated that the MIC and MFC for allicin were both 3.2 μg/mL. Quantitative data for optical density obtained through microplate reader indicated that p<0.05 at MIC value in comparison with untreated control. Observation of allicin-treated cells through SEM demonstrated complete abrogation of hyphae formation at 3.2 μg/mL and reduced mycelial growth at 1.6 μg/mL of allicin. This finding revealed anti-hyphal activity of allicin at 3.2 μg/mL. When A. fumigatus was incubated with 3.2 μg/mL allicin in the time course assay, the inhibitory effect of allicin was evident after 12 h incubation. Conclusion, significance and impact of study: Our finding strongly implied that allicin exerts its antifungal activity against A. fumigatus via inhibiting the fungal cell proliferation as well as hindering transformation of the conidia into hyphae. Thus, this study depicted potential antifungal property of allicin to be used as alternative therapy to alleviate invasive fungal infection caused by A. fumigatus

Comparative Characterisation of Genotypically Different Clones of MRSA in the Production of Biofilms

The ability to adhere and produce biofilms is characteristic of enhanced virulence among isolates of methicillin-resistant Staphylococcus aureus (MRSA). The aim of the study is to find out whether these characteristics are consistently similar among isolates variations of MRSA. The study used 30 various isolates of MRSA belong to 13 spa types and 5 MLST types and determined the aggregation, the adherence, and the production of biofilms and slime for each isolate. The methods used to evaluate these characteristics were a modified Congo red agar assay (MCRA), a microtiter plate assay (MPA), high-magnification light microscopy, scanning electron microscopy (SEM), and PCR. The study found that isolates belonging to similar Spa, SCCmec, and ST types have similar abilities to produce biofilms; however, their ability to produce slime on CRA was found to be different. Moreover, isolates that have different Spa types showed high variation in their ability to produce biofilms. The results of light microscope revealed the isolates that produced strong and weak biofilms and formed similar aggregation on the glass surfaces. SEM results showed that all 30 MRSA isolates that were tested were 100% positive for biofilm formation, although to varying degrees. Further testing using PCR confirmed that 100% of the 30 isolates tested were positive for the presence of the icaADBC, fnbA, eno, ebps, clfA, and clfB genes. The prevalence of fib, cna, fnbB, and bbp in MRSA clones was 90, 93.33, 53.33, and 10%, respectively. This study indicate that differences in biofilm production capacities are caused by the differences in surface protein A (Spa) type and are not due to differences in MLST and SCCmec types

Physiologically Relevant Alternative Carbon Sources Modulate Biofilm Formation, Cell Wall Architecture and the Stress and Antifungal Resistance of Candida glabrata

Acknowledgments: This study was funded by Fundamental Research Grant Scheme (FRGS) from Ministry of Education (MOE), Malaysia (Grant number: 01-01-14-1456FR). S.Y.C. is a recipient of the MyBrain 15 Scholarship from MOE, Malaysia. AB was supported by the UK Medical Research Council (www.mrc.ac.uk: MR/M026663/1), the Medical Research Council Centre for Medical Mycology (MR/N006364/1), the Wellcome Trust (www.wellcome.ac.uk: 097377), and the European Commission (FunHoMic: H2020-MSCA-ITN-2018-812969)Peer reviewedPublisher PD