Research Perspectives of Microbiology and Biotechnology Vol. 6

Efficacy of Antibiotics Available Along the Borders of Low-income Countries: A Case of Tanzania and Implications for Public Health

Kennedy D. Mwambete — 2024-09-11

The current generation of antibiotics is finding it harder and harder to cure bacterial illnesses in underdeveloped nations like Tanzania. Antibiotic resistance is facilitated by the widespread availability of substandard drugs, which puts the treatment of bacterial infections at risk. Antibiotics degrade more quickly when they are improperly stored or exposed to extreme tropical weather. Children under the age of five are estimated to suffer significant morbidity and mortality from infectious diseases, especially pneumonia and acute febrile illness when they lack access to conventional medical care, especially antibiotics. The majority of these incidents occur in low- and middle-income countries (LMICs).

Where antibiotic sellers are less common, where antibiotic prescriptions are tightly enforced, or where antibiotics are more costly, there is usually a lower consumption rate than in other settings, especially for mild conditions that probably don’t need antimicrobial treatment. Broad-spectrum antibiotics belonging to the Watch group of the World Health Organization's (WHO) AWaRe classification accounted for more antibiotic sales.

In Tanzania, over 60% of antibiotic and antimicrobial consumption is in accordance with WHO’s target and Tanzania’s Access component of the AWaRE classification. However, there is wide variation in the amount and types of antibiotics imported each year in the country, making it difficult to draw conclusions and identify meaningful trends going forward with regard to the consumption of certain classes of antibiotics.

The quality of imported medicine and methods for its assessment plays a major role in the effectiveness of therapies and the treatment of many infectious diseases. Poor-quality and/or falsified products are circulating in huge amounts in many LMICs, which is one of the major reasons why more and more resistant bacteria emerge. This conflicting finding calls for a better understanding of issues surrounding antibiotic access and use in LMICs because these countries simultaneously face high burdens of antimicrobial resistance.

Consequently, a need was felt to conduct a microbiological cross-sectional study on the quality of some antibiotics, selected from administrative regions along the borders of Tanzania. That study was complemented by a systematic literature search on the quality of antibiotics available in LMICs, with special emphasis on Tanzania. The microbiological analysis involved seventy-six antibiotics from 22 manufacturers, of which six were from anonymous manufacturers and 29 had no manufacturing or expiration dates. Different antibiotic samples of the same kind produced variable results. Ambiguous antibacterial profiles were exhibited by samples of ampicillin, chloramphenicol, cotrimoxazole, and amoxicillin as compared to their respective positive control antibiotics. The findings from the systematic review showed that in many cases, there were completely different active principal ingredients (APIs) compared to the declared ones. Therefore, these findings suggest the existence of counterfeit and/or substandard drugs in Tanzania, as significant variances in antibacterial effects were observed among antibiotics of the same type, which could have uncertain clinical outcomes.

The WHO describes substandard drugs as being “out-of-spec” and “authorized drugs that fail to meet either their quality standards or specifications, or both.” Substandard antibiotics may appear at the raw or crude API level because the antibiotic molecule may become unstable under specific storage circumstances or because there are too many potentially hazardous impurities.

Several factors have been pointed out to the availability of poor-quality antibiotics, which include weak penal sanctions, frail or absent national drug regulatory authorities, lack of proper drug law enforcement, lack of control of drugs for export, corruption, and conflict of interest, a dearth of political will and cooperation from stakeholders and other enforcers, just to mention a few.

Development and Evaluation of a Multiplex LAMP Assay for Detecting Mycobacterium tuberculosis in Clinical Samples

P. Gunavathy — 2024-09-11

It is crucial to rapidly and accurately diagnose tuberculosis (TB) to reduce morbidity, mortality, and the risk of transmission. A simple, cost-effective diagnostic test to rapidly detect M. tuberculosis in clinical samples is essential. We evaluated an in-house diagnostic test based on loop-mediated isothermal amplification (LAMP) targeting the M. tuberculosis 16S rRNA gene. It was compared with the Genotype and phenotype assay for diagnosing TB in India. Out of 874 samples processed, the overall sensitivity and diagnostic accuracy were found to be 97.06% (with a confidence interval of 95.69-98.09%) and 97.03% (95.67-98.05%), respectively. The sensitivity and accuracy of the LAMP assay against the GenoType MTBDRplus and MGIT assay were 96.41% (94.61-97.73%) and 98.74% (96.36-99.74%), and 96.38% (94.61-97.69%) and 98.74% (96.38-99.74%), respectively. The kappa values were approximately 0.64 and 0.40 for the genotypic and phenotypic assays. Based on these findings, the LAMP assay could be a suitable point-of-care test for rapid diagnosis of tuberculosis in resource-limited laboratory settings.

The Use of Marine Algae as a Denture Cleanser: A Narrative Review

Shivasakthy Manivasakan — 2024-09-11

Denture usage is increasing in the geriatric society, and denture stomatitis is one of the problems faced by the majority of denture wearers. Denture stomatitis is not merely a result of Candida albicans; it is formed by a biofilm of various species. Several mechanical and chemical methods have been employed, and many studies have tested the antifungal properties of commercially available denture cleansers and other agents such as coconut oil and eucalyptus oil. Marine bioactive products like seaweed have also been used. The brown seaweed Sargassum polycystum and Turbinaria conoides have antifungal and antibacterial activity. There is a need for further studies to be conducted to evaluate the efficacy of the seaweeds available.

A Study on the Use of Vitrification–Dehydration Method as a New Protocol for In-vitro Cryopreservation of Date Palm Shoot Tip Cultivars

Heba Allah A. Mohasseb — 2024-09-11

Over the past 40 years, scientists have developed and tested a range of cryopreservation techniques for preserving plant cells and tissues, but the routine storage of plant germplasm other than seeds in liquid nitrogen (LN) is a relatively new practice. The main objective of this study was to collect and preserve the germplasm of the date palm cultivars in vitro. This study evaluated the in vitro preservation and genetic stability of date palm shoot tip explants using dimethyl sulfoxide (DMSO) in the medium for long-term storage. This study was conducted using two data palm cultivars ‘Khalass and Sukari’. Shoot tip explants of about 2-3 cm in length were excised from in vitro cultures and were transferred to preservation media. The genetic similarity was calculated using the average linkage between groups. The results showed that the highest rates of survival (80%) and recovery (75%) were observed with 1.2 M sucrose. To determine the effect of vitrification on freezing tolerances, cultures were exposed to a solution that dissolved the glaze for 60-80 minutes. The maximum survival rate obtained with exposed cultures was 85%. RAPD (randomly amplified polymorphic DNA) was used to explain the differences in the genetic characteristics of cryogenic tissue cultures and non-cryogenic tissues of date palm. Both were similar to the germinated date palm in the open field. Finally, the cryopreserved plants were able to adapt to free-living conditions after acclimatization. All aspects will contribute to the improvement of the currently available techniques for the in vitro germplasm conservation of date palms. RAPD (randomly amplified polymorphic DNA) was used to explain the differences in the genetic characteristics of cryogenic tissue cultures and non-cryogenic tissues of date palm. Both were similar to the germinated date palm in the open field.

Evaluation of Antibacterial Efficacy and pH of Titanium Tetrafluoride-incorporated Mineral Trioxide Aggregate

Poojitha Suganthakumar — 2024-09-11

Microorganisms play an important role in causing inflammation in the pulp and periapical regions. Even after undergoing chemo-mechanical procedures during root canal treatment, bacteria may persist within dentinal tubules, posing a risk of disease recurrence. Mineral trioxide aggregate (MTA), introduced in 1993, has been investigated as a potential antibacterial material since 1995. The MTA material is composed of minute hydrophilic particles that, when exposed to water, undergo a process called colloidal gelation, which builds a solid cement. Calcium and phosphorus are the primary ions in MTA, and their antibacterial characteristics are attributed to the release of calcium hydroxide through surface hydrolysis of calcium silicate components. Previous studies have shown that MTA has limited antimicrobial properties. Several alterations have been made to enhance the biological properties of MTA, such as incorporating nanoparticles made from silver, zinc, gold and titanium. Therefore, in this study, TiF4 was added to MTA in an effort to enhance its antimicrobial properties. Titanium tetrafluoride (TiF4) has been extensively examined in the field of dentistry for its potential applications: prevention of dental caries, sealing of dentinal tubules in root canals, erosion prevention, mitigation of dentinal hypersensitivity, and as an antibacterial agent. This study compares and evaluates the antibacterial efficacy of MTA after the incorporation of TiF 4. A green and fast synthesis method is used to synthesize TiF 4. A total of 56 samples were made by mixing MTA with different weight proportions of TiF4(1wt%, 2wt% and 3wt%).28 samples were taken to test each of the following properties: antibacterial efficacy and pH. The specimens were prepared using stainless steel molds of recommended dimensions for testing the pH. The pH was evaluated using the pH meter and the antibacterial efficacy using the direct contact test.

Data regarding antibacterial efficacy and pH of MTA with various proportions of TiF4 were investigated for normality using the Kolmogorov Smirnov test and assessed a normal distribution. The antibacterial properties between the four groups were analyzed using One-way analysis of variance (ANOVA) followed by pairwise multiple comparisons using Tukey’s Honest significant difference test. The level of statistical significance was determined at p \(\le\)0.05.MTA when incorporated TiF4 showed enhanced antibacterial properties. The group treated with MTA with 3% TiF4 had the highest mean values of antimicrobial efficacy on day 1, with a mean of 4.67 \(\pm\) 0.04 CFU/mL × 10^8. The findings indicated that the incorporation of 3% TiF4 into MTA demonstrated the most pronounced antibacterial effectiveness on both day 1 and day 7, with notable variations observed among the different groups.

MTA incorporating TiF4 can be considered a promising material for improving antibacterial efficacy.

Effect of Gossypol on the Rumen Microbial Degradation of Whole Cotton Seed and Grass Hay Incubated in Consecutive Batch Cultures

Ismartoyo — 2024-09-11

It is well known that cottonseed is widely used as a feed supplement for ruminant animals. However, anti-nutrient gossypol in the seed of cottonseed may cause adverse effects on microbial degradation of the feed. An experiment was conducted to investigate the effects of gossypol on the rumen microbial degradation of whole cottonseed (WCS) and grass hay (GH) with and/or without antinutrient gossypol in a consecutive batch culture (CBC) system. The results obtained from this experiment suggest that the presence of gossypol (1 mM) inhibits dry matter (DM) degradation, gas production from grass hay (GH), and growth of rumen microorganisms in consecutive batch cultures. There was a change in the molar proportion of volatile fatty acids (VFA) when WCS was used as a substrate, suggesting the fermentation of WCS has altered the composition and the activity of the rumen microbial population. However, GH with 1 mM gossypol was still more degradable by mixed rumen microorganisms than WCS, and there was evidence that the microorganism might adapt to the presence of gossypol when GH was the substrate, but not when WCS was used.

Association between Candida in Oral Submucous Fibrosis and Oral Lichen Planus

Ashok Vikey — 2024-09-11

Candida species are component of oral micro flora with prevalence of 3-70%, and are generally regarded as being commensals, hence probable role of candida in oral carcinogenesis cannot be excluded. Various microbiological studies suggest association of candida with potentially malignant lesions. Pathogenicity of candida depends on many factors such as; nutritional disorders, diabetes mellitus, long-term antibiotic or corticosteroid use, head and neck cancer, radiation therapy and HIV infections.

Oral Submucous fibrosis (OSMF) is considered a as a high-risk precancerous condition that is associated with chewing areca nut. This is noticed that OSMF, patients show Candida colonization and further leading to malignant transformation. Similarly Oral Lichen Planus (OLP) is an autoimmune potentially malignant disorder. Recently researchers have noticed pathogenic microorganisms, such as Candida albicans in patients with oral lichen planus. Few studies have suggested that symptoms of Oral Lichen Planus may be exacerbated by candida overgrowth or infection. According to our findings; higher candida carriage revealed in OSMF+ OLP groups (23.3%); as compared to controls (10%). The species level findings showed 13.3% of candida albicans in OSMF+ OLP and6.7% in controls, candida krusei 6.7% in OSMF+ OLP and 3.3% in controls and non-candida albicans were 10% in OSMF+ OLP and 6.7% in control group respectively.

Conclusion: The association of candida species with potentially malignant disorders such as OSMF and OLP aggravate to malignancies through secondary infections. So early assessment of these microbes in preliminary state of cancers can avoid further complications and help for better interventions.

Degradation of Whole Cottonseed and Grass Hay by the Ruminal Bacteria and Their Survival in the Presence and Absence of Gossypol in Culture

Ismartoyo — 2024-09-11

Whole Cottonseed (WCS) in vitro rumen incubation was applied to determine their nutrient and gossypol degradation characteristics and bacterial degradation profile in a consecutive batch culture system. It has been found that the presence of gossypol at 1 mM significantly depressed dry matter loss, gas production, and survival of mixed rumen microbes in culture. Mixed rumen microbes appeared to adapt to the presence of gossypol in culture. However, it is still unclear which of the rumen microbes were affected by the gossypol. Fractionation of the rumen microbial population was conducted to separate as much as possible, rumen bacteria from rumen protozoa and fungi. The fermentation of whole cottonseed (WCS), grass hay (GH) by the bacteria was then studied in the presence and absence of gossypol in culture. The results of this experiment showed that there were significant differences (p<0.01) in the rumen bacterial degradation of WCS, GH with and without gossypol. GH was the most degradable and WCS the least degradable of these substrates for rumen bacteria. Similarly, fermentation of GH resulted in higher (p<0.01) gas production than that of WCS and GH with gossypol demonstrating that bacterial fermentation was reduced. Rumen bacteria did not appear to adapt to the presence of 1 mM gossypol suggesting that they were severely affected by gossypol.

Biosynthesis and Characterization of Selenium Nanoparticles Using Ethanol Extract of Bee Propolis and its Therapeutical Properties

Shubharani R. — 2024-09-11

Aim: Biosynthesis of selenium nanoparticles (SeNPs) has gained significant interest due to their distinctive chemical and biological properties that are essential for their potential application in various fields. Selenium (Se) is a vital trace element essential for various biological functions in living organisms. Its deficiency or excess can lead to significant health issues in humans. Selenium exists in different chemical forms, including selenite and selenate can be toxic at high concentrations. These forms of selenium are known to have adverse effects when ingested in excess, causing selenosis. In contrast, SeNPs have gained attention for their potential health benefits. SeNPs can be synthesized using various methods, including physical, chemical, and biological approaches. The low toxicity of SeNPs is appropriate for biomedical applications, including cancer treatment.

Place and Duration of the Study: Azyme Biosciences Laboratory, Bangalore, between February 2018 and September 2018.

Methodology: In the present study, propolis, the beehive product collected from 5 different Indian states—Haryana, Himachal Pradesh, Uttaranchal, Karnataka and Kerala, was used for the biosynthesis of SeNPs and characterized by using UV-vis Spectrophotometer, Fourier Transform Spectroscopy (FT-IR), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM).

Results: SeNPs biosynthesized by propolis were observed as crystalline, oval-shaped and smooth surface particles. The study also reports the efficiency of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric reducing antioxidant power (FRAP) and superoxide dismutase (SOD) assay to estimate the antioxidant potential. The antimicrobial assay was evaluated only for SeNPs synthesized from propolis extracts obtained from Karnataka state, which showed high antioxidant activity. The antibacterial activity against pathogenic gram-positive bacterial strains (Staphylococcus aureus, Bacillus cereus and Streptococcus mutans), gram-negative bacterial strains (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) was evaluated by resazurin microtiter plate method to check the minimum inhibition concentration (MIC). The antifungal activity of pathogenic fungi such as Aspergillus niger, Aspergillus flavon and Candida albicans were determined by well diffusion method.

Conclusion: It is the first report describing the biosynthesis of selenium nanoparticles using bee propolis. This study demonstrated the antioxidant and antimicrobial potential of SeNPs biosynthesised by using ethanol extract of propolis. Extensive research is vital to develop less toxic and cost-effective synthesis methods for selenium nanoparticles, as well as to control particle size and its application in medicine and healthcare.