S. aureus and K. pneumoniae on the Surface and within Core of Tonsils in Adults with Recurrent Tonsillitis

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CREATING A PROTOTYPE OF AN INTERACTIVE LEARNING GAME IN MOLECULAR AND CELL BIOLOGY

At the beginning of medical studies at Rīga Stradiņš University (RSU), students’ knowledge and skills differ widely. In the first semester, students must take a course, “Molecular and Cell Biology.” In many cases, problems in students’ abilities to absorb new information of this new, specific nature are evident. The reason for this is insufficient prior preparation. On average, 3-4 % of students failed this course each academic year. After focus group discussions and interviews with colleagues and leading specialists in information technologies, we concluded the need to create an interactive and pedagogically correct tool for improving students` competence in molecular and cell biology; one such tool could be an interactive learning game. This article describes the process of creating a learning game prototype in molecular and cellular biology. With the help of selected RSU students, a prototype was created. The involvement of students proved beneficial for them (improving understanding of the topics) and for us (clarifying students’ preferences for the game’s design).The learning game was tested with a target group (1st-semester students from the Medicine and Dentistry faculties of RSU). Initial feedback from the students and teachers certifies that this example is an opportunity to provide a desired, low-stress self-paced learning resource. 

EFFICACY OF FACIAL MASK USE IN COVID-19 TRANSMISSION USING A BACTERIAL MODEL

Publisher Copyright: © 2023 The Author(s).The prevention of COVID-19, caused by SARS-CoV-2, involves reducing transmission of infectious respiratory droplets and aerosols with different methods, including the use of face masks. There have been a variety of studies published about the effectiveness of face masks - they have been recognised as an inexpensive yet expedient prevention method. In this research we aimed to investigate the microbial contamination of used face masks and to compare the results based on mask usage time to determine the efficiency of facial mask use against COVID-19. Microbiological contamination of 51 used face masks was analysed by the imprinting method on suitable cultivation agars and colony forming units were determined. The majority of microorganisms found in our study were those of normal human skin and respiratory tract microbiota. A greater number of bacterial species was found on the outsides of the facial masks, which furthermore increased with prolonged usage time. We conclude that face mask use is effective in both detaining excreted microorganisms as well as protecting the wearer from microbes in the air, and therefore, should be implemented in the prevention strategies of respiratory diseases. Furthermore, our results show the importance of correct facial mask usage by their contamination with a spectrum of microorganisms.Peer reviewe

Toys in the playrooms of children’s hospitals : A potential source of nosocomial bacterial infections?

Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Pediatric patients are more susceptible and vulnerable to nosocomial infections, in part because of their nascent and developing immune system and in part due to certain congenital conditions. Consequently, we found limited literature that investigated and reported children’s toys in hospital playrooms as potential reservoirs of pathogenic microbes. Hence, in the present study, we aimed to investigate toys as potential vectors for nosocomial infections in children’s hospitals. Microbiological samples from 120 toys were collected between April 2018 and November 2018. The specimens were cultivated on suitable cultivation agars for 24–72 h at 37◦ C and CFU/cm2 (colony forming units) was determined. Antibiotic susceptibility testing was performed using disc diffusion and E-tests. Our results indicate that 84% of samples were contaminated with different microbes. Four distinct genera and thirty-seven species of bacteria were identified. The most frequently isolated pathogen was Sphingomonas paucimobilis (>603 CFU/cm2 ). Most of the identified microorganisms were members of normal human microbiota. Although Staphylococcus aureus and Acinetobacter baumannii were identified, CFU/cm2 was relatively low and they were found to be sensitive to antibiotics. Additionally, plastic toys showed the highest average CFU/cm2 of 91.9. Our results bolster the need for adoption and strict enforcement of proper disinfection techniques for toys in the hospital playrooms.publishersversionPeer reviewe

Adhesion and colonisation of microorganisms on porous TiO2 and TiO2-Silver Biomaterials

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Histopathological Findings of Oral Mucosa in Smokeless Tobacco Users : Case Report

Funding Information: We are grateful for help and support from the Department of Biology and Microbiology, Rīgas Stradiņa University. Funding Information: This research has been developed with financing from the European Social Fund and the Latvian state budget within project no. 8.2.2.0/20/I/004 ᰀSupport for involving doctoral students in scientific research and studies ? at Rīga Stradiņš University. Publisher Copyright: © 2022 Miļuna et al.Background: New tobacco products, such as smokeless tobacco, are becoming more popular every year. In talking with our patients, we determined several reasons for that trend. The sale of these products is prohibited in many countries; hence, people obtain the product illegally. This is important, since when these products are stored under inappropriate conditions and temperatures, the quality and properties of the product change, including their carcinogenic properties. Sometimes people use a lot of this product or more than one tobacco product daily. It is challenging for dental practitioners to question their patients about tobacco consumption and more challenging to visually detect oral mucosal changes, because patients usually do not have concerns or they do not pay attention. Methods: In the two cases presented here, the patients did not have any pain, nor did they notice when the lesions appeared. These patients used conventional cigarettes for some time and then switched to smokeless tobacco due to relocation to Latvia. Soft tissue excision was performed and sent for histopathological examination. Results: The findings were proliferation of oral epithelial cells from buccal region, their overgrowth, an excessive amount of fibroblasts, cell destruction and necrosis, and a large amount of inflammatory cells, eosinophil leukocytes, and plasma cells. Conclusion: We can conclude that these intraoral findings are important risk factors for possibly developing precancerous lesions. Such mucosal changes can occur with different forms of tobacco, including Swedish snus and betel leaves. Dental practitioners should always question patients about tobacco use and regularly check for mucosal changes for early detection.publishersversionPeer reviewe

The role of oral anaerobic bacteria, and influence of social and health factors in halitosis aethiology

The aim of this work was to identify the bacteria associated with halitosis, and by questionnaire to test whether diet, oral hygiene habits and illness factors were associated with bacterial amounts in the oral cavity and the Il-1α/Il-1β polymorphism. Bad breath is a frequent problem in Latvia and for many patients may cause important emotional and psychological distress. As there are different causes of halitosis, this might be also reflected in the bacterial community of the oral cavity. The concentration of bacteria in the oral cavity was significantly higher in halitosis patients than in the studied control group, who did not complain about halitosis. The PCR results corresponded with halimetric values. The main cause of halitosis was found to be oral pathology - increased amounts of oral anaerobic bacteria Porphyromonas gingivalis, Tannerella forsythietensis, Treponema denticola, and Prevotella intermedia.publishersversionPeer reviewe

Influence of antibiotic-impregnated biomaterials on inflammatory cytokines

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Use of Phage Cocktail BFC 1.10 in Combination With Ceftazidime-Avibactam in the Treatment of Multidrug-Resistant Pseudomonas aeruginosa Femur Osteomyelitis—A Case Report

Funding Information: We would like to thank the specialists at Queen Astrid Military Hospital: Peggy De Lenher, Jean-Paul Pirnay, and Maya Merabishvili for their help. Publisher Copyright: Copyright © 2022 Racenis, Rezevska, Madelane, Lavrinovics, Djebara, Petersons and Kroica.High-energy trauma with severe bone fractures can be complicated by infection, leading to the development of osteomyelitis. Pseudomonas aeruginosa is an important causative agent of such infections because of its high virulence profile and ability to develop resistance against a wide range of antimicrobials quickly. P. aeruginosa biofilms cause treatment failure and relapsing infections. Bacteriophages are viruses that can be used to treat biofilm-associated infections. Moreover, the combination of phages with certain antimicrobials have demonstrated synergistic and additive effects. We present a case of a 21-year-old patient with relapsing multidrug-resistant (MDR) P. aeruginosa femur osteomyelitis that developed after a road accident, with a proximal right femoral Grade III B open fracture and severe soft tissue damage. Despite extensive antimicrobial treatment and multiple surgical interventions with wound debridement, the infection persisted, with subsequent development of femoral osteomyelitis with a fistula. Patient care management included femoral head excision with wound debridement, intravenous (IV) ceftazidime-avibactam, and the local application of the lytic Pseudomonas bacteriophage cocktail BFC 1.10. Nine months after the intervention, the patient did not show any clinical, radiological, or laboratory signs of inflammation; therefore, hip replacement was performed. Nevertheless, recurrent P. aeruginosa infection evolved at the distal side of the femur and was successfully treated with conventional antimicrobials. In this case, wound debridement combined with antibiotics and bacteriophages resulted in bacterial eradication of proximal femoral segment, avoiding leg amputation, but failed to treat osteomyelitis in distal bone segment. An in vitro assessment of the isolated MDR P. aeruginosa strain for biofilm formation and phage susceptibility was performed. Additionally, the antimicrobial effects of ceftazidime-avibactam and BFC 1.10 were determined on planktonic cell growth and bacterial biofilm prevention was evaluated. The isolated bacterial strains were susceptible to the bacteriophage cocktail. Strong biofilm formation was detected 6 h after inoculation. Ceftazidime-avibactam combined with BFC 1.10 was most effective in preventing planktonic cell growth and biofilm formation. In both cases, the required concentration of ceftazidime-avibactam decreased two-fold. This study demonstrates the possible use of bacteriophages and antibiotics in difficult-to-treat bone and soft tissue infections, where the additive effects of phages and antibiotics were observed.publishersversionPeer reviewe

The Correlation of Swedish Snus, Nicotine Pouches and Other Tobacco Products with Oral Mucosal Health and Salivary Biomarkers

Funding Information: This research was funded by the European Social Fund and Latvian state budget within the project no. 8.2.2.0/20/l/004 “Support for involving doctoral students in scientific research and studies” at Rīga Stradiņš University. Funding Information: We are grateful for help and support from the Department of Biology and Microbiology, Rīgas Stradiņa University. Publisher Copyright: © 2022 by the authors.In society, tobacco products, such as e-cigarettes, and smokeless tobacco products, such as snus and nicotine pouches, are becoming more attractive. There is still a lack of information regarding the effects of these products on the oral mucosa and oral saliva biomarkers. The aim of this study is to evaluate oral mucosa and the presence of inflammatory biomarkers IL-6, IL-1, IL-8, TNF alpha and LRG-1 in saliva. Respondents were divided in four groups based on their tobacco product usage. Oral examination was carried out, saliva samples were taken, and the detection of IL-6, IL-8, IL-1, TNF alpha and LRG-1 levels in saliva was carried out. Out of the tobacco users, 30.8% were snus users, 48.7% were cigarette users and 20.5% were e-cigarette users. The control group was composed of respondents who did not use any tobacco products. E-cigarettes were used more by women, but snus was used more by men. Mucosal changes were seen in the group of snus users, and mucosal changes were only seen in men who had used 5–10 tobacco units per day for 5–10 years. Increased IL-6 levels in saliva were detected in respondents who also experienced mucosal changes. Mucosal changes were white, leathery and localized at the site where snus sachets were placed. Saliva, as an easily available biofluid, could be used as a first tool to detect potentially precancerous signs, but the LRG1 marker cannot be used as a prognostic marker.publishersversionPeer reviewe