Browsing by Author "Reinis, Aigars"
Now showing 1 - 20 of 27
Results Per Page
Sort Options
Item Antibacterial Efficiency of Hydroxyapatite Biomaterials with Biodegradable Polylactic Acid and Polycaprolactone Polymers Saturated with Antibiotics(2016-08-01) Kroiča, Juta; Skadiņš, Ingus; Salma, Ilze; Reinis, Aigars; Sokolova, Marina; Rostoka, Dagnija; Berza, Natalija; Department of Biology and MicrobiologyInfections continue to spread in all fields of medicine, and especially in the field of implant biomaterial surgery, and not only during the surgery, but also after surgery. Reducing the adhesion of bacteria could decrease the possibility of biomaterial-associated infections. Bacterial adhesion could be reduced by local antibiotic release from the biomaterial. In this in vitro study, hydroxyapatite biomaterials with antibiotics and biodegradable polymers were tested for their ability to reduce bacteria adhesion and biofilm development. This study examined the antibacterial efficiency of hydroxyapatite biomaterials with antibiotics and biodegradable polymers against Staphylococcus epidermidis and Pseudomonas aeruginosa. The study found that hydroxyapatite biomaterials with antibiotics and biodegradable polymers show longer antibacterial properties than hydroxyapatite biomaterials with antibiotics against both bacterial cultures. Therefore, the results of this study demonstrated that biomaterials that are coated with biodegradable polymers release antibiotics from biomaterial samples for a longer period of time and may be useful for reducing bacterial adhesion on orthopedic implants.Item Antimicrobial resistance in nosocomial isolates of gram-negative bacteria : Public health implications in the latvian context(2021-06-29) Jain, Nityanand; Jansone, Inese; Obidenova, Tatjana; Simanis, Raimonds; Meisters, Jānis; Straupmane, Dagnija; Reinis, Aigars; Department of Biology and Microbiology; Department of Infectology; Faculty of MedicineAntimicrobial resistance (AMR) is one of the most serious threats in modern medicine which requires the constant monitoring of emerging trends amongst clinical isolates. However, very limited surveillance data is available in the Latvian context. In the present study, we conducted a retrospective analysis of microbiological data from one of the largest public multispecialty hospitals in Latvia from 2017 to 2020. AMR trends for 19 gram-negative bacterial (GNB) genera were investigated. During the study period, 11,437 isolates were analyzed with Escherichia spp. (34.71%), Klebsiella spp. (19.22%) and Acinetobacter spp. (10.05%) being the most isolated. Carbapenems like Meropenem and Ertapenem were the most effective against GNBs (3% and 5.4% resistance rates, respectively) while high resistance rates (>50%) were noted against both Ampicillin and Amoxicillin/Clavulanic acid. Enterobacter spp. and Klebsiella spp. showed a significant increase in resistance rate against Ertapenem (p = 0.000) and Trimethoprim-Sulfamethoxazole (p = 0.000), respectively. A decrease in the prevalence of Extended-Spectrum Beta-Lactamase positive (ESBL+) Enterobacterales was noted. Despite the lower prescription levels of the penicillin group antimicrobials than the European average (as reported in ESAC-Net Surveillance reports), GNBs showed high average resistant rates, indicating the role of ESBL+ isolates in driving the resistance rates. Constant and careful vigilance along with proper infection control measures are required to track the emerging trends in AMR in GNBs.Item Comparing the Microbiome of the Adenoids in Children with Secretory Otitis Media and Children without Middle Ear Effusion(2024-08) Sokolovs-Karijs, Oļegs; Briviba, Monta; Saksis, Rihards; Rozenberga, Maija; Bunka , Laura; Girotto , Francesca; Osīte, Jana; Reinis, Aigars; Sumeraga, Gunta; Krūmiņa, Angelika; Department of Otorhinolaryngology; Department of Biology and Microbiology; Department of InfectologyBackground: The adenoids, primary sites of microbial colonization in the upper airways, can influence the development of various conditions, including otitis media with effusion (OME). Alterations in the adenoid microbiota have been implicated in the pathogenesis of such conditions. Aim: This study aims to utilize 16S rRNA genetic sequencing to identify and compare the bacterial communities on the adenoid surfaces of children with OME and children with healthy middle ears. Additionally, we seek to assess the differences in bacterial diversity between these two groups. Materials and Methods: We collected adenoid surface swabs from forty children, divided into two groups: twenty samples from children with healthy middle ears and twenty samples from children with OME. The V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplified and sequenced using the Illumina MiSeq platform. Alpha and beta diversity indices were calculated, and statistical analyses were performed to identify significant differences in bacterial composition. Results: Alpha diversity analysis, using Pielou’s index, revealed significantly greater evenness in the bacterial communities on the adenoid surfaces of the healthy ear group compared with the OME group. Beta diversity analysis indicated greater variability in the microbial composition of the OME group. The most common bacterial genera in both groups were Haemophilus, Fusobacterium, Streptococcus, Moraxella, and Peptostreptococcus. The healthy ear group was primarily dominated by Haemophilus and Streptococcus, whereas the OME group showed higher abundance of Fusobacterium and Peptostreptococcus. Additionally, the OME group exhibited statistically significant higher levels of Alloprevotella, Peptostreptococcus, Porphyromonas, Johnsonella, Parvimonas, and Bordetella compared with the healthy ear group. Conclusion: Our study identified significant differences in the bacterial composition and diversity on the adenoid surfaces of children with healthy middle ears and those with OME. The OME group exhibited greater microbial variability and higher abundances of specific bacterial genera. These findings suggest that the adenoid surface microbiota may play a role in the pathogenesis of OME. Further research with larger sample sizes and control groups is needed to validate these results and explore potential clinical applications.Item Comparison of outcome between blood culture positive and negative infective endocarditis patients undergoing cardiac surgery(2021-05-27) Meidrops, Kristians; Zuravlova, Arina; Osipovs, Janis Davis; Kalejs, Martins; Groma, Valerija; Petrosina, Eva; Reinis, Aigars; Strike, Eva; Dumpis, Uga; Erglis, Andrejs; Stradins, Peteris; Rīga Stradiņš University; Statistics Unit; Department of Biology and MicrobiologyBackground: Up to 30% or even more of all infective endocarditis (IE) cases are recognized as blood culture negative, meaning that the causative agent is left unidentified. The prompt diagnosis together with the identification of causative microorganism and targeted antibiotic treatment can significantly impact the prognosis of the disease and further patient’s health status. In some studies, blood culture negative endocarditis has been shown to be associated with delayed diagnosis, worse outcome and course of the disease, and a greater number of intra and postoperative complications. Methods: We retrospectively analysed the medical records of all patients who underwent cardiac surgery for endocarditis between years 2016 and 2019. The aim of this study was to analyse short and long-term mortality and differences of laboratory, clinical and echocardiography parameters in patients with blood culture positive endocarditis (BCPE) and blood culture negative endocarditis (BCNE) and its possible impact on the clinical outcome. Results: In our study population were 114 (55.1%) blood culture positive and 93 (44.9%) blood culture negative cases of infectious endocarditis. The most common pathogens in the blood culture positive IE group were S.aureus in 36 cases (31.6%), Streptococcus spp. in 27 (23.7%), E.faecalis in 24 (21.1%), and other microorganisms in 27 (23.7%). Embolic events were seen in 60 patients (28.9%). In univariate analyses, detection of microorganism, elevated levels of procalcitonin were found to be significantly associated with intrahospital death, however it did not reach statistical significance in multivariate analyses. Among microorganisms, S.aureus was significantly associated with intrahospital death in both univariate and multivariate analyses. Conclusions: There are no statistically significant differences between groups of BCPE and BCNE in terms of intrahospital mortality, hospital and ICU stay or 3-year mortality. There were higher levels of procalcitonin in BCPE group, however procalcitonin failed to show independent association with mortality in multivariate analysis. The most common microorganism in the BCPE group was S.aureus. It was associated with independently higher intrahospital mortality when compared to other causative microorganisms.Item Covid-19 and Ukrainian Crisis Exponentiates the Need for the Inclusion of Conflict and Disaster Medicine in Medical Curriculum(2022-04) Jain, Nityanand; Prasad, Sakshi; Bordeniuc, Alina; Tanasov, Andrei; Cheuk, Chun Pong; Panag, Deepkanwar Singh; S Wia Tek, Dorota; Platos, Emilia; Betka, Marta Maria; Senica, Simone Oliver; Patel, Shiv; Czárth, Zsófia Csenge; Jain, Shivani; Reinis, Aigars; Rīga Stradiņš University; Department of Biology and MicrobiologyConflict medicine is an age-old branch of medicine which focuses on delivering healthcare services to the injured in the setting of conflicts, wars, disasters, and/or other calamities. The course in its purest form has been traditionally given only in military medical schools while civilian medical students are usually taught parts of the course in other overlapping subjects like surgery, infectious diseases, etc. However, in a crisis situation, civilian doctors are expected to double up as military doctors, which leads to emotional, mental, and physical stress for the civilian doctors along with logistical and organizational challenges. The current Covid-19 pandemic and the Russo-Ukrainian conflict have highlighted once again the emergent need for the implementation of conflict medicine courses in regular medical curricula, so as to make the medical students situation-ready. With our present discussion, we aim to provide a brief overview of the course, its core modules, challenges to its implementation, and possible solutions. We believe that the complex management skills gained by this course are not only useful in conflict scenario but are also valuable in managing day-to-day medical emergencies.Item Culture Based Evaluation of Microbiota in Children with Acute Appendicitis(2020-04-01) Kroiča, Juta; Reinis, Aigars; Kakar, Mohit; Delorme, Mathilde; Broks, Renārs; Asare, Lāsma; Berezovska, Marisa; Janšins, Vladislavs; Zviedre, Astra; Enģelis, Arnis; Saxena, Amulya; Pētersons, Aigars; Department of Biology and Microbiology; Department of Paediatric Surgery; Statistics UnitTreatment strategies for acute uncomplicated appendicitis have evolved and now conservative antibacterial treatment is recommended over surgical treatment, especially for paediatric patients. The aim of this study was to evaluate microbiota in paediatric patients with acute uncomplicated and complicated appendicitis, and antibacterial susceptibility of the causative microorganisms. Bacteriological identification was conducted using the VITEK2 analyser. Antibacterial susceptibility tests were performed and the results were evaluated in accordance with the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) “Clinical breakpoints and dosing of antibiotics” (Version 7.0, January 2019). Serodiagnosis of Yersinia enterocolitica was performed using indirect haemagglutination. The results revealed differences in microbiota in cases of acute complicated and acute uncomplicated appendicitis. Pseudomonas aeruginosa was identified more frequently in cases of acute complicated appendicitis. Mixed culture was prevalent in cases of both acute complicated and acute uncomplicated appendicitis. Very few positive extended spectrum beta-lactamase (ESBL) Escherichia coli cultures were identified. Most of strains of Pseudomonas aeruginosa were resistant to amoxicillin with clavulanic acid, ertapenem, ampicillin and cefotaxime. Some of E. coli isolates were resistant to ampicillin and to amoxicillin with clavulanic acid.Item Determination of Adhesion and Colonisation Intensity of Staphylococcus epidermidis and Pseudomonas aeruginosa on the Surface of Originally Synthesised Biomaterials in vitro and in vivo Studies, and Their Impact on Inflammatory Cytokine Expression in Tissues. Summary of the Doctoral Thesis(Rīga Stradiņš University, 2016) Reinis, Aigars; Vētra, Jānis; Kroiča, JutaAim of this work was to investigate in vitro the adhesion and colonization intensity of the Staphylococcus epidermidis and Pseudomonas aeruginosa on surfaces of biomaterials originally synthesized in Latvia, as well as to assess bacterial colonization intensity in vivo, and to study its effects on expression of inflammatory cytokines (IL-10, TNF-α) and antimicrobial peptides (beta-defensin-2) in tissues. The normal microflora representatives have the ability to colonize the implanted objects which can cause implant-related infections; therefore during the research it was necessary to clarify biomaterials according to their chemical composition, manufacturing, and with ability to resist bacteria. Considering these features the most prospective biomaterials were chosen. In this study we used 32 originally synthesized biomaterials with different chemical compositions and different types of manufacturing. In vitro research showed that bacterial adhesion and colonization of HAp/TiO2 and HAp/Ag containing biomaterials was much less intense. Therefore these biomaterials were recommended for further development and practical application. The in vivo study discovered that ceramic biomaterials were colonized more intensely by P. aeruginosa than by S. epidermidis. Studies also showed that Pseudomonas tend to cause the depletion of β-defensin-2 production in the tissue, while after 3 months of exposure the expression of all cytokines was decreased in tissue samples only.Item Development of rapid antigen test prototype for detection of SARS-CoV-2 in saliva samples(2022-02-25) Kivrane, Agnija; Igumnova, Viktorija; Liepina, Elza Elizabete; Skrastina, Dace; Leonciks, Ainars; Rudevica, Zanna; Kistkins, Svjatoslavs; Reinis, Aigars; Zilde, Anna; Kazaks, Andris; Ranka, Renate; Rīga Stradiņš UniversityBackground: The development of easy-to-perform diagnostic methods is highly important for detecting current coronavirus disease (COVID-19). This pilot study aimed at developing a lateral flow assay (LFA)- based test prototype to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in saliva samples. Methods: Mice were immunized using the recombinant receptor-binding domain (rRBD) of SARS-CoV-2 virus spike protein. The combinations of the obtained mouse anti-receptor-binding domain (RBD) polyclonal antibodies (PAbs) and several commercial antibodies directed against the SARS-CoV-2 spike protein were used for enzyme-linked immunosorbent assay (ELISA) to select antibody pairs for LFA. The antibody pairs were tested in a LFA format using saliva samples from individuals with early SARS-CoV-2 infection (n = 9). The diagnostic performance of the developed LFA was evaluated using saliva samples from hospitalized COVID-19 patients (n = 111); the median time from the onset of symptoms to sample collection was 10 days (0-24 days, interquartile range (IQR): 7-13). The reverse transcription-polymerase chain reaction (rRT-PCR) was used as a reference method. Results: Based on ELISA and preliminary LFA results, a combination of mouse anti-RBD PAbs (capture antibody) and rabbit anti-spike PAbs (detection antibody) was chosen for clinical analysis of sample. When compared with rRT-PCR results, LFA exhibited 26.5% sensitivity, 58.1% specificity, 50.0% positive prediction value (PPV), 33.3% negative prediction value (NPV), and 38.7% diagnostic accuracy. However, there was a reasonable improvement in assay specificity (85.7%) and PPV (91.7%) when samples were stratified based on the sampling time. Conclusion: The developed LFA assay demonstrated a potential of SARS-CoV-2 detection in saliva samples. Further technical assay improvements should be made to enhance diagnostic performance followed by a validation study in a larger cohort of both asymptomatic and symptomatic patients in the early stage of infection.Item Epidemiological Characterization of Clinical Fungal Isolates from Pauls Stradins Clinical University Hospital, Latvia: : A 4-year Surveillance Report(2021-10) Jain, Nityanand; Jansone, Inese; Obidenova, Tatjana; Sīmanis, Raimonds; Meisters, Jānis; Straupmane, Dagnija; Reinis, Aigars; Department of Biology and Microbiology; Department of Infectology; Scientific Laboratory of Molecular GeneticsNosocomial fungal infections are an emerging global public health threat that requires urgent attention and proper management. With the limited availability of treatment options, it has become necessary to understand the emerging epidemiological trends, mechanisms, and risk factors. However, very limited surveillance reports are available in the Latvian and broader European context. We therefore conducted a retrospective analysis of laboratory data (2017–2020) from Pauls Stradinš Clinical University Hospital (PSCUH), Riga, Latvia, which is one of the largest public multispecialty hospitals in Latvia. A total of 2278 fungal isolates were analyzed during the study period, with Candida spp. comprising 95% of the isolates, followed by Aspergillus spp. and Geotrichum spp. Amongst the Candida spp., C. albicans and C. glabrata made up about 75% of the isolates. The Department of Lung Diseases and Thoracic Surgery had the highest caseload followed by Intensive Care Department. Majority of the fungal isolates were collected from the bronchoalveolar lavage (37%), followed by urine (19%) and sputum (18%) samples. A total of 34 cases of candidemia were noted during the study period with C. albicans being the most common candidemia pathogen. Proper surveillance of emerging epidemiological trends serve as the most reliable and powerful cornerstone towards tackling this emerging threat.Item European Countries Step-up Humanitarian and Medical Assistance to Ukraine as the Conflict Continues(2022) Jain, Nityanand; Prasad, Sakshi; Bordeniuc, Alina; Tanasov, Andrei; Shirinskaya, Anna Valerievna; Béla, Bucsai; Cheuk, Chun Pong; Banica, Daniel Cristi Nicu; Panag, Deepkanwar Singh; Świątek, Dorota; Savchenko, Elena; Platos, Emilia; Lolita, Jelic; Betka, Marta Maria; Phiri, Musawenkosi; Patel, Shiv; Czárth, Zsófia Csenge; Krygowska, Aleksandra Małgorzata; Jain, Shivani; Reinis, Aigars; Rīga Stradiņš UniversityOn the 24th of February 2022, the Russian Federation began an unprovoked invasion of Ukraine, marking the biggest military attack in Europe since the second world war. Over 4 million people have fled their homeland within the first month of the war and have triggered a large refugee crisis with impacts far beyond the Ukrainian border. People in the neighboring countries have shown tremendous support by stepping forward to donate food, clothes, medications, money, and other essential supplies. The governments and other regional stakeholders have also been supportive in accommodating and easing regulations for the incoming refugees. Herein, we summarize the humanitarian measures and medical donations that have been made by European countries as they stepped up their efforts to provide refugees with all necessary basic services. We further highlight potential oncoming challenges in Ukraine and the host countries along with relevant solutions to these challenges. The current scenario highlights the need for multi-party and multi-level collaborations (both public and private) to tackle the emerging situation.Item Evaluation of Antimicrobial Resistance in Clinical Isolates of Enterococcus spp. Obtained from Hospital Patients in Latvia(2024-06) Labecka, Linda; Ķibilds, Juris; Cīrulis, Aivars; Čeirāne, Evelīna Diāna; Zeltiņa, Indra; Reinis, Aigars; Vilima, Barba; Rudzīte, Dace; Erts, Renārs; Mauliņa, Inga; Bandere, Dace; Krūmiņa, Angelika; Department of Infectology; Department of Biology and Microbiology; Department of Pharmaceutical ChemistryBackground and Objective: Enterococci are typically found in a healthy human gastrointestinal tract but can cause severe infections in immunocompromised patients. Such infections are treated with antibiotics. This study addresses the rising concern of antimicrobial resistance (AMR) in Enterococci, focusing on the prevalence of vancomycin-resistant enterococcus (VRE) strains. Materials and Methods: The pilot study involved 140 Enterococci isolates collected between 2021 and 2022 from two multidisciplinary hospitals (with and without local therapeutic drug monitoring protocol of vancomycin) in Latvia. Microbiological assays and whole genome sequencing were used. AMR gene prevalence with resistance profiles were determined and the genetic relationship and outbreak evaluation were made by applying core genome multi-locus sequence typing (cgMLST). Results: The acquired genes and mutations were responsible for resistance against 10 antimicrobial classes, including 25.0% of isolates expressing resistance to vancomycin, predominantly of the vanB type. Genetic diversity among E. faecalis and E. faecium isolates was observed and seven potential outbreak clusters were identified, three of them containing sequence types ST6, ST78 and ST80. The prevalence of vancomycin resistance was highest in the hospital without a therapeutic drug-monitoring protocol and in E. faecium. Notably, a case of linezolid resistance due to a mutation was documented. Conclusions: The study illustrates the concerning prevalence of multidrug-resistant Enterococci in Latvian hospitals, showcasing the rather widespread occurrence of vancomycin-resistant strains. This highlights the urgency of implementing efficient infection control mechanisms and the need for continuous VRE surveillance in Latvia to define the scope and pattern of the problem, influencing clinical decision making and planning further preventative measures.Item Genomic and phenotypic inconsistencies in Pseudomonas aeruginosa resistome among intensive care patients(2024-06-21) Dolguševs, Mihails; Jain, Nityanand; Savicka, Oksana; Vangravs, Reinis; Bodrenko, Jevgenijs; Bergmanis, Edvins; Zemite, Dace; Selderina, Solvita; Reinis, Aigars; Rozentāle, Baiba; Department of Doctoral Studies; Statistics Unit; Department of Infectology; Department of Biology and Microbiology; Department of Public Health and EpidemiologyObjective: Pseudomonas aeruginosa, a difficult-to-manage nosocomial pathogen, poses a serious threat to clinical outcomes in intensive care (ICU) patients due to its high antimicrobial resistance (AMR). To promote effective management, it is essential to investigate the genomic and phenotypic differences in AMR expression of the isolates. Methods: A prospective observational study was conducted from July 2022 to April 2023 at Liepaja Regional Hospital in Latvia. The study included all adult patients who were admitted to the ICU and had a documented infection with P. aeruginosa, as confirmed by standard laboratory microbiological testing and short-read sequencing. Since ResFinder is the only sequencing-based database offering antibacterial susceptibility testing (AST) data for each antibiotic, we conducted a comparison of the resistance profile with the results of phenotypic testing, evaluating if ResFinder met the US Food and Drug Administration (FDA) requirements for approval as a new AMR diagnostic test. Next, to improve precision, AST data from ResFinder was compared with two other databases – AMRFinderPlus and RGI. Additionally, data was gathered from environmental samples to inform the implementation of appropriate infection control measures in real time. Results: Our cohort consisted of 33 samples from 29 ICU patients and 34 environmental samples. The presence of P. aeruginosa infection was found to be associated with unfavourable clinical outcomes. A third of the patient samples were identified as multi-drug resistant isolates. Apart from resistance against colistin, significant discrepancies were observed when phenotypic data were compared to genotypic data. For example, the aminoglycoside resistance prediction of ResFinder yielded a major errors value of 3.03% for amikacin, which was marginally above the FDA threshold. Among the three positive environmental samples, one sample exhibited multiple AMR genes similar to the patient samples in its cluster. Conclusion: Our findings underscore the importance of utilizing a combination of diagnostic methods for the identification of resistance mechanisms, clusters, and environmental reservoirs in ICUs.Item Group A streptococcal (GAS) infections amongst children in Europe : Taming the rising tide(2023-01) Jain, Nityanand; Lansiaux, Edouard; Reinis, Aigars; Faculty of MedicineA rising tide of Group A streptococcal infections is being reported in several European countries including the UK, Spain, Sweden, France, and Ireland. In this editorial, we shed light on the current scenario and present the discussion on the latest available interim clinical guidelines. We further explore the cause of this sudden rise and the interventional measures needed to tame the rising tide.Item Identifying the Microbiome of the Adenoid Surface of Children Suffering from Otitis Media with Effusion and Children without Middle Ear Effusion Using 16S rRNA Genetic Sequencing(2023-08) Sokolovs-Karijs, Oļegs; Briviba, Monta; Saksis, Rihards; Rozenberga, Maija; Girotto , Francesca; Osīte, Jana; Reinis, Aigars; Sumeraga, Gunta; Krūmiņa, Angelika; Department of Otorhinolaryngology; Department of Infectology; Department of Biology and MicrobiologyBackground: The upper respiratory tract harbors diverse communities of commensal, symbiotic, and pathogenic organisms, originating from both the oral and nasopharyngeal microbiota. Among the primary sites of microbial colonization in the upper airways are the adenoids. Alterations in the adenoid microbiota have been implicated in the development of various conditions, including secretory otitis media. Aim: This study aims to employ 16S rRNA genetic sequencing to identify the most common bacteria present on the surface of adenoids in children with otitis media with effusion and compare them with children without pathologies in the tympanic cavity. Additionally, we seek to determine and compare the bacterial diversity in these two study groups. Materials and Methods: A total of nineteen samples from the adenoid surfaces were collected, comprising two groups: thirteen samples from children without middle ear effusion and six samples from children with secretory otitis media. The libraries of the V3–V4 hypervariable region of the bacterial 16S rRNA gene was made and sequenced using MiSeq platform. Results: The most prevalent phyla observed in both groups were Proteobacteria, Firmicutes, and Bacteroidetes. The most common bacterial genera identified in both groups were Haemophilus, Streptococcus, Moraxella, Fusobacterium, and Bordetella, with Fusobacterium and Moraxella being more prevalent in the groups that had no middle ear effusion, while Haemophulus and Streptococcus were more prevalent in the otitis media with effusion group, although not in a statistically significant way. Statistical analysis shows a trend towards bacterial composition and beta diversity being similar between the study groups; however, due to the limited sample size and unevenness between groups, we should approach this data with caution. Conclusion: The lack of prolific difference in bacterial composition between the study groups suggests that the role of the adenoid microbiome in the development of otitis media with effusion may be less significant.Item An In Vitro and In Vivo Study on the Intensity of Adhesion and Colonization by Staphylococcus epidermidis and Pseudomonas aeruginosa on Originally Synthesized Biomaterials With Different Chemical Composition and Modified Surfaces and Their Effect on Expression of TNF-alpha, beta-Defensin 2 and IL-10 in Tissues(2011) Reinis, Aigars; Pilmane, Mara; Stunda, Agnese; Vetra, Janis; Kroica, Juta; Rostoka, Dagnija; Salms, Girts; Vostroilovs, Antons; Dons, Aleksejs; Berzina-Cimdina, Liga; Department of Biology and Microbiology; Institute of Anatomy and Anthropology; Rīga Stradiņš UniversityItem An in vitro and in vivo study on the intensity of adhesion and colonization by Staphylococcus epidermidis and Pseudomonas aeruginosa on originally synthesized biomaterials with different chemical composition and modified surfaces and their effect on expression of TNF-α, β-defensin 2 and IL-10 in tissues(2011) Reinis, Aigars; Pilmane, Mara; Stunda, Agnese; Vetra, Janis; Kroiča, Juta; Rostoka, Dagnija; Šalms, Ģirts; Vostroilovs, Antons; Dons, Aleksejs; Berziņa-Cimdiņa, Liga; Department of Biology and Microbiology; Institute of Anatomy and Anthropology; Rīga Stradiņš UniversityThe aim of this study was to determine adhesion and colonization of bacteria on the surface of originally synthesized glass-ceramic biomaterials and their effect on inflammation reactions in tissues surrounding the implant. Materials and Methods: Biomaterial discs were contaminated with bacterial suspensions of 10, 102, and 103 colony forming units (CFU)/mL (P. aeruginosa ATCC 27853 and S. epidermidis ATCC 12228), and after 2 hours of cultivation, the intensity of bacterial adhesion was determined. For in vivo tests, the samples were contaminated with 102, and 103 CFU/mL cultivated at 37°C for 2 h to ensure bacterial adhesion. Contaminated biomaterial samples were implanted in the interscapular area of chinchilla rabbits for 2 and 4 weeks. The biomaterials were removed, and using plate count and sonification methods, bacterial colonization on the surface of biomaterials was determined. Moreover, the expression of TNF-α, β-defensin 2, and IL-10 in the surrounding tissues was assessed by using immunohistochemistry methods. Results: P. aeruginosa more intensively colonized biomaterials in the in vivo study as compared with S. epidermidis. Il-10 is a regulatory cytokine, which reduces the intensity of inflammatory cell activity, thus reducing nonspecific resistance of the organism. Conclusions: The expression of TNF-α and IL-10 was not affected by short (2 and 4 weeks) biomaterial implantation. Pronounced cytokine expression in tissues around implanted biomaterials contaminated with P. aeruginosa was observed.Item Influence of antibiotic-impregnated biomaterials on inflammatory cytokines(2019) Skadiņš, Ingus; Kroiča, Juta; Šalma, Ilze; Reinis, Aigars; Sokolova, Marina; Rostoka, Dagnija; Department of Biology and Microbiology; Department of Oral and Maxillofacial Surgery and Oral MedicineItem Laser speckle imaging for visualization of hidden effects for early detection of antibacterial susceptibility in disc diffusion tests(2023-06-29) Balmages, Ilya; Reinis, Aigars; Kistkins, Svjatoslavs; Bliznuks, Dmitrijs; Plorina, Emilija V.; Lihachev, Alexey; Lihacova, Ilze; Department of Biology and MicrobiologyRapid identification of effective antibiotic treatment is crucial for increasing patient survival and preventing the formation of new antibiotic-resistant bacteria due to preventative antibiotic use. Currently utilized “gold standard” methods require 16–24 h to determine the most appropriate antibiotic for the patient’s treatment. The proposed technique of laser speckle imaging with subpixel correlation analysis allows for identifying dynamics and changes in the zone of inhibition, which are impossible to observe with classical methods. Furthermore, it obtains the resulting zone of inhibition diameter earlier than the disk diffusion method which is recommended by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). These results could improve mathematical models of changes in the diameter of the zone of inhibition around the disc containing the antimicrobial agent, thereby speeding up and facilitating epidemiological analysis.Item Microbiota Assessment of Pediatric Simple and Complex Acute Appendicitis(2022-09) Kakar, Mohit; Reinis, Aigars; Kroiča, Juta; Eņģelis, Arnis; Broks, Renārs; Asare, Lāsma; Vermeulen, Marelize; Senica, Simone Oliver; Saxena, Amulya; Pētersons, Aigars; Department of Paediatric Surgery; Department of Biology and Microbiology; Statistics UnitBackground and Objectives. The aim of this study is to determine the prevailing microbiota in samples from pediatric patients with acute appendicitis, as well as evaluate the antibacterial sensitivity of the isolated microorganisms, comparing the data obtained with the clinic's antibacterial therapy guidelines. Materials and Methods. The study group consisted of 93 patients between the ages of 7 and 18. All patients underwent a laparoscopic or conventional appendectomy. The children were hospitalized with signs and symptoms suggestive of acute appendicitis. Microbiological cultures from the appendix and abdominal cavity were collected intraoperatively. Results. E. coli was identified in most cases irrespective of the clinical presentation of acute appendicitis. Most strains were susceptible to ampicillin and amoxicillin/clavulanic acid. Five strains of E. coli produced extended spectrum beta-lactamase (ESBL). Pseudomonas aeruginosa (P. aeruginosa) was the second most commonly isolated causative agent. Furthermore, it was common in cases of acute complex appendicitis. Most strains of P. aeruginosa were resistant to amoxicillin/clavulanic acid, ertapenem, ampicillin and cefotaxime, yet were susceptible to ceftazidime. Regardless of the clinical presentation, the samples yielded mixed isolates. Conclusion. E. coli is the main causative agent of acute appendicitis in the pediatric population displaying susceptibility to various antibiotics. P. aeruginosa was more prevalent in cases of acute complex appendicitis. P. aeruginosa isolates were susceptible to ceftazidime; however, they were resistant to cefotaxime, which should, therefore, be removed from guidelines for empirical antibacterial treatment of acute appendicitis due to phenotypic resistance of P. aeruginosa. We recommend antibiotics with distinct implementation to avoid antibiotic resistance.Item Mutes dobuma anaerobo baktēriju loma, kā arī sociālo un veselības faktoru ietekme uz halitozes etiologiju(2011-01-01) Rostoka, Dagnija; Kroiča, Juta; Reinis, Aigars; Kuzņecova, Valentina; Department of Biology and MicrobiologyThe 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.