Найдено 39
Nasopharyngeal Colonization and Antimicrobial Susceptibility of Bacterial Isolates in Children and Young Adults with Acute, Protracted, and Chronic Cough: A Cross-Sectional Bulgarian Study
Velikova T., Ali H., Tomov L., Velinov T., Lazova S.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, PDF, doi.org, Abstract
Since the nasopharynx serves as an ecological niche for Streptococcus pneumoniae, Corynebacterium spp., Haemophilus influenzae, Moraxella catarrhalis, etc., colonization is influenced by antimicrobial treatments, host immune responses, viral infections, and vaccines, often leading to local and systemic infections. We aimed to investigate the patterns of nasopharyngeal colonization and antimicrobial susceptibility of bacterial isolates in Bulgarian individuals under 20 years of age presenting with acute, protracted, and chronic cough. We analyzed 1383 samples using conventional culture methods, MALDI-TOF MS, antimicrobial susceptibility testing, and genetic analyses for Bordetella pertussis and Mycoplasma spp. Among 896 isolates, H. influenzae was the most prevalent (26.23%), followed by M. catarrhalis (23.55%), S. pneumoniae (22.54%), and S. pyogenes causing 7.59% of infections. In children (0–10 years), M. catarrhalis (198 isolates) and H. influenzae (142 isolates) were the most common pathogens, followed by S. pneumoniae (73 isolates), while in those aged 10–20 years, S. pneumoniae was the most common isolate (129), followed by H. influenzae (93) and M. pneumoniae (21). Colonization in children and young adults serves as a reservoir for pathogen transmission to adults, highlighting its significant public health implications. Monitoring bacterial colonization and resistance patterns remains essential to inform targeted prevention and treatment strategies.
Development and Control of Biofilms in Diabetic Foot Infections: A Narrative Review
Ray H., Weis C., Nwaeze C., Zhou V., Basu P., Mitra A.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, Обзор, PDF, doi.org, Abstract
Diabetic foot ulcers (DFUs) are a multifactorial pathophysiologic condition that occurs in patients with diabetes mellitus (DM). Approximately 9.1 to 26.1 million people are affected by DFUs annually. This condition can lead to progressive foot infections and, ultimately, foot amputation. Various microbes contribute to DFUs, including methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli can form biofilms composed of complex matrices that create a protective shield around the microorganisms, enhancing their survival and resistance to treatment. Biofilm formation is a critical virulence factor directly associated with the onset and persistence of DFUs. It not only complicates the clinical management of these ulcers but also facilitates antibiotic resistance, necessitating a comprehensive approach to treatment. Effective management strategies must therefore target biofilm formation, and the virulence factors associated with these pathogens. By addressing these elements, conventional antibiotics can be rendered more effective in treating diabetic foot ulcers. This approach aims not only to promote wound healing but also to address underlying causes and prevent further complications. This article seeks to highlight the significance of biofilm formation in DFUs, explore methodologies for studying this condition, as well as discuss demographic considerations and treatment options.
Taxonomic Identification, Complete Genome Sequencing, and In Silico Genome Mining of the Actinobacterium Lentzea sp. JNUCC 0626 Isolated from Jeju Gotjawal
Hyun K., Boo K., Hyun C.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, PDF, doi.org, Abstract
In our previous study, Lentzea sp. JNUCC 0626 was isolated from Hwasun Gotjawal on Jeju Island, and its melanogenic effects were confirmed in B16F10 melanoma cells through the identification of 1-acetyl-β-carboline. In this study, we conducted a comprehensive taxonomic characterization of Lentzea sp. JNUCC 0626, including enzymatic activities, carbohydrate metabolism, growth conditions, and cellular composition. Major fatty acids identified were iso-C16:0, iso-C15:0, and C15:0 anteiso, with polar lipids such as diphosphatidylglycerol, phosphatidylethanolamine, and several unidentified lipids. Ubiquinone Q-9 was determined as the predominant respiratory quinone. Enzymatic activity analysis (API ZYM) showed alkaline phosphatase, esterase (C4), esterase lipase (C8), and leucine arylamidase activities, while carbohydrate metabolism analysis (API 50CHB) indicated acid production from esculin alone. Complete genome sequencing revealed a 10,602,950 bp linear chromosome and a 177,940 bp plasmid. This plasmid encodes essential plasmid-related genes, including a Type IV secretion system and ParA proteins critical for plasmid transfer and stability. These findings suggest that the plasmid in Lentzea sp. JNUCC 0626 could be utilized for developing host–vector systems to facilitate the combinatorial biosynthesis of novel bioactive compounds. Comparative genomic analysis identified Lentzea pudingi CGMCC 4.7319 as the closest relative, but significant genetic divergence (dDDH 46.7%, ANI 88.02%) strongly supports the classification of Lentzea sp. JNUCC 0626 as a novel species. AntiSMASH analysis revealed 34 biosynthetic gene clusters (BGCs), highlighting the strain’s capacity to produce diverse bioactive compounds. Finally, the JNUCC 0626 extract exhibited concentration-dependent NO inhibition in LPS-stimulated RAW 264.7 cells, demonstrating significant anti-inflammatory activity. This suggests that the secondary metabolites inferred from genomic analysis may contribute to these observed bioactivities.
The Trend of Long Pentraxin 3 and Other Inflammatory Serum Markers in the 30 Days After Total Hip Arthroplasty
Fidanza A., Marinucci V., Vitale L., Poppa G., Giusti I., Necozione S., Logroscino G.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, PDF, doi.org, Abstract
One of the most dangerous and difficult side effects to treat after total hip arthroplasty (THA) is periprosthetic or superficial site infection. Blood and synovial fluid biomarkers have recently come into focus in addition to conventional systemic indicators of inflammation in order to assess their potential utility in the diagnosis of infections. Long pentraxin 3 (PTX3) appears to be a sensitive biomarker of acute-phase inflammation. The purpose of this study is to determine plasma PTX3 in patients undergoing THA and compare its trend with other common serum markers, such as CRP, D-dimer, procalcitonin, and ESR up to 30 days post-operatively. Patients with hip arthritis or avascular necrosis of the femoral head were consecutively enrolled in a single-center study. Each patient underwent blood testing for ESR, CRP, procalcitonin, D-dimer, and PTX3 levels before surgery and at 1, 3, 5, 15, and 30 days after THA. PTX3 was measured using the ELISA method. Other markers’ values and trends were compared with PTX3’s. A total of 50 patients met our inclusion criteria. When different trends were evaluated, PTX3 was found to have a trajectory and sensitivity comparable to other inflammatory markers. Notably, PTX3 changed more quickly than the other markers, with a sharp increase immediately post-operatively, followed by normalization at the 5-, 15-, and 30-day follow-ups, corresponding to the resolution of the inflammatory condition. However, 30 days post surgery, no patients exhibited signs or symptoms of early prosthetic infection. PTX3 is confirmed as a reliable and promising serum biomarker for tracking the level of inflammation in patients undergoing total hip replacements. Blood PTX3 values rise even more rapidly than CRP and procalcitonin and then quickly return to normal values when the inflammatory process resolves. One of the primary barriers to PTX3’s inclusion in routine studies on early periprosthetic infections is the waiting period for PTX3 sample analysis.
Prevalence and Multidrug Resistance in Non-Typhoidal Salmonella in India: A 20-Year Outlook
Sahu A.A., Sephalika S., Mohakud N.K., Sahu B.R.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, Обзор, PDF, doi.org, Abstract
Non-typhoidal Salmonella (NTS) infection poses a significant public health challenge globally, particularly in developing countries like India. NTS, predominantly represented by S. enterica serovars, is a major cause of intestinal and extra-intestinal infections. This review provides a comprehensive overview of longitudinal analyses of the prevalence of NTS in different regions of India encountered in the last 20 years and their antimicrobial resistance patterns. We followed several research investigations published during 2000–2024 to examine the incidence and prevalence of different serovars of NTS in several parts of India and followed published articles on NTS showing resistance to different antibiotics. We pointed out NTS serovars, which are predominantly isolated in various human and non-human sources, as observed in several investigations conducted in different regions of India. Our analysis revealed that, among serovars detected from various sources, S. Typhimurium is the most predominant one occurring across both human and non-human sources, followed by S. Enteritidis and S. Weltevreden. The occurrence of similar serovars of Salmonella in both human and non-human sources may be due to zoonotic transmission between animals and humans. Extensive research conducted across many geographic locations reveals that NTS isolates exhibit resistance to several antibiotics, with multidrug-resistance (MDR) being more common. These MDR strains basically show resistance to three or more classes of antibiotics, including critically important antimicrobials such as nalidixic acid, ciprofloxacin, and third-generation cephalosporins. Temporal trends suggest an alarming increase in resistance to these antibiotics, particularly in serovars such as S. Typhimurium and S. Enteritidis. Overall, the current article sheds light on the urgent need for surveillance, judicious antibiotic use, and the development of alternative treatment strategies to combat the rising tide of antibiotic-resistant NTS strains.
The Role of Probiotics in Modulating Gut Microbiota and Metabolic Health for Weight Management: A Mini Review
Oudat Q., Okour A.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, Обзор, PDF, doi.org, Abstract
The rising global prevalence of obesity and its associated metabolic disorders highlights the urgent need for innovative, sustainable interventions. Probiotics, as modulators of gut microbiota, have emerged as promising agents in weight management by influencing metabolic health. This mini-review explores the role of probiotics in modulating gut microbiota to support energy metabolism, appetite regulation, and fat storage. Evidence underscores the strain-specific benefits of probiotics, such as Lactobacillus gasseri SBT2055, Bifidobacterium breve B-3, and Akkermansia muciniphila, in reducing visceral fat, improving glucose metabolism, and mitigating obesity-related inflammation. The mechanisms underlying these effects include short-chain fatty acid (SCFA) production, modulation of appetite-regulating hormones, and improvements in gut barrier integrity. While the findings are promising, variability in outcomes highlights the importance of tailored probiotic interventions and underscores the need for standardized methodologies in future research. By addressing these challenges, probiotics can serve as integral components of personalized nutrition strategies, advancing both metabolic health and public health objectives.
Dynamics of Primary Succession in Airborne Microbial Communities on Urban Masonry
Winn-Swanson K., Kostich L., Castañeda-Childress M., Solis I., Remillard J., Agustin A., Gonzalez D., Carmona-Galindo V.D.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, PDF, doi.org, Abstract
Microbial succession on urban masonry surfaces is a critical yet understudied aspect of environmental microbiology, with implications for public health within the One Health framework. This study investigated how building age, orientation, and vegetative cover influence microbial diversity on masonry, metal, and glass substrates at the University of La Verne, California. Biophysical characterizations were conducted, and microbial communities were analyzed using morphospecies richness and DNA sequencing. Significant variation in microbial species richness (χ2 = 20.3882, p = 0.0011) and diversity (Fisher’s LSD, p < 0.05) was observed. Masonry surfaces exhibited the highest microbial diversity, with a mean richness of 23 morphospecies compared to 14 on metal and 12 on glass. Penicillium fungi dominated masonry sites, comprising 45% of colonies, while Pseudomonas and Klebsiella were more prevalent on metal and glass surfaces (35% and 28%, respectively). Microbial succession did not follow a linear progression but showed non-sequential shifts influenced by local conditions. The abundance of Penicillium, known for antibiotic production, raises concerns about spreading antibiotic resistance genes. Opportunistic pathogens further highlight potential health risks. These findings underscore the importance of understanding primary successional processes in urban environments to manage microbial communities and mitigate public health risks.
A Review of Laboratory Biosafety and Infection Prevention and Control Guidelines on the Management of High-Risk Pathogens in Canada
Yeung E.Y.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, Обзор, PDF, doi.org, Abstract
The safety precautions required for certain pathogens are different in clinical laboratories and patient-facing healthcare settings, causing confusion for laboratorians and infection preventionists. The current review aims to summarize information from reputable Government of Canada guidance commonly used in clinical laboratories in Canada, including the Government of Canada Human Pathogens and Toxins Act and Regulations, the ePATHogen—Risk Group Database, biosafety directives and advisories, Transportation of Dangerous Goods Regulations, and the Canadian Biosafety Standard (2022). Guidelines from the Centers for Disease Control and Prevention’s (CDC) Biosafety in Microbiological and Biomedical Laboratories (2020), Clinical and Laboratory Standard Institution’s (CLSI) M29 Protection of Laboratory Workers from Occupationally Acquired Infections (2014), and Association of Public Health Laboratories’s Biothreat Agent Bench Cards for the Sentinel Laboratory (2018) were also used to supplement specific details. In comparison, information regarding infection prevention and control practices in patient-facing healthcare settings was summarized: Public Health Agency of Canada: Routine Practices and Additional Precautions for Preventing the Transmission of Infection in Healthcare Settings (2017) and CDC Infection Control Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings (2007). Contrasting levels of precautions exist between laboratories and patient-facing settings, especially for endemic fungi and certain security-sensitive biological agents. Acknowledging this contrast may facilitate risk communication relative to the counterparts to minimize the threat and disease effects and ensure public confidence.
COVID-19 and Myocarditis: Pathogenetic Mechanisms and Histological Features
Salzillo C., Marzullo A.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, PDF, doi.org, Abstract
The COVID-19 pandemic has highlighted several cardiovascular complications, including myocarditis, which can be a significant cause of sudden cardiac death in young people. SARS-CoV-2 infection can cause cardiac muscle inflammation through direct mechanisms, such as viral invasion of myocardial cells, and indirect mechanisms, such as the systemic inflammatory response. Myocarditis can lead to life-threatening electrical dysfunctions and arrhythmias. Although post-infection myocarditis is more common, rare cases of post-vaccination myocarditis have also been reported, especially with mRNA vaccines. However, these post-vaccination cases tend to be mild and self-limiting, with a good response to treatment. Despite the associated risks, the benefits of vaccination far outweigh the risks, significantly reducing the incidence and severity of COVID-19 infections and related heart complications. It is crucial to continue surveillance and research to better understand the association between COVID-19, myocarditis and sudden cardiac death in the young and improve prevention and intervention strategies. In this literature review, we analyzed the pathogenetic mechanisms and histological features of myocarditis associated with COVID-19 and its vaccination, and focused on the correlation with sudden cardiac death.
Cervical Tuberculosis Mimicking Cervical Cancer in a Postmenopausal Woman: A Case Report
Viegas de Carvalho L., Soares Nogueira F., Vale F., Nazaré P., Pereira E., Gaspar B., Gomes Pinto D.
Q4
Acta Microbiologica Hellenica, 2025, цитирований: 0, PDF, doi.org, Abstract
Cervical tuberculosis is a rare form of genital tuberculosis. A case of a 73-year-old woman who presented with cervical wall thickening on magnetic resonance imaging, suggesting an invasive malignant neoplasm, is documented. Cervical cone excision was performed for histopathological study. Microscopy showed epithelioid granulomas, without appreciable caseous necrosis, in the wall of the uterine cervix, associated with erosion of the overlying cervical mucosa. Histochemical stains for microorganisms (Ziehl–Neelsen, Grocott, and Warthin–Starry) were negative. Immunohistochemistry for Treponema pallidum revealed scarce, spiral-shaped bacilli, which raised the diagnostic possibility of secondary syphilis. The serological study for syphilis was negative, however. Polymerase chain reaction (PCR) tests for Mycobacterium tuberculosis and Treponema pallidum were performed in the formaldehyde-fixed, paraffin embedded tissue and resulted positive for Mycobacterium tuberculosis and negative for Treponema pallidum, confirming the diagnosis of cervical tuberculosis. Our objective was to report a rare case of cervical tuberculosis, discussing the advantages and limitations of complementary techniques used in the pathological diagnosis of infectious agents and highlighting diagnostic pitfalls. In conclusion, correct microbiological diagnosis requires the implementation of integrated workflows employing complementary techniques in a multidisciplinary setting to improve the accuracy of histopathological examination in infectious diseases.
Emerging Arboviruses in Europe
Papa A.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
Viruses transmitted by arthropods (arboviruses) pose a global public health threat. Sporadic cases or outbreaks caused by West Nile virus, Crimean–Congo haemorrhagic fever virus, tick-borne encephalitis virus, and phleboviruses are often reported in Europe. Recently, they expanded their distribution in geographic areas where they had never been observed before, while tropical viruses, like Dengue, Chikungunya, and Zika, started to cause autochthonous cases and outbreaks following the return of viraemic travellers from endemic countries. The primary or secondary vectors of these viruses are established in Europe, and the incidence of arboviral diseases is expected to increase due to several anthropogenic and/or environmental factors (mainly climate change, which affects the survival and amplification of the arthropod vectors). This is an update on the emerging arboviruses in Europe, associated challenges, and future perspectives.
Characterization of Aminoglycoside-Modifying Enzymes in Uropathogenic Enterobacterales of Community Origin in Casablanca, Morocco
Essalhi A., Nayme K., Maaloum F., Errami A., Zerouali K., Bousfiha A.A., El Kettani A.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
Community-acquired urinary tract infections (UTIs) represent a significant public health issue, primarily due to the increasing antibiotic resistance among uropathogens. This study assesses the resistance status of uropathogenic community Enterobacterales to various antibiotics, particularly aminoglycosides, and determines the prevalence of aminoglycoside-modifying enzyme (AME) genes, while investigating the coexistence of 16S rRNA methylating enzymes. We analyzed 628 clinical isolates of Enterobacterales obtained from 4282 cytobacteriological urine examinations at the Pasteur Institute Casablanca, Morocco, collected from October 2018 to December 2021. Identification and antibiotic susceptibility testing were conducted using the VITEK 2® COMPACT system, following CA-SFM guidelines. DNA extraction utilized the heat shock method, and subsequent PCR was performed. Gram-negative bacteria accounted for 85% of isolates, with Enterobacterales representing 91% of this group. E. coli (73%) and Klebsiella pneumoniae (20%) were the most common species among Enterobacterales. Resistance was particularly high for ampicillin (76.7%) and amoxicillin-clavulanate (58%). Among aminoglycosides, gentamicin and tobramycin resistance rates were 33.5% and 35%, respectively, while amikacin resistance was observed in 21.3% of isolates. High frequencies of AME genes were detected, with AAC(3′)-IIa (27.7%) and AAC(6′)-Ib (25.9%) being the most prevalent. Notably, no 16S rRNA methylation genes (rmtA, rmtB, rmtC, rmtD) were found. All tested strains exhibited biofilm-forming capacity, with K. pneumoniae demonstrating intense biofilm production. The study highlights a concerning trend of antibiotic resistance among uropathogenic Enterobacterales in the community setting, correlating genotype with resistance phenotype and emphasizing the need for enhanced surveillance and targeted treatment strategies.
Identification and Potential Functions of Ebola Virus-Encoded MicroRNAs in EBOV-Infected Human ARPE Cells
Mensah-Bonsu M., Doss C., Gloster C., Muganda P.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
Ebola virus (EBOV) causes Ebola virus disease (EVD), a severe and often fatal hemorrhagic fever. Although much research has focused on host miRNA expression during EBOV infection, it has been discovered that EBOV itself also produces miRNAs. However, further studies are needed to fully comprehend the role of these EBOV-encoded miRNAs in infection and disease development. This study aimed to identify known and novel EBOV-encoded miRNAs and their potential functions in the pathogenic mechanisms of EBOV. We reanalyzed previously available small RNASeq data to identify the miRNAs and predict their cellular targets and functions. We identified four EBOV-encoded miRNAs—EBOV-mir-M1 (4390–4414), EBOV-mir-M4, EBOV-mir-M2 (8288–8309), and EBOV-mir-M3 (9885–9906)—expressed specifically in Ebola-infected human adult retinal pigment epithelial (ARPE) cells. EBOV-mir-M1 (4390–4414) was expressed up to 19 times more than the other three miRNAs. The identified miRNAs were predicted to target genes associated with pathways such as calcium signaling, MAPK signaling, type I interferon signaling, and cytokine-mediated signaling, which play critical roles in Ebola infection and pathogenesis. This study contributes to our understanding of the role of EBOV-encoded miRNAs in infection and pathogenesis by demonstrating the expression of these miRNAs in human ARPE cells, providing insights into the mechanisms underlying EBOV pathogenesis.
Genomic and Epidemiological Surveillance of SARS-CoV-2 Epidemic in Northwestern Greece
Sakaloglou P., Bozidis P., Kourou K., Kostoulas C., Gouni A., Tsaousi E., Koumpouli D., Argyropoulou S., Oikonomidis P., Peponi H., Sarantaenas I., Christaki E., Georgiou I., Gartzonika K.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
In early 2020, Greece was affected by the SARS-CoV-2 epidemic, and since then, the continuous emergence of fast-spreading variants has caused surges of new SARS-CoV-2 infections. In this study, we performed genomic, phylogenetic, and epidemiological analyses to investigate the SARS-CoV-2 epidemic in northwestern Greece. From March 2020 to February 2022, nasopharyngeal samples obtained from patients suspected to have COVID-19 were tested for SARS-CoV-2 detection. Complete SARS-CoV-2 genomic sequences were generated from selected positive samples. Northwestern Greece experienced four distinct waves of the epidemic following the first wave, which was mainly observed in Attica and other parts of Greece. The positivity index was rising throughout the pandemic waves in several geographical units, with the highest levels recorded in prominent tourist destinations characterized by high agricultural density. The phylogenetic analyses revealed 34 different lineages, with B.1, B.1.1, B.1.1.305, B.1.1.318, B.1.177, B.1.1.7, B.1.617.2, AY.43, and BA.1 being the most prevalent lineages in the region. Although multiple lineages were co-circulating, each pandemic wave was dominated by a different lineage. The SARS-CoV-2 epidemic in northwestern Greece was characterized by the successive introduction of new lineages, resulting in surges of new SARS-CoV-2 infections.
Clinical and Prognostic Utility of Cycle Threshold (Ct) Value of SARS-CoV-2 in Pediatric Population: Single-Center Experience
Gambilonghi F., Fichera V., Sortino V., Grassi P., Collotta A.D., Vaccalluzzo M.S., Pulvirenti A., Marino S., Ruggieri M., Castiglione S., Falsaperla R.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
The cycle threshold (Ct) value of PCR, used to detect SARS-CoV-2 viral load, has been associated with disease severity in adults, but few studies have examined these relationships in pediatric patients. The aim of this study was to evaluate the relationship between the Ct value at hospital admission and the duration of fever, length of hospital stay, and the need for medical interventions in pediatric patients with COVID-19. We conducted a retrospective study of 124 pediatric patients with a positive nasopharyngeal swab for SARS-CoV-2 between April 2020 and March 2022. A negative correlation was observed between the Ct value and the duration of fever (p = 0.012), with a similar trend for length of hospital stay (p = 0.25). A low Ct value was also associated with the development of MIS-C (p = 0.026) and the need for respiratory support and steroid therapy (p = 0.036). The Ct value may be useful in stratifying pediatric patients with COVID-19, helping to predict the duration of fever and hospital stay, as well as the need for medical interventions.
Evaluation of the Antibacterial and Antibiofilm Activity of Erythrina senegalensis Leaf Extract Against Multidrug-Resistant Bacteria
Enupe O.J., Umar C.M., Philip M., Musa E., Oti V.B., Khaliq A.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
Biofilms are bacterial communities on surfaces within an extracellular matrix. Targeting biofilm-specific bacteria is crucial, and natural compounds with reported antibiofilm activity have garnered significant interest. The study evaluated the antibacterial and antibiofilm activity of Erythrina senegalensis leaf extract against multidrug-resistant (MDR) Gram-negative bacteria, including Salmonella typhimurium, Salmonella typhi, Salmonella enteritidis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The leaf extract was prepared using aqueous and ethanol solvents, and qualitative phytochemical screening revealed the presence of various bioactive compounds such as tannins, saponins, cardiac glycosides, flavonoids, terpenoids, alkaloids, anthraquinone, reducing sugar, and ketones. A Kirby–Bauer disc diffusion assay was performed to test the susceptibility of antibiotics, and the antibacterial efficacy of the aqueous and ethanol extracts of E. senegalensis was determined using the cup-plate method, while the antibiofilm activities were determined using the crystal violet titer-plate method. The aqueous and ethanol extracts of Erythrina senegalensis revealed the presence of tannins, saponins, cardiac glycosides, flavonoids, terpenoids, alkaloids, anthraquinone, reducing sugar, and ketones. The study found that the Gram-negative bacteria isolates that were MDR were S. typhimurium, S. enteritidis, and P. aeruginosa, while K. pneumoniae was resistant to beta-lactam and fluoroquinolones, and S. typhi was sensitive to all antibiotics tested. Statistically, susceptibility to antibiotics had an inverse, weak, and significant relationship with biofilm production (r = −0.453, −0.106, −0.124, −0.106, −0.018, n = 10, p < 0.05). The aqueous extract showed good biofilm inhibition against K. pneumoniae and P. aeruginosa, and poor biofilm inhibition against S. enteritidis, while S. typhimurium and Salmonella typhi exhibited no biofilm inhibition. The ethanol extract did not demonstrate any antibiofilm activity against the tested Gram-negative pathogens. The study suggests that the Gram-negative bacteria’s capacity to form biofilms is negatively associated with their antibiotic resistance phenotypes, and the aqueous extract of E. senegalensis exhibited moderate antibiofilm activity against K. pneumoniae, P. aeruginosa, and S. enteritidis.
Aspects of Tuberculosis in Greece over the Last Century: Historical Perspectives and Today’s Challenges
Pliatsikas A., Vrioni G., Papaparaskevas J., Tsiamis C., Tsakris A.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 1, PDF, doi.org, Abstract
Tuberculosis has had a long-standing prevalence in Greece over the last century, going hand in hand with the country’s overall socioeconomic situation. The current study explores aspects of tuberculosis in Greece since the interwar period and up to the present. Apparently, ignorance of the nature of the disease coupled with false medical perceptions sealed the fate of patients while unwittingly influencing public opinion and making societies hostile toward patients. Such paradigms are of great and timeless value for the cohesion and functioning of societies, not excluding modern ones. Although the present-day situation in Greece is utterly different from that in the previous century, considering the limited number of cases and minimal impact of the disease, new challenges have emerged, such as the under-reporting of cases, the emergence of multidrug-resistant tuberculosis, latent tuberculosis or the management of large refugee flows in the Eastern Mediterranean involving citizens from countries with a high prevalence of the disease. On the other hand, the study of tuberculosis is nowadays more urgent than ever, given the global concerns regarding the future of the disease in the midst of the COVID-19 pandemic, which has put enormous pressure on national health systems.
Association Between the Duration of Diarrhea and the Length of Hospitalization Among Clostridioides difficile Patients in Northern Nigeria
Adesoji A.T., Mgbere O., Darkoh C.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
The United States Centers for Disease Control and Prevention (CDC) has categorized Clostridioides difficile infection (CDI) as a significant concern in extended-care facilities, hospitals, and outpatient clinics. However, little is known about CDI in low- and middle-income countries. This study determined CDI prevalence and impact in outpatient adults presenting with diarrhea in Nigeria. Toxigenic culture and PCR were used to detect and validate C. difficile. Prior antibiotic use, medical history, and demographic data were also obtained. Descriptive and inferential statistics were used for data analysis. The patient demographics were 35.48% (22/62) for the 18–24 years age group and 32.26% (20/62) for both the 25–30 years age group and the 31+ years group, with an average age of 29.7 years. Forty-eight percent of the patients (30/62) tested positive for CDI, and the prevalence increased with age. Most patients (86.67%, 52/60) reported moderate/severe cases of diarrhea and 67.7% had no knowledge of antibiotics. The results showed that 62.30% of the cases were hospitalized with the duration of diarrhea being significantly associated (r = 0.98, p ˂ 0.001) with the length of hospitalization. These results suggest that C. difficile is common among diarrhea patients in this population and that Nigerian hospitals’ infection prevention and control measures must include this pathogen.
Urinary Neutrophil Gelatinase-Associated Lipocalin as a Predictor of COVID-19 Mortality in Hospitalized Patients
Švitek L., Zlosa M., Grubišić B., Kralik K., Perić N., Berišić B., Lišnjić D., Mandić S.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 1, PDF, doi.org, Abstract
Neutrophil gelatinase-associated lipocalin (NGAL) is a protein secreted by activated neutrophils and certain tissues. The aim of this study was to investigate the prognostic role of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in hospitalized COVID-19 patients with regard to mortality. The prospective observational cohort study involved 86 hospitalized adult COVID-19 patients. Patients’ urine samples were collected upon admission and 48–72 h after admission. General anamnesis and clinical status information were obtained from medical records. Within 24 h of sample collection, urine aliquots were centrifuged, the supernatant was separated, and samples were frozen at −80 °C until uNGAL concentration measurement, which was performed within two years of sample collection. The patients were categorized into groups based on disease outcome (survived/deceased). Data analysis was performed to identify predictive factors and diagnostic indicators for the unfavorable outcome group using logistic regression and ROC curve methods. Logistic regression associated age, cardiomyopathy, invasive mechanical ventilation, and uNGAL concentration (follow-up sampling) with mortality. ROC analysis identified uNGAL concentration (follow-up sampling) as an indicator of mortality, with a cut-off value of >23.8 ng/mL. This study concludes that there is an association between disease outcome and uNGAL concentration in COVID-19 patients. However, understanding the dynamics of uNGAL concentration during COVID-19 remains limited, which is crucial for its effective clinical application.
Evaluation of the Efficacy of Three Newcastle Disease Vaccines Produced at the National Veterinary Institute, Bishoftu, Ethiopia, at Different Temperature Storage Conditions
Degefa T., Birehanu M., Mulugeta D., Ferede H., Girma E., Alemu A., Muleta D., Aga A.M., Shimeket D., Woldemichael D.N., Akalu M., Woldemariyam F.T.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
Newcastle disease, which affects poultry and is endemic in many nations across the world, is caused by Avian Paramyxovirus-1 (APMV-1). This experimental study was conducted from January to June 2021 at the National Veterinary Institute (NVI) to evaluate the virus viability and antibody titer of Newcastle disease vaccines (Hichner’s B1, Lasota, and ThermostableI2) stored at different temperature storage conditions. Chickens (12 treatment groups and 1 control group) were vaccinated and challenged with the virulent ND virus (0.5 × 106.5 embryonic lethal dose fifty (ELD50)). The immune responses (antibody titers) of chickens were evaluated using hemagglutination (HA) and hemagglutination inhibition (HI) assays. The Newcastle disease vaccines (Hachiner’s B1 (ND-HB1), ND-Lasota, and ND-Thermostable I2) stored at +4 °C HI-induced antibody titers of 151 (±103.3), 136 (±53.4), and 145 (±91) on day 14, respectively, whereas on day 21, they increased to 160 (±82) for ND-HB1 and 144 (±74.5) for ND-Lasota. ND-Thermostable I2 showed a decrement to 133 (±44.8). All three vaccines stored at different temperature storage conditions (+4, +23, and +30 °C) used in this experiment induced antibody titers greater than 128 on day 28 post-vaccination, except the Newcastle disease vaccine Thermostable I2 stored at +30 °C. The vaccines collected from private veterinary drugstores (customer vaccines Hachiner’s B1 and ND-Thermostable I2) used in this experiment induced very low antibody titers, less than 128 antibody titers, from days 14 to 21. Statistically significant induced mean antibody titers were observed for chickens that received vaccines stored at different temperature storage conditions for 72 h (p < 0.05), except for the ND-HB1 mean HI-induced antibody titer at days 7 and 28. Further, vaccine protection was confirmed by inoculation of both the vaccinated (treatment groups) and control groups by the virulent ND virus, where the control group started dying three days post-challenge but all chicks that received the vaccines survived. Overall, this study showed the impact of temperature storage conditions on the antibody titer and their effect on the titer of the viable virus in the vaccine, and thereby its protective capacity, warranting appropriate cold chain management of the vaccines along the value chain.
Clostridioides difficile Infection-Related Hepatic Abscess: A Review of the Literature
Vongsavath T., Chun M., Tun K.M., Manne V.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, Обзор, PDF, doi.org, Abstract
Hepatic abscesses (HAs) are suppurative cavities caused by the infiltration of liver parenchyma by microbes. The etiology of HAs can include biliary disease, intra-abdominal infections, bile duct ischemia following pancreaticoduodenectomy, liver transplantation, and rarely septicemia, among others. While HA of a bacterial origin is rare, intra-abdominal biliary infections can be seen after appendicitis or proctitis. Empiric treatment generally involves antibiotic coverage and percutaneous drainage. Due to a high health care association, Clostridioides difficile infection (CDI) is becoming more frequent and has increasing antibiotic resistance. While generally limited to the gastrointestinal tract, extra intestinal CDIs are generally related to bacteremia, and related HAs are even rarer, with their prognostic courses not well described. A literature search was performed evaluating case reports and manuscripts relating to CDI-related HA. Articles with relevant information were analyzed for quality. Those fitting predetermined selection criteria and the level of evidence were included in this study. While most affected patients reported recent hospitalization and significant comorbidities, some of them reported no apparent risk factors at all. While all included individuals had HA, only 33.3% had CD-related bacteremia. Treatment of HA was managed with drainage as well as antibiotics and was generally successful, with one death. As CDI becomes more prevalent, studies such as this will be needed to address the management of associated HA.
Clinical and Ocular Inflammatory Inhibitors of Viral-Based Gene Therapy of the Retina
Ohlhausen M., Conrady C.D.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 1, PDF, doi.org, Abstract
Gene therapy is an emerging field of medicine that can target and treat previously untreatable blinding or lethal diseases. Within the field of ophthalmology, gene therapy has emerged to treat retinal degenerative disorders, but its exact role is in its infancy. While this exciting frontier is rapidly expanding, these typically viral-based gene therapy vectors trigger a host immune response. Thus, a better understanding of the host immune response to gene therapies is critical, in that harnessing immunity to these vectors may improve treatment efficacy and reduce the risk of vision loss from inflammation. As such, we will discuss innate and adaptive immunity to gene therapy vectors, and avenues through which this response may be harnessed to improve visual outcomes.
Anti-HIV Activity of Philippine Crocodile (Crocodylus mindorensis) Serum on Infected Human Mononuclear Cells
Hinay A.A., Cadotdot N.M., Tablizo M.V., Francisco A.F.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 0, PDF, doi.org, Abstract
The search for effective inhibitors of HIV-1 replication remains a critical research area of research in virology and immunology. Natural products have emerged as promising candidates for antiviral therapies. In the present study, we assessed the potential inhibitory activity of Philippine crocodile serum at both pre- and post-infection stages of the HIV-1 replication cycle. Freshly collected crocodile serum samples were used in a cell culture-based assay with peripheral blood mononuclear cells. HIV-1 reverse transcriptase activity in the treated cell culture system was assessed using colorimetric enzyme immunoassay. The crocodile serum at 0.5% and 0.25% vol/vol concentrations showed an inhibitory activity against HIV-1 replication both in pre-infection interactions (68.61 ± 1.67% and 69.95 ± 2.24%, respectively) and post-infection interactions (65.68 ± 2.93% and 69.92 ± 0.45%, respective). These findings suggest that Philippine crocodile serum may have potential as a natural inhibitor of HIV-1 replication and warrant further investigation into its therapeutic use.
Exploring Bacteriophage Applications in Medicine and Beyond
Elfadadny A., Ragab R.F., Abou Shehata M.A., Elfadadny M.R., Farag A., Abd El-Aziz A.H., Khalifa H.O.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 2, Обзор, PDF, doi.org, Abstract
Bacteriophages, or phages, are microscopic viruses that specifically infect and replicate within bacterial hosts. Their unique ability to target and control bacterial populations makes them valuable tools with applications ranging from human medicine and agriculture and environmental management to biotechnology. In this comprehensive review, we explore the diverse and promising medical and non-medical applications of bacteriophages, highlighting their pivotal role across various niches. From safeguarding food production through pathogen control to their innovative utilization in wastewater treatment, bacteriophages prove to be versatile agents. To achieve applications of phages on a larger scale, it is necessary to make the legal framework more suitable and flexible, create special approval programs (e.g., for novel antimicrobial drugs), and promote targeted research and development activities on phages. Additionally, a more intensive exchange between academia, industry, regulatory authorities, and stakeholders in the health system should be pursued.
Combating Malaria with Vaccines: Insights from the One Health Framework
Sutanto H.
Q4
Acta Microbiologica Hellenica, 2024, цитирований: 2, Обзор, PDF, doi.org, Abstract
Malaria remains a leading cause of morbidity and mortality worldwide, with significant efforts directed towards developing effective vaccines to curb its impact. The One Health concept, recognizing the interconnectedness of human, animal, and environmental health, offers a comprehensive approach to understanding and combating this disease. This review examines the development of malaria vaccine through the lens of the One Health framework, highlighting the integration of human, vector, and environmental factors in the fight against malaria. We discuss the current landscape of malaria vaccine development, including the deployment of the RTS,S/AS01 vaccine and the progress of other candidates such as the R21/Matrix-M and PfSPZ vaccine. The challenges posed by the complex lifecycle of the malaria parasite, its genetic diversity, and the environmental factors influencing transmission are explored. This review also discusses emerging technologies and innovations that could enhance vaccine efficacy and delivery. Additionally, we consider ethical, social, and economic factors critical to the successful implementation of vaccination programs. In concluding, this review underscores the importance of adopting a One Health approach to malaria vaccine development, advocating for integrated efforts to address the multifaceted challenges of malaria control and eradication.
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