Search Results (265)

Background: The COVID-19 pandemic has profoundly altered the clinical and microbiological landscape of respiratory tract infections (RTIs), potentially reshaping pathogen distribution and antimicrobial resistance (AMR) profiles across care settings. Objectives: The objective of this study was to assess temporal trends in respiratory bacterial pathogens, antimicrobial resistance, and polymicrobial infections across three pandemic phases—pre-COVID (2018–2019), COVID (2020–2022), and post-COVID (2022–2024)—in hospitalized and ambulatory patients. Methods: We retrospectively analyzed 1827 respiratory bacterial isolates (hospitalized patients, n = 1032; ambulatory patients, n = 795) collected at a tertiary care center in Northern Italy. Data were stratified by care setting, anatomical site, and pandemic phase. Species identification and susceptibility testing followed EUCAST guidelines. Statistical analysis included chi-square and Fisher’s exact tests. Results: In hospitalized patients, a significant increase in Pseudomonas aeruginosa (from 45.5% pre-COVID to 58.6% post-COVID, p < 0.0001) and Acinetobacter baumannii (from 1.2% to 11.1% during COVID, p < 0.0001) was observed, with 100% extensively drug-resistant (XDR) rates for A. baumannii during the pandemic. Conversely, Staphylococcus aureus significantly declined from 23.6% pre-COVID to 13.7% post-COVID (p = 0.0012). In ambulatory patients, polymicrobial infections peaked at 41.2% during COVID, frequently involving co-isolation of Candida spp. Notably, resistance to benzylpenicillin in Streptococcus pneumoniae reached 80% (4/5 isolates) in hospitalized patients during COVID, and carbapenem-resistant P. aeruginosa (CRPA) significantly increased post-pandemic in ambulatory patients (0% pre-COVID vs. 23.5% post-COVID, p = 0.0014). Conclusions: The pandemic markedly shifted respiratory pathogen dynamics and resistance profiles, with distinct trends observed in hospital and community settings. Persistent resistance phenotypes and frequent polymicrobial infections, particularly involving Candida spp. in outpatients, underscore the need for targeted surveillance and antimicrobial stewardship strategies. Full article

The increasing demand for sustainable and safer alternatives in the cosmetic industry has driven the search for multifunctional natural ingredients. Essential oils (EOs), known for their antimicrobial and antioxidant activities, are promising candidates with which to replace synthetic preservatives and antioxidants. This study aimed to evaluate the preservative and antioxidant potential of Lippia origanoides Kunth essential oil, in pure and encapsulated in β-cyclodextrin form, for cosmetic applications. The EO exhibited strong antioxidant activity, with low IC₅₀ values in DPPH and ABTS assays, and demonstrated antimicrobial efficacy, particularly against Escherichia coli and Staphylococcus aureus. Six cosmetic cream formulations were developed and tested for physicochemical and microbiological stability. Formulations with pure EO maintained high antioxidant performance and remained free of bacterial and fungal contamination over time, outperforming the commercial preservatives. In contrast, formulations with encapsulated EO exhibited delayed antioxidant and antimicrobial activity, indicating gradual release. Overall, Lippia origanoides EO proved to be an effective natural alternative to synthetic preservatives and antioxidants. This approach aligns with the current trend of eco-friendly formulations, offering a sustainable solution by incorporating plant-derived bioactives into cosmetic products. Full article

Weeksella virosa (W. virosa) is a rare, non-saccharolytic Gram-negative bacterium initially described in the 1970s, later proposed as a distinct genus in 1986. The genus Weeksella currently contains two species, namely W. virosa and W. massiliensis. Although primarily considered non-pathogenic, recent evidence has linked W. virosa to a limited number of clinical infections, mostly in immunocompromised patients. This review aims to consolidate the current body of knowledge on W. virosa, encompassing its microbiological and biochemical characteristics, involvement in human and animal infections, antimicrobial susceptibility profiles, and a critical evaluation of existing diagnostic methodologies. This review includes 13 case reports detailing 16 human cases retrieved from multiple databases, highlighting diagnostic inconsistencies and a lack of standardized antimicrobial susceptibility testing. Although W. virosa is generally susceptible to most antibiotics with the exception of aminoglycosides, recent reports seem to suggest a possible emerging resistance trend. The presence of this organism in hospital environments raises concerns about its potential transmission within healthcare settings. While biochemical testing appears to offer reasonably accurate identification of W. virosa, molecular confirmation may be warranted in some cases mainly due to the organism’s rarity. The reliability of MALDI-TOF MS for the identification of W. virosa remains currently uncertain. Further studies, including electron microscopy and genome-wide analysis, are urgently needed to clarify the pathogenic potential of this bacterium and guide clinical management. This review underscores the necessity for awareness among clinicians and microbiologists regarding this underrecognized pathogen. Full article

Objective: To evaluate the effect of a probiotic combination on clinical and oral microbiological parameters in patients with head and neck cancer (HNC) undergoing radiotherapy. Materials and Methods: A randomised, double-blind, placebo-controlled clinical trial was conducted with 72 HNC patients who had received radiotherapy within the past year. Participants were randomly assigned to receive either daily probiotic sachets or placebo for 30 days. Salivary parameters—including unstimulated and stimulated flow rates and pH—were evaluated alongside oral microbiota profiles, including total bacterial load and selected periodontopathogens. Assessments were performed at baseline and post-intervention using sialometry, pH analysis, bacterial culture, and quantitative real-time PCR (qPCR). Results: Sixty-one patients completed the study (31 in the probiotic group, 30 in the placebo group). Stimulated salivary flow increased significantly in the probiotic group (p = 0.0016), while unstimulated flow improved in both groups (p < 0.05). Salivary pH decreased significantly in the probiotic group (p = 0.0209); however, no intergroup differences were observed at the end of the intervention (p = 0.9839). qPCR showed significant reductions in total bacterial load (p = 0.0209) and Fusobacterium nucleatum (p = 0.0080). Culture confirmed the reduction of F. nucleatum (p = 0.0026), with a trend towards significance for total cultivable bacterial count (p = 0.0502). Conclusions: Daily supplementation with a probiotic combination may serve as a practical and well-tolerated adjunctive measure in clinical settings to improve salivary function and reduce key oral pathogens, particularly Fusobacterium nucleatum, in patients undergoing or recovering from radiotherapy for head and neck cancer. These findings support its potential integration into routine supportive care protocols to mitigate xerostomia and oral dysbiosis in this population. Full article

Background/Objectives: As an essential polyunsaturated fatty acid, linoleic acid (LA) plays an important role in maintaining the integrity of cellular membranes, modulating inflammatory responses, and mediating intracellular signaling. This review explores the structure, properties, and nutritional significance of LA and its bioactive derivatives, with particular attention to sustainable production methods and their potential applications. Methods: A comprehensive review of the recent literature was conducted, emphasizing the use of green synthesis techniques, such as enzyme-catalyzed biocatalysis and microbiological transformations, in order to obtain LA-derived nutraceuticals. Analyses were conducted on the key aspects related to food industry applications, regulatory frameworks, and emerging market trends. Results: Through green synthesis strategies, LA derivatives with antioxidant, anti-inflammatory, and antimicrobial properties have been developed. There is potential for these compounds to be incorporated into health-oriented food products. In spite of this, challenges remain regarding their stability and bioavailability. Furthermore, there are inconsistencies in international regulatory standards which prevent these compounds from being widely adopted. Conclusions: The development of functional and sustainable food products based on linoleic acid derivatives obtained using ecological methods offers significant potential. Research is required to optimize production processes, enhance compound stability, and clinically validate health effects. The integration of the market and the safety of consumers will be supported by addressing regulatory harmonization. Full article

Periodontitis is a chronic, multifactorial inflammatory disease characterized by the progressive destruction of the periodontal supporting tissues, including alveolar bone, potentially resulting in tooth loss. Etiopathogenesis involves a dysbiotic shift in the subgingival microbiota where the presence of pathogenic species such as Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Treponema denticola has been documented. This disbalance is combined with an inadequate host immune response, often exacerbated by other systemic comorbidities including diabetes mellitus and cardiovascular diseases. Conventional therapy typically comprises mechanical debridement and adjunctive local or systemic antimicrobials, but emerging antibiotic resistance highlights a need for alternative adjuvant therapeutic strategies. The present descriptive analysis of microbiome and clinical trends study evaluated the adjuvant effects of a clinoptilolite-based zeolite material, namely PMA-zeolite, with professional prophylaxis on clinical and microbiological parameters in patients with chronic periodontitis over a 10-week period. Clinical assessment revealed significant reductions in bleeding on probing (BoP) and periodontal pocket depth (PD), indicating improved inflammatory status. Microbiome profiling demonstrated a marked decrease in key periodontal pathogens, suggesting that PMA-zeolite can help rebalance the oral microbiome. These findings suggest that the combined therapy exhibits promising anti-inflammatory and antimicrobial properties, indicating its role in promoting microbial homeostasis and reducing periodontal inflammation. However, further investigation through larger, controlled clinical trials is needed to validate the efficacy of the therapy. Full article

Introduction: Urinary tract infections (UTIs) remain a significant public health issue worldwide, particularly affecting the geriatric population with increased morbidity and mortality. Aging-related immune changes, comorbidities, and urogenital abnormalities contribute to the higher incidence and complexity of UTIs in elderly patients. Antimicrobial resistance, especially extended-spectrum beta-lactamase (ESBL) production and carbapenem resistance, poses a major challenge in managing UTIs in this group. Methods: This retrospective, multicenter study included 776 patients aged 65 and older, hospitalized with a diagnosis of urinary tract infection between January 2019 and August 2024. Clinical, laboratory, and microbiological data were collected and analyzed. Urine samples were obtained under sterile conditions and pathogens identified using conventional and automated systems. Antibiotic susceptibility testing was performed according to CLSI standards. Logistic regression analyses were conducted to identify factors associated with ESBL production, carbapenem resistance, and mortality. Results: Among the patients, the median age was 78.9 years, with 45.5% female. ESBL production was detected in 56.8% of E. coli isolates and carbapenem resistance in 1.2%. Klebsiella species exhibited higher carbapenem resistance (37.8%). Independent predictors of ESBL production included the presence of urogenital cancer and antibiotic use within the past three months. Carbapenem resistance was associated with recent hospitalization, absence of kidney stones, and infection with non-E. coli pathogens. Mortality was independently associated with intensive care admission at presentation, altered mental status, Gram-positive infections, and comorbidities such as chronic obstructive pulmonary disease and urinary incontinence. Discussion: Our findings suggest that urinary pathogens and resistance patterns in elderly patients are similar to those in younger adults reported in the literature, highlighting the need for age-specific awareness in empiric therapy. The identification of risk factors for multidrug-resistant organisms emphasizes the importance of targeted antibiotic stewardship, especially in high-risk geriatric populations. Multicenter data contribute to regional understanding of resistance trends, aiding clinicians in optimizing management strategies for elderly patients with UTIs. Conclusions: This study highlights that E. coli and Klebsiella species are the primary causes of UTIs in the elderly, with resistance patterns similar to those seen in younger adults. The findings also contribute important data on risk factors for ESBL production and carbapenem resistance, supported by a robust patient sample. Full article

Background/Objectives: Antimicrobial stewardship programs (ASPs) optimize antimicrobial use, improving outcomes and reducing resistance. This study assessed the impact of a ward-specific ASP. Methods: A pre/post quasi-experimental study was conducted in an internal medicine ward at a tertiary hospital in Padua, Italy. During the intervention year (September 2023–August 2024), a multidisciplinary team (infectious disease consultants, pharmacists, microbiologists, nurses, and hygienists) held bi-weekly ward-based audits, reviewing antimicrobial prescriptions and performing bedside assessments. Therapy adjustments followed guidelines and local epidemiology. Educational sessions and infection prevention and control (IPC) protocols were also reinforced. Outcomes were compared to the previous year, considering patient characteristics. The primary outcome was antimicrobial consumption (DDD/100 patient days, DDD/100PD); secondary outcomes included cost savings, length of stay (LOS), and mortality. Results: Fifty audits assessed 1074 patients and 1401 antimicrobial treatments. Patient characteristics were similar. Antibiotic suspension or de-escalation occurred in 37.9% and 22% of patients, respectively. AWARE ACCESS class use increased (+17.5%), while carbapenem (−54.4%) and fluoroquinolone (−42.0%) use significantly declined (p < 0.05). IPC and microbiological culture guidance were provided in 12.1% of cases. Antimicrobial consumption dropped from 107.7 to 84.4 DDD/100PD (p < 0.05). No significant changes in LOS or mortality were observed. Antimicrobial costs fell by 48.8% (with EUR 57,100 saved). Conclusions: ASP reduced antimicrobial consumption, improved prescription quality, and cut costs without compromising patient outcomes. Multidisciplinary collaboration, audits, and education proved essential. Future studies should assess long-term resistance trends and integrate rapid diagnostics for enhanced stewardship. Full article

To determine the incidence, causative organisms, and treatment effectiveness for microbial keratitis (MK) in the Southwest of England. Retrospective analysis of 872 corneal scrapes (January 2018–December 2022). Microbiology results were evaluated for organism growth and antimicrobial sensitivity. Data were divided into two groups for trend analysis (A: 2018–2020, B: 2021–2022). Of the 872 scrapes, 357 (39.6%) were culture positive. Bacteria accounted for 90.2% of cases, followed by viruses (2.8%), fungi (2.5%), mixed bacterial growth (2.5%), and Acanthamoeba (2.0%). The estimated incidence of MK was 9.69/100,000/year. Group B had a significantly higher overall MK incidence, with no change in pathogen distribution. Pseudomonas aeruginosa was the most frequent isolate (69 cases, 19.3%). In vitro sensitivity to fluoroquinolones was 94.4% for Gram-positive and 98.6% for Gram-negative bacteria. All fungal isolates were sensitive to at least one antifungal. Bacterial pathogens dominate MK in the Southwest of England, with over 90% sensitivity to chloramphenicol, fluoroquinolones, and aminoglycosides, indicating low antimicrobial resistance. Fluoroquinolones remain the recommended first-line therapy for MK. Fungal and protozoal keratitis are rare (<3% of cases), supporting bacteria-focused empirical treatment with close monitoring. Full article

Microbiological safety and quality consistency are critical challenges in the production of traditional Indian fried snacks, particularly in small-scale food enterprises. With growing export demand, maintaining strict quality control measures is essential. This study assessed the microbiological and physicochemical quality of five traditional Indian fried snacks—Kerala Murukku, Kerala Mixture, Banana Chips, Tapioca Chips, and Achappam—produced in a Food Safety Management System (FSMS)-certified facility over a four-year period (2020–2023). Products were evaluated for moisture, pH, salt content, acid value, and Total Plate Count (TPC). The number of ingredients for each product was recorded from standardized product formulation documents. TPC levels remained within acceptable limits (below 50,000 CFU/g) across all products. Among them, Kerala Mixture consistently showed the highest microbial counts (up to 4.61 log CFU/g) and Achappam the lowest, with no detectable variance (1.00 log CFU/g). Statistically significant year-wise differences (p < 0.05) were observed in all quality parameters. Kerala Mixture showed variation in salt and microbial load; Kerala Murukku varied in moisture, pH, and salt; while Tapioca Chips varied in moisture and salt. PCA identified that TPC, salt content, number of ingredients, and pH were key contributors to product variability. Cluster analysis confirmed Kerala Mixture as the most susceptible product to contamination risk. These findings provide valuable insights into the quality trends within an FSMS-certified environment and highlight the importance of strict post-processing controls. Full article

Due to the significant number of microbiologically negative periprosthetic joint infections (PJIs), understanding the trend in etiology and resistance patterns is essential for the correct management of these infections. Currently, few studies have been published in Spain. In this study, we analyzed the incidence, clinical characteristics, etiology, and antibiotic resistance in patients with PJIs over the last 5 years in Navarra. In this multicentric and retrospective study, all patients diagnosed with PJIs in Navarra from 2019 to 2023 were included. Of the total 156 PJIs, 23% had negative cultures and 56% of these patients had been treated with antibiotics prior to sampling. Staphylococcus epidermidis with methicillin resistance was the predominant etiological agent, followed by Staphylococcus aureus and Cutibacterium acnes. Forty percent of the Gram-positive cocci (GPC) and 35% of the Gram-negative bacilli (GNB) were multidrug-resistant organisms (MDROs). Quinolone resistance was 46% for staphylococci and 18% for Gram-negatives. In addition, 9% of staphylococci were resistant to rifampicin. Antibiotic therapy administration prior to sampling is one of the main problems for microbiological diagnosis and is present more frequently in culture-negative PJIs (56%). New sequencing techniques could improve this difficulty. The high percentage of resistance in the microorganisms causing PJI leads us to reconsider the empirical treatment for suspected PJI, with the use of different therapeutic approaches depending on the time of infection and the possible use of new non-antibiotic therapies. Full article

Steak tartare is a ready-to-eat (RTE) meat product, prepared with finely chopped or ground raw beef, with a rich culinary history and increasing consumption trend in the last years. Yet, its microbiological safety and technological challenges remain largely under-investigated. This review analyses the regulations, the safety, and technological advances in steak tartare manufacturing, focusing on microbiological risks due to potential contamination by pathogens like Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7. From this perspective, the outbreaks associated with the consumption of raw meat products have confirmed the importance of good hygiene practice and process control, currently based on the presence of nitrite in the formulation and accurate cold chain management. Recently, the EU regulations have set stricter limits for the use of nitrites and nitrates in meat products, and this evolution has increased the interest in natural alternatives. The scientific literature indicates that plant-based antimicrobials, high-pressure processing (HPP), and novel starter cultures can be promising tools to improve raw meat safety and shelf life. This review analyses the possible options for nitrite replacement, which might involve combined interventions with natural antimicrobials, starter cultures, and packaging solutions. Future studies need to address the microbial behaviour and dynamics in nitrite-free formulations, including safety validation by challenge testing with foodborne pathogens. In this respect, steak tartare could be a model for innovation in the meat industry. However, considering the challenges that must be faced, collaboration across disciplines will be essential to meet regulatory constraints and consumer expectations while ensuring product quality and safety. Full article

The growing demand for more sustainable food systems has driven the development of solutions based on food microbiology, capable of integrating safety, functionality, and environmental responsibility. This paper presents a critical and up-to-date review of the most relevant advances at the interface between microbiology, sustainability, and food innovation. The analysis is structured around three main axes: (i) microbial fermentation, with a focus on traditional practices and precision technologies aimed at valorizing agro-industrial waste and producing functional foods; (ii) microbial biocontrol, including the use of bacteriocins, protective cultures, bacteriophages, and CRISPR-Cas (Clustered Regularly Interspaced Short Palindromic Repeats–CRISPR-associated)-based tools as alternatives to synthetic preservatives; and (iii) the development of functional foods containing probiotics, prebiotics, synbiotics, and postbiotics, with the potential to modulate the gut microbiota and promote metabolic, immune, and cognitive health. In addition to reviewing the microbiological and technological mechanisms involved, the paper discusses international regulatory milestones, scalability challenges, and market trends related to consumer acceptance and clean labeling. Finally, emerging trends and research gaps are addressed, including the use of omics technologies, artificial intelligence, and unexplored microbial resources. Food microbiology, by incorporating sustainable practices and advanced technologies, is positioned as a strategic pillar for building a healthy, circular, science-based food model. Full article

Periprosthetic joint infection (PJI) is a complex complication of total joint arthroplasty, with microbiological profiles varying across centers worldwide. However, most studies are limited to single-center or intra-country multicenter analyses, often including mixed cohorts of primary and revision PJI cases, with limited data regarding global antibiotic resistance patterns. This study compared the microbiological characteristics, polymicrobial culture rates, prevalence of culture-negative infections, and antibiotic resistance patterns in PJI cases across five referral centers from five continents. A total of 717 patients with primary hip and knee PJI were included from centers in Argentina, Canada, Turkey, England, and New Zealand. Staphylococcus aureus and Staphylococcus epidermidis were the most common pathogens (48.5%, p < 0.01). Culture-negative infection rates varied significantly, ranging from 4.2% (England) to 24.6% (Turkey) (p < 0.01). Polymicrobial infections were the most frequent in Canada (8.9%) and the least frequent in England (1.1%) (p < 0.01). Gram-negative bacteria comprised 13.1% of culture-positive cases, with no significant intercountry difference. Multidrug resistance was observed in all centers, ranging from 23.7% (Argentina) to 43.1% (Turkey), with no statistical significance. Vancomycin resistance was detected in England (2.3%) and Canada (1.2%) but absent in Turkey, New Zealand, and Argentina. These findings underscore significant intercontinental variability, emphasizing the need for regional considerations in regards to empiric antibiotic selection and PJI management. Full article

Bovine mastitis is a significant disease affecting dairy cattle worldwide, impacting milk quality and farm profitability. Understanding pathogen distribution is crucial for effective disease management. This study analyzed 319,634 individual cow milk samples submitted to the UC Davis Milk Quality Laboratory between 2009 and 2023 to assess pathogen prevalence, seasonal variations, and long-term trends. Routine microbiological cultures identified major and minor mastitis pathogens, with additional testing for Mycoplasma spp. Statistical analyses evaluated annual and seasonal trends in bacterial isolation rates. Results indicated that environmental pathogens, particularly non-aureus staphylococci and coliforms, were most frequently isolated, while contagious pathogens (Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp.) were less prevalent. Seasonal trends revealed higher contamination rates in Winter and increased no-growth samples in Summer. The study also observed a decline in sample submissions in recent years, possibly reflecting evolving dairy management practices. These findings provide a comprehensive perspective on mastitis pathogen dynamics in California’s Central Valley, supporting improved milk quality control measures and tailored mastitis prevention strategies. Full article