Search Results (522)

Polymicrobial biofilms involving fungal and bacterial species are increasingly recognized as contributors to persistent infections, particularly in the oral cavity. Candida albicans and Aggregatibacter actinomycetemcomitans are two commensals that can turn into opportunistic pathogens and are able to form robust biofilms. Objectives: This study aimed to assess the interaction dynamics between these two microorganisms and to evaluate their susceptibility to fluconazole and azithromycin in single- and mixed-species forms. Methods: Biofilm biomass was quantified using crystal violet assays, while biofilm cell viability was assessed through CFU enumeration (biofilm viability assay). To assess the resistance properties of single versus mixed-species coincubations, we applied the antimicrobial susceptibility test (AST) to each drug, and analysed spatial organization with confocal laser scanning microscopy, using PNA-FISH. Results: The results indicated that both species can coexist without significant mutual inhibition. However, a non-reciprocal synergism was also observed, whereby mixed-species biofilm conditions promoted the growth of A. actinomycetemcomitans, while C. albicans growth remained stable. As expected, antimicrobial tolerance was elevated in mixed cultures, likely due to enhanced extracellular matrix production and potential quorum-sensing interactions, contributing to increased resistance against azithromycin and fluconazole. Conclusions: This study provides novel insights into previously rarely explored interactions between C. albicans and A. actinomycetemcomitans. These findings underscore the importance of investigating interspecies interactions within polymicrobial biofilms, as understanding their mechanisms, such as quorum-sensing molecules and metabolic cooperation, can contribute to improved diagnostics and more effective targeted therapeutic strategies against polymicrobial infections. Full article

Background/Objectives: Limited robust data support the use of antibiotic combinations in the treatment of orthopedic infections. However, in certain situations, the combination of antibiotics seems to be beneficial. This review aims to outline the circumstances under which a combination of antibiotics may be utilized in the treatment of orthopedic infections. Methods: We reviewed the existing guidelines on orthopedic infections and focused on situations where antibiotic combinations are recommended or proposed optionally. We chose vitro and animal studies that provide evidence for the effectiveness of several widely recommended combinations. Results: The combinations serve multiple purposes: they provide empirical coverage while awaiting microbiological results, offer targeted treatment for difficult-to-treat infections, and facilitate oral treatment primarily for staphylococcal infections. The objectives include enhancing bacterial coverage against Gram-positive and Gram-negative bacteria, achieving synergistic effects with bactericidal agents, and reducing the risk of antibiotic resistance. The review outlines specific combinations for fracture-related infections, periprosthetic joint infections, spinal infections, and anterior cruciate ligament reconstruction infections, emphasizing the importance of tailoring antibiotic choices based on local epidemiology and patient history. The review also addresses potential drawbacks of combination therapy, such as toxicity, higher costs, and drug interactions, underscoring the complexity of managing orthopedic infections effectively. Conclusions: According to the guidelines, several different proposals are made, depending in part on the countries’ epidemiology. In a well-defined situation, various authors propose either monotherapy or a combination of antibiotics. When a combination is suggested, the choice of antibiotics is based on the expected effect: broadening the spectrum, enhancing bactericidal activity, achieving a synergistic effect, or reinforcing biofilm activity to optimize the treatment. Full article

Background: Fowl typhoid (FT), a septicemic infection caused by Salmonella Gallinarum (SG), and H9N2 avian influenza are two economically important diseases that significantly affect the global poultry industry. Methods: We exploited the live attenuated Salmonella Gallinarum (SG) mutant JOL3062 (SG: ∆lon ∆pagL ∆asd) as a delivery system for H9N2 antigens to induce an immunoprotective response against both H9N2 and FT. To enhance immune protection against H9N2, a prokaryotic and eukaryotic dual expression plasmid, pJHL270, was employed. The hemagglutinin (HA) consensus sequence from South Korean avian influenza A virus (AIV) was cloned under the Ptrc promoter for prokaryotic expression, and the B cell epitope of neuraminidase (NA) linked with matrix protein 2 (M2e) was placed for eukaryotic expression. In vitro and in vivo expressions of the H9N2 antigens were validated by qRT-PCR and Western blot, respectively. Results: Oral immunization with JOL3121 induced a significant increase in SG and H9N2-specific serum IgY and cloacal swab IgA antibodies, confirming humoral and mucosal immune responses. Furthermore, FACS analysis showed increased CD4+ and CD8+ T cell populations. On day 28 post-immunization, there was a substantial rise in the hemagglutination inhibition titer in the immunized birds, demonstrating neutralization capabilities of immunization. Both IFN-γ and IL-4 demonstrated a significant increase, indicating a balance of Th1 and Th2 responses. Intranasal challenge with the H9N2 Y280 strain resulted in minimal to no clinical signs with significantly lower lung viral titer in the JOL3121 group. Upon SG wildtype challenge, the immunized birds in the JOL3121 group yielded 20% mortality, while 80% mortality was recorded in the PBS control group. Additionally, bacterial load in the spleen and liver was significantly lower in the immunized birds. Conclusions: The current vaccine model, designed with a host-specific pathogen, SG, delivers a robust immune boost that could enhance dual protection against FT and H9N2 infection, both being significant diseases in poultry, as well as ensure public health. Full article

Mycoplasmas are known respiratory pathogens in tortoises, but few studies exist in snakes. To better understand the correlation with clinical signs and co-infections, samples from mycoplasma-positive snakes with and without clinical respiratory disease were analyzed. Oral swabs from 15 snakes (pythons n = 12, boas n = 3) were examined using polymerase chain reaction (PCR) and third-generation sequencing (TGS). Additionally, mycoplasma isolation assays were performed. Pathogens detected by PCR included Mycoplasmas (15/15, 100%), serpentoviruses (9/15, 60%), and Chlamydia sp. (2/15, 13%); those detected by TGS included Mycoplasmas (14/15, 93%), serpentoviruses (10/15, 67%), Chlamydia sp. (1/15, 7%), and 15 different bacterial species. Sequencing of the mycoplasma PCR products revealed a close genetic relationship to Mycoplasmopsis agassizii. TGS identified genetically distinct mycoplasmas and three different serpentoviruses. While mycoplasmas could not be successfully propagated, Brucella intermedia comb. nov. was identified in eight cultures. Respiratory disease in snakes is often multifactorial, involving various pathogens and environmental influences. This study demonstrates that comprehensive diagnostics are essential for understanding disease processes in snakes and improving the detection of diverse pathogens. Further research is needed to improve laboratory diagnostics for infectious diseases in reptiles and to better understand the roles of various pathogens in respiratory diseases in snakes. Full article

Subclinical mastitis causes economic losses due to reduced milk yield and elevated somatic cell counts (SCCs), despite no visible clinical signs. A higher incidence of subclinical mastitis has been reported in cattle infected with bovine leukemia virus (BLV). Levamisole (LMS), known for its immunomodulatory properties, has been suggested as a potential alternative to antibiotics for mastitis treatment; however, its efficacy in BLV-infected cows, particularly in relation to proviral load (PVL), remains unclear. This study aimed to evaluate the therapeutic effect of LMS on subclinical mastitis and its impact on milk immune responses by classifying BLV-infected cows based on PVL. A total of 42 dairy cows with subclinical mastitis (48 quarters) were grouped as BLV-negative, low-PVL, or high-PVL using a PVL cut-off value of 17.8 copies/10 ng DNA, and were administered LMS orally. Changes in viable bacterial counts, SCCs, and milk leukocyte populations were compared. LMS administration significantly reduced the SCC and milk macrophage numbers, especially in BLV-negative and low-PVL cows. These results suggest that LMS may improve subclinical mastitis in certain BLV-infected cows and that PVL may serve as a useful indicator for treatment responsiveness. However, the limited effect in high-PVL cows and the small sample size have limitations, warranting further investigation. Full article

Feline superficial non-healing corneal ulcers are persistent lesions requiring individualized treatment to reduce recurrence. This retrospective study evaluated 136 affected eyes (113 nonrecurrent; 23 recurrent) to identify clinical and treatment-related factors associated with recurrence. Recurrent ulcers were more common in older cats (7.2 ± 4.3 vs. 5.1 ± 4.6 years; p = 0.026). Domestic Shorthairs were the most frequently affected breed (50%), and central ulcer location predominated in both groups. Recurrent cases required more intensive management, with 16.9% needing ≥ 2 treatment courses, compared to 83% of nonrecurrent cases resolving after a single course. Healing time following corneal debridement was longer in recurrent cases (32.3 ± 34.4 vs. 25.5 ± 23.1 days; p = 0.272), and corneal sequestrum occurred more frequently (13.0% vs. 10.6%; p = 0.735). Corneal debridement was the primary treatment modality. Systemic medications were more often used in recurrent cases, notably oral lysine (47.8% vs. 26.5%; p = 0.049) and famciclovir (17.4% vs. 2.6%; p = 0.016). Recurrent cases also showed significantly higher rates of concurrent viral (p < 0.001) and bacterial/fungal infections (p = 0.027). In conclusion, recurrent superficial non-healing corneal ulcers were associated with age and systemic illness, emphasizing the need for early diagnosis and management of underlying conditions. Full article

Background/Objectives: The formation of oral biofilms in periodontal pockets and around dental implants with induction of periodontitis or peri-implantitis is an increasing problem in dental health. The intelligent design of a biofilm makes the bacteria embedded in the biofilm matrix highly tolerant to antiseptic therapy, often resulting in tooth or implant loss. The question therefore arises as to which mouthwashes have eradication potential against oral biofilm. Methods: A human oral biofilm model was developed based on donated blood plasma combined with buffy coats, inoculated with oral pathogenic bacterial species found in periodontal disease (Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus mitis, and Porphyromonas gingivalis). Over a span of 7 days, we tested different mouth rinsing and antiseptic solutions (Chlorhexidine, Listerine^®, NaOCl, Octenisept^®, and Octenident^®) covering the matured biofilm with 24 h renewal. Phosphate-buffered saline (PBS) was used as a control. Bacterial growth patterns were detected via quantitative polymerase chain reaction (qPCR) after 2, 4, and 7 days of treatment. Results: While all groups showed initial bacterial reduction, the control group demonstrated strong regrowth from day 2 to 4. Listerine showed a near-significant trend toward bacterial suppression. Additionally, strain-specific efficacy was observed, with Octenisept^® being most effective against Streptococcus mitis, Octenident^® and NaOCl showing superior suppression of Actinomyces naeslundii, and Listerine^® outperforming other solutions in reducing Fusobacterium nucleatum. Donor-specific, individual variability further influenced treatment outcomes, with distinct trends in bacterial suppression and regrowth observed across donors. Conclusions: These findings underscore the complexity of biofilm-associated infections and highlight the importance of targeted therapeutic approaches for managing bacterial biofilms. In this experiment, the donor-specific outcomes of the antimicrobial effects of the solutions may indicate that genetic predisposition/tolerance to oral infections appears to play a critical role in the control of oral biofilms. Full article

Background: Canine pyoderma and otitis externa are prevalent bacterial skin infections in veterinary practice, frequently complicated by the emergence of multidrug-resistant (MDR) pathogens. Objectives: To investigate the frequency, antimicrobial resistance (AMR) profiles, and frequency of MDR bacterial isolates from dogs with pyoderma or otitis externa in Hong Kong. Methods: A retrospective study of bacterial isolates from 215 clinical samples collected from dogs presenting with pyoderma (n = 63) or otitis externa (n = 152) at veterinary clinics across Hong Kong between 2018 and 2022. Bacterial isolates were identified and subjected to antimicrobial susceptibility testing against 13 antimicrobial classes. Results: Staphylococcus spp., particularly S. pseudintermedius, were the most commonly isolated species, followed by Pseudomonas spp. and Proteus spp. High resistance rates were observed for orbifloxacin (61.3% in pyoderma; 76.7% in otitis externa), doxycycline (59.3%; 69.2%), clindamycin (62%; 68.9%), and enrofloxacin (50%; 55.5%). Most isolates were sensitive to ofloxacin, ticarcillin–clavulanate, tobramycin, ciprofloxacin, cefpodoxime, cefuroxime, and cefixime. MDR was detected in 67.5% of pyoderma and 66.8% of otitis externa isolates. Gram-negative bacteria exhibited significantly higher MDR rates than Gram-positive isolates. The multiple antibiotic resistance (MAR) index averaged 0.41 for pyoderma and 0.52 for otitis externa isolates. We found no significant associations between MDR and non-modifiable risk factors (i.e., age, sex, breed, and reproductive status). Conclusions: These findings highlight the critical need for prudent antimicrobial use and continuous surveillance of AMR trends in companion animals. A higher focus should be placed on topical antiseptic therapy, with oral antibiotics used only in exceptional cases and after susceptibility testing. From a One Health perspective, the potential transmission of MDR bacteria between companion animals and humans underscores the importance of a coordinated approach to antimicrobial stewardship across both veterinary and human medicine. Full article

Background/Objectives: Optimal management of acute bacterial prostatitis (ABP) remains uncertain, but the use of antibiotics with good prostatic tissue penetration is critical to prevent recurrence and chronic progression. This study aimed to describe clinical characteristics and outcomes of ABP due to Escherichia coli (ABP-E.coli), compare effectiveness of sequential high-dose cefuroxime (ABP-CXM) versus ciprofloxacin (ABP-CIP), and identify risk factors for clinical failure. Methods: We conducted a retrospective study including men >18 years diagnosed with ABP-E. coli between January 2010 and November 2023 at a 400-bed hospital. Patients received oral cefuroxime (500 mg/8 h) or oral ciprofloxacin (500 mg/12 h). Outcomes over 90 days included clinical cure, recurrence and reinfection. Definitions: Clinical cure—resolution of symptoms without recurrences; recurrence—new ABP episode with the same E. coli strain; reinfection—ABP involving different microorganism or E. coli strain; clinical failure—lack of cure, recurrence, or reinfection. Results: Among 326 episodes (158 ABP-CXM, 168 ABP-CIP), ABP-CXM patients were younger (median 63.5 vs. 67.5 years, p = 0.005) and had fewer comorbidities. Clinical cure was higher in ABP-CIP (96.9% vs. 85.7%, p < 0.001). Recurrence occurred only in ABP-CXM (6.96% vs. 0%, p < 0.001), while reinfection and mortality were similar. Multivariable analysis showed ciprofloxacin was protective against clinical failure (OR: 0.16, 95% CI: 0.06–0.42, p < 0.001), while prior urinary tract infection (UTI) increased failure risk (OR: 2.87, 95% CI: 1.3–6.3). Conclusions: Ciprofloxacin was more effective than cefuroxime in treating ABP-E. coli. Patients with recent UTIs may need closer monitoring or alternative therapies. Full article

This study develops a dual-mode antibacterial orthodontic adhesive by integrating quaternary ammonium salt-modified large-pore mesoporous silica nanoparticles (QLMSN@CHX). The material integrates two antibacterial mechanisms: (1) contact killing via covalently anchored quaternary ammonium salts (QACs) and (2) sustained release of chlorhexidine (CHX) from radially aligned macropores. The experimental results demonstrated that QLMSN@CHX (5 wt%) achieved rapid biofilm eradication (near-complete biofilm eradication at 24 h) and prolonged antibacterial activity, while maintaining shear bond strength comparable to commercial adhesives (6.62 ± 0.09 MPa after 30-day aging). The large-pore structure enabled controlled CHX release without burst effects, and covalent grafting ensured negligible QAC leaching over 30 days. The composite demonstrated good biocompatibility with human dental pulp mesenchymal stem cells at clinically relevant concentrations. This dual-mode design provides a clinically viable strategy to combat bacterial contamination in orthodontic treatments, with potential applications in other oral infections. Future studies will focus on validating efficacy in complex in vivo biofilm models. Full article

Background and Objectives: Infant feeding practices play a crucial role in shaping the oral microbiome, modulating inflammatory responses, and maintaining epithelial health during the first year of life. Breastfeeding promotes the growth of beneficial bacteria and supports a diverse, stable microbial community. In contrast, formula feeding is associated with increased colonization by potentially pathogenic bacteria, such as Staphylococcus and Escherichia coli, which may elevate the risk of infections, oral diseases, and inflammation. This study investigates the effects of breastfeeding versus formula feeding on oral bacterial growth, epithelial cell integrity, and interleukin-17 (IL-17) expression in infants aged 1–12 months. Materials and Methods: A total of 60 infants (30 breastfed and 30 formula-fed) were recruited from pediatric clinics in the Qassim region. Microbial cultures quantified bacterial colony-forming units (CFUs), and epithelial cell morphology was assessed through the microscopic analysis of mucosal scrapings. IL-17 concentrations were quantified from the oral mucosa through enzyme-linked immunosorbent assay. Statistical analyses, including t-tests and chi-square tests, compared bacterial loads, IL-17 levels, and indicators of epithelial health between groups. Adjustment for potential confounders was achieved through multivariate statistical analysis. Results: Formula-fed infants showed significantly higher IL-17 levels than breastfed infants (p < 0.001), indicating a stronger pro-inflammatory profile. Breastfed infants exhibited lower inflammation, improved epithelial health, and reduced cellular debris compared to formula-fed infants, who had higher bacterial loads. A significant correlation was found between epithelial health and bacterial clustering, with clearer epithelial cells associated with lower bacterial colonization. Conclusions: Formula feeding was associated with increased salivary IL-17 levels, greater bacterial colonization, and compromised epithelial integrity, indicating a heightened pro-inflammatory state and potential vulnerability to mucosal irritation or infection. Breastfeeding appeared to confer protective effects by promoting healthier microbial balance, epithelial integrity, and reducing inflammatory responses. These findings underscore the immunological and microbial benefits of breastfeeding in supporting oral health during infancy. Full article

OPN is a phosphorylated glycoprotein found in all vertebrate organisms and expressed in many tissues and secretions. It is a pleiotropic protein that plays diverse roles in various pathological and physiological processes. OPN is involved in many tissue transformation events such as intestinal and brain development, the regulation of immune system activity, immune cell activation, and inflammatory responses. This protein increases the functionality of the digestive system by regulating the intestinal microbiome and may help strengthen the intestinal barrier. OPN can also influence cognitive development and behavior. In addition, its recent association with cancer has gained critical importance. The increased expression of OPN has been observed in many cancer types, which may promote tumor cell metastasis. OPN is also effective in bacterial interaction and infections; it can prevent bacterial adhesion, supporting the development of new therapeutic approaches for oral care. Furthermore, the supplementation of OPN in infant formula has positively influenced the immune and intestinal health of infants. Many recent studies have focused on these aspects. This article provides a review and comparison of the existing knowledge on the structure and functions of OPN. It emphasizes how milk-derived OPN impacts human and infant health and disease. Full article

Dental implant papilla (DIP) is susceptible to bacterial adhesion and biofilm formation, and oral pathogenic biofilms can cause persistent oral infections. Enrichment of bacterial biofilms on implants can lead to soft tissue irritation and adjacent bone resorption, severely compromising dental health and potentially leading to periodontitis, implant loss and costly follow-up care. Nanozymes (NZs) are recently used in biofilm removal as they can induce the production of reactive oxygen species (ROS), which can kill bacteria. However, the short lifespan of ROS limits their diffusion distance, and affects their therapeutic efficacy. In this study, we prepared Fe₃O₄ nanoparticles (NZs) with different morphologies: flower-like (F-Fe₃O₄), hollow spherical (M-Fe₃O₄), octahedral (O-Fe₃O₄), and conventional nanoparticles (N-Fe₃O₄). The ferromagnetic properties of Fe₃O₄ NZs allow them to move and penetrate the biofilm under the action of a magnetic field. The saturation magnetic intensities of the four samples were as follows: F-Fe₃O₄ (23.1 emu g⁻¹), M-Fe₃O₄ (73.34 emu g⁻¹), O-Fe₃O₄ (96.06 emu g⁻¹), and N-Fe₃O₄ (52.15 emu g⁻¹). The synergistic combination of photothermal action and catalytic sterilization can effectively remove the biofilm. In addition, the prepared Fe₃O₄ nanozymes were able to maintain high biological activity on the implant surface with some osteogenic effect. Full article

Background: The use of in-feed antibiotics was banned in numerous countries within the animal production industry as a result of the emergence of antibiotic-resistant bacteria and the presence of residual antibiotics. Bacteriophages, which are viruses that infect host bacterial cells, are considered the natural predators of bacteria. Over the past two decades, bacteriophages have garnered increasing attention for their potential in controlling pathogenic bacteria in weaned piglets. Aims: The aim of this overview was to update the progress of bacteriophage application in weaned piglets. Methods: For the section on bacteriophage application in weaned piglets, a systematic search was performed to identify relevant articles published before June 2025 in databases such as Web of Science. Results: In this review, we provide a brief overview of bacteriophages, followed by a summary of the isolation of specific bacteriophages in weaned piglets. In addition, we have summarized the application progress of bacteriophages in weaned piglets, including the effects of oral administration or dietary supplementation with bacteriophages on growth performance, diarrhea characteristics, intestinal morphology, intestinal pH, nutrient digestibility, inflammatory response, intestinal barrier function, and intestinal microecology. Conclusions: This updated overview novelly highlights the potential of bacteriophages as anti-pathogenic agents in mitigating infections caused by pathogenic bacteria in weaned piglets. This review could provide a scientific basis for controlling pathogenic bacteria infections in weaned piglets in the post-antibiotic era. Full article

Viral infections have been associated with multiple sclerosis (MS), an immune-mediated disease in the central nervous system (CNS). Since Theiler’s murine encephalomyelitis virus (TMEV) can induce MS-like demyelination, TMEV infection is the most widely used viral model for MS. Although the precise pathophysiology is unknown, altered fecal bacterial populations were associated with distinct immune gene expressions in the CNS. We aimed to determine the role of gut microbiota in TMEV infection by administering an antibiotic cocktail in drinking water before (prophylactic administration) or after (therapeutic administration) TMEV infection. The antibiotic administration reduced total eubacteria, including the phyla Bacillota and Bacteroidota, but increased the phylum Pseudomonadata in feces. Prophylactic administration did not alter TMEV-induced inflammatory demyelination clinically or histologically, without changes in anti-viral IgG1/IgG2c levels or lymphoproliferative responses; therapeutic administration temporarily suppressed the neurological signs. Although antibiotic treatment had minimal effects on TMEV infection, adding metronidazole and ampicillin in drinking water substantially reduced water intake in the antibiotic group of mice, resulting in significant body weight loss. Since dehydration and stress could affect immune responses and gut microbiota, caution should be exercised when planning or evaluating the oral antibiotic cocktail treatment in experimental animals. Full article