Search Results (574)

Pneumococcal meningoencephalitis is a severe infection associated with high morbidity and mortality. Although typically community-acquired, postoperative cases following elective ENT surgery are exceedingly rare. Antimicrobial resistance (AMR) among Streptococcus pneumoniae further complicates management, and missed opportunities for vaccination represent preventable risks. We report a case of a 41-year-old man with multiple comorbidities who developed fulminant S. pneumoniae meningitis 48 h after septoturbinoplasty. The clinical course was atypical, with altered consciousness but no classical meningeal signs, necessitating urgent intubation and intensive care admission. Cerebrospinal fluid cultures identified an MDR pneumococcal strain resistant to penicillin and macrolides but susceptible to vancomycin and meropenem. Empirical therapy with vancomycin and meropenem, combined with adjunctive corticosteroids and multidisciplinary ICU care, led to complete neurological recovery. This case highlights a rare but life-threatening postoperative complication and underscores two critical lessons. First, the growing challenge of multidrug-resistant pneumococcus requires timely recognition, aggressive empiric therapy, and access to effective agents. Second, the absence of pneumococcal vaccination in this high-risk surgical patient illustrates a preventable gap in care. Integrating vaccination screening into preoperative evaluations may reduce the risk of catastrophic postoperative CNS infections. Full article

Background/Objectives: Antibiotic resistance is a major public health concern, with considerable socio-economic consequences. Researchers are exploring alternative strategies, including nanotechnology, which has shown significance in targeted drug delivery. This study evaluates the synergistic antibacterial activity of azithromycin-loaded chitosan nanoparticles (AZM-CSNPs) against azithromycin-resistant clinical respiratory isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella pneumoniae (K. pneumoniae). Methods: A total of 87 sputum samples (n = 87) were collected and analyzed. The ermB gene for K. pneumoniae and the ermA gene for MRSA were used to confirm resistant isolates. Among 87 samples, 29 manifested K. pneumoniae, and 32 exhibited MRSA-positive cultures, confirmed through phenotypic and genotypic methods. The RT-PCR is performed by using a cDNA Kit to determine the gene expression. Results: The results elucidate resistance of K. pneumoniae against several antibiotics, including azithromycin (15 µg), chloramphenicol (30 µg), and amoxicillin (30 µg), while MRSA also showed resistance to cefoxitin (30 µg), azithromycin (15 µg), and gentamycin (10 µg). Reduction in the MIC value of the nanoparticle formulation showed their effectiveness. The AZM-CSNPs combined with cetirizine dihydrochloride helped to down-regulate the resistant genes. Conclusions: Notably, a strong synergistic effect was observed with AZM-CSNPs in combination with cetirizine, significantly enhancing antibacterial efficacy against resistant isolates. Full article

Background/Objectives: Antibiotic detection in honey is challenging due to the complexity of this product, the typically low levels of residues, and the absence of Maximum Residue Levels (MRLs) for beehive products. The use of antibiotics in apiculture poses potential risks to human health, including antimicrobial resistance and toxic effects. Reliable, sensitive, and selective analytical methods are essential to ensure food safety and enable accurate monitoring of antibiotic contamination in honey. This study aimed to validate a multi-analyte procedure in accordance with the parameters established in Commission Implementing Regulation (EU) 2021/808 for the identification and quantification of antibiotics, including tetracyclines, lincosamides, quinolones, macrolides, β-lactams, sulfonamides, and diaminopyrimidines. Methods: An extraction protocol was developed using 0.1% formic acid in ACN:H₂O (80:20, v/v), followed by a modified QuEChERS with the addition of 1 g NaCl and 2 g MgSO₄. The extracts were analyzed by UHPLC-TOF-MS. Results: The method, validated under CIR (EU) 2021/808, demonstrated robust performance, with recoveries ranging from 80.1% to 117.6%, repeatability between 0.5% and 32.2%, reproducibility between 2.3% and 31.6%, and determination coefficients (R²) ranging from 0.9429 to 0.9982. Validation was achieved for 15 antibiotic residues, with CCβ from 3 to 15 μg·kg⁻¹, LODs between 0.09 and 6.19 μg·kg⁻¹, and LOQs between 0.29 and 18.77 μg·kg⁻¹. Application to 10 commercial Portuguese honey revealed no detectable levels of the target antibiotics. Conclusions: The combination of a simplified extraction with UHPLC-TOF-MS provides a reliable approach for the determination of antibiotics in honey. This validated method represents a valuable tool for food safety monitoring and risk assessment of apiculture practices. Full article

Pertussis is an infectious disease that contributes to hundreds of thousands of deaths worldwide each year. Despite the prevalence of preventive vaccination programs, there has been an increasing number of new cases of the disease over the past few decades. This poses a particular problem for the pediatric population among whom the highest mortality from the disease is recorded. Several reasons for this phenomenon can be mentioned, but what is particularly important from the microbiological point of view is the correlation of the increased number of pertussis cases with the introduction of a new form of vaccine—the acellular vaccine in place of the whole-cell vaccine. In this review, we summarized the current state of knowledge on potential factors that may contribute to the decline in immunization efficacy against the pathogen. The post-vaccination response profile, symptomatic of vaccination with vaccination-acellular, is characterized by recruitment of Th₂ and Th₁₇ lymphocytes; it has been reported that in the long term, this results in insufficient activation of B cells and low titers of antibodies to key bacterial antigens (hemagglutinin, pertactin). Moreover, the immune response proceeds by bypassing the recruitment of tissue-resident memory T cells, resulting in a lack of protection against colonization of the nasal cavity by the bacterium despite vaccination. The decline in vaccination efficacy should also be attributed to the phenotypic variability of Bordetella. The popularization of the PtxP3 strain, characterized by its ability to incompletely activate immune mechanisms, poses a real threat to public health. The growing resistance of B. pertussis to standardly used antibiotics including macrolides also remains a problem. This makes it difficult to eradicate pathogens from the nasal cavity area and increases the pool of bacterial carriers in the population area. The increasing prevalence of the disease prompts reflection on more effective methods of prevention. Particularly promising in this field seem to be new vaccines, especially mucosally implemented, e.g., intranasal, or developed on the basis of B. pertussis antigens other than those used so far. Full article

Agricultural pesticides are significant drivers of antibiotic resistance in soil. However, the differential impacts of antibiotic versus non-antibiotic pesticides on the soil resistome are poorly characterized. Here, we analyzed sequencing data from soils exposed to either antibiotic or non-antibiotic pesticides to compare differences in antibiotic resistance gene (ARG) burden, diversity, assembly processes, network topology, and host taxonomy. Soils exposed to antibiotic pesticides exhibited a significantly higher ARG burden (0.52% vs. 0.27% of total genes), whereas soils exposed to non-antibiotic pesticides showed significantly higher alpha diversity (p < 0.05). ARG community compositions also differed significantly between antibiotic and non-antibiotic exposures (PERMANOVA, R² = 0.215, p < 0.001). Assembly analysis using the modified stochasticity ratio indicated that deterministic processes governed ARG community assembly in both groups, with stronger influence observed in non-antibiotic soils. Co-occurrence network analysis revealed contrasting patterns. A compact, highly centralized network emerged in antibiotic-exposed soils, while a larger, more dispersed network characterized non-antibiotic soils. In both networks, aminoglycoside ARGs served as keystone nodes, accompanied by the β-lactam ARG in antibiotic soils and the macrolide ARG in non-antibiotic soils. Pseudomonadota was the predominant ARG host (>60% contribution) across both exposures, though many other phyla exhibited significance (p < 0.05) between group differences in their ARG contributions. Non-pathogenic bacteria comprised the majority of ARG hosts in all samples. When examining ARG contributions from pathogenic hosts, zoonotic and animal-associated pathogens contributed significantly (p < 0.01) more in non-antibiotic soils than in antibiotic soils, whereas the ARG contribution from plant pathogens was comparable between the two pesticide groups. Overall, our study suggests that antibiotic and non-antibiotic pesticides shape distinct ARG network patterns and host–pathogen profiles, posing distinct risks to public health and agricultural ecosystems. Full article

Mycoplasma pneumoniae (MP), an important pathogen that causes pneumonia among children and young adults, caused an epidemic every four years in Japan until 2016, with the next epidemic occurring eight years later in 2024. This study compared the prevalence of MP infections among Japanese children in 2024 to previous years using real-time polymerase chain reaction (PCR) and the p1 genotype determined using the PCR restriction fragment length polymorphism typing method from nasopharyngeal swab specimens. Of the 133 total isolates collected in 2024, 54.1% were macrolide-resistant MP (MRMP), with 98.0% of those containing an A2063G mutation in the 23S rRNA gene associated with macrolide resistance. This annual rate of MRMP and incidence of the A2063G mutation was similar to those in 2016. However, the dominant p1 genotype among isolates in 2024 was type 1 (93.4%), whereas type 2 was dominant in the previous epidemic. Thus, although the rate of MRMP in 2024 was similar to that in the previous epidemic year, the distribution of p1 genotypes was different. Further, the rate of MRMP was lower than neighboring Asian countries, including China and Korea, but was higher than in European countries. Therefore, it is important to continue monitoring MP infections in Japan. Full article

Background/Objectives: This study was aimed to investigate the safety profile of traditional Montenegrin Njeguški cheese by quantifying genes associated with resistance to clinically important antibiotics. Methods: Samples of Njeguški cheese were sourced from three artisan producers in Montenegro, identified as A, B, and C, with three individual batches selected per producer. Quantitative PCR (qPCR) was performed on bacterial DNA extracted directly from samples to detect genes encoding resistance to macrolide–lincosamide–streptogramin B (MLS_B) [erm(A), erm(B), erm(C)], vancomycin (vanA, vanB), tetracyclines [tet(M), tet(O), tet(S), tet(K), tet(W)], β-lactams (mecA, blaZ), aminoglycosides [aac (6′)-Ie aph (2″)-Ia], and carbapenems (bla_KPC, bla_OXA-48, bla_NDM-1, bla_GES, and bla_VIM). Results: Among the MLS_B resistance genes, erm(B) was detected in all samples, erm(C) was present only in those from producer B, while erm(A) was found exclusively in batch 3 from producer C. Tetracycline resistance genes were widely distributed, except for tet(O), which was absent in batch 3 from producers A and B. Regarding β-lactam resistance, both blaZ and mecA were consistently detected across all samples, with statistically significant differences observed between producers. None of the samples tested positive for vancomycin resistance genes or the aminoglycoside resistance gene, regardless of producer. Among the carbapenemase genes analyzed, bla_NDM-1 was the only one detected, found in most samples from producers B and C. Conclusions: This research provides the first risk assessment of artisanal and commercial Njeguški cheese regarding antimicrobial resistance genes. The findings offer valuable insights to enhance the microbiological safety of traditional Montenegrin cheeses, supporting consumer confidence in local and international markets. Full article

In recent years, the incidence of severe Streptococcus pyogenes (group A Streptococcus, GAS) infections has been increasing worldwide, similar to trends observed prior to the COVID-19 pandemic, alongside a rise in antibiotic resistance. In the present study, we identified the circulating 12 emm types and 8 clusters of 70 GAS isolates among inpatients, investigated their association with antibiotic susceptibility, and compared these findings with earlier research conducted in our country. The predominant emm types and clusters were emm1, emm3, and emm4, and A-C3, E4, and, A-C5, respectively. emm1 was the most common among patients with skin and soft tissue infections or pneumonia, while emm3 was detected in patients with peritonsillar abscesses. All isolates demonstrated susceptibility to penicillin and linezolid, whereas the prevalence of resistance to macrolides, lincosamides, and tetracyclines was found to be 14.3%, 14.3%, and 18.6%, respectively. A notable change in the distribution of emm-types/clusters has been observed, with emm1/A-C3 now identified as the most prevalent, differing from our previous study conducted in the pre-COVID-19 period. Additionally, we noted a decrease in resistance to macrolides attributed to a lower prevalence of emm28 clone. The current research is important for monitoring isolates responsible for severe infections, which is crucial for GAS surveillance. Full article

Background/Objectives: This report documents the first confirmed case in Romania of fatal pneumonia and septicemia in a domestic rabbit caused by multidrug-resistant Escherichia coli, highlighting both its pathogenic potential and One Health implications. Case Study: An 8-month-old male German Giant Spotted rabbit raised on a rural farm under poor husbandry conditions developed acute respiratory distress and died within 48 h. Post-mortem examination revealed severe pulmonary congestion, tracheal inflammation, serofibrinous pericarditis, and systemic vascular lesions. Bacteriological analysis confirmed E. coli from lung, trachea, and bone marrow samples. The isolate demonstrated strong Congo red binding, was confirmed by MALDI-TOF mass spectrometry, and showed resistance to beta-lactams, fluoroquinolones, tetracyclines, sulfonamides, macrolides, and phenicols, remaining susceptible only to aminoglycosides. PCR screening identified virulence genes (fimH, papC, iutA, ompA) linked to adhesion, immune evasion, and iron acquisition, with potential for horizontal gene transfer. Conclusions: This first documented case in Romania emphasizes the clinical threat posed by multidrug-resistant E. coli in rabbits and the importance of early diagnosis, improved biosecurity, and responsible antimicrobial use. The zoonotic and environmental risks in backyard farming underscore the urgent need for integrated surveillance. Alternative control strategies, including phage therapy and probiotics, should be explored to reduce reliance on conventional antibiotics. Full article

Staphylococcus aureus, a Gram-positive coccus commonly found in the environment, is indeed a common cause of both superficial and deep infections. The aim of the study was to determine the virulence factors of S. aureus characteristic of chronic infections, including chronic furunculosis and chronic osteomyelitis. Phenotypic characteristics of the bacteria (ability to produce hemolysis, clumping factor, and coagulase; antibiotic susceptibility) and genotypic characteristics (presence of genes responsible for the production of enzymes and toxins; ability to form biofilm) were examined. The real-time PCR method was used to determine the presence of virulence genes. Biofilm production was confirmed using the crystal violet method. Antibiotic and chemotherapeutic susceptibility tests were performed using the disk diffusion method. In 90% of cases, S. aureus strains possessed the following virulence genes: clfA, clfB, spa, cna, eap, hlgA, hlgB, hlg, hld, bap, bbp, ebpS, fib, fnbA, fnbB, and pvl. A total of 82% of S. aureus strains showed susceptibility to methicillin (MSSA), whereas 12% of strains were susceptible to methicillin and simultaneously resistant to macrolides, lincosamides, and streptogramin B, including 10.5% with inducible resistance and 1.5% with constitutive resistance (MSSA/MLSB). In addition, 1.5% were methicillin-resistant S. aureus (MRSA) and susceptible to the remaining antimicrobial agents. The predominance of MSSA in the etiology of chronic furunculosis and chronic osteomyelitis was observed. It has been demonstrated that MSSA possesses a similar set of virulence genes to MRSA and that MSSA is responsible for most cases of chronic osteomyelitis and furunculosis. The findings indicate that S. aureus possesses numerous virulence factors that play a key role in the processes of adhesion to and proliferation within host cells. Full article

The impact of varying antibiotic residue levels on antibiotic resistance gene (ARG) removal during composting is still unclear. This study investigated the impact of different residue levels of tilmicosin (TIM), a common veterinary macrolide antibiotic, on ARG removal during pig manure composting. Three groups were used: the CK group (no TIM), the L group (246.49 ± 22.83 mg/kg TIM), and the H group (529.99 ± 16.15 mg/kg TIM). Composting removed most targeted macrolide resistance genes (MRGs) like ereA, ermC, and ermF (>90% removal), and reduced ermB, ermX, ermQ, acrA, acrB, and mefA (30–70% removal). However, ermA increased in abundance. TIM altered compost community structure, driving succession through a deterministic process. At low doses, TIM reduced MRG–bacteria co-occurrence, with horizontal gene transfer via intI1 being the main cause of ermA rebound. In conclusion, composting reduces many MRG levels in pig manure, but the persistence and rebound of genes like ermA reveal the complex interactions between composting conditions and microbial gene transfer. Full article

Background/Objectives: Antimicrobial resistance (AMR) poses a significant threat to public health, food security, and sustainable livestock production. Despite increasing concern, AMR remains poorly studied in cuniculture, particularly in regions where rabbit farming is predominantly small-scale and household-based. This study aimed to assess the prevalence and diversity of antimicrobial resistance genes (ARGs) in rabbit farms in northeastern Ukraine. Methods: A total of 100 fecal samples were collected from clinically healthy rabbits housed in two farms and one vivarium. DNA was extracted and analyzed using real-time PCR targeting 21 ARGs associated with resistance to major antibiotic classes, including tetracyclines, sulfonamides, β-lactams, macrolides, quinolones, carbapenems, and multidrug efflux systems. Results: A diverse and widespread resistome was identified. The most prevalent genes included sul1 (96%), blaTEM (95%), tetM (94%), and ermB (93%). AcrB (78%) and qnrS/oqxB (approximately 67%) were also frequently detected. Carbapenemase genes (blaKPC, blaNDM, blaVIM) were identified in 6% of samples, despite limited veterinary use of carbapenems. Notably, 96% of samples harbored ARGs from three or more antibiotic classes, indicating a high potential for multidrug resistance. Conclusions: The findings demonstrate a high prevalence and diversity of ARGs in rabbit farming systems in northeastern Ukraine. The presence of clinically significant resistance genes, including those conferring carbapenem resistance, underscores the urgent need for targeted AMR surveillance and improved antibiotic stewardship in cuniculture, particularly in regions with minimal regulatory oversight of antimicrobial use. Full article

Background/Objectives: Pasteurella multocida is responsible for a wide variety of animal diseases worldwide, causing major economic losses. These infections are usually treated with antibiotics; however, the emergence of multidrug-resistant (MDR) strains is increasingly hindering. Understanding antibiotic resistance in P. multocida is important for effective treatment strategies and public health, as it impacts both animal and human welfare. Methods: In this study, the antibiotic susceptibility of 80 P. multocida isolates was evaluated by phenotypic (disk diffusion and broth microdilution) and genotypic analysis via whole-genome sequencing, with particular attention to the occurrence of MDR strains. The strains were tested against antibiotics from nine antimicrobial classes (penicillins, cephalosporins, aminoglycosides, tetracyclines, macrolides, fluoroquinolones, lincosamides, phenicols, and sulfonamides). Antimicrobial resistance gene (ARG) sequences and single-nucleotide polymorphisms (SNPs) were evaluated in paired reads using the Bacterial and Viral Bioinformatics Resource Center (BV-BRC) and the Comprehensive Antibiotic Resistance Database (CARD) via Resistance Gene Identifier (RGI), respectively. Results: Phenotypic results indicated that cephalosporins and phenicols were the most effective drugs against P. multocida; however, the majority of strains were also susceptible to fluoroquinolones and tetracyclines. In contrast, high resistance rates were observed to sulfamethoxazole and clindamycin. The most prevalent resistance genes were strA, sul2, and tetH, while none of the strains harbored the bla-_TEM or erm (42) genes. Conclusions: Of the two phenotypic methods, MIC values showed a stronger positive correlation with genotypic results, making it a more suitable method for determining antibiotic susceptibility. The phenotypic results for phenicols, tetracyclines, and fluoroquinolones showed a strong correlation with the detected resistance genes. In contrast, resistance to sulfamethoxazole, β-lactams, and macrolides remained genetically unexplained, suggesting the existence of additional resistance mechanisms to be explored. Full article

Background and objectives: Antibiotic resistance in Cutibacterium acnes is undermining topical macrolides and clindamycin, prompting renewed interest in zinc oxide nanoparticles (ZnO-NPs) as non-antibiotic alternatives. We aimed to (i) determine the antimicrobial and anti-inflammatory performance of topical ZnO-NP formulations across in vitro, animal and early human models; (ii) identify physicochemical parameters that modulate potency and tolerance; and (iii) delineate translational gaps and priority design elements for randomised trials. Methods: We systematically searched PubMed, Scopus and Web of Science until 1 June 2025 for in vitro, animal and human studies that evaluated ≤100 nm ZnO-NPs applied topically to C. acnes cultures, extracting data on bacterial load, lesion counts, biophysical skin parameters and acute toxicity. Eight eligible investigations (five in vitro, two animal, one exploratory human) analysed particles 20–50 nm in diameter carrying mildly anionic zeta potentials. Results: Hyaluronic acid-coated ZnO-NPs achieved a sixteen-fold higher selective kill ratio over Staphylococcus epidermidis at 32 µg mL¹, while centrifugally spun polyvinyl alcohol dressings reduced C. acnes burden by 3.1 log₁₀ on porcine skin within 24 h, and plant-derived nanogels generated inhibition zones that were 11% wider than benzoyl-peroxide’s 5%. In human subjects, twice-daily 0.5% hyaluronic–ZnO nanogel cut inflammatory-lesion counts by 58% at week four and lowered transepidermal water loss without erythema. Preclinical safety was reassuring, zero mortality among animals at 100 µg mL¹ and no irritation among patients, although high-dose sunscreen-grade ZnO (20 nm) delayed rat wound closure by 38%, highlighting dose-dependent differences. Conclusions: Collectively, the evidence indicates that nanoscale reformulation markedly augments zinc’s antibacterial and anti-inflammatory performance while maintaining favourable acute tolerance, supporting progression to rigorously designed, adequately powered randomised trials that will benchmark ZnO-NPs against benzoyl peroxide and retinoids, optimise dosing for efficacy versus phototoxicity, and establish long-term dermatological safety. Full article

Vagococcus lutrae is an emerging pathogen that can cause severe disease, especially in immunocompromised patients. Unlike Vagococcus fluvialis, which is recognized as a human and animal pathogen, there are few reports of V. lutrae from human and animal infections. In humans, it has been reported in patients with severe skin lesions and bloodstream infections. In veterinary medicine, V. lutrae was accidentally isolated from a Eurasian otter and a largemouth bass, and only once from the genitourinary tract of a pig with a urinary tract infection. However, the prevalence may be underestimated due to difficulties in identification using traditional methods. In addition, V. lutrae could be a carrier of resistance genes and contribute to the spread of AMR. A neutered male cat with feline urological syndrome underwent urethrostomy surgery due to serious problems with dysuria and urolithiasis that could not be resolved through catheterizations. Urine culture revealed the presence of Vagococcus lutrae. The strain showed resistance genes against aminoglycoside, lincosamide, streptogramin a and b, pleuromutilin, macrolide, tetracycline, oxazolidinone, and amphenicol classes. We report the first isolation of V. lutrae from the urinary tract of a cat. Full article