Search Results (229)

Background: Infectious proctitis remains an underrecognized entity, although sexually transmitted diseases, especially bacterial infections, exhibit a marked increase in their incidence. Methods: Here, we report a case of a 44-year-old man who presented to the emergency department with lower abdominal and rectal pain, tenesmus, fever and night sweats for the past 6 days. Results: The computed tomography initially revealed a high suspicion of metastatic rectal cancer. The endoscopic findings showed a 5 cm rectal mass, suggestive of malignancy. The histologic examination showed, however, no signs of malignancy and lacked the classical features of an inflammatory bowel disease, so an infectious proctitis was further suspected. The patient reported to have had unprotected receptive anal intercourse, was tested positive for Treponema pallidum serology and received three doses of intramuscular benzathine penicillin G. A control rectosigmoidoscopy, imaging at 3 months and histological evaluation after antibiotic treatment showed a complete resolution of inflammation. Conclusions: Syphilitic proctitis may mimic various conditions such as rectal cancer or inflammatory bowel disease and requires a high degree of suspicion. Clinicians need to be aware of infectious proctitis in high-risk populations, while an appropriate thorough medical history may guide the initial diagnostic steps. Full article

Infections caused by Acinetobacter baumannii are increasing worldwide. We evaluated the antibiotic resistance profile, biofilm production, and the frequency of 12 genes encoding carbapenemases and 13 virulence factors in 90 isolates from patients of three hospitals in various regions of Poland. Antibiotic resistance survey was performed using the disc-diffusion method, genes encoding resistance to carbapenems and virulence factors were detected with PCR, and biofilm formation was tested using microtiter plates. A total of 52.2% of isolates were resistant to all tested antibiotic groups (penicillins with β-lactamase inhibitors, cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, and trimethoprim plus sulfamethoxazole). Among the genes encoding carbapenem resistance, the bla_OXA-23 (68.9%), bla_OXA-40 (83.3%), and ISAba-bla_OXA-51 (18.9%) were detected. The ompA, ata, and recA genes responsible for biofilm formation, adhesion, and stress response, respectively, occurred in all isolates. Genes responsible for the production of other adhesins (bap—94.4%, espA—4.4%, chop—37.7%), biofilm formation (pbpG—90.0%), production of siderophore (basD—97.7%), toxins (lipA—92.2%, cpaA—1.1%), glycoconjugates (bfmR—84.4%), and inducing host cell death (fhaB—71.1%, abeD—93.3%) were also found. A total of 68.8% of isolates produced biofilm. The isolates from Masovia had more virulence genes than isolates from the other regions; moreover, all isolates from Masovia and West Pomerania were multidrug-resistant (MDR), including resistance to carbapenems. Full article

In the present study, a quantitative analysis of culturable microflora of car cabin filters was accomplished, with a special focus on bacteria resistant to some antibiotics. The occurrence of antibiotic-resistant bacteria was considered in the filters with activated carbon and filters with antibacterial properties. The minimum inhibitory concentration was evaluated for selected bacterial strains isolated from the filters. It was found that cabin filters after long-time operation are not only heavily contaminated with bacteria and fungi but also constitute a habitat for numerous antibiotic-resistant bacteria. The numbers of culturable bacteria resistant to penicillin, nitrofurantoin, rifampicin, doxycycline, or gentamicin reached 10²–10³ CFU/g of filter material. No relationship was observed between car brand or filter type and the abundance of antibiotics-resistant bacteria. The lower bacterial content of antibacterial filters was not accompanied by a proportionally lower content of resistant microorganisms which may indicate that the present techniques are not sufficient to limit their growth effectively. Pseudomonas sp. isolates from the filter material were not sensitive even in relation to high concentrations of some antibiotics, which confirms their significant resistance potential and may be important in the context of the spread of drug resistance in the vehicles indoors. Full article

Background: Pyoderma is a superficial bacterial infection that is considered the formation of pus-containing lesions on the skin occurring in animals. Staphylococci, including Staphylococcus aureus and Staphylococcus pseudintermedius, that cause pyoderma in pet animals is a global health concern. The objectives of this study were to investigate antibiotic-resistant staphylococci isolated from pyoderma in dogs and cats and to analyse whole genome sequences of multidrug-resistant (MDR) staphylococci. Methods: A total of 56 pyoderma swabbing samples from 42 dogs and 14 cats located in Southern Thailand was collected to isolate staphylococci. Antibiotic susceptibility and antibiotic-resistant genes of staphylococcal isolates were investigated. Furthermore, the representative MDR isolates were investigated using whole genome sequence analysis. Results: 61 isolates were identified as staphylococci, which can be classified into 12 different species, mostly including 13 S. intermedius (13.26%), 13 S. saprophyticus (13.26%), 8 S. sciuri (8.16%), and Staphylococcus cohnii (8.16%). Remarkably, the main pyoderma-causing species that were isolated in this study were S. aureus (5.10%) and S. pseudintermedius (3.06%). Most staphylococci were resistant to penicillin G (30%), and the blaZ gene was found to be the highest prevalence of the resistance genes. Both MDR-S. aureus WU1-1 and MDR-S. pseudintermedius WU48-1 carried capsule-related genes as main virulence factor genes. Interestingly, MDR-S. pseudintermedius WU48-1 was resistant to seven antibiotic classes, which simultaneously carried blaZ, mecA, aac, dfrK, aph3, and tetM. Genes related to antibiotic efflux were the highest proportion of the mechanism found in both representatives. Remarkably, SCCmec cassette genes were found in both isolates; however, the mecA gene was found only in MDR-S. pseudintermedius WU48-1. In addition, these were mostly carried by macrolide- and tetracycline-resistance genes. Mobile gene transfer and horizontal gene transfer events frequently contain genes involved in the antibiotic target alteration mechanism. Conclusions: This study found that MDR staphylococci, especially S. aureus and S. pseudintermedius, are important in animals and owners in terms of One Health concern. The information on whole genome sequences of these MDR staphylococci, particularly antimicrobial resistance genes, mobile genetic elements, and horizontal gene transfer events, can help to understand gene transmission and be applied for antibiotic resistance surveillance in veterinary medicine. Full article

Background/Objectives: Antimicrobial resistance (AMR) poses a significant global health challenge, contributing to foodborne infections and diminishing the effectiveness of conventional antibiotics. In the quest for alternative strategies to mitigate resistance, this study has assessed the potential of T. capitata L. (Cav.) essential oil (TEO) to boost the antibiotic efficacy on L. monocytogenes. Methods: Five L. monocytogenes strains of different origins were tested with TEO alone and in combination with gentamicin, ampicillin, and penicillin G. Moreover, the cells were exposed to sublethal concentrations of TEO for 1 h to evaluate the effects on the antibiotic effectiveness. The antimicrobial activity was assessed by determining the Minimum Inhibitory (MICs) and Bactericidal Concentrations (MBCs), while potential interactions were evaluated using the Fractional Inhibitory Concentration Index and by studying the cell growth dynamics. Results: TEO demonstrated inhibitory activity against L. monocytogenes strains, both alone, in pre-exposure, and in combination with antibiotics, causing up to a seven-fold reduction in MIC and MBC values (from 8 to 1 µg/mL) and restoring susceptibility to the antimicrobial treatments. Positive interactions between TEO and antibiotics were observed, particularly for clinical isolates. Conclusions: TEO could be a promising antibiotic adjuvant in antimicrobial treatments, offering a natural and effective strategy to enhance antibiotic efficacy and to counteract resistance in L. monocytogenes. Full article

Filamentous fungi hold critical industrial value for their ability to produce enzymes, antibiotics, organic acids, and food fermentation. GATA transcription factors (TFs) serve as central regulators of nitrogen metabolism, synthesis of secondary metabolites, stress adaptation, and directly influence fungal development and pathogenicity in filamentous fungi. In this review, we primarily discuss the structural characterization, different types, and phylogenetic analysis of filamentous fungi GATA TFs in filamentous fungi. Subsequently, we systematically summarize the multifunctions of GATA TFs in the mycelial growth, morphological differentiation, and conidial development of filamentous fungi. In addition, we explore their functions in the synthesis of secondary metabolites such as antibiotics (e.g., cephalosporins, penicillins) and organic acids (e.g., ganoderic acid, fumaric acid) in filamentous fungi. Furthermore, we focus on the key roles of GATA TFs AreA and AreB in nitrogen and carbon metabolism in filamentous fungi and their potential synergistic regulatory relationships. Finally, we review the important roles of GATA TFs in the adaptation of filamentous fungi to environmental changes. This review provides research ideas for the development of genetically engineered strains with optimized growth characteristics, increased target metabolites in the fermentation production process, and enhanced environmental adaptability. Full article

A total of 30 hydropic fetuses, including 25 cases from published reports and 5 from our own series, were reviewed, validated, and analyzed. This review yielded the following key findings: (1) Unlike most cases of nonimmune hydrops fetalis (NIHF), hydrops caused by syphilis is not only preventable but also treatable, with complete resolution possible when appropriately managed. (2) Syphilis-associated hydrops carries a poor prognosis if timely and appropriate treatment is not administered. (3) Based on limited data, intravenous penicillin G is probably more effective than intramuscular benzathine penicillin in treating hydropic fetuses. (4) Middle cerebral artery peak systolic velocity (MCA-PSV) measurements are increasingly used as a reliable and noninvasive tool for assessing fetal anemia, determining the need for intrauterine transfusion (IUT), and monitoring treatment response. (5) A significant number of cases did not receive prenatal treatment due to false-negative serologic results caused by the prozone effect, as well as the omission of syphilis from the differential diagnosis of NIHF, leading to missed prenatal diagnoses. (6) IUT may help mitigate cellular damage in developing vital organs caused by anemic hypoxia, particularly while awaiting the effects of medical treatment. In conclusion, the modern approach to managing this ancient disease includes: (1) prioritizing intensive intravenous penicillin G therapy over conventional intramuscular benzathine penicillin G; (2) utilizing MCA-PSV in conjunction with other indicators of anemia to monitor its severity; and (3) implementing IUT to prevent anemic hypoxic injury in cases where the hematocrit falls below 30%. Full article

Probiotics exert beneficial effects on health improvement, infection prevention, and disease management. This study investigated the probiotic characteristics and safety parameters of Levilactobacillus brevis ZG2488, a novel strain isolated from healthy human feces. The strain exhibited robust tolerance to simulated gastrointestinal conditions, maintaining survival rates of 87.20% in artificial gastric juice (pH 3.0; 3 h) and 95.32% in 0.3% bile salt (24 h). Notably, L. brevis ZG2488 displayed superior microbial adhesion properties with high cell surface hydrophobicity (87.32%), auto-aggregation (81.15% at 24 h), and co-aggregation capacities with Escherichia coli ATCC 43895 (63.90%) and Salmonella typhimurium SL1344 (59.28%). Its adhesion to HT-29 cells (7.15%) surpassed that of the reference strain Lactobacillus rhamnosus GG (1.26%). Antimicrobial testing revealed broad-spectrum inhibitory effects against multidrug-resistant Klebsiella pneumoniae NK04152 and other pathogens. Comprehensive safety assessments confirmed the absence of hemolytic or DNase activity, along with appropriate antibiotic susceptibility to most antibiotics, except kanamycin, streptomycin, vancomycin, and penicillin G. Furthermore, L. brevis ZG2488 significantly enhanced nitric oxide production and upregulated the gene expression of nitric oxide synthase (iNOS) and proinflammatory cytokines (IL-1β, IL-6, and TNF-α) in RAW264.7 macrophages. These findings underscore L. brevis ZG2488 as a promising probiotic candidate with functionality in pathogen inhibition and immune modulation. Full article

The rapid increase in drug resistance in recent years has become a significant global public health concern. Escherichia coli are ubiquitous bacteria, widely distributed in various environments. This study isolated a bacterial strain (HD-593) from diseased Chinese soft-shelled turtles (Pelodiscus sinensis). The bacterium was identified based on morphology, biochemical tests, and 16S rRNA sequencing, confirming it as E. coli. Drug susceptibility tests revealed that the HD-593 strain was highly resistant to ceftriaxone, enrofloxacin, doxycycline, sulfadiazine, gentamicin, neomycin, florfenicol, carbenicillin, cefradine, erythromycin, penicillin, ampicillin, midecamycin, and streptomycin. Resistance gene analysis confirmed the presence of quinolone resistance genes (oqxA and oqxB), aminoglycoside resistance genes (aac(3)-II and aphA1), a β-lactam resistance gene (blaTEM), and an acylaminol resistance gene (floR) in HD-593. The median lethal dose (LD50) of HD-593 for P. sinensis was 6.53 × 10⁵ CFU/g. Biochemical analysis of serum revealed that HD-593 infection caused a significant reduction in total protein, albumin, and globulin levels, while markedly increasing the levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Histopathological analysis revealed severe intestinal damage characterized by villi detachment and muscle cell necrosis. Additionally, extensive splenocyte necrosis with nuclear marginalization, glomerular swelling, and pronounced hepatic steatosis accompanied by distended sinusoids were observed. This study identified a multidrug-resistant E. coli strain from deceased P. sinensis, suggesting that drug resistance genes may circulate in aquaculture ecosystems, posing potential risks to aquaculture. Full article

Together with Granulicatella spp., A. defectiva was formerly classified within the group of nutritionally variant streptococci (NVS). NVS-related endocarditis has been associated with higher rates of complications, bacteriological failure, and mortality compared to other streptococci, partially due to challenges related to timely and accurate identification. PJI caused by A. defectiva are rarely reported, and standardized management strategies have not yet been established. We describe a case of a 68-year-old man with concomitant A. defectiva PJI and native mitral valve endocarditis. The patient was managed conservatively for endocarditis and subsequently underwent a two-stage arthroplasty of the infected prosthetic knee. A. defectiva was identified using MALDI-TOF mass spectrometry on both synovial fluid and blood cultures. As penicillin susceptibility data were not available, the patient was treated with vancomycin at a dose of 2 g/day, resulting in a favorable clinical response. In addition, we performed a literature review on A. defectiva and Granulicatella PJI. Despite the limited number of reported cases in the literature, the findings suggest a potential correlation between clinical outcomes and antimicrobial treatment duration. Further comprehensive studies are needed to establish standardized management strategies for A. defectiva and Granulicatella PJI. Full article

Syphilis is a re-emerging sexually transmitted disease caused by Treponema pallidum subsp. pallidum (TPA). It especially affects vulnerable populations such as men who have sex with men (MSM) and people living with HIV. Despite being treatable with benzathine penicillin G, a substantial increase in TPA resistance to azithromycin has been reported in many countries. The objective of this study was to detect the resistance of T. pallidum (TPA) to macrolides in blood samples from men who have sex with men and people living with HIV using molecular methods in a cross-sectional study. The detection of both TPA and the resistance to azithromycin was achieved through molecular methodologies (nested PCR), which were applied to blood samples of people with asymptomatic syphilis. We report the first data on the molecular prevalence of TPA and the first identification of genetic resistance to azithromycin (punctual mutation A2058G) in Mexico. Resistance testing for syphilis is not routinely performed in Mexico, but azithromycin continues to be prescribed despite syphilis being treatable with benzathine penicillin G. Therefore, the surveillance of cases of syphilis treatment failure, especially in vulnerable populations, which are the population group that maintains the active transmission of TPA, is recommended. Full article

It is known that the ciliate Paramecium cell surface including cilia is completely covered by high-molecular-mass GPI-anchored proteins named surface antigens (SAgs). However, their functions are not well understood. It was found that ciliate Paramecium caudatum reversibly changes its SAgs depending on the absence or presence of the endonuclear symbiotic bacterium Holospora obtusa in the macronucleus. Immunofluorescence microscopy with a monoclonal antibody produced SAg of the H. obtusa-free P. caudatum strain RB-1-labeled cell surface of the H. obtusa-free P. caudatum RB-1 cell but not the H. obtusa-bearing RB-1 cell. When this antibody was added to the living P. caudatum RB-1 cells, only H. obtusa-free cells were immobilized. An immunoblot with SAgs extracted from Paramecium via cold salt/ethanol treatment showed approximately 266-kDa SAgs in the extract from H. obtusa-free cells and 188 and 149-kDa SAgs in the extract from H. obtusa-bearing cells. H. obtusa-free RB-1 cells produced from H. obtusa-bearing cells via treatment with penicillin-G-potassium re-expressed 266-kDa SAg, while the 188 and 149-kDa SAgs disappeared. This phenotypic change in the SAgs was not induced by degrees of starvation or temperature shifts. These results definitively show that Paramecium SAgs have functions related to bacterial infection. Full article

Artisanal cheeses face unique challenges due to changes in the present approaches to food safety, health, and environmental sustainability. This work aims at tackling such challenges in Pico cheese, by addressing outdated PDO criteria, the need to tackle coagulase-positive staphylococci (CoPS) and to promote circular economy by upgrading cheese whey. Model raw- and pasteurized milk cheeses were prepared with autochthonous lactic acid bacteria (LAB) as inoculants and analyzed for their composition, proteolysis, and microbiological parameters. CoPS were isolated and the risks they pose in terms of One Health evaluated by assessing phenotypic virulence factors and antibiotic resistance patterns. To assess the potential of autochthonous LAB for controlling CoPS, a challenge test was performed. Probiotic requeijão was prepared using autochthonous LAB as inoculants for upgrading whey. This work confirmed the need to update Pico cheese specifications regarding proteolysis indexes. Biofilm production was present in all Pico cheese CoPS, but resistance was only found against penicillin and cefoxitin. Adding salt or extending maturation time up to 60 days did not afford the desired level of CoPS control. Lactococcus lactis L1C21M1, however, was able to keep CoPS populations at 3 log cfu g⁻¹ in the challenge test. Requeijão was a suitable substrate for probiotic autochthonous Lactococcus lactis L3A21M1 and L3B1M7. Full article

Probenecid has long been a versatile drug in pharmacological therapies, primarily known for blocking active tubular secretion in the kidney, affecting both endogenous substances like uric acid and exogenous ones like penicillin. Beyond its renal applications, probenecid has shown capabilities in crossing the blood–brain barrier and modulating the activity of various membrane channels and transporters. This compound has emerged as a potent antiviral agent, demonstrating efficacy against multiple viruses, including influenza, COVID-19, and RSV. Clinical trials with COVID-19 patients have confirmed its antiviral potential, sparking further investigation into its mechanisms of action. This study explores probenecid’s significant anti-inflammatory properties, focusing on its ability to inhibit inflammasome activation. Our study aims to unravel the anti-inflammatory effects of probenecid on the NLRP3 inflammasome and MAPK signaling pathways using murine macrophages as a relevant inflammation model. We reveal that probenecid treatment blocks JNK and ERK signaling without affecting p38 MAPK, suppressing NLRP3 inflammasome activation. Additionally, probenecid does not affect NFκB-directed protein expression, although it efficiently inhibits NLRP3 inflammasome outputs, e.g., IL-1β and pyroptosis. These results indicate probenecid’s potential therapeutic applications. Full article

We have used single molecule tracking to investigate dynamics of four penicillin-binding proteins (PBPs) in Bacillus subtilis to shed light on their possible modes of action. We show that Pbp2a, Pbp3, Pbp4, and Pbp4a, when expressed at very low levels, show at least two distinct states of mobility: a state of slow motion, likely representing molecules involved in cell wall synthesis, and a mode of fast motion, likely representing freely diffusing molecules. Except for Pbp4, all other PBPs showed about 50% molecules in the slow mobility state, suggesting that roughly half of all molecules are engaged in a substrate-bound mode. We observed similar coefficients for the slow mobility state for Pbp4 and Pbp4a on the one hand, and for Pbp2a and Pbp3 on the other hand, indicating possible joint activities, respectively. Upon induction of osmotic stress, Pbp2a and Pbp4a changed from a pattern of localization mostly at the lateral cell membrane to also include localization at the septum, revealing that sites of preferred positioning for these two PBPs can be modified during stress conditions. While Pbp3 became more dynamic after induction of osmotic stress, Pbp4 became more static, showing that PBPs reacted markedly differently to envelope stress conditions. The data suggest that PBPs could take over functions in cell wall synthesis during different stress conditions, increasing the resilience of cell wall homeostasis in different environmental conditions. All PBPs lost their respective localization pattern after the addition of vancomycin or penicillin G, indicating that patterns largely depend on substrate availability. Our findings show that PBPs rapidly alter between non-targeted motion through the cell membrane and capture at sites of active cell wall synthesis, most likely guided by complex formation with other cell wall synthesis enzymes. Full article