Pathogens最新文献

Diabetic foot ulcer (DFU) infections frequently involve biofilm formation and exhibit limited responsiveness to conventional antibiotic therapy. In particular, Pseudomonas aeruginosa often participates in mono- and polymicrobial biofilms that display high tolerance to antimicrobial agents. This study evaluated the efficacy of methylene blue-mediated antimicrobial photodynamic therapy (aPDT), alone and in combination with antibiotics, against P. aeruginosa biofilms formed either as single-species or in mixed communities with Enterococcus faecalis, under conditions mimicking DFU infections. Macrocolony biofilms were challenged with amikacin alone (for single-species biofilms) or amikacin plus ampicillin (for mixed biofilms), aPDT, or sequential combinations of these treatments, and bacterial viability was quantified by colony-forming unit enumeration. Antibiotic treatment alone produced only modest reductions in P. aeruginosa viability, even at high concentrations, while aPDT using methylene blue was effective only at high photosensitizer concentrations. In contrast, sequential treatment with antibiotics followed by aPDT and a second antibiotic challenge resulted in a marked reduction in P. aeruginosa viability in both mono- and polymicrobial biofilms. Scanning electron microscopy revealed extensive structural damage in P. aeruginosa cells following combined treatments, whereas E. faecalis remained unaffected. Overall, our findings demonstrate that combining aPDT with antibiotics significantly enhances antibiofilm activity against P. aeruginosa, highlighting this approach as a promising alternative for the management of biofilm-associated DFU infections.

Salmonella remains a leading cause of foodborne illness worldwide, with poultry products representing a major source of human exposure, underscoring the need for rapid and reliable detection methods. Although qPCR offers sensitive and timely pathogen detection, assay performance is highly dependent on sample preparation efficiency and nucleic acid purity, particularly in complex food matrices. In this study, we systematically optimized the sample preparation workflow of a SYBR Green based qPCR assay for enrichment-free detection of Salmonella enterica in poultry. Multiple lysis chemistries, incubation times, DNA extraction methods, centrifugation strategies, inoculum sources, and magnetic nanoparticle (MNP) assisted workflows were evaluated using phosphate-buffered saline and chicken rinsate matrices. Among the conditions tested, lysis with 20 µL Proteinase K and 400 µL PrepMan™ for 20 min produced the lowest and most consistent Cq values. Although Promega Wizard^® produced slightly lower mean Cq values than PrepMan™, statistical analysis showed no significant differences between extraction methods or centrifugation protocols, indicating comparable overall performance. Broth-derived inocula yielded earlier and more reproducible Cq values than colony-derived preparations. In contrast, inclusion of MNP processing resulted in higher Cq values in both matrices compared to the non-MNP workflow. Overall, these findings demonstrate that optimized lysis, extraction, and centrifugation workflows enhances the consistency and analytical reliability of direct qPCR detection of Salmonella in poultry matrices, supporting laboratory-based rapid detection applications.

The occurrence of contact lens complications caused by inadequate cleaning of the lenses using "All-in-One" contact lens cleaning solutions (CLCSs) represents a medically relevant problem worldwide. This study explores the potential of cold atmospheric plasma (CAP) to enhance the efficacy of CLCSs and address complications from inadequate lens hygiene. It was examined whether exposure to CAP for 1-24 h could boost the antibacterial effects of CLCSs and other solutions, including Milli-Q water (M-QW), physiological saline (NaCl), and Dulbecco's Phosphate Buffered Saline (DPBS). Additionally, the stability of reactive oxygen and nitrogen species (RONS) and their impact on pH immediately after treatment and over 1-4 weeks was assessed. Furthermore, the cleaning efficacy of plasma-activated solutions (PASs) was tested on lipid-coated silicone hydrogel lenses. Results showed that CAP increased RONS concentrations immediately, with elevated levels persisting over time. While no significant improved antibacterial effect was observed against Escherichia coli in CLCSs, CAP treatment generated disinfectant properties in M-QW and NaCl solutions. Importantly, CAP-treated CLCSs significantly improved the cleaning performance on lipid-coated lenses, though M-QW's cleaning ability worsened post-treatment. pH measurements indicated notable decreases in M-QW and NaCl after CAP, whereas buffered solutions like CLCSs and DPBS remained stable. Overall, CAP demonstrates promise for contact lens disinfection and surface modification; however, further research and pre-clinical trials are necessary before clinical application in ophthalmology.

Helicobacter species affect humans and animals, mainly causing gastrointestinal but also extra-gastrointestinal pathologies. Besides Helicobacter pylori, which is the main human pathogen, Non-Helicobacter pylori Helicobacters (NHPH) are also associated with human diseases, thus raising concern about their zoonotic potential. Veterinarians are considered a risk group for NHPH infections and act as first-line communicators to animal owners about their prophylaxis. Therefore, we aimed to assess the knowledge and perception of veterinarians working in Greece about Helicobacter pylori and NHPH by asking them to participate anonymously in an online 34-question survey. The questionnaire consisted of three sections regarding environmental exposure to Helicobacter spp.; know-how about clinical signs in various species, including personal human experience; and willingness to get updated information about NHPH. Of the 111 respondents, 41.4% had not heard of H. suis (NHPH), and 35.0% were unaware of the species that could be affected. Almost 60.0% of companion animal veterinarians rarely suspect and 20.0% never suspect Helicobacter spp. infections in the case of gastritis. Nevertheless, 41.0% of respondents considered Helicobacter as zoonotic, and 87.0% wanted to receive information via professional channels and brochures. Despite the limited number of respondents and the exploratory nature of our study, as with similar data from Portugal, we emphasize the need to train veterinarians to have a more targeted focus on the zoonotic potential of Helicobacter within a One Health approach.

Rift Valley fever (RVF) transmission has intensified in southwestern Uganda since 2016. To quantify human and livestock exposure and associated risks, we conducted a cross-sectional serosurvey in Isingiro, Kabale and Rubanda districts between October and November 2023. A total of 766 humans and 2383 livestock were sampled and tested for RVF antibodies using ELISA, with structured questionnaires capturing demographic, behavioral and environmental data. Human seroprevalence was 11.5% (88/766), varying by district (13.8% Isingiro, 11.8% Rubanda, 6.8% Kabale; p = 0.04). Independent predictors from the multivariate model included raw-meat consumption (aOR 6.11; 95% CI 1.16-27.80), cattle ownership (aOR 2.33; 95% CI 1.27-4.36), male sex (aOR 1.64; 95% CI 1.02-2.66) and younger age compared with ≥50 years (31-49 years: aOR 2.02; 95% CI 1.20-3.48; 18-30 years: aOR 2.37; 95% CI 1.04-5.14). Herd-level seroprevalence was 42.5% (204/480), associated with cattle presence (aOR 6.48; 95% CI 4.10-10.40), lack of carcass burial (aOR 15.70; 95% CI 4.23-63.60), on-farm slaughter (aOR 2.14; 95% CI 1.21-3.89) and increased mosquito activity (aOR 1.75; 95% CI 1.13-2.73). Animal-level seroprevalence was 14.6% (347/2383), highest in cattle (33.8%), with cattle having markedly higher odds than goats (aOR 6.73; 95% CI 4.96-9.14). These findings demonstrate substantial transmission and highlight cattle-centered interfaces as primary targets for control to humans.

Congenital toxoplasmosis (CT) results from vertical transmission of Toxoplasma gondii during maternal infection in pregnancy. Early diagnosis in newborns is crucial to initiate timely therapy and prevent long-term sequelae. The IgM Immunosorbent Agglutination Assay (ISAGA) has historically been considered an important diagnostic tool for CT; however, its recent market withdrawal necessitates alternative approaches. We conducted a retrospective observational study at Fondazione IRCCS Policlinico San Matteo, Pavia, Italy, including 44 newborns born to mothers with confirmed toxoplasmosis between 2019 and 2022. Newborns were classified as CT (n = 19) or non-CT (n = 25) based on serological follow-up, comparative Western blot (CWB) and Interferon Gamma Release Assay (IGRA). Sensitivity and specificity of CWB, IgM Chemiluminescent Immunoassay (CLIA), and IgM ISAGA were assessed at birth and at one month. At birth, CWB demonstrated 88.9% sensitivity, significantly higher than IgM CLIA (52.6%) and IgM ISAGA (57.9%). Specificity was 100% at birth and 92% at one month. CWB retained high sensitivity at one month (81.8%). IGRA complemented CWB in confirming or excluding infection in cases with equivocal or false-negative serology. Comparative Western blot thus represents a robust diagnostic alternative for CT, ensuring early detection and timely treatment, particularly in the absence of IgM ISAGA.

Bats are hosts to many diseases that emerge in humans and livestock. Knowledge about the diversity and circulation of paramyxoviruses in European bat populations, despite their recognized importance, remains limited. Here, we present data on the first detection of paramyxoviruses in Poland in the new bat species of Cnephaeus serotinus and Cnephaeus nilsonii, which have never been previously recognized as paramyxovirus hosts, as well as in Myotis daubentonii and two unknown bat species. Viral RNA was detected in fecal and intestinal samples using the semi-nested RT-PCR protocol followed by Sanger sequencing. A widespread comprehensive phylogenetic study supported by haplotype network analyses of 376 nt sequences of paramyxoviruses detected in bats worldwide revealed that paramyxoviruses are closely related to the host and strongly correlate to the area of origin.

Early and rapid diagnosis of drug resistance in tuberculosis (TB) plays a key role in reducing the spread of resistance and enabling effective treatment. The aim of this study was to investigate mutations in drug resistance-associated gene regions of Mycobacterium tuberculosis complex (MTBC) isolates resistant to at least two first-line anti-tuberculosis drugs through sequence analysis, in order to characterize the core molecular features of these strains in the region and to identify previously unreported, geographically distinct novel mutation sites. The drug susceptibility of 23 clinical isolates was assessed using the BACTEC MGIT 960 system, and resistance-associated point mutations were identified through DNA sequence analysis and comparison with GenBank reference sequences. AAG → AGG mutation was detected in the rpsL gene region at codon 43 (n = 7) and codon 88 (n = 1). Additionally, GAG → GCG point mutation was identified at codon 70 (n = 2), representing a new region not previously reported in the literature. The most frequent mutation was AGC → ACC at katG codon 315 (n = 10), followed by a C → T substitution at position -15 of the inhA promoter region (n = 4). Additionally, TCG → TTG at rpoB codon 531 (n = 4) and ATG → GTG at embB codon 306 (n = 1) were detected. The detection of resistance-associated mutations is essential for controlling drug-resistant tuberculosis. In this study, a novel rpsL mutation (GAG → GCG) at codon 70 and a previously unreported codon 88 mutation in our country were identified, contributing to the understanding of molecular resistance mechanisms and epidemiology.

Microbial communities on obturator prosthesis biofilms have yet to be investigated. This pilot study explores eukaryotes, prokaryotes, and viruses present on obturator prosthesis biofilms using metagenomics. The prostheses of the selected patients (n = 3) were collected and their biofilms were physically removed. The total genomic DNA was extracted, followed by metagenomic analysis. The microbial diversity in each of the investigated biofilms was exceptionally abundant. Between 2616 to 3024 species were detected in the three biofilms. The highest percentage included prokaryotes and unclassified species, followed by low percentages of fungi, viruses, and archaea. Unusual pathogens rarely reported in oral biofilms, such as Mycobacterium and other species, were also found at very low percentages. Unigenes for functional pathways related to metabolism, cellular processes, human disease, and other microbial unigenes were abundant. In addition, unigenes for several antibiotic-resistance mechanisms were also detected. This study reveals, for the first time, that biofilm formation on obturator prostheses comprises a variety of dynamic microbial communities, suggesting a putative role in health and disease in patients following maxillofacial surgery.

In Brazil, cutaneous leishmaniasis is endemic and may be caused by Leishmania amazonensis. This species is the second most prevalent species in that country, and it is responsible for localized cutaneous and diffuse cutaneous leishmaniasis. Pentavalent antimony is still the first-line drug for cutaneous leishmaniasis treatment in Brazil. In this study, we investigated the in vitro susceptibility to antimony of a panel of L. amazonensis strains and clinical isolates responsible for cutaneous and diffuse cutaneous leishmaniasis. There was a significant variation in susceptibility to antimony not only within these strains and isolates evaluated at either promastigote or intracellular amastigote stages, but also between the two parasite stages for some of these strains and isolates. Additionally, we investigated whether this in vitro susceptibility variation to antimony would affect the in vivo response to treatment, using an experimental BALB/c mouse model of cutaneous leishmaniasis infected with three strains differing in susceptibility. Despite antimony could mildly reduce the lesion size in mice infected with one of these strains, no significant reduction in the parasite burden was found in treated animals, and they were completely refractory to drug treatment. These findings indicate that antimony treatment, even at high dosages via the intraperitoneal route, was not effective against L. amazonensis infection in this animal model. Finally, this study provides a preclinical dataset of the activity of antimony against a panel of strains and isolates of a species responsible for localized cutaneous and diffuse cutaneous leishmaniasis in Brazil.