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ACS ES&T Water Jun 2024Combinations of UV with oxidants can initiate advanced oxidation processes (AOPs) and enhance bacterial inactivation. However, the effectiveness and mechanisms of...
Combinations of UV with oxidants can initiate advanced oxidation processes (AOPs) and enhance bacterial inactivation. However, the effectiveness and mechanisms of UV-AOPs in damaging nucleic acids (e.g., antibiotic resistance genes (ARGs)) and cell integrity represent a knowledge gap. This study comprehensively compared ARG degradation and cell membrane damage under three different UV-AOPs. The extracellular ARG (eARG) removal efficiency followed the order of UV/chlorine > UV/HO > UV/peracetic acid (PAA). Hydroxyl radical (OH) and reactive chlorine species (RCS) largely contributed to eARG removal, while organic radicals made a minor contribution. For intracellular ARGs (iARGs), UV/HO did not remove better than UV alone due to the scavenging of OH by cell components, whereas UV/PAA provided a modest synergism, likely due to diffusion of PAA into cells and intracellular OH generation. Comparatively, UV/chlorine achieved significant synergistic iARG removal, suggesting the critical role of the RCS in resisting cellular scavenging and inactivating ARGs. Additionally, flow cytometry analysis demonstrated that membrane damage was mainly attributed to chlorine oxidation, while the impacts of radicals, HO, and PAA were negligible. These results provide mechanistic insights into bacterial inactivation and fate of ARGs during UV-AOPs, and shed light on the suitability of quantitative polymerase chain reaction (qPCR) and flow cytometry in assessing disinfection performance.
PubMed: 38903200
DOI: 10.1021/acsestwater.4c00350 -
BMC Veterinary Research Jun 2024Scale drop disease virus (SDDV) threatens Asian seabass (Lates calcarifer) aquaculture production by causing scale drop disease (SDD) in Asian seabass. Research on the...
Protective efficiency and immune responses to single and booster doses of formalin-inactivated scale drop disease virus (SDDV) vaccine in Asian seabass (Lates calcarifer).
BACKGROUND
Scale drop disease virus (SDDV) threatens Asian seabass (Lates calcarifer) aquaculture production by causing scale drop disease (SDD) in Asian seabass. Research on the development of SDDV vaccines is missing an in-depth examination of long-term immunity and the immune reactions it provokes. This study investigated the long-term immune protection and responses elicited by an SDDV vaccine. The research evaluated the effectiveness of a formalin-inactivated SDDV vaccine (SDDV-FIV) using both prime and prime-booster vaccination strategies in Asian seabass. Three groups were used: control (unvaccinated), single-vaccination (prime only), and booster (prime and booster). SDDV-FIV was administered via intraperitoneal route, with a booster dose given 28 days post-initial vaccination.
RESULTS
The immune responses in vaccinated fish (single and booster groups) showed that SDDV-FIV triggered both SDDV-specific IgM and total IgM production. SDDV-specific IgM levels were evident until 28 days post-vaccination (dpv) in the single vaccination group, while an elevated antibody response was maintained in the booster group until 70 dpv. The expression of immune-related genes (dcst, mhc2a1, cd4, ighm, cd8, il8, ifng, and mx) in the head kidney and peripheral blood lymphocytes (PBLs) of vaccinated and challenged fish were significantly upregulated within 1-3 dpv and post-SDDV challenge. Fish were challenged with SDDV at 42 dpv (challenge 1) and 70 dpv (challenge 2). In the first challenge, the group that received booster vaccinations demonstrated notably higher survival rates than the control group (60% versus 20%, P < 0.05). However, in the second challenge, while there was an observable trend towards improved survival rates for the booster group compared to controls (42% versus 25%), these differences did not reach statistical significance (P > 0.05). These findings suggest that the SDDV-FIV vaccine effectively stimulates both humoral and cellular immune responses against SDDV. Booster vaccination enhances this response and improves survival rates up to 42 dpv.
CONCLUSIONS
This research provides valuable insights into the development of efficient SDDV vaccines and aids in advancing strategies for immune modulation to enhance disease management in the aquaculture of Asian seabass.
Topics: Animals; Fish Diseases; Viral Vaccines; Vaccines, Inactivated; Immunization, Secondary; Iridoviridae; DNA Virus Infections; Formaldehyde; Antibodies, Viral; Vaccination; Immunoglobulin M; Perciformes; Bass
PubMed: 38902724
DOI: 10.1186/s12917-024-04132-6 -
BDJ Open Jun 2024Bacterial infection plays an important role in persistent periapical lesions and inadequate disinfection of root canals is considered the biggest factor responsible for...
BACKGROUND
Bacterial infection plays an important role in persistent periapical lesions and inadequate disinfection of root canals is considered the biggest factor responsible for endodontic treatment failure. Antimicrobial Photodynamic Therapy (aPDT) has become the latest choice to eradicate microorganisms in root canals.
OBJECTIVE
This study aims to evaluate the effectiveness of Antimicrobial Photodynamic Therapy (aPDT) in bacterial count reduction compared to Passive Ultrasonic Activation (PUI) and Ca(OH)2 dressings.
MATERIALS AND METHODS
Forty-five anterior single canal teeth with medium-sized periapical lesions (2-5 mm) were divided into three groups according to the disinfecting technique (each group consists of 15 canals with 1:1:1 allocation ratio): Group A: Ca(OH)2 dressing. Group B: Passive Ultrasonic Activation (PUI). Group C: Antimicrobial Photodynamic Therapy (aPDT). Direct bacterial viable count method was used to count the colonies forming units (CFU) before and after the disinfecting and the bacterial count reduction was estimated, the statistical analysis was performed at a 95% confidence level using the Chi-square and Mann-Whitney U test.
RESULTS
aPDT showed no statistically significant difference when compared to passive ultrasonic irrigation (P > 0.05) but showed higher and more promising results when compared to Ca(OH)2 dressings (P < 0.05).
CONCLUSIONS
aPDT has the ability and effectiveness as a disinfecting technique in necrotic and infected root canals.
CLINICAL SIGNIFICANCE OF THE STUDY
The results of this clinical trial provide that aPDT can be considered an adjunct method for root canal disinfection with the same effectiveness as passive ultrasonic irrigation.
PubMed: 38902230
DOI: 10.1038/s41405-024-00239-y -
PLoS Neglected Tropical Diseases Jun 2024Despite continued outbreaks of yellow fever virus (YFV) in endemic regions, data on its environmental stability or guidelines for its effective inactivation is limited....
Despite continued outbreaks of yellow fever virus (YFV) in endemic regions, data on its environmental stability or guidelines for its effective inactivation is limited. Here, we evaluated the susceptibility of the YFV 17D vaccine strain to inactivation by ethanol, 2-propanol, World Health Organization (WHO)-recommended hand rub formulations I and II, as well as surface disinfectants. In addition, two pathogenic strains were tested to compare inactivation kinetics by WHO-recommended hand rub formulations I and II. Furthermore, environmental stability of the vaccine strain was assessed. YFV 17D particles displayed infectivity half-life decay profiles of ~13 days at room temperature. Despite this extended environmental stability, YFV was efficiently inactivated by alcohols, WHO-recommended hand formulations, and four out of five tested surface disinfectants. These results are useful in defining disinfection protocols to prevent non-vector borne YFV transmission.
Topics: Yellow fever virus; Disinfectants; Virus Inactivation; Humans; World Health Organization; Yellow Fever; Hand Disinfection; Animals; Chlorocebus aethiops
PubMed: 38900788
DOI: 10.1371/journal.pntd.0012264 -
Journal of Hazardous Materials Jun 2024Parabens are emerging contaminants that have been detected in drinking water. Their presence in DW distribution systems (DWDS) can alter bacterial behaviour,...
Parabens are emerging contaminants that have been detected in drinking water. Their presence in DW distribution systems (DWDS) can alter bacterial behaviour, characteristics, and structure, which may compromise DW disinfection. This work provides insights into the impact of methylparaben (MP) on the tolerance to chlorine disinfection and antibiotics from dual-species biofilms formed by Acinetobacter calcoaceticus and Stenotrophomonas maltophilia isolated from DW and grown on high-density polyethylene (HDPE) and polypropylene (PPL). Results showed that dual-species biofilms grown on PPL were more tolerant to chlorine disinfection, expressing a decrease of over 50 % in logarithmic reduction values of culturable cells in relation to non-exposed biofilms. However, bacterial tolerance to antibiotics was not affected by MP presence. Although MP-exposed dual-species biofilms grown on HDPE and PPL were metabolically more active than non-exposed counterparts, HDPE seems to be the material with lower impact on DW risk management and disinfection, if MP is present. Overall, results suggest that MP presence in DW may compromise chlorine disinfection, and consequently affect DW quality and stability, raising potential public health issues.
PubMed: 38897118
DOI: 10.1016/j.jhazmat.2024.134883 -
British Journal of Biomedical Science 2024Within cystic fibrosis microbiology, there is often mismatch between the antibiotic susceptibility result of an isolated bacterial pathogen and the clinical outcome,...
Case Report: The Conundrum of What to Pick? Antibiotic Susceptibility Variability in in Cystic Fibrosis: Implications for Antibiotic Susceptibility Testing and Treatment.
Within cystic fibrosis microbiology, there is often mismatch between the antibiotic susceptibility result of an isolated bacterial pathogen and the clinical outcome, when the patient is treated with the same antibiotic. The reasoning for this remains largely elusive. Antibiotic susceptibility to four antibiotics (ceftazidime, meropenem, minocycline and trimethoprim-sulfamethoxazole) was determined in consecutive isolates ( = 11) from an adult cystic fibrosis patient, over a 63 month period. Each isolate displayed its own unique resistotype. The first isolate was sensitive to all four antibiotics, in accordance with Clinical and Laboratory Standards Institute methodology and interpretative criteria. Resistance was first detected at four months, showing resistance to ceftazidime and meropenen and intermediate resistance to minocycline and trimethoprim-sulfamethoxazole. Pan resistance was first detected at 18 months (resistotype IV), with three resistotypes (I, II and III) preceding this complete resistotype. The bacterium continued to display further antibiotic susceptibility heterogeneity for the next 45 months, with the description of an additional seven resistotypes (resistotypes V-XI). The Relative Resistance Index of this bacterium over the 63 month period showed no relationship between the development of antibiotic resistance and time. Adoption of mathematical modelling employing multinomial distribution demonstrated that large numbers of individual colony picks (>40/sputum), would be required to be 78% confident of capturing all 11 resistotypes present. Such a requirement for large numbers of colony picks combined with antibiotic susceptibility-related methodological problems creates a conundrum in biomedical science practice, in providing a robust assay that will capture antibiotic susceptibility variation, be pragmatic and cost-effective to deliver as a pathology service, but have the reliability to help clinicians select appropriate antibiotics for their patients. This study represents an advance in biomedical science as it demonstrates potential variability in antibiotic susceptibility testing with . Respiratory physicians and paediatricians need to be made aware of such variation by biomedical scientists at the bench, so that clinicians can contextualise the significance of the reported susceptibility result, when selecting appropriate antibiotics for their cystic fibrosis patient. Furthermore, consideration needs to be given in providing additional guidance on the laboratory report to highlight this heterogeneity to emphasise the potential for misalignment between susceptibility result and clinical outcome.
Topics: Cystic Fibrosis; Humans; Anti-Bacterial Agents; Microbial Sensitivity Tests; Burkholderia cenocepacia; Burkholderia Infections; Adult; Drug Resistance, Bacterial
PubMed: 38895586
DOI: 10.3389/bjbs.2024.12749 -
International Journal of Nanomedicine 2024Persistent endodontic infections (PEIs) mediated by bacterial biofilm mainly cause persistent periapical inflammation, resulting in recurrent periapical abscesses and...
INTRODUCTION
Persistent endodontic infections (PEIs) mediated by bacterial biofilm mainly cause persistent periapical inflammation, resulting in recurrent periapical abscesses and progressive bone destruction. However, conventional root canal disinfectants are highly damaging to the tooth and periodontal tissue and ineffective in treating persistent root canal infections. Antimicrobial materials that are biocompatible with apical tissues and can eliminate PEIs-associated bacteria are urgently needed.
METHODS
Here, ε-poly (L-lysine) derived carbon quantum dots (PL-CQDs) are fabricated using pyrolysis to remove PEIs-associated bacterial biofilms.
RESULTS
Due to their ultra-small size, high positive charge, and active reactive oxygen species (ROS) generation capacity, PL-CQDs exhibit highly effective antibacterial activity against (), which is greatly dependent on PL-CQDs concentrations. 100 µg/mL PL-CQDs could kill in 5 min. Importantly, PL-CQDs effectively achieved a reduction of biofilms in the isolated teeth model, disrupting the dense structure of biofilms. PL-CQDs have acceptable cytocompatibility and hemocompatibility in vitro and good biosafety in vivo.
DISCUSSION
Thus, PL-CQDs provide a new strategy for treating -associated PEIs.
Topics: Enterococcus faecalis; Quantum Dots; Biofilms; Polylysine; Carbon; Animals; Gram-Positive Bacterial Infections; Anti-Bacterial Agents; Humans; Reactive Oxygen Species; Mice
PubMed: 38895145
DOI: 10.2147/IJN.S453385 -
Frontiers in Public Health 2024The outbreak of norovirus represents a significant public health emergency within densely populated, impoverished, and underdeveloped areas and countries. Our objective...
BACKGROUND
The outbreak of norovirus represents a significant public health emergency within densely populated, impoverished, and underdeveloped areas and countries. Our objective is to conduct an epidemiology study of a norovirus outbreak that occurred in a kindergarten located in rural western China. We aim to raise awareness and garner increased attention towards the prevention and control of norovirus, particularly in economically underdeveloped regions.
METHODS
Retrospective on-site epidemiological investigation results, including data on school layout, case symptoms, onset time, disposal methods and sample testing results, questionnaire surveys, and case-control study were conducted in a kindergarten to analyze the underlying causes of the norovirus outbreak.
RESULTS
A total of 15 cases were identified, with an attack rate of 44.12% (15/34). Among them, 10 cases were diagnosed through laboratory tests, and 5 cases were diagnosed clinically. Vomiting (100%, 15/15) and diarrhea (93.33%, 14/15) were the most common symptoms in the outbreak. Case control study revealed that cases who had close contact (<1 m) with the patient's vomitus (OR = 5.500) and those who had close contact with similar patients (OR = 8.000) had significantly higher ORs compared to the control participants. The current study demonstrated that improper handling of vomitus is positively associated with norovirus outbreak. The absence of standardized disinfection protocols heightens the risk of norovirus outbreaks.
CONCLUSION
To our knowledge, this study represents the first investigation into a norovirus outbreak in rural areas of western China. We aspire that amidst rapid economic development, a greater emphasis will be placed on the prevention and control of infectious diseases in economically underdeveloped areas and countries.
Topics: Humans; Caliciviridae Infections; Disease Outbreaks; China; Norovirus; Female; Male; Case-Control Studies; Retrospective Studies; Rural Population; Gastroenteritis; Child, Preschool; Surveys and Questionnaires; Schools; Child; Developing Countries
PubMed: 38894991
DOI: 10.3389/fpubh.2024.1406133 -
Frontiers in Microbiology 2024Biofilms are the natural state for bacterial and fungal species. To achieve surface hygiene in commercial facilities, the presence of biofilms must be adequately... (Review)
Review
Biofilms are the natural state for bacterial and fungal species. To achieve surface hygiene in commercial facilities, the presence of biofilms must be adequately considered. However, standard disinfectant and sanitizer efficacy tests required by the US-EPA and the European Committee for Standardization (CEN) do not currently consider the role of environmental biofilms. This selective review will discuss what biofilms are and why they are important. We will also cover where they are commonly found in healthcare and food processing facilities and explore how current antimicrobial test methods required for product registration do not test for the presence of biofilms. Additionally, we will explore how a lack of efficacy against biofilms may play a role in the development of antimicrobial resistance in healthcare facilities due to the exchange of mobile genetic elements that occur readily in a biofilm matrix.
PubMed: 38894974
DOI: 10.3389/fmicb.2024.1405428 -
Cureus May 2024Several hundred different microbial taxa have made the oral cavity their home because of their evolution in multiple species communities within the special ecosystem. On... (Review)
Review
Several hundred different microbial taxa have made the oral cavity their home because of their evolution in multiple species communities within the special ecosystem. On the other hand, the dental pulp or internal tissue of the tooth is a connective tissue that is physiologically sterile and where any microbial infiltration is a harmful indication. It causes the pulp tissue to become inflamed, which leads to the death of the pulp and diffuses infection with inflammation to the peri-radicular tissues. Comprehending the biology of biofilms, the microbial makeup, and the host's reaction to infections in the pathobiology of root canal infections has received a lot of attention throughout the last few decades. Such comprehensive knowledge is required to design preventive medicines as well as clinically effective treatment regimens. Surprisingly, clinical approaches have concentrated more on radiographically perfecting channel preparation than on debridement of these intricate root canal systems, despite the clear realization that root canal infections are biofilm mediated. Since the present comprehension of the microbial etiopathogenesis of apical periodontitis highlights the significance of focusing on procedures such as "canal cleaning" and chemo-mechanical disinfection, the exclusive purpose of endodontic therapy is mainly missed while discussing "canal shaping." We thoroughly examine the state of our knowledge of the composition and functional traits of the root canal microbiome in this review. We also go into the difficulties with root canal disinfection and the cutting-edge approaches that try to solve these difficulties. In conclusion, we present essential guidance for prospective research areas, underscoring their significance as crucial considerations in the field of frontiers in oral health.
PubMed: 38894761
DOI: 10.7759/cureus.60577