Regulatory path for soil microbial communities depends on the type and dose of microplastics.

To reveal the feedbacks and regulating mechanisms of microplastic types and doses on microbial community, a microcosm experiment was carried out with two non-degradable microplastics [polyethylene (PE) and polyvinyl chloride (PVC)] and four biodegradable microplastics [poly(butylene succinate) (PBS), polyhydroxyalkanoates (PHA), poly(butyleneadipate-co-terephthalate) (PBAT), and polypropylene carbonate (PPC)] at different levels (1 %, 7 %, and 28 %). As a result, the content of total carbon (TC), soil organic carbon (SOC), and microbial biomass carbon (MBC) (expect MBC in PBS soil) increased with increasing doses of microplastics, and increased at the lowest PE dose rate. Biodegradable microplastics created a more active ecological niche while enriching more pathogens than non-degradable microplastics. Structural equation modeling indicated that microbial diversities were in a type-dependent assembly, whereas microbial compositions were more profoundly affected by the microplastic doses, ultimately. The standardized total effect coefficient of microplastic types on bacterial and fungal diversities was - 0.429 and - 0.282, and that of doses on bacterial and fungal compositions was 0.487 and 0.336, respectively. Both microplastic types and doses significantly impacted pH, electrical conductivity, total nitrogen, TC, SOC, and MBC, subsequently inhibiting microbial diversities and stimulating microbial compositions with particular pathways. The results provide a comprehensive understanding for evaluating the potential risk of microplastics.

Gallic Acid-Modified Polyethylenimine-Polypropylene Carbonate-Polyethylenimine Nanoparticles: Synthesis, Characterization, and Anti-Periodontitis Evaluation.

The aim of the research was to develop novel gallic acid (GA)-modified amphiphilic nanoparticles of polyethylenimine (PEI)-polypropylene carbonate (PPC)-PEI (PEPE) and comprehensively assess its properties as an antiperiodontitis nanoparticle targeting the Toll-like receptor (TLR). The first step is to evaluate the binding potential of GA to the core trigger receptors TLR2 and TLR4/MD2 for periodontitis using molecular docking techniques. Following this, we conducted NMR, transmission electron microscopy, and dynamic light scattering analyses on the synthesized PEPE nanoparticles. As the final step, we investigated the synthetic results and in vitro antiperiodontitis properties of GA-PEPE nanoparticles. The investigation revealed that GA exhibits potential for targeted binding to TLR2 and the TLR4/MD2 complex. Furthermore, we successfully developed 91.19 nm positively charged PEPE nanoparticles. Spectroscopic analysis indicated the successful synthesis of GA-modified PEPE. Additionally, CCK8 results demonstrated that GA modification significantly reduced the biotoxicity of PEPE. The in vitro antiperiodontitis properties assessment illustrated that 6.25 µM of GA-PEPE nanoparticles significantly reduced the expression of pro-inflammatory factors TNF-α, IL-1ß, and IL-6. The GA-PEPE nanoparticles, with their targeted TLR binding capabilities, were found to possess excellent biocompatibility and antiperiodontitis properties. GA-PEPE nanoparticles will provide highly innovative input into the development of anti- periodontitis nanoparticles.

Population analysis of heavy metal and biocide resistance genes in Salmonella enterica from human clinical cases in New Hampshire, United States.

Microbes frequently encounter heavy metals and other toxic compounds generated from natural biogeochemical processes and anthropogenic activities. Here, we analyzed the prevalence and association of genes conferring resistance to heavy metals, biocides, and antimicrobial compounds in 394 genome sequences of clinical human-derived S. enterica from New Hampshire, USA. The most prevalent was the gold operon (gesABC-golTSB), which was present in 99.2% of the genomes. In contrast, the other five heavy metal operons (arsenic, copper, mercury, silver, tellurite) were present in 0.76% (3/394)-5.58% (22/394) of the total population. The heavy metal operons and three biocide resistance genes were differentially distributed across 15 sequence types (STs) and 16 serotypes. The number of heavy metal operons and biocide resistance genes per genome was significantly associated with high number of antimicrobial resistance (AMR) genes per genome. Notable is the mercury operon which exhibited significant association with genes conferring resistance to aminoglycosides, cephalosporins, diaminopyrimidine, sulfonamide, and fosfomycin. The mercury operon was co-located with the AMR genes aac(3)-IV, ant(3")-IIa, aph(3')-Ia, and aph(4)-Ia, CTX-M-65, dfrA14, sul1, and fosA3 genes within the same plasmid types. Lastly, we found evidence for negative selection of individual genes of each heavy metal operon and the biocide resistance genes (dN/dS < 1). Our study highlights the need for continued surveillance of S. enterica serotypes that carry those genes that confer resistance to heavy metals and biocides that are often associated with mobile AMR genes. The selective pressures imposed by heavy metals and biocides on S. enterica may contribute to the co-selection and spread of AMR in human infections.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy.

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Genome characteristics of clinical Salmonella enterica population from a state public health laboratory, New Hampshire, USA, 2017-2020.

BACKGROUND: The implementation of whole genome sequencing (WGS) by PulseNet, the molecular subtyping network for foodborne diseases, has transformed surveillance, outbreak detection, and public health laboratory practices in the United States. In 2017, the New Hampshire Public Health Laboratories, a member of PulseNet, commenced the use of WGS in tracking foodborne pathogens across the state. We present some of the initial results of New Hampshire's initiative to transition to WGS in tracking Salmonella enterica, a bacterial pathogen that is responsible for non-typhoidal foodborne infections and enteric fever. We characterize the population structure and evolutionary history of 394 genomes of isolates recovered from human clinical cases in New Hampshire from 2017 to 2020. RESULTS: The New Hampshire S. enterica population is phylogenetically diverse, consisting of 78 sequence types (ST) and 67 serotypes. Six lineages dominate the population: ST 11 serotype Enteritidis, ST 19 Typhimurium, ST 32 Infantis, ST 118 Newport, ST 22 Braenderup, and ST 26 Thompson. Each lineage is derived from long ancestral branches in the phylogeny, suggesting their extended presence in the region and recent clonal expansion. We detected 61 genes associated with resistance to 14 antimicrobial classes. Of these, unique genes of five antimicrobial classes (aminocoumarins, aminoglycosides, fluoroquinolones, nitroimidazoles, and peptides) were detected in all genomes. Rather than a single clone carrying multiple resistance genes expanding in the state, we found multiple lineages carrying different combinations of independently acquired resistance determinants. We estimate the time to the most recent common ancestor of the predominant lineage ST 11 serotype Enteritidis (126 genomes) to be 1965 (95% highest posterior density intervals: 1927-1982). Its population size expanded until 1978, followed by a population decline until 1990. This lineage has been expanding since then. Comparison with genomes from other states reveal lack of geographical clustering indicative of long-distance dissemination. CONCLUSIONS: WGS studies of standing pathogen diversity provide critical insights into the population and evolutionary dynamics of lineages and antimicrobial resistance, which can be translated to effective public health action and decision-making. We highlight the need to strengthen efforts to implement WGS-based surveillance and genomic data analyses in state public health laboratories.

Applications of Titanium Dioxide Nanostructure in Stomatology.

Breakthroughs in the field of nanotechnology, especially in nanochemistry and nanofabrication technologies, have been attracting much attention, and various nanomaterials have recently been developed for biomedical applications. Among these nanomaterials, nanoscale titanium dioxide (nano-TiO2) has been widely valued in stomatology due to the fact of its excellent biocompatibility, antibacterial activity, and photocatalytic activity as well as its potential use for applications such as dental implant surface modification, tissue engineering and regenerative medicine, drug delivery carrier, dental material additives, and oral tumor diagnosis and treatment. However, the biosafety of nano-TiO2 is controversial and has become a key constraint in the development of nano-TiO2 applications in stomatology. Therefore, in this review, we summarize recent research regarding the applications of nano-TiO2 in stomatology, with an emphasis on its performance characteristics in different fields, and evaluations of the biological security of nano-TiO2 applications. In addition, we discuss the challenges, prospects, and future research directions regarding applications of nano-TiO2 in stomatology that are significant and worthy of further exploration.

pH-Responsive Polymer Nanomaterials for Tumor Therapy.

The complexity of the tumor microenvironment presents significant challenges to cancer therapy, while providing opportunities for targeted drug delivery. Using characteristic signals of the tumor microenvironment, various stimuli-responsive drug delivery systems can be constructed for targeted drug delivery to tumor sites. Among these, the pH is frequently utilized, owing to the pH of the tumor microenvironment being lower than that of blood and healthy tissues. pH-responsive polymer carriers can improve the efficiency of drug delivery in vivo, allow targeted drug delivery, and reduce adverse drug reactions, enabling multifunctional and personalized treatment. pH-responsive polymers have gained increasing interest due to their advantageous properties and potential for applicability in tumor therapy. In this review, recent advances in, and common applications of, pH-responsive polymer nanomaterials for drug delivery in cancer therapy are summarized, with a focus on the different types of pH-responsive polymers. Moreover, the challenges and future applications in this field are prospected.

A novel sustained release fluoride strip based Poly(propylene carbonate) for preventing caries.

Low-level fluoride in the oral environment for a long sustained period is more effective for preventing caries. However, the current fluoride delivery methods have a short fluoride retention time and high-dose fluoride administration may increase the risk of dental fluorosis. This study developed a novel fluoride strip based poly(propylene carbonate) (PPC), which can improve oral fluoride retention for desirable anticaries effect with minimal side effects. The fluoride strips based PPC (NaF-PPC strips) with different fluoride contents (0, 1.25, 2.5 and 5 wt.%) were developed by melt-blending method. The physico-chemical characteristics, drug loading, drug release properties, remineralization and antibacterial efficacy and biocompatibility of NaF-PPC strips were investigated. The in vitro drug release studies indicated that fluoride release in a sustained manner with no initial burst release and approximately 100% of fluoride ions were released from PPC strips over 24 days. NaF-PPC strips exhibited excellent remineralization and antibacterial potential when fluoride content up to 5%. Combination with biocompatibility, 2.5% NaF-PPC strips could be a promising fluoride application for preventing caries. This work provides an effective and novel topical fluoride delivery for general use.

The Application of Chitosan Nanostructures in Stomatology.

Chitosan (CS) is a natural polymer with a positive charge, a deacetylated derivative of chitin. Chitosan nanostructures (nano-CS) have received increasing interest due to their potential applications and remarkable properties. They offer advantages in stomatology due to their excellent biocompatibility, their antibacterial properties, and their biodegradability. Nano-CSs can be applied as drug carriers for soft tissue diseases, bone tissue engineering and dental hard tissue remineralization; furthermore, they have been used in endodontics due to their antibacterial properties; and, finally, nano-CS can improve the adhesion and mechanical properties of dental-restorative materials due to their physical blend and chemical combinations. In this review, recent developments in the application of nano-CS for stomatology are summarized, with an emphasis on nano-CS's performance characteristics in different application fields. Moreover, the challenges posed by and the future trends in its application are assessed.

Reactive Oxygen Species Responsive Polymers for Drug Delivery Systems.

Reactive oxygen species (ROS) play an essential role in regulating various physiological functions of living organisms; however, as the concentration of ROS increases in the area of a lesion, this may undermine cellular homeostasis, leading to a series of diseases. Using cell-product species as triggers for targeted regulation of polymer structures and activity represents a promising approach for the treatment. ROS-responsive polymer carriers allow the targeted delivery of drugs, reduce toxicity and side effects on normal cells, and control the release of drugs, which are all advantages compared with traditional small-molecule chemotherapy agents. These formulations have attracted great interest due to their potential applications in biomedicine. In this review, recent progresses on ROS responsive polymer carriers are summarized, with a focus on the chemical mechanism of ROS-responsive polymers and the design of molecular structures for targeted drug delivery and controlled drug release. Meanwhile, we discuss the challenges and future prospects of its applications.

Diverse lineages of multidrug resistant clinical Salmonella enterica and a cryptic outbreak in New Hampshire, USA revealed from a year-long genomic surveillance.

Salmonella enterica, the causative agent of gastrointestinal diseases and typhoid fever, is a human and animal pathogen that causes significant mortality and morbidity worldwide. In this study, we examine the genomic diversity and phylogenetic relationships of 63 S. enterica isolates from human-derived clinical specimens submitted to the Department of Health and Human Services (DHHS) in the state of New Hampshire, USA in 2017. We found a remarkably large genomic, phylogenetic and serotype variation among the S. enterica isolates, dominated by serotypes Enteritidis (sequence type [ST] 11), Heidelberg (ST 15) and Typhimurium (ST 19). Analysis of the distribution of single nucleotide polymorphisms in the core genome suggests that the ST 15 cluster is likely a previously undetected or cryptic outbreak event that occurred in the south/southeastern part of New Hampshire in August-September. We found that nearly all of the clinical S. enterica isolates carried horizontally acquired genes that confer resistance to multiple classes of antimicrobials, most notably aminoglycosides, fluoroquinolones and macrolides. Majority of the isolates (76.2%) carry at least four resistance determinants per genome. We also detected the genes mdtK and mdsABC that encode multidrug efflux pumps and the gene sdiA that encodes a regulator for a third multidrug resistance pump. Our results indicate rapid microevolution and geographical dissemination of multidrug resistant lineages over a short time span. These findings are critical to aid the DHHS and similar public health laboratories in the development of effective disease control measures, epidemiological studies and treatment options for serious Salmonella infections.

Genomic Epidemiology and Evolution of Diverse Lineages of Clinical Campylobacter jejuni Cocirculating in New Hampshire, USA, 2017.

Campylobacter jejuni is one of the leading causes of bacterial gastroenteritis worldwide. In the United States, New Hampshire was one of the 18 states that reported cases in the 2016 to 2018 multistate outbreak of multidrug-resistant C. jejuni Here, we aimed to elucidate the baseline diversity of the wider New Hampshire C. jejuni population during the outbreak. We used genome sequences of 52 clinical isolates sampled in New Hampshire in 2017, including 1 of the 2 isolates from the outbreak. Results revealed a remarkably diverse population composed of at least 28 sequence types, which are mostly represented by 1 or a few strains. A comparison of our isolates with 249 clinical C. jejuni from other states showed frequent phylogenetic intermingling, suggesting a lack of geographical structure and minimal local diversification within the state. Multiple independent acquisitions of resistance genes from 5 classes of antibiotics characterize the population, with 47/52 (90.4%) of the genomes carrying at least 1 horizontally acquired resistance gene. Frequently recombining genes include those associated with heptose biosynthesis, colonization, and stress resistance. We conclude that the diversity of clinical C. jejuni in New Hampshire in 2017 was driven mainly by the coexistence of phylogenetically diverse antibiotic-resistant lineages, widespread geographical mixing, and frequent recombination. This study provides an important baseline census of the standing pangenomic variation and drug resistance to aid the development of a statewide database for epidemiological studies and clinical decision making. Continued genomic surveillance will be necessary to accurately assess how the population of C. jejuni changes over the long term.

Large Outbreak of Hepatitis C Virus Associated With Drug Diversion by a Healthcare Technician.

Background: In May 2012, the New Hampshire (NH) Division of Public Health Services (DPHS) was notified of 4 persons with newly diagnosed hepatitis C virus (HCV) infection at hospital X. Initial investigation suggested a common link to the hospital cardiac catheterization laboratory (CCL) because the infected persons included 3 CCL patients and a CCL technician. NH DPHS initiated an investigation to determine the source and control the outbreak. Methods: NH DPHS conducted site visits, case patient and employee interviews, medical record and medication use review, and employee and patient HCV testing using enzyme immunoassay for anti-HCV, reverse-transcription polymerase chain reaction for HCV RNA, nonstructural 5B (NS5B) and hypervariable region 1 (HVR1) sequencing, and quasispecies analysis. Results: HCV HVR1 analysis of the first 4 cases confirmed a common source of infection. HCV testing identified 32 of 1074 CCL patients infected with the outbreak strain, including 3 patients coinfected with >1 HCV strain. The epidemiologic investigation revealed evidence of drug diversion by the HCV-infected technician, evidenced by gaps in controlled medication control, higher fentanyl use during procedures for confirmed cases, and building card key access records documenting the presence of the technician during days when transmission occurred. The employee's status as a traveling technician led to a multistate investigation, which identified additional cases at prior employment sites. Conclusions: This is the largest laboratory-confirmed drug diversion-associated HCV outbreak published to date. Recommendations to reduce drug diversion risk and to conduct outbreak investigations are provided.

Effects of Biochar-Derived Sewage Sludge on Heavy Metal Adsorption and Immobilization in Soils.

The object of this study was to evaluate the effect of sewage sludge biochar on adsorption and mobility of Cr, Mn, Cu, and Zn. Biochar (BC400) was produced via pyrolysis of municipal sewage sludge at 400 °C. Maximum adsorption capacities (qm) for Zn, Cr, Mn, and Cu were 5.905, 5.724, 5.681, and 5.342 mg·g-1, respectively, in the mono-metal solution and 2.475, 8.204, 1.01, and 5.415 mg·g-1, respectively, in the multi-metal solution. The adsorption capacities for Mn, Cu, and Zn decreased in the multi-metal solution due to competitive adsorption, whereas the capacity for Cr increased. Surface precipitation is an important mechanism in the sorption of these metals on BC400. The 360-day incubation experiment showed that BC400 application reduced metal mobility in contaminated soils, which was attributed to the substantial decreases in the acid-soluble fractions of Cr, Mn, Cu, and Zn (72.20%, 70.38%, 50.43%, and 29.78%, respectively). Furthermore, the leaching experiment using simulated acid rain indicated that the addition of BC400 enhanced the acid buffer capacity of contaminated soil, and the concentration of Cr, Mn, Cu, and Zn in the leachate was lower than in untreated soil. Overall, this study indicates that sewage sludge biochar application reduces the mobility of heavy metal in co-contaminated soil, and this adsorption experiment is suitable for the evaluation of biochar properties for remediation.

Performance of the OraQuick HCV rapid antibody test for screening exposed patients in a hepatitis C outbreak investigation.

During a nosocomial hepatitis C outbreak, emergency public clinics employed the OraQuick HCV rapid antibody test on site, and all results were verified by a standard enzyme immunoassay (EIA). Of 1,157 persons, 1,149 (99.3%) exhibited concordant results between the two tests (16 positive, 1,133 negative). The sensitivity, specificity, positive predictive value, and negative predictive value were 94.1%, 99.5%, 72.7%, and 99.9%, respectively. OraQuick performed well as a screening test during an outbreak investigation and could be integrated into future hepatitis C virus (HCV) outbreak testing algorithms.

Evaluation of a multitarget real-time PCR assay for detection of Bordetella species during a pertussis outbreak in New Hampshire in 2011.

A multitarget real-time PCR assay with three targets, including insertion sequence 481 (IS481), IS1001, and an IS1001-like element, as well as pertussis toxin subunit S1 (ptxS1), for the detection of Bordetella species was evaluated during a pertussis outbreak. The sensitivity and specificity were 77 and 88% (PCR) and 66 and 100% (culture), respectively. All patients with an IS481 C(T) of <30 also tested positive by ptxS1 assay and were clinical pertussis cases. No patients with IS481 C(T) values of ≥40 tested positive by culture. Therefore, we recommend that culture be performed only for specimens with IS481 C(T) values of 30 ≤ CT <40.

Detection of 2009 pandemic influenza A(H1N1) virus Infection in different age groups by using rapid influenza diagnostic tests.

BACKGROUND: The performance of rapid influenza diagnostic tests (RIDTs) in detecting influenza A(H1N1) 2009 has varied widely. Evaluations of RIDTs among infected individuals across all age groups have not been described in depth. OBJECTIVES: Determine RIDT clinical sensitivity in comparison with influenza detection using real-time RT-PCR among patients infected with influenza A(H1N1) 2009 across all age groups. STUDY DESIGN: This study analyzed respiratory specimens received by the New Hampshire Public Health Laboratories (NHPHL) from September 1, 2009, through December 31, 2009. RIDT performance was evaluated among different age groups of patients determined to be infected with influenza A (H1N1) 2009, and the association between age and RIDT sensitivity was determined. RESULTS: Of 1373 specimens examined, 269 tested positive for influenza A(H1N1) 2009 by real-time RT-PCR (rRT-PCR) and had RIDT results available. Overall clinical sensitivity and specificity of RIDTs were 53·9 and 98·5%, respectively. By age group, clinical sensitivity was 85·7% in patients <2 years old, 60·3% in patients between 2- and 39 years old, and 33·3% in patients aged 40 and older. Logistic regression analysis indicated that increasing age was negatively associated with RIDT performance. CONCLUSION: Rapid influenza diagnostic test sensitivity decreased significantly with increasing age. Findings from this study may impact a clinician's interpretation of RIDT test results and ultimately have implications in clinical decision-making.

HCV infection in voluntary donors and its influence on recruitment of donors in Chongqing area.

Blood donor recruitment models have changed from paid donors to employer-organized donors and to voluntary donors in China. Reports on the hepatitis C virus (HCV) infection among voluntary blood donors in China have been rarely found at present. The prevalence of anti-HCV and genotypes among the first-time voluntary blood donors was investigated in Chongqing area of China. A total of 13,620 serum samples were collected from the first-time voluntary blood donors in Chongqing, China. Anti-HCV antibody was tested by ELISA. The Core/E2 region of HCV RNA from HCV seropositive samples was amplified by RT-PCR for genotyping. The results indicated that the prevalence of anti-HCV averaged 0.49% (67/13,620), and the highest rate (0.86%) was obtained in the group aged 40 to 49. A higher prevalence was observed among the more educated donors, and metropolitan donors. The ratios of following genotypes 1b, 2a, 3a and 3b were 4 (18%), 5 (23%), 9 (41%) and 4 (18%) in all the 22 samples respectively. Genotype 3 (3a and 3b) was the predominant genotype. In conclusion, the prevalence of anti-HCV was low among the population of voluntary blood donors in Chonqing area. The genotyping results showed the possibility of presence of druggies among the voluntary blood donors. Therefore, more attention should be paid to exclude those high-risk persons from the volunteers.

HCV selection and HVR1 evolution in a chimpanzee chronically infected with HCV-1 over 12 years.

AIM: To study hepatitis C virus (HCV) selection and hypervariable region-1 (HVR1) evolution in a chimpanzee chronically infected with HCV-1 over 12 years after inoculation with a human factor VIII concentrate contaminated with HCV. METHODS: From the inoculum, the earliest chimpanzee plasma and 12 annual plasma samples, HCV fragments including HVR1 were amplified followed by cloning and sequencing. RESULTS: Five HCV subtypes - 1a, 1b, 2a, 2b, 3a - and multiple 1a strains were identified in the inoculum. Two 1a strains were found in the earliest chimpanzee sample, while a single HCV-1 strain was detected in the 12 annual samples. None of the chimpanzee sequences were identical to those found in the inoculum. Over 12 years, HVR1 patterns changed irregularly, but a few patterns showed identical nucleotide or amino acid sequences. In the last three years, the variety of HVR1 patterns decreased, while the proportion of major patterns increased. These corresponded to a higher virus load and a lower number of amino acid substitutions. Simultaneously, the HVR1 sequences became more similar to the consensus sequence of the 1a subtype. CONCLUSION: HCV selection was observed from the inoculum to the inoculated chimpanzee and from the early acute hepatitis to the persistent chronic infection. The selection occurred at three levels: among subtypes after transmission, among isolates during acute hepatitis and among quasispecies in chronic infection.