Progress in methods for the detection of viable Escherichia coli.

Escherichia coli (E. coli) is a prevalent enteric bacterium and a necessary organism to monitor for food safety and environmental purposes. Developing efficient and specific methods is critical for detecting and monitoring viable E. coli due to its high prevalence. Conventional culture methods are often laborious and time-consuming, and they offer limited capability in detecting potentially harmful viable but non-culturable E. coli in the tested sample, which highlights the need for improved approaches. Hence, there is a growing demand for accurate and sensitive methods to determine the presence of viable E. coli. This paper scrutinizes various methods for detecting viable E. coli, including culture-based methods, molecular methods that target DNAs and RNAs, bacteriophage-based methods, biosensors, and other emerging technologies. The review serves as a guide for researchers seeking additional methodological options and aiding in the development of rapid and precise assays. Moving forward, it is anticipated that methods for detecting E. coli will become more stable and robust, ultimately contributing significantly to the improvement of food safety and public health.

Rapid diagnosis of acute myocardial infarction based on reverse transcription-accelerated strand exchange amplification of miR-208a.

Acute myocardial infarction (AMI) is a prevalent cardiovascular disease associated with high morbidity and mortality, posing a significant threat to human health. Therefore, early diagnosis of AMI has become a focal point of research. MiR-208 is specifically expressed in the heart and is involved in the regulation of cardiomyocyte hypertrophy, cardiac fibrosis, and other myocardial gene expressions. It is expected to be applied in the clinical detection of AMI due to its release by damaged myocardial cells within 3 hours of AMI. In this study, we developed a denatured bubble-mediated reverse transcription-accelerated strand exchange amplification (RT-ASEA) method to detect the early biomarker miR-208a of AMI. The novel approach allowed rapid amplification of miR-208a in 15 minutes, with good performance in terms of repeatability (CV < 6%), determination limit (1 × 100 pmol L-1), and linearity (R2 = 0.9690). Based on the analysis of 42 clinical samples, a strong correlation was observed between the Ct value of miR-208a detected by the RT-ASEA method and the cTnI concentration, considered the gold standard for diagnosis of AMI. The research suggested that the RT-ASEA method could be applied to distinguish between AMI and healthy groups. The area under the receiver operating characteristic curve (AUC) was 0.9976, with a sensitivity of 96% and a specificity of 100%. Optimized RT-ASEA is a reliable and efficient method for miRNA detection. Furthermore, this study provides crucial data support for the development of miR-208a as an early biomarker for AMI, which is of great significance in life and health.

siRNA targeting Atp5a1 gene encoding ATPase α, the ligand of Peg fimbriae, reduced Salmonella Enteritidis adhesion.

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a zoonotic pathogen that can infect both humans and animals. Among the 13 types of fimbrial operons in S. Enteritidis, the highly conserved Peg fimbriae play a crucial role in the adhesion and invasion of S. Enteritidis into host cells but are not well studied. In this study, we identified the ATP synthase subunit alpha (ATPase α) as a ligand of Peg fimbriae using ligand blotting and mass spectrometry techniques. We confirmed the in vitro binding of ATPase α to the purified adhesion protein (PegD). Furthermore, we used siRNA to suppress the expression of ATPase α gene Atp5a1 in Leghorn male hepatoma (LMH) cells, which resulted in a significant reduction in the adhesion rate of S. Enteritidis to the cells (P < 0.05). The findings in this study provide insight into the mechanism of S. Enteritidis infection through Peg fimbriae and highlight the importance of ATPase α in the adhesion process.RESEARCH HIGHLIGHTS Ligand blotting was performed to screen the ligand of S. Enteritidis Peg fimbriae.Binding assay confirmed that ATPase α is the ligand of the Peg fimbriae.siRNA targeting ATPase α gene (Atp5a1) significantly reduced S. Enteritidis adhesion.

Bifunctional electrochemical biosensor based on PB-MXene films for the real-time analysis and detection of living cancer cells.

Circulating tumor cells (CTCs) are important prognostic markers for cancer diagnosis and metastasis, and their detection is an important means to detect cancer metastasis. Herein, we construct a novel bifunctional electrochemical biosensor based on the PB-MXene composite films. A simple electrostatic self-assembly approach was employed to prepare a film composed of PB nanocubes on the MXene substrates. Given that the PB is an artificial peroxidase for H2O2 sensing, the PB-MXene films can realize the real-time monitoring of H2O2 secretion from living CTCs. Besides, the anti-CEA attached biosensors can be utilized to quantify the corresponding CTCs. The synergic effects of the MXene with a large specific area and PB with enzyme-free catalysis for H2O2 resulted in PB-MXene films exhibiting high electrocatalytic and low cytotoxicity for both H2O2 sensing and living CTCs capturing. As a result, the biosensor shows a low detection limit of 0.57 µM towards H2O2 with a wide linear range (1 µM to 500 µM), as well as an excellent sensing performance for CTCs (an extremely low detection limit of 9 cells/mL in a wide linear range of 1.3 ×101 to 1.3 ×106 cells/mL). Moreover, the prepared biosensor showed satisfactory stability and anti-interference ability for potential applications in clinical cancer diagnosis and tumor metastasis.

Advances in detection methods for viable Salmonella spp.: current applications and challenges.

Salmonella is a common intestinal pathogen that can cause food poisoning and intestinal disease. The high prevalence of Salmonella necessitates efficient and sensitive methods for its identification, detection, and monitoring, especially of viable Salmonella. Conventional culture methods need to be more laborious and time-consuming. And they are relatively limited in their ability to detect Salmonella in the viable but non-culturable status if present in the sample to be tested. As a result, there is an increasing need for rapid and accurate techniques to detect viable Salmonella spp. This paper reviewed the status and progress of various methods reported in recent years that can be used to detect viable Salmonella, such as culture-based methods, molecular methods targeting RNAs and DNAs, phage-based methods, biosensors, and some techniques that have the potential for future application. This review can provide researchers with a reference for additional method options and help facilitate the development of rapid and accurate assays. In the future, viable Salmonella detection approaches will become more stable, sensitive, and fast and are expected to play a more significant role in food safety and public health.

High-Performance Detection of Exosomes Based on Synergistic Amplification of Amino-Functionalized Fe3O4 Nanoparticles and Two-Dimensional MXene Nanosheets.

Exosomes derived from cancer cells have been recognized as a promising biomarker for minimally invasive liquid biopsy. Herein, a novel sandwich-type biosensor was fabricated for highly sensitive detection of exosomes. Amino-functionalized Fe3O4 nanoparticles were synthesized as a sensing interface with a large surface area and rapid enrichment capacity, while two-dimensional MXene nanosheets were used as signal amplifiers with excellent electrical properties. Specifically, CD63 aptamer attached Fe3O4 nanoprobes capture the target exosomes. MXene nanosheets modified with epithelial cell adhesion molecule (EpCAM) aptamer were tethered on the electrode surface to enhance the quantification of exosomes captured with the detection of remaining protein sites. With such a design, the proposed biosensor showed a wide linear range from 102 particles µL-1 to 107 particles µL-1 for sensing 4T1 exosomes, with a low detection limit of 43 particles µL-1. In addition, this sensing platform can determine four different tumor cell types (4T1, Hela, HepG2, and A549) using surface proteins corresponding to aptamers 1 and 2 (CD63 and EpCAM) and showcases good specificity in serum samples. These preliminary results demonstrate the feasibility of establishing a sensitive, accurate, and inexpensive electrochemical sensor for detecting exosome concentrations and species. Moreover, they provide a significant reference for exosome applications in clinical settings, such as liquid biopsy and early cancer diagnosis.

A comparison of special intrauterine balloons and intrauterine contraceptive devices in the treatment of intrauterine adhesions.

PURPOSE: This study aimed to compare the efficacy of a special kind of intrauterine balloon (IUB) and that of an intrauterine contraception device (IUD) for patients with intrauterine adhesions (IUAs) after transcervical resection of adhesion (TCRA). METHODS: In this retrospective cohort study, after TCRA, 31 patients received a special IUB, and 38 patients received an IUD. The Fisher exact test, logistic regression method, Kaplan-Meier method and Cox proportional hazards regression model were used for statistical analysis. A two-sided value of P < 0.05 was considered statistically significant. RESULTS: The readhesion rate significantly differed between the IUB group and IUD group, at 15.39% and 54.06%, respectively (P = 0.002). For recurrent moderate IUA, patients in the IUB group had lower scores than patients in the IUD group (P = 0.035). There was a significant difference in the intrauterine pregnancy rate of IUA patients in the IUB group and IUD group after treatment, with rates of 55.56% and 14.29%, respectively (P = 0.015). CONCLUSION: Patients in the special IUB group had better outcomes than those in the IUD group, which has a certain guiding significance for clinical work.

Graphene oxide-assisted optimized narrow-thermal-cycling amplification for accurate detection of Salmonella spp.

Salmonella is a rod-shaped, Gram-negative zoonotic pathogen that poses a serious global socioeconomic and public health threat. Rapid and accurate detection of Salmonella spp. is critical for effective control of its infection. In this study, an accurate, sensitive and specific graphene oxide-assisted accelerated strand exchange amplification (GO-ASEA) method for rapid detection of Salmonella spp. was developed and validated. The detection limit of the GO-ASEA method was 8.6 × 101 fg µL-1 of Salmonella genomic DNA or 1 × 101 CFU g-1 of Salmonella in spiked chicken faeces free of pre-enrichment. And the GO-ASEA method could specifically detect Salmonella spp. without cross-reactivity with other enteric pathogens. In addition, the novel method achieved Salmonella detection within 30 min and was validated using 209 clinical samples, showing its good clinical applicability. Therefore, the GO-ASEA method is a new optional tool for the rapid detection of pathogenic microorganisms, which is ideal for food safety monitoring and high-throughput detection.

Hierarchical Au nanoarrays functionalized 2D Ti2CTx MXene membranes for the detection of exosomes isolated from human lung carcinoma cells.

Exosome is considered an important biomarker of liquid biopsy in early cancer screening, which can reflect the physiological and pathological status of cancer cells. Herein, we construct a novel electrochemical biosensor based on hierarchical Au nanoarray-modified 2D Ti2CTx MXene membranes for sensitive detection of exosomes. Ti2CTx MXene nanosheets were fabricated as the building blocks for preparing 2D membranes as the sensing platform via vacuum filtration. To enhance the conductivity of the MXene membrane, for the first time, hierarchical Au nanoarrays were further deposited in situ on the MXene membrane surface. The combination of MXene membrane with a large specific area and hierarchical Au nanoarrays with excellent conductivity make higher electrocatalytic and more active sites in aptamer immobilization. In this strategy, the composite membrane modified by EpCAM recognized aptamer can specifically capture target exosomes, meanwhile, these target exosomes anchor aptamer for CD63 to further enhance the sensing sensitivity and accuracy of the biosensor. As a result, the biosensor achieved high sensitivity and reliable performance for exosome sensing, with a low detection limit (58 particles/µL) in the linear range of 1 × 102 to 1 × 107 particles/µL. In addition, this biosensor showed satisfactory electrochemical stability and anti-interference ability for the detection of exosomes in real serum samples.

Accurate, rapid and highly sensitive detection of African swine fever virus via graphene oxide-based accelerated strand exchange amplification.

African swine fever is an acute, severe and highly contagious infectious disease caused by African swine fever virus (ASFV), posing a huge threat to the global swine industry. Rapid and accurate diagnostic methods are of great significance for the effective prevention and control of ASFV transmission. In this work, we established and evaluated a graphene oxide-based accelerated strand exchange amplification (GO-ASEA) method for rapid, highly sensitive, and quantitative detection of ASFV. The use of GO provided a novel solution reference for improving the specificity of strand exchange amplification and solving the potential false positive problem caused by primer dimers. The detection limit of the GO-ASEA assay was 5.8 × 10-1 copies per µL of ASFV (equal to 2.9 copies per reaction) or 5.8 × 100 copies per µL of ASFV in spiked swine nasal swabs. The selectivity of the GO-ASEA assay was supported by the ASFV DNA reference material and another seven porcine-derived viruses with similar clinical symptoms. The GO-ASEA assay took only about 29 minutes and was validated with 6 inactivated specimens and 52 swine nasal swabs, showing excellent clinical applicability. The novel assay is an accurate and practical method for rapid, highly sensitive detection of ASFV, and can potentially serve as a robust tool in epidemic prevention and point-of-care diagnosis.

Tri-primer-enhanced strand exchange amplification combined with rapid lateral flow fluorescence immunoassay to detect SARS-CoV-2.

The novel coronavirus disease 2019 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been surging rapidly around the world, which has exposed humanity to unprecedented economic, social and health impacts. To achieve efficient and accurate detection of SARS-CoV-2 on site, we developed and verified a rapid and sensitive fluorescence lateral flow immunoassay based on the innovative enhanced strand exchange amplification (ESEA-LFIA) in this study. With good amplification efficiency for short-sequence targets, ESEA is an ideal choice for the point-of-care testing of SARS-CoV-2 with a high mutation rate. ESEA reaction can be completed in one step and verified by restriction enzyme digestion. The design consisting of three working primers greatly improved the amplification efficiency. Amplification of the target sequences of the RdRP and N genes can be accomplished under the same reaction conditions, and does not require expensive instruments. The sensitivity of the ESEA-LFIA assay targeting the RdRP and N genes was 90 copies per µL and 70 copies per µL, respectively. Specificity tests showed that the novel assay can specifically detect SARS-CoV-2, and had no cross-reactivity with 9 closely-related human pathogenic coronaviruses and other common respiratory pathogens with similar clinical manifestations. The cutoff values of the RdRP and N gene assays are 11 and 12, respectively, and the assays can be completed within 1 h. The novel strategy proposed in this study is a sensitive and specific method for the rapid detection of SARS-CoV-2, and is suitable as an effective potential bioanalytical tool to respond to future regional or global outbreaks of emerging infectious pathogens with high mutation rates.

Lateral flow fluorescent immunoassay based on isothermal amplification for rapid quantitative detection of Salmonella spp.

Salmonella spp. are zoonotic pathogens of substantial public health concern. To enable detection in the field or under instrument-free conditions, we developed a rapid and robust lateral flow fluorescent immunoassay based on strand exchange amplification (SEA-LFIA) for the quantitative detection of Salmonella spp. As far as we know, this work is the first report regarding the use of Bst DNA polymerase-assisted SEA for fluorescence sensing to detect Salmonella spp. The SEA method was further confirmed by enzymatic digestion and Sanger dideoxy sequencing. The specificity of SEA-LFIA assay was verified by 89 Salmonella strains (18 Salmonella reference strains and 71 clinical isolates) and 15 non-Salmonella reference strains (different genera). The sensitivity of SEA-LFIA assay was 6 × 100 CFU mL-1 of Salmonella pure culture or 3 × 104 CFU 25 g-1 of artificially spiked raw chicken meat. Using this assay, it was found that 37 (16%) of the 236 samples collected were positive, which was consistent with the results of conventional PCR. The cutoff value is 15 and SEA-LFIA assay only takes ∼30 min without high equipment and reagent cost. In addition, the proposed strategy can be easily extended by redesigning the corresponding amplification primers to detect target analytes. In conclusion, the optimized SEA-LFIA assay is an efficient and specific method for the detection of Salmonella spp., and can potentially serve as a new on-site diagnostic tool in life sciences.

Rapid and sensitive detection of Shigella flexneri using fluorescent microspheres as label for immunochromatographic test strip.

BACKGROUND: Bacillary dysentery caused by Shigella genus is a major cause of morbidity and mortality worldwide. In China, the popular strain was mainly Shigella flexneri (S. flexneri). Therefore, fluorescent microspheres (FMs)-based immunochromatographic test strip (ICTS), as a novel, reliable, sensitive and uncomplicated method, was evaluated to detect S. flexneri. METHODS: Sixty-three clinical samples of S. flexneri were collected in this paper. Polymerase chain reaction (PCR) combined with FMs-ICTS based on magnetic purification assay was developed for the quantitative detection of Shigella. And the genus-specific gene of ipaH and drug resistant gene of CTX-M-9 from Shigella were selected to investigate the potential of this new method. The sensitivity and specificity of this method were demonstrated by classical microbiological methods (API Coryne System), PCR assay based on agarose gel electrophoresis (PCR-GE) and the real-time fluorescent quantitative PCR (RTFQ-PCR) method. RESULTS: Under optimized conditions, the lower detection limits of PCR-ICTS, PCR-GE and RTFQ-PCR were 2.5×10-7, 2.5×10-5 and the 3.2×10-7 ng/µL, respectively. Experiments demonstrated the PCR-ICTS has a diagnostic agreement of 100% with conventional PCR and RTFQ-PCR on detection of clinical samples and could correctly recognize Shigella and non-Shigella from different microbial samples. After the purification of PCR products with Silicon coated magnetic nanoparticles (Si-MNPs), the false positive results were removed because of the strong screening ability of the purification process. Our results showed that FM-based ICTS was promising for measurable and sensitive detection of S. flexneri within 3 h. CONCLUSIONS: The results from immunochromatographic test were agreement with those from API Coryne system and RTFQ-PCR. Hence, this developed method might be useful for screening and monitoring clinical sample of S. flexneri, due to its speed, non-poisonous, simplicity and low-cost and helpful for promoting the prevention and control of communicable diseases caused by enteric pathogens such as S. flexneri.

Polymerase chain reaction combined with fluorescent lateral flow immunoassay based on magnetic purification for rapid detection of canine parvovirus 2.

BACKGROUND: Canine parvovirus 2 (CPV-2) is one of the most common etiological agents that cause severe gastroenteritis in puppies. Early accurate diagnosis is important for infected dogs. In recent years, magnetic separation has become an efficient and useful tool for bioassays. In this study, polymerase chain reaction (PCR) combined with fluorescent lateral flow immunoassay (LFIA) based on magnetic purification assay was developed for the quantitative detection of CPV-2. RESULTS: The optimum working reaction volume and reaction time for LFIA was 100 µL and 2 min, respectively. The PCR-LFIA assay only detected CPV-2, and did not show cross-detection of non-CPV strains. Experiments showed analytical sensitivity of 3 × 101 copies/µL and demonstrated the PCR-LFIA has a diagnostic agreement of 100% with conventional PCR on detection of clinical samples (22.6% positive, 14/62). Cutoff value is 146. The results were further verified by sequencing and BLAST software. The entire process from PCR step only takes ~ 80 min. CONCLUSIONS: This approach provides an attractive platform for rapid and quantitative detection of CPV-2, indicating great promise as a convenient molecular detection tool to facilitate disease outbreak investigations and response timely.

Serovar-Specific Polymerase Chain Reaction for Detection of Salmonella enterica Serovar Indiana.

Salmonella enterica serovar Indiana (S. Indiana) is a newly emerging pathogen with high levels of drug resistance. It has become one of the most common Salmonella serovars in China with a worldwide distribution, posing significant public health concerns. Detection of S. Indiana by traditional bacteriological methods is time-consuming and laborious, which prevents timely surveillance and effective control of the pathogen. In this study, comparative genomics was used to identify an A7P63_13850 gene that is uniquely present in S. Indiana, but not in other Salmonella serovars or any non-Salmonella bacteria. Then, a polymerase chain reaction (PCR) assay targeting this serovar-specific gene was established for specific detection of S. Indiana. The detection limit of this method is 10 pg per reaction for bacterial genomic DNA, being equivalent to 100 colony-forming units (CFU) per reaction. The established PCR amplifies all S. Indiana strains (n = 56), but none of other Salmonella serovars (n = 146) and non-Salmonella species (n = 14). The assay established in this study was also used to detect clinical samples from poultry, showed a positivity of 14.7% (23/156) for S. Indiana, which were verified by bacteriological methods. The highly sensitive and serovar-specific PCR for S. Indiana established in this study is suitable and convenient for detection of S. Indiana which aids in surveillance and control of the pathogen.

Establishment of a Multiplex Loop-Mediated Isothermal Amplification Method for Rapid Detection of Sulfonamide Resistance Genes (sul1, sul2, sul3) in Clinical Enterobacteriaceae Isolates from Poultry.

Antimicrobial resistance genes play an important role in mediating resistance to sulfonamide in Gram-negative bacteria. While PCR is the current method to detect sulfonamide resistance genes (sul1, sul2, sul3), it is time-consuming and costly and there is an urgent need to develop a more convenient, simpler and rapid test for the sul. In this study, we describe a multiplex loop-mediated isothermal amplification (m-LAMP) assay we developed for the rapid and simultaneous detection of three sul. This m-LAMP assay successfully detected seven reference strains with different sul genotypes, but was negative for nine sul-negative reference strains. The m-LAMP products were verified by HinfI restriction enzyme digestion and the detection limit of the test was 0.5 pg genomic DNA per reaction. Testing 307 sulfonamide-resistant Enterobacteriaceae clinical isolates with the m-LAMP revealed all were positive for the sul with sul2 (79.5%) and sul1 (64.5%) being most prevalent, and sul3 the least (12.1%). Of the Enterobacteriaceae isolates tested, the Salmonella Indiana, a newly emerging serovar resistant to numerous antimicrobials, were most commonly positive with 33% having sul3.

Virulence Gene Distribution of Salmonella Pullorum Isolates Recovered from Chickens in China (1953-2015).

Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (Salmonella Pullorum) has strict host specificity for poultry, and pullorum disease seriously threatens the poultry industry. Virulence genes play a central role in Salmonella pathogenicity, but very few reports are available on the distribution of virulence genes in Salmonella Pullorum. In this study, we investigated 304 Salmonella Pullorum isolates recovered from chickens in China between 1953 and 2015 for the presence of 25 Salmonella virulence genes (invA, orgA, prgH, sitC, spaN, sifA, spiA, ttrC, mgtB, misL, siiE, spi4D, pipA, sipB, sopB, sefA, cdtB, pagC, shdA, msgA, lpfC, tolC, iroN, pefA, and spvB), including pathogenicity island genes, fimbriae genes, and virulence plasmid genes. PCR showed that 15 of the 25 virulence genes were present in all isolates tested, whereas cdtB was not present in any isolate. The presence rates of the remaining genes ranged from 97.7% to 99.7%. The variation rates of these virulence genes was low, and no significant differences were identified in the distribution of virulence genes over time. On the basis of the distribution of these virulence genes, the 304 Salmonella Pullorum isolates were divided into 10 virulence genotypes. The major genotype, which comprised 93.4% of all isolates, included isolates that carried 24 of the virulence genes assessed. The results of this study will help in the characterization of Salmonella Pullorum and in the study of the correlation between virulence genotypes and pathogenicity.

Nota de investigación- Distribución de genes de virulencia de los aislamientos de Salmonella pullorum recuperados de los pollos en China (1953­2015). Salmonella enterica subespecie enterica serovar Gallinarum biovar Pullorum (Salmonella Pullorum) tiene una estricta especificidad de hospedador en la avicultura y la enfermedad por S. Pullorum es una seria amenaza para la industria avícola. Los genes de virulencia desempeñan un papel central en la patogenicidad de Salmonella, pero hay muy pocos reportes disponibles sobre la distribución de los genes de virulencia en Salmonella Pullorum. En este estudio, se investigaron 304 aislamientos de Salmonella Pullorum recuperados de pollos en China entre los años 1953 y 2015 para detectar la presencia de 25 genes de virulencia de Salmonella (invA, orgA, prgH, sitC, spaN, sifA, spiA, ttrC, mgtB, misL, siiE, spi4D, pipA, sipB, sopB, sefA, cdtB, pagC, shdA, msgA, lpfC, tolC, iroN, pefA y spvB), incluidos los genes de las islas de patogenicidad, los genes de fimbrias y los genes de plásmidos de virulencia. Los métodos de PCR mostraron que 15 de los 25 genes de virulencia estaban presentes en todos los aislamientos analizados, mientras que el gene cdtB no estaba presente en ninguno de los aislados. Las tasas de prevalencia de los genes restantes oscilaron entre 97.7% y 99.7%. Las tasas de variación de estos genes de virulencia fueron bajas y no se identificaron diferencias significativas en la distribución de los genes de virulencia a lo largo del tiempo. Sobre la base de la distribución de estos genes de virulencia, los 304 aislamientos de Salmonella Pullorum se dividieron en 10 genotipos de virulencia. El genotipo principal, que comprendía al 93.4% de todos los aislamientos, incluía aislamientos que llevaban 24 de los genes de virulencia evaluados. Los resultados de este estudio ayudarán en la caracterización de Salmonella Pullorum y al estudio de la correlación entre los genotipos de virulencia y la patogenicidad.

High-Performance Poly(lactic-co-glycolic acid)-Magnetic Microspheres Prepared by Rotating Membrane Emulsification for Transcatheter Arterial Embolization and Magnetic Ablation in VX2 Liver Tumors.

Interventional embolization is a popular minimally invasive vascular therapeutic technique and has been widely applied for hepatocellular carcinoma (HCC) therapy. However, harmful effects caused by transcatheter arterial chemoembolization (TACE) and radioembolization, such as the toxicity of chemotherapy or excessive radiation damage, are serious disadvantages and significantly reduce the therapeutic efficacy. Here, a synergistic therapeutic strategy combined transcatheter arterial embolization and magnetic ablation (TAEMA) by using poly(lactic-co-glycolic acid) (PLGA)-magnetic microspheres (MMs) has been successfully applied to orthotopic VX2 liver tumors of rabbits. These MMs fabricated by novel rotating membrane emulsification system with well-controlled sizes (100-1000 µm) exhibited extremely low hemolysis ratio and excellent biocompatibility with HepG2 cells and L02 cells. Moreover, experimental results demonstrated that, while exposed to alternating magnetic field (AMF) after TAE, the tumor edge could be heated up by more than 15 °C both in vivo and in vitro, whereas only a negligible increase of temperature was observed in the normal hepatic parenchyma (NHP) nearby. Sufficient temperature increase induces apoptosis of tumor cells. This can further inhibit the tumor angiogenesis and results in necrosis compared to the rabbits only treated with TAE. In stark contrast, tumors rapidly grow and subtotal metastasis occurs in the lungs or kidneys, causing severe complications for rabbits only irradiated under AMF. Importantly, the results from the biochemical examination and the gene expression of relative HCC markers further confirmed that the treatment protocol using PLGA-MMs could achieve good biosafety and excellent therapeutic efficacy, which are promising for liver cancer therapy.

Loop-Mediated Isothermal Amplification of the sefA Gene for Rapid Detection of Salmonella Enteritidis and Salmonella Gallinarum in Chickens.

Salmonella spp. pose a threat to both human and animal health, with more than 2600 serovars having been reported to date. Salmonella serovars are usually identified by slide agglutination tests, which are labor intensive and time consuming. In an attempt to develop a more rapid screening method for the major poultry Salmonella serovars, we developed a loop-mediated isothermal amplification (LAMP) assay, which directly detected the sefA gene, a fimbrial operon gene existing in several specific serovars of Salmonella enterica including the major poultry serovars, namely Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) and Salmonella enterica serovar Gallinarum (Salmonella Gallinarum). With the 177 bacterial strains we tested, positive reactions were only observed with 85 strains of serovar Salmonella Enteritidis and Salmonella Gallinarum. The detection limit of the LAMP assay was 4 CFU/reaction with genomic DNAs of Salmonella Enteritidis (ATCC 13076) from pure culture and 400 CFU/ reaction with DNA extracted from spiked chicken feces. The LAMP assay was more sensitive than conventional culture, especially without enrichment, in detecting Salmonella Enteritidis (CMCC 50041) in the spiked fecal samples. The results show the sefA LAMP method is a rapid, sensitive, specific, and practical method for directly detection of Salmonella Enteritidis and Salmonella Gallinarum in chickens. The sefA LAMP assay can potentially serve as new on-site diagnostics in the poultry industry.

Highly Drug-Resistant Salmonella enterica Serovar Indiana Clinical Isolates Recovered from Broilers and Poultry Workers with Diarrhea in China.

Highly drug-resistant Salmonella enterica serovar Indiana became the most common serovar in broilers with diarrhea in China over the course of this study (15% in 2010 to 70% in 2014). While most S. Indiana isolates (87%, 384/440) were resistant to 13 to 16 of the 16 antibiotics tested, 89% of non-S. Indiana isolates (528/595) were resistant to 0 to 6 antibiotics. Class 1 integrons and IncHI2-type plasmids were detected in all S. Indiana isolates, but only in 39% and 1% of non-S. Indiana isolates.