Leucine-tRNA-synthase-2-expressing B cells contribute to colorectal cancer immunoevasion.

Immunoregulatory B cells impede antitumor immunity through unknown features and mechanisms. We report the existence of leucine-tRNA-synthase-2 (LARS2)-expressing B cell (LARS B) subset with a transforming growth factor-ß1 (TGF-ß1)-dominant regulatory feature in both mouse and human progressive colorectal cancer (CRC). Of note, LARS B cells exhibited a leucine nutrient preference and displayed active mitochondrial aminoacyl-tRNA biosynthesis. They were located outside the tertiary lymphoid structure and correlated with colorectal hyperplasia and shortened survival in CRC patients. A leucine diet induced LARS B cell generation, whereas LARS B cell deletion by Lars2 gene ablation or leucine blockage repressed CRC immunoevasion. Mechanistically, LARS2 programmed mitochondrial nicotinamide adenine dinucleotide (NAD+) regeneration and oxidative metabolism, thus determining the regulatory feature of LARS B cells in which the NAD-dependent protein deacetylase sirtuin-1 (SIRT1) was involved. We propose a leucine-dieting scheme to inhibit LARS B cells, which is safe and useful for CRC therapy.

USP28 Serves as a Key Suppressor of Mitochondrial Morphofunctional Defects and Cardiac Dysfunction in the Diabetic Heart.

BACKGROUND: The majority of people with diabetes are susceptible to cardiac dysfunction and heart failure, and conventional drug therapy cannot correct diabetic cardiomyopathy progression. Herein, we assessed the potential role and therapeutic value of USP28 (ubiquitin-specific protease 28) on the metabolic vulnerability of diabetic cardiomyopathy. METHODS: The type 2 diabetes mouse model was established using db/db leptin receptor-deficient mice and high-fat diet/streptozotocin-induced mice. Cardiac-specific knockout of USP28 in the db/db background mice was generated by crossbreeding db/m and Myh6-Cre+/USP28fl/fl mice. Recombinant adeno-associated virus serotype 9 carrying USP28 under cardiac troponin T promoter was injected into db/db mice. High glucose plus palmitic acid-incubated neonatal rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes were used to imitate diabetic cardiomyopathy in vitro. The molecular mechanism was explored through RNA sequencing, immunoprecipitation and mass spectrometry analysis, protein pull-down, chromatin immunoprecipitation sequencing, and chromatin immunoprecipitation assay. RESULTS: Microarray profiling of the UPS (ubiquitin-proteasome system) on the basis of db/db mouse hearts and diabetic patients' hearts demonstrated that the diabetic ventricle presented a significant reduction in USP28 expression. Diabetic Myh6-Cre+/USP28fl/fl mice exhibited more severe progressive cardiac dysfunction, lipid accumulation, and mitochondrial disarrangement, compared with their controls. On the other hand, USP28 overexpression improved systolic and diastolic dysfunction and ameliorated cardiac hypertrophy and fibrosis in the diabetic heart. Adeno-associated virus serotype 9-USP28 diabetic mice also exhibited less lipid storage, reduced reactive oxygen species formation, and mitochondrial impairment in heart tissues than adeno-associated virus serotype 9-null diabetic mice. As a result, USP28 overexpression attenuated cardiac remodeling and dysfunction, lipid accumulation, and mitochondrial impairment in high-fat diet/streptozotocin-induced type 2 diabetes mice. These results were also confirmed in neonatal rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes. RNA sequencing, immunoprecipitation and mass spectrometry analysis, chromatin immunoprecipitation assays, chromatin immunoprecipitation sequencing, and protein pull-down assay mechanistically revealed that USP28 directly interacted with PPARα (peroxisome proliferator-activated receptor α), deubiquitinating and stabilizing PPARα (Lys152) to promote Mfn2 (mitofusin 2) transcription, thereby impeding mitochondrial morphofunctional defects. However, such cardioprotective benefits of USP28 were largely abrogated in db/db mice with PPARα deletion and conditional loss-of-function of Mfn2. CONCLUSIONS: Our findings provide a USP28-modulated mitochondria homeostasis mechanism that involves the PPARα-Mfn2 axis in diabetic hearts, suggesting that USP28 activation or adeno-associated virus therapy targeting USP28 represents a potential therapeutic strategy for diabetic cardiomyopathy.

Targeting heat shock protein 47 alleviated doxorubicin-induced cardiotoxicity and remodeling in mice through suppression of the NLRP3 inflammasome.

AIM: Doxorubicin-induced cardiotoxicity (DIC) is an increasing problem, occurring in many cancer patients receiving anthracycline chemotherapy, ultimately leading to heart failure (HF). Unfortunately, DIC remains difficult to manage due to an ignorance regarding pathophysiological mechanisms. Our work aimed to evaluate the role of HSP47 in doxorubicin-induced HF, and to explore the molecular mechanisms. METHODS AND RESULTS: Mice were exposed to multi-intraperitoneal injection of doxorubicin (DOX, 4mg/kg/week, for 6 weeks continuously) to produce DIC. HSP47 expression was significantly upregulated in serum and in heart tissue in DOX-treated mice and in isolated cardiomyocytes. Mice with cardiac-specific HSP47 overexpression and knockdown were generated using recombinant adeno-associated virus (rAVV9) injection. Importantly, cardiac-specific HSP47 overexpression exacerbated cardiac dysfunction in DIC, while HSP47 knockdown prevented DOX-induced cardiac dysfunction, cardiac atrophy and fibrosis in vivo and in vitro. Mechanistically, we identified that HSP47 directly interacted with IRE1α in cardiomyocytes. Furthermore, we provided powerful evidence that HSP47-IRE1α complex promoted TXNIP/NLRP3 inflammasome and reinforced USP1-mediated NLRP3 ubiquitination. Moreover, NLRP3 deficiency in vivo conspicuously abolished HSP47-mediated cardiac atrophy and fibrogenesis under DOX condition. CONCLUSION: HSP47 was highly expressed in serum and cardiac tissue after doxorubicin administration. HSP47 contributed to long-term anthracycline chemotherapy-associated cardiac dysfunction in an NLRP3-dependent manner. HSP47 therefore represents a plausible target for future therapy of doxorubicin-induced HF.

Traceless Peptide and Protein Modification via Rational Tuning of Pyridiniums.

Herein, we report a versatile reaction platform for tracelessly cleavable cysteine-selective peptide/protein modification. This platform offers highly tunable and predictable conjugation and cleavage by rationally estimating the electron effect on the nucleophilic halopyridiniums. Cleavable peptide stapling, antibody conjugation, enzyme masking/de-masking, and proteome labeling were achieved based on this facile pyridinium-thiol-exchange protocol.

Performance of Artificial Intelligence Content Detectors Using Human and Artificial Intelligence-Generated Scientific Writing.

BACKGROUND: Few studies have examined the performance of artificial intelligence (AI) content detection in scientific writing. This study evaluates the performance of publicly available AI content detectors when applied to both human-written and AI-generated scientific articles. METHODS: Articles published in Annals of Surgical Oncology (ASO) during the year 2022, as well as AI-generated articles using OpenAI's ChatGPT, were analyzed by three AI content detectors to assess the probability of AI-generated content. Full manuscripts and their individual sections were evaluated. Group comparisons and trend analyses were conducted by using ANOVA and linear regression. Classification performance was determined using area under the curve (AUC). RESULTS: A total of 449 original articles met inclusion criteria and were evaluated to determine the likelihood of being generated by AI. Each detector also evaluated 47 AI-generated articles by using titles from ASO articles. Human-written articles had an average probability of being AI-generated of 9.4% with significant differences between the detectors. Only two (0.4%) human-written manuscripts were detected as having a 0% probability of being AI-generated by all three detectors. Completely AI-generated articles were evaluated to have a higher average probability of being AI-generated (43.5%) with a range from 12.0 to 99.9%. CONCLUSIONS: This study demonstrates differences in the performance of various AI content detectors with the potential to label human-written articles as AI-generated. Any effort toward implementing AI detectors must include a strategy for continuous evaluation and validation as AI models and detectors rapidly evolve.

Nerve Growth Factor/Tyrosine Kinase A Receptor Pathway Enhances Analgesia in an Experimental Mouse Model of Bone Cancer Pain by Increasing Membrane Levels of δ-Opioid Receptors.

BACKGROUND: The role of nerve growth factor (NGF)/tyrosine kinase A receptor (TrKA) signaling, which is activated in a variety of pain states, in regulating membrane-associated δ-opioid receptor (mDOR) expression is poorly understood. The hypothesis was that elevated NGF in bone cancer tumors could upregulate mDOR expression in spinal cord neurons and that mDOR agonism might alleviate bone cancer pain. METHODS: Bone cancer pain (BCP) was induced by inoculating Lewis lung carcinoma cells into the femoral marrow cavity of adult C57BL/6J mice of both sexes. Nociceptive behaviors were evaluated by the von Frey and Hargreaves tests. Protein expression in the spinal dorsal horn of animals was measured by biochemical analyses, and excitatory synaptic transmission was recorded in miniature excitatory synaptic currents. RESULTS: The authors found that mDOR expression was increased in BCP mice (BCP vs. sham, mean ± SD: 0.18 ± 0.01 g vs. mean ± SD: 0.13 ± 0.01 g, n = 4, P < 0.001) and that administration of the DOR agonist deltorphin 2 (Del2) increased nociceptive thresholds (Del2 vs. vehicle, median [25th, 75th percentiles]: 1.00 [0.60, 1.40] g vs. median [25th, 75th percentiles]: 0.40 [0.16, 0.45] g, n = 10, P = 0.001) and reduced miniature excitatory synaptic current frequency in lamina II outer neurons (Del2 vs. baseline, mean ± SD: 2.21 ± 0.81 Hz vs. mean ± SD: 2.43 ± 0.90 Hz, n = 12, P < 0.001). Additionally, NGF expression was increased in BCP mice (BCP vs. sham, mean ± SD: 0.36 ± 0.03 vs. mean ± SD: 0.16 ± 0.02, n = 4, P < 0.001), and elevated NGF was associated with enhanced mDOR expression via TrKA signaling. CONCLUSIONS: Activation of mDOR produces analgesia that is dependent on the upregulation of the NGF/TrKA pathway by increasing mDOR levels under conditions of BCP in mice.

Chiral Phosphine Ligands of COAP and SKP Switched Regiodivergent Asymmetric Allylic Alkylation of MBH Adducts.

The palladium-catalyzed highly regioselective asymmetric allylic alkylation of 3'-indolyl-3-oxindole derivatives with Morita-Baylis-Hillman (MBH) carbonates was developed to facilely construct chiral 3,3'-bisindole derivatives under mild reaction conditions. The regioselectivity (α/γ) of MBH carbonates was efficiently switched in the presence of chiral oxalamide phosphine or spiroketal-based diphosphine/Pd(0) complexes as a chiral catalyst. A series of multifunctional 3,3'-bisindole derivatives with all-carbon quaternary stereogenic centers were obtained in high yields with good to excellent enantio-, diastereo-, and regioselectivity. The present process is endowed with some salient features such as broad substrate scope, N-protecting group-free, excellent stereoselectivity, as well as adjustable regioselectivity.

Enhancement Effect Induced by the Second Metal to Promote Ozone Catalytic Oxidation of VOCs.

It is a promising research direction to develop catalysts with high stability and ozone utilization for low-temperature ozone catalytic oxidation of VOCs. While bimetallic catalysts exhibit excellent catalytic activity compared with conventional single noble metal catalysts, limited success has been achieved in the influence of the bimetallic effect on the stability and ozone utilization of metal catalysts. Herein, it is necessary to systematically study the enhancement effect in the ozone catalytic reaction induced by the second metal. With a simple continuous impregnation method, a platinum-cerium bimetallic catalyst is prepared. Also highlighted are studies from several aspects of the contribution of the second metal (Ce) to the stability and ozone utilization of the catalysts, including the "electronic effect" and "geometric effect". The synergistic removal rate of toluene and ozone is nearly 100% at 30 °C, and it still shows positive stability after high humidity and a long reaction time. More importantly, the instructive significance, which is the in-depth knowledge of enhanced catalytic mechanism of bimetallic catalysts resulting from a second metal, is provided by this work.

A GSH-resistant FK228 analogue containing a stable disulfide bond.

FK228 is a potent natural pan HDAC inhibitor approved by the FDA for the treatment of cutaneous T-cell lymphoma as well as peripheral T-cell lymphoma. It is generally believed that the mechanism of FK228 acting on HDACs is by reducing its disulfide bond after entering the cell, and the dithiol group may chelate with Zn2+ and form a weak reversible covalent bond with cysteine in the catalytic pocket of HDACs, therefore inhibiting the activity of HDACs. However, due to the weak stability of the disulfide bond in FK228, it has been difficult to obtain direct evidence for the above conjecture. Thus, improving the stability of the FK228 disulfide bond will help to explore the exact mechanism of FK228. In this study, based on the stability and target-induced covalent properties of the Cysteine-Penicillamine (Cys-Pen) disulfide bond reported previously, the Pen was introduced into the modification of FK228. Specifically, the d-Cys in FK228 was replaced by d-Pen, the total synthetic pathway was optimized, and the novel synthetic FK228 analogue (FK-P) stability was verified. FK-P can also be used as a new drug molecule in the future to participate in the research of related biological mechanisms or the treatment of diseases.

Dynamic modulation of multicolor upconversion luminescence of Er3+ via excitation pulse width.

Lanthanide-doped upconversion (UC) luminescent materials display multicolor emissions, making them ideal for a variety of applications, such as multi-channel biological imaging, fluorescence encryption, anti-counterfeiting, and 3D display. Manipulating the UC emissions of the luminescent materials with a fixed composition is crucial for their applications. Herein, we propose a facile strategy to achieve pulse-width-dependent multicolor UC emissions in NaYF4:Yb/Er/Tm nanocrystals. Upon excitation with a 980 nm continuous-wave laser diode, Er3+ ions in NaYF4:20%Yb,15%Er,1%Tm nanocrystals exhibited UC emissions with a red-to-green (R/G) ratio of 11.3. Nevertheless, by employing a 980 nm pulse laser with pulse widths from 0.1 to 10 ms, the UC R/G ratio can be easily adjusted from 0.9 to 11.3, resulting in continuous and remarkable color transformation from green, yellow, orange, to red. By virtue of the dynamic luminescence color variation of these NaYF4:20%Yb,15%Er,1%Tm nanocrystals, we demonstrated their potential applications in the areas of anti-counterfeiting and information encryption. These findings provide deep insights into the excited-state dynamics and energy transfer of Er3+ in NaYF4:Yb/Er/Tm nanocrystals upon 980 nm pulse excitation, which may pave the way for designing multicolor UC materials toward versatile applications.

A Case of Ocular Infection with Clostridium tertium Caused by a Salute Gun Explosion.

BACKGROUND: In February 2024, our hospital confirmed a case of ocular infection with Clostridium tertium caused by a salute gun explosion. The patient sought medical attention at our hospital due to a salute gun explosion injury in the right eye. Two days ago, a patient mistakenly believed that the fuse was not ignited when firing a salute gun. When observing, the salute gun exploded and injured his right eye. The patient immediately went to the local hos-pital for treatment. The CT scan of the local hospital showed rupture of the right eyeball. For additional diagnosis and treatment, the patient came to our hospital. The patient in this case has an acute onset, severe condition, no additional systemic diseases, and no history of drug or food allergies. METHODS: Intraocular exploration, cranial CT, local and systemic anti infection treatment. Pathogen examination items: bacterial smear, bacterial culture and identification. Venous blood test items: blood routine, liver function, kidney function, and coagulation function. RESULTS: Intraocular exploration showed conjunctival congestion and edema in the right eye, corneal haze and ede-ma, shallow anterior chamber, anterior chamber hemorrhage, and unclear intraocular structure. Clinical treatment: debridement and suturing of right eye rupture + repair of eyeball rupture + removal of intraocular foreign body + repair of superior rectus muscle detachment + anterior chamber flushing + anterior chamber shaping + suture of eyelid laceration. Pathogen examination item: Eye secretion bacterial smear (Gram staining): A large number of gram-positive bacilli were found, and the secretion bacterial culture and identification (MALDI-TOF MS): Clostridium tertium. Auxiliary examination: Blood routine (venous blood): White blood cells 10.89 x 109/L, neutrophil count 9.65 x 109/L, whole blood hypersensitive C-reactive protein 20.28 mg/L, renal function: urea 9.15 mmol/L, uric acid 428.5 µmol/L, fasting glucose 6.48 mmol/L, no further abnormalities observed. Clinical drug treatment plan: Tetanus human immunoglobulin 250 IU im, tobramycin eye drops 0.1 g ext qd, vancomycin 0.5 g ih qd, levofloxacin 0.5g ivgtt qd, aluminum magnesium suspension 15 mL po bid, potassium chloride sustained-release tablets 0.5 g po qd. After 7 days of treatment, the patient's body temperature returned to normal, conjunctival congestion and edema decreased, anterior chamber hemorrhage decreased, corneal incision closed properly, and the patient improved and was discharged. CONCLUSIONS: This article reports a case of ocular infection caused by a salute gun explosion with Clostridium tertium. Clostridium tertium was quickly and accurately identified by a mass spectrometer, and reasonable treatment measures were adopted clinically. The patient improved and was discharged. I hope that in the future, this study can provide assistance for the clinical diagnosis and treatment of special site infections caused by Clostridium tertium.

A Case of Mycolicibacterium mucogenicum Infection in the Right Back.

BACKGROUND: In November 2023, our hospital confirmed a case of Mycolicibacterium mucogenicum infection in the right back. The patient sought medical attention at our hospital due to "a right back lump for 2 months, ruptured for 1 month." Two months ago, the patient's back collided with a fire hose and developed a local walnut sized lump. The lump was soft, painless when pressed, and there was no obvious redness or swelling around it. The patient went to a private hospital for incision and drainage treatment on their own. One month later, the condition did not improve and there was yellow pus exuding from the incision site. For additional diagnosis and treatment, the patient went to our hospital for treatment. METHODS: Back MRI (Magnetic Resonance Imaging) and abdominal ultrasound. Right back abscess incision and drainage surgery, pus pathogen examination: pus bacterial smear, bacterial culture, and identification. Auxiliary examinations: urine routine, blood routine, liver function, kidney function, blood lipids, and blood sugar. RESULTS: Back MR: Abnormal signal shadow of subcutaneous soft tissue in the lower back, suggesting inflammatory lesions with abscess formation. Acid fast staining of pus: positive. Culture and identification of pus bacteria (Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, MALDI-TOF MS): Mycolicibacterium mucogenicum. Clinical treatment plan: Clarithromycin 500 mg bid po+ minocycline 100 mg bid po, abscess in-cision and drainage, 5-aminolevulinic acid photodynamic therapy (ALA-PDT) qd. After 14 days of treatment, the patient's incision base tissue showed excellent activity, no obvious bleeding or exudation, slight redness and swelling around the wound, and normal skin temperature. The patient improved and was discharged. CONCLUSIONS: This article reports a case of Mycolicibacterium mucogenicum infection in the right back. The Mycolicibacterium mucogenicum was quickly and accurately identified by MALDI-TOF MS, and clinical treatment with antibiotics combined with 5-aminolevulinic acid photodynamic therapy (ALA-PDT) was used. The patient improved and was discharged. I hope that in the future, this study can provide assistance for the clinical diagnosis and treatment of Mycolicibacterium mucogenicum.

A Rare Case Report of Skin Infection Caused by Nocardia brasiliensis in an HIV Patient.

BACKGROUND: In October 2023, our hospital confirmed a case of a patient with HIV with concurrent infection with Nocardia brasiliensis. A patient with HIV developed a lump on the surface of the dorsum of his left hand without any obvious cause. He used a nail clipper to trim it. Due to improper disinfection and treatment methods, the condition worsened, and he subsequently sought medical attention at our hospital. A series of clinical laboratory tests were conducted based on the patient's medical history, symptoms, and signs. Based on the test results, a reasonable clinical treatment plan was adopted, ultimately achieving satisfactory treatment outcomes for the patient. METHODS: Clinical implementation of pus bacterial culture and identification (matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry, MALDI-TOF MS), serum anti HIV detection, and Treponema pallidum antibody detection. Additional related auxiliary examinations: blood routine, liver function, kidney function, CRP, electrolytes. RESULTS: Blood routine and CRP (venous blood): White blood cell count 16.00 x 109/L, total number of lymphocytes 3.73 x 109/L, total monocyte count 1.66 x 109/L, total number of neutrophils 10.37 x 109/L, total number of basophils 0.10 x 109/L, average platelet volume 8.8 fL, whole blood high-sensitivity C-reactive protein 46.44 mg/L, urine routine: protein+-. Liver function test: Albumin 37.7 g/L, aspartate aminotransferase 55.5 U/L, alanine aminotransferase 63.7 U/L, blood lipid test: triglycerides 2.22 mmol/L, high-density lipoprotein cholesterol 0.77 mmol/L, coagulation function test: fibrinogen test 5.69 g/L, lymphocyte subgroup analysis: T4/T8 cell ratio 0.78, total mature T cell count 2.501 x 109/L, T8 cell count 1.351 x 109/L, B cell count 0.574 x 109/L. Serum pathogen test: anti HIV positive, Treponema pallidum antibody 214.70 IU/mL, unheated serum reactive hormone test positive (1:8). Gram staining of pus: a large number of Gram positive bacteria were found, arrange in a branching form, weak acid-fast staining: positive, pus culture and bacteria identified (MALDI-TOF MS): Nocardia brasiliensis. Clinical treatment includes trimethoprim/sulfamethoxazole 800 mg/160 mg po q12 hours, local wet compress with Baiduobang ointment, and abscess incised and drained. Seven days later, the patient had a circular ulcer on the left back without any new pustules. Slightly elevated skin temperature, no tenderness, and no purulent or bloody secretions. His condition had improved and he was discharged. Follow up infectious disease specialist hospitals treat HIV, syphilis, and other related diseases. CONCLUSIONS: Patients with HIV are prone to various types of infections, even rare bacteria, as their immune function decreases. At present, there are few reports about a patient with HIV with concurrent infection with Nocardia brasiliensis. This case can provide reference for clinical diagnosis and treatment of related diseases in the future. In addition, with the popularity of new identification methods such as mass spectrometry, laboratories should pay attention to traditional staining methods and use microscopes to detect pathogens.

Diagnosis of Mycobacterium marinum Infection by Metagenomic next-generation sequencing.

BACKGROUND: In December 2023, our hospital confirmed a case of finger infection with Mycobacterium marinum. The patient sought medical attention at our hospital due to a hard scratch on her left middle finger, which was red, swollen, and ulcerated for one month. PHYSICAL EXAMINATION: A lesion of approximately 1.5 cm x 2 cm in the patient's left middle finger, surrounded by redness and swelling, unclear boundaries, surface rupture, partial scabbing, and no tenderness during compression. She was treated at the previous clinic, common infectious diseases were considered, and was given intravenous infusion treatment: cefotaxime and clarithromycin, and erythromycin ointment was applied externally. She came to our hospital after poor treatment results. The patient has had hypertension for 3 years, no other systemic diseases, no similar medical history among family members, no history of drug or food allergies. METHODS: Clean the wound and remove the scab from the affected area, and use a surgical blade to scrape off necrotic tissue. Send the scraped tissue for pathogen testing: tissue bacterial culture+identification (matrix assisted laser desorption/ionization time-of-flight mass spectrometry, MALDI-TOF), tissue acid fast staining, and tissue metagenomic next-generation sequencing (mNGS). Other auxiliary examinations: blood routine, urine routine, blood fat, liver function, and kidney function. RESULTS: Tissue bacterial culture+identification: growth of Mycobacterium marinum; Acid fast staining of tissue: positive; Tissue mNGS: Mycobacterium marinum. Clinical treatment plan: clarithromycin 0.5 g bid po+rifampicin 0.45 g qd po+5-aminolevulinic acid photodynamic therapy (ALA-PDT) qw+boric acid wash wet compress tid. After 14 days of treatment, the area of redness and swelling significantly decreased, and the degree of redness and swelling was significantly reduced compared to admission. The degree of ulcer edge protrusion was also reduced compared to admission. There was a small amount of exudation from the wound, and no necrotic tissue was observed. The patient improved and was discharged. CONCLUSIONS: This article reports a case of finger infection with Mycobacterium marinum. Mycobacterium marinum was quickly and accurately identified by mNGS, and reasonable treatment measures were adopted clinically. The patient improved and was discharged. This study has important reference significance for the clinical diagnosis and treatment of Mycobacterium infection. In addition, mNGS as a novel detection method has considerable prospects for rapid diagnosis of pathogens.

A Case of IgA Nephropathy Complicated with Pulmonary Infection by Mycobacterium Abscess.

BACKGROUND: In August 2023, our hospital confirmed a case of IgA nephropathy complicated with pulmonary infection by Mycobacterium abscess. The patient sought medical attention at our hospital due to "gross hematuria for 10 years, recurrence for 10 days, coughing and sputum production". The patient had pulmonary tuberculosis 15 years ago and had been cured. He had bronchiectasis for 10 years. METHODS: Chest CT, fiberoptic bronchoscopy examination, urine routine (urine analysis + sediment quantification), urine trace protein measurement//urine creatinine (random urine), urine protein quantification (24-hour urine), antinuclear antibody measurement (ANA), sputum culture, alveolar lavage fluid bacterial culture, alveolar lavage fluid acid fast staining, and alveolar lavage fluid mNGS. RESULTS: Chest CT: Cystic dilation of bronchi in both lungs, mainly in the lower lungs, with visible phlegm clots inside. Fibrobronchoscopy: A large amount of white foam like secretions can be seen in the lumens of the middle lobe of the right lung and the lower lobes of both lungs. Urinary routine (urine analysis + sediment quantification): protein+↑, occult blood+++. Urine Microprotein Determination//Urine Creatinine (Random Urine): Microalbumin 156.00 mg/L, Urine mALB/Urine Creatinine 132.73 mg/g; Quantitative determination of urine protein (24-hour urine): total protein 0.93 g/24-hour urine; Antinuclear antibody assay (ANA): weakly positive; Sputum bacterial culture: negative; Bacterial culture of bronchoalveolar lavage fluid: Mycobacterium abscess++, NGS in bronchoalveolar lavage fluid: Mycobacterium abscess. Clinical treatment plan: 0.25 g of azithromycin qd po+ 0.4 g of amikacin sulfate qd ivgtt+ 1 g cefmetazole sodium q12hours ivgtt. After 10 days of treatment, the patient improved and was discharged. CONCLUSIONS: This article reports a case of IgA nephropathy complicated with pulmonary abscess mycobacterial infection. Mycobacterium abscess was quickly and accurately identified by mNGS. Reasonable treatment measures were adopted clinically. The patient improved and was discharged. This study has important reference significance for the clinical diagnosis and treatment of Mycobacterium abscess infection. In addition, mNGS, as a novel detection method, has considerable prospects for rapid diagnosis of pathogens.

A Case of Mycobacterium Fortuitum Infection in the Left Thigh.

BACKGROUND: In March 2024, our hospital confirmed a case of Mycobacterium fortuitum infection in the left thigh. In January 2024, the patient underwent buttock augmentation surgery at a private plastic surgery hospital. One month after the surgery, the patient sought medical attention at the plastic surgery hospital, due to pain in both legs while sitting. Upon examination, two subcutaneous masses were found in the left thigh, the tumors were painful to pressure, with obvious redness and swelling and elevated skin temperature; therefore, the patient was treated with intravenous infusion (cephalosporin drugs), but after one month of treatment, no significant improvement was observed. In order to seek additional diagnosis and treatment, the patient came to our hospital for treatment. METHODS: Clinical treatment of the left lower limb included wound debridement, abscess incision and drainage, and photodynamic therapy with 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT). During surgery, subcutaneous tough tissue was taken for pathogen examination, including acid fast staining, bacterial culture, and identification. Additional auxiliary examinations: urine routine, blood routine, coagulation function, liver function, kidney function, blood lipids, and blood sugar. RESULTS: Bacterial acid-fast staining: positive. Bacterial Culture and Identification (MALDI-TOF MS): Mycobacterium fortuitum. Clinical treatment plan: clarithromycin 500 mg po bid, moxifloxacin 400 mg po qd, abscess incision and drainage, ALA-PDT. After 24 days of treatment, the patient's condition was good, the surgical incision healed well, there was no bleeding, exudation, or bruising, no redness, swelling, or tenderness, and the skin temperature was normal. The patient improved and was discharged. CONCLUSIONS: This article reports a case of Mycobacterium fortuitum infection in the left thigh. The Mycobacterium fortuitum was quickly and accurately identified by MALDI-TOF MS, and reasonable treatment measures were adopted clinically. The patient improved and was discharged. I hope that in the future, this study can provide assistance for the clinical diagnosis and treatment of Mycobacterium fortuitum infections.

Establishment of a Rapid Detection Method for Highly Virulent Klebsiella Pneumoniae Based on Multienzyme Isothermal Rapid Amplification Technology.

BACKGROUND: This study aimed to establish a method for the rapid detection of highly virulent Klebsiella pneumoniae (hvKP) by using multienzyme isothermal rapid amplification (MIRA) technology. The laboratory can quickly, accurately, and conveniently diagnose highly virulent Klebsiella pneumoniae infection. METHODS: For this study, 7 laboratory standard strains and 184 clinical isolates (including 70 strains of Klebsiella pneumoniae) were collected and screened for highly virulent Klebsiella pneumoniae based on its colony morphology, wire drawing test, and next-generation sequencing (NGS) results. Based on the nucleic acid sequence of the peg344 gene of highly virulent Klebsiella pneumoniae on GenBank (no. AP006726.1), specific conserved regions were selected to design MIRA and real-time fluorescence quantitative PCR (qPCR) specific primers and probes. The MIRA and qPCR methods were used to detect the tested strain, and the specificity, sensitivity, and clinical performance of the MIRA method for detecting hvKP were evaluated. RESULTS: In total, 21 cases of hvKP were screened from clinical isolates. The MIRA detection method utilizes specific primers and probes to transmit significant fluorescence signals at 39°C, and the detection process takes 30 minutes. The specificity test results showed that only hvKP had a specific amplification curve, while the rest of non-highly virulent Klebsiella pneumoniae (non-hvKP) had no specific amplification curve. The sensitivity test results showed that the sensitivity of MIRA for detecting hvKP is 7 × 102 CFU/mL, which is consistent with the sensitivity of the real-time fluorescence qPCR method. A simultaneous detection of 184 clinical isolates was accomplished by using MIRA and qPCR methods. Twenty-one strains of hvKP have specific amplification curves, while the remaining 163 strains of non-hvKP have no specific amplification curves. The accuracy of both methods for detecting hvKP is 100%. CONCLUSIONS: The established multienzyme isothermal rapid amplification (MIRA) has the following characteristics: a short detection time, high sensitivity, and a strong specificity, and it can be used as a powerful tool for an early diagnosis and epidemiological monitoring of hvKp.

Three Cases of Non-Tuberculosis Mycobacterium Skin Infection Outbreak in Beauty Institutions.

BACKGROUND: From June 2021 to July 2021, our hospital confirmed 3 cases of Mycobacterium infection in skin abscesses. All 3 patients underwent thread embedding and weight loss surgery at the same informal beauty institution, with a history of silk protein injection. None of the patients had any other underlying diseases or surgical history. Symptoms and signs show that the disease is acute and the course of the disease is short. All patients have found subcutaneous masses in different parts of the body. In most cases, the masses show redness and swelling, and some of the masses are accompanied by tenderness, wave sensation, and rupture. After some of the masses rupture, purulent secretions can be seen. METHODS: The pus secreted by the skin lesions of the three patients were cultured to a single bacterium, which was identified by MALDI-TOF MS. Multiple locus sequence typing (MLST) was performed using three specific genes (hsp65, rpoB, and secA1) and seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH). The results were queried through the MLST database of Mycobacterium abscess. RESULTS: All three strains of bacteria were Mycobacterium abscess type ST279 massiliense subtype. Three antibacterial drugs including cefmetazole, amikacin, and clarithromycin were administered in combination with 5-aminolevulinic acid photodynamic therapy (ALA-PDT). After 3 - 6 months, there was no obvious redness or swelling in the surrounding tissues of the wound, and no obvious purulent secretions were observed. All patients were cured and discharged from the hospital. After a follow-up of six months, there was no recurrence of the lesions. CONCLUSIONS: Medical institutions must strictly follow infection control guidelines and take preventive measures to prevent such incidents from happening again. ALA-PDT as a combination therapy for nontuberculous Mycobacterium (NTM) skin infections can improve treatment efficacy and shorten antibiotic usage time.

Lumbar Spine Infected by Mycobacterium tuberculosis and Cryptococcus neoformans: a Rare Case Report.

BACKGROUND: In July 2023, our hospital confirmed one case of lumbar spine infected complicated by Mycobacterium tuberculosis and Cryptococcus neoformans. The patient was admitted due to lower back pain for 1 year and a hard lump for 3 months. Symptoms and signs: Dressing can be seen fixed on the lower back, with severe bleeding. When the dressing is removed, a hard and protruding lump with a size of 6 cm x 8 cm, a sinus tract can be seen near the mass, with a slightly red wound and a sinus depth of about 3 cm. Light red fluid can be seen flowing out. There are no symptoms such as redness, swelling, or heat in the rest of the lower back, and the patient has no other underlying diseases or surgical history. METHODS: Lumbar magnetic resonance imaging and lumbar CT examination; Percutaneous puncture lumbar vertebral biopsy was performed, and the biopsy tissue was subjected to pathological examination, mNGS (metagenomic next-generation sequencing), and acid-fast staining; Extract pus from the lump for fungal culture and ink staining, and identify the fungi through MALDI-TOF MS. RESULTS: Bone destruction and bone marrow edema in the L5 vertebral body, compression of the spinal canal at the L5 vertebral body level; The pathological results of the biopsy tissue indicate granulomatous lesions. The acid-fast staining of the tissue is positive, and the mNGS of the tissue indicates infection with Mycobacterium tuberculosis. A single fungus was cultured from pus and identified by MALDI-TOF MS as Cryptococcus neoformans. Clinically, isoniazid 0.3 g ivgtt + rifampicin 0.45 g qd po + ethambutol 0.25 g qd po + pyrazinamide 0.75 g qd po + fluconazole 0.3 g qd po was administered for treatment. After 11 days, there was slight pain at the incision site, and the original symptoms were significantly relieved. The wound dressing was fixed in place, dry and without obvious exudation. Improved and discharged, followed up for 3 months with no recurrence of the lesion. CONCLUSIONS: mNGS is an effective identification technique that can be used to accurately diagnose suspected infection cases. MALDI-TOF MS has significant advantages over traditional detection methods in shortening detection time. This case achieved satisfactory treatment results for patients through a reasonable treatment plan, which is of great significance for exploring the diagnosis and treatment of similar disease infections.