Introduction: Understanding drug resistance is important in drug selection for Helicobacter pylori (H. pylori) eradication, and drug resistance data are lacking in Beijing. Purpose: This cross-sectional study aimed to isolate H. pylori from patients with gastroduodenal diseases and to analyze drug resistance to clarithromycin (CLA) and levofloxacin (LEV), which are used frequently in China. Patients and Methods: One hundred and seventy-six patients with gastroduodenal diseases undergoing gastroduodenoscopy were selected by convenient sampling. Gastric mucosa samples were cultured and sub-cultured using a new medium broth. Active H. pylori strains were confirmed by microscopy observation as Gram-negative curved bacilli with positive test results for urease, oxidase, and catalase, and H. pylori 16S rRNA amplification by polymerase chain reaction (PCR). CLA and LEV resistance was identified by minimum inhibitory concentration (MIC) tests and sequencing of 23S rRNA, gyrA, and gyrB genes. Results: From the 176 clinical samples, 112 (112/176, 63.6%) were confirmed with H. pylori infection and 65 (65/176, 36.9%) active H. pylori strains were obtained and further confirmed by MIC assay. Overall, the rates of CLA-resistant and LEV-resistant mutations in the 112 samples were 50.9% and 33.0%, respectively. Mutation related to CLA resistance was A2143G in the 23S rRNA gene and mutations associated with LEV resistance were N87K, D91G, and D91Y in the gyrA gene. Of 112 samples, 22 (19.6%) presented dual resistance to CLA and LEV. Resistance of the H. pylori strains to CLA (r=0.846, P< 0.001) and LEV (r=0.936, P< 0.001) had a strong correlation in phenotypic and genotypic level. Conclusion: The results indicated that resistance of CLA and LEV is severe among patients with gastroduodenitis. A good consistency could be found as to drug resistance between genotypic or phenotypic assay, suggested extending the detection of H. pylori drug resistance from the MIC method to a genotypic assay.

: This study aimed to isolate and characterize phages as an alternative treatment of multidrug- or pan-drug-resistant Pseudomonas aeruginosa. Phage titers and bacterial densities correlated, with the phages disappearing after bacteria were eliminated. We isolated phages in filtered sewage water by a double-layered agar spot test. Fifty-eight P. aeruginosa strains were used to screen the host spectrum of the 14 phages isolated. Random amplification of polymorphic DNA-typing polymerase chain reaction was used to analyze the genomic homologies of the 58 host bacteria strains and four phages with a broad host spectrum. Transmission electron microscopy was used to observe the morphology of the four phages with a broad host spectrum. Mice with intraabdominal P. aeruginosa infection were used as an in vivo animal model to investigate the therapeutic effect of the selected phage. Four virulent phages with a broad host spectrum specific to P. aeruginosa strains were isolated. They were all double-stranded DNA viruses and belonged to four different genotypes. The test curve showed that phage I had the highest adsorption rate, the shortest latent period, and the largest burst size. The infected mouse model indicated that small doses of phage I could prevent the death of infected mice. Phage titers and bacterial densities correlated, with phages disappearing after bacteria were eliminated. Phage I was the most effective and promising treatment of drug-resistant P. aeruginosa.

Streptococcus pneumoniae is one of the most common bacterial pathogens of a wide range of community-acquired infections. It has been more and more recognized that this bacterium could also play a role as a cause of nosocomial infections. In this study, by retrospective analysis of the phenotypic resistance characteristics and genomic characteristics of 52 S. pneumoniae isolates in a hospital in Beijing, China, from 2018 to 2022, we explored the carriage of resistance genes and mutations in penicillin-binding proteins corresponding to the resistances, and identified the population diversity based on the prediction of serotypes and identification of sequence types (STs). The isolates displayed resistances to erythromycin (98%), tetracycline (96%), sulfonamide (72%) and penicillin G (42%). Among the 52 isolates, 41 displayed multiple-drug resistance. In total, 37 STs and 21 serotypes were identified, and the clonal complex 271 serogroup 19 was the most prevalent subtype. Only 24 isolates (46.2%) of 7 serotypes were covered by the 13-valent pneumococcal conjugate vaccination. The isolates showed high carriages of resistance genes, including tet(M) (100%) and erm(B) (98.1%); additionally, 32 isolates (61.5%) had mutations in penicillin-binding proteins. We also observed 11 healthcare-associated infections and 3 cases infected by different subtypes of isolates. We did not find nosocomial transmissions between the patients, and these cases might be associated with the asymptomatic colonization of S. pneumoniae in the human population. Our results called for further active surveillance of these subtypes, as well as the continuous optimization of the treatment protocols.

Background/Objectives: Static reference intervals (RIs) fail to capture the dynamic changes in bioanalytes. This study aimed to develop gender-based continuous age- and season-related RIs for neuron-specific enolase (NSE) using real-world data and to compare them with partitioned RIs. Methods: The NSE results from 4097 individuals were included after rigorous screening. Partitioned RIs were determined using the Hoffmann method. Generalized additive models for location, scale and shape (GAMLSS) were selected to develop continuous RIs. Results: The partitioned RIs are as follows: <16.4 µg/L for males aged ≥19 years; <14.47 µg/L for females aged 19–49 years; and <17.25 µg/L for females aged ≥50 years. For continuous RIs, NSE levels in males remain stable with age, while in females, NSE levels evidently increase around the age of 50. Although less impactful than age, seasonal changes still affect NSE levels. Dynamic changes and continuous RIs for NSE are visualized in this study. Conclusions: We developed gender-based continuous age- and season-integrated RIs for NSE in North China, highlighting the variation in NSE levels in females with age and season. Compared to static RIs, continuous RIs are more responsive to NSE, potentially enhancing the precision and individualization of health assessments.

Granulomatous lobular mastitis (GLM) is a rare benign breast inflammatory disease that affects women of childbearing age. Corynebacterium species, especially Corynebacterium kroppenstedtii, was reported as the pathogen of GLM. A recent study showed that the C. kroppenstedtii complex is composed of C. kroppenstedtii and two novel species, C. parakroppenstedtii and C. pseudokroppenstedtii. The study presents seven C. kroppenstedtii-like strains isolated from GLM patients. However, they turned out to be six strains of C. parakroppenstedtii and one strain of C. pseudokroppenstedtii according to 16sRNA sequencing. In order to conduct a phylogenetic study, we further sequenced the fusA and rpoB genes, which were frequently employed in studies of Corynebacterium species. Novel Mass Spectral Peaks (MSPs) for C. parakroppenstedtii were created with Bruker MALDI-TOF MS. Then, the identification power of the MSPs was tested by C. parakroppenstedtii strains and remotely related Corynebacterum spp. The antibiotic sensitivity tests were performed according to the CLSI M45 guidelines. All of the strains were not resistant to β-lactams, vancomycin or linezolid. However, applying erythromycin and clindamycin could be fruitless. Phenotypic identification using a Vitek2 ANC ID card proved all of the C. parakroppenstedtii strains were identified as Actinomycete naeslundii. The test of Ala-Phe-Pro arylamidase and urease could be employed as the characteristics to distinguish C. pseudokroppenstedtii from C. parakroppenstedtii. Here, we present the identification, antibiotic sensitivity tests (ASTs) and epidemiological investigation of two novel C. kroppenstedtii-like species with the purpose of improving the understanding of C. kroppenstedtii-like species and related diseases.