Objective This study investigates the expression levels of mucin 1 (MUC1), MUC2, occludin, and zonula occludens-1 (ZO-1) in necrotizing enterocolitis (NEC).Study Design Intestinal specimens of surgical patients suffering from NEC (the NEC group) and intestinal specimens of patients with congenital intestinal atresia (the control group) were collected. Immunohistochemical changes in MUC1, MUC2, occludin, and ZO-1 were compared between the two groups.Results Our study showed a significant decrease in the expression levels of MUC1 (p = 0.004), MUC2 (p = 0.001), occludin (p = 0.004), and ZO-1 (p = 0.013) in neonates suffering from NEC as compared with the control group.Conclusion Mucins and tight junctions are severely altered in NEC neonates. This finding might provide clues for rupture of the intestinal barrier. Further research is needed to investigate the gene expression as well as the exact mechanisms behind these changes. This will help us better understand the role of the intestinal barrier in NEC.Key Points

The 16S rDNA polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and sequencing method has been demonstrated to be valuable in detecting pathogens in the blood of patients suffering from fever or neutropenia. However, its use in the diagnosis of neonatal late‑onset septicemia (LOS) has not yet been reported. The aim of the present study was to investigate the efficiency of this method in detection of the type of bacterial infection in neonatal LOS. Blood specimens from 60 neonates in whom LOS was suspected were collected. Fourteen culture positive blood samples and 24 spiked 'infected' blood samples were analyzed by the 16S rDNA PCR‑DGGE and sequencing method or by pathogen‑specific PCR. Only in 5 of the 14 cases did the results of 16S rDNA PCR‑DGGE and sequencing match with the results of blood culturing. In the other 9 cases, the blood culture failed to detect bacteria, such as Neisseria sp. and Moraxella sp., which were detected by 16S rDNA PCR‑DGGE and sequencing. Furthermore, the 16S rDNA PCR‑DGGE and sequencing failed to detect blood culture‑proven bacteria, such as Klebsiella pneumonia. A competitive inhibitory effect in 16S rDNA PCR amplification may lead to the discrepancy between pathogen‑specific PCR and spiked 'infected' blood samples. When a certain species of bacteria was detected by 16S rDNA PCR, the competitive inhibitory effect presented a higher sensitivity in detecting this species in the blood samples that contained bacterial DNA only from this species compared with the blood samples that were blended with other bacterial DNAs. In conclusion, 16S rDNA PCR‑DGGE and sequencing can detect a more comprehensive spectrum of pathogens than blood culture. However, the competitive inhibitory effect, which may lead to false negative results should be taken into consideration when the 16S rDNA PCR-DGGE and sequencing method is applied to the diagnosis of neonatal LOS.

Pseudomonas aeruginosa is a major cause of healthcare-associated infections and a significant threat to global health, primarily due to its ability to form biofilms that protect it from host immune responses and block antibiotic efficacy. While bacteriophages (phages) are emerging as potential antimicrobial agents, their effectiveness is often limited by these bacterial biofilms. This study aimed to enhance the biofilm-disrupting capabilities of phages through genetic engineering. First, we validated the in vitro biofilm-inhibitory effects of two enzymes: the quorum-quenching lactonase ( Aiia ) and a phage-derived depolymerase ( DP ). To demonstrate their potential, we then used CRISPR-Cas9 to engineer the P. aeruginosa phage PaGZ-1 to express these biofilm-disrupting genes. The resulting engineered phages demonstrated superior inhibition of biofilm formation compared to the wild-type phage. Notably, the PaGZ-1-Aiia variant showed significant promise in both inhibiting biofilm formation and disrupting established biofilms. Our findings provide a straightforward method for introducing exogenous genes into non-model P. aeruginosa phage genomes, offering a novel and potentially effective strategy for combating drug-resistant, biofilm-forming infections.

Biofilm cells are well-known for their increased survival and metabolic capabilities and have been increasingly implemented in industrial and biotechnological processes. Corynebacterium glutamicum is one of the most widely used microorganisms in the fermentation industry. However, C. glutamicum biofilm has been rarely reported and little is known about its cellular basis. Here, the physiological changes and characteristics of C. glutamicum biofilm cells during long-term fermentation were studied for the first time. Results showed that the biofilm cells maintained stable metabolic activity and cell size was enlarged after repeated-batch of fermentation. Cell division was slowed, and chromosome content and cell proliferation efficiency were reduced during long-term fermentation. Compared to free cells, more biofilm cells were stained by the apoptosis indicator dyes Annexin V-FITC and propidium iodide (PI). Overall, these results suggested slow-growing, long-lived cells of C. glutamicum biofilm during fermentation, which could have important industrial implications. This study presents first insights into the physiological changes and growth behavior of C. glutamicum biofilm cell population, which would be valuable for understanding and developing biofilm-based processes.