The previous studies all focus on the effect of probiotics and antibiotics on infection after liver transplantation. Here, we focus on the effect of gut microbiota alteration caused by probiotics and antibiotics on hepatic damage after allograft liver transplantation. Brown-Norway rats received saline, probiotics, or antibiotics via daily gavage for 3 weeks. Orthotopic liver transplantation (OLT) was carried out after 1 week of gavage. Alteration of the intestinal microbiota, liver function and histopathology, serum and liver cytokines, and T cells in peripheral blood and Peyer's patch were evaluated. Distinct segregation of fecal bacterial diversity was observed in the probiotic group and antibiotic group when compared with the allograft group. As for diversity of intestinal mucosal microbiota and pathology of intestine at 2 weeks after OLT, antibiotics and probiotics had a significant effect on ileum and colon. The population of Lactobacillus and Bifidobacterium in the probiotic group was significantly greater than the antibiotic group and the allograft group. The liver injury was significantly reduced in the antibiotic group and the probiotic group compared with the allograft group. The CD4/CD8 and Treg cells in Peyer's patch were decreased in the antibiotic group. The intestinal Treg cell and serum and liver TGF-β were increased markedly while CD4/CD8 ratio was significantly decreased in the probiotic group. It suggested that probiotics mediate their beneficial effects through increase of Treg cells and TGF-β and deduction of CD4/CD8 in rats with acute rejection (AR) after OLT.

Listeria monocytogenes is more heat-resistant than most other non-spore-forming foodborne pathogens, posing a severe threat to food safety and human health, particularly during chilled food processing. The DegU orphan response regulator is known to control heat resistance in L. monocytogenes; however, the underlying regulatory mechanism is poorly understood. Here, we show that DegU contributes to L. monocytogenes exponential growth under mild heat-shock stress. We further demonstrate that DegU directly senses heat stress through autoregulation and upregulates the hrcA-grpE-dnaK-dnaJ operon, leading to increased production of heat-shock proteins. We also show that DegU can directly regulate the expression of the hrcA-grpE-dnaK-dnaJ operon. In conclusion, our results shed light on the regulatory mechanisms underlying how DegU directly activates the hrcA-grpE-dnaK-dnaJ operon, thereby regulating heat resistance in L. monocytogenes.

Nocardia usually manifests as opportunistic infections in immunocompromised hosts. Here, we report a rare case of an immunocompetent patient with lymphocutaneous nocardiosis. The patient was a 34-year-old man presenting with fever, multiple scattered pustules on both upper limbs and several subcutaneous nodules on the left elbow and forearm. Skin biopsy of the subcutaneous nodule revealed suppurative inflammation of the lymph nodes. Pus cultures were finally identified as Nocardia brasiliensis. The patient fully recovered without relapse after receiving optimized antimicrobial therapy consisting of linezolid combined with sulfonamides. Nocardiosis is a rare opportunistic disease which may be fatal and usually affects immunocompromised hosts, resulting in suppurative and granulomatous inflammation. Nocardia has a long culture cycle, is difficult to diagnose, and is more likely to be neglected in healthy young people. The present case suggests that physicians should be aware that nocardiosis is a differential diagnosis to consider in patients with suppurative infection, especially when anti-infective treatment is ineffective.

Backgroud Pregnant women are at high risk of developing febrile illness during the flu season. Early identification of a viral or bacterial infection is crucial in the management of febrile pregnant patients. Neutrophil CD64 (nCD64) has been shown to have more important diagnostic value in sepsis than traditional inflammatory indicators. Methods The pregnant women enrolled were divided into three groups according to disease: influenza A infection, bacterial infection and healthy controls. Peripheral blood CD64, leukocyte, C-reactive protein (CRP), procalcitonin (PCT) and human Th1/Th2-related cytokines levels were routinely measured. The correlation between and diagnostic value of the nCD64 index and other biomarkers were evaluated using Spearman’s correlation test and receiver operating characteristic (ROC) curve analysis. Results Pregnant women with bacterial infection had significantly elevated levels of leukocytes (8.4 vs. 5.95, 10^9/L; P=0.004), CRP (89.70 vs. 50.05, mg/ml; P=0.031), PCT (0.13 vs. 0.04, ng/ml; P=0.010), and TNF-α (0.46 vs. 0.38, pg/ml; P=0.012) and an elevated nCD64 index (12.16 vs. 0.81; P<0.001) compared to those with influenza A infection. The area under the curve (AUC) of the nCD64 index to discriminate bacterial infection among pregnant women (area = 0.9183, P < 0.0001) was the largest. The sensitivity and specificity of the nCD64 index at an optimal cut-off value of 3.16 were 84% and 100%, respectively, with a negative predictive value (NPV) of 94%. Conclusions Our study demonstrates the clinical value of the nCD64 index in distinguishing between bacterial infection and influenza A in pregnant women during the flu season.