Effect of RpoS on the survival, induction, resuscitation, morphology, and gene expression of viable but non-culturable Salmonella Enteritidis in powdered infant formula.

Involvement of the transcriptional regulator RpoS in the persistence of viable but non-culturable (VBNC) state has been demonstrated in several species of bacteria. This study investigated the role of the RpoS in the formation and resuscitation of VBNC state in Salmonella enterica serovar Enteritidis CICC 21482 by measuring bacterial survival, morphology, physiological characteristics, and gene expression in wild-type (WT) and rpoS-deletion (ΔrpoS) strains during long-term storage in powdered infant formula (PIF). The ΔrpoS strain was produced by allelic exchange using a suicide plasmid. Bacteria were inoculated into PIF for 635-day storage. Survival, morphology, intracellular reactive oxygen species (ROS) levels and intercellular quorum sensing autoinducer-2 (AI-2) contents were regularly measured. Resuscitation assays were conducted after obtaining VBNC cells. Gene expression was measured using real-time quantitative polymerase chain reaction (qPCR). The results showed that RpoS and low temperature conditions were associated with enhanced culturability and recoverability of Salmonella Enteritidis after desiccation storage in low water activity (aw) PIF. In addition, the synthesis of intracellular ROS and intercellular quorum sensing AI-2 was regulated by RpoS, inducing the formation and resuscitation of VBNC cells. Gene expression of soxS, katG and relA was found strongly associated with RpoS. Due to the lack of RpoS factor, the ΔrpoS strain could not normally synthesize SoxS, catalase and (p)ppGpp, resulting in its early shift to the VBNC state. This study elucidates the role of rpoS in desiccation stress and the formation and resuscitation mechanism of VBNC cells under desiccation stress. It serves as the basis for preventing and controlling the recovery of pathogenic bacteria in VBNC state in low aw foods.

Heat Resistance, Virulence, and Gene Expression of Desiccation-Adapted Salmonella Enteritidis During Long-Term Storage in Low-Water Activity Foods.

Desiccation stress could induce crossprotection and even affect virulence of Salmonella enterica. However, the influence of food matrices with low-water activity on desiccation adaptation of Salmonella still remains unclear. This study investigated the survival and adaptation of Salmonella Enteritidis in skim milk powder, ginger powder, and chocolate powder under desiccation storage conditions for a total of 12 weeks. High survival rates of Salmonella Enteritidis in all food matrices maintained over the long-term desiccation storage. Desiccation-adapted Salmonella Enteritidis enhanced heat resistance (p < 0.05) with the increase of storage time. Food composition plays an important role in the induction of crossresistance of desiccation-adapted Salmonella. After desiccation storage, Salmonella Enteritidis in ginger powder was most tolerant to heat treatment. Salmonella Enteritidis in skim milk powder was most resistant to the gastrointestinal simulation environment, and had strongest adhesion to Caco-2 cells. The effects of food composition on gene expression (rpoS, proV, otsA, otsB, grpE, dnaK, rpoH, and sigDE) in desiccation-adapted Salmonella Enteritidis were not significant (p > 0.05). At initial desiccation storage, osmotic protection-related genes (fadA, proV, otsA, and otsB), stress response regulator (rpoS), and heat-resistance-related genes (grpE, dnaK, and rpoH) were all significantly upregulated (p < 0.05). However, after 4-week storage, the expression level of desiccation-related genes, proV, otsA, otsB, grpE, dnaK, and rpoH, significantly decreased (p < 0.05). This study enables a better understanding of Salmonella's responses to long-term desiccation stress in different kinds of low-water activity foods.

Genetic Diversity of Domestic Cat Hepadnavirus in Southern Taiwan.

Domestic cat hepadnavirus (DCH) is an infectious disease associated with chronic hepatitis in cats, which suggests a similarity with hepatitis B virus infections in humans. Since its first identification in Australia in 2018, DCH has been reported in several countries with varying prevalence rates, but its presence in Taiwan has yet to be investigated. In this study, we aimed to identify the presence and genetic diversity of DCH infections in Taiwan. Among the 71 samples tested, eight (11.27%) were positive for DCH. Of these positive cases, three cats had elevated levels of alanine transaminase (ALT) and aspartate transaminase (AST), suggesting an association between DCH infection and chronic hepatitis. Four DCH-positive samples were also tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) coinfection. One sample (25%) was positive for FIV, whereas there was no positive sample for FeLV (0%). In addition, we performed whole genome sequencing on six samples to determine the viral genome sequences. Phylogenetic analyses identified a distinct lineage compared with previously reported sequences. This study highlights the importance of continuous surveillance of DCH and further research to elucidate the pathophysiology and transmission route of DCH.

The Role of Klotho Protein Against Sevoflurane-Induced Neuronal Injury.

The effects of general anesthetics on the developing brain have aroused much attention in recent years. Sevoflurane, a commonly used inhalation anesthetic especially in pediatric anesthesia, can induce developmental neurotoxicity. In this study, the differentially expressed mRNAs in the hippocampus of newborn rats exposed to 3% sevoflurane for 6 h were detected by RNA-Sequencing. Those data indicated that the mRNA of Klotho was increased after exposure to sevoflurane. Moreover, the protein expression of Klotho was assayed by Western Blot. Besides over-expression and under-expression of Klotho protein, we also detected changes of cell proliferation, ROS, JC-1, and Bcl-2/Bax ratio in PC12 cells exposed to sevoflurane. After exposure to 3% sevoflurane, the expression of Klotho protein increased in the hippocampus of neonatal rats. In PC12 cells, exposure to sevoflurane could increase cellular ROS level, reduce mitochondrial membrane potential and Bcl-2/Bax ratio. While overexpression of Klotho alleviated the above changes, knockdown of Klotho aggravated the injury of sevoflurane. Klotho protein could reduce oxidative stress and mitochondrial injury induced by sevoflurane in the neuron.

Critical lower extremity ischemia after snakebite: A case report.

BACKGROUND: Globally, the estimated annual incidence of snakebites is approximately 5 million, and approximately 100000 deaths occur from snakebites annually. Local tissue reaction, haemorrhagic clotting disorder, nephrotoxicity, and neurotoxicity are very common effects of snake envenomation, but other rarer complications, such as thrombosis, may also occur as a result of underlying disease. In the treatment of snakebite patients, attention should be paid to the patient's underlying diseases to avoid serious and catastrophic consequences secondary to snakebite. CASE SUMMARY: We report a 69-year-old man with critical right lower extremity pain after left foot snakebite 10 d prior without intermittent claudication or atrial fibrillation history. He was diagnosed with acute right lower extremity arterial thrombosis, which may have been caused by coagulopathy after snakebite and lower extremity atherosclerotic occlusive disease. Lower extremity computed tomography angiography at another hospital revealed that the aortoiliac and femoral arteries had neither filling defects nor atherosclerosis, but the right popliteal artery was occluded 2.3 cm below the tibial plateau. The patient received emergency catheter-directed thrombolysis, but amputation was carried out 11 d after admission because the patient had been admitted to the hospital too late to save the extremity. CONCLUSION: Acute ischaemia of the lower extremity due to snakebite is a rare event, and physicians should bear in mind the serious complications that may occur, especially in patients with atherosclerotic disease.

Thoracoscopic diagnosis of traumatic pericardial rupture with cardiac hernia: A case report.

BACKGROUND: Pericardial rupture caused by blunt chest trauma is rare in clinical practice. Because of its atypical clinical symptoms, and because surgeons are often unfamiliar with the clinical and radiological manifestations of the injury, preoperative diagnosis is difficult; it is easily misdiagnosed and causes serious consequences. CASE SUMMARY: A 60-year-old man, previously healthy, was transported to the emergency room after falling from a great height. Upon arrival, his vital signs were stable. Electrocardiography and echocardiography were performed, and there was no sign of cardiac injury or ischemia. Chest and abdomen computerized tomography revealed pneumopericardium, hemopneumothorax, lung contusion, multiple rib fractures on the right side (Figure 1), and right scapula and clavicle fractures. He was admitted to the inpatient department for further observation after tube thoracostomy. The next day, the patient suddenly experienced rapid arrhythmia (the ventricular rate reached 150-180 beats/min) when turning onto his right side, accompanied by a blood pressure drop to 70/45 mm Hg and a chief complaint of palpitation. Thoracoscopy was performed urgently, and a large vertical tear (8 cm × 6 cm) was found in the pericardium. The defect was successfully repaired using a heart Dacron patch. His postoperative condition was uneventful without any fluctuations in vital signs, and he was transferred to the orthopedics department for further surgery on postoperative day 8. CONCLUSION: Although the possibility of pericardial rupture combined with cardiac hernia is extremely low, it is one of the causes of cardiogenic shock following blunt trauma. Therefore, clinicians need to be more familiar with its characteristic manifestations and maintain a high degree of vigilance against such injuries to avoid disastrous consequences.

The Amplatzer device and pedicle muscle flap transposition for the treatment of bronchopleural fistula with chronic empyema after lobectomy: two case reports.

BACKGROUND: Bronchopleural fistula (BPF) refers to an abnormal channel between the pleural space and the bronchial tree. It is a potentially fatal postoperative complication after pulmonary resection and a complex challenge for thoracic surgeons because many patients with BPF ultimately develop refractory empyema, which is difficult to manage and has a major impact on quality of life and survival. Therefore, an operative intervention combined with conservative and endoscopic therapies may be required to control infection completely, to occlude BPF, and to obliterate the empyema cavity during treatment periods. CASE PRESENTATION: Two patients who suffered from BPF complicated with chronic empyema after lobectomy were treated in other hospitals for a long time and did not recover. In our department, we performed staged surgery and creatively combined an Amplatzer Septal Occluder (ASO) device (AGA Medical Corp, Golden Valley, MN, USA) with pedicled muscle flap transposition. First, open-window thoracostomy (OWT), or effective drainage, was performed according to the degree of contamination in the empyema cavity after the local infection was controlled. Second, Amplatzer device implantation and pedicled muscle flap transposition was performed at the same time, which achieved the purpose of obliterating the infection, closing the fistula, and tamponading the residual cavity. The patients recovered without complications and were discharged with short hospitalization stays. CONCLUSIONS: We believe that the union of the Amplatzer device and pedicle muscle flap transposition seems to be a safe and effective treatment for BPF with chronic empyema and can shorten the length of the related hospital stay.

STAT5 inhibitor attenuates atherosclerosis via inhibition of inflammation: the role of STAT5 in atherosclerosis.

Atherosclerosis is a chronic inflammatory disease driven by lipids, which occurs preferentially in the branches or curved areas of the middle and large arteries, contributing to increased morbidity and mortality of cardiovascular disease. Recently, it has been reported that STAT5 and its regulated immune response are closely related to non-tumor diseases. However, the role of STAT5 in the development of atherosclerosis remains unknown. In this study, atherosclerosis was induced by high-fat diet (HFD) in ApoE-/- mice, and STAT5-IN-1, a STAT5 inhibitor, was orally given. Macrophages stimulated by oxLDL were used as cell models in vitro. The effects of STAT5-IN-1 in ApoE-/- mice induced by HFD were assessed, and the underlying mechanisms were investigated by siRNA-induced gene silencing. The results revealed that treatment with STAT5 inhibitor significantly attenuated atherosclerosis in ApoE-/- mice induced by HFD via decreasing inflammation. Furthermore, it was demonstrated that inhibiting STAT5 could decrease oxLDL-induced inflammation. In summary, STAT5-IN-1 may be a potential drug for the treatment of atherosclerosis, and targeting STAT5 has the ability to be a potential therapeutic strategy for reducing atherosclerosis.

Peperomin E (PepE) protects against high fat diet-induced atherosclerosis in Apolipoprotein E deficient (ApoE-/-) mice through reducing inflammation via the suppression of NLRP3 signaling pathway.

Peperomin E (PepE) is a type of secolignan, a major component of the plant Peperomia dindygulensis. It has been shown to exert anti-inflammatory effects; however, the effects of PepE on human atherosclerosis remain unexplored. In the study, we investigated the role of PepE in high fat diet (HFD) induced atherosclerosis using apolipoprotein E defcient (ApoE-/-) mice. Elevated serum homocyteine, cholesterol, and triglyceride levels, accelerated progression of atherosclerosis and exacerbated macrophage infiltration into atherosclerotic lesions were observed in HFD-fed ApoE-/- mice, which were attenuated by PepE treatment. ApoE-/- mice fed with HFD exhibited significantly high levels of inflammation-associated regulators in artery tissues, accompanied with an increased expression of p-inhibitor of κBα (IκBα) and p-nuclear factor-kappa B (NF-κB), and the process was blocked by PepE administration. Further, we found NOD-like receptor pyrin 3 (NLRP3) inflammasome activation in artery tissues of HFD-fed ApoE-/- mice. In vitro, silencing NLRP3 using small interfering RNA efficiently inhibited oxidized-low-density lipoprotein (oxLDL)-induced ASC and Caspase-1 expressions, interleukin (IL)-1ß and IL-18 production in human aortic endothelial cells (HAECs). Further experiments indicated that NLRP3-ASC pathway was activated by reactive oxygen species (ROS), since ROS scavenger of N-acetyl-cysteine (NAC) prevented, which was further reduced by PepE addition. However, the anti-inflammatory effects of PepE on oxLDL-incubated HAECs were abolished by over-expression NLRP3. Together, our study revealed that PepE inhibited atherosclerosis development in HFD-fed ApoE-/- mice by suppressing NLRP3 inflammatory signaling pathway, and suggested that PepE might be a potential therapeutic strategy in the prevention of atherosclerosis.

Successful endovascular treatment of popliteal artery entrapment syndrome: a case report with 3-years follow-up.

Popliteal artery entrapment syndrome (PAES) is a rare cause of lower extremity arterial ischemia, especially in elder patients. At present, the role of the endovascular technique for PAES is still mainly auxiliary, there is no successful case treated successfully by endovascular treatment without open surgery, and also the long-term follow-up after endovascular treatment are lacking. We successfully treated a 51-year-old man with pale, cold right foot by endovascular therapy only, including percutaneous transluminal angioplasty and catheter directed thrombolysis. After endovascular treatment, the ABI of the right leg increased from 0.41 to 0.85, and the patient return to his life without claudication. Computed tomography angiography demonstrated the diagnosis of PAES. The 3-year follow-up showed a good clinical outcome, suggesting that for certain type of PAES, endovascular treatment alone may achieve good results. However, this result still requires confirmation in a large-sample study.

Structural and functional studies of Aspergillus oryzae cutinase: enhanced thermostability and hydrolytic activity of synthetic ester and polyester degradation.

Cutinases are responsible for hydrolysis of the protective cutin lipid polyester matrix in plants and thus have been exploited for hydrolysis of small molecule esters and polyesters. Here we explore the reactivity, stability, and structure of Aspergillus oryzae cutinase and compare it to the well-studied enzyme from Fusarium solani. Two critical differences are highlighted in the crystallographic analysis of the A. oryzae structure: (i) an additional disulfide bond and (ii) a topologically favored catalytic triad with a continuous and deep groove. These structural features of A. oryzae cutinase are proposed to result in an improved hydrolytic activity and altered substrate specificity profile, enhanced thermostability, and remarkable reactivity toward the degradation of the synthetic polyester polycaprolactone. The results presented here provide insight into engineering new cutinase-inspired biocatalysts with tailor-made properties.