Symbiosis of a lytic bacteriophage and Yersinia pestis and characteristics of plague in Marmota himalayana.

Surveillance for animal plague was conducted in the Marmota himalayana plague focus of the Qinghai-Tibet Plateau from 2020 to 2023. A 22.89% positive rate of serum F1 antibody was detected in live-caught marmots, alongside a 43.40% incidence of Yersinia pestis isolation from marmot carcasses. Marmot carcasses infected with plague exhibited a significantly higher spleen-somatic index (P < 0.05). Twenty-one Y. pestis-specific phages were isolated, among which one Y. pestis lytic phage (AKS2022HT87GU_phi) was isolated from the bone marrow of a marmot carcass (no. AKS2022HT87) and was found to be symbiotic with Y. pestis. Microscopy revealed the coexistence of lysed and non-lysed colonies of Y. pestis AKS2022HT87. Genome-wide analysis showed that certain strains of the Y. pestis AKS2022HT87 carried phage DNA fragments consistent with phage AKS2022HT87GU_phi. The rare symbiotic relationship between a lytic phage and Y. pestis observed in vitro was highlighted in this study, laying the basis for further exploring the relationship between Y. pestis and its bacteriophages.IMPORTANCEBacteriophages and host bacteria commonly coexist in vivo or in soil environments through complex and interdependent microbial interactions. However, recapitulating this symbiotic state remains challenging in vitro due to limited medium nutrients. In this work, the natural symbiosis between Yersinia pestis and specific phages has been discovered in a Marmota himalayana specimen. Epidemiological analysis presented the characteristics of the Y. pestis and specific phages in the area with a strong plague epidemic. Crucially, comparative genomics has been conducted to analyze the genetic changes in both the Y. pestis and phages over different periods, revealing the dynamic and evolving nature of their symbiosis. These are the critical steps to study the mechanism of the symbiosis.

Relationship Between Climate Change and Marmot Plague of Marmota himalayana Plague Focus - the Altun Mountains of the Qinghai-Xizang Plateau, China, 2000-2022.

Introduction: Plague is a zoonotic disease that occurs naturally in specific geographic areas. Climate change can influence the populations of the plague host or vector, leading to variations in the occurrence and epidemiology of plague in animals. Methods: In this study, we collected meteorological and plague epidemiological data from the Marmota himalayana plague focus in the Altun Mountains of the Qinghai-Xizang Plateau. The data spanned from 2000 to 2022. We describe the climatic factors and plague epidemic conditions and we describe their analysis by Pearson's correlation. Results: During the period from 2000 to 2022, the isolation rates of Yersinia pestis (Y.pestis) from marmots and fleas were 9.27% (451/4,864) and 7.17% (118/1,646), respectively. Additionally, we observed a positive rate of F1 antibody of 11.25% (443/3,937) in marmots and 18.16% (142/782) in dogs. With regards to climate, there was little variation, and a decreasing trend in blowing-sand days was observed. The temperature in the previous year showed a negative correlation with the Y. pestis isolation rate in marmots (r=-0.555, P=0.011) and the positive rate of F1 antibody in marmots (r=-0.552, P=0.012) in the current year. The average annual precipitation in the previous two years showed a positive correlation with marmot density (r=0.514, P=0.024), while blowing-sand days showed a negative correlation with marmot density (r=-0.701, P=0.001). Furthermore, the average annual precipitation in the previous three years showed a positive correlation with the isolation rate of Y. pestis from marmots (r=0.666, P=0.003), and blowing-sand days showed a negative correlation with marmot density (r=-0.597, P=0.009). Conclusions: The findings of this study indicate that there is a hysteresis effect of climate change on the prevalence of plague. Therefore, monitoring climate conditions can offer significant insights for implementing timely preventive and control measures to combat plague epidemics.

Pasteurella multocida strains of a novel capsular serotype and lethal to Marmota himalayana on Qinghai-Tibet plateau in China.

Pasteurella multocida is a zoonotic pathogen causing serious diseases in humans and animals. Here, we report P. multocida from wildlife on China's Qinghai-Tibet plateau with a novel capsular serotype, forming a single branch on the core-genome phylogenetic tree: four strains isolated from dead Himalayan marmot (Marmota himalayana) and one genome assembled from metagenomic sequencing of a dead Woolly hare (Lepus oiostolus). Four of the strains were identified as subspecies multocida and one was septica. The mouse model showed that the challenge strain killed mice within 24 h at an infectious dose of less than 300 bacteria. The short disease course is comparable to septicemic plague: the host has died before more severe pathological changes could take place. Though pathological changes were relatively mild, cytokine storm was obvious with a significant rise of IL-12p70, IL-6, TNF-αand IL-10 (P < 0.05). Our findings suggested P. multocida is a lethal pathogen for wildlife on Qinghai-Tibet plateau, in addition to Yersinia pestis. Individuals residing within the M. himalayana plague focus are at risk for P. multocida infection, and public health warnings are necessitated.

Case report: A case of brucellosis misdiagnosed as coronavirus disease 2019/influenza in China.

Brucellosis is an important zoonosis and a multisystem disease. The signs and symptoms of brucellosis are not specific. In the clinical, brucellosis is often ignored and misdiagnosed. We report a case of brucellosis who was misdiagnosed as coronavirus disease 2019 (COVID-19)/influenza and received delayed treatment during strict COVID-19 control. The neglect of other diseases due to COVID-19 and empirical diagnosis and treatment by medical staff are part of the reasons for misdiagnosis. Otherwise, the normal erythrocyte sedimentation rate (ESR), increased white blood cell count (WBC), and increased neutrophil count (NEUT) of this patient was also a cause of misdiagnosis, which is an important reminder for diagnosis. For patients with the unknown origin of fever and other symptoms related to brucellosis, especially those from endemic areas of brucellosis, brucellosis screening is a priority item, and grassroots doctors should be vigilant and standardize the diagnosis and treatment based on epidemiology history, clinical manifestation, and laboratory tests according to the diagnostic criteria of brucellosis.

The complex genomic diversity of Yersinia pestis on the long-term plague foci in Qinghai-Tibet plateau.

Plague is a typical natural focus disease that circulates in different ecology of vectors and reservoir hosts. We conducted genomic population and phylogenetic analyses of the Yersinia pestis collected from the 12 natural plague foci in China with more than 20 kinds of hosts and vectors. Different ecological landscapes with specific hosts, vectors, and habitat which shape various niches for Y. pestis. The phylogeographic diversity of Y. pestis in different kinds plague foci in China showed host niches adaptation. Most natural plague foci strains are region-and focus-specific, with one predominant subpopulation; but the isolates from the Qinghai-Tibet plateau harbor a higher genetic diversity than other foci. The Y. pestis from Marmota himalayana plague foci are defined as the ancestors of different populations at the root of the evolutionary tree, suggesting several different evolutionary paths to other foci. It has the largest pan-genome and widest SNP distances with most accessory genes enriched in mobilome functions (prophages, transposons). Geological barriers play an important role in the maintenance of local Y. pestis species and block the introduction of non-native strains. This study provides new insights into the control of plague outbreaks and epidemics, deepened the understanding of the evolutionary history of MHPF (M. himalayana plague focus) in China. The population structure and identify clades among different natural foci of China renewed the space cognition of the plague.

Identification of Novel Bartonella washoensis Sequence Type 22 in Marmota himalayana - Jiuquan City, Gansu Province, China, 2021-2022.

What is already known about this topic?: The prevalence of rodent-adapted Bartonella species has been increasing significantly. However, the specific Bartonella species carried by Marmota himalayana (M. himalayana), a large rodent species, and the potential risk it poses to human populations remain unknown. What is added by this report?: Bartonella washoensis (B. washoensis), associated with human endocarditis, was initially identified in M. himalayana, exhibiting a detection rate of approximately one-third and demonstrating a predilection for the heart and lungs. The discovery of the novel Sequence Type 22 has expanded both the isolation source and genetic lineage of B. washoensis. What are the implications for public health practice?: Individuals residing within the M. himalayana plague focus are at an elevated risk for B. washoensis infection. Consequently, there is a pressing need for public health warnings and efficient clinical case identification in this population.

Case Report: Screening and Analysis for Brucellosis in Akesai Kazak Autonomous County, China.

Brucellosis is a common zoonotic disease. For this study, the residents of Akesai Kazak Autonomous County, located in the high altitude of the Altun Mountains region of Gansu Province, were selected. These people rely on traditional animal husbandry for their main income. The prevalence of brucellosis and the change of antibody titer in this high-risk population were analyzed, and information on the epidemic in animals in the county was obtained from data records. One hundred ninety-nine persons were screened and 240 serum samples were collected. Eight persons and 27 serum samples were positive based on the rose bengal plate test, and seven persons were confirmed positive by standard agglutination test; 16,000 sheep were tested, of which 130 from nine different households were serum antibody positive. The results indicate that brucellosis seroprevalence increased among sheep and high-risk populations, and the occurrence of cases corresponded to the epidemic among animals. The incidence of human brucellosis was closely related to occupation, and the cases were mainly distributed among herdsmen and butchers. Most cases were asymptomatic or mild, and the serum antibody titers showed a high initial titer but a rapid decline in young cases, whereas those in older cases were relatively low but showed a slow decline.

Treatment of radiation-induced brain injury with bisdemethoxycurcumin.

Radiation therapy is considered the most effective non-surgical treatment for brain tumors. However, there are no available treatments for radiation-induced brain injury. Bisdemethoxycurcumin (BDMC) is a demethoxy derivative of curcumin that has anti-proliferative, anti-inflammatory, and anti-oxidant properties. To determine whether BDMC has the potential to treat radiation-induced brain injury, in this study, we established a rat model of radiation-induced brain injury by administering a single 30-Gy vertical dose of irradiation to the whole brain, followed by intraperitoneal injection of 500 µL of a 100 mg/kg BDMC solution every day for 5 successive weeks. Our results showed that BDMC increased the body weight of rats with radiation-induced brain injury, improved learning and memory, attenuated brain edema, inhibited astrocyte activation, and reduced oxidative stress. These findings suggest that BDMC protects against radiation-induced brain injury.

[Resveratrol pretreatment improves mitochondrial function and alleviates myocardial ischemia-reperfusion injury by up-regulating mi R-20b-5p to inhibit STIM2].

This study aimed to explore the mechanism of resveratrol(RES) pretreatment in improving mitochondrial function and alleviating myocardial ischemia-reperfusion(IR) injury by inhibiting stromal interaction molecule 2(STIM2) through microRNA-20 b-5 p(miR-20 b-5 p). Ninety rats were randomly assigned into sham group, IR group, IR+RES(50 mg·kg~(-1) RES) group, IR+RES+antagomir NC(50 mg·kg~(-1) RES+80 mg·kg~(-1) antagomir NC) group, and IR+RES+miR-20 b-5 p antagomir(50 mg·kg~(-1) RES+80 mg·kg~(-1) miR-20 b-5 p antagomir) group, with 18 rats/group. The IR rat model was established by ligation of the left anterior descending coronary artery. Two weeks before the operation, rats in the IR+RES group were intraperitoneally injected with 50 mg·kg~(-1) RES, and those in the sham and IR groups were injected with the same dose of normal saline, once a day. Ultrasonic instrument was used to detect the left ventricular internal diameter at end-diastole(LVIDd) and left ventricular internal diameter at end-systole(LVIDs) of rats in each group. The 2,3,5-triphenyte-trazoliumchloride(TTC) method and hematoxylin-eosin(HE) staining were employed to detect the myocardial infarction area and histopathology, respectively. Real-time quantitative PCR(qRT-PCR) was carried out to detect the expression of miR-20 b-5 p in myocardial tissue. Oxygen glucose deprivation/reoxygenation(OGD/R) was performed to establish an OGD/R model of H9 c2 cardiomyocytes. CCK-8 assay was employed to detect H9 c2 cell viability. H9 c2 cells were assigned into the control group, OGD/R group, OGD/R+RES group(25 µmol·L~(-1)), OGD/R+RES+inhibitor NC group, OGD/R+RES+miR-20 b-5 p inhibitor group, mimic NC group, miR-20 b-5 p mimic group, inhibitor NC group, and miR-20 b-5 p inhibitor group. Flow cytometry was employed to detect cell apoptosis. Western blot was employed to detect the expression of B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), cleaved-cysteine proteinase 3(cleaved-caspase-3), and STIM2 in cells. The mitochondrial membrane potential(MMP) assay kit, reactive oxygen species(ROS) assay kit, and adenosine triphosphate(ATP) assay kit were used to detect the MMP, ROS, and ATP levels, respectively. Dual luciferase reporter gene assay was adopted to verify the targeting relationship between miR-20 b-5 p and STIM2. Compared with the sham group, the modeling of IR increased the myocardial infarction area, LVIDd, LVIDs, and myocardial pathology and down-regulated the expression of miR-20 b-5 p(P<0.05). These changes were alleviated in the IR+RES group(P<0.05). The IR+RES+miR-20 b-5 p antagomir group had higher myocardial infarction area, LVIDd, LVIDs, and myocardial pathology and lower expression of miR-20 b-5 p than the IR+RES group(P<0.05). The OGD/R group had lower viability of H9 c2 cells than the control group(P<0.05) and the OGD/R+RES groups(25, 50, and 100 µmol·L~(-1))(P<0.05). Additionally, the OGD/R group had higher H9 c2 cell apoptosis rate, protein levels of Bax and cleaved caspase-3, and ROS level and lower Bcl-2 protein, MMP, and ATP levels than the control group(P<0.05) and the OGD/R+RES group(P<0.05). The OGD/R+RES+miR-20 b-5 p inhibitor group had higher H9 c2 cell apoptosis rate, protein levels of Bax and cleaved-caspase 3, and ROS level and lower Bcl-2 protein, MMP, and ATP levels than the OGD/R+RES group(P<0.05). miR-20 b-5 p had a targeting relationship with STIM2. The expression of STIM2 was lower in the miR-20 b-5 p mimic group than in the mimic NC group(P<0.05) and lower in the inhibitor NC group than in the miR-20 b-5 p inhibitor group(P<0.05). RES pretreatment can inhibit the expression of STIM2 by promoting the expression of miR-20 b-5 p, thereby improving the function of mitochondria and alleviating myocardial IR damage.

Severe hemolytic anemia and acute renal failure after mitral valve repair associated with non-endothelialization of artificial chordae tendinae: case report.

BACKGROUND: Mechanical hemolytic anemia and acute renal failure are rare complications of mitral valve repair. CASE PRESENTATION: We report a unique case of severe hemolytic anemia and severe acute renal failure after mitral valve repair using artificial chordae tendinae. Conservative therapy including plasmapheresis and blood transfusion was not effective. The major cause of the mechanical hemolysis was mild mitral regurgitation originating from the centre of the valve and striking the annuloplasty ring. The hemolytic anemia resolved gradually after the replacement of mitral valve. The new artificial chordae tendinae was found to be completely non-endothelialized in the surgery. Non-endothelialization of artificial chordae tendinae may also play a role in the genesis of mechanical anemia. CONCLUSIONS: The major cause of the mechanical hemolysis was mild mitral regurgitation originating from the centre of the valve and striking the annuloplasty ring. Non-endothelialization of foreign materials might be another mechanism of hemolysis after mitral repair.

Parachute mitral valve associated with reticular chordae tendineae in an adult: case report.

BACKGROUND: Parachute mitral valve with reticular chordae tendineae is an extremely rare anomaly. CASE PRESENTATION: We present a case of parachute mitral valve associated with distinctive reticular chordae tendineae in an adult. It was diagnosed from the echocardiogram. The patient was referred for surgery. Valve analysis showed thickened mitral valve leaflets and commissures. The chordae tendinae were lengthy and thick. All the chordae tendinae merged into a solitary papillary muscle. A distinctive reticular fibrous tissue was found on mitral valve apparatus as the chordae tendinae intermixed each other. The only functional communication between the left atrium and the left ventricle was through the reticular spaces. This anomaly was considered to be unrepairable and was replaced with a mechanical valve. CONCLUSIONS: An extremely rare and unique case of parachute mitral valve associated with reticular chordae tendineae was reported. Mitral valve replacement is a reasonable choice in patients with parachute mitral valve with reticular chordae tendineae.

Conservative treatment of left ventricular pseudoaneurysm after mitral valve replacement due to early left ventricular rupture: a case report.

BACKGROUND: Left ventricular pseudoaneurysm due to early left ventricle rupture is a serious complication after cardiac surgery. Urgent surgery is recommended in most cases with a high mortality rate. Conservative treatment of a left ventricular pseudoaneurysm due to early left ventricle rupture is very rare. CASE PRESENTATION: We present a 61-year-old woman with left ventricular pseudoaneurysm after mitral valve replacement due to early left ventricle rupture. This patient was treated in a conservative approach. This patient had an uneventful recovery. She was in good condition and remained asymptomatic 3.5 years after mitral valve surgery. CONCLUSION: This case suggests that medical treatment left ventricular pseudoaneurysm patients has a limited but acceptable role in selected and unusual circumstances.

Nickel-catalysed radical tandem cyclisation/arylation: practical synthesis of 4-benzyl-3,3-difluoro-γ-lactams.

Enabled by nickel catalysis, a practical access to the synthesis of 4-benzyl-3,3-difluoro-γ-lactams has been developed via radical tandem cyclisation/arylation. This method features a nickel catalyst, high reaction efficiency, and good substrate tolerance and scope. This protocol proceeds through an intramolecular radical addition to form a primary alkyl radical followed by intermolecular Suzuki-type coupling.

A case study of pulmonary embolism from the right atrial shunt after acute type a aortic dissection surgery.

This is one case report of a 46-year-old Chinese male with type A acute aortic dissection. It is an emergent surgery including Bentall procedure, interposition graft replacement of aortic arch, stented descending aorta with the modified right atrial shunt technique. In the early post operation period, the patient was complicated with pulmonary embolism. Pulmanary arteriography showed that the right main pulmonary embolism without an extrinsic compression. After the anticoagulant therapy, the patient was well recovered and discharged from hospital 1 month later. The origin of pulmonary embolism in the patient was believed to be the thrombosis in the shunt fistula. The right atrial shunt-related complications haven't been reported for more than thirty years. Pulmonary embolism could be a severe complication after the right atrial shunt in acute type A aortic dissection.

Mitral valve repair for double-orifice mitral valve.

We present an eight year-old girl who required an operation for moderate mitral insufficiency associated with partial atrioventricular septal defect. Echocardiography disclosed an ostium primum atrial septal defect and double-orifice mitral valve with moderate mitral regurgitation secondary to a cleft in the anterior leaflet and prolapse of the anterior leaflet. Intraoperative inspection revealed that the chordae from each orifice were attached to a single papillary muscle which resulted in a unique double-orifice mitral valve. Mitral valve repair using chordal shortening and cleft closure was successfully performed. Postoperative echocardiography observed trivial MR and no mitral stenosis.

Anterolateral minithoracotomy versus median sternotomy for mitral valve disease: a meta-analysis.

OBJECTIVE: Mitral valve disease tends to be treated with anterolateral minithoracotomy (ALMT) rather than median sternotomy (MS), as ALMT uses progressively smaller incisions to promote better cosmetic outcomes. This meta-analysis quantifies the effects of ALMT on surgical parameters and post-operative outcomes compared with MS. METHODS: One randomized controlled study and four case-control studies, published in English from January 1996 to January 2013, were identified and evaluated. RESULTS: ALMT showed a significantly longer cardiopulmonary bypass time (P=0.001) and aortic cross-clamp time (P=0.05) compared with MS. However, the benefits of ALMT were evident as demonstrated by a shorter length of hospital stay (P<0.00001). According to operative complications, the onset of new arrhythmias following ALMT decreased significantly as compared with MS (P=0.05); however, the incidence of peri-operative mortality (P=0.62), re-operation for bleeding (P=0.37), neurologic events (P=0.77), myocardial infarction (P=0.84), gastrointestinal complications (P=0.89), and renal insufficiency (P=0.67) were similar to these of MS. Long-term follow-up data were also examined, and revealed equivalent survival and freedom from mitral valve events. CONCLUSIONS: Current clinical data suggest that ALMT is a safe and effective alternative to the conventional approach and is associated with better short-term outcomes and a trend towards longer survival.

Chemical strategies for the synthesis of peptide-oligonucleotide conjugates.

The use of synthetic oligonucleotides and their mimics to inhibit gene expression by hybridizing with their target sequences has been hindered by their poor cellular uptake and inability to reach the nucleus. Covalent postsynthesis or solid-phase conjugation of peptides to oligonucleotides offers a possible solution to these problems. As feasible chemistry is a prerequisite for biological studies, development of efficient and reproducible approaches for convenient preparation of peptide-oligonucleotide conjugates has become a subject of considerable importance. The present review gives an account of the main synthetic methods available to prepare covalent conjugation of peptides to oligonucleotides.

Efficient inhibition of human cytomegalovirus UL122 gene expression in cell by small interfering RNAs.

In order to develop a gene therapy to human cytomegalovirus (HCMV), RNA interference (RNAi) was employed to inhibit the expression of HCMV UL122 gene in vitro. Recombinant vector pUL122-EGFP, which expressed UL122-EGFP fusion protein, and recombinant vectors psi122-1, psi122-2 and psi122-3, which expressed small interfering RNAs (siRNAs) targeted to UL122 were contransfected into AD293 cells. The fluorescence signal of pUL122-EGFP was greatly suppressed by psi122-1 and psi122-2, with an inhibitory rate of 82.0% +/- 1.0% and 79.5% +/- 2.5%, respectively. The mRNA of pUL122-EGFP of the cells transfected with psi122-1 and psi122-2 was decreased 97.3% +/- 0.6% and 98.0% +/- 0.1%, respectively. Vector psi122-3 showed a slightly low suppression rate. Therefore, it may be concluded that plasmids encoding siRNAs targeted to UL122 is able to in vitro reduce markedly the expression of UL122-EGFP. And it is very likely that the psi122-1 and psi122-2 are potentially efficacious siRNAs in the gene therapy of HCMV infection in vivo, in which further investigations are required. This study is expected to greatly facilitate the use of the RNAi technology for the anti-HCMV studies.