[Diversity of Zooplankton and Niche Characteristics of Keystone Species in the Weihe River Based on eDNA].

Environmental DNA(eDNA), a new tool for monitoring the biodiversity of aquatic ecosystems, is able to analyze characteristics of biodiversity from a microscopic perspective. Based on eDNA data collected from the Weihe River, diversity indexes, non-metric multidimensional scaling, cluster analysis, and correlation network analysis were employed to explore the diversity and community structure of zooplankton focusing on the niche differentiation of keystone species and environmental adaptability. The eDNA approach identified three types of zooplankton including Rotifera, Cladocera, and Copepoda, among which the dominant species was Brachionus calyciflorus. The zooplankton community shows significant differences in species composition, abundance, diversity and spatial distribution characteristics(P<0.01). The average values of the Chao1 index, ACE index, Shannon index, and Simpson index were 22.25, 22.38, 2.32, and 0.68, respectively. The downstream biodiversity is significantly higher than in the upstream area. Non-metric multidimensional scale analysis and hierarchical cluster analysis further showed that the zooplankton community structure shows distinct regional differences. The keystone species in the community have a high degree of connection with other species, with a high node degree, centrality, and modularity. The niche breadth(Bi) of the operational taxonomic units(OTUs) of the keystone species varied from 0.38 to 0.80. The medium niche species accounted for 63% of all keystone species. The average niche overlap index(Qik) was 0.72, and the degree of overlap was generally high. RDA analysis further identified that water environmental variables were closely related to changes in the zooplankton community structure and niche differentiation. For example, total nitrogen and water temperature were the main limiting factors, which play important roles in shaping the zooplankton community structure.

Combined Strategy for Post-Operative Patients with Central Nervous System Infections Caused by Extensively Drug-Resistant/Pan-Drug-Resistant Acinetobacter baumannii: A Retrospective Study.

Background: Post-operative central nervous system infections (PCNSIs) caused by extensively drug-resistant (XDR) or pan-drug-resistant (PDR) Acinetobacter baumannii are rare but intractable problems. To investigate a potential combined strategy to treat Acinetobacter baumannii organisms that are resistant to not only meropenem but also colistin. Methods: We retrospectively reviewed cerebrospinal fluid positive culture isolates of Acinetobacter baumannii in patients who underwent neurosurgery. Medical records were collected by standard forms and analyzed. Results: Sixteen patients met the criteria and most patients were middle-aged males who had undergone craniotomy or endonasal trans-sphenoidal surgery. A total of 68.8% Acinetobacter baumannii isolates were XDR bacteria, and 18.8% of isolates were PDR bacteria. Twelve patients were treated by meropenem-based regimen strategy. Another four patients were administered tetracycline-based regimens. A total of 93.8% patients were treated with therapeutic drainage and strict hygiene rules were followed. Finally, 12 patients survived their infections, and the average Glasgow Outcome Scale score was 2.9 ± 1.4 at discharge. The mortality rates of carbapenem-resistant Acinetobacter baumannii (CRAB) were 8.3%. Conclusions: Post-operative central nervous system infections caused by XDR/PDR Acinetobacter baumannii are a rare and serious complication. Combined therapy based on the individual situation, including appropriate antimicrobial agents, surgical management, and strict hygiene management might be an effective therapeutic strategy.

Sinocyclocheilus sanxiaensis, a new blind fish from the Three Gorges of Yangtze River provides insights into speciation of Chinese cavefish.

A blind fish of Sinocyclocheilus (Cypriniformes: Cyprinidae) was caught in open water in the Three Gorges (Sanxia) reservoir, at a depth of 20 m in the mainstream of Yangtze River in Zigui County, Hubei Province, China. This fish can be easily distinguished from all other congeners by external morphological characteristics, and is estimated to have diverged from its sister group about 0.55 million years ago (Ma). The geologically well separated locality of this species has expanded the distribution of Sinocyclocheilus cavefish from around N25°(latitude) to above N30°. Herein, we describe this new species as Sinocyclocheilus sanxiaensis sp. nov., and discuss the possible reasons why the species appears, surprisingly, in the Three Gorges reservoir.

Bromadiolone poisoning leading to subarachnoid haemorrhage: A case report and review of the literature.

WHAT IS KNOWN AND OBJECTIVE: Many cases of rodenticide poisoning have been reported. Bromadiolone, often called a super-warfarin, is a second-generation dicoumarin rodenticide with long half-life. The main clinical manifestations of bromadiolone poisoning are excessive or inappropriate bleeding of skin mucosa, digestive tract and urinary tract. However, the phenomenon of central nervous system (CNS) toxicity is an uncommon medical emergency. We present a case of SAH and intracerebral haematoma mediated by bromadiolone intoxication, revealing that bromadiolone poisoning might cause intracerebral haematoma. CASE DESCRIPTION: A 44-year-old woman presented with skin mucosa haemorrhage and haematuresis initially. The patient developed lethargy, headache, nausea and vomiting. The toxicology test result revealed that the presence of bromadiolone in her blood. Coagulation test results showed a longer prothrombin time (PT), activated partial thromboplastin time (APTT) and a high international normalized ratio (INR). SAH, frontal lobe haematoma, midline shift and brain oedema were discovered by skull CT examination. The coagulation disorders were addressed after the treatment of vitamin K and fresh frozen plasma. The intracranial symptoms were relieved after surgery and the treatment with mannitol. WHAT IS NEW AND CONCLUSION: This case suggests that bromadiolone poisoning should be diagnosed and treated as early as possible. Bromadiolone poisoning might cause SAH and intracerebral haematoma, which is rare but potentially lethal. It is important to strengthen the diagnosis and post-treatment monitoring.

[Advancement in Diagnosis and Treatment of Elevated Intracranial Pressure in Patients with Cryptococcal Meningitis].

Cryptococcal meningitis(CM)is often seen in immunocompromised patients and has become a global health concern. Elevated intracranial pressure(ICP)is a common complication of CM and often leads to poor prognosis. Monitoring and management of ICP is an important task in CM patients. Invasive intervention is often needed for the elevated ICP in CM patients due to the pathophysiological features of this condition. This article review the recent progress in the diagnosis and treatment of elevated ICP in CM patients.

Prevalence and antibiotic resistance of bacteria isolated from the cerebrospinal fluid of neurosurgical patients at Peking Union Medical College Hospital.

Background: Postoperative central nervous system infections (PCNSIs) represent a serious complication, and the timely use of antibiotics guided by the identification of the causative pathogens and their antibiotic sensitivities is essential for treatment. However, there are little data regarding the prevalence of PCNSI pathogens in China. The aim of this study is to investigate the features of pathogens in patients with PCNSIs, which could help clinicians to choose the appropriate empirical antibiotic therapy. Methods: We retrospectively examined the positive CSF cultures in patients who underwent craniotomy between January 2010 and December 2015. We collected data, including demographic characteristics, type of neurosurgery, laboratory data, causative organisms and antimicrobial susceptibility testing results. Results: A total of 62 patients with 90 isolates out of 818 patients with 2433 CSF culture samples were available for data analysis. The estimated incidence and culture-positive rate of PCNSIs were approximately 0.9 and 7.5%, respectively. The predominant organism was coagulase-negative staphylococci, of which most were methicillin-resistant coagulase-negative staphylococci (MRCoNS). All were susceptible to vancomycin, linezolid, rifampicin and amoxicillin-clavulanate. Acinetobacter baumannii was the most frequent causative Gram-negative agent and was resistant to 12 out of 18 antimicrobials tested. The sensitivity rates for tigecycline and minocycline were only 40 and 33%, respectively. Conclusion: PCNSIs could lead to high mortality. Although the MRCoNS were the predominant organism, the management of Acinetobacter baumannii was a major clinical challenge with few effective antimicrobials in PCNSIs.