Diagnostic Value of Interferon-Gamma Release Assays for Tuberculosis in the Immunocompromised Population.

Interferon-gamma release assays (IGRAs) are widely used in the diagnosis of Mycobacterium tuberculosis (M. tuberculosis) infection by detecting interferon-γ released by previously sensitized T-cells in-vitro. Currently, there are two assays based on either enzyme-linked immunosorbent assay (ELISA) or enzyme-linked immunospot (ELISPOT) technology, with several generations of products available. The diagnostic value of IGRAs in the immunocompromised population is significantly different from that in the immunocompetent population because their results are strongly affected by the host immune function. Both physiological and pathological factors can lead to an immunocompromised situation. We summarized the diagnostic value and clinical recommendations of IGRAs for different immunocompromised populations, including peoplewith physiological factors (pregnant and puerperal women, children, and older people), as well as people with pathological factors (solid organ transplantation recipients, combination with human immunodeficiency virus infection, diabetes mellitus, end-stage renal disease, end-stage liver disease, and chronic immune-mediated inflammatory diseases). Though the performance of IGRAs is not perfect and often requires a combination with other diagnostic strategies, it still has some value in the immunocompromised population. Hopefully, the newly developed IGRAs could better target this population.

Phylogenetic and morphological significance of an overlooked flying squirrel (Pteromyini, Rodentia) from the eastern Himalayas with the description of a new genus.

The flying squirrels (Pteromyini, Rodentia) are the most diverse and widely distributed group of gliding mammals. Taxonomic boundaries and relationships within flying squirrels remain an area of active research in mammalogy. The discovery of new specimens of Pteromys ( Hylopetes) leonardi Thomas, 1921 previously considered a synonym of Hylopetes alboniger, in Yunnan Province, China allowed a morphological and genetic reassessment of the status of this taxon. Phylogenetic reconstruction was implemented using sequences of two mitochondrial (12S ribosomal DNA and 16S ribosomal DNA) and one nuclear (interphotoreceptor retinoid-binding protein) gene fragments. Morphological assessments involved examinations of features preserved on skins, skulls, and penises of museum specimens, supplemented with principal component analysis of craniometric data. Together these assessments revealed that this taxon should be recognized not only as a distinct species, and should also be placed within a new genus, described here as Priapomys.

Diagnostic Yield of Pneumococcal Antigen Detection in Cerebrospinal Fluid for Diagnosis of Pneumococcal Meningitis Among Children in China.

OBJECTIVE: To determine the diagnostic accuracy of pneumococcal antigen detection in diagnosis of pneumococcal meningitis in children. METHODS: Purulent meningitis was diagnosed according to European Society for Clinical Microbiology and Infectious Diseases (ESCMID) guideline between July 2014 and June 2016. Along with a cerebrospinal fluid (CSF) culture, pneumococcal antigen detection in cerebrospinal fluid (CSF) was performed, and further identification of pathogens was done with 16S rDNA-PCR and high-throughput sequencing. RESULTS: CSF samples collected from 184 children (median age of 1.92 mo). CSF culture was used as the gold standard. 46 (25%) had positive results for culture and 10 (5.4%) were pneumococci; 34 (18.5%) were pneumococcal antigen positive. The sensitivity and specificity of pneumococcal antigen detection were 100% (95% CI: 89.4%-100%) and 86.2% (95% CI: 96.4%-99.9%), respectively. 92.3% (12/13) were confirmed by nucleic acid detection to be pneumococci. CONCLUSIONS: Pneumococcal antigen detection in CSF has adequate sensitivity and specificity in diagnosing pneumococcal meningitis.

Antibiotic Resistance Profiles of Haemophilus influenzae Isolates from Children in 2016: A Multicenter Study in China.

BACKGROUND AND OBJECTIVE: Haemophilus influenzae (HI) is a common cause of community-acquired pneumonia in children. In many countries, HI strains are increasingly resistant to ampicillin and other commonly prescribed antibiotics, posing a challenge for effective clinical treatment. This study was undertaken to determine the antibiotic resistance profiles of HI isolates from Chinese children and to provide guidelines for clinical treatment. METHODS: Our Infectious Disease Surveillance of Pediatrics (ISPED) collaboration group includes six children's hospitals in different regions of China. The same protocols and guidelines were used by all collaborators for the culture and identification of HI. The Kirby-Bauer method was used to test antibiotic susceptibility, and a cefinase disc was used to detect ß-lactamase activity. RESULTS: We isolated 2073 HI strains in 2016: 83.9% from the respiratory tract, 11.1% from vaginal secretions, and 0.5% from blood. Patients with respiratory isolates were significantly younger than nonrespiratory patients (P < 0.001). Of all 2073 strains, 50.3% were positive for ß-lactamase and 58.1% were resistant to ampicillin; 9.3% were ß-lactamase-negative and ampicillin-resistant. The resistance rates of the HI isolates to trimethoprim-sulfamethoxazole, azithromycin, cefuroxime, ampicillin-sulbactam, cefotaxime, and meropenem were 71.1%, 32.0%, 31.2%, 17.6%, 5.9%, and 0.2%, respectively. CONCLUSIONS: More than half of the HI strains isolated from Chinese children were resistant to ampicillin, primarily due to the production of ß-lactamase. Cefotaxime and other third-generation cephalosporins could be the first choice for the treatment of ampicillin-resistant HI infections.

In vitro activity and clinical efficacy of macrolides, cefoperazone-sulbactam and piperacillin/piperacillin-tazobactam against Bordetella pertussis and the clinical manifestations in pertussis patients due to these isolates: A single-centre study in Zhejiang Province, China.

BACKGROUND AND OBJECTIVE: Macrolides are the recommended antibiotics for treating pertussis and preventing transmission. The causative bacterium, Bordetella pertussis, has high macrolide resistance and has recently circulated in China. The objective of this study was to find effective alternative antibiotics for treatment by assessing the in vitro activity and clinical efficacy of antibiotics against Bordetella pertussis. METHODS: Bordetella pertussis was confirmed by agglutination with specific antisera and mass spectrometry. The MICs of antibiotics against isolates were determined using the Etest method. Treatment outcomes were clinically and microbiologically evaluated. RESULTS: A total of 126 pertussis patients were diagnosed based on culture, 69.8% of whom were aged ≤6 months and 72.1% were treated with previous macrolides. Leucocytosis and lymphocytosis were observed in 29.4% and 54.8% of all patients, respectively. Both MIC50 and MIC90 of erythromycin, azithromycin, and clindamycin were >256mg/L, and 75.4% were highly macrolide resistant. The MIC90 of trimethoprim-sulfamethoxazole, ampicillin, ampicillin-sulbactam, cefuroxime, ceftriaxone and cefoperazone-sulbactam were 0.38mg/L, 0.25mg/L, 0.19mg/L, 12mg/L, 0.19mg/L and 0.047mg/L, respectively. The MICs of piperacillin in all of the isolations were <0.016mg/L. Of the patients treated with single cefoperazone-sulbactam or piperacillin-tazobactam, 30 of 32 (93.8%) had significantly improved clinical symptoms and 24 of 25 (96%) had negative culture results after 2 weeks of therapy. CONCLUSION: Macrolide resistance in Bordetella pertussis is a serious problem in Zhejiang Province, China. Piperacillin/piperacillin-tazobactam and cefoperazone-sulbactam have potent antibacterial activity in vitro and in vivo, and may become the alternative choice for treating pertussis caused by macrolide-resistant isolates.

Sialic Acid and Iron Content in Breastmilk of Chinese Lactating Women.

OBJECTIVE: To study sialic acid and iron content in breastmilk in Chinese women during different lactation stages. METHODS: Sialic acid and iron content of colostrum, transitional milk, mature milk, and involutional milk were determined using a neuraminidase assay kit and the ferrozine method, respectively in 88 lactating women (58 Term, 30 Preterm). RESULTS: The mean (SD) sialic acid levels of colostrum, transitional milk, mature milk, and involutional milk were 2201.4 (676.6) mg/L, 1445.9 (423.4) mg/L, 395.3 (96.0) mg/L and 273.0 (76.9) mg/L, respectively. The median iron content were 0.05 mg/L, 0.06 mg/L, 0.25 mg/L and 0.35 mg/L, respectively, in successive stages of lactation. Sialic acid and iron were significantly higher in breast milk of preterm mothers compared to term mothers. CONCLUSION: Sialic acid and iron content in breast milk vary greatly throughout the lactation stages, which probably reflects the infants' needs for growth and development at different stages.

Epidemiological Features and Antibiotic Resistance Patterns of Haemophilus influenzae Originating from Respiratory Tract and Vaginal Specimens in Pediatric Patients.

STUDY OBJECTIVE: Haemophilus influenzae (H. influenzae) is a common pathogen of respiratory tract infections in children, however, as a possible cause of vulvovaginitis in prepubertal girls, its epidemiological features, antibiotic-resistance patterns, and treatment are seldom noted. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Specimens obtained from patients were inoculated on Haemophilus selective medium; and drug-sensitivities tests were determined using the disk diffusion method. A cefinase disk was used to detect ß-lactamase. RESULTS: A total of 610 H. influenzae strains, 81.6% (498/610) from the respiratory tract and 18.0% (110/610) from the vagina, were identified in the Children's Hospital in 2015. The age of the children with respiratory tract strains were significantly younger than those with vaginal strains (P < .001). The H. influenzae isolation rate in May was the highest. The ß-lactamase positive rate was 51.5% (314/610), and 52.5% (320/610) were resistant to ampicillin. The susceptibilities rates to cefuroxime, ampicillin/sulbactam, cefotaxime, clarithromycin, and sulfamethoxazole-trimethoprim were 72.1% (440/610), 95.9%, 96.4% (588/610), 81.8% (499/610), and 36.4% (222/610), respectively. Higher resistance to ampicillin, cefuroxime, clarithromycin, and sulfamethoxazole-trimethoprim were found in respiratory tract strains, compared with vaginal strains (P < .05). All of the patients with H. influenzae in the respiratory tract were cured with oral or intravenous ß-lactam antibiotics. Of all patients with vaginal strains, 50% (55/110) were cured with topical ofloxacin gel, and 44.5% (49/110) were cured with oral ß-lactam antibiotics. CONCLUSION: The drug-resistance rates of H. influenzae isolated from vagina were lower than those from the respiratory tract. Topical ofloxacin gel or oral ß-lactam antibiotics are effective treatments to eliminate the H. influenza causing infection in the vagina.

[Effects of spatial structure on predator-prey interactions: A review.] / ç©ºé—´ç»“æž„å¯¹æ•é£Ÿå ³ç³»å½±å“ç ”ç©¶è¿›å±•.

With increasing human disturbances (e.g., spatial fragmentation), drastic changes have taken place in spatial structure, which further affects the structure and function of ecosystem. The consequences of spatial changes on ecological processes are significantly associated with change in predator-prey interactions. Thus, exploring the relationships between spatial structure andpredator-prey interactions was of significance in understanding the underlying mechanisms of ecological changes in fragmented landscapes. This paper summarized current studies about the effects of typical spatial structures on predator-prey interactions, including the spatial size, spatial shape, spatial orientation, spatial distribution and spatial connectivity. Researches indicated that the stability and continuation of predator-prey system generally decreases with decreasing spatial size and connectivity, and excessive increase in the fragmentation of space, as well as changes in spatial shape and orientation which result in excessive increase in the grazing rate of predators. Effect of complicated spatial structure (coupled from above-mentioned structures) on predator-prey interactions, especially multispecies predator-prey interactions, should be focused on in the future.