Comparisons of clinical features and outcomes between Elizabethkingia meningoseptica and other glucose non-fermenting Gram-negative bacilli bacteremia in adult ICU patients

BackgroundClinical information of Elizabethkingia meningoseptica (EM) bacteremia in intensive care unit (ICU) patients is limited and the impact on outcomes uncertain. The aim of this study was to investigate the clinical features and impact of EM bacteremia compared to other glucose non-fermenting Gram-negative bacilli (GNF-GNB) bacteremia in ICU patients.MethodsThis retrospective cohort study enrolled 70 patients who developed GNF-GNB bacteremia after ICU admission, including 19 cases of EM bacteremia (19/70, 27.1%). The main outcome measure was in-hospital mortality.ResultsThe patients with EM bacteremia had a lower rate of appropriate antibiotic therapy (15.8% vs. 62.7%, p < 0.001) and a longer time to appropriate antibiotic therapy (76.8 ± 46.4 vs. 35.1 ± 38.7 h, p < 0.001), but with a less severity in acute physiology and chronic health evaluation (APACHE) II score and shock status (p < 0.05) at the onset of bacteremia, compared to those with non-EM bacteremia. The in-hospital mortality between those with EM bacteremia and non-EM bacteremia was similar (63.2% vs. 51.0%, p = 0.363). However, primary bacteremia was more frequently noted in EM compared with non-EM group (57.9% vs. 25.5%, p = 0.011), and odds ratio 4.294 (95% confidence interval 1.292–14.277, p = 0.017) in multivariate regression analysis.ConclusionAmong the patients with GNF-GNB bacteremia, the numbers of the cases with primary bacteremia and inappropriate therapy were significantly more in EM group than those in non-EM group.     

Peptidoglycan recognition proteins in Drosophila immunity

Innate immunity is the front line of self-defense against infectious non-self in vertebrates and invertebrates. The innate immune system is mediated by germ-line encoding pattern recognition molecules (pathogen sensors) that recognize conserved molecular patterns present in the pathogens but absent in the host. Peptidoglycans (PGN) are essential cell wall components of almost all bacteria, except mycoplasma lacking a cell wall, which provides the host immune system an advantage for detecting invading bacteria. Several families of pattern recognition molecules that detect PGN and PGN-derived compounds have been indentified, and the role of PGRP family members in host defense is relatively well-characterized in Drosophila. This review focuses on the role of PGRP family members in the recognition of invading bacteria and the activation and modulation of immune responses in Drosophila.     

Steps towards the discovery of Mycobacterium tuberculosis by Robert Koch, 1882

Palaeomicrobiology has detected the tuberculosis agent in animal and human skeletons that are thousands of years old. The German doctor Robert Koch was the first microbiologist to report in 1882 the successful isolation of the causative agent of tuberculosis, named 1 year later as Mycobacterium tuberculosis. This immense discovery, however, was not made from scratch, but involved the combining of previous scientific knowledge, chiefly the previous demonstration by the French doctor Jean-Antoine Villemin that tuberculosis was a transmissible disease, and two innovations—a new staining procedure that allowed R. Koch to consistently observe the new organism in tuberculous lesions, and use of a solidified, serum-based medium instead of broths for the culture. These innovations allowed R. Koch not only to isolate M. tuberculosis from animal and patient specimens for the first time, but also to reproduce the disease in experimentally inoculated guinea pigs. It is thanks to R. Koch that one of the most lethal diseases in human history could be diagnosed, could be treated and cured after the discovery of streptomycin 65 years later, and could be efficiently prevented by isolation of cases. His microbiological innovations are now being renewed with molecular and improved culture-based detection being the twenty-first century weapons in the fight against this disease, which remains a major killer.     

MBL2 deficiency is associated with higher genomic bacterial loads during meningococcemia in young children

Mannose binding lectin (MBL2) is a soluble pattern recognition receptor that is key to generating innate immune responses to invasive infection, including against the cardinal Gram-negative bacterium Neisseria meningitidis. Individuals homozygous or heterozygous for any of three variant alleles of MBL2 (O/O or A/O genotypes) have deficient concentrations of MBL2 in circulating blood, but previous studies linking MBL deficiency to susceptibility to meningococcal disease have not revealed a consistent association. We genotyped 741 patients with microbiologically – proven meningococcal disease and correlated MBL2 genotype with plasma bacterial load of N. meningitidis with blood samples taken during hospital admission. We show that individuals with genotypes compatible with MBL2 deficiency have higher measurable levels of bacterial plasma genomic load with the greatest effect seen in children <2 years of age. However, the overall impact of this is minor, because there was no evidence that such genotypes are more common in children with meningococcal disease compared with uninfected cohorts. The findings suggest that MBL2 supports innate immune defence against meningococcal disease in the early months of life, before acquired immunity is sufficiently robust for effective natural protection.     

苏州市某三甲医院2017年临床分离菌耐药性监测

摘要 目的 了解苏州大学附属第一医院2017年临床分离菌对临床常用抗菌药物的耐药性,为临床合理用药提供参考依据。方法 采用纸片扩散法和自动化仪器进行细菌体外药敏试验,并用Whonet 5.6软件进行统计分析。结果 2017年共分离9 106株非重复菌株,其中革兰阳性菌2 549株,占28.0%,革兰阴性菌6 557株,占72.0%。金黄色葡萄球菌(MRSA)和凝固酶阴性葡萄球菌中甲氧西林耐药株(MRCNS)的检出率分别为53.8%和71.6%。MRSA和MRCNS对绝大多数测试药物的耐药率均明显高于甲氧西林敏感株(MSSA和MSCNS)。MRSA中有94.0%菌株对甲氧苄啶-磺胺甲唑敏感;MRCNS中有76.4%的菌株对四环素敏感;未发现万古霉素耐药株。肠球菌属中粪肠球菌对多数测试抗菌药物(四环素除外)的耐药率均显著低于屎肠球菌,粪肠球菌检出1株利奈唑胺耐药株,屎肠球菌检出5株万古〖JP2〗霉素耐药株。除肺炎克雷伯菌外,多数肠杆菌科细菌对碳青霉烯类抗生素仍高度敏感,耐药率低于6%。mCIM试验显示CR-KPN 99.17%产碳青霉烯酶。结论 临床分离菌耐药率呈增长性趋势,尤其是碳青霉烯类耐药肺炎克雷伯菌,应继续加强抗菌药物应用管理,做好医院感染防控工作。〖JP〗     

Cefiderocol for Infections Caused by Multidrug-Resistant Gram-Negative Bacteria

In 2019, the U.S. Food and Drug Administration approved cefiderocol, a new treatment option for individuals with complicated urinary tract infections. Cefiderocol is a cephalosporin antibiotic indicated for use in adults 18 years or older who have minimal treatment options due to resistance for complicated urinary tract infections caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Enterobacter cloacae complex. The recommended dose of cefiderocol is 2 g intravenously every 8 hours infused over 3 hours. The dose is adjusted for individuals with creatinine clearance of less than 60 ml/min or greater than 120 ml/min. Gastrointestinal symptoms such as diarrhea and constipation are the most common adverse events reported by individuals taking cefiderocol.     

Detection of oqxA and oqxB efflux pump genes among nosocomial coliform bacilli: An observational cross-sectional study

Objectives: To identify and test the antibiotic susceptibility of nosocomial coliform bacilli and investigate the presence of oqxA and oqxB genes among the multidrug-resistant (MDR) phenotypes. Methods: One hundred and twenty different healthcare-associated infection samples were collected. Coliform bacilli were isolated, identified by conventional methods, and then antibiotic susceptibility tests were done using the VITEK2 system and disk diffusion methods. OqxAB operon was identified using a conventional PCR-based technique. oqxA and oqxB genes were compared between MDR Klebsiella pneumonia (K. pneumonia) phenotypes and MDR Escherichia coli (E. coli) phenotypes. Besides, oqxAB operons were compared between phenotypes of K. pneumonia and E. coli isolates. Results: Seventy coliform bacilli were isolated with the predominance of K. pneumonia and E. coli. Besides, 82.1％ of K. pneumonia strains and 53.3％ of E. coli isolates were MDR phenotypes. Significant more oqxB genes alone were found in MDR E. coli than that in MDR K. pneumoniae phenotypes (χ2=10.160, P=0.003). OqxAB operon was significantly more in MDR phenotypes of E. coli than that in the susceptible phenotypes (P<0.001). There was significantly less of this operon in susceptible E. coli isolates than that in susceptible K. pneumoniae isolates (P<0.001). OqxAB positive isolates that were also resistant to fluoroquinolones, tetracycline, trimethoprim, and chloramphenicol, most probably suggested functional pumps. Conclusions: MDR coliform bacilli are strongly implicated in healthcare-associated infection. Attention should be paid to the presence of oqxAB pump, as an important mechanism in the development of resistance against many antimicrobials because it contributes to co-resistance with other categories; therefore, this pump could be a good target for efflux pump inhibitors.     

Bruker Biotyper和Vitek MS系统质谱分析鉴定革兰阴性菌临床分离株的比较研究

目的比较并评价两种基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption ionization time of flight mass spectrometry,MALDI-TOF-MS)系统——Bruker MALDI Biotyper系统(以下简称Bruker Biotyper系统)和MALDITOF Vitek MS系统(以下简称Vitek MS系统)在革兰阴性菌临床分离株鉴定中的应用。方法收集沈阳军区总医院2012年3月—2013年1月分离自血液、尿液、脑脊液、分泌物、伤口拭子和痰液临床标本的革兰阴性菌共120株。应用Vitek 2 Compact生化鉴定系统将每株细菌鉴定到种,而后采用Bruker Biotyper和Vitek MS系统对其进行鉴定,三者鉴定结果存在差异的菌株经16S rDNA测序最终确认菌种。结果对于120株革兰阴性菌临床分离株,Bruker Biotyper和Vitek MS系统在属的水平上正确鉴定率分别为95.0%和92.5%,在种的水平上正确鉴定率分别为89.2%和86.7%,差异均无统计学意义。结论 Bruker Biotyper和Vitek MS系统对革兰阴性菌临床分离株的正确鉴定率不存在差异,两种系统的鉴定结果与各自的图谱数据库有密切关系。     

2005年至2007年中国CHINET脑脊液的分离菌及其耐药性

目的 了解2005年至2007年中国CHINET监测网脑脊液分离菌的分布及其耐药性.方法 对CHINET监测网2005年1月至2007年12月所有脑脊液标本按常规方法进行分离、培养、鉴定.按统一方案用Kirby-Bauer纸片扩散法进行抗菌药物敏感试验.结果 2005年至2007年脑脊液标本获分离菌941株,其中革兰阳性菌588株.占62.5%;革兰阴性菌349株,占37.1%;真菌4株,占0.4%.革兰阳性菌所占比例由2005年的59.9%增至2007年的64.6%,革兰阴性菌所占比例由2005年的39.6%降至2007年的35.4%.最常见的分离菌依次分别为凝固酶阴性葡萄球菌、不动杆菌属、肠球菌属、铜绿假单胞菌、金黄色葡萄球菌、大肠埃希菌、克雷伯菌属、肠杆菌属、肺炎链球菌、链球菌属和其他假单胞菌.葡萄球菌属和肠球菌属中未发现万古霉素耐药株,肺炎链球菌对青霉素的耐药率为42.9%.肠杆菌科细菌对碳青霉烯类高度敏感,不动杆菌属和铜绿假单胞菌对碳青霉烯类耐药率为24.1%～29.3%.结论 2005年至2007年脑脊液分离菌中革兰阳性菌多于革兰阴性菌,脑脊液分离株对常用抗菌药物耐药明显.