Gram-negative bacillary community acquired meningitis is not a rare entity in last two decades

The aim of this short note is to assess gram-negative bacillary community acquired meningitis (CBM) and nosocomial meningitis (NM) within 17 years nationwide survey. All cases of gram-negative bacillary CBM within 1990-2007 were assessed in national database of 372 patients with bacterial meningitis: 69 of gram-negative cases were nosocomial and 24 of gram-negative meningitis cases were CBM. Those 24 cases were compared with all CBM (201 cases) for risk factors and outcome. Among nosocomial gram-negative pathogens, A. baumannii in 23 cases, Ps. aeruginosa in 15 cases and Enterobacteriaceae in 31 cases were isolated. Among CBM, in 13 cases Enterobacteriaceae (Escherichia coli 6, Klebsiella pneumoniae 3, Proteus mirabilis 2, Enterobacter cloacae 2), in 5 cases Ps. aeruginosa and in 6 cases Acinetobacter baumannii were isolated from cerebrospinal fluid (CSF). The only significant risk factor for CBM due to gram-negative bacilli was neonatal age (12.5% vs. 3.5%, p=0.04) as underlying disease. However, mortality among gram-negative bacillary meningitis was significantly higher (12.4% vs. 37.5%, p=0.001) in comparison to other meningitis.     

耐亚胺培南鲍曼不动杆菌医院内感染流行的分子机制研究

目的研究耐亚胺培南鲍曼不动杆菌的耐药谱特征及其医院内感染流行和耐药性产生的分子机制,为临床防治提供依据.方法4株耐亚胺培南鲍曼不动杆菌分离自2002年10月至2003年1月外科重症监护病房的感染患者,采用纸片扩散法及E-test进行药物敏感性检测及MIC值测定,肠杆菌科基因组内重复一致序列聚集合酶链反应(ERIC-PCR)进行克隆株的DNA分型,耐药质粒转移及消除试验、等电聚焦电泳、PCR扩增β-内酰胺酶基因及其克隆测序以识别其耐药基因和进行质粒定位.结果4株菌除对头孢哌酮/舒巴坦复合制剂的MIC值较低外,对头孢菌素类、氨基糖甙类和氟喹喏酮类等抗生素均显示出了较高水平的多重耐药性;DNA分型证实为同一克隆株;产OXA-23型碳青霉烯酶和PER-1型超广谱β-内酰胺酶(ESBLs);OXA-23定位在质粒上,PER-1定位在染色体上.结论本组耐亚胺培南鲍曼不动杆菌为多重耐药株,同一克隆株在不同感染个体间的相互传播导致了本次医院内感染的流行,产OXA-23和PER-1型β-内酰胺酶是其耐药性产生的重要原因.     

Neuroinfections in developed versus developing countries

In recent supplement of neuroendocrinology letters, first time the authors from West and East, North and South of EU and the "Third World" present data on neuroinfections in high technology society - on nosocomial meningitis and vice versa in low technology and income countries of sub-Saharan Africa. 14 years survey of 171 cases of nosocomial paediatric meningitis is presented by Rudinsky et al. [1] and subpopulations of Acinetobacter baumannii and Pseudomonas aeruginosa [1,2] within last 20 years are briefly analyzed by Huttova et al. [2] and Ondrusova et al. [3]. All cases were complicating high technology procedures, such as neurosurgery, very low birth weight neonates after shunt implants etc. Current problems of management of nosocomial meningitis are reviewed by Bauer et al. [4] and consequence of inappropriate therapy by Huttova et al. [5]. Another high technology associated infection is septic embolisation followed by brain abscess and meningitis in patients with endocarditis after cardiac surgery (Kovac et al.) [6]. Experience from more than 600 cases is discussed in the article by Karvaj et al. [7] who outlines extremely high mortality in patients with endocarditis embolizing to central nervous system - up to 60%. The rest of papers are in contrary to problems of neuroinfections in EU and US focused on meningitis and cerebral malaria as commonest neuroinfections in the third world: 261 cases of cerebral malaria are discussed in a brief research note by Sudanese team of tropical programme in area of famine and civil war in southern Sudan (Bartkovjak and Ianetti et al.) [8]. Fungal neuroinfections complicating AIDS are of decreasing trend as reported by Njambi et al. from Kenya [9] and data from 497 cases from Uganda, Ethiopia and Burundi are presented by Benca et al. [10]. Finally an outbreak of meningococcal meningitis is reported by Benca et al. [11] from meningitis belt in Darfur and southern Sudan. We hope that the supplement may show difference in etiology, risk factors, therapy and outcome of neuroinfections (which is a burning public health and social problem in tropics) in other third world countries versus developed high-tech medical settings of US, EU and other high income countries, as presented by Benca et al. [12].     

多重耐药和广泛耐药鲍曼不动杆菌感染治疗的药物选择

鲍曼不动杆菌是医院内感染的重要病原体,其基于内在性和获得性的耐药机制,导致全球抗感染领域面临巨大挑战。目前,针对多重耐药和广泛耐药鲍曼不动杆菌引起的感染尚无有效治疗方案,本文对其可选用的治疗药物及最新进展进行综述。     

Antibacterial effects of Octenicept,and benzalkonium chloride on Acinetobacter baumannii strains isolated from clinical samples and determination of genetic diversity of isolates by RAPD-PCR method

Molecular Biology Reports - Acinetobacter baumannii (A. baumannii) is among the important causes of nosocomial infections. Due to the emergence of antibiotic resistance, many problems have been...     

Functional Exposed Amino Acids of CarO Analysis as a Potential Vaccine Candidate in Acinetobacter Baumannii

Acinetobacter baumannii is a well-recognized cause of nosocomial infections. This organism is recognized to be among the most difficult antimicrobial-resis     

主要医院感染病原菌与社区感染株耐药性比较

目的比较主要医院感染(HAI)病原菌与社区感染(CAI)株的耐药性,指导合理使用抗菌药物。方法收集永康市第一人民医院2003年1月至2006年6月所有标本中分离的主要HAI菌及其CAI株,分别统计其药物敏感试验。采用美国Dade Behring Microscan Walkaway 40全自动细菌鉴定及药敏测试仪及其配套药敏鉴定板测定MIC值。全国医院感染监测网软件和χ2统计分析。结果主要HAI菌为前4种革兰阳性(G )菌依次是金黄色葡萄球菌、表皮葡萄球菌、屎肠球菌、溶血葡萄球菌,前5种革兰阴性(G-)菌依次是大肠埃希菌、肺炎克雷伯菌、鲍曼不动杆菌、铜绿假单胞菌、阴沟肠杆菌。HAI株耐药率普遍高于CAI株,不同的细菌耐药率各具特点。不论HAI株还是CAI株,G 菌对万古霉素的耐药率最低,G-菌对亚胺培南的耐药率均较低,且两者耐药率差异均无显著性。金黄色葡萄球菌、大肠埃希菌、肺炎克雷伯菌、鲍曼不动杆菌4种HAI株对大多数抗菌药物的耐药率明显高于CAI株,其余5种细菌HAI株仅对少数抗菌药物的耐药率高于CAI株。结论HAI菌株耐药性比CAI菌株强,临床应区分感染性质合理使用抗菌药物,有针对性控制感染,从而减少抗菌药物的滥用和细菌耐药性的产生。     

鲍曼不动杆菌对碳青霉烯类抗生素的耐药性分析

目的了解鲍曼不动杆菌的耐药情况,并检测耐碳青霉烯类鲍曼不动杆菌的耐药基因,为指导临床合理用药、控制院内感染提供依据。方法利用K-B法检测45株鲍曼不动杆菌临床分离株的耐药情况,通过改良Hodge试验、Carba NP试验和EDTA协同试验对多重耐药鲍曼不动杆菌的碳青霉烯酶进行表型检测,并采用PCR技术检测鲍曼不动杆菌携带OXA-23和NDM-1型耐药基因的情况。结果 45株鲍曼不动杆菌临床分离株中共筛出42株多重耐药菌株;利用改良Hodge试验和Carba NP试验检出36株碳青霉烯酶阳性菌株;采用PCR扩增出OXA-23,未扩增出NDM-1。结论鲍曼不动杆菌耐药情况严重,且耐药基因OXA-23携带率高,治疗时应根据药敏试验结果合理用药。     

Proteomic analysis of a fraction enriched in cell envelope proteins of Acinetobacter baumannii

Acinetobacter baumannii is a multiresistant opportunistic nosocomial pathogen. A protein fraction was purified and analyzed by 2-DE. Twenty-nine major protein spots were selected for protein identification using trypsin digestion and MS analysis. As the A. baumannii genome has not yet been described, protein identification was performed by homology with other Acinetobacter species in the NCBi database. We identified ribosomal proteins, chaperones, elongation factors and outer membrane proteins (Omp), such as OmpA and the 33-36-kDa OMP. Proteomic analysis of A. baumannii provides a platform for further studies in antimicrobial resistance.     

鲍曼不动杆菌体外诱导耐药及其诱导前后交叉耐药和呼吸耗氧率分析

【背景】鲍曼不动杆菌是院内感染的重要病原菌,因其耐药率高、治疗难度大而备受关注。然而,对于该菌的交叉耐药及耐药相关因素尚未完全阐明。【目的】通过体外诱导分别获得耐美罗培南或耐替加环素的鲍曼不动杆菌菌株,并研究其诱导前后的交叉耐药性和细菌呼吸耗氧率差异。【方法】采用多步法对鲍曼不动杆菌ATCC19606进行体外诱导耐药,PCR扩增诱导前后菌株的16S rRNA基因并测序鉴定,微量肉汤稀释法检测诱导前后鲍曼不动杆菌对美罗培南、亚胺培南、替加环素、阿米卡星、头孢吡肟及左氧氟沙星等抗菌药物的最低抑菌浓度变化,Seahorse XF^e96细胞能量代谢实时测定仪对诱导前后菌株的耗氧率进行分析。【结果】通过88d的体外诱导实验,分别获得耐美罗培南或耐替加环素的鲍曼不动杆菌ATCC19606菌株。耐美罗培南鲍曼不动杆菌ATCC19606对替加环素、亚胺培南、阿米卡星、左氧氟沙星仍处于敏感状态,但是对头孢吡肟交叉耐药;耐替加环素鲍曼不动杆菌ATCC19606对美罗培南、亚胺培南、阿米卡星、左氧氟沙星及头孢吡肟仍处于敏感状态。鲍曼不动杆菌ATCC19606被美罗培南或替加环素诱导耐药...     

The role of bla(OXA-like carbapenemase) and their insertion sequences (ISS) in the induction of resistance against carbapenem antibiotics among Acinetobacter baumannii isolates in Tehran hospitals

This study aimed to evaluate the occurrence and dissemination of bla(OXA-like) carbapenemase genes and their insertion sequences among Acinetobacter baumannii isolates, taken from different hospitals in Tehran city and also their roles in the induction of resistance to carbapenem drugs. A total number of 100 non duplicate Acinetobacter baumannii with different origins, were isolated from patients with proved nosocomial infections at eight university hospital in Tehran city. Antimicrobial susceptibility of these strains was done by E-test against 7 antimicrobial agents according to CLSI guideline. PCR of bla(OXA-51-like), bla(OXA-23-like), bla(OXA-24-like), bla(OXA-58-like), IS(ABA-1), IS(1133) was carried out by specialized primers and then these strains were typed by REP-fingerprinting. Colistin, imipenem and meropenem were the most sensitive antibiotics against Acinetobacter baumannii isolates with 96%, 51% and 51% sensitivity respectively. All the isolates had a bla(OXA-51-like) intrinsic to these species. The rates of bla(OXA-23), 23 and 58-like were 38%, 32% and 1% respectively. Coexistence of bla(OXA-51/23/24-like) was observed among 16% of these isolates. All bla(OXA-23-like) carbapenemase genes had only one IS(ABA1). REP fingerprinting showed 5 genotypes among carbapenem resistant isolates, 16 of them being genotype A. This study emphasized on the major role of bla(OXA-like) carbapenemase, particularly bla(OXA-23-like) carbapenemase and their IS(ABA1), in the dissemination of carbapenem resistant Acinetobacter baumannii. This study confirmed a presumptive role of IS element neighboring the carbapenemase gene in the elevation of resistance to carbapenem drug among Acinetobacter baumannii isolates for the first time in Iran.     

Stereochemical insignificance discovered in Acinetobacter baumannii quorum sensing

Stereochemistry is a key aspect of molecular recognition for biological systems. As such, receptors and enzymes are often highly stereospecific, only recognizing one stereoisomer of a ligand. Recently, the quorum sensing signaling molecules used by the nosocomial opportunistic pathogen, Acinetobacter baumannii, were identified, and the primary signaling molecule isolated from this species was N-(3-hydroxydodecanoyl)-L-homoserine lactone. A plethora of bacterial species have been demonstrated to utilize 3-hydroxy-acylhomoserine lactone autoinducers, and in virtually all cases, the (R)-stereoisomer was identified as the natural ligand and exhibited greater autoinducer activity than the corresponding (S)-stereoisomer. Using chemical synthesis and biochemical assays, we have uncovered a case of stereochemical insignificance in A. baumannii and provide a unique example where stereochemistry appears nonessential for acylhomoserine lactone-mediated quorum sensing signaling. Based on previously reported phylogenetic studies, we suggest that A. baumannii has evolutionarily adopted this unique, yet promiscuous quorum sensing system to ensure its survival, particularly in the presence of other proteobacteria.     

Prevalence of OXA-type carbapenemase genes and genetic heterogeneity in clinical isolates of Acinetobacter spp. from Mangalore, India

The prevalence of OXA-type carbapenemase genes, ISAba1 insertion sequence, carbapenem resistance, biofilm forming ability and genetic heterogeneity in clinical isolates of Acinetobacter spp. from hospitals in Mangalore, South India was studied. Based on the presence of the bla(OXA-51) -like gene, the 62 isolates of Acinetobacter spp. were identified as 48 A. baumannii and 14 other Acinetobacter spp. The prevalence of bla(OXA-23) -like, bla(OXA-24) -like and bla(OXA-58) -like genes in A. baumannii was 47.9%, 22.9% and 4.2%, while in other Acinetobacter spp. it was 28.5%, 64.3% and 35.7% respectively. Several A. baumannii isolates (16/48) harbored the insertion sequence ISAba1 in the upstream region of the bla(OXA-23) -like gene. Resistance to meropenem was seen in 39.6% and 14.2% of A. baumannii and other Acinetobacter spp. isolates, respectively. The ability to form biofilm was observed to be higher among A. baumannii in comparison to other Acinetobacter spp. The present study shows that bla(OXA-23) -like genes are more common in A. baumannii,whereas bla(OXA-24) -like genes are common to other Acinetobacter spp. The study revealed genetic heterogeneity among the isolates, indicating multiple sources in the hospitals.     

Nosocomial meningitis caused by Staphylococcus other than S. aureus in children: multicentre study

Analysing 101 cases of nosocomial meningitis due to staphylococci other than S. aureus within last 15 years, coagulase negative staphylococci represented the commonest pathogen. Major risk factor for staphylococcal meningitis was prior neurosurgery, mainly ventriculoperitoneal shunt insertion. Ten of 101 cases were caused by glycopeptide intermediate resistant strains in patients pretreated with multiple combination of antibiotics including vancomycin and shunt exchanges: 76% of strains were also oxacillin resistant.     

Genome sequence of a dominant, multidrug-resistant Acinetobacter baumannii strain, TCDC-AB0715

Acinetobacter baumannii has emerged as a significant nosocomial pathogen worldwide. The increasing trend of carbapenem and fluoroquinolone resistance in A. baumannii severely limits the usage of therapeutic antimicrobial agents. Here we report the genome sequence of a multidrug-resistant A. baumannii strain, TCDC-AB0715, harboring both bla(OXA-23) and bla(OXA-66).     

Complete genome sequence of multidrug-resistant Acinetobacter baumannii strain 1656-2, which forms sturdy biofilm

Acinetobacter baumannii is a Gram-negative bacterium causing nosocomial infections worldwide. To gain quick insight into the molecular basis of biofilm formation in A. baumannii, we determined the complete genome sequence of A. baumannii strain 1656-2, which forms sturdy biofilm and is resistant to multiple drugs.     

346株鲍曼不动杆菌临床分布及耐药率分析

目的了解鲍曼不动杆菌引起医院感染的特点以及对抗菌药物的耐药性的变化趋势。方法应用美国BD公司Phoenix^TM100全自动细菌和药敏系统鉴定仪对所分离的364株鲍曼不动杆菌进行鉴定和药敏试验,并进行统计学分析。结果 346株鲍曼不动杆菌来自痰液、伤口分泌物、中段尿、静脉血及大便,分别占58.96%、30.92%、5.49%、4.34%、0.29%。药敏结果显示鲍曼不动杆菌对多粘菌素和米诺环素敏感性最高,耐药率低于10.4%。结论加强鲍曼不动杆菌的耐药监测,了解其耐药性变迁,可合理指导用药,有效控制鲍曼不动杆菌耐药菌株的产生。     

694株鲍曼不动杆菌的耐药性分析

目的了解大连市友谊医院临床分离的鲍曼不动杆菌的分布及耐药状况,为临床治疗鲍曼不动杆菌感染提供参考。方法对该院2007年至2009年住院患者送检的标本中分离到的694株鲍曼不动杆菌的分布及药敏结果做回顾性分析。结果鲍曼不动杆菌2007年检出112株（7．1％）,2008年检出210（11．3％）株,2009年检出372（14．7％）株;在所有临床送检的标本中,痰标本中的检出率最高,占88．7％;在对13种抗生素的药敏试验中,对美罗培南最为敏感,其次对头孢哌酮／舒巴坦较为敏感。结论鲍曼不动杆菌的检出率逐年增高,耐药率也逐年增高。     

Genome sequences of four divergent multidrug-resistant Acinetobacter baumannii strains isolated from patients with sepsis or osteomyelitis

Acinetobacter baumannii is a Gram-negative bacterium that causes nosocomial infections worldwide, with recent prevalence and higher frequency in wounded military personnel. Four A. baumannii strains from the Walter Reed Army Medical Center (WRAMC) isolated between 2008 and 2009 were sequenced, representing diverse, multidrug-resistant isolates from osteomyelitis or septic patients.     

鲍曼不动杆菌的临床分布及药物敏感性结果分析

目的了解鲍曼不动杆菌的临床分布及药物敏感性分析。方法收集2004年5月至2006年5月抚顺市中心医院住院及门诊患者的临床标本,从中分离鲍曼不动杆菌。质控菌株:大肠埃希菌ATCC 25922,铜绿假单胞菌ATCC 27853,采用美国BD公司生产的凤凰微生物鉴定/药敏分析仪,对62株鲍曼不动杆菌进行鉴定和药物敏感测定并分析其临床分布。结果62株鲍曼不动杆菌感染率高的有呼吸病房22例(35.5%),干部病房14例(22.6%),标本类型以痰为主52例(83.9%)。药敏监测该细菌对17种抗生素的耐药情况为亚胺培南、美洛培南、氨苄西林/舒巴坦、左氧氟沙星的敏感率较高,分别为100%、100%、75.8%、70.9%。有头孢唑林、氨苄西林、奥格门丁、氨曲南耐药率为90.3%、88.7%、80.6%、77.4%。结论鲍曼不动杆菌最有效的抗生素是亚胺培南、美洛培南,一旦临床发生感染,应及时调整和选用合理抗生素治疗,避免滥用抗生素,防止耐药菌株的产生,提高临床治愈率。