Postoperative meningitis due to a rare pathogen; Alcaligenes xylosoxidans

Alcaligenes xylosoxidans is non-fermenting gram-negative bacilli found in soil and water. It is an aerobic bacterium in the genus Achromobacter. This bacterium is motile, oxidase positive, and catalase positive, which is isolated uncommonly from clinical specimens. In the present paper, we report a case of meningitis associated with A. xylosoxidans in a 38-year-old male patient post neurosurgery.     

Characteristics of Pseudomonas aeruginosa isolates from intensive care unit

The study looked at the antimicrobial resistance patterns, serotypes, molecular types, metallo beta-lactamase, and chromosomal betalactamase enzymes of P. aeruginosa strains isolated from the patients and the staffs of the intensive care unit. P. aeruginosa isolates from the patients as nosocomial pathogens and from the staffs were evaluated for their susceptibilities to the antimicrobials by the disk diffusion and E-test methods. Metallo beta-lactamase enzymes were investigated by E-test, the inducibility of β - lactamase enzymes were detected by the disk antagonism test. Serotyping was performed by slide agglutination method. The P. aeruginosa isolates were typed by pulsed field gel electrophoresis. Twenty-five P. aeruginosa strains from the patients and three from the staffs were isolated. Fifteen P. aeruginosa, eleven of which composed of MDR bacteria, were found in serogroup E, 7 strains in G, 4 strains in B, and 1 strain in serogroup A. In all 12 bacteria in the MDR and serogroup E, metallo beta-lactamase enzyme was found to be positive. And in other 15 strains, except the bacterium which could not be serotyped, chromosomal beta-lactamase was found to be positive. The result of the molecular typing showed PFGE A pattern. In conclusion, a pattern in PFGE which included bacteria from MDR and serogroup E, G which was observed in the P. aeruginosa strains which was isolated from the staff’s hands and from the 5 patients, and PFGE F pattern were found to be observed the most. Finally, the two different clonal strains were found to be established in the intensive care.     

2018—2020年郑州市第七人民医院血流感染分离菌的分布及耐药性分析

目的 了解血流感染分离菌的分布及耐药特征,为临床防治血流感染提供指导和依据。方法 收集2018年1月—2020年12月郑州市第七人民医院血培养分离的非重复菌株,采用WHONET5.6软件统计菌株的分布及耐药特征。结果 共分离546株菌株,革兰阴性菌302株（55.31%）,革兰阳性菌220株（40.29%）,真菌24株（4.40%）。前6位分离菌依次为凝固酶阴性葡萄球菌（CNS,23.44%）、大肠埃希菌（18.68%）、肺炎克雷伯菌（14.84%）、金黄色葡萄球菌（6.04%）、鲍曼不动杆菌（4.21%）和铜绿假单胞菌（3.85%）。大肠埃希菌对碳青霉烯类最敏感,肺炎克雷菌碳对美罗培南和亚胺培南的耐药率分别为30.86%和35.80%,鲍曼不动杆菌耐药较严重,耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）和耐甲氧西林金黄色葡萄球菌（MRSA）的检出率分别为72.66%、42.42%,未发现利奈唑胺和万古霉素耐药的葡萄球菌。结论 革兰阴性菌是医院血流感染的主要致病菌,细菌耐药情况复杂,临床要根据药敏结果合理选择抗菌药物。     

Effect of linear alkylbenzene sulfonates on the growth of aerobic heterotrophic cultivable bacteria isolated from an agricultural soil

An enrichment culture technique was used to isolate soil bacteria capable of growing in the presence of two different concentrations of linear alkylbenzene sulfonates (LAS) (10 and 500 microg ml(-1)). Nine bacterial strains, representatives of the major colony types of aerobic heterotrophic cultivable bacteria in the enriched samples, were isolated and subsequently identified by PCR-amplification and partial sequencing of the 16S rRNA gene. Amongst the isolates, strains LAS05 (Pseudomonas syringae), LAS06 (Staphylococcus epidermidis), LAS07 (Delftia tsuruhatensis), LAS08 (Staphylococcus epidermidis) and LAS09 (Enterobacter aerogenes), were able to grow in pure culture in dialysed soil media amended with LAS (50 microg ml(-1)). The three Gram-negative strains grew to higher cell numbers in the presence of 50 microg ml(-1) of LAS, compared to LAS-unamended dialysed soil medium, and were selected for further testing of their ability to use LAS as carbon source. However, HPLC analysis of culture supernatants showed that the three strains can tolerate but not degrade LAS when grown in pure cultures. A higher concentration of soluble phosphates was recorded in dialysed soil media amended with LAS (50 microg ml(-1)) compared to unamended control media, suggesting an effect of the surfactant that enhanced the bioavailability of P from soil. The presence of LAS at a concentration of 50 microg ml(-1) had an important impact on growth of selected aerobic heterotrophic soil bacteria, a deleterious effect which may be relevant for the normal function and evolution of agricultural soil.     

462例血培养阳性结果分析

目的了解血液培养的常见病原菌种类和药敏情况,为临床正确选用抗生素提供依据。方法对郑州大学第三附属医院2010年1月～2011年12月的454份血培养阳性标本,采用BACT/ALERT120全自动血培养仪培养,VITEK32全自动细菌鉴定仪进行鉴定,MIC法进行细菌药敏试验。结果 454例血培养阳性标本共分离出细菌462株,其中革兰阳性球菌268株,革兰阴性杆菌139株,革兰阳性杆菌16株,真菌10株;居前4位的感染病原菌依次是表皮葡萄球菌、金黄色葡萄球菌、大肠埃希氏菌、白色念珠菌。药敏结果显示:未发现耐万古霉素的革兰阳性球菌,革兰阴性杆菌对碳青霉烯类抗生素高度敏感。结论及时了解血培养结果可以对临床抗菌治疗提供依据,提高治愈率,降低死亡率有重要的临床意义。     

穿龙薯蓣内生真菌分离鉴定及其抑菌活性研究

目的 分离纯化穿龙薯蓣内生真菌,并对分离得到的内生真菌进行抑菌活性筛选及分类鉴定。方法 采用组织分离法纯化穿龙薯蓣内生真菌,采用载片培养法、挑片培养法、插片培养法,对照《真菌鉴定手册》和《半知菌纲手册》进行初步鉴定;以金黄色葡萄球菌Staphylococcus aureus、白色葡萄球菌Staphylococcus albus、柠檬色葡萄球菌Staphylococcus citreu、四联球菌Micrococcus tetragenus、大肠杆菌Escherichia coli、伤寒杆菌Salmonella typhi、铜绿色假单胞菌Pseudomonas aeruginosa、变形杆菌Bacterium termo、肺炎杆菌Bacillus endocarditidis capsulatus、福氏痢疾杆菌Shigella flexneri、乙型副伤寒杆菌Bacterium paratyphosum B作为受试对象,检测内生真菌菌株发酵液以及菌丝提取物的抑菌活性,应用分子生物学方法对筛选出的活性菌株进行分类鉴定。结果 从穿龙薯蓣叶片中分离得到52株内生真菌,根据形态学特征将10株产孢子的内生真菌初步鉴定为2个目、3个科、9个属;其中有3株内生真菌的菌丝提取物具有广谱抗菌活性,结合形态学和分子生物学特征鉴定C37菌为赤霉属Gibberella真菌,C30和C50菌为链格孢属Alternaria真菌。结论 穿龙薯蓣叶片中存在具有抑菌活性的内生真菌,具有开发抑菌生物制剂的潜力。     

Cytotoxicity and secondary metabolites production in terrestrial Nostoc strains,originating from different climatic/geographic regions and habitats: Is their cytotoxicity environmentally dependent?

Extensive selection of cyanobacterial strains (82 isolates) belonging to the genus Nostoc, isolated from different climatic regions and habitats, were screened for both their secondary metabolite content and their cytotoxic effects to mammalian cell lines. The overall occurrence of cytotoxicity was found to be 33%, which corresponds with previously published data. However, the frequency differs significantly among strains, which originate from different climatic regions and microsites (particular localities). A large fraction of intensely cytotoxic strains were found among symbiotic strains (60%) and temperate and continental climatic isolates (45%); compared with the less significant incidences in strains originating from cold regions (36%), deserts (14%), and tropical habitats (9%). The cytotoxic strains were not randomly distributed; microsites that clearly had a higher occurrence of cytotoxicity were observed. Apparently, certain natural conditions lead to the selection of cytotoxic strains, resulting in a high cytotoxicity occurrence, and vice versa. Moreover, in strains isolated from a particular microsite, the cytotoxic effects were caused by different compounds. This result supports our hypothesis for the environmental dependence of cytotoxicity. It also contradicts the hypothesis that clonality and lateral gene transfer could be the reason for this phenomenon. Enormous variability in the secondary metabolites was detected within the studied Nostoc extracts. According to their molecular masses, only 26% of these corresponded to any known structures; thus, pointing to the high potential for the use of many terrestrial cyanobacteria in both pharmacology and biotechnology. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2011.     

血标本致病菌的分离鉴定与药物敏感性分析

目的：对本院在2010年1月～2011年6月期间进行的血培养实验中分离出致病菌的种类以及其药物敏感性进行分析。方法：所得患者的血液标本经过血培养仪器进行培养,阳性菌株应用药敏分析,细菌鉴定系统MicroScan walkAway-40进行药物的敏感性试验以及菌种的鉴定。结果：所选的2960份血液培养标本中,分离出菌株322株。其中有115株为革兰阴性细菌,其分离率为3.9%（115/2960）;172株为革兰阳性细菌,其分离率为5.8%（172/2960）;真菌35株,其分离率为1.2%（35/2960）。所得的分离致病菌当中以金黄色葡萄球菌、阴性凝固酶葡萄球菌、肺炎克雷伯菌、大肠埃希菌以及多种真菌为主。在革兰阳性细菌当中并未发现有菌株耐万古霉素,革兰阴性细菌普遍对碳青霉烯类抗生素具有高度敏感。结论：革兰阴性细菌的感染比例最高,革兰阳性细菌所占比例次之;分离培养所得的菌珠普遍对于临床常用抗生素存在低敏感性。     

Effect of telavancin on human intestinal microflora

Telavancin is a new lipoglycopeptide antibiotic for the treatment of Gram-positive infections. It has a dual mechanism of action by inhibiting bacterial cell wall synthesis and disrupting the bacterial plasma membrane. The purpose of the present study was to investigate the effect of administration of telavancin on the human intestinal microflora. Thirteen healthy subjects (six males and seven females; age range 18–40 years) received 10 mg/kg body weight telavancin by intravenous infusion over a 60-min period once every 24 h for 7 days. Plasma and urine were collected on Days 5, 6 and 7 for pharmacokinetic analysis of telavancin. Faecal samples were collected on Days −1 (pre-dose), 2, 5, 7, 9, 14 and 21. Faecal specimens were cultured on non-selective and selective media. Different colony types were counted, isolated in pure culture and identified to genus level. No measurable concentrations of telavancin were found in faeces. No significant effects on the number of Enterobacteriaceae, enterococci, Candida albicans, bifidobacteria, lactobacilli, clostridia and Bacteroides spp. were observed during the study period. No Clostridium difficile strains or toxins were found. No new colonising aerobic and anaerobic Gram-positive bacteria with telavancin minimum inhibitory concentrations of ≥2 mg/L were found. Based on the microbiological data, telavancin has no significant ecological impact on the human intestinal microflora.     

Fumonisin production of black Aspergilli in vitro,fumonisin and ochratoxin A production in figs of positive strains and their growth assessment

Abstract

Fumonisin B₁ (FB₁), B₂ (FB₂) and B₃ (FB₃), production of Aspergillus Section Nigri isolates obtained from dried fig samples were investigated using high-performance liquid chromatography (HPLC). The fumonisin (FUM) positive strains were investigated for ochratoxin A (OTA) production in fig paste, as well. Additionally, the growth rate and lag phase of these strains were determined. Almost 13% of total isolates (10/133 strains) produced FB₂, however none of the isolates produced FB₁ and FB₃ in the culture medium. All FB₂ positive strains in medium also produced FB₂ in the fig paste. None of the fumonisin positive strains produced OTA in culture medium and fig paste. The mean growth rate of all FUM-producing strains were faster at 30?°C than 25?°C in the culture medium.     

小儿呼吸道感染痰液培养细菌构成及药敏分析

目的 了解某院儿科呼吸道感染的患儿痰液培养细菌构成及药敏的耐药情况.方法 对2011年1月到2012年5月儿科呼吸道感染的1 451例患儿进行深部吸痰并进行细菌培养,对培养出的致病菌株进行药敏实验.结果 从1 451份痰标本中分离出273株致病菌,阳性率为18.8%,其中革兰阳性菌52株（19.0%）,革兰阴性菌198株（72.5%）,其他26株（9.5%）,培养分离的细菌排前列是大肠埃希氏菌58株（21.2%）、流感嗜血杆菌51株（18.7%）、金黄色葡萄球菌42株（15.4%）、肺炎克雷伯氏菌34株（12.5%）、阴沟肠杆菌16株（5.9%）、产酸克雷伯菌14株（5.1%）、铜绿假单胞菌9株（3.3%）、肺炎链球菌7株（2.6%）.体外药敏试验表明阴性杆菌对亚胺培南、阿米卡星,哌拉西林/他唑巴坦较为敏感,阳性球菌对万古霉素、利福平、复方新诺明较为敏感.结论 了解小儿呼吸道感染的细菌分布及细菌的耐药状况,可以指导临床合理运用抗生素,减少细菌耐药菌株的增多.     

Molecular identification and phylogenetic analysis of Bothrops insularis bacterial and fungal microbiota

Bothrops insularis, known as the golden lancehead snake, has its natural habitat restricted to Queimada Grande Island on the southern coast of Brazil. This culture-dependent study aimed to identify microorganisms obtained from the mouth, eyes, and cloaca of this species. Swabs from 20 snakes were collected for fungal and bacterial isolation. DNA was extracted from all samples, and identification was performed by amplifying the ITS1-5.8S-ITS2 regions and the 16S rDNA gene, respectively. All strains were identified and deposited in the GenBank nucleotide database. MEGA v6.0 software was utilized to construct phylogenetic trees. In total, 100 strains were isolated and characterized, from which 42 fungi were distributed into 23 species and 58 bacteria into 13 species. The genus Fusarium was predominant since 11 strains and probably a new species was isolated from this fungus. Pseudomonas aeruginosa and Enterococcus faecalis were the predominant groups of aerobic bacteria isolated. Phylogenetic analyses between bacterial and fungal sequences suggest a similarity between the microorganisms found on the island and on the continent. These findings may be attributed to anthropic actions resulting from both expeditions to the island and actions of migratory birds, which are the main sources of food for snakes.     

2017—2020年克拉玛依市中心医院抗菌药物使用强度与分离菌耐药性变化情况

目的 分析克拉玛依市中心医院2017—2020年住院患者常见分离菌分布及耐药率的变迁情况,为指导抗菌药物临床合理应用提供依据。方法 收集2017—2020年克拉玛依市中心医院住院患者抗菌药物使用情况及分离菌,分析主要分离菌对常见抗菌药物的耐药率变化趋势。结果 2017—2019克拉玛依市中心医院抗菌药物使用率和使用强度呈下降趋势,4年共有分离菌12 135株,其中革兰阳性菌2 567株,占21.15%;革兰阴性菌6 310株,占52.00%;真菌3 258株,占26.85%。居前5位的分离菌分别是白色假丝酵母菌（19.59%）、大肠埃希菌（16.84%）、肺炎克雷伯菌（13.33%）、鲍曼不动杆菌（8.71%）和铜绿假单胞菌（7.94%）。主要分离菌对常用抗菌药物耐药率总体呈下降趋势,肠杆菌科细菌对临床常用抗菌药物耐药性下降最明显。结论 克拉玛依市中心医院分离菌逐年增加,耐药率有下降趋势,抗菌药物临床应用基本合理,但需完善真菌检测能力。     

Mutagenicity and genotoxicity of acid yellow 17 and its biodegradation products

Acid yellow 17 (AY17), a very important commercial azo dye used in the textile industry, was degraded by Pseudomonas putida mt-2 at a concentration of up to 200?mg/L. High-performance liquid chromatography analysis of the biodegradation media revealed the presence of 4-aminobenzensulfonic acid (4-ABS) derived from AY17 azoreduction, which attests the expression of an azoreductase by this bacterium. This amine was identified only in the medium of static incubation, which is consistent with its biotransformation under shaken incubation (i.e., aerobic conditions). The mutagenicity of AY17 and its biodegradation products was evaluated by using Salmonella typhimurium TA102 and TA104. No mutagenicity was observed in the presence or absence of a metabolic activation system (S9). In addition, the ability of tested compounds to induce DNA damage in vitro with the DNA strand scission assay was evaluated. Results showed that only static decolorization culture of AY17 showed a significant ability to induce the pKS plasmid DNA opening. The present study showed that P. putida mt-2, cultivated under aerobic conditions, was able to decolorize, and especially to detoxify, AY17.     

Using the metabolic capacity of rhodobacter sphaeroides to assess heavy metal toxicity

Heavy metals can produce differential toxic effects on bacterial growth depending on the kind of metabolism the cells are using in relation to oxygen. Rhodobacter sphaeroides is a purple, nonsulfur, photosynthetic, gram-negative bacterium that grows preferentially in anaerobic conditions acting as a photoheterotroph, but it can also behave as a photoautotroph. In aerobic conditions, this microorganism has a chemoheterotrophic metabolism. Aerobic and anaerobic metabolism may differ in their susceptibility to heavy metal toxicity. The metabolic duality of R. sphaeroides allowed us to assay this issue. After incubation of R. sphaeroides, several indicators of bacterial growth such as optical density, dissolved oxygen concentration, protein content, and pigment content were determined. The parameter values obtained showed that the inhibitory effect exerted by zinc and cadmium on R. sphaeroides was stronger in aerobic conditions than in anaerobic ones. Microbial growth was considerably reduced when heavy metal concentration was higher than 1 mg L^?1. Besides, R. sphaeroides was quite tolerant to copper. Cultures to which copper was added from 0.01 to 10 mg L^?1 showed a relatively constant growth, both in aerobic and anaerobic conditions. Thus, we have shown that assessment of heavy metal toxicity using bacterial tests must take into account that bacteria may react in a different way when grown in anaerobic environments.     

Metronidazole: In Vitro Activity,Pharmacology and Efficacy in Anaerobic Bacterial Infections

Metronidazole is a 5-nitroimidazole that has selective activity against anaerobic microorganisms, including bacteria and protozoa. Intravenous metronidazole has recently been approved by the U.S. Food and Drug Administration for the treatment of serious anaerobic bacterial infections. It is usually bactericidal at low concentrations, and its spectrum of activity encompasses almost all anaerobic bacteria and some capnophilic organisms. Anaerobic bacteria known to be resistant to metronidazole include occasional anaerobic cocci, some nonsporulating gram-positive bacilli and propionibacterium. Metronidazole is the most active antimicrobial agent against Bacteroides fragilis, the most resistant of anaerobic bacteria. Kill-curve studies demonstrate that there is a 2 to 5 log decrease in the number of colony forming units of S. fragilis and Clostridium perfringens within one hour. The only well documented metronidazole-resistant strain is a B. fragilis isolated from the normal flora of a patient on long-term metronidazole therapy for Crohn's Disease. Metronidazole resistance in Trichomonas vaginalis has recently been described in a few strains that are able to survive at increased oxygen tensions. Metronidazole has been shown to be efficacious in certain protozoal infections including trichomonal vaginitis, extraintestinal amebiasis, and giardiasis. Clinical studies have shown metronidazole to be efficacious in the therapy of a variety of anaerobic infections, including non-traumatic brain abscesses, intraabdominal sepsis, pelvic suppuration and necrotizing soft tissue infections. There have been disappointing results in the therapy of anaerobic pleuropulmonary infections with a number of superinfections caused by aerobic bacteria. Since metronidazole lacks any activity against aerobic bacteria, it must be combined with other agents, usually aminoglycosides, in the treatment of mixed infections involving anaerobic and aerobic bacteria.     

儿童细菌性肺炎676例病原菌分布及耐药性分析

目的了解本地区儿童细菌性肺炎病原菌分布及耐药情况,为临床经验性治疗提供借鉴。方法对我院呼吸内科2007年1月至12月因肺炎住院治疗的患儿的合格痰标本进行细菌学培养,用TDR200B细菌鉴定及药敏诊断系统进行菌株的鉴定与药物敏感性检测。结果共分离到676株致病菌,革兰阳性菌503株,占74.4%,居前三位的依次是草绿色链球菌、肺炎链球菌、C群链球菌;革兰阴性菌173株,占25.6%,居前三位的依次是大肠埃希菌、铜绿假单胞菌、鲍氏不动杆菌。革兰阳性菌中的草绿色链球菌和肺炎链球菌对哌拉西林、头孢曲松的敏感性最好,其次是头孢噻肟、阿莫西林,而C群链球菌、耐甲氧西林表皮葡萄球菌、耐甲氧西林金黄色葡萄球菌、肠球菌属、屎肠球菌等广泛耐药,所有革兰阳性菌对万古霉素全部敏感;革兰阴性菌中的产ESBLs大肠埃希菌、产ESBLs肺炎克雷伯菌、大肠埃希菌对亚胺培南/西司他丁全部敏感,其次是头孢哌酮/舒巴坦,铜绿假单胞菌对头孢哌酮/舒巴坦的敏感性最好。结论不同地区的儿童细菌性肺炎流行菌株及其药物敏感性可能不同,临床应根据本地区的病原菌流行情况及耐药规律制定最佳的经验治疗方案。     

血液病患者医院感染细菌分布分析

目的 了解血液病住院发生医院内感染患者中分离细菌的分布及其耐药情况.方法 收集住院患者临床分离菌株,用最小抑菌浓度(MIC)法进行药敏试验.结果 各种标本中分离出细菌56株,主要分布于血液、痰液、尿液等,革兰阳性细菌占14.3%,革兰阴性细菌占85.7%.革兰阴性细菌中以大肠埃希菌和铜绿假单胞菌最多,各有12株,分别占革兰阴性细菌的21.4%.大肠埃希菌和肺炎克雷伯菌产ESBLs菌株的检出率分别为75.0%(8/12)和33.3%(2/6).结论 上述结果 对血液系统疾病合并感染患者的经验性用药有重要的参考价值.     

Antibacterial activity of the enniatin B,produced by Fusarium tricinctum in liquid culture,and cytotoxic effects on Caco-2 cells

The enniatins (ENs) are bioactive compounds of hexadepsipeptidic structure produced by several strains of Fusarium sp. The EN B was purified from extracts of Fusarium tricinctum growth on liquid culture of potato dextrose broth (PDB), using a semipreparative liquid chromatography (LC) followed by an analytical LC. The purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization–mass spectrometry (ESI-MS) study.

The pure fraction of EN B was utilized to determine the antibiotic effects on several bacterial strains that are considered normally pathogens of the intestinal tract: Escherichia coli, Enterococcus faecium, Salmonella enterica, Shigella dysenteriae, Listeria monocytogenes, Yersinia enterocolitica, Clostridium perfringens, Pseudomonas aeruginosa, and Staphylococcus aureus, and to study the cytotoxic effects on Caco-2 differentiated and undifferentiated cells.

The results obtained demonstrated that in several antibiograms, EN B induced the inhibition of the grown microorganisms tested and no significant differences over control were detected when Caco-2 cells were exposed to EN B, at any of the concentrations used.     

Peptides with antimicrobial activity of the brevinin-1 family isolated from skin secretions of the southern leopard frog,Rana sphenocephala

Abstract: Three peptides with growth-inhibitory activity towards the Gram-negative bacterium Eschericia coli were isolated from electrically stimulated secretions from the skin of the southern leopard frog, Rana sphenocephala. Structural characterization demonstrated that the peptides [brevinin-1Sa, minimum inhibitory concentration (MIC) = 55µm ; brevinin-1Sb, MIC = 17 µm ; brevinin-1Sc, MIC = 14 µm ] represent new members of the brevinin-1 family of antimicrobial peptides, previously isolated from several other species of frogs of the genus Rana. Their high concentration in skin secretions and extreme variability in amino acid sequence suggest that the brevinin family of peptides may be of value as molecular markers for the identification and taxonomic classification of Ranid frogs.