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1.
Ultrastructural Changes in Bacteria Isolated from Cases of Leprosy   总被引:6,自引:2,他引:4       下载免费PDF全文
One of two groups of rod-shaped bacteria (bacilli) isolated from cases of human leprosy have been found, under certain cultural conditions, to give rise to unusual phenotypes. In electron micrographs of ultrathin sections and negatively stained whole cells of these osmotically fragile bacteria, ultrastructural anomalies are apparent and seem to arise from disorder in the process(es) of septum formation or cell envelope biosynthesis or both. Two of the four strains examined are related to Corynebacterium acnes.  相似文献   

2.
Miniaturized methods for the characterization of streptococci, lactobacilli and aerobic Gram negative rods are described and the results obtained with 461 cultures from the calf rumen and quail gut tabulated. The methods afford a considerable saving in time and materials without concomitant loss of accuracy.  相似文献   

3.
A partially purified preparation of callose plug was obtainedfrom Camellia japonica pollen tube by limited enzymolysis anddensity centrifugation. The plug preparation consisted of proteinand polysaccharide at about 24% and 58% of dry weight, respectively.The plug polysaccharide was demonstrated to be a rß-1,3-glucanby staining reaction, acid hydrolysis, enzymatic digestion,infrared spectroscopy and methylation analysis. The averagedegree of polymerization of this glucan was calculated to beat least 90. This indicates that the plug callose has a longerchain than the tube wall callose. (Received June 15, 1983; Accepted November 26, 1983)  相似文献   

4.
Biofouling results in tremendous economic losses to maritime industries around the world. A recent global ban on the use of organotin compounds as antifouling agents has further raised demand for safe and effective antifouling compounds. In this study, 49 secondary metabolites, including diterpenoids, steroids, and polyketides, were isolated from soft corals, gorgonians, brown algae, and fungi collected along the coast of China, and their antifouling activity was tested against cyprids of the barnacle Balanus (Amphibalanus) amphitrite. Twenty of the compounds were found to inhibit larval settlement significantly at a concentration of 25 μg ml-1. Two briarane diterpenoids, juncin O (2) and juncenolide H (3), were the most promising non-toxic antilarval settlement candidates, with EC50 values less than 0.13 μg ml-1 and a safety ratio (LC50/EC50) higher than 400. A preliminary structure—activity relationships study indicated that both furanon and furan moieties are important for antifouling activity. Intriguingly, the presence of hydroxyls enhanced their antisettlement activity.  相似文献   

5.
Antibiotic sensitivity tests to determine the minimal inhibitory concentrations (MIC) and the minimal lethal concentrations (MLC) for six antibiotics were conducted against mastitic isolates of staphylococci in skim milk and broth. The MIC and the MLC for all the antibiotics except benzylpenicillin were considerably higher in skim milk than in broth. Benzylpenicillin was the most effective antibiotic tested in either medium, and dihydrostreptomycin was the least effective against the organisms tested.  相似文献   

6.
The DNA homology and cell wall sugar constituents of eight Streptococcus sanguis(-like) strains, three isolated from the patients with Behçet's disease (BD114-23, BD113-20, BD118-1), two from patients with Kawasaki disease (MCLS-1, MCLS-2), and three type and reference strains of ATCC (ATCC10556T: S. sanguis, ATCC10557: S. oralis, and ATCC10558T: S. gordonii) were analyzed. Strains BD114-23 and BD118-1 showed high DNA homology to ATCC10556T, and their cell wall constituents were identical. Conversely, BD113-20, MCLS-1, MCLS-2, and ATCC10557 showed little DNA homology to ATCC10556T and ATCC10558T, but showed approximately 50 to 60% homology to each other. The cell wall constituents of BD113-20, MCLS-1, MCLS-2, and ATCC10557, however, were somewhat different, indicating that some of the clinical isolates have different characters from those of the three ATCC strains.  相似文献   

7.
Current Fungal Infection Reports - This review summarizes the analysis of the internal transcribed spacers (ITS) sequencing of Coccidioides spp. strains isolated in the endemic region of...  相似文献   

8.
Characterization of Staphylococci Isolated from Raw Milk   总被引:2,自引:0,他引:2       下载免费PDF全文
To evaluate the pathogenicity of staphylococci from bovine raw milk, the general characteristics of 775 strains isolated from 798 samples of milk were studied. The coagulase test was performed by use of rabbit plasma. Chromogenesis, mannitol fermentation, and gelatin liquefaction were investigated on Chapman's Medium 110, after 48 hr of incubation. Production of β-hemolysin, which has been considered indicative of pathogenic staphylococci of animal origin, was determined by streaking different strains on sheep blood-agar plates in the presence of a strain of Lancefield group B streptococci. Plates were incubated at 37 C for 24 hr, and strong hemolysis was produced in the zone of interaction of β-hemolysin and some substance liberated by streptococcus (CAMP test). Of 404 strains found to be coagulase-positive, 95.8% exhibited a deep-orange pigment, 76.5% produced β-hemolysin, 91.8% fermented mannitol, and 75% liquefield gelatin. Of 371 strains which gave a negative coagulase test, about 16% fermented mannitol and liquefied gelatin; none of these strains produced β-hemolysin. When results are grouped according to pigmentation and coagulase production, β-hemolysin seems to be developed by pathogenic strains of Staphylococcus aureus only. If suitability of these tests for investigation of pathogenicity is compared, production of β-hemolysin appears to be the most useful one, since no “false positive” results were found. The use of the CAMP test as a simple and rapid technique to determine production of β-hemolysin by pathogenic strains of animal staphylococci during routine bacteriological work is suggested.  相似文献   

9.
Characterization of Micrococcaceae Isolated from Clinical Sources   总被引:7,自引:4,他引:3       下载免费PDF全文
The characterization of 556 Micrococcaceae isolates from various clinical sources has been presented. The incidence of coagulase-negative mannitol-positive staphylococci was 3.2% and that of coagulase-positive mannitol-negative staphylococci was 1.6%. There appears to be insufficient justification for the routine reporting of staphylococcal variants from a general bacteriology laboratory, and biotyping should be reserved for special circumstances.  相似文献   

10.
Characterization of Vibrio cholerae Isolated from Oysters   总被引:9,自引:8,他引:9       下载免费PDF全文
Of 790 samples of oyster shellstock freshly harvested during a 12-month survey, 111 (most of which were harvested from June through August) contained Vibrio cholerae non-O1 (611 strains), and seven contained O1 Inaba (11 strains) organisms. None of the V. cholerae strains isolated were enterotoxigenic by immunological and biological tests.  相似文献   

11.
12.
In contrast to developed countries, only limited data on the prevalence, resistance and clonal structure of Staphylococcus aureus are available for African countries. Since S. aureus carriage is a risk factor for postoperative wound infection, patients who had been hospitalized in surgical wards in a Nigerian University Teaching Hospital were screened for S. aureus carriage. All S. aureus isolates were genotyped (spa, agr) and assigned to multilocus sequence types (MLST). Species affiliation, methicillin-resistance, and the possession of pyrogenic toxin superantigens (PTSAg), exfoliative toxins (ETs) and Panton-Valentine Leukocidin (PVL) were analyzed. Of 192 patients screened, the S. aureus carrier rate was 31.8 % (n = 61). Of these isolates, 7 (11.5%) were methicillin-resistant (MRSA). The isolates comprised 24 spa types. The most frequent spa types were t064, t084, t311, and t1931, while the most prevalent MLST clonal complexes were CC5 and CC15. The most frequent PTSAg genes detected were seg/sei (41.0%) followed by seb (29.5%), sea (19.7%), seh (14.7%) and sec (11.5). The difference between the possession of classical and newly described PTSAg genes was not significant (63.9% versus 59.0% respectively; P = 0.602). PVL encoding genes were found in 39.3% isolates. All MRSA isolates were PVL negative, SCCmec types I and VI in MLST CC 5 and CC 30, respectively. Typing of the accessory gene regulator (agr) showed the following distribution: agr group 1 (n = 20), group II (n = 17), group III (n = 14) and group IV (n = 10). Compared to European data, enterotoxin gene seb and PVL-encoding genes were more prevalent in Nigerian methicillin-susceptible S. aureus isolates, which may therefore act as potential reservoir for PVL and PTSAg genes.  相似文献   

13.

Background

Staphylococcus aureus is one predominant cause of skin and soft-tissue infections (SSTIs), but little information exists regarding the characterization of S. aureus from non-native patients with SSTIs in China.

Methods

In this study, we enrolled 52 non-native patients with S. aureus SSTIs, and 65 native control patients with S. aureus SSTIs in Shanghai. 52 and 65 S. aureus isolates were collected from both groups, respectively. S. aureus isolates were characterized by antimicrobial susceptibility testing, toxin gene detection, and molecular typing with sequence type, spa type, agr group and SCCmec type.

Results

Methicillin-resistant S. aureus (MRSA) was detected in 8 non-native patients and 14 native patients with SSTIs. Overall, antimicrobial susceptibilities of S. aureus isolated from non-native patients were found higher than those from native patients. CC59 (ST338 and ST59) was found in a total of 14 isolates (4 from non-native patients; 10 from native patients), 9 of which were carrying lukS/F-PV (3 from non-native patients; 6 from native patients). ST7 was found in 12 isolates and all 12 isolates were found in native patients. The livestock-associated clone ST398 was found in 11 isolates (6 from non-native patients; 5 from native patients), and 5 ST398 lukS/F-PV-positive methicillin-susceptible S. aureus (MSSA) were all discovered among non-native patients. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. lukS/F-PV was more frequent in isolates originating from non-native patients with SSTIs compared to native patients (31 vs. 7, P <0.0001).

Conclusions

CC59 was the most common clonal complex among patients with SSTIs in Shanghai. The other most common sequence types were ST7 and Livestock ST398. The molecular epidemiology of S. aureus isolated from non-native patients was quite different from those from native patients. S. aureus isolated from non-native patients was more likely to carry lukS/F-PV.  相似文献   

14.
Vibrio cholerae O139 (synonym Bengal), a novel serovar of V. cholerae, is the causative agent of large outbreaks of cholera-like illness currently sweeping India and Bangladesh. Eight randomly selected V. cholerae O139 isolates were studied for their biological properties, which were compared with those of V. cholerae O1 and other V. cholerae non-O1. The V. cholerae O139 isolates were characterized by the production of large amount of cholera toxin, hemagglutination, weak hemolytic properties, resistance to polymyxin B, lysogeny with, and production of, kappa type phage (4/8 isolates only), and resistance to both classical and El Tor-specific phages. Thus, V. cholerae O139 isolates had an overall similarity with V. cholerae O1 El Tor.  相似文献   

15.
16.
Characterization of Pseudomonas Species Isolated from Clinical Specimens   总被引:12,自引:10,他引:12       下载免费PDF全文
More than 90 morphological and physiological characters of 227 strains of pseudomonads isolated from clinical specimens and 16 reference strains are described. The clinical isolates included P. aeruginosa (apyocyanogenic), P. fluorescens, P. putida, P. pseudomallei, P. cepacia, P. acidovorans, P. alcaligenes, P. pseudoalcaligenes, P. stutzeri, P. putrefaciens, P. maltophilia, and P. diminuta.  相似文献   

17.
Characterization of Granular Particles Isolated from Postsynaptic Densities   总被引:1,自引:1,他引:0  
Abstract: We describe here the isolation and biochemical characterization of a population of protein aggregates from the postsynaptic density (PSD) prepared from pig cerebral cortex. The protein constituents of these aggregates are linked together primarily by disulfide bonds. Negative staining electron microscopy revealed that the isolated protein aggregates were granular objects with an average outside diameter of ∼21 nm and with small protrusions on their surface. The major constituents of the isolated granular aggregates consist of tubulin and an unidentified protein of 70 kDa in size. Small amounts of the α subunit of calcium/calmodulin-dependent protein kinase II and subunits of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and NMDA subtypes of glutamate receptors were also detected by immunoblotting. Actin, however, was not found in these granular aggregates. We propose that these granular protein aggregates correspond to the ∼20-nm-diameter granular particles of the PSD on the basis of their biochemical and morphological characteristics. The spatial arrangement of these granular aggregates relative to other components of the postsynaptic terminal is also postulated here.  相似文献   

18.
Characterization of Leuconostoc oenos Isolated from Oregon Wines   总被引:4,自引:2,他引:2       下载免费PDF全文
This study was designed to characterize isolates of Leuconostoc species from Oregon wines. Gram-positive cocci were isolated, and their biochemical properties and abilities to decompose malic acid were determined. All of the isolates were heterofermentative, catalase negative, and facultatively anaerobic and occurred in pairs and chains. They produced acid from glucose, fructose, mannose, ribose, cellobiose, trehalose, and salicin but not from sucrose or lactose. They did not produce ammonia from arginine or dextran from sucrose. They grew at pH values of less than 4 and in 10% ethanol. Most but not all strains produced lactic acid and carbon dioxide from malic acid, as determined by paper chromatography and respirometry, respectively. These malolactic bacteria were considered to be strains of Leuconostoc oenos. We compared these isolates with reference strains for relative growth at pH values of 4.0, 3.5, 3.0, and 2.8 at 22°C. The isolates were similar in their growth responses at the two highest pH levels. At pH 3.0 and 2.8, however, the strains failed to grow but revealed variable abilities to dissimilate malic acid.  相似文献   

19.
首次对ECHO25病毒进行分子生物学分析,阐明ECHO25(Entric Cytopathic Human Orphanviruses Type25)病毒河南分离株的分子生物学特征及其与世界其它分离株的基因关系。逆转录-聚合酶链反应(RT-PCR)扩增出VP1蛋白编码基因并进行序列测定,将所测4株ECHO25病毒的VP1序列与GenBank上已发表的ECH-O25病毒VP1区进行同源性比较及遗传进化分析发现:河南省4株ECHO25与标准株JV-4核苷酸同源性为79.2%~80.1%,氨基酸同源性为89.0%~92.4%;河南省4株ECHO25核苷酸同源性为93.0%~99.0%,氨基酸同源性为92.4%~97.5%;HN-01分离株与HN-26分离株高度同源,其核苷酸同源性达99.0%;河南省4株ECHO25同属B1基因亚型。  相似文献   

20.
Non-polio enteroviruses (NPEVs) are among the most common viruses infecting humans worldwide. Most of these infections are asymptomatic but few can lead to systemic and neurological disorders like Acute Flaccid Paralysis (AFP). Acute Flaccid Paralysis is a clinical syndrome and NPEVs have been isolated frequently from the patients suffering from AFP but little is known about their causal relationship. The objective of this study was to identify and characterize the NPEV serotypes recovered from 184 stool samples collected from AFP patients in Federally Administered Tribal Areas (FATA) in north-west of Pakistan. Overall, 44 (95.6 %) isolates were successfully typed through microneutralization assay as a member of enterovirus B species including echovirus (E)-2, E-3, E-4, E-6, E-7, E-11, E-13, E-14, E-21 and E-29 while two isolates (PAK NIH SP6545B and PAK NIH SP1202B) remained untypeable. The VP1 and capsid regions analysis characterized these viruses as EV-B93 and EV-B106. Phylogenetic analysis confirmed that PAK NIH isolates had high genetic diversity and represent distinct genotypes circulating in the country. Our findings highlight the role of NPEVs in AFP cases to be thoroughly investigated especially in high disease risk areas, with limited surveillance activities and health resources.  相似文献   

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