Agricultural animals as a source of yersiniosis

The role of agricultural animals as the sources of infection was studied. 8 Yersinia strains were isolated from 83 samples taken from cattle. Yersinia were isolated from feces, udder washings and milk. In the examination of 63 samples obtained from sheep the infective agent was isolated from feces in 6 cases. 6 Yersinia strains were isolated from 92 fecal samples taken from pigs. Y. enterocolitica were isolated from sick animals. The isolated strains were classified with serovars 03, 058, 08 and 09. In the foci of animal infection thus revealed antibodies to various Yersinia strains were detected in the blood sera of the animal-tending personnel, which indicates the professional character of the spread of this infection among humans. The infection is probably transferred by the contact and alimentary routes.     

银杏内生菌的分离及其抑菌活性筛选

从健康的银杏（Ginkgo biloba）茎和叶片中分离内生菌,结果从银杏叶和茎上共分离到内生真菌20株,其中9株来自银杏茎部,11株来自银杏叶部;内生放线菌23株,其中15株来自于银杏茎部,8株来自于银杏叶部;内生细菌15株,其中8株来自于银杏茎部,7株来自于银杏叶部。以金黄色葡萄球菌（Staphylococcus aureus）、枯草芽胞杆菌（Bacillus subtilis）、大肠埃希菌（Escherichia coli）、黑曲霉（Aspergillus niger）、酿酒酵母（Saccharomyces cerevisiae）作为指示菌,采用双层平板法对内生菌进行抑菌活性筛选,结果表明：20株内生真菌中有12株出现了抑菌活性,有抑菌活性菌株的比例为60.0%;23株内生放线菌中,仅3株出现了抑菌活性,有抑菌活性菌株的比例为13.0%;15株内生细菌中,有4株出现了抑菌活性,有抑菌活性菌株的比例为26.7%。     

Interprotein Disulfide Bonds Formed During Isolation Process Tighten the Structure of the Postsynaptic Density

Postsynaptic densities (PSDs) isolated by biochemical means consist of a complex mixture of proteins that tightly bond to each other. The purpose of this report is to study whether the numerous interprotein disulfides found in the isolated PSDs contribute to the tight structure of the PSDs and whether these interprotein disulfides exist in vivo. PSDs were isolated from pig cerebral cortex by conventional methods except that iodoacetic acid (IAA) was added to all solutions to curtail the formation of disulfides during the isolation process. The PSDs thus isolated were fragmented easily by treatment with chaotropic reagents or ionic detergents, whereas the PSDs isolated in IAA-free solutions were resistant to these treatments. Electron microscopy revealed that the PSDs isolated in IAA-containing solutions were more fragmented than those isolated in IAA-free solutions. Furthermore, the PSD sample isolated in IAA-free solutions contained very large disulfide-linked aggregates that were virtually absent from the PSDs isolated in IAA-containing solutions. Our results suggest that the exceptionally tight structure of the PSDs isolated by conventional methods is due largely to the new disulfides formed during the isolation process and that the PSD proteins under in vivo conditions are held together primarily by noncovalent interactions.     

紫穗槐根瘤菌的分离与回接鉴定

采用YMA培养基对新鲜的紫穗槐(Amorpha fruticosa L.)根瘤提取物进行根瘤菌的分离培养,获得的菌落为圆形乳白色,表面凸起,直径0.4~0.5 cm,革兰反应阴性,显微观察显示为短杆状,分离菌株回接原宿主植物,同时接种于经60℃15 min水浴加热处理的紫穗槐种子,蛭石盆栽实验显示,接种此菌的紫穗槐植株都有结瘤,并与对照在结瘤数、瘤重、植株鲜重与干重间都有显著差异,实验证明所分离的菌株均为紫穗槐根瘤菌。     

2006年广州登革热病原体的分离鉴定及其生物学性质的观察

目的：对2006年广州流行登革热病原进行分离鉴定及生物学性质研究。方法：采用传代蚊细胞微量培养方法对2006年广州登革热病原进行分离,并通过脑内途径观察其对乳鼠的致病性;经间接免疫荧光和RT-PCR技术,对患者血清标本中的病毒特异抗体及新分离的病原体进行检测和鉴定;将此次分离的病原体与1980年分离的同型毒株进行生物学性质比较。结果：从57份患者血清标本中分离出10株病毒,在传代蚊细胞中可产生稳定的细胞病变并对乳鼠致病;其基因组为登革1型病毒特异的RNA分子,经鉴定为登革1型病毒;此次分离的登革1型病毒与1980年分离的同型毒株在致细胞产生病变的时间和严重程度,蚀斑的大小、形态以及致乳鼠发病的时间等生物学性质上有所不同。结论：2006年广州流行登革热病原为登革1型病毒,且与1980年分离的同型毒株在生物学性质方面存在明显差异。     

Sore Throat in Children: Its Causation and Incidence

Beta-haemolytic streptococci were isolated from 35% of 525 children who presented to their family doctors with sore throat. The first 306 were investigated bacteriologically and virologically and beta-haemolytic streptococci were isolated from 30% and viruses from 14·7%. The ages which had the highest incidence of sore throat, for both sexes, were 7, then 6, 8, and 5. Those with tonsils had a higher incidence of beta-haemolytic streptococci than those without, but the presence or absence of tonsils made no difference to the degree of growth of the streptococci.Viruses were isolated predominantly during the winter months, but streptococci, though mostly isolated in winter, were isolated throughout the rest of the year.     

Isolation of N-acetylglutamine, pyroglutamic acid and the butyl ester of pyroglutamic acid from human brain

N-acetyl-l -glutamine, pyroglutamic acid, and the butyl ester of pyroglutamic acid were isolated in pure form from an aqueous extract of human brain. These compounds were isolated by combination of paper and ion exchange chromatography. The isolated substance identified as N-acetyl-l -glutamine did not react with the ninhydrin reagent but yielded glutamic acid and ammonia upon acid hydrolysis. An acetyl hydrazide was identified by paper chromatography from hydrazinolysates of the isolated substance. The glutamic acid liberated by hydrolysis had the l -configuration. The results of elementary analysis of the isolated compound were in full accord with the analysis calculated for synthetic N-acetyl-l -glutamine. A large amount of pyroglutamic acid and a substance identical with the butyl ester of pyroglutamic acid were isolated in pure form. The results of our studies suggest that pyroglutamic and the butyl ester derivative were artifacts formed during the isolation and purification procedures.     

The polysaccharides of the brown seaweed Turbinaria murrayana

Polysaccharides of the brown seaweed Turbinaria murrayana were isolated. Laminaran (3.2%) was isolated from the hot-water extract of the algae by using ion-exchange chromatography. Fucans (2.1%) were isolated from the hot-water extract, as well (4.7%) as from the extract of the algae with dilute acid. Acid hydrolsysis of the isolated fucans revealed glucose, amnnose, fucose, glucuronic acid, xylose, and galactose. Alginic acid (22.6%) was separated, and reduced to a neutral polysaccharide. The polysaccharides isolated were analyzed by methylation and Smith degradation.     

Pneumococcal serotypes in various diseases of children

The serotyping of pneumococci isolated from different material obtained from children aged 0 to 11 years was carried out. Out of 156 patients with different diseases, hospitalized in two clinics in Moscow during February-May 1983, pneumococci were isolated from 67 patients (43%). The isolated pneumococcal strains belonged to 11 serotypes. Pneumococci of serotypes 3, 6, 9 and 19 were shown to occur most frequently in different diseases and constituted 50% of the isolated strains. The inoculation of the material by the quantitative method permitted the authors to find out the role of pneumococci as the etiological factor in the pathogenesis of some diseases. A certain dependence of diversity in the types of isolated pneumococci on the age of sick children was noted. Almost all isolated strains were found to be sensitive to penicillin, ampicillin and benzylpenicillin. But a few individual strains were sensitive only to one of these antibiotics. The data on some biological properties of pneumococci cultivated on solid culture media are presented.     

The flavonol glycosides in the fruit of Pyrus communis L. cultivar Bon Chrétien

1. Two new flavonol glycosides were isolated from the fruit of Pyrus communis L. cultivar Bon Chrétien. These were identified as isorhamnetin 3-rhamnogalactoside and a derivative of isorhamnetin 3-glucoside which was associated (possibly acylated) with an unknown aliphatic organic acid. 2. The melting point of isorhamnetin 3-glucoside isolated from Bon Chrétien pears is different from that of isorhamnetin 3-glucoside previously isolated from Argemone mexicana and Calendula officinalis. 3. Isorhamnetin 3-rhamnoglucoside was isolated from the fruit of Pyrus communis L. cultivar Bon Chrétien. This glycoside appears to be identical with narcissin, previously isolated from Narcissus tazetta and Lilium auratum. 4. Isoquercitrin, previously reported to be present in pear leaves, was isolated from the fruit of Bon Chrétien pears. 5. The isolated glycosides were present in the peels and flesh of the fruit, but were absent from the cores.     

Mycoflora of cave cricket Troglophilus neglectus cadavers

By using different techniques and media, microfungi were isolated from cadavers of the cave cricket Troglophilus neglectus, collected on the walls of a Slovenian cave. The isolated mycobiota was consistently different for adult and larval stages of T. neglectus cadavers. Fungi isolated with the highest frequency from the larval stage were represented by five different species of the genus Mucor, the prevailing one being a newly described species, M. troglophilus. The dominating fungus isolated from the adult stage was the well-known fungal entomopathogen Beauveria bassiana. The other isolated fungi were mainly primary and secondary saprotrophic colonizers. This revised version was published online in June 2006 with corrections to the Cover Date.     

A comprehensive evaluation of the biological properties of the causative agents of typhoid fever isolated from patients and carriers

The biological properties of 106 S. typhi cultures were studied; of these, 59 cultures were isolated from 45 chronic carriers and 47 cultures, from 23 typhoid fever patients. According to the degree of their virulence (CPD50 in the continuous cell-line culture Hep-2), the strains isolated from the patients were more virulent than those isolated from the chronic carriers. The mean value of lg CPD50 was 5.76 +/- 0.04 for the patients and 6.86 +/- 0.03 for the chronic carriers. The strains isolated from the patients showed greater variability in the degree of their virulence. The study of the plasmid spectrum showed that 9.4 +/- 5.6% of the strains contained plasmids. From the patients plasmid-containing strains were isolated more frequently than from the carriers (14.9 +/- 2.5% and 5.1 +/- 2.9%). Multiresistance to antibiotics in combination with the presence of plasmids was detected in 6 strains isolated from the typhoid patients with morbidity having the character of outbreaks.     

Characterization and genetic variability of Fusarium verticillioides strains isolated from corn and sorghum in Brazil based on fumonisins production, microsatellites, mating type locus, and mating crosses

Fusarium verticillioides (Gibberella fujikuroi mating population A) is a producer of fumonisins and one of the main contaminants of corn grains. In Brazil, some studies analyzing strains isolated from corn have demonstrated high levels of fumonisins, whereas the levels for strains isolated from sorghum have been found to be low. In the present study, we investigated the genetic diversity of 22 F. verticillioides strains isolated from corn and 21 strains isolated from sorghum cultivated in the State of S?o Paulo, Brazil. Differences in the genetic profile were observed between the strains isolated from the two substrates using single primer amplification reaction by polymerase chain reaction (SPAR-PCR). Fumonisins levels were higher in strains isolated from corn than in those isolated from sorghum. The MAT-1 and MAT-2 alleles were identified by PCR, and the isolates were subsequently crossed with Fusarium thapsinum (G. fujikuroi mating population F) reference strains because this species is morphologically similar to F. verticillioides and produces low levels of fumonisins. The SPAR haplotypes of some strains isolated from sorghum were similar to the F. thapsinum reference strain haplotypes, but there was no fertile mating between the strains isolated from the two substrates and the F. thapsinum references strains. The MAT-1:MAT-2 proportion was 5:17 and 14:7 for isolates from corn and sorghum, respectively.     

用流行性出血热单克隆抗体对我国不同地区出血热病毒株的抗原分析

从全国17个省市自治区收集了自病人及各种动物分离到的40株流行性出血热病毒(EHFV),用出血热病毒单克隆抗体(McAb)进行抗原分析,发现大多数省市分离的EHFV株能与MA25-1 McAb起反应,但湖北、湖南分离的EHFV不与之起反应,而该McAb对EHFVA9株抗原的滴度为1/2560。实验还发现,湖北省内长江以北地区分离的EHFV毒株Q25、J173。WP43和从江南地区分离的EHFV毒株A24和HA1018在抗原性上也有明显不同。     

Isolation rate of enterotoxigenic staphylococci in patients with sepsis, pneumonia and burns

The occurrence of Staphylococcus aureus strains producing enterotoxins of types SEA and SEB, which isolated from patients of different profile and caused the infectious process accompanied by pronounced intoxication without vomiting and enteric disturbances, was determined by means of the indirect hemagglutination test. The collection included 28 strains isolated in sepsis, 38 strains isolated in pneumonia, 57 strains isolated from patients with burns and 23, from the hands and nasopharynx of the medical staff. Among the staphylococcal strains isolated in sepsis, 75.6% synthesized SEA and 5.4%, SEB. The occurrence of SEA- and SEB-positive strains isolated in pneumonia was, respectively, 42.1% and 2.6%. From patients with burns SEA-positive staphylococci were mainly isolated (92.9%). Only 3% of the cultures isolated in wound infections produced SEA. From the medical staff, 13.4% of SEA-positive strains and 17.3% of SEB-positive strains were isolated. The data obtained from this study indicate the expediency of the determination of the enterotoxigenic properties of S. aureus clinical isolates in medical institutions for prophylactic measures with a view to the prevention of the spread of pathogenic clones.     

Comparison of the antibiotic sensitivity of lipophilic Corynebacterium sp. isolated from patients on the day of admission and during hospitalization

Lipophilic species of Corynebacterium are increasing problem in hospital infections. The aim of this study was to evaluate occurrence of these microorganisms in the materials taken from patients in the day of admission and during the hospitalization as well as comparison of their antibiotic sensitivity. The investigation included 65 strains isolated from hospitalized patients and 48 strains isolated from unchanged skin. Using Api Coryne test 5 species were identified. C. urealyticum dominated, the other were C. subsp. lipophilum and C. jeikeium. Among strains isolated from unchanged diseased skin the most C. jeikeium and C. accolens occurred. All strains were sensitive to glycopeptide, quinupristin/dalphopristin. The strains isolated from hospitalized patients were usually sensitive to fuside acid, doxycycline as well as tetracycline. Strains isolated from unchanged skin were sensitive to almost all tested antibiotics. In the group of 65 strains isolated from hospitalized patients 99.0% were multiresistant. In the group of strains isolated from unchanged skin only two strains were multiresistant. Differences in antibiotic sensitivity among analysed Corynebacterium sp. were confirmed. Majority of the "hospital strains" were characterized by multiresistance. Basing on these results it is possible to suppose, that multiresistance is main factor that favours lipophilic Corynebacterium species in the process of colonization of mucous membranes, skins as well as developing infections.     

Properties of Serratia marcescens strains isolated in septic diseases of newborn infants

As the result of the study of blood and liquor samples from 120 newborns, Serratia marcescens was isolated in 21 cases (17.5 %). 8 strains were isolated from the environment of these patients. Almost all strains isolated from both the patients and the environment (with the exception of one environmental strain) belonged to serotype 04. The isolated S. marcescens strains were resistant to penicillin, ampicillin, streptomycin, kanamycin, oxacillin, methicillin, ceporin and moderately sensitive to polymixin. 2 strains from the environment and 9 strains from the patients were mildly sensitive to gentamicin. In one hospital all isolated strains were found to have 2 transmissive R plasmids with the molecular weight 40 and 60 megadaltons. The presence of R plasmids with the same molecular weight in all S. marcescens strains isolated in this hospital, as well as their serological identity, suggest that in all patients infection originated from a common source.     

Response to antibiotics of Proteus strains isolated from different types of clinical material

The data on the study of the antibiotic response to 42 Proteus strains isolated from different sources in the hospitals of Kharkov are presented. The isolates belonged to P. mirabilis and P. vulgaris. Many strains were resistant to gentamicin, ampicillin and carbenicillin irrespective of the isolation source. 58.0 and 90.3 per cent of the strains isolated from patients with intestinal infections, 66.6 and 100 per cent of the strains isolated from patients with otitis, 33.3 and 66.6 per cent of the strains isolated from patients with bronchopulmonary affections and 100 and 100 per cent of the strains isolated from patients with urological diseases were resistant to gentamicin and carbenicillin, respectively. As for ampicillin, the respective figures were 74.2, 66.6, 66.6 and 100 per cent. All the strains of P. vulgaris isolated from patients with otitis, urological diseases and bronchopulmonary affections were resistant to ampicillin. The MIC of carbenicillin for all the strains except 4 indole-positive strains of P. vulgaris isolated from the faeces and bronchial excreta was much higher than the borderline values.     

Hemagglutinating and adhesive capacities of Klebsiella and Enterobacter strains

The authors analyze the data of studies on the hemagglutinating and adhesive capacity of 290 cultures, including 118 K. pneumoniae strains and 64 E. cloacae strains isolated from sick children, as well as 59 K. pneumoniae strains and 49 E. cloacae strains isolated from healthy children. The hemagglutinating properties of the strains were determined in the hemagglutination test with fresh, formalin- and tannin-treated red blood cells, the adhesive properties were studied by light microscopy. Among K. pneumoniae and E. cloacae strains isolated in acute intestinal infections, mannose-sensitive hemagglutination and pronounced adhesive activity were prevalent in most cases. Poorly adhesive and nonadhesive strains were characteristic of K. pneumoniae and E. cloacae cultures isolated from healthy children. The strains isolated from sick and healthy children differed only by the prevalence of adhesive cultures.     

Consequences of genetic erosion on fitness and phenotypic plasticity in European tree frog populations (Hyla arborea)

The detrimental effects of genetic erosion on small isolated populations are widely recognized contrary to their interactions with environmental changes. The ability of genotypes to plastically respond to variability is probably essential for the persistence of these populations. Genetic erosion impact may be exacerbated if inbreeding affects plastic responses or if their maintenance were at higher phenotypic costs. To understand the interplay 'genetic erosion-fitness-phenotypic plasticity', we experimentally compared, in different environments, the larval performances and plastic responses to predation of European tree frogs (Hyla arborea) from isolated and connected populations. Tadpoles from isolated populations were less performant, but the traits affected were environmental dependant. Heterosis observed in crosses between isolated populations allowed attributing their low fitness to inbreeding. Phenotypic plasticity can be maintained in the face of genetic erosion as inducible defences in response to predator were identical in all populations. However, the higher survival and developmental costs for isolated populations in harsh conditions may lead to an additional fitness loss for isolated populations.