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1.
L Y Martínez M M Arenas M Y Montes L J Martínez B E Baca 《Canadian journal of microbiology》1987,33(9):816-819
Antibiotic susceptibilities of 22 strains of Escherichia coli isolated from children from 0 to 3 years old at the University Hospital of Puebla were determined. Almost all strains were resistant to ampicillin, tetracycline, streptomycin, and kanamycin. Gel electrophoresis of DNA from 10 clinical strains of E. coli revealed a heterogeneous plasmid population. Plasmid DNA, ranging in molecular mass from 1.8 to 120 megadaltons, was demonstrated in 10 strains. Moreover, the frequency of antibiotic transfer ranged from 1.6/10(8) to 2/10, and the simultaneous transfer of the gene encoding heat-stable enterotoxin was also determined. Six out of 10 strains tested were able to cotransfer ST-a as demonstrated by the suckling mouse test. It is possible that antibiotic selective pressure may increase the isolation of enterotoxigenic E. coli strains. 相似文献
2.
The incidence of infections due to organisms resistant to β-lactam antibiotics has increased sharply in recent years. The goal of this study was to investigate the β-lactam resistance in 151 Escherichia coli strains isolated from chickens over a two-year period. Extended spectrum β-lactamases (ESBLs) were present in 24 strains (16%), ESBL phenotype was identified by interpretative reading of minimal inhibitory concentration values of ceftriaxon (CRT ≥ 7.1 mg/L), ceftazidime (CAZ ≥ 3.4 mg/L) and ceftiofur (CFF ≥ 8.7 mg/L). PCR detection revealed the presence of the bla CMY-2 gene and CTX-M-1 group. We detected high resistance to ampicillin (92%), streptomycin (63%), tetracyclin (70%), ceftiofur (40%), floroquinolones (enrofloxacin 68%, ciprofloxacin 62%), florfenicol (18%), chloramphenicol (21%) and cotrimoxazol (43%). We also investigated the presence of virulence factors and mobile genetic elements, and performed plasmid replicon typing in 24 selected strains. The most prevalent integrase among the isolates was the integrase 1 with gene cassettes dfrA, aadA and genes sul1 and sul2. Plasmid mediated quinolone resistances (qnrS) were also detected in two strains. Plasmid typing showed that the Y and IncI1 were dominant plasmid replicons. The genes iss, kpsII, tsh, iutA were the most frequently detected virulence genes in ESBL-positive strains. These results demonstrate that broilers in Slovakian food markets and farms could be the source of ESBL-producing E. coli, as well as virulent and resistant strains representing a potential risk for the human population. 相似文献
3.
Khan M. Khalilur Rahman Malik Abdul 《World journal of microbiology & biotechnology》2001,17(9):863-868
Seventy strains of Staphylococcus spp. and Escherichia coli (35 each) were isolated from various foodstuffs and identified on the basis of cultural, morphological and biochemical characteristics and were further tested for their antibiotic susceptibility with commonly used antibiotics/drugs. 69.2% of the strains of Staphylococci were resistant to co-trimazine and 34.6% were resistant to penicillin-G. 19.2% of the staphylococcal isolates exhibited resistance to cloxacillin, nalidixic acid, methicillin and tetracycline whereas 15.3% of the staphylococcal isolates were resistant to amoxycillin and nitrofurantoin. The isolated E. coli strains exhibited sharp peaks of resistance to antimicrobial agents such as tetracycline (72%), doxycycline (60%) and nalidixic acid (48%). Forty-four percent of the E. coli strains were resistant to nitrofurantoin and penicillin-G respectively. Among the 13 antibiotics/drugs tested for resistance, six different resistance patterns were observed in staphylococcal isolates and seven different resistance patterns were observed in the E. coli isolates from various foodstuffs. Bacterial strains exhibiting MIC values 100 g/ml for ampicillin and cloxacillin were screened for -lactamase activity and out of 10 staphylococcal isolates, seven were found to be positive for -lactamase, whereas out of 13 E. coli isolates tested for -lactamase production, only three were found to be positive. 相似文献
4.
Francesco Criscione 《Molluscan research.》2015,35(1):65-71
The new, monotypic camaenid genus Setocallosa is described for the new species S. pathutchingsae from Arnhem Land, Top End of the Northern Territory. This camaenid is characterized by a combination of distinct morphological features, such as a small, weakly elevated shell with widely open umbilicus and thick callus on the parietal wall, a wide epiphallic flagellum, elongated penis and short bursa copulatrix with subglobose end. The relationships of Setocallosa with the other camaenid genera in the area are investigated by means of mtDNA, but its phylogenetic position remains ambiguous. S. pathutchingsae occurs in sympatry with Arnhemtrachia ramingining, but based on morphology the two camaenids can be readily differentiated.http://zoobank.org/urn:lsid:zoobank.org:pub:1C50CF24-7FEE-446A-9724-A0A4E850B5AA 相似文献
5.
6.
J.-P. Mommaerts 《Hydrobiologia》1969,34(2):182-192
Résumé Le Tamar possède un estuaire à circulation d'eau typique (pas de mélange des eaux) mais présentant encore à ce point de vue, certaines particularités qu'il convient d'approfondir.Les quelques facteurs écologiques (température, transparence, salinité, phosphates et silicates) étudiés dans la zone la plus salée (de eu- à mésohaline) de l'estuaire montrent des variations importantes qui se réfléteront probablement dans la distribution du phytoplancton. La distribution des phosphates pose un certain nombre de problèmes et notamment celui de leur plus faible teneur en surface. Il conviendra de compléter cette étude préliminaire par des recherches sur la distribution des nitrates et l'exploration des zones oligohaline et limnétique.
Assistant au Laboratoire de Botanique systématique et Ecologie de l'Université Libre de Bruxelles. Boursier de l'U.N.E.S.C.O., stagiaire au Laboratoire de la Marine Biological Association of the U.K., Plymouth. 相似文献
Summary A typical water circulation pattern (no mixing of fresh and sea waters) is demonstrated in the Tamar estuary, however a few particular points still are to be elucidated.The ecological factors (temperature, transparence, salinity, inorganic phosphate and silicate) studied in the lower reaches of the estuary show some important variations.It is emphasized that an exceptionally low amount of inorganic phosphate is found at the surface or the subsurface.
Assistant au Laboratoire de Botanique systématique et Ecologie de l'Université Libre de Bruxelles. Boursier de l'U.N.E.S.C.O., stagiaire au Laboratoire de la Marine Biological Association of the U.K., Plymouth. 相似文献
7.
Baptista IM Oelemann MC Opromolla DV Suffys PN 《Memórias do Instituto Oswaldo Cruz》2002,97(8):1147-1152
Little is known about transmission and drug resistance of tuberculosis (TB) in Bauru, State of S o Paulo. The objective of this study was to evaluate risk factors for transmission of Mycobacterium tuberculosis strains in this area. Strains were collected from patients attended at ambulatory services in the region and susceptibility towards the main first line antibiotics was determined and fingerprinting performed. A total of 57 strains were submitted to susceptibility testing: 23 (42.6%) were resistant to at least one drug while 3 (13%) were resistant against both rifampicin and isoniazide. Resistant strains had been isolated from patients that had not (n = 13) or had (n = 9) previously been submitted to anti-TB treatment, demonstrating a preoccupying high level of primary resistance in the context of the study. All strains were submitted to IS6110 restriction fragment length polymorphism (IS6110-RFLP) and double repetitive element PCR (DRE-PCR). Using IS6110-RFLP, 26.3% of the strains were clustered and one cluster of 3 patients included 2 HIV-infected individuals that had been hospitalized together during 16 days; clustering of strains of patients from the hospital was however not higher than that of patients attended at health posts. According to DRE-PCR, 55.3% belonged to a cluster, confirming the larger discriminatory power of IS6110-RFLP when compared to DRE-PCR, that should therefore be used as a screening procedure only. No clinical, epidemiological or microbiological characteristics were associated with clustering so risk factors for transmission of TB could not be defined in the present study. 相似文献
8.
A checklist of the 31 Chinese species of Udea is given, including the new species and new records. Udea
curvata
sp. n. and Udea
albostriata
sp. n. are described and illustrated. Udea
exigualis (Wileman, 1911), Udea
stationalis Yamanaka, 1988, Udea
prunalis (Denis & Schiffermüller, 1775), Udea
elutalis (Denis & Schiffermüller, 1775) and Udea
cyanalis (La Harpe, 1855) are newly recorded for China. 相似文献
9.
Three new species of the streptaxid snail genus Perrottetia are described from north and northeastern Thailand, Perrottetia aquilonaria
sp. n., Perrottetia dermapyrrhosa
sp. n. and Perrottetia phuphamanensis
sp. n. Each species is endemic to a single or a few limestone mountain ranges. The species are characterized by the morphology of their genital organs, as well as by shell characters. Perrottetia aquilonaria
sp. n. has a club shaped distal penis and large penial hooks are present and penial papillae cover almost the entire penial hook portion; adjacent areas possess low reticulated folds. Perrottetia dermapyrrhosa
sp. n. has a long genital atrium and the penial sheath is about two-thirds of the penis length. Penial hooks are long, scattered and sunken into deep ovate hollows; vaginal hooks are present. Perrottetia phuphamanensis sp. n. has a rounded and protruded shell periphery. The aperture is subcircular, peristome is thick and the second parietal lamella is adjacent to the first parietal lamella; a basal lamella is the smaller than in the other Thai species. 相似文献
10.
We applied an integrative approach to re-evaluate the taxonomy of the conchologically highly diverse land snail genus Rossmaessleria from the Rif Mountains in Morocco and from Gibraltar, which has been classified into 12 nominal species so far. An analysis of cox1 and 16S rDNA sequences using the General Mixed Yule-coalescent approach with a single or multiple thresholds, its Bayesian implementation as well as the Automatic Barcode Gap Discovery method indicated that all Rossmaessleria populations can be classified into a single species, R. scherzeri (Zelebor, 1867). This result is confirmed by the lack of diagnostic differences in the genitalia as shown in a principal component analysis of the genital measurements. The variation of shell characters also does not allow an unambiguous subdivision of the complex. However, the populations of a mountain or a mountain ridge share characteristic combinations of shell characters so that they can be classified as geographic subspecies. The delimitation of the subspecies and their distribution is discussed and three subspecies are described as new to science: R. scherzeri periclitata ssp. nov. R. scherzeri ingae ssp. nov., and R. scherzeri eleanorae ssp. nov.http://zoobank.org/urn:lsid:zoobank.org:pub:187FE235-A257-423F-8FC3-957117546400 相似文献
11.
Twenty two species of the paper wasp genus Ropalidia Guérin-Méneville, 1831, are listed from China. Among them, R. malaisei van der Vecht, 1962, R. cyathiformis (Fabricius, 1804), R. santoshae Das & Gupta, 1989, R. scitula (Bingham, 1897), R. obscura Gusenleitner, 1996 and R. ornaticeps (Cameron, 1900) are new records from China. A new species, R. parartifex Tan & van Achterberg, is described. Their diagnostic characteristics are summarized in an illustrated key and 36 colourplates. 相似文献
12.
13.
The genus Trilasma Goodnight & Goodnight, 1942 is reinstated for Mexican ortholasmatines, and Cladolasma Suzuki, 1963 is reinstated for two species from Japan and Thailand, Cladolasma parvula Suzuki, comb. n. and Cladolasma angka (Schwendinger & Gruber), comb. n. Eight new species in the subfamily Ortholasmatinae Shear & Gruber, 1983 are described, as follows: Ortholasma colossussp. n. is from California, Trilasma tempestadosp. n., Trilasma hidalgosp. n., Trilasma trispinosumsp. n., Trilasma ranchonuevosp. n., Trilasma petersprouseisp. n. and Trilasma chipinquensis, sp. n. are from México, and Trilasma tropicumsp. n. from Honduras, the farthest south for a dyspnoan harvestman in the New World. A new distribution record for Martensolasma jocheni Shear 2006 is given. The recently described Upper Cretaceous amber fossil Halitherses grimaldii Giribet & Dunlop 2005 is not a member of the Ortholasmatinae, but is likely a troguloidean of an undiagnosed family. 相似文献
14.
Of 10 057 specimens of scrapings from skin, nails and scalp examined for dermatophytes, yeasts, pityriasis versicolor and systemic mycoses between 1963 and 1973, 30.4 percent were positive for fungi. Skin produced the highest proportion (68.6 percent) of positive scrapings, scalp the lowest (4.2 percent). Trichophyton rubrum was the predominant species (23.6 percent); of lesser prevalence were Microsporum canis (9.3 percent), T. mentagrophytes (8.4 percent) and Epidermophyton floccosum (4.8 percent). Double infections were encountered on 102 occasions; T. rubrum and Candida parapsilosis were the most frequent cohabiting species. The introduction in 1966 of periodic acid-Schiff staining for routine examination of scrapings resulted in better diagnostic results, particularly in the case of culturally nonproductive specimens and cases of pityriasis versicolor. Blastomyces dermatitidis and Cryptococcus neoformans were isolated from two patients in the course of routine investigation for dermatophytes. 相似文献
15.
L. E. Fuentes-Ramirez T. Jimenez-Salgado I. R. Abarca-Ocampo J. Caballero-Mellado 《Plant and Soil》1993,154(2):145-150
Thirteen cane cultivars grown on fields in México were sampled to assess the occurrence of Acetobacter diazotrophicus, a recently identified N2-fixing bacterium. Results showed that the isolation frequencies extended over a broad range (1.1 to 67%), likely to be related to the nitrogen fertilization level. The lowest isolation frequencies (1.1 to 2.5%) were obtained from plants growing at high nitrogen doses (275–300 kg ha-1) and the highest values (10–67%) from plants cultivated with 120 kg N ha-1. All eighteen strains of A. diazotrophicus produced indoleacetic acid (IAA) in defined culture medium. Estimates obtained from HPLC analyses revealed that A. diazotrophicus strains produced from 0.14 to 2.42 g IAA mL-1 in culture medium. Considering that A. diazotrophicus is found within the plant tissue, the biosynthesis of IAA suggests that the bacteria could promote rooting and improve sugarcane growth by direct effects on metabolic processes, in addition to their role in N2 fixation. 相似文献
16.
Anaplasmosis is a bovine intraerythrocytic disease caused by the bacterium Anaplasma marginale; it causes significant economic losses in tropical and subtropical regions, worldwide. The msp4 gene of an A. marginale strain isolated in Paran , Brazil, was amplified by PCR and sequenced; its cloning into the pET102/D-TOPO vector produced an msp4-6xHis-V5-HP thioredoxin fusion gene construct. This recombinant clone was over-expressed in Escherichia coli BL21(DE-3); the expressed fusion protein was found almost entirely in the insoluble form (inclusion bodies) in the cell lysate. The inclusion bodies were solubilized with urea and the recombinant protein was purified by Ni-NTA column and dialyzed. This method produced a relatively high yield of rMSP4, which was used to immunize rabbits. The deduced amino acid sequence encoded by MSP4 showed 99% homology to A. marginale isolates from Florida, USA, and from Minas Gerais, Brazil. Both rMSP4 and native MSP4 were recognized by post-immunization rabbit serum, showing that rMSP4 has conserved epitopes. As antigenicity was preserved, rMSP4 might be useful for the development of vaccine against anaplasmosis. 相似文献
17.
Pascal Neige Arnaud Brayard Sylvain Gerber Isabelle Rouget 《Comptes Rendus Palevol》2009,8(2-3):167-178
Ammonoids ruled the seas for 335 Myr and present themselves as an especially suitable model when analyzing biological evolution. This synthetic paper focuses on (1): the phylogenetic place of ammonoids within cephalopods and the choice of an extant reference model; (2): the establishment of phenotypic spaces supplying relevant insights into biological evolution; (3): the concordances and discordances between phylogenetic reconstructions and the fossil record, and (4): the postcrisis recoveries, as models to study large-scale evolution. It appears from these topics that ammonoids can be used as case studies for many themes in Paleontology (biodiversity dynamics, phylogenetics, analysis of the fossil record) that offered and continues to offer a better understanding of evolutionary patterns and processes, especially in the context of large-scale studies. 相似文献
18.
Cabral KG Lämmler C Zschöck M Langoni H de Sá ME Victória C Da Silva Av 《Canadian journal of microbiology》2004,50(11):901-909
In the present study, 87 Staphylococcus aureus isolates obtained from milk samples of 87 cows with mastitis in 6 different municipal districts of 2 regions of Sao Paulo State, Brazil, were compared pheno- and genotypically. Pulsed-field gel electrophoresis (PFGE) analysis of the strains was performed, and PCR was carried out to detect genes for a number of staphylococcal cell surface proteins, exoproteins, and 3 classes of agr genes. Nine distinct S. aureus lineages (LA-LI) were identified by PFGE. The lineages LA and LE, which accounted together for 63 strains (72.2%), were prevalent and had been collected from all of the 6 municipal districts, indicating a broad geographic distribution of these lineages; LB, LC, LD, LF, LG, LH, and LI, however, were isolated sporadically and accounted for 24 strains (27.8%). Some characteristics, like penicillin resistance and the presence of cap8 and agr class II genes, were associated with the prevalent lineages (LA and LE), and penicillin susceptibility and the presence of cna and cap5 genes were associated with sporadic lineages. According to the present results, some S. aureus lineages possess a combination of genes that confer the propensity to cause and disseminate infection, and only a limited number of clones are responsible for the cases of bovine mastitis on the various farms. 相似文献
19.
Anaplasma marginale, a tick-borne bacterium, causes bovine anaplasmosis responsible for significant economic losses in tropical and subtropical regions worldwide. Various major outer membranes have been described, and VirB9, a type IV secretion system protein, has been recently indicated as a candidate in vaccine development against anaplasmosis. The virB9 gene of an A. marginale strain isolated in Paraná, Brazil, was cloned by polymerase chain reaction and sequenced; its cloning into the pETSUMO vector produced a virB9-SUMO-6x His fusion gene construct. This recombinant clone was over-expressed in Escherichia coli BL21 (DE3), and the expressed fusion protein was solubilized with urea and purified with an Ni-NTA column. This method produced a relatively high yield of rVirB9. The deduced amino acid sequence encoded by VirB9 showed 99% homology to A. marginale isolates from St. Maries. rVirB9 was recognized by serum from cattle immunized with PR1 strain and by bovine sera infected with heterologous strains, showing that rVirB9 has conserved epitopes, which suggests that rVirB9 could be useful for the development of a vaccine against anaplasmosis. 相似文献
20.
Pekarsky O 《ZooKeys》2012,(187):9-34
Two new species of Pseudohadena, Pseudohadena anatinesp. n. and Pseudohadena gorbunovisp. n. (Lepidoptera, Noctuidae) are described from Ustyurt, Kazakhstan. Illustrations of adults and the genitalia of both sexes are provided. Microstructures of vesicae are described and illustrated. A diagnostic comparison is made with Pseudohadena evanida psammoxantha Ronkay, Varga & Fábián, 1995, Pseudohadena magnitudinis Hacker & Ebert, 2002 and Pseudohadena pseudamoena (Boursin, 1943). 相似文献