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At least 955 records · Page 53Linked to original sources
PubMed1991

Health status of salmonids in river systems in Natal. III. Isolation and identification of bacteria.

Both pathogenic and non-pathogenic bacteria were isolated from fish, both salmonid and non-salmonid, from selected river systems in Natal. Pasteurella pisicida was isolated for the first time from fish in South Africa. The isolation of Yersinia ruckeri, Aeromonas salmonicida, and Edwardsiella tarda were recorded for the first time from fish in Natal. A. hydrophila and Flexibacter columnaris were found to be widespread throughout the river systems in Natal. The Streptococcus species which caused serious disease problems in trout in the Cape Province and Transvaal was not isolated from any of the fish examined in Natal.

Aeromonas↗
PubMed1983

Identification and isolation of somatic pili from pathogenic Escherichia coli of turkeys.

Transmission electron microscopy was performed to identify the presence of somatic pili on Escherichia coli pathogenic to turkeys. Three common pathogenic serotypes of E coli (Ola, O2a, and O78) were used. They were cultured in tryptic soy, veal infusion, and Minca medium broth and were incubated at 37 C with and without CO2 (5%). The cultures were examined for the expression of pili after 24, 48, and 72 hours of incubation. Pili were on all strains of the 3 serotypes examined. These pili were also isolated and purified.

Animals↗
PubMed1993

[Progress in clinical microbiology of Mycobacterium avium complex and prospect on its future].

Recent advance of technology in isolation and identification methods for mycobacteria, including BACTEC 460 TB System, polymerase chain reaction (PCR), DNA probe test, etc., enabled us to perform rapid and accurate identification of mycobacterial pathogens from various clinical specimens. Our recent study revealed usefulness of BACTEC 460 TB System, on the basis of the high efficiency in detecting the organisms in sputum specimens with much shortened recovery time, as compared to the Ogawa method. Moreover, accurate identification was possible, when the diagnostic system was combined with AccuProbe test. PCR using appropriate primers specific to Mycobacterium, M. tuberculosis complex (MTC), or M. avium complex (MAC) is useful to detect mycobacterial organisms directly in clinical specimens in a rapid manner. By this technique, in particular nested PCR, it is now possible to detect very small number of the organisms, as few as one bacterium, in test specimen, although it is still needed to resolve some difficulties due to contaminating inhibitors in the specimens. In our nested PCR system using Mav17 and Mav18 primers specific for Mycobacterium, especially MAC, we found that detectable degree of DNA amplification was possible even by replacing purified DNA sample, extracted from the organisms by considerably time consuming procedures, with bacterial suspension as a DNA template, by adding about 10(4) of organisms. The three DNA probe testings, Gen-Probe, AccuProbe and SNAP kits, are useful for rapid identification of MAC, MTC, M. kansasii and M. gordonae, and consistent results were obtained by these diagnostic kits. SNAP is able to distinguish the X component of MAC from the other two types of MAC.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriology↗
PubMed2025

Genomic testing for RET in the clinic: UK and global perspective.

RET is a key oncogene in neuroendocrine cancer. Pathogenic germline variants lead to multiple different phenotypes, including multiple endocrine neoplasia type 2, medullary thyroid cancer (MTC), Hirschsprung disease and kidney malformations. Pathogenic somatic variants are also associated with MTC, and RET rearrangements are observed in papillary thyroid cancer, non-small cell lung cancer and pan-cancer syndromes. Testing for both germline and somatic variants is now feasible in everyday clinical practice, and their identification has important clinical consequences, both for affected individuals and their families. This mini-review will discuss current germline and somatic testing strategies in the UK and worldwide, as well as reporting and test outcomes (including variants of uncertain significance or incidental findings). It will explore actions following identification of a pathogenic germline variant, including predictive, reproductive and childhood testing, and somatic testing of RET variants in solid tumours informing personalised cancer treatment. Finally, it will discuss the challenge of delivering rapid and equitable access to genomic testing to ensure that all individuals can benefit promptly and appropriately to improve clinical outcomes.

Humans↗
PubMed2001

Evolution and function of tandem repeats in the major surface protein 1a of the ehrlichial pathogen Anaplasma marginale.

The major surface protein (MSP) 1a of the ehrlichial cattle pathogen Anaplasma marginale, encoded by the single-copy gene msp1alpha, has been shown to have a neutralization-sensitive epitope and to be an adhesin for bovine erythrocytes and tick cells. msp1alpha has been found to be a stable genetic marker for the identification of geographic isolates of A. marginale throughout development in acutely and persistently infected cattle and in ticks. The molecular weight of MSP1a varies among geographic isolates of A. marginale because of a varying number of tandemly repeated peptides of 28-29 amino acids. Variation in the sequence of the tandem repeats occurs within and among isolates, and may have resulted from evolutionary pressures exerted by ligand-receptor and host-parasite interactions. These repeated sequences include markers for tick transmissibility that may be important in the identification of ehrlichial pathogens because they may influence control strategies and the design of subunit vaccines.

Amino Acid Sequence↗
PubMed2004

[Amplification test-systems in the diagnosis of hemorrhagic fever with renal syndrome and in studies of viral pathogens].

The "VectoHantivirus-ampli" test system based on rtPCR was shown as fitting the detection of virus RNA in blood samples of patients with hemorrhagic fever with renal syndrome (HFRS) made at early stages and no later than 7 days from the disease onset. A sequence analysis of viral nucleotide sequences of PCR products produced by the test-system ensured the identification of Hantaviruses (pathogens of HFRS). Two genetic variants of Puumula virus were shown to circulate in the territory of the Bashkortostan Republic; they differ by 10.0-13.8%, one of them is absolutely new. The Hantan virus FE genetic variant was detected in the studied samples from the Khabarovsk Territory.

Bashkiria↗
PubMed1993

The equine herpesviruses.

Two viruses, EHV-1 and EHV-4, are now known to be responsible for disease conditions formerly considered caused by "equine rhinopneumonitis virus." Although these viruses share several laboratory and clinical features, they differ in epidemiology and pathogenic potential. EHV-4 is primarily associated with clinical respiratory disease, whereas EHV-1 is more frequently isolated from aborted fetuses, sickly foals, and neurologic cases. Both viruses frequently establish latent infections, but the relevance of latency to clinical disease is unclear. Diagnosis based on identification of the pathogen is generally superior to serologic methods. Vaccines containing each virus are available, and vaccination in concert with careful management limits the number of clinical cases. Immunity following vaccination or disease is not absolute, however, and improved disease prophylaxis awaits a better understanding of protective immune responses.

Abortion, Veterinary↗
PubMed2002

Molecular diagnostic procedures for production of pathogen-free propagation material.

Production of disease-free propagation material is a major means of controlling most bacterial diseases of plants, particularly when neither resistant clones nor effective chemical treatments are available. For this purpose sensitive, specific and rapid detection methods are required. The advent of molecular biology and, in particular, the polymerase chain reaction (PCR) has opened new ways for the characterization and identification of plant pathogens and the development of disease-management strategies. PCR-based detection methods rely on the development of primers for the specific detection of the pathogen. The use of pathogenicity genes as targets for primer design is the preferred procedure for obtaining specific primers but other procedures may also be useful for this purpose. In the present review we describe four examples of procedures for detecting four important bacterial pathogens in Israel: Erwinia herbicola pv gypsophilae in gypsophila, Xanthomonas campestris pv pelargonii in geranium, Agrobacterium tumefaciens in asters and roses, and Xanthomonas campestris pv campestris in crucifers. Procedures for constructing specific PCR primers for each bacterium are illustrated and discussed as well as the combination of PCR with other methods.

Agrobacterium tumefaciens↗
PubMed2006

SVARAP and aSVARAP: simple tools for quantitative analysis of nucleotide and amino acid variability and primer selection for clinical microbiology.

BACKGROUND: Simple computerized methods that analyse variability along alignments of nucleotide or amino acid sequences can be very useful in a clinical microbiology laboratory for two main purposes. First, to optimize primer selection, which is critical for the identification of infectious pathogens based on gene sequencing: primers must target conserved nucleotide regions bordering highly variable areas to ensure discrimination of species. Second, it can be of interest to reveal mutations associated with drug resistance of pathogen agents. Our aim was therefore to test easy and cost-free tools (SVARAP and aSVARAP) that require short hands-on work, little expertise, and which allow visual interpretation and statistical analysis of results. RESULTS: We first tested SVARAP to improve a strategy of identification of streptococci species of the Viridans Group targeting the groESL gene. Two regions with < 500 nucleotides were identified, one being significantly more discriminant than one of a similar length used in a previous study (mean number of nucleotide differences between species, 113 (range: 12-193) vs. 77 (range: 14-109); p < 10-3). Secondly, aSVARAP was tested on reverse transcriptase (RT) sequences from 129 HIV-1 clinical strains to identify natural polymorphisms and drug-selected mutations emerging under nucleoside RT inhibitor (NRTI)-selective pressure. It revealed eleven of the 18 RT mutations considered in a reference HIV-1 genotypic NRTI-resistance interpretation algorithm. CONCLUSION: SVARAP and aSVARAP are simple, versatile and helpful tools for analysis of sequence variability, and are currently being used in real practice in our clinical microbiology laboratory.

Amino Acid Sequence↗
PubMed1977

[Examination of the growth of pathogenic organisms on the elastic joints made of plastic material in swimming baths (author's transl)].

Roughly three months after a swimming bath had been put into operation a growth was observed on the permanently elastic joints made of plastic material at the bottom of the pool. Samples were taken and examined and bacteria, fungi, green algae as well as many monocellular organisms were found. The repeated identification of a pathogenic dermatophyte and of P. aeruginosa was of hygienic significance.

Chlorophyta↗
PubMed2006

Nasopharyngeal versus oropharyngeal sampling for isolation of potential respiratory pathogens in adults.

The optimal methodology for the identification of colonization by potential respiratory pathogens (PRP) in adults is not well established. The objectives of the present study were to compare the sensitivities of sampling the nasopharynx and the oropharynx for identification of PRP colonization and to compare the sensitivities of samples from the nasopharynx by swab and by washing for the same purpose. The study included 500 participants with a mean age of 65.1 +/- 17.8 years. Of these, 300 patients were hospitalized for acute febrile lower respiratory tract infection and 200 were controls. Each participant was sampled by oropharyngeal swab (OPS), nasopharyngeal swab (NPS), and nasopharyngeal washing (NPW). The samples were tested by conventional bacteriological methods to identify Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. OPS detected colonization by S. pneumoniae in 30% of the subjects compared with 89% by NPS and NPW (P < 0.000001). The corresponding rates for H. influenzae were 49% and 64%, respectively (no significant difference [NS]), and for M. catarrhalis were 72% and 46%, respectively (P < 0.0004). NPS identified 61% of the cases of colonization with S. pneumoniae, compared with 76% by NPW (NS). The corresponding rates for H. influenzae were 31% and 56%, respectively (P < 0.04), and for M. catarrhalis were 39% and 33%, respectively (NS). We conclude that the sensitivities of nasopharyngeal and oropharyngeal sampling for identification of PRP colonization in adults are different for each of the three bacteria in this category. The combined results of sampling from both sites are necessary to obtain a true picture of the rate of colonization. NPW is superior to NPS.

Adult↗
PubMed2005

Identification of bacteria by polymerase chain reaction followed by liquid chromatography-mass spectrometry.

Bloodstream infections are an important cause of serious morbidity and mortality. Rapid detection and identification of specific pathogens from blood or other clinical specimens could improve the rational use of antimicrobial therapy in clinical medicine and have a great impact on the outcome of patients with systemic infections. Polymerase chain reaction using generic primers was used to amplify genomic DNA of different bacterial strains. The identification was accomplished by measuring the molecular masses of the PCR products using ion-pair reversed-phase high-performance liquid chromatography hyphenated to electrospray ionization mass spectrometry. DNA from 10 bacterial species was amplified by PCR, and the resulting amplification products were analyzed. In all cases, the measured molecular masses of the PCR products matched the theoretical value for the species-specific DNA sequence. However, three pairs of bacteria could not be distinguished since the theoretical difference in amplicon molecular mass was < 1.0 Da (different sequence, same base composition of amplicon). Determination of intra- and interday mass reproducibility resulted in relative standard deviations of 0.0030 and 0.018%, respectively. The limit of detection of the presented method was shown to be 0.5 genome equivalents/PCR. The specificity of the method in a human background was successfully tested by amplifying and analyzing 1000-10000 genome equivalents of Staphylococcus aureus spiked into human plasma.

Bacteria↗
PubMed2004

Epidemiological study of Candida species in cutaneous candidiasis based on PCR using a primer mix specific for the DNA topoisomerase II gene.

BACKGROUND: We have previously reported a PCR-based identification system for pathogenic fungi by targeting the DNA topoisomerase II gene, in which primer mixes specific for this gene were used for the PCR amplifications. OBJECTIVE: To test the potential of the PCR using primer mix that is specific for the DNA topoisomerase II gene and are designated as PsVIc, for rapid identification of Candida species involved in cutaneous candidiasis, and to define the relation between Candida species and the infection lesion. METHODS: Scales from 48 patients with cutaneous candidiasis were cultured on GYEP agar plates, and the genomic DNAs were purified from the colonies and used as DNA templates for PCR amplifications. Candida was identified as individual species based on the sizes of the PCR products generated in the PCR amplifications using PsVlc. RESULTS: Four Candida species (five genotypes; Candida albicans, Candida glabrata, Candida parapsilosis I, Candida parapsilosis II and Candida tropicalis II) were identified in the patients' scales. In 19 of the patients (39.6%), multiple PCR products (two or three bands) were amplified in a DNA sample, especially derived from scales at the groin of bed-ridden older patients using napkins. CONCLUSION: The PCR-based identification using the primer mix was useful for an epidemiological study of Candida species in cutaneous candidiasis.

Adult↗