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At least 181 records · Page 10Linked to original sources
PubMed1998

Identification of unusual Campylobacter-like isolates from poultry products as Helicobacter pullorum.

Twenty-six unclassified Campylobacter-like strains previously isolated from 15 chicken carcasses and caecal contents, together with two more strains isolated from chicken faeces on a different occasion, were identified as Helicobacter pullorum using various phenotypic identification methods. API Campy identification kits and a 16-test identification scheme developed for campylobacters failed to identify these bacteria, or identified them as Campylobacter spp. Eighteen strains (including the two isolated on a different occasion) were chosen for examination using a more comprehensive probabilistic identification scheme. Using this method, 14 of the 18 strains were identified as H. pullorum with ID scores > 95%; two strains were also identified as H. pullorum with lower ID scores. Of the remaining two strains, one was not identified with this scheme and the other was misidentified to the H. acinonyx pylori complex. Whole cell protein profiling by SDS-PAGE confirmed the identity of these isolates as H. pullorum, affirming the value of a polyphasic approach for accurately identifying campylobacteria. The comparatively high prevalence of H. pullorum in poultry determined in this study (60%) suggests that routine isolation and identification methods should be amended to enable a thorough evaluation of its role in human gastroenteritis and avian hepatitis. Some phenotypic characters useful in identifying poultry campylobacteria are presented which could be utilized, along with other technique(s), for improved differentiation of the campylobacteria that are found in poultry.

Animals↗
PubMed2001

Comparison of methods for determining the numbers and species distribution of coliform bacteria in well water samples.

AIMS: Enumeration of coliform bacteria and Escherichia coli is the most widely used method in the estimation of hygienic quality of drinking water. The yield of target bacteria and the species composition of different populations of coliform bacteria may depend on the method.Three methods were compared. METHODS AND RESULTS: Three membrane filtration methods were used for the enumeration of coliform bacteria in shallow well waters. The yield of confirmed coliform bacteria was highest on Differential Coliform agar, followed by LES Endo agar. Differential Coliform agar had the highest proportion of typical colonies, of which 74% were confirmed as belonging to the Enterobacteriaceae. Of the typical colonies on Lactose Tergitol 7 TTC agar, 75% were confirmed as Enterobacteriaceae, whereas 92% of typical colonies on LES Endo agar belonged to the Enterobacteriaceae. LES Endo agar yielded many Serratia strains, Lactose Tergitol 7 TTC agar yielded numerous strains of Rahnella aquatilis and Enterobacter, whereas Differential Coliform agar yielded the widest range of species. CONCLUSION: The yield of coliform bacteria varied between methods. Each method compared had a characteristic species distribution of target bacteria and a typical level of interference of non-target bacteria. Identification with routine physiological tests to distinct species was hampered by the slight differences between species. High yield and sufficient selectivity are difficult to achieve simultaneously, especially if the target group is diverse. SIGNIFICANCE AND IMPACT OF THE STUDY: The results showed that several aspects of method performance should be considered, and that the target group must be distinctly defined to enable method comparisons.

Bacterial Typing Techniques↗
PubMed2003

The microbiology of glue ear in Australian Aboriginal children.

OBJECTIVE: To study the bacterial cultures of middle ear aspirates from 27 Aboriginal children with otitis media with effusion. METHODS: Standard bacteriological techniques were used to analyse the middle-ear aspirates collected during surgery to insert grommets in 27 Aboriginal children. Swabs of the tympanic membrane were taken for comparison. RESULTS: Forty-five aspirates were collected from 59 myringotomies. Positive cultures were obtained from 19 of these (13 children) with potentially pathogenic organisms identified in 11 children including Staphylococcus, Pseudomonas, Haemophilus influenzae, Moraxella, Achromobacter, Enterobacter and Corynebacterium. CONCLUSION: This is only the second study to look at the bacteria in middle ear effusions in Aboriginal children. Streptococcus pneumoniae was notable in its absence as was found in a previous study.

Age Distribution↗
PubMed1998

Simple and direct detection of Staphylococcus aureus in milk by a tube coagulase test.

A tube coagulase test (TCT) is described as a simple and non-expensive system for detection of Staphylococcus aureus directly in milk. The procedure is characterized by mixing milk samples with rabbit citrate plasma followed by incubation at 37 degrees C for clot formation. The tube coagulase test demonstrated 91.5% accuracy, 88.5% sensitivity and 100% specificity for the direct recognition of Staph. aureus in milk samples from quarters with subclinical mastitis, when compared with plating of milk on blood agar. The TCT has the potential to detect other coagulase positive staphylococci in milk. It is concluded that TCT may be of use to veterinary practitioners with limited laboratory facilities, or to dairy farmers as a simple diagnostic test on site.

Animals↗
PubMed2002

PCR/restriction fragment length polymorphism (RFLP) typing of human and poultry Campylobacter jejuni strains.

AIMS: The PCR/RFLP typing of 156 isolates Campylobacter jejuni originating from poultry and humans was performed (101 human and 55 poultry strains). METHODS AND RESULTS: On the basis of restrictive digest, six types were identified with AfaI, seven types with MboI and five types with HaeIII. With a combination of these three enzymes, 22 types were found. In human strains, the most frequently occurring types were Cj.4 (28%), Cj.1 (19%), Cj. 13 (13%) and Cj. 2 (5%). In the case of poultry strains, the most frequent types were Cj. 1 (34%), Cj. 11 (22%), C.j. 21 (16%) and Cj. 15 (11%). CONCLUSIONS: The findings support the hypothesis that poultry is a significant source but not sole source of Campylobacter sp. in relation to humans. SIGNIFICANCE AND IMPACT OF THE STUDY: The typing of Campylobacter sp. forms the basis for an evaluation of the current state and risk assessment of various Campylobacter sp. sources in relation to humans.

Animals↗
PubMed2004

A simple method to isolate biofilm-forming Bacillus subtilis and related species from plant roots.

A novel method was developed to isolate pure cultures of wild-type Bacillus subtilis and related species from plant roots, even roots washed free of adhering soil. The method uses casein digest-mannitol agarose (CM) media that promote rapid dendritic growth (low K+ ion) or profuse surface film formation (high K+ ion) of Bacillus species at 40 degrees C. Inoculation from the tips of surface growth on agarose leads to self-purification and streaking on CM agar plates (hard agar and high K+) leads to characteristic colony morphology. Phenotypic and 16S rDNA analysis revealed that most root isolates obtained by this method are spore-forming Bacillus species, with enrichment for B. subtilis and its close relatives. Of particular interest is the finding that the majority of these Bacillus isolates and the B. subtilis Marburg strain also form adhering biofilms on inert surfaces. Thus the methods presented may be useful in isolation of biofilm-forming Bacillus and investigation of their role on plant roots.

Bacillus subtilis↗
PubMed2003

Quantitative detection of probiotic Bifidobacterium strains in bacterial mixtures by using real-time PCR.

Strain-specific rRNA-targeted primers were designed for the quantitative detection of Bifidobacterium infantis Y1, B. breve Y8 and B. longum Y10 used in a pharmaceutical probiotic product (VSL-3). PCR and real-time PCR techniques with the selected primers were employed for the direct enumeration of the bifidobacteria in the probiotic preparation and for studying their kinetic characteristics in batch cultures. These analysis revealed that B. infantis Y1 was the predominant strain in the probiotic product and that its growth rate was the highest. Since B. infantis Y1, B. breve Y8 and B. longum Y10 are co-cultured during the industrial production of VSL-3, the kinetic characteristics of these strains can explain their different concentrations in the probiotic preparation. A validation of the PCR quantification method was performed by identifying a representative number of isolates from the bacterial mixtures with automated ribotyping. The methodology described represents a useful tool for the specific quantitative detection of bacterial strains and species in complex mixtures such as pharmaceutical preparations, dairy starter cultures, faecal samples and biopsies.

Bacterial Typing Techniques↗
PubMed2003

Molecular typing of the bacterial flora in sputum of cystic fibrosis patients.

Despite recent advances in therapy, lower airway infections remain the major cause of morbidity and mortality in cystic fibrosis (CF) patients. Bacterial colonisation of the lower airways in CF is limited to a few bacterial species, commonly Staphylococcus aureus, Pseudomonas aeruginosa and Haemophilus influenzae. Burkholderia cepacia colonisation is much rarer, but it has been thought to be associated with more advanced lung disease and increased mortality. A rapid characterisation of the bacterial flora in sputum of CF patients is of great importance for proper treatment. The aim of this study was to establish bacterial profiles and to identify pathogenic bacteria in respiratory specimens by means of molecular methods including temporal temperature gradient gel electrophoresis (TTGE) and DNA sequencing of PCR amplicons derived from 16S rDNA variable V3 and V6 regions. Sputa of 13 CF patients (7 males/6 females, age 19-59 years) collected at the Stockholm CF centre were analysed. TTGE revealed the presence of complex bacterial profiles in all samples. The V3 and V6 PCR amplicons were cloned and sequenced by real-time DNA Pyrosequencing. DNA from Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa, respectively, was identified together with sequences from normal oral cavity flora. The results were in reasonable agreement with those obtained by conventional bacterial culture, considering that only known CF pathogens are included in routine reports. However, the methodology seems too elaborate to be introduced into daily routine

Adult↗
PubMed1998

Potential misidentification of Burkholderia pseudomallei by API 20NE.

Biochemical confirmation of the identity of Burkholderia pseudomallei in Singapore previously relied on the API 20NE panel of tests. After introducing an alternative proprietary biochemical panel, the Microbact 24E (MedVet, Adelaide, Australia), we noted that the API panel identified some presumptive B. pseudomallei isolates as other species. We therefore compared the performance of the API 20NE against the Microbact 24E with 50 distinct clinical isolates of B. pseudomallei, after 24 hours and after five days incubation of primary cultures. The API panel correctly identified 40 isolates. Four results were unacceptable or uninterpretable. Six isolates were misidentified as other species; the commonest being Chromobacterium violaceum. One of these was again identified as C. violaceum by the repeat API panel. Fourteen isolates, including the six misidentified isolates and four isolate pairs from separate sources in four separate patients, were typed using PCR amplification of repetitive extragenic palindromic sequences (REPS). The isolates identified as C. violaceum appeared to have identical REPS patterns, suggesting that some of the errant API results may be due to a single locally prevalent strain of B. pseudomallei. A previous suggestion that C. violaceum may produce a melioidosis-like illness may therefore be due to laboratory misidentification of B. pseudomallei with the API 20NE biochemical test panel.

Bacterial Typing Techniques↗
PubMed1998

A blood micro-culture system for the diagnosis of bacteremia in pediatric patients.

The aim of this study was to evaluate the utility of a volume-modified blood culture system to diagnose bacteremia in newborns and infants. A total of 793 paired blood cultures, obtained from 464 patients (173 newborns and 291 infants), were analyzed. Vacutainer tubes containing 18 ml supplemented peptone broth sodium-polyanethol-sulfonate were used as the gold standard, in comparison with a blood micro-culture system containing 1.8 ml of the broth. Prior to antibiotic treatment, 2.2 ml of blood was obtained from each patient; 0.2 ml was inoculated in a blood micro-culture tube and 2 ml in a routine tube. Sensitivity, specificity and predictive values were calculated. Microorganisms were isolated in 153 standard blood culture tubes and 151 blood micro-culture tubes. The sensitivity of the blood micro-culture system was 95%, specificity 99% and positive and negative predictive values 96% and 99% respectively. The sensitivity and specificity of blood micro-culture in neonates and infants is high. We recommend that this system be used for the diagnosis of bacteremia in newborns and infants in laboratories where manual systems are still in use.

Bacteremia↗
PubMed1986

Serological diagnosis of typhoid fever by enzyme-linked immunosorbent assay (ELISA).

Serum sample from 22 bacteriologically proved cases of typhoid fever, 41 febrile cases who were culture negative and 70 sick and healthy age-matched controls were tested for enzyme-linked immunosorbent assay (ELISA) IgG and IgM antibodies using Salmonella typhi LPS antigen. IgG and IgM antibodies were present in 72.7% and 81.8% respectively as against Widal test which was positive in 40.9% in proved cases. In febrile controls IgG and IgM ELISA antibodies were present in 80.4% and 60.9% respectively as against 53.6% by Widal test. This difference between the two tests was statistically significant P less than 0.001. ELISA test was more sensitive than the Widal test and hence it may be useful in rapid serodiagnosis of typhoid fever and also in circumstances where bacteriological techniques are not available.

Enzyme-Linked Immunosorbent Assay↗
PubMed2002

Methicillin-resistant Staphylococcus aureus: laboratory detection methods in use in the Republic of Ireland and Northern Ireland.

There is no universally agreed laboratory protocol for the detection of methicillin-resistant Staphylococcus aureus (MRSA) and hence a variety of approaches are used. As part of an all-island survey of MRSA in the Republic of Ireland (the South) and Northern Ireland (the North), a questionnaire was circulated to 14 participating laboratories in the North and 49 in the South, to determine the methods used to isolate MRSA from clinical specimens, identify S. aureus and test for susceptibility to methicillin. Almost two-thirds (64%) of laboratories in the North but only 16% of laboratories in the South use enrichment culture. There is heavy reliance on commercial kits to confirm the identification of S. aureus in the South but all laboratories in the North use the staphylocoagulase test. More than 90% of all laboratories use a disc method for susceptibility testing and 71% of laboratories in the North supplement this with the E-test; however, a range of methicillin disk concentrations are in use. There is a need to review current laboratory methods used to detect MRSA, with follow-up audit on their implementation. Additional resources may be needed in some laboratories to comply with revised guidelines, and reference facilities are required to assess new commercially available techniques and to confirm the identification of unusual or difficult strains.

Bacterial Typing Techniques↗
PubMed1953

Antituberculous immunity induced in mice by vaccination with living cultures of attenuated tubercle bacilli.

The immunity induced in mice by vaccination with living attenuated cultures of tubercle bacilli was measured by two criteria. (a) Increase in survival time of the vaccinated animals after infection with a dose of virulent bacilli sufficient to kill all the unvaccinated controls within 10 to 20 days. (b) Difference in the number of living bacilli recovered from the spleen and lungs of vaccinated and normal animals infected with a small dose of virulent bacilli. The level of immunity induced was found to depend upon the extent of multiplication in vivo of the bacilli used for vaccination. This in turn was conditioned by the degree of attenuation characteristic of the bacterial strain used in the preparation of the vaccine, the amount of vaccine injected, the route of vaccination, and the time interval between vaccination and challenge infection. It was possible to prevent or retard the development of immunity by treating the mice in course of immunization with a drug, isoniazid, capable of interrupting the multiplication in vivo of the bacilli used as vaccine. Although immunity regularly developed and lasted for many weeks when the proper conditions of vaccination were used, the immune response was never sufficient to protect the animals against ultimate death from infection with virulent tubercle bacilli. The prolongation of life in the vaccinated mice was not consequent on a direct bactericidal effect but rather on a retarded or interrupted multiplication of the virulent bacilli in vivo. The quantitative bacteriological techniques used in the present study would appear to be of value for the analysis of certain problems of immunity, and for the appraisal of vaccines and techniques of vaccination.

Animals↗
PubMed1997

Microbiologic approaches for studying Campylobacter species in patients with Guillain-Barré syndrome.

Campylobacter jejuni is now considered to be the most common cause of bacterial diarrheal disease in the United States. Sufficient evidence exists to support the hypothesis that C. jejuni induces Guillain-Barré syndrome (GBS); however, many questions about the biology of the organism and host factors need to be answered. In order to study the role of C. jejuni and other Campylobacter species as a cause of GBS, isolates from patients with different forms of GBS and appropriate control populations must be obtained. To continue to study this association, research teams must have laboratory support for isolating and characterizing Campylobacter strains. This review summarizes current knowledge about the laboratory aspects of Campylobacter infection that may be pertinent to studies on GBS.

Bacterial Typing Techniques↗
PubMedDate not supplied

Septic arthritis caused by Bacteroides fragilis.

As improvements in bacteriologic techniques have enhanced the recovery of anaerobic bacteria from clinical specimens, there has been an increasing awareness of the role of anaerobes in disease. Bacteroides fragilis is the most common anaerobic organism found in clinical specimens. Although it is the anaerobe most frequently associated with bacteremia and a common isolate in intraabdominal infections, infections of the female genital tract, wounds, and abscesses, B. fragilis is a rare cause of septic arthritis. The isolation of this organism from four patients with septic arthritis in three Cleveland hospitals between 1978 and 1982 suggests that septic arthritis due to B. fragilis may be a more common clinical entity than previously appreciated. In this report we describe these cases and review the pertinent literature.

Adult↗