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B Dwyer

Publications and source records attributed to B Dwyer.

At least 55 records · Page 3Linked to original sources
PubMed1991

Identification of Mycobacterium kansasii by DNA hybridization.

A DNA probe specific for Mycobacterium kansasii was obtained from a plasmid clone library of EcoRI-digested genomic DNA. The probe specifically identified culture-confirmed isolates of M. kansasii and isolates in cultures of environmental water samples. In an attempt to distinguish between isolates of M. kansasii, we used two methods to demonstrate restriction fragment length polymorphisms in the genomic DNA. Both of these methods failed to detect any differences between the isolates. These isolates included the type strain TMC 1201, environmental isolates, and clinical isolates from Australia and the Solomon Islands. This result suggests that the genome of M. kansasii is highly conserved and that genetic divergence within this species in insignificant.

Australia↗
PubMed1991

Comparative evaluation of three selective media and a nonselective medium for the culture of Helicobacter pylori from gastric biopsies.

Plating on solid media is the standard technique used in most laboratories for the isolation of Helicobacter pylori from gastric biopsies. Recently, various selective media were developed for this purpose. We compared and evaluated three selective media, Skirrow's, Dent's CP, and modified Glupczynski's Brussels campylobacter charcoal media, and chocolate agar medium for the isolation of H. pylori. Gastric biopsies taken from a total of 203 patients were plated in parallel on all four media. An isolation rate of 51% (104 of 203) was obtained with a combination of all four media. Of the 104, 92 (88%) were positive with Dent's medium and with modified Glupczynski's medium. Skirrow's medium gave the highest isolation rate, 96% (100 of 104). However, growth of H. pylori was scant (only one to five colonies) when growth occurred on Skirrow's medium alone. Overall, modified Glupczynski's medium provided significantly heavier growth. Chocolate agar medium yielded a 76% (79 of 104) positivity rate. We recommend the use of a combination of two selective media for the maximum recovery of H. pylori from antral biopsies.

Bacteriological Techniques↗
PubMed1991

Legionella fairfieldensis sp. nov. isolated from cooling tower waters in Australia.

Three Legionella-like organisms were isolated from water from the cooling towers of two Australian institutions. The strains grew on buffered charcoal-yeast extract (BCYE) agar but not on BCYE agar in the absence of L-cysteine. Gas-liquid chromatography profiles of the isolates were consistent with those for Legionella spp. They were serologically distinct from other legionellae in a slide agglutination test. DNA hybridization studies showed that the three isolates belong to a new species of Legionella, Legionella fairfieldensis (ATCC 49588).

Australia↗
PubMed1991

Effect of agitation of BACTEC 13A blood cultures on recovery of Mycobacterium avium complex.

The effect of agitation of BACTEC 13A bottles (Becton Dickinson) on the recovery of Mycobacterium avium complex (MAC) from blood was compared with that of static incubation. A total of 265 blood specimens was inoculated in duplicate into BACTEC 13A bottles. One specimen was statically incubated at 35 degrees C, and the other was incubated with agitation on a Gyrotory shaker at 35 degrees C for the first 2 weeks and thereafter without shaking for up to 12 weeks. Of the 265 specimens, 77 (29.1%) were positive in either one or both of the paired bottles. The average detection times for the shaken and nonshaken bottles were 12.7 and 15.9 days, respectively. A total of 10.4% of the specimens in the shaken bottles became positive 1 week before those in the nonshaken bottles, and 16.9% of the shaken cultures were positive more than 2 weeks before their counterparts. A further 46.8% of the agitated specimens became positive while the corresponding nonagitated cultures remained negative. When both specimens became positive at the same time, 88% of the shaken cultures had higher growth indices than their nonshaken counterparts. A further 11 paired blood cultures were taken from patients known to be infected with MAC to assess the effect of agitation of bottles on the utility of making twice-weekly readings during the first 2 weeks of incubation. Ten of the 11 sets of specimens in the shaken bottles were positive 1 or more weeks before those in the corresponding nonshaken bottles. In the remaining set, both specimens became positive on the same day; however, the growth index of the agitated culture was higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗
PubMed1991

Helicobacter pylori serology using specimens collected on filter paper.

A simple method for the collection of blood specimens on filter paper for serology of Helicobacter pylori was devised. Blood was freshly applied to small Whatman 3 mm filter paper and allowed to dry. Serological activity, as measured by reactivity to H pylori antigens (AMRAD, Australia), was retained after storage for one month at both room temperature and at 4 degrees C. This technique eliminates formal venepuncture, separation of sera, and arduous packaging of specimens to be sent to the laboratory.

Antibodies, Bacterial↗
PubMed1991

Prevalence of antibodies to spotted fever group rickettsiae in dogs from southeastern Australia.

Recent epidemiologic data suggests that Rickettsia australis, the cause of Queensland tick typhus, is present in southeastern Australia. In order to further confirm this observation, a canine serosurvey was undertaken to determine if naturally occurring antibodies were present in pet and farm dogs from this newly-recognized endemic area. Thirty-five of 312 surveyed dogs (11.2%) had indirect immunofluorescent antibody titers of 1:64 or greater against R. australis antigen. Positive control sera were obtained from two dogs experimentally inoculated with R. australis. One of these dogs was serially sampled and a rickettsemia could not be documented. None of 26 control sera obtained from dogs from South Australia, New Zealand, western Victoria, or North Carolina had antibody titers greater than or equal to 1:64. These results suggest that spotted fever group rickettsiae are present in Southeastern Australia.

Animals↗
PubMed1990

Enzyme-linked immunosorbent assays for detecting antibody to Rickettsia australis in sera of various animal species.

New endemic areas of spotted fever-like rickettsial disease have been found in south-eastern Australia (Gippsland, Victoria and Flinders Island, Tasmania). The rickettsia responsible is currently unknown although it may be Rickettsia australis. To investigate serological evidence of rickettsial exposure in various wild animal species, a competitive ELISA was developed which detected antibodies to R. australis. It was based on inhibition of an indirect ELISA detecting antibody to R. australis in guinea pig sera. Pre- and post-infection sera from 2 dogs, 2 rabbits, 5 mice and 6 rats, experimentally infected with R. australis, were tested by competitive ELISA. The results showed that all pre-infection sera were negative and all post-infection sera positive for antibody to R. australis. To test the utility of the competitive ELISA for detecting natural rickettsial infection in non-laboratory animals, 51 dog sera, negative for rickettsial antibody by immunofluorescence (IF) and 20 IF positive dog sera (collected from various locations on the east coast of Australia) were tested. Compared to the IF test the competitive ELISA was 90% sensitive and 96% specific. This new test has potential for detecting antibody to R. australis in the sera of different wild animal species.

Animals↗
PubMed1990

Quadruple-drug therapy for Mycobacterium avium-intracellulare bacteremia in AIDS patients.

The mycobacterial response was evaluated for patients with Mycobacterium avium-intracellulare complex (MAC) bacteremia treated with a quadruple regimen of rifabutin, clofazimine, isoniazid, and ethambutol. Mycobacteremia was cleared in 22 of 25 patients who received this regimen, and 18 patients experienced complete resolution of symptoms associated with MAC infection. All of the patients were immunodeficient, with a mean CD4 cell count at the time of diagnosis of MAC infection of 54.7 +/- 54.6 cells/microliters. All MAC isolates were resistant to clofazimine, isoniazid, and ethambutol. Sixteen of 24 isolates were resistant to rifabutin. Improved results of treatment may be related to the use of a higher dose of rifabutin (300-600 mg/day) compared with other studies (150-300 mg/day), earlier diagnosis and institution of treatment, and synergy between rifabutin and ethambutol. The quadruple regimen used in this study appears effective in clearing mycobacteremia and in ameliorating symptoms of infection.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Gastroenteritis associated with Campylobacter cinaedi.

The atypical Campylobacter spp. are being associated increasingly with gastroenteritis in certain population groups. We report the clinical and laboratory features of four cases (in three homosexual men and one heterosexual man) of gastroenteritis that was associated with Campylobacter cinaedi. The infection that was caused by this organism clinically was indistinguishable from other mild gut infections and resolved spontaneously without treatment. Faecal microscopy was unhelpful in the diagnosis. Successful culture of C. cinaedi required incubation of the specimen at 37 degrees C under microaerophilic conditions on cephalothin-free media--a procedure that usually is not undertaken in culturing for the more-common faecal pathogens. C. cinaedi needs to be considered in the investigation of the cause of diarrhoea in population groups such as homosexual men.

Campylobacter↗
PubMed1988

Parasitic infections of refugees.

The Victorian refugee screening programme, in contrast to similar programmes elsewhere in Australia, includes an examination for faecal parasites. The results of such screening at Fairfield Infectious Diseases Hospital for the 16-month period December 1, 1984-March 31, 1986 are presented. For most of the population groups that were studied, there was a high prevalence of intestinal parasites, which often warranted treatment. Additionally, marked differences were noted among the nationalities in the range of parasites that was detected. This information is of particular importance for those who are delivering health services to members of these different ethnic communities, especially in other states where screening is less comprehensive.

Adolescent↗
PubMed1988

Campylobacter cryaerophila isolated from a human.

Campylobacter cryaerophila was recovered from a single stool specimen of a 35-year-old homosexual man who presented with intermittent diarrhea for 4 to 6 months. The isolate was identified as C. cryaerophila by using biochemical reactions and confirmed by DNA-DNA hybridization and gas-liquid chromatograph profiles. The base composition of DNA of the isolate was found to be 31.1 +/- 1 mol% (G+C). C. cryaerophila was previously reported to be associated with bovine and porcine abortions in animals. We believe this is the first report of recovery of C. cryaerophila from human stool.

Adult↗
PubMed1988

Serotyping of Streptococcus pneumoniae by latex agglutination.

A simple method is presented for serotyping Streptococcus pneumoniae which uses easily prepared sensitized polystyrene latex particles. The technique is simple, fast and reliable and can detect pneumococcal antigens in body fluids.

Antigens, Bacterial↗
PubMed1988

Antibody response to Campylobacter pylori in diverse ethnic groups.

Antibody response to Campylobacter pylori was measured in ethnic groups of Vietnamese, El Salvadorean and Ethiopian origin. The results were compared with the previously reported antibody titres found in sera of culture positive and culture negative patients, patients suffering from duodenal ulcer, white Australian blood donors and Australian Aboriginals. While in Vietnamese the prevalence of serologically positive sera was found to be similar to the white Australian population, numbers of serologically positive sera in El Salvadorean and Ethiopian ethnic groups was found to be very high. The high incidence of serologically positive sera in the Ethiopians correlated with the reported high incidence of duodenal ulcer in this population.

Adolescent↗