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Yuen LK, Ross BC, Jackson KM, Dwyer B. Characterization of Mycobacterium tuberculosis strains from Vietnamese patients by Southern blot hybridization. J Clin Microbiol 1993; 31:1615-8. [PMID: 8100244 PMCID: PMC265589 DOI: 10.1128/jcm.31.6.1615-1618.1993] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A total of 41 Mycobacterium tuberculosis strains from patients of Vietnamese origin were analyzed by Southern blot hybridization with two different probes, IS6110 (Otal, I., et al., J. Clin. Microbiol. 29:1252-1254, 1991; Ross, B. C., et al., J. Clin. Microbiol. 30:942-946, 1992; Thierry, D., et al., J. Clin. Microbiol. 28:2668-2673, 1990; van Soolingen, D., et al., J. Clin. Microbiol. 29:2578-2586, 1991) and pTBN12 (Ross, B. C., et al., J. Clin. Microbiol. 30:942-946, 1992). The restriction fragment patterns of nine of these strains were virtually identical when the pTBN12 probe was used; five strains had a single copy of IS6110, and four strains failed to hybridize with the IS6110 probe. This relatively high frequency of strains with no or one copy of IS6110 suggests that the usefulness of IS6110 for epidemiological study may be limited in certain populations.
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Morris A, Reller LB, Salfinger M, Jackson K, Sievers A, Dwyer B. Mycobacteria in stool specimens: the nonvalue of smears for predicting culture results. J Clin Microbiol 1993; 31:1385-7. [PMID: 8501249 PMCID: PMC262947 DOI: 10.1128/jcm.31.5.1385-1387.1993] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A previous recommendation suggests that stool be cultured for mycobacteria only if the smear is positive. We have correlated smear and culture results of 2,176 stool specimens submitted for mycobacterial culture. The sensitivity, specificity, and positive and negative predictive values for smears to predict culture results are 34, 99, 90, and 87%, respectively. We recommend that the stool smear not be used as a screening technique to decide which specimens from at-risk patients should be cultured because it lacks the necessary sensitivity.
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Rastogi N, Ross BC, Dwyer B, Goh KS, Clavel-Sérès S, Jeantils V, Cruaud P. Emergence during unsuccessful chemotherapy of multiple drug resistance in a strain of Mycobacterium tuberculosis. Eur J Clin Microbiol Infect Dis 1993; 11:901-7. [PMID: 1362540 DOI: 10.1007/bf01962370] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Serial isolates of Mycobacterium tuberculosis were cultured from a patient who failed to respond to standard antituberculous chemotherapy. Isolates were cultured in March 1989, July 1989, December 1989 and May 1990. Each successive isolate was found to be resistant to a wider range of antituberculous drugs than its predecessors. The initial isolate was resistant to isoniazid and rifampin, the second isolate was also resistant to ethambutol, the third was also resistant to pyrazinamide, ansamycin (= rifabutin) and ofloxacin and the last isolate was also resistant to ciprofloxacin and sparfloxacin. All four isolates' bacteriophage typing profiles and DNA restriction fragment patterns determined by Southern blot hybridization using the IS6110/IS986 probes and the new probe pTBN12 were concordant. It was concluded that this patient was persistently infected with a single strain of Mycobacterium tuberculosis which developed resistance to a number of families of drugs but did not show any significant change in typing patterns. The problem of acquired multiple drug resistance, particularly to fluoroquinolones and rifamycins, represents a new challenge in tuberculosis therapy.
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MESH Headings
- Adult
- Anti-Bacterial Agents/pharmacology
- Anti-Bacterial Agents/therapeutic use
- Anti-Infective Agents/pharmacology
- Anti-Infective Agents/therapeutic use
- Antibiotics, Antitubercular/pharmacology
- Antibiotics, Antitubercular/therapeutic use
- Antitubercular Agents/pharmacology
- Antitubercular Agents/therapeutic use
- Bacteriophage Typing
- Blotting, Southern
- Clofazimine/pharmacology
- Clofazimine/therapeutic use
- Colony Count, Microbial
- DNA, Bacterial/genetics
- Drug Resistance, Microbial/genetics
- Fluoroquinolones
- Humans
- Isoniazid/pharmacology
- Isoniazid/therapeutic use
- Lactams, Macrocyclic
- Male
- Microbial Sensitivity Tests
- Mycobacterium tuberculosis/classification
- Mycobacterium tuberculosis/drug effects
- Mycobacterium tuberculosis/genetics
- Polymorphism, Restriction Fragment Length
- Rifamycins/pharmacology
- Rifamycins/therapeutic use
- Tuberculosis, Pulmonary/drug therapy
- Tuberculosis, Pulmonary/microbiology
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54
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Ross BC, Dwyer B. Rapid, simple method for typing isolates of Mycobacterium tuberculosis by using the polymerase chain reaction. J Clin Microbiol 1993; 31:329-34. [PMID: 8381811 PMCID: PMC262760 DOI: 10.1128/jcm.31.2.329-334.1993] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
To develop a molecular typing method for Mycobacterium tuberculosis based on the polymerase chain reaction, oligonucleotide primers were designed to the ends of the insertion sequence IS6110 in an attempt to amplify DNA between clusters of this element on the genome. Although in many strains the copy number of this element is low and is distributed throughout the genome, most strains examined produced a banding pattern which varied between isolates including strains with one copy of IS6110. With strains isolated from patients in epidemiologic clusters of tuberculosis, the banding patterns were similar within each cluster but distinct from those in strains from different clusters. Similarly, multiple isolates from the same patient yielded a consistent banding pattern. Sequencing of four polymerase chain reaction products revealed that amplification was occurring between copies of IS6110 in two of the products and from a single copy of IS6110 to a nonspecific priming site in the other two. This technique provides a rapid and simple means of typing M. tuberculosis isolates for epidemiologic studies.
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Dwyer B, Jackson K, Raios K, Sievers A, Wilshire E, Ross B. DNA restriction fragment analysis to define an extended cluster of tuberculosis in homeless men and their associates. J Infect Dis 1993; 167:490-4. [PMID: 8093624 DOI: 10.1093/infdis/167.2.490] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A cluster of tuberculosis in men associated with shelters for the homeless in Melbourne, diagnosed between April 1984 and July 1991, was reviewed with respect to the genetic relatedness of the infecting strains. Relatedness was determined by examination of Southern blot analyses of restriction enzyme-digested genomic DNA, using probes for repetitive sequences. From the initial 24 cases selected, isolates were available from 19, and 18 were identical. A total of 571 other Australian and Solomon Islands strains were examined for relatedness to these strains. Nine additional case strains were found to be identical; all were from recent Melbourne residents and at least 7 were epidemiologically related to the original case cluster. The identification of a single infecting strain of Mycobacterium tuberculosis in these 27 cases suggests that reactivation disease in this group may not be as important as infection or reinfection from another case or cases.
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56
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Tee W, Mayall B, Lucas CR, Rayner R, Pearson S, Dwyer B. Use of ribosomal RNA gene restriction patterns to investigate two outbreaks of Campylobacter enteritis in Melbourne, Australia. J Med Microbiol 1992; 37:385-8. [PMID: 1281233 DOI: 10.1099/00222615-37-6-385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The analysis of ribosomal RNA (rRNA) gene patterns (ribotyping) has been used to differentiate strains within bacterial species. We used this method to investigate two outbreaks of campylobacter enteritis that occurred recently in Melbourne, Australia. The first outbreak involved seven patients although isolates from only five patients were available for typing. The second outbreak consisted of three patients infected with human immunodeficiency virus (HIV) on the same ward of a hospital. Analysis of the rRNA gene patterns revealed identical patterns for the isolates from five patients in the first outbreak, suggesting that these isolates were from the same source. However, ribotyping of the four isolates from the second outbreak showed three distinct ribotypes indicative of contact with unrelated sources. This study demonstrated that ribotyping is a useful, reliable and convenient typing scheme for epidemiological purposes.
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Baird RW, Lloyd M, Stenos J, Ross BC, Stewart RS, Dwyer B. Characterization and comparison of Australian human spotted fever group rickettsiae. J Clin Microbiol 1992; 30:2896-902. [PMID: 1452660 PMCID: PMC270549 DOI: 10.1128/jcm.30.11.2896-2902.1992] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The microbiological and molecular characteristics of the rickettsiae isolated from humans with Queensland tick typhus (QTT) caused by Rickettsia australis and the recently described Flinders Island spotted fever (FISF) were compared. Clinically and serologically, the diseases are similar. Cell culture reveals differences in the plaque-forming abilities of the isolates. Characterization of the gene encoding the genus-specific 17-kDa antigen of R. australis revealed a unique nucleotide sequence unlike those of the FISF isolate and Rickettsia rickettsii. Southern blot analysis of rickettsial DNA from the isolates with a 17-kDa-antigen gene probe revealed the presence of this gene in all isolates but no difference in banding patterns. When a probe for the rRNA genes was used, clear differences in banding patterns of isolates from patients with QTT and FISF were revealed. Thus, the rickettsiae isolated from patients with FISF differ from those from patients with QTT and may represent a new rickettsial species.
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Ross BC, Jackson K, Yang M, Sievers A, Dwyer B. Identification of a genetically distinct subspecies of Mycobacterium kansasii. J Clin Microbiol 1992; 30:2930-3. [PMID: 1280644 PMCID: PMC270554 DOI: 10.1128/jcm.30.11.2930-2933.1992] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
To assess the usefulness of a specific DNA probe for Mycobacterium kansasii, 105 isolates from Australia, Belgium, Japan, South Africa, and Switzerland were collected and analyzed. Twenty of these isolates were probe negative, of which 18 were from Belgium and Switzerland. Analysis of all isolates by Southern blot hybridization indicated a lack of variability among probe-positive isolates, while probe-negative isolates were clearly distinct and showed greater diversity. Sequence analysis of the 250 nucleotides at the 5' end of the 16S rRNA gene revealed that 19 of the 20 probe-negative isolates had a sequence different from that of M. kansasii. A total of five nucleotide differences were present in a cluster consisting of two nucleotide deletions and three nucleotide substitutions. These results suggest the existence of a genetic subspecies of M. kansasii.
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Jackson K, Sievers A, Ross BC, Dwyer B. Isolation of a fastidious Mycobacterium species from two AIDS patients. J Clin Microbiol 1992; 30:2934-7. [PMID: 1280645 PMCID: PMC270555 DOI: 10.1128/jcm.30.11.2934-2937.1992] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Two strains of fastidious mycobacteria were isolated from two patients with AIDS and clinical disease suggestive of Mycobacterium avium complex infection. Acid-fast bacilli were isolated from blood and bone marrow of both patients in BACTEC 12B and/or 13A media. The acid-fast bacilli failed to grow on subculture to routine Löwenstein-Jensen medium containing pyruvate and egg yolk agar. After several attempts, the strain from one patient was finally cultured on Middlebrook 7H9 medium with agar, charcoal, and yeast extract 13 months after the initial specimens were received in the laboratory. The second patient's strain was cultured on the same medium 6 weeks postinoculation with fresh BACTEC fluid and 5 months after specimen collection. Routine biochemical and growth tests were performed on these isolates but failed to give definitive identifications. 16S rRNA gene sequencing suggested that the organisms share at least 98.9% homology with M. simiae. Even greater homology (99.86%) was found with the recently described species "M. genavense." Recognition of the fastidious nature of some mycobacteria that infect AIDS patients is important in the treatment of infections in these patients and in understanding the epidemiology of atypical mycobacterial infections. It is suggested that a liquid culture medium such as BACTEC be employed for primary isolation of mycobacteria from AIDS patients and that subculture to the charcoal medium described here be carried out for those organisms that fail to grow on subculture to routine media.
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60
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Abstract
Several assay systems were compared for measuring the concentration of viable Rickettsia australis, including embryonated eggs, tissue cultures, and mouse inoculation. Direct rickettsial counts that included the enumeration of both viable and nonviable rickettsiae were used to obtain baseline values. Assays were conducted in parallel using serially diluted R. australis preparations to establish which assay displayed the greatest sensitivity and reproducibility. Overall, the plaque assay using buffalo green monkey kidney cells with centrifugation of the rickettsiae onto the monolayers was the most sensitive assay for detecting R. australis, while the embryonated egg assay and mouse lethality titrations were the least sensitive.
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61
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Dwyer B. Tuberculosis in Australia. Med J Aust 1992; 157:143. [PMID: 1463504 DOI: 10.5694/j.1326-5377.1992.tb137063.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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62
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Tee W, Lambert J, Smallwood R, Schembri M, Ross BC, Dwyer B. Ribotyping of Helicobacter pylori from clinical specimens. J Clin Microbiol 1992; 30:1562-7. [PMID: 1378063 PMCID: PMC265329 DOI: 10.1128/jcm.30.6.1562-1567.1992] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Ribotyping is a method used to type strains of bacteria by analyzing the restriction enzyme digestion patterns of the rRNA genes. This method was applied to 126 strains of Helicobacter pylori from 100 unrelated symptomatic patients who had endoscopies done and to 15 strains from 15 infected subjects from seven families. Analysis of the rRNA gene patterns revealed 77 distinct ribotypes from the 100 patients. From 15 of these subjects, isolates were recovered from antral mucosal biopsies at follow-up endoscopy. All follow-up isolates from the same patient, with one exception, yielded identical digest patterns. This patient had strains with two distinct digest patterns obtained from a set of three isolates cultured from biopsy specimens taken at different times. Five patients who had isolates recovered from different sites in the stomach (antrum, gastric body, duodenum, and pyloric channel) showed ribotyping patterns which were identical for each patient yet distinct between patients. In seven family groups studied, identical digest patterns were detected in members of two families, with variability in strains detected among members of the remaining families. This study demonstrates that ribotyping provides a useful, reliable, reproducible, and highly discriminatory typing scheme for the study of H. pylori infection.
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63
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Jackson KM, Ross BC, Sievers A, Dwyer B. A fastidious strain of Mycobacterium tuberculosis in a patient with AIDS. N Engl J Med 1992; 326:1434-5. [PMID: 1569993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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64
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Hanson AT, Samani Z, Dwyer B, Jacquez R. Heap Leaching as a Solvent-Extraction Technique for Remediation of Metals-Contaminated Soils. ACS SYMPOSIUM SERIES 1992. [DOI: 10.1021/bk-1992-0491.ch009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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65
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Abstract
OBJECTIVE To present a case of murine (endemic) typhus, the first to be reported within the last 30 years in Australia. CLINICAL FEATURES A 17-year-old pregnant woman presented with a viral-like illness and later developed a spotted rash, fever and headache. INVESTIGATION AND OUTCOME: Sera taken on Day 7 and Day 30 of the illness showed seroconversion to Proteus OX19 (Weil-Felix) and to Rickettsia typhi (by immunofluorescence), indicating recent infection with Rickettsia of the typhus group. Her illness was clinically compatible with murine typhus. She responded well to erythromycin and delivered a normal infant at term. CONCLUSION Infection with Rickettsia typhi (murine typhus) still occurs in Australia. It can be diagnosed by means of specific serological tests for rickettsial disease, which are superior to the non-specific Weil-Felix test.
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66
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Ross BC, Raios K, Jackson K, Dwyer B. Molecular cloning of a highly repeated DNA element from Mycobacterium tuberculosis and its use as an epidemiological tool. J Clin Microbiol 1992; 30:942-6. [PMID: 1572981 PMCID: PMC265190 DOI: 10.1128/jcm.30.4.942-946.1992] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In order to develop a technique for distinguishing between isolates of Mycobacterium tuberculosis, we cloned two hypervariable DNA fragments from NdeII-digested genomic DNA. The cloned DNA fragments of 3.8 and 4.7 kb were found to contain the same repetitive element, which was different from previously characterized repetitive elements. It is present in at least 30 copies per genome and is distributed among mycobacterial species other than those of the tuberculosis complex, including M. kansaii, M. gastri, and M. szulgai. When used as a probe on restriction enzyme-digested DNA, it can distinguish between strains from unrelated cases of tuberculosis while demonstrating identical banding patterns for isolates from epidemiologically related cases.
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67
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Kaldor J, Tong MQ, Dwyer B, Huang ZH, Johnston N, Talman P, Horne M. Guillain-Barré syndrome and Campylobacter jejuni/coli. Pathology 1992; 24:125-6. [PMID: 1641258 DOI: 10.3109/00313029209063639] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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68
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Baird R, Ross B, Stenos J, Dwyer B. Rapid detection and molecular characterization of australian human rickettsial isolates. Pathology 1992. [DOI: 10.1016/s0031-3025(16)36023-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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69
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Tee W, Fairley S, Smallwood R, Dwyer B. Comparative evaluation of three selective media and a nonselective medium for the culture of Helicobacter pylori from gastric biopsies. J Clin Microbiol 1991; 29:2587-9. [PMID: 1774265 PMCID: PMC270377 DOI: 10.1128/jcm.29.11.2587-2589.1991] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
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.
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70
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Abstract
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.
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71
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Mollison LC, Mijch A, McBride G, Dwyer B. Hypothyroidism due to destruction of the thyroid by Kaposi's sarcoma. REVIEWS OF INFECTIOUS DISEASES 1991; 13:826-7. [PMID: 1962092 DOI: 10.1093/clinids/13.5.826] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A case of hypothyroidism that manifested as depression and deteriorating functional status and that ultimately resulted in the death of a 41-year-old patient with AIDS is described. Postmortem examination revealed destruction of the thyroid gland by Kaposi's sarcoma. Analysis of stored serum samples revealed that the patient had become profoundly hypothyroid during his terminal illness. Practitioners are reminded of the need to exclude metabolic causes when treating encephalopathy in patients infected with human immunodeficiency virus.
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72
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Sexton DJ, Dwyer B, Kemp R, Graves S. Spotted fever group rickettsial infections in Australia. REVIEWS OF INFECTIOUS DISEASES 1991; 13:876-86. [PMID: 1962102 DOI: 10.1093/clinids/13.5.876] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
More than four decades ago, Rickettsia australis was discovered to be the etiologic agent of Queensland tick typhus (QTT), yet many unanswered questions persist about the ecology, epidemiology, and clinical features of this disease. We review 46 previously published cases of QTT along with 16 cases discovered by active surveillance. QTT is usually a mild disease. Patients often have regional lymphadenopathy and eschars. Some have vesicular rashes. Because clinical features overlap, serologic tests are necessary to distinguish QTT from other endemic Australian rickettsial diseases (scrub and murine typhus). Only two tick vectors of R. australis have been identified: Ixodes holocyclus and Ixodes tasmani. Until rickettsiae are isolated from patients in Victoria and Tasmania, it remains unproven that spotted fever group infections in these locations are due to R. australis. However, available serologic, epidemiologic, and clinical data suggest that QTT is not confined to the area in which R. australis was first isolated (Queensland); rather, it occurs along a 3,200-km span of eastern coastal Australia, from tropical to temperate climates.
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73
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Jackson K, Sievers A, Dwyer B. Effect of agitation of BACTEC 13A blood cultures on recovery of Mycobacterium avium complex. J Clin Microbiol 1991; 29:1801-3. [PMID: 1774299 PMCID: PMC270214 DOI: 10.1128/jcm.29.9.1801-1803.1991] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
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)
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74
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Sexton DJ, Banks J, Graves S, Hughes K, Dwyer B. Prevalence of antibodies to spotted fever group rickettsiae in dogs from southeastern Australia. Am J Trop Med Hyg 1991; 45:243-8. [PMID: 1877719 DOI: 10.4269/ajtmh.1991.45.243] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
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.
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75
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Johnson PD, Graves SR, Stewart L, Warren R, Dwyer B, Lucas CR. Specific syphilis serological tests may become negative in HIV infection. AIDS 1991; 5:419-23. [PMID: 2059384 DOI: 10.1097/00002030-199104000-00010] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The diagnosis of syphilis is frequently dependent upon the results of serological tests, but the reliability of syphilis serology in patients with HIV-1 infection has been questioned. We examined specific antibody to Treponema pallidum (TP) using the TP haemagglutination (TPHA) and fluorescent treponemal antibody-absorption (FTA-ABS) tests in AIDS patients and HIV-antibody-negative controls with a history of syphilis. Tests were carried out on two sera separated by an interval of at least 3 years from each patient. Twelve out of 29 AIDS patients compared with four out of 29 controls showed significant falls in titres of specific antibody as measured by the TPHA, FTA-ABS, or by both the TPHA and FTA-ABS (P = 0.02). Furthermore, in three out of 29 (10%) of the AIDS patients with past syphilis infections both the TPHA and FTA-ABS became non-reactive. We conclude that negative specific serology does not exclude a past syphilis infection in patients with AIDS.
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