The regulation of steroid receptors by epigallocatechin-3-gallate in breast cancer cells

It has been reported that phytoestrogen epigallocatechin gallate (EGCG) suppresses cancer cell proliferation and may have antitumor properties. In this study, we analyzed the effects of EGCG on estrogen receptor α (ERα) and progesterone receptor in hormone-dependent T-47D breast cancer cells. Western blot analysis revealed EGCG induced a concentration-dependent decrease in ERα protein levels, with a 56% reduction occurring with 60 µM EGCG when compared to controls. Downregulation of ERα protein levels was observed after 24-hour co-treatment of T-47D cells with 60 µM EGCG and 10 nM 17β-estradiol (E₂). The proliferative effect of E₂ on cell viability was reversed when treated in combination with EGCG. In contrast, the combination of EGCG with the pure ER antagonist, ICI 182, 780, showed no further reduction in cell number as only 5% of the cells were viable after 6 days of treatment. These studies may provide further understanding of the interactions among flavonoids and steroid receptors in breast cancer cells.

The effects of turmeric (curcumin) on tumor suppressor protein (p53) and estrogen receptor (ERα) in breast cancer cells

Curcumin (CUR) is a compound that has antibacterial, antiviral, anti-inflammatory, and anticancer properties. In this study, we have analyzed the effects of CUR on the expression of ERα and p53 in the presence of hormones and anti-hormones in breast cancer cells. Cells were cultured in a medium containing charcoal-stripped fetal bovine serum to deplete any endogenous steroids and treated with CUR at varying concentrations or in combination with hormones and anti-hormones. Protein analysis revealed a relative decrease in the levels of p53 and ERα upon treatment with 5–60 µM CUR. In cell proliferation studies, CUR alone caused a 10-fold decrease compared with the treatment with estrogen, which suggests its antiproliferative effects. Delineating the role of CUR in the regulation of p53, ERα, and their mechanisms of action may be important in understanding the influence of CUR on tumor suppressors and hormone receptors in breast cancer.

Potential donor families' experiences of organ and tissue donation-related communication, processes and outcome

We aimed to describe the experiences of families of potential organ and tissue donors eligible for donation after circulatory death or brain death. Forty-nine family members of potential donors from four Melbourne hospitals were interviewed to assess their experiences of communication, processes and the outcomes of donation. Interviews were recorded, transcribed verbatim and analysed thematically. Families expressed a range of perspectives on themes of communication, hospital processes and care, the processes of consent and donation and reflected on decisions and outcomes. They expressed satisfaction overall with communication when receiving bad news, discussing death and donation. Honest and frank communication and being kept up-to-date and prepared for potential outcomes were important aspects for families, especially those of post circulatory death donors. Participants reported high levels of trust in healthcare professionals and satisfaction with the level of care received. Many donor families indicated the process was lengthy and stressful, but not significantly enough to adversely affect their satisfaction with the outcome. Both the decision itself and knowing others' lives had been saved provided them with consolation. No consenting families, and only some non-consenting families, regretted their decisions. Many expressed they would benefit from a follow-up opportunity to ask questions and clarify possible misunderstandings. Overall, while experiences varied, Australian families valued frank communication, trusted health professionals, were satisfied with the care their family member received and with donation processes, despite some apparent difficulties. Family satisfaction, infrequently assessed, is an important outcome and these findings may assist education for Australian organ donation professionals.

Effect of arsenite on induction of CYP1A and CYP2H in primary cultures of chick hepatocytes

In earlier studies, treatment with sodium arsenite was shown to decrease total hepatic CYP in rats. A concomitant increase in heme oxygenase, the rate-limiting step in heme degradation to biliverdin, was considered responsible for the decrease in CYP. Here we investigated the effect of sodium arsenite on induction of CYP2H, CYP1A, and heme oxygenase in primary cultures of chicken embryo hepatocytes. When added simultaneously with inducer, arsenite inhibited phenobarbital-mediated increases in CYP2H and 3-methylcholanthrene-mediated increases in CYP1A, as measured enzymatically and immunochemically. Near maximal decreases were observed in these forms of CYP at a concentration of 2.5 microM sodium arsenite. The concentration-dependent decreases in CYP2H and CYP1A by sodium arsenite were concomitant with increases in heme oxygenase. Sodium arsenite was not toxic at concentrations as high as 10 microM, as indicated by protein synthesis and the reduction of MTT by intact cells. Sodium arsenite had no effect on induction of CYP2H1 mRNA, suggesting that the decreases in this form of CYP occurred post-transcriptionally. Treatment of cells with tin mesoporphyrin (SnMeso), an inhibitor of heme oxygenase, resulted in inhibition of arsenite-induced heme oxygenase. However, SnMeso did not alter the effect of arsenite to prevent phenobarbital-mediated increases in CYP2H protein. SnMeso alone inhibited phenobarbital-mediated increases in CYP2H. Inclusion of 2 or 5 microM exogenous heme with arsenite did not prevent the arsenite-mediated decrease in CYP2H. Combined treatment with heme and phenobarbital induced heme oxygenase to the same extent as treatment with heme, arsenite, and phenobarbital. However, CYP2H activity was decreased only when the treatment included arsenite. These results suggest that elevated levels of heme oxygenase alone are not responsible for arsenite-mediated decreases in CYP2H.

Clinical experience and outcomes of community-acquired and nosocomial methicillin-resistant Staphylococcus aureus in a northern Australian hospital

Methicillin-resistant Staphylococcus aureus (MRSA) is a well-recognized cause of hospital-acquired sepsis. We reviewed the clinical features of a new variant of community-acquired MRSA originally described from the Kimberley region of northern Western Australia (WA MRSA). This strain has become an increasing cause of community- and hospital-acquired sepsis at Royal Darwin Hospital (RDH) in the Northern Territory, especially in Aboriginal Australians from remote communities. Fifty percent of WA MRSA was community-acquired, with 76% in Aboriginals. Like the MRSA from eastern Australia (EA MRSA), WA MRSA commonly caused skin sepsis but was less likely to cause respiratory or urinary infections compared with EA MRSA. Twelve out of 125 (9.6%) WA MRSA and 7/93 (7.5%) EA MRSA infections were septicaemias. Septicaemia due to WA MRSA occurred in adult medical patients, especially those with temporary haemodialysis catheters, while EA MRSA septicaemia occurred throughout the hospital. Aboriginal people were more likely to develop both community- and hospital-acquired WA MRSA septicaemia [overall relative risk (RR) 12.3 (95% CI 3.7-40.7)]. Control of WA MRSA requires policies to reduce transmission in both hospitals and communities. Community-based control programmes need support for individual patient management, improved housing and hygiene, control of skin sepsis and appropriate use of antibiotics, especially in rural Aboriginal communities in northern Australia.

Emerging epidemic of community-acquired methicillin-resistant Staphylococcus aureus infection in the Northern Territory

OBJECTIVE

To investigate the epidemiology of WA MRSA (the recently recognised Western Australian strains of methicillin-resistant Staphylococcus aureus) in the north of the Northern Territory (NT).

DESIGN

Retrospective survey of data from hospital records.

SETTING

Royal Darwin Hospital (a tertiary referral hospital that serves the north of the NT) between January 1991 and July 1995.

SUBJECTS

All inpatients with clinical MRSA infection.

OUTCOME MEASURES

Incidence of MRSA infection, classification of MRSA as WA or EA (Eastern Australian) based on antibiotic susceptibility, patient demographic details (age, sex, ethnicity, region of residence), source of infection (nosocomial or community-acquired).

RESULTS

There were 125 WA MRSA and 93 EA MRSA infections, comprising 7% of all S. aureus infections. The incidence of WA MRSA infections consistently increased, while that of EA MRSA initially fell and then increased. All EA MRSA infections were nosocomial, while 50% of WA MRSA infections were community-acquired. Rates of WA MRSA infections were highest in patients from the west region of the NT, adjacent to the Kimberley region of Western Australia (WA). Community-acquired WA MRSA infections were more likely to affect Aboriginals than non-Aboriginals (relative risk [RR], 25.86; 95% confidence interval [CI], 12.51-53.47, based on population data; RR, 15.43; 95% CI, 7.85-30.32, based on admission data), as were nosocomial EA MRSA infections (RR, 2.54; 95% CI, 1.44-4.47, based on population data; RR, 2.30; 95% CI, 1.52-3.46, based on admission data).

CONCLUSIONS

Changes in the epidemiology of MRSA infection in the north of the NT are consistent with the hypothesis that community-acquired WA MRSA spread into and across the NT from the Kimberley region of WA. Alternatively, crowded living conditions, hygiene difficulties and increasing use of broad spectrum antibiotics may have led to independent emergence of WA MRSA in both regions. Current infection control policies and their use in rural Aboriginal communities must be reassessed.

Genetic variation in Australian spotted fever group rickettsiae

Rickettsiae were isolated by cell culture of buffy coat blood from six patients with spotted fever from southeastern Australia and Flinders Island in Bass Strait. The isolates were genetically compared with two previous Rickettsia australis patient isolates. The genus-specific 17-kDA genes from the isolates were compared after DNA amplification and restriction fragment analysis of the amplified DNA. This comparison revealed that mainland rickettsial isolates from southeastern Australia were identical to two previous isolates of R. australis from northeastern Australia. Rickettsial isolates from Flinders Island were distinct from the mainland isolates. The 16S rRNA gene sequences from the isolates were determined and compared. The Flinders Island rickettsial agent was most closely related (0.3% structural divergence) to Rickettsia rickettsii, Rickettsia conorii, and Rickettsia slovaca. The Flinders Island rickettsial agent was 1.3 and 2.1% structurally divergent from R. australis and Rickettsia akari, respectively. The 16S rRNA gene sequence from the Flinders Island agent shows that this rickettsia is more closely related to the rickettsial spotted fever group than is R. australis. We conclude that there are two populations of spotted fever group rickettsiae in Australia and propose that the genetically distinct causative organism of Flinders Island spotted fever be designated Rickettsia honei. The extent of distribution and animal host reservoirs remain to be elucidated.

Chromoblastomycosis: a retrospective study of six cases at the Royal Darwin Hospital from 1989 to 1994

Chromoblastomycosis, a localized chronic cutaneous and subcutaneous infection of the skin caused by pigmented fungi, is most common in the world's tropical and subtropical zones. The condition rarely occurs in Australia. We present 6 cases of chromoblastomycosis seen at the Royal Darwin Hospital, Northern Territory, from 1989 to 1994 and affecting predominantly male Caucasians ranging from 38 to 71 yrs of age. Clinically the lesions were verrucous or nodular. They mimicked basal or squamous cell carcinoma, nevi or solar keratoses. Histopathologic findings were nonspecific. The only pathognomonic finding was the presence of brown spores or sclerotic bodies within granulomata or within microabscesses in the skin.

Cytotoxin production by Helicobacter pylori from patients with upper gastrointestinal tract diseases

A cytotoxin produced by some Helicobacter pylori strains has recently been identified. The cytotoxin induces intracellular vacuolization of cultured cells. The aim of the present study was to examine the frequency of occurrence of cytotoxin-producing strains of H. pylori from subjects with upper gastrointestinal disease including nonulcer dyspepsia, gastric and duodenal ulcer disease, gastroesophageal reflux disease, and gastric cancer. Broth culture filtrates of clinical isolates of H. pylori recovered from 175 patients were used to inoculate Vero and HeLa cell monolayers for the detection of vacuolating cytotoxin activity. The results obtained demonstrated that the highest percentage of strains producing cytotoxin were found in subjects with peptic ulcer disease (gastric ulcer, 65%; duodenal ulcer, 66%; P < 0.01 compared with nonulcer dyspepsia, 38%). Of the 11 patients with gastroesophageal reflux disease, 4 of 5 patients in this group who had esophageal ulcers, were found to be infected with strains that produced cytotoxin. Three of the four patients with carcinoma of the stomach were also found to be infected with cytotoxic strains of H. pylori. With increasing severity of mucosal damage in subjects with a normal upper gastrointestinal tract, macroscopic gastritis, duodenitis, and peptic ulceration, there were corresponding increase in the proportion of strains producing cytotoxin; these increases were 32, 46, 50, and 66%, respectively. H. pylori strains from subjects with ulcer disease commonly produced vacuolating cytotoxin, suggesting that it may be a virulence factor in the pathogenesis of peptic ulcer disease.

A pseudoepidemic of Mycobacterium chelonae: contamination of a bronchoscope and autocleaner

BACKGROUND

At fibreoptic bronchoscopy the potential exists for contamination of bronchoscopes and microbiological specimens. Patients may also be cross infected with acid fast bacilli (AFB). During a five month period, 12 bronchial wash specimens of 65 patients undergoing bronchoscopy, one bronchoscope and an autocleaner, were contaminated with the AFB, Mycobacterium chelonae (MCH).

AIM

To eradicate AFB contamination of bronchoscopy specimens by identifying sources of contamination and modifying disinfection procedures.

METHODS

To identify the source of contamination, samples for AFB culture were taken from three bronchoscopes, the autocleaner and water taps. To eradicate MCH contamination, the bronchoscopes were soaked in 2% glutaraldehyde overnight and flushed with 70% alcohol. Disinfection procedures were altered by using sterile water and containers in cleaning. Autocleaner use was discontinued.

RESULTS

The autocleaner, one bronchoscope and 12 bronchial wash specimens were contaminated with MCH. All contaminants had similar electrophoretic banding on probing of their DNA fragments, suggesting a common clone of origin. After the alterations in disinfection procedures and despite prolonged soaking in 2% glutaraldehyde, three further contaminated wash specimens were isolated from one bronchoscope. Only after ethylene oxide sterilisation of this bronchoscope was the contamination overcome. Since then no further MCH contamination has occurred. No patient required treatment and there has been no clinical evidence of mycobacterial disease.

CONCLUSION

To avoid contamination of bronchoscopy specimens with MCH, use of autoclearners should be discouraged and sterile water and containers used in cleaning procedures. If MCH contamination occurs in this setting, the bronchoscope and dismantled valve mechanism should undergo ethylene oxide sterilisation.

Comparison of Pneumocystis carinii detection by toluidine blue O staining, direct immunofluorescence and DNA amplification in sputum specimens from HIV positive patients

Pneumocystis carinii pneumonia (PCP) is the commonest opportunistic infection in AIDS patients. By using the polymerase chain reaction (PCR), specific DNA sequences can be amplified and used in diagnosis of infections such as PCP where the causative pathogen is both difficult to grow and present in low numbers. Twenty HIV positive patients were investigated for PCP. Twenty sputa (15 induced and 5 expectorated) had toluidine blue O staining, direct immunofluorescence and PCR performed for Pneumocystis carinii in a blinded fashion. PCR was performed using primers pAZ102-E 5' GATGGCTGTTTCCAAGCCCA 3' and pAZ102-H 5' GTGTACGTTGCAAAGTACTC 3' from the gene coding for Pneumocystis carinii mitochondrial ribosomal RNA with a specific 346 base-pair sequence being amplified from positive specimens. Ten of the patients had Pneumocystis carinii shown by conventional tests and PCR. Another 3 patients were positive only by PCR, all had evidence of infection with Pneumocystis carinii; the first was positive by subsequent conventional stains, the second was treated for bacterial bronchitis but had a non-resolving chest infection with PCP found on postmortem after 4 mths, the third had a typical interstitial infiltrate on CXR and responded to empiric PCP treatment. PCR is more sensitive than toluidine blue O staining and direct immunofluorescence in detecting Pneumocystis carinii in sputum from HIV patients and may become the diagnostic method of choice for PCP.

A new trichrome-blue stain for detection of microsporidial species in urine, stool, and nasopharyngeal specimens

Detection of microsporidia in clinical specimens has relied on electron microscopy, histology, or staining. This article describes further alterations to the modified trichrome staining method which make it easier to identify microsporidial spores. The changes are a decrease in the phosphotungstic acid level and the substitution of a colorfast counterstain, aniline blue, for the fast green of the original stain. The modified stain provides good contrast between microsporidial spores and background material including human and fungal cells. Stool specimens from 139 human immunodeficiency virus-seropositive patients revealed that 5 patients were infected with Enterocytozoon bieneusi and 6 patients had larger spores. Thin-section electron microscopy of the larger spores showed a structure consistent with that of either Encephalitozoon or Septata species. Three of the patients with Encephalitozoon- or Septata-like species had disseminated infection, with spores detected in nasopharyngeal aspirates and urine samples.

The epidemiology of tuberculosis in Victoria

AIMS

To describe the epidemiology of Mycobacterium tuberculosis (MTb) in Victoria, Australia.

METHODS

We analysed data from the Victorian Mycobacterium Reference Laboratory database and MTb notifications to Health and Community Services Victoria, for the period 1948 to 1992.

RESULTS

The annual number of notified tuberculosis cases peaked at 1143 in 1954 and declined to 266 in 1992. The incidence rate decreased from 47 to 6.2 per 100,000 in the same period. The pattern of tuberculosis has changed significantly over the last two decades, reflecting the high prevalence of MTb in recent immigrants, particularly in those from South-East Asia. Among people born overseas the number of cases increased from 40% of notifications in 1970 to 80% in 1990; they are younger, more likely to be female and to have extrapulmonary disease, than their Australian-born counterparts. Between 1987 and 1991, the mean annual incidence of tuberculosis in people born in Australia and South-East Asia respectively was 1.5 and 47.5 per 100,000. People born in Vietnam, Cambodia and the Philippines had rates between 100 and 400 per 100,000. These rates have remained stable during the last six years. Almost 50% of migrant patients presented within five years, and 30% within two years, of arrival in Australia. The estimated mean annual incidence of MTb in homeless men between 1984 and June 1992 was 80 per 100,000. Resistance to all first-line drugs increased from 10.8% of all isolates in 1981 to 14.7% in 1990. The incidence of multi-drug resistant MTb (MDR-MTb) has been consistently less than 2% of isolates per year in the past 15 years. There were 14 cases of MTb and HIV between 1985 and June 1992. The mean annual incidence of MTb in people with AIDS is 1579 per 100,000 (range, 570-2420 per 100,000), with a relative risk of 236 (95% confidence interval [CI], 134-414). MDR-MTb has not been documented in HIV-infected individuals in Victoria.

CONCLUSION

Tuberculosis remains an important public health concern. Groups at high risk include people born overseas, the homeless, and people infected with HIV. Physicians caring for AIDS patients should consider the diagnosis of MTb, since its incidence in AIDS patients is so high. Our data suggest possible shortcomings in current methods of screening and prophylactic treatment of migrants and refugees. The rising rate of drug resistance cannot be ignored. We should consider strategies to ensure judicious use of anti-tuberculous drugs by physicians, and optimal patient compliance. These issues are critical to the future of tuberculosis control in Victoria.

Isolation of a DNA probe for identification of Mycobacterium kansasii, including the genetic subgroup

In order to develop a DNA-based assay to identify all Mycobacterium kansasii clinical isolates, a specific DNA probe was isolated in plasmid p6123. A total of 145 M. kansasii clinical isolates were collected from several countries and were examined with three probes by DNA hybridization. Of the 145 isolates, 115 (79%) were positive with the previously described probe pMK1-9 (Z. H. Huang, B. C. Ross, and B. Dwyer, J. Clin. Microbiol. 29:2125-2129, 1991), 129 (88%) were positive with the commercial Accu-probe assay (Gen-Probe), and 145 (100%) were positive with the p6123 probe. Southern blot analysis of EcoRI-digested M. kansasii chromosomal DNA with p6123 revealed that all Accu-probe-positive M. kansasii strains exhibited a 3-kb fragment, whereas all Accu-probe-negative M. kansasii strains displayed DNA fragments of variable molecular sizes. These results indicate that, unlike the previously described probes for M. kansasii, the fragment cloned into p6123 identified all 145 biochemically typical strains tested and provides an ideal target for future DNA-based speciation assays.

A new focus of scrub typhus in tropical Australia

A new focus of scrub typhus (Rickettsia tsutsugamushi) is described in a remote rain forest region of the Northern Territory of Australia. Five serologically confirmed cases, two near fatal with multisystem involvement, have occurred since the area became accessible to tourists. As tourism increases, other remote foci of vectors and organisms may also be recognized in tropical Australia.

Identification of an insertion sequence-like element in a subspecies of Mycobacterium kansasii

Analysis of a genomic DNA clone library of a strain from the genetic subspecies of Mycobacterium kansasii determined the existence of a repetitive insertion sequence-like element. The element is 947 bp long and is present in a minimum of 1 to 11 copies per genome. Similar to insertion sequences, it contains a 3-bp (TAG) direct repeat at its extremities and a transcription promoter-like sequence. In addition, for one of the clones sequenced, a potential cointegrate formation, a characteristic frequently observed with insertion sequences, was revealed. This insertion sequence does not contain short inverted repeats near the ends or a large open reading frame to code for a transposase enzyme. Its host range is restricted to a previously described genetic subspecies of M. kansasii and is not present in typical M. kansasii or other mycobacterial species. When used as a probe for Southern blot hybridization, significant heterogeneity between different isolates of the M. kansasii subspecies was observed. This repeated element will be useful in further studies on the characterization, diagnosis, and epidemiology of M. kansasii.

Spotted fever group rickettsial infection in south-eastern Australia: isolation of rickettsiae

Flinders Island spotted fever (FISF), a spotted fever group (SFG) rickettsial disease first described in 1991, occurs in south-eastern Australia. The isolation of the aetiological agent is described for the first time having been obtained from the blood of two patients. An additional 22 cases are also reported. Of these patients four had positive initial serology, and 20 showed seroconversion (using Rickettsia australis as antigen). Acute phase blood specimens taken from seven patients caused neonatal mice to seroconvert to R. australis and a blood specimen from one of these patients (and one other) yielded rickettsiae. A field survey for possible reservoir and vector animals on Flinders Island, Tasmania and in Gippsland, Victoria (both in south-eastern Australia) yielded 217 vertebrates and 1445 invertebrate ectoparasites, mostly ticks. Ixodes cornuatus from humans and dogs in Gippsland produced seroconversion to SFG rickettsia when inoculated into mice but no invertebrate pools from Flinders Island produced seroconversion in mice. Haemolymph from an individual I. cornuatus removed from a human in Gippsland, yielded a SFG rickettsia on tissue culture. Sera from several species of native vertebrates, especially the bush rat, Rattus fuscipes, were positive for antibodies to SFG rickettsia.

Comparative evaluation of detection assays for Chlamydia trachomatis

The performances of a commercial nucleic acid hybridization test (Gen-Probe Pace 2 Chlamydia trachomatis) and two commercial enzyme immunoassays (EIAs) (Abbott Chlamydiazyme and Pharmacia Chlamydia EIA) were evaluated against cell culture for the detection of C. trachomatis infection, with cervical swabs obtained from 1,037 women visiting a public sexual health center. The positivity rate by cell culture was 4.7%. Sensitivity and specificity for each test were as follows: Gen-Probe, 95.8 and 98.3%; Chlamydiazyme, 80.4 and 99.3%; Pharmacia EIA, 80.8 and 99.1%. Analysis of discrepant results with probe confirmation assay (Gen-Probe) and direct immunofluorescence (Syva Microtrak) revealed 12 cases of C. trachomatis infection for which culture was negative, resulting in the definition of a true-positive case as opposed to a culture positive. The positivity rate by true-positive definition was 5.9%, and sensitivity and specificity for each test were as follows: Gen-Probe, 96.7 and 99.6%; Chlamydiazyme, 77.5 and 100%; Pharmacia EIA, 77.0 and 100%; cell culture, 80.0 and 100%. We conclude that the Gen-Probe Pace 2 C. trachomatis test is a sensitive and specific alternative to cell culture for the detection of C. trachomatis.

Characterization of Mycobacterium tuberculosis strains from Vietnamese patients by Southern blot hybridization

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.

Mycobacteria in stool specimens: the nonvalue of smears for predicting culture results

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.

Emergence during unsuccessful chemotherapy of multiple drug resistance in a strain of Mycobacterium tuberculosis

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.

Rapid, simple method for typing isolates of Mycobacterium tuberculosis by using the polymerase chain reaction

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.

DNA restriction fragment analysis to define an extended cluster of tuberculosis in homeless men and their associates

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.

Use of ribosomal RNA gene restriction patterns to investigate two outbreaks of Campylobacter enteritis in Melbourne, Australia

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.

Characterization and comparison of Australian human spotted fever group rickettsiae

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.

Identification of a genetically distinct subspecies of Mycobacterium kansasii

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.

Isolation of a fastidious Mycobacterium species from two AIDS patients

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.

Quantification of Rickettsia australis

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.

Ribotyping of Helicobacter pylori from clinical specimens

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.

A case of murine typhus in Queensland

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.

Molecular cloning of a highly repeated DNA element from Mycobacterium tuberculosis and its use as an epidemiological tool

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.

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.

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.

Hypothyroidism due to destruction of the thyroid by Kaposi's sarcoma

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.

Spotted fever group rickettsial infections in Australia

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.

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)

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.

Specific syphilis serological tests may become negative in HIV infection

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.

Differentiation of Mycobacterium tuberculosis strains by use of a nonradioactive Southern blot hybridization method

The only means of dividing strains of Mycobacterium tuberculosis is by phage typing. Attempts at developing a convenient method based on differences in chromosomal DNA by detecting restriction fragment length polymorphisms (RFLP) have had limited success. This report describes the development of a nonradioactive RFLP technique that differs from most methods by using enzymes that have four base recognition sites rather than six. The restriction enzymes AluI, DdeI, HinfI, NdeII, RsaI, and TaqI were used to digest genomic DNA, and high-molecular-weight fragments were visualized after Southern blotting with digoxigenin-labeled M. tuberculosis DNA. Digestion with AluI resulted in different banding patterns among all eight clinical isolates of M. tuberculosis and three type strains from the tuberculosis complex. NdeII distinguished all but two strains, while HinfI and RsaI were unable to distinguish two pairs of strains. Digestion with the enzymes DdeI and TaqI failed to result in clearly discernible bands. These preliminary results suggest that this method provides a fine differentiation of M. tuberculosis strains and may be useful as an epidemiologic tool.

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).

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.