The influence of dietary selenium on common indicators of selenium status and liver glutathione peroxidase-1 messenger ribonucleic acid.

The objective of this research was to determine the influence of dietary Se on various indicators of Se status and relative liver glutathione peroxidase 1 (GPx-1) messenger RNA (mRNA) levels in growing Holstein bull calves. Calves (n = 14, 7/diet) were started 28 d after birth on a Se-adequate (SeA) or Se-deficient diet (SeD) and maintained on the diet until 180 d of age. Blood samples were taken from each calf for determination of erythrocyte GPx-1 and plasma GPx-3 activities and plasma Se concentration on d 28 of age, every 28 d thereafter, and at 180 d of age. To assess liver Se and GPx-1 mRNA, 3 calves were first killed at d 21 of age for baseline (BSL) measurements, and 4 calves from each treatment were killed at trial conclusion. Feed intake and ADG were not affected (P = 0.62) by dietary Se concentrations. However, liver Se concentration was greater (P < 0.05) for BSL calves and SeA calves than SeD calves, but no difference (P = 0.68) was observed between BSL calves and SeA calves. Plasma Se was greater for SeA calves (P < 0.01) than for SeD calves by d 56 of age. The GPx-1 activity was greater in SeA calves (P < 0.01) by d 84 of age, whereas GPx-3 activity was greater in SeA calves, but not until d 180 of age (P < 0.01). There was a 50% decrease in GPx-1 mRNA for the SeD calves (P < 0.05) compared with SeA calves. Thus, relative GPx-1 mRNA transcript level is reflective of Se status in the bovine. Furthermore, 152 d on a semi-purified, SeD diet is adequate to create a Se deficiency in growing Holstein bull calves started on a SeD diet at 28 d of age.

Age-specific cluster of cases of serotype 1 Streptococcus pneumoniae carriage in remote indigenous communities in Australia.

Seven-valent pneumococcal conjugate vaccination commenced in 2001 for Australian indigenous infants. Pneumococcal carriage surveillance detected substantial replacement with nonvaccine serotypes and a cluster of serotype 1 carriage. Our aim was to review Streptococcus pneumoniae serotype 1 carriage and invasive pneumococcal disease (IPD) data for this population and to analyze serotype 1 isolates. Carriage data were collected between 1992 and 2004 in the Darwin region, one of the five regions in the Northern Territory. Carriage data were also collected in 2003 and 2005 from four regions in the Northern Territory. Twenty-six cases of serotype 1 IPD were reported from 1994 to 2007 in the Northern Territory. Forty-four isolates were analyzed by BOX typing and 11 by multilocus sequence typing. In the Darwin region, 26 children were reported carrying serotype 1 (ST227) in 2002 but not during later surveillance. Scattered cases of serotype 1 carriage were noted in two other regions. Cocolonization of serotype 1 with other pneumococcal serotypes was common (34% serotype 1-positive swabs). In conclusion, pneumococcal carriage studies detected intermittent serotype 1 carriage and an ST227 cluster in children in indigenous communities in the Northern Territory of Australia. There was no apparent increase in serotype 1 IPD during this time. The rate of serotype 1 cocolonization with other pneumococcal serotypes suggests that carriage of this serotype may be underestimated.

A cluster of culture positive gonococcal infections but with false negative cppB gene based PCR.

OBJECTIVES: To describe the prevalence and characteristics of isolates of Neisseria gonorrhoeae grown from urine samples that produced negative results with nucleic acid amplification assays (NAA) targeting the cppB gene. METHODS: An initial cluster of culture positive, but cppB gene based NAA negative, gonococcal infections was recognised. Urine samples and suspensions of gonococci isolated over 9 months in the Northern Territory of Australia were examined using cppB gene based and other non-cppB gene based NAA. The gonococcal isolates were phenotyped by determining the auxotype/serovar (A/S) class and genotyped by pulsed field gel electrophoresis (PFGE). RESULTS: 14 (9.8%) of 143 gonococci isolated were of A/S class Pro(-/)Brpyut, indistinguishable on PFGE and negative in cppB gene based, but not other, NAA. CONCLUSIONS: This cluster represents a temporal and geographic expansion of a gonococcal subtype lacking the cppB gene with consequent loss of sensitivity of NAA dependent on amplification of this target. Gonococci lacking the cppB gene have in the past been more commonly associated with the PAU-/PCU- auxotype, a gonococcal subtype hitherto infrequently encountered in Australia. NAA based on the cppB gene as a target may produce false positive as well as false negative NAA. This suggests that unless there is continuing comparison with culture to show their utility, cppB gene based NAA should be regarded as suboptimal for use either as a diagnostic or supplemental assay for diagnosis of gonorrhoea, and NAA with alternative amplification targets should be substituted.

Surveillance of antibiotic resistance in invasive isolates of Neisseria meningitidis in Australia 1994-1999.

A total of 1434 strains of Neisseria meningitidis isolated from cases of invasive meningococcal disease (IMD) in Australia between 1994 and 1999 were examined by standard methods for susceptibility to antibiotics used for treatment and prophylaxis. The proportion of isolates fully susceptible to penicillin decreased from 45% in 1994 to 26% in 1999 (P<0.001). All the other isolates were less sensitive to penicillin except for two meningococci with a penicillin MIC of 1 mg/l. The geometric mean penicillin MIC increased from 0.045 to 0.065 mg/l from 1994 to 1999. There was no significant difference in the geometric mean penicillin MICs of serogroup B and serogroup C meningococci. Penicillin susceptibility was significantly associated with a poorer outcome. Isolates from survivors of IMD had a higher geometric mean penicillin MIC (0.06 mg/l) than those from fatal cases (0.048 mg/l) (P< 0.001). This suggests that factors other than the decrease in susceptibility to penicillin observed were more relevant to outcome in IMD. All isolates were fully susceptible to ceftriaxone. Rifampicin resistance was infrequent (eight isolates in 6 years) and sporadic. A single isolate had decreased quinolone susceptibility. Despite the significant shift in susceptibility to penicillin recorded, this group of antibiotics remains a suitable treatment for IMD in Australia.

Antibiotic susceptibility of Burkholderia pseudomallei from tropical northern Australia and implications for therapy of melioidosis.

From a prospective melioidosis study commencing in 1989 at Royal Darwin Hospital, 170 initial isolates of Burkholderia pseudomallei were available for susceptibility testing. Of these 163 (96%) were susceptible to meropenem/imipenem, ceftazidime, trimethoprim-sulphamethoxazole (SMX/TMP) and doxycycline. Seven (4%) showed primary resistance; three had low-level resistance to SMX/TMP, one to ceftriaxone and amoxycillin/clavulanate (AMOX/CA) and three to doxycycline. Of 167 patients who survived their initial presentation, seven (4%) had culture positive infections which persisted for greater than 3 months after start of therapy. All ultimately cleared carriage of B. pseudomallei though three required changing to SMX/TMP after development of doxycycline resistance. Nineteen (11%) of the initial survivors clinically relapsed and 17 of these had repeat isolates available for testing. Four of these had acquired resistance: one to doxycycline, one to AMOX/CA and ceftazidime, one to SMX/TMP and one to both SMX/TMP and doxycycline. Molecular typing using randomly amplified polymorphic DNA and pulsed-field gel electrophoresis showed all but one relapse isolate to be the same as the original strain. These data are similar to published data from Thailand. As melioidosis has a high mortality (21% in this series) these results emphasize the need for prolonged eradication therapy and regular clinical and microbiological monitoring so that the emergence of resistance can be detected early and appropriate treatment modifications made.

Cystic renal lymphangiectasia presenting as renal insufficiency in childhood.

Cystic renal lymphangiectasia is an unusual cause of cystic renal disease in childhood. We present a case of bilateral cystic renal lymphangiectasia in a 7-year-old boy who presented with asymptomatic renal insufficiency and anemia with decreased erythropoietin production. The clinical features of this condition and the diagnostic approach are reviewed. Although rare, this disorder should be considered in the differential diagnosis of cystic renal disease.

Endemic melioidosis in tropical northern Australia: a 10-year prospective study and review of the literature.

In a prospective study of melioidosis in northern Australia, 252 cases were found over 10 years. Of these, 46% were bacteremic, and 49 (19%) patients died. Despite administration of ceftazidime or carbapenems, mortality was 86% (43 of 50 patients) among those with septic shock. Pneumonia accounted for 127 presentations (50%) and genitourinary infections for 37 (15%), with 35 men (18%) having prostatic abscesses. Other presentations included skin abscesses (32 patients; 13%), osteomyelitis and/or septic arthritis (9; 4%), soft tissue abscesses (10; 4%), and encephalomyelitis (10; 4%). Risk factors included diabetes (37%), excessive alcohol intake (39%), chronic lung disease (27%), chronic renal disease (10%), and consumption of kava (8%). Only 1 death occurred among the 51 patients (20%) with no risk factors (relative risk, 0.08; 95% confidence interval, 0.01-0.58). Intensive therapy with ceftazidime or carbapenems, followed by at least 3 months of eradication therapy with trimethoprim-sulfamethoxazole, was associated with decreased mortality. Strategies are needed to decrease the high mortality with melioidosis septic shock. Preliminary data on granulocyte colony-stimulating factor therapy are very encouraging.

How effective are screening tests for microalbuminuria in random urine specimens?

The effectiveness of four urine screening tests-microalbumin (MAlb), total protein (TProt), total protein/creatinine ratio (TProt/Cr R), and dipstick (DPalb) test for albumin-were evaluated for the detection of MAlb in random urine specimens. The following criteria were used to assess the effectiveness of each urine screening test: 100% specificity (no false positive results); cost effectiveness; rapidity and ease of performing the screening test; and increased laboratory efficiency. A "gold standard" for presence of MAlb in random urine samples was defined as a microalbumin/creatinine ratio (MAlb/Cr R) of > or = 30 mg/g. The least costly urine screening test was the DPalb, which, if assigned a value of 1.0, allowed a cost ranking order for the screening tests-DPalb (1.0) < urine TProt (1.03) < urine TProt/Cr R (2.1) < urine MAlb (7.0). Two hundred urine samples from diabetic inpatients and outpatients were tested. Only two screening tests--MAlb and DPalb--achieved 100% specificity without increasing laboratory costs (small net savings), whereas the other two screening tests--TProt and TProt/Cr R-only achieved 100% specificity with increased laboratory costs. Theoretical prevalence rate analysis showed that urine MAlb screening would be effective at all prevalence rates for overt nephropathy. TProt and DPalb urine screening testing would be most effective in populations with prevalence rates of > or = 15% for overt nephropathy. The TProt/Cr R ratio would only be effective in populations with prevalence rates of > or = 30%. Of the four urine screening tests, only DPalb would significantly streamline the process of measuring urine MAlb. The dipstick test is inexpensive, easy and rapid to perform, does not delay measuring the ratio, since there is no wait for the screening test result, and can be used by referring laboratories to screen urine specimens before they are submitted to a central laboratory, thereby reducing laboratory workload.

Solitary renal myofibromatosis: an unusual cause of infantile hypertension.

INTRODUCTION: Renovascular disease accounts for the vast majority of cases of infantile hypertension with complications resulting from umbilical arterial catheterization predominating in the neonatal period and fibrodysplastic lesions of the renal artery predominating outside the neonatal period. We report a previously undescribed cause of renovascular hypertension: solitary renal myofibromatosis. CASE REPORT: A 9-month-old male infant was transported to the intensive care unit at Children's Hospital in Denver, Colorado, for evaluation and treatment of a dilated cardiomyopathy and severe systemic hypertension. The child was full-term with no perinatal problems. Specifically, the child never required umbilical arterial catheterization. He was well until 6 months of age when his parents noted poor weight gain. At 9 months of age, he was evaluated at the referral hospital for failure to thrive. On examination he was noted to have a blood pressure of 170/110 mm Hg, but no other abnormalities. A chest radiograph showed cardiomegaly. Laboratory studies demonstrated normal electrolytes, blood urea nitrogen, and creatinine. However, urinalysis demonstrated 4+ protein without red blood cells. An echocardiogram showed severe left ventricular dilatation with an ejection fraction of 16%. On admission the child was noted to be cachectic. His vital signs, including blood pressure, were normal for age. The physical examination was unremarkable. Serum electrolytes, blood urea nitrogen, and creatinine were normal. Echocardiographic studies suggested a dilated hypertrophic cardiomyopathy. He was started on digoxin and captopril. Subsequently, he demonstrated episodic hypertension ranging from 170/90 to 220/130 mm Hg. A repeat echocardiogram 24 hours after admission demonstrated a purely hypertrophic cardiomyopathy. Verapamil and nifedipine were added to the treatment regimen in an effort to better control the blood pressure without success. Urine and blood for catecholamines and plasma renin activity, respectively, were sent and treatment with phentolamine instituted because of a possible pheochromocytoma. A spiral abdominal computerized tomographic scan revealed a markedly abnormal right kidney with linear streaky areas of calcification around the hilum and also an area of nonenhancement in the posterior upper pole. The adrenals and the left kidney were normal. Doppler ultrasound revealed a decrease in right renal arterial flow. The urinary catecholamines were normal and surgery was scheduled after the blood pressure was brought under control by medical treatment. At surgery, tumorous tissue and thrombosis of the renal artery were found in the right upper pole. A right nephrectomy was performed. Pathologic examination of the kidney showed the presence of a diffuse spindle cell proliferation in the interstitium of the kidney. The angiogenic/angiocentric character of the proliferation was demonstrated in several large renal vessels. The lumen of most vessels was narrowed and some vessels were totally occluded with recanalization and dystrophic calcifications observed. Immunostaining of the tumor demonstrated strong desmin and vimentin positivity and minimal actin positivity in the spindle cells. Mitotic activity was not noted in the spindle cell process. These pathologic changes were consistent with a diagnosis of infantile myofibromatosis (IM). The child's preoperative plasma renin activity was 50 712 ng/dL/h (reference range, 235-3700 ng/dL/h). DISCUSSION: The causes of systemic hypertension in infancy are many although renal causes are by far the most common. Renal arterial stenosis or thrombosis accounts for 10% to 24% of cases of infantile hypertension. Renal artery thrombosis is usually a consequence of umbilical arterial catheterization, which can also lead to embolization of the renal artery. Renal artery stenosis may result from fibrodysplastic lesions (74%), abdominal aortitis (9%), a complication of renal transplantation (5%), and ren

CSF bacterial antigen detection tests offer no advantage over Gram's stain in the diagnosis of bacterial meningitis.

While bacterial antigen detection (BAD) tests have been used on cerebrospinal fluid (CSF) with success in the diagnosis of bacterial infection in developing countries, their value in the developed world has been recently questioned. In Darwin, Northern Territory (NT), there are good diagnostic resources but high rates of infectious disease, so it was unclear which findings were applicable to our own population. This study aimed to determine the utility of the BAD tests in detection of bacterial meningitis from CSF in patients studied at Darwin, using a retrospective review of hospital case records and microbiology laboratory reports, over a 19 month period, and utilising a clinical component in the case definition of bacterial meningitis. The sensitivity of the BAD test in the diagnosis of acute bacterial meningitis was 28.6%, with a specificity of 98.7% and a positive predictive value of 85.7%. The cost per positive test was computed at $240. No cases of bacterial meningitis which were positive on the BAD test were missed on Gram's stain of CSF. We conclude that in our setting BAD tests alone are not sensitive enough to confidently diagnose bacterial meningitis. BAD tests are more costly and offer no advantage in speed of diagnosis or in antibiotic pre-treated patients, compared to routine Gram's stain.

Failure of azithromycin therapy in gonorrhea and discorrelation with laboratory test parameters.

BACKGROUND: Azithromycin is efficacious in the treatment of chlamydial genital tract infection but less so in gonorrhea. However, MICs of azithromycin for gonococci from previously reported azithromycin treatment failures were consistently below the 'susceptible' MIC level of 2 mg/L. GOAL OF THIS STUDY: To examine gonococci not eliminated with 1 g azithromycin therapy to establish treatment outcome/MIC correlates in gonorrhea. STUDY DESIGN: The MICs and phenotypes of gonococci isolated from five cases of treatment failure after 1 g azithromycin therapy were determined and compared with the MICs of a systematic sample of routine isolates. RESULTS: Azithromycin MICs of gonococci from five cases of failed 1 g azithromycin treatment were 0.125 or 0.25 mg/L, well within the current 'susceptible' MIC range. None of the isolates were of the mtr phenotype. The MIC90 of a systematic sample of 219 gonococcal isolates was 0.25 mg/L. CONCLUSION: The antibiotic MIC/treatment outcome correlates that are usually found in gonorrhea do not apply for azithromycin. Current MIC criteria do not accurately define susceptibility or resistance of gonococci to azithromycin and by themselves do not predict the likely outcome of therapy. Pharmacokinetic factors may decrease the predictive value of MIC data.

Critical limits (alert values) for physician notification: universal or medical center specific limits?

The concept of critical limits (alert values), defined as an imminent life threatening laboratory result requiring immediate physician notification, has been widely adopted as a standard of good laboratory practice. Although virtually all laboratories have tests with critical limits, surveys have shown that there is no universal alert value list. Recently, nine VA medical centers in the New England region, which now constitute one consolidated entity, were surveyed with the objective of summarizing critical limits. Universal (100 percent) critical limit tests for clinical chemistry were: Calcium; mean low/high, 6.5/12.4 mg/dL: Glucose 48/432 mg/dL: Potassium 2.8/6.1 mmol/L: Sodium 121/159 mmol/L. Universal hematology tests included: Hematocrit 22.2/59.7 percent: Platelet count 61K/983K: white blood count 1.9K/29K. Although there was universal agreement that abnormal coagulation tests (PT, PTT) should be included on the hematology critical limit list, there was wide variation in the reporting of coagulation tests (seconds and INR) and patient therapeutic status (anticoagulant or no-anticoagulant). Universal alert values for microbiology were: Positive blood culture: Positive cerebral spinal fluid (CSF) culture: Positive CSF Gram stain. There was no universal agreement regarding critically high (potentially toxic) therapeutic drugs, with two medical centers declining to notify physicians of any abnormally high therapeutic drug level. No other qualitative critical limits for other laboratory sections, such as physician notification of an unexpected malignancy (surgical pathology) were universal. Medical center specific critical limits, designed to meet the clinical needs of each facility, are the norm in the nine medical centers. Laboratories do need periodically to review their critical limit lists with appropriate clinical input to avoid including critical limits for laboratory tests not required for urgent physician notification and patient evaluation and treatment.

Septic arthritis of the knee caused by Edwardsiella tarda after a catfish puncture wound.

Anglers are wary of catfish as their sharp fin spines may cause injury and, in some species, envenomation. We describe another complication of catfish spine injury--septic arthritis caused by Edwardsiella tarda. We believe this is the first report of this organism causing septic arthritis.

Culture of the causative organism of donovanosis (Calymmatobacterium granulomatis) in HEp-2 cells.

We report successful culture of Calymmatobacterium granulomatis by standard cell culture methods. Swabs were obtained from lesions in three patients with a clinical diagnosis of donovanosis. For two patients, there was histological confirmation of the disease (i.e., the presence of Donovan bodies in Giemsa-stained smears). Specimens were inoculated onto cycloheximide-treated HEp-2 cell monolayers in RPMI 1640 medium (supplemented with fetal calf serum, NaHCO3, vancomycin hydrochloride, and benzylpenicillin). At 48 h, organisms resembling Donovan bodies were identified in monolayer cultures from all three specimens. The organisms appeared as pleomorphic bacilli with characteristic bipolar staining and "safety pin" appearance. Using a PCR designed to differentiate C. granulomatis from the Klebsiella species (which have a high degree of molecular homology), we were able to demonstrate that the cultured organisms produced a PCR product identical to that obtained from the original swab specimens. It is now possible to test in vitro susceptibility of C. granulomatis to antibiotics and to provide a ready source of DNA and antigenic material to enable the development of serological tests and, possibly in the future, a vaccine.