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R Benn

Publications and source records attributed to R Benn.

At least 19 recordsLinked to original sources
PubMed2004

The impact of pan-resistant bacterial pathogens on survival after lung transplantation in cystic fibrosis: results from a single large referral centre.

Reported actuarial one-year survival for patients with cystic fibrosis (CF) after lung transplant is 55-91%. Infection is the most common cause of early death. Colonization with Burkholderia cepacia complex is associated with reduced survival and international lung transplant referral guidelines support individual unit assessment policies for patients colonized with other pan-resistant bacteria. We examined local data on survival after transplant for CF to determine the impact of colonization with pan-resistant bacteria. A retrospective review of all CF patients from Royal Prince Alfred Hospital (RPAH), Sydney, who underwent lung transplantation at St Vincent's Hospital, Sydney, 1989-2002, was performed. Sixty-five patients were listed for lung transplantation with 54 (male: female=29:25) receiving transplants. Of the 11 patients (17%) who died on the waiting list, six were colonized with pan-resistant Pseudomonas aeruginosa. Thirty of the 54 transplanted patients had at least one pan-resistant organism before transplant. In 28 this included P. aeruginosa. Overall one-year survival was 92% with a median survival of 67 months. Overall survival for the pan-resistant group (N = 30) was not significantly different to survival in those with sensitive organisms (N = 24) (Logrank chi square = 1.6, P = 0.2). Three patients colonized with B. cepacia complex pre-transplant survive at 11, 40 and 60 months post-transplant. Infection contributed to 11 of the 18 post-transplant deaths, with pre-transplant-acquired bacterial pathogens responsible in two cases. Patients continued to acquire multiresistant bacteria post-transplantation. Lung transplant survival at St Vincent's Hospital for CF adults from RPAH compares favourably with international benchmarks. Importantly, colonization with pan-resistant bacteria pre-transplant did not appear to adversely affect survival post-transplant.

Adult↗
PubMed1998

Evolution of an endemic methicillin-resistant Staphylococcus aureus population in an Australian hospital from 1967 to 1996.

The evolution over 30 years of a population of methicillin-resistant Staphylococcus aureus (MRSA) from a tertiary referral hospital was studied by phylogenetic analysis of SmaI-generated restriction fragment length polymorphisms (RFLPs). The results suggest that a new clone of MRSA appeared at the hospital in the early 1980s, which, although usually retaining its ancestral phage-type, developed four different RFLP pulsotypes in the next 16 years. This finding indicates that multiple RFLP patterns in MRSA do not necessarily represent multiple clones deriving from different mec gene transfer events. Such variation within a clone may be significant in the interpretation of RFLP patterns during outbreaks and emphasizes the need to use two typing methods in studies of such populations. Since the appearance of new clones of MRSA is a relatively rare event, cross-infection control is paramount in the prevention of MRSA dissemination.

Anti-Bacterial Agents↗
PubMed1997

Methicillin-resistant Staphylococcus aureus in a cystic fibrosis unit.

Methicillin-resistant Staphylococcus aureus (MRSA) infection in a cystic fibrosis (CF) unit was investigated. Two typing methods, phage-typing and restriction fragment length polymorphism (RFLP) by pulsed-field gel electrophoresis (PFGE) and phylogenetic analysis, showed that nonsocomial transmission of MRSA from the general hospital population had occurred. One instance of possible transmission between two patients was identified. However, transmission between two family members did not occur indicating a minimal risk of MRSA acquisition from social contact compared with hospital admission. This study supports policies for limiting CF-patient admission to hospital but transmission of MRSA does not appear to be a reason for limiting social contact with other CF patients.

Bacteriophage Typing↗
PubMed1994

Trends in bacterial infections in febrile neutropenic patients: 1986-1992.

BACKGROUND: Bacterial infection is a major cause of morbidity and mortality in neutropenic patients. AIMS: (1) To review patterns and trends in bacterial infections in three cohorts of febrile neutropenic patients managed by a single unit over a seven year period. (2) To relate any changes to the use of central venous (Hickman's) catheters and high-dose cytosine arabinoside chemotherapy. METHODS: Retrospective review of the results of initial bacteriological work-up performed on 344 episodes of febrile neutropenia. The three cohorts were 1986-87 (n = 102), 1989-90 (n = 92) and 1991-92 (n = 150). RESULTS: (1) The ratio of gram-negative to gram-positive bacteraemias fell from 1.36 in the first cohort to 1.05 in the second and 0.40 in the third (p = 0.03). There was a fall in both percentage and number of gram-negative isolates coupled with a rise in the frequency of gram-positive isolates. (2) Coincidentally there was a rise in the frequency of positive cultures from Hickman catheter entry wounds and an increasing frequency of simultaneous isolation of the same organism from the catheter entry site and the blood. The types of organisms isolated from catheter entry wounds showed a trend towards fewer gram-negative and more gram-positive. (3) A relationship was observed between the use of high-dose cytosine arabinoside chemotherapy and the incidence of bacteraemia (p = 0.025) but not with the change in types of organisms. CONCLUSIONS: Over seven years we have documented a major change in the types of infections, particularly bacteraemias, seen in febrile neutropenic patients. In our institution the more widespread use of intravenous catheters and high-dose cytosine arabinoside chemotherapy have been identified as two possible contributing factors.

Bacteremia↗
PubMed1991

Serological typing of coagulase-negative staphylococci using monoclonal antibodies.

This investigation was to determine whether monoclonal antibodies (Mabs) could be used to differentiate coagulase-negative staphylococci (C-NS) at species and strain level. Mabs were produced to four Staphylococcus epidermidis strains, two S. haemolyticus strains, one S. saprophyticus strain and one S. warneri strain. A panel of nine antibodies was tested for species and strain specificity against five type strains and 65 clinical isolates of C-NS by enzyme-linked immunosorbent assay (ELISA). Species specificity was found with Mab D150 produced to one S. haemolyticus strain. Using Mab D150 and Mab D198 in conjunction, identification of 90% of S. haemolyticus isolates to species level was achieved. S. saprophyticus Mab K84 reacted with most other strains of C-NS tested but only three S. haemolyticus strains (16%). This finding provides further evidence that S. haemolyticus possesses different surface determinants to other C-NS which could form the basis of a typing scheme for S. haemolyticus using Mabs D150, D198 and K84.

Antibodies, Monoclonal↗
PubMed1991

The role of viruses and atypical organisms in the pathogenesis of adult pneumonia in Papua New Guinea.

The role of viruses and atypical organisms in pneumonia is well known in western populations, yet very little documentation is available about their role in pneumonia in developing countries. In a study of 175 adults with community-acquired pneumonia in Papua New Guinea, serological methods were used to assess this issue. Five patients had high influenza A titres suggestive of recent infection. Adenovirus titres rose significantly in one patient with Haemophilus influenzae pneumonia, whilst no evidence of past or recent infection was found in the remainder of patients when tested for all pathogens. Bacterial cultures revealed the continued predominance of Streptococcus pneumoniae in the pathogenesis of pneumonia in this population. We conclude that viruses and atypical organisms (including Mycoplasma and Legionella) play a very limited role in this setting.

Adenovirus Infections, Human↗
PubMed1989

A national survey of antimicrobial resistance in Staphylococcus aureus in Australian teaching hospitals.

An extensive survey of the in-vitro susceptibility of clinical isolates of Staphylococcus aureus to 18 antimicrobial agents was conducted over three separate periods during 1986-1987 in 14 teaching hospitals in major Australian cities. The survey aimed to document the prevalence of resistance to a wide variety of drugs that are important as antistaphylococcal agents or as epidemiological markers. More than 7500 isolates were examined. Nationally, the prevalence of resistance was 85.3% to penicillin G, 14.4% to methicillin, 14.0% to amoxycillin/clavulanate, 9% to cephalothin, 5.4% to cephamandole, 9.9% to cefotaxime, 25.0% to erythromycin, 11.2% to clindamycin, 21.7% to tetracycline, 13.0% to gentamicin, 1.9% to amikacin, 5.8% to chloramphenicol, 18.3% to trimethoprim, 0.6% to rifampicin, 3.0% to fusidic acid and 1.2% to novobiocin. For none of the strains was resistance to vancomycin confirmed by minimal-inhibitory-concentration determination. A high proportion of the resistances was harboured in methicillin-resistant Staph. aureus, except for resistance to penicillin G, erythromycin and tetracycline. The prevalence of methicillin resistance varied widely among the states: 25.2% in Queensland, 23.5% in Victoria, 12.6% in New South Wales/the Australian Capital Territory, 11.3% in South Australia and 0.4% in Western Australia. Isolates from blood cultures were slightly-more susceptible to antimicrobial agents than were isolates from other body sites. Six common profiles of resistance to penicillin G, methicillin, erythromycin, clindamycin and tetracycline accounted for more than 95% of the isolates that were tested against all five agents. Vancomycin remains the most important antistaphylococcal drug in areas where resistance to methicillin is common.

Anti-Bacterial Agents↗
PubMed1989

Prevalence of peritonitis-associated coagulase-negative staphylococci on the skin of continuous ambulatory peritoneal dialysis patients.

The predominance of coagulase-negative staphylococci as normal skin flora is thought to be a factor in their association with episodes of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis. We investigated the prevalence of peritonitis-associated strains on the skin of 28 patients undergoing peritoneal dialysis. Coagulase-negative staphylococci were the most frequently isolated organisms, comprising 47% of peritoneal dialysis fluid isolates and 59% of body site isolates. A total of 142 coagulase-negative staphylococci were speciated, tested for their antimicrobial sensitivity and slime production, and identified by phage typing and plasmid-profile analysis. Staphylococcus epidermidis was the most commonly identified species from both peritoneal dialysis fluid (73%) and body sites (53%). Multiple antibiotic resistance was common, and the greater proportion of isolates were resistant to methicillin; 63.6% of peritoneal dialysis fluid isolates and 61.7% of body-site isolates. S. haemolyticus isolates were significantly more resistant to methicillin than other species. By phage typing and plasmid-profile analysis it was shown that peritonitis was rarely caused by skin-colonizing strains. In only 3 of 14 patients were peritonitis-associated strains isolated as skin colonizers, and no patients developed peritonitis due to organisms previously isolated as skin colonizers.

Bacteriophage Typing↗
PubMed1989

A randomised trial of empirical antibiotic therapy in febrile neutropenic patients with hematological disorders: ceftazidime versus azlocillin plus amikacin.

One hundred and two patients with neutropenia (less than 1 x 10(9)/L) secondary to primary hematological disorders or chemotherapy for hematological malignancies were prospectively randomised, upon the development of fever or other signs of infection, to receive empirical antibiotic treatment with either ceftazidime (+/- flucloxacillin) (n = 52) or azlocillin plus amikacin (+/- flucloxacillin) (A&A, n = 50). The two groups were equivalent with respect to clinical and laboratory parameters prior to antibiotic therapy and flucloxacillin was added to approximately 25% of the patients in each group on the clinical suspicion of Gram positive infection. When assessed at 96 hours, the complete response rates were 59.6% for the ceftazidime treated patients and 44% for A&A treated patients. Partial response rates were 17% and 20% respectively. This difference was not statistically significant. Eight patients died whilst on the trial, three of those initially randomised to ceftazidime and five initially randomised to A&A. Moderate to severe hypokalemia was encountered significantly less often in the ceftazidime treated group (p less than 0.01), whilst other parameters of toxicity were equivalent. No primary or acquired resistance to ceftazidime was encountered. Separate analysis of those patients who did not receive flucloxacillin yielded identical results. We conclude that ceftazidime (+/- flucloxacillin) is as efficacious as azlocillin plus amikacin (+/- flucloxacillin) in the empirical antibiotic management of such patients and is associated with a lower incidence of moderate to severe hypokalemia.

Adolescent↗
PubMed1989

A study of coagulase-negative staphylococci isolated from clinically significant infections at an Australian teaching hospital.

Some 151 isolates of coagulase-negative staphylococci isolated from patients at an Australian teaching hospital were characterized by biochemical analysis, antibiotic sensitivity patterns and slime production. S. epidermidis was the predominant species (64%) isolated from clinically significant infections, and all S. epidermidis isolates from true bacteremias produced slime. Forty-nine per cent were resistant to methicillin and 61% to gentamicin. S. haemolyticus isolates from clinically significant infections also showed antibiotic resistance and 80% were resistant to more than five antibiotics. The importance of coagulase-negative staphylococci as pathogens in this large teaching hospital was confirmed.

Anti-Bacterial Agents↗
PubMed1987

Incidence of motile, curved anaerobic rods (Mobiluncus species) in vaginal secretions.

Aerobic and anaerobic cultures as well as a Gram stain and wet mount preparation were made of vaginal swabs taken from various groups of women including those with vaginal discharge. The bacteria commonly found in cultures were lactobacilli, coryneforms, Staphylococcus epidermidis and facultative streptococci. Anaerobes were isolated from 75% (475 of 632) of specimens. The incidence of Trichomonas vaginalis, Candida species, Gardnerella vaginalis and Mobiluncus species in the five groups of women varied from 2.2-5.1%, 11.5-35.7%, 23.3-36.7% and 20.0-34.8% respectively. Except for Candida species, differences in the prevalence of these organisms between the groups of women were not significant. The isolation rates of Candida species in women attending the antenatal clinic and staff health clinic were significantly higher than women in the other groups. Mobiluncus species were found to occur either with T. vaginalis, Candida species or G. vaginalis alone or with any two or with all three or in the absence of these organisms. However, the incidence of Mobiluncus species was significantly higher in women colonized with G. vaginalis (112 of 185, or 60.5%) compared with women not infected (47 of 477, or 9.8%). Also, Mobiluncus species occurred in large numbers when found in the presence of G. vaginalis. When found without G. vaginalis, Mobiluncus species occurred in much smaller numbers. As with G. vaginalis, Mobiluncus species also occurred concomitantly with certain anaerobes, mainly Bacteroides species and peptostreptococci.

Animals↗
PubMed1985

Use of protected telescoping brush system in the management of bacterial pulmonary infection in intubated patients.

The diagnosis of pulmonary infection remains a major problem in the management of intubated patients with respiratory failure. We performed fibreoptic bronchoscopy and protected telescoping catheter brushing in 25 such patients, in order to assess the role of this technique in the diagnosis of bacterial pulmonary infection. All patients were intubated, demonstrated lung field opacities on chest radiograph and 23 had bacteria grown from tracheal aspirate culture. A single microorganism was recovered from plugged telescoping catheter (PTC) brush in eight patients, two or more organisms in nine patients and eight had a sterile culture. These results led to a specific management decision in 13 patients. All patients were ventilated with positive pressure and a pneumothorax, attributable to the procedure, developed in two. The difficulties in assessing the sensitivity and specificity of this technique in human studies are outlined. This procedure appears to have a useful role in the diagnosis of pneumonia in these patients and in further evaluating the importance of bacterial colonization of the airways and its relationship to parenchymal lung infection.

Adolescent↗
PubMed1984

Cortisol binding in uremic plasma. I. Absence of abnormal cortisol binding to cortisol binding to corticosteroid-binding globulin.

Increased morning plasma free cortisol levels have been reported previously in chronic renal failure (CRF) patients. To see whether binding abnormalities of plasma proteins contributed to the increase in morning free cortisol, binding characteristics of corticosteroid-binding globulin (CBG) were studied in pooled plasma from CRF patients and normal subjects. Using an isocolloidosmolar equilibrium dialysis method the unbound, albumin-bound, and CBG-bound fractions of plasma cortisol were measured within the physiologic range of plasma cortisol levels. Cortisol binding to CBG was equal in uremic and nonuremic plasma as determined by the affinity constants and the binding capacities of CBG for cortisol. In addition, the distribution of cortisol binding was identical in uremic and in nonuremic plasma samples at equal total cortisol concentrations. By confirming that cortisol binding properties of CBG are unaltered in CRF patients, these data support the assertion that elevated morning free cortisol levels in CRF patients are probably due to increases of plasma total cortisol.

Adult↗