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Biomedical subjects

R A Benn

Publications and source records attributed to R A Benn.

At least 19 recordsLinked to original sources
PubMed1998

Molecular epidemiology of Burkholderia cepacia in two Australian cystic fibrosis centres.

Forty individual patient sputum isolates of Burkholderia cepacia from two Australian cystic fibrosis (CF) centres more than 100 km apart were genotyped using pulsed-field gel electrophoresis (PFGE) with XbaI restriction enzyme digestion. Hospital 1 had an endemic strain with 19 of 20 isolates being closely related. This centre does not implement an inpatient segregation policy for its paediatric patients who constitute the majority of those colonized with B. cepacia. Hospital 2 did not have a single endemic strain; there were two different sibling clusters and a third cluster involving a cohabiting couple, but all other patients had unique isolates. One patient at Hospital 2 carried an organism closely related to the endemic strain from Hospital 1. Hospital 2 practises segregation of colonized inpatients and also segregation external to the hospital. It would appear that no nosocomial spread of infection is occurring with this policy.

Australia↗
PubMed1998

Detection of persistent vegetative bacteria and amplified viral nucleic acid from in-use testing of gastrointestinal endoscopes.

Hospital-acquired infection attributed to inadequate decontamination of gastrointestinal endoscopes prompted an in use evaluation of recommended procedures. Specimens were obtained from the internal channels of 123 endoscopes before, during and after decontamination by flushing with saline and brushing with a sterile brush, and examined for vegetative bacteria by broth and plate culture. Four endoscopy units were tested; the chemical disinfectants used were: 2% glutaraldehyde in Centres 1 and 2 (automated) and Centre 3 (manual); peracetic acid in Centre 4 (automated). Samples from patients in Centre 1 with known chronic hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV-1) infection were also examined for viral nucleic acid by ultracentrifugation, nucleic acid extraction, reverse transcription (for RNA) and polymerase chain reaction (PCR). No persistent vegetative bacteria were found following standard manual cleaning and disinfection for 20 min in 2% glutaraldehyde in Centres 2 and 3 (N = 37). At Centre 1, while plate culture yielded no growth, 34% of samples (10/29) grew vegetative bacteria in broth culture after cleaning and disinfection for 20 min in 2% glutaraldehyde. Investigation revealed an error in manual cleaning; no bacteria were detected in 37 samples taken after this was corrected. At Centre 4, despite the use of peracetic acid as a sterilant, three out of 20 (15%) of post decontamination samples grew bacteria; one contained persistent bacteria. HBV and HCV PCR analysis detected viral nucleic acid in three out of four and four out of six samples from viraemic patients undergoing endoscopy in Centre 1 during the period of improper manual washing. After proper cleaning was instituted, samples from nine out of nine HCV viraemic patients were negative. HIV RNA was detected in five of 14 samples taken from endoscopes after use on HIV positive patients but all post decontamination samples were negative. Detection of bacteria in washes from endoscope channels is a useful warning of a breakdown in decontamination practice. Inadequate brushing of internal channels may result in persistent HCV and HBV viral nucleic acid, the significance of which is not clear. These results reinforce the importance of adequate manual cleaning of endoscopes before chemical disinfection.

Bacteria↗
PubMed1997

A national collaborative study of the in vitro activity of oral cephalosporins and loracarbef (LY 163892). Australian Group for the Study of Antimicrobial Resistance (AGAR).

A national collaborative study involving the laboratories of 17 Australian hospitals examined the in vitro activity of loracarbef, cefaclor, cephalexin, amoxycillin and amoxycillin/clavulanate against 2661 recently isolated common bacterial pathogens. Loracarbef was the most active agent against Escherichia coli (MIC90 = 1 mg/l) and had activity comparable to other agents against Klebsiella pneumoniae and Proteus mirabilis. Like the oral cephalosporins, it had no activity against species of Enterobacter and Serratia. beta-lactamase-producing Staphylococcus aureus and Haemophilus influenzae were moderately sensitive to loracarbef (MIC90 = 8 mg/l for both species). Streptococcus pneumoniae was moderately sensitive to loracarbef (MIC90 = 2 mg/l) but strains which were insensitive to penicillin were often highly resistant.

Administration, Oral↗
PubMed1995

Multi-centre collaborative study for the in vitro evaluation of new macrolides dirithromycin and erythromycylamine. Australian Group for Antimicrobial Resistance (AGAR).

A national study was conducted to determine the in vitro activity of 2 newer macrolides, dirithromycin and erythromycylamine compared with that of erythromycin, tetracycline and penicillin. Nineteen major teaching hospitals participated in the study. Minimal Inhibitory Concentrations (MICs) were determined by agar dilution, mostly using Iso-Sensitest Agar and an inoculum of 10(4) cells per spot. 2284 clinically significant strains were isolated in late 1991 and early 1992, comprising 1736 Gram-positive cocci, 355 Haemophilus influenzae, 97 Moraxella catarrhalis, 32 Listeria monocytogenes, 25 Neisseria meningitidis and 39 Neisseria gonorrhoeae were tested. The study indicates that dirithromycin and erythromycylamine possess antibacterial activity equivalent to that of erythromycin against most Gram-positive cocci and M. catarrhalis. Strains resistant to erythromycin were also resistant to dirithromycin and to erythromycylamine. Tetracycline was as active as the macrolides against both penicillin-resistant and penicillin-susceptible strains of Staphylococcus aureus. Coagulase-negative penicillin-resistant staphylococci, compared with tetracycline, were relatively resistant to the macrolides. H. influenzae was less susceptible than the Gram-positive cocci.

Anti-Bacterial Agents↗
PubMed1989

Allergic fungal sinusitis presenting as a paranasal sinus tumour.

Allergic fungal rhinosinusitis is a rare complication of atopic upper airways disease which may present initially as an expansive tumour of the paranasal sinuses. This reported case was caused by the rare fungal pathogen Bipolaris hawiiensis and illustrates typical clinical and laboratory features of this disorder. Although the optimum management of allergic fungal sinusitis is controversial, combined therapy with surgical clearance, antifungal agents and corticosteroids produced a favourable outcome.

Adult↗
PubMed1984

Effect of antibiotic use on the incidence of cephalosporin resistance in two Australian hospitals.

The incidence of resistance of Gram-negative bacteria to three generations of cephalosporins was surveyed in two large hospitals with widely differing rates of cephalosporin usage. Overall resistance (MIC greater than 5 mg/l) of Enterobacteriaceae to cefotaxime in the hospital using large amounts of cephalosporins was 4% compared with 0.7% in the other. Enterobacter species accounted for most resistant isolates and resistant Enterobacter cloacae replaced sensitive strains in four patients given cefotaxime in 1983. The distribution of species colonizing intensive care areas was similar in both hospitals with cephalosporin-resistant Pseudomonas aeruginosa and Acinetobacter calcoaceticus predominating.

Bacteria↗
PubMed1980

Measurement of IgM antibodies in the diagnosis of mycoplasma pneumonia.

The sera of 30 patients with complement-fixing antibodies to Mycoplasma pneumoniae (titres larger than or equal to 32) were treated with staphylococcal protein A. This procedure effectively removed 90 to 95% of the IgG antibodies. The Mycoplasma-specific antibodies in the treated sera could then be measured by a complement fixation test. This provides a useful test for distinguishing serological responses to recent Mycoplasma pneumoniae infections from anamnestic responses due to past exposure to Mycoplasma pneumoniae.

Agglutinins↗