Episodes of fever and neutropenia are common complications of treatment for cancer. The use of prophylactic and early empirical antibiotics has reduced mortality but decreases the sensitivity of diagnostic tests based on culture. The aim of this study was to determine the potential of a broad diagnostic approach (eubacterial) based on 16S rRNA gene amplification and sequencing to augment cultural methods of diagnosis of bacteraemia in patients with fever and neutropenia in a regional paediatric oncology centre. One hundred eleven patient-episodes of fever and neutropenia were evaluated during the study period, 17 of which were associated with positive blood cultures, as follows: Staphylococcus epidermidis (n = 6 episodes), Enterococcus faecium (n = 2), Streptococcus sanguis (n = 3), Streptococcus mitis (n = 3), Staphylococcus aureus (n = 1), Micrococcus spp. (n = 1), and Stenotrophomonas maltophilia (n = 1). Eubacterial polymerase chain reaction (PCR) detected bacterial DNA in nine of 11 blood culture-positive episodes for which a sample was available for PCR; the species identified by sequence analysis were identical to those derived from the conventional identification of the cultured isolates. Bacterial DNA was detected in 20 episodes (21 bacterial sequences) associated with negative blood cultures, 18 of which occurred in patients who were receiving antibiotics at the time of sample collection. The species presumptively identified by partial 16S rRNA gene sequencing were as follows: Pseudomonas spp. (n = 6 episodes), Acinetobacter spp. (n =5 ); Escherichia spp. (n = 3); Moraxella spp. (n = 3); Staphylococcus spp. (n = 2); Neisseria spp. (n = 1); and Bacillus spp. (n = 1). The results of this study suggest that molecular techniques can augment cultural methods in the diagnosis of bacteraemia in patients who have been treated with antibiotics.

Episodes of fever and neutropenia are common complications of treatment for cancer. The use of prophylactic and early empirical antibiotics has reduced mortality but decreases the sensitivity of diagnostic tests based on culture. The aim of this study was to determine the potential of a broad diagnostic approach (eubacterial) based on 16S rRNA gene amplification and sequencing to augment cultural methods of diagnosis of bacteraemia in patients with fever and neutropenia in a regional paediatric oncology centre. One hundred eleven patient-episodes of fever and neutropenia were evaluated during the study period, 17 of which were associated with positive blood cultures, as follows: Staphylococcus epidermidis (n = 6 episodes), Enterococcus faecium (n = 2), Streptococcus sanguis (n = 3), Streptococcus mitis (n = 3), Staphylococcus aureus (n = 1), Micrococcus spp. (n = 1), and Stenotrophomonas maltophilia (n = 1). Eubacterial polymerase chain reaction (PCR) detected bacterial DNA in nine of 11 blood culture-positive episodes for which a sample was available for PCR; the species identified by sequence analysis were identical to those derived from the conventional identification of the cultured isolates. Bacterial DNA was detected in 20 episodes (21 bacterial sequences) associated with negative blood cultures, 18 of which occurred in patients who were receiving antibiotics at the time of sample collection. The species presumptively identified by partial 16S rRNA gene sequencing were as follows: Pseudomonas spp. (n = 6 episodes), Acinetobacter spp. (n =5 ); Escherichia spp. (n = 3); Moraxella spp. (n = 3); Staphylococcus spp. (n = 2); Neisseria spp. (n = 1); and Bacillus spp. (n = 1). The results of this study suggest that molecular techniques can augment cultural methods in the diagnosis of bacteraemia in patients who have been treated with antibiotics.

Summary:Over a 3-month period, four patients who had received unrelated donor (UD) bone marrow transplants (BMT) presented with severe mucocutaneous herpes simplex virus (HSV) infection while receiving acyclovir (ACV) prophylaxis. Sensitivity testing of the isolates revealed three to be acyclovir-resistant and in one patient the infection was also characterised by a marked failure to respond to foscarnet (phosphonoformic acid). The emergence of ACV-resistant HSV infections in themselves is a new and challenging problem, and yet a far greater problem will become evident if these infections develop resistance to non thymidine kinase dependent therapy. Keywords: acyclovir-resistant herpes simplex virus infections; bone marrow transplantation Herpes simplex virus (HSV) reactivates in 70-80% of seropositive recipients of allogeneic transplants, causing haemorrhagic mucocutaneous lesions which can add substantially to the morbidity of BMT. These infections are preventable with prophylactic acyclovir (ACV).1,2 The mode of action of acyclovir includes phosphorylation by viral thymidine kinase (TK) and then its incorporation into the viral DNA, thus terminating extension of the DNA chain. Resistance is usually due to loss of TK expression (TK−) and a correlation exists between the frequency with which resistant viruses are isolated and the degree of immunosuppression in the host.3,4 ACV-resistant HSV infections causing clinical problems in BMT patients have previously been documented, 5 as have resistant herpes virus infections generally. 6 We present a review of four patients who had received unrelated donor bone marrow transplants for the treatment of haematological malignancies and presented over a 3-month period between July and September 1995. They each had serological evidence of previous HSV infection at the time of transplant (complement fixing titres ranging from 24-64) and all four developed recurrent HSV lesions while receiving ACV prophylaxis. The standard regimen for ACV prophylaxis in UD BMT at the time was commenced at day −4 and continued until 6 months post-transplant, but was prolonged in the case of active graft-versus-host disease (GVHD). In patients at risk of cytomegalovirus (CMV) reactivation, the ACV was commenced at 500 mg/m 2 intravenously (i.v.) three times per day until day 30 and then changed to an oral dosage (200 mg five times per day). In those patients not deemed at risk for CMV, ACV was given orally throughout. The implications of the emergence of resistance in this population of immunosuppressed patients will be further discussed. Case reportPatient A, an 8-year-old girl with biphenotypic leukaemia developed mouth ulcers, culture positive for HSV-1, 5 days post-transplant (isolate A, day +5). She was changed from her oral ACV prophylaxis to high-dose intravenous ACV (10 mg/kg three times daily) for 2 weeks, to which she responded and was then converted back to oral therapy (400 mg × 5/day). However, on developing diarrhoea a week later the mouth ulcers recurred and on this occasion they...

An unexpected low efficacy of teicoplanin in the treatment of coagulase negative staphylococcal (CNS) infections on a regional Bone Marrow Transplant (BMT) Unit led to a retrospective study. CNS infections treated with gylcopeptides in BMT patients with in-dwelling central venous lines between May 1990 and May 1995 were reviewed. Efficacy rates of 50% for teicoplanin compared with 80% for vancomycin despite comparable antibiotic susceptibility. Glycopeptides have bactericidal action which is time dependent. Teicoplanin was administered by bolus injection during the study period and it is suggested that this observed difference in efficacy is caused by the short duration of exposure of luminal bacteria.

Computed tomography revealed a frontal empyema in an 8 month old boy who presented with a prolonged convulsion. Before admission he had received oral antibiotics and all specimens were negative on culture. The presence of bacteria in cerebrospinal and empyema fluid was demonstrated using the polymerase chain reaction (PCR) with 16S rRNA gene primers. A presumptive identification of Streptococcus pneumoniae was made by comparison of PCR products with those derived from known bacteria using denaturing gradient gel electrophoresis.