This review examines the contribution dental prescribing makes to the selection of antibiotic resistance in bacteria of the oral flora. The antibiotics commonly used in dental prescribing in the UK are discussed, together with the problems of resistance in members of the oral flora. The antibiotic prescribing habits of general dental practitioners are then reviewed with respect to therapeutic prescriptions and those drugs that are prescribed prophylactically. Not all antibiotic prescriptions for dental problems are written by dentists; prescribing outside the dental profession is also considered. The review then considers the support available to dentists from clinical diagnostic microbiology laboratories. It concludes that better use of diagnostic services, surveillance and improvements in dental education are required now to lessen the impact of antibiotic resistance in the future.

Talaromycosis is a fungal infection endemic in Southeast Asia. We report a case of a renal transplant recipient who developed infection after a trip to South China. She presented with constitutional symptoms and was found to have an FDG‐avid lung mass. Histopathology demonstrated small yeast cells and culture grew Talaromyces marneffei. The patient was treated with 2 weeks of liposomal amphotericin B followed by itraconazole. The dose of tacrolimus was significantly reduced because of the interaction with itraconazole. Mycophenolate mofetil was discontinued. After 12 months of treatment, the mass had completely resolved. Talaromycosis has mainly been reported in patients with AIDS and is uncommon among solid organ transplant recipients. The immune response against T. marneffei infection is mediated predominantly by T cells and macrophages. The diagnosis may not be suspected outside of endemic areas. We propose a therapeutic approach in transplant patients by extrapolating the evidence from the HIV literature and following practices applied to other endemic mycoses.

transplant 11 years previously and at presentation was immunosuppressed with tacrolimus and mycophenolate mofetil. Her symptoms started whilst sailing in Crete, prior to which she had travelled extensively in southern China for 8 weeks in 2016. She is a lifelong nonsmoker and for the last several years has been sailing around the Mediterranean with frequent trips back to the UK. A computed tomography scan of the chest was performed in Greece which revealed a large left upper lobe (LUL) mass. A subsequent positron emission tomography/computed tomography in the UK showed a highly avid 10.4-cm left upper lobe necrotic mass with a very high fluorodeoxyglucose uptake, standardised uptake value max 21.4, suggestive of primary lung malignancy. There were also sub-centimetre station 5 and 6 nodes with high fluorodeoxyglucose uptake (standardised uptake value max up to 6.0), suspicious of involvement. Diagnostic EBUS-TBFNA and transoesophageal endoscopic ultrasound-guided (EUS) FNA were performed. Samples were obtained from station 11L lymph nodes via EBUS-TBFNA and the LUL mass via both EBUS-TBFNA and EUS-FNA. Detailed methods relating to specimen preparation were as described previously. 3 ROSE revealed no malignant cells from the station 11L node.Five aspirates from the LUL mass via EBUS-TBFNA were prepared as five air-dried Rapi-Diffâ stained direct spreads that at ROSE showed necrotic debris. Thereafter, a further five aspirates were performed by EUS-FNA, which revealed granulomatous inflammation. In light of these ROSE findings, an additional two aspirates were taken for microbiology assessment.Within the cytoplasm of both the single macrophages and the granulomas, numerous organisms were identified at ROSE on the air-dried slides ( Figure 1A) and subsequently on the SurePathâ slide ( Figure 1B). These microorganisms had both pale and dark staining poles. They stained positive with Grocott's methenamine silver staining, confirming their fungal nature ( Figure 1C) and were noted to be oval in shape with a transverse septum dividing the hyphae ( Figure 1D). Microbiological assessment revealed organisms with a typicalTaralomyces micromorphology with fungal hyphae undergoing conidiation at 30°C. In addition, culture of the sample on a Sabouraud agar slope at 30°C produced a red, diffusing pigment characteristic for T. marneffei ( Figure 1E,F).Clinically, T. marneffei infection is a challenging diagnosis. As demonstrated in this case, taralomycosis may be suspected in cytological specimens based on its characteristic morphology. The organisms are oval, spherical and sausage-shaped, 2-6 µm, display lighter and darker staining poles and have a central transverse septum, which stains densely with silver stain. 4,5 These features are similar to those of another intracellular pathogen, Histoplasma capsulatum, which is also a dimorphic fungus and an AIDS defining infection. The key differentiating features are the sizes of the organisms and the culture patterns.

A male patient in his mid-60s presented with a severe pneumonia following return to the UK after travel to Crete. He was diagnosed with Legionnaire’s disease (caused by an uncommon serogroup of Legionella pneumophila). He was pancytopenic on admission, and during a long stay on critical care he was diagnosed with a disseminated Aspergillus infection. Bone marrow aspiration revealed an underlying hairy cell leukaemia that undoubtedly contributed to his acute presentation and subsequent invasive fungal infection.