(1,3) ß-D-Glucan in Bronchoalveolar Lavage of Lung Transplant Recipients for the Diagnosis of Invasive Pulmonary Aspergillosis.

(1,3) ß-D-Glucan (BDG) is present in the cell wall of most fungi. Its detection in serum has been useful in the diagnosis of invasive aspergillosis (IA) in patients with hematologic malignancies. However, assaying for BDG did not perform well in the serum of lung transplant recipients. We undertook to study the performance of BDG in the bronchoalveolar lavage (BAL) of lung transplant recipients for the diagnosis of invasive pulmonary aspergillosis (IPA). Available and stored BAL samples from lung transplant recipients at the Toronto General Hospital between October 2007 and April 2013 were tested for BDG using the Fungitell kit from the Associates of Cape Cod Inc, Falmouth, MA, USA : The International Society for Heart and Lung transplantation (ISHLT) criteria was used for the diagnosis of IA. Of 195 samples, there were ten episodes of IA. The sensitivity and specificity of the test were 80% and 53% and 60% and 70% at 41 pg/ml and 108 pg/ml cut-offs, respectively. On excluding 52 bronchoscopies due to receipt of anti-Aspergillus therapy during specimen collection, the sensitivity and specificity improved to 75% and 91%, respectively, at a 524 pg/ml cut-off. However, only four episodes of IA remained in this analysis. Using BDG in BAL of lung transplant recipients for the diagnosis of IA, our study demonstrated moderate sensitivity and specificity.

Simkania negevensis and acute cellular rejection in lung transplant recipients.

Simkania negevensis infection has been hypothesized to play a role in lung transplant rejection. The incidence of S. negevensis infection and its association with acute cellular rejection (ACR) were determined in a prospective cohort study of 78 lung transplant recipients (LTRs) in Toronto, Canada, and Pittsburgh, USA, from July 2007 to January 2010. Simkania negevensis testing was detected by quantitative polymerase chain reaction (PCR) on bronchoalveolar lavage fluid. The relationship between S. negevensis and ACR was examined using Cox proportional hazards models and generalized linear and latent mixed models. Cumulative incidence estimates for time-to-ACR in S. negevensis PCR-positive vs. PCR-negative LTRs were 52.7% vs. 31.1% at six months and 68.9% vs. 44.6% at one yr, respectively. Although not statistically significant, there was a trend toward a higher risk of ACR among S. negevensis PCR-positive vs. PCR-negative LTRs in all statistical models.

Indications of carbapenem resistance evolution through heteroresistance as an intermediate stage in Acinetobacter baumannii after carbapenem administration.

We describe an in vivo evolution of an antimicrobial profile from susceptibility to full-resistance to carbapenems, with heteroresistance as an intermediate stage, in an Acinetobacter baumannii strain. Heteroresistance was characterized by the growth of sub-populations within the susceptibility halo in both disk-diffusion and Etest. PCRs for the main A. baumannii carbapenemases were negative. The exact resistance mechanism, diagnostic methods and clinical relevance of heteroresistance in A. baumannii warrant further investigations. This is the first description of such phenomenon in vivo and the second report of heteroresistance to carbapenems in A. baumannii.

Corynebacterium striatum infecting a malignant cutaneous lesion: the emergence of an opportunistic pathogen.

We described a case of a 27-year old male patient with skin and soft tissue infection of a neoplastic lesion caused by Corynebacterium striatum, an organism which has been rarely described as a human pathogen. Identification was confirmed by DNA sequencing. Successful treatment with penicillin was achieved. The role of the C. striatum as an emerging opportunistic pathogen is discussed.

Indications of carbapenem resistance evolution through heteroresistance as an intermediate stage in Acinetobacter baumannii after carbapenem administration / Indicações da evolução da resistência ao carbapenem através da heteroresistência como estágio intermediário no Acinetobacter baumannii após administração de carbapenem

We describe an in vivo evolution of an antimicrobial profile from susceptibility to full-resistance to carbapenems, with heteroresistance as an intermediate stage, in an Acinetobacter baumannii strain. Heteroresistance was characterized by the growth of sub-populations within the susceptibility halo in both disk-diffusion and Etest. PCRs for the main A. baumannii carbapenemases were negative. The exact resistance mechanism, diagnostic methods and clinical relevance of heteroresistance in A. baumannii warrant further investigations. This is the first description of such phenomenon in vivo and the second report of heteroresistance to carbapenems in A. baumannii.

Descrevemos a evolução in vivo, de um perfil de sensibilidade aos antimicrobianos, passando de sensibilidade a resistência total aos antibióticos carbapenêmicos, com um estágio intermediário de heteroresistência em isolado de Acinetobacter baumannii. A heteroresistência foi caracterizada pelo crescimento de sub-população na zona de inibição pelo método de disco-difusão e pelo Etest. PCRs para as principais carbapenemases envolvidas com resistência neste microrganismo foram negativas. O exato mecanismo de resistência envolvido, método diagnóstico e relevância clínica justificam investigação adicional. Esta é a primeira descrição deste fenômeno in vivo e o segundo relato de heteroresistência em A. baumannii.

Corynebacterium striatum infecting a malignant cutaneous lesion: the emergence of an opportunistic pathogen / Corynebacterium striatum infectando lesão cutânea maligna: a emergência de um patógeno oportunista

We described a case of a 27-year old male patient with skin and soft tissue infection of a neoplastic lesion caused by Corynebacterium striatum, an organism which has been rarely described as a human pathogen. Identification was confirmed by DNA sequencing. Successful treatment with penicillin was achieved. The role of the C. striatum as an emerging opportunistic pathogen is discussed.

Descrevemos infecção de lesão neoplásica em paciente masculino de 27 anos, envolvendo pele e partes moles, causada por Corynebacterium striatum, um microrganismo raramente descrito como patógeno humano. A identificação foi confirmada por seqüenciamento de DNA. O paciente foi tratado com penicilina, com sucesso. O papel do C. striatum como patógeno oportunista é discutido.