Evolving strategies in microbe identification-a comprehensive review of biochemical, MALDI-TOF MS and molecular testing methods.

Detection and identification of microorganisms are the first steps to guide susceptibility testing and enable clinicians to confirm diseases and guide therapy. The faster the pathogen identification is determined, the quicker the appropriate treatment can be started. In the clinical microbiology laboratory, multiple methodologies can be used to identify organisms, such as traditional biochemical testing or more recent methods like MALDI TOF MS and nucleic acid detection/identification assays. Each of these techniques has advantages and limitations, and clinical laboratories need to determine which methodology is best suited to their particular setting in terms of clinical needs, availability of technical expertise and cost. This article presents a concise review of the history, utilization, advantages and limitations of the main methods used for identifying microorganisms in microbiology laboratories.

Strongyloides hyperinfection following hematopoietic stem cell transplant in a patient with HTLV-1-associated T-cell leukemia.

Strongyloides stercoralis has the potential to cause accelerated autoinfection in immunocompromised hosts. Screening tests for strongyloidiasis may be falsely negative in the setting of immunosuppression. We report a case of Strongyloides hyperinfection syndrome in a patient with human T-lymphotropic virus type 1-associated T-cell leukemia early after hematopoietic stem cell transplant. The diagnosis was made by stool ova and parasite examination, despite a negative screening enzyme-linked immunosorbent assay. Because of anticipated prolonged neutropenia, an extended course of treatment was utilized.

Prevalence and genetic relatedness of methicillin-susceptible Staphylococcus aureus isolates detected by the Xpert MRSA nasal assay.

Methicillin-susceptible Staphylococcus aureus (MSSA) isolates lacking mecA yet testing positive on the Xpert MRSA assay were recovered from culture for 7.7% of 248 Xpert-positive nasal samples. These "false-positive" Xpert results may be attributed to staphylococcal cassette chromosome (SCC) elements without the mecA gene. Pulsed-field gel electrophoresis (PFGE) analysis revealed a diverse population of MSSA strains.

Comparison of BD Phoenix AP Workflow with Vitek 2.

The BD Phoenix AP instrument reduced the manual setup time for the Phoenix system by 50%. For batches of 14 organisms, the average manual manipulation time per isolate was 89.5 s for BD Phoenix by the use of the AP instrument and 101 s for Vitek 2 (P<0.001).

Lymph Node With Extensive Involvement by Cryptococcus Shortly Following Liver Transplantation.

Herein, we present a case of extensive lymph node involvement by disseminated Cryptococcus infection developing in the immediate period after liver transplantation and initiation of immunosuppressive therapy. The patient, a 56 year old ethnicity unknown man, received a liver transplant for acute decompensated liver. Beginning 24 days after transplantation, he was found to have Cryptococcus neoformans infection, involving the pleural fluid, blood, cerebrospinal fluid (CSF), liver, and lymph nodes. He received treatment with amphotericin B and flucytosine; he was transitioned to fluconazole, and his response was good. This relatively rapid development of disease raises the possibility of donor-derived Cryptococcus infection.

Sensitivity of the Quidel Sofia Fluorescent Immunoassay Compared With 2 Nucleic Acid Assays and Viral Culture to Detect Pandemic Influenza A(H1N1)pdm09.

To confirm a diagnosis of influenza at the point of care, healthcare professionals may rely on rapid influenza diagnostic tests (RIDTs). RIDTs have low to moderate sensitivity compared with viral culture or real-time reverse-transcription polymerase chain reaction (rRT-PCR). With the resurgence of the influenza A (Flu A; subtype H1N1) pandemic 2009 (pdm09) strain in the years 2013 and 2014, we evaluated the accuracy of the United State Food and Drug Administration (FDA)-approved Sofia Influenza A+B Fluorescent Immunoassay to detect epidemic Flu A(H1N1)pdm09 in specimens from the upper-respiratory tract. During a 3-month period, we collected 40 specimens that tested positive via PCR and/or culture for Flu A of the H1N1 pdm09 subtype. Of the 40 specimens, 27 tested positive (67.5%) via Sofia assay for Flu A. Of the 13 specimens with a negative result via Sofia testing, 4 had coinfection, as detected by the GenMark Diagnostics eSensor Respiratory Viral Panel. This sensitivity of the RIDT Sofia assay to detect Flu A(H1N1) pdm09 was comparable to previously reported sensitivities ranging from 10% to 75% for older RIDTs.