Antimycobacterial Susceptibility Testing of Nontuberculous Mycobacteria.

Recommendations for first-line and second-line drug testing and organism group, specific methodologies, and reporting recommendations have been addressed by the Clinical and Laboratory Standards Institute (CLSI) and are important in the selection of appropriate antimicrobial treatment regimens for nontuberculous mycobacteria (NTM) disease. This review also includes recent information on new antimicrobials proposed for the treatment of NTM but not yet addressed by the CLSI and molecular (gene sequencing) methods associated with the detection of antimicrobial resistance of two major therapeutic antimicrobials, clarithromycin and amikacin.

Routine pathologic examination of tonsillectomy specimens: A 10-year experience at a tertiary care children's hospital.

Objective: To review histopathologic diagnoses from tonsillectomy specimens and determine whether routine pathologic exam is necessary.

Methods: Pathology reports of patients undergoing tonsillectomy from 2005 to 2014 at our pediatric tertiary care hospital were reviewed. Histopathologic diagnoses were recorded with special attention to identification of malignancy.

Pelvic Abscess Secondary to Mycoplasma Hominis after Vaginal Laceration.

Background: Mycoplasma hominis frequently colonizes the urogenital and respiratory tracts of healthy individuals. It has also been associated with genitourinary tract and extragenital syndromes.

Case: We present a 14-year-old girl who developed a pelvic abscess secondary to M.

Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Children.

Background: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain.

Methods: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence.

Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Children.

Background: Individuals infected with Mycobacterium tuberculosis (Mtb) may develop symptoms and signs of disease (tuberculosis disease) or may have no clinical evidence of disease (latent tuberculosis infection [LTBI]). Tuberculosis disease is a leading cause of infectious disease morbidity and mortality worldwide, yet many questions related to its diagnosis remain.

Methods: A task force supported by the American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America searched, selected, and synthesized relevant evidence.

Mycobacteria.

The immunocompromised host is at increased risk of Mycobacterium tuberculosis complex and nontuberculous mycobacteria infection. Although Mycobacterium tuberculosis complex is a significant mycobacterial pathogen, nontuberculous mycobacteria causes substantial disease in those with suppressed immune responses. Mycobacterial infections can cause significant morbidity and mortality in this patient population, and rapid identification and susceptibility testing of the mycobacterial species is paramount to patient management and outcomes.

Multiclonal methicillin-resistant Staphylococcus aureus (MRSA) outbreak and its control after use of the Veterans Affairs (VA) MRSA bundle in a VA long-term care facility, 2004-2014.

A multiclonal methicillin-resistant Staphylococcus aureus (MRSA) outbreak with 91 infections occurred in our Veterans Affairs (VA) community living center over 46 months. Both similar and unique strains were shown by repetitive polymerase chain reaction to contribute to the outbreak, including 1 strain causing infections over a 33-month period. Most infections were soft tissue infections (67%).

A 66-year-old woman with fever, cough, and a tongue lesion.

A 66-year-old woman presented with acute onset of fever, chills, and productive cough associated with right-sided chest pain. During a recent hospitalization for dyspnea, she had been diagnosed with Coombs-positive autoimmune hemolytic anemia and had been taking a tapering dose of prednisone starting approximately 6 weeks prior to admission. In the interim, her dyspnea had resolved on treatment with steroids.

IFN-γ release assay conversions and reversions. Challenges with serial testing in U.S. health care workers.

Rationale: IFN-γ release assays (IGRAs) including the QuantiFERON-TB gold in-tube test (QFT-GIT) are increasingly used in place of the tuberculin skin test (TST) in surveillance programs for Mycobacterium tuberculosis infection in the United States. However, data on conversions, reversions, and predictive value of QFT in such programs for health care workers (HCWs) are limited.

Objectives: The purpose of this study is to assess long-term reproducibility and conversion and reversion rates of QFT-GIT among HCWs who underwent serial testing at a tertiary care center in the United States.

In vitro activity of amikacin against isolates of Mycobacterium avium complex with proposed MIC breakpoints and finding of a 16S rRNA gene mutation in treated isolates.

Amikacin is a major drug used for the treatment of Mycobacterium avium complex (MAC) disease, but standard laboratory guidelines for susceptibility testing are not available. This study presents in vitro amikacin MICs for 462 consecutive clinical isolates of the MAC using a broth microdilution assay. Approximately 50% of isolates had amikacin MICs of 8 μg/ml, and 86% had MICs of ≤16 μg/ml.

Use of interferon-gamma release assays in a health care worker screening program: experience from a tertiary care centre in the United States.

Background: Interferon-gamma release assays including the QuantiFERON-TB Gold In-Tube test (QFT-GIT [Cellestis Ltd, Australia]) may be used in place of the tuberculin skin test (TST) in surveillance programs for Mycobacterium tuberculosis infection control. However, data on performance and practicality of the QFT-GIT in such programs for health care workers (HCWs) are limited.

Objectives: To assess the performance, practicality and reversion rate of the QFT-GIT among HCWs at a tertiary health care institution in the United States.

Multisite reproducibility of the broth microdilution method for susceptibility testing of Nocardia species.

Antimicrobial susceptibility testing (AST) of clinical isolates of Nocardia is recommended to detect resistance to commonly used antimicrobial agents; such testing is complicated by difficulties in inoculum preparation and test interpretation. In this study, six laboratories performed repetitive broth microdilution testing on single strains of Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, Nocardia nova, and Nocardia wallacei. For each isolate, a total of 30 microdilution panels from three different lots were tested at most sites.

Clinical and laboratory update on blastomycosis.

Blastomycosis is endemic in regions of North America that border the Great Lakes and the St. Lawrence River, as well as in the Mississippi River and Ohio River basins. Men are affected more often than women and children because men are more likely to participate in activities that put them at risk for exposure to Blastomyces dermatitidis.

Comparison of traditional phenotypic identification methods with partial 5' 16S rRNA gene sequencing for species-level identification of nonfermenting Gram-negative bacilli.

Correct identification of nonfermenting Gram-negative bacilli (NFB) is crucial for patient management. We compared phenotypic identifications of 96 clinical NFB isolates with identifications obtained by 5' 16S rRNA gene sequencing. Sequencing identified 88 isolates (91.

Repetitive-sequence-based PCR using the DiversiLab system for identification of Aspergillus species.

Repetitive-sequence-based PCR (rep-PCR) using the DiversiLab system was investigated for identification of Aspergillus. Ninety-five clinical isolates, identified by conventional methods, and five ATCC strains were tested. Sequencing of the internal transcribed spacer (ITS) region (ITS1-5.

Identification of Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species by repetitive-sequence-based PCR.

The performance of repetitive-sequence-based PCR (rep-PCR) using the DiversiLab system for identification of Coccidioides species, Blastomyces dermatitidis, and Histoplasma capsulatum was assessed by comparing data obtained to colony morphology and microscopic characteristics and to nucleic acid probe results. DNA from cultures of 23 Coccidioides, 24 B. dermatitidis, 24 H.

Mycobacterium arupense sp. nov., a non-chromogenic bacterium isolated from clinical specimens.

Several Mycobacterium-like organisms related to the Mycobacterium terrae complex have been isolated from clinical samples. In the clinical microbiology laboratory, partial 16S rRNA gene sequencing (approximately the first 500 bp) rather than full 16S rRNA gene sequencing is often used to identify Mycobacterium species. Partial 16S rRNA gene sequence analysis revealed 100 % similarity between 65 clinical isolates and Mycobacterium sp.

Comparison of real-time polymerase chain reaction using the Smart Cycler and the Gen-Probe amplified Mycobacterium tuberculosis direct test for detection of M. tuberculosis complex in clinical specimens.

The performance of a real-time polymerase chain reaction (PCR) assay using the Smart Cycler instrument and a minor groove binding MGB Eclipse probe (Epoch Biosciences, Bothell, WA) for identification of Mycobacterium tuberculosis complex in acid-fast bacillus smear-positive and smear-negative clinical specimens was assessed by comparing results to the Amplified M. tuberculosis Direct Test (MTD) and mycobacterial culture plus clinical diagnosis. After initial testing, the overall sensitivity, specificity, and positive and negative predictive values of PCR for the 172 specimens submitted for mycobacterial culture were 86.

Clinical evaluation of repetitive sequence-based polymerase chain reaction using the Diversi-Lab System for strain typing of vancomycin-resistant enterococci.

The reliability of the Diversi-Lab System, an automated method of microbial strain typing using repetitive sequence-based polymerase chain reaction (rep-PCR), was evaluated by comparing results with those obtained by pulsed-field gel electrophoresis (PFGE). Ninety-five clinical isolates of vancomycin-resistant enterococci (VRE; 13 groups, 2-17 isolates per group) sent to Associated Regional and University Pathologists (ARUP) Laboratories for typing were tested by both methods. Rep-PCR and PFGE results were concordant for 83 isolates: all 32 isolates in 6 of the groups and 51 of the 63 isolates in the other 7 groups.

Evaluation of a (1->3)-beta-D-glucan assay for diagnosis of invasive fungal infections.

The Fungitell assay (Associates of Cape Cod, Inc.) is a commercial test that detects (1-3)-beta-D-glucan (BG) and is intended for diagnosis of invasive fungal infections. To evaluate the Fungitell assay, we tested serum and plasma samples from healthy blood donors and from patients with blood cultures positive for yeast or bacteria.

Use of the MGB Eclipse system and SmartCycler PCR for differentiation of Mycobacterium chelonae and M. abscessus.

Although accurate in the identification of Mycobacterium species, partial 16S rRNA gene sequencing does not distinguish Mycobacterium chelonae from M. abscessus. Thus, we designed a SmartCycler PCR assay targeting the 16S-to-23S internal transcribed spacer (ITS) region with use of MGB Eclipse probes to distinguish each species.