Impact of introduction of the BD Kiestra InoqulA on urine culture results in a hospital clinical microbiology laboratory.

This study compared results from plating urine specimens with the BD InoqulA instrument using a 10-µl inoculum with results from cultures plated manually with a 1-µl loop for comparable 2-month periods. The positivity rates, turnaround times for positive cultures, and BD Phoenix identification and antimicrobial susceptibility test results were comparable for both time periods. We experienced no problems with culture interpretation as the result of moving to the 10-µl inoculum.

Executive summary: a guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a).

The critical role of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. This document, developed by both laboratory and clinical experts, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. Sections are divided into anatomic systems, including Bloodstream Infections and Infections of the Cardiovascular System, Central Nervous System Infections, Ocular Infections, Soft Tissue Infections of the Head and Neck, Upper Respiratory Infections, Lower Respiratory Tract infections, Infections of the Gastrointestinal Tract, Intraabdominal Infections, Bone and Joint Infections, Urinary Tract Infections, Genital Infections, and Skin and Soft Tissue Infections; or into etiologic agent groups, including Tickborne Infections, Viral Syndromes, and Blood and Tissue Parasite Infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. There is redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a reference to guide physicians in choosing tests that will aid them to diagnose infectious diseases in their patients.

A guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a).

The critical role of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. This document, developed by both laboratory and clinical experts, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. Sections are divided into anatomic systems, including Bloodstream Infections and Infections of the Cardiovascular System, Central Nervous System Infections, Ocular Infections, Soft Tissue Infections of the Head and Neck, Upper Respiratory Infections, Lower Respiratory Tract infections, Infections of the Gastrointestinal Tract, Intraabdominal Infections, Bone and Joint Infections, Urinary Tract Infections, Genital Infections, and Skin and Soft Tissue Infections; or into etiologic agent groups, including Tickborne Infections, Viral Syndromes, and Blood and Tissue Parasite Infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. There is redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a reference to guide physicians in choosing tests that will aid them to diagnose infectious diseases in their patients.

Automation in clinical microbiology.

Historically, the trend toward automation in clinical pathology laboratories has largely bypassed the clinical microbiology laboratory. In this article, we review the historical impediments to automation in the microbiology laboratory and offer insight into the reasons why we believe that we are on the cusp of a dramatic change that will sweep a wave of automation into clinical microbiology laboratories. We review the currently available specimen-processing instruments as well as the total laboratory automation solutions. Lastly, we outline the types of studies that will need to be performed to fully assess the benefits of automation in microbiology laboratories.

Empyema caused by Mycoplasma salivarium.

Mycoplasma salivarium infections outside the oral cavity are rare. We describe a 49-year-old man with laryngeal cancer and right pleural space infection with M. salivarium. To our knowledge, this is the first report of empyema due to Mycoplasma salivarium.

Comparative evaluation of the AccuProbe Group B Streptococcus Culture Test, the BD GeneOhm Strep B assay, and culture for detection of group B streptococci in pregnant women.

We compared a rigorous culture method with the Gen-Probe AccuProbe Group B Streptococcus Culture Test (APGB) and the BD GeneOhm StrepB assay (GOSB) for the detection of group B streptococci (GBS) from an 18- to 24-h LIM broth. Culture (95.3%) and GOSB (95.3%) were more sensitive than APGB (86.5%) for the detection of GBS.

First evaluation of the WASP, a new automated microbiology plating instrument.

Many laboratories are experiencing growing shortages of trained microbiology technologists and technicians. Consequently, there is considerable interest in new automation that could potentially lessen labor demands for specimen processing. In this study, we present the first published evaluation of a new microbiology instrument, the Walk Away Specimen Processor (WASP), manufactured by Copan, Inc., in which we evaluated cross-contamination, the accuracy of plating, and the quality of the results. The absence of cross-contamination was demonstrated by plating a total of 200 alternating inoculated and sterile specimen tubes. The ability of the WASP to subculture enrichment broths was evaluated with 106 Lim broth specimens, with the results being identical to those obtained by testing by routine methods. Plating of urine specimens with the WASP was compared to plating with the Dynacon Inoculab instrument. Three hundred specimens were plated in duplicate on both instruments with 1-microl loops, and 293 specimens were plated in duplicate on both instruments with 10-microl loops. The results of duplicate plating with the same instrument (replicate plating) and of the consensus agreement between the two instruments were compared. The replicate plating results were comparable for both instruments, while the WASP had more specimens with significant results than the Inoculab with the 1-microl loop only. Lastly, for the plating of 113 specimens in ESwab tubes, the manual method and WASP plating each yielded 90 potential pathogens. In summary, we report the first evaluation of a new microbiology specimen-plating instrument, the WASP, which offers opportunities for the automated plating of microbiology specimens to an extent that has not been possible to date.

Timing of specimen collection for blood cultures from febrile patients with bacteremia.

Bloodstream infections are an important cause of morbidity and mortality. Physician orders for blood cultures often specify that blood specimens be collected at or around the time of a temperature elevation, presumably as a means of enhancing the likelihood of detecting significant bacteremia. In a multicenter study, which utilized retrospective patient chart reviews as a means of collecting data, we evaluated the timing of blood culture collection in relation to temperature elevations in 1,436 patients with bacteremia and fungemia. The likelihood of documenting bloodstream infections was not significantly enhanced by collecting blood specimens for culture at the time that patients experienced temperature spikes. A subset analysis based on patient age, gender, white blood cell count and specific cause of bacteremia generally also failed to reveal any associations.

Severe gastroenteritis and hypovolemic shock caused by Grimontia (Vibrio) hollisae infection.

Vibrio hollisae is a halophilic species that was recently reclassified as Grimontia hollisae. This organism is known to cause moderate to severe cases of gastroenteritis. We report a case of an individual who suffered a more severe form of this disease, presenting with profound hypotension and acute renal failure, secondary to hypovolemic shock.

Propionibacterium acnes as a cause of prosthetic valve aortic root abscess.

Propionibacterium acnes isolates usually have relatively low virulence and are often classified as contaminants when isolated from blood and tissue cultures. We report a patient with Propionibacterium acnes bacteremia and late prosthetic valve endocarditis, complicated by an aortic root abscess.

Fontana-positive grains in mycetoma caused by Microsporum canis.

We describe mycetoma caused by Microsporum canis occurring in a 9-year-old African-American girl. Pathologic evaluation showed a granulomatous dermatitis with numerous large fungal grains containing septate hyphae that were Fontana-Masson positive. Two cultures of pure grains grew M. canis. Mycetoma due to dermatophytes is very uncommon. The few instances reported have been pseudomycetoma (grains in the absence of sinus tracts). Our patient developed sinus tracts (true mycetoma). No prior reports were found of M. canis staining Fontana positive. Differentiation of dermatophyte-induced mycetoma from kerion is important because mycetomas require a combined approach including surgical debridement in addition to oral antifungal therapy.

Routine incubation of BacT/ALERT FA and FN blood culture bottles for more than 3 days may not be necessary.

We reviewed time to detection for 35,500 blood cultures collected in BacT/ALERT FA and FN bottles. In the first 3 days of incubation, 97.5% of the 2,609 clinically significant isolates were detected, suggesting that routine incubation for more than 3 days may not be necessary for FA and FN bottles.

Use of swabs without transport media for the Gen-Probe Group A Strep Direct Test.

For several years we used rayon or Dacron swabs with liquid transport media for collection and transport of throat swab specimens for testing with the Gen-Probe Group A Strep Direct Test (GASDT). A report of favorable results with a Dacron swab without any transport media for GASDT by another laboratory prompted us to compare detection of group A streptococci (GAS) with and without transport media (referred to as "wet" and "dry" swabs, respectively). Phase one of this study used swabs seeded with GAS. Initially, six recent clinical isolates of GAS were inoculated onto wet and dry swabs and stored at room temperature (RT). After 1, 2, and 3 days of storage, colony counting and GASDT were performed with the swabs. The results, expressed as the mean percentage of the results at zero time, were as follows: for GASDT with wet swabs at 1, 2, and 3 days, 62, 51, and 56%, respectively; for GASDT with dry swabs at 1, 2, and 3 days, 105, 80, and 85%, respectively; for colony counts with wet swabs at 1, 2, and 3 days, 52, 26, and 13%, respectively; for colony counts with dry swabs at 1, 2, and 3 days, 10, 0, and 0%, respectively. An additional six strains of GAS were tested in a similar manner, except that extracts of pharyngeal flora (PF) were added to the inocula. The results obtained with extracts of PF were comparable to those obtained with GAS alone. We also compared the performance of GASDT with wet and dry swabs stored at RT and 4 degrees C. Ten strains of GAS were inoculated onto wet and dry swabs, and GASDT was performed each day for 9 days. The GASDT results for swabs on day 9, expressed as the mean percentage of the results obtained at zero time, were as follows: dry swab and 4 degrees C, 59%; wet swab and 4 degrees C, 31%; dry swab and RT, 33%; and wet swab and RT, 19%. In phase two of this study we conducted a clinical evaluation to determine whether the differences observed with seeded specimens would also be evident with patient specimens. We used a single dry Dacron swab paired with a single rayon Bacti-Swab with liquid Stuart transport medium for the clinical evaluation. Specimens were collected from 1,005 outpatients, plated onto a Strep Selective Agar plate, and then tested within 30 min by GASDT. If culture of GAS from the same swab is used to define a true-positive test result, the sensitivities and specificities were as follows: GASDT with wet swabs, 86.2 and 98.5%, respectively; GASDT with dry swabs, 90.7 and 98.1%, respectively. However, the use of culture as the "gold standard" may understate the actual performance characteristics of GASDT, particularly for the dry swabs. In conclusion, for GASDT the use of swabs without transport media may be preferable to the use of swabs with transport media.

Implantable defibrillator pocket infection and bacteremia caused by Nocardia nova complex isolate.

Nocardia spp. are common environmental organisms that, to our knowledge, have never been implicated as causing an implantable defibrillator or pacemaker infection. We describe a 70-year-old male with a recent implantable cardiac defibrillator revision and subsequent device infection and bacteremia caused by a Nocardia nova complex isolate.