Browsing by Author "Kirkpatrick, Lindsey M."

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    16S rRNA deep sequencing identifies Actinotignum schaalii as the major component of a polymicrobial intra-abdominal infection and implicates a urinary source
    (Microbiology Society, 2017-05-03) Bryan, Andrew; Kirkpatrick, Lindsey M.; Manaloor, John J.; Salipante, Stephen J.; Pediatrics, School of Medicine
    Introduction. It can be difficult to catalogue the individual organisms comprising polymicrobial patient infections, both because conventional clinical microbiological culture does not facilitate the isolation and enumeration of all members of a complex microbial community, and because fastidious organisms may be mixed with organisms that grow rapidly in vitro. Empiric antimicrobial treatment is frequently employed based on the anatomical site and the suspected source of the infection, especially when an appropriately collected surgical specimen is not obtained., Case presentation. We present a case of an intra-abdominal infection in a patient with complex anatomy and recurrent urinary tract infections. Imaging did not reveal a clear source of infection, no growth was obtained from urine cultures and initial abdominal fluid cultures were also negative. In contrast, 16S rRNA deep sequencing of abdominal fluid samples revealed mixed bacterial populations with abundant anaerobes, including Actinotignum schaalii (Actinobaculum schaalii). Ultimately, only Enterobacter cloacae complex and meticillin-resistant Staphylococcus aureus, both of which were identified by sequencing, were recovered by culture., Conclusion. The clinical application of 16S rRNA deep sequencing can more comprehensively and accurately define the organisms present in an individual patient's polymicrobial infection than conventional microbiological culture, detecting species that are not recovered under standard culture conditions or that are otherwise unexpected. These results can facilitate effective antimicrobial stewardship and help elucidate the possible origins of infections.
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    Simultaneous quantitation of five triazole anti-fungal agents by paper spray-mass spectrometry
    (De Gruyter, 2020-01-13) Skaggs, Christine L.; Ren, Greta J.; Elgierari, El Taher M.; Sturmer, Lillian R.; Shi, Run Z.; Manicke, Nicholas E.; Kirkpatrick, Lindsey M.; Pediatrics, School of Medicine
    Introduction: Invasive fungal disease is a life-threatening condition that can be challenging to treat due to pathogen resistance, drug toxicity, and therapeutic failure secondary to suboptimal drug concentrations. Frequent therapeutic drug monitoring (TDM) is required for some anti-fungal agents to overcome these issues. Unfortunately, TDM at the institutional level is difficult, and samples are often sent to a commercial reference laboratory for analysis. To address this gap, the first paper spray-mass spectrometry assay for the simultaneous quantitation of five triazoles was developed. Methods: Calibration curves for fluconazole, posaconazole, itraconazole, hydroxyitraconazole, and voriconazole were created utilizing plasma-based calibrants and four stable isotopic internal standards. No sample preparation was needed. Plasma samples were spotted on a paper substrate in pre-manufactured plastic cartridges, and the dried plasma spots were analyzed directly utilizing paper spray-mass spectrometry (paper spray MS/MS). All experiments were performed on a Thermo Scientific TSQ Vantage triple quadrupole mass spectrometer. Results: The calibration curves for the five anti-fungal agents showed good linearity (R2 = 0.98 – 1.00). The measured assay ranges (LLOQ – ULOQ) for fluconazole, posaconazole, itraconazole, hydroxyitraconazole, and voriconazole were 0.5 – 50 μg/mL, 0.1 – 10 μg/mL, 0.1 – 10 μg/mL, 0.1 – 10 μg/mL, and 0.1 – 10 μg/mL, respectively. The inter- and intra-day accuracy and precision were less than 25% over the respective ranges. Conclusion: We developed the first rapid paper spray MS/MS assay for simultaneous quantitation of five triazole anti-fungal agents in plasma. The method may be a powerful tool for near point-of-care TDM aimed at improving patient care by reducing turnaround time and for use in clinical research.