Browsing by Author "Salipante, Stephen J."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Effects of Therapeutic Antibiotic Exposure on the Oropharyngeal and Fecal Microbiota in Infants With Cystic Fibrosis
    (Wiley, 2025) Hayden, Hillary S.; Nelson, Maria T.; Ross, Sydney E.; Verster, Adrian J.; Bouzek, Drake C.; Eng, Alex; Waalkes, Adam; Penewit, Kelsi; Kopp, Benjamin T.; Siracusa, Christopher; Rock, Michael J.; Salipante, Stephen J.; Hoffman, Lucas R.; Sanders, Don B.; Pediatrics, School of Medicine
    Background: Systemic antibiotics can impact all microbes inhabiting patients, regardless of the intended target organism(s). We studied the simultaneous effects on respiratory and fecal microbiomes of β-lactam antibiotics administered for respiratory symptoms in infants with cystic fibrosis (IWCF). Objective: To compare the magnitude and duration of intended (respiratory) and unintended (fecal) antimicrobial action by analyzing oropharyngeal (OP) and fecal microbiota in IWCF. Design: Shotgun metagenomic sequencing and qPCR were performed on OP and fecal samples collected longitudinally from 14 IWCF (ages 1-17 months) during ("On Antibiotics") and after ("Off Antibiotics") β-lactam therapy, and from 5 IWCF (3-16 months) never treated with antibiotics. Results: Total bacterial loads (TBL) for On Antibiotics samples were lower than for both Never (OP and fecal) and Off Antibiotics samples (fecal only). α-diversities (within-sample) for OP On Antibiotics samples were lower than for Never and Off Antibiotics samples but did not differ between fecal sample groups. β-diversity (between-sample) differed between all OP sample groups and between fecal On and Never Antibiotics and Off and Never antibiotics samples; however, fecal On and Off Antibiotics sample β-diversities did not differ. Patterns of change in antibiotic resistance gene abundances reflected shifts in microbial community composition. Conclusions: β-lactam antibiotic exposure was followed by marked alterations in both OP and fecal microbiota. While microbiota appeared to rebound after treatment in both sample types, our results suggest that fecal microbiota recovered less than OP. The clinical consequences of these findings should be studied in IWCF and other populations frequently treated with antibiotics.