Assessment of Omitting MacConkey Agar as a Primary Inoculating Medium for MALDI-TOF MS-Based Bacterial Identification from Urine, Blood, and Respiratory Samples.

OBJECTIVE: MacConkey agar (MAC) is commonly used as a primary medium for conventional bacterial identification in clinical microbiology laboratories. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized microbial identification and is considered a reliable identification tool. While conventional identification methods rely on colony characteristics, MALDI-TOF MS requires a pure isolate on a solid medium. METHODS: This study investigated whether MAC can be omitted as a routine inoculation medium for urine, lower respiratory tract (LRT), and positive blood culture samples. The study included 462 clinical samples. Among these, 221 were urine samples, 141 were positive blood cultures, and the remaining 100 were LRT samples. The samples were inoculated on blood agar (BA) and MAC for the control group and on BA only for the experimental group, followed by incubation and identification with MALDI-TOF MS. RESULTS: The BA only group showed the same microbial identification using MALDI-TOF MS as the control BA and MAC groups for blood and LRT specimens. For urine samples, 99.1% (219/221) of the samples produced the same identification results for the two groups. The cause of discrepant results for two urine specimens was due to Proteus species overgrowth on BA, which hindered non-Proteus spp. identification for the BA-only group. CONCLUSION: Our results may indicate that omitting MAC has little or no impact on the recovery of organisms present in culture. However, due to possible Proteus spp. overgrowth, caution should be exercised in the decision to omit MAC from the primary inoculating medium, which necessitates further studies in other centers with a larger sample size.

Prospective research of human parechovirus and cytokines in cerebrospinal fluid of young children less than one year with sepsis-like illness: Comparison with enterovirus.

BACKGROUND: Human parechovirus (PeV) and enterovirus are important pathogens that cause viral infection and aseptic meningitis in young children. We aimed to investigate the rate of HPeV and enterovirus detection, and to characterize cytokine profiles in the cerebrospinal fluid (CSF) of young infants with sepsis-like illness or meningitis/encephalitis. STUDY DESIGN: This was a prospective cohort study. CSF samples were collected from 90 infants less than 1 year of age. PeV and enterovirus detection was performed using reverse transcription polymerase chain reaction. Fifteen cytokines in the CSF were measured simultaneously by using multiplex immunoassays. RESULTS: PeV (PeV-group) and enterovirus (EV-group) were detected in 10 (11.1%) and 12 (13.3%) CSF samples, respectively. Other aseptic meningitis (AM-group) was diagnosed in 22 (24.4%) patients. Forty-six (51.1%) patients exhibited non-central nervous system infection (Ngroup). The PeV-group had the lowest CSF leukocyte (2.1 ± 3.5/mm3, p=0.022) and blood leukocyte (7,953 ± 4,583/mm3, p=0.046) count and Creactive protein levels (0.2 ± 0.1 mg/dL, p=0.036), than did those in the EV- and AM-groups. CSF leukocyte count and protein levels were not significantly different between the PeV- and N-groups. The levels of interleukin (IL)-1ß, IL-5, IL-6, IL-12, and IL-17 were higher in the EVgroup; conversely, IL-2, IL-4, IL-7, and IL-13 were higher in the PeVgroup. CONCLUSIONS: Examinations to detect PeV in the CSF may help identify the etiological basis of undiagnosed febrile illness in young children. Significant differences in CSF and blood laboratory findings were observed between PeV- and enterovirus-infected children.

Characteristics of Bilirubin According to the Results of the Direct Antiglobulin Test and Its Impact in Hemolytic Disease of the Newborn.

BACKGROUND: Hyperbilirubinemia, which is a sign of hemolytic disease of the newborn (HDN), can irreversibly damage the central nervous system. OBJECTIVES: To determine the etiology of HDN in affected patients and characterize the changing pattern of bilirubin using direct antiglobulin testing (DAT). METHODS: We collected clinical data from newborns who underwent perinatal DAT and from their mothers, between August 2008 and July 2017. RESULTS: Among 303 neonates, 37 (12.2%) showed positive DAT results. The positive predictive values (PPVs) and negative predictive values (NPVs) based on DAT results were 75.7% and 28.9%, respectively, for starting phototherapy. Bilirubin levels increased more rapidly in the DAT-positive group, compared with the DAT-negative group. The initial bilirubin level differed significantly according to the etiology of hyperbilirubinemia. Further, neonates with anti-D showed higher delta bilirubin per day than neonates with other antibodies. CONCLUSION: Our results may help to determine the measurement period for bilirubin according to DAT results and etiology.

Comparison of Cerebrospinal Fluid Cytokine Levels in Children of Enteroviral Meningitis With Versus Without Pleocytosis.

In viral meningitis, proinflammatory cytokines were detected at higher levels in the cerebrospinal fluid (CSF) and might play an important role in the inflammatory process. Our goal was to compare the cytokine profiles in the CSF of children of enteroviral meningitis (EVM) with versus without CSF pleocytosis. In total, 158 patients were enrolled in this prospective cohort study and were classified as EVM (group-A, n = 101), nonenteroviral aseptic meningitis (group-B, n = 27), and control (group-C, n = 30) groups. Of the 101 children with EVM, 71 had CSF pleocytosis (group-A1) and 30 had CSF nonpleocytosis (group-A2). Fifteen cytokines/chemokines in the CSF were measured simultaneously by immunoassay. Significant differences were found in interleukin (IL)-2, IL-6, and IL-8 levels in the CSF across the 3 groups, with the highest levels in group-A, followed by group-B and group-C. The levels of IL-1ß, IL-2, IL-6, IL8, IL-10, interferon-γ, and tumor necrosis factor-α were significantly higher in the CSF of group-A1 than in that of group-A2. Group-A2 was significantly younger than group-A1 (3.4 ± 2.8 years versus 5.5 ± 3.2 years, P = 0.016). Significant differences between CSF pleocytosis and nonpleocytosis in EVM appear to be associated with distinct levels of CSF cytokines.

Increasing use of therapeutic apheresis as a liver-saving modality.

INTRODUCTION: Therapeutic plasma exchange (TPE) is used for temporary support of liver function in patients presenting with early graft dysfunction after liver transplantation (LT) or liver surgery. We analyzed the effect of therapeutic apheresis on patients with liver disease. METHODS: Between January 2011 and August 2016, 93 apheresis procedures were performed for 26 patients at our institution. Anti-ABO isoagglutination immunoglobulin (Ig) M titer was checked using a type A and type B 3% red blood cell (RBC) suspension in saline with two-fold serial dilutions of patient serum. Anti-ABO isoagglutination IgG titer was checked by a type A and B 0.8% RBC suspension using a low-ionic strength/Coombs card. RESULTS: ABO-incompatible (ABOi) LT was the most common (n=10, 38.5%) indication for apheresis; early graft dysfunction after LT (n=8, 30.7%) was the second most common. Median initial IgM and IgG anti-ABO titers for ABOi LT recipients were 1:16 (range, 1:8-1:128) and 1:48 (range, 1:8-1:2048). We performed preoperative TPE in 10 recipients (median number of sessions, 1.5; range, 1-11). Among patients with early graft dysfunction, those who underwent living donor LT had better survival (4/4; 100%) than those who underwent nonliving donor LT (0/3; 0%). Patients who underwent living donor LT first and then additional LT also survived after three TPE sessions. CONCLUSION: Therapeutic apheresis is associated with a good survival rate and is essential for liver support in patients with early graft dysfunction after LT or posthepatectomy liver failure and during preparation for ABOi LT.