Annals of Clinical Microbiology, The official Journal of the Korean Society of Clinical Microbiology

6

Weeks in Review

2

Weeks to Publication
Indexed in KCI, KoreaMed, Synapse, DOAJ
Open Access, Peer Reviewed
pISSN 2288-0585 eISSN 2288-6850

September, 2021. Vol. 24 No. 3.

Mini review

Clinical Usefulness of SARS-CoV-2 Antibody Test

Hyun Soo Kim

Ann Clin Microbiol 2021 September, 24(3): 67-73. Published on 20 September 2021.

SARS-CoV-2 antibody assay is a test that checks whether an antibody against the SARSCoV-2 virus has been formed in the blood after SARS-CoV-2 infection or vaccination. SARSCoV-2 antibody is detected 1–2 weeks after infection, and antibodies are produced in more than 90% of infected patients. The duration for the formation of antibodies differs by individual and by type of antibody. In the case of IgG, it is at least several months or longer, and the relationship between antibodies and immunity is being studied. As test methods, enzyme-linked immunosorbent assay (ELISA), chemiluminescence immunoassay (CIA), immunochromatographic assay, and neutralizing antibody assay have been developed and used. The target antibody to be detected differs depending on the type of recombinant antigen and the type of secondary antibody in reagents. Many kinds of commercialized SARS-CoV-2 antibody assays are currently being developed, and the S (spike) protein, N (nucleocapsid) protein, S1 or RBD (receptor binding domain) part of the S protein, and a mixture of these antigens are used as recombinant antigens of reagents. IgG, IgM, IgA, or total immunoglobulin antibodies in patients’ blood that react with these reagent antigens are detected. In this review, the types and performance of SARS-CoV-2 antibody tests and the guidelines for COVID-19 antibody tests published domestically and abroad were investigated.

[in Korean]

Original article

Comparison of Blood Culture Parameters between 2 and 10 mL Aerobic Bottles from Patients with Sepsis

Seong Chun Kim, Sunjoo Kim

Ann Clin Microbiol 2021 September, 24(3): 75-81. Published on 20 September 2021.

Background: Blood volume is the most important parameter for an optimal blood culture; however, the effect of blood volume on blood culture is not clearly understood from patients with sepsis.

Methods: Blood cultures were obtained from 1,049 patients (≥ 15 years old) who visited the emergency department (ED). Two sets of 20 mL each was collected from each patient, 12 mL of which was transferred to 2 and 10 mL FA Plus (aerobic) bottles (bioMérieux, USA) and the remaining into an FN Plus (anaerobic) bottle. Medical records were reviewed to confirm the diagnosis and clinical significance of the blood culture isolates. The positive rate and time-todetection (TTD) were compared between the 2 and 10 mL groups.

Results: Among the 2,098 sets collected, 612 sets (29.2%) were excluded due to inadequate (either too much or too little) blood volume. The positive rate of clinically significant pathogens was lower in the 2 mL group (6.1%) than in the 10 mL group (7.5%) (P = 0.003) among the 1,486 sets. However, there was no significant difference in the positive rate (11.0% vs. 12.5%, P = 0.152) and TTD (15.7 hours vs. 14.2 hours, P = 0.299) among the 585 (39.4%) patients with sepsis.

Conclusion: The positive rate and TTD were similar between the 2 and 10 mL groups from patients with sepsis who visited the ED, suggesting a high concentration of bacteremia in this group. Therefore, a smaller blood volume should be carefully considered in patients with sepsis in the ED.

Original article

Evaluation of Five Automated Urine Analyzers as Screening Instruments for Enhancing Diagnostic Efficiency in Urinary Tract Infection

Jooyoung Cho, Jung-Hyun Byun, Sang-Guk Lee, Kyeongjin Oh, Beomchan Jeon, Dongeun Yong, Jeong-Ho Kim

Ann Clin Microbiol 2021 September, 24(3): 83-96. Published on 20 September 2021.

Background: Although urine culture is considered a reference standard for the diagnosis of urinary tract infection (UTI), it is time-consuming, labor-intensive, and expensive. Here, we evaluated the performance of five recent automated urine analyzers for UTI diagnosis.

Methods: For the 510 specimens analyzed, the criterion for ‘significant bacteriuria’ was defined as ≥ 104 CFU/mL in the inoculated plate for all specimens or ≥ 103 CFU/mL for specimens from patients using a Foley catheter or with urinary symptoms. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of UTI were analyzed using indicators individually, in different combinations, or with various cut-off values.

Results: Seventy-one specimens (13.9%) exhibited ‘significant bacteriuria’. In the receiver operating characteristics curve analysis, UF-5000 (Sysmex Corp., Japan) showed the highest area under the curve values for both males and females (0.876 and 0.846, respectively). The PPVs for specimens from males with all indicators positive increased up to 100% after adjusting the cut-off values. NPVs for specimens with all indicators negative were 94.3%98.2% in males and 78.1%–93.8% in females after adjusting the cut-off values.

Conclusion: As a rapid and accurate diagnostic tool, urine sediment analyzers can be valuable for UTI diagnosis by reducing unnecessary culture and can help clinicians determine a treatment plan.

Original article

Fecal Microbiota Transplantation against Gut Colonization Using a Multidrug-Resistant Organism

Seul Ki Lee, Ji Eun Choi, Chae Min Shin, Mi-Na Kim

Ann Clin Microbiol 2021 September, 24(3): 97-104. Published on 20 September 2021.

Background: Fecal microbiota transplantation against gut colonization using a multidrugresistant organism is a technique used to treat infections through normalizing the gut microbiota via fecal microbiota transplantation in patients with confirmed colonization by carbapenem-resistant Enterobacteriaceae (CRE) or vancomycin-resistant enterococci (VRE) based on a fecal culture test within the past one week. In this study, we aimed to determine the safety and effectiveness of this technique.

Methods: The safety and effectiveness were assessed via a systematic review. A literature search was conducted using five Korean databases, such as KoreaMed, and international databases, including Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library.

Results: Main results are described here. From the studies retrieved using the aforementioned search strategy, the remaining 581 studies were screened using the inclusion and exclusion criteria, resulting in the selection of nine studies for further consideration. In terms of safety, many studies reported deaths and adverse reactions associated with different causes. Fewer studies reported the rate of colonization; however, the effect of colony rate was inconsistent when compared to no treatment group. Additionally, none of the studies assessed the recurrence rate, a decrease in the prevalence of diseases related to infection by multidrugresistant bacteria, and the quality of life.

Conclusion: Fecal bacterial colonization for the decolonization of intestinal multidrugresistant bacteria was evaluated using a technique that requires further research as there is insufficient literature evidence to validate its safety and efficacy in treating infections through normalizing the intestinal flora of patients with confirmed colonization by CRE or VRE.

[in Korean]

Original article

Nasal Colonization of Serine Protease esp-Positive Staphylococcus epidermidis Affecting Staphylococcus aureus Colonization

Goeun Kang, Hyun Soo Kim, Han-Sung Kim, Wonkeun Song, Jae-Seok Kim

Ann Clin Microbiol 2021 September, 24(3): 105-110. Published on 20 September 2021.

Background: Fecal microbiota transplantation against gut colonization using a multidrugresistant organism is a technique used to treat infections through normalizing the gut microbiota via fecal microbiota transplantation in patients with confirmed colonization by carbapenem-resistant Enterobacteriaceae (CRE) or vancomycin-resistant enterococci (VRE) based on a fecal culture test within the past one week. In this study, we aimed to determine the safety and effectiveness of this technique.

Methods: The safety and effectiveness were assessed via a systematic review. A literature search was conducted using five Korean databases, such as KoreaMed, and international databases, including Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library.

Results: Main results are described here. From the studies retrieved using the aforementioned search strategy, the remaining 581 studies were screened using the inclusion and exclusion criteria, resulting in the selection of nine studies for further consideration. In terms of safety, many studies reported deaths and adverse reactions associated with different causes. Fewer studies reported the rate of colonization; however, the effect of colony rate was inconsistent when compared to no treatment group. Additionally, none of the studies assessed the recurrence rate, a decrease in the prevalence of diseases related to infection by multidrugresistant bacteria, and the quality of life.

Conclusion: Fecal bacterial colonization for the decolonization of intestinal multidrugresistant bacteria was evaluated using a technique that requires further research as there is insufficient literature evidence to validate its safety and efficacy in treating infections through normalizing the intestinal flora of patients with confirmed colonization by CRE or VRE.

[in Korean]