2.Application and Prospect of Nanopore Sequencing Technology in Etiological Diagnosis of Blood Stream Infection.
Wei GUO ; Shuai-Hua FAN ; Peng-Cheng DU ; Jun GUO
Acta Academiae Medicinae Sinicae 2023;45(2):317-321
Blood stream infection (BSI),a blood-borne disease caused by microorganisms such as bacteria,fungi,and viruses,can lead to bacteremia,sepsis,and infectious shock,posing a serious threat to human life and health.Identifying the pathogen is central to the precise treatment of BSI.Traditional blood culture is the gold standard for pathogen identification,while it has limitations in clinical practice due to the long time consumption,production of false negative results,etc.Nanopore sequencing,as a new generation of sequencing technology,can rapidly detect pathogens,drug resistance genes,and virulence genes for the optimization of clinical treatment.This paper reviews the current status of nanopore sequencing technology in the diagnosis of BSI.
Humans
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Nanopore Sequencing
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Sepsis/diagnosis*
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Bacteremia/microbiology*
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Bacteria
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Blood Culture/methods*
3.Bacteremia Caused by Laribacter hongkongensis Misidentified as Acinetobacter lwoffii: Report of the First Case in Korea.
Dae Sik KIM ; Yu Mi WI ; Ji Young CHOI ; Kyong Ran PECK ; Jae Hoon SONG ; Kwan Soo KO
Journal of Korean Medical Science 2011;26(5):679-681
Laribacter hongkongensis is an emerging pathogen in patients with community-acquired gastroenteritis and traveler's diarrhea. We herein report a case of L. hongkongensis infection in a 24-yr-old male with liver cirrhosis complicated by Wilson's disease. He was admitted to a hospital with only abdominal distension. On day 6 following admission, he complained of abdominal pain and his body temperature reached 38.6degrees C. The results of peritoneal fluid evaluation revealed a leukocyte count of 1,180/microL (polymorphonuclear leukocyte 74%). Growth on blood culture was identified as a gram-negative bacillus. The isolate was initially identified as Acinetobacter lwoffii by conventional identification methods in the clinical microbiology laboratory, but was later identified as L. hongkongensis on the basis of molecular identification. The patient was successfully treated with cefotaxime. To the best of our knowledge, this case is the first report of hospital-acquired L. hongkongensis bacteremia with neutrophilic ascites.
Acinetobacter/isolation & purification
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Acinetobacter Infections/complications/diagnosis/microbiology
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Bacteremia/complications/*microbiology
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Cefotaxime/therapeutic use
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Diagnosis, Differential
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Gastroenteritis/complications/*diagnosis/*microbiology
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Hepatolenticular Degeneration/complications/microbiology
;
Humans
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Liver Cirrhosis/complications/microbiology
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Male
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Neisseriaceae/*isolation & purification
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Phylogeny
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Republic of Korea
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Young Adult
5.First Korean Case of Robinsoniella peoriensis Bacteremia in a Patient with Aspiration Pneumonia.
Yongbum JEON ; Taek Soo KIM ; Hong Bin KIM ; Kyoung Un PARK ; Junghan SONG ; Eui Chong KIM
Annals of Laboratory Medicine 2012;32(5):370-374
Robinsoniella peoriensis has recently been identified as a Gram-positive, spore-forming, anaerobic rod originally recovered from swine manure storage pits. To date, 6 cases of R. peoriensis infection have been reported, including 2 cases of bacteremia, 1 of abdominal fluid collection, and 3 of wound infection. In the present study, we report a 76-yr-old man with R. peoriensis bacteremia who developed aspiration pneumonia. Gram staining of a purified colony revealed Gram-positive, rod-shaped bacteria. Biochemical identification using API 20 A (bioMerieux, France) indicated presence of Clostridium spp. We performed both 500-bp and full-gene sequencing of 16S rRNA of the isolate. The sequence was analyzed with MicroSeq ID 16S rRNA Library v2.0 (Applied Biosystems, USA), GenBank Basic Local Alignment Search Tool (BLAST) (http://www.ncbi.nlm.nih.gov/genbank), and EzTaxon database v2.1 (http://www.eztaxon.org). The 500-bp 16S rRNA sequence of the blood culture isolate showed 99.16-99.79% similarity with R. peoriensis and the full-gene 16S rRNA sequence showed 98.87-99.50% similarity with R. peoriensis. The organism was confirmed as R. peoriensis by using all of the mentioned databases except for MicroSeq, which did not include the RNA sequence of this bacterium. This case suggests that identification of R. peoriensis might be challenging in clinical laboratories with no access to molecular methods, as certain commercial identification systems may not identify, or may misidentify, this organism. To the best of our knowledge, this is the first report of the isolation of R. peoriensis in Korea.
Aged
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Bacteremia/*microbiology
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Clostridium/classification/genetics/*isolation & purification
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Databases, Genetic
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Humans
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Male
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Phylogeny
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Pneumonia, Aspiration/*diagnosis/microbiology
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RNA, Ribosomal, 16S/chemistry/genetics
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Republic of Korea
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Sequence Analysis, DNA
6.A Case of Catheter-Related Bacteremia of Tsukamurella pulmonis.
Hyoeun Eun SHIM ; Heungsup SUNG ; Seung Mi BAEK ; Seung NAMGUNG ; Mi Na KIM ; Yong Gyun KIM ; Gyu Hyung LEE
The Korean Journal of Laboratory Medicine 2009;29(1):41-47
Tsukamurella pulmonis is an aerobic actinomycete. We report a catheter-related bacteremia of T. pulmonis. A 39 yr-old male with ALL was hospitalized to receive bone marrow transplantation (BMT). Although the patient developed a high fever at the 7th hospital day (HD), it subsided with vancomycin treatment, and he received BMT at 9th HD. Fever resurged at 16th HD despite sustained treatment with vancomycin, meropenem, and amphotericin B, but subsided with removal of Hickman catheter (HC) at 19th HD. Three sets of blood cultures comprising one from the HC and two from venipunctures were taken at 7th, 16th, and 19th HD, and the distal tip of the HC was also cultured. The aerobic vials of all 3 HC-withdrawn blood cultures and one peripheral blood culture taken at 19HD and the HC tip culture grew long, straight, thin gram-positive rods that were positive on modified Kinyoun stain. This organism showed tiny, rough, grey colonies after 3-day incubation and grew to large flat colonies when incubation was extended. It was catalase-positive, urease-positive, and alkaline-slant/alkaline-deep on triple sugar iron agar, and hydrolyzed hypoxanthine. The sequence of 1,296 base pairs of 16S rRNA of this organism showed a 100.0% homology with the published sequence of T. pulmonis DSM 44142T. To our knowledge, this is the first report of T. pulmonis bacteremia in Korea.
Actinomycetales/classification/genetics/isolation & purification
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Actinomycetales Infections/diagnosis/*microbiology/therapy
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Adult
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Bacteremia/*diagnosis/microbiology/therapy
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Bone Marrow Transplantation
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Catheter-Related Infections/*microbiology
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Humans
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Leukemia, Myeloid, Acute/therapy
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Male
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Phylogeny
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RNA, Ribosomal, 16S/genetics
7.A Case of Bacteremia by Neisseria gonorrhoeae Coincident with Massive Hemorrhage of Esophageal Varices.
Dahae WON ; Dongheui AN ; Mi Na KIM ; Young Sang LEE
The Korean Journal of Laboratory Medicine 2011;31(2):118-121
A 42-yr-old man with hepatitis B virus associated liver cirrhosis was admitted to the emergency room because of multiple seizures, a history of chills and myalgia over the previous 2 weeks, and 3 days of melena. He was febrile with a temperature of 38.0degrees C. There were no symptoms and signs related to the genitourinary system, skin, or joints. Three sets of blood cultures were obtained and oxidase-positive, gram-negative diplococci were detected after 25.9-26.9 hr of incubation in all aerobic vials. The organism was positive for catalase and oxidase, and was identified as Neisseria gonorrhoeae, using a Vitek Neisseria-Haemophilus Identification card (bioMerieux Vitek, Inc., USA). Further, 16S rRNA sequencing of this isolate revealed a 99.9% homology with the published sequence of N. gonorrhoeae strain NCTC 83785 (GenBank Accession No. NR_026079.1). Acute bleeding by variceal rupture seems to be a likely route of introduction of N. gonorrhoeae from the mucosa into the blood. To the best of our knowledge, this is the first case of gonococcal bacteremia in Korea.
Adult
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Bacteremia/complications/*diagnosis/microbiology
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Catalase/metabolism
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Esophageal and Gastric Varices/complications/*diagnosis
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Gastrointestinal Hemorrhage/*etiology
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Gonorrhea/complications/*diagnosis/microbiology
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Humans
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Ligation
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Liver Cirrhosis/diagnosis
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Male
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Neisseria gonorrhoeae/genetics/*isolation & purification
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Oxidoreductases/metabolism
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RNA, Ribosomal, 16S/chemistry/genetics
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Sequence Analysis, DNA
9.Comparison of Genotypes and Enterotoxin Genes Between Staphylococcus aureus Isolates from Blood and Nasal Colonizers in a Korean Hospital.
Kyong Ran PECK ; Jin Yang BAEK ; Jae Hoon SONG ; Kwan Soo KO
Journal of Korean Medical Science 2009;24(4):585-591
In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness.
Bacteremia/*microbiology
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Enterotoxins/genetics
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Genotype
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Hospitals
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Humans
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Korea
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Methicillin-Resistant Staphylococcus aureus/genetics/*isolation & purification
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Microbial Sensitivity Tests
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Nose/*microbiology
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Staphylococcal Infections/diagnosis/*microbiology
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Staphylococcus aureus/genetics/*isolation & purification