Kyutaeg Lee, Dae Soon Kim, Moo Sang Chong
Ann Clin Microbiol 2018 March, 21(1): 1-7. Published on 20 March 2018.
Background: We attempted to determine the characteristics of diarrheal pathogens according to species, seasonal variations, and patient age using multiplex PCR for the epidemiologic study of diarrheal disease in Jeju Island.
Methods: From March 2015 to Feb 2017, stool specimens were collected from 537 diarrheal patients older than 16 years. Multiplex PCR was used to identify pathogens and found Group A Rotavirus, enteric Adenovirus, Norovirus GI/GII, Astrovirus, Salmonella spp., Shigella spp., Vibrio spp., Campylobacter spp., Clostridium difficile toxin B (CDB), Clostridium perfringens, Yersinia enterocolitica, Aeromonas spp., Escherichia coli O157:H7, and verocytotoxin-producing E. coli (VTEC).
Results: Pathogens were isolated from 221 of 537 samples (41.2%); 9.3% were positive only for viral pathogens; 30.2%, only for bacterial pathogens; and 1.7%, for both viral and bacterial pathogens. Bacteria were more prevalent in spring, summer, and autumn, but viral pathogens were more prevalent in winter. Overall prevalence were Campylobacter spp. (26.7%), Clostridium perfringens (23.9%); Norovirus GII (11.4%), CDB (8.2%), Aeromonas spp. (6.3%), Group A Rotavirus (5.1%), Salmonella spp. (3.9%), Astrovirus (3.9%), Norovirus GI (3.1%), Vibrio spp (2.7%), enteric Adenovirus (1.6%), Shigella spp. (1.2%), VTEC (1.2%), and Yersinia enterocolitica (0.4%). Group A Rotavirus and Norovirus GII were more prevalent in winter and early spring. Campylobacter spp., CDB, and C. perfringens were detected frequently, without seasonal variation.
Conclusion: Bacterial pathogens are more prevalent than viruses in acute diarrhea in adults living in Jeju Island, especially in spring, summer, and autumn. Viral pathogens are prevalent in winter. Campylobacter spp., CDB, and Clostridium perfringens are the major pathogens occurring without seasonal variations. These data will be helpful in identifying diarrheal pathogens and for treatments and prevention strategies.
[in Korean]
Eunyoung Lee, Yangsoon Lee
Ann Clin Microbiol 2018 March, 21(1): 8-11. Published on 20 March 2018.
Background: Carbapenem-resistant Enterobacteriaceae (CRE) are increasingly being reported throughout the world, which is a significant problem for patient treatment and infection control. Carbapenem-resistance in Enterobacteriaceae is mainly due to carbapenem- hydrolyzing β-lactamase, which tends to spread through genetic mobile elements. Therefore, the detection of carbapenemase-producing Enterobacteriaceae (CPE) carriers is particularly important for the prevention and epidemiological monitoring of these infections. In this study, we performed surveillance cultures for CPE in patients admitted to the hospital and evaluated the prevalence of CPE.
Methods: Stool cultures were obtained from a total of 228 patients at our tertiary-care hospital between March and May 2017. Stool specimens were inoculated on ChromID CARBA agar (bioMérieux, France) and incubated for 18-24 hours. Suspicious colonies with pink or bluish-green color were screened for CPE by the modified Hodge test (MHT) and carbapenemase inhibition test (CIT). We performed PCR to detect five carbapenemase genes, blaKPC, blaIMP, blaVIM, blaNDM, and blaOXA-48.
Results: Among 228 isolates, seven were suspicious for CPE: four Klebsiella pneumoniae, one Escherichia coli, one Enterobacter aerogenes, and one Serratia marcescens. Two K. pneumoniae isolates showed positive reactions in both the modified Hodge test and inhibition test with phenylboronic acid. By PCR, blaKPC was identified in these two K. pneumoniae isolates.
Conclusion: Our results showed a very low prevalence (2/228, 0.9%) of CPE in our tertiary-care hospital based on surveillance culture in a recent three month period.
Hyunjung Kim, Hyun Yong Jeong, Sangkwon Han, Shinhun Han, Jungil Choi, Bonghwan Jin, Taegeun Lim, Eun-Geun Kim, Dong Young Kim, Sang Hoon Song, Taek Soo Kim, Sunghoon Kwon
Ann Clin Microbiol 2018 March, 21(1): 12-19. Published on 20 March 2018.
Background: Timely intervention in the treatment of bloodstream infection is important for prescription of appropriate antimicrobials. With prompt determination of the antimicrobial susceptibility of a causative agent, rapid antimicrobial susceptibility test (AST) can help select the appropriate antimicrobial therapy. This clinical study is for evaluation of the clinical performance of the QMAC-dRAST for rapid AST directly from positive blood culture (PBC)s with Gram-positive cocci.
Methods: A total of 115 PBC samples with Gram- positive organisms (76 Staphylococcus spp. and 39 Enterococcus spp.) were evaluated by the QMAC- dRAST system, and their pure culture isolates were evaluated by the MicroScan WalkAway (Beckman Coulter, USA) as the comparative AST system. Thirteen antimicrobial agents were included, and the agreement and discrepancy rates of the QMAC- dRAST system (Quantamatrix Inc., Republic of Korea) compared to the MicroScan WalkAway were calculated. To resolve discrepancies, the broth microdilution method was performed.
Results: The QMAC-dRAST system exhibited a categorical agreement rate of 94.9% (1,126/1,187) and an essential agreement rate of 98.3% (1,167/1,187). The QMAC-dRAST system yielded very major (false- susceptible) errors at 1.0% (5/485), major (false-resistant) errors at 1.3% (9/693), and minor errors at 4.0% (47/1,187) compared to the MicroScan WalkAway. The QMAC-dRAST system significantly eliminated 30 hours of total turnaround time by combination of direct inoculation of PBC and an image-based approach.
Conclusion: The results of the QMAC-dRAST system were highly accurate. Thereby, the QMAC-dRAST may provide essential information to accelerate therapeutic decisions for earlier and adequate antibiotic treatment and patient management in clinical settings.
Kyuhwa Hur, Eunyoung Lee, Jongmyeong Kang, Yangsoon Lee
Ann Clin Microbiol 2018 March, 21(1): 20-22. Published on 20 March 2018.
Campylobacter fetus may cause infections such as septicemia, peritonitis, meningitis, endocarditis, septic arthritis, and cellulitis, increasing the risk of spontaneous abortion but decreasing the likelihood of gastroenteritis. We identified C. fetus from continuous ambulatory peritoneal dialysis (CAPD) fluid using 16S rRNA gene sequencing. It is significant that this is the first case report in Korea of CAPD peritonitis caused by C. fetus, which is known to be rare. (Ann Clin Microbiol 2018;21:20-22)
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