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

June, 2022. Vol. 25 No. 2.

Original article

Inhibitory effects of copper, brass, and stainless steel surfaces on multidrug-resistant microorganisms in Korea

Jung-Beom Kim, Jae-Kwang Kim, Jaewoong Lee, Hiun Suk Chae, Hae Kyung Lee, Yeon-Joon Park

Ann Clin Microbiol 2022 June, 25(2): 31-39. Published on 20 June 2022.

Background: The aim of this study was to analyze the inhibitory effects of copper, brass (78% copper, 22% tin), and stainless steel surfaces on multidrug-resistant Acinetobacter baumannii (MRAB), extended-spectrum beta-lactamase (ESBL) Escherichia coli, and carbapenem-resistant Klebsiella pneumoniae (CRKP).

Methods: MRAB, ESBL E. coli, and CRKP were isolated at Uijeongbu St. Mary’s Hospital in 2020. A. baumannii ATCC BAA-747, E. coli ATCC 25922, and K. pneumoniae ATCC 700603 were used as reference strains. The initial bacterial cell count of each inoculum was adjusted to 8 log CFU/mL using phosphate buffered saline, Copper, brass, and stainless steel plates were inoculated with 9 mL of MRAB, ESBL E. coli, and CRKP inoculum solutions. The bacterial cell count was measured from the beginning to the 20th day in an incubator maintained at 35°C.

Results: MRAB, ESBL E. coli, and CRKP isolates were not detected on the copper and brass plates after 4, 5.5, and 6.5 hours, respectively. MRAB, ESBL E. coli, and CRKP isolates were not detected on the stainless steel plate after 15, 20, and 20 days, respectively. The bactericidal effects of copper and brass were much stronger than those of stainless steel.

Conclusion: The use of copper and copper alloys should be considered to prevent cross-infection in hospitals.

Original article

Antiviral resistance in human cytomegalovirus due to UL54 mutations without UL97 mutations in Korea

Kuenyoul Park, Kyu-Hwa Hur, Heungsup Sung, Sang-Ho Choi, Mi-Na Kim

Ann Clin Microbiol 2022 June, 25(2): 41-46. Published on 20 June 2022.

Background: The concurrent detection of human cytomegalovirus (CMV) with UL97 and UL54 mutations is crucial for prescribing adequate antiviral treatment when drug-resistant CMV infection is suspected. We investigated the frequency of resistance-conferring mutations among patients with persistent or recurrent CMV infection and further reviewed the subgroup with UL54 mutations without UL97 mutations.

Methods: Patients with persistent or recurrent CMV infection after 4 weeks of treatment with ganciclovir or foscarnet were consecutively enrolled between November 2012 and May 2019. The direct sequencing of UL97 and UL54 was performed to detect resistance mutations in CMV.

Results: A total of 101 sequencing datasets were obtained from 65 enrolled patients. CMV UL97 and UL54 mutations were detected in 15.4% (10/65) and 9% (6/65) of patients, respectively. The CMV retrieved from two patients (3%) had mutations in both genes. Four patients with CMV UL54 mutations alone had a history of haploidentical peripheral blood stem cell transplantation, and foscarnet was administered for over 4 weeks to these patients; 21.5% of patients had suspected resistant CMV infection with either UL97 or UL54 mutations.

Conclusion: In this study, CMV UL54 mutations but not UL97 mutations were found in patients subjected to prolonged foscarnet administration for CMV disease.

Original article

Clinical and microbiological risk factors for community-associated Clostridioides difficile infections in Korea

Young Ah Kim, Heejung Kim, Dokyun Kim, Changseung Liu, Seok Hoon Jeong

Ann Clin Microbiol 2022 June, 25(2): 47-52. Published on 20 June 2022.

Background: The incidence of community-associated (CA) Clostridioides difficile infection (CDI) has increased in Korea. In this study, we evaluated CA-CDI risk factors in terms of clinical features and ribotype considering its region-specific molecular epidemiology.

Methods: A retrospective case-control study was performed on two groups of CDI patients: 127 subjects with CA-CDI and 265 subjects with healthcare-associated (HA)-CDI. Risk factors for CA-CDI were evaluated in terms of clinical and microbiological features such as toxin type and ribotype.

Results: A comparison of the two groups of CDI patients revealed that inflammatory bowel disease, diarrhea, abdominal pain, and fever were more closely associated with CA-CDI. The toxin types and ribotypes of C. difficile were similar between the two groups. After adjusting for variables, no risk factors were identified for CA-CDI compared with HA-CDI.

Conclusion: Specific risk factors for CA-CDI were not identified in this study.

Original article

Current prevalence of the crpP gene in carbapenemase-producing Pseudomonas aeruginosa blood isolates in Korea

Jinho Heo, Yu Jeong Choi, Young Ah Kim, Seok Hoon Jeong, Jong Hee Shin, Kyeong Seob Shin, Jeong Hwan Shin, Young Ree Kim, Hyun Soo Kim, Young Uh, Nam Hee Ryoo

Ann Clin Microbiol 2022 June, 25(2): 53-59. Published on 20 June 2022.

Background: Recently, CrpP enzymes have been described as a novel cause of ciprofloxacin resistance. The crpP gene encodes a novel protein that specifically confers resistance to ciprofloxacin through an adenosine triphosphate-dependent mechanism that phosphorylates the antimicrobial. In this study, the current prevalence of the crpP gene in carbapenemase-producing Pseudomonas aeruginosa blood isolates was evaluated.

Methods: During the study of the Antimicrobial Resistance Surveillance System in Korea, 22 blood isolates of carbapenemase-producing P. aeruginosa were collected from nine general hospitals and two nursing homes in the year 2020. Resistance genes and phylogenic trees were analyzed with the whole genome sequencing data.

Results: A total of 11 P. aeruginosa blood isolates coharbored the crpP and carbapenemase genes (nine IMP-6 producers and two GES-5-producers). Nine NDM-1-producers coharbored aac(6′)-Ib-cr and qnrVC1. One GES-9-producer also carried aac(6′)-Ib-cr, and one NDM-1producer also carried qnrVC1. The phylogenic tree showed no epidemiologic link among the 22 carbapenemase-producing P. aeruginosa isolates.

Conclusion: This is the first report on the current prevalence of the crpP gene in carbapenemase-producing P. aeruginosa blood isolates in Korea.

Book review

Book review: “The New Microbiology: From Microbiomes to CRISPR”

Jung Oak Kang

Ann Clin Microbiol 2022 June, 25(2): 61-65. Published on 20 June 2022.

At the time when owing to COVID-19 pandemic, the public is more interested in infectious diseases and pathogens than in any other period, a book titled “The New Microbiology: From Microbiomes to CRISPR” by the renowned microbiologist Pascale Cossart was translated and published by our colleague. In this book, the author describes important discoveries and new conceptual advances in the field of microbiology over the past century. The author emphasizes that bacteria form a microbiome and lead a social life and explains the impact and importance of the microbiome on human health and ecosystem. Further, the discovery of ‘CRISPR,’ which led to the era of genome editing and gene therapy, has been described in details. This book will dramatically change our perspective regarding all living things, including bacteria, plants, animals, and even insects, as well as our eating habits and daily life, based on the new understanding of microorganisms. I recommend reading this book as I am sure that it will broaden the perspectives of both clinical microbiologists and health care workers.