Due to limited therapeutic options, the spread of extended-spectrum beta-lactamases (ESBLs) have become a major public health concern. We conducted a prospective, randomized, open-label comparison of the therapeutic efficacy of piperacillin-tazobactam (PTZ), cefepime, and ertapenem in febrile nosocomial urinary tract infection with ESBL-producing Escherichia coli (ESBL-EC). This study was conducted at three university hospitals between January 2013 and August 2015. Hospitalized adult patients presenting with fever were screened for healthcare-associated urinary tract infection (HA-UTI). When ESBL-EC was solely detected and susceptible to a randomized antibiotic in vitro, the case was included in the final analysis. Participants were treated for 10–14 days with PTZ, cefepime, or ertapenem. A total of 66 participants were evenly assigned to the PTZ and ertapenem treatment groups. After the recruitment of six participants, assignment to the cefepime treatment group was stopped because of an unexpectedly high treatment failure rate. The baseline characteristics of these participants did not differ from participants in other treatment groups. The clinical and microbiological response to PTZ treatment was estimated to be 94% and was similar to the response to ertapenem treatment. The efficacy of cefepime was 33.3%. In the cefepime group, age, Charlson comorbidity index, genotype, and minimal inhibitory concentration (MIC) did not significantly affect the success of treatment. Similarly, genotype seemed to be irrelevant with respect to clinical outcome in the PTZ group. Expired cases tended to involve septic shock with a high Charlson comorbidity index and high MIC. Results from this study suggest that PTZ is effective in the treatment of urinary tract infection caused by ESBL-EC when the in vitro test indicates susceptibility. In addition, cefepime should not be used as an alternative treatment for urinary tract infection caused by ESBL-EC. The trial was registered with the Clinical Research Information Service of Korea Centers for Disease Control and Prevention. (KCT0001895)

Seong Jin Choi, M.D., Soon Deok Park, M.S., In Ho Jang, M.S., Young Uh, M.D., and Anna Lee, M.D.. Ann Lab Med 2012;32:194-200. https://doi.org/10.3343/alm.2012.32.3.194

Methicillin-resistant Staphylococcus aureus (MRSA) is the most prevalent cause of bloodstream infections (BSIs) and is recognized as a major nosocomial pathogen. This study aimed to evaluate a newly designed multiplex real-time PCR assay capable of the simultaneous detection of mecA , S. aureus , and coagulase-negative staphylococci (CoNS) in blood culture specimens. The Real-MRSA and Real-MRCoNS multiplex real-time PCR assays (M&D, Republic of Korea) use the TaqMan probes 16S rRNA for Staphylococcus spp., the nuc gene for S. aureus , and the mecA gene for methicillin resistance. The detection limit of the multiplex real-time PCR assay was 10 ³ CFU/ml per PCR for each gene target. The multiplex real-time PCR assay was evaluated using 118 clinical isolates from various specimen types and a total of 350 positive blood cultures from a continuous monitoring blood culture system. The results obtained with the multiplex real-time PCR assay for the three targets were in agreement with those of conventional identification and susceptibility testing methods except for one organism. Of 350 positive bottle cultures, the sensitivities of the multiplex real-time PCR kit were 100% (166/166 cultures), 97.2% (35/36 cultures), and 99.2% (117/118 cultures) for the 16S rRNA, nuc , and mecA genes, respectively, and the specificities for all three targets were 100%. The Real-MRSA and Real-MRCoNS multiplex real-time PCR assays are very useful for the rapid accurate diagnosis of staphylococcal BSIs. In addition, the Real-MRSA and Real-MRCoNS multiplex real-time PCR assays could have an important impact on the choice of appropriate antimicrobial therapy, based on detection of the mecA gene.

Gyu Ri Kim, Ph.D., Eun-Young Kim, Ph.D., Si Hyun Kim, Ph.D., Hae Kyung Lee, M.D., Jaehyeon Lee, M.D., Jong Hee Shin, M.D., Young Ree Kim, M.D., Sae Am Song, M.D., Joseph Jeong, M.D., Young Uh, M.D., Yu Kyung Kim, M.D., Dongeun Yong, M.D., Hyun Soo Kim, M.D., Sunjoo Kim, M.D., Young Ah Kim, M.D., Kyeong Seob Shin, M.D., Seok Hoon Jeong, M.D., Namhee Ryoo, M.D., and Jeong Hwan Shin, M.D.. Ann Lab Med 2023;43:45-54. https://doi.org/10.3343/alm.2023.43.1.45

Jung IY, et al. Yonsei Med J. 2019 Jun;60(6):592-596. https://doi.org/10.3349/ymj.2019.60.6.592