Successful control of the first carbapenem-resistant Klebsiella pneumoniae outbreak in a Chinese hospital 2017-2019.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is considered as a serious global threat. CRKPs occurred only sporadically in the Second Hospital of Shanxi Medical University. Our study aimed to investigate and control the first outbreak of CRKP in our hospital occurred between October 2017 and August 2019. METHODS: The antimicrobial stewardship (AMS) workers have been implemented control measures properly. Clinical and epidemiological data were retrospectively collected from medical records. Carbapenemase genes were detected by modified carbapenem inactivation method (mCIM) test and the EDTA-modified carbapenem inactivation method (eCIM) test. Resistance genes were identified by polymerase chain reaction (PCR) and sequencing. Genetic relatedness was studied by multilocus sequence typing (MLST). RESULTS: During the outbreak, 31 patients were infected with CRKP isolates. 20 (64.5%) patients were infected with KPC-2 and/or NDM-1 producing K. pneumoniae. Mostly MLST-sequence types belonged to ST11 (21/31). The outbreak was two major K. pneumoniae clusters present in epidemiologically linked patients. CONCLUSIONS: Setting up AMS workers is potentially a highly efficient strategy for the successful control of the outbreak. A multimodal and multidisciplinary infection control strategy proved to be crucial. The emergence of CRKP in our hospital emphasizes the importance of continuous monitoring of these isolates, which helps to limit the spread of CRKPs and improve the level of management.

Synergetic Effects of Combined Treatment of Colistin With Meropenem or Amikacin on Carbapenem-Resistant Klebsiella pneumoniae in vitro.

The purpose of this study was to investigate the synergistic and bactericidal effects of combinations of colistin with meropenem or amikacin in vitro and provide laboratory data needed for development of therapeutic strategies for the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection. We found that minimum inhibitory concentration (MIC) of colistin, meropenem and amikacin were 2~32, 4~256, and 1~16384 µg/ml, respectively. The minimum bactericidal concentration of the antibiotics was either 1× or 2×MIC. Treatments of 6 CRKP isolates at 1 µg/ml colistin completely killed 2 of them and suppressed 4 others growth. 4 CRKP isolates at 16 µg/ml meropenem or amikacin completely killed and suppressed 2 others growth. 2 CRKP isolates showed synergic effects in all colistin combination and 3 CRKP isolates showed synergic effects in part of colistin combination. Our data suggest that colistin in combination with either meropenem or amikacin could be a valid therapeutic option against colistin-resistant CRKP isolates. Moreover, the combination of colistin-amikacin is less expensive to treat CRKP infections in Eastern Heilongjiang Province.

Treating complicated carbapenem-resistant enterobacteriaceae infections with ceftazidime/avibactam: a retrospective study with molecular strain characterisation.

Ceftazidime/avibactam (CAZ/AVI) is the first antimicrobial agent with activity against carbapenem-resistant Enterobacteriaceae (CRE) approved by the US Food and Drug Administration (FDA). Notably, human clinical outcome data for this indication are limited. Therefore, a retrospective study was performed to evaluate the clinical outcomes and bacterial genomic characteristics of patients hospitalised at a tertiary medical centre with CRE infections treated for the first time with CAZ/AVI. From a total of 44 patients with CRE infections, 6 patients were treated with CAZ/AVI. The duration of CAZ/AVI treatment ranged from 7 days to 28 days. Five patients achieved clinical cure, however two relapsed with the same carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strain within 3 weeks of completion of CAZ/AVI treatment. In addition, one patient with CR-Kp pneumonia experienced clinical failure despite having a documented CAZ/AVI-susceptible CR-Kp strain [minimum inhibitory concentration (MIC) = 2 mg/L]. Consequently, the overall rate of unsuccessful outcome in this small cohort of patients was 50%. All strains carried KPC-3, OXA-9 and different TEM and SHV ß-lactamases, but none carried the intrinsically avibactam-resistant class B metallo-ß-lactamases. No obvious differences in antibiotic resistance genes were observed. This study provides an early glimpse of the clinical outcomes of patients with CR-Kp infections treated with CAZ/AVI. Findings of clinical failure and relapse in patients with no prior exposure to CAZ/AVI and with documented susceptibility to CAZ/AVI highlight the urgent need for well-designed clinical studies evaluating the effectiveness of CAZ/AVI in the treatment of CRE infections.