Background The aim of this study was to elucidate the epidemiological features of carbapenemase-producing Enterobacterales (CPE) in the pediatric and neonatal patients, to describe clinical characteristics of neonatal patients with CPE infections, and to assess risk factors for neonatal rectal colonization with CPE. Results A total of 439 carbapenem-resistant Enterobacterales (CRE) isolates recovered from 367 infant patients were characterised, including 397 isolates of Klebsiella pneumoniae (KP) and 42 isolates of Escherichia coli (EC). Carbapenemase gene blaNDM-1 was the most commonly detected, accounting for 86.56% (n = 380), followed by blaKPC-2 (9.11%, 40) and blaIMP-4 (4.33%, 19). MLST analysis showed 17 different STs detected within CPKP isolates, with ST20, ST2068, ST36 and ST17 being the most frequently isolated types. Eleven STs were identified within CPEC isolates, with ST325 being the dominant types. Eight isolates of NDM-1 producing KP, belonging to ST23, were identified as having hypervirulent traits. The main infections caused by CPE were pneumonia (n = 90) and sepsis (n = 16). All infected patients received monotherapy, with meropenem and ciprofloxacin being the most commonly used antibiotics. All pneumonia patients were cured or improved after treatment. Of the 16 patients with sepsis, 9 were cured or improved, 3 died, and 4 abandoned treatment without any clinical improvement. The rectal prevalences of CPE in the 0–3 days old (DO), the 4–28 DO, and the 29 DO-1 year old groups were decreased from 15.31%, 27.37% and 14.29% in the first stool screening period to 11.78%, 19.59% and 4.07% in the second stool screening period, respectively. Multivariate analysis showed that cesarean section, acidosis, respiration failure, gastric lavage and enema were independent risk factors for rectal colonization in the 0–3 DO group, whereas cesarean section, cephalosporins, gastric lavage and residence in rural area were independently associated with rectal colonization in the 4–28 DO group. The implementation of a series of evidence-based control measures eventually contained the CPE transmission. Conclusions Continued vigilance, epidemiological studies, and multimodal infection prevention strategies are urgently needed due to frequent importations.

Background The increasing number of carbapenemase-producing Enterobacterales (CPE) has become a serious problem globally. This study aimed to elucidate their geographically epidemiological characteristics. Methods Resistance genes were identified by polymerase chain reaction (PCR) and sequencing. Bacterial genotyping was studied using multilocus sequence typing (MLST) and wzi typing. The transferability of carbapenemase genes was determined by a broth mating method. The relationships between the rates of antimicrobial consumption and the prevalence of CRE were performed by Pearson's or Spearman's correlation analyses. Results A total of 930 phenotypically confirmed carbapenem-resistant Enterobacterales (CRE) isolates collected from 19 hospitals were genotypically characterized. K. pneumoniae (KP) and E. coli isolates were 785 (85.14%) and 96 (10.41%) among 922 CPE isolates. Two major carbapenemase genes blaKPC-2 and blaNDM in CPE isolates accounted for 84.6% (n = 780) and 13.77% (n = 127). ST11 comprised 86.83% (633/729) of KPC-2 KP isolates. Different combinations of extended spectrum-β-lactamase (ESBL) genes of blaSHV, blaCTX, and blaTEM were found in KPC-2 producing KP isolates, and blaCTM-M-14/15, blaSHV-11/12 and blaTEM-1 were common ESBL genotypes. The wzi typing method could further subdivide ST11 KP group into at least five subgroups, among which wzi209 (69.83%, 442/633) was the most frequently isolated, followed by wzi141 (25.28%, 160/633). Conjugation assays showed that high conjugation rates were observed in CPE (15.24%, 32/210) for NDM plasmids, but relatively low (8.1%, 17/210) for KPC-2 plasmids. Different STs, different wzis and temperature could influence plasmid conjugation efficiency. No associations between the rates of antibiotics consumption and CPE prevalence were observed. The number of intra-hospital and inter-hospital transfers of CPE patients increased gradually from 18 (17.82%, 101) and 12 (11.88%, 101) in 2015 to 63 (30.73%, 205) and 51 (24.88%, 205) in 2018 (p = 0.016 and p = 0.008), respectively. Evidence-based measures could effectively reduce the prevalence of ST11-wzi209 clone but failed to control the dissemination of ST11-wzi141 KP clone. Conclusions Clonal spread of CPE, especially KPC-2 ST11 KP was the key factor contributing to the CPE increase in the region. Continued vigilance for the importations should be maintained. Coordinated regional interventions are urgently needed to reduce CPE threat.

Background: The increasing number of carbapenem-resistant Enterobacteriaceae (CRE) has become a serious problem globally. This study aimed to elucidate their geographically epidemiological characteristics and explore evidence-based infection control measures.Methods: Carbapenem-resistant genes were identified by polymerase chain reaction (PCR) and sequencing. Bacterial genotyping was studied using multilocus sequence typing (MLST) and wzi typing. The transferability of carbapenemase genes was determined by a broth mating method. The relationships between the rates of antimicrobial consumption and the prevalence of CRE were performed by Pearson's or Spearman's correlation analyses. The elucidation of transmission and the evaluation of control measures involved in electronic medical record review, environmental cultures, and outbreak evolution. Results: A total of 930 phenotypically confirmed CRE isolates collected from 19 hospitals were genotypically characterised. K.pneumoniae (KP) and E.coli isolates were 787 (85.17%) and 96 (10.39%) among 924 carbapenemase-producing Enterobacteriaceae (CPE) isolates. Two major carbapenemase genes KPC-2 and NDM in CPE isolates accounted for 84.63% (n = 782) and 13.74% (n = 127). ST11 comprised 86.32% (631/731) of KPC-2 KP isolates. Wzi typing could discriminate ST11 KP clones and precisely track their transmission. Conjugation assays demonstrated that Some KPC-2- and NDM-bearing plasmids could be conjugatively transferred. The transferability was influenced by different STs and different wzis. CRE patients were becoming increasingly younger due to nosocomial CRE acquisition. The average length of hospitalization of these patients showed a downward trend mainly due to significant increases in voluntarily discharged rates and mortality rates. The frequent transfers of CRE patients between intra- and inter-hospitals were the main driving factors for the CRE increase. No associations between the rates of antibiotics consumption and CRE prevalence were observed. Evidence-based measures could effectively reduce the prevalence of ST11-wzi209 clone but failed to control the dissemination of ST11-wzi141 KP clone. Conclusions: Continued vigilance for the importations should be maintained. Coordinated regional interventions are urgently needed to reduce CRE threat.

Background: Carbapenem-resistant Enterobacteriaceae (CRE) prevalence in neonatal patients continues to rise in china. However, very few epidemiological data are available to uncover the underlying mechanisms for the increase. This study aimed to elucidate their transmission modes and explore potential sources. Methods: The genotypic features of CRE isolates were analyzed by PCR and sequencing. The elucidation of transmission and sources involved in electronic medical record review, environmental cultures, screening cultures, and prospective case-control analysis. The transferability of carbapenem-resistant genes was performed by Conjugation experiments.Results: A total of 450 CRE isolates recovered from 369 infant patients were genotypically characterised. Carbapenemase genes NDM-1, KPC-2 and IMP-4 accounted for 86.22% (n = 388), 8.89% (n = 40) and 4.44% (n = 20), respectively. After implementation of intensified control measures, CRE rectal prevalence rates in both the 0-3 days and the 4-28 days age group were decreased from 15.53% (100/644) and 27.37% (52/190) to 11.78% (51/433) and 19.59% (19/97) (P = 0.082 and P = 0.148), respectively. Multivariate analysis showed that gastric lavage (odds ratio [OR]) 3.09, 95% confidence interval [CI] 1.49–6.39) and enema (OR 2.84, 95% CI 1.65–4.91) were independent risk factors for rectal colonisation in the 0-3 days age group, whereas Cephalosporins (OR 2.12, 95% CI 1.14–3.94), gastric lavage (OR 3.44, 95% CI 1.44–8.22) and residence in rural area (OR 2.22, 95% CI 1.19–4.13) were independently associated with rectal colonization in the 4-28 days age group. The transmission tracking of neonatal NDM-1 strains outbreaks revealed rivers contaminated with NDM genes. Most isolates with NDM genes could be successfully transferred.Conclusion: Continued vigilance for importations should be maintained to reduce CRE threat.

Background The increasing number of carbapenemase-producing Enterobacteriaceae (CPE) has become a serious problem globally. This study aimed to elucidate their geographically epidemiological characteristics. Results A total of 930 phenotypically confirmed carbapenem-resistant Enterobacteriaceae (CRE) isolates collected from 19 hospitals were genotypically characterised. K.pneumoniae (KP) and E.coli isolates were 785 (85.14%) and 96 (10.41%) among 922 CPE isolates. Two major carbapenemase genes KPC-2 and NDM in CPE isolates accounted for 84.6% (n = 780) and 13.77% (n = 127). ST11 comprised 86.83% (633/729) of KPC-2 KP isolates. The wzi typing method could further subdivide ST11 KP group into at least five subgroups, among which wzi209 (69.83%, 442/633) was the most frequently isolated, followed by wzi141 (25.28%, 160/633). Conjugation assays showed that high conjugation rates were observed in CPE (15.24%, 32/210) for NDM plasmids, but relatively low (8.1%, 17/210) for KPC-2 plasmids. No associations between the rates of antibiotics consumption and CPE prevalence were observed. The number of intra-hospital and inter-hospital transfers of CPE patients increased gradually from 18 (17.82%, 101) and 12 (11.88%, 101) in 2015 to 63 (30.73%, 205) and 51 (24.88%, 205) in 2018 (p = 0.016 and p = 0.008), respectively. Evidence-based measures could effectively reduce the prevalence of ST11-wzi209 clone but failed to control the dissemination of ST11-wzi141 KP clone. Conclusions Clonal spread of CPE, especially KPC-2 ST11 KP was the key factor contributing to the CPE increase in the region. Continued vigilance for the importations should be maintained. Coordinated regional interventions are urgently needed to reduce CPE threat.