No abstract

Carbapenem-resistant (CRE) infection is highly endemic in China, but estimates of the infection burden are lacking. We established the incidence of CRE infection from a multicenter study that covered 25 tertiary hospitals in 14 provinces. CRE cases defined as carbapenem-nonsusceptible, ,, or infections during January to December 2015 were collected and reviewed from medical records. Antimicrobial susceptibility testing and carbapenemase gene identification were performed. Among 664 CRE cases, most were caused by (73.9%), followed by (16.6%) and (7.1%). The overall CRE infection incidence per 10,000 discharges was 4.0 and differed significantly by region, with the highest in Jiangsu (14.97) and the lowest in Qinghai (0.34). Underlying comorbidities were found in 83.8% of patients; the median patient age was 62 years (range, 45 to 74 years), and 450 (67.8%) patients were male. Lower respiratory tract infections (65.4%) were the most common, followed by urinary tract infection (16.6%), intra-abdominal infection (7.7%), and bacteremia (7.7%). The overall hospital mortality rate was 33.5%. All isolates showed nonsusceptibility to carbapenems and cephalosporins. The susceptibility rate of polymyxin B was >90%. Tigecycline demonstrated a higher susceptibility rate against than against (90.9% versus 40.2%). Of 155 clinical isolates analyzed, 89% produced carbapenemases, with a majority of isolates producing KPC (50%) or NDM (33.5%)-type beta-lactamases among and The incidence of CRE infection in China was 4.0 per 10,000 discharges. The patient-based disease burden in tertiary hospitals in China is severe, suggesting an urgent need to enhance infection control.

Background/Aims: Spinal tuberculosis (TB) is a common and dangerous form of extrapulmonary TB with unclear mechanisms in its occurrence and progression. This study investigated the clinical significances of bone morphogenetic protein-4 (BMP-4), osteopontin (OPN), and vitamin D receptor (VDR) gene polymorphism, mRNA and protein expression in spinal TB patients. Methods: BMP-4 and OPN gene polymorphisms were detected by direct DNA sequencing, while VDR-FokI polymorphisms were analyzed using PCR-RFLP. mRNA and protein expression was measured using real-time PCR and Western blot, respectively. Results: A significant lower frequency of TT genotype and T allele at 6007C>T polymorphism in BMP-4 gene; higher frequency of GG genotype and G allele at -66T>G polymorphism in OPN gene, and higher frequency of the ff genotype and f allele at the VDR-FokI polymorphism were observed in patients with spinal TB compared to controls. TT genotype of 6007C>T polymorphism correlated with a lower BMP-4 mRNA and protein expression, -66GG genotype correlated with a high OPN mRNA and protein expression, and ff genotype correlated with the lower VDR mRNA and protein levels in the intervertebral disc tissues. The TT genotype and low BMP-4 gene expression; the -66GG genotype and high OPN gene expression; and the ff genotype and low VDR gene expression significantly correlated with the clinical severity of spinal TB. Conclusion: The 6007C>T polymorphism of BMP-4, -66T>G polymorphism of OPN, and VDR-FokI polymorphism are the susceptible factors of spinal TB and indicators of the clinical severity. These three genes may collaborate in the development of spinal TB.

This study was to investigate the prevalence of mcr-1 -positive Enterobacteriaceae (MPE) in intra-abdominal infections (IAIs), urinary tract infections (UTIs), and lower respiratory tract infections (LRTIs) in China. A total of 6,401 Enterobacteriaceae isolates were collected consecutively from IAI, UTI, and LRTI patients in 19 hospitals across mainland China during 2014–2016. MPE isolates were screened by PCR detection for the mcr gene. The resistance profiles were tested by antimicrobial susceptibility test. All MPE isolates were characterized by pulsed-field gel electrophoresis (PFGE), multi-locus-sequence typing, O and H serotyping, and whole-genome sequencing. Among the 6,401 Enterobacteriaceae isolates, 17 Escherichia coli strains (0.27%) were positive for the mcr-1 gene. The MPE prevalence rates in IAI, UTI, and LRTI patients were 0.34% (12/3502), 0.23% (5/2154), and 0% (0/745), respectively. The minimum inhibition concentrations (MICs) of colistin against 3 isolates were of 0.5–2 mg/L, and 4–8 mg/L against other 14 isolates. All the 17 isolates were susceptible to meropenem, imipenem, tigecycline, and ceftazidime/avibactam. The 17 MPE isolates belonged to 14 different ST types, and those that belonged to the same STs were not clonal by PFGE. The mcr-1 -harboring plasmid of ten MPE isolates could transfer to the recipients by conjugation and the colistin MICs of the transconjugants ranged from 0.5 to 8 mg/L. M cr-1 -carrying plasmids from the 17 MPE isolates could be grouped into four clusters, including 8 IncX4 type, 4 IncI2 type, 4 IncHI2A type, and 1 p0111 type. Multiple-drug resistance genes and virulence genes were detected. In conclusion, the prevalence of MPE in IAI, UTI, and LRTI were low in China, and no clonal transmission was identified in our study. Most MPE isolates exhibited low-level colistin resistance. However, our study indicated that MPE isolates always carried a variety of drug resistance and virulence genes, which should be paid more attention.