Search

Introduction: The clinical and molecular characteristics of hypervirulent Klebsiella pneumoniae (hvKp) in various provinces of China have been reported, however, there have been few reports in Hebei Province, North China. Methodology: The hvKp was identified by PCR amplification of hypervirulence-related genes, the hypermucoviscous phenotype was determined by the "string test", the drug susceptibility analysis was performed using the VITEK® 2 Compact Bacterial Identification and Monitoring System. Logistic regression was used to identify risk factors for hvKp infection. The molecular epidemiological characteristics of the strains were analyzed by pulsed-field gel electrophoresis (PFGE), and the capsular serotype of hvKp strain was detected by PCR. Results: Overall, 52.21% (59/113) of K. pneumoniae isolates were hvKp, and the ratios of patients with older ages or a higher PMN cell count among hvKp infection were higher than those among classical Klebsiella pneumoniae (cKp) infection. hvKp are more susceptible to antibacterial drugs than cKp, and one ESBLs-producing hvKp strain was detected. The main capsular serotype of hvKp were K2, K57 and K1. PFGE indicated that the 59 strains of hvKp could be classified into 51 PFGE band types, forming 6 PFGE clusters. Conclusions: In this study, the detection rate of hvKp was 52.21% (59/113) identified by virulence genes. People with older ages or a higher PMN cell count are more likely to gain hvKp infection. ESBLs-producing hvKp is emerging, indicating the importance of epidemiologic surveillance and clinical awareness of this pathogen in this region. [ABSTRACT FROM AUTHOR]

We detected the mcr-1 gene in 21 (14.8%) Salmonella isolates from pigs at slaughter; 19 were serovar Typhimurium sequence type 34. The gene was located on IncHI2-like plasmids that also harbored IncF replicons and lacked a conjugative transfer region. These findings highlight the need to prevent further spread of colistin resistance in animals and humans. [ABSTRACT FROM AUTHOR]

The article presents a report on emergence of Escherichia coli co-producing New Delhi metallo-b-lactamase-1(NDM-1) and Klebsiella pneumoniae carbapenemase 2 (KPC-2) from a retail vegetable, China. Topics discussed include use of agar dilution method for determining of minimum inhibitory concentration of antimicrobial agents; its resistance to imipenem, ceftazidime, cefotaxime; and a table depicting characteristics of E. coli TS79e and its transconjugants.

Background The emergence and wide distribution of the transferable gene for linezolid resistance, cfr, in staphylococci of human and animal origins is of great concern as it poses a serious threat to the public health. In the present study, we investigated the emergence and presence of the multiresistance gene, cfr, in retail meat sourced from supermarkets and free markets of Guangzhou, China. Results A total of 118 pork and chicken samples, collected from Guangzhou markets, were screened by PCR for cfr. Twenty-two Staphylococcus isolates obtained from 12 pork and 10 chicken samples harbored cfr. The 22 cfr-positive staphylococci isolates, including Staphylococcus equorum (n = 8), Staphylococcus simulans (n = 7), Staphylococcus cohnii (n = 4), and Staphylococcus sciuri (n = 3), exhibited 17 major SmaI pulsed-field gel electrophoresis (PFGE) patterns. In 14 isolates, cfr was located on the plasmids. Sequence analysis revealed that the genetic structures (including ΔtnpA of Tn558, IS21-558, ΔtnpB, and tnpC of Tn558, orf138, fexA) of cfr in plasmid pHNTLD18 of a S. sciuri strain and in the plasmid pHNLKJC2 (including rep, Δpre/mob, cfr, pre/mob and partial ermC) of a S. equorum strain were identical or similar to the corresponding regions of some plasmids in staphylococcal species of animal and human origins. Conclusions To the best of our knowledge, this is the first study to report the presence of the multiresistance gene, cfr, in animal meat. A high occurrence of cfr was observed in the tested retail meat samples. Thus, it is important to monitor the presence of cfr in animal foods in China. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the trends and the diversity of CTX-M types of extended-spectrum β-lactamase (ESBL) in Escherichia coli isolated from food animals in China over a ten-year period. From 2003 to 2012, 2815 E. coli isolates collected from diseased animals (chickens, pigs, and waterfowl) were screened for the prevalence of CTX-M genes. CTX-M-positive isolates were tested for their susceptibilities to 10 antimicrobial agents and the clonal relationship of CTX-M-producing E. coli isolates was also assessed. Overall, 677 (20.1%) of the 2815 E. coli isolates carried CTX-M genes. Eighteen different types of CTX-M ESBLs were identified, with CTX-M-14, CTX-M-55, and CTX-M-65 being the most dominant genotypes. The occurrence of CTX-M-producing E. coli increased significantly from 5.7% in 2003-2005 to 35.3% in 2009-2012 (p < 0.0001). High genetic heterogeneities were observed in the CTX-M-producing E. coli isolates. Most CTX-M-producing strains were also resistant to other classes of antimicrobials. Compared to isolates carrying CTX-M-9 subgroup of ESBLs, isolates carrying CTX-M-1 subgroup ESBLs showed significantly higher resistance rates to ceftazidime, amikacin, and fosfomycin (p < 0.01). The study reported the dramatic increase of CTX-M ESBLs in E. coli isolated from animals overtime in China. The increasing incidence of CTX-M-55 with high hydrolytic activity against ceftazidime and the widely spread co-resistance in CTX-M-producing isolates alarm the serious antimicrobial resistance situation in China and highlight the need for urgent control strategies to limit the dissemination of those resistant genes in China. [ABSTRACT FROM AUTHOR]

Escherichia coli play an important ecological role within resistant bacteria populations, and can be used as a bio-indicator of antimicrobial resistance. The aim of the present study was to use this feature of E. coli to investigate the prevalence of antimicrobial resistance and the degree of cross-species transmission of bacteria in pigs and poultry in China. A total of 592 E. coli strains, isolated from pigs and poultry (healthy and diseased animals), were tested for resistance to 22 antimicrobials representing eight antimicrobial drug types. E. coli isolates had high rates of resistance to ampicillin (99.5%), doxycycline (95.6%), tetracycline (93.4%), trimethoprim-sulfamethoxazole (74.3%), amoxicillin (65.1%), streptomycin (54.7%), and chloramphenicol (50.2%). Resistance to cephalosporins, quinolones, and aminoglycosides was also quite prevalent. The majority (81%) of isolates demonstrated multi-antimicrobial resistance, most commonly to 5-6 different antimicrobial types. One isolate was resistant to all 22 antimicrobials. Twenty-two cultures exhibiting multi-antimicrobial resistance were analysed by pulsed-field gel electrophoresis (PFGE) to assess their distribution between farms. Three distinct PFGE types were identified, indicating inter-farm transmission of multi-antimicrobial-resistant bacteria. The study confirmed the presence and transmission of multi-antimicrobial resistant E. coli strains amongst pigs and poultry in China and highlights the urgent need for appropriate monitoring programmes. [ABSTRACT FROM AUTHOR]