Effects of RNAi-mediated plasma membrane calcium transporting ATPase and inositol 1,4,5-trisphosphate receptor gene silencing on the susceptibility of Mythimna separata to wilforine.

Wilforine, a compound of sesquiterpene alkaloids isolated from Tripterygium wilfordii, exhibits excellent insecticidal activity against Mythimna separata. In order to clarify the action mechanism of wilforine, the plasma membrane calcium transporting ATPase (PMCA) and inositol 1,4,5-trisphosphate receptor (IP3R) from M. separata were studied. Results showed that the open reading frame of MsIP3R and MsPMCA were 8118 bp and 3438 bp in length, as well as encoded 2706 and 1146 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis revealed that the MsIP3R and MsPMCA had high homology with the IP3R and PMCA of other insects, but had low similarity with those of mammals, which means the IP3R and PMCA have potential to be the novel targets of insecticides with high selectivity between mammals and insects. Both MsIP3R and MsPMCA genes existed throughout the life cycle of M. separata, and were all predominantly expressed in somatic muscle of fifth-instar larvae and the adults. The susceptibilities of PMCA-silenced M. separata to wilforine were significantly lower than that of the normal M. separata, which illustrates that PMCA could be one of the targets of wilforine. However, the susceptibilities of IP3R-silenced M. separata to wilforine did not change significantly compared with the susceptibilities of normal M. separata, which shows that wilforine may not interact with the IP3R protein. These findings provide clues for elucidating the insecticidal mechanism of wilforine.

Annual point-prevalence of healthcare-associated infection surveys in a university hospital in China, 2007-2011.

Successive point-prevalence surveys were conducted annually from 2007 to 2011 to monitor the prevalence of healthcare-associated infections (HAIs) in a university hospital in Hubei Province in China. The surveys used the case definition criteria established by the Ministry of Health of the People's Republic of China. In the 5 surveys, the overall frequency of HAIs was 3.16% (301/9533). No significant differences were identified in the point prevalence measurements of HAIs in any of the years from 2007 to 2011. Of all the cases, proportionally, the most frequent infection site was the respiratory tract (2.34%), followed by surgical sites (0.43%) and urinary tract sites (0.28%). Gram-negative aerobic bacilli were the most common organisms mentioned; the most frequently isolated organism was Pseudomonas aeruginosa, followed by Escherichia coli and Acinetobacter baumannii. Approximately one-half of the patients were receiving antibiotics at the time of the surveys. Cephalosporin, penicillin, and quinolone were most commonly used for treatment or prevention. The differences found in HAI prevalence data across the 5 surveys given in the hospital were not statistically significant. In conclusion, this successive point-prevalence survey provides information about the trend of HAI prevalence, epidemical character, and the use of antibiotics among the university hospital's in-patients. This information allows us to initiate targeted programs for infection prevention and control.

Ventilator-associated pneumonia in intensive care units in Hubei Province, China: a multicentre prospective cohort survey.

A multicentre prospective cohort study was performed in 17 intensive care units (ICUs) in tertiary care hospitals in Hubei Province, China. Ventilator-associated pneumonia (VAP) was defined according to modified criteria from the published literature. Among 4155 ventilated patients, the crude incidence and incidence rate of VAP were 20.9% and 28.9 cases per 1000 ventilator-days. Multivariate analysis using logistic regression revealed risk factors including male sex [risk ratio (RR): 1.5; P<0.001], coma (RR: 2.1; P<0.001), chronic obstructive pulmonary disease (RR: 1.4; P<0.001), infections at other sites (RR: 1.6; P=0.001), serious disease predating the onset of VAP (RR: 1.6; P<0.001) and interventions including antacid treatment (RR: 1.4; P<0.001), antimicrobial treatment (RR: 5.1; P<0.001), bronchoscopy (RR: 1.5; P=0.041) and tracheostomy (RR: 1.4; P=0.014). The most frequently isolated causative pathogens were Pseudomonas aeruginosa and Acinetobacter baumannii. Of all Staphylococcus aureus isolates, 45.7% were meticillin resistant. Rates, risk factors and causal pathogens of VAP in ICUs in Hubei differ from those reported from developed countries. These data show the need for more effective infection control interventions in Hubei, China.

Point prevalence surveys of healthcare-associated infection in 13 hospitals in Hubei Province, China, 2007-2008.

Successive point prevalence surveys were conducted in November 2007 and 2008 to monitor the prevalence of healthcare-associated infection (HCAI) in 13 grade III, 1st class hospitals in Hubei Province of China, using the case definition criteria established by the Ministry of Health in the People's Republic of China. In total, of 20 350 patients surveyed, 833 (4.09%) HCAIs were observed in 790 (3.88%) patients. There was no significant difference between the overall prevalence of HCAI in 2007 (4.14%) and 2008 (3.72%). Respiratory tract infection was the most common HCAI (63.15%), followed by surgical site infection (9.60%) and urinary tract infection (8.64%). Only 35.29% (294/833) of HCAI patients had positive microbiology results. Gram-negative bacteria were isolated most frequently and the most frequent organism was Pseudomonas aeruginosa, followed by Escherichia coli, Acinetobacter baumannii and Staphylococcus aureus. Antibiotic use was documented for 10,344 (50.83%) patients, and cephalosporins, penicillins, and quinolones were the most commonly used agents for treatment or prophylaxis.