Population structure of food-borne Staphylococcus aureus in China / 中华流行病学杂志

Objective: To understand the population structure of food-borne Staphylococcus (S.) aureus in China. Methods: Whole genome sequencing was used to analyze 763 food-borne S. aureus strains from 16 provinces in China from 2006 to 2020. Multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and staphylococcal chromosome cassettemec (SCCmec) typing were conducted, and minimum spanning tree based on ST types (STs) was constructed by BioNumerics 7.5 software. Thirty-one S. aureus strains isolated from imported food products were also included in constructing the genome phylogenetic tree. Results: A total of 90 STs (20 novel types) and 160 spa types were detected in the 763 S. aureus isolates. The 72 STs (72/90, 80.0%) were related to 22 clone complexes. The predominant clone complexes were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, accounting for 82.44% (629/763) of the total. The STs and spa types in the predominant clone complexes changed over the years. The methicillin-resistant S. aureus (MRSA) detection rate was 7.60%, and 7 SCCmec types were identified. The ST59-t437-Ⅳa (17.24%, 10/58), ST239-t030-Ⅲ (12.07%, 7/58), ST59-t437-Ⅴb (8.62%, 5/58), ST338-t437-Ⅴb (6.90%, 4/58) and ST338-t441-Ⅴb (6.90%, 4/58) were the main types in MRSA strains. The genome phylogenetic tree had two clades, and the strains with the same CC, ST, and spa types clustered together. All CC7 methicillin sensitive S. aureus strains were included in Clade1, while 21 clone complexes and all MRSA strains were in Clade2. The MRSA strains clustered according to the SCCmec and STs. The strains from imported food products in CC398, CC7, CC30, CC12, and CC188 had far distances from Chinese strains in the tree. Conclusions: In this study, the predominant clone complexes of food-borne strains were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, which overlapped with the previously reported clone complexes of hospital and community-associated strains in China, suggesting that close attention needs to be paid to food, a vehicle of pathogen transmission in community and food poisoning.

Investigation and risk assessment for water quality hygiene in self-supply well water in four northern provinces of China / 中华疾病控制杂志

Objective To understand the water quality of self-supply wells in four provinces of northern China (Heilongjiang, Beijing, Inner Mongolia and Tibet), so as to provide a reference for supervision and management of self-supply wells. Methods Water were sampled from 233 self-supply wells in four northern provinces of China according to standard examination methods for drinking water (GB/T 5750-2006). In total, The samples were tested for 27 kinds of water quality parameters involving sensory properties, chemistry, bacteriology and toxicology, and then evaluated. Results The total unqualified rate of water quality in self-supply well water in four northern provinces of China was 52.36%. The water quality varied greatly among provinces. As for Heilongjiang, the main unqualified indicators of self-supply wells water involved turbidity, visible to the naked eye, manganese, arsenic and nitrate. In relation to Beijing, these referred to the nitrate and microorganism. In case of Inner Mongolia province, these included sulfate and fluoride. With reference to Tibet, these were zinc and chloride. Conclusions To ensure the safety of drinking water for residents, the management, disinfection and purifying measures of self-supply wells should be strengthened basing on their regional differences and water quality characteristics.

Safety evaluation of drinking water along the border of Inner Mongolia / 军事医学

Objective To find out about the sanitary conditions of drinking water along the border line of Inner Mongolia via safety evaluation of drinking water along the border line of Inner Mongolia.Methods 108 samples of drinking water along the border line of Inner Mongolia(70 samples of self-supply source water,21 ones of self-supply tap water and 17 ones of municipal tap water)were collected.Hygienic evaluation of sensory indexes, normal chemical indexes, toxicological indexes and microbiology indexes of water quality was performed according to hygienic standards for drinking water(GB 5749—2006).Results 58 samples were qualified with a total qualified rate of 53.7%.The unqualified rate of the total number of coliforms was the highest(20.4%),followed by fluoride(19.4%).As for deep wells, shallow wells and surface water,there was no statistically significant difference.Compared with municipal tap water,the unqualified rate of self-supply water(28.6%)was higher(17.7%).Conclusion The qualified rate along the border line of Inner Mongolia of drinking water is low.Treatment and disinfection facilities for drinking water,detection devices of water quality are needed.The cleaning and disinfection of storage tanks should be performed periodically in oder to prevent waterborne infectious diseases.

Treatment of osteochondritis lesion in the knee with reduction and fixation under arthroscopy / 中国骨伤

<p><b>OBJECTIVE</b>To study clinical results of reduction and fixation under arthroscopy for the treatment of osteochondrotical lesion in the knee.</p><p><b>METHODS</b>From December 2012 to December 2013, 4 patients with the knee joint osteochondritis lesion and free bone fragments were treated with arthroscopy to detect the stripped cartilage, and then the cartilages were reduced with small incision and fixed by cartilage nail. There were 3 males and 1 female, with age of 15, 15, 20 and 27 years old. The durations of the disease were 1 d, 5 d, 1 month and 1 year. All the patients had swelling and effusion in the knee joint, and the floating patellar test was positive. CT examination showed bone defects and loose bodies. The Lysholm, VAS, and Tegner scale were used to evaluate the knee joint functions before and after operation.</p><p><b>RESULTS</b>All the patients underwent successful surgery. Postoperative CT showed good location of the cartilage without loss of reduced bone and cartilage. All the patients were followed up, and the duration ranged from 10 to 13 months, with a mean of 12 months. In one patient, arthroscopy examination was conducted for a second time to examine the connection of the fracture part to the surrounding cartilage, and it showed that the internal fixator was not absorbed. The Lysholm, VAS and Tegner scale of all patients were better than those before operation.</p><p><b>CONCLUSION</b>Treatment of osteochondritis lesion with the fixation of absorbable cartilage nails may reconstruct the integrity of articular surface and recover the stability of joints, and it is an effective treatment method.</p>

Population-attributable risk estimates for breast cancer in Chinese females / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To estimate the contribution of known identified risk factors to breast cancer incidence and mortality in China, and provide evidence to support the prevention and control of breast cancer for Chinese females.</p><p><b>METHODS</b>We calculated the proportion of breast cancer attributable to specific risk factors. Data on exposure prevalence were obtained from Meta-analyses and large-scale national surveys of representative samples of the Chinese population. Data on relative risks were obtained from Meta-analyses and large-scale prospective studies. Cancer mortality and incidence were taken from the Third National Death Survey and from cancer registries in China.</p><p><b>RESULTS</b>The first 5 risk factors of breast cancer in China were benign breast disease (RR = 2.62), family history of breast cancer (RR = 2.39), smoking (RR = 1.86), overweight (RR = 1.60) and age at menarche (RR = 1.54). The proportion of breast cancer deaths attributable to reproductive factors, lifestyle factors, benign breast disease, the use of external hormone and family history of breast cancer was 27.84%, 23.55%, 15.09%, 3.60% and 2.49%, respectively. The total population attributable fraction (PAF) was 55.95% for risk factors in our study. Overall, we estimated that 79 862 breast cancer cases and 22 456 deaths were attributed to the five risk factors in China in 2005.</p><p><b>CONCLUSIONS</b>The prevention and control of unhealthy lifestyle factors may significantly reduce the number and death of breast cancer in China.</p>

A pilot study of hepatic fibrosis with magnetic resonance diffusion-weighted imaging in a rabbit model / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the role of MRI diffusion imaging in the diagnosis of hepatic fibrosis.</p><p><b>METHODS</b>Fifty-eight rabbits were divided randomly into a blank control group (n = 10) and a model group (n = 48). Carbon tetrachloride was injected intraperitoneally into the animals of the model group to induce liver fibrosis. SE-EPI sequence was used in diffusion weighted imaging for all the rabbits. Then apparent diffusion coefficient (ADC) and exponential apparent diffusion coefficient (EADC) of their livers were obtained with Functool 2.0 software. The degrees of liver fibrosis of the rabbits were graded with histological examinations. Statistical analysis was performed by SPSS 11.0 statistical software. One-way analysis of variance was used to compare every rank data respectively. P less than 0.05 was considered statistically significant.</p><p><b>RESULTS</b>When the b value was 300 s/mm2, ADC of diffusion-weighted imaging (DWI) was (2.460+/-0.424) x 10(-3) in the control group (S0). ADCs were (2.170+/-0.311) x 10(-3), (1.950+/-0.248) x 10(-3), (1.635+/-0.296) x 10(-3), (1.566+/-0.353) x 10(-3) in the model group (S1, S2, S3 and S4). EADC of DWI was 0.102+/-0.044 in the control group and were 0.167+/-0.047, 0.183+/-0.042, 0.216+/-0.054, 0.219+/-0.048 in the model group (S1, S2, S3 and S4). ADC and EADC of the control group and model group had significant differences (F = 12.13, P = 0.0006; F = 10.06, P = 0.004 respectively). When the b value was 500 s/mm2, ADC of DWI was (2.044+/-0.215) x 10(-3) in the control group, ADC were (1.907+/-0.223) x 10(-3), (1.785+/-0.232) x 10(-3), (1.542+/-0.268) x 10(-3), (1.312+/-0.212) x 10(-3) in the model group (S1, S2, S3 and S4). EADC of DWI was 0.1106+/-0.069 in the control group and EADCs of DWI were 0.1764+/-0.073, 0.1889+/-0.056, 0.2421+/-0.079, 0.2657+/-0.037 in the model group (S1, S2, S3 and S4). ADCs and EADCs of the control group and model group had significant differences (F = 14.57, P = 0.0002; F = 10.42, P = 0.003 respectively). There was a significant difference of ADCs between S1 and S4 of the model group when b value were 300 s/mm2 and 500 s/mm2 (P = 0.03, P = 0.044 respectively). No differences were found between other subgroups in the model group.</p><p><b>CONCLUSION</b>Our preliminary study shows that measuring ADCs and EADCs has a good potential in diagnosing and quantifying hepatic fibrosis, especially when using b values of 300 sec/mm2 and 500 sec/mm2.</p>