[Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020].

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

[Antimicrobial resistance and genomic characterization of Campylobacter isolates recovered from retailed poultry meat samples in 20 provinces of China in 2020].

Objective: To understand the antimicrobial resistance and genome characteristics of Campylobacter isolates recovered from retailed poultry meat samples in 20 provinces in China in 2020. Methods: In 2020, 265 Campylobacter strains including 244 Campylobacter jejuni and 21 Campylobacter coli collected from retailed poultry meat samples in China were tested for antimicrobial resistance to 9 antimicrobial compounds by using the agar dilution method. Forty-two selected isolates were sent for whole genome sequencing and 38 high-quality genomes were analyzed for their antimicrobial resistance genes, virulence genes, sequence types and genetic diversity. Results: The resistance rates of Campylobacter isolates from poultry meats to tetracycline, nalidixic acid and ciprofloxacin were the highest (84%-100%), with 53.2% of the isolates showing multidrug resistance in this study. The resistance rates of C. coli to erythromycin, azithromycin, telithromycin, gentamicin and clindamycin were significantly higher than those of C. jejuni (P<0.05). The resistance genes conferring resistance to ß-lactams (100%, 38/38), quinolones (94.7%, 36/38), tetracycline (81.6%, 31/38) and aminoglycosides (50%, 19/38) were the most frequently detected among 38 Campylobacter genomes. C. jejuni carried more virulence genes than C. coli. In total, 19 and 17 sequence types (ST) were obtained from 20 sequenced C. jejuni and 18 C. coli isolates, respectively, including 5 novel STs. The isolates showed a high genetic diversity based on their sequence types. Conclusion: The phenomenon of antimicrobial resistance in Campylobacter from poultry meat sources in China is relatively serious, and resistance and virulence genes are widely distributed in Campylobacter. There is genetic diversity in Campylobacter.

Aetiology of tinea capitis in China: a multicentre prospective study.

BACKGROUND: Tinea capitis is still common in developing countries, such as China. Its pathogen spectrum varies across regions and changes over time. OBJECTIVES: This study aimed to clarify the current epidemiological characteristics and pathogen spectrum of tinea capitis in China. METHODS: A multicentre, prospective descriptive study involving 29 tertiary hospitals in China was conducted. From August 2019 to July 2020, 611 patients with tinea capitis were enrolled. Data concerning demography, risk factors and fungal tests were collected. When necessary, the pathogens were further identified by morphology or molecular sequencing in the central laboratory. RESULTS: Among all enrolled patients, 74·1% of the cases were in patients aged 2-8 years. The children with tinea capitis were mainly boys (56·2%) and were more likely than adults to have a history of animal contact (57·4% vs. 35·3%, P = 0·012) and zoophilic dermatophyte infection (73·5% vs. 47%). The adults were mainly female (83%) and were more likely than children to have anthropophilic agent infection (53% vs. 23·9%). The most common pathogen was zoophilic Microsporum canis (354, 65·2%), followed by anthropophilic Trichophyton violaceum (74, 13·6%). In contrast to the eastern, western and northeastern regions, where zoophilic M. canis predominated, anthropophilic T. violaceum predominated in central China (69%, P < 0·001), where the patients had the most tinea at other sites (20%) and dermatophytosis contact (26%) but the least animal contact (39%). Microsporum ferrugineum was the most common anthropophilic agent in the western area, especially in Xinjiang province. CONCLUSIONS: Boys aged approximately 5 years were the most commonly affected group. Dermatologists are advised to pay more attention to the different transmission routes and pathogen spectra in different age groups from different regions.

[Phenotypic and genomic characterization for Salmonella isolates recovered from meat products in Beijing wholesale markets, 2014-2015].

Objective: To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods: A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results: The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, ß-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates. Conclusion: Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

[Clinical value of inflammatory biomarkers in predicting prognosis of patients with ureteral urothelial carcinoma].

OBJECTIVE: To evaluate the clinical value of inflammation-related markers in predicting the prognosis of patients with ureteral urothelial carcinoma. METHODS: 200 patients with ureteral urothelial carcinoma were randomly divided into two groups by split sample validation: modeling group and validation group. Paraffin embedded pathological specimens of the patients were reviewed. Immunohistochemical method was used to detect tumor-infiltrating neutrophil (TIN) (CD66b+), tumor-associated macrophage (TAM) (CD163+), lymphocyte (CD+, CD4+, CD8+) counts, peripheral blood neutrophil / lymphocyte ratio (NLR) and tumor tissue neutrophil/monocyte ratio (NMR). According to the results of pathological staging, the patients were divided into non-muscle-invasive and muscle-invasive ureteral urothelial carcinoma group. The resolution of the models was evaluated, and the prognostic nomogram models including only peripheral blood parameters and all parameters were established to compare the accuracy of the two models in predicting the prognosis of patients with urothelial carcinoma of the ureter. RESULTS: The median follow-up time was 36 months, the progression-free survival was 40 months, and 42 cases (21.0%) showed tumor progression within 3 years. Tumor size, pathological stage and pathological grade were all single-factor variables predicting the first recurrence of ureteral urothelial carcinoma three years after operation. Tumor size, pathological stage, pathological grade, TIN, TAM, NLR and NMR were multi-factor variables predicting the first recurrence three years after operation. Among 104 cases of non-muscle-invasive ureteral urothelial carcinoma, 10 cases (9.6%) recurred for the first time 3 years after operation, 96 cases (33.3%) of muscle invasive ureteral urothelial carcinoma, and the diffe-rence between the two groups was statistically significant (χ2=15.53, P < 0.05). The predictive nomogram model of progression free survival was established. The concordance index of progression free survi-val was 0.722 (95%CI: 0.70-0.78) in non-muscle-invasion group, and 0.725 (95%CI: 0.71-0.79) in muscle-invasion group, which was in good agreement with the observed 3-year survival rate. The results of discrimination test showed that the concordance index of the whole parameter prediction model of ureteral urothelial carcinoma was 0.726, which was higher than that of peripheral blood parameters (consistency index 0.672). The immune microenvironment of ureteral urothelial carcinoma improved the prediction accuracy of the model. CONCLUSION: The prognosis prediction model based on immune inflammation-related markers was established as a perfection and supplement for the existing pathological grading and staging system, providing a basis for accurate individualized treatment of patients with urete-ral urothelial carcinoma. The prognosis prediction model based on the relevant indicators of peripheral blood samples is established, which is easy to obtain specimens, and the detection method is simple and economical, which is more conducive to clinical application.

[The protective effects of α-lipoic acid on fluoride-induced reproductive lesion in rats via oxidative stress-mediated endoplasmic reticulum stress].

Objective: To determine the oxidative stress and endoplasmic reticulum stress and their changes after α-lipoic acid (α-LA) intervention, and to explore the effect and mechanism of fluoride-induced reproductive lesion. Methods: A total of 40 male Sprague-Dawley (SD) rats were randomly divided into four groups, control group(0.9% sodium chloride), α-LA group(100 mg/kg α-LA), NaF group(25 mg/kg NaF), and NaF+α-LA group(25 mg/kg NaF+100 mg/kg α-LA). Each group was treated in the way of intragastric administration for eight weeks. Sperm quality and the content of NaF in testis were analyzed. The morphologic changes of the testis were observed with the use of HE staining and the apoptosis was detected by the TUNEL assay. Biochemical method was used to measure oxidative stress. Western blot was used to detect the expression of endoplasmic reticulum stress markers, such as GRP78, PERK, and CHOP. Results: Compared with the control group, the NaF group had a low level in sperm density [(5.99±1.45)×10(6)/ml to (10.96±1.83)×10(6)/ml, P<0.01] and sperm vitality [(33.40±2.71)% vs (66.41±3.33)%, P<0.01], but a high level in sperm abnormality rate [(26.43±2.43)% vs (11.44±1.55)%, P<0.01]. Compared with the NaF group,the NaF+α-LA group had a high level in both sperm density [(8.47±0.82)×10(6)/ml vs (5.99±1.45)×10(6)/ml, P<0.05] and sperm vitality [(49.97±3.51)% vs (33.40±2.71)%, P<0.05], but a low level in sperm abnormality rate [(22.69±2.39)% vs (26.43±2.43)%, P<0.05].There was a significantly higher content of NaF in testis in the NaF group [(11.14±0.77) µg/g vs (5.78±0.28) µg/g, P<0.01] than the control group. Optical microscope was used to observe the morphologic changes of the testis, and it was showed that loose structure appeared both in spermatogenic cells and mature sperm cells while the amount of them decreased. However, after the administration of α-LA, there were complete organelles structure and exfoliated cells in the lumen ameliorated. TUNEL assay found that the apoptotic cells were in a high level in the NaF group [(61.32±7.14)% vs (6.99±2.17)%, P<0.01], while α-LA significantly suppressed the percentage of apoptotic cells in the NaF+α-LA group compared with the Naf group [(45.96±5.31)% vs (61.32±7.14)%, P<0.01].Oxidative stress assays showed that there were higher express of Malondialdehyde(MDA) content [(5.46±0.30) nmol/mgprot vs (3.24±0.58) nmol/mgprot, P<0.01], the activity of Superoxide Dismutase(SOD) [(6.04±0.71) U/mgprot vs (7.19±0.52) U/mgprot, P<0.01] and Glutathione peroxidase(GSH-Px) [(23.67±0.99) U/mgprot vs (26.91±1.67) U/mgprot, P<0.01] in the NaF group than the control group. To compared with the NaF group, the counterpart in the NaF+a-LA group of MDA content was less [(4.66±0.70) nmol/mgprot vs (5.46±0.30) nmol/mgprot, P<0.05] and the GSH-Px activity was high [(25.90±1.93) U/mgprot vs (23.67±0.99) U/mgprot, P<0.05]. Towards the detection of endoplasmic reticulum stress, we found that there were all in higher level in the NaF group that the expression of GRP78 [(0.79±0.05) vs (0.45±0.09), P<0.01], PERK [(0.71±0.04) vs (0.40±0.05), P<0.01], and CHOP[(0.79±0.09) vs (0.19±0.08), P<0.01] than the control group, and to compared with the NaF group, α-LA significantly supressed the expression of GRP78 [(0.46±0.06) vs (0.79±0.05), P<0.01] and CHOP[(0.52±0.09) vs (0.79±0.09), P<0.01]. Conclusion: α-lipoic acid plays a protective role in fluoride-induced reproductive lesion in rats by oxidative stress-mediated endoplasmic reticulum stress.

[Preliminary study of human serum albumin level in early warning onset of preeclampsia].

Objective: To observe the dynamic changes of human serum albumin (HSA) level during pregnancy and study the early warning significance of HSA level on the onset of preeclampsia (PE) . Methods: Totally 369 PE pregnant women (PE group) and 309 normal pregnant women (control group) without PE who admitted in Haidian Maternal and Child Health Hospital from January 2013 to December 2017 were selected. HSA levels were tested before meeting the criterion of PE in the first trimester, the early-third trimester and the late-third trimester, the difference between the two groups were compared. The relationship between the HSA level and the incidence of complications in PE patients was analyzed. Results: (1)The mean values of HSA level in PE group and control group were (41.9±3.1) versus (40.0±2.2) g/L, (34.2±2.7) versus (35.4±2.7) g/L and (33.7±2.9) versus (36.7±3.3) g/L in the first trimester,the early-third trimester and the late-third trimester respectively,the difference in the first trimester was no significance (P>0.05), while the differences in the early-third trimester and the late-third trimester were both significant (all P<0.05). (2) The HSA level during pregnancy of PE group showed a continuous downward trend, while the control group was V-shaped trend. The receiver operating characteristic (ROC) curve analysis showed that PE could be early warned by the decrease of HSA level in PE group [area under curve (AUC)=0.742, cut-off value=5.97 g/L, sensitivity 70.8%, specificity 62.8%], the same result was in severe PE (AUC=0.756, cut-off value=6.85 g/L, sensitivity 70.8%, specificity 72.0%). The level of HSA was negatively correlated with the incidence of complications (r=-0.19, P<0.01). Conclusions: Excessive decrease of HSA level is an early warning factor for PE onset. The higher the baseline of HSA level and the greater the extent of pregnancy decline, the risk of PE in pregnant women is higher. The lower of HSA level in PE, the incidence of complications is higher. The excessive decrease of HSA level may be the first clinical manifestation before the onset of clinical symptoms of PE, so it may be the warning factor and one of the laboratory indicators in the PE sub-clinical stage.

Two sphingomyelin synthase homologues regulate body weight and sphingomyelin synthesis in female brown planthopper, N. lugens (Stål).

Although sphingomyelins known to be are lipid constituents of the plasma membrane in vertebrates, much remains obscure about the metabolism of sphingomyelins in insects. With ultra performance liquid chromatography-time-of-flight-tandem mass spectrometry analysis, we revealed for the first time that sphingomyelins are abundant in Nilaparvata lugens (Stål), the brown planthopper (BPH), and their biosynthesis is carried out by sphingomyelin synthase-like protein 2 (SMSL2), which is homologous to sphingomyelin synthase-related protein (SMSr). Unlike other insect species, high concentrations of sphingomyelins rather than ceramide phosphoethanolamines exist in the BPH. Two putative genes, which are homologous to SMSr, are named Nilaparvata lugens SMS-like 1 (NlSMSL1) and 2 (NlSMSL2). Knockdowns of both NlSMSL2 and NlSMSL1 were conducted but only the first decreased concentrations of sphingomyelins in the BPH, indicating that NlSMSL2 plays a role in the biosynthesis of sphingomyelins. Real-time quantitative PCR analysis revealed both NlSMSL1 and NlSMSL2 are highly expressed in BPH adults, with NlSMSL1 specifically highly expressed in reproductive organs (ovaries and testes) whereas NlSMSL2 was highly expressed in the malpighian tubules. The knockdown of NlSMSL1 or NlSMSL2 increased BPH female body weight but not that of males, suggesting sex-specific roles for SMSLs in influencing BPH body weight. The results suggest that NlSMSL2 catalyses the synthesis of sphingomyelins and maintains female BPH body weight through alteration of sphingolipid content.

Research Progress and Forensic Identification of Alcoholic Cardiomyopathy.

ABSTRACT: With the rapid development of the social economy in China, the incidence of diseases caused by excessive drinking is gradually increasing as well. Alcoholic cardiomyopathy refers to long-term high intake of ethanol, and has typical dilated cardiomyopathy characteristics, such as, hemodynamic changes, symptoms, signs, and morphological features. It is a kind of cardiomyopathy that excludes other causes of dilated cardiomyopathy. Due to the lack of specific pathological changes, the forensic pathological identification of alcoholic cardiomyopathy can only be based on the patient's medical history and by ruling out other causes of cardiomyopathy. This paper reviews the pathogenesis and forensic identification of alcoholic cardiomyopathy in order to provide reference for forensic pathologists and clinicians.

[Overview of Staphylococcus aureus mobile genetic elements and horizontal gene transfer of antimicrobial resistance genes].

The mechanism of antimicrobial resistance transmission mediated by mobile genetic elements (MGEs) in Staphylococcus aureus is highly complicated, leading a significant challenge for controlling the spread of the resistant Staphylococcus aureus strains. Based on the latest literature acquired in this work, we have overviewed the transmission mechanism of antimicrobial resistance encoding MGEs. It is notably that there are a number of MGEs, which may encode different antimicrobial resistance determinants and possess specific transmission mechanism. In spite of this specificity of the strains to their host (human or animal), some Staphylococcus aureus strains can be transmitted from animals to humans or vice versa. This ability of cross staphylococci transfer is an additional means to acquire new genetic material encoded by MGE. It was suggested in this review that study on transmission mechanism of MGEs mediated antimicrobial resistance genes could provide important biological information of their spreading and effectively help prevent and control of the resistant strains and/or resistance genes among human, animals and ecologies.

[Overview of resistance mechanisms in Campylobacter].

Campylobacter is a major cause of food-borne gastroenteritis worldwide. While mortality is low when people was infected with Campylobacter, morbidity imparted by post-infectious sequelae such as Guillain-Barré syndrome and irritable bowel syndrome is significantly noteworthy. Although fluoroquinolones and macrolides were the first line drug for the treatment of Campylobacter infections, there is a tough challenge in clinical treatment with high antimicrobial resistant rate and multi antimicrobial resistance arise. Based on the latest literature acquired in this work, we have chosen five classes of antibiotics always used in clinical, and discussed antibiotic resistance mechanisms and transmission of Campylobacter, in order to provide proper therapy both in the veterinary and human populations, and support basis data for the development of new drugs.

[Laboratory-based characterization and traceability of an outbreak of necrotising enterocolitis].

Objective: Laboratory-based characterization and traceability were performed on an outbreak of necrotising enterocolitis (NEC) happened in a maternal and child health care hospital in China. Methods: Thirty-seven samples were collected from 3 NEC cases, that the clinical manifestations was bloody stools. Clostridium spp. isolation and identification were carried out on stool, breast milk, milk-based infant powder and environmental swab samples collected during NEC outbreak from October to November in 2016. Meanwhile, twenty-four swabs samples from ward environmental, staffs' hand as well as articles for neonates daily use were also collected and tested for Clostridium spp. after disinfection following outbreak. Pulsed-field gel electrophoresis (PFGE) analysis was performed on all Clostridium strains obtained. Results: 46% (17/37) samples were positive for a presumptive Clostridium spp. during the outbreak of NEC. One type of Clostridium spp. isolates was cultured from 10 samples including the hands of medical staffs, some medical equipments in the ward and milk-based infant powder ingested by the case, it was identified as C.butyricum. Another type of Clostridium spp. isolates was cultured from 2 samples including breast milk and inner wall of breast milk fresh-keeping bag, it was identified as C.sporogens. Both of these two types isolates were cultured from 5 samples including inner wall of breast milk box, inner wall of refrigerator, the handle of case's incubator and the case's stool. PFGE analysis showed that all 15 strains of C. butyricum and 7 strains of C.sporogens isolated from the samples mentioned above produced indistinguishable pulsotypes respectively. No NEC cases were found after disinfection following the outbreak and all samples collected after outbreak were negative for Clostridium spp. Conclusion: The outbreak of NEC was highly related to C. butyricum contamination within the hospital.

[Molecular typing characterization of food-borne methicillin-resistant Staphylococcus aureus in China].

Objective: To analyses the antimicrobial resistance and molecular characterization of 21 MRSA isolates cultured from retail foods from different provinces in China, and evaluate the molecular typing methods. Methods: Twenty-one MRSA isolates were obtained from national foodborne pathogen surveillance network in 2012 (Chinese salad, n=3; milk, n=1; cake, n=2; rice, n=1; cold noodle, n=1; spiced beef, n=1; dumpling, n=1; packed meal, n=1; salad, n=1; raw pork, n=9). The antimicrobial resistance of 21 strains to 12 antimicrobial agents was tested by broth dilution method. Polymerase chain reaction (PCR) and DNA sequencing were performed to obtain the genetic types of MLST (ST) and spa typing. The clonal complex (CC) was assigned by eBURST soft and the MLVA type (MT) and MLVA complex (MC) were identified via the database of the MLVA website (http://www.mlva.net). SmaI pulsed-field gel electrophoresis (SmaⅠ-PFGE) was also carried out to obtain the PFGE patterns of 21 strains. The genetic diversity and discriminatory power of typing were calculated by the Simpson's index of diversity (diversity index, DI) to find out the best genotyping method for MRSA. Results: All MRSA isolates showed multi-drug resistance(MDR), and were resistant to oxacillin, benzylpenicillin, clindamycin and erythromycin, and 71.4% (15/21), 47.6% (10/21), 42.9% (9/21) and 28.6% (6/21) of the MRSA isolates were resistant to tetracycline, ciprofloxacin, trimethoprim/sulfamethoxazole and gentamicin, respectively. Moreover, one strain was found to be resistant to all three antimicrobials of levofloxacin, moxifloxacin and rifampicin. Great diversity was found in these food-associated MRSA (6 STs, 7 spa types, and 9 MTs). PFGE patterns were more diverse than those of other three molecular typing methods (19 pulse types). The index of diversity (DI) of PFGE, MLVA, spa typing and MLST was 0.99, 0.80, 0.73, and 0.61, respectively. Among the MRSA isolates, CC9-ST9-t899-MT929-MC2236 (PFGE Cluster Ⅴ) was the most prevalent clone, which were all cultured from raw pork (9 isolates). Besides, two MRSA were identified as CC59-ST338-t437-MT621-MC621 (PFGE Cluster Ⅳ). Different clone had their own resistance spectrum profiles. Conclusion: The food-borne MRSA isolates were all MDR in this study. Different clones had their own resistance spectrum profiles. MLVA represented a promising tool for molecular epidemiology tracing of MRSA in foodborne disease events.

[Antimicrobial susceptibility and drug-resistance genes of Yersinia spp. of retailed poultry in 4 provinces of China].

Objective: To monitor the antimicrobial resistance and drug-resistance genes of Yersinia enterocolitis, Y. intermedia and Y. frederiksenii recovered from retailed fresh poultry of 4 provinces of China. Methods: The susceptibility of 25 isolated Yersinia spp. to 14 classes and 25 kinds of antibiotics was determined by broth microdilution method according to CLSI (Clinical and Laboratory Standards Institute). The antibiotic resistance genes were predicted with antibiotic resistance genes database (ARDB) using whole genome sequences of Yersinia spp. Results: In all 22 Y. enterocolitis tested, 63.7% (14 isolates), 22.8% (5 isolates), 4.6% and 4.6% of 1 isolates exhibited the resistance to cefoxitin, ampicillin-sulbactam, nitrofurantoin and trimethoprim-sulfamethoxazole, respectively. All the 25 isolates were multi-drug resistant to more than 3 antibiotics, while 64.0% of isolates were resistant to more than 4 antibiotics. A few Y. enterocolitis isolates of this study were intermediate to ceftriaxone and ciprofloxacin. Most Yersinia spp. isolates contained antibiotic resistance genes mdtG, ksgA, bacA, blaA, rosAB and acrB, and 5 isolates recovered from fresh chicken also contained dfrA1, catB2 and ant3ia. Conclusion: The multi-drug resistant Yersinia spp. isolated from retailed fresh poultry is very serious in the 4 provinces of China, and their contained many kinds of drug-resistance genes.

[Serotype distribution and antimicrobial resistance of Salmonella isolates from retail chicken carcasses in six provinces of China].

Objective: To obtain the serotype diversity and antimicrobial resistance of Salmonella isolates recovered from retail chicken carcasses for sale in six regions of China. Methods: From August 2010 to March 2012, each month 20 retail chicken carcasses including freshly slaughtered, chilled and frozen samples were collected from supermarkets and farmer's markets in 7 monitoring sites in Beijing, Jilin province, Inner Mongolia Autonomous, Shanxi province, Jiangsu province and Guangdong province, respectively. Samples were routinely collected for 12 months for each site. 1 680 chicken carcasses were collected in total and 2 629 Salmonella strains were isolated by PCR and biochemical method. Luminex xMAP method and classical slide agglutination method were carried out to determine isolates' serotypes. Minimal inhibitory concentrations (MICs) of 10 classes of antimicrobials including 14 agents were determined using broth micro-dilution method. Mocular methods were used to determine antimicrobial resistance genes of CIP-CTX-CT co-resistant isolates. Results: In all, 2 629 Salmonella isolates, there were 17 seorgroups and 58 serotypes, B and D1 were the dominant serogroups with rates of 34.7% (n=913) and 31.0% (n=815), Enteritidis (30.8%, n=810), Indiana (17.6%, n=463), Infantis (10.6%, n=278) were the top three serovars. We found 224 CIP-CTX co-resistant S. Indiana containing 3 colistin resistant strains, one of them carrying mcr-1 gene and being ESBLs positive, which demonstrated a nine multi drug resistance against 11 antimicrobials tested. Conclusion: These data began to describe the complicated serovar diversity and heavy antimicrobial resistance of Salmonella isolates recovered from retail chicken carcasses in six regions of China. The findings highlight the emergence of ciprofloxacin and cefotaxime co-resistant S. Indiana and also a mcr-1 positive S. Indiana with heavy multi drug resistance.

[Molecular characterization genetic diversity of extended-spectrum ß-lactamases-harboring conjugative plasmids identified in multi-drug resistant Escherichia coli isolated from food in China].

Objective: The purpose of this study was to investigate the molecular characteristics of ESBL-encoding conjugative plasmid identified in muti-drug resistant Escherichia coli isolated from food. Methods: 465 Escherichia coli isolates were collected from national foodborne disease surveillance net from 2013 to 2014 (salad, n=159; meat, n=102; processed meat, n=95; cakes/rice, n=46; cooked dish, n=63). ESBLs strain was detected by Mueller-Hinton agar plate, and then its drug resistance was tested by agar dilution method. Polymerase chain reaction (PCR) and DNA sequencing were performed to identify the corresponding ESBL genes. Plasmids were typed by PCR-based replicon typing and their characteristics were determined by S1-nuclease pulsed-field gel electrophoresis method. Broth mating assays were carried out for all isolates to determine whether the ESBL marker could be transferred by conjugation. Results: 12 E. coli were found to be resistant to cefotaxime, and all of which were confirmed as ESBLs. The 12 isolates all carried different types of CTX-M genes resistant to drug, and 7 of which carried TEM type as well. All 12 isolates contained at least one plasmid and some had four plasmids, with size ranging from 47-to 220-kb by S1-PFGE anaylsis. Seven isolates demonstrated the ability to transfer their cefotaxime resistance marker to the recotper strain J53 by only one plasmid. Conclusion: This study highlights the diversity of the multi-drug resistant E. coli and also the diversity of ESBL genes in China. Plasmids carrying these genes poses a serious threat to food safety in China.

A multicentre, randomized, single-blind comparison of topical clindamycin 1%/benzoyl peroxide 5% once-daily gel versus clindamycin 1% twice-daily gel in the treatment of mild to moderate acne vulgaris in Chinese patients.

BACKGROUND: Acne vulgaris affects up to 54% of Chinese adolescents. Combination therapy has become the recommended standard of care for acne. OBJECTIVE: The aim of this study was to compare the efficacy and safety of clindamycin (1%) and benzoyl peroxide (5%) (CDP/BPO) gel once daily vs. clindamycin (1%) (CDP) monotherapy gel twice daily in Chinese patients with mild to moderate acne. METHODS: 1020 patients (aged 12-45 years) with mild to moderate acne were randomized (1 : 1); 1016 patients were treated with CDP/BPO (n = 500) or CDP (n = 516) for a 12-week treatment period. Efficacy assessments were performed at baseline, and at weeks 1, 2, 4, 8 and 12; and primarily included change in total lesion count (inflammatory and non-inflammatory lesions), and proportion of patients with a minimum 2-grade improvement in Investigator's Static Global Assessment (ISGA) score. Patient safety and local tolerability were also evaluated. RESULTS: Patients in CDP/BPO group showed a greater per cent reduction in total lesion count compared with patients in CDP group at week 12 (delta = -0.05; 95% CI = -0.09, -0.02; P = 0.003); statistically significant reduction in lesion count was noted as early as week 1 and continued through week 12. A greater proportion of patients in CDP/BPO group showed a ≥2-grade improvement in ISGA score at week 12 compared with CDP group (30.2% vs. 22.7%; P = 0.018). Overall, the incidence of adverse events (AEs) was higher in the CDP/BPO group (14.4%) than in the CDP group (7.9%); the most commonly reported events were generally related to application site reactions (erythema, pruritus and swelling). Incidence of drug-related AEs was 8.6% in CDP/BPO group and 1.2% in CDP group. Both groups showed trends towards reduction in investigator and subject rated local tolerability scores. CONCLUSION: CDP/BPO gel demonstrated superior efficacy over CDP gel along with acceptable safety and tolerability in Chinese patients with mild to moderate acne. GOV NUMBER: NCT01915732.

[Nicotine alleviates the liver inflammation of non-alcoholic steatohepatitis induced by high-fat and high-fructose in mice].

OBJECTIVE: To investigate the anti-inflammation effects by activation of the cholinergic anti-inflammatory pathway and its mechanisms in non-alcoholic steatohepatitis (NASH) model mice. METHODS: 6-week-old male C57BL/6J (B6) mice were randomly divided into four groups: the first group was normal mice, injected with saline; the second group was normal mice, injected with nicotine; the third group was NASH model mice, injected with saline; the fourth group was NASH model mice, injected with nicotine. The experimental mice were fed with either standard chow (SC) or high-fat and high-fructose (HFHF) for 17 weeks to generate an NASH model mice. The mice received injection once daily for 3 weeks [nicotine dose, 400 µg/kg]. Then, their pathological characteristics and function of the liver were assessed. The expressions of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in serum were analyzed by enzyme linked immunosorbent assay (ELISA). The expressions of alpha 7 nicotinic acetylcholine receptors (α7nAChR), Toll-like receptors-4 (TLR-4) and nuclear factor κB of phosphory-lation (p-NF-κB) in Kupffer cells were determined by Western blot and immunofluorescence assays. RESULTS: We successfully generated NASH model mice by imitating the high-fat and high-fructose dietary style of NASH patients. The results of our investigation demonstrated that nicotine could reduce significantly the levels of IL-6, and TNF-α in serum (P<0.05). The expression of p-NF-κB protein in the group which was NASH model mice injected with nicotine declined significantly as compared with the group which was NASH model mice injected with saline (P<0.05). And the expression of α7nAChR protein elevated significantly conversely (P<0.05). CONCLUSION: Activation of the cholinergic anti-inflammatory pathway could inhibit the release of inflammatory factors as TNF-α and IL-6 in NASH model mice, and the mechanism for the inhibition of inflammatory was mediated by NF-κB pathway.

[Survey on fungi contamination and natural occurrence of mycotoxins in 94 corn feed ingredients collected from China].

Objective: To investigate fungi contamination and the natural occurrence of mycotoxins in corn feed ingredients collected from China. Methods: A total of 94 corn feed ingredient samples were collected from 8 Chinese provinces(i.e., Anhui, Hebei, Heilongjiang, Jilin, Jiangsu, Liaoning, Inner Mongolia, and Shandong)in February 2014. A tandem ultra-performance liquid chromatographymass spectrometry method was used for simultaneous detection of twelve kinds of mycotoxins, including aflatoxin(AF), type A and type B tricothecenes, and zearalenone(ZEN). Contaminated fungi were also identified and counted. Results: AF was detected in 36.2%(34/94)of samples; the concentration of AFB1 was the highest in the four AFs with the range: 0.3~181.3 µg/kg; and then followed by AFB2(range: 1.0-74.3 µg/kg). There were 7 samples(7.5%)with AFB1 concentrations higher than the tolerance limit of 50 µg/kg. The concentration of type A tricothecenes in all samples was lower(0.1-10.5 µg/kg). DON had the most serious contamination than other kind of type B tricothecenes(range: 0.7-606.6 µg/kg; median: 66.3 µg/kg). The DON concentration in all samples was below the tolerance limit of 1 000 µg/kg. ZEN was detected in 76.6%(72/ 94)of samples(median: 36.9 µg/kg), with 3 samples having ZEN concentrations higher than the tolerance limit of 500 µg/kg. The survey on fungi contamination showed that all samples were contaminated by fungi(range: 5.0-1.4×105 CFU/g). There were 18 and 3 samples with quantities of fungi higher than the tolerance and forbidden limits, respectively. The Aspergillus, Penicillium, Fusarium, Trichoderma and Mucor genuses were the predominant fungi in corn feed ingredients, with detection rates of 71.3%(67), 60.6%(57), 71.3%(67), 27.7%(26), and 24.5%(23), respectively. The detection rate of Fusarium moniliforme, 73.4%(69/94)was higher than that of Aspergillus flavus, 41.5%(39/94). Conclusion: In this survey, the corn feed ingredients were not seriously contaminated by AF and type A tricothecenes but mainly contaminated by type B trichothecenes, including DON and its derivatives, as well as ZEN. They were also contaminated by fungi such as Aspergillus, Penicillium, and Fusarium.

[Effect of nicotinic acetylcholine receptor α7 subunit gene on liver inflammatory reaction in mice with nonalcoholic steatohepatitis and related mechanisms].

Objective: To investigate the effect of nicotinic acetylcholine receptor α7 (α7nAChR) subunit gene on liver inflammation in mice with nonalcoholic steatohepatitis (NASH) and related mechanisms. Methods: C57BL/6J mice and α7nAChR gene knockout mice were fed for 24 weeks to establish the NASH model, and the mice were sacrificed to isolate and culture the primary liver macrophages. After the treatment with nicotine and endotoxin, ELISA was used to measure the levels of the inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in supernatant; indirect immunofluorescence assay and Western blot were used to observe the effect on the NF-κB signaling pathway, and quantitative PCR was used to measure the mRNA expression of Toll-like receptor-4 (TLR-4) in macrophages. An analysis of variance was used for comparison of means between multiple groups. Results: The results of ELISA showed that compared with the endotoxin+nicotine group of C57 NASH mice, the endotoxin+nicotine group of gene knockout NASH mice had significantly higher levels of IL-6 and TNF-α in supernatant (IL-6: 1 599±65 pg/ml vs 1 465±45 pg/ml, P < 0.05; TNF-α: 1 567±66 pg/ml vs 1 433±50 pg/ml, P < 0.05). The results of Western blot showed that compared with the endotoxin+nicotine group of C57 NASH mice, the endotoxin+nicotine group of gene knockout NASH mice had significantly higher relative protein expression of phosphorylated NF-κB and TLR-4 (NF-κB: 69 425±600 vs 51 133±200, P < 0.05; TLR-4: 93 387±684 vs 64 198±630, P < 0.05). The results of indirect immunofluorescence assay showed that the endotoxin+nicotine group of gene knockout NASH mice had a significantly higher fluorescence intensity of NF-κB than the endotoxin+nicotine group of C57 NASH mice. The results of PCR showed that the endotoxin+nicotine group of gene knockout NASH mice had significantly higher relative mRNA expression of TLR-4 than the endotoxin+nicotine group of C57 NASH mice (4.13±0.13 vs 2.93±0.14, P < 0.05). Conclusion: The α7nAChR gene knockout can aggravate the degree of inflammatory reaction in NASH, and its mechanism may be related to the fact that the NF-κB signaling pathway cannot be inhibited, which aggravates inflammatory reaction.