Objective To study the molecular characters of porA and porB genes which encode outer membrane proteins (OMP), and predominated clonal complex of Neisseria meningitidis isolates from Guangdong province. Methods Eighteen Neisseria meningitidis isolates from Guangdong province during year 1967 to 2007 were recovered and reconfirmed by API NH biochemical system, and serogrouped by antiserum. The characters of porA and porB gene were analyzed by DNA sequencing. The allele profiles and the sequence types (ST) were determined by multilocus sequence typing (MLST). Based on their allelic profiles, the evolution relationship was analyzed by PHYLIP software. The predominant clonal complex was determined through comparing with the information of reference strains from the PubMLST database. Results For porA gene, type 20 was more frequently in the variable region (VR) 1 and type 9 in VR2 before year 2004. However, for porB gene, type 4 was more frequently in VR Ⅰ, type7 in VR Ⅳ, type 11 in VR Ⅴ,and type 10 in VR Ⅵ, respectively. The multi-types character was presented in VR Ⅴ and VR Ⅵ after2004. VR Ⅶ and VR Ⅷ can not be found among all the isolates except for one W135 isolate in 2007. Among the seven housekeeping genes, the polymorphism of abcZ was the lowest one with 4 allele numbers, while pgm was the highest one with 13 allele numbers. The predominant clonal complex was ST-5 before 2004. The ST-4821 clone complex appeared in 2004 and caused cases every year since then. More important, highly invasive ST-11 clonal complex firstly appeared in Guangdong in 2007. Conclusion The molecular characteristic of OMP genes presents polymorphism for the Neisseria meningitidis isolates from patients in Guangdong province during 1967 to 2007. ST-5 is the predominant clonal complex before 2004 and the highly invasive clonal complex is circulating in recent 3 years. It suggests that the surveillance based on laboratory should be further enhanced.

Objective To investigate the antimicrobial resistance pattern of non-typhoidal Salmonella isolated from diarrhea cases in Guangdong province,China.The multidrug-resistant strains were analyzed by pulsed field gel electrophoresis(PFGE) typing.Methods All the non-typhoidal Salmonella strains isolated between 2009 and 2011 were serotyped,then the antimicrobial resistance was detected by the disk diffusion method and molecular typed by PFGE.Results 91.76％ (256/279) S.typhimurium isolates were multiple resistant to 3 and more antimicrobials.Forty S.typhimurium isolates were multiple resistant to 9 and more antimicrobials and 3 out of which were multiple resistant to all the 12 antimicrobials in vitro.96.91％ (94/97) Salmonella I4,5,12:i:-isolates were multiple resistant to 3 and more antimicrobials.Nine Salmonella I4,5,12:i:- isolates were multiple resistant to 9 and more antimicrobials and I out of which was multiple resistant to all the 12 antimicrobials1 in vitro.47％ (47/100) S.enteritidis isolates were multiple resistant to 3 and more antimicrobials.Only 1 S.enteritidis isolates was multiple resistant to 9 and more antimicrobials.4.27％ (27/632) non-typhoidal Salmonella isolates was resistant to ciprofloxacin,including 17 S.typhimurium and 6 Salmonella 14,5,12:i:- isolates.Also,there were 3 1.96％ ( 202/632 ) non-typhoidal Salmonella isolates was intermediary to ciprofloxacin.The PFGE patterns of the predominant strains which were highly resistant and multidrug-resistant had different genotypes and demonstrated significant genetic diversity.Conclusion The situation about the multiple antimicrobial resistances of non-typhoidal Salmonella in Guangdong province has showed the prevalent problem.The PFGE types of the multiple drug-resistant strains prompted these strains were come from different clones.This requires that we continue to strengthen the resistance monitoring and control of the rational use of antibiotics.

To compare and evaluate the discriminatory ability and potential value of pulsed field gel electrophoresis (PF-GE) and multiple locus VNTRs analysis (MLVA) on the genotyping of Brucella ,a total of 60 strains of Brucella and three standards (16M ,544A ,1330S) were genotyped simultaneously by PFGE and MLVA .The result indicated that the similarity coefficient among the 63 isolates was from 72 .1-100 .0% by PFGE ,and could distinguish three species of B .melitensis ,B .su-is and B .abortus at the similarity level of 94 .4% .There were 14 clusters and 29 PFGE types identified by PFGE with discrim-inatory index (DI) of 0 .957 5 at the similarity level of 100% ;the similarity coefficient among the 63 isolates was from 16 .9-100 .0% by MLVA ,and could distinguish three species of Brucella at the similarity level of 52 .3% .There were 8 clusters and 47 MLVA types identified by MLVA with discriminatory index (DI) of 0 .985 2 at the similarity level of 100% .It's suggested that PFGE and MLVA could be used to distinguish three species of Brucella in the similarity coefficient of certain ,but could not effectively distinguish the type in the same species .Both of these two methods could be used for Brucella molecular typing , but MLVA is better than PFGE for its relatively higher discriminating ability .

Objective To analyze the serotype distribution and antibiotic resistance characteristics of Salmonella strains isolated in Guangdong province for better understanding the condition of Salmonella infection in patients with diarrhea.Methods Fecal samples collected from patients with diarrhea in Guangdong province were used to isolate Salmonella strains.Biochemical analysis was performed to identify these isolated strains.Serotyping and antimicrobial susceptibility testing were carried out for further analysis of the isolated Salmonella strains.Results The rate of Salmonella infection was 7.64％in 2015, and the male to female patient ratio was 1.52∶1.A total of 2 377 patients of all age groups were positive for Salmonella infection and the patients aged 0-6 years accounted for 81.74％.The isolation rate of Salmonella strains in the summer and autumn was higher than that in the winter and spring (10.73％ vs 4.24％;X2=463.77, P<0.01).The Salmonella isolation rates in different areas were as follows: 16.82％ in Zhuhai, 15.85％ in Heyuan, 11.81％ in Yangjiang, 10.68％ in Jiangmen, 8.49％ in Zhongshan, 8.07％ in Maoming, 8.05％ in Jieyang, 7.35％ in Shaoguan, 6.97％ in Foshan, 6.03％ in Dongguan, 5.48％ in Guangzhou and 0.00％ in Zhanjiang.And the differences between different regions were statistically significant (X2=367.67, P<0.01).The 2 377 isolated Salmonella strains were classified into 108 serotypes except for oneSalmonella strain that could not be classified.The top four predominant serotypes were 4,5,12:i:-, Salmonella enteritidis,Salmonella stanley and Salmonella typhimurium.Most Salmonella strains were sensitive to imipenem, azithromycin, ceftazidime, cefotaxime and trimethoprim/sulfamethoxazole, but multidrug resistance was common among those strains.Conclusion Salmonella serotypes of 4,5,12:i:-and Salmonella enteritidis are the predominant pathogens causing human Salmonella infections in Guangdong province.Ceftazidime and cefotaximeare are preferred in the treatment of Salmonella infections.Surveillance for drug resistance in Salmonella should be strengthened as multidrug resistant strains have become a serious problem in Guangdong province.

Objective To prepare simulated stool specimens for proficiency testing ( PT) by mix-ing lentils with Salmonella, Shigella and Escherichia coli strains and to establish an assessment scheme for the detection of Salmonella and Shigella in clinical samples. Methods Salmonella, Shigella and Escherich-ia coli strains were respectively spiked to lentils in Cary-Blair transport medium to create simulated stool specimens. Various ratios of Escherichia coli to Salmonella strains were spiked to lentils to prepare mixed simulated stool specimens. The accuracy and stability of prepared stool samples for PT were tested in-house. Results of sample detection were collected from participating laboratories for further external quality assess-ment. Results The Escherichia coli and Salmonella strains mixed at ratios of 100 ∶ 1 to 106 ∶ 1 could be ef-ficiently isolated from the media. Enrichment was needed in order to effectively isolate Salmonella strains from the media when the ratios of Escherichia coli to Salmonella strains were 104 ∶ 1 to 106 ∶ 1. Of the16 participating laboratories, 14 laboratories (87. 5%) received a grade of“satisfactory” and the other 2 labo-ratories (12. 5%) received a grade of “mainly satisfactory”. Conclusion The simulated stool specimens and the PT procedures designed in this study were suitable for proficiency testing program on the detection of Salmonella, Shigella and other similar microbes.

Objective To investigate the infection status, serotype distribution, drug sensitivity and molecular characteristics of diarrheagenic Escherichia coli (DEC) in patients with diarrhea in Guangdong Province. Methods Fecal samples were collected, cultured and isolated by traditional methods. Suspected Escherichia coli isolates were confirmed by multiplex PCR used for detecting specific virulence genes and bio-chemical methods. Positive strains were serotyped, characterized for drug sensitivity and analyzed by pulsed-field gel electrophoresis ( PFGE). Results The total positive rate of DEC in patients with diarrhea was 6.26%. The positive rates of enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), enterohemorrhagic Escherichia coli (EHEC), enteroadherent Escherichia coli (EAEC) and en-teroinvasive Escherichia coli (EIEC) were 2. 47% , 1. 54% , 1. 32% , 0. 62% and 0. 09% , respectively, with infections primarily in children aged 0-<7 years. The total seropositive rate was 52. 54% , with EHEC accounting for 15. 00% . DEC showed high sensitivity to imipenem, ciprofloxacin, ceftazidime and cefo-taxime. The multidrug resistance rate of DEC was 58. 45% , with EPEC being the most serious for multidrug resistance. PFGE results showed that ETEC, EHEC, EPEC and EAEC had a high degree of polymorphism. Conclusion EPEC is the predominant type of DEC circulating in Guangdong Province. Third-generation cephalosporins are the first drugs of choice for treating infections in children. Ciprofloxacin can be used to treat adults. The problem of multiple drug resistance of DEC is severe and efforts to monitor DEC infections and drug resistance should be strengthened.

Objective To investigated the etiologic characteristics of Shigella (S.) sonnei strains causing outbreaks and sporadic cases in some areas of Guangdong province and Guangxi Zhuang Autonomous Region during 2014-2016. Methods Fourteen S. sonnei strains isolated from outbreaks and 6 S. sonnei strains from sporadic cases from Guangdong and Liuzhou of Guangxi Zhuang Autonomous Region were tested for antimicrobial resistance and analyzed by pulsed-field gel electrophoresis (PFGE). Six typical strains were selected for whole genome sequencing typing and compared with 51 strains isolated both at home and abroad from NCBI genome database. Results The antibiotic resistance test indicated the isolates had high resistance rate to ampicillin, tetracycline, gentamicin, trimethoprim/sulfamethoxazole and nalidixic acid, while sensitive to azithromycin, chloromycetin and imipenem. PFGE showed high similarity (93.2%) among the strains isolated from different areas. The whole genome sequencing analysis also revealed that all the typical strains wereclustered into a same evolution branch, close to some strains from Korea. Conclusions The S. sonnei strains isolated from some areas of Guangdong and Guangxi Zhuang Autonomous Region showed high resistance to commonly used antibiotics, but they were sensitive to azithromycin, chloramphenicol and imipenem. The isolates in this study also showed similar PFGE patterns and close phylogenic evolution.

Vocal fatigue（VF） is the common clinical symptom of voice diseases. It can also be a separate symptom and is considered to be a signal for the body to rest and to avoid pathological damage to the vocal cords. Therefore, the early identification and evaluation of vocal fatigue is of great value to the early prevention and treatment of vocal diseases. In recent years, there are many researches on the evaluation methods of vocalization fatigue. We searched the relevant literature and summarized the application status of vocal fatigue assessment methods, in order to provide reference for the selection and development of vocal fatigue assessment tools in clinical practice.
Humans ; Voice Quality ; Voice Disorders/diagnosis* ; Vocal Cords ; Surveys and Questionnaires ; Dysphonia/diagnosis*

Objective To study the effect and mechanism of epigallocatechol gallate (EGCG) combined with trastuzu-mab on the proliferation of human epidermal growth factor receptor 2 (HER2) overexpressing breast cancer cells. Methods Trastuzumab was expressed and purified. The cell proliferation of HER2 overexpressing breast cancer cells BT474 and SK-BR-3 treated with trastuzumab, EGCG, or trastuzumab plus EGCG was evaluated by CCK8 assay. The effects of EGCG and trastuzumab on the expression of HER2, epidermal growth factor receptor (EGFR), mitogen-activated protein kinase (MAPK), protein kinase B (Akt), and their phosphorylated proteins in BT474 breast cancer cells were detected by Western blot. Results The results of cell proliferation assay indicated that EGCG and trastuzumab, alone or in combination, effectively inhibited the proliferation of BT-474 and SK-BR-3 cells. And within a certain concentration range, EGCG and trastuzumab showed a synergistic proliferation inhibitory effect on HER2 overexpressing breast cancer cells. Consistent with these results, Western blot results showed that trastuzumab and EGCG, alone or in combination significantly reduced the phosphorylation levels of Akt, MAPK, EGFR, and HER2 in BT474 cells. Moreover, the inhibition effect of EGCG plus trastuzumab was significantly more potent than either EGCG or trastuzumab. Conclusion EGCG and trastuzumab could synergistically inhibit the proliferation of HER2 overexpressing breast cancer cells, which may be related to the regulation of Akt and MAPK signaling pathways.