ABSTRACT
Objective To understand the main serotypes, antibiotic resistance profiles and molecular typing characteristics of Listeria monocytogenes（LM) isolated from foods in Shandong Province from 2013 to 2016. Methods The antibiotic sensitivity of LM was tested by broth microdilution method. The serotypes were determined by slide agglutination and PCR, and the molecular typing was carried out by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing(MLST) . Results Most of 191 LM strains were sensitive to the eight antibiotics tested. Tetracycline resistance was most prevalent (15/191, 7.85%). There was no significant difference in the 8 antibiotic resistance monitored for 4 years (P=1.000). The serotype 1/2a, 1/2b and 1/2c accounted for 38.82% (66/170), 18.82% (32/170), and 42.36% (72/170), respectively. The patterns of SDSRZXDZ016, S2014L031 and SDSRZX030, totally accounted for 33.78%, were the dominant types. The main ST types were ST9, ST8 and ST121, which accounted for 81.18% (69/85). The clinical common types, ST3, ST7 and ST87 accounted for 8.23% (7/85), mainwhile new ST type was not found. Conclusion The LM strains isolated in Shandong Province from 2013 to 2016 were sensitive to most antibiotics, but some strains were resistant to tetracycline and erythromycin. The dominant serotypes were 1/2c and 1/2a. Serotype 4b, prone to outbreaks of listeriosis, was not found. The main PFGE types were SDSRZXDZ016, S2014L031 and SDSRZX030, which were continuously found from 2013 to 2016. The main ST types were ST8, ST9 and ST121. The clinical types, ST3, ST7 and ST87 were isolated from food and should be paid seriously attention to.
ABSTRACT
To analyze the etiology and epidemiological characteristics of gastroenteritis virus in foodborne diseases from three cities in Shandong. From January to December 2017, six sentinel hospitals in Jinan, Yantai and Linyi city of Shandong Province were selected as the research sites. Stool samples of 1 397 diarrhea patients were collected, as well as basic information and clinical symptoms. Duplex quantitative RT-PCR was used to detect Norovirus genogroupⅠ (Nov GⅠ) and genogroupⅡ (Nov GⅡ), Sapovirus (SAV) and Human astrovirus (HAstV), respectively, quantitative RT-PCR was used to detect group A Rotavirus (RVA), and quantitative PCR was used to detect Enteric adenovirus (EAdV). The specific gene of the virus were sequenced and typed. It was compared that the gastroenteritis virus rate in cases with different characteristics and the clinical symptoms difference between the virus positive and negative cases. The median age ((25), (75)) was 23 (1, 42) , mainly male, 57.48% with 803 cased and children under 5 years old, 36.36% with 508 cases. The positive rate of gastroenteritis virus was 33.93% (474 cases), and that of Jinan, Linyi and Yantai City were 32.03% (147/459), 41.54% (189/455) and 28.57% (138/483), respectively (0.001). Nov GⅡ had the highest positive rate, 16.54% (231 cases), which, mainly GⅡ.P16/GⅡ.2 (48.28%, 56/116), peaked in May (24.75%, 50/202) and June (19.59%, 38/194). In patients of gastroenteritis virus positive, 44.51% (211/474) had vomiting symptoms, higher than that of patients of gastroenteritis virus negative (34.13%, 315/923). The difference was statistically significant (0.001). In Shandong Province, the majority of gastroenteritis patients were male and children under 5 years old. Nov GⅡ possessed highest epidemic intensity, and peaked in spring and summer. Viral gastroenteritis had atypical clinical symptoms.
ABSTRACT
Objective To study the characteristics and epidemic trend of Shigella in Shandong province through the analysis of serotype, virulence genes, molecular typing and drug sensitivity. Methods The serotype was classified using the method of slide agglutination. Polymerase chain reaction (PCR) was used to amplify the related virulence genes. The molecular typing was carried out by pulsed field gel electrophoresis (PFGE), and the antibiotic sensitivity of the strains was determined by micro-broth dilution method. Results The main serogroups of 44 Shigella strains were Shigella flexneri (54.55%) and Shigella sonnei (43.18%). The carrying rates of ipaH, Set1, Sen and ial were 100%, 43.18%, 56.82% and 50.00%, respectively. By PFGE typing, the strains of Shigella flexneri were divided into 18 patterns with a low similarity. The strains of Shigella sonnei were divided into 14 patterns, and the similarity of 89.47% of the strains was more than 90%. 44 strains of Shigella had different levels of resistance to 14 of the 15 antibiotics. 93.18% of the strains were multidrug resistant. Conclusion The Shigella in Shandong province is dominated by serogroups of Shigella flexneri and Shigella sonnei, with high virulence gene carrying rate, clustering distribution and severe antibiotic resistance. It is necessary to strengthen the monitoring on serotype, traceability and antibiotic resistance of Shigella in Shandong province.