RESUMO
To conduct outbreak identification and transmission factor analysis of typhoid epidemic occurred in Xinqiao town, Jiangyin city from June to September 2016. A total of 14 strains of Salmonella typhi isolated from confirmed cases were collected, and 65 external environment samples and 13 food samples related to the outbreak were taken. Real-time PCR was used to detect specific gene of Salmonella typhi in the samples. Conventional method was used to isolate strains. The strains isolated from both the samples and patients in the epidemic were subjected to antimicrobial susceptibility testing and PFGE molecular characteristics. Salmonella typhi strain was isolated from one external sample (well water of a deli processing plant). The results of drug susceptibility showed that 15 strains were resistant to nalidixic acid. A total of 15 strains of Salmonella typhi were divided into 2 molecular patterns by pulsed field gel electrophoresis. The fingerprints of PFGE from the 13 patients and the environmental isolate were completely consistent, and there was one band difference from the other patient isolate. Combined with the epidemiological investigation and laboratory test results, it was determined that the outbreak was caused by genetic clone of the same Salmonella typhi. Food processing plant should be one of the key links.
Assuntos
DNA Bacteriano/genética , Surtos de Doenças , Epidemias , Salmonella enterica/genética , Salmonella typhi/genética , Febre Tifoide/epidemiologia , Antibacterianos/uso terapêutico , China/epidemiologia , Resistência Microbiana a Medicamentos , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase em Tempo Real , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/isolamento & purificação , Salmonella typhi/classificação , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/isolamento & purificação , Febre Tifoide/diagnóstico , Febre Tifoide/tratamento farmacológico , Febre Tifoide/microbiologiaRESUMO
Objective: To retrospectively analyze the antimicrobial resistance phenotype and molecular typing characteristics of Salmonella (S.) typhi and S. paratyphi in Jiangsu province from 2012 to 2015. Methods: The samples were collected from typhoid and paratyphoid patients in Jiangsu province. The biochemical identification and serotyping were carried out after isolation and culture. Kirby-Bauer (K-B) testing was used to detect the drug susceptibility of the strains. The molecular typing characteristics of S. typhi and S. paratyphi were analyzed by pulsed field gel electrophoresis (PFGE). Results: The resistant rates of 134 S. typhi and S. paratyphi A strains to nalidixic acid were highest (61.2% and 86.7%), while the resistant rates to remaining antibiotics were less than 15.0%. Most of S. typhi and S. paratyphi A strains were resistant to only one antibiotic. Multidrug-resistant (MDR) strains of S. typhi and S. paratyphi A accounted for 2.6% and 13.3% respectively. The composition of the all-sensitive strains of S. typhi increased by 44.3% in 2015, at the same time, there were also MDR S. paratyphi A strains, which were resistant to 5 and 6 antibiotics. S. paratyphi A could be divided into eight molecular patterns by PFGE, showing that the similarity between the MDR strains and other strains was relatively low. The S. paratyphi A strains with same pattern were resistant to same antibiotics. S. typhi could be divided into 68 molecular patterns by PFGE, with large variability between different patterns. There was no corresponding relationship between the patterns and the drug resistance characteristics. Conclusions: The overall antibiotic resistance of S. typhi and S. paratyphi A strains showed a decreasing trend, but the number of antibiotics to which they were resistant increased. PFGE patterns of S. typhi showed diversity without correspondence to antibiotic characteristics. PFGE patterns of S. paratyphi A were less with correspondence to antibiotic characteristics. We should pay more attention to key patterns in key areas.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Tipagem Molecular/métodos , Salmonella paratyphi A/efeitos dos fármacos , Salmonella paratyphi A/genética , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/genética , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Febre Paratifoide/microbiologia , Salmonella paratyphi A/classificação , Salmonella paratyphi A/isolamento & purificação , Salmonella typhi/classificação , Salmonella typhi/isolamento & purificação , Sorotipagem , Febre Tifoide/microbiologiaRESUMO
We investigated the first presence of qnrA among Shigella sonnei clinical isolates in Jiangsu Province, China. The qnrA-positive isolates coexisted with the mutation in gyrA at codon 83, these isolates were resistant to nalidixic acid and 22·2% (2 of 9) of them were resistant to norfloxacin.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Ácido Nalidíxico/farmacologia , Norfloxacino/farmacologia , Shigella sonnei/efeitos dos fármacos , China , Shigella sonnei/genética , Shigella sonnei/isolamento & purificaçãoRESUMO
A rapid and high performance gas chromatographic method for the determination of 20 organchlorinated pesticides in oils, fruits and vegetables has been developed. The samples of fruits and vegetables were extracted with petroleum ether-acetone, while those of oils were extracted with acetonitrile-hexane. The extract was purified by Florisil column with ethyl ether-hexane(15:85, V/V) or ethyl ether-petroleum ether(15:85, V/V) as eluent. Chromatographic analysis was performed on wide-bore capillary column with ECD detector. Satisfactory separation and detection of these organchlorinated pesticides are presented with the proposed method. The detection limits of this method were 1.0 ng/g-20.0 ng/g(S/N = 5), the recoveries 83.2%-106.8% and the relative standard deviations 2.0%-9.5%.
