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There are some concerns about the safety of live attenuated yellow fever vaccines (YF–live), particularly viscerotropic adverse events, which have a high mortality rate. The cellular production of the vaccine will not cause these adverse effects and has the potential to extend applicability to those who have allergic reactions, immunosuppression, and age. In this study, inactivated yellow fever (YF) was prepared and adsorbed with Alum/CpG. The cellular and humoral immunities were investigated in a mouse model. The results showed that Alum/CpG (20 μg/mL) could significantly increase the binding and neutralizing activities of the antibodies against YF. Moreover, the antibody level at day 28 after one dose was similar to that of the attenuated vaccine, but significantly higher after two doses. At the same time, Alum/CpG significantly increased the levels of IFN-γ and IL-4 cytokines. [ABSTRACT FROM AUTHOR]

Objective: To investigate the correlation between sulfamethoxazole-trimethoprim (SXT) resistance in Shigella flexneri ( S.flexneri ) and the presence of integrons and relevant antibiotic resistance genes., Methods: We collected 115 strains of Shigella flexneri isolated from feces of children with diarrhea in Jinan from 2012 to 2020 and determined the minimum inhibitory concentration (MIC) of SXT by Etest method. The presence of class 1, class 2, and class 3 integron genes, variable region antibiotic resistance gene cassettes, and sul1, sul2, sul3 , and SXT elements were detected using polymerase chain reaction (PCR). Positive results were further analyzed by DNA sequencing and BLAST comparison., Results: In total, the resistance rate to SXT was 60.9% among the 115 S.flexneri strains. The prevalence of class 1 and class 2 integrons were 88.7% and 87.0%, respectively, with no class 3 integrons detected. Among the strains, 13.0% carried typical class 1 integrons with variable region antibiotic resistance gene cassettes dfrA17-aadA5 and dfrV , while 85.2% carried atypical class 1 integrons with variable region antibiotic resistance gene cassette blaoxa-30-aadA1 . The variable region antibiotic resistance gene cassettes of class 2 integrons were all dfrA1+sat1+aadA1 . There was a statistical difference between the presence of class 1 integrons and class 2 integrons between the SXT-sensitive and resistant S.flexneri strains (χ 2 =22.800, χ 2 =16.365, P<0.01, P<0.01). Integrons carrying dfrV and dfrA1 by integrons also showed a statistical difference in SXT resistance (χ 2 =9.422, χ 2 =16.365, P<0.01, P<0.01). PCR revealed the presence of sul1 and sul2 in 13.0% and 47.0% of strains, respectively, with neither sul3 nor SXT elements detected. There was a significant difference between the presence of sul1, sul2 between the SXT-sensitive and resistant S.flexneri strains (χ 2 =9.588, χ 2 =65.445, P<0.01, P<0.01)., Conclusion: In summary, integrons are involved in SXT resistance of S.flexneri , and dfrV, dfrA1, sul1, sul2 are closely related to SXT resistance of S.flexneri ., Competing Interests: None., (AJTR Copyright © 2024.)

The present study was to identify the drug resistance, resistance mechanism and the extended-spectrum β-lactamase (ESBLs) genotypes of Shigella flexneri ( S. flexneri ) in Jinan. Susceptibility tests were performed by MIC-determination. The genotypes of β-lactamase were identified using PCR and DNA sequencing. The resistance transfer ability of the ESBL-producing strains was examined by conjugation tests. A total of 105 S. flexneri isolates were collected, and 34 (32.4%) were ESBL-producing isolates. All ESBL-producing isolates were susceptible to cefoxitin and imipenem, and 35.3% isolates were resistant to ciprofloxacin. ESBL-producing isolates showed high level resistant to ampicillin (100%), cefotaxime (100%), tetracycline (100%), chloramphenicol (100%), trimethoprim/sulfamethoxazole (100%), ceftazidime (73.5%) and cefepime (73.5%). Three types of β-lactamase genes ( bla TEM, bla OXA and bla CTX-M) were identified in all ESBL-producing isolates, and the genotypes were confirmed as bla TEM-1 (23/34), bla OXA-30 (34/34), bla CTX-M-14 (9/34) and bla CTX-M-15 (25/34) by sequencing. In conclusion, the Shigella strains isolated in Jinan are cross-resistant and multi-drug resistant. The main genotypes of ESBLs are CTX-M-14 and CTX-M-15., (© 2019 The Author(s).)

Objective: To investigate the correlation between Shigella flexneri multi-drug resistance and drug resistance gene cassette of integrons., Method: All 79 strains of Shigella flexneri were isolated from the feces of children ranged in age from 6 months to 14 years in some hospitals of Jinan, between May 2009 and April 2012.The resistance was detected by Kirby Bauer agar diffusion method, 1, 2 and 3 integron gene was amplified by PCR, the variable region of positive strains treated with enzyme digestion and determined by Series Analysis., Result: Among 79 Shigella flexneri strains, the resistance rate was 91% (72/79) to ampicillin, chloramphenicol, tetracycline, streptomycin, 70% (55/79) to sulfamethoxazole/trimethoprim, 30% (24/79), 23% (18/79), 33% (26/79) and 32% (25/79) to cefotaxime, ceftazidime, ciprofloxacin and levofloxacin.All 79 strains were susceptible to cefoxitin, imipenem, cefoperazone/sulbactam. The common drug resistance pattern is ampicillin tetracycline-chloramphenicol-streptomycin, accounted for 91% (72/79); 91% (72/79) strains carried integrons of class 1, 86% (68/79) strains carried integrons of class 2, No intI3 was detected. The resistance to ampicillin, streptomycin, tetracycline, chloramphenicol of atypical class 1 integron positive strains was significantly higher than the negative strains (χ² = 35.96, P<0.01). The sequencing results:dfrV was detected in class 1 integron variable regions of 9 strains, dfrA17-aadA5 in 2 strains, blaOXA-30-aadA1 in 70 strains, 2 strains were not detected resistance gene cassette, all resistance gene cassettes were dfrA1-sat1-aadA1 in class 2 integron variable regions., Conclusion: The muti-drug resistance of Shigella flexneri in Jinan was closely associated with integrons.