ABSTRACT
SARS-CoV-2 has caused a global pandemic, infecting millions of people. An effective preventive vaccine against this virus is urgently needed. Here, we designed and developed a novel formulated recombinant receptor-binding domain (RBD) nucleocapsid (N) recombinant vaccine candidates. The RBD and N were separately expressed in E. coli and purified using column chromatography. The female Balb/c mice were immunized subcutaneously with the combination of purified RBD and N alone or formulated with saponin adjuvant in a two-week interval in three doses. Neutralization antibody (Nabs) titers against the SARS-CoV-2 were detected by a Surrogate Virus Neutralization (sVNT) Test. Also, total IgG and IgG1, and IgG2a isotypes and the balance of cytokines in the spleen (IFN-γ, Granzyme B, IL-4, and IL-12) were measured by ELISA. The percentages of CD4+ and CD8+ T cells were quantified by flow cytometry. The lymphoproliferative activity of restimulated spleen cells was also determined. The findings showed that the combination of RBD and N proteins formulated with saponin significantly promoted specific total IgG and neutralization antibodies, elicited robust specific lymphoproliferative and T cell response responses. Moreover, marked increase in CD4+ and CD8+ T cells were observed in the adjuvanted RBD and N vaccine group compared with other groups. The results suggest that the formulations are able to elicit a specific long-lasting mixed Th1/Th2 balanced immune response. Our data indicate the significance of the saponin-adjuvanted RBD/N vaccine in the design of SARS-CoV-2 vaccines and provide a rationale for the development of a protective long-lasting and strong vaccine.
Subject(s)
COVID-19 , Saponins , Viral Vaccines , Adjuvants, Immunologic , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Escherichia coli , Female , Granzymes , Humans , Immunity, Cellular , Immunoglobulin G , Interleukin-12 , Interleukin-4 , Mice , Mice, Inbred BALB C , Nucleoproteins , SARS-CoV-2 , Vaccines, SyntheticABSTRACT
Nowadays, increasing extended-spectrum ß-lactamase (ESBL)-producing bacteria have become a global concern because of inducing resistance toward most of the antimicrobial classes and making the treatment difficult. In order to achieve an appropriate treatment option, identification of the prevalent species which generate ESBL as well as their antibiotic susceptibility pattern is essential worldwide. Hence, this study aimed to investigate the prevalence of ESBL-producing bacteria and assess their drug susceptibility in Fardis Town, Iran. A total of 21,604 urine samples collected from patients suspected to have urinary tract infection (UTI) were processed in the current study. The antimicrobial susceptibility of the isolates was tested by the disk diffusion method. The ESBL producing bacteria were determined by Double Disc Synergy Test (DDST) procedure. Bacterial growth was detected in 1408 (6.52%) cases. The most common bacterial strains causing UTI were found E. coli (72.16%), followed by K. pneumoniae (10.3%) and S. agalactiae (5.7%). Overall, 398 (28.26%) were ESBL producer. The highest ESBL production was observed in E. coli, followed by Klebsiella species. ESBL producers revealed a higher level of antibiotic resistance compared with non-ESBLs. In conclusion, ESBL production in uropathogens was relatively high. Carbapenems and Aminoglycosides were confirmed as the most effective treatment options for these bacteria.
Subject(s)
Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Escherichia coli/enzymology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/enzymology , Streptococcus agalactiae/drug effects , Streptococcus agalactiae/enzymology , Urine/microbiology , beta-Lactamases/metabolism , Aminoglycosides/isolation & purification , Aminoglycosides/pharmacology , Carbapenems/pharmacology , Cross-Sectional Studies , Drug Resistance, Bacterial , Escherichia coli/isolation & purification , Humans , Klebsiella pneumoniae/isolation & purification , Microbial Sensitivity Tests/methods , Streptococcus agalactiae/isolation & purificationABSTRACT
BACKGROUND: Pseudomonas aeruginosa is a major cause of hospital-acquired infection due to its high antibiotic resistance and biofilm formation ability. P. aeruginosa produces elastase lasB during biofilm formation, which can influence properties of biofilm. This study was carried out to evaluate the antibiotic resistance and distribution of the lasB gene among biofilm-producing P. aeruginosa strains isolated from burn patients. METHODS: A total of 128 clinical samples were collected from burn patients. The P. aeruginosa isolates were identified using standard bacteriological procedures. Antibiotic susceptibility test was performed by the disk diffusion method. Biofilm formation was measured by microtiter plate assay. The presence of lasB gene was detected by PCR. RESULTS: A total of 75 samples were positive for P. aeruginosa. A high rate of resistance was seen against ceftriaxone, cefotaxime, and piperacillin/tazobactam. Biofilm formation was seen in 57.3% of the isolates and the prevalence of the lasB gene was 85.3%. Biofilm formation in isolates without lasB was lower and these isolates were more sensitive to imipenem and piperacillin/tazobactam. CONCLUSIONS: In the present study, we did not find a statistically significant relationship among elastase gene (lasB) presence, antibiotic resistance, and biofilm formation in P. aeruginosa strains isolated from burn patients.
