Enterotoxigenic Bacteroides fragilis (ETBF) is an enterotoxin-producing bacterium that possibily has a role in the occurrence and progression of colorectal cancer (CRC) by modulating the mucosal immune response and inducing epithelial cell changes. The aim of this study was to investigate the frequency of ETBF in stool samples of CRC patients and healthy volunteers. A total of 60 stool samples from confirmed CRC patients and 60 stool samples from healthy volunteers with no personal or familial history or diagnosis of colorectal disease were collected. Stool samples were screened for direct detection of B. fragilis using PCR targeting the marker genes of neu and bft. Enterotoxin isotypes bft-1, bft-2 and bft-3 were also detected in B. fragilis positive samples. The frequency of B. fragilis among CRC and control cases was 58.3 and 26.6%, respectively (P < 0.05). The rate of bft gene in CRC cases was significantly higher than in controls (P < 0.05). Also, the presence of bft gene in CRC patients stage III was significantly higher than stages I and II (P < 0.05). Enterotoxin isotype bft-2 was detected with higher frequency among CRC patients than healthy control (P < 0.05). Our results show the association between fecal ETBF and CRC, and we suggest that detection of ETBF may be a potential marker for colorectal cancer diagnosis. However, additional investigations on tumor and paired normal tissue samples are required to substantiate this possible correlation.
Objective: Multi and extensively drug-resistant (MDR and XDR), Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii) are two main causative agents of nosocomial infections leading to increased morbidity and mortality. We aim to study the prevalence of MDR and XDR-A. baumannii and P. aeruginosa phenotypes in clinical specimens. We conducted this for 1 year (2017–2018) and isolated bacteria from the clinical samples. Then, XDR and MDR strains were determined by susceptibility testing (disc diffusion). Results: Out of 3248 clinical samples, A. baumannii and P. aeruginosa strains were detected in 309(9.51%) of them. Susceptibility testing indicated that (16.50%) and (15.53%) of the P. aeruginosa and (74.75%) and (73.13%) of the A. baumannii isolates were screened as the MDR and XDR strains. The frequency of MDR isolates was higher in wound samples 222 (71.8%). This rate in behavioral intensive care unit (BICU) and restoration ward, were 187 (60.5%) and 63 (20.4%). The frequency of XDR isolates in BICU 187 (59.54%), restoration 58(18.77%), and burns 30 (9.70%) were assessed as well. Considering high isolation rates of MDR and XDR of mentioned strains, it is necessary to apply prevention criteria for eradication of the mentioned bacteria from hospital wards.
4 June 2020 in Human Vaccines & Immunotherapeutics
The number and frequency of multidrug-resistant (MDR) strains as a frequent cause of nosocomial infections have increased, especially for Methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis, in part due to device-related infections. The transition to antibiotic-resistance in related bacterial genes and the capability for immune escape have increased the sustainability of biofilms produced by these bacteria. The formation and changes in biofilms have been suggested as a target to prevent or treat staphylococcal infections. Thus, this study reviews the development of candidate staphylococcal vaccines by database searching, and evaluates the immunogenicity and efficacy profiles of bacterial components involved in biofilms. The literature suggests that using common staphylococcal vaccine antigens and multivalent vaccines should further enhance vaccine efficacy.
Since the 1960s, the frequency of methicillin-resistant Staphylococcus aureus as a recurrent cause of nosocomial infections has increased. Since multidrug-resistant Staphylococcus has overcome antimicrobial treatment, the development of putative vaccines based on virulence factors could be a great help in controlling the infections caused by bacteria and are actively being pursued in healthcare settings. This mini-review provides an overview of the recent progress in vaccine development, immunogenicity, and therapeutic features of some S. aureus macromolecules as putative vaccine candidates and their implications against human S. aureus-related infections. Based on the reviewed experiments, multivalent vaccines could prevent the promotion of the diseases caused by this bacterium and enhance the prevention chance of S. aureus infections.
Objective: Staphylococcus aureus and S. epidermidis as opportunistic pathogens, notable for their frequency and severity of infections are recognized as the most usual reasons for medical device-associated infections that strike hospitalized patients and also immunocompromised individuals. In this study, the polysaccharide intercellular adhesion (PIA) and Glycerol teichoic acid) Gly-TA) as two major macromolecules in the biofilm formation process were purified under the native condition and their structure was analyzed by using colorimetric assays and Fourier Transform Infrared spectroscopy (FTIR). Afterward, the immune response of macromolecules and the mixture of them were assessed by measuring total IgG titers. Subsequently, biofilm inhibitory effects of raising antibodies to biofilm former S. aureus and S. epidermidis were evaluated. Results: Obtained data were shown a significant rise in levels of antibodies in immunized mice with mentioned antibodies in comparison with the control group. According to the obtained findings, mentioned antibodies could eliminate S. aureus and S. epidermidis biofilm formation in vitro assays. This survey confirms the proposal that immunization of mice with a mixture of Gly-TA and PIA vaccine could be secure and protected against S. epidermidis and S. aureus infection.