Comparison of ferment sugars, produce hemolysis and measuring growth in methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from inpatients and healthcare workers in Gorgan Hospitals, North of Iran

The mec A gene in Staphylococcus aureus leads to production of new penicillin-binding protein called PBP2a.This change may follow some changes in other phenotypes. The aim of this study was the comparison of Ferment Sugars, Produce Hemolysis and Measuring Growth in MRSA and MSSA isolates. 188 Staphylococcus aureus isolates separated from inpatients and healthcare workers (healthy carriers)were studied.Bacterialcultures in blood agar environment at 37°C during 24h and at 4°C during other 24h were applied for studying hemolysis. Sugar fermentation carried out in phenol red Broth medium, containing glucose, galactose, arabinose, fructose, xylose, ramnose, mannose, sucrose, trehalose, raffinose or maltose. For determining bacterial growth,bacterial concentration of 103was taken each hour during 12 cultured in MHAand colonies were counted after 24h.The mean amount of hemolysis diameter in MRSA isolates was rather more than that of MSSA isolates. The difference between MRSA and MSSA isolates were significant as to fermenting ramnose, trehalose, galactose and xylose. The mean rate of growth in MRSAwere significantly different from that of MSSAisolates (p<0.05).Resistance to methicillin in Staphylococcus aureus isolates accompanies the increase of ability to ferment sugars. This phenomenon may be one of reasons for increased pathogenicity of MRSA isolates; So results shows the logarithmic phase is longer in MRSA isolates, This may implicate that PBP2a production in methicillin-resistant isolates follows slowing down nutrients entrance into the bacterium that in turn may causes slow growth

Influence of ZnO nanoparticles on candida albicans isolates biofilm formed on the urinary catheter

Background and Objectives: The aim of this study was to determine the effect of zinc oxide nanoparticle (ZnO-np) solution in the surface catheter on C. albicans adhesion and biofilm formation. Materials and Methods: Out of 260 isolates from urinary catheter, 133 were determined as C. albicans by common phenotypic and genotyping methods. ZnO nanoparticles with 30 nm were made by the sol-gel method, which was confirmed by XRD (X-ray diffraction) and scanning electron microscope (SEM) methods. Candidal adhesion and biofilm assays were performed on catheter surfaces for 2 and 48 hours, respectively. The effect of sub-MIC (minimum inhibitory concentrations) and MIC concentrations of ZnO-np on biofilm formation was evaluated after 24 hours using Crystal violet (CV), colony-forming unit (CFU), and SEM. Results: Out of 133 C. albicans isolates, 20 (15) fluconazole-resistant and 113 (85) susceptible isolates were determined by the disk diffusion method. Results showed that both isolates adhered to biofilm formation on the catheter surfaces. A significantly (P< 0.05) higher number of CFUs was evident in fluconazole-resistant biofilms compared to those formed by susceptible isolates. ZnO-np reduced biofilm biomass and CFUs of dual isolate biofilms (P< 0.05). ZnO nanoparticles had a significantly (P< 0.05) greater effect on reducing fluconazole-resistant C. albicans biofilm biomass compared to susceptible isolates. Conclusion: Zno-np exhibits inhibitory effects on biofilms of both isolates. These findings provide an important advantage of ZnO that may be useful in the treatment of catheter-related urinary tract infection. © 2019, Tehran University of Medical Science. All right reserved

Design and construction of a new recombinant fusion protein (2b2t+EPC1) and its assessment for serodiagnosis of cystic echinococcosis

The immunodiagnostic tests for cystic echinococcosis (CE) are mostly serological tests based on ELISA that use hydatid cyst antigens for primary screening because of its simple preparation and availability. The challenge to develop new serological methods (as compared to those based on the hydatid cyst fluid antigens) to meet the gold standard remains. Appropriate sources of antigenic material are necessary for application to improve the efficacy of immunodiagnostic tests at a population level. In the current study, a fusion protein containing the coding sequence of antigen B2t and two sequences of EPC1 antigen with some modifications was reconstructed. Using bioinformatics tools, these sequences were joined together by applying the sequence of a rigid α-helix-forming linker to obtain an appropriate structure of a fusion protein. Synthetic recombinant fusion protein was expressed using pET28a as a vector and evaluated by indirect ELISA test for sera from patients with hepatic CE and other parasitic infections. The sensitivity of the fusion protein was lower (88.46) than the available ELISA kit (96.15). However, the differences in sensitivity were not statistically significant as compared to the recombinant fusion peptide with the commercial kit (p = 0.269). The specificity of the recombinant fusion protein (95.45) was not significantly lower than the commercial kit (96.59; p = 1.000). Moreover, surprisingly there was no difference in the cross-reactivity values of performance between the recombinant-ELISA and commercial kit. The positive and negative predictive values of the recombinant antigen were achieved as 92 and 93.33, respectively, while for the commercial kit, they were obtained as 94.33 and 97.70, respectively. In conclusion, as an early evaluation of these antigens the performance of our recombinant fusion protein in ELISA is relatively promising. Although, it seemed that this peptide with specific antigenic epitopes might be more appropriate for the serological evaluation of CE by use of bioinformatics tools, our findings showed that cross-reactions and a negative reaction could occur in clinical performance. This fusion protein may have utility for diagnosis in humans, but further evaluation is needed using the WHO ultrasound classification for CE. © 2018 APMIS. Published by John Wiley & Sons Lt

Molecular identification of Leishmania species isolated from patients with cutaneous leishmaniosis in gonbad Kavoos, northeastern of Iran using hSP70 and ITS-based PCR-RFlP

Cutaneous leishmaniosis (CL) is mainly caused by Leishmania major (rural-type) and Leishmania tropica (urban-type). CL is a major health problem in many regions of the world, and it is associated with health complications and economic loss. The identification and differentiation of Leishmania species are critical because the prevention and control methods, as well as management and therapeutic strategies, are different for each type of CL. The present study aimed to identify the parasite species responsible for CL in the study area using ITS1 and HSP70- based PCR-RFLP methods. A total of 147 stained slides were prepared from samples collected from CL patients, and these slides were positive for amastigotes of Leishmania species on microscopic examination. Forty-three Giemsastained slides with 2+ to 4+ grades were selected for molecular studies for the identification of the Leishmania species. DNA was extracted from the selected slides for the molecular studies. The amplification of HSP70 and ITS1 genes was performed by the PCR method. The PCR products were digested with the HaeIII restriction enzyme, and banding patterns of all samples were compared with reference strains. Overall, patterns of all the samples were found to correspond to the reference strains of L. major based on RFLP-PCR targeting HSP70 and ITS1 genes of the parasite, demonstrating the dominance of L. major as the causative agent of zoonotic cutaneous leishmaniosis (zCL) in the study area. This area is endemic for zoonotic CL, and further studies are required to determine the reservoir and natural infection of sand flies in this county

Global status of phenotypic pyrazinamide resistance in Mycobacterium tuberculosis clinical isolates: an updated systematic review and meta-analysis

Pyrazinamide (PZA) is an essential first-line tuberculosis drug for its unique mechanism of action active against multidrug-resistant-TB (MDR-TB). Thus, the aim of updated meta-analysis was to estimate the PZA weighted pooled resistance (WPR) rate in M. tuberculosis isolates based on publication date and WHO regions. We systematically searched the related reports in PubMed, Scopus, and Embase (from January 2015 to July 2022). Statistical analyses were performed using STATA software. The 115 final reports in the analysis investigated phenotypic PZA resistance data. The WPR of PZA was 57 (95 CI 48-65) in MDR-TB cases. According to the WHO regions, the higher WPRs of PZA were reported in the Western Pacific (32; 95 CI 18-46), South East Asian region (37; 95 CI 31-43), and the Eastern Mediterranean (78; 95 CI 54-95) among any-TB patients, high risk of MDR-TB patients, and MDR-TB patients, respectively. A negligible increase in the rate of PZA resistance were showed in MDR-TB cases (55 to 58). The rate of PZA resistance has been rising in recent years among MDR-TB cases, underlines the essential for both standard and novel drug regimens development