ABSTRACT
@#Candida species are the most common cause of fungal infections that range from non-life-threatening mucocutaneous illness to life-threatening invasive processes that may involve virtually any organ. Such a broad range of infections requires an equally broad range of therapeutic approach. Persian shallot (Allium stipitatum Regel.) is a medicinal plant that has been widely used in tradition Persian medicine for various ailments. Allium stipitatum is also used in modern medicine and has been reported to have a range of health benefits including antibiotic (antifungal) properties. The present study assessed the in vitro anticandidal and antibiofilm potential of hexane (ASHE) and dichloromethane (ASDE) extracts of Allium stipitatum (Persian shallot) against planktonic and biofilm forms of 5 medically important Candida spp. Antifungal activity was assessed by disk diffusion, minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and time-kill assay. The antibiofilm activity of ASHE and ASDE against reference strain C. albicans ATCC 14053 was determined by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide] reduction assay. The zone of inhibition ranged from 22 to 40 mm, while the MICs ranged from 8 to 32 μg mL-1. The MFCs of ASHE and ASDE were in the range of 16 to 32 μg mL-1 each respectively. Time-kill kinetics showed that both extracts were strongly fungicidal against planktonic cultures of C. albicans with ~ 1.45 log reduction in CFU at 4 h post-treatment (hpt). In addition, both ASHE and ASDE were shown to inhibit preformed C. albicans biofilms in a concentration-dependent manner. The results demonstrated that ASHE and ASDE were broad-spectrum in action, and could be developed as a promising alternative to synthetic antifungals in controlling infections due to Candida spp. of clinical significance.
ABSTRACT
Objectives: Reduced biocide susceptibility in Staphylococci is associated with various antiseptic resistance genes encoding efflux systems. Our aim was to determine the susceptibility to three disinfectant agents, including benzalkonium chloride [BAC], benzethonium chloride [BZT], and chlorhexidine digluconate [CHDG] among clinical isolates of Staphylococcus aureus and coagulase-negative Staphylococci [CoNS]
Methods: The minimum inhibitory concentration [MIC] of 60 methicillin-resistant S. aureus [MRSA], 54 methicillin-sensitive S. aureus [MSSA] and 51 CoNS isolates from a single hospital to three biocidal agents [BAC, BZT, and CHDG] was determined. Biocide resistance genes [qacA/B, smr, qacG, qacH, qacJ, and norA] were analyzed by the polymerase chain reaction assay
Results: All isolates had MICs for BAC and BZT from 0.25 to 8 microg/mL, and for CHDG from 0.5 to 64 microg/mL. qacA/B was the most common biocide resistance gene among all 165 Staphylococcus isolates [76; 46%], which comprised 38 [63.3%] MRSA, 14 [25.9%] MSSA, and 24 [47%] CoNS. Eleven [6.7%] and 24 [14.5%] isolates among the 165 Staphylococci carried smr and norA genes, respectively. In contrast, other resistance genes such as qacG, qacH, and qacJ were absent in all Staphylococci studied. The qacA/B and smr genes were detected concomitantly in 3% of isolates, and 23.6% strains of the total 165 Staphylococcus isolates were negative for each studied gene
Conclusions: The carriage of several biocide resistance genes, including qacA/B, smr, and norA, alone or concurrently, is associated with reduced susceptibility. Use of antiseptics may select for antibiotic-resistant strains and assist their survival in the healthcare environment
ABSTRACT
The aim of this study was compared the efficacy of the designed primers and already published primers for detection of the exoA, oprL and algD genes by PCR assay for finding a rapid, accurate and highly sensitive and specific procedure to detect the Pseudomonas aeruginosa in the serious and fatal infections such as cystic fibrosis disease, burned individual. A total of 150 clinical specimens were inoculated in to routine and selective culture media for Pseudomonas aeruginosa isolation. Specific primers were designed by bioinformatics analysis for detection of the virulence genes exoA, oprL and algD. The available sequences of these three genes were obtained from NCBI and multiple alignments were performed to find the conserved sequences of each gene for primer designing. Both multiple alignment and primer designing steps were carried out by AlleleID software, version 7.0. Microbiological culture methods were showed that 70 Pseudomonas aeruginosa strains isolated from the 150 clinical specimens. PCR assay performed by using the designed primers shown 68, 70 and 69 positive results from 70 direct specimens for exoA, oprL and algD respectively that shown 97.2%, 100% and 98.6% sensitivity for above genes. PCR assay performed by using the already published primers shown 57, 49 and 28 positive results for above genes respectively that shown 81.5%, 70% and 40% sensitivity. The present study shows that by using the high specific primers for detection of the mentioned genes of the Pseudomonas aeruginosa. The conventional PCR assay detected the early colonization of the organism in Cystic Fibrosis patients with more sensitivity and specificity before several mounts to obtain positive culture. Indeed PCR assay with high specific primers has more sensitivity and specificity as a rapid and accurate diagnosis of the organism in other deadly infections by using the direct clinical specimens.