INCIDENCE AND VIRULENCE TRAITS OF CANDIDA DUBLINIENSIS ISOLATED FROM CLINICALLY SUSPECTED PATIENTS

            Objective: Fungal infections are caused by Candida species are increasing mainly in immunocompromised patients. Among Candida species, Candida dubliniensis has recently increasing opportunistic pathogenic yeast. The present study was aimed to assess the incidence and virulence factors of C. dubliniensis isolated from urine samples of various hospitalized clinically suspected patients. Methods: Totally 1,406 urine samples were processed, among that 9(0.64%) were identified as C. dubliniensis by germ tube production, biochemical test (Candida identification kit), CHROM agar Candida differential medium and growth at 45°C. Virulence factors of the C. dubliniensis viz., phospholipase, proteinase, esterase, lipase, haemolysin and biofilm production were detected by standard procedures. Results: Maximum number of C.dubliniensis have ability to produce protienase 6(66.66%), followed by esterase 5(55.55%), biofilm formation 4(44.44%), haemolysin 2(22.22%) and phospholipase, lipase 1(11.1%) respectively. Conclusion: The result revealed that these enzymes are potential virulence factors are the most important thing to realize pathogenesis of C. dubliniensis.Â

PREVALENCE OF EXTENDED-SPECTRUM BETA-LACTAMASE PRODUCING ENTEROBACTERIACEAE MEMBERS ISOLATED FROM CLINICALLY SUSPECTED PATIENTS

 Objective: Emergence of extended-spectrum beta-lactamases (ESBLs) production poses another clinical problem with Gram-negative bacterial infections. The present study was aimed to evaluate the ESBL producers among various clinical samples of clinically suspected patients.Methods: A total of 1279 samples (urine [918], pus [207] and stool [154]) were collected and 465 isolates (Escherichia coli [320], Enterobacter aerogenes [119] and Klebsiella pneumoniae [26]) were isolated and screened for the presence of ESBL producers using combination disc method and double disc synergy test.Results: Of the 465 culture positive isolates, 130 (E. coli 93 [29.06%], E. aerogenes 35 [29.41%] and K. pneumoniae 2 [7.69%]) were identified as ESBL producers. Among the three Enterobacteriaceae members, E. coli 93 (29.06%) was found to be predominant ESBL producer next in order E. aerogenes 35 (29.41%) and K. pneumoniae 2 (7.69%). Maximum number of ESBL producers were recovered from urine (n=111) followed by pus (n=14) and stool (n=5). All the ESBL-producing isolates were subjected to antibiotic sensitivity test using 10 different antibiotics. ESBL producers were chiefly resistance to ceftriaxone followed by ceftazidime and cefotaxime. Of 130 ESBL producers, 15 (E. coli (8), E. aerogenes (6) and K. pneumoniae (1)] strains were selected for genotypic identification. Among, only two strains of E. aerogenes were positive isolates for CTX-M type ESBL in polymerase chain reaction.Conclusion: This study concluded that among Enterobacteriaceae members, E. coli was the predominant ESBL producers and urine was noted as the prime source for the ESBL positive isolates when compared to other source. Genotypic identification was the best method to differentiate ESBL types which were essential to provide proper treatment

Transcriptomics-based characterization of the toxicity of ZnO nanoparticles against chronic myeloid leukemia cells

Introduction: Zinc oxide nanoparticles (ZnO NPs) have recently attracted attention as potential anti-cancer agents. To the best of our knowledge, the toxicity of ZnO NPs against human chronic myeloid leukemia cells (K562 cell line) has not been studied using transcriptomics approach. Objective: The goals of this study were to evaluate the capability of ZnO NPs to induce apoptosis in human chronic myeloid leukemia cells (K562 cells) and to investigate the putative mechanisms of action. Methods: We used viability assay and flowcytometry coupled with Annexin V-FITC and propidium iodide to investigate the toxicity of ZnO NPs on K562 cells and normal peripheral blood mononuclear cells. Next we utilized a DNA microarray-based transcriptomics approach to characterize the ZnO NPs-induced changes in the transcriptome of K562 cells. Results: ZnO NPs exerted a selective toxicity (mainly by apoptosis) on the leukemic cells (p≤ 0.005) and altered their transcriptome; 429 differentially expressed genes (DEGs) with fold change (FC)≥ 4 and p≤ 0.008 with corrected p≤ 0.05 were identified in K562 cells post treatment with ZnO NPs. The over-expressed genes were implicated in “response to zinc”, “response to toxic substance” and “negative regulation of growth” (corrected p≤ 0.05). In contrast, the repressed genes positively regulated “cell proliferation”, “cell migration”, “cell adhesion”, “receptor signaling pathway via JAK-STAT” and “phosphatidylinositol 3-kinase signaling” (corrected p≤ 0.05). Lowering the FC to ≥ 1.5 with p≤ 0.05 and corrected p≤ 0.1 showed that ZnO NPs over-expressed the anti-oxidant defense system, drove K562 cells to undergo mitochondrial-dependent apoptosis, and targeted NF-κB pathway. Conclusion: Taken together, our findings support the earlier studies that reported anti-cancer activity of ZnO NPs and revealed possible molecular mechanisms employed by ZnO NPs to induce apoptosis in K562 cells

Efficacy and Mechanism of Traditional Medicinal Plants and Bioactive Compounds against Clinically Important Pathogens

Traditional medicinal plants have been cultivated to treat various human illnesses and avert numerous infectious diseases. They display an extensive range of beneficial pharmacological and health effects for humans. These plants generally synthesize a diverse range of bioactive compounds which have been established to be potent antimicrobial agents against a wide range of pathogenic organisms. Various research studies have demonstrated the antimicrobial activity of traditional plants scientifically or experimentally measured with reports on pathogenic microorganisms resistant to antimicrobials. The antimicrobial activity of medicinal plants or their bioactive compounds arising from several functional activities may be capable of inhibiting virulence factors as well as targeting microbial cells. Some bioactive compounds derived from traditional plants manifest the ability to reverse antibiotic resistance and improve synergetic action with current antibiotic agents. Therefore, the advancement of bioactive-based pharmacological agents can be an auspicious method for treating antibiotic-resistant infections. This review considers the functional and molecular roles of medicinal plants and their bioactive compounds, focusing typically on their antimicrobial activities against clinically important pathogens

One-step Synthesis of Silver Nanoparticles Using Saudi Arabian Desert Seasonal Plant Sisymbrium irio and Antibacterial Activity Against Multidrug-Resistant Bacterial Strains

Globally, antimicrobial resistance has grown at an alarming rate. To combat the multidrug-resistant (MDR) superbugs, silver nanoparticles (Ag NPs) were synthesized using an aqueous leaf extract of seasonal desert plant Sisymbrium irio obtained from the central region of Saudi Arabia by a simple one-step procedure. The physical and chemical properties of the Ag NPs were investigated through ultraviolet visisble analysis (UV-vis), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis. The UV-vis spectrum showed an absorption band at 426 nm. The XRD results showed a highly crystalline face-centered cubic structure. The surface morphology analyzed using SEM and TEM analyses showed the particle size to be in the range 24 nm to 50 nm. Various concentrations of Ag NPs were tested against MDR Pseudomonas aeruginosa and Acinetobacter baumanii that cause ventilator-associated pneumonia (VAP). American Type Culture Collection (ATCC) Escherichia coli-25922 was used as the reference control strain. The Ag NPs effectively inhibited tested pathogens, even at the lowest concentration (6.25 µg) used. The bacterial inhibitory zone ranged from 11–21 mm. In conclusion, the newly synthesized Ag NPs could be a potential alternative candidate in biomedical applications in controlling the spread of MDR pathogens

Antifungal Efficacy of Marine Macroalgae against Fungal Isolates from Bronchial Asthmatic Cases

Fungal sensitization is very common in bronchial asthmatic cases, and the connection with airway colonization by fungi remains uncertain. Antifungal therapy failure is a significant fraction of the cost and morbidity and mortality in the majority of the asthmatic cases. Hence, the present study aimed to investigate the antifungal activity of five marine macroalgae—Acanthaophora specifera, Cladophoropsis sp., Laurencia paniculata, Tydemania sp., and Ulva prolifera—which were tested on selected fungal pathogens isolated from 15 sputum of 45 bronchial asthmatic patients. The highest antifungal activity was observed in ethanol fractions of L. paniculata followed by U. prolifera, Cladophoropsis sp., A. specifera, and Tydemania sp. The minimum fungicidal concentration and minimum inhibitory concentration values of the ethanolic fractions of algal species were found to be 125⁻1000 µg/mL and 125⁻500 µg/mL, respectively. The algal extracts contained terpene alcohol, diterpene, steroids, sesquiterpene, and sesquiterpene alcohol, as determined by GC⁻MS/MS analyses. The present study shows that the marine macroalgae containing bioactive compounds had excellent inhibitory activity against a variety of fungal pathogens, which may be useful for combating fungal infections and recovering from chronic asthmatic states

In Vitro Antioxidant and Bactericidal Efficacy of 15 Common Spices: Novel Therapeutics for Urinary Tract Infections?

Background and Objectives: Bacterial urinary tract infection (UTI) is the most common ailment affecting all age groups in males and females. The commercial antibiotics usage augments antibiotics resistance and creates higher recurrence rates of such communal infections. Hence, this study is aimed at investigating the antibacterial and antioxidant potentials of 15 common spices against 11 UTI-causing bacterial pathogens. Materials and Methods: The antioxidant potential of the methanolic extracts was analyzed as contents of total phenols and flavonoids; radical scavenging, total reducing power, the ferric reducing power assay. Urinary pathogens were subjected to spice extracts to investigate antibacterial assays. Results: Preliminary phytochemical study of spices was performed to find those containing alkaloids, flavonoids, phenolic compounds, and steroids that can be recognized for their noteworthy bactericidal effects. The outcome of the antioxidative potential from the four methods demonstrated the sequence of potent antioxidant activity: Acorus calamus > Alpinia galanga > Armoracia rusticana > Capparis spinosa > Aframomum melegueta. The total polyphenols and flavonoids in the studied species positively correlated with their antioxidant properties. The four most effective spices (A. calamus, A. galanga, A. rusticana, and C. spinosa) had a zone of inhibition of at least 22 mm. A. calamus, A. melegueta, and C. spinosa had the lowest minimum inhibitory concentration (MIC) value against Enterobacter aerogenes, Staphylococcus aureus and Proteus mirabilis. All 15 spices had the lowest minimum bactericidal concentration (MBC) value against most of the pathogenic bacteria. Conclusion: The four highly potent and unique spices noted for the in vitro control of UTI-causing pathogens could be pursued further in the development of complementary and alternative medicine against UTI-causing pathogens

Efficacy and Mechanisms of Flavonoids against the Emerging Opportunistic Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTM) are the causative agent of severe chronic pulmonary diseases and is accountable for post-traumatic wound infections, lymphadenitis, endometritis, cutaneous, eye infections and disseminated diseases. These infections are extremely challenging to treat due to multidrug resistance, which encompasses the classical and existing antituberculosis agents. Hence, current studies are aimed to appraise the antimycobacterial activity of flavonoids against NTM, their capacity to synergize with pharmacological agents and their ability to block virulence. Flavonoids have potential antimycobacterial effects at minor quantities by themselves or in synergistic combinations. A cocktail of flavonoids used with existing antimycobacterial agents is a strategy to lessen side effects. The present review focuses on recent studies on naturally occurring flavonoids and their antimycobacterial effects, underlying mechanisms and synergistic effects in a cocktail with traditional agents

Anti-Fungal Efficacy and Mechanisms of Flavonoids

The prevalence of fungal infections is growing at an alarming pace and the pathogenesis is still not clearly understood. Recurrence of these fungal diseases is often due to their evolutionary avoidance of antifungal resistance. The development of suitable novel antimicrobial agents for fungal diseases continues to be a major problem in the current clinical field. Hence, it is urgently necessary to develop surrogate agents that are more effective than conventional available drugs. Among the remarkable innovations from earlier investigations on natural-drugs, flavonoids are a group of plant-derived substances capable of promoting many valuable effects on humans. The identification of flavonoids with possible antifungal effects at small concentrations or in synergistic combinations could help to overcome this problem. A combination of flavonoids with available drugs is an excellent approach to reduce the side effects and toxicity. This review focuses on various naturally occurring flavonoids and their antifungal activities, modes of action, and synergetic use in combination with conventional drugs

Screening and antibacterial efficacy of selected Indian medicinal plants

Objective: To evaluate the antibacterial efficacy of five Indian medicinal plants such as Acalypha indica L. (A. indica), Aerva lanata (L.) Juss. ex Schult. (A. lanata), Clerodendrum inerme (L.) Gaertn., Pergularia daemia (Forsk.) Chiov. and Solanum surattense Burm. f. against opportunistic bacterial pathogens isolated from HIV infected patients for the potential phytoconstituents in plant extracts. Methods: The opportunistic bacterial pathogens such as Escherichia coli (E. coli), Pseudomonas aeruginosa, Salmonella typhi and Serratia marcescens from Gram-negative group and Staphylococcus aureus from Gram-positive group were isolated from HIV infected patients. The antibacterial efficacy of ethanolic extracts of selected medicinal plants was carried out by disc diffusion method. The potential phytoconstituents of medicinal plant extracts were identified by gas chromatography and mass spectrometry (GC–MS) analysis. Results: Among the five medicinal plants tested, A. indica and A. lanata showed the significant antibacterial activity. A. indica showed potential activity against Staphylococcus aureus and E. coli. A. lanata significantly exhibited antibacterial activity against E. coli, Salmonella typhi and Pseudomonas aeruginosa. A total of 19 phytoconstituents were identified in the ethanolic extract of A. indica and A. lanata by GC–MS analysis respectively. Conclusions: The results of the present investigation revealed that A. indica and A. lanata, possessed significant antibacterial activity when compared with the other plant extracts tested. The presence of 3-O-methyl-d-glucose by GC–MS analysis in both A. indica and A. lanata extracts has not been reported elsewhere in the literature and the findings in this study could be the first one to report