Fluorescence Spectroscopy Based Identification of Pseudomonas Aeruginosa and Escherichia Coli Suspensions.

In this article, Fluorescence spectroscopy has been employed for the identification of Pseudomonas aeruginosa (PA) and Escherichia coli (E. coli) in water suspension. Emission spectra of PA and E. coli suspensions have been acquired by using excitation wavelengths from 270 to 420 nm with steps of 10 nm to explore their spectral features. It has been found that the emission spectra of tryptophan, tyrosine, NADH and FAD, being the intracellular biomolecules present in both bacteria, can be used as fingerprints for their identification, differentiation and quantification. Both bacterial strains can clearly be differentiated from water and from each other by using λex 270-290 nm through spectral analysis and from λex: 300-500 nm by applying statistical analysis. Furthermore, calibration curves for different bacterial loads of PA and E. coli suspensions have been produced between colonies forming units per ml (CFUs/ml) the integrated intensities of their emission spectra. CFUs/ml of both bacterial suspensions have been determined through plate count method which was used as cross-reference for the analysis of emission spectra of both bacterial suspensions. These curves may be used to estimate CFU/ml of both PA and E. coli in unknown water suspensions by determining the integrating intensity of their emission spectra.

In vitro study: methylene blue-based antibacterial photodynamic inactivation of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is one of the most antibiotic-resistant and opportunistic pathogens in immunocompromised and debilitated patients. It is considered the cause of most severe skin infections and is frequently found in hospital burn units. Due to its high antibiotic resistance, eliminating P. aeruginosa from skin infections is quite challenging. Therefore, this study aims to assess the novel in vitro antibacterial activity of methylene blue using a 635-nm diode laser to determine the effective power and energy densities for inhibition of P. aeruginosa. The strain was treated with various concentrations of methylene blue and 635-nm diode laser at powers of 300 mW/cm2 and 250 mW/cm2. The diode laser's potency in the photo-destruction of methylene blue and its degradation through P. aeruginosa were also evaluated. Colony-forming unit (CFU)/ml, fluorescence spectroscopy, optical density, and confocal microscopy were used to measure the bacterial killing effect. As a result, the significant decrease of P. aeruginosa was 2.15-log10, 2.71-log10, and 3.48-log10 at 60, 75, and 90 J/cm2 after excitation of MB for 240, 300, and 360 s at a power of 250 mW/cm2, respectively. However, a maximum decrease in CFU was observed by 2.54-log10 at 72 J/cm2 and 4.32-log10 at 90 and 108 J/cm2 after 300 mW/cm2 of irradiation. Fluorescence images confirmed the elimination of bacteria and showed a high degree of photo-destruction compared to treatment with methylene blue and light alone. In conclusion, MB-induced aPDT demonstrated high efficacy, which could be a potential approach against drug-resistant pathogenic bacteria. KEY POINTS: • Combination of methylene blue with 635-nm diode laser for antibacterial activity. • Methylene blue photosensitizer is employed as an alternative to antibiotics. • aPDT showed promising antibacterial activity against Pseudomonas aeruginosa.

Antimicrobial photodynamic therapy against Escherichia coli by exploiting endogenously produced Protoporphyrin IX- In vitro study.

Due to antimicrobial drug resistance, there is a growing interest in the development of light based alternative antibacterial therapies. This research work is focused on the inactivation of Escherichia coli (E. coli) by exploiting the absorption bands 405, 505, 542, 580 and 631 nm of its indigenously produced Protoporphyrin IX (PpIX) excited by three LEDs with broad emission bands at 418, 522 and 630 nm and two laser diodes with narrow emission bands at 405 and 635 nm. Fluorescence spectroscopy and plate count method have been employed for studying the inactivation rate of E. coli strain in autoclaved water suspension. It has been found that LEDs at 418, 522 and 630 nm produced pronounced antimicrobial photodynamic effect on E. coli strain comparing laser diodes at 405 and 635 nm, which might be attributed to the overlapping of broad emission bands of LEDs with the absorption bands of PpIX than narrow emission bands of laser diodes. Particular effect of LED at 522 nm has been noticed because its broad emission band overlaps three absorption bands 505, 542 and 580 nm of PpIX. The gold standard plate count method strongly correlates with Fluorescence spectroscopy, making it an innovative tool to administer bacterial inactivation. The experimental results suggested the development of a light source that entirely overlap absorption bands of PpIx to produce a pronounced antimicrobial photodynamic effect, which might become an effective modality for in vivo disinfection of antibiotic resistant microbes in wounds and lesions.

Sudachitin Alleviates Paraquat Instigated Testicular Toxicity in Albino Rats via Regulating Nrf-2/Keap-1, Inflammatory, Steroidogenic, and Histological Profile.

Paraquat (PQ) is a noxious herbicide which adversely affects the vital organs including male reproductive system. Sudachitin (SCN) is a naturally occurring flavonoid that demonstrates a wide range of biological potentials. The current study was designed to investigate the alleviative potential of SCN to avert PQ-induced testicular toxicity in rats. Forty-eight male rats (Rattus norvegicus) were apportioned into four groups including control, PQ (5 mg/kg), PQ + SCN (5 mg/kg + 30 mg/kg), and SCN (30 mg/kg) only treated group. Our findings elucidated that PQ treatment reduced the expression of nuclear factor erythroid 2-related factor 2 (Nrf-2) and its antioxidant genes as well as the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSR) and glutathione peroxidase (GPx), while elevating the levels of reactive oxygen species (ROS), and malondialdehyde (MDA). Furthermore, PQ intoxication upregulated the expressions of Keap-1 while downregulating the expression of 3-beta hydroxysteroid dehydrogenase (3ß-HSD), 17-beta hydroxysteroid dehydrogenase (17ß-HSD), and steroidogenic acute regulatory protein (StAR). Moreover, sperm anomalies were increased following the exposure to PQ. Besides, PQ exposure decreased the levels of plasma testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) while increasing the levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), nuclear factor-kappa B (NF-κB), interleukin-1beta (IL-1ß), and cyclooxygenase-2 (COX-2). Additionally, PQ treatment escalated the expressions of cysteinyl aspartate-specific proteases-3 (Caspase-3) and Bcl-2-associated X-protein (Bax) while downregulating the expressions of B-cell lymphoma-2 (Bcl-2). Furthermore, PQ exposure disrupted the normal architecture of testicular tissues. However, SCN treatment remarkably protected the testicular tissues via regulating the aforementioned disruptions owing to its antioxidant, anti-inflammatory, and androgenic potential.

Fluorescence Spectroscopy Based Characterization of Pseudomonas Aeruginosa Suspension.

In this article, optical characterization of Pseudomonas aeruginosa (PA) suspension has been performed by using Fluorescence spectroscopy. Optical density (OD) and plate count methods have been employed as a reference for the analysis of emission spectra of Pseudomonas aeruginosa in water suspension. Emission spectra of PA suspension has been acquired by using excitation wavelengths from 270 to 420 nm with step of 10 nm to explore its spectral behavior. It has been found that emission spectra of tryptophan, tyrosine, NADH and FAD, the intracellular biomolecules of bacteria, can be used as finger prints for the detection of Pseudomonas aeruginosa. Furthermore, the effect of water matrix on the spectral emission of Pseudomonas aeruginosa has been investigated that might be one of the limitation of Fluorescence spectroscopy for complex water matrices. Moreover, a calibration curve has been produced between ODs600 of Pseudomonas aeruginosa suspensions of different bacterial load and integrated intensities of the emission spectra of same samples. These ODs600 and integrating intensities have been further vetted through plate count method by determining their corresponding colony forming units per ml (CFU/ml). This calibration curve may be used to determine CFU/ml of Pseudomonas aeruginosa in water sample by determining integrating intensity of its emission spectrum.

Fluorescence Spectroscopy for the Assessment of Microbial Load in UVC Treated Water.

In this article, Fluorescence spectroscopy has been employed for the assessment of microbial load and it has been compared with the gold standard colony forming unit (CFU) and optical density (OD) methods. In order to develop a correlation between three characterization techniques, water samples of different microbial loads have been prepared by UVC disinfection method through an indigenously developed NUVWater sterilizer, which operates in close cycle flow configuration. A UV dose of 58.9 mJ/cm2 has been determined for 99.99% disinfection for a flow rate of 0.8 l/min. The water samples were excited at 270 nm which results in the tryptophan like fluorescence at 360 nm that decreases gradually with increase of UVC dose, indicating the bacterial degradation and it has been confirmed by OD and CFU methods. In addition, it has been proved that a close cycle water flow around UV lamp is imperative so that an appropriate dose must be delivered to microorganisms for an efficient disinfection. It has been found that due to the sensitive nature of Fluorescence spectroscopy, it yields immediate results, whereas, for CFU and OD methods, water samples needs to be inoculated for 24 h. Fluorescence spectroscopy, therefore, provide a fast, online, reliable and sensitive method for the monitoring of pathogenic quantification in drinking water.

Effective Treatment of Solitary Rectal Ulcer Syndrome by Using Photobiomodulation Therapy: A Case Report.

Objective: To investigate the efficacy of Photobiomodulation therapy (PBMT) for the treatment of solitary rectal ulcer syndrome (SRUS). Background: SRUS is a benign disease, diagnosed by symptoms, clinical, and histological findings. PBMT has been reported for the treatment of various inflammation-based diseases including aphthous ulcer, but still no such study on the treatment of SRUS is published. Materials and methods: A 29-year Asian women, diagnosed for SRUS of 0.57 cm diameter, was treated by a laser at 635 nm through seven sessions. Laser fluence of 85 J/cm2 was delivered to ulcer lesion during each session for 10 min. Clinical results were valued by physician with sigmoid probe throughout PBMT sessions and no medicines were prescribed to the patient. Results: After seven sessions, the lesion was completely healed with 100% clinical response. In follow-up, patient did not respond to any additional/recurring abnormality, and no side effects were observed. Conclusions: In conclusion, PBMT by using laser at 635 nm is an effective treatment for SRUS without any side effects and patient remained comfortable throughout treatment sessions. Patient registration No. H-744/23.