Synergistic evaluation of Moringa oleifera extract and ß-lactam antibiotic to restore the susceptibility of methicillin-resistant Staphylococcus aureus.

INTRODUCTION: The antibiotic resistance has become a major threat to global health. The combinatorial use of two or more compounds to develop a new formulation may overcome the emerging cases of drug resistance. Moringa oleifera has been utilized as a strong nutritional, immunomodulator and therapeutic agent for decades. In this study, different parts of Moringa oleifera were screened for bioactive compounds that can act as a resistance modifying agent for multi-drug resistant organisms (MDROs). METHODOLOGY: Initially, the combined effect of stem bark extracts and ampicillin was calculated by checkerboard assay. Active compounds of effective extract were assessed by High Performance Liquid Chromatography (HPLC). Minimal Inhibitory Concentration (MIC) and Fractional Inhibitory Concentration Index (FICI) were calculated to evaluate the synergistic behavior of stem bark extract with ampicillin. To study the blocking of resistance pathways of Methicillin-Resistant Staphylococcus aureus (MRSA) western blot was performed. RESULTS: The results revealed that stem bark has significant anti-MRSA activity. The methanolic extract of stem bark in combination with ampicillin showed the highest synergistic effect (FICI value ≤ 0.237) against MRSA. Killing kinetics and membrane potential of ampicillin alone and in combination revealed an increase in the inhibitory potential of ampicillin against MRSA. Decolourization in iodometric assay confirmed the inhibition of ß-lactamase, western blot results confirmed the blocking of penicillin-binding protein (PBP2a) expression with the restoration of MRSA sensitivity against ß-lactams. CONCLUSION: It can be concluded that methanolic extract of Moringa oleifera stem bark has bioactive compounds and can be used as an adjuvant with antibiotics to modify the resistance of MDROs.

Screening, purification and characterization of thermostable, protease resistant Bacteriocin active against methicillin resistant Staphylococcus aureus (MRSA).

BACKGROUND: The emergence of serious issues of multidrug resistance in the past few years have enforced the use of bacteriocins for combating infections. Threat posed to public health by various multidrug resistant (MDR) organisms can be resolved by discovering new antimicrobial proteins with broad spectrum of inhibition. RESULTS: In the current study, Bacteriocin (BAC-IB17) produced by Bacillus subtilis KIBGE-IB17 is found to be effective against different strains of methicillin resistant Staphylococcus aureus (MRSA). The approximate molecular mass of BAC-IB17 is 10.7 kDa. This unique bacteriocin is found to be highly thermostable and pH stable in nature. It also showed its stability against various heavy metals, organic solvents, surfactants and proteolytic enzymes. Amino acid profile of BAC-IB17 clearly showed that this protein mainly consists of non-polar and basic amino acids whereas; some acidic amino acids were also detected. Sequence of first 15 amino acid residues obtained from N-terminal sequencing of BAC-IB17 were NKPEALVDYTGVXNS. CONCLUSIONS: The anti-MRSA property of purified bacteriocin may be used to prevent the spread of MRSA infections. Remarkable features of BAC-IB17 suggests its applications in various pharmaceutical and food industries as it can function under a variety of harsh environmental conditions.

Role of nutrients and environmental conditions for the production of dextransucrase from L. mesenteroides KIBGE-IB26.

The bacterial strains capable of producing dextransucrase enzyme were isolated from different fruits and vegetables sources. In primary screening, five strains were selected on the basis dextransucrase production and among them L. mesenteroides KIBGE- IB26 isolated from bottle gourd (Lagenaria Vulgaris) was selected for further studies. For the enhancement of enzyme production, different physicochemical parameters were optimized. Maximum production of dextransucrase was achieved after 06 hrs using sucrose (20.0 g/l) as a substrate at 25°C. Maximum dextransucrase production was achieved when medium pH was kept 7.5 before sterilization. In addition, medium was also supplemented with CaCl2 and K2HPO4 and maximum enzyme production was achieved at 0.0025 g/dl calcium chloride and 2.0 g/dl K2HPO4with enzyme activity of 87 DSU/ml/hr. Production of dextransucrase in shorter period of time makes this strain an attractive candidate for commercial production of dextransucrase.

Antibacterial potential of Calotropis procera (flower) extract against various pathogens.

Increased bacterial resistance towards commonly used antibiotics has become a debated issue all over the world in a last few decades. Due to this, consumer demand towards natural anti-microbial agents is increasing day by day. Natural anti-microbial agents have gained enormous attention as an alternative therapeutic agent in pharmaceutical industry. Current study is an effort to explore and identify a bactericidal potential of various solvent extracts of Calotropis procera flower. Flowers of C. procera were extracted with hexane, butanol, ethyl acetate and aqua to evaluate the antibacterial activity by agar well diffusion method against the various human pathogens. The microorganisms used in this study includes Salmonella typhi, Escherichia coli (O157:H7), Micrococcus luteus KIBGE-IB20 (Gen Bank accession: JQ250612) and methicillin resistant Staphylococcus aureus (MRSA) KIBGE-IB23 (Gen Bank accession: KC465400). Zones of inhibition were observed against all four pathogenic strains. Fraction soluble in hexane showed broad spectrum of inhibition against all the studied pathogens. However, fractions soluble in ethyl acetate inhibited the growth of E. coli, MRSA, and M. luteus. In case of butanol and aqueous extracts only growth of M. luteus was inhibited. Results revealed that the flower extracts of C. procera have a potential to be used as an antibacterial agent against these pathogenic organisms.

Gastrointestinal somatization in males and females with depressive disorder.

OBJECTIVE: To assess gastrointestinal symptoms among depressed patients presenting in an outpatient psychiatric clinic. METHODS: All consecutive and consenting cases of depressive disorder presenting to the clinic from Jan' 02 to Dec' 05 were inducted in the study. A descriptive study was carried out in a clinical setting at the Neuro-Spinal Medical Institute, Karachi, Pakistan. The assessment was based on detailed history, physical examination, mental state examination and filling of semi structured proforma designed for this purpose. For diagnostic purpose WHO classification ICD-10 criteria was used. RESULTS: A total of 1165 (Male: 56%, Female: 43.2%) patients were assessed. The age ranged from 6 to 90 years for male and 5 to 80 for females with p-value of 0.001. Majority were married. Their educational status revealed that 20.4% of males and 45.1% females were illiterate. The most frequently reported gastrointestinal symptom was decreased appetite (67.7%) followed by constipation (57.7%) and diarrhoea (42.3%). Other reported symptoms included abdominal pain, vomiting, gas, indigestion and nausea in order of frequency. In males 13.7% and 12.7% females had suffered for > 10 years before seeking psychiatric consultation. Surprisingly, about 26.3% of the patients had previously pursued alternative modes of treatment (homeopathic, faith healers and hakeems). CONCLUSION: Somatic symptoms manifesting as gastrointestinal symptoms are common in patients with depressive disorder. Awareness about such an association is essential and will be useful for primary care physicians and gastroenterologists for establishing early diagnosis and management, thus avoiding unnecessary investigations in patients with poor resources.