1.
Efficacy of Various Disinfectants Against Newcastle Disease Virus Isolates In Relation To Different Temperatures
by Momena Habib | Dr. Jawad Nazir | Prof.Dr.Aftab Ahmed Anjum | Dr. Yasin Tipu.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Newcastle disease (ND) is an infectious viral disease of birds and has been considered as one of the most significant diseases of poultry and other avian species around the globe (Aldous and Alexander 2001). The disease is endemic in Pakistan and causes major economic losses to poultry industry each year (Rehman H et al. 2013). Although incidence of ND in broiler and layers remains higher during the course of year, it reaches its plateau during seasonal stress (January-February and June-July). One report shows that during September 2011 - January 2012, the diseases has killed 45 million birds and resulted into a loss of approximately 65 million US $ to the country (Anonymous). ND virus (NDV) is an enveloped, single stranded RNA virus and grouped into the genus Avulavirus within family Paramyxoviridae(Calibeo-Hayes et al. 2003). Isolates of NDV may be categorized into three main pathotypes (lentogenic, mesogenic and velogenic) depending upon the severity of disease in chickens (Seal et al. 2000).
NDV is most commonly transmitted through fecal-oral and respiratory route provided that birds are in close contact (Alexander 1988). Infected birds excrete large amount of virus in their feces (Calibeo-Hayes et al. 2003). Virus is present in most tissue secretions of acutely infected birds even 24 hours prior to appearance of clinical signs. Under certain conditions, NDV can survive up to 20 days in fecal material (anonymous) and presence of organic matter might enhance the virus survival rates (Clarke et al. 1956). In order to control the spread of disease, decontaminate the infected premises is of prime importance. Strict biosecurity measures in conjunction with mass vaccination programs are also employed for the control of the disease. In past few decades, implementation of extensive vaccination programs in commercial poultry has reduced the
Introduction
2
disease incidence to some extent in Pakistan. However, this might also led to the generation of novel genotypes under high immune pressure(Miller et al. 2009). Disinfection of farm premises plays significant role to break the disease cycle of microbial pathogens(Fawzia1 et al. 2013). Such procedures gain more significance on the farms that experience disease outbreaks. Dry cleaning, burning and fumigation followed by chemical disinfection is routinely practiced in Pakistan. Although, physical method are helpful to reduce the pathogen load on farm premises but complete disinfection cannot be achieved without the use of chemical disinfectants. Commercial disinfectants employed in Pakistan are grouped into oxidizing agents, aldehydes, quaternary ammonium compounds, and phenolic preparations. The products containing these ingredients are available either alone or various combinations under different brand names. (Stringfellow et al. 2009).
All of the disinfectants do vary in their disinfection power but to achieve proper disinfectants appropriate interaction time is necessary. Under clean conditions such interaction time is low but longer contact times are needed in presence of organic matter. Some studies show that environmental temperature influences the interaction time of disinfects with matter/surfaces to achieve proper disinfection. In case of chlorine disinfection of adenovirus inactivation time was increased 2-3 times when temperature was lowered to an extent of 10°C (Clarke et al. 1956). Similarly, virucidal activity of some disinfectants including aldehyde, chlorine and iodine compounds against infectious bursaI disease virus (IBDV) was also decreased at lower temperatures (Benton et al. 1967). Availability: Items available for loan: UVAS Library [Call number: 2226-T] (1).
2.
Antimicrobial Potential Of Bovine Lactoferrin Against Foodborne Pathogens
by Ammarah Khatoon (2012-VA-631) | Prof. Dr. Muhammad Ayaz | Mr. Ishtiaque Ahmed | Prof. Dr. Aftab Ahmed Anjum.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Health is recourse of everyday life, but not the object to live. It is positive to give special importance to personal and social resources. However, in Pakistan and other developing countries conditions are different, most people have low income and they live in un-sanitized environment. They eat un-hygienic food and also lack safe drinking water. People do not adopt any preventive measure to minimize the risk of contamination. Food storage is also un-hygienic. These conditions lead towards contamination and result in foodborne infections and gastro-enteritis. Foodborne illnesses are always a serious health issue in the Pakistan and throughout the world. Individual’s record for foodborne illnesses is impossible but it is reported that 7 out of 10 people suffer from foodborne illness caused by different microbes each year worldwide (WHO survey 2012).
Foodborne illness is caused by eating contaminated food with pathogenic bacteria. Some common pathogens are Escherichia coli, Campylobacter jejuni, Clostridium botulinum, Clostridium perfringens, Listeria monocytogens, Bacillus cereus, Staphylococcus aureus and Salmonellaspecies. Incubation period for onset of symptoms of food poisoning ranges from hours to days. Nausea, vomiting, abdominal cramps, fever and diarrhea are symptoms which appear commonly in most of food poisoning. However, foodborne illnesses if left untreated can lead severe dehydration, imbalance of intestinal micro flora, digestive disorders and even death in some cases. It was recorded that 2.2 million people killed from foodborne illness globally every year and the burden arising from foodborne diseases is larger (Kuchenmuller et al. 2009).
Antibioticsare massively used to overcome food poisoning; however, from health point of view they badly affect thenormal micro flora of gut but also microbes become antibiotic
resistance. The problem needs to be dealt with some other way like adding bio preservatives or antimicrobial agents in food.
To control microbes in foods, numerous methods have been adopted including the use of synthetic and natural antimicrobial agents. Scope of natural antimicrobial agents are increasing day by day and different natural sources are being utilized to get these agents. Among these natural sources milk is best and widely utilized source from long times. Milk contains many biologically active compounds among which lactoferrin is one of them.
Lactoferrin is a multifunctional globular glycoprotein from transferrin family, an iron-binding protein. It is part of innate immune system and has antibacterial activity known as far back as 1930. It was first isolated in 1939 from cow milk (Charrondiere et al. 2011). Lactoferrin belongs to the transferrin family having ability to bind iron two times higher than other transferrin proteins. Its molecular weight is 80 kDa and has about 700 amino acids depending upon species e.g. cow, buffalo, goat and sheep (Adlerova et al. 2008). Lactoferrin molecule consists of simple polypeptide chain folded into two symmetrical and highly homologous lobes (N and C) connected by a hinge region. Both lobes bind two metal ions in synergy with carbonate (CO32-). Not only Fe2+ and Fe3+ ions but Cu2+, Zn2+ and Mn2+ ions can also bind. Lactoferrin can bind Fe3+ reversibly so it can exist as free of Fe3+ (Apo-Lf) or in association with Fe3+ (Holo-Lf) and exhibits different three dimensional structure depending upon binding to Fe3+. Apo-Lf has an open structure and holo-Lf has closed which provide resistance to proteolysis. At iron-binding site Aspirin, two Tyrosine, and Histidine amino acids are directly involved in each lobe and Arginine is bound to CO32- ions. Number and position of Cystine-residues allows intermolecular disulfide bridges and Asparagine-residues in both lobes provide several sites for N-glycosylation (Farnaud and Evans 2003).
Lactoferrin is produced by mucosal epithelial mammary cells of human, cows, buffaloes, goat, horses, many other mammals and fish. It is widely distributed in body tissues and present in mucosal surfaces, specific granules of leukocytes and in biological fluids like tears, saliva, digestive fluids, seminal fluids and most abundant in milk comprising the second highest protein in human milk after casein. Concentration of lactoferrin in different species is for cow milk (80-500 mg/L), buffalo milk (50-320 mg/L), camel milk (200-728 mg/L), goat milk (98-150 mg/L) and sheep milk (20-140 mg/L) (Krol et al. 2011).
Many physiological functions of lactoferrin have been attributed. It plays an important role in iron regulation, non-specific immune response, regulation of cells growth and differentiation, protection from cancer, anti-inflammatory, anti-oxidant and strong antimicrobial activity against bacteria, fungi, yeast, viruses and parasites (Conneely et al. 2005). Another dominant role of lactoferrin is during involution of mammary gland. Concentration of lactoferrin increased dramatically from 0.1-0.3mg/ml in normal milk to 20-30mg/ml by 30 days in dry period. It is particularly important for bacteriostatic properties and non-specific defense against invading bacteria. Lactoferrin also affects phagocyte function and limit oxidative degeneration of cell components during inflammation and involution (Welty et al. 1976).
Lactoferrin exhibits strong antimicrobial activity against different bacteria, virus, protozoa, fungi and yeast (Hancock and Janssen 2009). The antibacterial activity of lactoferrin is due to two mechanisms; by binding the iron at infection sites, making it unavailable to bacteria and direct interaction of N-terminal of lactoferrin with micro-organism (Cruz et al. 2009, Orsi 2004). Lactoferrin acts differently with Gram-positive and Gram-negative bacteria (Sharma et al. 2013). It damages Gram-positive cell wall through interaction with negatively charged lipoteichoic acid causing reduction in negative charge on cell wall and favor contact between lysozyme and inner peptidoglycan (Fayad 2012). Gram-negative bacteria are destroyed by interaction of lactoferrin with external lipopolysaccharides by preventing contact with Ca2+ and Mg2+ ions which cause release of lipopolysaccharides, increase permeability and ensures damage (Ochoa and Cleary 2009, Ekins et al. 2004).
Milk and milk products are one of main diet in Pakistan and all over the world. During manufacturing different milk products, a number of by-products are obtained. Among them, cheese whey is produced in high volumes. It is commonly dumped off into sewerage which cause serious environmental problem as it contain high organic matter as well as loss of valuable nutrients it contain. Whey has Biological Oxygen Demand (BOD) ranges from 40,000 to 60,000 ppm (Sayadi et al. 2006) while permitted limit for BOD of domestic sewerage is 200 to 300 ppm. In order to overcome this problem there is need of effective and permanent way for treatment of whey. However, conversion of whey into non-food items like biogas is unreasonable as it is rich in unique nutrients.
Now-a-days there is an interest growing on to find new ways of whey utilization throughout the world. One option is to use the whey in processes in which saleable food or pharmaceutical products can be obtained. Whey could be subjected to different techniques to isolate different components like lactose, lysozyme and immunoglobulin. Likewise, lactoferrin can be isolated from cheese whey by cation exchange chromatography without loss of its biological properties in single step method and about 90% purity (Wu et al. 2011, Moradian et al. 2014).
In this study, we anticipated to use lactoferrin from bovine milk as natural antimicrobial agent. It has been shown that lactoferrin hasstrong antimicrobial activity against different bacteria, fungi, yeast, viruses and parasites (Conneely et al. 2005). In our country, very little work has been carried out onlactoferrin as natural anti-microbial agent. In fact, all over the world, the research scenario is now changing and concentrating toward the extraction of natural agents for product safety and health improvement. The lactoferrin has a potent anti-microbial activity against common foodborne pathogens. Due to the negative health effects of synthetic anti-microbial agents, the uses of natural sources are being encouraged all over the world. Our main focus of this study is to check the anti-microbial activity of lactoferrin against three pathogenic bacteria Escherichia coli, Staphylococcus aureus and Salmonella enteritidis isolatedduring our previous study.
Availability: Items available for loan: UVAS Library [Call number: 2265-T] (1).
3.
Production Of Single Cell Protein By Using Banana Peels As Substrate And Its Biological Evaluation In Broiler Chicks
by Muhammad Sheraz Yasin (2012-VA-603) | Miss Shagufta Saeed | Dr. Muhammad Tayyab | Prof. Dr. Aftab Ahmed Anjum.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: The term single cell protein (SCP) refers to dead, dry microbial cells or total proteins extracted from pure microbial cell culture and is produced using a number of different microorganisms including bacterium, fungus and algae. It can also be called biomass, bioprotein or microbial protein.
Besides high protein content (about 60-82% of dry cell weight), SCP also contains fats, carbohydrates, nucleic acids, vitamins and minerals.
Fermentation media containing grinded banana peel as substrate was used to check the production of single cell protein for the selected Arachniotus sp. Different parameters were optimized for higher production of SCP e.g: Incubation period, pH, volume of inoculum, carbohydrate source, concentration of corn steep liquor and ionic salts concentration.
The biomass yield was estimated for total protein content by Lowrymethod. Biomass produced from fermentation was used for biological evaluation in feed trials of broiler chicks.
It is found that Arachniotus sp gave maximum single cell protein 7.49 g/L using 10 g banana peels at 72 hours incubation period. And protein concentration increased 7.58 g/L by optimizing volume of inoculum 2ml. It is observed in present study carbohydrate source also increases the protein concentration 8.41 g/L when carbohydrate source was optimized (glucose 3%).
Later on it was found that nitrogen source also enhance the protein production upto 12.61 g/L by using 2% corn steep liquor. Results also revealed that ionic salt concentration also play important role in the production of biomass protein, addition of 0.075% CaCl2.H2O produced 14.45 g/L single cell protein using above mentioned optimized conditions. 0.050 %
K2HPO4 produced 15.06 g/L. Addition of 0.050% MgSO4.7H2O produced maximum protein 15.86 g/L.
Biological evaluation in broiler chicks of this biomass protein shown there is no deleterious effects on weight gain, feed conversion ratio, protein efficiency ratio and net protein utilization. Maximum weight gain observed 215.6 grams in the group (C) in which 50% sunflower meal was replaced with biomass protein.
Feed conversion ratio in group (C) was 2.64 in which 50% sunflower meal was replaced by biomass protein and in group (B) was 2.51 in which 25% sunflower meal was replaced. And in control group (A) feed conversion ratio was 2.41.
Protein efficiency ratio was observed with non-significant value. And same results were shown by Chaves et al (1988) who reported non-significant differences among the standard and test diet when Chaetominumcellulolyticum biomass was fed to chicks. Net protein utilization observed in present study gave significant P value among the groups.
So it is concluded that single cell protein produced by this method is cheap and can be used in the food industry as food supplements and can also be included in poultry feed. The study findings suggested that microbial biomass produced by Arachniotus sp using banana peels as substrate can be replaced upto 50% of the protein supply by sunflower meal without any deleterious effects on growing broiler chicks. Moreover, it will also help in the reduction of pollution by using waste i.e. banana peel for useful purpose.
Availability: Items available for loan: UVAS Library [Call number: 2347-T] (1).
4.
Proteomic And Genomic Analysis Of Methicillin-Resistant Staphylococcus Aureus And Efficacy Of Indigenous Medicinal Plants Essential Oils
by Sarwat Ali Raja | Prof. Dr. Muhammad Ashraf | Dr. Tayyaba Ijaz | Dr. Aqeel Javeed | Prof. Dr. Aftab Ahmed Anjum.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: A Cohort study (prospective and observational) was performed to study the prevalence of Methicillin resistant Staphylococcus aureus from the healthy individuals of community, hospitalized patients and associated health-care workers and indigenous plants essential oils were screened as new, improved & potent antibacterial/s against resistant strains of MRSA.
The method involved isolation and identification of MRSA from surgical wounds of hospitalized patients & associated health care workers in a tertiary care hospital in Lahore and healthy volunteers from the community. Plant essentials oils & extracts were evaluated for their antibacterial activity against selected MRSA isolates. Oils were recovered by steam distillation using an all-glass distillation assembly. Then in vitro sensitivity and MICs of plant essential oils were determined using vancomycin and linezolid as commercial standards. The essential oils were screened further for the active constituents by column chromatography using various solvents and identification of compounds were performed by GC/MS analysis and the fractions which showed prompt results were evaluated for antimicrobial activity against the MRSA isolates in quest to find new therapeutic options. Finally effective essential oils and their active fractions were studied for their toxicity using in vitro Genotoxic assays such as Ames and Comet assays. To further ensure their beneficial effects antimutagenic effect of the essential oils were also studied.
Prevalence of S. aureus among patients was 52.9%, in HCWs 86.5% and in community 74% with an overall percentage of 72.6%. Among S. aureus those declared as MRSA were 91.8% from patients, 50.6% from HCWs and 59.5% from community with an overall percentage of 62.2% MRSA. Among the isolated MRSA overall 90.6% were Coagulase positive and 75.2% were biofilm positive.
SUMMARY
211
The pattern of MRSA resistance against current antibiotics have shown an overall increase in the resistance with maximum shown for lincomycin followed by tetracycline, ampicillin, fusidic acid, amoxicillin and piperacillin with tazobactam. The most effective options among current regime were tigecyclin, amikacin and meropenem showing an overall least resistance. Resistance against linezolid was observed with an overall percentage of 25.6 % and vancomycin 33.3% by disc diffusion method.
The MRSA isolates resistant to one or more groups of antibiotics were declared as MDRs. Among patients and health-care workers all were declared as MDRs where as in community 93.1% isolates were MDRs.
Upon Protein profiling using whole cell proteins 44 bands of the polypeptides were produced with molecular size 10-200kDa from the three sampling groups and were categorized into 5 clusters showing an overall significance correlation with each other explaining an interesting fact that all these strains were interlinked establishing the fact of flow of hospital acquired MRSA in the community and vice versa. This analysis also gave an insight in explaining the fact of horizontal transmission of infection within the hospital.
Keeping in view the raise in resistance among current available antibiotics indigenous medicinal plants essential oils were screened for active constituents exhibiting anti-bacterial effects against MRSA isolates.
Maximum yield was obtained from Carum copticum followed by Cuminum cyminum and minimum yield was obtained in case of Zingiber officinale. Upon qualitative analysis of all five essential oils Carum copticum essential oil showed zones of inhibition greater than the standards vancomycin and linezolid followed Cuminum cyminum and Zingiber officinale in all three
SUMMARY
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sampling groups. Anethum sowa and Myristica fragrans essential oils showed no activity against MRSA.
Minimum inhibitory concentration of the three essential oils determined by micro broth dilution method indicated that Carum copticum showed least value in all three types of MRSA isolates followed by Zingiber officinale and Cuminum cyminum.
Effective essential oils were further fractioned using silica gel gravity columns. All the fractions obtained were screened for the anti-bacterial activity against all three types of MRSA isolates. Only fraction F1 of Carum copticum showed activity greater than pure essential oil and the two commercial standards of vancomycin and linezolid.
For the identification of active constituents GC/MS analysis was performed on all three essential oils and their respective fractions. In case of fraction F1 the most dominant constituents were Carvacrol, p-Cymene, Ʈ-Terpinene and Apiol. In other two plants none of the fractions were effective. Therefore it was concluded to use pure essential oils in case of Zingiber officinale and Cuminum cyminum rather than their individual fractions and incase of Carum copticum Fraction F1 has shown superior activity.
Finally these essential oils were tested for possible mutagenic effect using bacterial reversion mutation assay and Comet assay. No mutagenic effects were observed at MIC and above doses. These effective essential oils were also evaluated for possible antimutagenic effect. Both Carum copticum and Zingiber officinale essential oils showed strong antimutagenic effects and weak antimutagenic effect by Cuminum cyminum. Upon analysis of nuclear damage none of the plants essential oils and fraction F1 of Carum copticum showed genotoxic effects and indicated to be safe. Thus from the study it was concluded that Carum copticum essential oil and its fraction F1 were the most effective to be further investigated as an alternative treatment for MRSA infections. Availability: Items available for loan: UVAS Library [Call number: 2410-T] (1).
