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Dr. Imad AL KASSAA
Lebanese University, Food Science and technology, Faculty Member
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One of the most important characteristics of lactic acid bacteria (LAB) is the production of a large variety of active substances, such as acids, active ribosomal proteins, non-ribosomal peptide synthetase (NRPS), hydrogen peroxide, and... more
One of the most important characteristics of lactic acid bacteria (LAB) is the production of a large variety of active substances, such as acids, active ribosomal proteins, non-ribosomal peptide synthetase (NRPS), hydrogen peroxide, and other metabolites. In recent decades, several studies have evaluated the importance of these active substances in both the medical and food sectors. LAB have been used for several years in food fermentation to give good taste and protect the food against spoilage and pathogenic microorganisms. In this chapter, we focus on the antiviral activity of LAB metabolites.
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Research Interests: Medicine and Malnutrition
Introduction: Haemophilus influenzae is an important cause of respiratory infections,including acute otitis media, sinusitis, and chronic bronchitis, which arepreceded by asymptomatic H. influenzae colonization of the human pharynx.... more
Introduction: Haemophilus influenzae is an important cause of respiratory infections,including acute otitis media, sinusitis, and chronic bronchitis, which arepreceded by asymptomatic H. influenzae colonization of the human pharynx. Theaim of this study is to investigate the rate of H.influenzae nasopharyngeal colonizationamong students ages 2 to 3 years.Material and methods: A total of 21 isolates of clinical H. influenzae wereisolated from 87 nasopharyngeal specimens of children between April and June2011. The isolates were identified by using molecular techniques (PCR), biotypeswere determined by using the following tests: ornithin decarboxylase, urease andtryptophanase, and capsular typing was performed by SAST by using polyclonaland specific b antisera (Difco-BD®-USA).The prevalence of β -lactams resistance, β-lactamase production, the level of macrolideresistance was recorded for each strain by using disc diffusion and E-teststrip methods and chromogenic cephalosporin test (ce...
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Research Interests: Medicine and Malnutrition
Viral infections are the most critical among infectious diseases, especially those that can lead to chronic diseases. The control and the prevention of chronic diseases represent a challenge for public health organizations. These chronic... more
Viral infections are the most critical among infectious diseases, especially those that can lead to chronic diseases. The control and the prevention of chronic diseases represent a challenge for public health organizations. These chronic diseases are the major cause of death worldwide. To achieve the greatest impact, public health campaigns should focus on creating novel treatment and prevention strategies against chronic viral diseases. Probiotics are defined as live microorganisms with beneficial effects for humans. Probiotic strains have shown antiviral activity against a variety of infectious viruses such as respiratory and enteric viruses. In this chapter, we discuss the possible role of probiotic strains in chronic viral infections and their benefits in therapy strategies against such diseases. Data from numerous studies has shown that the use of probiotic as therapeutic agents is safe and inexpensive and can avoid the need for invasive treatment for several chronic viral infections caused by HIV, HCV, HTLV, HPV, CVB4, etc. The principal mechanisms of the antiviral activity of the probiotic strains studied until now were the production of antiviral compounds, the immunomodulatory effect, and virus trapping by the probiotic cell wall.
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This study was conducted to assess food safety knowledge, attitudes and practices among restaurant food handlers in North Lebanon and to determine what impact the food safety intervention had on the performance of workers. A structured... more
This study was conducted to assess food safety knowledge, attitudes and practices among restaurant food handlers in North Lebanon and to determine what impact the food safety intervention had on the performance of workers. A structured questionnaire of 35 questions has been used to collect information on socio-demographic characteristics, knowledge, attitudes and practices for 110 food handlers randomly working in 38 food service establishments via face-to-face questioning interviews during three months. The intervention was made to a subgroup of 13 participants followed by a reassessment. The average percentage scores of all food handlers for knowledge, attitudes, and practices were 63.78%, 83.63% and 81%, respectively. For the 13 participants who received the intervention, a significant improvement was observed in their performance after the training (p ˂ 0.001).
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Mycobacterium bovis is the etiologic agent of bovine tuberculosis (BTB), a serious infectious disease in both humans and animals. BTB is a zoonotic disease primarily affecting cattle and occasionally humans infected through close contact... more
Mycobacterium bovis is the etiologic agent of bovine tuberculosis (BTB), a serious infectious disease in both humans and animals. BTB is a zoonotic disease primarily affecting cattle and occasionally humans infected through close contact with infected hosts or the consumption of unpasteurized dairy products. Zoonotic tuberculosis is strongly associated with poverty and poor hygiene, and low- and middle-income countries bear the brunt of the disease. BTB has been increasingly recognized as a growing public health threat in developing countries. However, the lack of effective surveillance programs in many of these countries poses a barrier to accurately determining the true burden of this disease. Additionally, the control of BTB is threatened by the emergence of drug-resistant strains that affect the effectiveness of current treatment regimens. Here, we analyzed current trends in the epidemiology of the disease as well as the antimicrobial susceptibility patterns of M. bovis in the M...
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Dans ce travail, nous avons déterminé la composition de la flore vaginale d'un échantillon signatificatif de femmes Libanaises, puis évaluer l’effet antagoniste des souches lactiques notamment des lactobacilles contre certains... more
Dans ce travail, nous avons déterminé la composition de la flore vaginale d'un échantillon signatificatif de femmes Libanaises, puis évaluer l’effet antagoniste des souches lactiques notamment des lactobacilles contre certains pathogènes vaginales. Ainsi, sur les 135 prélèvements effectués, 53 isolats ont été identifiés par les méthodes de galerie API50 CH et pyroséquençage des régions variables (V1 et V2) du gène ADNr 16S. Les résultats obtenus ont montré une discordance entre les deux méthodes utilisées et sus-citées. Les résultats de l'effet antagoniste montrent que 7 souches sont antagonistes. L’identification des souches antagonistes a été confirmée par séquençage complet du gène ADNr 16S. En sus du potentiel antagoniste de ces lactobacilles, nous avons regardé d'autres propriétés biologiques de ces souches pouvant permettre une application probiotique. Trois isolats ont montré des propriétés intéréssantes d'hydrophobicité, d'autoaggrégation et dépourvues de...
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International audienc
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Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate... more
Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate beneficial LAB from llama milk that can be used as potential probiotics active against bacterial pathogens. LAB strains were isolated from llama milk samples. In vitro functional characterization of the strains was performed by evaluating the resistance against gastrointestinal conditions and inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatory properties of the strains were assessed. The functional studies were complemented with a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillus salivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared to that of other tested strains. The TUCO-L2 strain was resistant to pH and high bile salt concentrations and demonstrated antimicrobial activ...
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Introduction: The raw goat milk is considered as a good source of novel bacteriocinogenic lactic acid bacteria (LAB) strains. Method: The bacteriocin, which named enterocin CMUL20-2 was secreted by Enterococcus faecium CMUL20-2. This... more
Introduction: The raw goat milk is considered as a good source of novel bacteriocinogenic lactic acid bacteria (LAB) strains. Method: The bacteriocin, which named enterocin CMUL20-2 was secreted by Enterococcus faecium CMUL20-2. This bacterial strain was originally isolated from raw goat’s milk, was extracted by using a modified adsorption-desorption method and purified via RP-HPLC. antimicrobial activity was tested against several pathogenic and spoilage microbes. Results: The enterocin CMUL20-2 showed a strong adsorption on cell wall of producer strain even in acidic environment which facilitate its extraction in only two simple steps. The recovered purified enterocin has decreased procedure time and diminished the number of undesirable molecules present in Rogosa and Sharpe (MRS) broth. The recovered enterocin showed antimicrobial activity against several foodborne pathogenic and spoilage microbes. Conclusion: The recovered enterocin was able to tolerate a variety of food chain ...
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Background and Objectives: Several LAB species were evaluated and characterized for potential probiotic use. Besides the antimicrobial activity, probiotics showed recently a capacity to prevent and to alleviate inflammatory and chronic... more
Background and Objectives: Several LAB species were evaluated and characterized for potential probiotic use. Besides the antimicrobial activity, probiotics showed recently a capacity to prevent and to alleviate inflammatory and chronic diseases. Immunomodulation effect is one of the modes of actions of such probiotics, called immunobiotics, which can be used in several chronic diseases such as Inflammatory Bowel Diseases (IBD). The aim of this study was to isolate, identify and char- acterize lactobacilli strains from healthy baby’s feces in order to select some strains with potential immunobiotic application especially strains which can stimulate anti-inflammatory responses. Materials and Methods: Forty-two LAB strains were isolated and identified by the MALDI-TOF / MS technique. In addi- tion, strains were subjected to several assessments such as antimicrobial activity, the capacity to form biofilm in polystyrene microplate and immunomodulation activity in a PBMC model. Results: R...
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ABSTRACT 1. The real burden of Campylobacter spp. in Lebanon is still unknown. The aims of this study were to unravel the epidemiology of Campylobacter spp. in broilers at slaughterhouses in Tripoli, North of Lebanon and to characterise... more
ABSTRACT 1. The real burden of Campylobacter spp. in Lebanon is still unknown. The aims of this study were to unravel the epidemiology of Campylobacter spp. in broilers at slaughterhouses in Tripoli, North of Lebanon and to characterise their antibiotic resistance profiles. 2. From May to November 2015, sampling was performed through five repeated surveys from 15 slaughterhouses that sold chicken directly to Lebanese customers. Isolates were subjected to pulsed field gel electrophoresis (PFGE) and flaA-restriction fragment length polymorphism (flaA-RFLP). 3. All investigated slaughterhouses were found to be positive for Campylobacter spp. Campylobacter coli was the predominant species (38 isolates) followed by C. jejuni (eight isolates). A noticeable level of resistance was detected among isolates against ciprofloxacin (97% of C. coli and 87.5% of C. jejuni), amoxicillin (89% of C. coli and 75% of C. jejuni), gentamicin (79% of C. coli and 50% of C. jejuni), and co-amoxiclav (24% of C. coli and 25% of C. jejuni). Erythromycin and ertapenem resistance were observed only in C. coli with the following percentages 74% and 13% respectively, but not in C. jejuni. PFGE and flaA-RFLP using DdeI as restriction enzyme divided the strains into 27 and 25 types respectively. 4. The high observed genetic diversity of Campylobacter spp. revealed the complexity of the spread of this genus in broilers. This study highlighted the pressing need to monitor antibiotic resistance and to ensure food safety from ‘farm to fork’ in Lebanon.
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Research Interests: Food Science and Biology
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Viral infections are the most critical among infectious diseases, especially those that can lead to chronic diseases. The control and the prevention of chronic diseases represent a challenge for public health organizations. These chronic... more
Viral infections are the most critical among infectious diseases, especially those that can lead to chronic diseases. The control and the prevention of chronic diseases represent a challenge for public health organizations. These chronic diseases are the major cause of death worldwide. To achieve the greatest impact, public health campaigns should focus on creating novel treatment and prevention strategies against chronic viral diseases. Probiotics are defined as live microorganisms with beneficial effects for humans. Probiotic strains have shown antiviral activity against a variety of infectious viruses such as respiratory and enteric viruses. In this chapter, we discuss the possible role of probiotic strains in chronic viral infections and their benefits in therapy strategies against such diseases. Data from numerous studies has shown that the use of probiotic as therapeutic agents is safe and inexpensive and can avoid the need for invasive treatment for several chronic viral infections caused by HIV, HCV, HTLV, HPV, CVB4, etc. The principal mechanisms of the antiviral activity of the probiotic strains studied until now were the production of antiviral compounds, the immunomodulatory effect, and virus trapping by the probiotic cell wall.
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The “antiviral probiotic” term is not yet used in science nor approved by FDA and WHO. Indeed, the evaluation of antiviral activity of probiotic strains needs to be standardized and approved. Until now, “antiviral probiotics” are not used... more
The “antiviral probiotic” term is not yet used in science nor approved by FDA and WHO. Indeed, the evaluation of antiviral activity of probiotic strains needs to be standardized and approved. Until now, “antiviral probiotics” are not used either in the medical or food sectors. Furthermore, this type of probiotic is not widely recognized by health organizations such as the WHO and FDA. However, antiviral probiotics (AvPrs) have shown an efficient antiviral effect in the prevention and treatment of several viral infections. In last decade, many studies have been conducted to evaluate the antiviral activity of some probiotic strains. Few studies have showed the mechanisms behind such activity. The needs and the importance of antiviral probiotics have encouraged researchers to deeply investigate the antiviral mechanism. A probiotic strain needs to be tested and evaluated by many experiment to be recognized and approved as antiviral probiotics. Besides cytotoxicity, probiotic characteristics and immunomodulation effect of probiotic strain, choosing cell line, indicator virus and addition time of bacterial cells are the essential criteria for this selection.
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One of the most important characteristics of lactic acid bacteria (LAB) is the production of a large variety of active substances, such as acids, active ribosomal proteins, non-ribosomal peptide synthetase (NRPS), hydrogen peroxide, and... more
One of the most important characteristics of lactic acid bacteria (LAB) is the production of a large variety of active substances, such as acids, active ribosomal proteins, non-ribosomal peptide synthetase (NRPS), hydrogen peroxide, and other metabolites. In recent decades, several studies have evaluated the importance of these active substances in both the medical and food sectors. LAB have been used for several years in food fermentation to give good taste and protect the food against spoilage and pathogenic microorganisms. In this chapter, we focus on the antiviral activity of LAB metabolites.
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The aim of this study was to determine the capsular typing and type b prevalence of clinical Haemophilus influenzae strains in north Lebanon in both invasive and non-invasive disease and to determine the susceptibility pattern and the... more
The aim of this study was to determine the capsular typing and type b prevalence of clinical Haemophilus influenzae strains in north Lebanon in both invasive and non-invasive disease and to determine the susceptibility pattern and the mechanism of resistance to β-lactams [β-lactamase-producing strains and β-lactamase-negative ampicillin resistant (BLNAR) strains]. Fifty-two strains of clinical H. influenzae were isolated from 312 clinical specimens; the resistance pattern to β-lactams of these strains was determined by using the disc diffusion and E-test methods followed by molecular methods such as PCR of blaTEM et blaROB genes. Nine (17.4%) of the 52 strains were resistant to ampicillin; all of them produced type TEM-1 β-lactamase. In the susceptible strains 15.3% were not fully susceptible to β-lactams or considered low BLNAR strains. Slide agglutination serotyping showed that 30.7% of the strains were type b.
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Research Interests: Microbiology, Biofilms, Biology, Industrial Biotechnology, Medicine, and 15 moreFood Microbiology, Biofilm, Escherichia coli, Mice, Animals, Lactobacillus, Bacteria, Pseudomonas aeruginosa, Food Sciences, Pseudomonas Aeruginosa, Bacterial Adhesion, Food Processing Industry, Polystyrenes, Antibiosis, and food spoilage
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Research Interests: Microbiology, Lebanon, Biology, Medicine, Humans, and 13 moreMutation, Length of Stay, Pseudomonas aeruginosa, Anti-Bacterial Agents, Dna Gyrase, Microbial Sensitivity Tests, Pseudomonas Aeruginosa, Topoisomerase IV, Ciprofloxacin, University Hospitals, Hospital Mortality, Fluoroquinolones, and Pharmacology and pharmaceutical sciences
Background Coronavirus disease 2019 (COVID-19) has affected millions of lives globally. However, the disease has presented more extreme challenges for developing countries that are experiencing economic crises. Studies on COVID-19... more
Background Coronavirus disease 2019 (COVID-19) has affected millions of lives globally. However, the disease has presented more extreme challenges for developing countries that are experiencing economic crises. Studies on COVID-19 symptoms and gut health are scarce and have not fully analyzed possible associations between gut health and disease pathophysiology. Therefore, this study aimed to demonstrate a potential association between gut health and COVID-19 severity in the Lebanese community, which has been experiencing a severe economic crisis. Methods This cross-sectional study investigated SARS-CoV-2 PCR-positive Lebanese patients. Participants were interviewed and gut health, COVID-19 symptoms, and different metrics were analyzed using simple and multiple logistic regression models. Results Analysis of the data showed that 25% of participants were asymptomatic, while an equal proportion experienced severe symptoms, including dyspnea (22.7%), oxygen need (7.5%), and hospitalizat...