Impact of Antimicrobials use in chickens on emergence of drug-resistant Campylobacter organisms in humans

The objective of this review is to present the impact of uncontrolled use of antimicrobialagents in chicken husbandry on emergence of drug-resistant Campylobacterin humans. The absence of an Antimicrobial Resistance Monitoring System(ARMS) in most developing countries of the world, amidst trade’s globalization ofanimals and animal products, helped in the recent decade in spreading of drugresistantorganisms across the world’s food chains.The emergence of drug resistance in Campylobacter organisms was associated withtheir transmission from animals and their products to humans. This transmissionof drug-resistant Campylobacter resulted in serious failure of treatment regimensprescribed to infected humans

Highly Resistant Yersinia enterocolitica Isolated from Dairy Based Foods in Lebanon

Yersinia is small rod shaped, gram negative coccibacilli known as a food borne pathogen that may cause intestinal and systemic diseases known as yersiniosis. It has been reported that it may be transmitted by eating contaminated dairy foods.  This study aims at evaluating the presence of Yersinia enterocolitica in Lebanese three dairy based foods which include Kishk, Shankleesh and Baladi cheese and reporting their susceptibilities to commonly used antimicrobial agents. In total, sixteen Y. enterocolitica isolates were recovered and subjected to relevant biochemical tests and finally identified by API system.  Eleven of those isolates were from Baladi cheese, three from Shankleesh and two from Kishk. The API results confirmed their identity, and were then subjected for susceptibility testing against: chloramphenicol (30µg), trimethoprim/ sulfamethoxazole (1.25µg+23.75µg), gentamicin (10µg), ciprofloxacin (5µg), nalidixic acid (30µg), Kanamycin (30µg) and streptomycin (10µg). Surprisingly, all the tested Y. enterocolitica isolates showed high rates of resistance to all the antimicrobials used with highest resistance to kanamycin (81.2%) and streptomycin (87.5%). The data showed that the antimicrobial resistance levels exceeded by far all the levels reported elsewhere. Based on the data, it may be concluded that dairy based foods in Lebanon, especially cheese that is prepared under unaccepted conditions, not abiding by proper hygienic practices. This might be the cause of a public health hazard, as cheese might act as a potential vehicle for the transmission of many resistant bacterial pathogens to human consumers. For this reason, it is advisable to use strict conditions in cheese processing to reduce the hazards that may be involved with its consumption

Green Synthesis of Zn(OH)₂/ZnO-Based Bionanocomposite using Pomegranate Peels and Its Application in the Degradation of Bacterial Biofilm

The ability and potency of bacterial species to form biofilms, which show antibiotic resistance thereby avoiding antibiotic surfaces, is a major cause of prolonged infections. Various advanced approaches have been employed to prevent or damage bacterial biofilms, formed by a variety of bacterial strains, to help prevent the associated infectious disease. In this context, zinc-based nanostructures have been recognized as a potential antibiotic agent against a broad spectrum of bacterial communities. As a result, a sustainable and green synthesis method was adapted in the present study to synthesize a Zn(OH)(2)/ZnO-based bionanocomposite, in which aqueous extracts of waste pomegranate peels (Punica granatum) were employed as a natural bioreducing agent to prepare the bionanocomposite at room temperature. Furthermore, FT-IR, XRD, DLS, UV-Visible, PL spectroscopy, FE-SEM, and TEM were used to characterize the green route synthesized a Zn(OH)(2)/ZnO bionanocomposite. The average crystallite size was determined using the Scherrer relation to be 38 nm, and the DLS results indicated that the Zn(OH)(2)/ZnO bionanocomposite had a hydrodynamic size of 170 nm. On the other hand, optical properties investigated through UV-Vis and PL spectroscopy explored the energy bandgap between 2.80 and 4.46 eV, corresponding to the three absorption edges, and it covered the blue spectrum when the sample was excited at 370 nm. Furthermore, the impact of this green route synthesized a Zn(OH)(2)/ZnO bionanocomposite on the biofilm degradation efficiency of the pathogenic bacterial strain Bacillus subtilis PF_1 using the Congored method was investigated. The Congored assay clearly explored the biofilm degradation efficiency in the presence of a 50 mg/mL and 75 mg/mL concentration of the Zn(OH)(2)/ZnO bionanocomposite against the bacterial strain Bacillus subtilis PF_1 grown for 24 h. This study can be further applied to the preparation of bionanocomposites following a low-cost green synthesis approach, and thus prepared nanostructures can be exploited as advanced antimicrobial agents, which could be of great interest to prevent various infectious diseases

Oxidative Stress in Human Pathology and Aging: Molecular Mechanisms and Perspectives

Reactive oxygen and nitrogen species (RONS) are generated through various endogenous and exogenous processes; however, they are neutralized by enzymatic and non-enzymatic antioxidants. An imbalance between the generation and neutralization of oxidants results in the progression to oxidative stress (OS), which in turn gives rise to various diseases, disorders and aging. The characteristics of aging include the progressive loss of function in tissues and organs. The theory of aging explains that age-related functional losses are due to accumulation of reactive oxygen species (ROS), their subsequent damages and tissue deformities. Moreover, the diseases and disorders caused by OS include cardiovascular diseases [CVDs], chronic obstructive pulmonary disease, chronic kidney disease, neurodegenerative diseases and cancer. OS, induced by ROS, is neutralized by different enzymatic and non-enzymatic antioxidants and prevents cells, tissues and organs from damage. However, prolonged OS decreases the content of antioxidant status of cells by reducing the activities of reductants and antioxidative enzymes and gives rise to different pathological conditions. Therefore, the aim of the present review is to discuss the mechanism of ROS-induced OS signaling and their age-associated complications mediated through their toxic manifestations in order to devise effective preventive and curative natural therapeutic remedies

Network-based approach for targeting human kinases commonly associated with amyotrophic lateral sclerosis and cancer

BackgroundAmyotrophic Lateral Sclerosis (ALS) is a rare progressive and chronic motor neuron degenerative disease for which at present no cure is available. In recent years, multiple genes encode kinases and other causative agents for ALS have been identified. Kinases are enzymes that show pleiotropic nature and regulate different signal transduction processes and pathways. The dysregulation of kinase activity results in dramatic changes in processes and causes many other human diseases including cancers.MethodsIn this study, we have adopted a network-based system biology approach to investigate the kinase-based molecular interplay between ALS and other human disorders. A list of 62 ALS-associated-kinases was first identified and then we identified the disease associated with them by scanning multiple disease-gene interaction databases to understand the link between the ALS-associated kinases and other disorders.ResultsAn interaction network with 36 kinases and 381 different disorders associated with them was prepared, which represents the complexity and the comorbidity associated with the kinases. Further, we have identified 5 miRNAs targeting the majority of the kinases in the disease-causing network. The gene ontology and pathways enrichment analysis of those miRNAs were performed to understand their biological and molecular functions along with to identify the important pathways. We also identified 3 drug molecules that can perturb the disease-causing network by drug repurposing.ConclusionThis network-based study presented hereby contributes to a better knowledge of the molecular underpinning of comorbidities associated with the kinases associated with the ALS disease and provides the potential therapeutic targets to disrupt the highly complex disease-causing network

Determinants of response at 2 months of treatment in a cohort of Pakistani patients with pulmonary tuberculosis

Mycobacterium tuberculosis infection continues to be a major global challenge. All patients with pulmonary tuberculosis are treated with a standard 6-month treatment regimen. Historical data suggest that even with shortened treatment, most patients achieve long-term remission. Risk stratification is a goal for reducing potentially toxic prolonged treatment. This study aimed to determine the factors associated with the early clearance of sputum acid-fast bacilli (AFB). A total of 297 freshly diagnosed patients with pulmonary tuberculosis were included and enrolled in this study. Information related to their ethno-demographic and anthropometric characteristics was collected. We also assessed their complete blood counts, and blood iron, folate, and vitamin B12 levels. We found that the presence of higher levels of acid-fast bacilli (AFB) in diagnostic sputum microscopy was the single most significant prognostic factor associated with early clearance of sputum AFB after 2 months of treatment. All of our patients achieved treatment success after 6 months of treatment and were disease free. Our results support the data obtained from previous studies indicating that AFB clearance at 2 months is unlikely to be a clinically useful biomarker or indicator for therapeutic stratification. Furthermore, demographic, anthropometric, and nutritional factors are not clinically useful biomarkers

Evaluation of the sensitivity of enteric viruses in effluent to chemical disinfection.

The literature indicates a considerable degree of ambiguity and contradiction in the efficiency of various wastewater disinfectants. This largely reflects on the absence of standardization in these studies and the use of only a single disinfctant and virus rather than multiple studies. It thus seemed appropriate to carry out a comparative study on several commonly used wastewater disinfectants against representative enteric viruses. The chosen disinfectants were chlorine, chlorine dioxide, ozone and peracetic acid because they represent those most likely to be useful in wastewater disinfection. The selected viruses were bacteriophage f[2] and poliovirus 1 which have been commonly used, also echovirus 1 and Coxsackievirus B5 to extend the range of enteroviruses and finally simian rotavirus (SA11) and human rotovirus, the latter, being one of the most important enteric viral pathogens present in wastewater. The effect of various parameters which might influence the efficiency of the disinfectants such as pH, temperature, suspended solids and peptone concentration as well as the effects of combining disinfectants were investigated. The results obtined from this study indicated that lower levels of disinfectants were required than most of those levels already reported in the literature which was probably due to the quality of effluent used and emphasized the need to standardize this before disinfection studies. Chlorine dioxide, although more expensive than chlorine, may be a useful alternative to chlorine because its virucidal efficacy was only slightly affected by changes in pH, temperature and presence of organic matter. Furthermore it does not react with organic matter to form some classes of chlorinated organic compounds considered hazardous to public health and it was easy to obtain reliable assay of its residual concentration. Ozone may also be a promising alternative to chlorine because its efficacy is not greatly affected over the pH range 6-10 which is normally that encountered in effluent and temperature (2-30°C). Furthermore, it does not leave a toxic residual and it adds dissolved oxygen to water. However, its disadvantages are the high capital cost for the establishment of the plant, difficulties in its reliable assay in effluent, it requires good quality effluent and it does not maintain a stable residual. Peracetic acid is another possible alternative disinfectant. It does not form toxic by-products, effluent does not exert a demand for it which leaves it available for disinfection. However, the high concentrations required reduced the pH of the effluent and increased the BOD5 of the treated product. It was found that the combination of disinfectants did not produce a synergistic effect but only a complementary, additive or combined effect. It was interesting to note that the different viruses reacted differently to each disinfectant which explains the argument against the use of model or indicator virus studies. In this regard, it was particularly worth noting that the human rotavirus isolate was the most resistant virus to disinfectants although surprisingly simian rotavirus was the least. Therefore, for the proper evaluation of a wastewater disinfectant it would be advisable to test it against as many representative enteric viruses as practicable

Evaluation of the sensitivity of enteric viruses in effluent to chemical disinfection.

The literature indicates a considerable degree of ambiguity and contradiction in the efficiency of various wastewater disinfectants. This largely reflects on the absence of standardization in these studies and the use of only a single disinfctant and virus rather than multiple studies. It thus seemed appropriate to carry out a comparative study on several commonly used wastewater disinfectants against representative enteric viruses. The chosen disinfectants were chlorine, chlorine dioxide, ozone and peracetic acid because they represent those most likely to be useful in wastewater disinfection. The selected viruses were bacteriophage f[2] and poliovirus 1 which have been commonly used, also echovirus 1 and Coxsackievirus B5 to extend the range of enteroviruses and finally simian rotavirus (SA11) and human rotovirus, the latter, being one of the most important enteric viral pathogens present in wastewater. The effect of various parameters which might influence the efficiency of the disinfectants such as pH, temperature, suspended solids and peptone concentration as well as the effects of combining disinfectants were investigated. The results obtined from this study indicated that lower levels of disinfectants were required than most of those levels already reported in the literature which was probably due to the quality of effluent used and emphasized the need to standardize this before disinfection studies. Chlorine dioxide, although more expensive than chlorine, may be a useful alternative to chlorine because its virucidal efficacy was only slightly affected by changes in pH, temperature and presence of organic matter. Furthermore it does not react with organic matter to form some classes of chlorinated organic compounds considered hazardous to public health and it was easy to obtain reliable assay of its residual concentration. Ozone may also be a promising alternative to chlorine because its efficacy is not greatly affected over the pH range 6-10 which is normally that encountered in effluent and temperature (2-30°C). Furthermore, it does not leave a toxic residual and it adds dissolved oxygen to water. However, its disadvantages are the high capital cost for the establishment of the plant, difficulties in its reliable assay in effluent, it requires good quality effluent and it does not maintain a stable residual. Peracetic acid is another possible alternative disinfectant. It does not form toxic by-products, effluent does not exert a demand for it which leaves it available for disinfection. However, the high concentrations required reduced the pH of the effluent and increased the BOD5 of the treated product. It was found that the combination of disinfectants did not produce a synergistic effect but only a complementary, additive or combined effect. It was interesting to note that the different viruses reacted differently to each disinfectant which explains the argument against the use of model or indicator virus studies. In this regard, it was particularly worth noting that the human rotavirus isolate was the most resistant virus to disinfectants although surprisingly simian rotavirus was the least. Therefore, for the proper evaluation of a wastewater disinfectant it would be advisable to test it against as many representative enteric viruses as practicable

Antimicrobial-resistance of Streptococcus pneumoniae isolated from the Lebanese environment

The aim of this study was to isolate and molecularly characterize Streptococcus pneumoniae in samples collected from the aquatic environment in Lebanon. For this purpose, 57 samples of ground waters, sea water, sediments and crabs were collected. Biochemical tests as well as PCR were used for further identification and molecular characterization of 46 suspected isolates using specific primers for the lytA-gene and protein 2B-gene. The confirmed isolates were evaluated for their antimicrobial resistance, using the minimum inhibitory concentration method. Crab samples exhibited a high contamination level of an average count of 8.2 × 104 CFU/g. In water samples, the highest contamination was recorded near a coastal landfill with a bacterial count of 1.8 × 103 CFU/ml whereas the lowest bacterial counts (non detectable) were observed in ground water samples. Twenty out of the 46 suspected isolates came from sea water, and 17 out of those were characterized by PCR as S. pneumoniae. Testing the antimicrobial resistance of the 20 isolates to various antimicrobials showed that all sea water isolates were resistant to vancomycin, gentamicin, and oxacillin (100%), whereas 62.5% were resistant to clindamycin, and only 25% were erythromycin resistant. Resistance rates were higher in the case of fresh water samples, with 57% resistance to erythromycin, and 100% resistance to vancomycin, gentamicin, clindamycin and oxacillin. Alternatively, all tested crab isolates were susceptible to erythromycin. However, they showed a high resistance of 80% against vancomycin, gentamicin, clindamycin and 100% against oxacilli