Search Results (14)

Tuberculosis (TB) is an infectious disease caused by bacteria that primarily target the lungs. The transmission of this disease occurs through the air in the form of droplet nuclei. Unfortunately, there has been an emergence of resistance to strains of such infections, such as multidrug- as well as extensively drug-resistant strains. Healthcare workers (HCWs) are particularly vulnerable to contracting TB due to their direct contact with patients. This study aims to evaluate the knowledge, attitude, and practices among Lebanese healthcare workers towards TB and its resistant forms, particularly multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). This study is a cross-sectional, descriptive, questionnaire-based research study that was conducted on HCWs in Lebanon. A total of 517 HCWs were included in this study. The findings displayed that 48.52% of HCWs had good knowledge of TB and MDR-TB/XDR-TB, 49.52% had average knowledge, and 2.13% had bad knowledge. Moreover, only 16.25% had a good attitude, 71.92% had an average attitude, and 11.8% had a bad attitude. Furthermore, only 14.7% had good practices, 54.74% had average practices, and 30.56% had bad practices. Having a history of testing for TB was found to be related to increased attitude. Also, the history of having TB-infected family members was found to be linked to both increased attitude and practice scores. Moreover, this study highlights the idea that high knowledge scores do not mean high attitude or high practices scores. On the same note, acceptable attitude scores do not inflict acceptable practice scores. The findings of this study showed that there is an overall good knowledge regarding TB, MDR-TB, and XDR-TB, average attitude, and average-to-bad practices. Gaps are seen in all sectors, even knowledge, especially with matters related to the diagnosis of MDR-TB/XDR-TB and its treatment duration. Also, the attitude section revealed a gap in the understanding of the modes of transmission of such an infection. Full article

Despite the significant advancements in wastewater treatment technologies, the field still lacks a comprehensive synthesis of recent developments in heavy metal removal using functionalized mesoporous silica materials. Adsorption has emerged as a preferred method due to its versatility, efficiency, and cost-effectiveness. Mesoporous silica stands out as a leading adsorbent due to its porous structure and surface modification potential, yet there remains a critical need to systematically analyze and evaluate recent innovations in this rapidly evolving field. This review addresses this knowledge gap by consolidating and critically analyzing the recent literature on functionalized mesoporous silica for heavy metal ion removal from wastewater. Through a detailed examination of the maximum adsorption efficiencies of organically modified mesoporous silica-based materials for various metal ions, with particular emphasis on recent trends in removing heavy metal ions, this work provides a crucial foundation for understanding current capabilities and limitations. Additionally, by identifying patterns in synthesis methods, surface functionalization strategies, and performance metrics across different studies, this review offers valuable insights into optimization opportunities and unexplored research directions. The systematic compilation and analysis of these data will serve as an essential resource for researchers working to advance the design and application of modified mesoporous silica for diverse water pollutant removal applications. Full article

Background: Over the past 100 years, the discovery of antibiotics is regarded as one of the most significant advances in medical research and has saved millions of lives. However, the emergence of antimicrobial-resistant bacteria has significantly reduced the efficacy of antibiotics against infectious disorders. Antimicrobial resistance is mostly caused by antibiotic misuse for conditions that may be treated with self-care. During the COVID-19 pandemic, antibiotic use has been out of control among the general population. Aim: The objective of this study is to investigate the prevalence of antibiotic misuse during the COVID-19 pandemic in Lebanon. Methods: In January 2024, a descriptive cross-sectional study was conducted amongst students registered at the Islamic University of Lebanon. Individuals who have been infected with COVID-19 at least once were eligible for the study and were selected by a non-random snowball sampling technique. Descriptive and quantitative analyses were performed using SPSS 21. Results: Out of the 478 participants who completed the questionnaire, 40.2% (n = 192) received antibiotics during the COVID-19 infection. A physician’s prescription is mentioned by some participants (51%, n = 98), followed by a pharmacist’s (23.4%, n = 45), self-taken (14.5%, n = 28), and others as family or friends (10.9%, n = 21). Moreover, 59.3% (n = 114) of the respondents respected the antibiotic therapy’s rules, and 40.6% (n = 78) discontinued taking the antibiotic when they felt better. Conclusion: Our results showed that participants were likely to show unsatisfactory compliance and to use non-prescribed antibiotics. Campaigns are urgently needed to promote appropriate antibiotic use. Full article

Background: Effort–reward imbalance (ERI) refers to the situation where there is a mismatch between the effort that healthcare workers (HCWs) put into their work and the rewards they receive in return. Burnout, on the other hand, is a psychological syndrome characterized by emotional exhaustion, depersonalization, and reduced personal accomplishment. This study aimed to assess the impact of ERI and burnout on the compliance with standard precautions (SPs) among nurses and midwives in Lebanese hospitals under the economic crisis and after the COVID-19 pandemic. Methods: Cross-sectional correlational study, based on self-administered questionnaire data, measuring the compliance with SPs, ERI, and burnout, in addition to the relationship between these factors, was performed among 409 nurses and midwives, working in Lebanese hospitals. Results: ERI was significantly associated with exposure to burnout among nurses and midwives, and burnout was found to be a significant predictor of nurses and midwives’ self-reported adherence with SPs. Conclusions: This study highlights the contribution of ERI and burnout to the chain of infection by decreased adherence to infection control SPs of nurses and midwives. Full article

The opportunistic pathogen Klebsiella pneumoniae (K. pneumoniae) can colonize mucosal surfaces and spread from mucosae to other tissues, causing fatal infections. Medical equipment and the healthcare setting can become colonized by Klebsiella species, which are widely distributed in nature and can be found in water, soil, and animals. Moreover, a substantial number of community-acquired illnesses are also caused by this organism worldwide. These infections are characterized by a high rate of morbidity and mortality as well as the capacity to spread metastatically. Hypervirulent Klebsiella strains are thought to be connected to these infections. Four components are critical to this bacterium’s pathogenicity—the capsule, lipopolysaccharide, fimbriae, and siderophores. Siderophores are secondary metabolites that allow iron to sequester from the surrounding medium and transport it to the intracellular compartment of the bacteria. A number of variables may lead to K. pneumoniae colonization in a specific area. Risk factors for infection include local healthcare practices, antibiotic use and misuse, infection control procedures, nutrition, gender, and age. Full article

Salmonella enterica (S. enterica) serovars Enteritidis and Typhimurium are the main causes of bacterial gastroenteritis worldwide. This Gram-negative rods bacterium possesses several virulence factors that enable it to survive the host’s nutritional immunity. Toxins and metallophores are among these factors. Heavy metals, in particular, are essential for the survival of all living organisms including bacteria. During infection, S. enterica competes with the host for the available heavy metals by secreting metallophores, which are secondary metabolites. Once produced in the extracellular medium, metallophores complex heavy metals thus allowing Salmonella to acquire metal ions through importing them via channels embedded in their membranes. This review highlights the biosynthesis, export, import, and genetic regulation of different metallophores synthesized by this germ. Full article

The pathogenic anaerobic bacteria Yersinia pestis (Y. pestis), which is well known as the plague causative agent, has the ability to escape or inhibit innate immune system responses, which can result in host death even before the activation of adaptive responses. Bites from infected fleas in nature transmit Y. pestis between mammalian hosts causing bubonic plague. It was recognized that a host’s ability to retain iron is essential in fighting invading pathogens. To proliferate during infection, Y. pestis, like most bacteria, has various iron transporters that enable it to acquire iron from its hosts. The siderophore-dependent iron transport system was found to be crucial for the pathogenesis of this bacterium. Siderophores are low-molecular-weight metabolites with a high affinity for Fe³⁺. These compounds are produced in the surrounding environment to chelate iron. The siderophore secreted by Y. pestis is yersiniabactin (Ybt). Another metallophore produced by this bacterium, yersinopine, is of the opine type and shows similarities with both staphylopine and pseudopaline produced by Staphylococcus aureus and Pseudomonas aeruginosa, respectively. This paper sheds light on the most important aspects of the two Y. pestis metallophores as well as aerobactin a siderophore no longer secreted by this bacterium due to frameshift mutation in its genome. Full article

P. aeruginosa is a common Gram-negative bacterium found in nature that causes severe infections in humans. As a result of its natural resistance to antibiotics and the ability of biofilm formation, the infection with this pathogen can be therapeutic challenging. During infection, P. aeruginosa produces secondary metabolites such as metallophores that play an important role in their virulence. Metallophores are metal ions chelating molecules secreted by bacteria, thus allowing them to survive in the host under metal scarce conditions. Pyoverdine, pyochelin and pseudopaline are the three metallophores secreted by P. aeruginosa. Pyoverdines are the primary siderophores that acquire iron from the surrounding medium. These molecules scavenge and transport iron to the bacterium intracellular compartment. Pyochelin is another siderophore produced by this bacterium, but in lower quantities and its affinity for iron is less than that of pyoverdine. The third metallophore, pseudopaline, is an opine narrow spectrum ion chelator that enables P. aeruginosa to uptake zinc in particular but can transport nickel and cobalt as well. This review describes all the aspects related to these three metallophore, including their main features, biosynthesis process, secretion and uptake when loaded by metals, in addition to the genetic regulation responsible for their synthesis and secretion. Full article

The ubiquitous bacterium Staphylococcus aureus causes many diseases that sometimes can be fatal due to its high pathogenicity. The latter is caused by the ability of this pathogen to secrete secondary metabolites, enabling it to colonize inside the host causing infection through various processes. Metallophores are secondary metabolites that enable bacteria to sequester metal ions from the surrounding environment since the availability of metal ions is crucial for bacterial metabolism and virulence. The uptake of iron and other metal ions such as nickel and zinc is one of these essential mechanisms that gives this germ its virulence properties and allow it to overcome the host immune system. Additionally, extensive interactions occur between this pathogen and other bacteria as they compete for resources. Staphylococcus aureus has high-affinity metal import pathways including metal ions acquisition, recruitment and metal–chelate complex import. These characteristics give this bacterium the ability to intake metallophores synthesized by other bacteria, thus enabling it to compete with other microorganisms for the limited nutrients. In scarce host conditions, free metal ions are extremely low because they are confined to storage and metabolic molecules, so metal ions are sequestered by metallophores produced by this bacterium. Both siderophores (iron chelating molecules) and staphylopine (wide- spectrum metallophore) are secreted by Staphylococcus aureus giving it infectious properties. The genetic regulation of the synthesis and export together with the import of metal loaded metallophores are well established and are all covered in this review. Full article

Background: COVID-19, caused by the novel coronavirus SARS-CoV-2, was declared by WHO in early 2020 as a worldwide pandemic. Several known risk markers are associated with COVID-19 morbidity and mortality, including age, gender, and diseases, such as hypertension, diabetes, and chronic cardiovascular diseases. Recent studies have shown an association between COVID-19 infection and the ABO blood groups. Objective: To assess the prevalence of SARS-CoV-2 among suspected COVID-19 patients as well as the risk markers for COVID-19 associated with ABO blood group, Rhesus factor, and patient’s address during the past year. Methods: 69,019 nasopharyngeal swab samples were collected and analyzed by reverse transcription polymerase chain reaction technique for the detection of SARS-CoV-2 in patients attending a tertiary health care center in South Lebanon during the period between August 2020 and July 2021. Results: Among all tested subjects, the prevalence of SARS-CoV-2 infection was 19.2% (95% CI: 18.9% to 19.5%). Among those with known blood group (N = 17,462), odds of SARS-CoV-2 were higher in group A (Odds Ratio = 1.12, 95% CI: 1.02 to 1.23) and group AB (OR = 1.19, 95% CI: 1.00 to 1.41) relative to the reference group O (OR = 1). Odds of SARS-CoV-2 in the Rh-negative group (OR = 1.02, 95% CI: 0.89 to 1.16) were not significantly different from the Rh-positive group. Among those with known address (N = 30,060), odds of SARS-CoV-2 were lower in residents of remote areas (OR = 0.89, 95% CI: 0.80 to 0.99) relative to central cities. Conclusion: There is a modestly higher risk of SARS-CoV-2 infection associated with blood groups A and AB, and a lower risk associated with living in remote, less crowded regions. Full article

Background: An outbreak of an unknown respiratory illness caused by a novel coronavirus, SARS-CoV-2, emerged in the city of Wuhan in Hubei Province, China, in December 2019 and was referred to as coronavirus disease-2019 (COVID-19). Soon after, it was declared as a global pandemic by the World Health Organization (WHO) in March 2020. SARS-CoV-2 mainly infects the respiratory tract with different outcomes ranging from asymptomatic infection to severe critical illness leading to death. Different SARS-CoV-2 variants are emerging of which three have raised concerns worldwide due to their high transmissibility among populations. Objective: To study the prevalence of COVID-19 in the region of Nabatieh-South Lebanon during the past year and assess the presence of SARS-CoV-2 variants and their effect on the spread of infection during times of lockdown. Methods: In our study, 37,474 nasopharyngeal swab samples were collected and analyzed for the detection of SARS-CoV-2 virus in suspected patients attending a tertiary health care center in South Lebanon during the period between 16 March 2020 and 21 February 2021. Results: The results demonstrated a variation in the prevalence rates ranging from less than 1% during full lockdown of the country to 8.4% upon easing lockdown restrictions and reaching 27.5% after the holidays and 2021 New Year celebrations. Interestingly, a new variant(s) appeared starting January 2021 with a significant positive association between the prevalence of positive tests and the percentage of the variant(s). Conclusions: Our results indicate that the lockdown implemented by the Lebanese officials was an effective intervention to contain COVID-19 spread. Our study also showed that lifting lockdown measures during the holidays, which allowed indoor crowded gatherings to occur, caused a surge in COVID-19 cases and rise in the mortality rates nationwide. More importantly, we confirmed the presence of a highly transmissible SARS-CoV-2 variant(s) circulating in the Lebanese community from at least January 2021 onwards. Full article

Background: Familial Mediterranean Fever (FMF) is an autosomal recessive auto-inflammatory disease characterized by pathogenic variants in the MEFV gene, with allele frequencies greatly varying between countries, populations and ethnic groups. Materials and methods: In order to analyze the spectrum of MEFV variants and genotypes among clinically diagnosed FMF patients from South Lebanon, data were collected from 332 participants and 23 MEFV variants were screened using a Real-Time PCR Kit. Results: The mean age at symptom onset was 17.31 ± 13.82 years. The most prevalent symptoms were abdominal pain, fever and myalgia. MEFV molecular analysis showed that 111 patients (63.79%) were heterozygous, 16 (9.20%) were homozygous, and 47 (27.01%) carried two variants or more. E148Q was the most encountered variant among heterozygous subjects. E148Q/M694V was the most frequent in the compound heterozygous/complex genotype group, while M694I was the most common among homozygous patients. Regarding allele frequencies, M694V was the most common variant (20.7%), followed by E148Q (17.1%), V726A (15.7%) and M694I (13.2%). Conclusion: The high percentage of heterozygous patients clinically diagnosed as FMF highlights the pseudo-dominant transmission of the disease in Lebanon and emphasizes the importance of molecular testing for a more accurate diagnosis and better management and treatment of FMF. Full article

Background: Urinary tract infections (UTIs) are major healthcare problems that are usually treated empirically. However, antimicrobial resistance has been increasing across many settings. This study aims to elucidate the antibiotic resistance profiles of three common uropathogens, Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), and Proteus mirabilis (P. mirabilis) and compare between extended spectrum beta-lactamase (ESBL) and non-ESBL strains among Lebanese patients. Methods: This retrospective study was conducted at multiple tertiary healthcare centers in South Lebanon, between January and September 2017, including 551 patients of all age groups. Demographic, clinical, and laboratory data of patients were collected and analyzed statistically. Results: The prevalence of UTI in Lebanon was highest in adults between 19 and 64 years (44%). E. coli was the predominant uropathogenic organism (67.1%) followed by K. pneumoniae (10%) and P. mirabilis (3.7%). ESBL represented 32.9% of the UTI agents. The three common uropathogens studied were found to be most susceptible to imipenem (100%) and meropenem (100%). Interestingly, 115 (25.1%) out of the 458 E. coli isolates were resistant to more than eight antibiotics while 107 (23.4%) were susceptible to all antibiotics studied. Conclusions: Our study underlined the importance of adequate antimicrobial prescription for UTIs in Lebanon to avoid multidrug resistance. Full article

In bacterial pathology, metallophores fabricated by bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa are exported to surrounding physiological media via a specific process to sequester and import metals, resulting in enhanced virulence of the bacteria. While these mechanisms are understood at qualitative levels, our investigation presents a complementary original view based on quantum chemical computations. Further understanding of the active centers in particular was provided for pseudopaline and staphylopine metallophores, which were described chemically and with vibration spectroscopy. Then, for complexes formed with a range of transition metal divalent ions (Ni, Cu, and Zn), description and analyses of the frontier molecular orbitals (FMOs) are provided, highlighting a mechanism of metal-to-ligand charge transfer (MLCT), based on excited-states calculations (time-dependent density functional theory (TD-DFT)) at the basis of the delivery of the metallic ionic species to the bacterial medium, leading eventually to its enhanced virulence. Such investigation gains importance especially in view of stepwise syntheses of metallophores in the laboratory, providing significant progress in the understanding of mechanisms underlying the enhancement of bacterial pathologies. Full article