Limiting the Spread of Multidrug-Resistant Bacteria in Low-to-Middle-Income Countries: One Size Does Not Fit All.

The spread of multidrug-resistant organisms (MDRO) is associated with additional costs as well as higher morbidity and mortality rates. Risk factors related to the spread of MDRO can be classified into four categories: bacterial, host-related, organizational, and epidemiological. Faced with the severity of the MDRO predicament and its individual and collective consequences, many scientific societies have developed recommendations to help healthcare teams control the spread of MDROs. These international recommendations include a series of control measures based on surveillance cultures and the application of barrier measures, ranging from patients' being isolated in single rooms, to the reinforcement of hand hygiene and implementation of additional contact precautions, to the cohorting of colonized patients in a dedicated unit with or without a dedicated staff. In addition, most policies include the application of an antimicrobial stewardship program. Applying international policies to control the spread of MDROs presents several challenges, particularly in low-to-middle-income countries (LMICs). Through a review of the literature, this work evaluates the real risks of dissemination linked to MDROs and proposes an alternative policy that caters to the means of LMICs. Indeed, sufficient evidence exists to support the theory that high compliance with hand hygiene and antimicrobial stewardship reduces the risk of MDRO transmission. LMICs would therefore be better off adopting such low-cost policies without necessarily having to implement costly isolation protocols or impose additional contact precautions.

In vitro evaluation of enterococcus faecalis growth in different conditions on dentinal substrate.

The aim of this study was to find the best growth conditions of Enterococcus faecalis on a dentinal substrate in order to be used for the development of a complex multispecies endodontic biofilm. Fifty two single rooted extracted human teeth and fifty two dentinal disks were mechanically prepared, sterilized, inoculated with Enterococcus faecalis and divided randomly into 8 groups where the substrate, the inoculation technique, the medium type, and the pre-treatment with collagen type I was varied. Bacterial count was evaluated and colonies were counted and confirmed by colony morphology observation on blood agar and Gram staining at 3,7, 14, 21, and 28 days. On day 14 of the culture, the bacterial count showed the highest values in all groups. Root canals and Type 1 collagen pre-treatment and glucose proved to have significant positive effects on the bacterial count compared to dentinal disks and BHI media only. The increase in bacterial count found with the direct inoculation technique was not significantly different from that of the indirect technique.

The Microbiome of the Lebanese Wild Apple, Malus trilobata, is a Rich Source of Potential Biocontrol Agents for Fungal Post-harvest Pathogens of Apples.

The widespread use of harmful fungicides in the agricultural sector has led to a demand for safer alternatives to protect against crop pathogens. The domestic apple is the second most highly consumed fruit in the world and encounters several pre- and post-harvest fungal and bacterial phytopathogens. The goal of this study was to explore the uncharacterized microbiome of a wild apple, Malus trilobata, as a potential source of novel biocontrol agents for two post-harvest fungi that affect commercial apples: Botrytis cinerea and Penicillium expansum. We sampled microflora associated with the leaves, bulk soil, and roots of Malus trilobata in two regions of Lebanon: Ehden reserve in the north and Dhour EL Choueir near Beirut. The two regions have different soil types Dhour EL Choueir and samples from the two regions showed very different microbial compositions, with greater microbial diversity among those from Ehden reserve. Molecular characterization revealed a wide variety of genera displaying activity against the two fungal pathogens, including several with previously unknown antifungal activity: Bosea, Microlunatus, Microbacterium, Mycetecola, Rhizobium and Paraphoma. In total, 92 strains inhibited Penicillium expansum (39%) and 87 strains inhibited Botrytis cinerea (38%) out of 237 screened. Further chemical and genetic characterization of one or more selected strains could pave the way for future development of new biocontrol agents for post-harvest applications.

Expression and Roles of Antimicrobial Peptides in Innate Defense of Airway Mucosa: Potential Implication in Cystic Fibrosis.

The treatment of respiratory infections is associated with the dissemination of antibiotic resistance in the community and clinical settings. Development of new antibiotics is notoriously costly and slow; therefore, alternative strategies are needed. Antimicrobial peptides (AMPs), the central effector molecules of the immune system, are being considered as alternatives to conventional antibiotics. Most AMPs are epithelium-derived and play a key role in host defense at mucosal surfaces. They are classified on the basis of their structure and amino acid motifs. These peptides display a range of activities, including not only direct antimicrobial activity, but also immunomodulation and wound repair. In the lung, airway epithelial cells and neutrophils, in particular, contribute to AMP synthesis. The relevance of AMPs for host defense against infection has been demonstrated in animal models and is supported by observations in patient studies, showing altered expression and/or unfavorable circumstances for their action in a variety of lung diseases. Of note, AMPs are active against bacterial strains that are resistant to conventional antibiotics, including multidrug-resistant bacteria. Several strategies have been proposed to use these peptides in the treatment of infections, including direct administration of AMPs. In this review, we focus on studies related to direct bactericidal effects of AMPs and their potential clinical applications with a particular focus on cystic fibrosis.

Lebanese students' motivation in medical school: does it change throughout the years? A cross-sectional study.

BACKGROUND: Students entering medical school are driven by different types of motivation: autonomous motivation, controlled motivation, or amotivation. Motivation types can influence students' performance, outcome and well-being. To our knowledge, this topic has never been studied in Lebanese medical students. This study aims to identify students' motivation types in the first 5 years of medical school at two Lebanese universities (USJ and USEK). It also aims to determine the predominant motivation type of the whole sample. Results may be the first step towards raising awareness about this topic and implementing actions that enhance autonomous motivation. METHODS: A cross-sectional study was performed between January and June 2017. A questionnaire was sent to medical students by e-mail. The students' academic motivation was assessed using the Academic Motivation Scale. RESULTS: A higher mean autonomous motivation score was found in each academic year, as compared to the mean controlled motivation and amotivation scores. The highest mean autonomous motivation score was seen among second year students, whereas the lowest score was noted in fifth year students. The highest scores for controlled motivation and amotivation belonged to the fourth-year students, and the lowest to the first-year students. Students who were still satisfied with medical studies had a higher autonomous motivation score. Finally, USJ students who were satisfied with their second year training had a higher mean autonomous motivation score than those who were not. CONCLUSION: This study showed high levels of autonomous motivation in the first five years of medical school. Autonomous motivation was the predominant type in the whole sample. The highest scores of controlled motivation and amotivation were noted in the fourth year. Moreover, high levels of self-determination were seen in students who enjoyed their early contacts with patients through trainings. Actions should be implemented in medical schools to enhance and maintain autonomous motivation, and consequently students' outcome and health-care quality.

Optimization of enzymatic analytical method for poultry meat.

Chilling and freezing are essential for poultry meat preservation. Fresh poultry, visually indistinguishable from frozen-thawed poultry, presents an attractive target for adulteration. Activity levels of the mitochondrial enzyme ß-hydroxyacyl-CoA-dehydrogenase (HADH) can indicate previous freezing. This study aims to optimize the analysis method and determine a more sensitive cut-off limit distinguishing fresh from frozen poultry. 125 chicken breasts were sampled from the Lebanese market. Two sets of chilled breasts were analyzed before and after freezing at -22 °C for 5 days, with/without defrosting at 4 °C for 24 h. Frozen breasts samples were studied before and after refreezing at -22 °C. HADH activity was measured by spectrophotometry and found to be significantly higher for frozen samples. Using a cut off limit of 0.3, resulted in the correct identification of all frozen poultry samples instead of 93%. Greater control over incorrectly labelled poultry meat and increased consumer protection can be achieved using the modified thermal identification method.

Role of outer membrane permeability, efflux mechanism, and carbapenemases in carbapenem-nonsusceptible Pseudomonas aeruginosa from Dubai hospitals: Results of the first cross-sectional survey.

OBJECTIVES: Carbapenem resistance in Pseudomonas aeruginosa is growing and results from variable mechanisms. The objectives of the current study were to investigate mechanisms of carbapenem resistance and genetic relatedness of P. aeruginosa isolates recovered in Dubai hospitals. METHODS: From June 2015 through June 2016, carbapenem-nonsusceptible P. aeruginosa were collected from 4 hospitals in Dubai, and subjected to antimicrobial susceptibility testing, molecular investigation of carbapenemases by PCR-sequencing, analysis of outer membrane porin OprD2 and multidrug efflux channel MexAB-OprM levels by qPCR, and fingerprinting by ERIC-PCR. RESULTS: Out of 1969 P. aeruginosa isolated during the study period, 471 (23.9%) showed reduced carbapenem susceptibility. Of these, 37 were analyzed and 32% of them produced VIM-type metallo-ß-lactamases, including VIM-2, VIM-30, VIM-31, and VIM-42, while GES-5 and GES-9 co-existed with VIM in 5.4% of isolates. Outer membrane impermeability was observed in 73% of isolates and 75.6% displayed overproduced MexAB-OprM. ERIC-PCR revealed one large clone including most carbapenemase-producing isolates indicating clonal dissemination. CONCLUSION: This is the first study on carbapenem-nonsusceptible P. aeruginosa from Dubai, incriminating VIM production as well as outer membrane permeability and efflux systems as resistance mechanisms. Further studies on carbapenem-nonsusceptible P. aeruginosa in Dubai are warranted for containment of such health hazard.

Cationic antimicrobial peptides: alternatives and/or adjuvants to antibiotics active against methicillin-resistant Staphylococcus aureus and multidrug-resistant Pseudomonas aeruginosa.

BACKGROUND: Methicillin-resistant Staphylococcus aureus and multidrug-resistant Pseudomonas aeruginosa are becoming difficult to treat with antibiotics whereas Cationic Antimicrobial Peptides (CAMPs) represent promising alternatives. The effects of four CAMPs (LL-37: human cathelicidin, CAMA: cecropin(1-7)-melittin A(2-9) amide, magainin-II and nisin) were investigated against clinical and laboratory S. aureus (n = 10) and P. aeruginosa (n = 11) isolates either susceptible or resistant to antibiotics. Minimal Inhibitory Concentrations (MICs), Minimal Bactericidal Concentrations (MBCs), and bacterial survival rates (2 h post-treatment) were determined by microbroth dilution. The antipseudomonal effects of the antibiotics colistin or imipenem combined to LL-37 or CAMA were also studied. The toxicity of CAMPs used alone and in combination with antibiotics was evaluated on two human lung epithelial cell lines by determining the quantity of released cytoplasmic lactate dehydrogenase (LDH). Attempts to induce bacterial resistance to gentamicin, LL-37 or CAMA were also performed. RESULTS: The results revealed the rapid antibacterial effect of LL-37 and CAMA against both antibiotic susceptible and resistant strains with almost a total reduction in bacterial count 2 h post-treatment. Magainin-II and nisin were less active against tested strains. When antibiotics were combined with LL-37 or CAMA, MICs of colistin decreased up to eight-fold and MICs of imipenem decreased up to four-fold. Cytotoxicity assays revealed non-significant LDH-release suggesting no cell damage in all experiments. Induction of bacterial resistance to LL-37 was transient, tardive and much lower than that to gentamicin and induction of resistance to CAMA was not observed. CONCLUSION: This study showed the potent and rapid antibacterial activity of CAMPs on both laboratory and clinical isolates of S. aureus and P. aeruginosa either susceptible or resistant to antibiotics. Most importantly, CAMPs synergized the efficacy of antibiotics, had non toxic effects on human cells and were associated with transient and low levels of induced resistance.

Preterm infants with necrotising enterocolitis demonstrate an unbalanced gut microbiota.

AIM: This Lebanese study tested the hypothesis that differences would exist in the gut microbiota of preterm infants with and without necrotising enterocolitis (NEC), as reported in Western countries. METHODS: This study compared 11 infants with NEC and 11 controls, all born at 27-35 weeks, in three neonatal intensive care units between January 2013 and March 2015. Faecal samples were collected at key time points, and microbiota was analysed by culture, quantitative PCR (qPCR) and temperature temporal gel electrophoresis (TTGE). RESULTS: The cultures revealed that all preterm infants were poorly colonised and harboured no more than seven species. Prior to NEC diagnosis, significant differences were observed by qPCR with a higher colonisation by staphylococci (p = 0.034) and lower colonisations by enterococci (p = 0.039) and lactobacilli (p = 0.048) in the NEC group compared to the healthy controls. Throughout the study, virtually all of the infants were colonised by Enterobacteriaceae at high levels. TTGE analysis revealed no particular clusterisation, showing high interindividual variability. CONCLUSION: The NEC infants were poorly colonised with no more than seven species, and the controls had a more diversified and balanced gut microbiota. Understanding NEC aetiology better could lead to more effective prophylactic interventions and a reduced incidence.

Investigating Pneumonia Etiology Among Refugees and the Lebanese population (PEARL): A study protocol.

Background: Community-acquired pneumonia (CAP), a leading cause of mortality, mainly affects children in developing countries. The harsh circumstances experienced by refugees include various factors associated with respiratory pathogen transmission, and clinical progression of CAP. Consequently, the etiology of CAP in humanitarian crisis situations may differ to that of settled populations, which would impact appropriate case management. Therefore, the Pneumonia Etiology Among Refugees and the Lebanese population (PEARL) study was initiated with the objective of identifying the causal pathogenic microorganisms in the respiratory tract of children and adults from both the refugee and host country population presenting with signs of CAP during a humanitarian crisis. Methods: PEARL, a prospective, multicentric, case-control study, will be conducted at four primary healthcare facilities in Tripoli and the Bekaa valley over 15 months (including two high-transmission seasons/winters). Sociodemographic and medical data, and biological samples will be collected from at least 600 CAP cases and 600 controls. Nasopharyngeal swabs, sputum, urine and blood samples will be analyzed at five clinical pathology laboratories in Lebanon to identify the bacterial and viral etiological agents of CAP. Transcriptomic profiling of host leukocytes will be performed. Conclusions: PEARL is an original observational study that will provide important new information on the etiology of pneumonia among refugees, which may improve case management, help design antimicrobial stewardship interventions, and reduce morbidity and mortality due to CAP in a humanitarian crisis.

Establishment and development of the intestinal microbiota of preterm infants in a Lebanese tertiary hospital.

The establishment and development of the intestinal microbiota is known to be associated with profound short- and long-term effects on the health of full-term infants (FTI), but studies are just starting for preterm infants (PTI). The data also mostly come from western countries and little information is available for the Middle East. Here, we determined the composition and dynamics of the intestinal microbiota during the first month of life for PTI (n = 66) and FTI (n = 17) in Lebanon. Fecal samples were collected weekly and analyzed by quantitative PCR (q-PCR) and temporal temperature gradient gel electrophoresis (TTGE). We observed differences in the establishment and composition of the intestinal microbiota between the two groups. q-PCR showed that PTI were more highly colonized by Staphylococcus than FTI in the first three weeks of life; whereas FTI were more highly colonized by Clostridium clusters I and XI. At one month of life, PTI were mainly colonized by facultative anaerobes and a few strict anaerobes, such as Clostridium cluster I and Bifidobacterium. The type of feeding and antibiotic treatments significantly affected intestinal colonization. TTGE revealed low species diversity in both groups and high inter-individual variability in PTI. Our findings show that PTI had altered intestinal colonization with a higher occurrence of potential pathogens (Enterobacter, Clostridium sp) than FTI. This suggests the need for intervention strategies for PTI to modulate their intestinal microbiota and promote their health.

Does diclofenac increase the risk of cervical necrotizing fasciitis in a rat model?

Non-steroidal anti-inflammatory drugs (NSAIDs) are known for aggravating in vitro infections and were reported in many cases of cervical necrotizing fasciitis (CNF). We developed a rat model of CNF, mimicking as closely as possible the human-CNF, to study the effect of a NSAIDs, diclofenac, as a promoting factor. Twenty rats were injected bilaterally in the neck with peptostreptococcus and with a fresh saliva specimen for another 20 rats. Half of each group was given an intramuscular injection of 4 mg/kg diclofenac at the time of inoculation and 24 h later, and the other half saline injections; rats were killed at day 7 and clinical, bacterial and histological studies were performed to assess the infectious process and the incidence of CNF. No statistically significant difference was found between groups treated with diclofenac vs. the saline injection groups. However a significant correlation was noted between clinical observation, bacterial density and histological signs of inflammation. CNF has a high mortality rate and the use of NSAIDs in conditions potentially leading to CNF is very common. However, our rat model does not support the hypothesis of a promoting role of diclofenac which was occasionally suggested in the medical literature. This study suggests that diclofenac does not seem to increase the risk of occurrence of CNF. Nonetheless, NSAIDs can mask inflammatory signs of an already spreading CNF.

A simple, sensitive, and rapid method for the determination of cotinine in urine by high-performance liquid chromatography with UV detection.

Cotinine levels in biological fluids are a reliable indicator of the presence of nicotine. In this paper, a simple and sensitive high-performance liquid chromatography (HPLC) procedure for the determination of cotinine in urine following liquid-liquid extraction with dichloromethane in an alkaline medium is described. Calibration curves show linearity over the 50 to 3000 ng/mL range with low intra- and interday variability as well as good selectivity and specificity. No solid-phase extraction is performed because the liquid dichloromethane extraction step yields excellent results. This method is a good alternative for routine analysis of urinary cotinine in laboratories where gas chromatography or HPLC-mass spectrometry is not available.

Penicillin-resistant Streptococcus pneumoniae in Lebanon: the first nationwide study.

A total of 123 clinical isolates of Streptococcus pneumoniae were collected from all over Lebanon and tested for their susceptibility to penicillin: 30.1% were susceptible (minimum inhibitory concentration (MIC) < or = 0.06 microg/mL), 56.1% were intermediately susceptible (MIC 0.09-1.0 microg/mL) and 13.8% were resistant (MIC > 1.0 microg/mL). The oxacillin disk screening test detected all penicillin-resistant isolates, but erroneously designated two penicillin-intermediate isolates as penicillin susceptible. All isolates were consistently susceptible to levofloxacin, but cross-resistance between penicillin and the three tested cephalosporins was frequently noted. The in vitro activity of amoxicillin/clavulanic acid paralleled that of penicillin; however, 92.7% of the isolates were designated as susceptible based on the recommended interpretive cut-off point (MIC < or = 2/1 microg/mL). This discrepancy represents a paradox that deserves serious consideration.