Effect of Active and Passive Smoking on Retinal Nerve Fibre Layer and Ganglion Cell Complex

Aim. To evaluate the possible structural and functional changes in the retinal nerve fibre layer (RNFL) and the ganglion cell complex (GCC) of chronic smokers and compare them with those of passive healthy smokers using spectral domain optical coherence tomography (SD-OCT) and pattern electroretinogram (PERG). Materials and Methods. We include 80 active chronic smokers and 80 age- and sex-matched healthy passive smokers. After a full ophthalmological examination, SD-OCT and PERG were tested for all participants. Urinary levels of cotinine and creatinine with subsequent calculation of the cotinine creatinine ratio (CCR). Results. Inferior and superior quadrants of RNFL were thinner in group I, but nasal and temporal quadrants did not show significant difference between the groups. There were no significant differences of GCC values between the two groups. There was no significant difference of PERG-P50 amplitude and latency; however, PERG-N95 showed significant difference between the two groups. Multiple regression analyses demonstrated that the number of cigarettes/day, urinary cotinine, and PERG-N95 amplitude are the most important determinants for both superior and inferior RNFL thicknesses. Conclusion. RNFL thickness decreases in chronic, healthy, heavy cigarette smokers, and this thinning is related to the number of cigarettes/day, urinary cotinine, and PERG-N95 latency and amplitude

On a Moving Four-Level λ-Type Atom Interacting with a Single-Mode Quantized Field in Intensity-Dependent Coupling

The interaction between a moving four-level atom and a single-mode cavity field are discussed in the presence of intensity dependent atom field coupling. For this purpose, we first demonstrate the feasibility of the effective Hamiltonian and evaluate the explicit time-dependent form of the state vector of the whole system by choosing special initial conditions for atom, field. Considering the field to be initially in a coherent state, and the atom is initially prepared in the excited state. The wave function is obtained in three different cases: resonance case, off-resonance case, finally we obtained it in the general form. We study the nonclassical features of the system such as Atomic inversion, Filed entropy, purity, Fidelity, Mandel Q-parameter, Mean photon number and normal squeezing. The results show that, The temporal evolution of field entropy (entanglement), Mandel parameter, mean photon number and normal squeezing are sensitive to intensity-dependent coupling, which changes the quantum statistical behaviour of the atom-field state to a full sub-Poissonian statistics. Finally, conclusions and some features and comments are given

Methicillin-Resistant <i>Staphylococcus</i> <i>aureus</i> Strains Isolated from Burned Patients in a Tunisian Hospital: Molecular Typing, Virulence Genes, and Antimicrobial Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of a variety of infections in hospitals and the community. Their spread poses a serious public health problem worldwide. Nevertheless, in Tunisia and other African countries, very little molecular typing data on MRSA strains is currently available. In our study, a total of 64 MRSA isolates were isolated from clinical samples collected from burned patients hospitalized in the Traumatology and Burns Center of Ben Arous in Tunisia. The identification of the collection was based on conventional methods (phenotypic and molecular characterization). The characterization of the genetic support for methicillin resistance was performed by amplification of the mecA gene by polymerase chain reaction (PCR), which revealed that 78.12% of S. aureus harbors the gene. The resistance of all the collection to different antibiotic families was studied. Indeed, the analysis of strain antibiotic susceptibility confirmed their multi-resistant phenotype, with high resistance to ciprofloxacin, gentamicin, penicillin, erythromycin, and tetracycline. The resistance to the last three antibiotics was conferred by the blaZ gene (73.43%), the erm(C) gene (1.56%), the msr(A) gene (6.25%), and tet(M) gene (7.81%), respectively. The clonal diversity of these strains was studied by molecular typing of the accessory gene regulator (agr) system, characterization of the SCCmec type, and spa-typing. The results revealed the prevalence of agr types II and III groups, the SCCmec type III and II cassettes, and the dominance of spa type t233. The characterization of the eight enterotoxins genes, the Panton-Valentine leukocidin and the toxic shock syndrome toxin, was determined by PCR. The percentage of virulence genes detected was for enterotoxins (55%), tst (71.88%), leukocidin E/D (79.69%), and pvl (1.56%) factors. Furthermore, our results revealed that the majority of the strains harbor IEC complex genes (94%) with different types. Our findings highlighted the emergence of MRSA strains with a wide variety of toxins, leukocidin associated with resistance genes, and specific genetic determinants, which could constitute a risk of their spread in hospitals and the environment and complicate infection treatment

Dissemination of epidemic ST239/ST241-t037-agrI-SCCmecIII methicillin-resistant Staphylococcus aureus in a Tunisian trauma burn intensive care unit

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen causing health care -infections in the world, especially in burns. The aim of this study was to assess the extent of dissem-ination of MRSA isolated from burn patients in Burn Intensive Care Unit in Tunisia and to evaluate the frequency of virulence and antibiotics resistance genes. Among the 72 S. aureus isolates analyzed in the study, 54% were MRSA. The majority of MRSA (94.8%) were multidrug resistant and they had a high resistance rates to kanamycin (94.8%), tobramycin (90%), tetracycline (94.8%) and ciprofloxacin and rifampicin (87%, each). The gene aac(60)-Ie-aph(200)-Ia conferring resistance to kanamycine and tobtamycin were detected in all isolates and the aph(30)-Ia gene conferring resistance to gentamicin were detected in 2.8% of resistant isolates. Tetracycline resistance genes tet(M), tet(K) and tet(L) were detected in 100%, 10.8% and 2.8% of the isolates, respectively. The SCCmec type III and the agr type I were the most predominant (69.2% and 90%, respectively). The 27 SCCmecIII-agrI isolates were clustered into two PFGE types A and B. The two representative isolates of PFGE clusters A and B belonged to ST239-t037 and ST241-t037 respectively. As conclusion, our results showed a high prevalence of MRSA in trauma burn intensive care unit belonging to two multidrug resistant clones ST239/ST241-agrI-t037-SCCmecIII MRSA. We also demonstrated that MRSA was disseminated between burn patients

Detection of carbapenem resistant Pseudomonas aeruginosa co-harboring blaVIM-2 and blaGES-5 in burn patients

Pseudomonas aeruginosa is one of the major infectious agents in burn patients. Globally, high rates of antimicrobial resistance in P. aeruginosa have been reported, which is a cause of concern. The objective of this study was to determine the rate of resistance to carbapenems in P. aeruginosa isolates recovered from burn patients in Tunisia, to search genes encoding for carbapenemases and to determine their epidemiological markers (serotypes). A retrospective study was conducted in the Burn Intensive Care Unit (BICU) of the Trauma and Burn Centre of Ben Arous, Tunisia, and P. aeruginosa isolates collected from burn patients, from January to December 2018 were investigated. Carbapenemase screening was performed by Carbapenem Inactivation Method (CIM) and by EDTA-disk test for all carbapenem resistant isolates. Genes encoding carbapenemases (blaVIM, blaIMP, blaGES, blaNDM, and blaKPC) were investigated by PCR and selected carbapenemase genes were sequenced. During the study period, 104 non duplicated P. aeruginosa isolates were recovered. Most of them were isolated from skin samples (45.1%) and blood culture (22.1%) and belonged to O:11 (19.2%), O:12, and O:5 (12.5%, each) sero-types. High rates of resistance were observed for carbapenems (64.4%). Among the 67 carbapenem resistant isolates, 58 (86.5%) harbored blaVIM gene and 55 (82%) blaGES gene; in addition, 48 (71.6%) co-harbored blaVIM and blaGES genes. After sequencing, the blaVIM-2 and blaGES-5 gene variants were identified in seven randomly selected isolates. To the best of our knowledge, this is the first description of P. aeruginosa simultaneously harboring blaVIM-2 and blaGES-5 genes